Compositions and methods for enhancing the immunogenicity of antigens

1. A recombinant nucleotide encoding a recombinant polypeptide comprising an N-terminal fragment of an ActA protein consisting of the first 390 amino acids of the Listeria monocytogenes ActA protein fused to a tumor antigen or a fragment thereof, wherein said ActA fragment comprises a PEST-like sequence selected from the sequences set forth in SEQ ID No: 2-5 and wherein said tumor antigen is a self antigen.

2. The recombinant nucleotide of claim 1 , wherein said self antigen is selected from the group consisting of Her-2/Neu, tyrosinase-related protein (TRP)-2, melanoma antigen (MAGE)-1, MAGE-3, gp-100, tyrosinase, melanoma antigen recognized by T-cells (MART)-1, heat shock protein (HSP)-70, beta-human chorionic gonadotropin (HCG), carcinoembryonic antigen (CEA), the ras protein, the p53 protein, Muc1, and prostate specific antigen (PSA).

3. The recombinant nucleotide of claim 1 , wherein said self antigen and said N-terminal fragment of an ActA protein are expressed from a promoter selected from the group consisting of an hly promoter, a prfA promoter, and a p60 promoter.

4. The recombinant nucleotide of claim 1 , wherein said Listeria monocytogenes is the 10403s strain.

5. A recombinant vector expressing a recombinant polypeptide comprising an N-terminal fragment of an ActA protein consisting of the first 390 amino acids of the Listeria monocytogenes ActA protein fused to a tumor antigen or a fragment thereof, wherein said ActA fragment comprises a PEST-like sequence selected from the sequences set forth in SEQ ID No: 2-5 and wherein said tumor antigen is a self antigen.

6. The recombinant vector of claim 5 , wherein said self antigen is selected from the group consisting of Her-2/Neu, tyrosinase-related protein (TRP)-2, melanoma antigen (MAGE)-1, MAGE-3, gp-100, tyrosinase, melanoma antigen recognized by T-cells (MART)-1, heat shock protein (HSP)-70, beta-human chorionic gonadotropin (HCG), carcinoembryonic antigen (CEA), the ras protein, the p53 protein, Muc1, and prostate specific antigen (PSA).

7. The recombinant vector of claim 5 , wherein said self antigen and said N-terminal fragment of an ActA protein are expressed from a promoter selected from the group consisting of an hly promoter, a prfA promoter, and a p60 promoter.

8. The recombinant vector of claim 5 , wherein said Listeria monocytogenes is the 10403s strain.

9. A recombinant Listeria strain comprising a recombinant nucleotide, said recombinant nucleotide encoding a recombinant polypeptide comprising an N-terminal fragment of an ActA protein consisting of the first 390 amino acids of the Listeria monocytogenes ActA protein fused to a tumor antigen or a fragment thereof, wherein said ActA fragment comprises a PEST-like sequence selected from the sequences set forth in SEQ ID No: 2-5 and wherein said tumor antigen is a self antigen.

10. The recombinant Listeria strain of claim 9 , wherein said self antigen is selected from the group consisting of Her-2/Neu, tyrosinase-related protein (TRP)-2, melanoma antigen (MAGE)-1, MAGE-3, gp-100, tyrosinase, melanoma antigen recognized by T-cells (MART)-1, heat shock protein (HSP)-70, beta-human chorionic gonadotropin (HCG), carcinoembryonic antigen (CEA), the ras protein, the p53 protein, Muc1, and prostate specific antigen (PSA).

11. The recombinant Listeria strain of claim 9 , wherein said self antigen and said N-terminal fragment of an ActA protein are expressed from a promoter selected from the group consisting of an hly promoter, a prfA promoter, and a p60 promoter.

12. The recombinant Listeria strain of claim 9 , wherein said Listeria monocytogenes is the 10403s strain.

13. A method of killing a cell of a Her-2 transformed tumor comprising administering a recombinant Listeria strain comprising a recombinant nucleotide, said recombinant nucleotide encoding a recombinant polypeptide comprising an N-termninal fragment of an ActA protein consisting of the first 390 amino acids of the Listeria monocytogenes ActA protein fused to Her-2/Neu tumor antigen or a fragment thereof, wherein said ActA fragment comprises a PEST-like sequence selected from the sequences set forth in SEQ ID NO: 2-5, thereby killing the cell of a Her-2 transformed tumor.

