Fig. 1

IgM⁺ IgD⁻ B cells in human GALT and peripheral blood (PB). (A) Representative flow cytometry plots of IgM and IgD expression on CD19⁺, CD38^Low/− B cells from human tonsil, appendix, and PB. Gating strategy for cell surface phenotype analysis (Supplementary Fig. 1). (B) Frequency of IgM⁺IgD⁻ B cells in tonsil, appendix and PB. N (tonsil) = 44, (appendix) = 39, (PB) = 17. Results are presented as mean ± SEM; two-tailed unpaired Student’s t-test, ^****P = 0.0001.