scholarly journals Porcine Dendritic Cells and Viruses: An Update

Viruses ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 445 ◽  
Author(s):  
Giulia Franzoni ◽  
Simon P. Graham ◽  
Silvia Dei Giudici ◽  
Annalisa Oggiano
Keyword(s):  
Dendritic Cells ◽  
Viral Infections ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Classical Swine Fever ◽  
Fever Virus ◽  
Porcine Circovirus ◽  
Economic Losses ◽  
Swine Industry ◽  
Emerging Viral Diseases

Several viral infections of swine are responsible for major economic losses and represent a threat to the swine industry worldwide. New tools are needed to prevent and control endemic, emerging, and re-emerging viral diseases. Dendritic cells (DC) play a central role in linking the innate and adaptive arms of the immune system, so knowledge regarding their interaction with pathogens is necessary to understand the mechanisms underlying diseases pathogenesis and protection. In the first part of this review, we provide an update on the heterogeneous cell subsets that comprise the porcine DC family. In the second part of this review, we provide an overview of how three viruses, affecting pork production at a global level, African swine fever virus (ASFV), classical swine fever virus (CSFV), and porcine circovirus 2 (PCV2), modulate DC function.

scholarly journals Short and Long-read Sequencing Survey of the Dynamic Transcriptomes of African Swine Fever Virus and its Host

2020 ◽  
Author(s):  
Ferenc Olasz ◽  
Dóra Tombácz ◽  
Gábor Torma ◽  
Zsolt Csabai ◽  
Norbert Moldován ◽  
...  
Keyword(s):  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Fever Virus ◽  
Economic Losses ◽  
Swine Industry ◽  
Rna Molecules ◽  
Oxford Nanopore ◽  
Combined Use ◽  
Long Read ◽  
Low Coverage

AbstractAfrican swine fever virus (ASFV) is an important animal pathogen causing substantial economic losses in the swine industry globally. At present, little is known about the molecular biology of ASFV, including its transcriptome organization. In this study, we applied cutting-edge sequencing approaches, namely the Illumina short-read sequencing (SRS) and the Oxford Nanopore Technologies long-read sequencing (LRS) techniques, together with several library preparation chemistries to analyze the ASFV dynamic transcriptome. SRS can generate a large amount of high-precision sequencing reads, but it is inefficient for identifying long RNA molecules, transcript isoforms and overlapping transcripts. LRS can overcome these limitations, but this approach also has shortcomings, such as its high error rate and the low coverage. Amplification-based LRS techniques produce relatively high read counts but also high levels of spurious transcripts, whereas the non-amplified cDNA and direct RNA sequencing techniques are more precise but achieve lower throughput. The drawbacks of the various technologies can be circumvented by the combined use of these approaches.

scholarly journals Point-of-service diagnostic technology for detection of swine viral diseases

2020 ◽  
Vol 64 (1) ◽  
pp. 15-23 ◽  
Author(s):  
Lapo Nannucci ◽  
Paolo Barattini ◽  
Ioannis Bossis ◽  
Grzegorz Woźniakowski ◽  
Gyula Balka ◽  
...  
Keyword(s):  
Diagnostic Tool ◽  
African Swine Fever Virus ◽  
Swine Influenza Virus ◽  
Swine Influenza ◽  
African Swine Fever ◽  
Classical Swine Fever ◽  
Fever Virus ◽  
Porcine Circovirus ◽  
Respiratory Syndrome Virus ◽  
Time Required

AbstractIntroductionA research project is underway aiming to develop a field diagnostic tool for six important viruses of the pig sector, namely: African swine fever virus (ASFV), porcine reproductive and respiratory syndrome virus (PRRSV), swine influenza virus (SIV), porcine parvovirus (PPV), porcine circovirus (PCV2), and classical swine fever virus (CSFV).Material and MethodsTo obtain a preliminary sounding of the interest in this type of instrument among its potential operators, a questionnaire was drawn up and submitted to three categories of stakeholders: farmers, veterinarians, and others (including scientific and technical staff working on animal farms). Four countries participated: Italy, Greece, Hungary, and Poland.ResultsIn total, 83 replies were collected and analysed in a breakdown by stakeholder type and pertinence, where the areas were the importance of the main diseases within the different countries, diagnostic tool operational issues, and economic issues.ConclusionThe main end-users of this kind of instrument are expected to be private veterinarians and pig producers. The infectious agents seeming to be most interesting to diagnose with the instrument are PRRSV, SIV, PPV, and PCV2. The most decisive parameters which have been selected by the stakeholders are sensitivity, cost, simplicity, and time required to obtain results. The economic issue analysis showed that the majority of those who would prefer to buy rather than rent the device are willing to pay up to €3,000 for a diagnostic field tool.

