Compositions and Methods for Generating an Immune Response to a Flavivirus
The compositions and methods are described for generating an immune response to a flavivirus such as Zika virus. The compositions and methods described herein relate to a modified vaccinia Ankara (MVA) vector encoding one or more viral antigens for generating a protective immune response to a member of genus Flavivirus (such as a member of species Zika virus), in the subject to which the vector is administered. The compositions and methods of the present invention are useful both prophylactically and therapeutically and may be used to prevent and/or treat an infection caused by Flavivirus.
This application claims the benefit of U.S. 62/290,744 filed Feb. 3, 2016, the contents of which are incorporated by reference herein in their entirety.
FIELD OF THE INVENTIONThe present invention is directed to compositions, including vaccine compositions, for generating an immune response to a Flavivirus such as a Zika virus, as well as methods of manufacture and use thereof. More specifically, the compositions and methods described herein relate to a modified vaccinia Ankara (MVA) vector encoding one or more viral antigens for generating a protective immune response to a member of the Flaviviridae family in asubject to which the vector is administered. The compositions and methods of the present invention are useful both prophylactically and therapeutically.
BACKGROUND OF THE INVENTIONZika virus disease (”Zika“) is an emerging infectious disease. It was first isolated in 1947 in Uganda, but until 2007 was known only to cause small outbreaks of minor public health significance (Enfissi, A., et al., The Lancet 387, 2 (2016)). Large epidemics occurred in 2007 in Yap Island in Micronesia and in 2013 in French Micronesia, raising the profile of Zika as an emerging disease (Oehler, E., et al. Eurosurveillance 19, 3 (2014) Zanluca, C., et al. Mem Inst Oswaldo Cruz 110, 4 (2015)). Beginning in 2015, with the appearance of the infection in Brazil, it became clear that Zika is a serious threat potentially capable of causing a pandemic (Zanluca, C., et al. Mem Inst Oswaldo Cruz 110, 4 (2015); Fauci, A.S. & Morens, D. M. New England Journal of Medicine (2016)). Today, Zika continue to spread- with multiple cases imported into the US by travelers from endemic regions. This rapid increase in transmission has prompted the world's public health authorities to mobilize quickly to control the epidemic. However, there is currently no treatment or vaccine available to fight the epidemic (CDC. Zika virus. Vol. 2016 (US Department of Health and Human Services, CDC, Atlanta, Ga., 2016)).
The etiologic agent of Zika is Zika virus (ZIKV), a member of the Flaviviridae family which also includes dengue fever, yellow fever, Japanese encephalitis, tick-borne encephalitis and West Nile viruses (Zanluca, C., et al. Mem Inst Oswaldo Cruz 110, 4 (2015)). ZIKV is transmitted primarily through bites from infected Aedes mosquitoes, but human-to-human sexual transmission may also occur (CDC. Zika virus. Vol. 2016 (US Department of Health and Human Services, CDC, Atlanta, Ga., 2016) Musso, D., et al. Emerg Infect Dis 21, 3 (2015)). Phylogenetic analyses of ZIKV demonstrate that this Flavivirus consists of one serotype and 2 major lineages: African and Asian, which are >96% identical in amino acid sequences across the genome. The Asian lineage has been responsible for all ZIKV outbreaks in the Pacific and the Americas. A vaccine composed of sequences from either lineage should theoretically protect against all Zika viruses. Monkeys are believed to be the animal reservoir, and humans are occasional/accidental hosts (Faye, O., et al. PLoS neglected tropical diseases 8, 10 (2014)).
ZIKV infection is asymptomatic in approximately 80% of cases (Petersen, E. M., et al. MMWR Morb Mortal Wkly Rep 65, 4 (2016)). Symptoms are generally mild, usually last no more than a week, and may include fever, malaise, headache, dizziness, anorexia, rash, arthralgia, and conjunctivitis (Petersen, E. M., et al. MMWR Morb Mortal Wkly Rep 65, 4 (2016)). ZIKV infections complicated by Guillain-Barré syndrome have been reported since 2004 (Oehler, E., et al. Eurosurveillance 19, 3 (2014) Petersen, E. M., et al. MMWR Morb Mortal Wkly Rep 65, 4 (2016)). More recently, an alarming association between ZIKV infection and fetal brain abnormalities including microcephaly has emerged (Melo, A. S. O., et al. Ultrasound Obstet Gynecol 47, 2 (2016)). With no approved preventive or therapeutic products currently available to fight the ZIKV epidemic, public health officials have no specific medical products at their disposal and their recommendations are limited to avoiding of exposure to ZIKV, delaying in becoming pregnant and following basic supportive care (fluids, rest, and ibuprofen) after infection (CDC. Zika virus. Vol. 2016 (US Department of Health and Human Services, CDC, Atlanta, Ga., 2016)). A vaccine is urgently needed to prevent a Zika pandemic.
Ab-dependent enhancement (ADE) of viral infection has been documented in vitro and in vivo as a significant risk with ZIKV E protein-directed vaccines when applied in dengue endemic areas (Dejnirattisai, W., et al. Dengue virus sero-cross-reactivity drives antibody-dependent enhancement of infection with zika virus. Nat Immunol 17, 1102-1108 (2016). Kawiecki, A. B. & Christofferson, R. C. Zika Virus-Induced Antibody Response Enhances Dengue Virus Serotype 2 Replication In Vitro. J Infect Dis 214, 1357-1360 (2016). Smith, S. A., et al. Dengue Virus prM-Specific Human Monoclonal Antibodies with Virus Replication-Enhancing Properties Recognize a Single Immunodominant Antigenic Site. J Virol 90, 780-789 (2015); Stettler, K., et al. Specificity, cross-reactivity and function of antibodies elicited by Zika virus infection (Science 353, 823-826 (2016)). Large-scale studies have not yet been performed to rule out the threat of ADE (e.g. use of ZIKV vaccines in dengue endemic countries), and E protein-targeted zika vaccines could potentially present a risk to those vaccinated. Moreover, PrM, a chaperon protein for E, induces limited neutralizing activities (Aaskov et al., 1988; Beltramello et al., 2010; Kaufman et al., 1989; Vazquez et al., 2002). It has been suggested that these antibodies contribute to the pathogenesis of DENV virus infection (Dejnirattisai et al., 2010; Rodenhuis-Zybert et al., 2010). Given that ZIKV and DENV are co-endemic throughout their distributions, an alternative to prME proteins as a vaccine target is attractive.
Currently, there is no vaccine for humans against the Zika virus. What is therefore needed are vaccine compositions and methods of use to prevent and treat disease caused by Zika virus infection.
SUMMARY OF THE INVENTIONThe compositions and methods of the invention described herein are useful for generating an immune response to at least one Flaviviridae virus in a subject in need thereof. Advantageously, the compositions and methods may be used prophylactically to immunize a subject against Zika virus infection, or used therapeutically to prevent, treat or ameliorate the onset and severity of disease.
In a first aspect, the present invention is a recombinant modified vaccinia Ankara (MVA) vector comprising at least one nucleic acid sequence encoding a Flavivirus protein, wherein the at least one nucleic acid sequence is inserted into the MVA vector under the control of at least one promoter compatible with poxvirus expression systems.
In one embodiment, the recombinant MVA vector comprises at least two nucleic acid sequences encoding Flavivirus proteins, wherein the at least two nucleic sequences are inserted into the MVA vector under the control of at least two promoters capable compatible with poxvirus expression systems.
In one embodiment, the recombinant MVAvector comprises a first nucleic acid sequence encoding a Flavivirus structural protein and a second nucleic sequence encoding a Flavivirus nonstructural (NS) protein, wherein both the first and second nucleic acid sequences are inserted into the MVA vector under the control of promoters compatible with poxvirus expression systems.
In one embodiment, the the Flavivirus structural protein is selected from premembrane-E (PrM-E), soluble E without a transmembrane domain, E protein domain I, E protein domain II, or E protein domain III, PrM and fragments thereof.
In one embodiment, the the Flavivirus non-structural protein is selected from NS1, NS2A, NS2B, NS3, NS4A, NS4B, NS5 and fragments thereof.
In one embodiment, the the Flavivirus non-structural protein is a NS1 non-structural protein sequence.
In one embodiment, the first and second nucleic acid sequences are inserted into one or more deletion sites of the MVA vector.
In one embodiment, the first and second nucleic acid sequences are inserted into the recombinant MVA vector in a natural deletion site, a modified natural deletion site, or between essential or non-essential MVA genes.
In another embodiment, the first and second nucleic acid sequences are inserted into the same natural deletion site, a modified natural deletion site, or between the same essential or non-essential MVA genes
In another embodiment, the first nucleic acid sequence is inserted into a deletion site selected from I, II, III, IV, V or VI and the nonstructural protein sequence is inserted into a deletion site selected from I, II, III, IV, V or VI.
In another embodiment, the first and second nucleic acid sequences or fragments thereof are inserted into different natural deletion sites, modified deletion sites, or between different essential or non-essential MVA genes.
In another embodiment, the first nucleic sequence is inserted in a first deletion site and the second nucleic acid sequence is inserted into a second deletion site.
In a particular embodiment, the first nucleic acid sequence is inserted between two essential and highly conserved MVA genes and the second nucleic acid sequence is inserted into a restructured and modified deletion III.
In a particular embodiment, the non-structural protein is NS1.
In one embodiment, the deletion III is modified to remove non-essential sequences and the second nucleic acid sequence is inserted between essential genes.
In a particular embodiment, the first nucleic acid sequence is inserted between two essential and highly conserved MVA genes to limit the formation of viable deletion mutants.
In a particular embodiment, the first nucleic acid sequence is inserted between MVA genes, 18R and G1L.
In one embodiment, the promoter is selected from the group consisting of Pm2H5, Psyn II, and mH5 promoters or combinations thereof.
In one embodiment, the first nucleic acid sequence is optimized. In a particular embodiment, the first nucleic acid sequence is optimized by i) changing selected codons to other synonymous codons that are optimal for structural protein expression by MVA, ii) interrupting homopolymer stretches using silent mutations, iii) interrupting transcription terminator motifs using silent mutations, and iv) combinations thereof.
In one embodiment, the recombinant MVA vector expresses structural protein and non-structural proteins that assemble into VLPs.
In one embodiment, the structural protein sequence and the non-structural protein sequence are from a Flavivirus species.
In a second aspect, the present invention is a pharmaceutical composition comprising the recombinant MVA vector of the present invention and a pharmaceutically acceptable carrier.
In one embodiment, the recombinant MVA vector is formulated for intraperitoneal, intramuscular, intradermal, epidermal, mucosal or intravenous administration.
In a third aspect, the present invention is a pharmaceutical composition comprising a first recombinant MVA vector and a second recombinant MVA vector, each comprising a first nucleic acid sequence encoding a Flavivirus structural protein and a second nucleic acid sequence encoding a Flavivirus non-structural protein, wherein (i) the first nucleic acid sequence of the first recombinant MVA vector is different than the first nucleic acid sequence of the second recombinant MVA vector and/or (ii) the second nucleic acid sequence of the first recombinant MVA vector is different than the second nucleic acid sequence of the second recombinant MVA vector.
In a particular embodiment, the first nucleic sequence encodes premembrane-E, and the first nucleic acid sequence of the first recombinant MVA vector is from a different species than the first nucleic acid sequence of the second recombinant MVA vector.
In another particular embodiment, the seconc nucleic acid sequence of the first recombinant MVA vector is from a different species than the second nucleic acid sequence of the second recombinant MVA vector.
In a particular embodiment, at least one of the species of Flavivirus is Zika virus
In a particular embodiment, the non-structural protein sequence is NS1.
In a fourth aspect, the present invention is a pharmaceutical composition comprising three or more recombinant MVA vectors each comprising a first nucleic acid sequence encoding a Flavivirus structural protein and a second nucleic acid sequence encoding a Flavivirus non-structural protein sequence, wherein (i) the first nucleic acid sequence of the three or more recombinant MVA vectors are different and/or (ii) the second nucleic acid sequence of the three recombinant MVA vectors are difference.
