FIGURE 3.

Effect of protein tyrosine kinase (PTK) inhibitors on the stimulatory effect of immunoglobulin D (IgD) in CD4⁺ T cells. Human CD4⁺ T cells were cultured with IgD (3 μg/ml) and inhibitors herbimycin A (HA; 1 μmol/l) or A770041 (0.5 μmol/l) for 24 h. Trypan blue-labeled CD4⁺ T cells in each group indicated that cells were 98% viable. (A) Proliferation of CD4⁺ T cells, as detected by CCK-8. Flow cytometry was used to analyze the proportions of CD69⁺ (B) and CD154⁺ (C) in CD4⁺ T cell populations. ^∗P < 0.05, ^∗∗P < 0.01 vs. control; ^#P < 0.05, ^##P < 0.01 vs. IgD (3 μg/ml) group.