24 January 2013

How does the flu "timer" work?

Microbiologists have hacked the "internal clock" of the flu virus

<url>After entering a cell of a living organism, the flu, like any other virus, must multiply as quickly as possible and infect neighboring cells in order to have enough strength to search for the next victim.

Therefore, it embeds its own RNA into the genome of the host cell and begins to produce its copies. But, as you know, any action causes a reaction. When infected with a virus, defense mechanisms are activated in the cell, which send alarm signals and cause an immune response of the body. Internal cell control systems find the intruder and destroy it along with the affected cell.

Scientists have suggested that the virus should have a mechanism that allows it to track how much time is left to fully utilize the resources of the cell and leave it before the immune system intervenes. After all, if you act too quickly, he will not be able to create a sufficient number of copies, and delay means meeting with T-killers – killer cells of the immune system.

"We knew that the virus has about eight hours to spread to other cells before antiviral signaling is triggered, and about two days of continuous activity to infect enough cells and pass to another person," says the head of research, Dr. Benjamin Tenoever. "We set out to find the internal clock of the flu, by dismantling which it would be possible to prevent its spread."

The results of the study, published in the journal Cell Reports (Chua et al., Influenza A Virus Uses Suboptimal Splicing to Coordinate the Timing of Infection; for a popular summary, see the Mount Sinai Researchers press release Discover How the Flu Tells Time), showed that during its active activity, the virus slowly accumulates a special protein NEP (Nuclear export protein), which is necessary for him to exit the cell.

Scientists began to manipulate the concentration of this protein and found that if it accumulates very quickly, the virus leaves the cell much earlier than usual. The reverse process, during which the production of NEP was delayed, led to the fact that the virus remained in place until the immune system reacted and died.

In the future, the discovery of American scientists may contribute to the creation of a new type of drugs that will disrupt the "internal alarm clock" of the flu, preventing its spread through the body. There may also be new ways of vaccination. Today, two main types of vaccines are used in the world: one contains a dead virus, the other – its weakened form. The second option is considered more effective, but it is associated with an increased risk, therefore it has a number of contraindications. If you change a weakened strain to a virus with a "broken clock", the safety and effectiveness of such a vaccine will increase significantly, scientists believe.

Portal "Eternal youth" http://vechnayamolodost.ru24.01.2013

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