Figure 5

Most Th17 cells are ICOS⁺, and ICOS⁺ Th17 cells produce higher IL-17 than ICOS⁻ Th17 cells. Single spleen cells or lung mononuclear cells isolated from IL-10 KO and WT mice before infection (A, B) or at d 7 (C, D) after Cm lung infection (1 × 10³ IFUs) were analyzed by four-color staining on surface CD3ε, CD4 and ICOS and intracellular IL-17A. (A) Representative dot plots of ICOS expression on Th17 cells in spleen and lung before Cm infection. Cells were gated on CD4⁺CD3ε⁺ population. (B) Summary of the percentages of ICOS⁺ and ICOS⁻ Th17 cells (CD3ε⁺CD4⁺IL-17⁺) in total Th17 cells in the uninfected mice. (C) Representative dot plots of ICOS expression on Th17 cells in spleen and lung at d 7 after Cm infection. (D) Summary of the percentages of ICOS⁺ and ICOS⁻ Th17 cells (CD3ε⁺CD4⁺IL-17⁺) in total Th17 cells in the infected mice. (E) The MFI of ICOS⁺ and ICOS⁻ Th17 cells (CD3ε⁺CD4⁺IL-17⁺) after Cm infection. Data are shown as the mean ± SD for each group (n = 4). *p < 0.05; **p < 0.01; ***p < 0.001. Representative data of three independent experiments are shown.