# US 2010/0167377 A1 · Recombinant viruses comprising the membrane-proximal domain of VSV G protein

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- Number: US 2010/0167377 A1
- Document ID: US20100167377A1
- Status: Published application
- Kind: A1
- Application number: 10/327,673
- Filed: 2002-12-23
- Published: 2010-07-01
- Earliest claimed: 1997-12-22
- Assignees: The University of Tennessee Research Corporation
- Inventors: Michael A. Whitt; Clinton S. Robison
- Web page: https://patentgrep.com/patent/US20100167377A1

## CPC

- C07K 14/005: from viruses
- A61P 29/00: Non-central analgesic, antipyretic or antiinflammatory agents, e.g. antirheumatic agents; Non-steroidal antiinflammatory drugs [NSAID]
- A61P 31/00: Antiinfectives, i.e. antibiotics, antiseptics, chemotherapeutics
- A61P 35/00: Antineoplastic agents
- C12N 15/86: Viral vectors
- C07K 2319/00: Fusion polypeptide
- C12N 2760/18022: New viral proteins or individual genes, new structural or functional aspects of known viral proteins or genes
- C12N 2760/20222: New viral proteins or individual genes, new structural or functional aspects of known viral proteins or genes
- C12N 2760/20243: viral genome or elements thereof as genetic vector
- C12N 2810/855: from receptors; from cell surface antigens; from cell surface determinants
- C12N 2810/859: from immunoglobulins
- C12N 2840/20: translation of more than one cistron
- C07K: PEPTIDES (peptides in foodstuffs A23; obtaining protein compositions for foodstuffs, working-up proteins for foodstuffs A23J; preparations for medicinal purposes A61K; peptides containing beta-lactam rings C07D; cyclic dipeptides not having in their molecule any other peptide link than those which form their ring, e.g. piperazine-2,5-diones, C07D; ergot alkaloids of the cyclic peptide type C07D519/02; macromolecular compounds having statistically distributed amino acid units in their molecules, i.e. when the preparation does not provide for a specific; but for a random sequence of the amino acid units, homopolyamides and block copolyamides derived from amino acids C08G69/00; macromolecular products derived from proteins C08H1/00; preparation of glue or gelatine C09H; single cell proteins, enzymes C12N; genetic engineering processes for obtaining peptides C12N15/00; compositions for measuring or testing processes involving enzymes C12Q; investigation or analysis of biological material G01N33/00)
- A61P: SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
- C12N: MICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA (microbiological testing media C12Q1/00)

## Abstract

Recombinant viruses, isolated nucleic acids and methods of generating same encoding for a Rhabdoviral G stem polypeptide are disclosed. Methods, compounds and compositions for target cell fusion potentiation mediated by Rhabdoviral G stem polypeptides, and applications of same are provided.

## Claims

### Claim 1

A recombinant Vesicular Stomatitis Virus (VSV) comprising a nucleic acid sequence of a Vesicular Stomatitis Virus (VSV) genome wherein said Vesicular Stomatitis Virus (VSV) genome comprises:
(a) a deletion in a nucleic acid sequence encoding a Vesicular Stomatitis Virus (VSV) G protein; and
(b) an insertion of an isolated nucleic acid sequence encoding the Vesicular Stomatitis Virus (VSV) G stem polypeptide set forth in SEQ ID NO: 2, (ii) an isolated nucleic acid sequence encoding a functional fragment of the Vesicular Stomatitis Virus (VSV) G stem polypeptide set forth in SEQ ID NO: 2, (iii) an isolated nucleic acid sequence encoding the amino acid sequence of residues 10-42 of SEQ ID NO: 2, or (iv) an isolated nucleic acid sequence that is at least 95% identical to SEQ ID NO: 1,
wherein said deletion comprises the nucleic acid sequence encoding an amino acid sequence of residues 1 to at least 404 of a mature Vesicular Stomatitis Virus (VSV) G protein.

### Claim 2

(canceled)

### Claim 3 (depends on 1)

The recombinant Vesicular Stomatitis Virus (VSV) of claim 1, wherein said Vesicular Stomatitis Virus (VSV) genome further comprises a nucleic acid sequence encoding a heterologous fusion facilitating polypeptide expressed from a separate transcriptional unit.

