Involvement of CCR3 in MAP kinase activation by eotaxin.

Eosinophils were preincubated with blocking monoclonal anti-CCR3 antibodies (7B11) or isotype-specific control antibodies for 30 minutes and stimulated with eotaxin (10⁻⁸ mol/L) for 1 minute. Cytosolic extracts underwent Western blotting with antibodies against dual threonine-tyrosine–phosphorylated ERK2 (α-PT/PY-ERK1/2) (A) or dual threonine-tyrosine–phosphorylated p38 (α-PT/PY-p38) (B). 7B11 blocked the phosphorylation of both ERK2 and p38.