In pigs, expression and amounts of biologically active transforming growth factors (TGFs) at the conceptus-maternal interface increase significantly as conceptuses elongate and begin the implantation process. Before their activation, secreted TGFs are non-covalently associated with their respective, isoform-specific latency-associated peptides (LAPs) which contain the Arg-Gly-Asp (RGD) amino acid sequence that serves as a ligand for numerous integrins. Objectives of this study were to determine if TGF1 increases production of fibronectin by porcine trophectoderm, if porcine trophectoderm adheres specifically to fibronectin and LAP, and if functional interactions between porcine trophectoderm and the two TGF-associated proteins, fibronectin and LAP, are integrin-mediated. Porcine trophectoderm cells (pTr2) were cultured in presence of TGF1, LAP, or pan-neutralizing anti-TGF antibody; TGF specifically increased (P < 0.05) fibronectin mRNA levels, as determined by Northern and slot blot analyses. Immunofluorescence microscopy demonstrated a TGF-induced increase in fibronectin in pTr2 cells. In dispersed cell adhesion assays, adhesion of pTr2 cells to fibronectin was inhibited by an RGD-containing peptide (P < 0.05) and pTr2 cells attached to recombinant LAP but not to an LAP mutant which contained an RGE sequence rather than the RGD site (P < 0.05). Fibronectin- and LAP-coated microbeads induced integrin activation at apical surfaces of both trophectoderm and uterine luminal epithelial cells, as indicated by aggregation and transmembrane accumulation of talin detected with immunofluorescence microscopy. Cell surface biotinylation and immunoprecipitation revealed integrin subunits v and 1 on apical membranes of pTr2 cells. These results suggest multiple effects of TGF at the porcine conceptus-maternal interface, including integrin-mediated conceptus-maternal communication through LAP.