CD4+CD25highforkhead box protein 3+ regulatory T lymphocytes suppress interferon‐γ and CD107 expression in CD4+ and CD8+ T cells from tuberculous pleural effusions

• Published in: Clinical and experimental immunology Vol. 175; no. 2; pp. 235 - 245
• Main Authors: Geffner, L., Basile, J. I., Yokobori, N., Sabio y García, C., Musella, R., Castagnino, J., Sasiain, M. C., Barrera, S.
• Format: Journal Article
• Language: English
• Published: Blackwell Science Inc 01.02.2014
• Subjects: CD107; Mycobacterium tuberculosis; Original; pleural effusions; T regulatory; tuberculosis
• ISSN: 0009-9104; 1365-2249
• DOI: 10.1111/cei.12227

Summary Tuberculous pleural effusion is characterized by a T helper type 1 (Th1) profile, but an excessive Th1 response may also cause tissue damage that might be controlled by regulatory mechanisms. In the current study we investigated the role of regulatory T cells (Treg) in the modulation of Th1 responses in patients with tuberculous (TB) pleurisy. Using flow cytometry we evaluated the proportion of Treg (CD4+CD25highforkhead box protein 3+), interferon (IFN)‐γ and interleukin (IL)‐10 expression and CD107 degranulation in peripheral blood (PB) and pleural fluid (PF) from patients with TB pleurisy. We demonstrated that the proportion of CD4+CD25+, CD4+CD25highFoxP3+ and CD8+CD25+ cells were increased in PF compared to PB samples. Mycobacterium tuberculosis stimulation increased the proportion of CD4+CD25low/negIL‐10+ in PB and CD4+CD25low/negIFN‐γ+ in PF; meanwhile, CD25high mainly expressed IL‐10 in both compartments. A high proportion of CD4+CD107+ and CD8+CD107+ cells was observed in PF. Treg depletion enhanced the in‐vitro M. tuberculosis‐induced IFN‐γ and CD4+ and CD8+ degranulation responses and decreased CD4+IL‐10+ cells in PF. Our results demonstrated that in TB pleurisy Treg cells effectively inhibit not only IFN‐γ expression but also the ability of CD4+ and CD8+ cells to degranulate in response to M. tuberculosis.