Superior molecular vaccine linking the translocation domain of a bacterial toxin to an antigen
Nucleic acids encoding a chimeric or fusion polypeptide which polypeptide comprises a first domain comprising a translocation polypeptide; and a second domain comprising at least one antigenic peptide are disclosed. The preferred translocation polypeptide is a bacterial toxin translocation polypeptide, such as domain II of Pseudomonas aeruginosa exotoxin A (ETA(dII)). Such nucleic acids, expression vectors thereof, and cells expressing these vectors are used as vaccine compositions in a method for enhancing an antigen specific immune response, a method of increasing the numbers of CD8 + CTLs specific for a selected desired antigen in a subject, or a method of inhibiting the growth of a tumor in a subject.
1. A particle comprising a nucleic acid encoding a chimeric or fusion polypeptide that is an expression vector expressible in a eukaryotic cell, which nucleic acid comprises:
(a) a first nucleotide sequence encoding a first polypeptide domain which consists of the Pseudomonas aeruginosa exotoxin A domain II (ETA(dII)) having SEQ ID NO: 3;
(b) a second nucleotide sequence encoding a second polypeptide domain comprising at least one antigenic peptide; and
(c) operably linked thereto, a promoter active in said eukaryotic cell;
wherein the nucleic acid does not comprise a nucleotide sequence encoding a Pseudomonas aeruginosa exotoxin A protein other than the first polypeptide domain.
2. The particle of claim 1 , wherein the antigenic peptide comprises an epitope that binds to and is presented on the cell surface by MHC class I proteins.
3. The particle of claim 2 wherein the epitope is between about 8 and about 11 amino acid residues in length.
4. The particle of claim 1 , wherein the antigen
(i) is derived from a pathogen selected from the group consisting of a mammalian cell, a microorganism or a virus; or
(ii) cross-reacts with an antigen of the pathogen.
5. The particle of claim 1 , wherein the antigen is a tumor-specific or tumor-associated antigen.
6. The particle of claim 4 , wherein the virus is a human papilloma virus.
7. The particle of claim 1 , wherein the antigen is an HPV-16 E6 peptide or polypeptide.
8. The particle of claim 6 , wherein the antigen is an HPV-16 E7 peptide or polypeptide.
9. The particle of claim 8 , wherein the HPV-16 E7 peptide or polypeptide is non-oncogenic.
10. The particle of claim 4 , wherein the pathogen is a bacterium.
11. The particle of claim 8 , wherein the first and the second nucleotide sequences are fused together and encode a fusion protein comprising the amino acid sequence from amino acid 1 to amino acid 269 of SEQ ID NO: 5.
12. The particle of claim 1 , wherein the promoter is one that is active in a mammalian cell so that said nucleic acid is expressible in the mammalian cell.
13. The particle of claim 12 , wherein the promoter is one which is expressed in an antigen presenting cell (APC).
14. The particle of claim 13 , wherein the APC is a dendritic cell.
15. The particle of claim 1 , wherein the promoter is one that is active in a human cell so that said nucleic acid is expressible in the human cell.
16. The particle of claim 1 , wherein the first and the second nucleotide sequences are fused together and encode a fusion protein comprising the first polypeptide domain fused to the second domain.
17. The particle of claim 1 , further comprising one or more regulatory elements that enhance expression of said nucleic acid in said cell.
18. The particle of claim 1 , wherein the vector is a viral vector or a plasmid.
19. The particle of claim 1 , wherein the vector is a self-replicating RNA replicon.
20. The particle of claim 19 , wherein the self-replicating RNA replicon is a Sindbis virus RNA replicon.
21. The nucleic acid particle of claim 20 , wherein the Sindbis virus RNA replicon is SINrep5.
22. The particle of claim 1 , which comprises a material that is suitable for introduction into a cell or an animal by particle bombardment.
23. The particle of claim 22 , wherein the material is gold.
24. An isolated mammalian cell which has been modified to comprise the particle of claim 1 , and which expresses said nucleic acid.
25. The cell of claim 24 , which is an APC.
26. The cell of claim 25 , wherein the APC is a dendritic cell, a keratinocyte, a macrophage, a monocyte, a B lymphocyte, a microglial cell, an astrocyte, or an activated endothelial cell.
27. An isolated mammalian cell which has been modified to comprise the particle of claim 12 , and which expresses said nucleic acid.
28. An isolated mammalian cell which has been modified to comprise the particle of claim 6 , and which expresses said nucleic acid.
29. An isolated human cell which has been modified to comprise the particle of claim 1 , and which expresses said nucleic acid.
30. A pharmaceutical composition capable of inducing or enhancing an antigen specific immune response, comprising the particle of claim 1 , and a pharmaceutically acceptable carrier or excipient.
31. A pharmaceutical composition capable of inducing or enhancing an antigen specific immune response, comprising the particle of claim 6 , and a pharmaceutically acceptable carrier or excipient.
32. A pharmaceutical composition capable of inducing or enhancing an antigen specific immune response, comprising the particle of claim 23 , and a pharmaceutically acceptable carrier or excipient.
33. A pharmaceutical composition capable of inducing or enhancing an antigen specific immune response, comprising the cell of claim 29 , and a pharmaceutically acceptable carrier or excipient.
34. A pharmaceutical composition capable of inducing or enhancing an antigen specific immune response, comprising the cell of claim 25 , and a pharmaceutically acceptable carrier or excipient.
35. A pharmaceutical composition capable of inducing or enhancing an antigen specific immune response, comprising the cell of claim 24 , and a pharmaceutically acceptable carrier or excipient.
36. A pharmaceutical composition capable of inducing or enhancing an antigen specific immune response, comprising the particle of claim 12 , and a pharmaceutically acceptable carrier or excipient.