High-throughput screening and selection of yeast cell lines expressing monoclonal antibodies

J Ind Microbiol Biotechnol. 2010 Sep;37(9):961-71. doi: 10.1007/s10295-010-0746-1. Epub 2010 Aug 15.

Abstract

The methylotrophic yeast Pichia pastoris has recently been engineered to express therapeutic glycoproteins with uniform human N-glycans at high titers. In contrast to the current art where producing therapeutic proteins in mammalian cell lines yields a final product with heterogeneous N-glycans, proteins expressed in glycoengineered P. pastoris can be designed to carry a specific, preselected glycoform. However, significant variability exists in fermentation performance between genotypically similar clones with respect to cell fitness, secreted protein titer, and glycan homogeneity. Here, we describe a novel, multidimensional screening process that combines high and medium throughput tools to identify cell lines producing monoclonal antibodies (mAbs). These cell lines must satisfy multiple selection criteria (high titer, uniform N-glycans and cell robustness) and be compatible with our large-scale production platform process. Using this selection process, we were able to isolate a mAb-expressing strain yielding a titer (after protein A purification) in excess of 1 g/l in 0.5-l bioreactors.

MeSH terms

  • Antibodies, Monoclonal / biosynthesis*
  • Antibodies, Monoclonal / genetics
  • Bioreactors
  • Cell Culture Techniques
  • Cell Line
  • DNA, Fungal / genetics
  • Fermentation
  • Gene Expression
  • Genetic Engineering*
  • Glycoproteins / biosynthesis*
  • Glycoproteins / genetics
  • Glycosylation
  • Humans
  • Microbiological Techniques
  • Pichia / genetics
  • Pichia / isolation & purification*
  • Pichia / metabolism
  • Recombinant Proteins / biosynthesis*
  • Recombinant Proteins / genetics
  • Selection, Genetic
  • Transformation, Genetic

Substances

  • Antibodies, Monoclonal
  • DNA, Fungal
  • Glycoproteins
  • Recombinant Proteins