Organogenic role of B lymphocytes in mucosal immunity

Follicle-associated epithelium (FAE) in the intestinal Peyer's patches cont ains M cells that deliver pathogens to organized Lymphoid tissue. Developme nt of Peyer's patches, FAE, and M cells was found to be impaired in mice th at had no B cells. Transgenic expression of membrane-bound immunoglobulin M restored B cells and FAE development. The Lack of M cells abrogated infect ion with a milk-borne retrovirus. Thus, in addition to secretion of antibod ies and presentation of antigens, B cells are important for organogenesis o f the mucosal immune barriers.