Germfree (GF) mice on a C57BL/6J background were bred and housed in flexible film isolators in the New York University School of Medicine Gnotobiotics Animal Facility29 . Absence of fecal bacteria and fungi was confirmed by aerobic culture in brain heart infusion, sabaraud, and nutrient broth (Sigma) and qPCR for bacterial 16S (UniF340 5′-ACTCCTACGGGAGGCAGCAGT-3′; UniR514 5′-ATTACCGCGGCTGCTGGC-3′) and eukaryotic 18S ribosomal RNA genes (B2F 5′-ACTTCGATGGTAGGATAG-3′; B4R 5′-TGATCGTCTTCGATCCCCTA-3′) through sampling of stool from individual cages in each isolator on a monthly basis. Mono-association with MNV as described in Extended data figure 1 was performed within a dedicated isolator by inoculating 3 male and 3 female GF mice with 3×106 plaque forming units (pfu) of MNV.CR6 from an endotoxin-free stock prepared as described below. MNV mono-associated GF mice (GF+MNV) were bred to each other (F0 generation), and successful transmission to offspring was confirmed by performing a plaque assay on stool collected from 8-10 week old adult progeny (4-5 weeks after weaning) (Extended data figure 1 ). Progeny (F1) was used for experimental analyses or further breeding to generate additional mice for analyses (F2). Absence of bacteria and fungi was confirmed as described above. Control GF mice were bred and maintained in a separate isolator free of MNV. Unless stated otherwise, GF and GF+MNV mice remained in isolators until the time of analyses.
Conventional C57BL/6J wild-type and IFNAR1−/− (B6.129S2-Ifnar1tm1Agt/Mmjax) mice were purchased from Jackson Laboratories and bred onsite in a MNV and Helicobacter-negative specific pathogen free (SPF) animal facility. The absence of segmented filamentous bacteria (SFB) was determined by PCR (SFB736F 5′-GACGCTGAGGCATGAGAGCAT-3′; SFB844R 5′-GACGGCACGGATTGTTATTCA-3′). Age (6-9 weeks) and gender-matched mice were used in all experiments and assigned randomly to experimental groups. Sample size for animal experiments was chosen based on prior data generated in the laboratory. All animal studies were performed according to protocols approved by the NYU School of Medicine Institutional Animal Care and Use Committee (IACUC).
Conventional C57BL/6J wild-type and IFNAR1−/− (B6.129S2-Ifnar1tm1Agt/Mmjax) mice were purchased from Jackson Laboratories and bred onsite in a MNV and Helicobacter-negative specific pathogen free (SPF) animal facility. The absence of segmented filamentous bacteria (SFB) was determined by PCR (SFB736F 5′-GACGCTGAGGCATGAGAGCAT-3′; SFB844R 5′-GACGGCACGGATTGTTATTCA-3′). Age (6-9 weeks) and gender-matched mice were used in all experiments and assigned randomly to experimental groups. Sample size for animal experiments was chosen based on prior data generated in the laboratory. All animal studies were performed according to protocols approved by the NYU School of Medicine Institutional Animal Care and Use Committee (IACUC).
