Fig. 5: Acetate controls IAV replication by enhancing IFN-I induction via the MAVS-TBK1-IRF3 axis in macrophages.

a–c BMDMs were pretreated with 250 μM SA for 24 h and then infected with PR8 (MOI = 2) for 24 h. a Representative images of PR8-infected BMDMs after staining of viral nucleoprotein (NP, blue). b Relative PR8 M1 gene expression to Gapdh in BMDMs (n = 2). c Viral load in the supernatant of infected BMDMs (n = 2). d BMDMs were pretreated with 250 μM SA for 24 h and then infected with PR8 for 3 h, 6 h or 24 h. Relative Ifna1 and Ifnb1 expression to Gapdh was determined (n = 2). e–k BMDMs were pretreated with 250 μM SA for 24 h and then transfected with 200 ng polyI:C for 12 h (e, g, j) or 0.5 h − 1 h (f, h, i, k): (e, g, j) Concentrations of IFN-α2/4 and IFN-β released from BMDMs (n = 2) were determined by ELISA; (f, i, k) The cell lysates were subjected to immunoblot analysis with indicated antibodies. The relative ratios of pIRF3 (Ser396) to total IRF3, pTBK1 (Ser172) to total TBK1 and MAVS monomer to β-Actin were analyzed with ImageJ v2.0 and marked below; (h) Crude mitochondria extracts were prepared from the BMDMs and then subjected to semidenaturing detergent agarose gel electrophoresis (SDD-AGE) and immunoblotted with rabbit anti-MAVS antibody, and the intensity of MAVS aggregation was analyzed with ImageJ v2.0 and marked below. l Mavs^−/− mice were given drinking water with or without 50 mM SA (n = 13 or 12), and then intranasally infected with PR8. Body weights and survival rates were assessed. Results represent three (a–i) or two independent experiments (j–l). Data in (b–e, g, j, l) (changes of body weight) are presented as mean (± SEM), two-tailed Student’s t test (b–e, g, l), one-way ANOVA with Dunnett’s post-hoc test (j). Survival rates shown in (l) are analyzed with Log-rank (Mantel–Cox) test. Significant values are defined by *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001. Source data are provided as a Source Data file.