title: CHO cell engineering to prevent polypeptide aggregation and improve therapeutic protein secretion.
abstract: The ability to efficiently produce recombinant proteins in a secreted form is highly desirable and cultured mammalian cells such as CHO cells have become the preferred host as they secrete proteins with human-like post-translational modifications. However, attempts to express high levels of particular proteins in CHO cells may consistently result in low yields, even for non-engineered proteins such as immunoglobulins. In this study, we identified the responsible faulty step at the stage of translational arrest, translocation and early processing for such a "difficult-to-express" immunoglobulin, resulting in improper cleavage of the light chain and its precipitation in an insoluble cellular fraction unable to contribute to immunoglobulin assembly. We further show that proper processing and secretion were restored by over-expressing human signal receptor protein SRP14 and other components of the secretion pathway. This allowed the expression of the difficult-to-express protein to high yields, and it also increased the production of an easy-to-express protein. Our results demonstrate that components of the secretory and processing pathways can be limiting, and that engineering of the secretory pathway may be used to improve the secretion efficiency of therapeutic proteins from CHO cells.
authors: Selexis SA, 18 Ch. des Aulx, Geneva, Switzerland; Laboratory of Molecular Biotechnology, Institute of Biotechnology, University of Lausanne, and Center for Biotechnology UNIL-EPFL, Lausanne, Switzerland.
authors: Valérie
authors: V
authors: Le Fourn
authors: Selexis SA, 18 Ch. des Aulx, Geneva, Switzerland.
authors: Pierre-Alain
authors: PA
authors: Girod
authors: Selexis SA, 18 Ch. des Aulx, Geneva, Switzerland.
authors: Montse
authors: M
authors: Buceta
authors: Selexis SA, 18 Ch. des Aulx, Geneva, Switzerland.
authors: Alexandre
authors: A
authors: Regamey
authors: Laboratory of Molecular Biotechnology, Institute of Biotechnology, University of Lausanne, and Center for Biotechnology UNIL-EPFL, Lausanne, Switzerland. Electronic address: Nicolas.Mermod@unil.ch.
authors: Nicolas
authors: N
authors: Mermod
mesh_terms: D000818:Animals; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D005818:Genetic Engineering; D006801:Humans; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D055571:Secretory Pathway / Q000235:genetics*; D018271:Signal Recognition Particle / Q000235:genetics / Q000378:metabolism*
chemical_list: D011994:Recombinant Proteins; C490326:SRP14 protein, human; D018271:Signal Recognition Particle
keywords: CHO cells; Immunoglobulins; Metabolic engineering; Protein secretion; Therapeutic proteins