Fig. 2. BATF deficiency in ILCs results in susceptibility to Influenza virus Infection.

(A and B) Batf^fl/fl (WT) and Batf^fl/fl PLZF-cre (cKO) mice were infected with sublethal PR8 influenza virus (50 PFU) and monitored for survival (A) and body weight changes (B) for two weeks after infection. (C-D) BAL was harvested at day 14 from lungs of Batf^fl/fl (WT) and BATF cKO mice given sublethal PR8 influenza infection. Visual appearance (C) and numbers of red blood cells (D) in BAL fluid are shown. (E) The frequency of neutrophils (CD45.2⁺CD11b⁺Ly6G⁺), inflammatory macrophages (CD45.2⁺CD11b⁺CD11c⁻F4/80⁺Ly6C⁺), and inflammatory monocytes (CD45.2⁺CD11b⁺F4/80⁻Ly6C⁺) in the BAL fluids of WT and cKO mice infected with sublethal PR8 virus infection at day 14 (n=3–4 mice per group). (F and G) Lung histology of Batf^fl/fl (WT) and cKO mice infected with sublethal PR8 influenza at the indicated days (F) and inflammatory score of the lungs (G). Scale bar, 100 μm. (H) Tissue virus titers in the lungs of Batf^fl/fl (WT) and BATF cKO mice infected with sublethal PR8 influenza. (I) Quantified total cell number of NP₃₉₆ tetramer positive CD8⁺ T cells in the lung of Batf^fl/fl (WT) and cKO mice at day 9 after influenza virus infection. (J) qRT-PCR analysis of mRNA expression of Il33 and Areg in the lung homogenates after sublethal PR8 virus infection at the indicated days. Data shown as the mean ± SEM. * p < 0.05, ** p < 0.01, *** p < 0.001 (two-tailed unpaired t-test). Each dot represents one mouse. Data are pooled from three (A) or five (B) or two (I) independent experiments or are representative of at least two independent experiments.