Antibody epitope repertoire analysis enables rapid antigen discovery and multiplex serology

• Published in: Scientific reports Vol. 10; no. 1; p. 5294
• Main Authors: Kamath, Kathy, Reifert, Jack, Johnston, Timothy, Gable, Cameron, Pantazes, Robert J., Rivera, Hilda N., McAuliffe, Isabel, Handali, Sukwan, Daugherty, Patrick S.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 24.03.2020; Nature Publishing Group
• Subjects: 631/250/2152; 631/250/2152/2153; 631/250/2499; 631/61; 631/61/24; Adult; Antibodies, Protozoan - blood; Antibodies, Protozoan - immunology; Antigens; Antigens, Protozoan - immunology; Chagas disease; Chagas Disease - blood; Chagas Disease - diagnosis; Chagas Disease - immunology; Chagas Disease - parasitology; Epitopes; Epitopes - immunology; Female; Humanities and Social Sciences; Humans; Leishmania; Male; multidisciplinary; Next-generation sequencing; Parasites; Pathogens; Peptide Library; Peptides; Protozoa; Science; Science (multidisciplinary); Serology; Trypanosoma cruzi - immunology; Vector-borne diseases
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-020-62256-9

The detection of pathogen-specific antibodies remains a cornerstone of clinical diagnostics. Yet, many test exhibit undesirable performance or are completely lacking. Given this, we developed serum epitope repertoire analysis (SERA), a method to rapidly discover conserved, pathogen-specific antigens and their epitopes, and applied it to develop an assay for Chagas disease caused by the protozoan parasite Trypanosoma cruzi . Antibody binding peptide motifs were identified from 28 Chagas repertoires using a bacterial display random 12-mer peptide library and next-generation sequencing (NGS). Thirty-three motifs were selected and mapped to candidate Chagas antigens. In a blinded validation set (n = 72), 30/30 Chagas were positive, 30/30 non-Chagas were negative, and 1/12 Leishmania sp . was positive. After unblinding, a Leishmania cross-reactive epitope was identified and removed from the panel. The Chagas assay exhibited 100% sensitivity (30/30) and specificity (90/90) in a second blinded validation set including individuals with other parasitic infections. Amongst additional epitope repertoires with unknown Chagas serostatus, assay specificity was 99.8% (998/1000). Thus, the Chagas assay achieved a combined sensitivity and specificity equivalent or superior to diagnostic algorithms that rely on three separate tests to achieve high specificity. NGS-based serology via SERA provides an effective approach to discover antigenic epitopes and develop high performance multiplex serological assays.