Chimeric vaccines
The invention provides chimeric proteins and nucleic acids encoding these which can be used to generate vaccines against selected antigens. In one aspect, a chimeric protein comprises an antigen sequence and a domain for trafficking the protein to an endosomal compartment, irrespective of whether the antigen is derived from a membrane or non-membrane protein. In one preferred aspect, the trafficking domain comprises a lumenal domain of a LAMP polypeptide. Alternatively, or additionally, the chimeric protein comprises a trafficking domain of an endocytic receptor (e.g., such as DEC-205 or gp200-MR6). The vaccines (DNA, RNA or protein) can be used to modulate or enhance an immune response against any kind of antigen. In one preferred aspect, the invention provides a method for treating a patient with cancer by providing a chimeric protein comprising a cancer-specific antigen or a nucleic acid encoding the protein to the patient.
1. A DNA vaccine comprising a chimeric vector encoding a fusion protein which comprises an antigen domain comprising at least one epitope inserted between a trafficking domain and a transmembrane domain of a lysosomal membrane polypeptide, wherein the trafficking domain is the luminal domain of a lysosomal membrane polypeptide and directs both membrane and non-membrane proteins to an endosomal/lysosomal compartment in a cell or to a lysosome-related organelle, and a pharmaceutical carrier.
2. The DNA vaccine of claim 1 , wherein the antigen domain is fused in frame with the trafficking domain.
3. The DNA vaccine of claim 1 , wherein the trafficking domain directs both membrane and non-membrane proteins to an endosomal or lysosomal compartment in a cell or to a lysosome-related organelle.
4. The DNA vaccine of claim 1 , wherein the trafficking domain comprises a polypeptide trafficking domain of an endocytic receptor.
5. The DNA vaccine of claim 1 , wherein the lysosomal membrane polypeptide comprises lysosome associated membrane protein (LAMP)-1, LAMP-2, LAMP-3, DC-LAMP, or LIMP polypeptide.
6. The DNA vaccine of claim 1 , wherein the fusion protein further comprises one or more domains selected from the group consisting of: a targeting domain for targeting a protein to a endosomal/lysosomal compartment or lysosome-related organelle; a signal domain; a di-leucine domain; a Tyr motif domain; a proline rich domain; and a Ser-Val-Val domain.
7. The DNA vaccine of claim 6 , wherein the Tyr motif domain comprises the tetrapeptide sequence Tyr-Xaa-Xaa-Xbb, wherein Xaa is any amino acid and Xbb is a hydrophobic amino acid.
8. The DNA vaccine of claim 1 , wherein the compartment or organelle comprises MHC class II molecules.
9. The DNA vaccine of claim 1 , wherein trafficking to the compartment and/or organelle results in processing of the antigen.
10. The DNA vaccine of claim 9 , wherein the processed antigen is expressed on the surface of a cell bound to an MHC class II molecule.
11. The DNA vaccine of claim 1 , wherein the antigen is selected from the group consisting of: a portion of an antigenic material from a pathogenic organism.
12. The DNA vaccine of claim 11 , wherein the pathogenic organism is a virus, microorganism, or parasite.
13. The DNA vaccine of claim 12 , wherein the virus is an HIV virus.
14. The DNA vaccine of claim 1 , wherein the endosomal compartment is selected from the group consisting of: MIIC, CIIV, melanosomes, secretory granule, lytic granule, platelet-dense granule, basophil granule, Birbeck granule, phagolysosome, and secretory lysosome.
15. The DNA vaccine of claim 1 , wherein the chimeric protein elicits an antigen-specific immune response.
16. The DNA vaccine of claim 1 , wherein said compartment or organelle comprises a LAMP polypeptide.
17. A DNA vaccine comprising a chimeric vector encoding a fusion protein comprising an antigen domain comprising at least one epitope inserted between two trafficking domains, wherein the two trafficking domains are the luminal domain of a lysosome associated membrane protein and a polypeptide trafficking domain of an endocytic receptor and a pharmaceutical carrier.
18. The DNA vaccine of claim 17 , wherein the antigen domain is fused in frame with the trafficking domains.
19. The DNA vaccine of claim 17 , wherein the trafficking domains direct both membrane and non-membrane proteins to an endosomal or lysosomal compartment in a cell or to a lysosome-related organelle.
20. The DNA vaccine of claim 17 , wherein the lysosome associated membrane protein comprises lysosome associated membrane protein (LAMP)-1, LAMP-2, LAMP-3, DC-LAMP, or lysosomal integral membrane protein (LIMP) polypeptide.
21. The DNA vaccine of claim 17 , wherein the antigen domain is an antigen domain from a pathogenic organism.
22. The DNA vaccine of claim 21 , wherein the pathogenic organism is a virus, microorganism, or parasite.
23. The DNA vaccine of claim 22 , wherein the virus is an HIV virus.