Effect of fibronectin on the production of leukotriene C4 by eosinophils.

The effect of fibronectin on leukotriene C4 (LTC4) production by eosinophils was examined. Eosinophils obtained from patients with bronchial asthma were cultured for 3 h with or without fibronectin and culture supernatants were assayed for LTC4 by specific enzyme immunoassay. LTC4 was produced in a time- and dose-dependent manner in the presence of fibronectin, and maximum production of LTC4 was observed 3 h after addition of 100 micrograms/ml of fibronectin. These results suggest that eosinophils may be activated by interaction with extracellular matrix proteins, including fibronectin, and play a role in the pathogenesis of bronchial asthma.