Fig. 1

The role of GPCRs in the development of B cells. G2A is highly expressed in pre-B cells, and then down-regulates in pre-B and immature B cells. CXCR4 promotes the retention of precursor B cells within BM, and down-regulation of CXCR4 allows B cells to exit the BM and enter the periphery. Naive recirculating B cells migrate to B cell follicles or EF regions via the CXCL13-CXCR5 axis. The entry of B cells into lymphoid tissue through HEV is mediated by CCR7 and CXCR4. EBI2 and P2RY8 play roles in B cells clustering in follicles and forming GC. In GC, Centroblasts with high expression of CXCR4 are distributed in DZ. When CXCR4 is down-regulated, they enter the LZ to become centrocytes. P2RY8 and S1PR mediate the movement and retention of B cells within GC, ultimately giving rise to memory B cells or PC. MZ B cells and memory B cells are present in the marginal zone. S1PR1, S1PR3, CXCR5, and CB2 mediate the localization and shuttling of MZ B cells within the MZ