FIG. 7.
Cell cycle reentry and mitogen sensitivity of p130−/−;p107−/− T lymphocytes. (A) p130+/−;p107+/− (solid lines) and p130−/−;p107−/− (dotted lines) purified splenic T cells were stimulated with concanavalin A (3 μg/ml) and incubated in the presence (closed symbols) or absence (open symbols) of murine IL-2 (100 U/ml). S-phase entry was monitored as described in the legend to Fig. 1, and results are presented as the percentage of maximum thymidine incorporation. Similar results were obtained upon stimulation with PMA plus ionomycin (data not shown). Data are representative of two independent experiments. (B) p130+/−;p107+/− (solid bars) and p130−/−;p107−/− (open bars) purified splenic T lymphocytes were either untreated or stimulated with PMA plus ionomycin (ion.) various concentrations of concanavalin A (conA), or plate-bound CD3 antibody. Twenty-eight hours after stimulation (middle of the first S phase), the cultures were pulsed with [3H]thymidine (1 μCi) for 2 h. Results are presented as means ± standard errors of the means. Data are representative of two independent experiments.