### Claim 4

(canceled)

### Claim 5

(canceled)

### Claim 6 (depends on 1)

The recombinant Vesicular Stomatitis Virus (VSV) of claim 1, wherein said functional fragment comprises the amino acid sequence set forth in SEQ ID Nos: 3, 4, 5, 6, 7, 8 or 9.

### Claim 7

(canceled)

### Claim 8 (depends on 1)

The recombinant Vesicular Stomatitis Virus (VSV) of claim 1, where said Vesicular Stomatitis Virus (VSV) G stem polypeptide or fragment thereof further comprises an N-terminal epitope tag.

### Claim 9 (depends on 8)

The fragment of a Vesicular Stomatitis Virus (VSV) G stem polypeptide of claim 8, wherein said N-terminal epitope tag is a FLAG synthetic or a human influenza hemagglutinin-derived polypeptide.

### Claim 10 (depends on 3)

The recombinant Vesicular Stomatitis Virus (VSV) of claim 3, wherein said fusion facilitating polypeptide comprises polypeptides derived from the simian virus 5 (SV5) F protein or HIV envelope proteins.

### Claim 11

(canceled)

### Claim 12 (depends on 1)

The recombinant Vesicular Stomatitis Virus (VSV) of claim 1, further comprising a nucleic acid sequence encoding an anti-receptor protein or a polypeptide fragment thereof effective to target said recombinant Vesicular Stomatitis Virus (VSV) to a cell.

### Claim 13 (depends on 12)

The recombinant Vesicular Stomatitis Virus (VSV) of claim 12, wherein said anti-receptor protein or polypeptide fragment thereof comprises an antibody or antibody fragment, which specifically recognizes a target antigen expressed on a cell membrane.

### Claim 14 (depends on 12)

The recombinant Vesicular Stomatitis Virus (VSV) of claim 12, wherein said anti-receptor protein or polypeptide fragment thereof comprises a ligand for a cell surface receptor, wherein said ligand binds said cell surface receptor expressed on a target cell membrane.

### Claim 15 (depends on 14)

The recombinant Vesicular Stomatitis Virus (VSV) of claim 14, wherein said ligand specifically binds CD4 or erbB proteins expressed on a target cell membrane.

### Claim 16

(canceled)

### Claim 17 (depends on 1)

A vector comprising the recombinant Vesicular Stomatitis Virus (VSV) of claim 1.

### Claim 18 (depends on 17)

A cell comprising the vector of claim 17.

### Claim 19 (depends on 1, 3, 12)

A viral particle comprising the recombinant Vesicular Stomatitis Virus (VSV) of claim 1, 3 or 12.

### Claim 20 (depends on 1, 3, 12)

A liposome comprising the recombinant Vesicular Stomatitis Virus (VSV) of claim 1, 3 or 12.

### Claim 21 (depends on 1, 12)

A method of fusing a cell with the recombinant Vesicular Stomatitis Virus (VSV) of claim 1 or 12, comprising contacting said cell with said recombinant Vesicular Stomatitis Virus (VSV) under conditions facilitating fusion of a viral envelope of said recombinant Vesicular Stomatitis Virus (VSV) with a cell membrane of said cell.

### Claim 22

A method of producing a recombinant Vesicular Stomatitis Virus (VSV), said recombinant Vesicular Stomatitis Virus (VSV) comprising a deletion in the nucleic acid sequence encoding a Vesicular Stomatitis Virus (VSV) G protein, an insertion of a nucleic acid sequence encoding a Vesicular Stomatitis Virus (VSV) G stem polypeptide fragment and a nucleic acid sequence encoding a heterologous fusion facilitating polypeptide, comprising the steps of:
(a) contacting a cell with a minivirus comprising cis-acting elements facilitating Vesicular Stomatitis Virus (VSV) replication;
(b) inserting into said cell a polynucleotide sequence encoding Vesicular Stomatitis Virus (VSV) proteins, a nucleic acid sequence encoding a fragment of a Vesicular Stomatitis Virus (VSV) G stem polypeptide and a nucleic acid sequence encoding a heterologous fusion facilitating polypeptide, wherein said G stem polypeptide fragment potentiates membrane fusion;
(c) culturing said cell under conditions permitting expression of said nucleic acid sequences to produce said recombinant Vesicular Stomatitis Virus (VSV); and
(d) isolating said recombinant Vesicular Stomatitis Virus (VSV),
thereby producing said recombinant Vesicular Stomatitis Virus (VSV).