14. A method of reducing the size of a Her-2 transformed tumor comprising administering a recombinant Listeria strain comprising a recombinant nucleotide, said recombinant nucleotide encoding a recombinant polypeptide comprising an N-terminal fragment of an ActA protein consisting of the first 390 amino acids of the Listeria monocytogenes ActA protein fused to a Her-2/Neu tumor antigen or a fragment thereof, wherein said ActA fragment comprises a PEST-like sequence selected from the sequences set forth in SEQ ID NO: 2-5, thereby reducing the size of said Her-2 transformed tumor.

15. A method of treating a subject having a Her-2 transformed tumor comprising administering to said subject a recombinant Listeria strain comprising a recombinant nucleotide, said recombinant nucleotide encoding a recombinant polypeptide comprising an N-terminal fragment of an ActA protein consisting of the first 390 amino acids of the Listeria monocytogenes ActA protein fused to a Her-2/Neu tumor antigen or a fragment thereof, wherein said ActA fragment comprises a PEST-like sequence selected from the sequences set forth in SEQ ID NO: 2-5, thereby treating said subject having said Her-2 transformed tumor.

16. A method for overcoming the immune tolerance of a subject to a self antigen-expressing tumor comprising administering to said subject a composition comprising a recombinant Listeria strain comprising a recombinant nucleotide, said recombinant nucleotide encoding a recombinant polypeptide comprising an N-terminal fragment of an ActA protein consisting of the first 390 amino acids of the Listeria monocytogenes ActA protein fused to a tumor antigen or a fragment thereof, wherein said ActA fragment comprises a PEST-like sequence selected from the sequences set forth in SEQ ID No: 2-5 and wherein said tumor antigen is a self antigen, whereby said subject mounts an immune response against said self-antigen-expressing tumor, thereby overcoming the immune tolerance of said subject to said self-antigen-expressing tumor.

17. A method of suppressing the formation of a self antigen-expressing tumor in a subject comprising administering to said subject a composition comprising a recombinant Listeria strain comprising a recombinant nucleotide, said recombinant nucleotide encoding a recombinant polypeptide comprising an N-terminal fragment of an ActA protein consisting of the first 390 amino acids of the Listeria monocytogenes ActA protein fused to a tumor antigen or a fragment thereof, wherein said ActA fragment comprises a PEST-like sequence selected from the sequences set forth in SEQ ID No: 2-5 and wherein said tumor antigen is a self antigen, whereby said subject mounts an immune response against said self-antigen-expressing tumor, thereby suppressing the formation of said self-antigen-expressing tumor.

18. A recombinant nucleotide encoding a recombinant polypeptide consisting of a PEST-like sequence selected from the sequences set forth in SEQ ID No: 2-5 fused to a tumor antigen or a fragment thereof, wherein said tumor antigen is a self antigen.

19. The recombinant nucleotide of claim 18 , wherein said self antigen is selected from the group consisting of Her-2/Neu, tyrosinase-related protein (TRP)-2, melanoma antigen (MAGE)-1 MAGE-3, gp-100, tyrosinase, melanoma antigen recognized by T-cells (MART)-1, heat shock protein (HSP)-70, beta-human chorionic gonadotropin (HCG), carcinoembryonic antigen (CEA), the ras protein, the p53 protein, Muc1, and prostate specific antigen (PSA).

20. The recombinant nucleotide of claim 18 , wherein said self antigen and said PEST-like sequence are expressed from a promoter selected from the group consisting of an hly promoter, a prfA promoter, and a p60 promoter.

21. A recombinant vector expressing a recombinant polypeptide, consisting of a PEST-like sequence selected from the sequences set forth in SEQ ID No: 2-5 fused to a tumor antigen or a fragment thereof, wherein said tumor antigen is a self antigen.

