van Schie R C, Verstraten H G, Tax W J, van den Berkmortel F W, van de Winkel J G, de Mulder P H
Department of Internal Medicine, University Hospital Nijmegen, The Netherlands.
Scand J Immunol. 1992 Sep;36(3):385-93. doi: 10.1111/j.1365-3083.1992.tb02952.x.
Human monocytes and macrophages express an isoform of IgG Fc receptor II (Fc gamma RII), Fc gamma RIIa. Two allotypic variants of this receptor could be distinguished with respect to their ability to bind murine (m)IgG1 complexes either strongly or weakly, defined as high-responder (HR) and low-responder (LR), respectively. We investigated the effect of recombinant (r)IFN-gamma on the ability of freshly isolated monocytes, and those cultured for 40 h and 9 days, to mediate antibody-dependent cell-mediated cytotoxicity (ADCC). Using human erythrocytes (E) sensitized with mIgG1 as target cells, Fc gamma RII was studied selectively. Cells which had been cultured for 40 h exhibit a significantly decreased Fc gamma RII expression, and Fc gamma RII-mediated ADCC activity as compared with freshly isolated monocytes. Co-culture with rIFN-gamma (40 h) reversed this decrease. Short-term rIFN-gamma-cultured cells, and fresh cells express similar numbers of Fc gamma RII, and exhibit comparable Fc gamma RII-mediated ADCC activity. Phagocytic activity was not affected. Prolonged culture of monocytes for 9 days, co-cultured with rIFN-gamma either from day 0 or from day 7, did not affect expression or functional activity of Fc gamma RII. Furthermore, the effects were observed in both HR and LR individuals. Our results show that rIFN-gamma has strong effects on Fc gamma RII-mediated responses specifically during the early stages of monocyte maturation, most likely by affecting receptor expression levels.
人类单核细胞和巨噬细胞表达免疫球蛋白G Fc受体II（FcγRII）的一种同种型，即FcγRIIa。根据该受体与鼠（m）IgG1复合物结合能力的强弱，可区分出两种同种异型变体，分别定义为高反应者（HR）和低反应者（LR）。我们研究了重组（r）干扰素-γ对新鲜分离的单核细胞以及培养40小时和9天的单核细胞介导抗体依赖性细胞介导的细胞毒性（ADCC）能力的影响。以用mIgG1致敏的人类红细胞（E）作为靶细胞，对FcγRII进行了选择性研究。与新鲜分离的单核细胞相比，培养40小时的细胞FcγRII表达和FcγRII介导的ADCC活性显著降低。与r干扰素-γ共培养（40小时）可逆转这种降低。短期用r干扰素-γ培养的细胞和新鲜细胞表达相似数量的FcγRII，并表现出相当的FcγRII介导的ADCC活性。吞噬活性未受影响。单核细胞延长培养9天，从第0天或第7天开始与r干扰素-γ共培养，均不影响FcγRII的表达或功能活性。此外，在HR和LR个体中均观察到了这些效应。我们的结果表明，r干扰素-γ对FcγRII介导的反应有强烈影响，特别是在单核细胞成熟的早期阶段，很可能是通过影响受体表达水平来实现的。
