scholarly journals Serum-Derived Extracellular Vesicles from African Swine Fever Virus-Infected Pigs Selectively Recruit Viral and Porcine Proteins

Viruses ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 882 ◽  
Author(s):  
Montaner-Tarbes ◽  
Pujol ◽  
Jabbar ◽  
Hawes ◽  
Chapman ◽  
...  
Keyword(s):  
Extracellular Vesicles ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Surface Expression ◽  
Fever Virus ◽  
Effective Vaccine ◽  
Control Group ◽  
Specific Proteins ◽  
Negative Controls ◽  
Socioeconomic Consequences

: African swine fever is a devastating hemorrhagic infectious disease, which affects domestic and wild swines (Sus scrofa) of all breeds and ages, with a high lethality of up to 90–100% in naïve animals. The causative agent, African swine fever virus (ASFV), is a large and complex double-stranded DNA arbovirus which is currently spreading worldwide, with serious socioeconomic consequences. There is no treatment or effective vaccine commercially available, and most of the current research is focused on attenuated viral models, with limited success so far. Thus, new strategies are under investigation. Extracellular vesicles (EVs) have proven to be a promising new vaccination platform for veterinary diseases in situations in which conventional approaches have not been completely successful. Here, serum extracellular vesicles from infected pigs using two different ASFV viruses (OURT 88/3 and Benin ΔMGF), corresponding to a naturally attenuated virus and a deletion mutant, respectively, were characterized in order to determine possible differences in the content of swine and viral proteins in EV-enriched fractions. Firstly, EVs were characterized by their CD5, CD63, CD81 and CD163 surface expression. Secondly, ASFV proteins were detected on the surface of EVs from ASFV-infected pig serum. Finally, proteomic analysis revealed few specific proteins from ASFV in the EVs, but 942 swine proteins were detected in all EV preparations (negative controls, and OURT 88/3 and Benin ΔMGF-infected preparations). However, in samples from OURT 88/3-infected animals, only a small number of proteins were differentially identified compared to control uninfected animals. Fifty-six swine proteins (Group Benin) and seven proteins (Group OURT 88/3) were differentially detected on EVs when compared to the EV control group. Most of these were related to coagulation cascades. The results presented here could contribute to a better understanding of ASFV pathogenesis and immune/protective responses in the host.

scholarly journals The Role of Interleukine-10 and Interferon-γ as Potential Markers of the Evolution of African Swine Fever Virus Infection in Wild Boar

Pathogens ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 757
Author(s):  
Sandra Barroso-Arévalo ◽  
Jose A. Barasona ◽  
Estefanía Cadenas-Fernández ◽  
José M. Sánchez-Vizcaíno
Keyword(s):  
Wild Boar ◽  
Vaccine Candidate ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Interferon Γ ◽  
Fever Virus ◽  
Control Group ◽  
Challenge Virus ◽  
Ifn Γ

African swine fever virus (ASFv) is one of the most challenging pathogens to affect both domestic and wild pigs. The disease has now spread to Europe and Asia, causing great damage to the pig industry. Although no commercial vaccine with which to control the disease is, as yet, available, some potential vaccine candidates have shown good results in terms of protection. However, little is known about the host immune mechanisms underlying that protection, especially in wild boar, which is the main reservoir of the disease in Europe. Here, we study the role played by two cytokines (IL-10 and IFN-γ) in wild boar orally inoculated with the attenuated vaccine candidate Lv17/WB/Rie1 and challenged with a virulent ASFv genotype II isolate. A group of naïve wild boar challenged with the latter isolate was also established as a control group. Our results showed that both cytokines play a key role in protecting the host against the challenge virus. While high levels of IL-10 in serum may trigger an immune system malfunctioning in challenged animals, the provision of stable levels of this cytokine over time may help to control the disease. This, together with high and timely induction of IFN-γ by the vaccine candidate, could help protect animals from fatal outcomes. Further studies should be conducted in order to support these preliminary results and confirm the role of these two cytokines as potential markers of the evolution of ASFV infection.

scholarly journals African Swine Fever Virus Infection of Porcine Aortic Endothelial Cells Leads to Inhibition of Inflammatory Responses, Activation of the Thrombotic State, and Apoptosis

