Adoptive transfer of WT CD4⁺ T cells into <i>Cxcr3^−/−</i> mice confers resistance to infection.

<p>(A) Splenocytes from naïve WT mice were sorted for CD4⁺ T cells by magnetic bead separation. Pre-sort and post-sort fractions were stained for CD4 and CD8 to confirm efficacy of the sort. (B) Purified CD4⁺ T cells (5×10⁶) from noninfected mice were adoptively transferred by intravenous injection into <i>Cxcr3^−/−</i> recipients (n = 5 mice per group). Mice were orally challenged 24 hr post-transfer with <i>T. gondii</i> (30 cysts), and survival was monitored. ***, p<0.001 comparing <i>Cxcr3^−/−</i> with <i>Cxcr3^−/−</i>+CD4⁺ T cells. (C–E) Lamina propria leukocytes were isolated from WT, <i>Cxcr3^−/−</i> controls, and <i>Cxcr3^−/−</i> CD4⁺ T-cell recipients at Day 9 post-infection (n = 5 mice per group). (C) Total cells were stained for <i>Toxoplasma</i> surface antigen (SAG)-1 to determine parasite infection. (D) Cells were also cultured in the presence of Brefeldin-A for 6 hours, after which they were surface stained for CD11b, Gr-1, and Ly6G and stained intracellularly forIL-12 and TNF-α. (E) Small intestinal length was compared between WT, <i>Cxcr3^−/−</i>, and <i>Cxcr3^−/−</i> adoptive transfer recipient mice (WT: n = 11; KO: n = 10; Transfer: n = 3). Data are represented as mean +/− SEM, where * p<0.05 and ** p<0.01.