iNKT cells rapidly sense apoptotic cell death and alter their cytokine profile. (A) Plot showing CD69 expression on viable splenic B cells and iNKT cells 5 d after i.v. injection of apoptotic cells or control. (B) Data from supernatants of splenocyte cultures prepared from mice 5 d after injection of apoptotic cells and stimulated with αGalCer for 72 h. IFN-γ and IL-10 measured by ELISA. (C) Intracellular IFN-γ FACS data of splenic CD4⁺ iNKT and NK cells 5 d after injection of apoptotic cells and ex vivo stimulation with PMA/ionomycin/Brefeldin A. (D) IFN-γ measurement of WT and Jα18^−/− splenocytes stimulated with αGalCer as in B, but comparing cells from mice injected with apoptotic cells four times, instead of once. (E) Viable B and T cells in cultures from D measured using propidium iodine exclusion with FACS. Results are expressed as individual mice and mean in A (n = 6) and C (n = 3–16) and mean ± SEM in B (n = 6), D (n = 7), and E (n = 4–7). n.s. = not significant. *, P < 0.05; **, P < 0.01. Data are representative of at least two independent experiments.