腺苷受体A2B亚型增加肠黏膜树突状细胞对Crohn’s病的致病性  

Highly expressed adenosine receptor A2B in mucosa dendritic cells is associated with enhanced path- ogenicity of Crohn＇s disease

作　　者：赵嵘[1] 周树民[2] 左爱军[3] 

机构地区：[1]天津市人民医院肛肠四科,300191 [2]天津医科大学第二附属医院检验科 [3]CA91016美国南加州大学

出　　处：《中华微生物学和免疫学杂志》2014年第2期116-122,共7页Chinese Journal of Microbiology and Immunology

摘　　要：目的研究Crohn’S病存在时其肠黏膜树突状细胞（dendriticcell，DC）中腺苷受体（ADOR）A2A及A2B的表达是否发生了变化，及对DC的功能产生了何种影响。方法自不同来源的肠组织中分离肠黏膜pc（mucosaDC，mDC），real—timePCR测定ador-a2a及a2b基因的表达；放射性配体结合实验测定腺苷与mDC的结合能力及受体选择性。选择性激活mDC中的ADOR—A2A及A2B通路，以此DC刺激分离的CIM’细胞，ELISA测定细胞因子的分泌，荧光抗体染色及流式细胞仪分析检测CIM’细胞的分化。分离外周血单个核细胞（PBMC）诱导分化为树突状细胞（Mo-DC），以不同Toll样受体（TLR）的配体进行干预，测定ador—a2a及a2b基因的表达；选择性激活Mo—DC中的ADOR—A2B通路，检测其对CD4’细胞的刺激作用。结果Crohn’s病患者肠黏膜DC中ador—a2b基因的表达显著升高，该受体被激活后可刺激mDC分泌IL-1、IL-6及IL—12，并可促进CIM’细胞向Th1、Th17细胞的分化。TLR2的配体pam3csk4或TLR4的配体LPS可促进Mo—DC中ador—a2b基因的表达；该受体与LPS相协同显著增加Mo—DC的致病性。结论Crohn’S病肠黏膜DC中存在腺苷受体A2B亚型的高表达，该受体可增加mDC的致病功能且其在DC中的表达会受到某些T0u样受体通路的调节。Objective To investigate the expression of adenosine receptor （ADOR） subtypes （A2A and A2B subtypes） in the mucosal dendritic cells （DCs） from patients with Crohn＇s disease and their pathogenic roles. Methods Mucosal DCs （mDCs） were isolated from resected intestine of patients with or without Crohn＇s disease. Some of the mDCs were cultured in vitro and others were used to extract RNA. The expression of ador-a2a and ador-a2b were detected by real-time qPCR. mDCs in culture were treated with selective ADOR-A2A and ADOR-A2B agonists （CGS 21680 and BAY 60-6583） and then the concentration of IL-1, IL-6 and IL-12 in the medium were measured by ELISA. The binding affinities of ADOR-A2A and ADOR-A2B to adenosine were determined by 3H-adenosine in combination with selective ADOR-A2A and A2B antagonists （SCH58261 and MRS1706）. Naive CD4^＋ cells were collected from human umbilical cord blood and co-cultured with mDCs treated by different ADOR agonists to observe T cell responses. The pro- duction of cytokines in culture was measured by ELISA. The polarization of CD4^＋ cells was analyzed by in- tracellular cytokine staining and FACs analysis. Peripheral blood mononuclear cells （PBMCs） were treated with IL-4 and GMCSF to induce the expression of monocyte-derived DCs （Mo-DCs）. Mo-DCs were treated with different toll-like receptor ligands to investigate their effects on the expression of ador-a2a and ador- a2b. Moreover, Mo-DCs were treated with LPS and BAY 60-6583 individually or in the combination to stim- ulate CD4^＋ cells. Then the production of cytokines and the polarization of CD4^＋ cells were evaluated. Re- suits Compared with patients without Crohn＇s disease, patients with Crohn＇s disease showed no change in the expression of ador-a2a but a significantly increased expression of ador-a2b in mCDs （CD-mDCs） , enab- ling to bind more adenosines. Activated ADOR-A2B signaling pathway induced CD-mDCs to secret more proinflammatory cytokines and to promote polarization of CD4^

关 键 词：Crohn’s病 树突状细胞 腺苷受体 亚型 致病性 

分 类 号：R574.62[医药卫生—消化系统]