2001 ◽  
Vol 75 (21) ◽  
pp. 10372-10382 ◽  
Author(s):  
Isabelle Vallée ◽  
Stephen W. G. Tait ◽  
Penelope P. Powell
Keyword(s):  
Endothelial Cells ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Surface Expression ◽  
Fever Virus ◽  
Parp Cleavage ◽  
Aortic Endothelial Cells ◽  
Porcine Aortic Endothelial Cells ◽  
Aortic Endothelial

ABSTRACT African swine fever (ASF) is an asymptomatic infection of warthogs and bushpigs, which has become an emergent disease of domestic pigs, characterized by hemorrhage, lymphopenia, and disseminated intravascular coagulation. It is caused by a large icosohedral double-stranded DNA virus, African swine fever virus (ASFV), with infection of macrophages well characterized in vitro and in vivo. This study shows that virulent isolates of ASFV also infect primary cultures of porcine aortic endothelial cells and bushpig endothelial cells (BPECs) in vitro. Kinetics of early and late gene expression, viral factory formation, replication, and secretion were similar in endothelial cells and macrophages. However, ASFV-infected endothelial cells died by apoptosis, detected morphologically by terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling and nuclear condensation and biochemically by poly(ADP-ribose) polymerase (PARP) cleavage at 4 h postinfection (hpi). Immediate-early proinflammatory responses were inhibited, characterized by a lack of E-selectin surface expression and interleukin 6 (IL-6) and IL-8 mRNA synthesis. Moreover, ASFV actively downregulated interferon-induced major histocompatibility complex class I surface expression, a strategy by which viruses evade the immune system. Significantly, Western blot analysis showed that the 65-kDa subunit of the transcription factor NF-κB, a central regulator of the early response to viral infection, decreased by 8 hpi and disappeared by 18 hpi. Both disappearance of NF-κB p65 and cleavage of PARP were reversed by the caspase inhibitor z-VAD-fmk. Interestingly, surface expression and mRNA transcription of tissue factor, an important initiator of the coagulation cascade, increased 4 h after ASFV infection. These data suggest a central role for vascular endothelial cells in the hemorrhagic pathogenesis of the disease. Since BPECs infected with ASFV also undergo apoptosis, resistance of the natural host must involve complex pathological factors other than viral tropism.

scholarly journals Development and clinical application of a novel CRISPR-Cas12a based assay for the detection of African swine fever virus

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Xiaoying Wang ◽  
Sheng He ◽  
Na Zhao ◽  
Xiaohong Liu ◽  
Yongchang Cao ◽  
...  
Keyword(s):  
African Swine Fever Virus ◽  
Diagnostic Technique ◽  
African Swine Fever ◽  
Cross Reactivity ◽  
Fever Virus ◽  
Effective Vaccine ◽  
Highly Sensitive ◽  
Resource Poor ◽  
Good Consistency ◽  
Virus Genotypes

Abstract Background As no treatment or effective vaccine for African swine fever virus (ASFV) is currently available, a rapid, highly sensitive diagnostic is urgently needed to curb the spread of ASFV. Results Here we designed a novel CRISPR-Cas12a based assay for ASFV detection. To detect different ASFV genotypes, 19 crRNAs were designed to target the conserved p72 gene in ASFV, and several crRNAs with high activity were identified that could be used as alternatives in the event of new ASFV variants. The results showed that the sensitivity of the CRISPR-Cas12a based assay is about ten times higher than either the commercial quantitative PCR (qPCR) kit or the OIE-recommended qPCR. CRISPR-Cas12a based assay could also detect ASFV specifically without cross-reactivity with other important viruses in pigs and various virus genotypes. We also found that longer incubation times increased the detection limits, which could be applied to improve assay outcomes in the detection of weakly positive samples and new ASFV variants. In addition, both the CRISPR-Cas12a based assay and commercial qPCR showed very good consistency. Conclusions In summary, the CRISPR-Cas12a based assay offers a feasible approach and a new diagnostic technique for the diagnosis of ASFV, particularly in resource-poor settings.

scholarly journals Rapid Sequence-Based Characterization of African Swine Fever Virus by Use of the Oxford Nanopore MinION Sequence Sensing Device and a Companion Analysis Software Tool

