Cells raise the alarm for invasion

Scientists have identified how a protein sounds an alarm when it detects a virus invading a cell.

The study, which was published by journal the Cell and undertaken by a team at the European Molecular Biology Laboratory (EMBL) will further aid the understanding of the innate immune response and illustrate how cells respond so rapidly to a wide range of viruses.

In order to sense invading agents, cells use proteins known as pattern recognition receptors, which recognise and bind to molecular signatures carried only by the intruder, a process which then causes the receptors to change shape, triggering a chain reaction that alerts surrounding cells to invasion.

Stephen Cusack, who led the work, said that scientists were particularly keen to discover how this process works for all RNA viruses, including influenza, measles and hepatitis C.

"RIG-I is activated in response to viral RNA, but a similar mechanism is likely to be used by a number of other immune receptors, whether they are specific to viruses or bacteria," says PhD student Eva Kowalinski, who carried out most of the work.