Analysis of Immune Responses against a Wide Range of Mycobacterium tuberculosis Antigens in Patients with Active Pulmonary Tuberculosis

Characterizing host immune responses to molecular targets ofMycobacterium tuberculosis is essential to develop effective im-munodiagnostics and better vaccines. We investigated the immune response against a large series ofM. tuberculosis antigens, including 5 classical and 64 nonclassical (39 DosR regulon-encoded, 4 resuscitation-promoting factor [RPF], and 21 reactiva-tion-associated) antigens in active-pulmonary-tuberculosis (TB) patients. Whole blood from TB patients (n 34) was stimu-lated in vitro withM. tuberculosis antigens. Gamma interferon (IFN-) was measured after 7 days of stimulation, using an en-zyme-linked immunosorbent assay (ELISA). The majority of the study participants responded to the classicalM. tuberculosis antigens TB10.4 (84.8%), early secreted antigenic target-6 kDa (ESAT-6)/CFP-10 (70.6%), and purified protein derivative (PPD) (55.9%). However, only 26.5 % and 24.2 % responded to HSP65 and Ag85A/B, respectively. Of the 64 nonclassical antigens, 23 (33.3%) were immunogenic (IFN- levels,>62 pg/ml) and 8 were strong inducers of IFN- (IFN- levels,>100 pg/ml). The RPF antigens were the most immunogenic. In addition, we observed distinct cytokine expression profiles in response to severalM. tuberculosis antigens by multiplex immunoassay. Tumor necrosis factor alpha (TNF-), interleukin 10 (IL-10), and IL-6 were commonly detected at high levels after stimulation with 4/15 latency antigens (Rv0081, Rv2006, Rv2629, and Rv1733c) and wer