Recent advances in recombinant protein production

Abstract

Designing appropriate expression vectors is one of the critical steps in the generation of stable cell lines for recombinant protein production. Conventional expression vectors are severely affected by the chromatin environment surrounding their integration site into the host genome, resulting in low expression levels and transgene silencing. In the past, a new generation of expression vectors and different strategies was developed to overcome the chromatin effects. Bacterial artificial chromosomes (BAC s) are cloning vectors capable of accommodating up to 350 Kb. Thus, BAC s can carry a whole eukaryotic locus with all the elements controlling the expression of a gene; therefore, BAC s harbor their own chromatin environment. Expression vectors based on BAC s containing open or permissive chromatin loci are not affected by the chromatin surrounding their integration site in the host cell genome. Consequently, BAC -based expression vectors containing the appropriate loci confer predictable and high levels of expression over time. These properties make BAC -based expression vectors a very attractive tool applied to the recombinant protein production field.