Figure 5.

Ifp35^−/− mice have attenuated clinical symptoms after lethal influenza virus infection

(A–C) Body weight loss (percent) (A), clinical score (B), and survival rate (percent) (C) of C57BL/6J wild-type mice and Ifp35^−/− mice infected with PR8 (2LD₅₀); n = 12.

(D) H&E staining of the lung tissue. Lymphocyte and macrophage infiltration in the multifocal lesions is indicated by black arrow. Fibrin exudation in the alveolar space and alveolar septum is indicated by a red arrow. Degenerative and desquamated bronchial epithelial cells are indicated by a green arrow. Scale bars, 100 μm. The picture is shown as original magnifications ×100.

(E) The pathological score of the lung tissue in Ifp35^−/− mice.

(F and G) Serum TNF and IL-6 (pg/mL) in mice 3 days after PR8 infection, detected by ELISA; n = 5.

(H) qRT-PCR results of PR8 viral genome RNA (nucleoprotein, NP) in the lung tissue of C57BL/6J wild-type mice and Ifp35^−/− mice 3 days after infection; n = 6.

Data in (E)–(H) are mean values ± SEM. Significance in (A) and (B) was calculated with two-way ANOVA with Sidak’s post-test. Significance in (C) was determined using log rank test. Significance in (E)–(H) was assessed by Mann-Whitney U test. ^∗p < 0.05,^∗∗p < 0.01, ^∗∗∗p < 0.001; ns, no significance.