scholarly journals Susceptibility of Four Abalone Species, Haliotis gigantea, Haliotis discus discus, Haliotis discus hannai and Haliotis diversicolor, to Abalone asfa-like Virus

Viruses ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2315
Author(s):  
Tomomasa Matsuyama ◽  
Ikunari Kiryu ◽  
Mari Inada ◽  
Tomokazu Takano ◽  
Yuta Matsuura ◽  
...  
Keyword(s):  
African Swine Fever Virus ◽  
Sequence Similarity ◽  
African Swine Fever ◽  
Viral Disease ◽  
Adult Mortality ◽  
Mass Mortality ◽  
Abalone Species ◽  
Haliotis Discus ◽  
Novel Virus ◽  
Partial Genome

Abalone amyotrophia is a viral disease that causes mass mortality of juvenile Haliotis discus and H. madaka. Although the cause of this disease has yet to be identified, we had previously postulated a novel virus with partial genome sequence similarity to that of African swine fever virus is the causative agent and proposed abalone asfa-like virus (AbALV) as a provisional name. In this study, three species of juvenile abalone (H. gigantea, H. discus discus, and H. diversicolor) and four species of adult abalone (the above three species plus H. discus hannai) were experimentally infected, and their susceptibility to AbALV was investigated by recording mortality, quantitatively determining viral load by PCR, and conducting immunohistological studies. In the infection test using 7-month-old animals, H. gigantea, which was previously reported to be insusceptible to the disease, showed multiplication of the virus to the same extent as in H. discus discus, resulting in mass mortality. H. discus discus at 7 months old showed abnormal cell masses, notches in the edge of the shell and brown pigmentation inside of the shell, which are histopathological and external features of this disease, while H. gigantea did not show any of these characteristics despite suffering high mortality. Adult abalones had low mortality and viral replication in all species; however, all three species, except H. diversicolor, became carriers of the virus. In immunohistological observations, cells positive for viral antigens were detected predominantly in the gills of juvenile H. discus discus and H. gigantea, and mass mortality was observed in these species. In H. diversicolor, neither juvenile nor adult mortality from infection occurred, and the AbALV genome was not increased by experimental infection through cohabitation or injection. Our results suggest that H. gigantea, H. discus discus and H. discus hannai are susceptible to AbALV, while H. diversicolor is not. These results confirmed that AbALV is the etiological agent of abalone amyotrophia.

scholarly journals Live Attenuated African Swine Fever Viruses as Ideal Tools to Dissect the Mechanisms Involved in Cross-Protection

Viruses ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 1474
Author(s):  
Elisabeth Lopez ◽  
Juanita van Heerden ◽  
Laia Bosch-Camós ◽  
Francesc Accensi ◽  
Maria Jesus Navas ◽  
...  
Keyword(s):  
Vaccine Development ◽  
African Swine Fever Virus ◽  
Virulent Strain ◽  
Sequence Similarity ◽  
Clinical Signs ◽  
African Swine Fever ◽  
Cross Protection ◽  
Sub Saharan Africa ◽  
Genotype I ◽  
Genotype Ii

African swine fever (ASF) has become the major threat for the global swine industry. Furthermore, the epidemiological situation of African swine fever virus (ASFV) in some endemic regions of Sub-Saharan Africa is worse than ever, with multiple virus strains and genotypes currently circulating in a given area. Despite the recent advances on ASF vaccine development, there are no commercial vaccines yet, and most of the promising vaccine prototypes available today have been specifically designed to fight the genotype II strains currently circulating in Europe, Asia, and Oceania. Previous results from our laboratory have demonstrated the ability of BA71∆CD2, a recombinant LAV lacking CD2v, to confer protection against homologous (BA71) and heterologous genotype I (E75) and genotype II (Georgia2007/01) ASFV strains, both belonging to same clade (clade C). Here, we extend these results using BA71∆CD2 as a tool trying to understand ASFV cross-protection, using phylogenetically distant ASFV strains. We first observed that five out of six (83.3%) of the pigs immunized once with 106 PFU of BA71∆CD2 survived the tick-bite challenge using Ornithodoros sp. soft ticks naturally infected with RSA/11/2017 strain (genotype XIX, clade D). Second, only two out of six (33.3%) survived the challenge with Ken06.Bus (genotype IX, clade A), which is phylogenetically more distant to BA71∆CD2 than the RSA/11/2017 strain. On the other hand, homologous prime-boosting with BA71∆CD2 only improved the survival rate to 50% after Ken06.Bus challenge, all suffering mild ASF-compatible clinical signs, while 100% of the pigs immunized with BA71∆CD2 and boosted with the parental BA71 virulent strain survived the lethal challenge with Ken06.Bus, without almost no clinical signs of the disease. Our results confirm that cross-protection is a multifactorial phenomenon that not only depends on sequence similarity. We believe that understanding this complex phenomenon will be useful for designing future vaccines for ASF-endemic areas.

