Identification and validation of specific B-cell epitopes of hantaviruses associated to hemorrhagic fever and renal syndrome

Abstract

BackgroundOrthohantavirus infection is a neglected global health problem affecting approximately 200,000 people/year, spread by rodent hosts and associated to fatal human diseases, such as hemorrhagic fever with renal syndrome (HFRS) and orthohantavirus cardiopulmonary syndrome (HCPS). Circulation of HFRS-associated orthohantaviruses, such as Seoul, Gou, Amur, Dobrava and Hantaan, are supposed to be restricted to Eurasian countries even though their hosts can be a worldwide distribution. Few confirmed HFRS orthohantavirus infections in humans have been reported in American countries, but due to lower medical awareness of the symptoms of this zoonosis, it could be associated to viral underreporting or to misdiagnosis with several tropical hemorrhagic diseases. Serological evidence of orthohantavirus infections, using enzyme-linked immunosorbent assay for the presence of immunoglobulin M and G against recombinant nucleoprotein protein, remains as an essential assay for viral surveillance. In this study, we aimed to identify in silico immunogenic B-cell linear epitopes present on orthohantavirus nucleoprotein that are exclusive to HFRS-related species.Methodology/Principal findingsIn silico analysis were performed using Seoul orthohantavirus nucleoprotein (SHNP) sequence as a model. Linear B-cell-epitopes on SHNP and its immunogenicity were predicted by BepiPred-2.0 and Vaxijen algorithms, respectively. The conservancy of predicted epitopes was compared with the most clinically relevant HFRS or HCPS-associated orthohantavirus, aiming to identify specific sequences from HFRS-orthohantavirus. Peptide validation was carried out by ELISA using Balb/c mice sera immunized with purified recombinant rSHNP. Peptides cross-reactivity against HCPS orthohantavirus were evaluated using immunized sera from mice injected with recombinant Juquitiba orthohantavirus nucleoprotein (rJHNP).Conclusion/SignificanceIn silico analysis revealed nine potential immunogenic linear B-cell epitopes from SHNP; among them, SHNP(G72-D110) and SHNP(P251-D264) showed a high degree of sequence conservation among HFRS-related orthohantavirus and were experimentally validated against rSHNP-IMS and negatively validated against rJHNP-IMS. Taken together, we identified and validated two potential antigenic B-cell epitopes on SHNP, which were conserved among HFRS-associated orthohantavirus and could be applied to the development of novel immunodiagnostic tools for orthohantavirus surveillance.

The Serological Cross-Detection of Bat-Borne Hantaviruses: A Valid Strategy or Taking Chances?

“…Remarkably, NP is the major hantavirus antigen that elicits early humoral immune responses and has been used as a serological target and for antigen detection in animals and patients [ 40 , 41 , 42 ]. This protein contains both serotype-specific and common group epitopes [ 43 , 44 , 45 ] and has been used to investigate the presence of hantaviruses in bats [ 18 ] and shrews [ 46 ] and to screen bats that could harbor hantaviruses in the New World [ 19 , 20 ]. However, there are no studies comparing the similarity of B-cell epitopes among bat- and rodent-borne hantaviruses.…”

“…Epitopes can be distributed over the whole NP, but it is thought that the C-terminal half of NP contains rather conformation- and multimerization-dependent epitopes, which should be more serotype-specific [ 47 , 48 ]. In a recently published work from our group, we demonstrated that NP amino acid sequence conservation among Orthohantavirus associated to HFRS (SEOV, HNTV, Amur virus , Dobrava-Belgrade orthohantavirus , and Puumala orthohantavirus ) and associated to HCPS (ANDV, SNV, and Laguna Negra orthohantavirus ) ranged from 62% to 95% [ 45 ]. The N-terminal quarter of hantaviral NP bears linear and immunodominant epitopes, but as seen here, a possible and interesting antigenic site was found in the C-terminal half [ 47 ].…”

Integrative Analysis of HTNV Glycoprotein Derived MHC II Epitopes by In Silico Prediction and Experimental Validation

“…However, it is well known that inactivated vaccines do not provide long-lasting immunity without multiple boosters ( Song et al., 2016 ). Therefore, many studies have explored novel candidate vaccines against hantavirus with new epitope designs ( Sankar et al., 2017a ; Sankar et al., 2017b ; Conte et al., 2019 ) and different methods evaluating efficacy ( Zhao et al., 2012 ; Hooper et al., 2013 ; Ma et al., 2016 ). These studies mainly focused on CD8+ T cells and B cell-mediated immunity.…”

Identification of Immunogenic Linear B-Cell Epitopes in C. burnetii Outer Membrane Proteins Using Immunoinformatics Approaches Reveals Potential Targets of Persistent Infections

“…The antigenicity of predicted linear epitopes was evaluated using the VaxiJen algorithm. Based on this evaluation, eight predicted epitopes were considered antigenic, among which were the four sequences predicted as linear B-cell epitopes by the three used algorithms (OMP-H (51)(52)(53)(54)(55)(56)(57)(58)(59) , OMP-H (98)(99)(100)(101)(102)(103)(104)(105)(106) , Com-1 (57)(58)(59)(60)(61)(62)(63)(64)(65)(66)(67)(68)(69)(70)(71)(72)(73)(74)(75)(76) , and Com-1 (191)(192)(193)(194)(195)(196)(197)(198)(199)(200)(201)(202)(203)(204)…”