Miettinen A, Stow J L, Mentone S, Farquhar M G
J Exp Med. 1986 May 1;163(5):1064-84. doi: 10.1084/jem.163.5.1064.
Antibodies specific for the core protein of basement membrane HSPG (Mr = 130,000) were administered to rats by intravenous injection, and the pathologic consequences on the kidney were determined at 3 min to 2 mo postinjection. Controls were given antibodies against gp330 (the pathogenic antigen of Heymann nephritis) or normal rabbit IgG. The injected anti-HSPG(GBM) IgG disappeared rapidly (by 1 d) from the circulation. The urinary excretion of albumin increased in a dose-dependent manner during the first 4 d, was increased 10-fold at 1-2 mo, but remained moderate (mean = 12 mg/24 h). By immunofluorescence the anti-HSPG(GBM) was seen to bind rapidly (by 3 min) to all glomerular capillaries, and by immunoperoxidase staining the anti-HSPG was seen to bind exclusively to the laminae rarae of the GBM where it remained during the entire 2-mo observation period. C3 was detected in glomeruli immediately after the injection (3 min), where it bound exclusively to the lamina rara interna; the amount of C3 bound increased up to 2 h but decreased rapidly thereafter, and was not detectable after 4 d. Mononuclear and PMN leukocytes accumulated in glomerular capillaries, adhered to the capillary wall, and extended pseudopodia through the endothelial fenestrae to contact in the LRI of the GBM where the immune deposits and C3 were located. At 1 wk postinjection, staining for C3 reappeared in the glomeruli of some of the rats, and by this time most of the rats, including controls injected with normal rabbit IgG, had circulating anti-rabbit IgG (by ELISA) and linear deposits of rat IgG along the GBM (by immunofluorescence). Beginning at 9 d, there was progressive subepithelial thickening of the GBM which in some places was two to three times its normal width. This thickening was due to the laying down of a new layer of basement membrane-like material on the epithelial side of the GBM, which gradually displaced the old basement membrane layers toward the endothelium. The results show that the core proteins of this population of basement membrane HSPG (Mr = 130,000), which are ubiquitous components of basement membranes, are exposed to the circulation and can bind anti-HSPG(GBM) IgG in the laminae rarae of the GBM. Binding of these antibodies to the GBM leads to changes (C3 deposition, leukocyte adherence, moderate proteinuria, GBM thickening) considered typical of the acute phase of anti-GBM glomerulonephritis. Antibody binding interferes with the normal turnover of the GBM, presumably by affecting the biosynthesis and/or degradation of basement membrane components.
将针对基底膜硫酸乙酰肝素蛋白聚糖核心蛋白（分子量 = 130,000）的抗体通过静脉注射给予大鼠，并在注射后3分钟至2个月测定对肾脏的病理影响。对照组给予抗gp330（海曼肾炎的致病抗原）抗体或正常兔IgG。注射的抗HSPG（GBM）IgG迅速（1天内）从循环中消失。在最初4天内，白蛋白尿排泄呈剂量依赖性增加，在1 - 2个月时增加了10倍，但仍处于中等水平（平均 = 12 mg/24 h）。通过免疫荧光观察到抗HSPG（GBM）在3分钟内迅速与所有肾小球毛细血管结合，通过免疫过氧化物酶染色观察到抗HSPG仅与GBM的内疏松层结合，并在整个2个月的观察期内一直存在。注射后立即（3分钟）在肾小球中检测到C3，它仅与内疏松层内部结合；结合的C3量在2小时内增加，但此后迅速减少，4天后无法检测到。单核细胞和PMN白细胞在肾小球毛细血管中积聚，黏附于毛细血管壁，并通过内皮窗伸出伪足，与GBM内疏松层中免疫沉积物和C3所在位置接触。注射后1周，部分大鼠肾小球中C3染色再次出现，此时大多数大鼠，包括注射正常兔IgG的对照组，循环中出现抗兔IgG（通过ELISA检测），并且沿GBM出现大鼠IgG的线性沉积物（通过免疫荧光检测）。从第9天开始，GBM出现进行性上皮下增厚，在某些部位增厚至正常宽度的两到三倍。这种增厚是由于在GBM上皮侧沉积了一层新的基底膜样物质，该物质逐渐将旧的基底膜层向内皮方向推移。结果表明，这种基底膜硫酸乙酰肝素蛋白聚糖群体的核心蛋白（分子量 = 130,000）是基底膜的普遍成分，暴露于循环中，并能在GBM的疏松层中结合抗HSPG（GBM）IgG。这些抗体与GBM的结合导致了抗GBM肾小球肾炎急性期典型的变化（C3沉积、白细胞黏附、中度蛋白尿、GBM增厚）。抗体结合可能通过影响基底膜成分的生物合成和/或降解来干扰GBM的正常更新。
