Nearly three years after it first struck, SARS-CoV-2, the virus that causes Covid-19, remains dominant in our lives. With new cases popping up across the world, including in India, scientists have now unraveled the battle plans of this virus, revealing the mystery of how it wins the war against the human immune system.
Scientists working on coronaviruses have discovered that the Middle East Respiratory Syndrome (MERS) and Severe Acute Respiratory Syndrome (SARS) proteins block the induction of antiviral proteins, which prevents us from mounting a strong immune response against infections.
SARS and MERS emerged in 2002 and 2012, respectively, and both not only had a high transmission rate but also a high fatality rate similar to Covid-19.
While different, both MERS and SARS bear a great deal of similarity to SARS-COV-2 and therefore the new discovery helps in providing a blueprint that could be key to invading their defense mechanism and providing new therapeutic options for treating coronavirus of today and even those that could emerge in the future.
Led by Dr. Nigel Stevenson, Assistant Professor in Viral Immunology at Trinity Biomedical Sciences Institute (TBSI), the team discovered that SARS and MERS viruses have proteins that essentially block the work of the Interferon antiviral pathway, which — under normal circumstances — activates a cascade of responses in human cells, to produce hundreds of antiviral proteins that block viral replication.
About 6.5 million people have lost their lives to Covid since the pandemic began. (File Pic)
“Viruses have also evolved over time to suppress and avoid our immune system responses. And our research aims to understand how viruses suppress the response to interferons,” Dr. Nigel Stevenson said in a statement. He added that research has discovered that SARS and MERS prevent key proteins from being activated and entering the nucleus in our cells. The nucleus is where our DNA is stored and where genes are switched on, to generate a proper immune response.
The research, published in the journal MDPI, states while the observations highlight cell line-specific differences in the immune evasion effects of MERS-CoV and SARS-CoV-1 proteins, they also demonstrate the broad spectrum of immune evasion strategies these deadly coronaviruses use to stunt antiviral responses.
“The hope is that if we can design new drugs to inhibit the ability of coronaviruses to suppress the Interferon pathway, we should be able to treat people far more effectively. And given the similarity in coronaviruses and their modes of action, such a drug would likely prove effective against all the deadly coronaviruses,” Dr. Nigel Stevenson added.
Scientists hope that if they could restore the natural ability of the human immune system to fight viral infection and prevent viral replication, they could treat infected people with greater success.