Figure 2.
Acutely infected TAP-1−/− mice exhibit defective CD4+ T cell responses. WT, TAP-1−/−, and CD8−/− mice were infected i.p. with 20 ME-49 cysts, and PECs and spleens were harvested on day 7 after infection (peak of CD4+ T cell response). (A) IFN-γ production by CD4+ T cells from PECs and splenocytes was measured by ICS 5 h after restimulation with plate-bound anti-CD3 mAb. The background staining of CD4+ T cells from uninfected animals is shown in the shaded portions of the plots. Numbers represent the percentage of IFN-γ–producing CD4+ T cells. The histograms shown are from one representative mouse per group (n = 3 per group). (B) Frequency of activated (CD44highCD62Llow) CD4+ T cells directly isolated from PECs of day 7–infected versus uninfected mice. Numbers represent the percentage of CD4+ T cells with high or low expression of the indicated surface marker. The histograms and dot plots shown in A and B are gated on CD4+ T cells and are representative of at least four experiments performed. (C) IFN-γ production by MACS-sorted CD4+ T cells from spleens of the animals described. The CD4+ T cells were restimulated with DCs that were exposed to soluble parasite extract (DC-STAg) or T. gondii infected (DC-RH), and the cytokine in 48-h supernatants was measured by ELISA. Values shown are the mean ± SD of the ELISA readings from three mice per group and are representative of three experiments performed. *, P < 0.05; **, P < 0.02.