FIG 4.

Low-dose intradermal T. congolense infection leads to systemic expansion of CD4⁺ CD25⁺ Foxp3⁺ cells (Tregs). Groups of mice (4 or 5 mice per group) were infected either i.d. or i.p. with 10³ T. congolense parasites. At the indicated days, infected mice were sacrificed, and single-cell suspensions of the spleen and draining lymph nodes were stained with fluorochrome-conjugated antibodies against CD4, CD25, and Foxp3, and the percentages (A, B, C, E, F, and G) and absolute numbers (D and H) of Tregs were assessed by flow cytometry. Panels A, B, E, and F are representative dot plots (percentages and standard deviations [SD]), while panels C and G are line graphs of the means ± SEM of 4 or 5 mice per group. The data presented are representative of 3 different experiments with similar results. Bars show means ± SEM. *, P < 0.05; **, P < 0.01; ***, P < 0.001.