Study On The Effects Of Tea Glycoprotein On The Function Of Dendritic Cells

Tea, Camellia sinensis, as the famous maximum beverage, is one of the first set of medicinal herbs documented in ancient Chinese medicinal literature. Suposedly originated from China, a large number of coarse old tea are unmarketable or overstocked. To date, it has been reported that the polysaccharide components from tea have a broad range of nutritional and therapeutic values in lowering blood sugar, lowering blood pressure, lowering blood lipids, slowing heartbeat, aniblood coagulation, antitumor, anti-HIV, protecting blood phase and enhancing human nonspecific immunity.We establish a screening model of DCs in order to illustrate the immune effects of tea glycoprotein (TGP). The main results are listed as follows:1. Investigated the cytotoxity of TGP on bone marrow cells. We found that TGP had not significant inhibition and apoptosis on cell growth and proliferation through cellular morphology, MTT assay and flow cytometry. So it has been proved that TGP can be used in following research for the reason that it has no cytotoxity on bone marrow-derived cells.2. Established the DCs screening model of immunological activity. Cytokines (rmGM-CSF and rmIL-4) and MACS system were used in our research to induce bone marrow-derived cells to dendritic cells. While the morphology and the expression level of surface molecular of DCs were tested. The results showed that the method of gaining high purity of DCs was established stably, and which could used for the following studies.3. Investigate the effects of TGP on the phenotypic and functional of DCs. We observed the sheet-like processes typical morphology of DCs stimulated by TGP. We found that TGP could enhance the expression level of MHCⅡ, CD80, CD83, CD86 and CD40 and there was a concentration-dependent relationship. The phagocytosis of DCs was significantly decreased after treated with TGP.4. Investigated the effect of TGP on the secretion activity of DCs. We found that TGP could enhance the secretion level of nitric oxide and the Th1 related cytokine such as IL-12p70, IL-1βand RANTES but inhibit significantly the IL-10 secretion (p <0.01), besides these effects were dose-depended. These results showed that TGP could impact the secretion activity of DCs.5. Investigated regulatory effects of TGP on the proliferation of T lymphocyte induced by DCs. The results demonstrated that TGP could enhance antigen presenting ability of DCs to syngeneically naive and allogeneically primed T lymphocytes by using MLR examination. The expression level of IL-2, IFN-γand IL-10 of T lymphocyte was enhanced when the regulatory effects of DCs treated with TGP.6. Investigated effects of TGP on the expression of CCR7 and CXCR4 mRNA on DCs. The expression level of the chemotactic receptor CCR7 and CXCR4 mRMA was analyzed by using seim-quantitation PCR method. The results show that the mRNA expression of chemotactic factor receptor of DCs could enhanced by TGP.