Virus-mimicking antibodies may explain rare side effects of COVID-19


Innovative delivery of SARS-CoV-2 particles (not to scale). Credit: National Institute of Allergy and Infectious Diseases, National Institutes of Health

With around 256 million cases and more than 5 million deaths worldwide, the COVID-19 pandemic has challenged scientists and medical professionals. Researchers are working to find effective vaccines and treatments, as well as to understand the long-term effects of the infection.

While vaccines have been crucial in fighting the epidemic, researchers are still learning how and how well they work. This is especially true with the emergence of new viral variants and the rare side effects of the vaccine such as allergic reactions, heart inflammation (myocarditis) and blood clots (thrombosis).

Critical questions about the infection itself remain. One in four patients infected with the COVID-19 virus develop long-term symptoms, even after recovering from the virus. These symptoms, known as “COVID Long”, are non-target side effects of vaccines are believed to be caused by infection of the patient immune response.

In an article published today in The New England Journal of MedicineUC Davis Vice President of Research and Professor of Dermatology and Distinguished Internal Medicine William Murphy and Professor of Medicine at Harvard Medical School Dan Longo offered a possible explanation for the diverse immune responses to the virus and vaccines.

Antibodies mimic the virus

Drawing on classical immunological concepts, Murphy and Longo suggest that the network hypothesis Nobel laureate Niels Gern may offer insights.

Jerne’s hypothesis illustrates a method for immune system to regulate antibodies. Describes a series in which the immune system initially triggers protective antibody responses to an antigen (eg a virus). These same protective antibodies can subsequently trigger a new antibody response toward themselves, causing them to disappear over time.

These secondary antibodies, called autotyped antibody, can bind to and deplete protective primary antibody responses. They have the ability to reverse or act like the original antigen itself. This may lead to adverse effects.

Corona virus and the immune system

When SARS-CoV-2, the virus that causes COVID-19, enters the body, its elevated protein binds to the ACE2 receptor, gaining entry into the cell. The immune system responds by producing protective antibodies that bind to the invading virus, blocking or neutralizing its effects.

As a form of downregulation, these protective antibodies can also elicit immune responses with antibody to dimple type. Over time, these blunt-patterned antibody responses can clear primary protective antibodies and likely lead to limited efficacy of antibody-based therapies.

“One fascinating aspect of newly formed antibodies is that some of their structures can be a mirror image of the original antigen and act like the same receptors that the viral antigen binds to. This binding can lead to undesirable actions and diseases, particularly on Long term,” Murphy said.

The authors point out that the anti-stupid pattern Antibodies It likely targets the same ACE2 receptors. In blocking or turning on these receptors, they can affect various normal ACE2 functions.

“Given the critical functions and wide distribution of ACE2 receptors on many cell types, it will be important to determine whether these regulatory immune responses could be responsible for some of the long-term or long-term effects that are being reported,” Murphy commented. “These responses may also explain why such long-term effects occur long after the viral infection has cleared.”

For COVID-19 vaccines, the primary antigen used is the SARS-CoV-2 protein. According to Murphy and Longo, current research studies on antibody responses to these vaccines focus primarily on primary protective responses and virus neutralization efficacy, rather than other long-term aspects.

“With the staggering impact of the pandemic and our reliance on vaccines as our primary weapon, there is an enormous need for more basic scientific research to understand the complex immune pathways at play. This need follows what is needed to continue protective responses, as well as the potentially unwanted side effects of both infections and the various SARS-CoV -2 Serum “Especially with boosting now being applied,” Murphy said. “The good news is that these are testable questions that can be addressed in part in the lab and, in fact, have been used with other viral models.”

COVID-19 antibodies remain in the body 10 months after infection

more information:
William J. Murphy et al, Possible role of anti-placebo antibody in SARS-CoV-2 infection and vaccination, New England Journal of Medicine (2021). doi: 10.1056/NEJMcibr2113694

the quote: Antibodies that mimic virus may explain COVID-19 in the long run, Rare vaccine side effects (November 25-2021) Retrieved November 26, 2021 from virus-haul-covid-.html

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