Setting: DosR regulon genes are considered essential for Mycobacterium tuberculosis dormancy, and their products are demonstrated to have immunogenicity in M. tuberculosis-infected individuals, suggesting that DosR regulon-encoded proteins are suitable targets for vaccines to control the reactivation of dormant M. tuberculosis.
Objective: Prospective analysis of T-cell and antibody responses against DosR regulon-encoded antigens in M. tuberculosis-infected individuals in Japan to identify effective vaccine targets.
Design: T-cell responses against 33 DosR regulon-encoded antigens were investigated in 26 consecutive M. tuberculosis-infected individuals--14 with latent tuberculosis infection (LTBI) and 12 with active pulmonary tuberculosis (PTB)--using enzyme-linked immunosorbent spot assay, and antibody responses in 42 consecutive individuals, 14 with LTBI and 28 with PTB.
Result: Six antigens (Rv0570, Rv1996, Rv2004c, Rv2028c, Rv2029c and Rv3133c) induced stronger T-cell responses in LTBI than in PTB, In contrast, antigen-specific antibody responses to five antigens (Rv0080, Rv1738, Rv2007c, Rv2031c and Rv2032) were found to be stronger in PTB than in LTBI cases.
Conclusion: T-cell responses to six antigens might contribute to natural protection against dormant M. tuberculosis. These antigens are therefore considered to be potential targets of novel vaccines to control M. tuberculosis reactivation in the Japanese population.