In a particular embodiment, the first nucleic acid sequence encodes premembrane-E, and the first nucleic acid sequence of the first recombinant MVA vector is from a different species than the first nucleic acid sequence of the second recombinant MVA vector and is from a different species than the first nucleic acid sequence of the third recombinant MVA vector.
In a particular embodiment, the first nucleic acid sequence of each recombinant vector are from the same species.
In a particular embodiment, the first nucleic acid sequence of the three or more recombinant MVA vectors are from different species.
In a particular embodiment, at least one of the species of Flavivirus is Zika virus.
In a fifth aspect, the present invention is a method of inducing an immune response in a subject in need thereof, said method comprising administering the composition of the present invention to the subject in an amount sufficient to induce an immune response.
In one embodiment, the immune response is a humoral immune response, a cellular immune response or a combination thereof.
In a particular embodiment, the immune response comprises production of binding antibodies against the flavivirus.
In a particular embodiment, the immune response comprises production of neutralizing antibodies against the flavivirus.
In a particular embodiment, the immune response comprises production of non-neutralizing antibodies against the flavivirus.
In a particular embodiment, the immune response comprises production of a cell-mediated immune response against the flavivirus.
In a particular embodiment, the immune response comprises production of neutralizing and non-neutralizing antibodies against the flavivirus.
In a particular embodiment, the immune response comprises production of neutralizing antibodies and cell-mediated immunity against the flavivirus.
In a particular embodiment, the immune response comprises production of non-neutralizing antibodies and cell-mediated immunity against the flavivirus.
In a particular embodiment, the immune response comprises production of neutralizing antibodies, non-neutralizing antibodies, and cell-mediated immunity against the Flaviviridae virus.
In a particular embodiment, the immune response comprises production of neutralizing antibodies, non-neutralizing antibodies, and cell-mediated immunity against the Zika virus.
In a sixth aspect, the present invention is a method of preventing a Flaviviridae virus infection in a subject in need thereof, said method comprising administering the recombinant MVA vector of the present invention to the subject in a prophylactically effective amount.
In one embodiment, the viral infection is a Zika virus infection.
In a seventh aspect, the present invention is a method of inducing an immune response in a subject in need thereof, said method comprising administering the recombinant MVA vector of the present invention to the subject in a prophylactically effective amount.
In one embodiment, the immune response is considered a surrogate marker for protection.
In one embodiment, the method induces an immune response against a Zika virus.
In an eighth aspect, the present invention is a method of treating Flaviviridae virus infection in a subject in need thereof, said method comprising administering the recombinant MVA vector in a therapeutically effective amount to the subject.
In one embodiment, the Flaviviridae virus infection is caused by a Zika virus.
In one embodiment, the subject is exposed to Flaviviridae fever virus, but not yet symptomatic of Flaviviridae virus infection. In a particular embodiment, treatment results in prevention of a symptomatic infection.
In another embodiment, the subject is recently exposed but exhibits minimal symptoms of infections.
In another embodiment, the method results in amelioration of at least one symptom of infection.
In one embodiment, the symptom of infection is selected from mild headaches, maculopapular rash, fever, malaise, conjunctivitis, joint pains or a combination thereof.
In another embodiment, the method results in reduction or elimination of the subject's ability to transmit the infection to an uninfected subject.
In one embodiment, the method prevents or ameliorates a Zika virus infection.
In a ninth aspect, the present invention is a method manufacturing a recombinant MVAvector comprising inserting at least one nucleic acid sequence encoding premembrane-E and at least one nucleic acid sequence encoding a non-structural protein sequence into the recombinant MVA vector, wherein each nucleic acid sequence is operably linked to a promoter compatible with poxvirus expression systems.
In one embodiment, the non-structural sequence is NS1and the premembrane-E sequence is PrM-E.
In a particular embodiment, the NS1 sequence and the PrM-E sequence are from a Zika virus.
In one embodiment, the recombinant MVA viral vector expresses Zika virus premembrane-E and NS1 proteins that assemble into VLPs.
The numbering illustrates the positions (in kilobase pairs) of the various elements in the genome of the MVA vaccine vector. For clarity and brevity, the diagram is not to scale; pairs of diagonal lines indicate a section of the MVA genome that is not illustrated because its contents are not relevant to the invention. Arrows labeled “PrM-E′ and “NS1” illustrate the positions of the genes encoding premembrane-E and NS1, respectively, for use with Zika virus sequences. Rectangles labeled “I8R” and “G1L” indicate the positions of the two MVA genetic elements flanking the gene encoding PrME. Rectangles labeled “A5OR” and “B1R” indicate the positions of the two MVA genetic elements flanking the gene encoding NS1.
The ampicillin resistance marker, allowing the vector to replicate in bacteria, is illustrated with a block labeled “amp-R.” The two flanking sequences, allowing the vector to recombine with the MVA genome, are illustrated with a block and a block labeled “Flank 1” and “Flank 2” respectively. The green fluorescent protein (GFP) selection marker, allowing the selection of recombinant MVAs, is illustrated with an arrow labeled “GFP.” The block labeled “DR” illustrates the location of a sequence homologous to part of Flank 1 of the MVA sequence. DR enables removal of the GFP sequence from the MVA vector after insertion of PrM-E into the MVA genome. The modified H5 (mH5) promoter, which enables transcription of the inserted heterologous gene, is illustrated with a triangle between the DR and PrM-E elements. The flavivirus PrM-E gene is illustrated with an arrow labeled “PrM-E”.
The ampicillin resistance marker, allowing the vector to replicate in bacteria, is illustrated with a block labeled “amp-R.” The two flanking sequences, allowing the vector to recombine with the MVA genome, are illustrated with blocks labeled “Flank 1” and “Flank 2.” The green fluorescent protein (GFP) selection marker, allowing the selection of recombinant MVAs, is illustrated with an arrow labeled “GFP.” The block labeled “DR” illustrates the location of a sequence homologous to part of Flank 1 of the MVA sequence. DR enables removal of the GFP sequence from the MVA vector after insertion of NS1 into the MVA genome. The modified H5 (mH5) promoter, which enables transcription of the inserted heterologous gene, is illustrated with a triangle between the DR and NS1 elements. The flavivirus NS1 gene is illustrated with an arrow labeled “NS1.”
The ampicillin resistance marker, allowing the vector to replicate in bacteria, is illustrated with a block labeled “amp-R.” The two flanking sequences, allowing the vector to recombine with the MVA genome, are illustrated with blocks labeled “Flank 1” and “Flank 2.” The green fluorescent protein (GFP) selection marker, allowing the selection of recombinant MVAs, is illustrated with an arrow labeled “GFP.” The block labeled “DR” illustrates the location of a sequence homologous to part of Flank 1 of the MVA sequence. DR enables removal of the GFP sequence from the MVA vector after insertion of NS1 into the MVA genome. The modified H5 (mH5) promoter, which enables transcription of the inserted heterologous gene, is illustrated with a triangle between the DR and NS1 elements. The flavivirus TruncNS1 gene is illustrated with an arrow labeled “TruncNS1.”
The ampicillin resistance marker, allowing the vector to replicate in bacteria, is illustrated with a block labeled “amp-R.” The two flanking sequences, allowing the vector to recombine with the MVA genome, are illustrated with blocks labeled “Flank 1” and “Flank 2.” The green fluorescent protein (GFP) selection marker, allowing the selection of recombinant MVAs, is illustrated with an arrow labeled “GFP.” The block labeled “DR” illustrates the location of a sequence homologous to part of Flank 1 of the MVA sequence. DR enables removal of the GFP sequence from the MVA vector after insertion of NS1 into the MVA genome. The modified H5 (mH5) promoter, which enables transcription of the inserted heterologous gene, is illustrated with a triangle between the DR and NS1 elements. The flavivirus prM-E gene is illustrated with an arrow labeled “prM” and “E”.
The ampicillin resistance marker, allowing the vector to replicate in bacteria, is illustrated with a block labeled “amp-R.” The two flanking sequences, allowing the vector to recombine with the MVA genome, are illustrated with blocks labeled “Flank 1” and “Flank 2.” The green fluorescent protein (GFP) selection marker, allowing the selection of recombinant MVAs, is illustrated with an arrow labeled “GFP.” The block labeled “DR” illustrates the location of a sequence homologous to part of Flank 1 of the MVA sequence. DR enables removal of the GFP sequence from the MVA vector after insertion of NS1 into the MVA genome. The modified H5 (mH5) promoter, which enables transcription of the inserted heterologous gene, is illustrated with a triangle between the DR and NS1 elements. The flavivirus prM and soluble E (sE) genes are illustrated with arrows labeled “prM” and “sE”.
The ampicillin resistance marker, allowing the vector to replicate in bacteria, is illustrated with a block labeled “amp-R.” The two flanking sequences, allowing the vector to recombine with the MVA genome, are illustrated with blocks labeled “Flank 1” and “Flank 2.” The green fluorescent protein (GFP) selection marker, allowing the selection of recombinant MVAs, is illustrated with an arrow labeled “GFP.” The block labeled “DR” illustrates the location of a sequence homologous to part of Flank 1 of the MVA sequence. DR enables removal of the GFP sequence from the MVA vector after insertion of NS1 into the MVA genome. The modified H5 (mH5) promoter, which enables transcription of the inserted heterologous gene, is illustrated with a triangle between the DR and NS1 elements. The flavivirus prM and soluble E (sE) genes are illustrated with arrows labeled “prM” and “sE”.
(B-C) Mice were challenged IC with 105 pfu ZIKV (MR766) 28 days after vaccination. Mice immunized by Prime Only (B) or Prime-Boost (C) regimen maintained weight (left) and were rescued from death (right).
Compositions and methods are provided to produce an immune response to a flavivirus, such as a Zika virus, in a subject in need thereof. The compositions and methods of the present invention can be used to prevent infection in an unexposed person or to treat disease in a subject exposed to a flavivirus who is not yet symptomatic or has minimal symptoms. In one embodiment, treatment limits an infection and/or the severity of disease.
Ideal immunogenic compositions or vaccines are safet, effective, and provide sufficient scope of protection and longevity. However, compositions having fewer than all of these characteristics may still be useful in preventing viral infection or limiting symptoms or disease progression in an exposed subject treated prior to the development of symptoms. In one embodiment the present invention provides a vaccine that permits at least partial, if not complete, protection after a single immunization.
In exemplary embodiments, the immune responses are long-lasting and durable so that repeated boosters are not required, but in one embodiment, one or more administrations of the compositions provided herein are provided to boost the initial primed immune response.
I. Definitions
Where a term is provided in the singular, the inventors also contemplate aspects of the invention described by the plural of that term. As used in this specification and in the appended claims, the singular forms “a”, “an” and “the” include plural references unless the context clearly dictates otherwise, e.g., “a peptide” includes a plurality of peptides. Thus, for example, a reference to “a method” includes one or more methods, and/or steps of the type described herein and/or which will become apparent to those persons skilled in the art upon reading this disclosure.
The term “antigen” refers to a substance or molecule, such as a protein, or fragment thereof, that is capable of inducing an immune response.
The term “binding antibody” or “bAb” refers to an antibody which either is purified from, or is present in, a body fluid (e.g., serum or a mucosal secretion) and which recognizes a specific antigen. As used herein, the antibody can be a single antibody or a plurality of antibodies. Binding antibodies comprise neutralizing and non-neutralizing antibodies.
The term “”cell-mediated immune response” refers to the immunological defense provided by lymphocytes, such as the defense provided by sensitized T cell lymphocytes when they directly lyse cells expressing foreign antigens and secrete cytokines (e.g., IFN-gamma.), which can modulate macrophage and natural killer (NK) cell effector functions and augment T cell expansion and differentiation. The cellular immune response is the 2nd branch of the adaptive immune response.
