Takaishi H, Ohara S, Hotta K, Yajima T, Kanai T, Inoue N, Iwao Y, Watanabe M, Ishii H, Hibi T
Department of Internal Medicine, School of Medicine, Keio University, Tokyo, Japan.
J Gastroenterol. 2000;35(1):20-7. doi: 10.1007/pl00009971.
To clarify the role of colonic mucin in the autoimmune process of ulcerative colitis, circulating antibodies against human colonic mucin were investigated. Purified colonic mucin, obtained from human colonic mucosa by gel filtration, using a Bio-Gel A-1.5-m column and CsCl equilibrium density gradient, was divided into soluble mucin (S-mucin) secreted extracellularly and membranous mucin (M-mucin) binding to cell membrane. Sodium dodecylsulfate polyacrylamide gel electrophoresis and Western blotting analysis showed that antibodies in the serum samples of some patients with ulcerative colitis recognized purified S- and M-mucin of >180-kD. By enzyme-linked immunosorbent assay (ELISA), anti-mucin antibodies were detected in 11 of 60 patients with ulcerative colitis (18%). In contrast, the antibodies were not detected in 22 patients with Crohn's disease. The titers of antimucin antibodies against S-mucin and M-mucin were not different in each patient. By ELISA using mucin in which the sugar chains were destroyed by neuraminidase or NaIO4 treatment, it was demonstrated that anti-mucin antibodies recognized the epitopes of either the sugar chain or the core protein exposed through destruction of the sugar chains. We then investigated the relationship between anti-mucin antibodies and the patients' clinical features. Anti-mucin antibodies were detected in 6 of 15 patients with chronic continuous type ulcerative colitis (40%) and in 5 of 26 patients with relapsing-remitting type (19%), but there was no antimucin antibody-positive serum in patients who had had only one attack without any relapse. These results suggest that anti-mucin antibodies could be a disease marker for ulcerative colitis and that immunological abnormalities in colonic mucin contribute to the persistence of colonic mucosal inflammation.
为阐明结肠黏蛋白在溃疡性结肠炎自身免疫过程中的作用，对人结肠黏蛋白的循环抗体进行了研究。通过凝胶过滤从人结肠黏膜中获得的纯化结肠黏蛋白，使用Bio-Gel A-1.5-m柱和CsCl平衡密度梯度，被分为细胞外分泌的可溶性黏蛋白（S-黏蛋白）和与细胞膜结合的膜性黏蛋白（M-黏蛋白）。十二烷基硫酸钠聚丙烯酰胺凝胶电泳和蛋白质印迹分析表明，一些溃疡性结肠炎患者血清样本中的抗体可识别分子量>180 kD的纯化S-黏蛋白和M-黏蛋白。通过酶联免疫吸附测定（ELISA），在60例溃疡性结肠炎患者中有11例（18%）检测到抗黏蛋白抗体。相比之下，22例克罗恩病患者未检测到该抗体。每位患者针对S-黏蛋白和M-黏蛋白的抗黏蛋白抗体滴度无差异。通过使用经神经氨酸酶或高碘酸钠处理破坏糖链的黏蛋白进行ELISA，结果表明抗黏蛋白抗体识别通过糖链破坏而暴露的糖链或核心蛋白的表位。然后我们研究了抗黏蛋白抗体与患者临床特征之间的关系。在15例慢性持续型溃疡性结肠炎患者中有6例（40%）检测到抗黏蛋白抗体，在26例复发缓解型患者中有5例（19%）检测到，但在仅发作一次且无任何复发的患者中未检测到抗黏蛋白抗体阳性血清。这些结果表明，抗黏蛋白抗体可能是溃疡性结肠炎的疾病标志物，并且结肠黏蛋白的免疫异常有助于结肠黏膜炎症的持续存在。
