Protective Efficacy of Recombinant Proteins Adenylate Kinase, Nucleoside Diphosphate Kinase, and Heat-Shock Protein 70 against Mycobacterium tuberculosis Infection in Mice. |
Seung Heon Lee, Eun Gae Lee, Su Yeon Kim, Sang Nae Cho, Young Kil Park, Gill Han Bai |
1Department of Molecular Biology, Korean Institute of Tuberculosis, Seoul, Korea. gbai@hotmail.com 2Department of Microbiology, Yonsei University College of Medicine, Seoul, Korea. |
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Abstract |
BACKGROUND Priming and boosting vaccination strategy has been widely explored for new vaccine development against tuberculosis. As an effort to identify other vaccine candidates, this study was initiated to evaluate protective efficacy of adenylate kinase (AK), nucleoside diphosphate kinase (NdK), and heat shock protein 70 (Hsp70) of Mycobacterium tuberculosis. METHOD: M. tuberculosis genes encoding AK, NdK, and Hsp70 proteins were amplified by PCR and cloned into E. coli expression vector, pQE30. Recombinant AK, NdK, and Hsp70 was purified through Ni-NTA resin. To evaluate immune responses, we performed enzyme-linked immunosorbent assay (ELISA) for IgG isotype and IFN-gamma after mice were immunized subcutaneously with recombinant proteins delivered in dimethyl dioctadecylammonium bromide (DDA). Immunized- and control groups were challenged by aerosol with M. tuberculosis. The spleens and lungs of mice were removed aseptically and cultured for CFU of M. tuberculosis. RESULT: Vaccination with recombinant proteins AK, NdK, and Hsp70 delivered in DDA elicited significant level of antibody and IFN-gamma responses to corresponding antigens but no protective immunity comparable to that achieved with Mycobacterium bovis BCG. CONCLUSION: Recombinant proteins AK, NdK, and Hsp70 do not effectively control growth of M. tuberculosis in mice when immunized with DDA as an adjuvant. |
Key Words:
Adenylate kinase, Nucleoside diphosphate kinase, Heat shock protein70, Mycobacterium tuberculosis, Protective efficacy |
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