Abstract:

Objective   To screen the soluble ScFv antibodies which were specific for human prostatic cancer from the successfully constructed phage antibody library and analyse their biological characteristics. Methods   Normal human noncancerous epithelial line BPH was used to deplete the phage library of nonspecific binders. Supernatant containing depleted phage library was then incubated with prostate cancer cells DU145. The phage library was enriched by three cycles of binding, elution and amplification.The prostate cancer cells DU145 was used to screen the positive clones with high affinity using FACS. The screening postive clone was sub-cloned and infected by TG1 to get the soluble ScFv antibody. The biological characteristics of ScFv were identified by the method of FACS and immunofluorescence. Results   19 phage antibodies were gotten with the antigens of DU145. C11 had the highest affinity with DU145 cells among all the above antibodies. C11 ScFv monoclonal antibody was expressed and purified after sub-cloning. The results of FACS and immunofluorescence both indicated that C11 ScFv could bind to DU145 and PC3 cells but could not bind to BPH cells. Conclusions   The soluble ScFv antibody which has high affinity with prostatic cancer cell line is successfully producted by phage antibody display technology. This may be useful for futher study of target therapy of antibody.

Key words: Phage display technology; Prostatic neoplasms; ScFv antibody; Benign prostatic hyperplasia cells; DU145 cells; PC3 cells