Inflammatory macrophages are severely diminished in Irf8^−/− mice. (A) Peritoneal exudate cells (PECs) from WT and Irf8^−/− mice 4 days after the intraperitoneal injection of TG. Representative data from flow cytometric analysis and Wright-Giemsa stains are shown in the upper panels. The absolute numbers of total PECs and CD11b⁺ F4/80⁺ B220⁻ Ly6G⁻ cells are shown in the bottom bar graphs. Values are mean ± standard deviation from three mice of each genotype. (B) Bronchoalveolar lavage cells. The absolute numbers of CD11c⁺ F4/80⁺ alveolar macrophages are shown in the bar graph. Values are mean ± standard deviation from four mice of each genotype. (**) P < .01 (Student t test). NS, not significant.