Search

BK polyomavirus (BKPyV) persists lifelong in renal and urothelial cells with asymptomatic urinary shedding in healthy individuals. In some immunocompromised persons after transplantation of hematopoietic stem cells (HSCT), the BKPyV high-rate replication is associated with haemorrhagic cystitis (HC). We tested whether the status of BKPyV immunity prior to HSCT could provide evidence for the BKPyV tendency to reactivate. We have shown that measurement of pretransplant anti-BKPyV 1 and 4 IgG levels can be used to evaluate the HC risk. Patients with anti-BKPyV IgG in the range of the 1st–2nd quartile of positive values and with positive clinical risk markers have a significantly increased HC risk, in comparison to the reference group of patients with “non-reactive” anti-BKPyV IgG levels and with low clinical risk (LCR) (p = 0.0009). The predictive value of pretransplant BKPyV-specific IgG was confirmed by determination of genotypes of the shed virus. A positive predictive value was also found for pretransplant T-cell immunity to the BKPyV antigen VP1 because the magnitude of IFN-γ T-cell response inversely correlated with posttransplant DNAuria and with HC. Our novel data suggest that specific T-cells control BKPyV latency before HSCT, and in this way may influence BKPyV reactivation after HSCT. Our study has shown that prediction using a combination of clinical and immunological pretransplant risk factors can help early identification of HSCT recipients at high risk of BKPyV disease.

Coxsackievirus B3 (CVB3), an enterovirus (EV) in the family of Picornaviridae, is a global human pathogen for which effective antiviral treatments and vaccines are lacking. Previous research demonstrated that EV-D68 downregulated the membrane fusion protein SNAP47 (synaptosome associated protein 47) and SNAP47 promoted EV-D68 replication via regulating autophagy. In the current study, we investigated the interplay between CVB3 and cellular SNAP47 using HEK293T/HeLa cell models. We showed that, upon CVB3 infection, protein levels of SNAP47 decreased independent of the activity of virus-encoded proteinase 3C. We further demonstrated that the depletion of SNAP47 inhibited CVB3 infection, indicating a pro-viral function of SNAP47. Moreover, we found that SNAP47 co-localizes with the autophagy-related protein ATG14 on the cellular membrane fractions together with viral capsid protein VP1, and expression of SNAP47 or ATG14 enhanced VP1 conjugation. Finally, we revealed that disulfide interactions had an important role in strengthening VP1 conjugation. Collectively, our study elucidated a mechanism by which SNAP47 and ATG14 promoted CVB3 propagation through facilitating viral capsid assembly.

Abstract Background In 2011–2012, Northern Vietnam experienced its first large scale hand foot and mouth disease (HFMD) epidemic. In 2011, a major HFMD epidemic was also reported in South Vietnam with fatal cases. This 2011–2012 outbreak was the first one to occur in North Vietnam providing grounds to study the etiology, origin and dynamic of the disease. We report here the analysis of the VP1 gene of strains isolated throughout North Vietnam during the 2011–2012 outbreak and before. Methods The VP1 gene of 106 EV-A71 isolates from North Vietnam and 2 from Central Vietnam were sequenced. Sequence alignments were analyzed at the nucleic acid and protein level. Gene polymorphism was also analyzed. A Factorial Correspondence Analysis was performed to correlate amino acid mutations with clinical parameters. Results The sequences were distributed into four phylogenetic clusters. Three clusters corresponded to the subgenogroup C4 and the last one corresponded to the subgenogroup C5. Each cluster displayed different polymorphism characteristics. Proteins were highly conserved but three sites bearing only Isoleucine (I) or Valine (V) were characterized. The isoleucine/valine variability matched the clusters. Spatiotemporal analysis of the I/V variants showed that all variants which emerged in 2011 and then in 2012 were not the same but were all present in the region prior to the 2011–2012 outbreak. Some correlation was found between certain I/V variants and ethnicity and severity. Conclusions The 2011–2012 outbreak was not caused by an exogenous strain coming from South Vietnam or elsewhere but by strains already present and circulating at low level in North Vietnam. However, what triggered the outbreak remains unclear. A selective pressure is applied on I/V variants which matches the genetic clusters. I/V variants were shown on other viruses to correlate with pathogenicity. This should be investigated in EV-A71. I/V variants are an easy and efficient way to survey and identify circulating EV-A71 strains.

An Agrobacterium-mediated transient gene expression assay was carried out in alfalfa (Medicago sativa) leaves for expression of a chimeric gene encoding a part of capsid protein of Foot and Mouth Disease virus called VP1. The plant leaves were transformed via agroinfiltration procedure. The presence of the foreign gene and its expression in transformed plants were evaluated by polymerase chain reaction (PCR), real time PCR, protein Dot blot and ELISA. Moreover, gene expression in the transformed leaves was quantified by ELISA method. The results obtained in this investigation indicated high level of gene expression in alfalfa leaves, showing that transient gene expression can be applied as an effective and time-saving procedure for the production of recombinant proteins. The procedures for transformation, detection of recombinant protein and its application for molecular experiments are described in the study.

Human bocaviruses (HBoV) are mainly associated with respiratory and gastroenteric infections. These viruses belong to the family Parvoviridae, genus Bocaparvovirus and are classified in four subtypes (HBoV1-4). Recombination and point mutation have been described as basis of parvovirus evolution. In this study three viral sequences were obtained from positives HBoV sewage samples collected in two Uruguayan cities and were characterised by different methods as recombinant strains. This recombination event was localised in the 5’ end of VP1 gene and the parental strains belonged to subtypes 3 and 4. These three Uruguayan strains are identical at the nucleotide sequences in the analysed genome region of the virus. As far as we known, this study represents the first detection of HBoV recombinants strains in the Americas.

Chinese sacbrood virus (CSBV) is the major cause and lead to the collapse of Apis cerana colonies. VP1, the structural protein of CSBV, shows the highest variation in the amino acid sequences among proteins from different CSBV strains as well as exhibits excellent immunogenicity. However, its function with host protein still remains unclear. To clarify its function with host protein, we screened out host cellular proteins that interact with VP1 using the membrane protein yeast two-hybrid system. In addition, we verified interactions between heat shock protein 70 cognate 5 (Hsp70-c5) and VP1 using glutathione S-transferase (GST) pull-down and co-immunoprecipitation assays. VP1 and Hsp70-c5 were colocalized in the cytoplasm and nucleus. Using western blot and real-time polymerase chain reaction (PCR), Hsp70-c5 expression in CSBV-infected larvae was upregulated compared with that in healthy larvae. We observed that when we silenced Hsp70-c5, VP1 expression was significantly downregulated. These results demonstrate that Hsp70-c5 is involved in at least one stage(s) of the viral life cycle.