22. The recombinant vector of claim 21 , wherein said self antigen is selected from the group consisting of Her-2/Neu, tyrosinase-related protein (TRP)-2, melanoma antigen (MAGE)-1, MAGE-3, gp-100, tyrosinase, melanoma antigen recognized by T-cells (MART)-1, heat shock protein (HSP)-70, beta-human chorionic gonadotropin (HCG) carcinoembryonic antigen (CEA) the ras protein, the p53 protein, Muc1, and prostate specific antigen (PSA).

23. The recombinant vector of claim 21 , wherein said self antigen and said PEST-like sequence are expressed from a promoter selected from the group consisting of an hly promoter, a prfA promoter, and a p60 promoter.

24. A recombinant Listeria strain comprising a recombinant nucleotide, said recombinant nucleotide encoding a recombinant polypeptide consisting of a PEST-like sequence selected from the sequences set forth in SEQ ID No: 2-5 fused to a tumor antigen or a fragment thereof, wherein said tumor antigen is a self antigen.

25. The recombinant Listeria strain of claim 24 , wherein said self antigen is selected from the group consisting of Her-2/Neu, tyrosinase-related protein (TRP)-2, melanoma antigen (MAGE)-1, MAGE-3, gp-100, tyrosinase, melanoma antigen recognized by T-cells (MART)-1, heat shock protein (HSP)-70, beta-human chorionic gonadotropin (HCG) carcinoembryonic antigen (CEA) the ras protein, the p53 protein, Muc1, and prostate specific antigen (PSA).

26. The recombinant Listeria strain of claim 24 , wherein said self antigen and said N-terminal fragment of an ActA protein are expressed from a promoter selected from the group consisting of an hly promoter, a prfA promoter, and a p60 promoter.

27. A method of killing a cell of a Her-2 transformed tumor comprising administering a recombinant Listeria strain comprising a recombinant nucleotide, said recombinant nucleotide encoding a recombinant polypeptide consisting of a PEST-like sequence selected from the sequences set forth in SEQ ID NO: 2-5 fused to a Her-2/Neu tumor antigen or a fragment thereof, thereby killing said cell of said Her-2 transformed tumor.

28. A method of reducing the size of a Her-2 transformed tumor comprising administering a recombinant Listeria strain comprising a recombinant nucleotide, said recombinant nucleotide encoding a recombinant polypeptide consisting of a PEST-like sequence selected from the sequences set forth in SEQ ID NO: 2-5 fused to a Her-2/Neu tumor antigen or a fragment thereof, thereby reducing the size of said Her-2 transformed tumor.

29. A method of treating a subject having a Her-2 transformed tumor comprising administering to said subject a recombinant Listeria strain comprising a recombinant nucleotide, said recombinant nucleotide encoding a recombinant polypeptide consisting of a PEST-like sequence selected from the sequences set forth in SEQ ID NO: 2-5 fused to a Her-2/Neu tumor antigen or a fragment thereof, thereby treating said subject having said Her-2 transformned tumor.

30. A method for overcoming the immune tolerance of a subject to a self antigen-expressing tumor, comprising administering to said subject a composition comprising a recombinant Listeria strain comprising a recombinant nucleotide, said recombinant nucleotide encoding a recombinant polypeptide consisting of a PEST-like sequence selected from the sequences set forth in SEQ ID No: 2-5 fused to a tumor antigen or a fragment thereof, wherein said tumor antigen is a self antigen, whereby said subject mounts an immune response against said self-antigen-expressing tumor, thereby overcoming the immune tolerance of said subject to said self-antigen-expressing tumor.

31. A method of suppressing a formation of a self antigen-expressing tumor in a subject, comprising administering to said subject a composition comprising a recombinant Listeria strain comprising a recombinant nucleotide said recombinant nucleotide encoding a recombinant polypeptide consisting of a PEST-like sequence selected from the sequences set forth in SEQ ID No: 2-5 fused to a tumor antigen or a fragment thereof, wherein said tumor antigen is a self antigen, whereby said subject mounts an immune response against said self-antigen-expressing tumor, thereby suppressing the formation of said self-antigen-expressing tumor in the subject.