The Ifng/Thy1.1+ T cell population expresses Tfh markers.

Splenocytes from day 7 p.i (A) C57Bl/6J mice were analyzed for expression of CXCR5, Blimp-1, ICOS, SLAM, and BTLA in naïve (CD44loCD127+, grey), IFN-γ+ (black line), and IFN-γ- (dotted line) effector T cells (CD127-) as determined by intracellular cytokine staining. Bar graphs show mean fluorescence intensity (MFI). (B) Contour plots of PD-1 and CXCR5 from Ifng/Thy1.1 knock-in (KI) mice effector T cells (CD4+CD127-, as shown in Fig 2) are gated on naïve T cells from uninfected, Ifng/Thy1.1+, and Ifng/Thy1.1- mice. Bar graph shows percentages of Ifng/Thy1.1+/—subsets out of total effector T cells. (C) Contour plot of IL-21 and CXCR5 expression. (D) Percentages of IL-21 within effector subsets. (E) Histogram showing Bcl6 expression in CXCR5-IL-21+ (C, red box), CXCR5+IL-21+ (C, blue box), and CXCR5+IL-21- (C, green box) subsets relative to naïve and Ifng/Thy1.1- GC Tfh T cells. Bar graph shows average MFI of Bcl6 staining shown for each subset. (F) Contour plots for IFN-γ, IL-21 and IL-10 by intracellular cytokine staining in C57Bl/6J splenocytes day 7 p.i. Data are representative of four independent experiments with 3 mice per group. Statistical significance was obtained using Students t test. Error bar represents SEM; ★p ★★p ★★★p