Dendritic cell (DC)–specific Toll-like receptor 4 (TLR4) regulates polymorphonuclear leukocyte (PMN) recruitment to peritoneum after cecal ligation and puncture (CLP). Wild-type (WT), global Tlr4-/-, Flox, and DC-Tlr4-/- mice were subjected to CLP without antibiotic treatment. Peritoneal lavage fluid (PLF) was collected 4 and18 hours after CLP. A, Percentage and number of PMNs were measured by flow cytometry. Number indicates percentage of CD11b and Ly6G double-positive cells. The total number of PMNs in the peritoneal cavity is specified as the mean ± standard deviation (SD) for 6 mice per group. Statistical difference was tested using a 2-tailed paired t test. B, Chemokine level in PLF. PLF was collected 4 and 18 hours after CLP. CXCL1, CXCL2, CXCL5, and CCL2 concentrations in PLF were measured by enzyme-linked immunosorbent assay. Data are means ± SD from 8 mice per group from 2 separate experiments. Statistical difference was tested using a 2-tailed paired t test. C, CXCR2 expression on peritoneal PMNs. PLF was collected from out-of-box control mice (Cont) and 4 and 18 hours after CLP. Mean fluorescence intensity (MFI) for CXCR2 expression was measured by flow cytometry. Data are means ± SD for 3 mice in the control group and 6 mice per CLP group. Statistical difference was tested using a 2-tailed unpaired t test.