Developing tools for COVID-19 research and new drugs
There is an urgent need for improved diagnostic tools both to detect SARS-CoV-2 in clinical specimens and to test for antibodies. We have developed SARS-CoV-2 spike protein-pseudotyped lentiviruses that are highly useful for measuring neutralizing antibody to the virus. The pseudotypes are HIV virions that have been rendered harmless and display the SARS-CoV-2 spike protein. The viruses infect cells through ACE2 and express luciferase and GFP reporters. Infected cells can be detected either by luciferase luminescent assay or flow cytometry for GFP. We have validated the assay by testing it against a panel of 100 sera from convalescent patients and comparing the results to those obtained in a live SARS-CoV-2 neutralization assay. We have now automated the assay on the Opentrons OT2 robotic pipetting machine so that we can rapidly process hundreds of sera to get accurate measures of neutralizing antibody titers. We have shown that all of the infected patients had detectable neutralizing antibody and that some had very high titers. We have established collaborations with many research groups doing a variety of studies on Covid19 patients and are collaborating with groups to develop monoclonal antibodies with very high EC50s. We provide the viruses and do the neutralizing antibody titers. In addition, we have developed a new assay that can detect neutralizing antibodies, simply and in just 4 hours.