识别胸腺髓质上皮细胞和胸腺树突状细胞的单链抗体的筛选

A new surface antigen shared by subsets of thymic medullary epithelial cells and thymic dendritic cells recognized by a novel single chain antibody

目的 利用噬菌体展示技术寻找胸腺基质细胞表面的新抗原。方法 用培养的胸腺基质细胞系MTDC作为靶抗原富集初级噬菌体抗体库 ,从经过富集后的次级抗体库中挑选克隆 ,制备单链抗体 ,并在冰冻切片及培养的细胞系上检测抗体的特异性。结果 从经 4轮富集的次级抗体库中挑选到一个新的克隆。用此克隆制备的单链抗体可同时辨认胸腺髓质上皮细胞亚群和胸腺树突状细胞亚群。结论 胸腺髓质上皮细胞和胸腺树突状细胞均具有异质性 ,同时噬菌体展示技术可以作为寻找细胞表面新分子的强有力工具。

Objective To search for new antigens expressed on the surface of thymic stromal cells using phage display technology. Methods The primary phage library was selected with thymic dendritic cell line MTDC to obtain subtracted library. The positive clones were picked up from subtracted library and single chain antibodies were made from these clones. The reactivities of single chain antibodies were tested on mouse frozen sections and various mouse cultured cell lines. Results From the subtracted library of fourth round selection we obtained one new clone. Single chain antibody derived from this clone can recognize a new antigen expressed on the surface of subsets of both thymic medullary epithelial cells and thymic dendritic cells. Conclusion Both epithelial cells and dendritic cells are highly heterogeneous in thymic medulla. Phage display technology can be used as a powerful tool in searching for new antigens on thymic stromal cells.