Mycobacterial SecA2 mutants
View Patent ↗Provided are mycobacteria comprising (a) a mutation that is not in a SecA2 gene that attenuates the virulence of the mycobacteria in a mammalian host, and (b) a mutation in a SecA2 gene that eliminates SecA2 activity. Also provided are mycobacteria that comprise a mutation in a SecA2 gene that eliminates SecA2 activity, where the mycobacteria are not Mycobacterium tuberculosis or Mycobacterium smegmatis . Additionally provided are methods of inducing an immune response in a mammal and methods of inducing an immune response to a pathogenic mycobacterium in a human using the above mycobacterial mutants.
1. An isolated mycobacterium comprising
(a) a mutation in a gene of the mycobacterium controlling production of an amino acid which renders the mycobacterium auxotrophic for lysine; and
(b) a mutation in a SecA2 gene, wherein the mutation eliminates SecA2 activity, wherein the mycobacterium is an M. tuberculosis or an M. bovis BCG.
2. The mycobacterium of claim 1 , wherein the mycobacterium is an M. bovis BCG.
3. The mycobacterium of claim 1 , wherein the mycobacterium is an M. tuberculosis.
4. The mycobacterium of claim 1 , wherein at least one of the mutations was made by genetic engineering methods.
5. The mycobacterium of claim 1 , further comprising a recombinant gene encoding an antigen of a mammalian pathogen operably linked to a promoter that directs expression of the gene when the mycobacterium infects a mammalian cell.
6. The mycobacterium of claim 5 , wherein the pathogen is a virus.
7. The mycobacterium of claim 5 , wherein the pathogen is a bacterium.
8. The mycobacterium of claim 5 , wherein the pathogen is a eukaryotic parasite.
9. The mycobacterium of claim 5 , wherein the mammalian pathogen is a human pathogen.
10. The mycobacterium of claim 6 , wherein the virus is HIV, hepatitis C, herpes, influenza, smallpox, diphtheria, tetanus, measles, mumps, rabies or polio virus.
11. The mycobacterium of claim 7 , wherein the bacterium is a pathogenic mycobacteria or Salmonella sp.
12. The mycobacterium of claim 8 , wherein the eukaryotic parasite is malaria or Leishmania.
13. An isolated mycobacterium comprising
(a) a deletion of the gene encoding nlaA having the sequence set forth in SEQ ID NO:11; and
(b) a mutation in a SecA2 gene, wherein the mutation eliminates SecA2 activity, wherein the mycobacterium is an M. tuberculosis or an M. bovis BCG.
14. The mycobacterium of claim 13 , wherein the mycobacterium is an M. bovis BCG.
15. The mycobacterium of claim 13 , wherein the mycobacterium is an M. tuberculosis.
16. The mycobacterium of claim 13 , wherein at least one of the mutations was made by genetic engineering methods.
17. The mycobacterium of claim 13 , further comprising a recombinant gene encoding an antigen of a mammalian pathogen operably linked to a promoter that directs expression of the gene when the mycobacterium infects a mammalian cell.
18. The mycobacterium of claim 17 , wherein the pathogen is a virus.
19. The mycobacterium of claim 17 , wherein the pathogen is a bacterium.
20. The mycobacterium of claim 17 , wherein the pathogen is a eukaryotic parasite.
21. The mycobacterium of claim 17 , wherein the mammalian pathogen is a human pathogen.
22. The mycobacterium of claim 18 , wherein the virus is HIV, hepatitis C, herpes, influenza, smallpox, diphtheria, tetanus, measles, mumps, rabies or polio virus.
23. The mycobacterium of claim 19 , wherein the bacterium is a pathogenic mycobacteria or Salmonella sp.
24. The mycobacterium of claim 20 , wherein the eukaryotic parasite is malaria or Leishmania.