Abstract: The present invention relates to a new class of virus fusion inhibitors or virus entry inhibitors. More specifically the present invention relates to bivalent molecules that are pre-fusion inhibitors of viruses that makes use of the type (1) fusion mechanism belonging to the groups consisting of Othomyxoviridae, Paramyxoviridae, Retroviridae, Filoviridae and Coronaviridae, in particular HIV. The bivalent molecules of the present invention are molecules that comprise a first part capable of mimicking the function of a mammalian cell receptor, and a second part capable of binding to a virus, preferably HIV, resulting in the neutralization of the virus which is thus rendered harmless. Further, the present invention relates to compositions comprising the pre-fusion inhibitors, as well as to methods for obtaining the pre-fusion inhibitors and the use of the pre-fusion inhibitors.

Abstract: The present invention relates to a retroviral vector which expresses a gene, e.g. for therapeutic use and/or of viral origin, under the translational control of an internal ribosomal entry site (IRES) resulting in the efficient translation of said gene.

Abstract: The present invention relates to a purified polypeptide, which is capable of mediating infection of a cell, by use of the polytropicixenotropic receptor encoded by the Rmc1 locus from a NIH Swiss inbred NFS/N mouse for entry, and unable of mediating infection of a cell by use of a human polytropic/xenotropic receptor encoded by the human RMC1 locus. The present invention especially relates to an envelope protein from the Murine leukaemia Virus (MLV) strain SL3-2, which is capable of infecting murine cells through usega of the polytropic receptor encoded by the Rruc1 locus, but lacks the ability of infecting human cells expressing the corresponding xenotropic receptor encoded by the RMC locus. The present invention furthermore demonstrate that replacements of at least one specified amino acid in the polypeptide can alter the tropism and enable the SL3-2 envelope to infect a human cell by use of the human polytropic/xenotropic receptor encoded by the RMC1 locus for entry.

Abstract: The present invention relates to improved vectors useful in gene therapy which improvement particularly resides in improved safety of such vectors. The improvement is achieved by incorporating sequences into the gene therapy vector which promote dimer formation of transcripts derived from said vector. Such sequences are in a preferred embodiment self-complementary palindromic or nonpalindromic sequences.

Abstract: The present invention relates to a retroviral vector which expresses a gene, e.g. for therapeutic use and/or of viral origin, under the translational control of an internal ribosomal entry site (IRES) resulting in the efficient translation of said gene.

Abstract: Biologically active peptides and nucleic acids are identified by a method comprising the following steps: (a) production of a pool of appropriate vectors each containing totally or partly random DNA sequences, (b) efficient transduction of said vectors into a number of identical eukaryotic cells in such a way that a single ribonucleic acid and possibly peptide is expressed or a limited number of different random ribonucleic acids and peptides are expressed by each cell, (c) screening of said transduced cells to see whether some of them have changed a certain phenotypic trait, (d) selection and cloning of said changed cells, (e) isolation and sequencing of the vector DNA in said phenotypically changed cells, and (f) deducing the ribonucleic acid and peptide sequences from the DNA sequence. The peptide sequences may be introduced into or fused to a larger protein, preferably an antibody molecule or a fragment thereof.

Abstract: A library is composed of viral vectors in which each of the vectors (a) involves a peptide expression cassette containing a random nucleotide sequence, (b) transduces a eukaryotic cell to allow expression of the random nucleotide sequence, and (c) is produced by (i) conventional random oligonucleotide synthesis or (ii) random codon synthesis where codons encode an even distribution of random amino acids.

Abstract: A retroviral vector comprising a retrovirus with infectivity for birds and/or mammals in which at least part of the genomic RNA sequences carrying information for the production of viral proteins required in trans for retroviral replication have been replaced by one or more sequences carrying information to be introduced in a target cell chromosome, characterized in that the primer binding site (PBS) has been modified to a sequence that does not allow strong base pairing with the 3' end or other priming sequence in any naturally occurring tRNA. The present application is directed to the tRNA-like primer.

Abstract: A retroviral vector comprising a retrovirus with infectivity for birds and/or mammals in which at least part of the genomic RNA sequences carrying information for the production of viral proteins required in trans for retroviral replication have been replaced by one or more sequences carrying information to be introduced in a target cell chromosome, characterized in that the primer binding site (PBS) has been modified to a sequence that does not allow strong base pairing with the 3' end or other priming sequence in any naturally occurring tRNA.

Abstract: A retroviral vector comprising a retrovirus with infectivity for birds and/or mammals in which at least part of the genomic RNA sequences carrying information for the production of viral proteins required in trans for retroviral replication have been replaced by one or more sequences carrying information to be introduced in a target cell chromosome, characterized in that the primer binding site (PBS) has been modified to a sequence that does not allow strong base pairing with the 3' end or other priming sequence in any naturally occurring tRNA. The present application is directed to the tRNA-like primer.

Abstract: A retroviral vector comprising a retrovirus with infectivity for birds and/or mammals in which at least part of the genomic RNA sequences carrying information for the production of viral proteins required in trans for retroviral replication have been replaced by one or more sequences carrying information to be introduced in a target cell chromosome, characterized in that the primer binding site (PBS) has been modified to a sequence that does not allow strong base pairing with the 3' end or other priming sequence in any naturally occurring tRNA.