Peutz-Kootstra C J, Hansen K, De Heer E, Abrass C K, Bruijn J A
Department of Pathology, Leiden University Medical Center, Leiden, The Netherlands.
J Pathol. 2000 Nov;192(3):404-12. doi: 10.1002/1096-9896(2000)9999:9999<::AID-PATH707>3.0.CO;2-L.
Mice with chronic graft-versus-host disease (GvHD) develop a lupus-like disease with severe immune complex glomerulonephritis. Previous studies with this model have shown that anti-laminin autoantibodies are involved in immune complex formation and that glomerular laminin expression alters qualitatively. The present study investigated glomerular laminin chain expression and autoantibody reactivity with matrix antigens during disease development in mice with chronic GvHD, killed before and 6, 8, 10, and 11 weeks after disease induction, using antibodies raised against laminin chain peptides, in immunofluorescence and western blotting studies. Decreased glomerular expression of the laminin beta1 chain, unaltered expression of the laminin beta2 and gamma1 chains, and increased expression of the laminin alpha1 chain and filamin/actin-binding protein 280 (ABP 280) were found during disease progression. Furthermore, 4 weeks after disease induction, autoantibodies appeared which were reactive with laminin alpha1, beta1, beta2, and gamma1 chains, and filamin in rat mesangial cell matrix. Ten weeks after disease induction, autoantibodies reacted with filamin, and beta2 and gamma1 laminin chains. Autoantibodies reacted with laminin chains only and not with other proteins in matrices extracted from glomeruli of normal and diseased mice. Staining with H50, an anti-laminin alpha1 chain/anti-filamin monoclonal autoantibody derived from an MRL/lpr mouse with spontaneous lupus nephritis, confirmed these observations and showed identical anti-laminin/anti-filamin autoantibody reactivity in two different models for lupus nephritis. In summary, differential glomerular expression of laminin chains was found during the development of chronic GvHD. Concomitantly with expression of the laminin alpha1 chain and/or filamin in the glomerulus, anti-laminin alpha1 and/or anti-filamin reactivity was present, pointing towards a role for (neo) antigen expression in the epitope spreading of the immune response. Furthermore, glomerular expression of laminin beta1 decreased in conjunction with decreased presence of anti-laminin beta1 reactivity, presumably due to antigen masking or shedding of immune complexes into the urine. These changes in anti-laminin chain autoantibodies, with concomitant alterations in the glomerular expression of laminin chains, may aggravate progressive immune injury in this model for lupus nephritis.
患有慢性移植物抗宿主病（GvHD）的小鼠会患上一种类似狼疮的疾病，并伴有严重的免疫复合物性肾小球肾炎。此前对该模型的研究表明，抗层粘连蛋白自身抗体参与免疫复合物的形成，且肾小球层粘连蛋白的表达在质量上发生了改变。本研究使用针对层粘连蛋白链肽产生的抗体，通过免疫荧光和蛋白质印迹研究，调查了慢性GvHD小鼠在疾病发展过程中肾小球层粘连蛋白链的表达以及自身抗体与基质抗原的反应性。这些小鼠在疾病诱导前以及诱导后6、8、10和11周被处死。在疾病进展过程中，发现肾小球层粘连蛋白β1链的表达减少，层粘连蛋白β2链和γ1链的表达未改变，层粘连蛋白α1链和细丝蛋白/肌动蛋白结合蛋白280（ABP 280）的表达增加。此外，在疾病诱导4周后，出现了与大鼠系膜细胞基质中的层粘连蛋白α1、β1、β2和γ1链以及细丝蛋白发生反应的自身抗体。在疾病诱导10周后，自身抗体与细丝蛋白以及层粘连蛋白β2和γ1链发生反应。自身抗体仅与层粘连蛋白链发生反应，而不与从正常和患病小鼠肾小球中提取的基质中的其他蛋白质发生反应。用H50（一种源自患有自发性狼疮性肾炎的MRL/lpr小鼠的抗层粘连蛋白α1链/抗细丝蛋白单克隆自身抗体）进行染色，证实了这些观察结果，并显示在两种不同的狼疮性肾炎模型中存在相同的抗层粘连蛋白/抗细丝蛋白自身抗体反应性。总之，在慢性GvHD的发展过程中发现了肾小球层粘连蛋白链的差异表达。伴随着肾小球中层粘连蛋白α1链和/或细丝蛋白的表达，出现了抗层粘连蛋白α1和/或抗细丝蛋白反应性，这表明（新）抗原表达在免疫反应的表位扩展中起作用。此外，肾小球层粘连蛋白β1的表达下降，同时抗层粘连蛋白β1反应性的存在减少，这可能是由于抗原掩盖或免疫复合物向尿液中脱落所致。抗层粘连蛋白链自身抗体的这些变化，以及层粘连蛋白链在肾小球表达中的伴随改变，可能会加重该狼疮性肾炎模型中的进行性免疫损伤。
