MIP-3α/CCL20 preferentially attracts sIgD⁻ memory B cells in transmigration chemotaxis assays.

Chemotactic response of B cells to MIP-3α/CCL20 in Transwell chemotaxis assay. MIP-3α/CCL20 (500 ng/mL) or migration buffer was placed in individual lower wells of 24-well Transwell plates, and unfractionated B cells or purified sIgD⁻CD44^high memory B cells were layered into upper wells. The phenotype of medium- and MIP-3α-migrating B cells harvested after a 3-hour incubation at 37°C was compared to that of input B cells using anti–CD19-FITC and anti–IgD-PE MoAbs. The representative dot plots of input cells and transmigrated sIgD^high naive and sIgD⁻ memory subsets of B cells are shown in panel A. Absolute cell numbers (no./count) of naive and memory B cells that transmigrated are given. The percentage of naive and memory B cells that transmigrated toward MIP-3α (■) or migration buffer (□) are shown in panel B. Data represent mean ± SEM values obtained in 6 independent experiments using cells from different donors. Statistical difference between migration of naive and memory B-cell groups was analyzed by unpaired Student t test. The percentage of purified sIgD⁻CD44^high memory B cells toward MIP-3α/CCL20 versus migration buffer is shown in panel C. Data from one representative experiment is shown.