Omid Mohammadian
1, Masoumeh Rajabibazl
1, Hadi Bayat
2,3, Azam Rahimpour
2,3*1 Department of Clinical Biochemistry, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
2 Nano-Technology and Tissue Engineering Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
3 Department of Tissue Engineering and Applied Cell Sciences, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Abstract
Background: Monoclonal antibodies (mAbs) are considered the most
important and financially successful category of the biopharmaceuticals.
Extensive optimization of the expression vector, host system and culture
parameters are required for the successful production of active monoclonal
antibodies in mammalian cells. In this regards, transient expression enables
rapid and cost-effective production of recombinant proteins for initial
characterization.
Methods: In the present study, an internal ribosome entry site
(IRES) based bicistronic expression system has been evaluated for the transient
expression of an anti-CD52 monoclonal antibody in mammalian cells. The IRES
based bicistronic vector was generated through sequential cloning of the Light
chain (LC), IRES, and Heavy chain (HC) in an intermediate vector and transfer
of the resulting fragment to the expression vector. Transfection of the HEK293T
cells was performed and antibody expression was analyzed in cell culture
supernatant.
Results:
Restriction enzyme analysis
indicated successful cloning of the antibody coding unit in the expression
vector. Analysis of EGFP expression indicated successful transfection of the
HEK293T cells. Production levels of 220 µg/L of antibody were achieved in
HEK293T cells during three days of culture.
Conclusion: Our results show the convenience and efficiency of
the bicistronic expression system for transient expression of the whole
monoclonal antibodies in mammalian cells.