scholarly journals Production and application of mouse monoclonal antibodies targeting linear epitopes in pB602L of African swine fever virus

2022 ◽  
Author(s):  
Pengfei Wang ◽  
Chunguo Liu ◽  
Shida Wang ◽  
Lili Wen ◽  
Zhibin Shi ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Immunohistochemical Staining ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Diagnostic Tools ◽  
Hemorrhagic Disease ◽  
Structural Protein ◽  
Linear Epitopes ◽  
Group 2 ◽  
Basic And Applied Research

AbstractAfrican swine fever (ASF) is an acute hemorrhagic disease of domestic pigs. The causative agent of ASF, ASF virus (ASFV), is a double-stranded DNA virus, the sole member in the family Asfarviridae. The non-structural protein pB602L of ASFV is a molecular chaperone of the major capsid protein p72 and plays a key role in icosahedral capsid assembly. This protein is antigenic and is a target for developing diagnostic tools for ASF. To generate monoclonal antibodies (mAbs) against pB602L, a prokaryotically expressed recombinant pB602L protein was produced, purified, and used as an antigen to immunize mice. A total of eight mouse mAbs were obtained, and their binding epitopes were screened by Western blot using an overlapping set of polypeptides from pB602L. Three linear epitopes were identified and designated epitope 1 (366ANRERYNY373), epitope 2 (415GPDAPGLSI423), and epitope 3 (498EMLNVPDD505). Based on the epitope recognized, the eight mAbs were placed into three groups: group 1 (B2A1, B2F1, and B2D10), group 2 (B2H10, B2B2, B2D8, and B2A3), and group 3 (B2E12). The mAbs B2A1, B2H10, and B2E12, each representing one of the groups, were used to detect pB602L in ASFV-infected porcine alveolar macrophages (PAMs) and pig tissues, using an indirect fluorescence assay (IFA) and immunohistochemical staining, respectively. The results showed that pB602L was detectable with all three mAbs in immunohistochemical staining, but only B2H10 was suitable for detecting the proteins in ASFV-infected PAMs by IFA. In summary, we developed eight anti-pB602L mouse mAbs recognizing three linear epitopes in the protein, which can be used as reagents for basic and applied research on ASFV.

scholarly journals Epitope mapping of African swine fever virus (ASFV) structural protein p30

2021 ◽  
Author(s):  
yao zhang ◽  
Aiping Wang ◽  
Jingming Zhou ◽  
Hongliang Liu ◽  
Yumei Chen ◽  
...  
Keyword(s):  
Epitope Mapping ◽  
African Swine Fever Virus ◽  
Cell Epitope ◽  
African Swine Fever ◽  
Fever Virus ◽  
Economic Losses ◽  
Diagnostic Tools ◽  
Structural Protein ◽  
Different Strains ◽  
Key Steps

Since African swine fever (ASF) was first reported in 1921, it has brought huge economic losses to the world pig industry. No vaccine or therapy is available. Rapid and effective diagnostics are key steps in managing ASF. We generated three monoclonal antibodies (mAbs) against the African swine fever virus (ASFV) phosphoprotein p30 and designated these as 7D2, 8C8 and 2F6. Epitope mapping revealed that mAb 7D2 recognized VFHAG SLYNW of p30, and mAb 8C8 and 2F6 recognized MDFIL NISMK MEVIF KTDLR of p30. Furthermore, epitope MDFIL NISMK MEVIF KTDLR and VFHAG SLYNW could be well recognized by ASFV-positive sera from natural infected pigs, suggesting that they were natural linear B-cell epitope. Conservation analysis indicated that epitope MDFIL NISMK MEVIF KTDLR and VFHAG SLYNW were highly conserved among the different strains of ASFV. This is the first research to characterize specific mAbs against p30 protein. These findings may facilitate further understanding the function of p30 protein and development of diagnostic tools.

scholarly journals Linear epitopes in African swine fever virus p72 recognized by monoclonal antibodies prepared against baculovirus-expressed antigen

