99 results about "Viral envelope" patented technology

We have made retrovirus particles displaying a functional antibody fragment. We fused the gene encoding an antibody fragment directed against a hapten with that encoding the viral envelope protein (Pr80env) of the ecotropic Moloney murine leukemia virus. The fusion gene was co-expressed in ecotropic retroviral packaging cells with a retroviral plasmid carrying the neomycin phosphotransferase gene (neo), and retroviral particles with specific hapten biding activities were recovered. Furthermore the hapten-binding particles were able to transfer the neo gene and the antibody-envelope fusion gene to mouse fibroblasts. In principle, the display of antibody fragments on the surface of recombinant retroviral particles could be used to target virus to cells for gene delivery, or to retain the virus in target tissues, or for the construction of libraries of viral display packages.

Fusion of the viral envelope, or infected cell membranes with uninfected cell membranes, is an essential step in the viral life cycle. Recent studies involving the human immunodeficiency virus type 1(HIV-1) demonstrated that synthetic peptides (designated DP-107 and DP-178) derived from potential helical regions of the transmembrane (TM) protein, gp41, were potent inhibitors of viral fusion and infection. A computerized antiviral searching technology (C.A.S.T.) that detects related structural motifs (e.g., ALLMOTI 5, 107x178x4, and PLZIP) in other viral proteins was employed to identify similar regions in the Epstein-Barr virus (EBV). Several conserved heptad repeat domains that are predicted to form coiled-coil structures with antiviral activity were identified in the EBV genome. Synthetic peptides of 16 to 39 amino acids derived from these regions were prepared and their antiviral activities assessed in a suitable in vitro screening assay. These peptides proved to be potent inhibitors of EBV fusion. Based upon their structural and functional equivalence to the known HIV-1 inhibitors DP-107 and DP-178, these peptides should provide a novel approach to the development of targeted therapies for the treatment of EBV infections.

This invention provides an isolated nucleic acid which comprises a nucleotide segment having a sequence encoding a viral envelope protein comprising a viral surface protein and a corresponding viral transmembrane protein wherein the viral envelope protein contains one or more mutations in amino acid sequence that enhance the stability of the complex formed between the viral surface protein and transmembrane protein. This invention also provides a viral envelope protein comprising a viral surface protein and a corresponding viral transmembrane protein wherein the viral envelope protein contains one or more mutations in amino acid sequence that enhance the stability of the complex formed between the viral surface protein and transmembrane protein. This invention further provides methods of treating HIV-1 infection.

A method for producing viral vectors is described using packaging and producer cell lines is described. The producer cell comprises: (i) a first nucleotide sequence (NS) encoding a toxic viral envelope protein operably linked to a promoter; wherein the promoter is operably linked to at least one copy of a TRE; (ii) a second NS wherein the second NS comprises a sequence encoding a tetracycline modulator; (iii) a third NS encoding a retrovirus nucleocapsid protein; and (iv) a fourth NS comprising a retroviral sequence capable of being encapsidated in the nucleocapsid protein such that the retroviral vector particle titre obtainable from the producer cell is regulatable by tetracycline and an initial stimulus with sodium butyrate or functional analogues thereof.

The present invention provides infectious recombinant viral vectors (e.g., parainfluenza virus (PIV) and a respiratory syncytial virus (RSV) vectors) comprising a viral genome comprising a heterologous nucleic acid of interest. Also provided are pseudotyped recombinant viral vectors comprising (i) a viral envelope and (ii) a viral genome comprising heterologous nucleic acids of interest. The viral envelope comprises a structural protein selected from the group consisting of envelope proteins from PIV and/or RSV. Further provided are methods of delivering heterologous nucleic acids of interest into airway epithelial cells comprising introducing viral vectors of the present invention comprising nucleic acids of interest into airway epithelial cells so that the nucleic acids of interest are expressed therein.

The invention relates to the production of virosome-like-particles. The invention provides a method for producing a virosome-like-particle comprising contacting an enveloped virus with a solution containing a short-chain phospholipid allowing solubilisation of the viral envelope of said virus further comprising removing short-chain phospholipid from said solution allowing formation of a functionally reconstituted viral envelope.

The present invention discloses method to coat nanoparticles with viral envelope containing specific proteins. The present invention also discloses that such viral envelope coated nanoparticles can be targeted to specific cells and cellular entry pathway, thereby permitting their use as vaccines, in targeted delivery of therapeutic products and in the study of virus adsorption, cell penetration and viral entry pathways.

Antibodies to two new epitopes on the HCV envelope proteins were identified which allow routine detection of native HCV envelope antigens, in tissue or cells derived from the host. The new epitopes are: the E1 region aa 307-326 and the N-terminal hyper variable region of E2 aa 395-415. Surprisingly, we characterised an antibody that reacts with various sequences of the hypervariable domain of E2. Specific monoclonal antibodies directed against these epitopes and allowing routine detection of viral antigen are described.

The invention described herein provides a method for screening pathogenic viral envelope proteins and protein complexes to identify protein constructs with enhanced effectiveness as vaccine immunogens. The method is carried out by (i) expressing of a membrane-bound isotype of an antibody that has the same binding activity and specificity of an antibody that is known, or identified, to bind and neutralize the targeted virus, and that has the capacity to activate signaling pathways down-stream of B cell receptor ligand binding and activation—a modified neutralizing antibody-based B cell receptor; (ii) exposing the cell to antigen; and (iii) assay for signaling downstream of B cell receptor activation. The present invention also provides the antigens identified using the as say described herein, and neutralizing antibodies derived by immunization with the antigens identified using the assay described herein.

The present invention relates to a new method for purification of viral vectors particularly those belonging to the Retroviridae family, which is based on the expression in the packaging cell line that produced such vectors of an exogenous gene encoding a cell surface marker. The incorporation of the cell surface marker in the viral envelope of the vector allows purification with immunological methods.

The invention relates to chimeric polytropic viral envelope polypeptides and uses thereof, as well as to polynucleotides encoding said chimeric polypeptides and constructs comprising said polypeptides and/or polynucleotides. The invention also relates to chimeric retroviral envelope polypeptides, polynucleotides and vectors encoding said chimeric retroviral envelope polypeptides, virus particles and cells harbouring said chimeric envelope polypeptides. Said chimeric polypeptide comprise an envelope polypeptide, or fragment thereof, and a polypeptide sequence of a receptor binding region, ligand or polypeptide sequence of a ligand binding region, and optionally a linker sequence. The invention include methods of targeting receptors, methods of treatment and methods for delivery of agents using said chimeric retroviral envelope polypeptides. The invention is applicable for directed targeting and controlled fusion of virus particles with other cellular membranes.

The invention provides novel methods, materials and systems that can be used to generate viral vectors having altered tissue and cell targeting abilities. In illustrative embodiments of the invention, the specificity of lentiviral vectors was modulated by a thin polymer shell that synthesized and coupled to the viral envelope in situ. The polymer shell can confers such vectors with new targeting ability via agents such as cyclic RGD (cRGD) peptides that are coupled to the polymer shell. These polymer encapsulated viral vectors exhibit a number of highly desirable characteristics including a higher thermal stability, resistance to serum inactivation in vivo, and an ability to infect dividing and non-dividing cells with high efficiencies.