Flu and other viral infections could be stopped by boosting natural protein

An influenza virus particle, or “virion.”

An influenza virus particle, or “virion.”  (

Boosting a naturally occurring protein may help the body to detect and fend off certain viral infections on its own.

The discovery could lead to new, more effective treatments for many dangerous viruses – such as hepatitis C and influenza.

In a new study published in the journal Immunity, researchers from the University of Pittsburgh Cancer Institute (UPCI) detailed their investigation into the protein oligoadenylate synthetases-like, or OASL.  They revealed that by amplifying OASL in human cells, they were able to effectively inhibit viral replication.

According to the researchers, OASL is a key component of the body’s innate immune system, a subsystem of the overall immune system that allow our cells to intrinsically defend against pathogens.

“It was initially thought the [adaptive] immune system is all we have to protect against invasion – the one that makes antibodies and cells that can essentially destroy infected cells,” lead author Saumendra Sarkar, assistant professor of microbiology and molecular genetics at UPCI, told “But what was missing for a while is that every cell has an intrinsic ability to detect some of these invasions by pathogens… and then [they] can mount a cellular resistance.”

OASL plays an important role in a process known as RNA sensing.  Hepatitis C, influenza, the childhood respiratory illness RSV, and many other viruses are known as ribonucleic acid (RNA) viruses.  When these pathogens spread throughout the body, they will inject their genetic material – comprised of RNA – inside of healthy cells, taking them over and replicating to form new viruses.

Sarkar and his team discovered that OASL acts as a sensing mechanism inside of cells, detecting when foreign RNA is injected and alerting other cells to the virus’s presence. This helps to activate the innate immune system, causing other cells to sense the virus and inhibit its spread.

The only problem? It takes a lot of virus to activate OASL.

“There has to be quite a bit of virus production and replication before the system can detect it,” Sarkar said. ...There’s always a threshold for any detection – beyond the threshold, it’ll fire up the response and below the threshold, it won’t.  By [boosting OASL], this firing threshold goes [down], and OASL will fire more quickly.”

To test this idea, the researchers boosted OASL in a collection of human cells, which effectively stopped viral replication.  In a follow up experiment, they generated a group of mice that lacked the OASL gene, finding that the rodents were much more sensitive to viral infection.

Given these findings, Sarkar hopes to determine the most efficient way for boosting OASL in the body.  Such a method could offer an alternative to current methods for treating viruses such as interferon therapy, which has major side effects and isn’t effective for all RNA viruses.  Additionally, many RNA viruses don’t respond to vaccine treatments either.

But moving forward, Sarkar says there is still much more work to be done to determine how to turn this method into a viable treatment option.

“So essentially, if we can boost it, it can work against a whole range of RNA viruses,” Sarkar said. “The hardest thing to do is get it in the body. We can engineer RNA and deliver it into a cell, but delivering that into a whole, full organism is much more difficult.”