DEVELOPMENT OF BIFUNCTIONAL VECTORS FOR ANTIBODY LIBRARY SCREENING AND PRODUCTION IN CHO CELLS

Abstract

Monoclonal antibodies are highly valuable in the biopharmaceutical industry, but their development is complex and expensive. Traditionally, methods like in vivo immunisation or in vitro phage display are employed for antibody discovery, while CHO cells are used for production. However, the differences between cells and antibody formats used between these phases can significantly complicate the process. To mitigate this, this thesis aims to develop a bifunctional vector which can help integrate full-form IgG antibody into CHO cells to facilitate discovery and early production. In previous work, an in-house CHO clone with genomic landing pads was established. With recombinase-mediated cassette exchange, plasmid vectors can be targeted into the landing pad, enabling rapid generation of stable expression cell lines. This thesis aims to equip this CHO master cell line with antibody library screening functionalities. It consists of three parts: (1)develop bifunctional vectors that permits simultaneous display and secretion of antibodies, (2)compare multiple promoters, IRES, Fm-T2A, for co-expression of light chain and heavy chain, and (3)validate the vector for isolating high binding antibody from a library.