US research has revealed that genetically altered cows can produce human insulin proteins in their milk, giving hope of solving the current problems of global insulin supply.
The search for sustainable production of insulin – essential in the treatment of diabetes – has been ongoing since the hormone's discovery in 1921.
Initially sourced from the pancreas of cows and pigs, the production shifted in the late 70s to using genetically engineered bacteria and then yeast.
Researchers at the University of Illinois Urbana-Champaign integrated a segment of human DNA coding for proinsulin – the precursor molecule for the in-body production of insulin in humans – into the cells of 10 cow embryos and then implanted these in the wombs of regular cows, resulting in one genetically altered calf.
The team then successfully induced pregnancy in the newly modified cow, which, with help from the University of São Paulo, Brazil, revealed the presence of human proinsulin and insulin in the cow's milk.
The unexpected outcome, published in the Biotechnology Journal, demonstrated the cow's ability to convert proinsulin directly into insulin, potentially surpassing current production methods in yield and cost-effectiveness.
Matthew Wheeler, the lead scientist at Illinois, said: "Our goal was to make proinsulin, purify it out to insulin, and go from there. But the cow basically processed it herself."
The next steps involve scaling up the production process and ensuring the method's safety and efficacy for large-scale insulin production.