The immune responses of central and effector memory BCG-specific CD4+ T cells in BCG-vaccinated PPD+ donors were modulated by Treg cells.
Most of the studies evaluating the function of tuberculosis (TB)-specific T cells were only based on the ability to produce cytokines, which may not fully reflect the function of T cells. In the present study, we confirmed that Bacille Calmette Guerin (BCG) could significantly induce cytokine production by CD4(+) T cells from BCG-vaccinated PPD(+) donors. In addition, CD4(+) T cells were activated, divided and proliferated in response to BCG stimulation. Phenotypic analysis showed that IFN-γ(+)CD4(+) T cells displayed CD45RA(-)CCR7(+/-)CD62L(-), indicating that these CD4(+) T cells were central and effector memory cells. The analysis of cytokine profiles demonstrated that most of BCG-specific BrdU(+)CD4(+) T cells produced Th1 cytokines in response to polyclonal stimulation. In addition, we found that regulatory T cells (Treg) suppressed BCG-induced proliferation and IFN-γ production by memory CD4(+) T cells. The suppressive effects of Treg on BCG-specific responses of CD4(+) T cells could be partially reversed by blocking the production of IL-10. Taken together, our results demonstrated that functional central and effector memory BCG-specific CD4(+) T cells could be detected based on the activation, proliferation and division of these cells, and modulated by Treg in PBMCs from BCG-vaccinated PPD(+) donors.
Department of Immunology, Zhongshan School of Medicine, Key Laboratory of Tropical Disease Control Research of Ministry of Education, Sun Yat-sen University, 74 Zhongshan 2nd Road, Guangzhou 510080, PR China.
Li
L
Li
Dan
D
Qiao
Xianlan
X
Zhang
Zhihui
Z
Liu
Changyou
C
Wu
D000328:Adult; D001500:BCG Vaccine / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D049109:Cell Proliferation; D016207:Cytokines / Q000096:biosynthesis / Q000276:immunology; D005260:Female; D006801:Humans; D007109:Immunity / Q000276:immunology*; D007156:Immunologic Memory / Q000276:immunology*; D016130:Immunophenotyping; D007963:Leukocytes, Mononuclear / Q000276:immunology; D008213:Lymphocyte Activation / Q000276:immunology; D008297:Male; D008875:Middle Aged; D009163:Mycobacterium bovis / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*; D018417:Th1 Cells / Q000276:immunology; D014373:Tuberculin / Q000276:immunology*; D014376:Tuberculosis / Q000276:immunology; D055815:Young Adult
D001500:BCG Vaccine; D016207:Cytokines; D014373:Tuberculin