Termaat R M, Assmann K J, van Son J P, Dijkman H B, Koene R A, Berden J H
Department of Pathology, University Hospital Nijmegen, The Netherlands.
Lab Invest. 1993 Feb;68(2):164-73.
MRL/l mice with diffuse proliferative glomerulonephritis, and graft-versus-host (GVH) mice with membranous glomerulonephritis, are both regarded as models for human systemic lupus erythematosus. In these two models, the specificity of the nephritogenic antibodies was analyzed.
The nephritogenic antibodies were eluted from isolated glomeruli with an acid buffer. The antibodies were purified from these eluates on protein-A sepharose under high salt conditions to exclude the presence of antigens potentially bound to the antibodies. The specificities of the antibodies were analyzed towards components of the glomerular basement membrane (GBM), nuclear antigens and brush border of proximal epithelial cells in the indirect immunofluorescence (IF), enzyme linked immunosorbent assay, and Crithidia luciliae assay. Furthermore, we studied the glomerular binding by IF and immunoelectron microscopy after intravenous injection of the eluted antibodies into control mice.
Glomerular eluates of both MRL/l and GVH mice showed nuclear staining and linear to homogeneous binding to GBM and tubular basement membrane in IF on normal mouse kidney. In enzyme linked immunosorbent assay, both eluates reacted not only with DNA, but also with histones and laminin, an important component of the GBM, however not with brush border. Reactivity with dsDNA was also found in the Crithidia luciliae assay for both eluates. In vivo binding was determined by injection of eluates into control MRL/n and F1 hybrid mice. The GVH eluate showed linear to homogeneous binding to the GBM 1.5 hour after injection which changed into a granular, membraneous pattern after 5 days, as determined by IF and immunoelectron microscopy. The MRL/l eluate also demonstrated linear to homogeneous binding to the GBM 1.5 hour after intravenous injection, that had decreased after 5 days, but did not change into a granular pattern.
In these two models of systemic lupus erythematosus nephritis not only antibodies to DNA and histones, but also antibodies to laminin are involved in the induction of murine systemic lupus erythematosus nephritis. The latter antibody specificity has not been identified before in renal or glomerular eluates obtained from diseased MRL/l mice.
患有弥漫性增殖性肾小球肾炎的MRL/l小鼠和患有膜性肾小球肾炎的移植物抗宿主（GVH）小鼠，均被视为人类系统性红斑狼疮的模型。在这两种模型中，对致肾炎抗体的特异性进行了分析。
用酸性缓冲液从分离出的肾小球中洗脱致肾炎抗体。在高盐条件下，在蛋白A琼脂糖凝胶上从这些洗脱液中纯化抗体，以排除可能与抗体结合的抗原的存在。通过间接免疫荧光法（IF）、酶联免疫吸附测定和利什曼原虫检测，分析抗体对肾小球基底膜（GBM）成分、核抗原和近端上皮细胞刷状缘的特异性。此外，在将洗脱的抗体静脉注射到对照小鼠体内后，我们通过IF和免疫电子显微镜研究了肾小球结合情况。
MRL/l和GVH小鼠的肾小球洗脱液在正常小鼠肾脏的IF中均显示核染色，以及与GBM和肾小管基底膜呈线性至均匀结合。在酶联免疫吸附测定中，两种洗脱液不仅与DNA反应，还与组蛋白和GBM的重要成分层粘连蛋白反应，但不与刷状缘反应。在两种洗脱液的利什曼原虫检测中也发现了与双链DNA的反应性。通过将洗脱液注射到对照MRL/n和F1杂交小鼠体内来确定体内结合情况。通过IF和免疫电子显微镜测定，GVH洗脱液在注射后1.5小时显示与GBM呈线性至均匀结合，5天后变为颗粒状、膜状模式。MRL/l洗脱液在静脉注射后1.5小时也显示与GBM呈线性至均匀结合，5天后有所下降，但未变为颗粒状模式。
在这两种系统性红斑狼疮肾炎模型中，不仅DNA和组蛋白抗体，层粘连蛋白抗体也参与了小鼠系统性红斑狼疮肾炎的诱导。后一种抗体特异性在从患病MRL/l小鼠获得的肾脏或肾小球洗脱液中此前尚未被鉴定出来。
