Mechanisms Of Immunologic Enhancement Mediated By Polysaccharide From Fruit Of Physalis Alkekengi L. By TLR4 On Surface Of Murine Bone Marrow Dendritic Cell

recently years,polysaccharides immunomodulation activity has become a research focus.Dendritic cells(DC)is known as the strongest antigen-presenting cells(APC)in human immune system at present,its maturing is a important process to activates immune response,while the Toll-Like Receptors(TLRs)expressed on DC is an significance bridge jointting natural immune and adaptive immune responses.Our group have studied on PPSB through experiments,the results show that,PPSB have adjuvant effect in Candida albicans nucleic acid vaccine,and the immunologic enhancement have relation to the phenotypic and functional maturation of murine bone marrow derived dendritic cells(BMDC),and preliminary evidence that PPSB binding to the surface of BMDC via TLR4.With DC as the experiment cell,TLR4 as the receptor,this thesis discussed the mechanism of immunologic enhancement by PPSB.Research results obtained as follows:1.PPSB activate BMDC through MAPKs and NF-?B signaling pathwayWe extraction bone marrow cells of C57BL/6 mice,induced the BMDC by rmGM-CSF and rm IL-4 together,on day 6,then we used PPSB with concentration of10?g/ml,30?g/ml,50?g/ml treated immature BMDC,in order to detect the effect of PPSB on BMDC signaling pathway Western blot was used,and RPMI1640 medium as control group.The results show that,compared with the control group,different concentration of PPSB could increase the level of phosphorylation of MAPKs(including ERK1/2,JNK,p38),NF-?B and I?B?,indicating that PPSB can activate BMDC through MAPKs and NF-?B two signal pathways.2.Immunologic enhancement mediated by PPSB affected by TLR4 on Surface of BMDCIn order to further investigate that PPSB have relation to TLR4 on Surface of BMDC,we extraction TLR4 defect type and wild type C57 BL / 10 mice bone marrow cells,then used PPSB with concentration of 10?g/ml,30?g/ml,50?g/ml treated two types immature BMDC,and analyze them by the following two methods:(1)Detect the level of phosphorylation of MAPKs?NF-?B?I?B? in BMDC,which from WT andTLR4-/-mice.The results showed that,PPSB can activate MAPKs and NF-?B signaling pathway through TLR4 on Surface of BMDC;(2)Detect the effects of PPSB on the level of cytokine secretion in BMDC,derived from WT and TLR4-/-mice.The results showed that,BMDC Secrete IL-4,IL-10,IL-12 and IL-18 induced by PPSB have relation to TLR4 on Surface of BMDC.In conclusion,TLR4 on Surface of BMDC play an important role in immunologic enhancement mediated by PPSB.