Compositions and methods for generating an immune response utilizing alphavirus-based vector systems

1. An isolated Sindbis alphavirus which infects human dendritic cells, and which comprises an E2 glycoprotein comprising glycine in the position corresponding to residue 160, wherein residue 160 is numbered according to wild-type Sindbis alphavirus E2 glycoprotein encoded by a nucleic acid molecule of SEQ ID NO: 1 and wherein residue 160 in wild-type Sindbis alphavirus E2 glycoprotein is glutamic acid, with the proviso that said Sindbis alphavirus is not ATCC # VR-2526.

2. The isolated Sindbis alphavirus according to claim 1 wherein said alphavirus is ATCC No. VR-2643.

3. An isolated nucleic acid molecule which encodes the isolated Sindbis alphavirus according to claim 1 .

4. A Sindbis alphavirus structural protein expression cassette, comprising a promoter operably linked to a nucleic acid sequence encoding at least one Sindbis alphavirus structural protein, wherein said nucleic acid sequence comprises a sequence encoding an E2 glycoprotein a glycine in the position corresponding to residue 160, wherein residue 160 is numbered according to wild-type Sindbis alphavirus E2 glycoprotein encoded by a nucleic acid molecule of SEQ ID NO: 1 and wherein residue 160 in wild-type Sindbis alphavirus E2 glycoprotein is glutamic acid.

5. An isolated alphavirus packaging cell, comprising a host cell and a Sindbis alphavirus structural protein expression cassette according to claim 4 .

6. An isolated Sindbis alphavirus producer cell, comprising a packaging cell according to claim 5 and a vector selected from the group consisting of a Sindbis alphavirus RNA vector replicon, Sindbis alphavirus vector construct, and a eukaryotic layered vector initiation system.

7. A recombinant Sindbis alphavirus particle, comprising a particle produced from a producer cell line according to claim 6 .

8. A recombinant Sindbis alphavirus particle, comprising a particle produced from a packaging cell line according to claim 5 .

9. A recombinant Sindbis alphavirus particle which infects human dendritic cells, with the proviso that said recombinant Sindbis alphavirus particle is not derived from ATCC # VR-2526 wherein said particle comprises a Sindbis alphavirus E2 glycoprotein comprising glycine in the position corresponding to residue 160, wherein residue 160 is numbered according to wild-type Sindbis alphavirus E2 glycoprotein encoded by a nucleic acid molecule of SEQ ID NO: 1 and wherein residue 160 in wild-type Sindbis E2 glycoprotein is glutamic acid.

10. A method for introducing a heterologous nucleotide sequence into cells, comprising infecting said cells with a recombinant Sindbis alphavirus particle according to claim 9 , such that said heterologous sequence is introduced into said cell.

11. The method according to claim 10 wherein said heterologous sequence is a sequence that encodes a protein.

12. The method according to claim 11 wherein said protein is an antigen from a pathogenic agent.

13. The method according to claim 12 wherein said antigen is from a virus, bacteria, parasite, or fungus.

14. The method according to claim 12 wherein said antigen is from a cancerous cell.

15. The method according to claim 11 wherein said protein is selected from the group consisting of IL-1, IL-2, IL-3, IL-4, IL-5, IL-6, IL-7, IL-8, IL-9, IL-10, IL-11, IL-12, IL-13, IL-14, IL-15, alpha-IFN, beta-IFN, gamma-IFN, G-CSF, and GM-CSF.

16. The method according to claim 10 wherein said heterologous sequence is a ribozyme or antisense.

17. The method according to claim 10 wherein said cell is infected ex vivo.

18. The method according to claim 10 wherein said cell is infected in vivo.

19. The method according to claim 10 wherein said cell is a population of cells comprising dendritic cells.

20. The method according to claim 19 wherein said dendritic cells are human dendritic cells.

21. The isolated nucleic acid molecule of claim 3 which comprises SEQ ID NO:2.