2019 ◽  
Vol 58 (1) ◽  
Author(s):  
Vivian K. O’Donnell ◽  
Frederic R. Grau ◽  
Gregory A. Mayr ◽  
Tracy L. Sturgill Samayoa ◽  
Kimberly A. Dodd ◽  
...  
Keyword(s):  
Real Time ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Fever Virus ◽  
Full Genome Sequence ◽  
Effective Vaccine ◽  
Fast Analysis ◽  
Rapid Acquisition ◽  
Oxford Nanopore

ABSTRACT African swine fever virus (ASFV) is the causative agent of a severe and highly contagious viral disease of pigs that poses serious economic consequences to the swine industry due to the high mortality rate and impact on international trade. There is no effective vaccine to control African swine fever (ASF), and therefore, efficient disease control is dependent on early detection and diagnosis of ASFV. The large size of the ASFV genome (∼180 kb) has historically hindered efforts to rapidly obtain a full-genome sequence. Rapid acquisition of data is critical for characterization of the isolate and to support epidemiological efforts. Here, we investigated the capacity of the Oxford Nanopore MinION sequence sensing device to act as a rapid sequencing tool. When coupled with our novel companion software script, the African swine fever fast analysis sequencing tool (ASF-FAST), the analysis of output data was performed in real time. Complete ASFV genome sequences were generated from cell culture isolates and blood samples obtained from experimentally infected pigs. Removal of the host-methylated DNA from the extracted nucleic acid facilitated rapid ASFV sequence identification, with reads specific to ASFV detected within 6 min after the initiation of sequencing. Regardless of the starting material, sufficient sequence was available for complete genome resolution (up to 100%) within 10 min. Overall, this paper highlights the use of Nanopore sequencing technology in combination with the ASF-FAST software for the purpose of rapid and real-time resolution of the full ASFV genome from a diagnostic sample.

scholarly journals Study on the Immunogenicity of Three Recombinant Lactic Acid Bacteria Expressing ASFV p14.5 Protein

2021 ◽  
Author(s):  
Quntao Huang ◽  
Tian-Ming Niu ◽  
Bo-Shi Zou ◽  
Jun-Hong Wang ◽  
Jun-Hong Xin ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Fusion Gene ◽  
African Swine Fever Virus ◽  
Expression System ◽  
African Swine Fever ◽  
Fever Virus ◽  
Control Group ◽  
Adjuvant Effect

Abstract The African Classical Swine Fever Virus (ASFV) has spread severely all over the world. The lack of vaccines has dealt a heavy blow to the pig industry.In this study, the p14.5 protein encoded by the African swine fever virus was used as the antigen, and the p14.5 protein gene was expressed in vitro using the Lactobacillus expression system. Three new functional recombinant Lactobacillus plantarum((L. plantarum) were constructed and the p14.5 was successfully detected using western technology.Protein, fusion gene p14.5-IL-33-mouse（P14.5-IL-33-Mus） protein and CTA1-p14.5-DD protein expression.After oral immunization of SPF mice with recombinant lactic acid bacteria, flow cytometry and ELISA were used to detect that the differentiation and maturity of T, B, and DC cells of the mice were higher than those of the control group, and specific antibodies were produced. In contrast, the immune effect of the adjuvant group was stronger than that of the single antigen group, and the IL-33 adjuvant effect was stronger than that of the CTA1-DD adjuvant. This study provides effective data support for the prevention of African swine fever virus infection with new lactic acid bacteria preparations, and has certain innovative significance.

scholarly journals African Swine Fever Virus A528R Inhibits TLR8 Mediated NF-κB Activity by Targeting p65 Activation and Nuclear Translocation

Viruses ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 2046
Author(s):  
Xueliang Liu ◽  
Da Ao ◽  
Sen Jiang ◽  
Nengwen Xia ◽  
Yulin Xu ◽  
...  
Keyword(s):  
Promoter Activity ◽  
Nuclear Translocation ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Viral Proteins ◽  
Fever Virus ◽  
Economic Losses ◽  
Effective Vaccine ◽  
Hemorrhagic Disease ◽  
Host Innate Immunity

