Mycobacterium tuberculosis dormancy-associated antigen of Rv2660c induces stronger immune response in latent Mycobacterium tuberculosis infection than that in active tuberculosis in a Chinese population

Abstract

One-third of the world's human population is latently infected with Mycobacterium tuberculosis (M. tb), and adult tuberculosis (TB) is largely caused by the resuscitation of latent M. tb. Rv2660c, an M. tb dormancy-related antigen, is preferentially expressed during latent infection. Identification and characterization of Rv2660c are crucial to understanding host-pathogen interactions and to develop drug target and vaccine candidates. In this study, T-cell and antibody immune responses against recombinant Rv2660c protein were respectively investigated in latent M. tb infection (LTBI) cases, pulmonary tuberculosis (PTB) patients, and healthy individuals (HI). After stimulation with recombinant Rv2660c protein, stronger cellular responses were induced in LTBI cases compared with those in PTB patients or in HI. Meanwhile, Rv2660c stimulated higher levels of IgG, IgG1, and IgG2a antibody titers in LTBI cases compared with those in PTB patients. The results showed that Rv2660c is able to elicit prominent cellular immune responses and strong humoral immunity in a Chinese LTBI population, suggesting that Rv2660c is a potential target to develop new vaccines and drugs to control LTBI.