High-level expression of human-mouse chimeric antibody HCAb against human colorectal cancer in CHO cells

[Objective] To high-level express human-mouse chimeric antibody against human colorectal cancer. [Methods] Human-mouse chimeric antibody HCAb was expressed by cloning the light and heavy chain variable region genes from the hybridoma which secretes murine antibody. Then we constructed the light and heavy chain expression vectors and transfected CHO-dhfr-cells. The transfected cells were screened with G418 and subjected to gene amplification in medium containing gradually increasing methotrexate (MTX). The expressed chimeric antibody was quantitated by ELISA. [Results] The chimeric antibody was expressed in CHO cells successfully. The results of RT-PCR and ELISA proved that the expression product was humanized. The antibody production achieved 20 mg/L. [Conclusion] Our work lays a good foundation for its further application into diagnosis reagents and immunotherapeutic tracers against human colorectal cancer.