Cytokine-mediated regulation of human B cell differentiation into Ig-secreting cells: Predominant role of IL-21 produced by CXCR5 T follicular helper cells

Abstract

Differentiation of B cells into Ig-secreting cells (ISC) is critical for the generation of protective humoral immune responses. Because of the important role played by secreted Ig in host protection against infection, it is necessary to identify molecules that control B cell differentiation. Recently, IL-21 was reported to generate ISC from activated human B cells. In this study, we examined the effects of IL-21 on the differentiation of all human mature B cell subsets-neonatal, transitional, naive, germinal center, IgM-memory, and isotype-switched memory cells-into ISC and compared its efficacy to that of IL-10, a well-known mediator of human B cell differentiation. IL-21 rapidly induced th..