Potent SARS-CoV-2 neutralising antibody gene IGHV3-53 may help develop COVID-19 vaccine

More than 13 million people have been infected with COVID-19 infection across the globe, of which over seven million people have recovered. Scientists have found that people who recover from this infection develop antibodies against the virus. These antibodies can be used to treat other patients who are currently infected with the disease. In their recent research, scientists from the Scripps Research Institute found a common molecule in these antibodies that helps in neutralising the SARS-CoV-2 virus. How antibodies work against the novel coronavirus The outer layer of the SARS-CoV-2 virus contains a spike protein, also called S protein which helps the virus bind to the ACE-2 receptor cells present in different parts of the body such as lungs, heart and other organs. After an encounter with the SARS-CoV-2 virus, the immune system of the body produces antibodies against it. These antibodies bind to the receptor-binding site present on the virus, thus blocking the binding with ACE-2 receptors. This neutralises the virus and makes it impossible for the virus to further infect the body. The antibody study Antibodies are Y-shaped proteins which are produced by the immune cells (B-cells) of the body after an infection strikes the body. Every B-cell makes a specific antibody type which contains a unique combination of antibody genes in it. In their study published in the journal Science on 13th July 2020, scientists from the Scripps Research Institute studied 294 antibody samples from the patients who recovered from COVID-19 infection. On testing all these samples, the scientists found that an antibody gene called the immunoglobulin heavy chain gene (IGHV gene) was the most common gene present in all of them. They further added that IGHV3-53 was the most frequently appearing gene in all the samples. The scientists further used high-resolution X-ray crystallography technique to find out the binding ability of this gene on the novel coronavirus. The results of this technique showed that there were two different IGHV3-53 antibodies, CC12.1 and CC12.3, that attach themselves to the receptor-binding site (present on the S protein) thus neutralising the SARS-CoV-2 virus. Promising nature of IGHV3-53 antibody gene From their research, the scientists found that antibodies collected from some of the recovered coronavirus patients had a powerful virus-neutralizing antibody gene called the IGHV3-53. The researchers found that this IGHV3-53 gene contains a short variant of H3 CDR loop which increases the potency of the antibody to bind with the antigen (any foreign virus or bacteria). They further found that the antibodies with IGHV3-53 gene were more potent in neutralizing the SARS-CoV-2 virus than those without this gene. Another beneficial factor about this gene was that it showed a very minimal mutation (change) in its structure which indicates that neutralizing antibodies with IGHV3-53 gene can be used in producing a vaccine against COVID-19. For more information, read our article on Convalescent plasma therapy. Health articles in Firstpost are written by myUpchar.com, India’s first and biggest resource for verified medical information. At myUpchar, researchers and journalists work with doctors to bring you information on all things health.