2018 ◽  
Vol 30 (3) ◽  
pp. 406-412 ◽  
Author(s):  
Mallory E. Heimerman ◽  
Maria V. Murgia ◽  
Ping Wu ◽  
Andre D. Lowe ◽  
Wei Jia ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Major Capsid Protein ◽  
Vaccine Development ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Vero Cells ◽  
Fever Virus ◽  
E Coli ◽  
Important Target ◽  
Linear Epitopes

Protein p72 is the major capsid protein of African swine fever virus (ASFV) and is an important target for test and vaccine development. Monoclonal antibodies (mAbs) were prepared against a recombinant antigenic fragment, from amino acid (aa) 20–303, expressed in baculovirus. A total of 29 mAbs were recovered and tested by immunofluorescent antibody (IFA) staining on ASFV Lisbon-infected Vero cells. Six antibodies were IFA-positive and selected for further characterization. Epitope mapping was performed against overlapping polypeptides expressed in E. coli and oligopeptides. Based on oligopeptide recognition, the mAbs were divided into 4 groups: mAb 85 (aa 165–171); mAbs 65-3 and 6H9-1 (aa 265–280); mAbs 8F7-3 and 23 (aa 280–294); and mAb 4A4 (aa 290–303). All mAbs were located within a highly conserved region in p72. This panel of antibodies provides the opportunity to develop new assays for the detection of ASFV antibody and antigen.

scholarly journals Computational Analysis of African Swine Fever Virus Protein Space for the Design of an Epitope-Based Vaccine Ensemble

Pathogens ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1078 ◽  
Author(s):  
Albert Ros-Lucas ◽  
Florencia Correa-Fiz ◽  
Laia Bosch-Camós ◽  
Fernando Rodriguez ◽  
Julio Alonso-Padilla
Keyword(s):  
T Cell ◽  
Vaccine Development ◽  
De Novo ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Fever Virus ◽  
Economic Losses ◽  
Virus Protein ◽  
Hemorrhagic Disease ◽  
Starting Point

African swine fever virus is the etiological agent of African swine fever, a transmissible severe hemorrhagic disease that affects pigs, causing massive economic losses. There is neither a treatment nor a vaccine available, and the only method to control its spread is by extensive culling of pigs. So far, classical vaccine development approaches have not yielded sufficiently good results in terms of concomitant safety and efficacy. Nowadays, thanks to advances in genomic and proteomic techniques, a reverse vaccinology strategy can be explored to design alternative vaccine formulations. In this study, ASFV protein sequences were analyzed using an in-house pipeline based on publicly available immunoinformatic tools to identify epitopes of interest for a prospective vaccine ensemble. These included experimentally validated sequences from the Immune Epitope Database, as well as de novo predicted sequences. Experimentally validated and predicted epitopes were prioritized following a series of criteria that included evolutionary conservation, presence in the virulent and currently circulating variant Georgia 2007/1, and lack of identity to either the pig proteome or putative proteins from pig gut microbiota. Following this strategy, 29 B-cell, 14 CD4+ T-cell and 6 CD8+ T-cell epitopes were selected, which represent a starting point to investigating the protective capacity of ASFV epitope-based vaccines.

scholarly journals African Swine Fever Laboratory Diagnosis—Lessons Learned from Recent Animal Trials

Pathogens ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 177
Author(s):  
Jutta Pikalo ◽  
Paul Deutschmann ◽  
Melina Fischer ◽  
Hanna Roszyk ◽  
Martin Beer ◽  
...  
Keyword(s):  
African Swine Fever Virus ◽  
Clinical Signs ◽  
African Swine Fever ◽  
Laboratory Diagnosis ◽  
Lessons Learned ◽  
Hemorrhagic Disease ◽  
Passive Surveillance ◽  
Animal Trials ◽  
Fit For Purpose ◽  
The Impact

