Publications Antibody Affinity Governs the Inhibition of SARS-CoV-2 Spike/ACE2 Binding in Patient Serum Published on January 6th, 2021 Authors: Sebastian Fiedler, Monika A. Piziorska, Viola Denninger, Alexey S. Morgunov, Alison Ilsley, Anisa Y. Malik, Matthias M. Schneider, Sean R. A. Devenish, Georg Meisl, Adriano Aguzzi, Heike Fiegler, Tuomas P. J. Knowles ACS Infect. Dis. 2021, 7, 8, 2362–2369. DOI: 10.1021/acsinfecdis.1c00047 Abstract The humoral immune response plays a key role in suppressing the pathogenesis of SARS-CoV-2. The molecular determinants underlying the neutralization of the virus remain, however, incompletely understood. Here, we show that the ability of antibodies to disrupt the binding of the viral spike protein to the angiotensin-converting enzyme 2 (ACE2) receptor on the cell, the key molecular event initiating SARS-CoV-2 entry into host cells, is controlled by the affinity of these antibodies to the viral antigen. Learn more about the technology involved in this research DISCOVER MORE By using microfluidic antibody-affinity profiling, we were able to quantify the serum-antibody mediated inhibition of ACE2–spike binding in two SARS-CoV-2 seropositive individuals. Measurements to determine the affinity, concentration, and neutralization potential of antibodies were performed directly in human serum. Using this approach, we demonstrate that the level of inhibition in both samples can be quantitatively described using the binding energies of the binary interactions between the ACE2 receptor and the spike protein, and the spike protein and the neutralizing antibody. These experiments represent a new type of in-solution receptor binding competition assay, which has further potential areas of application ranging from decisions on donor selection for convalescent plasma therapy, to identification of lead candidates in therapeutic antibody development, and vaccine development. READ THE FULL PAPER Instrument: Fluidity One-W Serum Therapeutic area: COVID A full list of recent publications in which our technology has been applied can be accessed here.