The term “conservative amino acid substitution” refers to substitution of a native amino acid residue with a non-native residue such that there is little or no effect on the size, polarity, charge, hydrophobicity, or hydrophilicity of the amino acid residue at that position, and without resulting in substantially altered immunogenicity. For example, these may be substitutions within the following groups: valine, glycine; glycine, alanine; valine, isoleucine, leucine; aspartic acid, glutamic acid; asparagine, glutamine; serine, threonine; lysine, arginine; and phenylalanine, tyrosine. Conservative amino acid modifications to the sequence of a polypeptide (and the corresponding modifications to the encoding nucleotides) may produce polypeptides having functional and chemical characteristics similar to those of a parental polypeptide.
The term “deletion” in the context of a polypeptide or protein refers to removal of codons for one or more amino acid residues from the polypeptide or protein sequence. The term deletion in the context of a nucleic acid refers to removal of one or more bases from a nucleic acid sequence.
As used herein, the term “E” refers to the flavivirus E protein or the gene or transcript encoding the flavivirus E protein.
The terms “gene”, “polynucleotide”, “nucleotide” and “nucleic acid” are used interchangeably herein.
The term “flavivirus” refers collectively to members of the Flaviridae family of single stranded (−) RNA viruses including West Nile virus, dengue virus, tick-borne encephalitis virus, yellow fever virus, and Zika viruses.
The term “fragment” in the context of a proteinaceous agent refers to a peptide or polypeptide comprising an amino acid sequence of at least 2 contiguous amino acid residues, at least 5 contiguous amino acid residues, at least 10 contiguous amino acid residues, at least 15 contiguous amino acid residues, at least 20 contiguous amino acid residues, at least 25 contiguous amino acid residues, at least 40 contiguous amino acid residues, at least 50 contiguous amino acid residues, at least 60 contiguous amino residues, at least 70 contiguous amino acid residues, at least 80 contiguous amino acid residues, at least 90 contiguous amino acid residues, at least 100 contiguous amino acid residues, at least 125 contiguous amino acid residues, at least 150 contiguous amino acid residues, at least 175 contiguous amino acid residues, at least 200 contiguous amino acid residues, or at least 250 contiguous amino acid residues of the amino acid sequence of a peptide, polypeptide or protein. In one embodiment, a fragment of a full-length protein retains activity of the full-length protein. In another embodiment, the fragment of the full-length protein does not retain the activity of the full-length protein.
The term “fragment” in the context of a nucleic acid refers to a nucleic acid comprising an nucleic acid sequence of at least 2 contiguous nucleotides, at least 5 contiguous nucleotides, at least 10 contiguous nucleotides, at least 15 contiguous nucleotides, at least 20 contiguous nucleotides, at least 25 contiguous nucleotides, at least 30 contiguous nucleotides, at least 35 contiguous nucleotides, at least 40 contiguous nucleotides, at least 50 contiguous nucleotides, at least 60 contiguous nucleotides, at least 70 contiguous nucleotides, at least contiguous 80 nucleotides, at least 90 contiguous nucleotides, at least 100 contiguous nucleotides, at least 125 contiguous nucleotides, at least 150 contiguous nucleotides, at least 175 contiguous nucleotides, at least 200 contiguous nucleotides, at least 250 contiguous nucleotides, at least 300 contiguous nucleotides, at least 350 contiguous nucleotides, or at least 380 contiguous nucleotides of the nucleic acid sequence encoding a peptide, polypeptide or protein. In a preferred embodiment, a fragment of a nucleic acid encodes a peptide or polypeptide that retains activity of the full-length protein. In another embodiment, the fragment encodes a peptide or polypeptide that of the full-length protein does not retain the activity of the full-length protein.
As used herein, the phrase “heterologous sequence” refers to any nucleic acid, protein, polypeptide or peptide sequence which is not normally associated in nature with another nucleic acid or protein, polypeptide or peptide sequence of interest.
As used herein, the phrase “heterologous gene insert” refers to any nucleic acid sequence that has been, or is to be inserted into the recombinant vectors described herein. The heterologous gene insert may refer to only the gene product encoding sequence or may refer to a sequence comprising a promoter, a gene product encoding sequence (such as GP, VP or Z), and any regulatory sequences associated or operably linked therewith.
The term “homopolymer stretch” refers to a sequence comprising at least four of the same nucleotides uninterrupted by any other nucleotide, e.g., GGGG or TTTTTTT.
The term “humoral immune response” refers to the stimulation of Ab production. Humoral immune response also refers to the accessory proteins and events that accompany antibody production, including T helper cell activation and cytokine production, affinity maturation, and memory cell generation. The humoral immune response is one of two branches of the adaptive immune response.
The term “humoral immunity” refers to the immunological defense provided by antibody, such as neutralizing Ab that can directly block infection; or, binding Ab that identifies a virus or infected cell for killing by such innate immune responses as complement (C′)-mediated lysis, phagocytosis, and natural killer cells.
The term “immune” or “immunity” refers refers to protection from disease (e.g., preventing or attenuating (e.g., suppression) of a sign, symptom or condition of the disease) upon exposure to a pathogen (e.g., a virus) capable of causing the disease.
The term “immune response” refers to any response to an antigen or antigenic determinant by the immune system of a subject (e.g., a human). Exemplary immune responses include humoral immune responses (e.g., production of antigen-specific antibodies) and cell-mediated immune responses (e.g., production of antigen-specific T cells).
The term “improved therapeutic outcome” relative to a subject diagnosed as infected with a particular virus (e.g., a flavivirus) refers to a slowing or diminution in the growth of virus, or viral load, or detectable symptoms associated with infection by that particular virus; or a reduction in the ability of the infected subject to transmit the infection to another, uninfected subject.
The term “inducing an immune response” means eliciting a humoral response (e.g., the production of antibodies) or a cellular response (e.g., the activation of T cells) directed against a virus (e.g., zika virus) in a subject to which the composition (e.g., a vaccine) has been administered.
The term “insertion” in the context of a polypeptide or protein refers to the addition of one or more non-native amino acid residues in the polypeptide or protein sequence. Typically, no more than about from 1 to 6 residues (e.g. 1 to 4 residues) are inserted at any one site within the polypeptide or protein molecule.
The term “modified vaccinia Ankara,” “modified vaccinia ankara,” “Modified Vaccinia Ankara,” or “MVA” refers to a highly attenuated strain of vaccinia virus developed by Dr. Anton Mayr by serial passage on chick embryo fibroblast cells; or variants or derivatives thereof. MVA is reviewed in (Mayr, A. et al. 1975 Infection 3:6-14; Swiss Patent No. 568,392).
The term “neutralizing antibody” or “NAb” refers to an antibody which is either purified from, or is present in, a body fluid (e.g., serum or a mucosal secretion) and which recognizes a specific antigen and inhibits the effect(s) of the antigen in the subject (e.g., a human). As used herein, the antibody can be a single antibody or a plurality of antibodies.
The term “non-neutralizing antibody” or “nnAb” refers to a binding antibody that is not a neutralizing antibody.
As used herein, the term “NS” refers to the flavivirus nonstructural protein or the gene or transcript encoding the flavivirus nonstructural protein. There are 7 nonstructural proteins in flavivirus denoted NS1, NS2a, NS2b, NS3, NS4a, NS4b, and NSS.
The term “operably linked”, when used with reference to a promoter, refers to a configuration in which the promoter is placed at an appropriate position relative to the coding sequence of a polynucleotide such that the promoter directs expression of the coding sequence. As used herein, the term “PrM” refers to the flavivirus premembrane protein or the gene or transcript encoding the flavivirus premembrane protein.
The term “prevent”, “preventing” and “prevention” refers to the inhibition of the development or onset of a condition (e.g., a flavivirus infection or a condition associated therewith), or the prevention of the recurrence, onset, or development of one or more symptoms of a condition in a subject resulting from the administration of a therapy or the administration of a combination of therapies.
The term “prophylactically effective amount” refers to the amount of a composition (e.g., the recombinant MVA vector or pharmaceutical composition) which is sufficient to result in the prevention of the development, recurrence, or onset of a condition or a symptom thereof (e.g., a flavivirus infection or a condition or symptom associated therewith) or to enhance or improve the prophylactic effect(s) of another therapy.
The term “recombinant” means a polynucleotide of semisynthetic, or synthetic origin that either does not occur in nature or is linked to another polynucleotide in an arrangement not found in nature.
The term “recombinant,” with respect to a viral vector, means a vector (e.g., a viral genome) that has been manipulated in vitro (e.g., using recombinant nucleic acid techniques) to express heterologous viral nucleic acid sequences.
The term “regulatory sequence” “regulatory sequences” refers collectively to promoter sequences, polyadenylation signals, transcription termination sequences, upstream regulatory domains, origins of replication, internal ribosome entry sites (“IRES”), enhancers, and the like, which collectively provide for the transcription and translation of a coding sequence. Not all of these control sequences need always be present so long as the selected gene is capable of being transcribed and translated.
The term “shuttle vector” refers to a genetic vector (e.g., a DNA plasmid) that is useful for transferring genetic material from one host system into another. A shuttle vector can replicate alone (without the presence of any other vector) in at least one host (e.g., E. coli). In the context of MVA vector construction, shuttle vectors are usually DNA plasmids that can be manipulated in E. coli and then introduced into cultured cells infected with MVA vectors, resulting in the generation of new recombinant MVA vectors.
The term “silent mutation” means a change in a nucleotide sequence that does not cause a change in the primary structure of the protein encoded by the nucleotide sequence, e.g., a change from AAA (encoding lysine) to AAG (also encoding lysine).
The term “subject” is means any mammal, including but not limited to, humans, domestic and farm animals, and zoo, sports, or pet animals, such as dogs, horses, cats, cows, rats, mice, guinea pigs and the like.
The term “surrogate endpoint” means a clinical measurement other than a measurement of clinical benefit that is used as a substitute for a measurement of clinical benefit.
The term “surrogate marker” means a laboratory measurement or physical sign that is used in a clinical or animal trial as a substitute for a clinically meaningful endpoint that is a direct measure of how a subject feels, functions, or survives and is expected to predict the effect of the therapy (Katz, R., NeuroRx 1:189-195 (2004); New drug, antibiotic, and biological drug product regulations; accelerated approval—FDA. Final rule. Fed Regist 57: 58942-58960, 1992.)
The term “surrogate marker for protection” means a surrogate marker that is used in a clinical or animal trial as a substitute for the clinically meaningful endpoint of prevention of flavivirus infection.
The term “synonymous codon” refers to the use of a codon with a different nucleic acid sequence to encode the same amino acid, e.g., AAA and AAG (both of which encode lysine). Codon optimization changes the codons for a protein to the synonymous codons that are most frequently used by a vector or a host cell.
The term “therapeutically effective amount” means the amount of the composition (e.g., the recombinant MVA vector or pharmaceutical composition) that, when administered to a mammal for treating an infection, is sufficient to effect treatment for the infection.
The term “treating” or “treat” refer to the eradication or control of a flavivirus, a reduction in the titer of the flavivirus, a reduction in the numbers of the flavivirus, the reduction or amelioration of the progression, severity, and/or duration of a condition or one or more symptoms caused by the flavivirus resulting from the administration of one or more therapies, or the reduction or elimination of the subject's ability to transmit the infection to another, uninfected subject.
The term “vaccine” means material used to provoke an immune response and confer immunity after administration of the material to a subject. Such immunity may include a cellular or humoral immune response that occurs when the subject is exposed to the immunogen after vaccine administration.
The term “vaccine insert” refers to a nucleic acid sequence encoding a heterologous sequence that is operably linked to a promoter for expression when inserted into a recombinant vector. The heterologous sequence may encode a PrM-E or nonstructural protein described here.