African swine fever virus (ASFV) causes a hemorrhagic disease in pigs with high socio-economic consequences. To lower the impact of disease incursions, early detection is crucial. In the context of experimental animal trials, we evaluated diagnostic workflows for a high sample throughput in active surveillance, alternative sample matrices for passive surveillance, and lateral flow devices (LFD) for rapid testing. We could demonstrate that EDTA blood is significantly better suited for early ASFV detection than serum. Tissues recommended by the respective diagnostic manuals were in general comparable in their performance, with spleen samples giving best results. Superficial lymph nodes, ear punches, and different blood swabs were also evaluated as potential alternatives. In summary, all matrices yielded positive results at the peak of clinical signs and could be fit for purpose in passive surveillance. However, weaknesses were discovered for some matrices when it comes to the early phase of infection or recovery. The antigen LFD showed variable results with best performance in the clinical phase. The antibody LFD was quite comparable with ELISA systems. Concluding, alternative approaches are feasible but have to be embedded in control strategies selecting test methods and sample materials following a “fit-for-purpose” approach.

scholarly journals African Swine Fever Virus pB119L Protein Is a Flavin Adenine Dinucleotide-Linked Sulfhydryl Oxidase

2006 ◽  
Vol 80 (7) ◽  
pp. 3157-3166 ◽  
Author(s):  
Irene Rodríguez ◽  
Modesto Redrejo-Rodríguez ◽  
Javier M. Rodríguez ◽  
Alí Alejo ◽  
José Salas ◽  
...  
Keyword(s):  
Disulfide Bonds ◽  
Flavin Adenine Dinucleotide ◽  
Virus Assembly ◽  
Nonstructural Protein ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Fever Virus ◽  
Structural Protein ◽  
Sulfhydryl Oxidase ◽  
Infected Cells

ABSTRACT Protein pB119L of African swine fever virus belongs to the Erv1p/Alrp family of sulfhydryl oxidases and has been described as a late nonstructural protein required for correct virus assembly. To further our knowledge of the function of protein pB119L during the virus life cycle, we have investigated whether this protein possesses sulfhydryl oxidase activity, using a purified recombinant protein. We show that the purified protein contains bound flavin adenine dinucleotide and is capable of catalyzing the formation of disulfide bonds both in a protein substrate and in the small molecule dithiothreitol, the catalytic activity being comparable to that of the Erv1p protein. Furthermore, protein pB119L contains the cysteines of its active-site motif CXXC, predominantly in an oxidized state, and forms noncovalently bound dimers in infected cells. We also show in coimmunoprecipitation experiments that protein pB119L interacts with the viral protein pA151R, which contains a CXXC motif similar to that present in thioredoxins. Protein pA151R, in turn, was found to interact with the viral structural protein pE248R, which contains disulfide bridges and belongs to a class of myristoylated proteins related to vaccinia virus L1R, one of the substrates of the redox pathway encoded by this virus. These results suggest the existence in African swine fever virus of a system for the formation of disulfide bonds constituted at least by proteins pB119L and pA151R and identify protein pE248R as a possible final substrate of this pathway.

scholarly journals African Swine Fever Virus Structural Protein pE120R Is Essential for Virus Transport from Assembly Sites to Plasma Membrane but Not for Infectivity

2001 ◽  
Vol 75 (15) ◽  
pp. 6758-6768 ◽  
Author(s):  
Germán Andrés ◽  
Ramón Garcı́a-Escudero ◽  
Eladio Viñuela ◽  
Marı́a L. Salas ◽  
Javier M. Rodrı́guez
Keyword(s):  
Plasma Membrane ◽  
African Swine Fever Virus ◽  
Growth Curves ◽  
African Swine Fever ◽  
Fever Virus ◽  
Virus Yield ◽  
Virus Infectivity ◽  
Structural Protein ◽  
Virus Growth ◽  
Extracellular Virus

