Diminished ability of macFoxp1tg mice to mount an acute inflammatory response after chemical peritonitis. (A) Representative flow cytometry of peritoneal leukocytes. Thioglycolate was injected intraperitoneally, and leukocytes were harvested at 24 hours and stained by 2-color flow cytometry to distinguish neutrophil and monocyte/macrophage populations, as described in Document S1, “Flow cytometry.” CD11b^hiLy6G^hiCD49^hiCD90^hiB220^hiNK1.1^hi cells are designated as neutrophils (oval) and CD11b^hiLy6G^midCD49^midCD90^midB220^midNK1.1^mid cells as monocytes/macrophages (rectangular box). (B) Neutrophil and monocyte/macrophage gates were quantified as mean plus or minus SD from peritoneal lavage obtained from 5 mice per genotype. (C) Double staining of peritoneal cells with MOMA-2 and either Gr-1, Mac-3, F4/80, or CD11b. Data represent percentage of gate (mean ± SD) from cells isolated from 3 mice per genotype. (D) Peritoneal lavage cell number (mean ± SD) in wild-type and macFoxp1tg mice 72 hours after intraperitoneal thioglycoate injection. (E) In vitro transmigration assay. Peripheral blood monocytes were harvested 6 hours after intraperitoneal injection of thioglycolate and incubated in Transwell inserts in presence or absence of murine MCP-1. Number of cells per well passing to the bottom chamber was counted (mean ± SD, n = 4-5 per genotype).