Virus thrives by hiding

After invading a cell, some viruses cozy up to it’s internal membranes before reproducing, but scientists haven’t been sure why. Now they’ve seen that one such microbe, the flock house virus, reproduces in cocoons within the membranes.

The cocoons are havens where the virus can replicate safe from the cell’s defenses, says Paul Ahlquist at the University of Wisconsin–Madison. But before the virus can hide itself, it must produce proteins that make up the pouches. “The early phase of [viral] replication is a point of significant vulnerability,” says Ahlquist, who led the research. Drugs that interfere with the cocoons’ proteins or otherwise thwart the creation of the cavities could leave the viruses exposed to attack by the cell, Ahlquist says.

The protein pockets made by flock house virus are similar to protective protein shells created by viruses in other major virus classes. Unlike flock house virus, however, these other viral types use the shells to travel between cells. The similarity between the shells and the cocoons suggests an evolutionary link among the virus classes, the team reports in the September PLoS Biology.

Scientists could exploit this commonality to develop treatments that are broadly effective against diseases including AIDS, severe acute respiratory syndrome, and hepatitis C, Ahlquist suggests.