The term “viral infection” means an infection by a viral pathogen (e.g., a member of genus Flavivirus) wherein there is clinical evidence of the infection based on symptoms or based on the demonstration of the presence of the viral pathogen in a biological sample from the subject.
The term “virus-like particles” or “VLP” refers to a structure which resembles the native virus antigenically and morphologically.
The term “Zika virus” which is synonymous with “zikavirus” and “ZIKV” refers to a member of the flavivirus family flaviviridae. Zika virus is enveloped and icosahedral and has a non-segmented, single-stranded, positive-sense RNA genome.
II. Flaviviruses
The compositions of the present invention are useful for inducing an immune response to a flavivirus.
Flavivirus is a genus of viruses in the family Flaviviridae. This genus includes the West Nile virus, dengue virus, tick-borne encephalitis virus, yellow fever virus, Zika virus and several other viruses which may cause encephalitis (Shi, P-Y (editor) (2012). Molecular Virology and Control of Flaviviruses. Caister Academic Press).
Flaviviruses share several common aspects: common size (40-65 nm), symmetry (enveloped, icosahedral nucleocapsid), nucleic acid (positive-sense, single-stranded RNA around 10,000-11,000 bases), and appearance in the electron microscope. Like all flaviviruses, ZIKV is a single-stranded RNA virus with a positive-polarity RNA genome of approximately 11 kb. Both termini of the genomic contain sequences that do not encode viral proteins, known as the 5′ and the 3′ untranslated region. The encoded polyprotein is translated and co- and posttranslationally processed by viral and cellular proteases into three structural (capsid [C], premembrane [prM] or membrane [M], and envelope [E]) and seven nonstructural (NS1, NS2a, NS2b, NS3, NS4a, NS4b, and NS5) proteins.
Zika virus Species and Sequences
The term Zika virus (ZIKV) refers to a genus within the family Flavivirus. Like other Flaviviruses, species within the Zika virus genus consist of a single strand of positive sense RNA that is approximately 11 kb in length with 2 flanking non-coding regions (5′ and 3′ NCR) and a single long open reading frame encoding a polyprotein: 5′-C-prM-E-NS1-NS2A-NS2B-NS3-NS4A-NS4B-NS5-3′, that is cleaved into capsid (C), precursor of membrane (prM), envelope (E) and seven non-structural proteins (NS). The E protein (≈53 kDa) is the major virion surface protein and is involved in various aspects of the viral cycle, mediating binding and membrane fusion. The 3′NCR of the ZIKV genome contains about 428 nucleotides, including 27 folding patterns that may be involved in the recognition by cellular or viral factors, translation, genome stabilization, RNA packaging, or cyclization.
Zika fever is a mosquito-borne illness caused by a flavivirus. Human infections with ZIKVcan cause fever, malaise and cutaneous rash. Despite several reports since 1947, when it was first isolated at Zika forest in Uganda, molecular evolution of ZIKV as an emerging agent remains poorly understood. Moreover, despite several ZIKV reports from Africa and Asia, few human cases were notified until 2007 when an epidemic took place in Micronesia. In West Africa, surveillance programs have reported periodic circulation of the virus since 1968.
Using current methodology, Zika virus is detectable in blood only after onset of symptoms, which accompany the rise in circulating virus. It may take up to three days after symptoms start for the virus to reach detectable levels. Laboratory tests used in diagnosis include, for example, antigen-capture enzyme-linked immunosorbent assay (ELISA) testing, IgM ELISA, polymerase chain reaction (PCR), virus isolation, and-later in the course of infection or recovery-detection of IgM and IgG antibodies.
No vaccine or therapeutic has been approved by the FDA for Zika virus, for either prophylactic or therapeutic use.
III. Recombinant Viral Vectors
In one aspect, the present invention is a recombinant viral vector comprising one or more genes of a flavivirus virus, such as Zika virus. In certain embodiments, the recombinant viral vector is a vaccinia viral vector, and more particularly, an MVA vector, comprising one or more genes of a flavivirus, such as Zika virus.
Vaccinia viruses have also been used to engineer viral vectors for recombinant gene expression and for the potential use as recombinant live vaccines (Mackett, M. et al 1982 PNAS USA 79:7415-7419; Smith, G. L. et al. 1984 Biotech Genet Engin Rev 2:383-407). This entails DNA sequences (genes) which code for foreign antigens being introduced, with the aid of DNA recombination techniques, into the genome of the vaccinia viruses. If the gene is integrated at a site in the viral DNA which is non-essential for the life cycle of the virus, it is possible for the newly produced recombinant vaccinia virus to be infectious, that is to say able to infect foreign cells and thus to express the integrated DNA sequence (EP Patent Applications No. 83,286 and No. 110,385). The recombinant vaccinia viruses prepared in this way can be used, on the one hand, as live vaccines for the prophylaxis of infectious diseases, on the other hand, for the preparation of heterologous proteins in eukaryotic cells.
Several such strains of vaccinia virus have been developed to avoid undesired side effects of smallpox vaccination. Thus, a modified vaccinia Ankara (MVA) has been generated by long-term serial passages of the Ankara strain of vaccinia virus (CVA) on chicken embryo fibroblasts (for review see Mayr, A. et al. 1975 Infection 3:6-14; Swiss Patent No. 568,392). The MVA virus is publicly available from American Type Culture Collection as ATCC No.: VR-1508. MVA is distinguished by its great attenuation, as demonstrated by diminished virulence and reduced ability to replicate in primate cells, while maintaining good immunogenicity. The MVA virus has been analyzed to determine alterations in the genome relative to the parental CVA strain. Six major deletions of genomic DNA (deletion I, II, III, IV, V, and VI) totaling 31,000 base pairs have been identified (Meyer, H. et al. 1991 J Gen Virol 72:1031-1038). The resulting MVA virus became severely host cell restricted to avian cells.
Furthermore, MVA is characterized by its extreme attenuation. When tested in a variety of animal models, MVA was proven to be avirulent even in immunosuppressed animals. More importantly, the excellent properties of the MVA strain have been demonstrated in extensive clinical trials (Mayr A. et al. 1978 Zentralbl Bakteriol [B] 167:375-390; Stickl et al. 1974 Dtsch Med Wschr 99:2386-2392). During these studies in over 120,000 humans, including high-risk patients, no side effects were associated with the use of MVA vaccine.
MVA replication in human cells was found to be blocked late in infection preventing the assembly to mature infectious virions. Nevertheless, MVA was able to express viral and recombinant genes at high levels even in non-permissive cells and was proposed to serve as an efficient and exceptionally safe gene expression vector (Sutter, G. and Moss, B. 1992 PNAS USA 89:10847-10851). Additionally, novel vaccinia vector vaccines were established based on MVA having foreign DNA sequences inserted at the site of deletion III within the MVA genome (Sutter, G. et al. 1994 Vaccine 12:1032-1040).
Recombinant MVA vaccinia viruses can be prepared as set out hereinafter. A DNA-construct which contains a DNA-sequence which codes for a foreign polypeptide flanked by MVA DNA sequences adjacent to a predetermined insertion site (e.g. between two conserved essential MVA genes such as I8R/G1L; in restructured and modified deletion III; or at other non-essential sites within the MVA genome) is introduced into cells infected with MVA, to allow homologous recombination. Once the DNA-construct has been introduced into the eukaryotic cell and the foreign DNA has recombined with the viral DNA, it is possible to isolate the desired recombinant vaccinia virus in a manner known per se, preferably with the aid of a marker. The DNA-construct to be inserted can be linear or circular. A plasmid or polymerase chain reaction product is preferred. Such methods of making recombinant MVA vectors are described in PCT publication WO/2006/026667 incorporated by reference herein. The DNA-construct contains sequences flanking the left and the right side of a naturally occurring deletion. The foreign DNA sequence is inserted between the sequences flanking the naturally occurring deletion. For the expression of a DNA sequence or gene, it is necessary for regulatory sequences, which are required for the transcription of the gene, to be present on the DNA. Such regulatory sequences (called promoters) are known to those skilled in the art, and include for example those of the vaccinia 11 kDa gene as are described in EP-A-198,328, and those of the 7.5 kDa gene (EP-A-110,385). The DNA-construct can be introduced into the MVA infected cells by transfection, for example by means of calcium phosphate precipitation (Graham et al. 1973 Virol 52:456-467; Wgler et al. 1979 Cell 16:777-785), by means of electroporation (Neumann et al. 1982 EMBO J. 1:841-845), by microinjection (Graessmann et al. 1983 Meth Enzymol 101:482-492), by means of liposomes (Straubinger et al. 1983 Meth Enzymol 101:512-527), by means of spheroplasts (Schaffher 1980 PNAS USA 77:2163-2167) or by other methods known to those skilled in the art.
The MVA vectors described and tested herein were unexpectedly found to be effective after a single prime or a homologous prime/boost regimen. Other MVA vector designs require a heterologous prime/boost regimen, while still other published studies have been unable to induce effective immune responses with MVA vectors. Conversely, the present MVA vector design and methods of manufacture are useful in producing effective MVA vaccine vectors for eliciting effective T-cell and antibody immune responses. Furthermore, the utility of an MVA vector capable of eliciting effective immune responses and antibody production after a single homologous prime boost is significant for considerations such as use, commercialization and transport of materials especially to affected third world locations.
In one embodiment, the present invention is a recombinant viral vector (e.g., an MVA vector) comprising one or more heterologous gene inserts of a flavivirus (e.g., a Zika virus). The viral vector (e.g., an MVA vector) may be constructed using conventional techniques known to one of skill in the art. The one or more heterologous gene inserts encode a polypeptide having desired immunogenicity, i.e., a polypeptide that can induce an immune reaction, cellular immunity and/or humoral immunity, in vivo by administration thereof. The gene region of the vector (e.g., an MVA vector) where the gene encoding a polypeptide having immunogenicity is introduced is flanked by regions that are indispensable. In the introduction of a gene encoding a polypeptide having immunogenicity, an appropriate promoter may be operatively linked upstream of the gene encoding a polypeptide having desired immunogenicity.
The one or more genes may be selected from any species of flavivirus. In one embodiment, the one more genes are selected from a Zika virus species. In exemplary embodiments, the gene encodes a polypeptide or protein capable of inducing an immune response in the subject to which it is administered, and more particularly, an immune response capable of providing a protective and/or therapeutic benefit to the subject. In one embodiment, the one or more genes encode the virus premembrane protein (PrM), the E protein (E), the or one or more nonstructural proteins (e.g. NS1, NS2a, NS2b, NS3, NS4a, NS4b, and NS5)). The heterologous gene inserts are inserted into one or more deletion sites of the vector under the control of promoters compatible with poxvirus expression systems.
In one embodiment, the deletion III site is restructured and modified to remove non-essential flanking sequences.
In exemplary embodiments, the vaccine is constructed to express an Zika virus premembrane-E protein (PrM-E), which is inserted between two conserved essential MVA genes (I8R and G1L) using shuttle vector pGeo-PrM-E; and to express Zika virus NS1, which is inserted into deletion III using shuttle vector pGeo-NS1. pGeo-PrM-E and pGeo-NS1 are constructed with an ampicillin resistance marker, allowing the vector to replicate in bacteria; with two flanking sequences, allowing the vector to recombine with a specific location in the MVA genome; with a green fluorescent protein (GFP) selection marker, allowing the selection of recombinant MVAs; with a sequence homologous to part of Flank 1 of the MVA sequence, enabling removal of the GFP sequence from the MVA vector after insertion of NS1 into the MVA genome; with a modified H5 (mH5) promoter, which enables transcription of the inserted heterologous gene insert; and with a flavivirus gene. pGeo-PrM-E and pGeo-NS1 differ in that pGeo-PrM-E contains the PrM-E sequence, whereas pGeo-NS1 contains the NS1 sequence; and in that pGeo-PrM-E recombines with sequences of MVA I8R and G1L (two essential genes) and pGeo-NS1 recombines with regions flanking the restructured and modified Deletion III of MVA.
