Immunological responses and epitope mapping by tuberculosis-associated antigens within the RD1 region in Japanese patients

Tuberculosis remains a major global health problem worldwide,and hence there is a need for novel vaccines that better induce cellular-mediated immunity (cmi). in search of a better vaccine target,the quantiferon-tb gold in-tube test (qft-git) and the interferon-γ elispot assay (elispot) were used to compare themagnitude of cmi in patients. results of the elispot assay led to the discovery of specific epitopes within the early secreted antigenic target 6 kda (esat-6) and culture filtrate protein 10 kda (cfp-10) proteins. both peptides showed a strong association with several hla class iidrb1 molecules in the japanese population. using esat-6-specific hla class ii tetramers,we determined that the expression of esat-6-specific cd4+ lymphocytes was significantly decreased in treated patients compared with active patients. in addition,programmed death-1 (pd-1)/killer cell lectin-like receptor g1 (klrg-1) double positive cells were found only in treated patients and not in those with active tb. these data could provide clues for the development of novel tuberculosis vaccines. copyright © 2014 hideaki nagai et al.