African swine fever (ASF) is mainly an acute hemorrhagic disease which is highly contagious and lethal to domestic pigs and wild boars. The global pig industry has suffered significant economic losses due to the lack of an effective vaccine and treatment. The African swine fever virus (ASFV) has a large genome of 170–190 kb, encoding more than 150 proteins. During infection, ASFV evades host innate immunity via multiple viral proteins. A528R is a very important member of the polygene family of ASFV, which was shown to inhibit IFN-β production by targeting NF-κB, but its mechanism is not clear. This study has shown that A528R can suppress the TLR8-NF-κB signaling pathway, including the inhibition of downstream promoter activity, NF-κB p65 phosphorylation and nuclear translocation, and the antiviral and antibacterial activity. Further, we found the cellular co-localization and interaction between A528R and p65, and ANK repeat domains of A528R and RHD of p65 are involved in their interaction and the inhibition of p65 activity. Therefore, we conclude that A528R inhibits TLR8-NF-κB signaling by targeting p65 activation and nuclear translocation.

scholarly journals I267L Is Neither the Virulence- Nor the Replication-Related Gene of African Swine Fever Virus and Its Deletant Is an Ideal Fluorescent-Tagged Virulence Strain

Viruses ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 53
Author(s):  
Yanyan Zhang ◽  
Junnan Ke ◽  
Jingyuan Zhang ◽  
Huixian Yue ◽  
Teng Chen ◽  
...  
Keyword(s):  
Fluorescent Protein ◽  
African Swine Fever Virus ◽  
Clinical Signs ◽  
Case Fatality ◽  
African Swine Fever ◽  
Fever Virus ◽  
Economic Losses ◽  
Effective Vaccine ◽  
Domestic Pigs

African swine fever virus (ASFV) is the causative agent of African swine fever (ASF) which reaches up to 100% case fatality in domestic pigs and wild boar and causes significant economic losses in the swine industry. Lack of knowledge of the function of ASFV genes is a serious impediment to the development of the safe and effective vaccine. Herein, I267L was identified as a relative conserved gene and an early expressed gene. A recombinant virus (SY18ΔI267L) with I267L gene deletion was produced by replacing I267L of the virulent ASFV SY18 with enhanced green fluorescent protein (EGFP) cassette. The replication kinetics of SY18ΔI267L is similar to that of the parental isolate in vitro. Moreover, the doses of 102.0 TCID50 (n = 5) and 105.0 TCID50 (n = 5) SY18ΔI267L caused virulent phenotype, severe clinical signs, viremia, high viral load, and mortality in domestic pigs inoculated intramuscularly as the virulent parental virus strain. Therefore, the deletion of I267L does not affect the replication or the virulence of ASFV. Utilizing the fluorescent-tagged virulence deletant can be easy to gain a visual result in related research such as the inactivation effect of some drugs, disinfectants, extracts, etc. on ASFV.

scholarly journals Structure of African Swine Fever Virus and Associated Molecular Mechanisms Underlying Infection and Immunosuppression: A Review

2021 ◽  
Vol 12 ◽  
Author(s):  
Yue Wang ◽  
Weifang Kang ◽  
Wenping Yang ◽  
Jing Zhang ◽  
Dan Li ◽  
...  
Keyword(s):  
Immune Response ◽  
Molecular Mechanism ◽  
Molecular Mechanisms ◽  
African Swine Fever Virus ◽  
Animal Health ◽  
African Swine Fever ◽  
Fever Virus ◽  
Economic Losses ◽  
Cell Immune Response ◽  
Effective Vaccine

African swine fever (ASF) is an acute, highly contagious, and deadly infectious disease. The mortality rate of the most acute and acute ASF infection is almost 100%. The World Organization for Animal Health [Office International des épizooties (OIE)] lists it as a legally reported animal disease and China lists it as class I animal epidemic. Since the first diagnosed ASF case in China on August 3, 2018, it has caused huge economic losses to animal husbandry. ASF is caused by the African swine fever virus (ASFV), which is the only member of Asfarviridae family. ASFV is and the only insect-borne DNA virus belonging to the Nucleocytoplasmic Large DNA Viruses (NCLDV) family with an icosahedral structure and an envelope. Till date, there are still no effective vaccines or antiviral drugs for the prevention or treatment of ASF. The complex viral genome and its sophisticated ability to regulate the host immune response may be the reason for the difficulty in developing an effective vaccine. This review summarizes the recent findings on ASFV structure, the molecular mechanism of ASFV infection and immunosuppression, and ASFV-encoded proteins to provide comprehensive proteomic information for basic research on ASFV. In addition, it also analyzes the results of previous studies and speculations on the molecular mechanism of ASFV infection, which aids the study of the mechanism of clinical pathological phenomena, and provides a possible direction for an intensive study of ASFV infection mechanism. By summarizing the findings on molecular mechanism of ASFV- regulated host cell immune response, this review provides orientations and ideas for fundamental research on ASFV and provides a theoretical basis for the development of protective vaccines against ASFV.

