Can Viruses Produce Insulin?

Scientists at the Joslin Diabetes Center have found four viruses they say produce insulin-like proteins (viral insulin-like peptides, or VILPs)

The VILPs bound to human insulin receptors and stimulated all the signaling pathways that are stimulated by insulin.

The VILPs also bound to receptors for insulin-like growth factor 1, an insulin-like hormone that affects growth.

Mice injected with the peptides (peptides, like proteins, are chains of amino acids, but they're shorter) had lower blood glucose (BG) levels, indicating that the VILPs can have some of the actions of insulin.

So would these viruses affect BG levels under ordinary circumstances? It's known that they can infect fish and amphibians. And analyses showed that humans are exposed to these viruses in the intestine, possibly as a result of eating fish.

But do the viruses get into human cells? No one knows yet. The mice with lower BG levels were injected with the VILPs rather than getting the viruses from eating infected food.

Because this is such a new finding there's not yet much information about viral hormones that could affect humans, but because scientists think there are more than 300,000 viruses that can infect or be carried in mammals, there are certainly a lot of possibilities.

This finding has no practical application yet, but it opens up a whole new way of looking at hormones, and new approaches often lead to major breakthroughs.

Stay tuned.