Functional Characterization of Murine CD25 Expressing B Cells

B cells are an important part of both innate and adaptive immune system. Their ability to produce antibodies, cytokines and to present antigen makes them a crucial part in defence against pathogens. In this study, we have in naive Naval Medical Research Institute mice functionally characterized a subpopulation of splenic B cells expressing CD25, which comprise about 1% of the total B cell compartment. Murine spleen cells were sorted into two highly purified B cell populations either CD19+ CD25+ or CD19+ CD25-. We found that CD25+ B cells secreted higher levels of IL-6, IL-10 and INF gamma in response to different TLR-agonists, and were better at presenting alloantigen to CD4+ T cells. CD25 expressing B cells spontaneously secreted immunoglobulins of IgA, IgG and IgM subclass and had better migratory ability when compared with CD25- B cells. In conclusion, our results demonstrate that CD25+ B cells are highly activated and functionally mature. Therefore, we suggest that this population plays a major role in the immune system and may belong to the memory B-cell population.