Mucus secretion studies using anti-gastric mucin monoclonal antibodies

胃粘蛋白是大鼠胃粘液的主要成分，由存在于粘膜上皮的几种不同细胞合成和分泌。一般认为，胃粘膜特定区域和层的细胞对粘蛋白分泌和合成的调节机制不同于其他细胞。识别和估计胃粘膜的特异性粘蛋白对于了解粘液在胃粘膜的生理和病理中的作用是非常重要的。在本研究中，我们制备了几种与特定粘蛋白分子反应的单抗，并应用这些抗体建立了一些研究胃粘液代谢的方法。1)RGM11、21和24是与大鼠胃粘膜表面上皮细胞中的粘蛋白发生特异性反应的单抗。已有研究表明，RGM11和RGM21识别粘蛋白分子特有的寡糖结构。RGM24可与完整的粘蛋白分子反应，但反应蛋白会随着粘蛋白分子中糖基残基的去除而消失。2)我们以纯化的人结肠粘蛋白为免疫原，研制了14种新型单抗(简称HCM系列单抗)。在这些单抗中，有8株能够识别粘蛋白分子中含唾液酸的寡糖结构。3)我们利用RGM11单抗和HIK1083单抗建立了一种夹心ELISA法，分别用于识别和定量大鼠胃单个粘膜样本提取液中的表面粘液细胞来源的粘蛋白和腺体粘液细胞来源的粘蛋白。

Gastric mucin known as a major component of rat gastric mucus is synthesized in and secreted from several different kind of cells present at the mucosal epithelium. It is generally accepted that the regulation mechanism on the secretion and synthesis of mucin in a kind of cells present at the specific region and layr of gastric mucosa differ from the others. It is important to recognaize and estimate the specific mucin of gastric mucosa for understanding the role of mucus in the physiology and pathology of gastric mucosa. In this study we developed several monoclonal antibodies reacting specific mucin molecules and applied these antibodies to establish some methods to study the metabolism of gastric mucins.1) RGM11,21 and 24, are the monoclonal antibodies specifically react with the mucin present at the surface epithelial cells of rat gastric mucosa. It has been demonstrated that RGM11 and 21 recognize the specific oligosaccharide structure of mucin molecule. RGM24 reacts intact mucin molecules but the reactin disappears by the removal of saccharide residue from the mucin molecules.2) We developed 14 novel monoclonal antibodies (MAbs) using purified human colonic mucin as the immunogens (designated as HCM series MAbs). Among these MAbs, 8 MAbs are proved to recognize sialic acid-containing oligosaccaride structure of mucin molecule. In addition, some of these MAbs binding to sialic acid containing sugar chains are specifically react with the intestinal metaplastic mucosa in human stomach.3) We developed a sandwich ELISA mehtod using RGM11 and HIK1083 MAbs to recognize and quantify the surface mucous cell- and gland mucous cell-derived mucin, respectively, included in an extract of single mucosal specimen of rat stomach.