In:
PLOS Neglected Tropical Diseases, Public Library of Science (PLoS), Vol. 16, No. 7 ( 2022-7-11), p. e0010619-
Abstract:
Schistosoma japonicum is one of three major species of blood flukes causing schistosomiasis, a disease, which continues to be a major public health issue in the Philippines. SjSAP4, a member of a multigene family of saposin-like proteins, is a recognized immunodiagnostic biomarker for schistosomiasis japonica. This study aimed to identify linear B-cell epitopes on SjSAP4 and to validate their potential as components of a multi-epitope assay for the serological diagnosis of schistosomiasis japonica. Methodology SjSAP4-derived peptides were expressed as GST-peptide-fused proteins and these were Western blot probed with human serum samples from S . japonicum Kato-Katz (KK)-positive individuals and uninfected controls. A core epitope was further identified by Western blotting through probing a series of truncated peptides with the schistosomiasis patient sera. The diagnostic performance of the core epitope-containing peptides and the full-length SjSAP4 was evaluated by enzyme-linked immunosorbent assay (ELISA) using a panel of sera collected from subjects resident in a schistosomiasis-endemic area of the Philippines. Main findings As a result of the peptide mapping, one peptide (P15) was found to be highly immunogenic in the KK-positive individuals. We subsequently showed that -S 163 QCSLVGDIFVDKYLD 178 - is a core B-cell epitope of P15. Subsequent ELISAs incorporating SjSAP4, SjSAP4-Peptide and SjSP-13V2-Peptide showed a sensitivity of 94.0%, 46.0% and 74.0%, respectively, and a specificity of 97.1%, 100% and 100%, respectively. Notably, complementary recognition of the B-cell epitopes (SjSAP4-Peptide and SjSP-13V2-Peptide) was observed in a subset of the KK-positive individuals. A dual epitope-ELISA (SjSAP4-Peptide + SjSP-13V2-Peptide-ELISA) showed a diagnostic sensitivity of 84.0% and a specificity of 100%. Conclusions/Significance In this study, -S 163 QCSLVGDIFVDKYLD 178 - was identified as a dominant linear B-cell epitope on SjSAP4. This peptide and the complementary recognition of other B-cell epitopes using sera from different KK-positive individuals can provide the basis of developing a multi-epitope assay for the serological diagnosis of schistosomiasis.
Type of Medium:
Online Resource
ISSN:
1935-2735
DOI:
10.1371/journal.pntd.0010619
DOI:
10.1371/journal.pntd.0010619.g001
DOI:
10.1371/journal.pntd.0010619.g002
DOI:
10.1371/journal.pntd.0010619.g003
DOI:
10.1371/journal.pntd.0010619.g004
DOI:
10.1371/journal.pntd.0010619.g005
DOI:
10.1371/journal.pntd.0010619.g006
DOI:
10.1371/journal.pntd.0010619.s001
DOI:
10.1371/journal.pntd.0010619.s002
DOI:
10.1371/journal.pntd.0010619.s003
DOI:
10.1371/journal.pntd.0010619.s004
Language:
English
Publisher:
Public Library of Science (PLoS)
Publication Date:
2022
detail.hit.zdb_id:
2429704-5
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