Human norovirus (HuNoV) GII.P17-GII.17 (Kawasaki2014 variant) reportedly emerged in 2014 and caused gastroenteritis outbreaks worldwide. To clarify the evolution of both VP1 and RNA-dependent RNA polymerase (RdRp) regions of GII.P17-GII.17, we analyzed both global and novel Japanese strains detected during 2013–2017. Time-scaled phylogenetic trees revealed that the ancestral GII.17 VP1 region diverged around 1949, while the ancestral GII.P17 RdRp region diverged around 2010. The evolutionary rates of the VP1 and RdRp regions were estimated at ~2.7 × 10−3 and ~2.3 × 10−3 substitutions/site/year, respectively. The phylogenetic distances of the VP1 region exhibited no overlaps between intra-cluster and inter-cluster peaks in the GII.17 strains, whereas those of the RdRp region exhibited a unimodal distribution in the GII.P17 strains. Conformational epitope positions in the VP1 protein of the GII.P17-GII.17 strains were similar, although some substitutions, insertions and deletions had occurred. Strains belonging to the same cluster also harbored substitutions around the binding sites for the histo-blood group antigens of the VP1 protein. Moreover, some amino acid substitutions were estimated to be near the interface between monomers and the active site of the RdRp protein. These results suggest that the GII.P17-GII.17 virus has produced variants with the potential to alter viral antigenicity, host-binding capability, and replication property over the past 10 years.

Between July and September 2017, samples collected from six unvaccinated chickens in Namibia were shown to be positive for infectious bursal disease virus (IBDV) by RT-PCR. Partial sequence and phylogenetic analysis of the VP1 and VP2 genes from six viruses revealed that they all belong to the very virulent pathotype (Genogroup 3) and are genetically very similar to IBDVs identified in neighbouring Zambia. This is the first molecular characterisation of IBDV in Namibia and has implications on the control and management of the disease in the country.

Acute gastroenteritis associated with human norovirus infection was reported in Phuket, Thailand, in June 2023. We amplified GII.8[P8] from the outbreak stool specimens. Retrospective sample analysis identified infrequent GII.8[P8] in the country beginning in 2018. In all, the 10 whole-genome GII.8[P8] sequences from Thailand we examined had no evidence of genotypic recombination.

The present study investigated five poultry flocks (size 142-600 birds) suspected of chicken infectious anemia (CIA) from Maharashtra, India. The necropsy of dead birds revealed severe atrophy of the thymus, gelatinization of bone marrow, subcutaneous hemorrhages, growth impairment, and severe anemia. Specific PCR targeting, 1390 bp fragment of the CIAV, VP1 gene was used in this study. Sequence analysis revealed that CIAV sequences of this study were grouped in genotype A. At the nucleotide level identity of 99.6% or more was seen between field sequences. At the amino acid level identity of 100% was seen between field sequences and NGP-1. Also, VP1 protein sequences of this study showed high identity with TJBD40, GD-K-12 strains from China and AB046590 strain from Japan. Further, the protein sequences of field CIAV had 0.7% to 2.5% divergence from VP1 sequences of vaccine strains. Antigenic epitopes of VP1 protein were predicted by SVMTriPtool and the field CIAV presented substitutions in two epitopes. To conclude, present study confirms the circulation of genotype A of CIAV in Maharashtra, India and predicted VP1 proteins of field CIAV revealed changes in two epitopes compared to vaccine strains.

The rotavirus polymerase VP1 mediates all stages of viral RNA synthesis within the confines of subviral particles and while associated with the core shell protein VP2. Transcription (positive-strand RNA [+RNA] synthesis) by VP1 occurs within double-layered particles (DLPs), while genome replication (doublestranded RNA [dsRNA] synthesis) by VP1 occurs within assembly intermediates. VP2 is critical for VP1 enzymatic activity; yet, the mechanism by which the core shell protein triggers polymerase function remains poorly understood. Structural analyses of transcriptionally competent DLPs show that VP1 is located beneath the VP2 core shell and sits slightly off-center from each of the icosahedral 5-fold axes. In this position, the polymerase is contacted by the core shell at 5 distinct surface-exposed sites, comprising VP1 residues 264 to 267, 547 to 550, 614 to 620, 968 to 980, and 1022 to 1025. Here, we sought to test the functional significance of these VP2 contact sites on VP1 with regard to polymerase activity. We engineered 19 recombinant VP1 (rVP1) proteins that contained single- or multipoint alanine mutations within each individual contact site and assayed them for the capacity to synthesize dsRNA in vitro in the presence of rVP2. Three rVP1 mutants (E265A/L267A, R614A, and D971A/S978A/I980A) exhibited diminished in vitro dsRNA synthesis. Despite their loss-of-function phenotypes, the mutants did not show major structural changes in silico, and they maintained their overall capacity to bind rVP2 in vitro via their nonmutated contact sites. These results move us toward a mechanistic understanding of rotavirus replication and identify precise VP2-binding sites on the polymerase surface that are critical for its enzymatic activation. [ABSTRACT FROM AUTHOR]

Human norovirus (HuNoV) GII.P17-GII.17 (Kawasaki2014 variant) reportedly emerged in 2014 and caused gastroenteritis outbreaks worldwide. To clarify the evolution of both VP1 and RNA-dependent RNA polymerase (RdRp) regions of GII.P17-GII.17, we analyzed both global and novel Japanese strains detected during 2013–2017. Time-scaled phylogenetic trees revealed that the ancestral GII.17 VP1 region diverged around 1949, while the ancestral GII.P17 RdRp region diverged around 2010. The evolutionary rates of the VP1 and RdRp regions were estimated at ~2.7 × 10−3 and ~2.3 × 10−3 substitutions/site/year, respectively. The phylogenetic distances of the VP1 region exhibited no overlaps between intra-cluster and inter-cluster peaks in the GII.17 strains, whereas those of the RdRp region exhibited a unimodal distribution in the GII.P17 strains. Conformational epitope positions in the VP1 protein of the GII.P17-GII.17 strains were similar, although some substitutions, insertions and deletions had occurred. Strains belonging to the same cluster also harbored substitutions around the binding sites for the histo-blood group antigens of the VP1 protein. Moreover, some amino acid substitutions were estimated to be near the interface between monomers and the active site of the RdRp protein. These results suggest that the GII.P17-GII.17 virus has produced variants with the potential to alter viral antigenicity, host-binding capability, and replication property over the past 10 years. [ABSTRACT FROM AUTHOR]

