Down-regulation of CCR6 expression and MIP-3α/CCL20 responsiveness following B-cell Ag receptor cross-linking.

(A) Tonsillar B cells were cultured for 24 or 48 hours in CM alone or in the presence of anti-IgM Ab (5 μg/mL) with or without IL-4 (20 ng/mL). Cells were then analyzed by FACS for cell surface CCR6 expression. Data from 1 representative experiment of 5 are shown. (B) The response to MIP-3α/CCL20 of B cells stimulated for 48 hours with anti-IgM Ab (5 μg/mL), alone or in combination with anti-CD40 MoAb (1 μg/mL) or IL-4 (20 ng/mL), was assessed by F-actin polymerization assay, as described in “Materials and methods.” Representative data from 4 independent experiments are shown.