Abstract: Disclosed are compositions and methods for enhancing the circulating half-life of antibody-based fusion proteins. Disclosed methods and compositions rely on altering the amino acid sequence of the junction region between the antibody moiety and the fused protein moiety in an antibody-based fusion protein. An antibody-based fusion protein with an altered amino acid sequence in the junction region has a greater circulating half-life when administered to a mammal. Disclosed methods and compositions are particularly useful for reducing tumor size and metastasis in a mammal.

Abstract: Immunoconjugates for the selective delivery of a cytokine to a target cell are disclosed. The immunoconjugates are comprised of an immunoglobulin heavy chain having a specificity for the target cell, such as a cancer or virus-infected cell, and a cytokine, such as lymphotoxin, tumor necrosis factor alpha, interleukin-2, or granulocyte-macrophage colony stimulating factor, joined via Aits amino terminal amino acid to the carboxy-Aterminus of the immunoglobulin. Nucleic acid sequences encoding these immunoconjugates and methods of their preparation by genetic engineering techniques are also disclosed.

Abstract: Disclosed are nucleic acid sequences, for example, DNA or RNA sequences, which encode an immunoglobulin Fc-Interferon-alpha fusion protein. The nucleic acid sequences can be inserted into a suitable expression vector and expressed in mammalian cells. Also disclosed is a family of immunoglobulin Fc-Interferon-alpha fusion proteins that can be produced by expression of such nucleic acid sequences. Also disclosed are methods of using such nucleic acid sequences and/or fusion proteins for treating conditions, for example, hepatitis, which are alleviated by the administration of interferon-alpha.

Abstract: A method of producing recombinant heterotetrameric immunoglobulin from a procaryotic organism which includes providing a procaryotic organism that has been transformed with DNA encoding the heavy and light chains of an immunoglobulin having a binding site for immunologically binding a preselected antigen and an amino acid sequence which signals the export of the immunoglobulin from the cytoplasm of the organism, the DNA being operationally associated with a promoter recognizable by RNA polymerase endogenous to the organism, and culturing the transformed procaryote for a time and under conditions sufficient to allow the organism to export the immunoglobulin from the cytoplasm, wherein the exported heterotetrameric immunoglobulin retains its native conformation and binding specificity for the preselected antigen.

Abstract: Disclosed are chemical agents for modulating certain cellular immune reactions that can lead to autoimmune disorders. By specific modulation, harmful immune reactions can be lessened in severity or even prevented without resorting to potentially dangerous general immune suppression. The described chemical agents inhibit IL-12 induction of the secretion of key immune modulators. The described chemical agents are specific inhibitors of IL-12 induced Th1 immune response.

Abstract: Disclosed is a method of producing increased amounts of a protein of interest in a cell by induction. The method includes transfecting a cell with multiple copies of an expression vector, each copy of which includes an expressible gene encoding an enzymatically functional dihydrofolate reductase (DHFR) and an expressible gene encoding a protein of interest. Transfected cells are cultured in the presence of methotrexate (MTX) to produce a plurality of clones. A clone containing plural copy number of the vectors which co-express DHFR and the protein of interest is then selected and cultured. The cultured clone is treated with MTX to enhance the expression of the protein of interest by inducing an increase in transcription without substantially amplifying the genes encoding the protein of interest and DHFR.

Abstract: Disclosed are DNAs produced by recombinant techniques for inducing the expression and subsequent secretion of a target protein. The DNAs encode, in their 5' to 3' direction, a secretion cassette, including a signal sequence and an immunoglobulin Fc region, and a target protein. The DNAs can be transfected into a host cell for the expression, production and subsequent secretion of the target protein as a fusion protein. The secreted protein can be collected from the extracellular space, and further purified as desired. The secreted fusion protein additionally can be proteolytically cleaved to release the target protein from the secretion cassette.

Abstract: Disclosed are vectors for achieving high level expression in eucaryotic cells. The vectors include an expressible gene encoding a protein product of interest, an expressible gene encoding a marker protein which permits selection of useful transformants, and an enhancer element, preferably a cellular enhancer element, which functions to increase the level of transcription of genes disposed on its 3' and 5' sides. A blocking element is interposed between the enhancer element and the marker gene which shields the promoter of the marker gene from the transcription-stimulating function of the enhancer, thereby limiting the effect of the enhancer to transcriptions of the DNA encoding the protein product of interest. Use of the vectors permits isolation of viable clones characterized by a very high level of expression of the protein of interest.

