Aten J, Veninga A, Coers W, Sonnenberg A, Timpl R, Claessen N, van Eendenburg J D, de Heer E, Weening J J
Department of Pathology, University of Amsterdam, The Netherlands.
Am J Pathol. 1995 Jun;146(6):1467-80.
Exposure to mercuric chloride induces the development of a membranous glomerulopathy with high proteinuria in DZB rats, in which immunoglobulin (Ig)G1 and IgG2a bound in the glomeruli were previously found to react with laminin of the EHS tumor and several unidentified glomerular basement membrane components. Monoclonal antibodies were prepared by fusing cervical and mandibular lymph node cells from a HgCl2-treated DZB rat with a nonsecreting mouse myeloma. Monoclonal antibodies were screened for reactivity with collagenase-digested glomerular basement membrane and kidney sections; upon subcloning, eight stable hybridomas were obtained, named MEC1 to MEC8. MEC2 (IgG1, kappa), MEC3 (IgM, kappa), and MEC5 (IgG1, kappa), as well as the polyclonal glomerular eluate, reacted preferentially with the P1 fragment of the laminin-1 (alpha 1 beta 1 gamma 1) isoform. MEC8 (IgM, kappa) reacted with the P1 and the E4 fragment of laminin. Both MEC6 (IgM, kappa) and MEC8 bound to actin and to various other, unidentified cellular antigens, indicating that MEC6 and MEC8 are polyreactive antibodies. MEC7 (IgM, kappa) bound to a cytoskeleton-linked cell membrane antigen, present on various epithelial cells and between heart muscle fibers and associated with small peripheral, intramuscular nerves. Several of the MEC monoclonal antibodies bound in vivo along the glomerular capillary wall. Although discrete electron-dense subepithelial immune aggregates were not detected and proteinuria was not induced, MEC3 localization changed from a continuous pattern into a fine granular pattern along the glomerular basement membrane, and focally along the TBM, upon passive transfer into naive DZB rats. These findings suggest a pathogenetic role for the P1 fragment of laminin either in the induction phase of HgCl2-induced membranous glomerulopathy as an immunogen or in the effector phase as a target antigen.
在DZB大鼠中，接触氯化汞会诱发伴有高蛋白尿的膜性肾小球病，此前发现肾小球中结合的免疫球蛋白（Ig）G1和IgG2a与EHS肿瘤的层粘连蛋白及几种未鉴定的肾小球基底膜成分发生反应。通过将经HgCl2处理的DZB大鼠的颈淋巴结和下颌淋巴结细胞与非分泌型小鼠骨髓瘤细胞融合，制备了单克隆抗体。筛选单克隆抗体与胶原酶消化的肾小球基底膜和肾脏切片的反应性；亚克隆后，获得了8个稳定的杂交瘤，命名为MEC1至MEC8。MEC2（IgG1，κ）、MEC3（IgM，κ）和MEC5（IgG1，κ）以及多克隆肾小球洗脱液优先与层粘连蛋白-1（α1β1γ1）异构体的P1片段发生反应。MEC8（IgM，κ）与层粘连蛋白的P1和E4片段发生反应。MEC6（IgM，κ）和MEC8均与肌动蛋白及其他几种未鉴定的细胞抗原结合，表明MEC6和MEC8是多反应性抗体。MEC7（IgM，κ）与一种细胞骨架连接的细胞膜抗原结合，该抗原存在于各种上皮细胞上、心肌纤维之间，并与小的外周肌内神经相关。几种MEC单克隆抗体在体内沿肾小球毛细血管壁结合。尽管未检测到离散的电子致密上皮下免疫复合物，也未诱发蛋白尿，但将MEC3被动转移至未接触过抗原的DZB大鼠后，其在肾小球基底膜上的定位从连续模式变为细颗粒模式，并在肾小管基底膜上呈局灶性改变。这些发现表明，层粘连蛋白的P1片段在HgCl2诱导的膜性肾小球病的诱导期作为免疫原或在效应期作为靶抗原发挥致病作用。
