A Rapid Assay for Detecting Neutralizing Antibody Against SARS-Cov2

K.S. Seo, N. Park, J.Y. Park
Mississippi State University,
United States

Keywords: SARS-CoV-2, neutralizing antibody, a lateral flow assay, a protein binding assay


SARS-COV-2 expresses a unique spike protein that interacts with human angiotensin-converting enzyme 2 (ACE2) for invading human respiratory epithelial cells. Studies have shown that antibody which binds to the specific domain of the spike protein that interacts with ACE2 can neutralize the virulence of SARS-COV-2. From experience during the pandemic of SARS-COV-2, it is interesting to know whether a person has developed immunity from the vaccination or natural infection that will protect against reinfection of SARS-COV-2, referring to the development of neutralizing antibody. Current assays detecting immunoglobin are not designed to specifically detect development of a neutralizing antibody. This technology refers to the development of chimeric proteins that aim to differentiate neutralizing antibodies from non-neutralizing antibodies, where the results can be produced in a rapid detection test. The test can produce results in 30mins by untrained individuals in a non-laboratory environment. Studies have shown that a specific domain of spike protein known as SARS-COV-2-RBD from SARS-COV-2 interacts with human angiotensin converting enzyme 2 (ACE2) from host cells which allows entry of the virus into human cells. The invention generates a chimeric protein in which the receptor binding domain (RPD) of spike protein is fused with green fluorescent protein for the visualization of assay results under a portable UV lamp. It is also fused with another chimeric protein in which extracellular domain of ACE2 is fused with constant regions of mouse immunoglobulin for a different detection of SARS-COV-2 from a non-specific human. This invention can produce rapid results of antibodies within 30 minutes and can be administered by non-professionals in a non-laboratory setting. This technology fulfils the gap of current assays that aren’t designed to specifically detect the development of a neutralizing antibody. This invention would be extremely beneficial in the commercial space currently during this pandemic and into the future as the constant fight against minimizing the virus remains apparent.