ReScan, a Multiplex Diagnostic Pipeline, Pans Human Sera for SARS-CoV-2 Antigens

Comprehensive understanding of the serological response to SARS-CoV-2 infection is important for both pathophysiologic insight and diagnostic development. Here, we generate a pan-human coronavirus programmable phage display assay to perform proteome-wide profiling of coronavirus antigens enriched by 98 COVID-19 patient sera. Next, we use ReScan, a method to efficiently sequester phage expressing the most immunogenic peptides and print them onto paper-based microarrays using acoustic liquid handling, which isolates and identifies nine candidate antigens, eight of which are derived from the two proteins used for SARS-CoV-2 serologic assays: spike and nucleocapsid proteins. After deployment in a high-throughput assay amenable to clinical lab settings, these antigens show improved specificity over a whole protein panel. This proof-of-concept study demonstrates that ReScan will have broad applicability for other emerging infectious diseases or autoimmune diseases that lack a valid biomarker, enabling a seamless pipeline from antigen discovery to diagnostic using one recombinant protein source. [Display omitted] ReScan is a whole proteome screen to isolate and identify serologic assay targetsAntibodies to linear peptides in COVID-19 sera bind spike and nucleocapsid proteinsRapid workflow that seamlessly translates biomarkers into a functional diagnosticMultiplexing linear S and N SARS-CoV-2 peptides can increase diagnostic specificity Rapid serologic assay development remains challenging in scenarios in which antigens are unknown and is particularly crucial during a pandemic. Zamecnik et al. use ReScan, which combines paper-based microarrays and programmable phage display, to screen for and isolate the most immunogenic peptides for SARS-CoV-2 antibody diagnostics.