12/15-LO and PPARγ are downstream effectors of the PS-dependent enhancement of X-CGD MØ efferocytosis. (A) PBS, PS, or PC liposomes were injected intraperitoneally for 24 hours and RPMØs plated ex vivo for 24 hours in the presence or absence of either GW9662 or PD146176 before efferocytosis assays were performed. Data represent means plus or minus SEM; N = 3 experiments.*P ≤ .005 compared with PS-treated X-CGD. Significant differences demonstrated in Figure 6 were maintained but not designated for clarity. (B) Model: PS-dependent enhancement of efferocytosis is mediated by IL-4–dependent PPARγ activation and production of PPARγ activation ligands by 12/15-LO.