Optimizing Gene Expression in Mammalian Cells

Important post-translational modifications affect both the physicochemical identity and the biological activity of many recombinant polypeptides. Mammalian cells are essential to perform such modifications correctly, and efficient methods have been established to transduce or transfect them, based on either viral or synthetic vectors, or combinations of both. Several parameters affect the efficiency of expression of the transgene, such as the nature and molecular design of the vector, the strength and identity of transcription regulatory signals, and the transfection procedure. Each of these parameters can be optimized to increase gene expression. An approach based on transfection of mammalian cells with DNA consisting of multiple copies of the gene of interest is described in this chapter.