Mammalian cell display for rapid screening scFv antibody therapy.

Abstract

Human antibodies are beginning to draw attention for use in immune gene therapy. The efficient generation of effective therapeutic monoclonal antibodies suitable for the treatment of cancers and infectious diseases would be enormously valuable. Antibody display methods are increasingly used to screen human monoclonal antibodies. Here we report the construction of a mammalian cell display method derived from a naive antibody repertoire, for which human single-chain variable fragments (scFv) have been transiently displayed on 293T cell surfaces based on a pDisplay vector. The sizes of the current pDisplay-scFv antibody repertoires have been estimated to be 0.74 × 10(7). An immunoblot assay confirmed the expression of the scFv antibody library. The subcellular distribution of ErbB3-scFv expression plasmid facilitated the display of ErbB3 scFv on the cell membrane surface and the efficiency of the display was evaluated by fluorescence-activated cell sorting. This method of mammalian cell display was verified by successfully screening ErbB3 scFv candidates. A published scFv control was used to confirm the feasibility of the ErbB3 scFv screening process. Three ErbB3 scFv candidates were produced and they were found to have affinity similar to the published scFv candidate. Thus, the present screening system provided an optimal alternative for rapid acquisition of a novel candidate scFv sequence to target genes with high affinity in vitro.