Chinese sacbrood virus (CSBV) is the major cause and lead to the collapse of Apis cerana colonies. VP1 , the structural protein of CSBV, shows the highest variation in the amino acid sequences among proteins from different CSBV strains as well as exhibits excellent immunogenicity. However, its function with host protein still remains unclear. To clarify its function with host protein, we screened out host cellular proteins that interact with VP1 using the membrane protein yeast two-hybrid system. In addition, we verified interactions between heat shock protein 70 cognate 5 (Hsp70-c5) and VP1 using glutathione S-transferase (GST) pull-down and co-immunoprecipitation assays. VP1 and Hsp70-c5 were colocalized in the cytoplasm and nucleus. Using western blot and real-time polymerase chain reaction (PCR), Hsp70-c5 expression in CSBV-infected larvae was upregulated compared with that in healthy larvae. We observed that when we silenced Hsp70-c5 , VP1 expression was significantly downregulated. These results demonstrate that Hsp70-c5 is involved in at least one stage(s) of the viral life cycle. [ABSTRACT FROM AUTHOR]

BKPyV replication is a risk factor for the development of polyomavirus‐associated nephropathy in kidney transplant recipients. Here, the case of a 42 years old Caucasian patient is described who developed a kidney allograft failure because of uncontrolled BKPyV replication 7 months after transplant despite a strong reduction of the immunosuppressive therapy. The genetic analysis of the noncoding control region did not show rearrangement but two point mutations at nucleotide positions 18 and 31 within P block. The mutation at position 31 involved the nuclear factor‐1 site. Sequencing of the VP1 region revealed a subtype I/subgroup b‐1. Highlights: Uncontrolled replication of BKPyV can cause PyVAN in Kidney transplant patients.Reduction of immunosuppressive therapy usually allows to control BKPyV replication.Here, PyVAN develops despite reduction of immunosuppressive therapy.No significant genetic changes were found in VP1 gene and NCCR of the virus. [ABSTRACT FROM AUTHOR]

• A L. lactis expressing VP1 protein of DHAV-3 was successfully constructed. • Effective cellular and humoral immunity was induced in the immunized mice. • Effective cellular and humoral immunity was induced in the immunized ducklings. • The immunized ducklings were effectively protected from natural infection of DHAV-3. Duck hepatitis A virus (DHAV) is the major pathogen of duck viral hepatitis, which has caused great economic losses to duck breeding industry. As an effective delivery tool for protein antigens, Lactococcus lactis (L. lactis) has been successfully used to stimulate mucosal and systemic immune response. In this study, a recombinant L. lactis named NZ3900-VP1 was constructed, which could express VP1 protein of DHAV type 3 (DHAV-3) by using a nisin-controlled expression (NICE) system. The animal experiment in both mice and ducklings were performed to detect the immune response and protection effect of oral vaccination by the recombinant L. lactis. The results showed that oral vaccination with L. lactis NZ3900-VP1 significantly induced specific anti-VP1 IgG antibodies and mucosal secretory immunoglobulin A (sIgA) of DHAV-3 in mice and ducklings, and cytokines including interleukin-2 (IL-2), interferon gamma (IFN-γ), interleukin-10 (IL-10) and interleukin-4 (IL-4). Notably, the ducklings vaccinated with L. lactis NZ3900-VP1 were effectively protected when facing natural infestation of DHAV-3, which indicated that the recombinant L. lactis could serve as an effective vaccine to prevent DHAV-3 infection in ducklings. [ABSTRACT FROM AUTHOR]

Copyright of Acta Agronomica Sinica is the property of Crop Science Society of China and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Live vector-based vaccine is a modern approach to overcome the drawbacks of inactivated foot-and-mouth disease (FMD) vaccines such as improper inactivation during manufacture. Listeria monocytogenes (LM), an intracellular microorganism with immune-stimulatory properties, is appropriate to be utilized as a live bacterial vaccine vector. FMDV-VP1 protein has the capability to induce both cellular and humoral immune responses since it is considered the most immunogenic part of FMDV capsid and has the most of antigenic sites for viral neutralization. The codon-optimized vp1 gene was ligated to the integrative pCW702 plasmid to construct the target cassette. The antigen cassette was integrated successfully into the chromosome of mutant LM strain via homologous recombination for more stability to generate a candidate vaccine strain LM△actAplcB-vp1. Safety evaluation of recombinant LM△actAplcB-vp1 revealed it could be eliminated from the internal organs within 3 days as a safe candidate vaccine. Mice groups were immunized I.V. twice with the recombinant LM△actAplcB-vp1 at an interval of 2 weeks. Antigen-specific IgG antibodies and the level of CD4+- and CD8+-specific secreted cytokines were estimated to evaluate the immunogenicity of the candidate vaccine. The rapid onset immune response was detected, strong IgG humoral immune response within 14 days post immunization and augmented again after the booster dose. Cellular immunity data after 9 days post the prime dose indicated elevation in CD4+ and CD8+ secreted cytokine level with another elevation after the booster dose. This is the first report to explain the ability of attenuated mutant LM to be a promising live vector for FMDV vaccine. [ABSTRACT FROM AUTHOR]

Duck virus hepatitis (DVH) caused by duck hepatitis A virus type 1 (DHAV-1) is an acute and highly contagious disease affecting young ducklings. The VP1 protein is one of the major structural proteins of DHAV-1 carries critical epitopes responsible for the induction of neutralizing antibodies. In this study, we have successfully constructed an immune phage display VHHs library against DHAV-1 with the size of 6 × 106 colonies. A nanobody (Nb) against VP1 protein of DHAV-1, named Nb25, was identified from the immunized phage display library. Nb25 could react with the conserved linear B-cell epitope of 174PAPTST179 in DHAV-1 VP1, even though Nb25 showed no neutralizing activity to DHAV-1. To the best of our knowledge, this is the first report about preparation of anti-DHAV-1 Nbs and identification of the specific conserved linear B-cell epitope of DHAV-1 with Nb, which will facilitate the serologic diagnosis of DHAV-1 infection. • A specific Nb against DHAV-1 VP1 protein is successfully produced. • Nb25 has good binding activity and specificity with DHAV-1 VP1. • A linear epitope of DHAV-1 was recognized by Nb25. • The epitope of 174PAPTST179 in VP1 was conserved among different DHAV-1 strains. [ABSTRACT FROM AUTHOR]

The purpose of this study was to construct a Coxsackie virus A16 (CA16) mucosal vaccine and evaluate its ability to induce immune response. VP1 gene of CA16 was inserted into the genome of Bacillus subtilis via recombination and displayed on the surface of the spores. This Bacillus-based vaccine was used for intranasal immunization of mice and the serum antibody titer was determined by enzyme-linked immunosorbent assay (ELISA). Neutralization activity of the serum from immunized mice was analyzed by an in vitro neutralizing test. VP1 gene was successfully integrated into the genome of Bacillus subtilis and was expressed on the surface of Bacillus spores. Intranasal immunization of mice with this vaccine induced a higher level of VP1 specific IgA and IgG than in mice of the control group (p < 0.05). The neutralizing antibody titer in the spore immunization group was 1 : 169, which was higher than that in the control group (p < 0.05). We concluded that vaccine prepared by displaying CA16 VP1 protein on the surface of Bacillus subtilis spores can stimulate mice to produce protective neutralizing antibodies, which provides foundations for the development of CA16 mucosal vaccine. [ABSTRACT FROM AUTHOR]