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 BA71ΔCD2: a New Recombinant Live Attenuated African Swine Fever Virus with Cross-Protective Capabilities

2017 ◽  
Vol 91 (21) ◽  
Author(s):  
Paula L. Monteagudo ◽  
Anna Lacasta ◽  
Elisabeth López ◽  
Laia Bosch ◽  
Javier Collado ◽  
...  
Keyword(s):  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Fever Virus ◽  
Sub Saharan Africa ◽  
Swine Industry ◽  
Lethal Challenge ◽  
Major Threat ◽  
Attenuated Viruses ◽  
Genotype Ii

ABSTRACT African swine fever is a highly contagious viral disease of mandatory declaration to the World Organization for Animal Health (OIE). The lack of available vaccines makes its control difficult; thus, African swine fever virus (ASFV) represents a major threat to the swine industry. Inactivated vaccines do not confer solid protection against ASFV. Conversely, live attenuated viruses (LAV), either naturally isolated or obtained by genetic manipulation, have demonstrated reliable protection against homologous ASFV strains, although little or no protection has been demonstrated against heterologous viruses. Safety concerns are a major issue for the use of ASFV attenuated vaccine candidates and have hampered their implementation in the field so far. While trying to develop safer and efficient ASFV vaccines, we found that the deletion of the viral CD2v (EP402R) gene highly attenuated the virulent BA71 strain in vivo. Inoculation of pigs with the deletion mutant virus BA71ΔCD2 conferred protection not only against lethal challenge with the parental BA71 but also against the heterologous E75 (both genotype I strains). The protection induced was dose dependent, and the cross-protection observed in vivo correlated with the ability of BA71ΔCD2 to induce specific CD8+ T cells capable of recognizing both BA71 and E75 viruses in vitro. Interestingly, 100% of the pigs immunized with BA71ΔCD2 also survived lethal challenge with Georgia 2007/1, the genotype II strain of ASFV currently circulating in continental Europe. These results open new avenues to design ASFV cross-protective vaccines, essential to fight ASFV in areas where the virus is endemic and where multiple viruses are circulating. IMPORTANCE African swine fever virus (ASFV) remains enzootic in most countries of Sub-Saharan Africa, today representing a major threat for the development of their swine industry. The uncontrolled presence of ASFV has favored its periodic exportation to other countries, the last event being in Georgia in 2007. Since then, ASFV has spread toward neighboring countries, reaching the European Union's east border in 2014. The lack of available vaccines against ASFV makes its control difficult; so far, only live attenuated viruses have demonstrated solid protection against homologous experimental challenges, but they have failed at inducing solid cross-protective immunity against heterologous viruses. Here we describe a new LAV candidate with unique cross-protective abilities: BA71ΔCD2. Inoculation of BA71ΔCD2 protected pigs not only against experimental challenge with BA71, the virulent parental strain, but also against heterologous viruses, including Georgia 2007/1, the genotype II strain of ASFV currently circulating in Eastern Europe.

scholarly journals Identification of E2 with improved secretion and immunogenicity against CSFV in piglets

2020 ◽  
Author(s):  
Huiling Xu ◽  
Yanli Wang ◽  
Guangwei Han ◽  
Weihuan Fang ◽  
fang he
Keyword(s):  
Single Dose ◽  
Signal Peptide ◽  
Classical Swine Fever Virus ◽  
Subunit Vaccine ◽  
Classical Swine Fever ◽  
Cost Effective ◽  
Fever Virus ◽  
Economic Losses ◽  
Swine Industry ◽  
Virus Challenge

