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Ostuni A, Monné M, Crudele MA, Cristinziano PL, Cecchini S, Amati M, De Vendel J, Raimondi P, Chassalevris T, Dovas CI, Bavoso A. Design and structural bioinformatic analysis of polypeptide antigens useful for the SRLV serodiagnosis. J Virol Methods 2021; 297:114266. [PMID: 34454989 DOI: 10.1016/j.jviromet.2021.114266] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 06/30/2021] [Accepted: 08/18/2021] [Indexed: 10/20/2022]
Abstract
Due to their intrinsic genetic, structural and phenotypic variability the Lentiviruses, and specifically small ruminant lentiviruses (SRLV), are considered viral quasispecies with a population structure that consists of extremely large numbers of variant genomes, termed mutant spectra or mutant cloud. Immunoenzymatic tests for SRLVs are available but the dynamic heterogeneity of the virus makes the development of a diagnostic "golden standard" extremely difficult. The ELISA reported in the literature have been obtained using proteins derived from a single strain or they are multi-strain based assay that may increase the sensitivity of the serological diagnosis. Hundreds of SRLV protein sequences derived from different viral strains are deposited in GenBank. The aim of this study is to verify if the database can be exploited with the help of bioinformatics in order to have a more systematic approach in the design of a set of representative protein antigens useful in the SRLV serodiagnosis. Clustering, molecular modelling, molecular dynamics, epitope predictions and aggregative/solubility predictions were the main bioinformatic tools used. This approach led to the design of SRLV antigenic proteins that were expressed by recombinant DNA technology using synthetic genes, analyzed by CD spectroscopy, tested by ELISA and preliminarily compared to currently commercially available detection kits.
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Affiliation(s)
- Angela Ostuni
- Department of Sciences, University of Basilicata, viale Ateneo Lucano 10, 85100, Potenza, Italy.
| | - Magnus Monné
- Department of Sciences, University of Basilicata, viale Ateneo Lucano 10, 85100, Potenza, Italy
| | | | - Pier Luigi Cristinziano
- Department of Sciences, University of Basilicata, viale Ateneo Lucano 10, 85100, Potenza, Italy
| | - Stefano Cecchini
- Department of Sciences, University of Basilicata, viale Ateneo Lucano 10, 85100, Potenza, Italy
| | - Mario Amati
- Department of Sciences, University of Basilicata, viale Ateneo Lucano 10, 85100, Potenza, Italy
| | | | | | - Taxiarchis Chassalevris
- Diagnostic Laboratory, School of Veterinary Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, 11 Stavrou Voutyra Str., 54627, Thessaloniki, Greece
| | - Chrysostomos I Dovas
- Diagnostic Laboratory, School of Veterinary Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, 11 Stavrou Voutyra Str., 54627, Thessaloniki, Greece
| | - Alfonso Bavoso
- Department of Sciences, University of Basilicata, viale Ateneo Lucano 10, 85100, Potenza, Italy
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Picotto LD, Fuentealba NA, Bertoni G, Patrucco M, Sguazza GH, Echeverria MG, Panei CJ. Argentinian small ruminant lentivirus (SRLV) p55gag antigen fused to maltose binding protein to use in SRLV serological confirmatory diagnosis. Virus Res 2021; 296:198332. [PMID: 33549642 DOI: 10.1016/j.virusres.2021.198332] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 01/31/2021] [Accepted: 02/01/2021] [Indexed: 12/28/2022]
Abstract
The complete gag gene from small ruminant lentiviruses (SRLV) encodes for a polyprotein of 55 kDa, known as p55gag. p55gag presents multiple antigenic epitopes, which can be recognized by antibodies, increasing the opportunity to detect SRLV-positive animals. Therefore, this polyprotein is considered an excellent candidate to use in diagnostic tests to detect antibodies against SRLV. Different studies have suggested that the selection of the recombinant antigen, which must be representative of the virus strains circulating in the test population, is crucial to avoid false negative results. Thus, the use of proteins from different viral strains isolated from goats or sheep of a given region or country may be a useful strategy to increase the ability to detect SRLV-infected animals. In the present study, the pMAL-p5X vector was used to express and purify p55gag (now called rp55gag for recombinant polyprotein 55 gag). The cloned gene was inserted downstream from the malE gene of Escherichia coli, which encodes a maltose-binding protein (MBP), resulting in the expression of an MBP fusion protein. The complete gag gene was amplified by RT-PCR. Finally, after digestion, the product was cloned into the pMAL-p5X vector and used to transform E. coli ER2325 cells. After the purification of MBP-rp55gag by affinity chromatography, the eluted fraction was observed by SDS-PAGE and Western Blot (WB). The WB was carried out with 85 serum samples from small ruminants previously analysed and compared by two commercial ELISAs. The results show that 76 of the serum samples were concordant with those by both ELISAs. Regarding the other nine serum samples, which showed discordant results between both ELISAs, were positive by WB. The results thus show that the rp55gag could be considered as an antigen in a confirmatory diagnostic assay to detect SRLV by WB. For this purpose, a future study with a high number of sera to determine the test specificity and sensitivity, using the p55gag of the circulating strain in Argentina will be necessary.
