Figure 1.

T-CD4 T cells rapidly produce high levels of IL-4 and IFN-γ. (A) 2 h after tail vein injection of PBS or 10 μg anti-CD3 antibody, WT and CIITA^Tg mice were killed and blood was collected. Cytokine levels in the serum were determined by ELISA. Each symbol in the histograms represents an individual mouse. (B) Splenocytes from the indicated mice were stimulated with PMA and ionomycin for 5 h, followed by ICS. Plots were gated on NK1.1⁻ CD4 T cells. The percentage of positive cells in each quadrant is shown. (C) Splenic CD4 T cells from WT and CIITA^Tg mice were stimulated with anti-CD3 and anti-CD28 for 2 d. Cytokines in the culture supernatants were determined by ELISA. Results from three independent experiments are shown.