Distribution in Tissue and Biosynthesis of ABO Blood Group Substances Specific for Tissue.

本研究首次应用自行研制的确定丹参ABO血型物质组织特异性表位的单抗，对唾液腺中ABO血型物质的分布进行了研究。用荧光或胶体金标记型抗体作为第二抗体的显微镜和电子显微镜观察表明，该抗体只与唾液腺的粘液细胞反应，而不与其他灵长类动物唾液腺的粘液细胞反应。不幸的是，ABO血型物质或其前体的细胞内分布并不明显，因为实验中使用的唾液腺是从身体上采集的。接下来，我们建立了一种针对肠化生的单抗。结果表明，该抗体识别仅在胃肠上皮化生中表达的糖链，在抗体所定义的糖蛋白分子上也存在携带ABO和Lewis血型活性的糖链。由于众所周知，肠上皮化生组织中ABO和Lewis血型的活性低于正常组织，因此，抗体识别的糖链似乎是生物合成途径中ABO和Lewis血型活性的糖链的前体或前体物质。用该抗体亲和层析可纯化出约数百万kD的抗原糖蛋白。因此，我们认为，通过从大量的胃粘膜中纯化抗原糖蛋白，并明确该抗体所定义的糖链结构，可以明确ABO血型物质在组织中的生物合成途径。

In this study, the monoclonal antibody defining tissue-specific epitope on the ABO blood group substances in salvia, which has been already produced by us, was first applied for investigation to the distribution of the ABO blood group substances in salival gland. In the microscopic and electron microscopic observation using fluorescence or gold colloid conjugated blood group antibody as a second antibody, the antibody reacted with only mucous cells in salival gland, but not react with the the those in salival gland of other primates and animals. Unfortunately, the intracellular distribution of the ABO blood group substances or its precursors ws not obvious, since salival gland used in this experiment was collected from cadavers.Next, we established a monoclonal antibody specific for intestinal metaplasia. It was made clear that the antibody recognized the carbohydrate chain expressing in only intestinal metaplasia of stomach, and that the carbohydrate chain carrying ABO and Lewis blood group activities also existed on the glycoprotein molecules defined by the antibody. Since it is well known that the tissue of intestinal metaplasia shows lower activity of ABO and Lewis blood groups than normal tissues, it seems that the carbohydrate chain recognized by the antibody is a precursor or a precursor-like material of the carbohydrate chain active to ABO and Lewis blood groups in the biosynthetic pathway. Furthermore, about millions kD antigenic glycoprotein could be purified in the affinity chromatography using the antibody. Therefore, we consider to clear biosynthetic pathway of the ABO blood group substances in the tissue by purifying of the antigenic glycoprotein from a large amount of gastric mucosa, and by making out obvious the structure of the carbohydrate chain defined by this antibody.