Selp−/−, CD169-DTR, Csf2−/− mice, Tg[Hu-miniLCRα1GγAγδβS] Hba−/− Hbb−/− (Berkeley sickle cell mice) and Tg[Hu-miniLCRα1GγAγδβS] Hba−/− Hbb+/− (hemizygous control mice) have been described11 (link),14 (link),17 (link),19 (link). B6.129P2-Lyz2tm1(cre)Ifo/J (LysM-Cre), B6.129P2(SJL)-Myd88tm1Defr/J (Myd88fl/fl) and B6;129S-Tnftm1Gkl/J (Tnf−/−) mice were purchased from The Jackson Laboratory. Tlr2−/− and Tlr4−/− mice were kindly provided by Dr. Eric G. Pamer (Memorial Sloan-Kettering Cancer Center, NY). C57BL/6 CD45.1 and CD45.2 mice were purchased from the National Cancer Institute. Six to eight week old mice were used for experiments. All mice were housed in specific pathogen-free conditions and fed with autoclaved food, and experimental procedures preformed on mice were approved by the Animal Care and Use Committee of Albert Einstein College of Medicine. Germ-free C57/BL6 mice were maintained in sterile isolators with autoclaved food and water in the Gnotobiotic Core of Icahn School of Medicine at Mount Sinai. For fecal transplantation experiments, 100 mg of feces pellets was resuspended in 1 ml of PBS, homogenized, and filtered through a 70 μm strainer. Recipient GF mice were gavaged with 200 μl of the filtrate.