IL16 Promotes Plasma Cell Differentiation

The regulation of terminal differentiation of B cells into plasma cells is influenced by transcription factors, epigenetics, and cytokines. Both human and murine B cells possess the capacity to produce interleukin 16 (IL16), a pleiotropic cytokine that serves as a chemoattractant. Despite its production, the precise role of IL16 in B cells has remained elusive. In this study, we showed that IL16 overexpression promoted primary B cell differentiation into B220 low CD138 + plasma cells. This effect was independent of the secreted form of IL16. The overexpression of IL16 resulted in an increase in the expression of plasma transcription factors Blimp‐1, IRF4, and Xbp‐1, as well as the expression of immunoglobulin genes. Consistently, upon the inoculation of mice with influenza A virus, the absence of IL16 led to a decrease in the number of plasma cells and the production of virus‐specific antibodies. Our data demonstrate that IL16 contributes to the terminal differentiation of B cells to plasma cells.