A workflow for rapid SARS-CoV-2 epitope discovery on peptide microarrays is herein reported. The process started with a proteome-wide screening of immunoreactivity based on the use of a high-density microarray followed by a refinement and validation phase on a restricted panel of probes using microarrays with tailored peptide immobilization through a click-based strategy. Progressively larger, independent cohorts of Covid-19 positive sera were tested in the refinement processes, leading to the identification of immunodominant regions on SARS-CoV-2 spike (S), nucleocapsid (N) protein and Orf1ab polyprotein. A summary study testing 50 serum samples highlighted an epitope of the N protein (region 155–71) providing good diagnostic performance in discriminating Covid-19 positive vs. healthy individuals. Using this epitope, 92% sensitivity and 100% specificity were reached for IgG detection in Covid-19 samples, and no cross-reactivity with common cold coronaviruses was detected. Likewise, IgM immunoreactivity in samples collected within the first month after symptoms onset showed discrimination ability. Overall, epitope 155–171 from N protein represents a promising candidate for further development and rapid implementation in serological tests.
【저자키워드】 COVID-19, serological test, SARS-CoV-2, click chemistry, epitope mapping, peptide microarrays, 【초록키워드】 IgG, IgM, diagnostic, peptide, cross-reactivity, Protein, sensitivity, specificity, Cohort, Region, nucleocapsid, sera, implementation, N protein, Microarray, epitope, serological, SARS-CoV-2 spike, healthy individuals, immunoreactivity, symptoms onset, common cold coronavirus, peptide microarray, positive, serum sample, immunodominant, polyprotein, probe, high-density, independent, tested, collected, reported, reached, the N protein, 【제목키워드】 Region, mapping, Strong,