Nicolas Mermod
University of Lausanne, Switzerland
Title: DNA Recombination Engineering for Improved and More Reliable Protein Expression from DNA Vectors
Biography
Biography: Nicolas Mermod
Abstract
Epigenetic regulatory DNA elements can be added to expression vectors to increase transgene genomic integration, to dampen silencing, and to provide overall a more reliable expression in cultured mammalian cells. Nevertheless, expression remains variable from one cell clone to the next. We have sequenced the genomes of CHO cell clones expressing recombinant proteins, yielding information on the molecular mechanisms that allowed the genomic integration of the plasmid vectors. This provided an approach to transiently silence unwanted recombination pathways, so as to favor a microhomology-based recombination mechanism that mediates integration into expression-permissive genomic loci. When combined to MAR epigenetic regulatory elements, this provides much more predictable and homogeneous levels of transgene expression in polyclonal cell populations expressing a gene of interest.