Figure 1. Peritoneal B cell IL-10 production.
(A) IL-10 expression by CD19+ B cells within the peritoneal cavity (PC), mesenteric lymph nodes (MLN), colonic lamina propria (LP), and Peyer's patches (PP). B cells isolated from either wild type or IL-10−/− mice were stimulated ex vivo with LPS, PMA, ionomycin and monensin (L+PIM) for 5 h before cell surface CD19 and cytoplasmic IL-10 immunofluorescence staining with flow cytometry analysis. Positive IL-10 gating was established using IL-10−/− or wild type B cells that were incubated with monensin alone with similar results. Numbers indicate cell frequencies within the indicated gates. Bar graphs show mean (±SEM) IL-10-competent B cell frequencies (n=4-8 mice per group). (B) The lamina propria (LP) and intraepithelial lymphocyte (IEL) subsets include B10 cells. IL-10+CD19+ B cells were identified as in (A) among B cell subsets isolated from the colon and small intestine. Bar graphs show mean (±SEM) IL-10-competent B cell frequencies (n=4 mice per group). Differences between tissues were not significant. (C) Peritoneal cavity and spleen IL-10+ B cell phenotypes. IL-10+CD19+ B cells identified as in (A) are shown (thick empty lines) in comparison with IL-10−CD19+ B cells (thin shaded histograms) and background control mAb staining (dotted lines). MHC class II (MHCII). Histograms represent results from ≥3 mice.