Even before the COVID-19 pandemic, most people in the United States had already been ill with coronavirus, though much less dangerous. This is because at least four coronaviruses of the same general family as SARS-CoV-2 cause the benign but annoying disease known as the common cold.
In a new study that appears in Communications on Nature, scientists at Scripps Research investigated how previous immune system exposure to cold-causing coronaviruses affects the immune response to COVID-19. In doing so, they discovered a cross-reactive coronavirus antibody that was triggered during a COVID-19 infection.
The findings will help in the search for a vaccine or antibody treatment which works against most or all coronaviruses, says lead author Raiees Andrabi, Ph.D., a researcher in the Department of Immunology and Microbiology.
“When examining blood samples collected before the pandemic and comparing them with samples from people who had been sick with COVID-19, we were able to identify the types of antibodies that reacted cross-linked with benign coronaviruses as well as with SARS-CoV-2, ”he says. Andrabi, who works closely with Professor Dennis Burton’s lab, Ph.D.
In later tests, the antibody also neutralized SARS-CoV-1, the coronavirus that causes SARS, or severe acute respiratory syndrome.
“We were able to determine that this type of cross-reactive antibody is probably produced by a memory B cell that is initially exposed to a coronavirus that causes the common cold and is then remembered during a COVID-19 infection,” Andrabi says.
Memory B cells are an essential part of the immune system. They “remember” the first threats of disease and can circulate through the bloodstream for decades, ready to be put back into action if the threat reappears. These cells are responsible for producing specific targets antibodies.
The discovery could be an important step in the eventual development of a pan-coronavirus vaccine, which would be able to protect itself from possible coronaviruses that may arise in the future, says Burton, James and Jessie’s minor chair of immunology in the department of Immunology and Microbiology at Scripps Research.
“Another deadly coronavirus will probably appear in the future, and when it does, we want to be better prepared,” Burton says. “Our identification of a cross-reactive antibody against SARS-CoV-2 and the most common coronaviruses is a promising development on the road to a vaccine or broad-acting therapy.”
Burton’s lab is also investigating neutralizing antibodies that can be used to protect against many forms of flu, which is another virus that could cause a pandemic in the future.
In the new study, the team used electron microscopy to understand how the cross-reactive antibody is able to neutralize various coronaviruses. They saw that it primarily binds to the base of the virus’s ear protein, an area that doesn’t change much from strain to strain, says first author Ge “Sophie” Song, a graduate student at Burton’s lab.
“The study highlights the importance of fully understanding the nature of pre-existing immunity, especially with respect to coronaviruses,” Song says. “Previous exposure to a coronavirus, even a benign virus that causes colds, affects the nature and level of antibodies produced when more serious coronavirus threats appear.”
Ge Song, Wan-ting He, Sean Callaghan, Fabio Anzanello, Deli Huang, James, have written the study “Serum B Cell Responses and Spike Protein Cross-Reaction Memory in SARS-CoV-2 and in coronavirus endemic infection “. Ricketts, Jonathan Torres, Nathan Beutler, Linghang Peng, Sirena Vargas, Jon Cassell, Mara Parren, Linlin Yang, Caroline Ignacio, Davey Smith, James Voss, David Nemazee, Andrew Ward, Thomas Rogers, Dennis Burton and Raiees Andrabi.
Ge Song et al, Cross-reaction serum and memory B cell responses to peak protein in SARS-CoV-2 and endemic coronavirus infection, Communications on Nature (2021). DOI: 10.1038 / s41467-021-23074-3
The Scripps Research Institute
Citation: Versatile coronavirus antibody may be the starting point for wider-action vaccines (2021, May 28) retrieved May 28, 2021 at https://medicalxpress.com/news/2021-05- versatile-coronavirus-antibody-broader-acting-vaccines. html
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