scholarly journals Crystal Structure of African Swine Fever Virus pS273R Protease and Implications for Inhibitor Design

2020 ◽  
Vol 94 (10) ◽  
Author(s):  
Guobang Li ◽  
Xiaoxia Liu ◽  
Mengyuan Yang ◽  
Guangshun Zhang ◽  
Zhengyang Wang ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Structural Information ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Hydrolytic Activity ◽  
Viral Disease ◽  
Fever Virus ◽  
Dna Virus ◽  
Core Domain ◽  
The Core

ABSTRACT African swine fever (ASF) is a highly contagious hemorrhagic viral disease of domestic and wild pigs that is responsible for serious economic and production losses. It is caused by the African swine fever virus (ASFV), a large and complex icosahedral DNA virus of the Asfarviridae family. Currently, there is no effective treatment or approved vaccine against the ASFV. pS273R, a specific SUMO-1 cysteine protease, catalyzes the maturation of the pp220 and pp62 polyprotein precursors into core-shell proteins. Here, we present the crystal structure of the ASFV pS273R protease at a resolution of 2.3 Å. The overall structure of the pS273R protease is represented by two domains named the “core domain” and the N-terminal “arm domain.” The “arm domain” contains the residues from M1 to N83, and the “core domain” contains the residues from N84 to A273. A structure analysis reveals that the “core domain” shares a high degree of structural similarity with chlamydial deubiquitinating enzyme, sentrin-specific protease, and adenovirus protease, while the “arm domain” is unique to ASFV. Further, experiments indicated that the “arm domain” plays an important role in maintaining the enzyme activity of ASFV pS273R. Moreover, based on the structural information of pS273R, we designed and synthesized several peptidomimetic aldehyde compounds at a submolar 50% inhibitory concentration, which paves the way for the design of inhibitors to target this severe pathogen. IMPORTANCE African swine fever virus, a large and complex icosahedral DNA virus, causes a deadly infection in domestic pigs. In addition to Africa and Europe, countries in Asia, including China, Vietnam, and Mongolia, were negatively affected by the hazards posed by ASFV outbreaks in 2018 and 2019, at which time more than 30 million pigs were culled. Until now, there has been no vaccine for protection against ASFV infection or effective treatments to cure ASF. Here, we solved the high-resolution crystal structure of the ASFV pS273R protease. The pS273R protease has a two-domain structure that distinguishes it from other members of the SUMO protease family, while the unique “arm domain” has been proven to be essential for its hydrolytic activity. Moreover, the peptidomimetic aldehyde compounds designed to target the substrate binding pocket exert prominent inhibitory effects and can thus be used in a potential lead for anti-ASFV drug development.

scholarly journals Development of an Indirect ELISA to Detect African Swine Fever Virus pp62 Protein-Specific Antibodies

2022 ◽  
Vol 8 ◽  
Author(s):  
Kexin Zhong ◽  
Mengmeng Zhu ◽  
Qichao Yuan ◽  
Zhibang Deng ◽  
Simeng Feng ◽  
...  
Keyword(s):  
Indirect Elisa ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Viral Disease ◽  
Fever Virus ◽  
Serum Samples ◽  
Swine Industry ◽  
Detection Techniques ◽  
Positive Serum ◽  
Great Reactivity

