TLR2-dependent LTC₄ and PGD₂ generation in BMMCs requires cPLA₂α. (A) BMMCs from wild-type (▬) and Pla2g4a-null (▭) mice were incubated for 60 minutes with the indicated concentrations of Pam₃CSK₄. Supernatants were assayed for LTC₄ (left panel) and PGD₂ (right panel) by EIA. The values are the mean ± SEM of 2 independent experiments with 3 separate cultures of each strain of BMMCs (n = 3). (B-C) BALB/c BMMCs were treated with the indicated concentration of UO126 or with DMSO for 15 minutes and stimulated with (■) or without (□) 3 μg/mL Pam₃CSK₄ for 30 minutes. The supernatants were assayed for LTC₄ (left panel) and PGD₂ (right panel) by EIA (B); the values are the mean ± SEM (n = 3). The phosphorylation of ERK-1/2 and cPLA₂α was assessed by Western blotting (C).