IDENTIFICATION OF POTENTIAL CD8(-CELL EPITOPES OF THE 19 KDA AND AHPCPROTEINS FROM MYCOBACTERIUM-TUBERCULOSIS - NO EVIDENCE FOR CD8(+) T-CELL PRIMING AGAINST THE IDENTIFIED PEPTIDES AFTER DNA-VACCINATION OF MICE() T)

Mycobacterium tuberculosis is one of the major killers among infectiou s agents. It is of great importance to develop an efficient vaccine ag ainst M. tuberculosis since the only available vaccine M. bovis-BCG, h as a low efficacy. Furthermore, the emergence of multi-drug-resistant M. tuberculosis strains makes it difficult to cure the disease, CD8(+) T cells have been implied to play an important role in protective imm unity against M. tuberculosis, A good vaccination strategy for the ind uction of cytotoxic CD8(+) T-cell responses is naked DNA-injection of eukaryotic expression vectors. The use of DNA-injection in an attempt to induce cytotoxic CD8(+) T-cell responses against epitopes of the 19 kDa or AhpC proteins from M. tuberculosis in mice was studied. MHC cl ass I binding assays, of peptides derived from these proteins, demonst rated the presence of potential CD8(+) T-cell epitopes. However, CD8() T-cell responses against the peptides after DNA-injection were not d etected. Furthermore, no difference in the kinetics of bacterial clear ance was observed in vaccinated versus unvaccinated animals, even thou gh 19 kDa and AhpC specific antibodies were readily detected in the se rum of vaccinated animals, Taken together these results suggest that t he 19 kDa and AhpC genes are not good candidates for DNA vaccines agai nst M. tuberculosis. (C) 1998 Elsevier Science Ltd. All rights reserve d.