In exemplary embodiments, the present invention provides a recombinant MVA vector comprising a gene encoding the PrM-E gene and a gene encoding NS1, in each case, from a Zika virus.
In certain embodiments, the polypeptide, or the nucleic acid sequence encoding the polypeptide, may have a mutation or deletion (e.g., an internal deletion, truncation of the amino- or carboxy-terminus, or a point mutation).
The one or more genes introduced into the recombinant viral vector are under the control of regulatory sequences that direct its expression in a cell.
The nucleic acid material of the viral vector may be encapsulated, e.g., in a lipid membrane or by structural proteins (e.g., capsid proteins), that may include one or more viral polypeptides.
In exemplary embodiments, the present invention is a recombinant viral vector (e.g., a recombinant MVA vector) comprising one or more genes, or one or more polypeptides encoded by the gene or genes, from a Zika virus. The Zika virus gene may encode a polypeptide or protein capable of inducing an immune response in the subject to which it is administered, and more particularly, an immune response capable of providing a protective and/or therapeutic benefit to the subject, e.g., the Zika virus PrM-E. The nucleic acid sequences of Zika virus premembrane and E proteins and nonstructural are published and are available from a variety of sources, including, e.g., GenBank and PubMed. Exemplary GenBank references including Zika virus sequences include those corresponding to accession numbers KU312312.
In certain embodiments, the one or more genes encodes a polypeptide, or fragment thereof, that is substantially identical (e.g., at least 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 98%, 99%, or even 100% identical) to the selected Zika virus PrM-E over at least 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, or 70 contiguous residues of the selected Zika virus PrM or E that retain immunogenic activity.
In certain embodiments, the one or more genes encodes a polypeptide, or fragment thereof, that is substantially identical (e.g., at least 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 98%, 99%, or even 100% identical) to the selected Zika virus E over at least 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, or 70 contiguous residues of the selected Zika virus E that retains immunogenic activity.
In exemplary embodiments, the recombinant viral vector may also include an Zika virus PrM-E present on its surface. The Zika virus PrM-E may be obtained by any suitable means, including, e.g., application of genetic engineering techniques to a viral source, chemical synthesis techniques, recombinant production, or any combination thereof.
In another embodiments, the present invention is a recombinant MVA vector comprising at least one heterologous gene insert from an Zika virus, wherein the gene is selected from the group encoding the premembrane protein (PrM), the E protein (E), the or one or more nonstructural proteins (e.g. NS1, NS2a, NS2b, NS3, NS4a, NS4b, and NS5).
In a particular embodiment, the present invention is a recombinant MVA vector comprising a gene encoding PrM-E and a gene encoding NS1. In another embodiment, the present invention is a recombinant MVA vector comprising genes encoding PrM-E, and NS1. The heterologous gene inserts are inserted into one or more deletion sites of the MVA vector under the control of promoters compatible with poxvirus expression systems.
In one embodiment, the PrM-E is inserted into deletion site I, II, III, IV, V or VI of the MVA vector, and the NS1 is inserted into deletion site I, II, III, IV, V or VI of the MVA vector.
In one embodiment, the PrM-E is inserted between 18R and G1L of the MVA vector, or into restructured and modified deletion III of the MVA vector; and the NS1 is inserted between I8R and G1L of the MVA vector, or into restructured and modified deletion site III of the MVA vector.
In exemplary embodiments, the present invention is a recombinant MVA vector comprising at least one heterologous gene insert (e.g., one or more gene inserts) from a Zika virus which is under the control of regulatory sequences that direct its expression in a cell. The gene may be, for example, under the control of a promoter selected from the group consisting of Pm2H5, Psyn II, or mH5 promoters.
In one embodiment, the recombinant MVA vaccine expresses proteins that assemble into virus-like particles (VLPs) comprising the PrM-E and NS1 proteins. While not wanting to be bound by any particular theory, it is believed that the PrM-E is provided to elicit a protective immune response and the NS1 (nonstructural protein) is provided to enable assembly of VLPs and as a target for T cell immune responses, thereby enhancing the protective immune response and providing cross-protection.
One or more genes may be optimized for use in the MVA vector. Optimization includes codon optimization, which employs silent mutations to change selected codons from the native sequences into synonymous codons that are optimally expressed by the host-vector system. Other types of optimization include the use of silent mutations to interrupt homopolymer stretches or transcription terminator motifs. Each of these optimization strategies can improve the stability of the gene, improve the stability of the transcript, or improve the level of protein expression from the gene. In exemplary embodiments, the number of homopolymer stretches in the PrM-E or NS1 sequence is reduced to stabilize the construct. A silent mutation may be provided for anything similar to a vaccinia termination signal.
In exemplary embodiments, optimization of genes may include interrupting homopolymer sequences (≥4 G/C and ≥A/T) by silent mutations, adding a second TAA stop codon, or adding a Vaccinia Transcription Terminator Sequence at the end of the gene such as TTTTTAT.
In exemplary embodiments, the PrM-E and NS1 sequences are codon optimized for expression in MVA using a computer algorithm; PrM-E and NS1 sequences with runs of ≥5 deoxyguanosines, ≥5 deoxycytidines, ≥5 deoxyadenosines, and ≥5 deoxythymidines are interrupted by silent mutation to minimize loss of expression due to frame shift mutations; and the PrM-E sequence is modified through addition of an extra nucleotide to express the transmembrane, rather than the secreted, form of Zika virus PrM-E.
The recombinant viral vectors of the present invention may be used alone or in combination. In one embodiment, two different recombinant viral vectors are used in combination, where the difference may refer to the one or more heterologous gene inserts or the other components of the recombinant viral vector or both. In exemplary embodiments, two or more recombinant viral vectors are used in combination in order to protect against infection by all versions of Flavivirus in humans.
The present invention also extends to host cells comprising the recombinant viral vector described above, as well as isolated virions prepared from host cells infected with the recombinant viral vector.
IV. Pharmaceutical Composition
The recombinant viral vectors of the present invention are readily formulated as pharmaceutical compositions for veterinary or human use, either alone or in combination. The pharmaceutical composition may comprise a pharmaceutically acceptable diluent, excipient, carrier, or adjuvant.
In one embodiment, the present invention is a vaccine effective to protect and/or treat a Flavivirus (e.g., a Zika virus) comprising a recombinant MVA vector that expresses at least one Flavivirus polypeptide (e.g., a PrM-E) or an immunogenic fragment thereof. The vaccine composition may comprise one or more additional therapeutic agents.
The pharmaceutical composition may comprise 1, 2, 3, 4 or more than 4 different recombinant MVA vectors.
As used herein, the phrase “pharmaceutically acceptable carrier” encompasses any suitable pharmaceutical carrier, such as those suitable for parenteral administration, such as, for example, by intramuscular, intraarticular (in the joints), intravenous, intradermal, intraperitoneal, and subcutaneous routes. Examples of such formulations include aqueous and non-aqueous, isotonic sterile injection solutions, which contain antioxidants, buffers, bacteriostats, and solutes that render the formulation isotonic with the blood of the intended recipient, and aqueous and non-aqueous sterile suspensions that can include suspending agents, solubilizers, thickening agents, stabilizers, and preservatives. One exemplary pharmaceutically acceptable carrier is physiological saline.
Other physiologically acceptable diluents, excipients, carriers, or adjuvants and their formulations are known to those skilled in the art.
The compositions utilized in the methods described herein can be administered by a route any suitable method, e.g., parenteral, intramuscular, intraarterial, intravascular, intravenous, intraperitoneal, subcutaneous, dermal, transdermal, ocular, inhalation, buccal, sublingual, perilingual, nasal, topical administration, and oral administration. The preferred method of administration can vary depending on various factors (e.g., the components of the composition being administered and the severity of the condition being treated). Formulations suitable for oral administration may consist of liquid solutions, such as an effective amount of the composition dissolved in a diluent (e.g., water, saline, or PEG-400), capsules, sachets or tablets, each containing a predetermined amount of the vaccine. The pharmaceutical composition may also be an aerosol formulation for inhalation, e.g., to the bronchial passageways. Aerosol formulations may be mixed with pressurized, pharmaceutically acceptable propellants (e.g., dichlorodifluoromethane, propane, or nitrogen).
For the purposes of this invention, pharmaceutical compositions suitable for delivering a therapeutic or biologically active agent can include, e.g., tablets, gelcaps, capsules, pills, powders, granulates, suspensions, emulsions, solutions, gels, hydrogels, oral gels, pastes, eye drops, ointments, creams, plasters, drenches, delivery devices, microneedles, suppositories, enemas, injectables, implants, sprays, or aerosols. Any of these formulations can be prepared by well-known and accepted methods of art. See, for example, Remington: The Science and Practice of Pharmacy (21.sup.st ed.), ed. A. R. Gennaro, Lippincott Williams & Wilkins, 2005, and Encyclopedia of Pharmaceutical Technology, ed. J. Swarbrick, Informa Healthcare, 2006, each of which is hereby incorporated by reference.
The immunogenicity of the composition (e.g., vaccine) may be significantly improved if the composition of the present invention is co-administered with an immunostimulatory agent or adjuvant. Suitable adjuvants well-known to those skilled in the art include, e.g., aluminum phosphate, aluminum hydroxide, QS21, Quil A (and derivatives and components thereof), calcium phosphate, calcium hydroxide, zinc hydroxide, glycolipid analogs, octodecyl esters of an amino acid, muramyl dipeptides, polyphosphazene, lipoproteins, ISCOM-Matrix, DC-Chol, DDA, cytokines, and other adjuvants and derivatives thereof.
Pharmaceutical compositions according to the present invention may be formulated to release the composition immediately upon administration (e.g., targeted delivery) or at any predetermined time period after administration using controlled or extended release formulations. Administration of the pharmaceutical composition in controlled or extended release formulations is useful where the composition, either alone or in combination, has (i) a narrow therapeutic index (e.g., the difference between the plasma concentration leading to harmful side effects or toxic reactions and the plasma concentration leading to a therapeutic effect is small; generally, the therapeutic index, TI, is defined as the ratio of median lethal dose (LD50) to median effective dose (ED50)); (ii) a narrow absorption window in the gastro-intestinal tract; or (iii) a short biological half-life, so that frequent dosing during a day is required in order to sustain a therapeutic level.
Many strategies can be pursued to obtain controlled or extended release in which the rate of release outweighs the rate of metabolism of the pharmaceutical composition. For example, controlled release can be obtained by the appropriate selection of formulation parameters and ingredients, including, e.g., appropriate controlled release compositions and coatings. Suitable formulations are known to those of skill in the art. Examples include single or multiple unit tablet or capsule compositions, oil solutions, suspensions, emulsions, microcapsules, microspheres, nanoparticles, patches, and liposomes.
Formulations suitable for oral administration can consist of (a) liquid solutions, such as an effective amount of the vaccine dissolved in diluents, such as water, saline or PEG 400; (b) capsules, sachets or tablets, each containing a predetermined amount of the vaccine, as liquids, solids, granules or gelatin; (c) suspensions in an appropriate liquid; (d) suitable emulsions; and (e) polysaccharide polymers such as chitins. The vaccine, alone or in combination with other suitable components, may also be made into aerosol formulations to be administered via inhalation, e.g., to the bronchial passageways. Aerosol formulations can be placed into pressurized acceptable propellants, such as dichlorodifluoromethane, propane, nitrogen, and the like.
Suitable formulations for rectal administration include, for example, suppositories, which consist of the vaccine with a suppository base. Suitable suppository bases include natural or synthetic triglycerides or paraffin hydrocarbons. In addition, it is also possible to use gelatin rectal capsules which consist of a combination of the vaccine with a base, including, for example, liquid triglycerides, polyethylene glycols, and paraffin hydrocarbons.
