Spectrum of Autoimmune Gastrointestinal Dysmotility

描述（由申请方提供）：本研究提案的目的是在动物模型中研究导致自身免疫性胃肠道（G.I.）运动障碍靶向肠神经系统（ENS）神经节和外源性自主神经节中神经元的自身免疫在临床上与肺癌相关，并且可能是几种特发性胃肠道疾病的原因。运动障碍，包括不能用公认的基因缺陷解释的先天性病例。研究计划的基本原理是基于神经节中发现的炎症病理学和血清中发现的IgG标志物，副肿瘤实体的患者。公认的IgG标志物是特异性的神经节烟碱乙酰胆碱受体（AChR）和神经元细胞核和细胞质抗原。在一些特发性GI患者中也发现了对神经节AChR特异的IgG。运动障碍这种IgG伴随GI。用神经节AChR α 3亚基的重组片段或合成肽免疫的兔中的运动障碍，并引起G. I.当注射到健康小鼠中时，具体目标是：1）阐明AChR-IgG在成年动物中致病的机制，2）研究AChR-IgG转移G. I. 3）定义IgG的抗原决定簇和T细胞应答，有助于G. I.运动障碍，并确定炎性ENS神经节炎是否将由免疫策略引起，所述免疫策略被设计为激活对源自神经元核、胞质或AChR抗原的肽特异性的细胞毒性（CD 8+）T细胞。方法包括胃肠功能测试。运动性、神经节突触传递的细胞内微电极研究、细胞和体液免疫应答的分析、单克隆神经节AChR-IgG的产生和表征、使用眼镜蛇毒因子消耗补体、使用缺乏IgG依赖性细胞介导的细胞毒性所需的补体调节蛋白或Fc受体的敲除小鼠、神经节组织的组织学、免疫组织化学和电子显微镜分析，和在子宫内暴露于AChR-IgG的GFP转基因小鼠中ENS发育阶段的延时荧光显微镜记录。从这些研究中预期的见解将改善特发性胃肠道动力障碍的诊断和辅助分类，并证明早期考虑免疫调节治疗的合理性。这项研究也与癌症免疫具有高度的临床相关性。

DESCRIPTION (provided by applicant): The objective of this research proposal is to investigate in animal models the immunopathogenic mechanism(s) accounting for autoimmune gastrointestinal (G.I.) dysmotility. Autoimmunity targeting neurons in ganglia of the enteric nervous system (ENS), and extrinsic autonomic ganglia, is well-documented clinically in association with lung cancer, and may be a cause of several idiopathic forms of G.I. dysmotility, including congenital cases that are not explained by recognized gene defects. The rationale for the research plan is based on the inflammatory pathology found in ganglia, and IgG markers found in serum, of patients with the paraneoplastic entity. Recognized IgG markers are specific for ganglionic nicotinic acetylcholine receptor (AChR) and neuronal nuclear and cytoplasmic antigens. IgG specific for the ganglionic AChR is also found in some patients with idiopathic G.I. dysmotility. This IgG accompanies G.I. dysmotility in rabbits immunized with recombinant fragments or synthetic peptides of the ganglionic AChR a3 subunit, and causes G.I. dysmotility when injected into healthy mice. The Specific Aims are: 1)to elucidate mechanisms responsible for the pathogenicity of AChR-IgG in adult animals, 2) investigate the potential of AChR-IgG to transfer G.I. dysmotility transplacentally, 3) define antigenic determinants of IgG and T cell responses contributing to G.I. dysmotility, and determine if inflammatory ENS ganglionitis will result from immunization strategies designed to activate cytotoxjc (CD8+) T cells specific for peptides derived from neuronal nuclear, cytoplasmic or AChR antigens. Methods include functional tests of G.I. motility, intracellular microelectrode studies of ganglionic synaptic transmission, analyses of cellular and humoral immune responses, production and characterization of monoclonal ganglionic AChR-lgGs, use of cobra venom factor to deplete complement, use of knock-out mice deficient in complement regulatory proteins or Fc receptors required for IgG-dependent cell-mediated cytotoxicity, histological, immunohistochemical and electronmicroscopic analyses of ganglionic tissues, and time lapse fluorescence photomicroscopic recording of ENS development stages in GFP transgenic mice exposed in utero to AChR-IgG. Insights anticipated from these studies will improve the diagnosis and aid classification of idiopathic G.l.dysmotilities, and justify early consideration of immunomodulatory therapies. The proposed research also has high clinical relevance to cancer immunity.