Effect Of The Polysaccharide Isolated From The Fruit Of Physalis Alkekengi L. On Immune Function Of Murine Bone Marrow Dendritic Cells

Physalis alkekengi L. is a member of the family of Solanacese,the whole plant can be used as medicine. And it’s fruit has been proved has many functions as heat-clearing, diuresis,anti-cough and so on. The extraction of the fruit(PPSB)can resist cancers and inhibit the activity of antigen on the surface of a variety of bacteria and viruse.Our laboratory has been studied,PPSB as the adjuvant of DNA vaccine has significant immune-enhancing effect.then studying its internal mechanism that has been found PPSB can induce murine bone marrow dendritic cells(BMDC) maturation,and through the experiment first infered PPSB can combination with BMDC by TLR4.So the question what happened after PPSB binding to TLR4 then caused this significant immune-enhancing effect is the Center of my article.The experiment’s main work is studying on the immune regulation mechanism of PPSB to murine bone marrow dendritic cells, collecting the immature BMDC induced by GM-CSF/IL-4 Through 5 days then for the next experiments:1.The influence of PPSB on BMDC’s phagocytosis: BMDC were stimulated with different concentrations of PPSB,then detect the phagocytosis of BMDC to FITC-dextran with flow cytometry. The result shows that PPSB can significantly decresae the endocytosis of BMDC and promote its functions maturation2.PPSB and PE-TLR4/MD-2 competition combined with BMDC: BMDC was incubated with different concentrations of PPSB, then adding PE-TLR4/MD-2 stimulated the same time, detect the binding rate of PE-TLR4 / MD-2 to BMDC with flow cytometry.Found PPSB can inhibit PE-TLR4 / MD-2 binding to BMDC, that proved PPSB’s binding site is TLR4 once more.3.The influence of PPSB on BMDC’s Secretory function about IL-10,IL-12 and MIP-1α: BMDC were stimulated with different concentrations of PPSB,then centrifuging and collecting the supernatant of each group, ELISA detect the Concentration of IL-10,IL-12 and MIP-1α.The result shows that PPSB can promote BMDC secreting cytokines like IL-10,IL-12 and MIP-1α, and has a dose-dependent manner.The experiment shows that PPSB can binding to BMDC through TLR4 on its surface,and significantly enhance its function of immune, promote Th0 to Th1 and Th2. All the above results laid a solid foundation for the further study on PPSB’s immune regulation molecular mechanism.