-
Viruses Mar 2024Extracellular vesicles (EVs) such as exosomes have been shown to play physiological roles in cell-to-cell communication by delivering various proteins and nucleic acids....
Extracellular vesicles (EVs) such as exosomes have been shown to play physiological roles in cell-to-cell communication by delivering various proteins and nucleic acids. In addition, several studies revealed that the EVs derived from the cells that are infected with certain viruses could transfer the full-length viral genomes, resulting in EVs-mediated virus propagation. However, the possibility cannot be excluded that the prepared EVs were contaminated with infectious viral particles. In this study, the cells that harbor subgenomic replicon derived from the Japanese encephalitis virus and dengue virus without producing any replication-competent viruses were employed as the EV donor. It was demonstrated that the EVs in the culture supernatants of those cells were able to transfer the replicon genome to other cells of various types. It was also shown that the EVs were incorporated by the recipient cells primarily through macropinocytosis after interaction with CD33 and Tim-1/Tim-4 on HeLa and K562 cells, respectively. Since the methods used in this study are free from contamination with infectious viral particles, it is unequivocally indicated that the flavivirus genome can be transferred by EVs from cell to cell, suggesting that this pathway, in addition to the classical receptor-mediated infection, may play some roles in the viral propagation and pathogenesis.
Topics: Extracellular Vesicles; Humans; Genome, Viral; Replicon; Encephalitis Virus, Japanese; Viral Proteins; Virus Replication; Flavivirus; Dengue Virus; HeLa Cells; K562 Cells; Animals; Cell Line; Subgenomic RNA
PubMed: 38675867
DOI: 10.3390/v16040524 -
Frontiers in Immunology 2024A 54-year-old Japanese man presented with headache and fever the day after SARS-CoV-2 vaccination. He became deeply unconscious within a week. Brain MRI showed...
A 54-year-old Japanese man presented with headache and fever the day after SARS-CoV-2 vaccination. He became deeply unconscious within a week. Brain MRI showed periventricular linear enhancements and a few spotty lesions in the cerebral white matter. Cerebrospinal fluid (CSF) testing showed mild pleocytosis. He was treated with intravenous methylprednisolone and plasma exchange. However, the white matter lesions enlarged to involve the brainstem and cerebellum, and long cord spinal lesions appeared. Anti-glial fibrillary acidic protein (GFAP) antibody was positive in the CSF and serum, and he was therefore diagnosed as autoimmune GFAP-astrocytopathy (GFAP-A). In addition, high-dose immunoglobulin therapy was administered twice, but his symptoms did not improve; the white matter lesions enlarged further, and modified Rankin Scale score increased to 5. A brain biopsy specimen showed infiltration of macrophages and CD lymphocytes together with neuron and oligodendrocytic injuries and glial scar. Although GFAP-A generally responds well to steroids, the present case developed GFAP-A following SARS-CoV-2 vaccination, with refractory to intensive immunosuppressive therapy and atypical pathologic findings of infiltration of CD lymphocytes and demyelination.
Topics: Humans; Male; Middle Aged; Glial Fibrillary Acidic Protein; COVID-19; SARS-CoV-2; Immunosuppressive Agents; Astrocytes; COVID-19 Vaccines; Autoantibodies; Vaccination; Brain
PubMed: 38665914
DOI: 10.3389/fimmu.2024.1361685 -
Journal of Virology May 2024The host cytoskeleton plays crucial roles in various stages of virus infection, including viral entry, transport, replication, and release. However, the specific...
UNLABELLED
The host cytoskeleton plays crucial roles in various stages of virus infection, including viral entry, transport, replication, and release. However, the specific mechanisms by which intermediate filaments are involved in orthoflavivirus infection have not been well understood. In this study, we demonstrate that the Japanese encephalitis virus (JEV) remodels the vimentin network, resulting in the formation of cage-like structures that support viral replication. Mechanistically, JEV NS1 and NS1' proteins induce the translocation of CDK1 from the nucleus to the cytoplasm and interact with it, leading to the phosphorylation of vimentin at Ser56. This phosphorylation event recruits PLK1, which further phosphorylates vimentin at Ser83. Consequently, these phosphorylation modifications convert the typically filamentous vimentin into non-filamentous "particles" or "squiggles." These vimentin "particles" or "squiggles" are then transported retrogradely along microtubules to the endoplasmic reticulum, where they form cage-like structures. Notably, NS1' is more effective than NS1 in triggering the CDK1-PLK1 cascade response. Overall, our study provides new insights into how JEV NS1 and NS1' proteins manipulate the vimentin network to facilitate efficient viral replication.
IMPORTANCE
Japanese encephalitis virus (JEV) is a mosquito-borne orthoflavivirus that causes severe encephalitis in humans, particularly in Asia. Despite the availability of a safe and effective vaccine, JEV infection remains a significant public health threat due to limited vaccination coverage. Understanding the interactions between JEV and host proteins is essential for developing more effective antiviral strategies. In this study, we investigated the role of vimentin, an intermediate filament protein, in JEV replication. Our findings reveal that JEV NS1 and NS1' proteins induce vimentin rearrangement, resulting in the formation of cage-like structures that envelop the viral replication factories (RFs), thus facilitating efficient viral replication. Our research highlights the importance of the interplay between the cytoskeleton and orthoflavivirus, suggesting that targeting vimentin could be a promising approach for the development of antiviral strategies to inhibit JEV propagation.
