Al Arfaj Abdurahman Saud, Chowdhary Abdul Rauf, Khalil Najma, Ali Rashid
Division of Rheumatology, Department of Medicine, College of Medicine, King Saud University, Riyadh, Saudi Arabia.
Clin Immunol. 2007 Jul;124(1):83-9. doi: 10.1016/j.clim.2007.03.548. Epub 2007 May 30.
Reactive oxygen species (ROS)-modified DNA has been shown to be a better and more discriminating immunogen than native DNA (nDNA) for the production of anti-DNA autoantibodies in SLE (systemic lupus erythematosus). Among ROS, the role of hydroxyl radical (.OH) in the induction of damage and modification of nDNA has been extensively studied while such documentation implicating singlet oxygen ((1)O(2)) in inducing immunogenicity in nDNA leading to the production of anti-double-stranded (ds) DNA autoantibodies in SLE is not yet available. This prospective study was undertaken to evaluate the immunogenicity of healthy human dsDNA modified with (1)O(2) generated by methylene blue plus radiant light. Female rabbits were immunized with (1)O(2)-modified human dsDNA to raise anti-dsDNA antibodies. (1)O(2)-modified anti-dsDNA rabbit immune sera and the (1)O(2)-modified anti-dsDNA rabbit purified immunoglobulin G (IgG) were tested against a variety of dsDNA antigenic substrates through direct enzyme-linked immunosorbent assay (ELISA). The immunogenicity of (1)O(2)-modified human dsDNA was further evaluated by studying its immunoreactivity with SLE patients' sera and SLE patients' purified anti-dsDNA IgG. As compared to healthy human sera, (1)O(2)-modified anti-dsDNA rabbit immune sera as well as the (1)O(2)-modified anti-dsDNA rabbit purified IgG demonstrated a strong affinity towards (1)O(2)-modified human dsDNA(.)(1)O(2)-modified human dsDNA proved to be potentially more immunogenic against SLE patients' whole sera and SLE patients' purified IgG as compared to healthy human sera. Our findings suggest that (1)O(2) may also be inducing immunogenicity in native dsDNA resulting in the production of anti-dsDNA autoantibodies as seen in SLE patients.
活性氧（ROS）修饰的DNA已被证明比天然DNA（nDNA）是更好、更具特异性的免疫原，可用于在系统性红斑狼疮（SLE）中产生抗DNA自身抗体。在ROS中，羟基自由基（·OH）在诱导nDNA损伤和修饰方面的作用已得到广泛研究，而关于单线态氧（¹O₂）诱导nDNA免疫原性从而导致SLE中产生抗双链（ds）DNA自身抗体的相关文献尚不存在。本前瞻性研究旨在评估经亚甲蓝加辐射光产生的¹O₂修饰的健康人dsDNA的免疫原性。用¹O₂修饰的人dsDNA免疫雌性兔以产生抗dsDNA抗体。通过直接酶联免疫吸附测定（ELISA），针对多种dsDNA抗原底物检测¹O₂修饰的抗dsDNA兔免疫血清和¹O₂修饰的抗dsDNA兔纯化免疫球蛋白G（IgG）。通过研究其与SLE患者血清和SLE患者纯化的抗dsDNA IgG的免疫反应性，进一步评估¹O₂修饰的人dsDNA的免疫原性。与健康人血清相比，¹O₂修饰的抗dsDNA兔免疫血清以及¹O₂修饰的抗dsDNA兔纯化IgG对¹O₂修饰的人dsDNA表现出强烈的亲和力。与健康人血清相比，¹O₂修饰的人dsDNA对SLE患者的全血清和SLE患者纯化的IgG具有更强的潜在免疫原性。我们的研究结果表明，¹O₂也可能在天然dsDNA中诱导免疫原性，从而导致如SLE患者中所见的抗dsDNA自身抗体的产生。
