NS2B-D55E and NS2B-E65D Variations Are Responsible for Differences in NS2B-NS3 Protease Activities Between Japanese Encephalitis Virus Genotype I and III in Fluorogenic Peptide Model.

Japanese encephalitis virus (JEV) NS2B-NS3 is a protein complex composed of NS3 proteases and an NS2B co-factor. The N-terminal protease domain (180 residues) of NS3 (NS3(pro)) interacts directly with a central 40-amino acid hydrophilic domain of NS2B (NS2B(H)) to form an active serine protease. In this study, the recombinant NS2B(H)-NS3(pro) proteases were prepared in and used to compare the enzymatic activity between genotype I (GI) and III (GIII) NS2B-NS3 proteases.

Porcine reproductive and respiratory syndrome virus nsp4-mediated β2M downregulation contributes to SLA-I decrease and virus infection in vivo and in vitro.

Porcine reproductive and respiratory syndrome virus (PRRSV) infection inhibits swine leukocyte antigen class I (SLA-I) expression in pigs, resulting in inefficient antigen presentation and subsequent low levels of cellular PRRSV-specific immunity as well as persistent viremia. We previously observed that the non-structural protein 4 (nsp4) of PRRSV contributed to inhibition of the β2-microglobulin (β2M) and SLA-I expression in cells. Here, we constructed a series of nsp4 mutants with different combination of amino acid mutations to attenuate the inhibitory effect of nsp4 on β2M and SLA-I expression.

Development of Colloidal Gold-Based Immunochromatographic Strips for Rapid Detection and Surveillance of Japanese Encephalitis Virus in Dogs across Shanghai, China.

Japanese encephalitis virus (JEV) causes acute encephalitis in humans and is of major public health concern in most Asian regions. Dogs are suitable sentinels for assessing the risk of JEV infection in humans. A neutralization test (NT) or an enzyme-linked immunosorbent assay (ELISA) is used for the serological detection of JEV in dogs; however, these tests have several limitations, and, thus, a more convenient and reliable alternative test is needed.

NS2B-D55E and NS2B-E65D Variations are Responsible for Differences in NS2B-NS3 Protease Activities Between Japanese Encephalitis Virus Genotype I and III in Fluorogenic Peptide Model.

Japanese Encephalitis Virus (JEV) NS2B-NS3 is a protein complex composed of NS3 proteases and a NS2B cofactor. The N-terminal protease domain (180 residues) of NS3 (NS3(pro)) interacts directly with a central 40-amino acid hydrophilic domain of NS2B (NS2B(H)) to form an active serine protease. In this study, the recombinant NS2B(H)-NS3(pro) proteases were prepared in and used to compare the enzymatic activity between genotype I (GI) and III (GIII) NS2B-NS3 proteases.

Construction of a Recombinant Japanese Encephalitis Virus with a Hemagglutinin-Tagged NS2A: A Model for an Analysis of Biological Characteristics and Functions of NS2A during Viral Infection.

Nonstructural protein 2A (NS2A) of the Japanese encephalitis virus (JEV) contributes to viral replication and pathogenesis; however, a lack of NS2A-specific antibodies restricts studies on the underlying mechanisms. In this study, we constructed a recombinant JEV with a hemagglutinin (HA)-tagged NS2A (JEV-HA/NS2A/∆NS1') to overcome this challenge. An HA-tag was fused to the N-terminus of NS2A (HA-NS2A) at the intergenic junction between NS1 and NS2A.

Molecular Epidemic Characteristics and Genetic Evolution of Porcine Circovirus Type 2 (PCV2) in Swine Herds of Shanghai, China.

Porcine Circovirus 2 (PCV2) is a crucial swine pathogen and considered a primary causative agent of porcine circovirus-associated diseases (PCVADs), posing a serious economic threat to the swine industry across globe. The world's biggest agricultural conglomerates have teamed up to create giant commercial pig farms across Shanghai due to the proximity of this region to more affluent lean-pork markets. Since its discovery, PCV2 has displayed extraordinary genetic diversity, and its genome is swiftly evolving through a series of mutations and recombinations.

The interactions of flaviviruses with cellular receptors: Implications for virus entry.

Flaviviruses are a group of enveloped viruses that enter the host cells through receptor-mediated endocytosis. The entry of flaviviruses into the cells is a multi-step process which involves several host factors that trigger the uptake of the virus. The initial step in the virus life cycle is the interactions between viral envelope proteins and the specific receptors on the surface of host cell.

A Novel Recombinant Virus-Like Particles Displaying B and T Cell Epitopes of Japanese Encephalitis Virus Offers Protective Immunity in Mice and Guinea Pigs.

Virus-like particles (VLPs) are non-replicative vectors for the delivery of heterologous epitopes and are considered one of the most potent inducers of cellular and humoral immune responses in mice and guinea pigs. In the present study, VLP-JEVe was constructed by the insertion of six Japanese encephalitis virus (JEV) envelope protein epitopes into different surface loop regions of PPV VP2 by the substitution of specific amino acid sequences without altering the assembly of the virus; subsequently, the protective efficacy of this VLP-JEVe was evaluated against JEV challenge in mice and guinea pigs. Mice immunized with the VLP-JEVe antigen developed high titers of neutralizing antibodies and 100% protection against lethal JEV challenge.

A Metagenomic Analysis of Mosquito Virome Collected From Different Animal Farms at Yunnan-Myanmar Border of China.

Metagenomic analysis of mosquito-borne and mosquito-specific viruses is useful to understand the viral diversity and for the surveillance of pathogens of medical and veterinary importance. Yunnan province is located at the southwest of China and has rich abundance of mosquitoes. Arbovirus surveillance is not conducted regularly in this province particularly at animal farms, which have public health as well as veterinary importance.

