Can The Flu Virus Tell Time?

(Ivanhoe Newswire) -- We all know what time of year it is, flu virus time! Now new research suggests that the flu can tell time, too.

Scientists at the Icahn School of Medicine at Mount Sinai have discovered that the flu knows how much time it has to multiply, infect healthy cells, and spread to other people. They suggest that if it leaves a cell too soon, then the virus is too weak; if it leaves too late, then the immune system has time to kill the virus.

The discovery provides scientists with needed information that could lead to new antiviral drugs that can make the viral clock dysfunctional.

The flu virus only has ten major components, so it needs to steal most of its resources from cells to multiply. This process allows the virus to trip certain “alarms” that changes our immune system’s ability to detect it and kill the virus. Lead researcher, Dr. Benjamin tenOver, suggested that the virus must have a mechanism to keep track of how much time it has to abduct other resources before the immune system attacks the virus. This led Dr. tenOver and his team to find out how the virus knows how much time it has.

"We knew that the virus has about eight hours in a cell to create enough copies of itself to continue spreading before the cell's antiviral alarm would be set off. On a broader level, the virus needs two days of continuous activity to infect enough cells to permit spread to another human being. We wanted to tap into the flu's internal clock and find a way to dismantle it to prevent the spread of the virus,” Benjamin tenOever, PhD, Fishberg Professor of Microbiology at Mount Sinai, was quoted as saying.

They examined the processes that control the timing of infection and discovered that by relying on a quirk in our cell biology, the virus can slowly accumulate a certain protein that it needs to exit the cell and spread to other cells and other people.

Researchers manipulated the timer by making the virus acquire the protein too fast. It caused the flu to exit the cell too quickly and not have time to make more viruses. Then, they altered the process to make the flu acquire this protein too slowly, giving the immune system time to launch a response before the virus could escape and resulting in the virus being killed.

People currently have the option to receive a vaccine by a shot or a nasal spray, which contains a live, weakened flu virus. The nasal spray vaccine is believed to be the most effective, but it is only FDA approved for people ages 2 to 49. With this new information, scientists will be able to develop a new nasal spray vaccine that has a virus with a “defective clock,” which could be safer for all ages.

SOURCE: Cell Reports, January 2013