Fig 1: CLEC5A is critical for P. aeruginosa–induced cell infiltration and inflammation in the lung.WT and Clec5a–/– mice were intratracheally inoculated with median lethal dose (LD50) of P. aeruginosa (Xen41, PAO1 strain); WT mice were injected with DNase I (4 U/mouse) via i.p. route for comparison. (A) Lung tissue was collected at 24 hours after infection for H&E staining. Scale bar: 200 µm. (B) Lung tissue was harvested at 8 hours after infection for measurement of cytokine and chemokine mRNA levels. Data are mean ± SEM (mock: WT, n = 6; WT + DNase 1, n = 5; Clec5a–/–, n = 5; Xen41LD50: WT, n = 4; WT + DNase 1, n = 3; Clec5a–/–, n = 5). (C) BALF was collected at 15 hours after infection, and cytokines and chemokines were quantified by ELISA. Data are mean ± SEM (mock: WT, n = 3; WT + DNase 1, n = 3; Clec5a–/–, n = 3; Xen41LD50: WT, n = 5; WT + DNase 1, n = 5; Clec5a–/–, n = 7). (D) Lung cell suspensions from WT and Clec5a–/– mice were stained with PE/Cy7-conjugated anti-CD45 Ab, PerCP/Cy5.5-conjugated anti-CD64 Ab, APC/Cy7-conjugated anti-IA/IE Ab, BV421-conjugated anti–Siglec-F Ab, BV510-conjugated anti–TNF-a Ab, PE-conjugated anti–pro–IL1ß Ab, APC-conjugated anti–IL-6 Ab, PE-conjugated anti-RANTES Ab to measure intracellular TNF-a, IL-6, pro–IL-1ß, and RANTES in alveolar macrophage (AM?: CD45+CD64+IA/IE+Siglec-F+). Cytokine/chemokine MFIs were normalized to mock for WT and Clec5a–/– mice, and the data (fold change of MFI) are presented as mean ± SEM (mock: WT, n = 3; Clec5a–/–, n = 3; Xen41LD50: WT, n = 4; Clec5a–/–, n = 4). Statistical calculations were performed with 2-way ANOVA. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001.