Effect of human pancreatic cancer cell supernatant on expression of TIM-3 and function of dendritic cells / 中国病理生理杂志

ABSTRACT

AIM:To investigate the influence and mechanisms of human pancreatic cancer tumor microenvironments on T-cell immunoglobulin mucin-3 (TIM-3) expression and function of dendritic cells (DCs).METHODS:Tumor-infiltrating dendritic cells (TIDC) and para-carcinoma tissue DCs were isolated by Ficoll-Hypaque density centrifugation from trypsinized pancreatic carcinoma tissues, and the peripheral blood mononuclear cells were isolated from pancre-atic cancer patients or healthy people.The expression of TIM-3 on DCs was detected by flow cytometry.DCs isolated from healthy people peripheral blood mononuclear cells were induced by rhGM-CSF and IL-4.The expression of TIM-3 in the DCs treated with the culture supernatants of Capan-2, SW1990 and Panc-1 pancreatic cancer cells or human skin fibroblast (Hs27) cells for 48 h, and in the DCs treated with supernatants of Capan-2 cells, anti-VEGF-R2, anti-IL-10 and EP2 re-ceptor blocking peptide were evaluated by flow cytometry.The releases of IFN-βand IL-12 in the culture supernatants of DCs pretreated with monoclonal antibody ( mAb) to TIM-3 or DNase+RNase, followed by stimulation with apoptotic Ca-pan-2 cells, were detected by ELISA.RESULTS:DCs in tumor microenvironments had higher expression of TIM-3 than the DCs from para-carcinoma tissues and pancreatic cancer patient or healthy people peripheral blood ( P<0.01 ) .TIM-3 expression in the DCs treated with the culture supernatants of Capan-2, SW1990 and Panc-1 pancreatic cancer cells for 48 h was much higher than that in Hs27 cells (P<0.05).Treatment with a combination of anti-VEGF-R2, anti-IL-10 and EP2 receptor blocking peptide largely diminished the upregulation of TIM-3 on the DCs mediated by Capan-2 cell superna-tants (P<0.05).The concentrations of IFN-βand IL-12 in the DCs with high expression level of TIM-3 were lower than those in the DCs with low TIM-3 expression level.Treatment with mAb to TIM-3 resulted in much more IFN-βand IL-12 releases (P<0.01), but DNase+RNase made this effect disappear.CONCLUSION:TIM-3 serves as a negative regula-tor of DCs innate immune responses in the pancreatic cancer microenvironments.The secretion of soluble factors to tumor microenvironment by pancreatic cancer cells, including IL-10, VEGF and PGE2 , may contribute to the regulation of TIM-3 expression.