Pharmaceutical compositions comprising any of the nucleic acid molecules encoding flavivirus viral proteins of the present invention are useful to immunize a subject against disease caused by flavivirus infection. Thus, this invention further provides methods of immunizing a subject against disease caused by flavivirus infection, comprising administering to the subject an immunoeffective amount of a pharmaceutical composition of the invention. This subject may be an animal, for example a mammal, such as a primate or preferably a human.
The vaccines of the present invention may also be co-administered with cytokines to further enhance immunogenicity. The cytokines may be administered by methods known to those skilled in the art, e.g., as a nucleic acid molecule in plasmid form or as a protein or fusion protein.
KitsThis invention also provides kits comprising the vaccines of the present invention. For example, kits comprising a vaccine and instructions for use are within the scope of this invention.
V. Method of Use
The compositions of the invention can be used as vaccines for inducing an immune response to a Flavivirus, such as a Zika virus.
In exemplary embodiments, the present invention provides a method of preventing a Flavivirus (e.g., Zika virus) infection to a subject in need thereof (e.g., an unexposed subject), comprising administering the composition of the present invention to the subject in a prophylactically effective amount. The result of the method is that the subject is partially or completely immunized against the virus.
In exemplary embodiments, the present invention provides a method of treating a flavivirus (e.g., Zika virus) infection in a subject in need thereof (e.g., an exposed subject, such as a subject who has been recently exposed but is not yet symptomatic, or a subject who has been recently exposed and is only mildly symptomatic), comprising administering the composition of the present invention to the subject in a therapeutically effective amount. The result of treatment is a subject that has an improved therapeutic profile.
Typically, the vaccines will be in an admixture and administered simultaneously, but may also be administered separately.
A subject to be treated according to the methods described herein (e.g., a subject infected with, a Zika virus) may be one who has been diagnosed by a medical practitioner as having such a condition. Diagnosis may be performed by any suitable means. A subject in whom the development of an infection is being prevented may or may not have received such a diagnosis. One skilled in the art will understand that a subject to be treated according to the present invention may have been identified using standard tests or may have been identified, without examination, as one at high risk due to the presence of one or more risk factors (e.g., exposure to Zika virus, etc.).
Prophylactic treatment may be administered, for example, to a subject not yet exposed to or infected by a Flavivirus but who is susceptible to, or otherwise at risk of exposure or infection with an a Flavivirus.
Therapeutic treatment may be administered, for example, to a subject already exposed to or infected by a Flavivirus who is not yet ill, or showing symptoms or infection, suffering from a disorder in order to improve or stabilize the subject's condition (e.g., a patient already infected with a flavivirus). The result is an improved therapeutic profile. In some instances, as compared with an equivalent untreated control, treatment may ameliorate a disorder or a symptom thereof by, e.g., 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, or 100% as measured by any standard technique. In some instances, treating can result in the inhibition of viral replication, a decrease in viral titers or viral load, eradication or clearing of the virus.
In other embodiments, treatment may result in amelioration of one or more symptoms of the infection, including any symptom identified above. According to this embodiment, confirmation of treatment can be assessed by detecting an improvement in or the absence of symptoms.
In other embodiments, treatment may result in reduction or elimination of the ability of the subject to transmit the infection to another, uninfected subject. Confirmation of treatment according to this embodiment is generally assessed using the same methods used to determine amelioration of the disorder, but the reduction in viral titer or viral load necessary to prevent transmission may differ from the reduction in viral titer or viral load necessary to ameliorate the disorder.
In one embodiment, the present invention is a method of inducing an immune response in a subject (e.g., a human) by administering to the subject a recombinant viral vector that encodes at least one gene from a Flavivirus, such as a Zika virus. The immune response may be a cellular immune response, a humoral immune response or a combination thereof. The immune response may be a T-cell response, a B-cell response or an antibody response.
In a particular embodiment, the present invention is a method of inducing an immune response in a subject (e.g., a human) in need thereof by administering to the subject a recombinant viral vector that encodes at least one gene from a Zika virus.
The composition may be administered, e.g., by injection (e.g., intramuscular, intraarterial, intravascular, intravenous, intraperitoneal, or subcutaneous).
It will be appreciated that more than one route of administering the vaccines of the present invention may be employed either simultaneously or sequentially (e.g., boosting). In addition, the vaccines of the present invention may be employed in combination with traditional immunization approaches such as employing protein antigens, vaccinia virus and inactivated virus, as vaccines. Thus, in one embodiment, the vaccines of the present invention are administered to a subject (the subject is “primed” with a vaccine of the present invention) and then a traditional vaccine is administered (the subject is “boosted” with a traditional vaccine). In another embodiment, a traditional vaccine is first administered to the subject followed by administration of a vaccine of the present invention. In yet another embodiment, a traditional vaccine and a vaccine of the present invention are co-administered.
It will also be appreciated that single or multiple administrations of the vaccine compositions of the present invention may be carried out. For example, subjects who are particularly susceptible to Flavivirus infection may require multiple immunizations to establish and/or maintain protective immune responses. Levels of induced immunity can be monitored by measuring amounts of binding and neutralizing secretory and serum antibodies as well as levels of T cells, and dosages adjusted or vaccinations repeated as necessary to maintain desired levels of protection.
In one embodiment, administration is repeated at least twice, at least 3 times, at least 4 times, at least 5 times, at least 6 times, at least 7 times, at least 8 times, or more than 8 times.
In one embodiment, administration is repeated twice.
In one embodiment, about 2-8, about 4-8, or about 6-8 administrations are provided.
In one embodiment, about 1-4-week, 2-4 week, 3-4 week, 1 week, 2 week, 3 week, 4 week or more than 4 week intervals are provided between administrations.
In one specific embodiment, a 4-week interval is used between 2 administrations.
DosageThe vaccines are administered in a manner compatible with the dosage formulation, and in such amount, as will be therapeutically effective, immunogenic and protective. The quantity to be administered depends on the subject to be treated, including, for example, the capacity of the immune system of the individual to synthesize antibodies, and, if needed, to produce a cell-mediated immune response. Precise amounts of active ingredient required to be administered depend on the judgment of the practitioner and may be monitored on a patient-by-patient basis. However, suitable dosage ranges are readily determinable by one skilled in the art and generally range from about 5.0×106 TCID50 to about 5.0×109 TCID50. The dosage may also depend, without limitation, on the route of administration, the patient's state of health and weight, and the nature of the formulation.
The pharmaceutical compositions of the invention are administered in such an amount as will be therapeutically effective, immunogenic, and/or protective against a pathogenic species of Zika virus. The dosage administered depends on the subject to be treated (e.g., the manner of administration and the age, body weight, capacity of the immune system, and general health of the subject being treated). The composition is administered in an amount to provide a sufficient level of expression that elicits an immune response without undue adverse physiological effects. Preferably, the composition of the invention is a heterologous viral vector that includes one or more polypeptides of the flavivirus (e.g., the Zika virus PrM-E protein and NS1 protein), or a nucleic acid molecule encoding one or more genes of the Flavivirus, and is administered ata dosage of, e.g., between 1.0×104 and 9.9×1012 TCID50 of the viral vector, preferably between 1.0×105 TCID50 and 1.0×1011 TCID50 pfu, more preferably between 1.0×106 and 1.0×1010 TCID50 pfu, or most preferably between 5.0×106 and 5.0×109 TCID50. The composition may include, e.g., at least 5.0×106 TCID50 of the viral vector (e.g., 1.0×108 TCID50 of the viral vector). A physician or researcher can decide the appropriate amount and dosage regimen.
The composition of the method may include, e.g., between 1.0×104 and 9.9×1012 TCID50 of the viral vector, preferably between 1.0×105 TCID50 and 1.0×1011 TCID50 pfu, more preferably between 1.0×106 and 1.0×1010 TCID50 pfu, or most preferably between 5.0×106 and 5.0×109 TCID50. The composition may include, e.g., at least 5.0×106 TCID50 of the viral vector (e.g., 1.0×108 TCID50 of the viral vector). The method may include, e.g., administering the composition to the subject two or more times.
In certain embodiments, pharmaceutical compositions may comprise, for example, at least about 0.1% of an active compound. In other embodiments, an active compound may comprise between about 2% to about 75% of the weight of the unit, or between about 25% to about 60%, for example, and any range derivable therein. However, a suitable dosage range may be, for example, of the order of several hundred micrograms active ingredient per vaccination. In other non-limiting examples, a dose may also comprise from about 1 microgram/kg/body weight, about 5 microgram/kg/body weight, about 10 microgram/kg/body weight, about 50 microgram/kg/body weight, about 100 microgram/kg/body weight, about 200 microgram/kg/body weight, about 350 microgram/kg/body weight, about 500 microgram/kg/body weight, about 1 milligram/kg/body weight, about 5 milligram/kg/body weight, about 10 milligram/kg/body weight, about 50 milligram/kg/body weight, about 100 milligram/kg/body weight, about 200 milligram/kg/body weight, about 350 milligram/kg/body weight, about 500 milligram/kg/body weight, to about 1000 mg/kg/body weight or more per vaccination, and any range derivable therein. In non-limiting examples of a derivable range from the numbers listed herein, a range of about 5 mg/kg/body weight to about 100 mg/kg/body weight, about 5 microgram/kg/body weight to about 500 milligram/kg/body weight, etc., can be administered, based on the numbers described above. A suitable regime for initial administration and booster administrations (e.g., inoculations) are also variable, but are typified by an initial administration followed by subsequent inoculation(s) or other administration(s).
The invention also features a method of inducing an immune response to flavivirus in a subject (e.g., a human) that includes administering to the subject an effective amount of a recombinant viral vector that encodes at least one gene from the flavivirus (e.g., the Zika virus PrM-E protein and NS1 protein). The subject being treated may not have, but rather be at risk of developing, an infection by a flavivirus. Alternatively, the subject may already be infected with a flavivirus. The composition may be administered, e.g., by injection (e.g., intramuscular, intraarterial, intravascular, intravenous, intraperitoneal, or subcutaneous).
The term “effective amount” is meant the amount of a composition administered to improve, inhibit, or ameliorate a condition of a subject, or a symptom of a disorder, in a clinically relevant manner (e.g., improve, inhibit, or ameliorate infection by flavivirus or provide an effective immune response to infection by flavivirus). Any improvement in the subject is considered sufficient to achieve treatment. Preferably, an amount sufficient to treat is an amount that prevents the occurrence or one or more symptoms of flavivirus infection or is an amount that reduces the severity of, or the length of time during which a subject suffers from, one or more symptoms of flavivirus infection (e.g., by at least 10%, 20%, or 30%, more preferably by at least 50%, 60%, or 70%, and most preferably by at least 80%, 90%, 95%, 99%, or more, relative to a control subject that is not treated with a composition of the invention). A sufficient amount of the pharmaceutical composition used to practice the methods described herein (e.g., the treatment of flavivirus infection) varies depending upon the manner of administration and the age, body weight, and general health of the subject being treated. Ultimately, the prescribers or researchers will decide the appropriate amount and dosage.
It is important to note that the value of the present invention may never be demonstrated in terms of actual clinical benefit. Instead, it is likely that the value of the invention will be demonstrated in terms of success against a surrogate marker for protection. For an indication such as flavivirus infection, in which it is impractical or unethical to attempt to measure clinical benefit of an intervention, the FDA's Accelerated Approval process allows approval of a new vaccine based on efficacy against a surrogate endpoint. Therefore, the value of the invention may lie in its ability to induce an immune response that constitutes a surrogate marker for protection.
Similarly, FDA may allow approval of vaccines against flavivirus based on its Animal Rule. In this case, approval is achieved based on efficacy in animals. The value of the invention may lie in its ability to protect relevant animal species against infection with flaviviruses, thus providing adequate evidence to justify its approval.
The composition of the method may include, e.g., between 1.0×104 and 9.9×1012 TCID50 of the viral vector, preferably between 1.0×105 TCID50 and 1.0×1011 TCID50 pfu, more preferably between 1.0×106 and 1.0×1010 TCID50 pfu, or most preferably between 5.0×106 and 5.0×109 TCID50. The composition may include, e.g., at least 5.0×106 TCID50 of the viral vector. The method may include, e.g., administering the composition two or more times.
