Influence of epigallocatechin gallate on the immune function of dendritic cells after ultraviolet B irradiation  

作　　者：DAN LUO, BING RONG ZHOU XIJI 

机构地区：[1]Department of Dermatology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, P. R.China

出　　处：《Journal of Microbiology and Immunology》2007年第2期90-98,共9页中华微生物学和免疫学（英文版）

摘　　要：To investigate the protective effect of epigallocatechin gallate （EGCG） on the immune function of dendritic cells （DCs） after ultraviolet B irradiation （UVB） and its underlying mechanisms, the monocytes were isolated from peripheral blood and cultivated into DCs with cytokines, such as GM-CSF and IL-4. DCs were harvested after cultivation for 7 d and subjected to irradiation with different dosages of UVB. Then, 200 μg/ml of EGCG were added in certain groups immediately after irradiation. DCs simply treated with UVB or treated with both UVB and EGCG were co-cultured with lymphocytes, and MTT assay was used to detect the ability of DCs to stimulate proliferation of lymphocytes. Surface markers CDS0, CD86, HLA-DR and CD40 were detected by flow cytometry, and the levels of IL-10 and IL-12 secreted from DCs 2d h after cultivation were measured by ELISA. It was demonstrated that UVB irradiation could inhibit the ability of DCs to stimulate the proliferation of lymphocytes and surface expressions of CDS0, CD86, HLA-DR and CD40 on DCs in a dose-dependent manner. The inhibition rate of DCs was improved to some extent after treatment with 200μg/ml of EGCG. When the concentra- tion of EGCG exceeded 100 μg/ml, the enhancing effect of EGCG on the expression of the co-stimulating molecules on DCs could be demonstrated in a dose-dependent manner. UVB showed no significant influence on the secretion of IL-10 and IL-12 from DCs, while EGCG could down-regulate the secretion level of IL-12 and up-regulate that of IL-10. It is concluded that EGCG can antagonize the inhibitory effect on DCs induced by UVB irradiation. This function has some relationship with its protecting effect of the expression of the co-stimulating molecule on the surface of DCs and the secretion level of IL-10 and IL-12.To investigate the protective effect of epigallocatechin gallate(EGCG)on the immune func- tion of dendritic cells(DCs)after ultraviolet B irradiation(UVB)and its underlying mechanisms,the monocytes were isolated from peripheral blood and cultivated into DCs with cytokines,such as GM-CSF and IL-4.DCs were harvested after cultivation for 7 d and subjected to irradiation with different dosages of UVB.Then,200μg/ml of EGCG were added in certain groups immediately after irradiation.DCs simply treated with UVB or treated with both UVB and EGCG were co-cultured with lymphocytes,and MTF assay was used to detect the ability of DCs to stimulate proliferation of lymphocytes.Surface markers CDS0,CD86,HLA-DR and CD40 were detected by flow cytometry,and the levels of IL-10 and IL-12 secreted from DCs 24 h after cultivation were measured by ELISA.It was demonstrated that UVB irradiation could inhibit the ability of DCs to stimulate the proliferation of lymphocytes and surface expressions of CDS0,CD86,HLA-DR and CD4 on DCs in a dose-dependent manner.The inhibition rate of DCs was improved to some extent after treatment with 200μg/ml of EGCG.When the concentra- tion of EGCG exceeded 100μg/ml,the enhancing effect of EGCG on the expression of the co-stimulat- ing molecules on DCs could be demonstrated in a dose-dependent manner.UVB showed no significant influence on the secretion of IL-10 and IL-12 from DCs,while EGCG could down-regulate the secretion level of IL-12 and up-regulate that of IL-10.It is concluded that EGCG can antagonize the inhibitory effect on DCs induced by UVB irradiation.This function has some relationship with its protecting effect of the expression of the co-stimulating molecule on the surface of DCs and the secretion level of IL-10 and IL-12.

关 键 词：Epigalloeatechin gallate Ultraviolet B Dendritic cells 

分 类 号：Q5[生物学—生物化学]