T Cell Apoptosis Was Inhibited by Fas of Antisense Oligonucleotide

We investigate the effect of specific antisense oligodeoxynucleotide (ASO DN) inhibition of Fas expression on T cell apoptosis induced by gastric carcinoma cell . Fas receptor (Fas) and Fas ligand (FasL) expressed by the gastric carcinoma cell line SGC-7901 and Jurkat T cells were detected by flow cytometry (FCM) and the ability of FasL-inducing T cell apoptosis was tested by co-culture assay in vitro with SGC-7901 cells and Jurkat T cells. The Jurkat cells were transfected with Fas-ASODN using lipofectin, and the effects of Fas-ASODN on Fas mRNA level, Fas expression on T cells surface, and apoptosis were investigated by RT-PCR, FCM and co-culture assay, respectively. SGC-7901 cells expressing functional FasL could induce the apoptosis of Jurkat cells as demonstrated by co-culture assays. After the Jurkat cells were transfected with Fas ASODN, the level of Fas mRNA, the expression rate of Fas and the apoptotic rate induced by gastric carcinoma cells were all decreased. Gastric carcinoma cells expressing FasL can induce apoptosis in Fas-expressing T cells, indicating that transfection of Fas ASODN can partially convert the immune inhibitory condition induced by gastric carcinoma cells. Fas ASODN may be a useful tool in the armamentarium of tumor immune therapy.