Functional expression of B7H1 on pancreatic carcinoma panc-1 cells

AIM: To observe the effect of B7H1 expression in pancreatic carcinoma cells on the proliferation and activation of co-cultured T lymphocytes. METHODS: B7H1 expression in panc-1 cells before and after interferon-γ(IFN-γ) treatment or B7H1-siRNA transfection was evaluated by RT-PCR and flow cytometry. The influence of B7H1 expression on co-cultured PHA-activated T lymphocytes was determined by the methods of MTT and enzyme-linked immunosorbent assay (ELISA). RESULTS: B7H1 was highly expressed in panc-1 cells and up-regulated after IFN-γ stimulation. Such up-regulation led to the significant inhibition of T cell proliferation and secretion of cytokines such as IFN-γ and interleukin-2(IL-2). However, IL-10 production was enhanced. In contrast, knockdown of B7H1 expression in panc-1 cells by RNA interference resulted in increased T cell proliferation as well as IFN-γ and IL-2 production. Meanwhile, the IL-10 secretion decreased. CONCLUSION: B7H1-expressing panc-1 cells suppress T cell function by inhibiting T cell proliferation and production of Th1 cytokines. Suppression of B7H1 expression through siRNA restores T cell immune functions, indicating a potential strategy for immunotherapy against pancreatic cancer.