Abstract: Immunoconjugates for the selective delivery of a cytokine to a target cell are disclosed. The fusion proteins are comprised of an immunoglobulin heavy chain having a specificity for the target cell, such as a cancer or virus-infected cell, and a cytokine, such as lymphotoxin, tumor necrosis factor alpha, interleukin-2, or granulocyte-macrophage colony stimulating factor, joined via its amino terminal amino acid to the carboxy-terminus of the immunoglobulin. Nucleic acid sequences encoding these fusion proteins and methods of their preparation by genetic engineering techniques are also disclosed.

Abstract: Disclosed are DNAs produced by recombinant techniques for inducing the expression and subsequent secretion of a target protein. The DNAs encode, in their 5' to 3' direction, a secretion cassette, including a signal sequence and an immunoglobulin Fc region, and a target protein. The DNAs can be transfected into a host cell for the expression, production and subsequent secretion of the target protein as a fusion protein. The secreted protein can be collected from the extracellular space, and further purified as desired. The secreted fusion protein additionally can be proteolytically cleaved to release the target protein from the secretion cassette.

Abstract: Disclosed are methods of producing fusion proteins including those with dual biological activities. These methods include the provision of a first and second DNA sequence encoding a first and second polypeptide, repectively, the digestion of the first DNA sequence at a restriction site adjacent its 3' or 5' terminus, and the ligation of a linker/adapter sequence (l/a) to the restricted end of the first DNA sequence, thereby forming a cassette. The l/a includes, at one end, that portion of the first DNA sequence extending from its terminus nearest the restriction site to the restriction site, and at the other end, one side of a splice site. A eucaryotic host cell is transfected with the cassette and the second DNA sequence having, at one end, one side of a splice site compatible with the side of the splice site on the l/a. The transfected host cell is cultured to express the transfected DNA as a single chain fusion protein.

Abstract: Disclosed are methods of producing fusion proteins including those with dual biological activities. These methods include the provision of a first and second DNA sequence encoding a first and second polypeptide, repectively, the digestion of the first DNA sequence at a restriction site adjacent its 3' or 5' terminus, and the ligation of a linker/adapter sequence (l/a) to the restricted end of the first DNA sequence, thereby forming a cassette. The l/a includes, at one end, that portion of the first DNA sequence extending from its terminus nearest the restriction site to the restriction site, and at the other end, one side of a splice site. A eucaryotic host cell is transfected with the cassette and the second DNA sequence having, at one end, one side of a splice site compatible with the side of the splice site on the l/a. The transfected host cell is cultured to express the transfected DNA as a single chain fusion protein.

Abstract: Disclosed is a method of increasing production of proteins, e.g., human tPA, in mammalian cells which normally secrete immunoglobulins. Degradation of mRNA transcribed from recombinant DNA is decreased by decreasing the length of the untranslated region of the mRNA. The untranslated region of DNA encoding a protein of interest is altered to produce a shorter recombinant DNA having an untranslated region comprising a poly A addition signal (AATAAA) and less than about 300 nucleotide bases interposed between said poly A signal and the stop codon 3' of the coding region of the gene of interest. The mammalian cell line is transfected and cultured to produce greater amounts of the protein of interest than the same cell line transfected with the unaltered DNA.

Abstract: Disclosed is a method of enhancing expression of recombinant DNA in eucaryotic cells. A tissue specific enhancer element obtained from the genome of an organism and active in a selected tissue type is combined with a transcriptionally competent transcription unit comprising a promoter and exons encoding for the proteinaceous material of interest (or its precursor). This recombinant DNA is transfected into cells derived from the same tissue as the tissue in which the enhancer element normally functions to enhance expression of endogeneous DNA. The resulting transformants express the exons of the transcription unit at high levels as the enhancer element increases the copy number of mRNA. The enhancer element operates to increase transcription independent of its orientation and position provided it is located within an active region on the DNA, generally between about 1-10 kilobases (kb) from the 3' or 5' end of the transcription unit.