髓源抑制性细胞功能特点与疾病干预潜能在不同T细胞免疫应答病理机制炎性肠病动物模型中的研究

Myeloid-derived suppressor cells (MDSCs）suppress significantly T cell immune responses，and the strategy of limiting autoimmune reactions through MDSCs is promising for clinical treatment of autoimmune diseases. The applicants have developed animal models of inflammatory bowel dieases(IBD), successfully expanded MDSCs in vitro from PBMCs collected from normal mice,and suppressed significantly airway inflammation in a mouse model of asthma by adoptive MDSCs transfer. Based on IBD models showing different pahtologic mechanisms of T cell immune response,the current project was designed: 1)to understand the characteristics of MDSCs accumulation and functions in different IBD models including Th2 responses-driven ulcerative colitis and Th1 and/or Th17-driven acute or chronic Chron's dieases. 2）to investigate the effects of regulating endogenous MDSCs funtions on the development of pathologic responses, and also the affects of pathologic microenvironment on MDSCs functions. 3)to study the effects of adoptive MDSCs transfer on the development of pathologic responses. The project sought to investigate the relation between pathologic microenvironment and MDSCs functions, as well as the involved mechanisms, and is expected to add important information to our undrstanding on the roles and mechanisms of MDSCs functioning in IBD, and indicate the potentials of regulating MDSCs functions or adoptive MDSCs transfer for the clinical treatment of IBD.

髓源性抑制细胞（MDSCs）具有对T细胞免疫应答显著的抑制作用，通过其限制自身免疫反应，具有临床疾病干预潜能。MDSCs在炎性肠病（IBD）中的研究鲜有报道。课题组拥有成熟的IBD模型研究平台,掌握了MDSCs体外扩增技术并在哮喘模型中有效抑制了疾病发展，拟在本项目中，利用不同病理机制IBD模型开展以下工作：1）了解Th2主导的溃疡性结肠炎及Th1和/或Th17主导的克隆氏病急、慢性模型中MDSCs的积累与功能特点；2）探讨内源MDSCs的功能调控与IBD病理应答的相互作用；3）研究外源MDSCs过继转移对IBD疾病进程的影响。项目探讨不同T细胞免疫应答病理机制及病灶微环境与MDSCs扩增与功能发挥的相互关系，了解可能涉及的分子机制，从而借助动物模型，提升对MDSCs在IBD中角色与相应调控、效应机制的理解，并揭示MDSCs功能调控或过继转移策略临床干预IBD疾病发展的应用潜能。

髓源抑制性细胞（MDSCs）具有对T细胞免疫应答显著的抑制作用，通过其限制自身免疫反应，具有临床疾病干预潜能，对于MDSCs在疾病中的角色及相关机制研究极为重要。MDSCs在炎性肠病（IBD）中的研究鲜有报道。本研究利用半抗原oxzalone诱导的Th2应答驱动的UC模型及TNBS诱导的Th1/Th17主导的CD模型,在不同模型时间点，分离脾及肠固有层（LP）淋巴细胞，通过流式细胞仪分析CD11b、ly-6C、ly-6G标记，了解MDSCs表型细胞群体的存在和比例，考察不同病理、组织微环境不同亚群MDSCs的扩增积累。通过这些工作了解了MDSCs不同组织积累及不同亚群激活，显示在TNBS或Oxazolone诱导的IBD模型中，MDSCs的产生与疾病严重程度相关，不同模型代表性时间点MDSCs特定群体扩增存在差异。经磁珠纯化分选LP中不同亚群MDSCs，在体外检测了其对T细胞的免疫抑制功能及功能介质arginase和iNOS的表达和活性。通过这些检测，了解了特定背景下MDSCs功能特点。以real-time PCR检测MDSCs中反映其作用机制的转录因子STAT1、STAT3、STAT5、NF-κB的表达，以Western-blot分析这些分子的磷酸化激活状态。通过这些检测，了解特定背景下MDSCs可能作用机制。本研究利用动物模型，揭示MDSCs与IBD疾病发展相关，并与疾病微环境存在相互影响。