Why Pancreatic Alpha Cells Survive: Scientists Find a Virus-Fighting Gene That Beta Cells Lack

Type 1 diabetes develops when the immune system attacks insulin-producing beta cells in the pancreas. But the pancreas contains another cell type nearby—alpha cells, which produce glucagon—and these cells are largely spared from the same attack. Scientists have long wondered why.

Viral infections, particularly diabetogenic viruses like coxsackievirus, are believed to be a major environmental trigger for Type 1 diabetes. Yet alpha cells show remarkable resistance to these same viruses, even though they sit alongside vulnerable beta cells. A new study suggests the answer may lie in gene expression—specifically, genes that fight off viral threats.

Bats are famously resilient to viruses. Despite harboring many dangerous pathogens, they rarely develop the severe diseases that plague other mammals. Researchers wondered whether alpha cells might share some of the same antiviral tricks that make bats so resistant.

To test this idea, scientists compared gene activity in bat cells exposed to viral material against the gene activity in human pancreatic alpha and beta cells. The results were striking: alpha cells matched the antiviral gene profile of bat cells far more closely than beta cells did. This suggests that alpha and beta cells evolved different strategies for handling viral exposure—and alpha cells borrowed from the bat playbook.

Among the genes that differed most between alpha and beta cells was one called ISG15 (interferon-stimulated gene 15). This gene is a known player in antiviral defense in both humans and bats. Researchers found that ISG15 is consistently expressed at much higher levels in alpha cells compared to beta cells, across multiple datasets of human pancreatic tissue and lab-grown cells.

But identifying the gene difference was only the first step. The researchers then tested whether ISG15 actually protects beta cells from viral damage.

When scientists removed ISG15 from beta cells grown in the laboratory, the cells became significantly more vulnerable. They died more readily even without viral exposure, and when exposed to interferon or diabetogenic coxsackievirus, cell death increased sharply and more virus was produced.

The reverse experiment also worked: when researchers added extra ISG15 to beta cells, the cells showed improved protection against viral infection. This two-way effect—vulnerability when ISG15 is removed, protection when it is boosted—suggests ISG15 plays a genuine protective role.

These findings help explain a longstanding mystery: why beta cells are selectively attacked in Type 1 diabetes while alpha cells survive. The data suggest that beta cells lack a key antiviral defense system that alpha cells possess, making them more susceptible to viral damage and immune targeting.

The research is still in the discovery phase. It shows that ISG15 is important for beta cell survival under viral stress, but understanding how to safely boost ISG15 in patients—or whether doing so could prevent Type 1 diabetes—will require further research. Scientists are now building on these findings to explore whether enhancing this natural protective mechanism could one day help prevent or delay Type 1 diabetes in people at risk.

Source: bioRxiv : the preprint server for biology. Evidence type: PubMed indexed literature. Type1Cure is an information and intelligence hub, not a medical advice service. This article summarizes published research and does not provide diagnosis, treatment, or personal medical guidance. Always talk to your own care team before changing anything about your Type 1 diabetes management.