ABSTRACT This report examines the role of African swine fever virus (ASFV) structural protein pE120R in virus replication. Immunoelectron microscopy revealed that protein pE120R localizes at the surface of the intracellular virions. Consistent with this, coimmunoprecipitation assays showed that protein pE120R binds to the major capsid protein p72. Moreover, it was found that, in cells infected with an ASFV recombinant that inducibly expresses protein p72, the incorporation of pE120R into the virus particle is dependent on p72 expression. Protein pE120R was also studied using an ASFV recombinant in which E120R gene expression is regulated by the Escherichia coli lacrepressor-operator system. In the absence of inducer, pE120R expression was reduced about 100-fold compared to that obtained with the parental virus or the recombinant virus grown under permissive conditions. One-step virus growth curves showed that, under conditions that repress pE120R expression, the titer of intracellular progeny was similar to the total virus yield obtained under permissive conditions, whereas the extracellular virus yield was about 100-fold lower than in control infections. Immunofluorescence and electron microscopy demonstrated that, under restrictive conditions, intracellular mature virions are properly assembled but remain confined to the replication areas. Altogether, these results indicate that pE120R is necessary for virus dissemination but not for virus infectivity. The data also suggest that protein pE120R might be involved in the microtubule-mediated transport of ASFV particles from the viral factories to the plasma membrane.

scholarly journals Characterization of the African Swine Fever Virus Structural Protein p14.5: A DNA Binding Protein

Virology ◽  
1997 ◽  
Vol 229 (1) ◽  
pp. 201-211 ◽  
Author(s):  
Luisa Martinez-Pomares ◽  
Carmen Simon-Mateo ◽  
Carlos Lopez-Otin ◽  
Eladio Viñuela
Keyword(s):  
Dna Binding ◽  
African Swine Fever Virus ◽  
Binding Protein ◽  
African Swine Fever ◽  
Dna Binding Protein ◽  
Fever Virus ◽  
Structural Protein

scholarly journals Two African Swine Fever Virus Proteins Derived from a Common Precursor Exhibit Different Nucleocytoplasmic Transport Activities

2004 ◽  
Vol 78 (18) ◽  
pp. 9731-9739 ◽  
Author(s):  
A. Eulálio ◽  
I. Nunes-Correia ◽  
A. L. Carvalho ◽  
C. Faro ◽  
V. Citovsky ◽  
...  
Keyword(s):  
Nuclear Import ◽  
Mammalian Cells ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Nucleocytoplasmic Transport ◽  
Proteolytic Processing ◽  
Fever Virus ◽  
Hemorrhagic Disease ◽  
Common Precursor ◽  
Green Fluorescent

ABSTRACT African swine fever virus (ASFV), a large icosahedral deoxyvirus, is the causative agent of an economically relevant hemorrhagic disease that affects domestic pigs. The major purpose of the present study was to investigate the nuclear transport activities of the ASFV p37 and p14 proteins, which result from the proteolytic processing of a common precursor. Experiments were performed by using yeast-based nucleocytoplasmic transport assays and by analysis of the subcellular localization of different green fluorescent and Myc fusion proteins in mammalian cells. The results obtained both in yeast and mammalian cells clearly demonstrated that ASFV p14 protein is imported into the nucleus but not exported to the cytoplasm. The ability of p37 protein to be exported from the nucleus to the cytoplasm of both yeast and mammalian cells was also demonstrated, and the results clearly indicate that p37 nuclear export is dependent on the interaction of the protein with the CRM-1 receptor. In addition, p37 was shown to exhibit nuclear import activity in mammalian cells. The p37 protein nuclear import and export abilities described here constitute the first report of a nucleocytoplasmic shuttling protein encoded by the ASFV genome. Overall, the overlapping results obtained for green fluorescent protein fusions and Myc-tagged proteins undoubtedly demonstrate that ASFV p37 and p14 proteins exhibit nucleocytoplasmic transport activities. These findings are significant for understanding the role these proteins play in the replication cycle of ASFV.

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