Although cervical carcinoma cells may express the human papillomavirus protein E6 and E7, they fail to induce an effective specific cytotoxic T lymphocyte response. Recent studies suggest that expression of CD-80 (B7-1) on tumor cells is effective to induce antitumor immune responses. In our study, CD-80 gene was transfected into human Hela cell line with a CD-80 expression plasmid (B7-1⁺pcDNA₃) by electroporation, then the immunogeneeity of the modified Hela cell was tested in TLMC (tumor lymphocyte mixed culture) system. [3H]thymidine lymphocyte proliferation assays showed that the response of human peripheral blood lymphocytes (PBLS) to CD-80 positive Hela cells demonstrated a substantial increase in cell proliferation compared to the response to control cells. Cocultivatiou of allogeneic PBLs with CD.80 positive tumor cells for three days can induce an increased secretion of IL.2. Our results demonstrate an immunostimulatory effect of CD. 80 expression on cervical cancer cells, which provides a basis for the development of a therapeutic tumor vaccine.