AcuraBio is helping a leading Australian children’s health charity to develop a vaccine for Helicobacter pylori, a bacterial infection that can lead to stomach cancer.

A type of bacteria, Helicobacter pylori (H. pylori) can enter the human body, typically during childhood, where it can live in the digestive tract for many years. It is estimated to be present in more than half of the world’s population.

In later years, infection with H. pylori can cause ulcers in the stomach and duodenum, the upper part of the small intestine, and can also develop into stomach cancers such as gastric adenocarcinoma — the fifth most common cancer worldwide and the third leading cause of cancer-related death, according to the World Health Organisation.

The Challenge

As with all vaccine projects, the challenge was to develop an expression system for a low cost of production recombinant protein. AcuraBio was provided with a sequence of the protein (for development as a potential vaccine) and then tasked with establishing a robust Escherichia coli (E. coli) expression strain suitable for the production of the protein, and to deliver it in sufficient quantity for the preclinical phase of the vaccine’s development.

To meet the needs of the client, AcuraBio needed to solve the following challenges:

  • A suitably expressing E. coli strain
  • A host/vector system that is IP free
  • Fermentation conditions that maximise the yield while avoiding the formation of inclusion bodies
  • A selective purification process that would minimise protein losses

The Solution
Using AcuraBio’s extensive expertise in upstream and downstream drug development, their team first engineered a cDNA sequence, which improved the protein yield and also expression leakage. Next, they selected appropriate bacterial lines/plasmids that allow for ease of access, ease of fermentation robustness, and ease of mid-stream processing by trialling 5 plasmids together with 2-3 different host combinations. Finally, the fermentation processes were adjusted to allow for the controlled secretion of the native target protein into the periplasmic space, which can significantly simplify downstream processing, increase protein stability, improve folding, and decrease aggregation.

The Outcome
AcuraBio successfully:

  • Created a new, rhamnose induced, highly performing plasmid/host combination that proved to be a highly tuneable and tightly regulated induction system for use with the E. coli strain.
  • Determined the optimal conditions for maximal native protein expression, with new point mutations implemented to prevent protein cleavage during production.
  • Reduced the purification process to two chromatographic steps, which increased protein yield and purity.
  • Produced enough protein for both the in-vivo and in-vitro evaluation of the protein.

AcuraBio not only met the client’s needs but also laid the foundations for an efficient and straightforward cGMP manufacturing process to produce a cost-effective vaccine. Contact us now to explore your next project with us.

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