Fig. 7. Altered homeostasis of GALT with increased IgA coated fecal bacteria in Pik3cd^E1020K/+ mice.

(a-h) Analysis of 10–12-week-old naïve wild-type and Pik3cd^E1020K/+ mice. a, Cellularity of mesenteric LN (mLN) and Peyer’s patches (PPs). b, Numbers of GC B cells (B220⁺CD19⁺GL-7⁺FAS⁺) and T_FH cells (CD4⁺B220^—PD-1⁺CXCR5⁺Foxp3^—) in mLN and PPs (wild-type n=5, Pik3cd^E1020K/+ n=6). c, IgA ELISA on fecal wash (n=3 per group). d, Representative contour plots for fecal bacteria (Syto⁺) and percentage of IgA-coated bacteria; right, summary histograms of percentages of IgA-coated bacteria (wild-type n=19, Pik3cd^E1020K/+ n=21). e, Volcano plot of mean fold change IgA scores of coated bacteria in Pik3cd^E1020K/+ versus wild-type mice. f, Top bacterial taxa with differential IgA-coating scores in wild-type versus Pik3cd^E1020K/+. Serial Mann-Whitney U tests were performed on all taxa that were detected in at least four mice from each group and Benjamini-Hochberg q values were calculated (e, f wild-type n=7, Pik3cd^E1020K/+ n=9). g, Faith’s phylogenetic alpha diversity in wild-type (n=8) and Pik3cd^E1020K/+ (n=6) mice (significance analyzed by Unpaired t test). h, Correlation between alpha diversity and overall percentage of IgA-coated fecal bacteria in Pik3cd^E1020K/+ (n=6). Data are representative of 3 independent experiments (a-c, e-h). Data in (d) are pooled from 5 independent experiments. Data in (a-d, g) are expressed as mean ± SEM with each dot indicating one mouse. Significance in (a, b, d) analyzed by Mann-Whitney U test. *P < 0.05; **P < 0.01; ***P < 0.001.