Efficient production of recombinant secretory IgA against Clostridium difficile toxins in CHO-K1 cells

• Published in: Journal of biotechnology Vol. 331; pp. 1 - 13
• Main Authors: Bhaskara, Venugopal, Leal, Maria Trinidad, Seigner, Jacqueline, Friedrich, Theresa, Kreidl, Emanuel, Gadermaier, Elisabeth, Tesarz, Manfred, Rogalli, Azra, Stangl, Laura, Wallwitz, Jacqueline, Hammel, Katharina, Rothbauer, Mario, Moll, Herwig, Ertl, Peter, Hahn, Rainer, Himmler, Gottfried, Bauer, Anton, Casanova, Emilio
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 10-04-2021
• Subjects: BAC-based expression system; CHO-K1 cells; Dimeric IgA; Flow cytometry sorting; Recombinant protein production; Secretory IgA; Flow cytometry sorting; Recombinant protein production; Secretory IgA; CHO-K1 cells; Dimeric IgA; BAC-based expression system
• ISSN: 0168-1656; 1873-4863
• DOI: 10.1016/j.jbiotec.2021.02.013

•Establishment of a fast and reliable expression system in CHO-K1 cells that allows to develop cell lines in six weeks expressing dimeric IgAs and glyco-engineered human secretory component, hSC.•Establishment of a protocol to purify dimeric IgAs and the hSC.•Establishment of a protocol to reconstitute SIgA.•Validation of the functionality of two dimeric and secretory IgAs against toxins TcdA and TcdB produced with our system.
Despite the essential role secretory IgAs play in the defense against pathogenic invasion and the proposed value of recombinant secretory IgAs as novel therapeutics, currently there are no IgA-based therapies in clinics. Secretory IgAs are complex molecules and the major bottleneck limiting their therapeutic potential is a reliable recombinant production system. In this report, we addressed this issue and established a fast and robust production method for secretory IgAs in CHO-K1 cells using BAC-based expression vectors. As a proof of principle, we produced IgAs against Clostridium difficile toxins TcdA and TcdB. Recombinant secretory IgAs produced using our expression system showed comparable titers to IgGs, widely used as therapeutic biologicals. Importantly, secretory IgAs produced using our method were functional and could efficiently neutralize Clostridium difficile toxins TcdA and TcdB. These results show that recombinant secretory IgAs can be efficiently produced, thus opening the possibility to use them as therapeutic agents in clinics.