In some instances it may be desirable to combine the flavivirus vaccines of the present invention with vaccines which induce protective responses to other agents, particularly other viruses. For example, the vaccine compositions of the present invention can be administered simultaneously, separately or sequentially with other genetic immunization vaccines such as those for influenza (Ulmer, J. B. et al., Science 259:1745-1749 (1993); Raz, E. et al., PNAS 1050 (USA) 91:9519-9523 (1994)), malaria (Doolan, D. L. et al., J. Exp. Med. 183:1739-1746 (1996); Sedegah, M. et al., PNAS (USA) 91:9866-9870 (1994)), and tuberculosis (Tascon, R. C. et al., Nat. Med. 2:888-892 (1996)).
AdministrationAs used herein, the term “administering” refers to a method of giving a dosage of a pharmaceutical composition of the invention to a subject. The compositions utilized in the methods described herein can be administered by a route selected from, e.g., parenteral, dermal, transdermal, ocular, inhalation, buccal, sublingual, perilingual, nasal, rectal, topical administration, and oral administration. Parenteral administration includes intravenous, intraperitoneal, subcutaneous, intraarterial, intravascular, and intramuscular administration. The preferred method of administration can vary depending on various factors (e.g., the components of the composition being administered and the severity of the condition being treated).
Administration of the pharmaceutical compositions (e.g., vaccines) of the present invention can be by any of the routes known to one of skill in the art. Administration may be by, e.g., intramuscular injection. The compositions utilized in the methods described herein can also be administered by a route selected from, e.g., parenteral, dermal, transdermal, ocular, inhalation, buccal, sublingual, perilingual, nasal, rectal, topical administration, and oral administration. Parenteral administration includes intravenous, intraperitoneal, subcutaneous, and intramuscular administration. The preferred method of administration can vary depending on various factors, e.g., the components of the composition being administered and the severity of the condition being treated.
In addition, single or multiple administrations of the compositions of the present invention may be given to a subject. For example, subjects who are particularly susceptible to flavivirus infection may require multiple administrations to establish and/or maintain protection against the virus. Levels of induced immunity provided by the pharmaceutical compositions described herein can be monitored by, e.g., measuring amounts of neutralizing secretory and serum antibodies. The dosages may then be adjusted or repeated as necessary to maintain desired levels of protection against viral infection.
The claimed invention is further described by way of the following non-limiting examples. Further aspects and embodiments of the present invention will be apparent to those of ordinary skill in the art, in view of the above disclosure and following experimental exemplification, included by way of illustration and not limitation, and with reference to the attached figures.
EXAMPLES Example 1 MVA Vaccine Vectors and Native Zika Virus SequencesThis example provides information on exemplary MVA vaccine vectors. Table 1 lists five MVA vaccine vectors.
Native sequences are provided below which were used for development of viral inserts
This example shows the optimization of one PrM-E sequence. A vaccine construct is designed that encodes both the PrM gene and the E gene in the same construct. These two gene products are synthesized in the cell as a polyprotein and after translocation into the ER membrane are cleaved by signal peptidase into their individual forms.
Sequences of whole Zika genomes and of the PrM+E genes were acquired from across several different Zika viruses and the variability of the sequences were determined by multiple sequence alignment and analysis with Clustal Omega. From this analysis, it was decided that the sequence of the most recent viral isolate from Suriname (Genbank accession numbers ALX35659 (protein) and KU312312 (nucleic acid)) would be used as the template from which to create the PrM-E construct.
According to the gene annotation of the French Polynesian isolate of Zika, ‘PrM’ is located at position 126-290 of the amino acid sequence and ‘E’ is located at position 291-794 of the amino acid sequence. The amino acid sequence from position 126-794 is the sequence that we will therefore use for vaccine development. This sequence is 669 amino acids in length.
This sequence is as follows, with PrM distinguished from E by underlining the sequence and the predicted transmembrane helix domains marked by Boldlettering:
The signal sequence for PrM that directs the viral polyprotein to the ER translocon is located in the C-terminal end of the C gene. This signal sequence is complicated by the fact that under normal viral infection it is targeted by both the signal peptidase (in the ER lumen) and the viral protease NS3 (in the cytoplasm).
For the present design, a Japanese Encephalitis Virus (JEV) signal sequence is used instead that has been optimized for prM-E VLP production in other Flaviviruses. This JEV signal sequence is 24 amino acids long and the sequence is as follows:
Appending the JEV signal sequence (underlined) provides the following sequence:
Appending this signal sequence to the N-terminal of prM-E results in the following sequence:
Using this sequence, codon optimization for Vaccinia was performed using the IDT Codon Optimization Tool. This yielded the following codon-optimized DNA sequence of length 2079 bp:
PrM-E DNA Final Optimized Nucleotide Sequence
According to the Zika annotation of the French Polynesian Zika isolate (GenBank Accession AHZ13508), NS1 is present as amino acids 796-1148 of the Zika polyprotein. This sequence is 353 nt long and is as follows:
SEQ ID 02: Full-length Zika virus NS1 protein sequence:
The nucleotide sequence used to encode the full-length Zika virus NS1 protein is as follows:
A soluble C-terminal part of the protein can be isolated and used in place of the full length protein. This sequence is provided as follows:
A ZIKV soluble E (sE) gene was cloned into pLW-73. This method for production of sE required only a C-terminal truncation, so a second method is used to derive sE by PCR from the E sequences already in-house.
In short, pGZ-02 (the original prME shuttle vector in which the prME gene was cloned into pLW-73) was used as substrate for PCR. The PCR reaction incorporated (i) a forward primer that was placed upstream of the 5′ restriction site for pLW-73 cloning (Smal), and (ii) a reverse primer that truncated the E gene at the codon encoding the final lumenal amino acid (just in front of the first amino acid of the first transmembrane domain of the E protein) using a primer with a tail that introduced two stop codons as well as the 3′ restriction site for pLW-73 cloning (SalI).
A map of the PCR substrate pGZ-02 is shown in
This plasmid was designed to drive expression of the following ZIKV polyprotein behind the mH5 MVA promoter:
Tunneling down to the DNA sequence level, primers were designed to touch down on the substrate at the following locations (indicated by gray arrows, with partial 5′→3′ primer sequences visible inside the arrows):
The forward (F) and reverse (R) primer sequences used here for annealing to the substrate are as follows:
In addition, it was necessary to add a 5′ tail to the R primer to facilitate introduction of stop codons and a Sall restriction site. In order to keep the primers comparable in composition, a 5′ tail were added to the F primer as well. Thus, the final primer sequences (with physical characteristics annotated) were as follows, with 5′ tails marked by underlying and the Sall restriction site in lower-case letters:
-
- 28 nt annealing, 12 nt tail: 40 nt total
- predicted Tm: 62.8° C. (annealing), 73.8° C. (final)
- 38% CG content
-
- 24 nt annealing, 16 nt tail: 40 nt total
- predicted Tm: 60.1° C. (annealing), 73.8° C. (final)
- 38% CG content
PCR of the pGZ-02 plasmid with these two primers yielded a PCR product 1989 nt in length, as follows with the Smal site labeled as BOLD and the SalI site labeled as BOLD ITALIC in green and the start codon and two stop codons underlined:
Once digested with Smal and Sall, this sequence was ligated into similarly digested pLW-73. The resulting plasmid was named pGZ-05. This plasmid was slightly different from pGZ-04 (the sE shuttle plasmid constructed from the synthetic gene produced by Genscript) by (1) using stop codons of sequence ‘TAG’ (as necessitated by primer design) whereas pGZ-04 uses stop codons of sequence ‘TAA’, and (2) pGZ-05 is 1 nt smaller in size than pGZ-04 because the last nt of the second codon is also the first nt of the Sall site in pGZ-05, whereas these two are juxtaposed and non-overlapping in pGZ-04.
The map for pGZ-05 is shown in
For completeness, it should be noted that this construct drives expression of the following gene product from the mH5 MVA promoter:
In addition to the prME-expressing vector, a soluble version was created wherein the transmembrane domains of the E protein have been removed to facilitate expression and secretion of E.
The soluble E (sE) sequence uses the same prME sequences, but in this case the sE protein is truncated just upstream of the first transmembrane domain.
According to the gene annotation of the French Polynesian isolate of Zika, ‘prM’ is located at position 126-290 of the amino acid sequence and ‘E’ is located at position 291-794 of the amino acid sequence. The amino acid sequence from position 126-794 is the sequence that was used for vaccine development. This sequence is 669 amino acids in length. Prediction of transmembrane helix domains of E was obtained from ViPR Virus Pathogen Resource annotation of the gene (http://bit.ly/29m7yfi). This sequence is as follows, with prM distinguished from E by underlining the sequence and the predicted transmembrane helix domains marked by BOLD lettering:
It should be possible to create sE by truncating the sequence after amino acid 619 to yield the following sequence for prMsE:
The signal sequence for prM that directs the viral polyprotein to the ER translocon is located in the C-terminal end of the C gene. This signal sequence is complicated by the fact that under normal viral infection it is targeted by both the signal peptidase (in the ER lumen) and the viral protease NS3 (in the cytoplasm). This construct was chosen to utilize a Japanese Encephalitis Virus signal sequence that has been optimized for prM-E VLP production in other Flaviviruses. This JEV signal sequence is 24 amino acids long and the sequence is as follows:
Appending this signal sequence to the N-terminal of prMsE results in the following sequence:
Using this sequence, codon optimization for Vaccinia was performed using the IDT Codon Optimization Tool. This yielded the following codon-optimized DNA sequence of length 1929 bp:
The preparation of the sequence used the following protocol:
1. Start with the natural sequence
2. Codon optimize DNA sequence for vaccinia virus
3. Research the sequence for homopolymers stretches of >4 nt: and ≥G, ≥C, ≥T and ≥A
4. If any, interrupt all homopolymer sequences by silent mutations
5. Research sequence for vaccinia virus transcription terminator: T5NT (UUUUUNU)
6. If any, interrupt all transcription terminator motifs by silent mutation
7. Add a second stop codon (TAA)
8. Add restriction enzymes for cloning of the Zika genes into MVA-shuttles plasmids
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- i. Modified deletion III: SmaI-SalI
- ii. Between essential genes (I8/G1): SmaI-SalI
9. Choose the site and location of the gene into MVA virus
10. Choose the appropriate MVA-shuttle
No homopolymer stretches of >4 nt were found in the sequence for bases G, C, or T after steps 1-2. One A5 sequences was found at sites 1446-1450. The AAAAA was changed to AAAGA, a silent mutation for lysine.
Next the sequence was scanned for vaccinia virus transcriptional terminator sequences. None were found.
Two stop codons were appended to the end of the sequence (TAATAA), as no stop codon was present in the original sequence above.
The sequence was scanned for internal SmaI or SalI restriction sites. A SalI restriction site (GTCGAC) was found at 688-693. This sequence was changed to GTAGAC, a silent mutation for valine.
A SmaI site (CCCGGG) was added to the 5′ end of the construct. A SalI (GTCGAC) site was added to the 3′ end of the construct. This yielded a final seauence of length 1947 nt as follows:
This construct was submitted for synthesis and cloning into pLW-73, driven by the mH5 promoter, with the P11 promoter driving GFP expression in the same plasmid and all CDS flanked 5′ by I8 (I8R) and 3′ by G1 (G1L). This plasmid will be named pGZ-04. A map is shown in
Western Blots and Electron Microscopy.
The expression of full-length prME and NS1 was confirmed by western blot (WB). MVA-Zika plaques were stained with Zika specific antibodies directed to the E proteins (
Efficacy Testing of MVA-ZIKA Vaccine Candidates in Mice.
