title: Optimization of heterologous protein production in Chinese hamster ovary cells under overexpression of spliced form of human X-box binding protein.
abstract: BACKGROUND
  The optimization of protein production is a complex and challenging problem in biotechnology. Different techniques for transcription, translation engineering and the optimization of cell culture conditions have been used to improve protein secretion, but there remain many open problems involving post-translational modifications of the secreted protein and cell line stability.
  
  
  RESULTS
  In this work, we focus on the regulation of secreted protein specific productivity (using a recombinant human immunoglobulin G (IgG)) by controlling the expression of the spliced form of human X-box binding protein (XBP-(s)) in Chinese hamster ovary cells (CHO-K1) under doxycycline (DOX) induction at different temperatures. We observed a four-fold increase in specific IgG productivity by CHO cells under elevated concentrations of DOX at 30°C compared to 37°C, without detectable differences in binding activity in vitro or changes in the structural integrity of IgG. In addition, we found a correlation between the overexpression of human XBP-1(s) (and, as a consequence, endoplasmic reticulum (ER) size expansion) and the specific IgG productivity under DOX induction.
  
  
  CONCLUSIONS
  Our data suggest the T-REx system overexpressing human XBP-1(s) can be successfully used in CHO-K1 cells for human immunoglobulin production.
authors.affiliation: Institute of Biological Sciences, Department of Cell Biology, University of Brasilia, Campus Universitário Darcy Ribeiro, Brasília, DF 70910-900, Brazil. gulis001@gmail.com.
authors.forename: Galina
authors.initials: G
authors.lastname: Gulis
authors.forename: Kelly Cristina Rodrigues
authors.initials: KC
authors.lastname: Simi
authors.forename: Renata Rodrigues
authors.initials: RR
authors.lastname: de Toledo
authors.forename: Andrea Queiroz
authors.initials: AQ
authors.lastname: Maranhao
authors.forename: Marcelo Macedo
authors.initials: MM
authors.lastname: Brigido
mesh_terms: D000818:Animals; D016466:CHO Cells; D003412:Cricetulus; D003470:Culture Media; D004268:DNA-Binding Proteins / Q000235:genetics*; D004318:Doxycycline; D004721:Endoplasmic Reticulum; D006801:Humans; D007074:Immunoglobulin G / Q000096:biosynthesis*; D010957:Plasmids; D020033:Protein Isoforms / Q000235:genetics; D000071701:Regulatory Factor X Transcription Factors; D013696:Temperature; D014157:Transcription Factors / Q000235:genetics*; D014162:Transfection; D000071717:X-Box Binding Protein 1
chemical_list: D003470:Culture Media; D004268:DNA-Binding Proteins; D007074:Immunoglobulin G; D020033:Protein Isoforms; D000071701:Regulatory Factor X Transcription Factors; D014157:Transcription Factors; D000071717:X-Box Binding Protein 1; C000605543:XBP1 protein, human; D004318:Doxycycline
references.citation: J Biotechnol. 2008 Jun 1;135(2):217-23
references.pmid: 18448183
references.citation: Biotechnol Bioeng. 2007 Oct 15;98(3):611-5
references.pmid: 17421043
references.citation: Biotechnol Prog. 2005 Jan-Feb;21(1):17-21
references.pmid: 15903236
references.citation: Biotechnol Bioeng. 2002 Dec 20;80(6):706-16
references.pmid: 12378612
references.citation: Cytotechnology. 2000 Jan;32(1):45-61
references.pmid: 19002966
references.citation: Biotechnol Bioeng. 1999 Jun 5;63(5):573-82
references.pmid: 10397813
references.citation: Eur J Pharm Biopharm. 2010 Feb;74(2):127-38
references.pmid: 19853660
references.citation: Biotechnol Prog. 2004 Nov-Dec;20(6):1683-8
references.pmid: 15575699
references.citation: Biotechnol Bioeng. 2003 May 5;82(3):289-98
references.pmid: 12599255
references.citation: Biotechnol Bioeng. 2002 Mar 20;77(6):704-16
references.pmid: 11807766
references.citation: Front Immunol. 2013 Jul 29;4:217
references.pmid: 23908655
references.citation: Biotechnol Bioeng. 1995 Oct 20;48(2):118-22
references.pmid: 18623467
references.citation: Immunity. 2004 Jul;21(1):81-93
references.pmid: 15345222
references.citation: Metab Eng. 2006 May;8(3):264-72
references.pmid: 16635796
references.citation: Biotechnol Bioeng. 2005 Sep 20;91(6):722-32
references.pmid: 15981277
references.citation: J Biotechnol. 2010 Apr 15;146(4):198-206
references.pmid: 19958799
references.citation: Biotechnol Bioeng. 2003 Feb 20;81(4):496-504
references.pmid: 12491534
references.citation: Biotechnol Bioeng. 1999 Dec 5;65(5):542-9
references.pmid: 10516580