Hyperactivation of the Immune System May Cause Post-COVID Syndromes Skip to main content Close Select your preferred language English عربى 简体中文 繁體中文 فارسي עִברִית 日本語 한국어 Русский Español Tagalog Menu Close Call 1-800-CEDARS-1 toggle search form Close Los Angeles, 07 July 2022 09:00 AM America/Los_Angeles Hyperactivation of the Immune System May Cause Post-COVID Syndromes SARS-CoV-2 is thought to latch on to cells via spikes that exist on its surface. Tiny molecular motifs on the spike protein may have what scientists call "superantigen" characteristics. Photo by Getty. Illustration of SARS-CoV-2 coronavirus particles. SARS-CoV-2 is an enveloped RNA (ribonucleic acid) virus. Within the membrane are spike proteins (centre, large dark spikes), membrane proteins and envelope proteins. SARS-CoV-2 causes the respiratory infection Covid-19, which can lead to fatal pneumonia. Cedars-Sinai Investigators Describe Mechanism That May Lead to Long COVID and MIS-C Investigators at Cedars-Sinai have proposed a theory for how SARS-CoV-2, the virus that causes COVID-19, infects the body. Their hypothesis, published in Frontiers in Immunology, could explain why some people still have symptoms long after the initial infection. “We’ve put together different pieces of data to create a bigger picture that may explain what causes some people’s immune systems to go haywire, leading to post-acute syndromes, including multisystem inflammatory syndrome in children (MIS-C) and long COVID in children and adults,” said Moshe Arditi, MD, executive vice chair of the Department of Pediatrics for Research, part of Cedars-Sinai Guerin Children’s, and senior author of the paper. MIS-C is a rare but dangerous condition in children that may occur weeks after infection with SARS-CoV-2. Long COVID-19—often referred to as long COVID—is a term used to describe a constellation of health problems that some people experience as a result of their infection with SARS-CoV-2. Symptoms can last months or even years. SARS-CoV-2 is thought to latch on to cells via spikes that exist on the surface of the virus. These spike proteins are comprised of molecular motifs, stretches of amino acids that make a protein. These tiny molecular motifs may have what the scientists call “superantigen” characteristics, meaning that the immune system can overreact to their presence. The spike protein, according to the authors, may also have neurotoxic motifs that can cross the blood-brain barrier and damage brain cells. This hypothesis could explain the “brain fog” and other neurological symptoms associated with COVID-19 and long COVID. The hypothesis is based on several published studies on COVID-19 and other diseases caused by viruses. One such study by Arditi and his longtime collaborator Ivet Bahar, PhD, was published in the Proceedings of the National Academy of Sciences in 2020. Bahar and Arditi created a computer model showing how molecular motifs on the spike protein interact with immune cells. The superantigen molecular motifs cause the immune cells to release an abundance of infection-fighting proteins known as cytokines that fight the virus but also may mistakenly attack the body’s organs. In children, this may manifest as MIS-C. Other studies have reported that people with long COVID may carry fragments of the virus in their gut or other parts of their bodies months after initial infection. Continuous exposure to motifs that lodge themselves in different parts of the body and have superantigen-like properties may cause autoimmune symptoms in people with long COVID and MIS-C, according to the authors. “We need to conduct more research to prove if this is indeed the mechanism that causes long COVID so that we can develop treatments to block it,” said Magali Noval Rivas, PhD, an investigator at Cedars-Sinai and first author of the paper. Arditi, the GUESS?/Fashion Industries Guild Chair in Community Child Health at Cedars-Sinai who leads the Infectious and Immunologic Diseases Research Center, and colleagues are currently conducting a study in which they are analyzing cerebral spinal fluid samples from people with long COVID symptoms for evidence of neurotoxic motifs. Rebecca A. Porritt, PhD, assistant professor in the departments of Pediatrics and Biomedical Sciences at Cedars-Sinai, also contributed to this work. Funding: The study was funded by the National Institutes of Health (award numbers R01AI072726, R01AI072726-10S, GM103712, R01GM139297, R01HL139766 and R01HL159297) the American Heart Association (Career Development Award AHA 20CDA35260258), and the Cedars-Sinai Precision Health Award. Read more: COVID-19: What You Need to Know Follow Cedars-Sinai Academic Medicine on Twitter for more on the latest basic science and clinical research from Cedars-Sinai. 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Physician-scientists hope this … Read more Show previous items Show next items Contact the Media Team Email: [email protected] Contact Stephanie CajigalProject Associate, Communications stephanie.cajigal@cshs.org Share this release Hyperactivation of the Immune System May Cause Post-COVID Syndromes Share on: Twitter Share on: Facebook Share on: LinkedIn Search Our Newsroom Social media Follow us on Twitter (opens in new window) Visit our Facebook page (opens in new window) (opens in new window) Visit our Youtube profile (opens in new window) Latest news 07 Oct 2022 - HealthDay: Black Women Less Likely to Get Laparoscopic Fibroid Surgeries 07 Oct 2022 - Faculty Publications: Sept. 29-Oct. 6 07 Oct 2022 - Fine-Tuning Organ-Chip Technology 06 Oct 2022 - KCRW: Want New Omicron Booster? Wait at Least 2 Months After Last Shot 05 Oct 2022 - Cedars-Sinai Schedules Free Flu Vaccine Clinics 04 Oct 2022 - Cedars-Sinai Showcases Hispanic and Latinx Art Newsroom Home