Scientists have made a groundbreaking discovery involving a genetically modified cow that produces human insulin proteins in its milk. This innovative experiment sparks hope that a group of such cows could potentially address global insulin shortages.
The idea of using a herd of genetically modified cows for insulin production is still in its early stages. However, researchers believe this method could eventually surpass the current insulin production techniques, which depend on genetically modified yeast and bacteria.
Insulin plays a crucial role in managing diabetes, a discovery made back in 1921. Initially, insulin treatments for diabetics came from the pancreases of cattle and pigs. However, the landscape changed in 1978 when scientists first produced ‘human’ insulin by using proteins from genetically engineered E. coli bacteria. Today, this method, along with others that utilize yeast, remains the primary way of producing medical insulin.
The concept of sourcing human insulin from cows isn’t new, but this study marks the first successful attempt at producing ‘human’ insulin in a genetically modified cow. Led by animal scientist Matt Wheeler from the University of Illinois Urbana-Champaign, the research team inserted a segment of human DNA responsible for proinsulin into cow embryos. These embryos were then implanted into the wombs of regular cows.
Out of the 10 genetically modified embryos, only one led to a successful pregnancy, resulting in the birth of a living, transgenic calf. As the calf grew, the team tried various methods to impregnate the genetically modified cow, including artificial insemination and in vitro fertilization, without success. They suggest the difficulties might be related to the embryo’s creation process rather than its genetic modifications.
Eventually, the team managed to induce lactation in the cow using a method developed by animal reproduction technologist Pietro Baruselli from the University of São Paulo. Although the cow produced less milk than it would during pregnancy, the milk was analyzed for specific proteins. The analysis revealed the presence of proteins closely resembling human proinsulin and insulin, which were absent in the milk of non-transgenic cows.
“Our goal was to create proinsulin, purify it into insulin, and proceed from there. However, it turns out the cow processed it on her own, producing a significant amount of biologically active insulin,” Wheeler explains.
This achievement follows a similar genetic modification in mice, which resulted in their milk containing human proinsulin. While the concentration levels in this new study were not specified, the potential for scaling up the process is promising.
Wheeler estimates that each cow could produce one gram of insulin per liter of milk, equating to tens of thousands of insulin units. He envisions a future where a relatively small herd of these cows could meet the insulin needs of an entire country, or even the world, with a larger herd.
This research, published in the Biotechnology Journal, opens up new possibilities for insulin production, potentially revolutionizing how we address the global demand for this vital medication.