Scientists just cracked the viral equivalent of the Enigma code

Peter Stockley is at war with the common cold. It’s a wily adversary: a single, seemingly indecipherable strand of genetic material that lacks a brain or even a complete cell, yet somehow knows how to latch on to an unsuspecting respiratory lining and replicate itself, wreaking havoc on the immune system. 

But now Stockley, a professor at Britain’s University of Leeds, thinks he has the upper hand. He has cracked the viral equivalent of the Nazi “Enigma code,” which proved key to winning World War II: a genetic message embedded within the virus’s RNA that tells it how to assemble new versions of itself during replication.

“Down at the kind of molecular level, this kind of biology is like molecular warfare,” Stockley told The Washington Post in a phone interview from his home in Leeds (where he happened to be battling a viral infection of his own). “And this code is a vital part of how the virus attacks.”

Stockley’s findings, which were published in the Proceedings of the National Academy of Sciences Wednesday, are the result of a collaboration between Leeds and the University of York. The first breakthrough came in 2012, when Stockley and his team at Leeds published the first observation of how viruses are assembled.

Viruses consist of a strand of genetic information, RNA, encased in protein. Once they have attached to a host cell (in the case of a cold, those that line the lungs of their victim), they unspool their genetic contents and take control of the cell’s machinery to churn out copied versions of the RNA strand and the protein shell it comes in. What happens next was documented for the first time in Stockley’s report: The newly created proteins instantaneously fold the RNA up and encase it within themselves, as if by magic. In an essay for the Huffington Post, Stockley called the phenomenon viral assembly’s “Harry Potter moment.”

Stockley is a biologist, not a wizard, and he knew that the proteins must be getting instruction on how to “pack” the RNA from somewhere. The strands of RNA offered no guidance — the genetic material they contained appeared entirely benign (except for the whole infecting people part).

It took mathematician Reidun Twarock, a professor at the University of York, to crack the code: The instructions for assembly were right there among the mundane material of the RNA — but they only appeared once the RNA had been folded.

Understanding the code — and finding a way to disrupt it — could lead to vastly improved treatments for a whole class of viral infections, not just the common cold but also polio, HIV, hepatitis C and the winter vomiting disease norovirus.

That’s because viruses mutate so quickly that traditional treatments, like vaccines, aren’t effective at teaching the body to recognize and combat them. A drug that scrambled the viral assembly code would preempt the body’s immune response by disarming the virus before it can reproduce itself.

Stockley’s team has done preliminary studies on a potential scrambling mechanism, but he warns that a cure for the common cold is still a long way off.

He should know — he’s still got one himself.