Role of CD80 in stimulating T lymphocyte activation

AIM:To observe biological characteristics of hepatocar- cinoma cells before and after CD80 transfection and to compare the effect of CD80-transfected hepatocarcinoma cells on T lymphocyte activation. METHODS:Retro virus vector carrying CD80 gene was transfected into HepG2 cells to establish CD80- transfected hepatocarcinoma cells(HepG2/hCD80).Flow cytometry(FCM)was performed to detect CDS0 expres- sion in the transfected cells.RT-PCR was used to evalu- ate CD80 expression at mRNA level.In the presence of anti-CD3 mAb,the proliferation of T lymphocyte was observed by MTT.Meanwhile,the expression of activated molecule marker CD25 was analyzed through FCM. RESULTS:A stable cell line HepG2/hCD80 expressing the human CD80 was established.Growth curve showed that the molecule CD80 could obviously decrease the growth of tumor cells.HepG2/hCD80 was evidenced to have a potency to enhance T cell proliferation and up- regulate CD25 expression. CONCLUSION:CD80 transfection can lower ma- lignant phenotype of hepatocarcinoma cells.CD80 transfection has a down-regulatory effect to activated T cells in vitro.