CONSTRUCTION AND EXPRESSION OF SINGLE-CHAIN FV ANTIBODY AGAINST HUMANBLADDER-CARCINOMA

We designed two sets of oligonucleotide primers to amplify the immunog lobulin heavy- and light-chain variable-region genes from genomic DNA radical by polymerase chain reaction (PCR). The genomic DNA was extrac ted from hybridoma BDI-1 cells, which secreted a monoclonal antibody ( mAb) against human bladder carcinoma. The primers contained special re striction sites that allowed the variable-region genes to be easily cl oned for sequencing and expression. The recombinants were sequenced by Sanger's method. It was proved that the full lengths of the V-H and V -K genes were 366 and 324 bp, respectively. Compared with other publis hed sequences: the V-H gene was a member of mouse heavy-chain V-H subg roup II and originated from the rearrangement of V-H, Dsp2.2 and J(H4) . The V-K gene was V-K subgroup IV and from V-K and J(K4). The V-H and V-K genes was inserted expression vector pWAI80. By inducement, the S cFv antibodies were expressed and secreted from Escherichia coil. Bind ing activities against the bladder carcinoma cells were detected. We s uggest that ScFv antibody recognized the antigen specifically.