Mannhalter J W, Eibl M M
Institut für Immunologie der Universität Wien, Austria.
Int Rev Immunol. 1989;5(2):173-9. doi: 10.3109/08830188909061984.
IVIgG preparations are now widely applied for immune modulatory treatment in various forms of autoimmune and immune complex diseases. Several controlled studies clearly demonstrated the clinical efficacy of this type of treatment; the underlying pathophysiological mechanisms, however, have yet to be elucidated. Among the mechanisms suggested to play a role in this context is the interaction of gamma globulin with Fc gamma receptors (Fc gamma R) expressed in the membrane of immunocompetent cells. Our studies concentrated on these aspects and focused on possible functional consequences of IgG-Fc gamma R interaction. By using the peripheral blood monocyte as a model system for an Fc gamma R-bearing cell, we confirmed previous reports by showing differences in Fc gamma R binding and Fc gamma R modulation induced by IgG in its various forms (monomeric IgG, Polymeric IgG, immune complexes). As biological consequences of Fc gamma R modulation, changes in effector and accessory function of these cells were observed. The results presented in this brief review emphasize especially the difference between ligand-oriented Fc gamma R diffusion (induced by surface-bound IgG) and true long-term down-modulation of Fc gamma R (mediated by fluid-phase IgG polymers) and show that only the down-modulation of Fc gamma R correlated with impaired functions of the affected cell.
静脉注射免疫球蛋白制剂目前已广泛应用于各种自身免疫性疾病和免疫复合物疾病的免疫调节治疗。多项对照研究清楚地证明了这类治疗的临床疗效；然而，其潜在的病理生理机制尚未阐明。在这一过程中被认为起作用的机制包括γ球蛋白与免疫活性细胞膜上表达的Fcγ受体（FcγR）的相互作用。我们的研究集中在这些方面，并关注IgG-FcγR相互作用可能产生的功能后果。通过将外周血单核细胞作为携带FcγR细胞的模型系统，我们证实了先前的报道，即不同形式的IgG（单体IgG、多聚体IgG、免疫复合物）诱导的FcγR结合和FcγR调节存在差异。作为FcγR调节的生物学后果，观察到这些细胞的效应和辅助功能发生了变化。本简要综述中呈现的结果特别强调了配体导向的FcγR扩散（由表面结合的IgG诱导）与FcγR真正的长期下调（由液相IgG聚合物介导）之间的差异，并表明只有FcγR的下调与受影响细胞功能受损相关。
