title: Analysis of immune responses against a wide range of Mycobacterium tuberculosis antigens in patients with active pulmonary tuberculosis.
abstract: Characterizing host immune responses to molecular targets of Mycobacterium tuberculosis is essential to develop effective immunodiagnostics and better vaccines. We investigated the immune response against a large series of M. tuberculosis antigens, including 5 classical and 64 nonclassical (39 DosR regulon-encoded, 4 resuscitation-promoting factor [RPF], and 21 reactivation-associated) antigens in active-pulmonary-tuberculosis (TB) patients. Whole blood from TB patients (n = 34) was stimulated in vitro with M. tuberculosis antigens. Gamma interferon (IFN-γ) was measured after 7 days of stimulation, using an enzyme-linked immunosorbent assay (ELISA). The majority of the study participants responded to the classical M. 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-γ levels, >62 pg/ml) and 8 were strong inducers of IFN-γ (IFN-γ levels, ≥100 pg/ml). The RPF antigens were the most immunogenic. In addition, we observed distinct cytokine expression profiles in response to several M. tuberculosis antigens by multiplex immunoassay. Tumor necrosis factor alpha (TNF-α), 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 were found especially in supernatants of the three strong IFN-γ inducers (Rv2629, Rv1009, and Rv2389c). IL-8, IL-6, and IL-17 were exclusively detected after stimulation with Rv0574c, Rv2630, Rv1998, Rv054c, and Rv2028c. In conclusion, in active-pulmonary-TB patients, we identified 23 new immunogenic M. tuberculosis antigens. The distinct expression levels of IFN-γ, TNF-α, IL-6, and IL-10 in response to specific subsets of M. tuberculosis antigens may be promising for the development of immunodiagnostics.
authors.affiliation: Infectious and Noninfectious Diseases Research Directorate, Ethiopian Health and Nutrition Research Institute, Addis Ababa, Ethiopia.
authors.forename: Desta
authors.initials: D
authors.lastname: Kassa
authors.forename: Leonie
authors.initials: L
authors.lastname: Ran
authors.forename: Wudneh
authors.initials: W
authors.lastname: Geberemeskel
authors.forename: Mekashaw
authors.initials: M
authors.lastname: Tebeje
authors.forename: Amelewerk
authors.initials: A
authors.lastname: Alemu
authors.forename: Alemayehu
authors.initials: A
authors.lastname: Selase
authors.forename: Belete
authors.initials: B
authors.lastname: Tegbaru
authors.forename: Kees L M C
authors.initials: KL
authors.lastname: Franken
authors.forename: Annemieke H
authors.initials: AH
authors.lastname: Friggen
authors.forename: Krista E
authors.initials: KE
authors.lastname: van Meijgaarden
authors.forename: Tom H M
authors.initials: TH
authors.lastname: Ottenhoff
authors.forename: Dawit
authors.initials: D
authors.lastname: Wolday
authors.forename: Tsehaynesh
authors.initials: T
authors.lastname: Messele
authors.forename: Debbie
authors.initials: D
authors.lastname: van Baarle
mesh_terms: D000328:Adult; D000942:Antigens, Bacterial / Q000276:immunology*; D002478:Cells, Cultured; D003430:Cross-Sectional Studies; D016207:Cytokines / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007159:Immunologic Tests / Q000379:methods; D007963:Leukocytes, Mononuclear / Q000276:immunology; D008297:Male; D009169:Mycobacterium tuberculosis / Q000276:immunology*; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis / Q000276:immunology*
chemical_list: D000942:Antigens, Bacterial; D016207:Cytokines; C072681:Mycobacterium tuberculosis antigens