Figure 6. Reduced Th17 responses in ICOS-KO and ICOS-YF mice correspond to disease severity.

Single cell suspensions of spleen and lung mononuclear cells of WT, ICOS-KO and ICOS-YF mice were prepared at day 14 post-infection and the IL-17 expressing CD4 T cells were detected by intracellular cytokine staining as described in Materials and Methods. Representative flow cytometric plots (A) and a summary of the results (B) are shown. Data are presented as mean ± SD (7 ICOS-WT, 4 ICOS-KO, and 7 ICOS-YF mice) from one representative experiment out of three independent experiments with consistent results. * p<0.05, ** p<0.01.