Expression of markers of Th1 differentiation is reduced at the peak of IFN-γ production.

Ifng/Thy1.1 KI mice were infected with P. chabaudi iRBC, and splenocytes were analyzed. (A) Contour plots show expression of CXCR3, T-bet, and RUNX3 gated on CD4+Ifng/Thy1.1+ on days 5, 7, and 9 post-infection. The numbers depicted on the plots are average percentages. Gates were drawn using fluorescence minus one (FMO, CXCR3) or isotype (T-bet, Runx3) controls for each day, as shown to the left. (B) Bar graphs showing percentages of CXCR3, T-bet, and RUNX3 positive cells in Thy1.1+ Teff population on each day. Data is summarized in (C) pie charts of Boolean gating analysis of all possible combinations of CXCR3+, Runx3+, and T-bet+ within CD4+Ifng/Thy1.1+ effector T cells. Ifng/Thy1.1+ T cells expressing all three Th1 markers are shown in black. Two markers are shown in dark grey, and one marker is indicated by light grey. Data are representative of three independent experiments with three animals per timepoint. Statistical significance was obtained using Students t test. Error bar represents SEM; ★p ★★p ns = not significant.