Unexpected discovery points to a powerful new antiviral

An unexpected observation by Dr Merja Joensuu from AIBN could lead to a new treatment for deadly infectious diseases including COVID -19, pneumonia and viral infections caused by Ebola and hantavirus. 

Dr Joensuu and her team have identified a new antiviral approach that targets host cells rather than the virus itself. Using a cancer drug that disrupts host cell function can lead to improperly formed viruses and reduced infection levels.

“This could be a very effective antiviral, for example for treating respiratory conditions, used in the form of a nasal spray or an inhaler,” Dr Joensuu said.

The lightbulb moment

“We were studying how certain processes work inside human brain when I noticed a disruption in a pathway that numerous human viruses rely on to spread from one cell to the next,” Dr Joensuu said.  

“That was the lightbulb moment." 

Cancer drug disrupts cell function

“We realised that if we interfere with that pathway, we might be able to stop viruses from forming properly.” 

With her collaborator Professor Giuseppe Balistreri from the University of Helsinki, the research team searched for a compound that could inhibit this pathway and found one currently being trialled as a cancer treatment.  

Human enzyme N-myristoyltransferase 1 (NMT1) is an essential cellular enzyme that helps direct where proteins are located and how they function within human cells. 

“Viruses can’t reproduce on their own, so they hijack human cells to make new copies,” Professor Balistreri said.  

“This drug disrupts how the cell functions, causing new viruses to be assembled incorrectly.  

Malformed viruses can’t infect properly

“The virus doesn’t know this and keeps making and releasing less-effective versions of itself, which would give the immune system time to clean up the infection,” he said.  

In laboratory studies, the researchers tested the drug against a range of viruses in cell cultures including SARS CoV 2 (which causes COVID 19), respiratory syncytial virus, a major cause of pneumonia in infants, and vesicular stomatitis virus, which causes disease in cattle, horses and occasionally humans.   

They found infection levels dropped by about half after 1 day, and by up to 90 per cent after 2 days.  

Targeting host cells not the virus

“The reduction is quite striking,” Dr Joensuu said.  

“The study also suggests this strategy could potentially work on viruses with high mortality rates and long incubation time like Ebola, and hantavirus.  

“All viruses rely on exploiting host cell processes to replicate and spread.  

“And because we are interfering with the host cell instead of directly targeting the virus, there is less chance of a virus mutating and building resistance to the drug.”  

Researchers emphasised the drug is not yet approved for this use, with further studies needed to confirm safety and effectiveness, but Dr Joensuu said it showed a lot of promise.  

“You can imagine that this could be a very effective antiviral, for example for treating respiratory conditions, used in the form of a nasal spray or an inhaler,” she said.  

The research is published in Nature Communications.

This research was supported by the facilities and staff at the Centre for Microscopy and Microanalysis and the Queensland Node of Metabolomics and Proteomics Australia, both of which are housed at the AIBN and funded by the Australian Government’s National Collaborative Research Infrastructure Strategy (NCRIS).