The Differential Roles of LFA-1 and Mac-1 in Host Defense Against Systemic Infection with Streptococcus pneumoniae

摘要: Mice deficient in CD18, which lack all four CD11 integrins, have leukocytosis and increased susceptibility to bacterial infection. To determine the effect of deficiencies LFA-1 (CD11a/CD18) or Mac-1 (CD11b/CD18) on host defense against systemic infection, knockout mice were inoculated i.p. with Streptococcus pneumoniae. Increased mortality occurred both −/− (15 17 vs 13 35 wild type (WT), p (17 34 6 25, after 72 h, whereas most deaths within 24–48 h. At 24 21 27 bacteremic, 15 25 WT ( = 0.05); no difference was observed between WT. bacteria recovered from spleens at 2 h 0.03) 0.002) livers 0.001) by No mice, but 0.008) 0.04). Baseline peak leukocyte counts similar WT, elevated . 8 peritoneal neutrophils , not significantly different Histopathologically, animals had bacteremia lymphoid depletion, consistent sepsis. incidence otitis media meningitis/encephalitis 96 Both play important distinct roles S.