The new approach to produce monoclonal antibody toward differntiated antigens by the aid of immunotolerance.

最近的研究表明，细胞表面糖蛋白和糖脂中的寡糖具有重要的生物学作用，如细胞黏附和发育事件。鉴于精糖链的潜在重要性，我试图研制出能够区分分化抗原和普通抗原的单抗。在免疫耐受的帮助下，免疫动物在注射分化细胞之前，大部分产生抗共同抗原抗体的淋巴样细胞被清除。本实验以嗜铬细胞瘤细胞(PC12)和PC12D细胞为模型抗原。我已经成功地通过联合注射环磷酰胺消除辅助性T细胞来诱导免疫耐受，但未能产生识别分化抗原的单抗。然而，在研究过程中，我发现PC12和PC12D细胞的膜糖蛋白含量有显著差异。在NGF诱导的PC12细胞分化过程中，其分子上含有多聚乳糖胺链的膜糖蛋白比例明显降低。这些结果表明，糖蛋白中聚(N-乙酰乳糖胺)残基含量的减少可能与细胞形态的变化有关。

Recent studies have shown that the oligosacchrides in glycoproteins and glycolipids on the cell surface have inportant biological roles, such as cell adhesion and developmental events. Inview of the potential importance of ologosaccharide chain, i have tried to produce monoclonal antibodies which can discriminate differentiated antigens from commn antigens. By the aid of immunotolerance the most of the lymphoid cells which produce antibodies against the common antigen are eliminated from the immunized animals before injection of differentiated cells. It make us possible to produce specfic miniclonal antibodies toward differentiated antigens.Pheochromocytoma cells(PC12) and PC12D cells, a new subline derived from PC12, were used as a model antigen for this experiment. I have succeeded in the induction of immunotolerance by the elimination of helper T-cells with co-injection of cyclophosphamide, but failed to produce monoclonal antibodies recognized differntiated antigens. However, during the courceof this investigation I found that the amount of membrane glycoproteins deffered significantly between PC12 and PC12D cells. In the NGF induced differntiation of PC12 cells also led to significant decrease in the proportion of membrane glycoproteins which have polylactosamine chains on its molecules. These results suggest that there may be some correlation between the decrease in content of poly(N-acetyllactosaminyl) residues in goycoproteins and the changes in cell morphology.