Induction of passive Heymann nephritis with antibodies specific for a synthetic peptide derived from the receptor-associated protein.
Induction of passive Heymann nephritis with antibodies specific for a synthetic peptide derived from the receptor-associated protein.
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DOI：
10.1084/jem.183.5.2007
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发表时间：
1996-05-01
期刊：
影响因子：
--
通讯作者：
Farquhar MG
中科院分区：
文献类型：
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作者：
Kerjaschki D;Ullrich R;Exner M;Orlando RA;Farquhar MG
被动型Heymann肾炎（pHN）是人类膜性肾小球病的实验性大鼠模型。在pHN中，上皮下免疫沉积物（ID）的形成涉及作为抗原靶的膜糖蛋白gp 330/megalin和44-kD受体相关蛋白（RAP）。ID诱导抗体（Ab）的单一结合位点先前定位于RAP的86个NH 2末端氨基酸（RAP 1 -86）。为了进一步缩小该表位，将从肾小球洗脱的Ab免疫印迹在加载有代表RAP的氨基酸序列的重叠合成肽的膜上（SPOTs系统）。检测到具有序列PVRLAF（氨基酸39-44）和HSD-LKIQE（氨基酸46-53）的两个相邻Ab结合结构域，其在氨基酸45处被单个L残基分开。针对单独含有这些结构域的合成肽（P31- 44和P46-53）产生的兔Ab未能处理肾小球ID。相比之下，针对更大的复合肽（P31-53）的Abs在3d内诱导牢固交联至肾小球基底膜的ID。这些数据表明，抗体在体内的结合依赖于抗原靶序列的构象，该序列保存在合成肽P31-53中，其覆盖RAP的整个抗体结合结构域，但不包括其亚结构域P31-44和P46-53。总的来说，这些结果将RAP的唯一ID诱导表位定位于氨基酸39-53。
Passive Heymann nephritis (pHN) is an experimental rat model for human membranous glomerulopathy. In pHN, the formation of subepithelial immune deposits (ID) involves as antigenic targets the membrane glycoprotein gp330/megalin and the 44-kD receptor-associated protein (RAP). A single binding site for ID- inducing antibodies (Abs) was previously mapped to the 86 NH2-terminal amino acids of RAP (RAP1-86). To further narrow this epitope, Abs eluted from the glomeruli were immunoblotted on membranes that were loaded with overlapping synthetic peptides representing the amino acid sequence of RAP (SPOTs system). Two adjacent Ab-binding domains with the sequences PVRLAF, (amino acids 39-44) and HSD-LKIQE (amino acids 46-53), which were separated by a single L residue at amino acid 45, were detected. Rabbit Abs raised against synthetic peptides containing these domains individually (P31- 44 and P46-53) failed to procedure glomerular IDs. By contrast, Abs raised against a larger composite peptide (P31-53) induced IDs within 3d that were firmly cross linked to the glomerular basement membrane. These data suggest that Ab binding in vivo depends on the conformation of the antigenic target sequence that is preserved in the synthetic peptide P31-53, which covers the entire Ab-binding domain of RAP but not in its subdomains, P31-44 and P46-53. Collectively, these results locate the sole ID-inducing epitope of RAP to amino acids 39-53.