Plasma cells: finding new light at the end of B cell development

Plasma cells are cellular factories devoted entirely to the manufacture and export of a single product: soluble immunoglobulin (Ig). As the final medi ators of a humoral response, plasma cells play a critical role in adaptive immunity. Although intense effort has been devoted to studying the regulati on and requirements for early B cell development, little information has be en available on plasma cells. However, more recent work-including studies o n genetically altered mice and data from microarray analyses-has begun to i dentify the regulatory cascades that initiate and maintain the plasma cell phenotype. This review will summarize our current understanding of the mole cules that regulate commitment to a plasma cell fate and those that mediate plasma cell function.