Effect Of DON On The Of Phenotype And Immune Function Of Mouse Bone Marrow-derived Dendritic Cells

Deoxynivalenol?DON?,mainly produced by fusanrium fungi,is considered a very common contaminant in food and foodstuff.DON has immunotoxicity,which can lead to immne dysfunction and harm to health after human and livestock chronic exposure to DON.Dendritic cells?DC?are the most powerful antigen presenting cells,which can activate the specific immune response,and play a crucial role in briging innate and adaptive immunity.Mouse bone marrow-derived DC was cultured with GM-CSF and IL-4.of the effect of DON on phenotype and immune function of DC in lipopolysaccharide?LPS?induce murine bone marrow-derived DC maturation.This implied that DON cause immunosuppression mechanism,to provide the basis of the test for further explaining mycotoxin lead to immnuosuppression mechanism.Test I Culture of murine bone marrow-derived dendritic cells in vtroThe murine bone marrow cells from C57BL/6 mouse were cultured and induced into immature dendritic cells.The cellular morphological changes were observed by inverted microscope.The results showed that after 7 days of culture,under the inverted microscope,the clusters of DC were visible,and there were many dendritie-like processes on the surface of the cultured cells.The expression of CD11c on the surface of DC was about 80%,which can meet the requirements of subsequent test.Test II Effect of DON the phenotype and morphology of murine bone marrow derived dendritic cellsThe cultured cells were treated in experiment 1.Experiment groups were divided into blank group,LPS group and DON group,respectively.The cultured cells were exposed for 6 h to increasing concentrations of DON(125,250,500 ng·mL^-1)before adding LPS(1?g·mL^-1)for further 18 h.In each experiment,untreated cells and cells incubated with LPS,respectively.After 24 h,morphological changes were observed under the inverted microscope,and viability of DCs was measured using the CCK-8 kit,and DCs were phenotypically ananlyzed by FACS.The results showed that the large clusters of DC were formed in LPS group,on which there were many dendritie-like processes.In low concentration and middle concentration of DON,the clusters and dendritie-like processes were formed.But,in high concentration of DON,dendritie-like processes was not formed.LPS did not exert any effect on cell viability?p>0.05?.Low concentration and middle concentration of DON did not exert any effect on cell viability?p>0.05?,but the cell viability was reduced in high concentration of DON?p>0.05?.The phenotypic expression of CD80,CD86,and MHC-? were up-regulated on LPS-stimalted immature dendritic cells.We found that the phenotypic of LPS-induced DCs at the level of low concentration and middle concentration of DON were not changed?p>0.05?.The expression of phenotypic markers?MHC-?,CD80,CD86?were down-regulated?P<0.05?at the high concentration of DON.Test ? Effect of DON on immune function of murine bone marrow-derived dendritic cellsThe cultured cells were treated in experiment 1.Experiment groups were divided into blank group,LPS group and DON group,respectively.The cultured cells were exposed for 6 h to increasing concentrations of DON(125,250,500 ng·mL^-1)before adding LPS(1?g·mL^-1)for further 18 h.In each experiment,untreated cells and cells incubated with LPS,respectively.After 24 h,nitric oxide concentration was determined in culture supernatants.Relative expressions of cytokine were assessed by RT-PCR.Flow cytometry was used to analyze phagocytic ability of FITC-dextran in DC.The results showed that NO concentration in culture supernatants was reduction with in-creasing concentration of DON.The gene expressions of cytokines?IL-6,IL-10,IL-12 and TNF-??and phagocytic ability of FITC-dextran were not significant in Low concentration and middle concentration,however,gene expressions of IL-6,IL-10,IL-12,and TNF-? were reduced,and the phagocytic ability of FITC-dextran were elevated by 12.2%in high concentration of DON.