Foot and Mouth Disease (FMD) is the most economically important viral-induced livestock disease worldwide. From April to May of 2015, tongue epithelial tissue samples were collected from 36 cattle in six villages, which share the border with Iran. Samples were screened using RT-PCR to amplify a conserved region in the VP1 gene, and phylogenetic tree analysis was performed based on the VP1 nucleotide sequence results. Furthermore, the nucleotide sequence was converted to an amino acid sequence in order to detect similarities between the studied samples and those previously published in GenBank (NCBI). Epidemically, based on the amino acid residues, genetic similarity, and amino acid substitutions, the VP1 nucleotide sequences were determined to be close to a novel group, group VII, with 94% identity. The VP1 amino acid sequence analysis revealed a close relationship to the Asia/BAL/PAK/iso-2/2011 isolate (Accession no. JX435109), with 95.7% identity. Analysis of the studied samples revealed that the FMDV serotype Asia1 causing the outbreak in the Basne district belonged to group VII, which was introduced from the Balochistan province of Pakistan through illegal movement of animals from this region. [ABSTRACT FROM AUTHOR]

Between July and September 2017, samples collected from six unvaccinated chickens in Namibia were shown to be positive for infectious bursal disease virus (IBDV) by RT-PCR. Partial sequence and phylogenetic analysis of the VP1 and VP2 genes from six viruses revealed that they all belong to the very virulent pathotype (Genogroup 3) and are genetically very similar to IBDVs identified in neighbouring Zambia. This is the first molecular characterisation of IBDV in Namibia and has implications on the control and management of the disease in the country. [ABSTRACT FROM AUTHOR]

Abstract In this study, a virulent systemic (VS) feline calicivirus (FCV) strain, SH, was isolated from a household cat with severe systemic clinical signs, and its full-length genome was determined and analyzed. Through immunofluorescence assays (IFA) and western blotting assays, we found that FCV SH strain, like other isolates, can stably proliferate in Crandell feline kidney (CRFK) cells. Moreover, the typical morphology of FCV particles, with a diameter of about 35 nm, was observed using electron microscopy. The full-length genome of FCV strain SH was sequenced and determined to be 7704 nucleotides (nt) in length with a 5′-terminal untranslated region (UTR) of 19 nt and a 3′-terminal UTR of 67 nt. Three open reading frames (ORF1, ORF2, and ORF 3) were found within the genome, coding for a polypeptide, a capsid precursor (VP1) and a minor structural protein (VP2), respectively. Amino acid sequence comparison revealed diversity (from 82.2% to 88.5% homology) between the VP1 protein sequences of the SH/14 isolate and those of 33 reference isolates from different regions. Phylogenetic analyses using alignments of VP1 protein sequences showed that the SH/14 isolate shares the highest sequence homology with the reported VS-FCV George strain (88.5%), and is located in the same clade as other reported VS-FCV isolates, indicating that the FCV SH/14 strain is a VS-FCV isolate. However, the SH/14 strain does not belong to the same lineage as most other Chinese FCV isolates, suggesting that, in China, a very large geographical entity, the virulent systemic FCV might has emerged. Highlights • A virulent systemic (VS) feline calicivirus (FCV) strain, SH, was isolated from a household cat. • The SH/14 strain does not belong to the same lineage as most other Chinese FCV isolates. • The virulent systemic feline calicivirus virulence has emerged in China. [ABSTRACT FROM AUTHOR]

Foot-and-mouth disease virus (FMDV) causes a highly contagious and devastating disease in livestock animals and has a great potential to cause severe economic loss worldwide. The major antigen of FMDV capsid protein, VP1, contains the major B-cell epitope responsible for effectively eliciting protective humoral immunity. In this study, irradiated Salmonella Typhimurium (KST0666) were used as transgenic vectors containing stress-inducible plasmid pRECN-VP1 to deliver the VP1 protein from FMDV-type A/WH/CHA/09. Mice were orally inoculated with ATOMASal-L3 harboring pRECN-VP1, and FMDV virus-like particles, where (VLPFMDV)-specific humoral, mucosal, and cellular immune responses were evaluated. Mice vaccinated with attenuated Salmonella (KST0666) expressing VP1 (named KST0669) showed high levels of VLP-specific IgA in feces and IgG in serum, with high FMDV neutralization titer. Moreover, KST0669-vaccinated mice showed increased population of IFN-γ (type 1 T helper cells; Th1 cells)-, IL-5 (Th2 cells)-, and IL-17A (Th17 cells)-expressing CD4+ as well as activated CD8+ T cells (IFN-γ+CD8+ cells), detected by stimulating VLPFMDV. All data indicate that our Salmonella vector system successfully delivered FMDV VP1 to immune cells and that the humoral and cellular efficacy of the vaccine can be easily evaluated using VLPFMDV in a Biosafety Level I (BSL1) laboratory.

• The RdRp and VP1-based dual typing by genetic analysis of circulating NoVs in Iran. • GII.4 Sydney_2012[P16] was determined as the most common strain. • GII.8[P8] viruses were also found to be as the second most common. The present study was aimed to both detect emerging noroviruses and investigate RdRp and VP1-based dual typing of circulating noroviruses in hospitalized children less than 5 years of age with acute gastroenteritis (AGE) in Iran. For this purpose, a total of 200 stool specimens were screened during 2021–2022 by real-time RT-PCR for genogroup I and II (GI and GII) and dual-typed by sequence analysis of PCR products, using a web-based norovirus Typing Tool and phylogenetic analysis. The GI and GII noroviruses were detected in 20% of 200 specimens. The GII.4 norovirus was found to be the most common VP1 genotype (53%) followed by GII.8 (32%), GII.7 (6%), GII.17 (6%), and GII.3 (3%). The GII.P16 norovirus was also found as the predominant RdRp type (53%) followed by GII.P8 (32%), GII.P7 (6%), GII.P17 (6%), and GII.P31 (3%). To our knowledge, this is the first report that highlights the dominancy of recombinant norovirus GII.4Sydney[P16] and newly emerging of norovirus GII.8 [P8], GII.17 [P17] and GII.3 [P16] in Iran. These findings further indicate inter-genotype recombinant strains of noroviruses. [ABSTRACT FROM AUTHOR]

Polyomaviruses are ubiquitous human pathogens that cause lifelong, asymptomatic infections in healthy individuals. Although these viruses are restrained by an intact immune system, immunocompromised individuals are at risk for developing severe diseases driven by resurgent viral replication. In particular, loss of immune control over JC polyomavirus can lead to the development of the demyelinating brain disease progressive multifocal leukoencephalopathy (PML). Viral isolates from PML patients frequently carry point mutations in the major capsid protein, VP1, which mediates virion binding to cellular glycan receptors. Because polyomaviruses are non-enveloped, VP1 is also the target of the host’s neutralizing antibody response. Thus, VP1 mutations could affect tropism and/or recognition by polyomavirus-specific antibodies. How these mutations predispose susceptible individuals to PML and other JCPyV-associated CNS diseases remains to be fully elucidated. Here, we review the current understanding of polyomavirus capsid mutations and their effects on viral tropism, immune evasion, and virulence.

