Infection with mutant Salmonella strains and infection of Hfe^−/−Lcn2^−/− double KO mice. Hfe^+/+ and Hfe^−/− macrophages were infected with WT S Typhimurium and various mutants, and bacterial numbers were enumerated by plating of cell lysates (A). Hfe^+/+ and Hfe^−/− mice were intraperitoneally infected with 500 CFU entC mutant S Typhimurium. Hfe^+/+ mice infected with the identical number of WT S Typhimurium served as a comparison. Survival of subgroups was monitored during an observation period of 10 days and compared using the Wilcoxon (Gehan) test (B). P = .001 for Hfe^+/+ WT Salmonella versus Hfe^+/+entC mutant Salmonella, P = .951 for Hfe^+/+entC mutant Salmonella versus Hfe^−/−entC mutant Salmonella. C57BL/6 WT, Hfe^−/−, Lcn2^−/−, and Hfe^−/−Lcn2^−/− mice were infected with 500 CFU of WT S Typhimurium. At day 2 of infection, animals were killed, and the bacterial load in livers (C) and spleens (D) enumerated by plating appropriated dilutions of organ homogenates. Data are presented as detailed in the legend to Figure 3. Primary peritoneal macrophages of the indicated genotypes were infected with S Typhimurium (S Tm) or left untreated (Ctrl.). After 24 hours, the expression of Fpn1, Lcn2, and Actin was determined by Western blot as described in the “Immunoblotting” section of supplemental Methods. One of 3 representative experiments is shown.