CCL4 inhibits CXCL12-induced phosphorylation of the MAPK pathway in bone marrow B cells.

(A) Early- and late-lineage B cells were stimulated with medium alone, CCL4, CXCL12 or prestimulated first with CCL4, and then after 5 minutes, stimulated with CXCL12. The lysates were run on the gel, transferred to membrane, and immunoblotted with antibodies antiphospho-ERK1/2 or antiphospho-p38, followed by reprobing with anti-ERK1/2 or anti-p38 antibodies to verify the amount of proteins on the gels. (B) Densitometric histograms of the Western blot experiments. The fold increases in phosphorylation after stimulation represent mean values ± SD obtained from 2 experiments. *P < .05 paired t test 2-sided, where P represents a statistically significant decrease in ERK1, ERK2, and p38 phosphorylation in cells prestimulated with CCL4.