Yeast-Based Production of DNase1 Marks a Breakthrough in Biopharmaceutical Manufacturing
A Historic Protein, Modern Challenges
Deoxyribonuclease I (DNase1) is among the oldest therapeutic proteins known, introduced commercially as early as 1958. It plays a critical role today in the treatment of conditions like cystic fibrosis. However, traditional manufacturing methods involve cultivating immortalized hamster ovary cells—a process that is both technically demanding and financially burdensome. Researchers have long sought a more accessible alternative.
A research team at Ruhr University Bochum, led by Professor Beate Brand-Saberi and Dr. Markus Napirei from the Department of Anatomy and Molecular Embryology, has now successfully developed a yeast-based production method for human DNase1—achieving this for the first time. “This achievement is the culmination of years of dedicated research,” notes Dr. Napirei. “It paves the way for cost-effective production of DNase1 in yeast for therapeutic applications.” Their findings were published in PLOS One on April 29, 2025.
Pichia pastoris: A Powerful Ally in Biotech
The yeast species Pichia pastoris is increasingly favored in biotechnology for the production of bioactive proteins. Scientists introduce the gene encoding the desired protein into the yeast using electroporation with a synthetic DNA construct. The yeast cells then integrate this gene into their genome, express the encoded protein, and secrete it into the culture medium.
“Compared to mammalian cells, yeast offers multiple advantages—cheaper cultivation, rapid growth, no requirement for immortalization, and lower vulnerability to contaminants,” explains Napirei.
During his doctoral research, Jan-Ole Krischek, under the supervision of Dr. Napirei and Professor Hans Georg Mannherz, successfully expressed and purified human DNase1 from Pichia pastoris for the first time. Interestingly, the yeast produced significantly less human DNase1 compared to mouse DNase1, even though both proteins are 82% structurally similar. According to Dr. Napirei, this discrepancy likely stems from differences in the proteins’ folding behavior. Mouse DNase1, with its established biochemical profile, continues to serve as a reference for the development of pharmacologically optimized human DNase1 variants.
Therapeutic Potential and Broader Applications
DNase1 naturally exists in human secretions and bodily fluids, where it plays a key role in degrading extracellular DNA. This function is especially important in diseases such as cystic fibrosis, which causes thick mucus laden with DNA fragments to accumulate in the lungs. Since 1993, DNase1 used for inhalation therapy has been produced using hamster ovary cells. The enzyme breaks down the sticky DNA content in the mucus, easing clearance from the respiratory tract.
The potential applications of DNase1 extend far beyond cystic fibrosis. The enzyme is crucial in breaking down neutrophil extracellular traps (NETs), which are released by immune cells to trap pathogens. In conditions such as sepsis or severe COVID-19, excessive NET formation contributes to dangerous microthrombi. “DNase1 could help break down these DNA-rich clots,” says Napirei.
Additionally, its therapeutic utility is being explored in acute ischemic stroke, where DNase1 may aid in dissolving clots in cerebral arteries. Ongoing clinical trials are assessing the enzyme’s effectiveness in these new contexts, highlighting its growing significance in modern medicine.
