title: Long-lived immune response to early secretory antigenic target 6 in individuals who had recovered from tuberculosis.
abstract: We sought to understand the persistence and relevance of the long-lived immune response to early secretory antigenic target (ESAT-6) of Mycobacterium tuberculosis in humans. ESAT-6 is recognized by memory cells involved in protection of animals against tuberculosis (TB). Recent reports also showed that ESAT-6 response can be recovered in patients with TB and in those soon after anti-TB therapy. We chose 18 individuals who had recovered from pulmonary TB (some in remission for >5 years), and 14 bacille Calmette-Guérin-vaccinated healthy individuals for this study. The results showed that peripheral blood mononuclear cells of 10 (55.6%) of 18 patients with TB remission responded to ESAT-6 with stimulation indices >3.0, whereas none of the healthy controls responded. Functional analysis showed that 13 (72.2%) of 18 patients with TB remission produced significant amounts of IFN-gamma in response to ESAT-6, whereas only 1 (7.1%) of the 14 healthy control subjects did so. It appears that responses to ESAT-6 can persist in individuals who had recovered from pulmonary TB.
authors.affiliation: Graduate Institute of Immunology, National Taiwan University College of Medicine, Taipei, Taiwan, ROC. wuhsiehb@ha.mc.ntu.edu.tw
authors.forename: B A
authors.initials: BA
authors.lastname: Wu-Hsieh
authors.forename: C K
authors.initials: CK
authors.lastname: Chen
authors.forename: J H
authors.initials: JH
authors.lastname: Chang
authors.forename: S Y
authors.initials: SY
authors.lastname: Lai
authors.forename: C H
authors.initials: CH
authors.lastname: Wu
authors.forename: W C
authors.initials: WC
authors.lastname: Cheng
authors.forename: P
authors.initials: P
authors.lastname: Andersen
authors.forename: T M
authors.initials: TM
authors.lastname: Doherty
mesh_terms: D000328:Adult; D000368:Aged; D000942:Antigens, Bacterial / Q000276:immunology*; D001500:BCG Vaccine / Q000276:immunology; D001426:Bacterial Proteins; D005260:Female; D006801:Humans; D007371:Interferon-gamma / Q000096:biosynthesis; D007963:Leukocytes, Mononuclear / Q000276:immunology; D008213:Lymphocyte Activation; D008297:Male; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000276:immunology*; D013997:Time Factors; D014397:Tuberculosis, Pulmonary / Q000276:immunology*
chemical_list: D000942:Antigens, Bacterial; D001500:BCG Vaccine; D001426:Bacterial Proteins; C093276:ESAT-6 protein, Mycobacterium tuberculosis; D007371:Interferon-gamma