Transforming Growth Factor-beta Increases Adhesion but Not Migration of Bovine Bronchial Epithelial Cells to Matrix Proteins

We have evaluated the effect of transforming growth factor-beta (TGF-beta) on migration and adhesion characteristics of bovine bronchial epithelial cells. TGF-beta was a chemoattractant for bronchial epithelial cells; however, prior treatment of primary cultures of bovine bronchial epithelial cells with TGF-beta did not increase their migration when fibronectin, vitronectin, laminin, and type IV collagen were used as attractants in blind-well chamber migration assays. Similarly, treatment with TGF-beta reduced the sheet migration of bovine bronchial epithelial cells over matrix-coated dishes. However, treatment of bovine bronchial epithelial cells with TGF-beta did increase their attachment to matrix-coated dishes. Using antisera to integrins for fibronectin and vitronectin, flow cytometry analysis, and immunoprecipitation, we demonstrated that the expression of these receptors on bovine bronchial epithelial cells was enhanced by TGF-beta. Adhesion to a 60 kd tryptic fragment of fibronectin that is not involved in integrin-mediated cell binding was also increased by TGF-beta. Thus TGF-beta has important effects on bronchial epithelial cells that enhance the ability of these cells to adhere to matrix proteins but not to migrate to these same proteins.