Viruses responsible for colds may have a new weak point

A newly discovered footprint on the surface of viruses that cause many diseases, including colds, could be their Achilles heel – and a possible target for effective drugs.

When scientists tested antiviral compounds on cells grown in the laboratory, the team discovered one that was blocking the replication of an enterovirus. Cryogenic electron microscopy revealed that the compound bound to the protein shell of the virus and appeared to cover it PLOS Biology.

Additional tests suggest that the pocket is widespread among picornaviruses, the viral family which includes enteroviruses – which cause foot-and-mouth disease as well as more dangerous infections – and rhinoviruses, which cause colds. There is no antiviral medicine to treat these pathogens.

The pouch "is an excellent target for antivirals" that could be effective against many of these types of viruses, says Susan Hafenstein, a structural virologist at the Penn State College of Medicine, who did not participate in the study. ;study.

These viruses mutate very frequently, which allows them to "escape a drug more easily," she says. To identify drug targets in viruses, "it is essential to identify the essential components of the work" necessary for the survival of these pathogens.

During an infection, the viruses inject their genetic material into the cells and support the cellular machinery to produce more viral particles. In picornaviruses, a protein shell surrounds the inner nucleus of the virus, made up of genetic material. Previous research suggests that the shell changes shape when these viruses are ready to expel their genetic load during an infection.

But a chemical compound, identified by structural virologist Sarah Butcher of the University of Helsinki and virologist Johan Neyts of the University of Leuven in Belgium and his colleagues, binds to the newly discovered pocket in the protein shell and seems lock it. "This lock prevents the virus from infecting the cells," says Butcher, because the shell can not change shape or release genetic material.

The researchers then tested other similar compounds and found that they could block many other picornaviruses, indicating that the pouch is a common feature of the entire family and plays a crucial role in the cycle. viral life, Butcher said.

The team is currently modifying these compounds to improve their properties to be used as drugs against this viral Achilles heel, says Neyts.