Scientists have identified a protein in coronavirus that acts as a “Trojan horse” by hiding it from the human body’s natural immune system.
Called NSP16, the enzyme allows Sars-Cov-2 – the virus that causes Covid-19 – to stay under the radar by chemically modifying its RNA, or genetic material.
According to the team led by Oxford Brookes University, this Trojan horse feature allows the virus to replicate in human cells and spread throughout the body.
The researchers said they have also identified a series of small molecules which are able to inhibit the function of NSP16, which could lead to the development of new drugs to treat Covid-19.
Dr Victor Bolanos-Garcia, senior lecturer in clinical biochemistry at Oxford Brookes University, said: “Although several vaccine programmes are currently under way, including the recently announced Pfizer-BioNTech where preliminary data suggest a 90% efficacy, and some drugs have been repurposed to aid the treatment of Covid-19, effective drug therapies to treat the virus do not currently exist.
“Many viral diseases are treated with antiviral drugs. Therefore, expanding the repertoire of therapeutic drugs to treat Covid-19 is important and timely.”
Dr Bolanos-Garcia, who is lead author on the paper published in the journal Catalysts, added: “Stopping the NSP16 enzyme from functioning leaves the virus RNA exposed to recognition by the human immune system, which severely limits the replication of the Sars-Cov-2 virus in infected cells.
“The small molecules we have identified as inhibitors of NSP16 show promising pharmacological properties.
“They provide a solid scientific base to develop novel inhibitors of NSP16 to treat Covid-19.”
As part of the next steps, the research team are looking to create the new molecules in the laboratory and assess whether they are toxic to human cells.
Professor Agatha Bastida, from the Spanish National Research Council (CSIC), added: “So far, Remdesivir and Favipiravir are the most promising antiviral drugs against Sars-Cov-2 tested in clinical trials.
“However, a recent study on Sars-Cov-2 found mutations in different genes of this virus that showed resistance to these antiviral drugs.
“These findings demonstrate the urgency to develop more effective antivirals to treat Covid-19.”