Regulation of Organized Intestinal Lymphoid Tissues by TRANCE/RANKL

TRANCE/RANKL 对有组织肠淋巴组织的调节

• 批准号: 8325162
• 负责人: IFOR R WILLIAMS
• 金额: $ 38.82万
• 依托单位: EMORY UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-04-01 至 2014-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8325162
• 关键词: Adult; Antibodies; Antigen-Presenting Cells; Antigens; Area; Attention; B-Lymphocytes; Bacteria; CCR6 gene; Caliber; Cell Differentiation process; Cell physiology; Cells; Colon; Dendritic Cells; Development; Drug Formulations; Enterocytes; Epithelial Cells; Epithelium; Fostering; Goals; Health; Helper-Inducer T-Lymphocyte; Human; Immune; Immune response; Immune system; In Situ Hybridization; Inflammatory Bowel Diseases; Intestines; Kinetics; Knockout Mice; Knowledge; Lactation; Lamina Propria; Large Intestine; Lead; Link; Lymphocyte; Lymphoid; Lymphoid Follicle; Lymphoid Tissue; M cell; Maintenance; Mammary gland; Mesentery; Methods; Mucous Membrane; Mus; Oral; Organogenesis; Oryctolagus cuniculus; Osteoclasts; Particulate; Pathway interactions; Phenotype; Play; Progress Reports; Property; Proteins; Recombinants; Regulation; Reporting; Research; Role; Signal Pathway; Signal Transduction; Site; Small Intestines; Source; Specialized Epithelial Cell; Staining method; Stains; Stem cells; Stromal Cells; Structure; Structure of aggregated lymphoid follicle of small intestine; T-Lymphocyte; TNF gene; TNFSF11 gene; TRANCE protein; Testing; Thymic epithelial cell; Tumor necrosis factor receptor 11b; Ulex europaeus agglutinin-1; Wild Type Mouse; chemokine receptor; histogenesis; insight; lymph nodes; macrophage; member; mouse model; novel; oral tolerance; oral vaccine; pathogen; prevent; receptor; reconstitution; research study; restoration; uptake; vaccination strategy

DESCRIPTION (provided by applicant): Peyer's patches (PP) and isolated lymphoid follicles (ILF) are organized mucosal lymphoid tissues in the intestine that serve as inductive sites for immune responses to antigens in the intestinal lumen. We discovered that RANKL (also known as TRANCE and TNFSF11), a member of the TNF superfamily previously shown to have obligatory roles in the development of lymph nodes, the differentiation of medullary thymic epithelial cells, the differentiation of osteoclasts, and mammary gland lactation, is also present on stromal cells in ILF and PP. These RANKL-expressing stromal cells are concentrated in the subepithelial dome area in close apposition to the follicle-associated epithelium. PP in RANKL null mice were previously characterized as smaller than those in wild type mice, but additional phenotypic abnormalities were not reported. We find that the PP of RANKL null mice have a large deficit in the development of M cells, specialized epithelial cells capable of rapid uptake and delivery of particulate antigens into antigen-presenting cells (APC) found within and beneath the epithelium. On average, the small intestine of RANKL null mice has 74-fold fewer M cells detected by staining with the UEA-1 lectin than wild type control mice. The loss of UEA-1+ M cells in RANKL null mice correlates with a nearly complete loss in the ability of RANKL null PP to translocate 200 nm diameter fluorescent beads from the intestinal lumen into APC located in the PP subepithelial dome. M cell development in RANKL null mice can be rescued by treatment with recombinant RANKL for 7 days. Treatment of wild type mice with neutralizing anti- RANKL antibodies reproduces the loss of M cells observed in RANKL null mice. The central hypothesis guiding the proposed experiments is that RANKL acting through its receptor RANK on epithelial cells is a critical signaling pathway required for normal M cell differentiation and function. While M cells were first described in the rabbit appendix over 30 years ago and are known to have a central role in uptake of particulate antigens in mucosal tissues while also being exploited as a portal of entry by pathogens, the details of the histogenesis of these cells have largely remained a mystery. The first aim of the proposal is to determine whether stromal cells are the major source of RANKL involved in induction of M cell differentiation in the FAE and whether the action of RANKL to induce M cell differentiation is restricted to stem cells in the dome-associated crypts. The second aim is to determine whether the functional activity of M cells can be altered by manipulation of RANKL- RANK signaling with exogenous RANKL and neutralizing anti-RANKL antibody. The third aim is to determine how local expression of the osteoprotegerin (OPG) soluble decoy receptor and RANKL-induced effects on intestinal DC and macrophages influence the effects of stromal cell RANKL on RANK-expressing enterocytes. Mechanistic insights into how the RANKL-RANK pathway supports pathways of antigen handling by the gut immune system that foster development of tolerance of antigens normally encountered in the gut lumen may be useful in developing oral vaccination strategies and in the treatment of human inflammatory bowel disease. PUBLIC HEALTH RELEVANCE: The goal of this research is to identify the role of a protein known as RANKL (RANK ligand) and RANK (its receptor) in the establishment and normal functioning of organized lymphocyte containing structures in the small and large intestine. These lymphoid structures such as Peyer's patches normally contribute to protecting the host from pathogens and preventing inappropriate immune responses to antigens normally encountered in the intestinal microenvironment. These studies are expected to contribute to existing knowledge of how specific imbalances in the intestinal immune system can lead to various forms of human inflammatory bowel disease.

