PITTSBURGH (KDKA) — A researcher at the University of Pittsburgh School of Medicine has discovered how coronavirus can cause harmful and escalating inflammation.
It is because of a region on the spike protein she calls a superantigen.
“That region would be expected to trigger a very strong response, adaptive immune response, and now the response is so exaggerated,” says Ivet Bahar, Ph.D., distinguished professor and John K. Vries Chair of computational and systems biology at Pitt School of Medicine.
Her work came about by trying to get a better handle on what happens in the severe pediatric coronavirus-related illness MIS-C or multisystem inflammatory syndrome in children. The symptoms of low blood pressure, fever and rash looked very similar to toxic shock syndrome, a potentially fatal illness caused by bacterial toxins.
By using computer models, she found a surprise.
“We started to compare the sequence and structure to existing superantigens, bacterial toxins, and found that there is a region that is very similar to a known bacterial toxin,” says Dr. Bahar.
This segment of the spike protein causes an excessive reaction in certain immune system cells and signals. This overreaction can lead to organ damage. Collaborators in Germany were able to show how her computer discovery actually happens in real-life patients.
“We know now that it’s not only children, we are observing the same phenomenon with also adults with severe COVID-19,” Dr. Bahar says.
But why it only happens in some people is still a mystery.
“Different people react in different ways somehow,” says Dr. Bahar. “That is something to further explore.”
The next step is to develop treatments to target the superantigen. Dr. Bahar hopes existing antibodies that target bacterial toxins might work.