Figure 4.

T. gondii-infected mice induce long-lived CD4⁺ T cells that are reactivated during sepsis. C57BL/6 mice were infected with 5 cysts of T. gondii or treated with 3% dextran sodium sulfate (DSS) to induce colitis. After 40 days of T. gondii infection or DSS treatment, the animals were subjected to CLP. The frequency of central memory-like (CD4⁺CD44⁺CD62L⁺ or CCR7⁺) (A,B) and effector memory-like (CD4⁺CD44⁺CD62L⁻ or CCR7⁻) (C,D) T cells was quantified in the mesenteric lymph nodes of control, coinfected, and colitis-induced mice. IFN-γ- or TNF-α-producing CD4⁺ T cells were recovered from the mesenteric lymph nodes (E,G) or peritoneal lavage and quantified (F,H). Data are presented as the means ± SEM for 4 animals in three different experiments. The lymphocytes were analyzed using flow cytometry, and statistical analysis was performed using ANOVA followed by Tukey's test; ^*p < 0.05; ^**p < 0.01; ^***p < 0.001.