从IL23R多态调控Th17细胞角度研究Behcet病的发生及机制

Behcet's disease (BD) is a multi-systemic autoinflammation disease mainly mediated by genetic predisposition, infections and immunological abnormalities. However the mechanism is still undetermined. Recently we showed that IL23R was identified as a susceptibility gene of BD in a Han Chinese population. It was reported that rs17375018 SNP in IL23R gene controlled this gene expression. Besides the priming of T cells with its ligand, IL23R controlled the activation of macrophages and TH17 cell and contributed to initiation of innate immune responses as well as the subsequent induction of adaptive immune responses. Therefore, we propose that IL23R polymorhpims control its expression, subsequent TH17 cell activation and contribute to the BD development. To test this hypothesis, we determine to study the role of IL23R polymorphism in activation of TH17 cell in the development of BD. The project mainly includes three parts as follow. (1) Expression of IL23R will be investigated to study influence of rs17375018 variant on IL23R translations. (2) Phenotype, mature and functional properties of TH17 cell will be explored to determine the role of IL23R in TH17 cell activation. (3) Activation status and interaction of STAT3 and RORγt with IL23R and effect of STAT3, RORγt on the activation of a reporter for this pathway will be determined to study the underlying mechanism of IL23R on the activation of TH17 cell in Behcet's diseases. The incidence and severity of experimental autoimmune uveitis (EAU),phenotype,mature and functional of TH17, and freqencies of Th17 will be assessed to study the role of IL23R in EAU. These studies are expected to gain a deep insight into the initiating mechanisms involved in BD from IL23R and to provide a new strategy in the prevention and treatment for this disease.

Behcet病是累及多器官、多系统的自身炎症性疾病。目前认为遗传因素、免疫紊乱在其发病中起重要作用，其机制尚不完全清楚。最近我们发现IL23R与Behcet病显著相关，精细定位发现疾病相关多态为rs17375018，且为功能性多态，可能上调IL23R基因转录。文献报道IL23R是TH17终末分化的必要分子。据此推测IL23R多态可能调控蛋白表达，进而影响TH17细胞分化、功能并导致该病发生。为证实此假设，本研究以rs17375018多态为切入点，探讨该多态对IL23R基因转录功能的影响，以阐明此多态生物学功能；研究此多态对TH17分化、成熟和功能影响，以明确其免疫学功能；通过检测STAT3及RORγt通路中分子磷酸化水平，阐明该多态影响TH17分子机制； 通过此研究将可能揭示IL23R多态通过何种机制参与Behcet病发生这一科学问题，为Behcet病个体化防治提供新靶点。

Behcet病是累及多器官、多系统的自身炎症性疾病。目前认为遗传因素、免疫紊乱在其发病中起重要作用，其机制尚不完全清楚。我们发现IL23R与BD显著相关，精细定位发现疾病相关多态为功能性多态，可能上调IL23R基因转录。据此推测IL23R多态可能调控蛋白表达，进而影响TH17细胞分化、功能并导致该病发生。.本研究以IL23R多态为切入点，探讨与BD相关的不同基因型IL23R多态对IL23R表达的影响；检测了不同基因型IL23R多态对Th17细胞功能的影响；进一步探讨了T细胞和NK细胞在EAU中的表达，分布；在BD和VKH中，明确凋亡相关基因与其配体的表达情况及作用；进一步拓展延伸，研究了炎症相关分子MCP-1，TLR4基因多态在糖尿病视网膜病变中的作用及其功能变化。.结果表明, 在BDt病人和加入刺激剂的正常人中，IL23R的rs17375018位点GG型的表达水平明显高于AG和AA基因的IL23R的表达水平。在Behcet病人和正常人中，IL-17、IL-6、TNF-α表达水平在加入抗-CD3和CD28刺激剂后GG基因型患者明显高于AG和AA基因患者，而IFN-γ的表达无差异。EAU模型在接受抗原免疫后的第6天出现炎症，第12天达到最高峰，第21天炎症细胞消失。第6天见NK细胞，第9天NK细胞显著增加，第12天较第9天明显减少，第16天NK细胞基本消失。CXCL10第9天较其他时间点有统计学差异，而CXCL12无差异。PD-1，PD-L1和PD-L2的表达在两组葡萄膜炎中显著降低。PD-L2表达在仅出现葡萄膜炎病人或应用激素病人中显著降低。TLR4基因的rs1927914位点TT基因型和T等位基因在2型糖尿病中显著下降，rs1927911位点CC基因型和C等位基因在2型糖尿病中显著增高；rs1927914位点C等位基因在DR病人中显著增高。MCP-1的表达水平在NPDR和PDR组明显高于DWR组，MCP-1基因的-2518GG基因型和G等位基因在DR组频率高于DWR组。在PDR病人中，GG基因型组MCP-1的表达水平高于其他两种基因型组。.通过此研究揭示了IL23R多态通过影响IL23R基因的表达，进而引起炎症因子的表达增加，导致免疫过度而发生BD。为其个体化防治，精准免疫学治疗提供新靶点。本研究为探索NK细胞在BD中的作用及机制提供可靠依据。