Department of Medical Sciences, University Hospital, Uppsala University, SE-751 85 Uppsala, Sweden.
Eur J Gastroenterol Hepatol. 2010 Apr;22(4):429-36. doi: 10.1097/MEG.0b013e32833283b1.
Autoantibodies against goblet cells in the gastrointestinal mucosa have been described in patients with inflammatory bowel disease (IBD) but a corresponding autoantigen has not yet been identified. The aim of this study was to identify such an antigen.
First, 10 candidate autoantigens were discarded based on double stainings of appendiceal sections and a mucin-producing cell line (HT29-mtx). Second, an appendiceal cDNA library was immunoscreened with IBD sera.
Three out of 48 positive clones were identified as complement C3. Using immunoprecipitation of in vitro transcribed and translated C3, seven of 17 primary sclerosing cholangitis patient sera, 15 of 65 IBD sera, and none out of 54 sera from healthy blood donors showed C3 immunoreactivity. The results were confirmed using western blot and an enzyme-linked immunosorbent assay with alternative sources of C3 protein.
In conclusion, we have identified complement C3 as a potential autoantigen in IBD and primary sclerosing cholangitis.
在炎症性肠病（IBD）患者的胃肠道黏膜中发现了针对杯状细胞的自身抗体，但尚未鉴定出相应的自身抗原。本研究旨在鉴定这种抗原。
首先，根据阑尾切片和粘蛋白产生细胞系（HT29-mtx）的双重染色，排除了 10 种候选自身抗原。其次，用 IBD 血清对阑尾 cDNA 文库进行免疫筛选。
在 48 个阳性克隆中，有 3 个被鉴定为补体 C3。使用体外转录和翻译的 C3 进行免疫沉淀，7 例原发性硬化性胆管炎患者血清、15 例 IBD 患者血清和 54 例健康献血者血清中均无 C3 免疫反应。使用 Western blot 和酶联免疫吸附试验（使用 C3 蛋白的替代来源）对结果进行了验证。
总之，我们已经鉴定出补体 C3 是 IBD 和原发性硬化性胆管炎的潜在自身抗原。
