Enhancing recombinant protein yield and quality using novel CHO GT cells in high density fed-batch cultures

Abstract

Chinese Hamster Ovary (CHO) cells are regarded as one of the a??work-horsesa?? for complex biotherapeutics production. Currently, batch (BC) and fed-batch (FBC) cultures are the main culture modes for a vast majority of industrial bioprocesses due to their ease of operation and reliability. During both BC and FBC, loss in viability attributed to apoptosis often results in lower recombinant protein yield and affects protein quality. It is hypothesized that extension of culture life can potentially improve recombinant glycoprotein yield and quality. Using an a??in-housea?? developed CHO cDNA array and a mouse oligonucleotide array for time profile expression analysis of CHO BC and FBC, the genetic circuitry that regulates and executes apoptosis induction were examined. Genes such as Fadd, Faim, Alg-2, and Requiem were identified to be key apoptosis signaling genes during CHO cell cultures. Four CHO GT (Gene Targeted) cell lines were developed,in which each of these early apoptotic genes was either knocked down or overexpressed.These novel cell lines were shown to be effective in prolonging culture life resulting in higher cell densities and significantly enhancing glycoprotein yield and quality.