ABSTRACT
Objective To investigate the phenotypes and percentages of B 10 cells in different tis-sues from wild-type mice and to identify their biological functions .Methods The percentages of B10 cells derived from different tissues of mice and their responses to lipopolysaccharide ( LPS) stimulation were ana-lyzed by flow cytometry .Magnetic-activated cell sorting ( MACS ) and fluorescence-activated cell sorting (FACS) were used to purify B10 cells, CD4+CD25-T cells and Treg cells.CD4+CD25-T cells and Treg cells labeled by CFSE were co-cultured with or without B10 cells, and then their proliferation were evaluated after 72 h.Results (1) A subset of CD19+CD5+CD1dhigh regulatory B cells was identified in spleen , pe-ripheral blood and lymph nodes from wild-type mice , of which the highest frequency was detected in spleen (3.95%±0.79%, P<0.05).The isolated B cells from different tissues were stimulated by LPS , PMA, ionomycin and monensin (L+PIM) in vitro to express IL-10.Among them, splenic CD19+IL-10+B cells showed the highest expression of IL-10 (P<0.05).(2) Prolonged LPS stimulation (48 h) to CD5+CD1dhigh B cells enhanced the expressions of IL-10 (P<0.01).(3) CD19+CD5+CD1dhigh B cells inhibited the prolif-eration of CD4+CD25-T cells in vitro in a dose-dependent manner (P<0.01), but increased the secretion of IL-10 by CD4+T cells (P<0.01) and the proliferation of Treg cells in vitro (P<0.01).Conclusion Com-pared with other tissues , the percentage of B10 cell subset in spleen is the highest in wild-type mouse , and B10 cells subset can be activated through Toll-like receptor ( TLR ) signaling pathway .The responses of CD4+CD25-T cells and Treg cells in co-culture with B10 cells are regulated by B 10 cell subset through an increased IL-10 production .B10 cells might be a useful cell population for the treatment of inflammatory au-toimmune diseases.