African swine fever (ASF) is a highly detrimental viral disease caused by African swine fever virus (ASFV). The occurrence and prevalence of this disease have become a serious threat to the global swine industry and national economies. At present, the detection volume of African swine fever is huge, more sensitive and accurate detection techniques are needed for the market. pp62 protein, as a protein in the late stage of infection, has strong antigenicity and a high corresponding antibody titer in infected pigs. In this study, the CP530R gene was cloned into expression vector pET-28a to construct a prokaryotic expression plasmid, which was induced by IPTG to express soluble pp62 protein. Western blot analysis showed that it had great reactivity. Using the purified recombinant protein as an antigen, an indirect ELISA method for detecting ASFV antibody was established. The method was specific only to ASFV-positive serum, 1:1600 diluted positive serum could still be detected, and the coefficients of variation (CV) of the intra assay and inter assay were both <10%. It turns out that the assays had excellent specificity, sensitivity, and repeatability. This provides an accurate, rapid, and economical method for the detection of ASFV antibody in clinical pig serum samples.

scholarly journals Regulation and Evasion of Host Immune Response by African Swine Fever Virus

2021 ◽  
Vol 12 ◽  
Author(s):  
Lei Wu ◽  
Bincai Yang ◽  
Xu Yuan ◽  
Jinxuan Hong ◽  
Min Peng ◽  
...  
Keyword(s):  
Immune Response ◽  
Latin America ◽  
Cellular Immunity ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Host Immune Response ◽  
Viral Disease ◽  
Dna Virus ◽  
Double Stranded Dna ◽  
Different Levels

African swine fever (ASF) is an acute lethal hemorrhagic viral disease in domestic pigs and wild boars; is widely epidemic in Africa, Europe, Asia, and Latin America; and poses a huge threat to the pig industry worldwide. ASF is caused by the infection of the ASF virus (ASFV), a cytoplasmic double-stranded DNA virus belonging to the Asfarviridae family. Here, we review how the virus regulates the host immune response and its mechanisms at different levels, including interferon modulation, inflammation, apoptosis, antigen presentation, and cellular immunity.

scholarly journals The Addition of Nature Identical Flavorings Accelerated the Virucidal Effect of Pure Benzoic Acid against African Swine Fever Viral Contamination of Complete Feed

Animals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 1124
Author(s):  
Hengxiao Zhai ◽  
Chihai Ji ◽  
Maria Carol Walsh ◽  
Jon Bergstrom ◽  
Sebastien Potot ◽  
...  
Keyword(s):  
Benzoic Acid ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Preventive Measure ◽  
Viral Disease ◽  
Fever Virus ◽  
Swine Industry ◽  
Effective Measure ◽  
Viral Survival ◽  
Polymerase Chain

African swine fever virus is one of the most highly contagious and lethal viruses for the global swine industry. Strengthening biosecurity is the only effective measure for preventing the spread of this viral disease. The virus can be transmitted through contaminated feedstuffs and, therefore, research has been conducted to explore corresponding mitigating measures. The purpose of the current study was to test a combination of pure benzoic acid and a blend of nature identical flavorings for their ability to reduce African swine fever viral survival in feed. This virus was inoculated to feed with or without the supplementation of the test compounds, and the viral presence and load were measured by a hemadsorption test and quantitative real time polymerase chain reaction. The main finding was that the combination of pure benzoic acid and nature identical flavorings could expedite the reduction in both viral load and survival in a swine feed. Therefore, this solution could be adopted as a preventive measure for mitigating the risk of contaminated feed by African swine fever virus.

scholarly journals Remarkable sequence similarity between the dinoflagellate-infecting marine girus and the terrestrial pathogen African swine fever virus

