An Efficient Transient Expression System for Enhancing the Generation of Monoclonal Antibodies in 293 Suspension Cells.
BACKGROUND
Recombinant monoclonal antibodies (mAbs) are useful in research, diagnosis, and therapy. The increased demands of recombinant mAbs require efficient production systems. A variety of expression vectors have been developed for stable or transient production of mAbs in mammalian cells. Although a few commercial expression systems of mAbs can be listed, the high expense often impedes academic research.


METHODS
In this study, we described the development of a transient mammalian system based on a bicistronic vector, which contained an internal ribosome entry site (IRES) and enhancer elements to express the IgG1 light chain (LC) and heavy chain (HC) in one transcript. Optimization of all components of the expression system, including gene transfer methods and regulatory elements, yielded maximal expression levels in serum-free 293 suspension cells (Freestyle 293-F).


RESULTS
This method enabled consistent production of the anti-programmed cell death protein 1 (PD-1) mAb up to 300 mg/L in less than one week under transiently transfected conditions. Furthermore, purified anti-PD-1 IgGs showed specific affinity to the target antigen human PD-1 and PHA-stimulated human T cells.


CONCLUSION
The simplicity of the procedure made it suitable for the fast and high-yield production of IgG antibodies in small scales, which expedited the screening of a large number of recombinant candidates.
['Zhang|Guoquan|G|', 'Liu|Jie|J|', 'Fan|Wanting|W|', 'Chen|Qianyi|Q|', 'Shi|Bin|B|']
D000911:Antibodies, Monoclonal D002452:Cell Count D003001:Cloning, Molecular D016895:Culture Media, Serum-Free D015870:Gene Expression D005822:Genetic Vectors D057809:HEK293 Cells D006801:Humans D007074:Immunoglobulin G D007143:Immunoglobulin Heavy Chains D007147:Immunoglobulin Light Chains D061026:Programmed Cell Death 1 Receptor D011994:Recombinant Proteins D013601:T-Lymphocytes D014162:Transfection
transient expression Antibody 293 suspension cell PD-1 human β-globin intron mammalian expression