The TLR2 ligand LTA inhibits human blood monocyte chemotactic response to CCL2 and CCL5. (A) Human blood-isolated monocytes were tested for migration toward increasing concentrations of CCL2 (■) or CCL5 (▩) with the use of a multiwell microchemotaxis chamber. (B) Migration was assessed with (□) or without (■) pretreatment with 10 μg/mL LTA. (C) Similar assays were carried out on monocytes exposed to 10nM CCL2 or CCL5 (■), pretreated with LTA in the presence of a neutralizing anti-TLR2 monoclonal antibody (▩) or an isotype control antibody (□). Assays were performed in duplicate; each graph represents the average result from N independent experiments. *P < .05, **P < .01, and ***P < .005.