scholarly journals The African Swine Fever Virus with MGF360 and MGF505 Deleted Reduces the Apoptosis of Porcine Alveolar Macrophages by Inhibiting the NF-κB Signaling Pathway and Interleukin-1β

Vaccines ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1371
Author(s):  
Qi Gao ◽  
Yunlong Yang ◽  
Weipeng Quan ◽  
Jiachen Zheng ◽  
Yizhuo Luo ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Alveolar Macrophages ◽  
Molecular Mechanisms ◽  
Vaccine Development ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Fever Virus ◽  
Effective Vaccine ◽  
Wild Type ◽  
Mrna Transcription

African swine fever virus (ASFV) poses serious threats to the swine industry. The mortality rate of African swine fever (ASF) is 100%, and there is no effective vaccine currently available. Complex immune escape strategies of ASFV are crucial factors affecting immune prevention and vaccine development. CD2v and MGF360-505R genes have been implicated in the modulation of the immune response. The molecular mechanisms contributing to innate immunity are poorly understood. In this study, we discover the cytopathic effect and apoptosis of ΔCD2v/ΔMGF360-505R-ASFV after infection in porcine alveolar macrophages (PAMs) was significantly less than wild-type ASFV. We demonstrated that CD2v- and MGF360-505R-deficient ASFV decrease the level of apoptosis by inhibiting the NF-κB signaling pathway and IL-1β mRNA transcription. Compared with wild-type ASFV infection, the levels of phospho-NF-κB p65 and p-IκB protein decreased in CD2v- and MGF360-505R-deficient ASFV. Moreover, CD2v- and MGF360-505R-deficient ASFV induced less IL-1β production than wild-type ASFV and was attenuated in replication compared with wild-type ASFV. We further found that MGF360-12L, MGF360-13L, and MGF-505-2R suppress the promoter activity of NF-κB by reporter assays, and CD2v activates the NF-κB signaling pathway. These findings suggested that CD2v- and MGF360-505R-deficient ASFV could reduce the level of ASFV p30 and the apoptosis of PAMs by inhibiting the NF-κB signaling pathway and IL-1β mRNA transcription, which might reveal a novel strategy for ASFV to maintain the replication of the virus in the host.

scholarly journals The African Swine Fever Virus (ASFV) Topoisomerase II as a Target for Viral Prevention and Control

Vaccines ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 312 ◽  
Author(s):  
João Coelho ◽  
Alexandre Leitão
Keyword(s):  
Topoisomerase Ii ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Fever Virus ◽  
Effective Vaccine ◽  
Type Ii ◽  
Cancer Treatments ◽  
Promising Target ◽  
Multicellular Organisms ◽  
And Control

African swine fever (ASF) is, once more, spreading throughout the world. After its recent reintroduction in Georgia, it quickly reached many neighboring countries in Eastern Europe. It was also detected in Asia, infecting China, the world’s biggest pig producer, and spreading to many of the surrounding countries. Without any vaccine or effective treatment currently available, new strategies for the control of the disease are mandatory. Its etiological agent, the African swine fever virus (ASFV), has been shown to code for a type II DNA topoisomerase. These are enzymes capable of modulating the topology of DNA molecules, known to be essential in unicellular and multicellular organisms, and constitute targets in antibacterial and anti-cancer treatments. In this review, we summarize most of what is known about this viral enzyme, pP1192R, and discuss about its possible role(s) during infection. Given the essential role of type II topoisomerases in cells, the data so far suggest that pP1192R is likely to be equally essential for the virus and thus a promising target for the elaboration of a replication-defective virus, which could provide the basis for an effective vaccine. Furthermore, the use of inhibitors could be considered to control the spread of the infection during outbreaks and therefore limit the spreading of the disease.

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