CHROMOSOME 6P AND DEVELOPMENTAL DEFECTS

6P 染色体与发育缺陷

• 批准号: 6182387
• 负责人: FRED S. ROSEN
• 金额: $ 27.12万
• 依托单位: IMMUNE DISEASE INSTITUTE, INC.
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-07-01 至 2004-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6182387
• 关键词: B lymphocyte; anergy; animal breeding; complement; developmental genetics; disease /disorder model; gene targeting; genetically modified animals; immune tolerance /unresponsiveness; immunodeficiency; immunogenetics; immunoglobulin isotypes; laboratory mouse; lysozyme; systemic lupus erythematosus; transfection

Systemic lupus erythematosus (SLE) is an autoimmune disorder which affects over 200,000 women in the USA and it is characterized by anti-nuclear antibodies and a high incidence of glomerulonephritis. A major risk factor for SLE is deficiency in early classical pathway complement components C1, C2 or C4. This association presents a paradox because it is not expected that an immune deficiency would result in an autoimmune disease. One explanation is that early complement is involved in maintenance of B cell tolerance and in its absence, self-reactive B cells accumulate in the periphery where they potentially may be activated. The goal of this proposal is to test this hypothesis and it is divided into 3 specific aims: (i) Test the hypothesis that early classical pathway complement components C1, C4 and C3 are directly involved in negative selection of self-reactive B lymphocytes. The approach used in this aim is to breed mice deficient in C1, C4, or C3 with two well established immunoglobulin transgenic models (anti-HEL and anti-dsDNA) and determine if complement is essential in B cell anergy. (ii) The second aim will test the hypothesis that deficiency in classical pathway complement results in increased severity of disease in a well defined mouse model of lupus, i.e. lpr strain. The advantage of this aim is that it will examine the importance of early complement in the autoimmune response to natural lupus antigens such as dsDNA and nuclear proteins. (iii) The third aim will test the hypothesis that impaired self-tolerance in C4null mice can be rescued by protein replacement or gene therapy and if so compare C4A and C4B isotypes. It will also examine the mechanism of C4 in B cell tolerance using a fusion protein of C4d linked to sHEL antigen to uncouple solubilization of immune complexes from targeting of antigen to the lymphoid compartment via C4d. This aim is important as it will establish the feasibility of protein or gene therapy in lupus and clarify our understanding of B cell tolerance.

系统性红斑狼疮(SLE)是一种自身免疫性疾病，在美国有20多万妇女患病，其特点是抗核抗体和肾小球肾炎的高发。SLE的一个主要危险因素是早期经典途径补体成分C1、C2或C4的缺乏。这种联系是一个悖论，因为人们并不认为免疫缺陷会导致自身免疫性疾病。一种解释是，早期补体参与了B细胞耐受性的维持，在没有补体的情况下，自我反应的B细胞聚集在外围，在那里它们可能被激活。这项建议的目的是检验这一假说，它分为三个特定的目的：(I)检验早期经典途径补体成分C1、C4和C3直接参与自身反应性B淋巴细胞负选择的假说。本研究的目的是用两种成熟的免疫球蛋白转基因模型(抗HEL和抗dsDNA)培育C1、C4或C3缺陷的小鼠，并确定补体在B细胞无能中是否是必需的。(Ii)第二个目标将在明确定义的狼疮小鼠模型，即LPR品系中，测试经典途径补体缺乏导致疾病严重程度增加的假设。这个目的的好处是，它将检查早期补体在对自然狼疮抗原(如dsDNA和核蛋白)的自身免疫反应中的重要性。(Iii)第三个目标将测试C4零小鼠的自我耐受性受损可以通过蛋白质替代或基因治疗来挽救的假设，如果是这样的话，比较C4a和C4b的同种类型。它还将研究C4在B细胞耐受中的机制，使用连接到SHEL抗原的C4D融合蛋白来解偶联免疫复合物的增溶作用，使其从通过C4D靶向淋巴间隔室。这一目标很重要，因为它将确立蛋白质或基因治疗在狼疮中的可行性，并澄清我们对B细胞耐受的理解。