ACTIVATED MACROPHAGE/MONOCYTE TGFB1-INDUCED UPREGULATION OF COLLAGEN SYNTHESIS

系统性硬化症/硬皮病是一种慢性自身免疫性疾病， 病因学，其特征在于胶原蛋白的过度沉积， 内脏和皮肤，改变细胞介导的免疫力，和生产 自身抗体现有的硬皮病小鼠模型在以下方面受到限制： 它们对研究复杂的免疫异常的有用性，以及 人类疾病很难研究，因为早期的变化是微妙的， 并且诊断常常被延迟。来自体外和体内研究的证据 人类硬皮病的肺部病变表明， 浸润的单核细胞是胶原基因上调的有力刺激物 导致纤维化一种小鼠硬皮病移植物抗 宿主疾病（GVHD）模型（C57 BL/6 J至LP/J），其中动物发生 骨髓移植后GVHD、皮肤增厚和自身抗体 跨次要组织相容性位点（H-2b）提供了理想的机会 在一个完整的有机体中研究这些事件。对照小鼠接受 LP/6至C57 BL/6 J的相互骨髓移植发生GVHD， 真皮单核细胞浸润，但不发育皮肤 增厚本提案的目标一将充分描述 硬皮病GVHD小鼠，并确认其作为模型的有用性， 人类硬皮病疾病进展将与组织学， 通过测量皮肤厚度的生化和免疫参数， 完整皮肤和组织学的超声和物理测量 切片，通过抗核抗体试验测定自身抗体的产生， 真皮单核细胞浸润细胞的免疫表型，和 通过北方印迹分析定量真皮胶原基因表达， 在移植后的时间点从真皮中制备的总RNA， 硬皮病动物和对照动物。目标二检验了 产生TGF β 1的单核细胞引起胶原基因上调， 皮肤纤维化免疫表型和原位杂交， TGF β 1和pro-alpha（I）胶原蛋白探针，以证明TGF β 1和pro-alpha（I）胶原蛋白的共定位。 早期乳腺癌中产生TGF β 1的单核细胞和产生胶原的成纤维细胞 皮肤损伤是本建议工作的目标。最后对模型 提供了一个系统，在该系统中，可以操纵变量来测试 假设单核细胞TGF β 1的产生对于启动和 纤维化的进展，这里提出的工作的逻辑延伸。 建立小鼠模型，确认其对硬皮病的有效性， 确定硬皮病的主要早期免疫学事件将提供一个 在体内测试创新的免疫疗法。

Systemic sclerosis/scleroderma is a chronic autoimmune disease of unknown etiology, characterized by the excessive deposition of collagen in viscerae and skin, altered cell-mediated immunity, and the production of autoantibodies. Existing murine models for scleroderma are limited in their usefulness for study of the complex immunologic abnormalities, and human disease is difficult to study because the early changes are subtle and diagnosis is often delayed. Evidence from in vitro and in vivo work on pulmonary lesions in human scleroderma suggest that TGFbeta1 produced by infiltrating monocytes is a potent stimulus for collagen gene upregulation by fibroblasts leading to fibrosis. A murine sclerodermatous graft-versus- host disease (GVHD) model (C57BL/6J to LP/J) in which animals develop GVHD, skin thickening and autoantibodies after bone marrow transplantation across minor histocompatibility loci (H-2b) provides the ideal opportunity to study these events in an intact organism. Control mice receiving the reciprocal bone marrow transplantation LP/6 to C57BL/6J develop GVHD and dermal mononuclear cell infiltrates, but do not develop the skin thickening. Aim I of this proposal will characterize fully the sclerodermatous GVHD mice and confirm their usefulness as a model for human scleroderma. Disease progression will be correlated with histologic, biochemical and immunologic parameters by measuring dermal thickness using ultrasonography and physical measurements of intact skin and histologic sections, assaying autoantibody production by antinuclear antibody tests, immunophenotyping of the dermal mononuclear infIltrating cells, and quantifying dermal collagen gene expression by northern blot analysis of total RNA prepared from dermis at time points after transplantation in sclerodermatous and control animals. Aim II tests the central role of TGFbeta1-producing monocytes in causing collagen gene upregulation leading to skin fibrosis. Immunophenotyping and in situ hybridization using TGFbeta1 and pro-alpha(I)collagen probes to demonstrate co-localization of TGFbeta1-producing monocytes and collagen-producing fibroblasts in early skin lesions is the goal of this proposed work. Finally, the model provides a system in which variables can be manipulated to test the hypothesis that monocyte TGFbeta1 production is critical to initiation and progression of fibrosis, a logical extension of the work proposed here. Developing the murine model, confirming its validity for scleroderma, and identifying major early immunologic events in scleroderma will provide a means to test innovative immunotherapies in vivo.