Alam Khurshid, Jabeen Suraya
Department of Biochemistry, Faculty of Medicine, J.N. Medical College, A.M.U., Aligarh 202 002, India.
Cell Immunol. 2007 May;247(1):12-7. doi: 10.1016/j.cellimm.2007.06.007. Epub 2007 Aug 22.
Mitochondria consume about 90 percent of oxygen used by the body, and are a particularly rich source of reactive oxygen species (ROS). In this research communication mitochondrial DNA (mtDNA) was isolated from fresh goat liver and modified in vitro by hydroxyl radical generated from UV irradiation (254 nm) of hydrogen peroxide. As a consequence of hydroxyl radical modification, mtDNA showed hyperchromicity and sensitivity to nuclease S1 digestion as compared to control mtDNA. Animals immunized with mtDNA and ROS-modified mtDNA induced antibodies as detected by direct binding and competition ELISA. The data suggest that immunogenicity of mtDNA got augmented after treatment with hydroxyl radical. IgG isolated from immune sera showed specificity for respective immunogen and cross-reaction with other nucleic acids. Binding of induced antibodies with array of antigens clearly indicates their polyspecific nature. Moreover, the polyspecificity exhibited by induced antibodies is unique in view of similar multiple antigen binding properties of naturally occurring anti-DNA antibodies derived from SLE patients.
线粒体消耗身体所使用氧气的约90%，并且是活性氧（ROS）的特别丰富来源。在本研究通讯中，线粒体DNA（mtDNA）从新鲜山羊肝脏中分离出来，并在体外通过过氧化氢的紫外线照射（254nm）产生的羟基自由基进行修饰。作为羟基自由基修饰的结果，与对照mtDNA相比，mtDNA表现出增色效应和对核酸酶S1消化的敏感性。通过直接结合和竞争ELISA检测，用mtDNA和ROS修饰的mtDNA免疫的动物诱导产生了抗体。数据表明，mtDNA经羟基自由基处理后免疫原性增强。从免疫血清中分离的IgG对各自的免疫原具有特异性，并与其他核酸发生交叉反应。诱导抗体与一系列抗原的结合清楚地表明了它们的多特异性性质。此外，鉴于源自SLE患者的天然存在的抗DNA抗体具有相似的多重抗原结合特性，诱导抗体表现出的多特异性是独特的。
