Antibody reactions of horses against various domains of the EHV-1 receptor-binding protein gD1.

Autor: Schramm A; Institute of Virology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland., Ackermann M; Institute of Virology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland., Eichwald C; Institute of Virology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland., Aguilar C; Institute of Virology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland., Fraefel C; Institute of Virology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland., Lechmann J; Institute of Virology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland.
Jazyk: angličtina
Zdroj: PloS one [PLoS One] 2024 Jul 12; Vol. 19 (7), pp. e0301987. Date of Electronic Publication: 2024 Jul 12 (Print Publication: 2024).
DOI: 10.1371/journal.pone.0301987
Abstrakt: Equid alphaherpesviruses 1 (EHV-1) and 4 (EHV-4) are closely related and both endemic in horses worldwide. Both viruses replicate in the upper respiratory tract, but EHV-1 may additionally lead to abortion and equine herpesvirus myeloencephalopathy (EHM). We focused on antibody responses in horses against the receptor-binding glycoprotein D of EHV-1 (gD1), which shares a 77% amino acid identity with its counterpart in EHV-4 (gD4). Both antigens give rise to cross-reacting antibodies, including neutralizing antibodies. However, immunity against EHV-4 is not considered protective against EHM. While a diagnostic ELISA to discriminate between EHV-1 and EHV-4 infections is available based on type-specific fragments of glycoprotein G (gG1 and gG4, respectively), the type-specific antibody reaction against gD1 has not yet been sufficiently addressed. Starting from the N-terminus of gD1, we developed luciferase immunoprecipitation system (LIPS) assays, using gD1-fragments of increasing size as antigens, i.e. gD1_83 (comprising the first 83 amino acids), gD1_160, gD1_180, and gD1_402 (the full-length molecule). These assays were then used to analyse panels of horse sera from Switzerland (n = 60) and Iceland (n = 50), the latter of which is considered EHV-1 free. We detected only one true negative horse serum from Iceland, whereas all other sera in both panels were seropositive for both gG4 (ELISA) and gD1 (LIPS against gD1_402). In contrast, seropositivity against gG1 was rather rare (35% Swiss sera; 14% Icelandic sera). Therefore, a high percentage of antibodies against gD1 could be attributed to cross-reaction and due to EHV-4 infections. In contrast, the gD1_83 fragment was able to identify sera with type-specific antibodies against gD1. Interestingly, those sera stemmed almost exclusively from vaccinated horses. Although it is uncertain that the N-terminal epitopes of gD1 addressed in this communication are linked to better protection, we suggest that in future vaccine developments, type-common antigens should be avoided, while a broad range of type-specific antigens should be favored.
Competing Interests: The authors have declared that no competing interests exist.
(Copyright: © 2024 Schramm et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)
Databáze: MEDLINE
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