Figure 4. IL-18R, but not IL-1R, is upregulated in CD4⁺T cells upon activation following infection.

(A) Gate strategy and mean percentage of CD44^hiCD4⁺ and T-bet⁺CD44^hiCD4⁺ cells gated on CD4⁺ T splenocytes from non-infected controls and infected B6 mice at day 14 pi. (B) Representative dot plot of IL-1R, IL-18R and T-bet expression, gated on CD44^hiCD4⁺ T cells as in (A). (C) Representative histograms and mean percentages of IL-1R and IL-18R expression, gated on T-bet⁺CD44^hiCD4⁺ T cells, as shown in (A) and (B). (D) Representative dot plot of CD44 and CD62L expression, gated on CD4⁺ T cells and mean percentages of IL-1R and IL-18R expression on CD44^loCD62L⁺, CD44^hiCD62L^- and CD44^hiCD62L⁺ gated on CD4⁺ T cells (n = 3 to 4). Error bars = SEM, *p≤0.05; **p≤0.01; ****p≤0.0001; ns = non significant (two-tailed Student t-test). Data are representative of 3 independent experiments. Kinetics of IL-1β and IL-18 levels in the serum, as well as of the appearance of IFN-γ⁺CD4⁺ T cells in the spleen are shown in Figure 4—figure supplement 1.

Figure 4—figure supplement 1. Kinetics of IL-1β and IL-18 levels in the serum, as well as of the appearance of IFN-γ⁺CD4⁺T cells in the spleen of infected mice.

(A, B) Serum levels of (A) IL-1β and (B) IL-18. (C) Mean percentages of IFN-γ⁺CD4⁺ T cells gated on splenic CD4⁺ T lymphocytes. Symbols represent the mean value of 4 individually analyzed B6 mice, infected ip with 2 × 10³ blood trypomastigotes of the Y strain. Error bars = SEM. Data are representative of 2 independent experiments.