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Development of a Manufacturing Platform for Recombinant Bet v1.0101 using Chinese Hamster Ovary cells


J. Rook, H. Warmenhoven, O. Brugman,  D. Verbart, A. Huybens, H. van Schijndel 
1HALIX B.V., Leiden, The Netherlands, 2 HAL Allergy BV, Leiden, The Netherlands

Background & Aim:

Chinese Hamster Ovary (CHO) cells are widely used for the production of therapeutic proteins. Unlike bacterial expression systems, CHO cells possess human-like posttranslational modification machineries enabling the production of properly folded recombinant proteins while no endotoxins are produced. In this study bioreactor-scale manufacturing processes were employed and a feeding strategy was developed to optimize the yield of rBet v1.0101 expressed by a stable CHO cell line previously established at HAL Allergy BV


  • A single use 2 L shaker bioprocess reactor and a 10 L bioreactor were inoculated with pre-cultures of stably growing CHO-rBet v1.0101 cells. Cells were supplemented with D-glucose and fed with a proprietary feed. A shake flask culture of CHO-rBet v1.0101 cells fed with the same feed and D-glucose served as control.
  • In parallel the effect of several commercial CHO feeds on the cell growth and rBet v1.0101 yield was investigated in a separate shaker flask study. Cells were fed with D-glucose and 6 different feeds. A culture fed only with D-glucose served as control.
  • During all experiments cell density and viability were monitored at various time intervals using an electronic cell counter (Casy counter). The metabolites were analyzed using a Biochemistry analyser (Nova Bioprofiler). D-glucose levels were monitored using a hand-held glucose meter (Betacheck G5). Recombinant Bet v1.0101 titers were determined using a commercially available Bet v1 ELISA.


  • The single use 2 L bioprocess reactor and 10 L bioreactor showed similar rBet v1.0101 titers compared to the control culture (Figure 1).
  • The feed screen study in shaker flasks delivered higher viable cell densities, prolonged viability (Figure 2) and higher rBet v1.0101 titers (Figure 3) compared to the control culture.
  • The best performing feed of the feed screen study yielded approximately 14 times more Bet v1.0101 compared to control culture (Figure 3).


  • Based on the data obtained the 10 L bioreactor and 2 L bioprocess reactor can be regarded as suitable manufacturing platforms to produce higher volumetric yields of recombinant Bet v1.0101 compared to a 125 ml shake flasks.
  • Screening several proprietary feeds revealed notable differences in product titer which should be taken into account when optimizing the yield of a CHO cell line.
  • Combining a bioreactor scale platform and an optimized feed strategy increases the rBet v1.0101 production. It is anticipated that, eventually, economically viable yields can be reached.

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About HAL Allergy

HAL Allergy Group is active in the field of biopharmaceuticals and is located at the Bio Science Park in Leiden, The Netherlands. Our core business is the development and manufacturing of therapies and diagnostics for allergic diseases. In addition, we offer contract manufacturing services focusing on the production of biopharmaceutical products for (pre-) clinical studies. With offices in major European countries, HAL Allergy is one of the European top players in the allergy immunotherapy business. Established in 1959 HAL Allergy has long experience in developing, producing and selling allergy therapies with an immuno-modulatory effect causing a reduction in symptoms and long-term disease suppression. The allergy therapies are used against common allergies such as hay fever, house dust mites allergy and allergic reactions towards wasp or bee stings. More information is available on:   

The main shareholder of HAL Allergy GmbH is Droege International Group AG, which is an independent Advisory and Investment Company, based in Düsseldorf, Germany. More information is available on: 

HAL Allergy Group

Monique Lutgens
Manager Corporate Communications
Tel. + 31 (0)88 1959010