Follicular stromal cells and lymphocyte homing to follicles

Abstract

Follicular dendritic cells (FDCs), the best defined stromal cell subset within lymphoid follicles, play a critical role in presenting intact antigen to B lymphocytes. The discovery that many follicular stromal cells make B-lymphocyte chemoattractant (BLC), a CXC chemokine that attracts CXCR5+ cells, provides a basis for understanding how motile B cells come into contact with stationary FDCs. Here we review our work on BLC and discuss properties of BLC-expressing follicular stromal cells. We also review the properties of primary follicle and germinal center FDCs and suggest a model of FDC development that incorporates information about BLC expression. Finally, we consider how antigen recognition causes T and B lymphocytes to undergo changes in chemokine responsiveness that may help direct their movements into, or out of, lymphoid follicles.