### Claim 23

A recombinant virus comprising an isolated nucleic acid sequence encoding
(a) the Vesicular Stomatitis Virus (VSV) G stem polypeptide set forth in SEQ ID NO: 2, an amino acid sequence that is 95% identical to SEQ ID NO: 2, a functional fragment of SEQ ID NO: 2, or an amino acid sequence of residues 10-42 of SEQ ID NO: 2,
(b) further comprising a nucleic acid sequence encoding a viral fusion facilitating polypeptide,
wherein said recombinant virus does not comprise a nucleic acid sequence encoding aa 1-404 of a VSV G protein.

### Claim 24

(canceled)

### Claim 25

(canceled)

### Claim 26 (depends on 23)

The recombinant virus of claim 23, wherein said functional fragment comprises an amino acid sequence that is at least 85% identical to SEQ ID Nos: 4, 5, 6, 7, 8 or 9.

### Claim 27 (depends on 23)

The recombinant virus of claim 23, wherein said Vesicular Stomatitis Virus (VSV) G stem polypeptide or fragment thereof comprises a transmembrane anchor and cytoplasmic tail region of a Vesicular Stomatitis Virus (VSV) G protein.

### Claim 28 (depends on 23)

The recombinant virus of claim 23, where said Vesicular Stomatitis Virus (VSV) G stem polypeptide further comprises an N-terminal epitope tag.

### Claim 29 (depends on 28)

The recombinant virus of claim 28, wherein said N-terminal epitope tag is a FLAG synthetic or a human influenza hemagglutinin-derived polypeptide.

### Claim 30

(canceled)

### Claim 31

(canceled)

### Claim 32 (depends on 23)

The recombinant virus of claim 23, wherein said viral fusion facilitating polypeptide comprises polypeptides derived from the simian virus 5 (SV5) F protein or HIV envelope proteins.

### Claim 33 (depends on 23)

The recombinant virus of claim 23, further comprising a nucleic acid sequence encoding an anti-receptor protein or a polypeptide fragment thereof effective to target said recombinant virus to a cell.

### Claim 34 (depends on 33)

The recombinant virus of claim 33, wherein said anti-receptor protein or polypeptide fragment thereof comprises an antibody or antibody fragment, which specifically recognizes a target antigen expressed on a cell membrane.

### Claim 35 (depends on 33)

The recombinant virus of claim 33, wherein said anti-receptor protein or polypeptide fragment thereof comprises a ligand for a cell surface receptor, wherein said ligand binds said cell surface receptor expressed on a target cell membrane.

### Claim 36 (depends on 34)

The recombinant virus of claim 34, wherein said ligand specifically binds CD4 or erbB proteins expressed on a target cell membrane.

### Claim 37 (depends on 23, 26, 27, 28)

A vector comprising the recombinant virus of claim 23, 26, 27, 28, or 33.

### Claim 38 (depends on 37)

A cell comprising the vector of claim 37.

### Claim 39 (depends on 23, 26, 27, 28)

A viral particle comprising the recombinant virus of claim 23, 26, 27, 28, or 33.

### Claim 40 (depends on 23, 26, 27, 28)

A liposome comprising the recombinant virus of claim 23, 26, 27, 28, or 33.

### Claim 41

(canceled)

### Claim 42

An isolated nucleic acid molecule encoding the Vesicular Stomatitis Virus (VSV) G stem polypeptide set forth in SEQ ID NO: 2, a functional fragment SEQ ID NO: 2, an amino acid sequence of residues 10-42 of SEQ ID NO: 2, or an amino acid sequence that is at least 95% identical to SEQ ID NO: 2.

### Claim 43 (depends on 42)

The isolated nucleic acid molecule of claim 42, wherein said functional fragment is at least 85% identical to SEQ ID No: 4, 5, 6, 7, 8 or 9.

