Inflammatory macrophages contraction during resolution is controlled by apoptotic cell death. (A) FACS plot illustrating the gating strategy used for neutrophils (ii, CD115⁻ Gr-1⁺) and Ly-6C^hi monocytes (i, CD115⁺ Gr-1⁺) in the inflamed peritoneal cavity. Quantification of neutrophils (B) as well as Ly-6C^hi monocytes (C) up to day 5 in mice injected with thioglycollate (n = 5 per time). (D) Quantification of annexin V staining in inflammatory macrophages from day 3 to 8 after intraperitoneal administration of thioglycollate (n = 5 per time). (E-F) Ratios of F4/80^int inflammatory macrophages competed after injection into thioglycollate-inflamed peritoneum at day 5 (injected) and recovered at day 8 (recovered). Two competitions are shown: between macrophages derived from WT and CD68-Bcl2 (Mφ-hBcl2^Tg) transgenic mice and between macrophages derived from WT and Bim^−/− mice. Each symbol represents data from 1 mouse. (G) Quantification of F4/80^int inflammatory macrophages in the peritoneal of irradiated recipient mice transplanted with bone marrow from CD68-Bcl2 (Mφ-hBcl2^Tg) or WT mice during a 12-day period after i.p. administration of thioglycollate. (H) Heat maps depict gene expression patterns of mRNA transcripts that mediate or are induced in response to efferocytosis. Three replicates are shown for different macrophage populations.