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Affiliation(s)
- Leandro Daniel Picotto
- Virology Laboratory, Faculty of Veterinary Sciences, National University of La Plata, 60&118, CC 296, 1900, La Plata, Argentina; National Scientific and Technical Research Council (CONICET), Argentina
| | - Nadia Analía Fuentealba
- Virology Laboratory, Faculty of Veterinary Sciences, National University of La Plata, 60&118, CC 296, 1900, La Plata, Argentina; National Scientific and Technical Research Council (CONICET), Argentina
| | - Giuseppe Bertoni
- Institute of Virology and Immunology, Department of Infectious Diseases and Pathobiology, University of Bern, CH-3012, Bern, Switzerland
| | - Marianela Patrucco
- Virology Laboratory, Faculty of Veterinary Sciences, National University of La Plata, 60&118, CC 296, 1900, La Plata, Argentina
| | - Guillermo Hernán Sguazza
- Virology Laboratory, Faculty of Veterinary Sciences, National University of La Plata, 60&118, CC 296, 1900, La Plata, Argentina
| | - María Gabriela Echeverria
- Virology Laboratory, Faculty of Veterinary Sciences, National University of La Plata, 60&118, CC 296, 1900, La Plata, Argentina; National Scientific and Technical Research Council (CONICET), Argentina
| | - Carlos Javier Panei
- Virology Laboratory, Faculty of Veterinary Sciences, National University of La Plata, 60&118, CC 296, 1900, La Plata, Argentina; National Scientific and Technical Research Council (CONICET), Argentina.
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Gazarian K, Setién AA, Gazarian T, Pierle SA. Phage display identifies two Caprine Arthritis Encephalitis Virus env epitopes. Vet Res 2011; 42:87. [PMID: 21781322 PMCID: PMC3162499 DOI: 10.1186/1297-9716-42-87] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2010] [Accepted: 07/22/2011] [Indexed: 11/10/2022] Open
Abstract
Using phage display and IgG of a goat infected with Caprine Arthritis Encephalitis Virus (CAEV) we obtained families of 7 mer constrained peptides with consensus motifs LxSDPF/Y and SWN/KHWSY and mapped the epitopes mimicked by them at the Env 6-LISDPY-11 and 67-WNTYHW-72 sites of the mature gp135 amino acid sequence. The first epitope fell into the N-terminal immunogenic aa1-EDYTLISDPYGFS- aa14 site identified previously with a synthetic peptide approach; the second epitope has not been described previously. The first epitope is mostly conserved across CAEV isolates whereas the second newly described epitope is extremely conserved in Small Ruminant Lentiviruses env sequences. As being immunodominant, the epitopes are candidate targets for mimotope-mediated diagnosis and/or neutralization.
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Affiliation(s)
- Karlen Gazarian
- Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México (UNAM), México D,F,, Ciudad Universitaria, 04510, México.
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