### Claim 44

(canceled)

### Claim 45 (depends on 42)

The isolated nucleic acid molecule of claim 42, wherein said functional fragment is at least 85% identical to SEQ ID Nos: 4, 5, 6, 7, 8 or 9.

### Claim 46 (depends on 42)

The isolated nucleic acid molecule of claim 42, wherein said Vesicular Stomatitis Virus (VSV) G stem polypeptide or fragment thereof comprises a transmembrane anchor and cytoplasmic tail region of a Vesicular Stomatitis Virus (VSV) G protein.

### Claim 47 (depends on 42)

The isolated nucleic acid molecule of claim 42, wherein said Vesicular Stomatitis Virus (VSV) G stem polypeptide fragment further comprises an N-terminal epitope tag.

### Claim 48 (depends on 47)

The isolated nucleic acid molecule of claim 47, wherein said N-terminal epitope tag is a FLAG synthetic or a human influenza hemagglutinin-derived polypeptide.

### Claim 49 (depends on 42)

The isolated nucleic acid molecule of claim 42, wherein said fusion facilitating polypeptide is derived from simian virus 5 (SV5) F or HIV envelope proteins.

### Claim 50

(canceled)

### Claim 51 (depends on 42)

The isolated nucleic acid molecule of claim 42, further comprising a nucleic acid sequence encoding an anti-receptor protein or a polypeptide fragment thereof.

### Claim 52 (depends on 51)

The isolated nucleic acid molecule of claim 51, wherein said anti-receptor protein or polypeptide fragment thereof comprises an antibody or antibody fragment, which specifically recognizes a target antigen expressed on a cell membrane.

### Claim 53 (depends on 51)

The isolated nucleic acid molecule of claim 51, wherein said anti-receptor protein or polypeptide fragment thereof comprises a ligand for a cell surface receptor expressed on a cell membrane.

### Claim 54 (depends on 53)

The isolated nucleic acid molecule of claim 53, wherein said ligand specifically binds CD4 or erbB proteins expressed on a cell membrane.

### Claim 55 (depends on 42)

The isolated nucleic acid molecule of claim 42, further comprising at least one non-Vesicular Stomatitis Virus (VSV) nucleic acid sequence.

### Claim 56 (depends on 42, 43, 45, 46, 47, 51)

A vector comprising the isolated nucleic acid molecule of claim 42, 43, 45, 46, 47, 51, or 55.

### Claim 57 (depends on 56)

A cell comprising the vector of claim 56.

### Claim 58

A method for targeted cell or tissue lysis, comprising the steps of contacting said cell or tissue with an effective amount of a recombinant Vesicular Stomatitis Virus (VSV), wherein a genome of said recombinant Vesicular Stomatitis Virus (VSV) comprises:
(a) a deletion in the nucleic acid sequence encoding a G protein;
(b) an insertion of a nucleic acid sequence encoding a Vesicular Stomatitis Virus (VSV) G stem polypeptide fragment, wherein said fragment potentiates membrane fusion;
(c) a nucleic acid sequence encoding a heterologous fusion facilitating polypeptide; and
(d) a nucleic acid sequence encoding an anti-receptor protein or a polypeptide fragment thereof,
wherein said anti-receptor protein or polypeptide fragment thereof binds its cognate ligand or receptor, expressed on a surface of said targeted cell or tissue, facilitating targeting of said recombinant Vesicular Stomatitis Virus (VSV) for entry into said cell or tissue, thereby causing targeted cell or tissue lysis.

### Claim 59 (depends on 58)

The method of claim 58, wherein said cell or tissue is diseased.

### Claim 60 (depends on 59)

The method of claim 59, wherein said diseased cell or tissue is a neoplastic cell, a pre-neoplastic cell, a benign tumor, a polyp or a cell infected with an intracellular pathogen.

### Claim 61 (depends on 58)

The method of claim 58, wherein said anti-receptor protein or polypeptide fragment thereof comprises an antibody or antibody fragment, which is directed to a target antigen expressed on said cell or tissue.

### Claim 62 (depends on 58)

The method of claim 58, wherein said anti-receptor protein or polypeptide fragment thereof comprises a ligand for a cell surface receptor expressed on said cell or tissue.