Abstract Background: Outbreaks of Classical swine fever virus (CSFV) cause significant economic losses in the swine industry. Vaccination is the major method to prevent and control the disease. As live attenuated vaccines fail to elicit differentiable immunity between infected and vaccinated animals, subunit vaccine was considered as an alternative candidate to prevent and eradicate CSFV. Subunit vaccines present advantages in DIVA immunogenicity and safety. The technology was limited due to the low yield and the high cost with multiple and large doses. The native E2 signal peptide has not been well defined before. Here, the aim of this study is to develop a cost-effective and efficacious E2 vaccine candidate against CSFV with signal peptide and E2 sequence selection. Results: A novel CSFV E2 sequence (E2ZJ) was identified from an epidemic strain of Zhejiang for outstanding secretion in baculovirus and enhanced immunogenicity. E2 secretion induced with the selected signal peptide, SPZJ (SP23), increase at least 50% as compared to any other signal peptides tested. Besides, unique antigenic features were identified in E2ZJ. E2ZJ elicited CSFV antibodies at the earlier stage than other E2 types tested in mice. Moreover, higher level of neutralization antibodies against both genotypes 1 and 2 CSFV with E2ZJ was detected than other E2s with the same dosage. Further, in piglets, E2ZJ successfully elicited neutralizing immunity. A single dose of 5 μg of E2ZJ was sufficient to induce protective antibodies against CSFV in piglets and provided 100% protection against lethal virus challenge. Conclusions: Our studies provide evidence that E2ZJ guided by a novel E2 signal peptide (SPZJ) was efficiently secreted and presented significantly improved immunogenicity than conventional E2 vaccines. Moreover, a single dose of 5 μg E2ZJ is efficacious against CSFV in piglets. Keywords: Classical swine fever virus; novel signal peptide; SPZJ-E2ZJ; subunit vaccine; protective immunity

scholarly journals Risk of African swine fever virus introduction into the United States through smuggling of pork in air passenger luggage

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Cristina Jurado ◽  
Lina Mur ◽  
María Sol Pérez Aguirreburualde ◽  
Estefanía Cadenas-Fernández ◽  
Beatriz Martínez-López ◽  
...  
Keyword(s):  
Western Europe ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
The United States ◽  
Economic Losses ◽  
Swine Industry ◽  
Virus Surveillance ◽  
Global Epidemiology ◽  
The Us ◽  
Mean Risk

Abstract African swine fever causes substantial economic losses in the swine industry in affected countries. Traditionally confined to Africa with only occasional incursions into other regions, ASF began spreading into Caucasian countries and Eastern Europe in 2007, followed by Western Europe and Asia in 2018. Such a dramatic change in the global epidemiology of ASF has resulted in concerns that the disease may continue to spread into disease-free regions such as the US. In this study, we estimated the risk of introduction of ASF virus into the US through smuggling of pork in air passenger luggage. Results suggest that the mean risk of ASFV introduction into the US via this route has increased by 183.33% from the risk estimated before the disease had spread into Western Europe or Asia. Most of the risk (67.68%) was associated with flights originating from China and Hong Kong, followed by the Russian Federation (26.92%). Five US airports accounted for >90% of the risk. Results here will help to inform decisions related to the design of ASF virus surveillance strategies in the US.

scholarly journals Development of a Directly Visualized Recombinase Polymerase Amplification–SYBR Green I Method for the Rapid Detection of African Swine Fever Virus

2020 ◽  
Vol 11 ◽  
Author(s):  
Shuai Zhang ◽  
Aijun Sun ◽  
Bo Wan ◽  
Yongkun Du ◽  
Yanan Wu ◽  
...  
Keyword(s):  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Sybr Green ◽  
Fever Virus ◽  
Diagnostic Methods ◽  
Sybr Green I ◽  
Recombinase Polymerase Amplification ◽  
Economic Losses ◽  
Field Samples ◽  
Standard Plasmid

