IgA production requires B cell interaction with subepithelial dendritic cells in Peyer's patches.
Reboldi A, Arnon TI, Rodda LB, Atakilit A, Sheppard D, Cyster JG. IgA production requires B cell interaction with subepithelial dendritic cells in Peyer's patches. Science. 2016 May 13; 352(6287):aaf4822.