### Claim 63 (depends on 62)

The method of claim 62, wherein said ligand specifically binds CD4 or erbB proteins expressed on said cell or tissue.

### Claim 64 (depends on 58)

The method of claim 58, wherein administering to said cell or tissue an effective amount of a recombinant Vesicular Stomatitis Virus (VSV) is accomplished in vivo or in vitro.

### Claim 65 (depends on 58)

The method of claim 58, used as a therapy for treating a subject suffering from a disease.

### Claim 66 (depends on 65)

The method of claim 65, wherein said disease is a cancer, a cell proliferative disorder, an inflammatory cell disorder or an infection.

### Claim 67

An isolated nucleic acid sequence encoding the Vesicular Stomatitis Virus (VSV) G stem polypeptide set forth in SEQ ID NO: 2 or a functional fragment thereof, wherein said G stem polypeptide or said fragment thereof potentiates membrane fusion.

### Claim 68

(canceled)

### Claim 69

(canceled)

### Claim 70 (depends on 67)

A vector comprising the isolated nucleic acid molecule of claim 67.

### Claim 71 (depends on 67)

A liposome comprising the isolated nucleic acid molecule of claim 67.

### Claim 72 (depends on 70)

A cell comprising the vector of claim 70.

### Claim 73 (depends on 70)

A liposome comprising the vector of claim 70.

### Claim 74 (depends on 38, 57, 72)

A method for potentiating target cell fusion, comprising the steps of contacting said target cell with an effective amount of the cells of claim 38, 57 or 72, wherein the membrane of said cells fuses with a lipid bilayer surrounding said target cells at a rate or quantity greater than fusion of wild-type cells alone, thereby potentiating target cell fusion.

### Claim 75 (depends on 70)

The vector of claim 70, further comprising at least one non-Vesicular Stomatitis Virus (VSV) nucleic acid sequence.

### Claim 76 (depends on 75)

A cell comprising the vector of claim 75.

### Claim 77 (depends on 75)

A liposome comprising the vector of claim 75.

### Claim 78 (depends on 75)

The vector of claim 75, wherein said at least one non-Vesicular Stomatitis Virus (VSV) nucleic acid sequence functions to facilitate membrane fusion.

### Claim 79 (depends on 78)

A cell comprising the vector of claim 78.

### Claim 80 (depends on 78)

A liposome comprising the vector of claim 78.

### Claim 81 (depends on 75)

The vector of claim 75, wherein said at least one non-Vesicular Stomatitis Virus (VSV) nucleic acid sequence functions to facilitate specific cell targeting.

### Claim 82 (depends on 75)

The vector of claim 75, wherein said at least one non-Vesicular Stomatitis Virus (VSV) nucleic acid sequence comprises a sequence encoding an anti-receptor protein or a polypeptide fragment thereof.

### Claim 83 (depends on 75)

The vector of claim 75, wherein said at least one non-Vesicular Stomatitis Virus (VSV) nucleic acid sequence comprises a sequence encoding an antibody or antibody fragment, which specifically recognizes a target antigen expressed on a cell membrane.

### Claim 84 (depends on 81, 82, 83)

A cell comprising the vector of claim 81, 82 or 83.

### Claim 85 (depends on 81, 82, 83)

A liposome comprising the vector of claim 81, 82 or 83.

### Claim 86

A recombinant Vesicular Stomatitis Virus (VSV) comprising a nucleic acid sequence of a Vesicular Stomatitis Virus (VSV) genome wherein said Vesicular Stomatitis Virus (VSV) genome comprises:
(a) a deletion in a nucleic acid sequence encoding a Vesicular Stomatitis Virus (VSV) G protein; and
(b) an insertion of an isolated nucleic acid sequence encoding the Vesicular Stomatitis Virus (VSV) G stem polypeptide set forth in SEQ NO: 9, a functional fragment SEQ ID NO: 9, or an amino acid sequence that is at least 95% identical to SEQ ID No: 9.

### Claim 87

(canceled)

### Claim 88 (depends on 86)

The recombinant Vesicular Stomatitis Virus (VSV) of claim 86, wherein said Vesicular Stomatitis Virus (VSV) genome further comprises a nucleic acid sequence encoding a heterologous fusion facilitating polypeptide expressed from a separate transcriptional unit.

