Produce immunogenic monocyte derived-dendritic cells by Toxoplasma gondii proteins (TUM4P.904)

Abstract

Abstract Background: DCs based immunotherapy is considered as a promising approach for activating immune responses against tumor antigens. It has been believed that TLR ligands derived from microorganisms are more potent in activating DCs. In this study, the effects of Toxoplasma gondii (T.gondii) protein and DNA components on human DCs maturation were evaluated. Method: T.gondii Tachyzoites were obtained by intraperitoneal passage in mice. Protein and DNA components were extracted by relevant kits. Subsequently, protein lysate was fractionated by increasing amounts of ammonium sulfate and after that by ion-exchange chromatography. Protein fractions and DNA components were added to human monocyte derived DCs. After 20h, phenotype markers (CD80, CD83, CD86 and HLA-DR) on DCs were determined by flow cytometry. Also, IL-12p70 and IL-10 concentration in DCs supernatants were evaluated. Ultimately, the effects of different fractions on phagocytosis activity of DCs were compared. Results: We found that T.gondii protein components are more potent in activating DCs than DNA components. Moreover, there is a considerable difference in phenotype markers and phagocytic activity between DCs matured by different protein fractions. Also, the ability of some protein fractions is higher in activating DCs to produce IL-12p70 and lower IL-10. Conclusion: The protein fractions with high ability can be used to produce potent DCs for instructing immune responses against tumor antigens.