Pre-clinical testing of MVA-ZIKV-NS1 and MVA-ZIKV-prME in mice demonstrated outstanding protection for the MVA-ZIKV-NS1 vaccine (
Due to its structure, NS1 is expressed by cells as either a dimer that non-covalently binds to the surface of cells or as a hexamer that is secreted. As an immunogen, NS1 provides two potential targets for protective immune responses: (i) intracellular NS1 as a target for CD8+ T cell responses, and (ii) cell-associated extracellular dimeric NS1 is present as repetitive epitopes on the surface of infected cells as a target for Fc-mediated Ab killing. Expression of NS1 alone does not lead to VLP formation. Our data indicate that cells infected with the MVA-ZIKV-NS1 vaccine express both the cell-associated NS1 and secrete NS1 into the supernatant (
MVA-ZIKV-prME drives excellent production of E protein in infected cells (
Using the MVA platform, two vaccines have been constructed: (1) an MVA vaccine that expresses ZIKV NS1 in host cells, leading to both endogenous expression and secretion of NS1 (MVA-ZIKV-NS1); and (2) an MVA vaccine that drives expression of ZIKV prME in host cells and has the additional feature of budding virus-like particles (VLPs) that display E protein in its native form from the same cells (MVA-ZIKV-prME). The sequences used in these vaccine constructs were derived from the Asian Suriname isolate Z1106033 of the 2015 ZIKV epidemic. The Asian and American strains have maintained >96% amino acid homologies with their African ancestors (Lanciotti, R. S., Lambert, A. J., Holodniy, M., Saavedra, S. & del Carmen Castillo, L. Phylogeny of Zika Virus in Western Hemisphere, 2015. Emerging Infectious Disease journal 22(2016); Stauft, C. B., Gorbatsevych, O., Cello, J., Wimmer, E. & Futcher, B. Comparison of African, Asian, and American Zika Viruses in Swiss Webster mice: Virulence, neutralizing antibodies, and serotypes. bioRxiv (2016) (e.g. MR766 used in our challenge studies) and immunity to one strain has been shown to confer immunity to other strains (Dowd, K. A., et al. Broadly Neutralizing Activity of Zika Virus-Immune Sera Identifies a Single Viral Serotype. Cell Rep 16, 1485-1491 (2016). Both African and Asian lineages shown to induce microcephaly in mice. NS1 and prME sequences in our vaccine maintain 96-99% identity with their Asian and African strains indicating that our vaccines will likely be effective for all circulating strains.
Although NS1 is expressed on infected cells, it is not incorporated into ZIKV virions (Diamond, M. S., Pierson, T. C. & Fremont, D. H. The structural immunology of antibody protection against West Nile virus. Immunol Rev 225, 212-225 (2008). The expression of prME is sufficient to generate secreted VLPs (Fuchs, J., et al. Investigating the efficacy of monovalent and tetravalent dengue vaccine formulations against DENV-4 challenge in AG129 mice. Vaccine 32, 16 (2014). Galula, J. U., Shen, W.-F., Chuang, S.-T., Chang, G.-J. J. & Chao, D.-Y. Virus-Like Particle Secretion and Genotype-Dependent Immunogenicity of Dengue Virus Serotype 2 DNA Vaccine. Journal of Virology 88, 18 (2014). Vaughan, K., Greenbaum, J., Blythe, M., Peters, B. & Sette, A. Meta-analysis of All Immune Epitope Data in the Flavivirus Genus: Inventory of Current Immune Epitope Data Status in the Context of Virus Immunity and Immunopathology. Viral Immunol 23, 26 (2010). The prME proteins are expressed as a single polypeptide chain, which is cleaved into prM and E proteins by signal peptidase in the host cells (Faye, O., et al. Molecular Evolution of Zika Virus during Its Emergence in the 20th Century. PLoS Negl Trop Dis 8, 10 (2014). Perera, R., Khaliq, M. & Kuhn, R. J. Closing the door on flaviviruses: Entry as a target for antiviral drug design. Antiviral Research 80, 11-22 (2008). The prM protein is in turn cleaved into pr (non-M) and M proteins during virus maturation, with M protein being primarily incorporated into mature virions to produce a heterodimer with trimers of E protein (Lee, P. D., et al. The Fc region of an antibody impacts the neutralization of West Nile viruses in different maturation states. J Virol 87, 13729-13740 (2013). These Ags were chosen based on documented evidence that flavivirus NS1 or prME proteins are sufficient to elicit a protective immune response (Edeling, M. A., Diamond, M. S. & Fremont, D. H. Structural basis of Flavivirus NS1 assembly and antibody recognition. Proceedings of the National Academy of Sciences 111, 4285-4290 (2014). Heinz, F. X. & Stiasny, K. Flaviviruses and flavivirus vaccines. Vaccine 30, 4301-4306 (2012). This novel combination of vector platform and native Ag conformation yields a vaccine that is expected to elicit a strong, broad, and durable immune response.
The ideal ZIKV vaccine is safe for women of child-bearing age, cost effective to manufacture, and induces protective levels of long-lasting antibody and T cell responses after a single dose. Given that ZIKV is currently circulating predominantly in developing countries, the MVA-NS1 vaccine is attractive for accelerated development of a ZIKV vaccine because it provides the potential for single dose elicitation of durable immune responses (Marzi et al, in preparation) and cost effective manufacturability. MVA vaccines are replication competent in avian cells used for vaccine production, yet replication deficient in mammalian cells making them safe for humans, including immunocompromised individuals. MVA has been shown to be safe in >120,000 individuals, including HIV-infected individuals, and has shown no reproductive toxicity in studies in pregnant rats (CHMP), C.f.M.P.f.H.U. Assessment report, IMVANEX, Common name: Modified Vaccinia Ankara virus, Procedure No. EMEA/H/C/002596. (ed. (CHMP), C.f.M.P.f.H.U.) (European Medicines Agency, London, UK, 2013). Cosma, A., et al. Therapeutic vaccination with MVA-HIV-1 nef elicits Nef-specific T-helper cell responses in chronically HIV-1 infected individuals. Vaccine 22, 21-29 (2003). Carroll, M. W. & Moss, B. Host range and cytopathogenicity of the highly attenuated MVA strain of vaccinia virus: propagation and generation of recombinant viruses in a nonhuman mammalian cell line. Virology 238, 198-211 (1997). For ZIKV vaccines, WHO recommended non-live/inactivated approaches for vaccination of women of child-bearing age (WHO and experts prioritize vaccines, diagnostics and innovative vector control tools for Zika R&D. (2016). Our approach is in line with this recommendation as MVA-ZIKV vaccines match the excellent safety profile of non-live/inactivated vaccines without the need for an adjuvant, and additionally offer potential for high levels of immunogenicity and efficacy after a single dose. Moreover, the NS1 vaccine poses no potential risk of induction of ADE in vaccinated subjects living in dengue endemic areas
Using the very high bar of intracranial inoculation with heterologous virus, MVA-ZIKV-prME vaccine showed good protection (
The foregoing discussion discloses and describes merely exemplary embodiments of the present invention. One skilled in the art will readily recognize from such discussion, and from the accompanying drawings and claims, that various changes, modifications and variations can be made therein without departing from the spirit and scope of the invention as defined in the following claims.
All references cited herein are incorporated by reference in their entirety.
Claims
1. A recombinant modified vaccinia Ankara (MVA) vector comprising at least one nucleic acid sequence encoding at least one Flavivirus protein, wherein the at least one nucleic acid sequence is inserted into the MVA vector under the control of at least one promoter compatible with poxvirus expression systems.
2. The recombinant MVA vector of claim 1 wherein the recombinant modified vaccinia Ankara (MVA) vector comprises a first nucleic acid sequence encoding a Flavivirus structural protein and a second nucleic acid sequence encoding a Flavivirus nonstructural (NS) protein, wherein both the first nucleic acid sequence and the second nucleic acid sequence are inserted into the MVA vector under the control of promoters compatible with poxvirus expression systems.
3. The recombinant MVA vector of claim 2, wherein the Flavivirus structural protein selected from premembrane-E (PrM-E), soluble E without a transmembrane domain, E protein domain I, E protein domain II, or E protein domain, III, PrM, and fragments thereof.
4. The recombinant MVA vector of claim 2, wherein the Flavivirus non-structural protein selected from NS1, NS2A, NS2B, NS3, NS4A, NS4B or NS5.
5. The recombinant MVA vector of claim 2, wherein the Flavivirus non-structural protein is t NS1.
6. The recombinant MVA vector of claim 2, wherein the Flavivirus structural protein is premembrane-E sequence and the first nucleic acid sequence is inserted into a deletion site selected from I, II, III, IV, V or VI; and wherein the second nucleic acid sequence is inserted into a deletion site selected from I, II, III, IV, V or VI.
7. The recombinant MVA vector of claim 2, wherein the Flavivirus structural protein is premembrane-E sequence and the first nucleic acid sequence is inserted between two essential and highly conserved MVA genes; and wherein the second nucleic acid sequence is inserted into a restructured and modified deletion III.
8. The recombinant MVA vector of claim 2, wherein the Flavivirus structural protein is premembrane-E protein sequence, and the first nucleic acid sequence is inserted between MVA genes, I8R and G1L.
9. The recombinant MVA vector of claim 1, wherein the at least one promoter is selected from the group consisting of Pm2H5, Psyn II, and mH5 promoters or combinations thereof.
10. The recombinant MVA vector of claim 2, wherein the Flavivirus protein structural protein sequence is a premembrane-E sequence and both the premembrane E-sequence and the non-structural protein sequence are from a flavivirus species.
11. A pharmaceutical composition comprising a recombinant MVA vector comprising a first nucleic acid sequence encoding a Flavivirus structural protein and a second nucleic acid sequence encoding a Flavivirus non-structural (NS) protein, wherein both the first and second nucleic acid sequences are inserted into the MVA vector under the control of promoters compatible with poxvirus expression systems.
12. The pharmaceutical composition of claim 10, wherein the recombinant MVA vector is formulated for intraperitoneal, intramuscular, intradermal, epidermal, mucosal or intravenous administration.
13. A method of inducing an immune response in a subject in need thereof, said method comprising administering to the subject an amount of a recombinant MVA vector effective to induce an immune response, wherein the recombinant MVA vector comprises a first nucleic acid sequence encoding a Flavivirus structural protein and a second nucleic acid sequence encoding a Flavivirus nonstructural (NS) protein, and
- wherein both the first and second nucleic acid sequences are inserted into the MVA vector under the control of promoters compatible with poxvirus expression systems.
14. The method of claim 12, wherein the immune response is a humoral immune response, a cellular immune response or a combination thereof.
15. The method of claim 12, wherein the immune response comprises production of binding antibodies against the flavivirus.
16. The method of claim 12, wherein the immune response comprises production of neutralizing antibodies against the flavivirus.
17. The method of claim 12, wherein the immune response comprises production of a cell-mediated immune response against the flavivirus.
18. A method of treating a Flaviviridae virus infection in a subject in need thereof, said method comprising administering to the subject an amount of a recombinant MVA vector effective to induce an immune response, wherein the recombinant MVA vector comprises a first nucleic acid sequence encoding a Flavivirus structural protein and a second nucleic acid sequence encoding a Flavivirus nonstructural (NS) protein sequence, and
- wherein both the first and second nucleic acid sequences are inserted into the MVA vector under the control of promoters compatible with poxvirus expression systems.
19. The method of claim 17, wherein the Flaviviridae virus infection is caused by a Zika virus.
20. The method of claim 17, wherein the subject is exposed to Flaviviridae virus, but not yet symptomatic of Flaviviridae virus infection.
21. (canceled)
Type: Application
Filed: Feb 1, 2017
Publication Date: Jan 31, 2019
Inventors: Farshad Guirakhoo (Atlanta, GA), Arban Domi (Atlanta, GA), Nathanael Paul McCurley (Decatur, GA)
Application Number: 16/074,947
