Rgs1 and Gnai2 Regulate the Entrance of B Lymphocytes into Lymph Nodes and B Cell Motility within Lymph Node Follicles

Summary Signaling by G protein-coupled receptors coupled to Gα i assists in triggering lymphocyte movement into and out of lymph nodes. Here, we show that modulating the signaling output from these receptors dramatically alters B cell trafficking. Intravital microscopy of adoptively transferred B cells from wild-type and Rgs1 −/− mice revealed that Rgs1 −/− B cells stick better to lymph node high endothelial venules, home better to lymph nodes, and move more rapidly within lymph node follicles than do wild-type B cells. In contrast, B cells from Gnai2 −/− mice enter lymph nodes poorly and move more slowly than do wild-type B cells. The Gnai2 −/− mice often lack multiple peripheral lymph nodes, and their B cells respond poorly to chemokines, indicating that Gα i1 and Gα i3 poorly compensate for the loss of Gα i2 . These results demonstrate opposing roles for Rgs1 and Gnai2 in B cell trafficking into and within lymph nodes.