Written by: Laasya Dopplapudi (11th Grade/Ashburn, VA USA) Editor: Noelle A. Koo (11th Grade/Ashburn, VA USA)
Research Problem:
Gaebler et al. (2020) investigated the role of memory B cells in creating antibodies more resistant to mutations of SARS-CoV-2.
Summary:
Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is an airborne, contagious disease that resulted in the COVID-19 global pandemic, which began in December of 2019 and the early months of 2020. When a virus enters the human body, antibodies are created to protect against infection. Antibodies, also called immunoglobulins (Ig), are Y-shaped proteins that attach themselves to the virus and to other compounds that could kill the virus or help the immune system. The antibodies that are in the bloodstream or enter organs in the body are IgG and IgM (the first response of antibodies to a virus). B-cells, a type of white blood cell, have IgM antibodies on their surface, so they can bind to an antigen. When the B-cell detects a foreign virus, pathogen, or bacteria, it activates the antibody. It is known that antibody levels decrease overtime after exposure to the virus. It was hypothesized that if reinfection occurred, memory B cells could remember the pathogens from the virus and produce antibodies to protect the human body.
Nussenzweig and his team conducted a human trial of adults who had either been diagnosed with COVID-19 or had been in close contact with someone who was. After their first sign of symptoms, the participants returned in 5 months to measure antibody responses from B cells. They found that the number of antibodies produced by B-cells did not decrease as antibodies normally do. In fact, they found that the memory B-cells had experienced mutation after the infection. Thus, they were able to produce antibodies that were more effective, meaning the antibodies could recognize mutations of SARS-CoV-2 and grasp the virus more tightly.
This conclusion has extreme significance in the modern scientific community because very little research has been conducted on reinfection of the coronavirus. Understanding the importance of memory B-cells and the antibodies created by memory B-cells would be a step in combating against other reinfection and even mutations of the coronavirus from various countries such as South Africa and the United Kingdom.
Interest:
A fascinating aspect of this research was how the memory B-cell was able to evolve in approximately 5 months. After the initial infection, the number of antibodies declined. However, by about 6 months, the antibodies produced by the memory B-cell remained relatively constant and even increased. The research completed by Nussenzweig demonstrated how these B-cell antibodies had a greater somatic hypermutation, which means that the B-cells were able to mutate more effectively to produce antibodies, which leads to increased resistance against mutations. This discovery paves the way for more research on B cells and the coronavirus and how this could even be possibly incorporated into the creation of vaccines to protect against mutations that have arisen all over the world.
Journal Citation:
Gaebler, C., Wang, Z., Lorenzi, J.C.C. et al. Evolution of antibody immunity to SARS-CoV-2. Nature (2021). https://doi.org/10.1038/s41586-021-03207-w
Additional Resources
More Information on Antibodies and B cells: https://www.livescience.com/antibodies.html#:~:text=Antibodies%20are%20Y%2Dshaped%20proteins,system%20to%20get%20to%20work.&text=Antibodies%20are%20specialized%2C%20Y%2Dshaped,%2C%20bacteria%2C%20fungi%20or%20parasites.
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