从EVB转化B细胞克隆中获得抗大肠癌高亲和力单链抗体

B lymphocytes of the colorectal cancer patients were immunized in vitro by purified colorectal cancer antigen-Hb3 and transformed by Epstein-Parr virus. Dectection of Sanwich ELISA showed that 25 percent of B cells transformed by EBV could produce anti-cancer antigen antibodies. 2 types of VH genes and 2 types of VL genes were amplified by PCR and combined to single chain fragments of variable region(scFv) genes. ScFv genes were cloned into vector pET25b(+) and obtained soluble scFv. The VH and VL genes of the scFv were derived from the same B cell clone and their pairs were natural, which could enhance the affinity of scFv and finally paved a way for clinic diagnosis and therapy of colorectal cancer.

用纯化的大肠癌抗原(CA-Hb3)体外致敏大肠癌病人B淋巴细胞，EB病毒转化后，筛选出抗肿隹乖腂细胞克隆并建株。然后扩增其免疫球蛋白V区基因，组装成ScFv，克隆入pET25b(+)表达载体，表达后获得可溶性单链抗体。ScFv基因中VH/VL源自同一B细胞克隆，其配对是天然的，可以极大提高ScFv的亲和力，从而为制备高亲和力人源化抗体提供一条可能的新途径。.