Efficient production of bispecific antibodies—optimization of transfection strategy leads to high-level stable cell line generation of a Fabs-in-tandem immunoglobin

Abstract Bispecific antibodies (bsAbs) are often composed of more than two component chains, such as Fabs-in-tandem immunoglobin (FIT-Ig) comprising three different which bring challenges for generating a high proportion the correctly assembled bsAbs in stable cell line. During CHO-K1 line construction FIT-Ig, we investigated FIT-Ig chain ratio transfection, where sets expression vectors were designed. Both designs utilized co-transfection. Multiple transfections with plasmid adjustment applied, and resultant minipools evaluated titer quality produced FIT-Ig. The results suggested that abundant outer Fab short chains (twofold genes versus other chains) can promote complete assembly therefore reduce fragmental impurities This ratios at beginning is beneficial to generation brings favorable clones process development.