描述(申请人提供)：Peyer‘s Patches(PP)和孤立淋巴滤泡(ILF)是肠道中有组织的粘膜淋巴组织，作为对肠腔中抗原的免疫反应的诱导部位。我们发现，RANKL(也称为TRANCE和TNFSF11)是以前被证明在淋巴结发育、胸腺髓质上皮细胞分化、破骨细胞分化和乳腺泌乳中起重要作用的肿瘤坏死因子超家族成员，在ILF和PP的基质细胞上也存在RANKL。这些表达RANKL的基质细胞集中在上皮下穹隆区域，靠近滤泡相关上皮。RANKL基因缺失小鼠的PP比野生型小鼠小，但未见其他表型异常的报道。我们发现RANKL缺失小鼠的PP在M细胞的发育方面有很大的缺陷，M细胞是一种特殊的上皮细胞，能够快速摄取颗粒抗原并将其运送到上皮内和下的抗原提呈细胞(APC)中。平均而言，RANKL基因缺失小鼠的小肠中，通过UEA-1凝集素染色检测到的M细胞比野生型对照小鼠少74倍。RANKL基因缺失小鼠UEA-1+M细胞的丢失与RANKL基因缺失PP将直径200 nm的荧光珠子从肠腔转移到位于PP上皮下穹顶的APC的能力几乎完全丧失有关。重组RANKL治疗7天可挽救RANKL缺失小鼠的M细胞发育。用中和的抗RANKL抗体治疗野生型小鼠，可以复制在RANKL缺失小鼠中观察到的M细胞的丢失。指导实验的中心假设是RANKL通过其在上皮细胞上的受体等级作用，是正常M细胞分化和功能所需的关键信号通路。虽然M细胞最早是在30多年前在兔的阑尾被描述的，并且已知在粘膜组织中摄取颗粒抗原的过程中起着核心作用，同时也被病原体利用作为进入的门户，但这些细胞的组织发生的细节在很大程度上仍然是一个谜。该方案的第一个目的是确定RANKL是否是参与FAE中M细胞分化的主要RANKL来源，以及RANKL诱导M细胞分化的作用是否仅限于穹顶相关隐窝中的干细胞。第二个目的是确定是否可以通过外源性RANKL和中和抗RANKL抗体来操纵RANKL-RANK信号来改变M细胞的功能活性。第三个目的是确定局部表达骨保护素(OPG)的可溶性诱骗受体和RANKL对肠道DC和巨噬细胞的作用如何影响基质细胞RANKL对表达RANK的肠细胞的作用。对RANKL-RANK通路如何支持肠道免疫系统处理抗原的途径的机械性见解可能有助于开发口服疫苗策略和治疗人类炎症性肠病。公共卫生相关性：这项研究的目标是确定一种名为RANKL(RANK配体)和RANK(其受体)的蛋白质在小肠和大肠中有组织的淋巴细胞结构的建立和正常功能中的作用。这些淋巴结构，如Peyer氏斑，通常有助于保护宿主免受病原体的侵袭，并防止对肠道微环境中通常遇到的抗原的不适当免疫反应。预计这些研究将有助于现有关于肠道免疫系统的特定失衡如何导致各种形式的人类炎症性肠病的知识。