COVID-19 Immunology: Study Indicates That Prior Exposure To Common Cold Coronaviruses Creates Memory T Cells That Can Recognize SARS-CoV-2
Source: COVID-19 Immunology Aug 05, 2020 4 years, 3 months, 2 weeks, 2 days, 17 hours, 39 minutes ago
COVID-19 Immunology: A new study led by researchers from La Jolla Institute for Immunology (LJI) indicates that memory helper T cells that recognize common cold coronaviruses also recognize matching sites on SARS-CoV-2, the virus that causes COVID-19.
.jpg)
According to the research paper, the immune system's 'memory' T cells keep track of the viruses they have seen before. This immune cell memory gives the cells a head start in recognizing and fighting off repeat invaders.
The study findings were published in the journal: Science.
https://science.sciencemag.org/content/early/2020/08/04/science.abd3871
The research findings may explain why some individuals have milder COVID-19 cases than others though the researchers emphasize that this is speculation and much more data is needed.
LJI Research Assistant Professor Dr Daniela Weiskopf, Ph.D., who co-led the new study with LJI Professor Dr Alessandro Sette, Dr. Biol. Sci. told Thailand Medical News, "We have now proven that, in some individuals, pre-existing T cell memory against common cold coronaviruses can cross-recognize SARS-CoV-2, down to the exact molecular structures. This could help explain why some people show milder symptoms of disease while others get severely sick."
Please Help To Donate To Sustain This Site And Other Research We Are Propelling. Thank You. https://www.thailandmedical.news/p/sponsorship
Dr Sette added, "Immune reactivity may translate to different degrees of protection. Having a strong T cell response or a better T cell response may give you the opportunity to mount a much quicker and stronger response."
The research builds on a recent
Cell paper from the Sette Lab and the lab of LJI Professor Shane Crotty, Ph.D., which showed that 40 to 60 percent of people never exposed to SARS-CoV-2 had T cells that reacted to the virus. Their immune systems recognized fragments of the virus it had never seen before.
https://www.cell.com/cell/fulltext/S0092-8674(20)30610-3
This research finding turned out to be a global phenomenon and was reported in individuals from the Netherlands, Germany, the United Kingdom and Singapore.
Researchers wondered if these T cells came from people who had previously been exposed to common cold coronaviruses what Dr Sette calls SARS-CoV-2's "less dangerous cousins." If so, was exposure to these cold viruses leading to immune memory against SARS-CoV-2?
In this new study, the researchers relied on a set of samples collected from study participants who had never been exposed to SARS-CoV-2. They defined the exact sites of the virus that are responsible for the cross-reactive T cell response. Their analysis showed that
unexposed individuals can produce a range of memory T cells that are equally reactive against SARS-CoV-2 and four types of common cold coronaviruses.
The new discovery suggests that fighting off a common cold coronavirus can indeed teach the T cell compartment to recognize some parts of SARS-CoV-2 and provides evidence for the hypothesis that common cold viruses can, in fact, induce cross-reactive T cell memory against SARS-CoV-2.
Dr Sette added, "We knew there was pre-existing reactivity, and this study provides very strong direct molecular evidence that memory T cells can 'see' sequences that are very similar between common cold coronaviruses and SARS-CoV-2.”
Upon detail analysis, the researchers found that while some cross-reactive T cells targeted the SARS-CoV-2's spike protein, the region of the virus that recognizes and binds to human cells, pre-existing immune memory was also directed to other SARS-CoV-2 proteins.
This new finding is relevant, Dr Sette explains, since most vaccine candidates target mostly the spike protein. These findings suggest the hypothesis that inclusion of additional SARS-CoV-2 targets might enhance the potential to take advantage of this cross reactivity and could further enhance vaccine potency.
For more on
COVID-19 Immunology, keep on logging to Thailand Medical News.
Please Help To Donate To Sustain This Site And Other Research We Are Propelling. Thank You. https://www.thailandmedical.news/p/sponsorship
