Figure 7. Nuclear retention of NP—and not NS1—is a key mechanism underlying the anti‐IAV effect of succinate.

• A–C
  Human bronchial epithelial BEAS‐2B cells were infected for 4 h with influenza A/PR/8/34 (H1N1) virus, either wild‐type (PR8 WT; at MOI = 10 (A, B)) or carrying a deletion of the NS1 coding sequence (PR8ΔNS1; at MOI = 4 (C)), and subsequently treated or not for 20 h with 4 mg/ml of succinate (Suc). Expression of NP (A, C) and NS1 (A) proteins was analyzed by confocal immunofluorescence microscopy. Viral proteins are stained in green, DNA in blue and actin in red. For a given antibody, pictures were taken on the exact same day with the same laser power settings. They are representative of three independent experiments; scale bar 10 µM. (B) Neuraminidase (NA) activity in the supernatants of epithelial cells infected by PR8 WT treated or not with succinate. Data are represented as the mean ± SEM of 4 independent experiments. Statistical analysis was performed using the Student’s t‐test, (*P < 0.05).