FIG. 3.

ERK function is required for MHC-II-mediated cell death. (A to C) K46 cells were stimulated with biotin-MHC-II (M5/114; 20 μg/ml) plus avidin (20 μg/ml) for the indicated times and detergent lysates prepared. Transfers of SDS-PAGE-fractionated whole-cell lysates were probed with the indicated Abs (n = 4). (D to F) K46 cells were treated with the indicated doses of LY294002, SB203580, or PD98059 as described in Materials and Methods and then stimulated, lysed, and probed as for panels A to C. Cell death was stimulated and measured as for panel C of Fig. 2. Shaded bars denote biotin-anti-MHC-stimulated samples. Open bars denote biotin-anti-FcR-stimulated samples. Error bars represent standard deviations of triplicates (n > 3).