Sphingosine-1-phosphate receptor-2 (S1P2)-deficient mice develop diffuse large B cell lymphoma. However, the role of S1P2 in normal germinal center (GC) physiology is unknown. Here we show that S1P2-deficient GC B cells outgrow their wild-type counterparts in chronically-established GCs. We find that S1P2-, G12–G13- and p115RhoGEF-mediated antagonism of Akt regulates cell viability and is required for growth control in chronically proliferating GCs. We also find that S1P2 inhibits GC B cell responses to follicular chemoattractants and helps confine cells to the GC. Moreover, S1P2 overexpression promotes centering of activated B cells within the follicle. We suggest that by inhibiting Akt activation and migration, S1P2 helps restrict GC B cell survival and localization to an S1P-low niche at the follicle center.

Laidlaw et al. show that Ephrin-B1 is a specific marker of mature germinal center (GC) B cells. Use of Ephrin-B1 allows for the identification of phenotypically distinct GC B cell subsets, including a population that may represent memory precursor B cells.

Chemokine receptor CXCR4 promotes B cell localization to CXCL12+ perilymphatic zones and egress from Peyer’s patches.