The BAFF-mediated increase of CXCL13-dependent chemotaxis is stronger with memory B cells than with naive B cells. Mock- and BAFF- treated B cells were analyzed for their migration to 250 ng/mL CCL21, 250 ng/mL CXCL12, and 500 ng/mL CXCL13. Input populations and migrated cell populations were stained with CD44-FITC and IgD-PE. Representative dot-plots of input cells (A,B) and transmigrated cells to medium or CXCL13 (C,D) are shown. The numbers of cells in the input and transmigrated populations from each B-cell subset are given in each quadrant (A-D). The percentages of naive (dotted bars) and memory B cells (hatched bars) that specifically migrated to the indicated chemokines are shown in panels E and F for mock- and BAFF-treated cells, respectively. The percentages of total B cells migrating to each chemokine are indicated below the histograms (E,F). Data from one representive experiment of 6 are shown (A-F). The experiment was repeated with samples from 6 different donors, and results are expressed as the mean BAFF-induced percentage increase plus or minus SD of total (■), naive (dotted bars), and memory B cells (hatched bars) that specifically migrated to the indicated chemokines. Basal migration was 4.8% (± 0.8%), 4% (± 0.6%), and 7.6% (± 1.8%) for total, naive, or memory B cells in mock-treated cultures, and 4.9% (± 0.7%), 3.8% (± 1%), and 7.9% (± 2.9%) in BAFF-treated cultures, respectively. (G). *P < .05.