title: Evaluating the expression profile and stability of different UCOE containing vector combinations in mAb-producing CHO cells.
abstract: As the demand for monoclonal antibodies (mAb) increases, more efficient expression methods are required for their manufacturing process. Transcriptional gene silencing is a common phenomenon in recombinant cell lines which leads to expression reduction and instability. There are reports on improved antibody expression in ubiquitous chromatin opening element (UCOE) containing both heavy and light chain gene constructs. Here we investigate the impact of having these elements as part of the light chain, heavy chain or both genes during cell line development. In this regard, non-UCOE and UCOE vectors were constructed and stable Chinese hamster ovary (CHO) cell pools were generated by different vector combinations.
  
  
  
  Expression analysis revealed that all UCOE cell pools had higher antibody yields compared to non-UCOE cells, Moreover the most optimal expression was obtained by cells containing just the UCOE on heavy chain. In terms of stability, it was shown that the high level of expression was kept consistence for more than four months in these cells whereas the expression titers were reduced in the other UCOE pools.
  
  
  
  In conclusion, UCOE significantly enhanced the level and stability of antibody expression and the use of this element with heavy chain provided more stable cell lines with higher production level.
authors.affiliation: Biotechnology Research Center, Pasteur Institute of Iran, Tehran, 1316943551, Iran.
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Nematpour
authors.affiliation: Biotechnology Research Center, Pasteur Institute of Iran, Tehran, 1316943551, Iran.
authors.forename: Fereidoun
authors.initials: F
authors.lastname: Mahboudi
authors.affiliation: Biotechnology Research Center, Pasteur Institute of Iran, Tehran, 1316943551, Iran.
authors.forename: Behrouz
authors.initials: B
authors.lastname: Vaziri
authors.affiliation: Biotechnology Research Center, Pasteur Institute of Iran, Tehran, 1316943551, Iran.
authors.forename: Vahid
authors.initials: V
authors.lastname: Khalaj
authors.affiliation: Biotechnology Research Center, Pasteur Institute of Iran, Tehran, 1316943551, Iran.
authors.forename: Samira
authors.initials: S
authors.lastname: Ahmadi
authors.affiliation: Biotechnology Research Center, Pasteur Institute of Iran, Tehran, 1316943551, Iran.|Departments of Medical Biotechnology, Semnan University of Medical Sciences, Semnan, 3519899951, Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Ahmadi
authors.affiliation: Biotechnology Research Center, Pasteur Institute of Iran, Tehran, 1316943551, Iran.
authors.forename: Saedeh
authors.initials: S
authors.lastname: Ebadat
authors.affiliation: Biotechnology Research Center, Pasteur Institute of Iran, Tehran, 1316943551, Iran. f_davami@pasteur.ac.ir.
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Davami
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000096:biosynthesis* / Q000235:genetics*; D016466:CHO Cells; D002843:Chromatin / Q000235:genetics*; D003412:Cricetulus; D005786:Gene Expression Regulation / Q000235:genetics*; D005822:Genetic Vectors / Q000235:genetics*; D011401:Promoter Regions, Genetic / Q000235:genetics; D015202:Protein Engineering / Q000379:methods*; D019076:Transgenes / Q000235:genetics
chemical_list: D000911:Antibodies, Monoclonal; D002843:Chromatin
keywords: Cell line development; Chinese hamster ovary (CHO); Monoclonal antibody (mAb); Ubiquitous chromatin opening elements (UCOE)