Immune escape of human lung carcinoma cell lines mediated by Fas/FasL pathway

AIM: To investigate the expression of Fas/FasL system in human lung carcinoma cell lines (A549, EBC-1, LCSC) and T-lymphocytes (Jurkat), and to search the possibilities of immune escape and counterattack mediated by Fas/FasL pathway in human lung carcinoma cells. METHODS: The protein and mRNA expression of Fas and FasL were detected by FACScan, RT-PCR, respectively. Cell apoptosis was assessed by fluorescent staining. Cell growth was determined by a trypan blue exclusion assay. RESULTS: Fas and FasL were expressed in 3 human lung carcinoma cell lines and T-cells, Jurkat. The lung carcinoma cells inhibited the growth (P0.05) and induced the apoptosis of Jurkat cells in coculture experiments. The growth inhibition was blocked by FasL neutralized antibody, NOK1, in coculture. CONCLUSION: These human lung carcinoma cell lines-induced growth inhibition and the apoptosis of Jurkat cells are mediated by Fas/FasL system. FasL neutralized antibody can effectively prevent the counterattack of carcinoma cells and protect immune system.