Figure 5.

Proliferation of highly purified CD4⁺ T cells from CD48-deficient mice in response to T cell receptor stimulation in the presence of PMA. Purified T cells (>98% CD4⁺) were prepared from wild-type (WT, □) and CD48-deficient mice (KO, ■) as described (4) and were incubated at a density of 10⁶ cells/ml in the presence of PMA (10 ng/ml). Con A (A), anti-CD3 mAb 145–2C11 (B), and ionomycin (C) were added at the concentrations indicated on the x axes. All cultures were set up in triplicate and were pulsed with 1 μCi (37 kBq) of [³H]thymidine per well for the last 6–8 hr of the 48-hr incubation period to assay for T cell proliferation. Results are representative of eight independent experiments