López-Bote J P, Langa C, Lastres P, Rius C, Marquet A, Ramos-Ruiz R, Bernabéu C
Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain.
Scand J Immunol. 1993 May;37(5):593-601. doi: 10.1111/j.1365-3083.1993.tb02577.x.
Human immunoglobulins treated at 55 degrees C in vitro are able to interact with maleylated bovine serum albumin (mBSA), but not with unmodified BSA. Gel filtration experiments demonstrated that the mBSA binding is associated with a high molecular weight complex of aggregated IgG. This aggregated IgG with binding capacity for mBSA could also be generated in vitro by treatment of human IgG at 37 degrees C or 40 degrees C and by incubation with human neutrophils. Furthermore, IgG aggregates with binding activity for mBSA could be detected in untreated synovial fluids from rheumatoid arthritis patients, indicating that these complexes occur in vivo. The phenomenon of binding to aggregated IgG was extended to other modified proteins such as maleylated human serum albumin (mHSA), acetyl low density lipoprotein (Ac-LDL) and BSA reacted with oxidized linolenic acid. Soluble forms of these modified proteins were able to compete for the interaction between aggregated IgG and surface-bound mBSA. We also found that aggregated IgG enhanced the Ac-LDL-dependent foam cell formation. These findings suggest a role for aggregated IgG in the metabolism of oxidized proteins.
在体外55摄氏度处理的人免疫球蛋白能够与马来酰化牛血清白蛋白（mBSA）相互作用，但不能与未修饰的BSA相互作用。凝胶过滤实验表明，mBSA结合与聚集的IgG高分子量复合物相关。这种对mBSA具有结合能力的聚集IgG也可在体外通过在37摄氏度或40摄氏度处理人IgG以及与人中性粒细胞孵育产生。此外，在类风湿性关节炎患者未经处理的滑液中可检测到对mBSA具有结合活性的IgG聚集体，表明这些复合物在体内存在。与聚集IgG结合的现象扩展到其他修饰蛋白，如马来酰化人血清白蛋白（mHSA）、乙酰低密度脂蛋白（Ac-LDL）以及与氧化亚麻酸反应的BSA。这些修饰蛋白的可溶形式能够竞争聚集IgG与表面结合的mBSA之间的相互作用。我们还发现聚集IgG增强了Ac-LDL依赖性泡沫细胞的形成。这些发现表明聚集IgG在氧化蛋白的代谢中起作用。
