Fig. 2: WNV infection in the GI tract is restricted by type I IFN responses.
Stat1-/- and Ifnar1-/- mice, as well as WT mice treated with either isotype control or blocking IFNAR1 antibodies, were inoculated subcutaneously in the footpad with 102 FFU of WNV. a Immunofluorescent confocal microscopy imaging of duodenal and jejunal cryosections of the GI tract at 4-5 dpi show WNV antigen (red), Paneth and goblet cells (UEA-1, green), EpCAM (white), and nuclei (Hoechst 33258, blue). Scale bar, 100 μm. Data are representative of 4 experiments; from left to right, n = 8, 13, 15, 8, and 8 mice per group. b, c Quantitation of WNV antigen positive cells in different regions along the GI tract was determined as a percentage of total Hoechst 33258-positive cells per field (b) or as a percentage of total EpCAM-positive epithelial cells per field (c). Lines indicate mean values. Data are from 4 experiments; from left to right, n = 13, 15, 8, 12, 8, 11, 11, and 15 per group. d Serum concentrations of 10, 70, and 250 kDa dextrans at 3 h after oral gavage in uninfected or WNV-infected (5 dpi) mice treated with anti-IFNAR1 or isotype control Ab. Data are from 3 experiments with lines indicating mean values; from left to right, n = 9, 6, 16, 16, 9, 6, 16, 16, 9, 6, 8, and 7 mice per group. Statistical analysis, from left to right: (b, c) two-tailed Mann-Whitney test: ****P < 0.0001, **P = 0.0013, **P = 0.0094, ***P = 0.0004 (b); ****P < 0.0001 (c); and (d) two-tailed Mann-Whitney test with Bonferroni correction: ns, not significant, ***P = 0.0006, ***P = 0.0003, **P = 0.0036.
