TLR7/8 agonist (resiquimod) enhances peritoneal B1 and neutrophil recruitment and phagocytosis, whereas TLR4 agonist (LPS) enhances neutrophil recruitment and ROS production. (A) Percentages of neonatal peritoneal neutrophils (PMN) and peritoneal B1 cells from nonseptic sham (normal saline)–pretreated versus poly I:C–pretreated, resiquimod-pretreated, and LPS-pretreated neonatal mice at 24 hours after pretreatment. (B) Percentage (percentage of that cell population that registered greater than the baseline mean fluorescence intensity [expressed <1000 MFI]) of Dil⁺ peritoneal PMN and B1 cells from sham (normal saline)–pretreated versus poly I:C–pretreated, resiquimod-pretreated, and LPS-pretreated neonatal mice 24 hours after pretreatment and 2 hours after cecal slurry adminstration. (C) Percentage (percentage of PMNs that registered greater than the baseline mean fluorescence intensity [expressed <100 MFI]) of ROS production in PMNs from sham (normal saline)–pretreated versus poly I:C–pretreated, resiquimod-pretreated, and LPS-pretreated neonatal mice 24 hours after pretreatment and 2 hours after cecal slurry administration. (D) Percentage (percentage of PMNs that registered greater than the baseline mean fluorescence intensity [greater than 100 MFI]) of ROS production in PMNs from sham (normal saline)–pretreated versus TLR4(LPS)-pretreated neonatal mice 24 hours after pretreatment and measured 30 minutes, 2 hours, and 6 hours after cecal slurry administration. (E) Time course of recruitment of PMNs following TLR4 (LPS) pretreatment measured at 30 minutes, 2 hours, and 6 hours after cecal slurry as compared with sham pretreatment (normal saline). Data shown are representative of 3 separate experiments. Bar graphs represent means with standard deviation (*P < .05 compared with sham; ‡P < .05 as compared with sham and TLR7/8; †P < .05 as compared with all, by Student t test or 1-way ANOVA). In panels D and E, means are shown, with error bars representing SD.