### Claim 89 (depends on 86)

The recombinant Vesicular Stomatitis Virus (VSV) of claim 86, wherein said Vesicular Stomatitis Virus (VSV) G protein lacks amino acid residues 1 to at least 404 of a mature Vesicular Stomatitis Virus (VSV) G protein.

### Claim 90 (depends on 86)

The recombinant Vesicular Stomatitis Virus (VSV) of claim 86, wherein said Vesicular Stomatitis Virus (VSV) genome comprises a nucleic acid sequence encoding the amino acid sequence set forth in SEQ ID NO: 9.

### Claim 91 (depends on 86)

The recombinant Vesicular Stomatitis Virus (VSV) of claim 86, wherein said Vesicular Stomatitis Virus (VSV) G stem polypeptide or fragment thereof comprises a transmembrane anchor and cytoplasmic tail region of a Vesicular Stomatitis Virus (VSV) G protein.

### Claim 92 (depends on 86)

The recombinant Vesicular Stomatitis Virus (VSV) of claim 86, where said Vesicular Stomatitis Virus (VSV) G stem polypeptide or fragment thereof further comprises an N-terminal epitope tag.

### Claim 93 (depends on 92)

The recombinant Vesicular Stomatitis Virus (VSV) G stem polypeptide of claim 92, wherein said N-terminal epitope tag is a FLAG synthetic or a human influenza hemagglutinin-derived polypeptide.

### Claim 94 (depends on 88)

The recombinant Vesicular Stomatitis Virus (VSV) of claim 88, wherein said fusion facilitating polypeptide comprises polypeptides derived from the simian virus 5 (SV5) F protein or HIV envelope proteins.

### Claim 95

(canceled)

### Claim 96 (depends on 86)

The recombinant Vesicular Stomatitis Virus (VSV) of claim 86, further comprising a nucleic acid sequence encoding an anti-receptor protein or a polypeptide fragment thereof effective to target said recombinant Vesicular Stomatitis Virus (VSV) to a cell.

### Claim 97 (depends on 96)

The recombinant Vesicular Stomatitis Virus (VSV) of claim 96, wherein said anti-receptor protein or polypeptide fragment thereof comprises an antibody or antibody fragment, which specifically recognizes a target antigen expressed on a cell membrane.

### Claim 98 (depends on 96)

The recombinant Vesicular Stomatitis Virus (VSV) of claim 96, wherein said anti-receptor protein or polypeptide fragment thereof comprises a ligand for a cell surface receptor, wherein said ligand binds said cell surface receptor expressed on a target cell membrane.

### Claim 99 (depends on 98)

The recombinant Vesicular Stomatitis Virus (VSV) of claim 98, wherein said ligand specifically binds CD4 or erbB proteins expressed on a target cell membrane.

### Claim 100

(canceled)

### Claim 101 (depends on 86)

A vector comprising the recombinant Vesicular Stomatitis Virus (VSV) of claim 86.

### Claim 102 (depends on 101)

A cell comprising the vector of claim 101.

### Claim 103 (depends on 86)

A viral particle comprising the recombinant Vesicular Stomatitis Virus (VSV) of claim 86.

### Claim 104 (depends on 86)

A liposome comprising the recombinant Vesicular Stomatitis Virus (VSV) of claim 86.

### Claim 105 (depends on 86)

A method of fusing a cell with the recombinant Vesicular Stomatitis Virus (VSV) of claim 86, comprising contacting said cell with said recombinant Vesicular Stomatitis Virus (VSV) under conditions facilitating fusion of a viral envelope of said recombinant Vesicular Stomatitis Virus (VSV) with a cell membrane of said cell.

### Claim 106

A recombinant virus comprising an isolated nucleic acid sequence encoding a Rhabdoviral G stem polypeptide, or a functional fragment thereof, wherein said isolated nucleic acid sequence encodes an amino acid sequence that is at least 95% identical to SEQ ID No: 9.

### Claim 107

(canceled)

### Claim 108 (depends on 106)

The recombinant virus of claim 106, wherein said fragment comprises between 10 and 42 amino acid residues of a membrane-proximal region of a Vesicular Stomatitis Virus (VSV) G protein.

