COVID Antibodies Discovered in 20-Year-Old Antibody Library
A research conducted by an international team of scientists describes the function of a versatile combinatorial antibody library established in 1999 in imitating the process of natural immunity selection and detecting new antibodies that will tackle the spike protein. So far, researchers have discovered that laboratory-produced monoclonal antibodies (mAbs) are efficient neutralizers used for treating viruses such as Ebola, SARS, respiratory viruses and infections, and even COVID-19. MAbs target the SARS-Cov-2 spike protein required for the virus to bind with the host cells.
As the generation of antibodies commences with the mutation and selection from the human B cell repertoire, combinatorial libraries allow for this same process to occur in a laboratory setting, after which it is possible to recover and record the history of an individual’s antibody responses. The authors explained that combinatorial libraries simplify the identification of unexpected antibodies with high binding and neutralization potential.
These neutralizing antibodies (NAbs) are sourced from various donor domains, such as SARS patients, memory B cells from patients recovered from SARS-CoV-2, and several animal domains. The team discovered three powerful SARS-CoV-2 antibodies, S-E6, S-B8, and S-D4. These antibodies compete to create a bond with the spike protein and deplete the virus. In combination with antibodies from recovered patients, the selected antibodies bear high treatment potential and possibly could trigger an immune response to new SARS-CoV-2 strains.
The fact that these NAbs were available in a library formed long before the pandemic implies the possibility that the donors were already exposed to similar coronaviruses in the past. These antibodies have high somatic hypermutation (SHM), meaning they have already evolved and adapted to confront similar viral infections. Additionally, further investigation of the immune response involving the interaction between NAbs and their particles which bind to SARS-CoV-2, might serve as a building block for future development of vaccines.
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