Jasin H E
Inflammation. 1987 Mar;11(1):117-29. doi: 10.1007/BF00917777.
Incubation of immune complexes (IC) bound to plastic surfaces with human blood monocytes for 48 hours resulted in the cross-linking of a proportion of antibody molecules. This process was largely inhibited by the addition of sodium azide to the cultures. Cross-linking was defined as the inability of strong chaotropic solutions (3 M MgCl2 or 5 M guanidine) or acid pH (0.1 N HCl) to solubilize 125I-labeled rabbit anti-human serum albumin attached to plastic-bound antigen. Addition to the cultures of a suitable hydrogen donor such as catechol (0.5 mM) resulted in a large increase in cross-linking of IC. This process was shown to depend on the presence of viable phagocytic cells because incubation with dead monocytes or with viable T lymphocytes failed to induce cross-linking. Quantitation of rabbit immunoglobulin remaining in the wells by enzyme-linked immunoassay techniques excluded the possibility that the increase in 125I bound was merely due to a transiodination reaction. Experiments using various oxygen metabolite inhibitors and scavengers indicated that catechol-dependent protein cross-linking depended on the action of hydrogen peroxide and enzyme systems inhibitable by sodium azide, probably monocyte-peroxidase. Superoxide dismutase, 1O2, and OH X radical scavengers failed to inhibit cross-linking, whereas addition of catalase resulted in almost complete abolition of the process. These observations suggest that catechol-dependent cross-linking of IC may be due to oxidation of catechol to orthoquinone and that this strong oxidant is responsible for nonenzymic chemical action on proteins leading to intermolecular covalent bond formation. Cell-mediated protein cross-linking by oxidative mechanisms may be a prominent feature of drug-related reactions and of acute and chronic inflammatory processes in general. The possible mechanisms involved in catechol-dependent and -independent cross-linking of IC by human mononuclear phagocytes are discussed.
将结合在塑料表面的免疫复合物（IC）与人血单核细胞一起孵育48小时，导致一定比例的抗体分子发生交联。向培养物中添加叠氮化钠可在很大程度上抑制这一过程。交联的定义为强离液剂溶液（3M MgCl2或5M胍）或酸性pH值（0.1N HCl）无法溶解附着在塑料结合抗原上的125I标记的兔抗人血清白蛋白。向培养物中添加合适的氢供体，如儿茶酚（0.5mM），会导致IC交联大幅增加。已证明这一过程取决于活吞噬细胞的存在，因为与死亡单核细胞或活T淋巴细胞孵育无法诱导交联。通过酶联免疫分析技术对孔中剩余兔免疫球蛋白进行定量，排除了125I结合增加仅仅是由于转碘化反应的可能性。使用各种氧代谢物抑制剂和清除剂的实验表明，儿茶酚依赖性蛋白交联取决于过氧化氢的作用以及可被叠氮化钠抑制的酶系统，可能是单核细胞过氧化物酶。超氧化物歧化酶、单线态氧和羟基自由基清除剂无法抑制交联，而添加过氧化氢酶几乎可完全消除这一过程。这些观察结果表明，IC的儿茶酚依赖性交联可能是由于儿茶酚氧化为邻苯醌，并且这种强氧化剂对蛋白质进行非酶促化学作用导致分子间共价键形成。细胞介导的通过氧化机制进行的蛋白交联可能是药物相关反应以及一般急慢性炎症过程的一个突出特征。本文讨论了人单核吞噬细胞对IC进行儿茶酚依赖性和非依赖性交联所涉及的可能机制。
