From Left: Dr Ng Say Kong, Tang Wen Qin, Dr Zhang Wei, Dr Bi Xuezhi
Science
Neutrophil elastase is an enzyme that is essential in fighting infections in the lungs. However, neutrophil elastase can also damage the healthy lungs tissues if there is insufficient amount of alpha-1-antitrypsin (A1AT) to neutralise it, leading to the condition known as emphysema. To treat this condition, human-plasma derived A1AT has to be administered to the patients at high frequency and dosage amounts. The treatment is also costly due to the limited supply of human plasma from donors. This research scaled up the production of recombinant human A1AT (rhA1AT) in a 10L orbital shaking bioreactor, to enable cost-effective rhA1AT production, which provides a potentially more consistent and safe supply of A1AT for patients.
Societal Impact
The project team has demonstrated the scaling up of recombinant A1AT production via single use shaking bioreactor. This can potentially enable a stable supply of rhA1AT and reduce the reliance on human plasma derived A1AT. With the use of a single use bioreactor, the rhA1AT can be produced in a multi-product facility and the initial capital investment could be reduced, thus reducing risks for manufacturers to scale-up rhA1AT production.
Technical Summary
Ten CHO single cell clones producing A1AT were generated and evaluated for their production stability over 12 weeks in the presence and absence of selection agent methotrexate (MTX). The highest performing clone in terms of specific productivity and growth rate was then selected for larger scale production. This was followed by the evaluation of rhA1AT production in both shake flasks and orbital shaking bioreactor, where the selected rhA1AT-producing CHO clone was cultured in fed-batch mode at a starting volume of 100mL and 8L respectively. Similar growth, nutrients and metabolites profiles were observed at both scales. The cell specific productivities in the shake flasks and bioreactor were also found to be comparable at 9.6 to 12 pg/cell/day. These findings demonstrated the scalability of the production process from shake flasks to benchtop bioreactor.
The harvested product was also purified and checked for the activity levels. An improvement in activity levels from 37% to 65% was observed after purification, suggesting that the purification method was effective in removing protein aggregates and fragments. In addition, the identity of the purified product was verified via peptide mapping.
References
Tang, W.Q., Jiang, C.Q.Z., Zheng, Z.Y. et al. Scaled up fed-batch production of recombinant alpha-1-antitrypsin by CHO cells in single-use surface aerated orbital shaken bioreactor. Sci Rep 16, 7790 (2026). https://doi.org/10.1038/s41598-026-37353-w