CTX and PTX stimulate the MCP-1–induced JNK1 and p38 activations, but not the ERK activation.

MonoMac6 cells, untreated or preincubated 4 hours with 250 ng/mL pertussis toxin (PTX) or 10 μg/ml cholera toxin (CTX), were exposed following different time courses to 20 nM MCP-1. The activity and the amount of each MAPK were evaluated as previously described in Figure 1and in “Materials and methods.” The results are representative of 3 experiments.