Fig. 3: Mannose rewires virus-induced mitochondrial dysfunction and inflammatory dysregulation.

a Human primary hNEc and (b) SAEc cells were analyzed the oxygen consumption rates of mitochondria after H1N1 infection and mannose treatment (n = 4 biological repeats). c Human PBMCs were treated with mannose in the indicated concentration for overnight. After treatment, cells were collected and stained with fluorescently labeled antibodies specific for B cell surface markers CD1d before flow cytometry analysis (n = 3 independent donors). d Transcriptomic analysis of H1N1-infected A549 cells suggests decreased inflammatory response whereas enhanced tolerance induction after mannose treatment. Gene set enrichment analysis enrichment plots of the most significant target classes are shown. e Schematic illustration showing the glycolysis/succinate/HIF-1α/ IL-1β axis that mannose interferes with. f The succinic acid level in the supernatant of H1N1-infected cells were determined (n = 4 biological repeats). g The HIF-1α protein expression after mannose treatment was assessed by western blotting in SARS-CoV-2-infected Calu3 cells (0.1 MOI, 24hpi) and H1N1-infected A549 cells (0.1 MOI, 24hpi), respectively. h The mitochondrial membrane potential of H1N1-infected cells were analyzed by flow cytometry after JC-1 dye staining (n = 4 biological repeats). i Experimental design showing the investigation of in vivo inflammation response after oral mannose treatment. H1N1 (400PFU) infected and mannose-treated BALB/c mice were sacrificed on 4dpi for downstream analysis. j The IL-1β amount in the bronchoalveolar lavage (BAL) fluid of mice (n = 4 mice per group) were determined by ELISA. k The amount of succinic acid in mouse lung homogenates (n = 4 mice per group) were detected by ELISA. l The reactive oxygen species (ROS) intensity in the mouse lung were stained with three specific dyes for superoxide. Shown are representative images randomly selected from a pool of images for each group (n = 4 mice/group). The results are qualified as O^-₂, ONOO^-, and ON positive cells per mm³ in four randomly selected areas, respectively. All the results are shown as mean ± SD. One-way ANOVA with Dunnett’s post hoc test was used for (a, b, c, f, g, h, j, k, l). ****P < 0.0001, ***P < 0.001, **P < 0.01, *P < 0.05, and n.s. indicates non-significant. Left part of (d), and (e), and (i) were created with BioRender.com.