Chemotaxis of human tonsil B lymphocytes to CC chemokine receptor (CCR) 1, CCR2 and CCR4 ligands is restricted to non-germinal center cells

We have investigated the effects of nine CC chemokines, i.e. macrophage inflammatory protein (MIP)-1α/CCL3, MIP-1β/CCL4, MIP-3α/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-1α, MIP-5, MCP-1, MCP-2, MCP-3 and MDC. CC chemokine receptor (CCR) 1 to CCR6 were up-regulated after culture, MIP-1β, MIP-3α 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-1α, 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.