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-b eta) on migration and adhesion characteristics of bovine bronchial epi thelial cells. TGF-beta was a chemoattractant for bronchial epithelial cells; however, prior treatment of primary cultures of bovine bronchi al epithelial cells with TGF-beta did not increase their migration whe n fibronectin, vitronectin, laminin, and type IV collagen were used as attractants in blind-well chamber migration assays. Similarly, treatm ent with TGF-beta reduced the sheet migration of bovine bronchial epit helial cells over matrix-coated dishes. However, treatment of bovine b ronchial epithelial cells with TGF-beta did increase their attachment to matrix-coated dishes. Using antisera to integrins for fibronectin a nd vitronectin, flow cytometry analysis, and immunoprecipitation, we d emonstrated that the expression of these receptors on bovine bronchial epithelial cells was enhanced by TGF-beta. Adhesion to a 60 kd trypti c fragment of fibronectin that is not involved in integrin-mediated ce ll binding was also increased by TGF-beta. Thus TGF-beta has important effects on bronchial epithelial cells that enhance the ability of the se cells to adhere to matrix proteins but not to migrate to these same proteins.