### Claim 109 (depends on 106)

The recombinant virus of claim 106, wherein said fragment comprises a transmembrane anchor and cytoplasmic tail region of a Vesicular Stomatitis Virus (VSV) G protein.

### Claim 110 (depends on 106)

The recombinant virus of claim 106, where said G stem polypeptide further comprises an N-terminal epitope tag.

### Claim 111 (depends on 110)

The recombinant virus of claim 110, wherein said N-terminal epitope tag is a FLAG synthetic or a human influenza hemagglutinin-derived polypeptide.

### Claim 112

(canceled)

### Claim 113 (depends on 106)

The recombinant virus of claim 106, further comprising a nucleic acid sequence encoding a fusion facilitating polypeptide.

### Claim 114 (depends on 113)

The recombinant virus of claim 113, wherein said fusion facilitating polypeptide comprises polypeptides derived from the simian virus 5 (SV5) F protein or HIV envelope proteins.

### Claim 115 (depends on 106)

The recombinant virus of claim 106, further comprising a nucleic acid sequence encoding an anti-receptor protein or a polypeptide fragment thereof effective to target said recombinant virus to a cell.

### Claim 116 (depends on 115)

The recombinant virus of claim 115, wherein said anti-receptor protein or polypeptide fragment thereof comprises an antibody or antibody fragment, which specifically recognizes a target antigen expressed on a cell membrane.

### Claim 117 (depends on 115)

The recombinant virus of claim 115, wherein said anti-receptor protein or polypeptide fragment thereof comprises a ligand for a cell surface receptor, wherein said ligand binds said cell surface receptor expressed on a target cell membrane.

### Claim 118 (depends on 117)

The recombinant virus of claim 117, wherein said ligand specifically binds CD4 or erbB proteins expressed on a target cell membrane.

### Claim 119 (depends on 106)

A vector comprising the recombinant virus of claim 106.

### Claim 120 (depends on 119)

A cell comprising the nucleic acid vector of claim 119.

### Claim 121 (depends on 106)

A viral particle comprising the recombinant virus of claim 106.

### Claim 122 (depends on 106)

A liposome comprising the recombinant virus of claim 106.

### Claim 123 (depends on 103, 121)

A method for potentiating target cell fusion, comprising the step of contacting said target cell with an effective amount of the recombinant Vesicular Stomatitis Virus (VSV) particle of claim 103 or 121, wherein said recombinant Vesicular Stomatitis Virus (VSV) particle envelope fuses with the membrane of said target cell at a rate or quantity greater than fusion of wild-type Vesicular Stomatitis Virus (VSV) particles alone, thereby potentiating target cell fusion.

### Claim 124

An isolated nucleic acid molecule comprising a nucleic acid sequence encoding a Vesicular Stomatitis Virus (VSV) G stem polypeptide or a fragment thereof, wherein said Vesicular Stomatitis Virus (VSV) G stem polypeptide or fragment thereof is at least 95% homologous to SEQ ID No: 9, and a nucleic acid sequence encoding a heterologous fusion facilitating polypeptide.

### Claim 125 (depends on 124)

The isolated nucleic acid molecule of claim 124, wherein said Vesicular Stomatitis Virus (VSV) G stem polypeptide or fragment thereof comprises between 10 and 42 amino acid residues of a membrane-proximal region of a Vesicular Stomatitis Virus (VSV) G protein.

### Claim 126 (depends on 124)

The isolated nucleic acid molecule of claim 124, wherein said Vesicular Stomatitis Virus (VSV) G stem polypeptide or fragment thereof comprises a transmembrane anchor and cytoplasmic tail region of a Vesicular Stomatitis Virus (VSV) G protein.

### Claim 127 (depends on 124)

The isolated nucleic acid molecule of claim 124, wherein said Vesicular Stomatitis Virus (VSV) G stem polypeptide fragment further comprises an N-terminal epitope tag.

### Claim 128 (depends on 127)

The isolated nucleic acid molecule of claim 127, wherein said N-terminal epitope tag is a FLAG synthetic or a human influenza hemagglutinin-derived polypeptide.

### Claim 129 (depends on 124)

The isolated nucleic acid molecule of claim 124, wherein said fusion facilitating polypeptide is derived from simian virus 5 (SV5) F or HIV envelope proteins.

