SR-A and MARCO regulate NM-mediated inflammatory chemokine secretion. (A) After NM stimulation, Bg-PM from SR-A^−/−, MARCO^−/−, and DKO mice (all n = 4) produced enhanced levels of the inflammatory chemokines MIP2 (left panel) and KC (right panel) compared with WT cells. Mouse strains were stimulated with 20 MOI of ethanol-inactivated NM for 16 hours. Levels of MIP2 and KC were measured by ELISA. No chemokine was detected in the untreated groups (data not shown). (B) Enhanced levels of MIP2 (left panel) and KC (right panel) were produced in the peritoneal cavity of SR-A^−/−, MARCO, and DKO mice injected intraperitoneally with 10⁵ CFU of inactivated NM or an equal volume of PBS. After 2 hours, animals were killed and peritoneal lavage performed using 1 mL of PBS. Levels of MIP2 and KC were measured by ELISA. No chemokine was detected in vehicle-injected controls in any mouse strain (data not shown). Statistical significance was assessed by 2-way ANOVA with Bonferroni posttest. One-way ANOVA with Dunnett multiple comparison test was used to assess statistical significance. *P ≤ .05; ***P < .001.