Immune mechanisms that lead to irreversible scleroderma.

导致不可逆硬皮病的免疫机制。

• 批准号: 6848873
• 负责人: ANITA C GILLIAM
• 金额: $ 30.99万
• 依托单位: CASE WESTERN RESERVE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-02-01 至 2009-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6848873
• 关键词: RNA interference; autoimmune disorder; biological signal transduction; cell cell interaction; cell population study; collagen; dendritic cells; disease /disorder model; fibroblasts; fibrosis; graft versus host disease; immune response; immunogenetics; immunologic assay /test; immunomodulators; immunopathology; inflammation; inhibitor /antagonist; laboratory mouse; macrophage; monocyte; monocyte chemoattractant protein 1; phenotype; protein biosynthesis; scleroderma; tissue /cell culture; transforming growth factors

DESCRIPTION (provided by applicant): Scleroderma is a chronic autoimmune disease characterized by fibrosis of organs and skin, due to upregulated synthesis of collagen by fibroblasts. There is no effective treatment for scleroderma to date. We are using murine sclerodermatous graft versus host disease (Scl GVHD) to model early scleroderma, which may be more amenable to therapy. In this model, we can generate measurable (up to 40% thicker) skin thickening within 21-28 days post bone marrow transplantation in mice with Scl GVHD. We and others have shown that in scleroderma and in early inflammatory Scl GVHD, the chemokine macrophage chemotactic protein-1 (MCP-1), an infiltrating monocyte/macrophage cell population and the cytokine transforming growth factor-beta TGF-beta are major players. We have also prevented murine Scl GVHD with early administration of a specific inhibitor of TGF-beta, latency-associated peptide (LAP) in vivo. In later fibrosing disease, inflammation subsides, and the fibroblasts are thought to have a permanently altered phenotype of unregulated collagen synthesis. The triggers for the switch from early reversible inflammatory disease and later noninflammatory fibrotic disease are not known. We hypothesize that the unique cutaneous environment in early inflammatory fibrosis involves cross talk between immune cells and fibroblasts. Critical fibroblast signals are required for immune cells to home to skin and become activated, and critical immune signals are required to produce an irreversible fibroblast phenotype. We plan to examine the cross talk between immune cells and fibroblasts in the following studies that are focused on cutaneous dendritic cells as initiators of the immune response, monocyte/macrophages and MCP-1. Aim 1: Immune cell studies. A. When can LAP no longer prevent or reverse skin fibrosis? This will establish "reversible" versus " irreversible" disease clinically. B. What are the effects of interventions stimulating (Fit3 ligand) or inhibiting (CTLA41g) dendritic cells, which are essential to initiate an immune response? C. What are the effects of monocyte/ macrophage interventions? Can we still generate Scl GVHD with macrophage-depleted bone marrow or by depleting macrophages in vivo after BMT? Can we generate Scl GVHD in MCP-1 knockout mice? Aim II. Fibroblast studies. A. Do cutaneous fibroblasts secrete immunomodulatory molecules (particularly MCP-1) in early inflammatory Scl GVHD? Can we inhibit fibroblast MCP-1 with interference RNA (RNAi) and block activation of immune cells and an altered fibroblast phenotype in vitro? B. What immunologic triggers are related to the excessive and persistent secretion of collagen by fibroblasts? Is SMAD dysregulation a critical event? Do clones of cells resistant to apoptosis explain the irreversible fibroblast phenotype? Are increased numbers of myofibroblasts generated in Scl GVHD that signal the onset of irreversible fibrosis? We are one of the few laboratories using this valuable model for scleroderma. We have the expertise in cutaneous immunobiology, and in dendritic cell and monocyte/macrophage biology. We are ideally suited to carry out this project to examine the cross talk between immune cells and fibroblasts in fibrosing disease, an entirely new and exciting area of research in scleroderma research. Developing more effective diagnostic tools and immunomodulatory therapies for early scleroderma is the ultimate goal of this research.

描述(由申请人提供)： 硬皮病是一种慢性自身免疫性疾病，以器官和皮肤纤维化为特征，原因是成纤维细胞合成胶原蛋白上调。到目前为止，硬皮病还没有有效的治疗方法。我们正在使用小鼠硬皮瘤性移植物抗宿主病(Scl GVHD)来模拟早期硬皮病，这可能更适合治疗。在这个模型中，我们可以在患有SCL GVHD的小鼠骨髓移植后21-28天内产生可测量的(高达40%厚的)皮肤增厚。我们和其他人已经证明，在硬皮病和早期炎症性SCL GVHD中，趋化因子巨噬细胞趋化蛋白-1(MCP-1)、浸润性单核/巨噬细胞群和细胞因子转化生长因子-β转化生长因子-β是主要参与者。我们还通过在体内早期给予转化生长因子-β的特异性抑制物潜伏期相关肽(LAP)来预防小鼠SCL GVHD。在后来的纤维化疾病中，炎症消退，成纤维细胞被认为具有永久改变的不受调节的胶原合成的表型。从早期可逆性炎症性疾病到后来的非炎性纤维性疾病的触发因素尚不清楚。我们假设，早期炎性纤维化的独特皮肤环境涉及免疫细胞和成纤维细胞之间的串扰。免疫细胞需要关键的成纤维细胞信号才能回到皮肤并被激活，而关键的免疫信号是产生不可逆转的成纤维细胞表型所必需的。我们计划在以下研究中检查免疫细胞和成纤维细胞之间的相互作用，这些研究集中在皮肤树突状细胞作为免疫反应的启动者、单核/巨噬细胞和单核细胞趋化蛋白-1。目的1：免疫细胞研究。什么时候LAP不再能预防或逆转皮肤纤维化？这将在临床上确立“可逆”与“不可逆”的疾病。B.刺激(Fit3配体)或抑制(CTLA41g)树突状细胞的干预措施有什么效果，这是启动免疫反应所必需的？C.单核/巨噬细胞干预的效果是什么？我们是否仍然可以用去巨噬细胞的骨髓或在骨髓移植后体内去巨噬细胞的方法来产生SCL GVHD？我们能在MCP-1基因敲除小鼠中产生scl GVHD吗？目的II.成纤维细胞的研究。在早期炎症性SCL GVHD中，皮肤成纤维细胞是否分泌免疫调节分子(特别是MCP-1)？我们能否通过干扰RNA(RNAi)抑制成纤维细胞MCP-1，并在体外阻断免疫细胞的激活和改变成纤维细胞的表型？什么免疫诱因与成纤维细胞过度和持续分泌胶原蛋白有关？SMAD监管失调是一个关键事件吗？抗凋亡细胞克隆能解释不可逆转的成纤维细胞表型吗？SCL移植物抗宿主病中产生的肌成纤维细胞数量增加是否预示着不可逆纤维化的开始？ 我们是为数不多的使用这种有价值的硬皮病模型的实验室之一。我们在皮肤免疫生物学、树突状细胞和单核/巨噬细胞生物学方面拥有专业知识。我们非常适合开展这一项目，以检验纤维化疾病中免疫细胞和成纤维细胞之间的相互作用，这是硬皮病研究中一个全新且令人兴奋的领域。为早期硬皮病开发更有效的诊断工具和免疫调节疗法是本研究的最终目标。