Montgomery R R, Nathanson M H, Malawista S E
Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut 06520.
J Infect Dis. 1994 Oct;170(4):890-3. doi: 10.1093/infdis/170.4.890.
The Fc receptor (FcR) for immunoglobulin has been assigned a major role in the ingestion of Borrelia burgdorferi, the Lyme disease spirochete, by macrophages. Yet macrophages readily take up and kill B. burgdorferi that have not been opsonized. By use of doubly-labeled macrophages infected with spirochetes and analyzed by confocal fluorescence microscopy, simultaneous localization of both FcR and spirochetes (opsonized and unopsonized) was quantified. After infection with unopsonized spirochetes, bacterial surface antigen and the FcR remained distinct, confirming the expectation that unopsonized uptake of B. burgdorferi is largely independent of the FcR. A similar lack of colocalization was seen when opsonized spirochetes were ingested by macrophages whose FcRs were sequestered by an immune complex-coated substrate. Furthermore, comparable efficiency of uptake was observed whether or not the FcR was engaged.
免疫球蛋白的Fc受体（FcR）在巨噬细胞摄取莱姆病螺旋体——伯氏疏螺旋体的过程中被认为起主要作用。然而，巨噬细胞能够轻易摄取并杀死未被调理素化的伯氏疏螺旋体。通过使用感染了螺旋体的双标记巨噬细胞，并利用共聚焦荧光显微镜进行分析，对FcR和螺旋体（调理素化和未调理素化的）的同时定位进行了定量。在用未调理素化的螺旋体感染后，细菌表面抗原和FcR仍然是分开的，这证实了未调理素化的伯氏疏螺旋体摄取在很大程度上独立于FcR这一预期。当FcR被免疫复合物包被的底物隔离的巨噬细胞摄取调理素化的螺旋体时，也观察到了类似的缺乏共定位的情况。此外，无论FcR是否参与，都观察到了相当的摄取效率。
