Pseudotyped lentiviral vectors and uses thereof

1. A vector system comprising a first vector containing a lentiviral gag gene encoding a lentiviral gag protein, wherein the lentiviral gag gene is operably linked to a promoter and a polyadenylation sequence, wherein said lentiviral gag gene is from a primate immunodeficiency virus or a feline immunodeficiency virus (FIV);

a second vector containing an env gene encoding a functional envelope protein, wherein the env gene is operably linked to a promoter and a polyadenylation sequence;

a lentiviral pol gene encoding a lentiviral pol protein on the first or second vectors or on at least a third vector, wherein said lentiviral pol gene is operably linked to a promoter and a polyadenylation sequence, wherein said lentiviral pol gene is from a primate immunodeficiency virus or FIV;

a) wherein said at least first, second and third vectors do not contain sufficient nucleotides to encode the lentiviral gag and pol and the envelope protein on a single vector; and

b) wherein said vectors do not contain nucleotides of the lentiviral genome referred to as a packaging segment to effectively package lentiviral RNA; and

c) wherein the lentiviral proteins and the envelope protein when expressed in combination form a lentivirus virion containing an envelope protein around a lentiviral capsid;

a packaging vector containing a nucleic acid sequence encoding a desired molecule, where the nucleic acid sequence is operably linked to an inducible promoter and a lentiviral packaging sequence including portions of lentiviral long terminal repeat (LTR) sequences necessary to package the lentiviral RNA into the lentiviral virion; and

d) wherein said packaging vector contains a deletion of the U3 portion of the lentiviral LTR sufficient to inactivate the lentiviral promoter and/or does not express a tat protein that has transactivating functions; and

wherein the envelope protein is encoded by a filovirus envelope gene.

2. The vector system of claim 1 , wherein the envelope protein is a protein encoded by an Ebola virus gene.

3. The vector system of claim 1 , wherein the lentivirus is a primate lentivirus.

4. The vector system of claim 1 , wherein the gag and pol genes are on the same vector.

5. The vector system of claim 1 , wherein the gag and pol genes are on the same vector, wherein the first and second vectors do not contain lentiviral LTRs and, wherein the first and second vectors are designed to reduce homology by reducing the number of homologous regions shared by the vectors by deletions of homologous nucleotides or insertion of nucleotide substitutions in the homologous regions shared by the vectors.

6. The vector system of claim 1 , wherein the lentivirus is a feline immunodeficiency virus (FIV).

7. The vector system of claim 2 , wherein the lentivirus is the human immunodeficiency virus.

8. The vector system of claim 3 , wherein the primate lentivirus is a hybrid of a human immunodeficiency virus and simian immunodeficiency virus referred to as SHIV.

9. The vector system of claim 4 , wherein the first and second vectors do not contain lentiviral LTRs.

10. A vector system comprising a first vector containing a primate lentiviral gag gene encoding a primate lentiviral gag protein, wherein the primate lentiviral gag gene is operably linked to a promoter and a polyadenylation sequence;

a second vector containing an env gene encoding a functional envelope protein, wherein the env gene is operably linked to a promoter and a polyadenylation sequence;

a lentiviral pol gene encoding a lentiviral pol protein on the first or second vectors or on at least a third vector, wherein said lentiviral pol gene is operably linked to a promoter and a polyadenylation sequence;

a) wherein said at least first, second and third vectors do not contain sufficient nucleotides to encode the lentiviral gag and pol and the envelope protein on a single vector; and

b) wherein said vectors do not contain nucleotides of the lentiviral genome referred to as a packaging segment to effectively package lentiviral RNA; and

c) wherein the lentiviral proteins and the envelope protein when expressed in combination form a lentivirus virion containing an envelope protein around a lentiviral capsid;

a packaging vector containing a nucleic acid sequence encoding a desired molecule, where the nucleic acid sequence is operably linked to an inducible promoter and a lentiviral packaging sequence including portions of lentiviral long terminal repeat (LTR) sequences necessary to package the lentiviral RNA into the lentiviral virion; and

d) wherein said packaging vector contains a deletion of the U3 portion of the lentiviral LTR sufficient to inactivate the lentiviral promoter and/or does not express a tat protein that has transactivating functions,

wherein the env gene encodes a viral envelope protein which is expressed by a virus selected from the group of viruses consisting of influenza virus, alpha viruses, arenaviruses, flaviviruses, and orthomyxoviruses.

11. A vector system comprising a first vector containing a primate lentiviral gag gene encoding a primate lentiviral gag protein, wherein the primate lentiviral gag gene is operably linked to a promoter and a polyadenylation sequence;

a second vector containing an env gene encoding a functional envelope protein, wherein the

env gene is operably linked to a promoter and a polyadenylation sequence;

a lentiviral poi gene encoding a lentiviral pol protein on the first or second vectors or on at least a third vector, wherein said lentiviral pol gene is operably linked to a promoter and a polyadenylation sequence;

a) wherein said at least first, second and third vectors do not contain sufficient nucleotides to encode the lentiviral gag and pol and the envelope protein on a single vector; and

b) wherein said vectors do not contain nucleotides of the lentiviral genome referred to as a packaging segment to effectively package lentiviral RNA; and

c) wherein the lentiviral proteins and the envelope protein when expressed in combination form a lentivirus virion containing an envelope protein around a lentiviral capsid;

a packaging vector containing a gene encoding a desired molecule, where the gene is operably linked to an inducible expression system and a lentiviral packaging sequence including portions of lentiviral long terminal repeat (LTR) sequences necessary to package the lentiviral RNA into the lentiviral virion;

wherein the inducible expression system comprises a tetracycline repressor (tetR) and at least one tetracycline operator (tetO) positioned downstream of a promoter, such that in the presence of tetracycline the gene expresses the desired protein and in the absence of tetracycline the desired protein is not expressed;

d) wherein said packaging vector contains a deletion of the U3 portion of the lentiviral LTR sufficient to inactivate the lentiviral promoter and/or does not express a tat protein that has transactivating functions.

12. A vector system comprising a first vector containing a feline lentiviral gag gene encoding a feline lentiviral gag protein, wherein the feline lentiviral gag gene is operably linked to a promoter and a polyadenylation sequence;

a second vector containing an env gene encoding a functional envelope protein, wherein the

env gene is operably linked to a promoter and a polyadenylation sequence;

a lentiviral pol gene encoding a lentiviral pol protein on the first or second vectors or on at least a third vector, wherein said lentiviral pol gene is operably linked to a promoter and a polyadenylation sequence;

a) wherein said at least first, second and third vectors do not contain sufficient nucleotides to encode the lentiviral gag and pol and the envelope protein on a single vector; and

b) wherein said vectors do not contain nucleotides of the lentiviral genome referred to as a packaging segment to effectively package lentiviral RNA; and

c) wherein the lentiviral proteins and the envelope protein when expressed in combination form a lentivirus virion containing an envelope protein around a lentiviral capsid;

a packaging vector containing a gene encoding a desired molecule, where the gene is operably linked to an inducible expression system and a lentiviral packaging sequence including portions of lentiviral long terminal repeat (LTR) sequences necessary to package the lentiviral RNA into the lentiviral virion;

wherein the inducible expression system comprises a tetracycline repressor (tetR) and at least one tetracycline operator (tetO) positioned downstream of a promoter, such that in the presence of tetracycline the gene expresses the desired protein and in the absence of tetracycline the desired protein is not expressed;

d) wherein said packaging vector contains a deletion of the U3 portion of the lentiviral LTR sufficient to inactivate the lentiviral promoter and/or does not express a tat protein that has transactivating functions.