Assessment of pH control and feeding of amino acid and carbon sources to optimize the onco-rBCG-pertussis immunotherapy production in 1 and 10 L bioreactors

• Grant number: 22/15269-4
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: August 01, 2023
• End date: November 30, 2023
• Field of knowledge: Engineering - Chemical Engineering
• Principal Investigator: Viviane Maimoni Gonçalves
• Grantee: Maria Carolina Pereira Gonçalves
• Host Institution: Instituto Butantan. Secretaria da Saúde (São Paulo - Estado). São Paulo , SP, Brazil
• Associated research grant: 17/24832-6 - Development of vaccines based on recombinant BCG: Tuberculosis, Pertussis, Pneumococcus and Schistosoma, AP.TEM

Abstract

Tuberculosis (TB) is the leading cause of death in the world from a single infectious agent and the largest responsible for the death of people with HIV. The first human vaccination for TB was applied in Paris in 1921 using an attenuated strain called bacillus Calmette-Guérin (BCG). More than a hundred years after its development, the BCG vaccine is still the preferred prophylactic option for TB prevention worldwide. BCG can also be used in the treatment of bladder cancer (BC) in about 70% of cases. However, 30 to 40% of people do not respond to conventional BCG treatment. For this reason, research is being directed towards the use of recombinant strains of BCG (rBCG) as an alternative to improve the immune response against BC (and other diseases). Andrade et al. (2010) have already demonstrated that the use of the rBCG-pertussis strain developed in our research group by Nascimento et al. (2000) was more effective in treating BC than the conventional BCG. This strain can be used both as a vaccine for TB and whooping cough and as an immunotherapy (onco-rBCG-pertussis) in the treatment of BC, with the dose used for the immunotherapy being ten times greater than the vaccine dose. The traditional (static) culture method of BCG is still the most used today and prevents further advances in the development of the onco-BCG, since the challenge to achieve higher cell densities is more important in this case, due to the higher dose required. An alternative to this traditional method would be the submerged culture of the strain in bioreactors, which would bring productivity and quality gains to the BCG production process. Therefore, this postdoctoral project aims to develop a submerged culture process of rBCG-pertussis in bioreactors with a focus on its use in the treatment of BC. Primarily, we intend to control the pH and the feeding of amino acid and carbon sources throughout the cultures in a 1 L bioreactor in order to maximize cell growth and viability. Then, the best conditions obtained in the 1 L bioreactor will be validated in a 10 L bioreactor. Finally, analyzes of the quality of the product obtained will be performed to validate the process. In this way, we expect to contribute to the development of the submerged culture of rBCG-pertussis in bioreactors, seeking to ensure batch reproducibility and reduce contamination in comparison to traditional cultivation, focusing on obtaining higher cell densities and viabilities.