Fas signaling through RANKL in DCs. (A) BMDCs from normal B6, MRL^+/+, and MRL/lpr mice were cultured with RANKL from 0 to 72 hours. Fas expression on the DCs was detected by flow cytometry. Numbers above horizontal lines indicate percentage of Fas⁺ cells. Results are representative of 3 independent experiments. (B) BMDCs from MRL^+/+ and MRL/lpr mice were incubated with anti-Fas mAb, or anti-Fas mAb and RANKL, for 48 hours. Apoptotic cells were detected by flow cytometric analysis. Numbers above horizontal lines indicate percentage of Annexin-V⁺ cells. Results are representative of 3 independent experiments. (C) Apoptotic cells stimulated with anti-Fas mAb (1-100 ng/mL), RANKL (1-100 ng/mL), or RANKL and anti-Fas mAb (100 ng/mL) for 48 hours. B6 (●), MRL^+/+ (○), and MRL/lpr (■) mice are shown. Data are means ± SD of 3 independent experiments. *P > .05; **P > .01. (D) BMDCs (5 × 10⁴ cells) were cultured treated with RANKL (100 ng/mL) and anti-Fas mAb (100 ng/mL) in the presence or absence of inhibitor z-VAD for 48 hours. The expressions of caspase-9, caspase-3, caspase-8, and FLIP_L of the stimulated BMDCs from control mice were analyzed by Western blot. GAPDH was used as a control for loading. Results are representative of 3 independent experiments. (E) FLIP_L expression of RANKL-stimulated BMDCs from MRL^+/+ and MRL/lpr mice was detected by immunoblot. GAPDH was used as a control for loading. Results are representative of 3 independent experiments.