Fig. 2: Th17 is the response of recent thymic emigrants in TCR-transgenic 6.5 mice.

a Recent thymic emigrants secrete more IL-17 and less IFN-γ in the infected lungs of 6.5 mice: Left panel: lung-infiltrating HA-specific CD4⁺ T cell population kinetics in infected 6.5 mice. WT mice with adoptively transferred cells served as controls, as described in text. Middle and right panels: CD24 and Qa2 expression profiles of IL-17 or IFN-γ producing lung-infiltrating CD4⁺ T cells in infected 6.5 mice. b–d Thymectomy abolishes the supply of recent thymic emigrants and thymectomized 6.5 mice suffer from severe disease with less IL-17 production: b IL-17 and IFN-γ production with ROR-γt and T-bet induction of lung-infiltrating HA-specific CD4⁺ T cells and c Virus burden in the lungs on day 7. d Body weight loss after infection. Non-thymectomized 6.5 mice served as controls. WT mice with adoptively transferred cells served as another group of control mice, as described in text. Histograms and dot-plots are representatives, and other values are means ± s.d. of at least 3 experiments (n = 6/group; ***p < 0.0001; two-tailed P values for unpaired t-test to compare two groups at a specific time point, Two-way ANOVA for body weight curves).