Fig. 1: Complement plays a vital role in restricting H. pylori gastric colonization.
a Schematic diagram of complement pathways activation. b Schematic illustration of mouse infection analysis. C57BL/6J WT (n = 6) or C3−/− (n = 7) mice were infected by oral gavage with GFP+ H. pylori PMSS1 for two weeks. Stomachs were isolated from infected mice and separated into corpus and antrum pieces and processed to obtain the total bacterial numbers (colony forming units, CFUs) by plating, to enumerate bacteria in glands using microscopy. Bacteria were visualized by GFP expression (green), while gland cells were visualized using a DNA Hoechst stain (blue). c Total bacterial number from gastric antrum (gray) and corpus (red) of infected WT or C3−/− mice normalized to tissue weight (CFUs/g). Gray dotted line, limit of detection. d Percentage of glands occupied by H. pylori in the gastric antrum (gray) and corpus (red) of infected WT or C3−/− mice, determined by analyzing 100 randomly selected isolated glands of each infected mouse. e Number of H. pylori per colonized gland in the gastric antrum (gray) and corpus (red) of infected WT or C3−/− mice. f Gastric pH levels in either antrum or corpus region of both WT and C3−/− mice, in H. pylori free or infected condition. g, h Gastric L-lactate levels were measured using samples for bacterial plating. For all dot plots, each dot represents one mouse sample. For all panels, black bars represent mean of samples. For plot d and e, the box shows the 10th to 90th percentiles of the dataset; the black whiskers represent the maxima and minima of the dataset. The p values were obtained by one-way ANOVA with Tukey’s multiple comparisons test (c, d, e, f), and unpaired two-tailed t-tests (g, h). The significance is indicated as * (p < 0.05); ** (p < 0.01). Source data and exact p values are provided in the Source Data file.