2009 ◽  
Vol 6 (1) ◽  
pp. 178 ◽  
Author(s):  
Hiroyuki Ogata ◽  
Kensuke Toyoda ◽  
Yuji Tomaru ◽  
Natsuko Nakayama ◽  
Yoko Shirai ◽  
...  
Keyword(s):  
African Swine Fever Virus ◽  
Sequence Similarity ◽  
African Swine Fever ◽  
Fever Virus

scholarly journals Dynamic Variations in Infrared Skin Temperature of Weaned Pigs Experimentally Inoculated with the African Swine Fever Virus: A Pilot Study

2021 ◽  
Vol 8 (10) ◽  
pp. 223
Author(s):  
Sang-Ik Oh ◽  
Hu Suk Lee ◽  
Vuong Nghia Bui ◽  
Duy Tung Dao ◽  
Ngoc Anh Bui ◽  
...  
Keyword(s):  
Skin Temperature ◽  
Incubation Period ◽  
Clinical Symptoms ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Viral Disease ◽  
Pilot Scale ◽  
Post Inoculation ◽  
Contact Method ◽  
Swine Industry

African swine fever (ASF) is a devastating viral disease in pigs and is therefore economically important for the swine industry. ASF is characterized by a short incubation period and immediate death, making the early identification of ASF-infected pigs essential. This pilot-scale study evaluates whether the infrared thermography (IRT) technique can be used as a diagnostic tool to detect changes in skin temperature (Tsk) during the early stages of disease development in experimentally ASF-infected pigs. Clinical symptoms and rectal temperatures (Tcore) were recorded daily, and IRT readings during the experimental ASF infection were analyzed. All infected pigs died at 5–8 days post inoculation (dpi), and the incubation period was approximately 4 dpi. The average Tcore increased from 0 dpi (38.9 ± 0.3 °C) to 7 dpi (41.0 ± 0.5 °C) and decreased by 8 dpi (39.8 ± 0 °C). The maximum Tsk of ASF-infected pigs increased from 2 (35.0 °C) to 3 dpi (38.5 °C). The mean maximum Tsk observed from three regions on the skin (ear, inguinal, and neck) significantly increased from 2 to 3 dpi. This study presents a non-contact method for the early detection of ASF in infected pigs using thermal imaging at 3 days after ASF infection.

scholarly journals African Swine Fever Virus Proteinase Is Essential for Core Maturation and Infectivity

2003 ◽  
Vol 77 (10) ◽  
pp. 5571-5577 ◽  
Author(s):  
Alí Alejo ◽  
Germán Andrés ◽  
María L. Salas
Keyword(s):  
African Swine Fever Virus ◽  
Sequence Similarity ◽  
Cysteine Proteinase ◽  
African Swine Fever ◽  
Virus Production ◽  
Electron Microscopic Examination ◽  
Proteolytic Processing ◽  
Fever Virus ◽  
Core Shell ◽  
Electron Microscopic

ABSTRACT African swine fever virus (ASFV) encodes two polyprotein precursors named pp220 and pp62 that are sequentially processed during viral infection, giving rise to six major structural proteins. These reside at the core shell, a matrix domain located between the endoplasmic reticulum-derived inner envelope and the DNA-containing nucleoid. Proteolytic processing of the polyprotein precursors is catalyzed by the viral proteinase pS273R, a cysteine proteinase that shares sequence similarity with the SUMO1-processing peptidases. We describe here the construction and characterization of an ASFV recombinant, vS273Ri, that inducibly expresses the ASFV proteinase. Using vS273Ri, we show that repression of proteinase expression inhibits polyprotein processing and strongly impairs infective virus production. Electron microscopic examination of vS273Ri-infected cells showed that inhibition of proteolytic processing leads to the assembly of defective icosahedral particles containing a noncentered electron-dense nucleoid surrounded by an abnormal core shell of irregular thickness. The analysis of purified extracellular defective particles revealed that they contain the unprocessed pp220 and pp62 precursors, as well as the major DNA-binding nucleoid proteins p10 and pA104R. Altogether, these results indicate that the proteolytic processing of the polyproteins is not required for their incorporation into the assembling particles nor for the incorporation of the DNA-containing nucleoid. Instead, the ASFV proteinase is involved in a late maturational step that is essential for proper core assembly and infectivity.

