A COVID Mystery Solved

We're still learning about COVID four years after it first appeared in the United States.

From News-Medical.net - An AZoNetwork Site: "Zombie" viral fragments trigger inflammation to cause serious COVID-19 outcomes

"There are many lingering mysteries from the COVID-19 pandemic. For instance, why does SARS-CoV-2, the virus behind the disease, cause severe symptoms in some patients, while many other coronaviruses don't? And what causes strange symptoms to persist even after the infection has been cleared from a person's system?

"The world may now have the beginning of answers. In a study published today in the journal Proceedings of the National Academy of Sciences, a UCLA-led multidisciplinary research team explores one way that COVID-19 turns the immune system -- which is crucial for keeping people alive -- against the body itself, with potentially deadly results.

"Using an artificial intelligence system they developed, the study authors scanned the entire collection of proteins produced by SARS-CoV-2 and then performed an exhaustive series of validation experiments. The scientists found that certain viral protein fragments, generated after the SARS-CoV-2 virus is broken down into pieces, can mimic a key component of the body's machinery for amplifying immune signals. Their discoveries suggest that some of the most serious COVID-19 outcomes can result from these fragments overstimulating the immune system, thereby causing rampant inflammation in widely different contexts such as cytokine storms and lethal blood coagulation.

"The study was led by corresponding author Gerard Wong, a professor of bioengineering at the UCLA Samueli School of Engineering and in the UCLA College's chemistry and biochemistry department and microbiology, immunology and molecular genetics department.

"'What we found deviates from the standard picture of viral infection,' said Wong, who is also a member of the California NanoSystems Institute at UCLA.  'The textbooks tell us that after the virus is destroyed, the sick host 'wins,' and different pieces of virus can be used to train the immune system for future recognition. COVID-19 reminds us that it's not this simple.'

"The findings could influence treatment for COVID-19 and efforts to identify and surveil future coronaviruses capable of causing pandemics."