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

<p>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 <i>Materials and Methods</i>. Representative flow cytometric plots (<b>A</b>) and a summary of the results (<b>B</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. * <i>p</i><0.05, ** <i>p</i><0.01.