Anticardiolipin Antibodies and Oxidized Phospholipids

抗心磷脂抗体和氧化磷脂

• 批准号: 6642174
• 负责人: Joseph L. Witztum
• 金额: $ 41.15万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-01-01 至 2005-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6642174
• 关键词: anticoagulants; antigen antibody reaction; antioxidants; antiphospholipid syndrome; atherosclerosis; autoantibody; autoimmune disorder; blood coagulation; blood vessel occlusion; cardiolipins; clinical research; discoid lupus erythematosus; human tissue; laboratory mouse; monoclonal antibody; oxidation; peroxidation; protein C; protein S; systemic lupus erythematosus

Patients with the antiphospholipid antibody syndrome (APS) have autoantibodies to certain phospholipids (aPL) such as cardiolipin and/or the lupus anticoagulant and clinically experience recurrent venous or arterial thrombosis, history of fetal death and autoimmune thrombocytopenia. Increased aPL also appear to predict increased risk of stroke and myocardial infarction in otherwise healthy men as well. However, controversy exists about the target antigens of aPL, and even university laboratories cannot agree who has elevated aPL titers. In turn, clinical management is hampered by lack of an underlying hypothesis to explain why antibodies should form to such ubiquitous compounds as PL. We have developed the novel hypothesis that many aPL are directed against epitopes of oxidized PL (OxPL) and/or against covalent adducts of OxPL and associated PL binding proteins, such as beta2GPI. Our hypothesis suggests that states of enhanced lipid peroxidation, as occurs in inflammation or atherosclerosis, leads to oxidation of PL (such as in LDL or in membranes of apoptotic or dying cells) which creates neo self-determinants and immunogenic epitopes. The resultant autoantibodies can then target such neoepitopes in many tissues, and may have a variety of biological consequences. Cardiolipin (CL) is the most common PL used to test for aPL. We have shown that APS plasma bind exclusively to OxCL, or to OxCL adducts with beta2GPI, and not to native CL. We propose to further test our hypothesis by determining if antibodies to other OxPL are also present in sera from patients and mice with lupus- like syndromes. We will generate a panel of such aOxPL murine monoclonals from (NZWxBXSB) F1 males. Similar Fab and scFv antibodies will be generated from a human phage-display library. We will determine the epitopes to which they bind and their impact on in vitro and in vivo coagulation, with an emphasis on the Protein C pathway. We will treat lupus-prone mice with potent antioxidants to see if changes in aPL titers and/or other clinical parameters occur. Understanding the etiology of even some of the aPL should lead not only to development of more standardized assays, which should improve our ability to detect high risk individuals, but also to consideration of new therapeutic modalities for patients with aPL and APS (e.g. aggressive anti-inflammatory and/or antioxidant interventions).

抗磷脂抗体综合征（APS）患者具有针对某些磷脂（aPL）的自身抗体，如心磷脂和/或狼疮抗凝剂，临床经历静脉或动脉血栓形成复发，有胎儿死亡史和自身免疫性血小板减少症。在其他方面健康的男性中，aPL升高似乎也预示着中风和心肌梗死的风险增加。然而，关于aPL的靶抗原存在争议，甚至大学实验室也不能就谁的aPL滴度升高达成一致。反过来，由于缺乏一个潜在的假设来解释为什么抗体会形成像PL这样普遍存在的化合物，临床管理受到阻碍。我们已经提出了一个新的假设，即许多aPL是针对氧化PL （OxPL）的表位和/或OxPL的共价加合物和相关的PL结合蛋白，如beta2GPI。我们的假设表明，脂质过氧化增强的状态，如在炎症或动脉粥样硬化中发生，导致PL氧化（如在LDL或凋亡或死亡细胞的膜中），从而产生新的自我决定因子和免疫原性表位。由此产生的自身抗体可以靶向许多组织中的这些新表位，并可能产生各种各样的生物学后果。心磷脂（CL）是检测aPL最常用的PL。我们已经证明APS血浆只与OxCL结合，或与beta2GPI的OxCL加合物结合，而不与天然CL结合。我们建议通过确定其他OxPL抗体是否也存在于狼疮样综合征患者和小鼠的血清中来进一步验证我们的假设。我们将从（NZWxBXSB） F1雄性中产生一组这样的aOxPL小鼠单克隆。相似的Fab和scFv抗体将从人类噬菌体展示文库中产生。我们将确定它们结合的表位及其对体外和体内凝血的影响，重点是蛋白C途径。我们将用强效抗氧化剂治疗狼疮易感小鼠，以观察aPL滴度和/或其他临床参数是否发生变化。了解一些aPL的病因不仅可以开发更标准化的检测方法，从而提高我们检测高风险个体的能力，而且还可以考虑针对aPL和APS患者的新治疗方式（例如积极的抗炎和/或抗氧化干预）。