Integrin αβ (CD11d/CD18) Modulates Leukocyte Accumulation, Pathogen Clearance, and Pyroptosis in Experimental Typhimurium Infection.

β integrins are critical in host defense responses to invading pathogens and inflammation. Previously, we reported that genetic deficiency of integrin αβ in mice altered outcomes in experimental systemic infections including accelerated mortality in animals infected with serovar Typhimurium. Here, we show that deficiency of αβ results in impaired accumulation of leukocytes in response to peritoneal infection by . Typhimurium, impaired pathogen clearance , defective bacterial elimination by cultured peritoneal macrophages, and enhanced pyroptosis, a cell death process triggered by . -infected animals deficient in αβ had increased levels of peritoneal cytokines in addition to other markers of pyroptosis, which may contribute to inflammatory injury and increased mortality in the context of impaired bacterial killing. These observations indicate important contributions of leukocyte integrins to the host response in experimental infection and reveal previous activities of αβ in bacterial infection.