Figure 3.

TRIM35 dampens the replication and virulence of IAV. (A) IB analysis of TRIM35 expression in A549 cells transfected with siRNA targeting TRIM35 or with scrambled siRNA for 48 h. (B) Cell viability of siRNA-treated A549 cells as in (A). (C and D) Replication of WSN (H1N1) virus (MOI = 0.1) in siRNA-treated A549 cells as in (A). Supernatants collected at the indicated timepoints were subjected to plaque assay on MDCK cells (C). Virus infected cells were visualized by bright-field microscopy (D). Scale bars, 400 µm. (E) IB analysis of TRIM35 expression in A549 cells transfected with plasmid expressing TRIM35-V5 or control vector. (F) Replication of WSN (H1N1) virus (MOI = 0.1) in TRIM35-overexpressing or control A549 cells as in (E). Supernatants collected at the indicated timepoints were subjected to plaque assay on MDCK cells. (G) Replication of WSN (H1N1) virus (MOI = 0.1) in peritoneal macrophages isolated from Trim35^+/+ and Trim35^−/− mice. Supernatants collected at the indicated timepoints were subjected to plaque assay on MDCK cells. (H and I) Survival (H) and body weight (I) of 6-week-old female Trim35^+/+ and Trim35^−/− mice (n = 6 per group) intranasally infected with WSN (H1N1) virus (2 × 10³ pfu/mouse). (J) Titers of WSN (H1N1) virus, determined by plaque assay, in the lungs of Trim35^+/+ and Trim35^−/− mice on day 3 p.i. as in (H and I). (K and L) Hematoxylin-and-eosin staining (K) or immunohistochemical (IHC) staining (L) of lung sections prepared on day 3 p.i. from Trim35^+/+ and Trim35^−/− mice as in (H and I). Scale bars, 200 µm (K) and 50 µm (L). Data are representative of at least three independent experiments. Means ± SD are shown in (B, C, F, G) (n = 3), and (J) (n = 6). The values for body weights in (I) are means ± SD from live mice. Two-tailed unpaired t-test was used for the statistical analysis, **P < 0.01, ***P < 0.001