Human BK polyomavirus (BKPyV) prevalence has been increasing due to the introduction of more potent immunosuppressive agents in transplant recipients, and its clinical interest. BKPyV has been linked mostly to polyomavirus-associated hemorrhagic cystitis, in allogenic hematopoietic stem cell transplant, and polyomavirus-associated nephropathy in kidney transplant patients. BKPyV is a circular double-stranded DNA virus that encodes for seven proteins, of which Viral Protein 1 (VP1), the major structural protein, has been extensively used for genotyping. BKPyV also contains the noncoding control region (NCCR), configured by five repeat blocks (OPQRS) known to be highly repetitive and diverse, and linked to viral infectivity and replication. BKPyV genetic diversity has been mainly studied based on the NCCR and VP1, due to the high occurrence of BKPyV-associated diseases in transplant patients and their clinical implications. Here BKTyper is presented, a free online genotyper for BKPyV, based on a VP1 genotyping and a novel algorithm for NCCR block identification. VP1 genotyping is based on a modified implementation of the BK typing and grouping regions (BKTGR) algorithm, providing a maximum-likelihood phylogenetic tree using a custom internal BKPyV database. Novel NCCR block identification relies on a minimum of 12-bp motif recognition and a novel sorting algorithm. A graphical representation of the OPQRS block organization is provided.

Enterovirus A71 (EV-A71) is a major pathogen that causes severe and fatal cases of hand-foot-and-mouth disease (HFMD). HFMD caused by EV-A71 seriously endangers children’s health. Although autophagy is an important antiviral defense mechanism, some viruses have evolved strategies to utilize autophagy to promote self-replication. EV-A71 can utilize autophagy vesicles as replication scaffolds, indicating that EV-A71 infection is closely related to its autophagy induction mechanism. VP1, a structural protein of EV-A71, has been reported to induce autophagy, but the underlying mechanism is still unclear. In this study, we found that the C-terminus (aa 251–297) of VP1 induces autophagy. Mass spectrometry analysis suggested that prohibitin 2 (PHB2) interacts with the C-terminus of the EV-A71 VP1 protein, and this was further verified by coimmunoprecipitation assays. After PHB2 knockdown, EV-A71 replication, viral particle release, and viral protein synthesis were reduced, and autophagy was inhibited. The results suggest that PHB2 interaction with VP1 is essential for induction of autophagy and the infectivity of EV-A71. Furthermore, we confirmed that EV-A71 induced complete autophagy that required autolysosomal acidification, thus affecting EV-A71 infection. In summary, this study revealed that the host protein PHB2 is involved in an autophagy mechanism during EV-A71 infection.

Viruses have evolved mechanisms to manipulate microtubules (MTs) for the efficient realization of their replication programs. Studying the mechanisms of replication of mouse polyomavirus (MPyV), we observed previously that in the late phase of infection, a considerable amount of the main structural protein, VP1, remains in the cytoplasm associated with hyperacetylated microtubules. VP1−microtubule interactions resulted in blocking the cell cycle in the G2/M phase. We are interested in the mechanism leading to microtubule hyperacetylation and stabilization and the roles of tubulin acetyltransferase 1 (αTAT1) and deacetylase histone deacetylase 6 (HDAC6) and VP1 in this mechanism. Therefore, HDAC6 inhibition assays, αTAT1 knock out cell infections, in situ cell fractionation, and confocal and TIRF microscopy were used. The experiments revealed that the direct interaction of isolated microtubules and VP1 results in MT stabilization and a restriction of their dynamics. VP1 leads to an increase in polymerized tubulin in cells, thus favoring αTAT1 activity. The acetylation status of MTs did not affect MPyV infection. However, the stabilization of MTs by VP1 in the late phase of infection may compensate for the previously described cytoskeleton destabilization by MPyV early gene products and is important for the observed inhibition of the G2→M transition of infected cells to prolong the S phase.

Enterovirus 71 (EV71) has become an important public health problem in the Asia-Pacific region in the past decades. EV71 infection might cause neurological and psychiatric complications and even death. Although an EV71 vaccine has been currently approved, there is no effective therapy for treating EV71-infected patients. Virus infections have been reported to shape host T cell receptor (TCR) repertoire. Therefore, understanding of host TCR repertoire in EV71 infection could better the knowledge in viral pathogenesis and further benefit the anti-viral therapy development. In this study, we used a mouse-adapted EV71 (mEV71) model to observe changes of host TCR repertoire in an EV71-infected central nervous system. Neonate mice were infected with mEV71 and mouse brainstem TCRβ repertoires were explored. Here, we reported that mEV71 infection impacted host brainstem TCRβ repertoire, where mEV71 infection skewed TCRβ diversity, changed VJ combination usages, and further expanded specific TCRβ CDR3 clones. Using bioinformatics analysis and ligand-binding prediction, we speculated the expanded TCRβ CDR3 clone harboring CASSLGANSDYTF sequence was capable of binding cleaved EV71 VP1 peptides in concert with major histocompatibility complex (MHC) molecules. We observed that mEV71 infection shaped host TCRβ repertoire and presumably expanded VP1-specific TCRβ CDR3 in mEV71-infected mouse brainstem that integrated EV71 pathogenesis in central nervous system.

Porcine circovirus-like virus P1 is an important pathogen of the current pig industry, the infection mechanism is not entirely clear. Wnt signaling pathway plays an important role in the growth of young animals and infection of some viruses. This study was designed to demonstrate the effects of P1 infection on the Wnt signaling pathway. In vivo experiments, we demonstrated the down-regulatory effects of P1 infection in piglets and mice on the downstream components expression levels of Wnt signaling pathway, and the effects of Wnt signaling pathway activation on the pathogenesis of P1. In vitro studies, we found P1 infection down-regulated protein level of β-catenin and mRNA level of mmp2, prevented the β-catenin from entering into nucleus, abolished the TCF/LEF promoter activity, proved that P1 could inhibit the activation of Wnt signaling pathway in vitro. Finally, we found that VP1 of P1 virus also had the inhibitory effects on Wnt signaling pathway in vitro, elucidated the mechanism of P1’s inhibitory effects on the Wnt signaling pathway and offered the possibility that the suppression of Wnt signaling pathway was involved in the post-weaning multisystemic wasting syndrome (PMWS), laying a foundation for elucidating the pathogenesis of P1.

