We have investigated the effects of nine CC chemokines, i.e. macrophage inflammatory protein (MIP)-1alpha/CCL3, MIP-1beta/CCL4, MIP-3alpha/CCL20, MIP-5/CCL15, monocyte chemotactic protein (MCP)-1/CCL2, MCP-2/CCL8, MCP-3/CCL7, eotaxin/CCL11 and macrophage-derived chemokine (MDC)/CCL22 on the locomotion of human tonsil B lymphocytes and their subsets. Upon isolation, B cells were poorly responsive, but, following short-term culture, they displayed statistically significant chemotactic responses (P < 0.001) to MIP-1alpha, MIP-5, MCP-1, MCP-2, MCP-3 and MDC. CC chemokine receptor (CCR) 1 to CCR6 were up-regulated after culture. MIP-1beta, MIP-3alpha and eotaxin did not stimulate B cell migration. Scattered information is available on B cell subset responses to chemokines. Therefore, we investigated the effects of MIP-1alpha, MIP-5, MCP-1, MCP-2, MCP-3 and MDC on the in vitro locomotion of non-germinal center (GC) (CD38(-)) and GC (CD38(+)) B cells. All chemokines enhanced significantly (P < 0.001) the migration of the former, but not of the latter, cells. CCR1, CCR2 and CCR4 were detected by flow cytometry on non-GC (i.e. naive and memory) B cells, whereas they were absent (CCR1 and CCR2) or poorly expressed (CCR4) on GC B cells.