Enzyme points to new way to fight the flu

Ian Rodrigue-Gervais says the discovery suggests it may be possible to suppress features of flu-inflicted tissue injury. "What we saw in this study is that if the enzyme cIAP2 is present, the host can better tolerate the infection and then reduce the illness." (Credit: Jared Polin/Flickr)

Researchers have found an enzyme that protects us from the flu by helping our lungs resist tissue damage.

“It’s a discovery that offers exciting new avenues for controlling influenza, since until now attempts to target the virus itself have proven challenging, especially in the face of emerging new strains of the virus,” says study leader Maya Saleh of McGill University.

“The results from our study now suggest that one effective way of countering influenza infections may instead be offered by enhancing the body’s resistance to the virus.”

Strong defense

Like many other battles, fighting the flu is a combination of both control and defense.

[related]

On the one hand, on the control end of the process, our immune system comes into play to prevent the virus from replicating inside our cells, and attacking with increasing strength.

At the same time, on the defensive side, our bodies need to actively resist the destruction and harmful cell death that is caused by the virus.

By investigating the role played by the enzyme cIAP2 in mice with the H1N1 influenza A virus, what Saleh and her team discovered was that the enzyme is necessary to control the nature of cell death during influenza infection.

They found that cIAP2, which functions by modifying and activating survival factors in the cell, steers the body away from an inflammatory and auto-destructive process known as necrotic death. The enzyme is, in effect, a gatekeeper of cell death.

In its absence, the same factors that depend on cIAP2 to keep the cell alive, reveal a destructive side and induce a harmful form of cell death. cIAP2 therefore not only protects the infected cells from dying in such a manner, but also protects uninfected neighboring cells in the same tissue.

New drugs

By doing so, this enzyme increases the resistance of the lung to influenza infection and associated pathology.

The researchers believe that the identification of this pathway of resistance to flu opens a number of avenues for future drug development.

Ian Rodrigue-Gervais, a postdoctoral fellow in Saleh’s lab and one of the authors on the paper, says what is truly exciting about this discovery is that it suggests that it may be possible to suppress features of flu-inflicted tissue injury.

“What we saw in this study is that if the enzyme cIAP2 is present, the host can better tolerate the infection and then reduce the illness.”

The Canadian Institutes for Health Research, the Burroughs Wellcome Fund, the Fonds de recherche en santé du Québec, the Canadian Association of Gastroenterology/Abbott, the Strauss Foundation, the Kidney Cancer Association, and the National Institutes of Health funded the work.

The findings are published in the journal Cell Host & Microbe.

Source: McGill University