Human norovirus (HuNoV) is a leading cause of viral gastroenteritis worldwide, of which GII.4 is the most predominant genotype. Unlike other genotypes, GII.4 has created various variants that escaped from previously acquired immunity of the host and caused repeated epidemics. However, the molecular evolutionary differences among all GII.4 variants, including recently discovered strains, have not been elucidated. Thus, we conducted a series of bioinformatic analyses using numerous, globally collected, full-length GII.4 major capsid (VP1) gene sequences (466 strains) to compare the evolutionary patterns among GII.4 variants. The time-scaled phylogenetic tree constructed using the Bayesian Markov chain Monte Carlo (MCMC) method showed that the common ancestor of the GII.4 VP1 gene diverged from GII.20 in 1840. The GII.4 genotype emerged in 1932, and then formed seven clusters including 14 known variants after 1980. The evolutionary rate of GII.4 strains was estimated to be 7.68 × 10−3 substitutions/site/year. The evolutionary rates probably differed among variants as well as domains [protruding 1 (P1), shell, and P2 domains]. The Osaka 2007 variant strains probably contained more nucleotide substitutions than any other variant. Few conformational epitopes were located in the shell and P1 domains, although most were contained in the P2 domain, which, as previously established, is associated with attachment to host factors and antigenicity. We found that positive selection sites for the whole GII.4 genotype existed in the shell and P1 domains, while Den Haag 2006b, New Orleans 2009, and Sydney 2012 variants were under positive selection in the P2 domain. Amino acid substitutions overlapped with putative epitopes or were located around the epitopes in the P2 domain. The effective population sizes of the present strains increased stepwise for Den Haag 2006b, New Orleans 2009, and Sydney 2012 variants. These results suggest that HuNoV GII.4 rapidly evolved in a few decades, created various variants, and altered its evolutionary rate and antigenicity.

The icosahedral capsid structure of simian virus 40 (diameter, 45 nm) consists of 72 pentameric subunits, with each subunit formed by five VP1 molecules. Electron microscopy, immuno-gold labeling, and ζ-potential analysis showed that purified recombinant VP1 pentamers covered polystyrene beads measuring 100, 200, and 500 nm in diameter, as well as silica beads. In addition to covering spherical beads, VP1 pentamers covered cubic magnetite beads, as well as the distorted surface structures of liposomes. These findings indicate that VP1 pentamers could coat artificial beads of various shapes and sizes larger than the natural capsid. Technology based on VP1 pentamers may be useful in providing a capsid-like surface for enclosed materials, enhancing their stability and cellular uptake for drug delivery systems.

Human polyomaviruses, BK virus (BKV) and JC virus (JCV), are world widely distributed in human population. After primary infection, BKV and JCV establish latency in kidneys and upper part of urinary tract. In seropositive healthy individuals asymptomatic reactivation of both viruses occurs in in 0.5-20%. On the other hand, reactivation of these viruses in imunosuppressed patients, primarily in patients with T cell immunodeficiency, can lead to development of polyomavirus-associated diseases. Some of these diseases such as progressive multifocal leukoencephalopathy (PML), polyomavirus-induced nephropathy (PVN), hemorrhagic cystitis (HC) are life-threatening diseases with high mortality and morbidity rate. However, they do not affect all immunosuppressed patients, suggesting that other factors, such as genetic variability of BKV and JCV, can contribute to their occurrence. Immunosuppression leads to increased levels of replication of both viruses. Increased levels of replication are associated with higher incidence of mutations in the VP1 gene. Mutations, especially those located in outer loops, may lead to changed tropism and generation of more aggressive variants of BKV and JCV. This review is focused on clinical significance of BK and JC virus infection in immunosuppressed patients, especially in HIV-infected, and sequence changes in the VP1 gene that can contribute to selection of more virulent variants of BKV and JCV via adaptive evolution.

Foot and mouth diseases are among the important threats in the animal husbandry industry which lead to huge economic losses. In this regard, the current project aimed to inhibit the VP1 protein of foot and mouth disease viruses using specific peptides. For this purpose, a wide range of potential antiviral peptides were collected from the database. Physicochemical properties, hydrophobicity/hydrophilicity, and solubility properties of potential antiviral peptides were investigated using reliable servers. Afterward, the tertiary structures of the selected peptides along with the VP1 protein were modeled by the I-TASSER server. Moreover, interactions between VP1 protein and selected antiviral peptides were investigated using the ClusPro 2.0 server. Finally, the outputs of molecular docking were assessed by LigPlot+ and visualized by PyMol software. The results revealed that Dermaseptin-3 , Ginkbilobin , Circulin-F , Maximin1 , Cycloviolin-A , Cycloviolin-D , Circulin-C , Cycloviolin-C , and Antihypertensive protein BDS-1 peptides with a hydrophobicity value of > 30 were soluble with positive instability index and positive net charge. Moreover, the results of the molecular docking process demonstrated that Dermaseptin-3 and Ginkbilobin peptides could strongly inhibit the VP1 protein using 10 hydrogen bonds. Therefore, these two peptides, which had the most hydrogen bonds, were introduced as the best anti-foot and mouth disease virus peptides to apply., Competing Interests: The authors declare there is no conflict of interest.

Feline calicivirus (FCV) causes upper respiratory tract diseases and even death in cats, thereby acting as a great threat to feline animals. Currently, FCV prevention is mainly achieved through vaccination, but the effectiveness of vaccination is limited. In this study, 105 FCV strain VP1 sequences with clear backgrounds were downloaded from the NCBI and subjected to a maximum likelihood method for systematic evolutionary analysis. Based on the genetic analysis results, FCV-positive sera were prepared using SPF mice and Chinese field cats as target animals, followed by a cross-neutralization assay conducted on the different genotype strains and in vivo challenge tests were carried out to further verify with the strain with best cross-protection effect. The results revealed that FCV was mainly divided into two genotypes: GI and GII. The GI genotype strains are prevalent worldwide, but all GII genotype strains were isolated from Asia, indicating a clear geographical feature. This may form resistance to FCV prevention in Asia. The in vitro neutralization assay conducted using murine serum demonstrated that the cross-protection effect varied among strains. A strain with broad-spectrum neutralization properties, DL39, was screened. This strain could produce neutralizing titers (10 × 2 3.08 -10 × 2 0.25 ) against all strains used in this study. The antibody titers against the GI strains were 10 × 2 3.08 -10 × 2 0.5 and those against the GII strains were 10 × 2 0.75 -10 × 2 0.25 . Preliminary evidence suggested that the antibody titer of the DL39 strain against GI was higher than that against GII. Subsequent cross-neutralization assays with cat serum prepared with the DL39 strain and each strain simultaneously yielded results similar to those described above. In vivo challenge tests revealed that the DL39 strain-immunized cats outperformed the positive controls in all measures. The results of several trials demonstrated that strain DL39 can potentially be used as a vaccine strain. The study attempted to combine the genetic diversity and phylogenetic analysis of FCV with the discovery of potential vaccines, which is crucial for developing highly effective FCV vaccines., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Yang, Liu, Chen, Feng, Qi, Zheng, Wang, Kang, Jiang, Yang, Qu and Liu.)