African swine fever (ASF) is a lethal disease in swine caused by etiologic African swine fever virus (ASFV). The global spread of ASFV has resulted in huge economic losses globally. In the absence of effective vaccines or drugs, pathogen surveillance has been the most important first-line intervention to prevent ASF outbreaks. Among numerous diagnostic methods, recombinase polymerase amplification (RPA)-based detection is capable of producing sensitive and specific results without relying on the use of expensive instruments. However, currently used gene-specific, probe-based RPA for ASFV detection is expensive and time-consuming. To improve the efficiency of ASFV surveillance, a novel directly visualized SYBR Green I-staining RPA (RPAS) method was developed to detect the ASFV genome. SYBR Green I was added to the amplified RPA products for direct visualization by the naked eye. The sensitivity and specificity of this method were confirmed using standard plasmid and inactivated field samples. This method was shown to be highly specific with a detection limit of 103 copies/μl of ASFV in 15 min at 35°C without any cross-reactions with other important porcine viruses selected. In summary, this method enables direct sample visualization with reproducible results for ASFV detection and hence has the potential to be used as a robust tool for ASF prevention and control.

scholarly journals A Simple Method for Sample Preparation to Facilitate Efficient Whole-Genome Sequencing of African Swine Fever Virus

Viruses ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1129 ◽  
Author(s):  
Ferenc Olasz ◽  
István Mészáros ◽  
Szilvia Marton ◽  
Győző L. Kaján ◽  
Vivien Tamás ◽  
...  
Keyword(s):  
Sample Preparation ◽  
African Swine Fever Virus ◽  
Animal Health ◽  
African Swine Fever ◽  
Fever Virus ◽  
Whole Genome ◽  
Swine Industry ◽  
Viral Dna ◽  
Simple Method ◽  
Generation Sequencing

In the recent years, African swine fever has become the biggest animal health threat to the swine industry. To facilitate quick genetic analysis of its causative agent, the African swine fever virus (ASFV), we developed a simple and efficient method for next generation sequencing of the viral DNA. Execution of the protocol does not demand complicated virus purification steps, enrichment of the virus by ultracentrifugation or of the viral DNA by ASFV-specific PCRs, and minimizes the use of Sanger sequencing. Efficient DNA-se treatment, monitoring of sample preparation by qPCR, and whole genome amplification are the key elements of the method. Through detailed description of sequencing of the first Hungarian ASFV isolate (ASFV_HU_2018), we specify the sensitive steps and supply key reference numbers to assist reproducibility and to facilitate the successful use of the method for other ASFV researchers.

scholarly journals Estimation of the transmission dynamics of African swine fever virus within a swine house

2017 ◽  
Vol 145 (13) ◽  
pp. 2787-2796 ◽  
Author(s):  
J. P. NIELSEN ◽  
T. S. LARSEN ◽  
T. HALASA ◽  
L. E. CHRISTIANSEN
Keyword(s):  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Simulation Models ◽  
Fever Virus ◽  
Economic Consequences ◽  
Estimation Of Parameters ◽  
Swine Industry ◽  
Transmission Parameters ◽  
The Individual ◽  
The Impact

SUMMARYThe spread of African swine fever virus (ASFV) threatens to reach further parts of Europe. In countries with a large swine production, an outbreak of ASF may result in devastating economic consequences for the swine industry. Simulation models can assist decision makers setting up contingency plans. This creates a need for estimation of parameters. This study presents a new analysis of a previously published study. A full likelihood framework is presented including the impact of model assumptions on the estimated transmission parameters. As animals were only tested every other day, an interpretation was introduced to cover the weighted infectiousness on unobserved days for the individual animals (WIU). Based on our model and the set of assumptions, the within- and between-pen transmission parameters were estimated to βw = 1·05 (95% CI 0·62–1·72), βb = 0·46 (95% CI 0·17–1·00), respectively, and the WIU = 1·00 (95% CI 0–1). Furthermore, we simulated the spread of ASFV within a pig house using a modified SEIR-model to establish the time from infection of one animal until ASFV is detected in the herd. Based on a chosen detection limit of 2·55% equivalent to 10 dead pigs out of 360, the disease would be detected 13–19 days after introduction.

Sign in / Sign up

Export Citation Format

Share Document