scholarly journals Designing BH3-mimetic Peptide Inhibitors for the Viral Bcl-2 Homologs A179L and BHRF1: Importance of long-range electrostatic interactions

2021 ◽  
Author(s):  
C. Narendra Reddy ◽  
Ramasubbu Sankararamakrishnan
Keyword(s):  
Long Range ◽  
Electrostatic Interactions ◽  
African Swine Fever Virus ◽  
Sequence Similarity ◽  
African Swine Fever ◽  
Barr Virus ◽  
Long Range Interactions ◽  
Infected Cells ◽  
Epstein Barr ◽  
Bh3 Mimetic

Viruses have evolved strategies to prevent apoptosis of infected cells at early stages of infection. The viral proteins (vBcl-2s) from specific viral genes adopt a helical fold that is structurally similar to that of mammalian anti-apoptotic Bcl-2 proteins and exhibit little sequence similarity. Hence vBcl-2 homologs are attractive targets to prevent viral infection. However, very few studies have focused on developing inhibitors for vBcl-2 homologs. In this study, we have considered two vBcl-2 homologs, A179L from African swine fever virus and BHRF1 from Epstein-Barr virus. We generated two sets of 8000 randomized BH3-like sequences from eight wild-type pro-apoptotic BH3 peptides. During this process, the four conserved hydrophobic residues and an Asp residue were retained at their respective positions and all other positions were substituted randomly without any bias. We constructed 8000 structures each for A179L and BHRF1 in complex with BH3-like sequences. Histograms of interaction energies calculated between the peptide and the protein resulted in negatively skewed distributions. The BH3-like peptides with high helical propensities selected from the negative tail of respective interaction energy distributions exhibited more favorable interactions with A179L and BHRF1 and they are rich in basic residues. Molecular dynamics studies and electrostatic potential maps further revealed that both acidic and basic residues favorably interact with A179L while only basic residues have the most favorable interactions with BHRF1. As in mammalian homologs, the role of long range interactions and non-hotspot residues have to be taken into account while designing specific BH3-mimetic inhibitors for vBcl-2 homologs.

scholarly journals The Mimivirus L375 Nudix enzyme hydrolyzes the 5’ mRNA cap

2021 ◽  
Author(s):  
Grace Kago ◽  
Susan Parrish
Keyword(s):  
African Swine Fever Virus ◽  
Sequence Similarity ◽  
African Swine Fever ◽  
Host Protein ◽  
Mrna Turnover ◽  
Dna Viruses ◽  
Mrna Decapping ◽  
Double Stranded Dna ◽  
Nucleocytoplasmic Large Dna Viruses ◽  
Host Protein Synthesis

AbstractThe giant Mimivirus is a member of the nucleocytoplasmic large DNA viruses (NCLDV), a group of diverse viruses that contain double-stranded DNA (dsDNA) genomes that replicate primarily in eukaryotic hosts. Two members of the NCLDV, Vaccinia Virus (VACV) and African Swine Fever Virus (ASFV), both synthesize Nudix enzymes that have been shown to decap mRNA, a process thought to accelerate viral and host mRNA turnover and promote the shutoff of host protein synthesis. Mimivirus encodes two Nudix enzymes in its genome, denoted as L375 and L534. Importantly, L375 exhibits sequence similarity to ASFV-DP and eukaryotic Dcp2, two Nudix enzymes shown to possess mRNA decapping activity. In this work, we demonstrate that recombinant Mimivirus L375 cleaves the 5’ m7GpppN mRNA cap, releasing m7GDP as a product. L375 did not significantly cleave mRNAs containing an unmethylated 5’GpppN cap, indicating that this enzyme specifically hydrolyzes methylated-capped transcripts. A point mutation in the L375 Nudix motif completely eliminated cap hydrolysis, showing that decapping activity is dependent on this motif. Addition of methylated cap derivatives or uncapped RNA inhibited L375 decapping activity, suggesting that L375 recognizes its substrate through interaction with both the mRNA cap and RNA body.

Sign in / Sign up

Export Citation Format

Share Document