A protein in the lungs that sticks to the Covid-19 virus-like velcro and immobilizes it was found by Australian researchers. This breakthrough may explain why some people never become sick with the virus while others suffer from a serious illness.

The findings of the research conducted by Greg Neely, a professor of functional genomics with the University of Sydney’s Charles Perkins Centre, in collaboration with Dr. Lipin Loo, a postdoctoral researcher, and Matthew Waller, a Ph.D. student, were published in the journal PLOS Biology on Friday.

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Through using Crispr, a genetic engineering tool, they were able to turn on all genes in the human genome which are later tested for their ability to bind to the Sars-CoV-2 spike protein, which plays a crucial role in the virus’s ability to infect human cells and elongate symptoms.

“This let us find this new receptor protein, LRRC15,” Neely said.

“We then used lungs from patients that died of Covid or other illnesses and found the serious Covid patients had tons of this LRRC15 in their lungs.”

When Sars-coV-2 enters the body, this causes LRRC15 to be present in humans; this appears to be a new immune barrier that may protect individuals from severe Covid-19 symptoms by activating the body’s antiviral response. Researchers believe that even though individuals who have died of Covid-19 had produced LRRC15, it was produced in later stages which were too late to help.

Neely assured that there is much of this protein in the lungs of past patients. However, the real struggle is the inability to perform a lung biopsy on live people (Covid-19 survivors) to confirm this. They hypothesize that there is more of this protein in survivors than there is in those who didn’t make it. 

A similar study was conducted in London, which examined blood samples for LRC15 where they found that it showed lower amounts in patients who showcased severe symptoms as opposed to those with mild symptoms. 

“Our data suggest that higher levels of LRRC15 would result in people having less severe disease,” Neely said.

“The fact that there’s this natural immune receptor that we didn’t know about, that’s lining our lungs and blocks and controls virus – that’s crazy interesting.”

The aim is to use this new receptor and design broad-acting drugs, which would have the ability to block viral infections or at least suppress them. These sorts of drugs do not yet exist. 

Prof Stuart Turville, a virologist with the Kirby Institute at the University of New South Wales, refers to the finding as “a powerful example” of what happens when different teams work together in Australia, emphasizing that Neely’s team is brilliant at functional genomics. 

“That is the ability to wake up or turn off thousands of proteins at a time and when looking at new viruses, this is really important. Our team provided the platforms and virus for testing in this setting and these collaborations are really powerful both now and also in the future for emerging pathogens," he added.

The importance of this research lies in the fact that the comprehension of these pathways can enable us to prevent a virus or at least put it on hold until our immune system can catch up and respond to it.