Bozic B, Cucnik S, Kveder T, Rozman B
University Medical Centre, Division of Internal Medicine, Department of Rheumatology, Ljubljana, Slovenia.
Autoimmun Rev. 2006 Nov;6(1):28-32. doi: 10.1016/j.autrev.2005.12.005. Epub 2006 Jan 27.
The immune response may be changed due to altered proteins or modifications of immunoglobulins, including oxidative processes. The susceptibility to oxidative modifications depends greatly on amino-acid moiety composition due to chemical characteristics (instability) of their side-chains. Initial steps of oxidation may change the specificity and avidity of immunoglobulins due to chemical alteration of the hypervariable region. The oxidation of antibodies increases the hydrophilic nature of the paratopes and makes them more susceptible for the binding to cationic surfaces even without the strong surface-to-surface fitting. The electro-oxidation of IgG significantly changes the immunoreactivity and specificity of IgG fractions, regardless of the initial immunoreactivity to a specific autoantigen also in healthy persons. Data are presented on changes in the immunoreactivity as well as the avidity of antibodies against beta2-glycoprotein I after being exposed to direct current. ELISA measurements showed increased reactivity of anti-beta2-glycoprotein I antibodies at the beginning and various, fluctuating results after prolonged exposure to electro-oxidation. Inter-individual differences in chemical stability of immunoglobulins and patient's antioxidative status may influence the range of their alterations and their impact on health/disease balance.
免疫反应可能会因蛋白质改变或免疫球蛋白修饰（包括氧化过程）而发生变化。由于其侧链的化学特性（不稳定性），氧化修饰的易感性在很大程度上取决于氨基酸部分的组成。氧化的初始步骤可能会因高变区的化学改变而改变免疫球蛋白的特异性和亲和力。抗体的氧化增加了互补决定区的亲水性，即使没有强烈的表面对表面契合，也使其更容易与阳离子表面结合。IgG的电氧化显著改变了IgG组分的免疫反应性和特异性，无论健康人对特定自身抗原的初始免疫反应性如何。本文展示了暴露于直流电后抗体针对β2-糖蛋白I的免疫反应性以及亲和力的变化数据。酶联免疫吸附测定显示，抗β2-糖蛋白I抗体在开始时反应性增加，而在长时间暴露于电氧化后结果各异且波动。免疫球蛋白化学稳定性的个体差异以及患者的抗氧化状态可能会影响其改变的范围及其对健康/疾病平衡的影响。
