Attachment and migration of bronchial epithelial cells are important in re-epithelialization after tissue injury. We hypothesized that inflammatory cytokines alter bronchial epithelial cell attachment and migration. To test this hypothesis, we studied the effects of mononuclear-cell-conditioned medium on attachment and migration of bronchial epithelial cells in response to fibronectin in vitro. This medium was prepared from bovine blood mononuclear cells that were stimulated with concanavalin A; it stimulated bronchial epithelial cell migration but inhibited attachment to fibronectin. Sephadex G-75 column chromatography of the medium revealed two peaks of activity for stimulation of migration. Activity in the higher molecular weight peak was partially inhibited by anti-TNF-alpha antibodies. Activity in the low-molecular-weight peak was lipid-extractable, which suggests that it reflected an arachidonate metabolite. We also studied the effect of bovine herpes virus-1 infection on migration of bronchial epithelial cells. Infection with this virus reduced the migration of bronchial epithelial cells; by 6 hours after infection, staining of alpha v beta 3 integrins had become more diffuse and was not localized. Thus, mononuclear cells produce inflammatory cytokines with important effects on the migration of bronchial epithelial cells. Viral infection affects the interactions of bronchial epithelial cells with the extracellular matrix.