Cell adhesion molecules of human dermal fibroblasts play an important role in the processes of wound healing. The effects of tumor necrosis factor- alpha (TNF) on the expression of integrin beta 1 subfamily in human dermal fibroblasts were examined. TNF preferentially induced the expression of alpha 2 beta 1 integrins, receptors for collagen and laminin, in a time and dose dependent manner. Cell attachment to type I collagen increased by the treatment with TNF. However, cell attachment to fibronectin and laminin was not increased. This TNF-induced cell attachment could be reduced significantly by anti-integrin alpha 2 beta 1 antibody. Antibodies against receptors other than alpha 2 beta 1 integrin did not significantly reduce cell attachment. These data suggest that the increased attachment of human dermal fibroblasts to type I collagen appears to be mediated predominantly through the augmentation of integrin alpha 2 beta 1 expression by TNF.