### Claim 130

(canceled)

### Claim 131 (depends on 124)

The isolated nucleic acid molecule of claim 124, further comprising a nucleic acid sequence encoding an anti-receptor protein or a polypeptide fragment thereof.

### Claim 132 (depends on 131)

The isolated nucleic acid molecule of claim 131, wherein said anti-receptor protein or polypeptide fragment thereof comprises an antibody or antibody fragment, which specifically recognizes a target antigen expressed on a cell membrane.

### Claim 133 (depends on 131)

The isolated nucleic acid molecule of claim 131, wherein said anti-receptor protein or polypeptide fragment thereof comprises a ligand for a cell surface receptor expressed on a cell membrane.

### Claim 134 (depends on 133)

The isolated nucleic acid molecule of claim 133, wherein said ligand specifically binds CD4 or erbB proteins expressed on a cell membrane.

### Claim 135 (depends on 124)

The isolated nucleic acid molecule of claim 124, further comprising at least one non-Vesicular Stomatitis Virus (VSV) nucleic acid sequence.

### Claim 136 (depends on 124)

A vector comprising the isolated nucleic acid molecule of claim 124.

### Claim 137 (depends on 136)

A cell comprising the vector of claim 136.

### Claim 138

(canceled)

### Claim 139 (depends on 124)

The isolated nucleic acid molecule of claim 124, wherein said Vesicular Stomatitis Virus (VSV) G stem polypeptide or fragment thereof functions to potentiate membrane fusion.

### Claim 140 (depends on 124)

A vector comprising the isolated nucleic acid molecule of claim 124.

### Claim 141 (depends on 124)

A liposome comprising the isolated nucleic acid molecule of claim 124.

### Claim 142 (depends on 140)

A cell comprising the vector of claim 140.

### Claim 143 (depends on 140)

A liposome comprising the vector of claim 140.

### Claim 144 (depends on 140)

The vector of claim 140, further comprising at least one non-Vesicular Stomatitis Virus (VSV) nucleic acid sequence.

### Claim 145 (depends on 144)

A cell comprising the vector of claim 144.

### Claim 146 (depends on 144)

A liposome comprising the vector of claim 144.

### Claim 147 (depends on 140)

The vector of claim 140, wherein said at least one non-Vesicular Stomatitis Virus (VSV) nucleic acid sequence functions to facilitate membrane fusion.

### Claim 148 (depends on 147)

A cell comprising the vector of claim 147.

### Claim 149 (depends on 147)

A liposome comprising the vector of claim 147.

### Claim 150 (depends on 144)

The vector of claim 144, wherein said at least one non-Vesicular Stomatitis Virus (VSV) nucleic acid sequence functions to facilitate specific cell targeting.

### Claim 151 (depends on 144)

The vector of claim 144, wherein said at least one non-Vesicular Stomatitis Virus (VSV) nucleic acid sequence comprises a sequence encoding an anti-receptor protein or a polypeptide fragment thereof.

### Claim 152 (depends on 144)

The vector of claim 144, wherein said at least one non-Vesicular Stomatitis Virus (VSV) nucleic acid sequence comprises a sequence encoding an antibody or antibody fragment, which specifically recognizes a target antigen expressed on a cell membrane.

### Claim 153 (depends on 150, 151, 152)

A cell comprising the vector of claim 150, 151 or 152.

### Claim 154 (depends on 150, 151, 152)

A liposome comprising the vector of claim 150, 151 or 152.

### Claim 155 (depends on 39)

A method for potentiating target cell fusion, comprising the step of contacting said target cell with an effective amount of the recombinant Vesicular Stomatitis Virus (VSV) particle of claim 39, wherein said recombinant Vesicular Stomatitis Virus (VSV) particle envelope fuses with the membrane of said target cell at a rate or quantity greater than fusion of wild-type Vesicular Stomatitis Virus (VSV) particles alone, thereby potentiating target cell fusion.

### Claim 156

(canceled)

### Claim 157 (depends on 1)

The recombinant Vesicular Stomatitis Virus (VSV) of claim 1, wherein said functional fragment encodes an amino acid sequence at least 95% homologous to SEQ ID No: 9.