Foot and Mouth Disease (FMD) is a very dangerous livestock disease which causes a serious loss in the production of milk and meat. Therefore, producing an effective recombinant subunit vaccine virus this disease is of great importance. Transient gene expression is a valuable tool to reach rapid and acceptable recombinant vaccine. An Agrobacterium-mediated transient gene expression assay was carried out in spinach (Spinacia oleracea) leaves for expression of a chimeric gene encoding a part of capsid protein of Foot and Mouth Disease virus called VP1. The plant leaves were transformed via agroinfiltration procedure. The presence of foreign gene and its expression in transformed plants were confirmed through polymerase chain reaction (PCR), real time PCR, protein Dot blot and ELISA. The results obtained in this examination showed quite a high level of gene expression in spinach leaves, showing that transient gene expression can be applied as an effective and time-saving procedure for the production of recombinant proteins. The procedures for transformation, detection of recombinant protein and its application for molecular experiments are described in the study.

Chlamydia trachomatis is the leading cause of sexually transmitted bacterial infections. C. trachomatis genital infection may lead to pelvic inflammatory disease, ectopic pregnancy and tubal infertility, which are major public health problems. However, the pathogenic mechanisms of this bacterium remain unclear, and the efficacy of clinical therapeutics is unsatisfactory. In the current study, whether Vp1 can alleviate the cytotoxicity induced by Chlamydia trachomatis infection was investigated. C. trachomatis was pre-treated with BSA or purified Vp1 protein and used to infect HeLa cells. It was observed that Vp1 significantly inhibited the infectivity of C. trachomatis in cell cultures. In addition, the Vp1 pretreatment reduced the chlamydial Hsp60 protein levels and decreased the C. trachomatis inclusion number. The Vp1 pretreatment also prevented C. trachomatis-induced cytotoxicity in host cells. Furthermore, the chlamydial suppression of host cell proapoptotic p53 protein and the induction of antiapoptotic cIAP-2 and Mcl-1 gene expression were reversed by the Vp1 pretreatment. These observations suggest that Vp1 has a clear inhibitory effect on C. trachomatis growth in vitro. [ABSTRACT FROM AUTHOR]

Nebovirus is a new genus within the family Caliciviridae and is a causative agent of calf diarrhea. The limited nebovirus genomic sequences that are currently available has hampered understanding of nebovirus genetic evolution. The aim of the present study was to determine the genomic characterization of strain Bo/LZB-1/17/CH, which was previously identified as being similar to the novel genotype strain Bo/DijonA216/06/FR based on partial capsid sequences. Our results show that the complete RNA genome of strain Bo/LZB-1/17/CH is 7453 nucleotides (nt) in length and shares 79.0%–83.5% nt identity with all available nebovirus genomes in the GenBank database. A phylogenetic analysis based on its complete genome sequence revealed that strain Bo/LZB-1/17/CH clustered into an independent branch. Two interesting characteristics were observed in the genome of strain Bo/LZB-1/17/CH. First, the major capsid protein (VP1) of strain Bo/LZB-1/17/CH shares 96.6% amino acid (aa) identity with strain Bo/DijonA216/06/FR but shares only 75.2%–76.8% aa identity with other nebovirus strains and has an even lower identity in the P2 domain (61.1%–65% aa identity). Second, the RNA-dependent RNA polymerase (RdRp) of strain Bo/LZB-1/17/CH is more closely related to NB-like strains than it is to strain Bo/DijonA216/06/FR, and a recombination event was identified within the 3′ end of the RdRp in strain Bo/LZB-1/17/CH. In conclusion, the results in this study indicate that strain Bo/LZB-1/17/CH may represent a novel nebovirus strain. To the best of our knowledge, this is the first description of a recombinant event in nebovirus RdRp. [ABSTRACT FROM AUTHOR]

Chlamydia trachomatis is the most common cause of bacterial sexually transmitted infections. The effect of antibiotic treatment is not satisfactory, and there is currently no vaccine to prevent C. trachomatis infection. Our results showed that Chlamydia virus CPG1 capsid protein Vp1 treatment significantly inhibited C. trachomatis growth in cell culture, and the inclusion numbers of different C. trachomatis serotypes were decreased. In addition, we conducted a preliminary investigation of the possible mechanisms behind the Vp1 inhibition effects and the C. trachomatis molecules targeted by Vp1. Using far-western blot and GST pull-down assay, we found that purified Vp1 can bind to the C. trachomatis outer membrane protein PmpI. PmpI polyclonal antibody treatment markedly reduced the inhibitory effect of Vp1 on C. trachomatis infectivity. On the basis of these experimental results, we infer that PmpI participates in the inhibitory effect of Vp1 and may be a potential receptor of Vp1 in the outer membrane of C. trachomatis. Our research provides clues regarding the molecular mechanisms underlying the interactions between chlamydia virus and chlamydia. [ABSTRACT FROM AUTHOR]

In immunocompromised individuals, especially in patients with T cell immunodeficiency, reactivation of JCPyV can cause serious life-threatening diseases. Nowadays, HIV infection is one of the most important factor for reactivation of JCPyV and the development of of the progressive multifocal leukoencephalopathy (PML). Mutations in the outer loops of the VP1 region can lead to the selection of the viral variants with changed tropism and increased pathological potential. The aims of this study were to determine sequence variation and amino acid changes within VP1 loops and the structure of non-coding control region (NCCR) of urinary excreted JCPyV isolates among HIV-infected patients and healthy donors. Single urine samples from 114 HIV-infected patients and 120 healthy donors were collected. PCR was performed for amplification of VP1 and NCCR. Amplified fragments were directly sequenced and analyzed by using bioinformatics tools. Nucleotide substitutions were detected within DE and EF loops and in the β-sheets of both studied groups. In HIV-infected patients group, 70% of mutations were detected within receptor domains. Among healthy donors, one mutation was identified within β-sheets while the remaining were located within receptor domains. The most prevalent mutation was L157V in both groups. Analysis of NCCR revealed that all isolates had archetype structure with some minor changes. Since single point mutations at specific place within outer loop of VP1 region can cause formation of variants with changed receptor specificity, identification of these mutations in HIV-infected patients can help to single out those with higher risk for development of polyomavirus-associated diseases. [ABSTRACT FROM AUTHOR]

