Figure 3.
Effect of the Y500F mutation on IL-4–induced lymphocyte proliferation and gene expression. (A) T cell proliferation. (Left) CD4+ splenic T cells of WT and homozygous Y500F littermate mice were cultured with plate-bound anti-TCRβ mAb (100 ng/ml) and IL-4 as indicated. Proliferation was assessed by 3H-thymidine incorporation. Results are mean responses of triplicate cultures ± SE and are representative of three experiments. (Right) Purified CD4+ T cells were cultured with PMA (25 ng/ml) and ionomycin (1 μM) or with plate-bound anti-TCRβ and IL-2 (100 U/ml). (B) B cell proliferation. (Left) Splenic B cells were cultured with anti-CD40 mAb (1 μg/ml) and IL-4 as indicated. (Right) Splenic B cells were cultured with IL-4 (10 ng/ml), anti-IgM antibodies (10 μg/ml), or IL-4 and anti-IgM antibodies as indicated. (C) IL-4–induced up-regulation of CD23 and MHC class II antigens. Splenic B cells were cultured for 48 h in the absence (thin line) or in the presence (thick line) of IL-4 at 50 ng/ml and then examined for CD23 and I-Ad expression by flow cytometry. Results are representative of five experiments.