Rifai A, Mannik M
J Exp Med. 1984 Jul 1;160(1):125-37. doi: 10.1084/jem.160.1.125.
To characterize the physiology of circulating IgA immune complexes (IgA-IC), the dynamics of IgA-IC removal by the liver were examined. After intravenous injection, covalently cross-linked IgA antibodies to the dinitrophenyl determinant were rapidly removed from the circulation by the liver. Immunofluorescence microscopy and light and electron microscope autoradiography showed that the IgA-IC were associated with Kupffer cells. With increasing doses of injected IgA-IC the clearance velocity approached a maximum, thus prolonging the circulation of IgA-IC. All these observations indicated a receptor-mediated process. Saturating doses of various potential receptor-blocking agents, heat-aggregated mouse IgG, microaggregated human serum albumin, and purified dimeric IgA did not influence the clearance pattern and hepatic uptake of radiolabeled IgA-IC. Mouse livers were also perfused via the portal vein with 1 microgram of IgA-IC. In the presence or absence of serum proteins, 43% of the perfused IgA-IC were removed in a single passage. This liver uptake was not reduced with simultaneous perfusion of large doses of aggregated mouse IgG, aggregated human serum albumin, or purified free dimeric mouse IgA. In contrast, the liver uptake of radiolabeled IgA-IC was decreased by 88% with the addition of 1 mg unlabeled IgA-IC. These observations support the conclusion that removal of IgA-IC from circulation is mediated by a specific IgA receptor on Kupffer cells.
为了描述循环中IgA免疫复合物（IgA-IC）的生理学特征，研究了肝脏清除IgA-IC的动力学。静脉注射后，与二硝基苯基决定簇共价交联的IgA抗体迅速被肝脏从循环中清除。免疫荧光显微镜检查以及光镜和电镜放射自显影显示，IgA-IC与库普弗细胞相关。随着注射的IgA-IC剂量增加，清除速度接近最大值，从而延长了IgA-IC的循环时间。所有这些观察结果表明这是一个受体介导的过程。各种潜在受体阻断剂的饱和剂量，热聚集的小鼠IgG、微聚集的人血清白蛋白和纯化的二聚体IgA均不影响放射性标记的IgA-IC的清除模式和肝脏摄取。还通过门静脉向小鼠肝脏灌注1微克IgA-IC。在有或没有血清蛋白的情况下，43%的灌注IgA-IC在单次通过时被清除。同时灌注大剂量的聚集小鼠IgG、聚集人血清白蛋白或纯化的游离二聚体小鼠IgA时，肝脏摄取并未减少。相反，加入1毫克未标记的IgA-IC后，放射性标记的IgA-IC的肝脏摄取减少了88%。这些观察结果支持以下结论：从循环中清除IgA-IC是由库普弗细胞上的特异性IgA受体介导的。
