A research team from Ruhr University Bochum has achieved a significant breakthrough in biotechnology by successfully producing human DNase1 enzyme in yeast cells for the first time, potentially revolutionizing the manufacturing of this critical therapeutic protein used to treat cystic fibrosis patients.
The team, led by Professor Beate Brand-Saberi and Dr. Markus Napirei, utilized the yeast fungus Pichia pastoris to produce human DNase1, marking a departure from the expensive hamster cell production methods that have been the industry standard for over three decades. "This is the result of years of work, and could lay the groundwork for the manufacture of human DNase1 in yeast as a biological agent," said Napirei.
Revolutionary Production Method
The researchers implanted lab-produced DNA into the yeast using an electric pulse, allowing the yeast to stably integrate the gene and begin releasing human DNase1. Doctoral student Jan-Ole Krischek, working under the supervision of Napirei and Professor Hans Georg Mannherz, successfully expressed, purified, and analyzed the enzyme in yeast.
"The advantages of yeast over mammalian cells are cost-effective culture conditions, a high rate of reproduction without the need to immortalize cells, and lower susceptibility to pathogens," explained Napirei. This represents a significant improvement over mammalian cells from hamster ovaries, which have been used for DNase1 production since 1993 but require chemical or genetic alteration to keep dividing indefinitely, adding complexity, cost, and time to the manufacturing process.
Production Challenges and Optimization Opportunities
Despite the breakthrough, researchers encountered lower-than-expected yields of human DNase1 compared to a similar mouse version of the enzyme. "This is partly due to the specific folding behaviors of the two proteins," Napirei noted. Mouse DNase1 shares 82% of its primary structure with the human form, and the team had initially used it as a model, but structural differences affected production efficiency.
Clinical Applications and Therapeutic Potential
Human DNase1 plays a critical role in treating cystic fibrosis by breaking down DNA in thick bronchial mucus, making it easier for patients to breathe and cough out secretions. The enzyme has been produced from hamster ovary cells for over three decades specifically for this application.
Beyond cystic fibrosis treatment, DNase1 shows promise in addressing other serious medical conditions. The enzyme helps remove neutrophil extracellular traps (NETs), which the body uses to trap bacteria but can become problematic in certain diseases. In conditions like sepsis or COVID-19, NETs can become overactive and form dangerous microthrombi.
"It could be useful to use DNase1 to better dissolve these microthrombi that contain DNA," said Napirei. Researchers are also exploring DNase1's potential role in treating strokes caused by blocked brain arteries.
Manufacturing and Access Implications
The successful production of DNase1 in yeast could significantly lower manufacturing costs and simplify the production process. This development has the potential to improve global access to treatments for cystic fibrosis patients and could open doors to new therapeutic applications that were previously cost-prohibitive.
With the foundational work now established, further research efforts will focus on optimizing yield and exploring broader medical applications for this versatile enzyme. The findings were published in PLOS One, marking a significant step forward in biotechnology manufacturing processes.
