IL-2 rescues CD4XL cells from apoptosis. (A) Time course study of the effect of IL-2 on CD4 cross-linking induced-apoptosis. PBMC treated with or without Leu3a/GAM were cultured in the absence or presence of IL-2 (30 U/mL). Cells were harvested on days 1, 2, and 3 after treatment and analyzed for the percent of A0 cells by flow cytometry. The percentages of A0 cells (% A0) are indicated in the histograms. (B) Comparison of the % A0 cells in CD4XL samples with and without addition of IL-2. The (□) indicate results on day 2 (n = 4) and the (•) indicate results on day 3 (n = 4) after CD4XL. Values of statistical significance determined by paired t test are indicated.