Identification of Cleavage Sites Proteolytically Processed by NS2B-NS3 Protease in Polyprotein of Japanese Encephalitis Virus.

Understanding the proteolytic processing of polyprotein mediated by NS2B-NS3 protease contributes to the exploration of the mechanisms underlying infection of Japanese encephalitis virus (JEV), a zoonotic flavivirus. In this study, eukaryotic and prokaryotic cell models were employed to identify the cleavage sites mediated by viral NS2B-NS3 protease in JEV polyprotein. Artificial green fluorescent protein (GFP) substrates that contained the predicted cleavage site sequences of JEV polyprotein were expressed in swine testicle (ST) cells in the presence and absence of JEV infection, or co-expressed in with the recombinant NS2B-NS3 protease that was generated by fusing the N-terminal protease domain of NS3 to the central hydrophilic domain of NS2B.

Unification of frequentist inference and machine learning for pterygomaxillary morphometrics.

Background: The base of the skull, particularly the pterygomaxillary region, has a sophisticated topography, the morphometry of which interests pathologists, maxillofacial and plastic surgeons. The aim of the study was to conduct pterygomaxillary morphometrics and test relevant hypotheses on sexual and laterality-based dimorphism, and causality relationships.

Materials And Methods: We handled 60 dry skulls of adult Asian males (36.

Downregulation of miR-296-3p by highly pathogenic porcine reproductive and respiratory syndrome virus activates the IRF1/TNF-α signaling axis in porcine alveolar macrophages.

Porcine reproductive and respiratory syndrome virus (PRRSV, species Betaarterivirus suid 1 or 2) is a major pathogen affecting pigs on farms throughout the world. miR-296-3p is a multifunctional microRNA involved in the regulation of the inflammatory response in mice and humans. However, little is known about the biological functions of miR-296-3p in pigs.

Mosquito defensin facilitates Japanese encephalitis virus infection by downregulating the C6/36 cell-surface antiviral protein HSC70B.

Japanese encephalitis virus (JEV) is a viral zoonosis that can cause viral encephalitis, death and disability whose primary vector is the Culex mosquito. Viral infection induces a series of antimicrobial peptide responses in mosquitoes, and the effector defensin enhances JEV replication in mosquitoes. However, the underlying mechanisms by which defensin enhances JEV are not fully understood.

Adaptation of a live-attenuated genotype I Japanese encephalitis virus to vero cells is associated with mutations in structural protein genes.

The SD12-F120 is a live-attenuated genotype I strain of Japanese encephalitis virus (JEV) and was obtained by serial passage of wild-type strain SD12 on BHK-21 cells combined with multiple plaque purification and virulence selection in mice. The large scale production and vast clinical trials always demand ideal safety and efficacy profile of live-attenuated vaccines. In the present study, SD12-F120VC has undergone serial passaging of P1-P30 in WHO qualified Vero cells to assess the potential effect of adaptation to growth on Vero cells.

Mosquito Defensins Enhance Japanese Encephalitis Virus Infection by Facilitating Virus Adsorption and Entry within the Mosquito.

Japanese encephalitis virus (JEV) is a viral zoonosis that can cause viral encephalitis, death, and disability. Although the mosquito is the primary vector of JEV, little is known about JEV transmission by this kind of mosquito. Here, we found that mosquito defensin facilitated the adsorption of JEV on target cells via the defensin/lipoprotein receptor-related protein 2 (LRP2) axis.

Phenotypic and Genotypic Comparison of a Live-Attenuated Genotype I Japanese Encephalitis Virus SD12-F120 Strain with Its Virulent Parental SD12 Strain.

The phenotypic and genotypic characteristics of a live-attenuated genotype I (GI) strain (SD12-F120) of Japanese encephalitis virus (JEV) were compared with its virulent parental SD12 strain to gain an insight into the genetic changes acquired during the attenuation process. SD12-F120 formed smaller plaque on BHK-21 cells and showed reduced replication in mouse brains compared with SD12. Mice inoculated with SD12-F120 via either intraperitoneal or intracerebral route showed no clinical symptoms, indicating a highly attenuated phenotype in terms of both neuroinvasiveness and neurovirulence.

Duck karyopherin α4 (duKPNA4) is involved in type I interferon expression and the antiviral response against Japanese encephalitis virus.

Karyopherin α4 (KPNA4) is an adaptor molecule that mediates type I interferon (IFN) production by facilitating the nuclear translocation of IFN transcription factors. Here, we cloned the duck KPNA4 (duKPNA4) gene and analyzed its involvement in type I IFN expression as well as antiviral response against Japanese encephalitis virus (JEV). The full-length duKPNA4 gene encoded a 520-amino acid protein that shared 97.

The emerged genotype I of Japanese encephalitis virus shows an infectivity similar to genotype III in Culex pipiens mosquitoes from China.

Japanese Encephalitis virus (JEV) is a zoonotic flavivirus that represents the most significant etiology of childhood viral neurological infections throughout the Asia. During the last 20 years, JEV genotype dominance has shifted from genotype III (GIII) to genotype I (GI). To date, the exact mechanism of this displacement is still not known.

A viral metagenomic analysis reveals rich viral abundance and diversity in mosquitoes from pig farms.

Mosquitoes harbour a diversity of viruses and are responsible for several mosquito-borne viral diseases of humans and animals, thereby leading to major public health concerns, and significant economic losses across the globe. Viral metagenomics offers a great opportunity for bulk analysis of viral genomes retrieved directly from environmental samples. In this study, we performed a viral metagenomic analysis of five pools of mosquitoes belonging to Aedes, Anopheles and Culex species, collected from different pig farms in the vicinity of Shanghai, China, to explore the viral community carried by mosquitoes.