Copyright of Avian Diseases is the property of American Association of Avian Pathologists, Inc. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Although the human neurotropic polyomavirus, JC virus (JCV), was isolated almost a half century ago, understanding the molecular mechanisms governing its biology remains highly elusive. JCV infects oligodendrocytes and astrocytes in the central nervous system (CNS) and causes a rare fatal brain disease known as progressive multifocal leukoencephalopathy (PML) in immunocompromised individuals including AIDS. It has a small circular DNA genome (∼5 kb) and generates two primary transcripts from its early and late coding regions, producing several predicted alternatively spliced products mainly by cis‐splicing. Here, we report the discovery and characterization of two novel open reading frames (ORF1 and ORF2) associated with JCV late transcripts, generated by an unusual splicing process called trans‐splicing. These ORFs result from (i) the trans‐splicing of two different lengths of the 5′‐short coding region of VP1 between the coding regions of agnoprotein and VP2 after replacing the intron located between these two coding regions and (ii) frame‐shifts occurring within the VP2 coding sequences terminated by a stop codon. ORF1 and ORF2 are capable of encoding 58 and 72 aa long proteins respectively and are expressed in infected cells and PML patients. Each ORF protein shares a common coding region with VP1 and has a unique coding sequence of their own. When the expression of the unique coding regions of ORFs is blocked by a stop codon insertion in the viral background, the mutant virus replicates less efficiently when compared to wild‐type, suggesting that the newly discovered ORFs play critical roles in the JCV life cycle. [ABSTRACT FROM AUTHOR]

Enterovirus 71 (EV71) is the primary pathogen of hand-foot-and-mouth disease (HFMD) in children and virus infections are associated with severe neurological dysfunctions and even death. MIR2911 is a honeysuckle-encoded atypical microRNA with extreme stability. Here, we report that MIR2911 directly inhibits EV71 replication by targeting the VP1 gene. Bioinformatics prediction and luciferase reporter assay showed that MIR2911 could target the VP1 gene of EV71. Transfection experiments using synthetic MIR2911 and extracted RNA from HS decoction shown that each of these preparations was capable of inhibiting EV71 VP1 protein expression; however, these preparations did not impact EV71 mutants in which the MIR2911-binding sites were mutated. Furthermore, EV71 replication was increased by antagomirs against MIR2911 in the HS decoction, implying that MIR2911 was physiologically functional in controlling EV71 replication in vitro . These results indicated that, by targeting VP1 gene, MIR2911 may effectively inhibit EV71 replication. Our results also provide a potential novel strategy on the therapy and/or prevention of HFMD originating from EV71 virus infection. [ABSTRACT FROM AUTHOR]

Porcine circovirus-like virus P1 is an important pathogen of the current pig industry, the infection mechanism is not entirely clear. Wnt signaling pathway plays an important role in the growth of young animals and infection of some viruses. This study was designed to demonstrate the effects of P1 infection on the Wnt signaling pathway. In vivo experiments, we demonstrated the down-regulatory effects of P1 infection in piglets and mice on the downstream components expression levels of Wnt signaling pathway, and the effects of Wnt signaling pathway activation on the pathogenesis of P1. In vitro studies, we found P1 infection down-regulated protein level of b-catenin and mRNA level of mmp2, prevented the b-catenin from entering into nucleus, abolished the TCF/LEF promoter activity, proved that P1 could inhibit the activation of Wnt signaling pathway in vitro. Finally, we found that VP1 of P1 virus also had the inhibitory effects on Wnt signaling pathway in vitro, elucidated the mechanism of P1's inhibitory effects on the Wnt signaling pathway and offered the possibility that the suppression of Wnt signaling pathway was involved in the post-weaning multisystemic wasting syndrome (PMWS), laying a foundation for elucidating the pathogenesis of P1. [ABSTRACT FROM AUTHOR]

BK polyomavirus (BKV) is an opportunist agent associated with nephropathy (BKVAN) in 1–10% of kidney transplant recipients. BKV is classified into genotypes or subgroups according to minor nucleotidic variations with unknown biological implications. Studies assessing the possible association between genotypes and the risk of BKVAN in kidney transplant patients have presented conflicting results. In these studies, genotype Ia, which is highly prevalent in Brazil, was less frequently found and, thus, comparative data on the biological properties of this genotype are lacking. In this study, BKV Ia and Ib1 genotypes were compared according to their viral load, genetic evolution (VP1 and NCCR) – in a cohort of renal transplant recipients. The patients infected with Ia (13/23; 56.5%) genotype exhibited higher viral loads in urine [>1.4 log over Ib1 (10/23; 43.5%); p = 0.025]. In addition, genotype Ia was associated with diverse mutations at VP1 loops and sites under positive selection outside loops, which were totally absent in Ib1. Although the number of viremic patients was similar, the three patients who had BK nephropathy (BKVAN) were infected with Ia genotype. NCCR architecture (ww or rr) were not distinctive between Ia and Ib1 genotypes. Ia genotype, which is rare in other published BKV cohorts, presented some diverse biological properties in transplanted recipients in comparison to Ib1. [ABSTRACT FROM AUTHOR]

The BK virus (BKPyV) is a member of the Polyomaviridae family first isolated in 1971. BKPyV causes frequent infections during childhood and establishes persistent infections with minimal clinical implications within renal tubular cells and the urothelium. However, reactivation of BKPyV in immunocompromised individuals may cause serious complications. In particular, with the implementation of more potent immunosuppressive drugs in the last decade, BKPyV has become an emerging pathogen in kidney and bone marrow transplant recipients where it often causes associated nephropathy and haemorrhagic cystitis, respectively. Unfortunately, no specific antiviral against BKPyV has been approved yet and the only therapeutic option is a modulation of the immunosuppressive drug regimen to improve immune control though it may increase the risk of rejection. A better understanding of the BKPyV life cycle is thus needed to develop efficient treatment against this virus. In this review, we provide an update on recent advances in understanding the biology of BKPyV. [ABSTRACT FROM AUTHOR]

Encephalomyocarditis virus (EMCV) can cause acute myocarditis in young pigs or reproductive failure in sows. It has been recognized worldwide as a pathogen infecting many species and causes substantial economic losses. In the present study, an indirect ELISA was developed for the detection of antibodies to EMCV. The VP1 gene of EMCV was amplified by reverse transcription-quantitative polymerase chain reaction and expressed in Escherichia coli with 49.3 kDa under the condition of isopropyl-ß-d-thiogalactoside. Following this, the authors obtained the recombinant protein VP1 as a coating antigen. The antigen concentration and serum dilution were optimized using a checkerboard titration. Compared with viral neutralization tests, the sensitivity and specificity of the indirect ELISA was 95.7% and 92.9%, respectively. A total of 265 clinical swine serum samples from different pig farms in China were used to a serological survey. The seropositive rate of the serum samples was 81.9%. In conclusion, the developed indirect ELISA assay is sensitive and specific, which will be useful for large-scale serological survey in EMCV infection and monitoring antibodies titers against EMCV. [ABSTRACT FROM AUTHOR]