Engagement of Toll-like receptor 2 on CD4(+) T cells facilitates local immune responses in patients with tuberculous pleurisy.
BACKGROUND
Although it has been recognized that Mycobacterium tuberculosis contains large amounts of Toll-like receptor 2 (TLR2) ligands, their direct effects on CD4(+) T cells and the clinical implications have not been determined.


METHODS
With the recent finding that activated CD4(+) T cells express TLR2 as a costimulatory receptor, we hypothesized that M. tuberculosis and its components may directly affect CD4(+) T cells by engaging TLR2, thus facilitating the expansion and function of these lymphocytes in tuberculous pleura.


RESULTS
Our results indicate that CD4(+) T cells from the pleural fluid and peripheral blood of patients with tuberculosis show significantly increased TLR2 expression, compared with those from healthy donors. TLR2 ligand activity was also significantly higher in the tuberculous pleural fluid than in the serum from healthy donors or patients with pulmonary tuberculosis. M. tuberculosis TLR2 ligands, 19-kDa lipoprotein, and live bacillus Calmette-Guérin all modulated cytokine production (interferon gamma and interleukin 17), cellular proliferation, survival, and migration of CD4(+) T cells isolated from pleural fluid and activated with anti-CD3 and anti-CD28.


CONCLUSIONS
These data indicate that direct interaction between M. tuberculosis TLR2 ligands and CD4(+) T cells facilitated local CD4(+) T cell immune responses in patients with tuberculous pleurisy.
Chen
Xinchun
X
Shenzhen Clinical Research Center for Infectious Diseases, Shenzhen Third Hospital, Shenzhen, China. chenxinchun@hotmail.com
Zhang
Mingxia
M
Zhu
Xiuyun
X
Deng
Qunyi
Q
Liu
Haiying
H
Larmonier
Nicolas
N
Graner
Michael W
MW
Zhou
Boping
B
D000328:Adult; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D016022:Case-Control Studies; D002465:Cell Movement; D002478:Cells, Cultured; D005260:Female; D005786:Gene Expression Regulation / Q000276:immunology; D006801:Humans; D016209:Interleukin-8 / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000378:metabolism; D051195:Toll-Like Receptor 2 / Q000276:immunology / Q000378:metabolism*; D014396:Tuberculosis, Pleural / Q000276:immunology*; D014397:Tuberculosis, Pulmonary / Q000276:immunology; D055815:Young Adult
D016209:Interleukin-8; C495342:TLR2 protein, human; D051195:Toll-Like Receptor 2