Fig. 4.

Impaired retention of RA-GEF-deficient B cells within the bone marrow. a (Top) Representative B220 and IgM profiles of B220⁺-gated bone marrow cells from WT or RA-GEF B DKO (DKO) mice. (Middle) Cell numbers of IgM^low or IgM^high, B220^low immature B cells, IgM^low, B220^high mature B cells in the bone marrow (n = 5). *¹P < 0.001, *²P < 0.001, *³P < 0.001 versus corresponding WT cells. (Bottom) Representative CXCR4 and VLA-4 profiles of B220⁺ bone marrow cells. b (Top) Representative B220 and IgM profiles of B220⁺-gated blood cells from WT or DKO mice. (Middle) Representative IgM and IgD profiles of B220⁺-gated blood cells. (Bottom) Cell numbers of IgM^high, IgD^low immature and IgM^low, IgD ^high mature B cells from B220⁺-gated blood cells (n = 5). *¹P < 0.001, *²P < 0.001 versus corresponding WT cells. c (Top) Representative IgM and CD43 profiles of B220^low, IgM⁻-gated cells (progenitor B cells) from the bone marrow of WT or DKO mice. (Bottom) Cell numbers of IgM⁻, CD43^low pre-B and IgM⁻, CD43 ^high pro-B cells from B220^low, IgM⁻-gated bone marrow cells (n = 5). *P < 0.001 versus corresponding WT cells. d (Top) Representative CD21 and CD23 profiles of B220⁺-gated spleen cells from WT or DKO mice. (Bottom) Cell numbers of CD21⁻, CD23⁻ immature, CD21^high, CD23 ^low marginal zone (MZB) and CD21^high, CD23 ^high follicular (FOB) B cells from B220⁺-gated spleen cells (n = 3). *¹P < 0.001, *²P < 0.001 versus corresponding WT cells. e (Left) Lysates from WT or DKO B cells stimulated with CXCL12 at the indicated times were subjected to the pull-down assay. Bound Rap1 (Rap1-GTP) and total Rap1 were detected with anti-Rap1. (Right upper) Displacement of WT or DKO B cells was measured on VCAM-1 with or without CXCL12 (n = 30). (Lower) Representative tracks of WT or DKO B cells with CXCL12 are shown. Each line represents a single-cell track. Each bar graph represents the means ± SEM