A pioneering therapy which floods the body with decoy ‘cells’ to hoodwink viruses into ignoring healthy cells, is being developed by scientists.
US scientists from Northwestern University came up with the idea to tackle Covid-19, but believe it could be repurposed for any cell-invading disease, and rolled out quickly during another pandemic.
The treatment works by engineering nanoparticles so they resemble real cells, but carry more of the receptors that a virus needs to attach.
For Covid-19, this means adding more ACE2 receptors for the virus to grab. With such easy pickings available, the virus ignores human cells and instead latches on to the decoys.
The therapy would be particularly helpful for viruses like Covid-19 which mutate frequently, to get around drugs and vaccines. But because the receptor remains the same, the virus would still be drawn to the decoys.
“For the virus to get into a cell, it has to bind to the ACE2 receptor,” said Dr Joshua Leonard, co-senior author of the study of Northwestern, Illinois.
“Decoy nanoparticles present an evolutionary challenge for Covid-19. The virus would have to come up with an entirely different way to enter cells in order to avoid the need to use ACE2 receptors. There is no obvious evolutionary escape route.
“We showed that decoy nanoparticles are effective inhibitors of all different viral variants. Even variants that escape other drugs did not escape our decoy nanoparticles.”
More effective than current antivirals
To design the decoy nanoparticles, the team made use of tiny particles, called extracellular vesicles, which are naturally released from the cells.
They engineered cells producing these particles to overexpress the gene for ACE2, leading to many ACE2 receptors on the particles’ surfaces.
When Covid-19 came into contact with the decoy, it bonded tightly to these receptors allowing the nanoparticles to soak up the virus like a sponge, preventing it from infecting the rest of the body.
Although the technique has only been tried in a lab, it was found to be 50 times more effective than current antivirals at combating viral mutations, and 1,500 times more effective when the mutant was specifically designed to resist treatment.
As well as the original Wuhan Covid strain,the treatment was found to work on beta, delta, delta-plus and lambda variants.
“As we were conducting the study, different variants kept popping up around the world,” said Dr Neha Kamat, also a co-senior author of the study.
“We kept testing our decoys against the new variants, and they just kept working. It’s very effective.”
Although more research and clinical evaluations are needed, the researchers believe decoy nanoparticle infusions someday could potentially be used to treat patients with severe or prolonged viral infections.
The research was published in the journal Small.