Establishment of Detection Systems and Expression Systems for Organ-Specific Mucins

本课题的目的是建立检测各种人上皮粘蛋白的系统，并建立获得表达粘蛋白核心多肽cDNA的稳定转染细胞的系统，具体而言，制备特异于独特粘蛋白的单克隆抗体，并制备含有粘蛋白核心多肽cDNA的表达载体。本课题的主要研究结果如下：（1）建立了一种新的唾液酸化MUC 1单克隆抗体MY.1E12。(2)已经制备了含有嵌合粘蛋白（MUC 1/MMGL和MUC 2/MMGL）的载体。(3)已使用人肾癌细胞制备了稳定的转染细胞系和克隆。研究了这些细胞的生物学行为。(4)将通过转染K562人红白血病细胞表达的MUC 1粘蛋白的糖基化与内源性白细胞粘蛋白的糖基化进行比较。(5)分离出一种肠杆菌属菌株表达的凝集素，该凝集素与MUC 2粘蛋白结合，但不与MUC 1粘蛋白结合。(6)从该细菌中分离出一种新的凝集素。(7)MUC 1粘蛋白基因的一个可诱导的转录顺式作用元件已被鉴定。从乳腺癌细胞的核提取物中分离出与该元件结合的蛋白质。(8)克隆并表达了人巨噬细胞凝集素的cDNA。已证明该凝集素的碳水化合物结合特异性结合Tn和唾液酸-Tn抗原。

The aims of this proposal is to establish systems to detect various human epithelial mucins and to establish systems to obtain stable transfectant cells expressing mucin core polypeptide cDNA.Specifically, preparation of monoclonal antibodies specific for unique mucins and preparation of expression vectors containing mucin core polypeptide cDNA were conducted. Elucidation of the transcriptional regulation of mucin core polypeptides was also performed.The following list consists of the findings obtained during the project term : (1) A novel monoclonal antibody MY.1E12 specific for sialylated MUC1 mucin was established. (2) Vectors containing chimera mucins (MUC1/MMGL and MUC2/MMGL) have been prepared. (3) A stable transfectant cell line and clones have been prepared using human renal carcinoma cells. The biological behavior of these cells were investigated. (4) Glycosylation of MUC1 mucins expressed by transfection of K562 human erythroleukemia cells was compared to the glycosylation of endogenous leukocyte mucins. (5) A lectin expressed by a strain of enterobacterium was isolated and shown to bind MUC2 mucin but not MUC1 mucin. (6) A novel lecting that was isolated from this bacterium. (7) An inducible transcriptional cis-acting element for MUC1 mucin gene has been identified. Binding proteins to this element were isolated from nuclear extracts of mammary carcinoma cells. (8) A cDNA corresponding to human macrophage lectin has been cloned and expressed. The carbohydrate binding specificity of this lectin has been demonstrated to bind to Tn and sialyl-Tn antigens.