Pad2 deficiency promoted Alveolar macrophages (AMs) towards M2 polarization through autophagy. (A) The Pad2-/- and WT mice were infected with 2.5×106 CFU Pseudomonas aeruginosa (PA) Xen-41/mouse, whole animal imaging of bioluminescence was obtained using IVIS XRII system 24 hours after mice challenged with PA. (B) Pad2-/- and WT mice were infected with 2.5×106 CFU PA 19660/mouse for 24 hours, and 0.5 hours after PA challenge, mice were treated with or without 15mg/kg 3MA. Survival rates were monitored for 10 days (n=8/group), and analysis was conducted using Mantel-Cox test. (C) Lung tissue samples were collected 24 hours after PA infection and subjected to H&E staining. (D) BALF was collected from both groups of mice, with or without 3MA treatment, and the levels of inflammation cytokines (TNF-α, IL-6, and IL-10) were determined using ELISA. (E) AMs from Pad2-/- and WT mice were lysed, and the expression of iNOS and CD206 were quantified by western blotting. Data are representative of three independent experiments expressed as means ± SEM. *p < 0.05; **p<0.01 vs WT; ***p<0.001 vs WT; ##p < 0.01 vs Pad2-/-.