Topics: Animals; Humans; CDC2 Protein Kinase; Cell Cycle Proteins; Cell Line; Encephalitis Virus, Japanese; Encephalitis, Japanese; HEK293 Cells; Host-Pathogen Interactions; Phosphorylation; Polo-Like Kinase 1; Protein Serine-Threonine Kinases; Vimentin; Viral Nonstructural Proteins; Virus Replication
PubMed: 38656209
DOI: 10.1128/jvi.00195-24 -
International Immunopharmacology May 2024Japanese encephalitis virus (JEV) infection is considered a global public health emergency. Severe peripheral neuropathy caused by JEV infection has increased disability...
Japanese encephalitis virus (JEV) infection is considered a global public health emergency. Severe peripheral neuropathy caused by JEV infection has increased disability and mortality rates in recent years. Because there are very few therapeutic options for JEV infection, prompt investigations of the ability of clinically safe, efficacious and globally available drugs to inhibit JEV infection and ameliorate peripheral neuropathy are urgently needed. In this study, we found that high doses of intravenous immunoglobulin, a function inhibitor of acid sphingomyelinase (FIASMA), inhibited acid sphingomyelinase (ASM) and ceramide activity in the serum and sciatic nerve of JEV-infected rats, reduced disease severity, reversed electrophysiological and histological abnormalities, significantly reduced circulating proinflammatory cytokine levels, inhibited Th1 and Th17 cell proliferation, and suppressed the infiltration of inflammatory CD4 + cells into the sciatic nerve. It also maintained the peripheral nerve-blood barrier without causing severe clinical side effects. In terms of the potential mechanisms, ASM was found to participate in immune cell differentiation and to activate immune cells, thereby exerting proinflammatory effects. Therefore, immunoglobulin is a FIASMA that reduces abnormal immune responses and thus targets the ASM/ceramide system to treat peripheral neuropathy caused by JEV infection.
Topics: Animals; Humans; Male; Rats; Ceramides; Cytokines; Encephalitis Virus, Japanese; Encephalitis, Japanese; Immunoglobulins, Intravenous; Peripheral Nervous System Diseases; Rats, Sprague-Dawley; Sciatic Nerve; Signal Transduction; Sphingomyelin Phosphodiesterase; Th1 Cells; Th17 Cells
PubMed: 38648714
DOI: 10.1016/j.intimp.2024.112083 -
Virus Research Jul 2024Zika virus (ZIKV) and Japanese encephalitis virus (JEV) are antigenically related flaviviruses that co-circulate in many countries/territories. The interaction between...
Zika virus (ZIKV) and Japanese encephalitis virus (JEV) are antigenically related flaviviruses that co-circulate in many countries/territories. The interaction between the two viruses needs to be determined. Recent findings by ourselves and other labs showed that JEV-elicited antibodies (Abs) and CD8T cells exacerbate and protect against subsequent ZIKV infection, respectively. However, the impact of JEV envelope (E) protein domain III (EDIII)-induced immune responses on ZIKV infection is unclear. We show here that sera from JEV-EDIII-vaccinated mice cross-react with ZIKV-EDIII in vitro, and transfer of the same sera to mice significantly decreases death upon lethal ZIKV infection at a dose-dependent manner. Maternally acquired anti-JEV-EDIII Abs also significantly reduce the mortality of neonatal mice born to JEV-EDIII-immune mothers post ZIKV challenge. Similarly, transfer of ZIKV-EDIII-reactive IgG purified from JEV-vaccinated humans increases the survival of ZIKV-infected mice. Notably, transfer of an extremely low volume of JEV-EDIII-immune sera or ZIKV-EDIII-reactive IgG does not mediate the Ab-mediated enhancement (ADE) of ZIKV infection. Similarly, transfer of JEV-EDIII-elicited CD8T cells protects recipient mice against ZIKV challenge. These results demonstrate that JEV-EDIII-induced immune components including Abs and T cells have protective roles in ZIKV infection, suggesting EDIII is a promising immunogen for developing effective and safety JEV vaccine.
Topics: Animals; Zika Virus Infection; CD8-Positive T-Lymphocytes; Zika Virus; Antibodies, Viral; Viral Envelope Proteins; Mice; Encephalitis Virus, Japanese; Cross Protection; Female; Cross Reactions; Encephalitis, Japanese; Humans; Immunoglobulin G; Disease Models, Animal; Immunization
PubMed: 38643856
DOI: 10.1016/j.virusres.2024.199376 -
Biologicals : Journal of the... May 2024This study aimed to investigate the prevalence of viral agents causing reproductive failure in pigs in Korea. In addition, two types of multiplex real-time PCR (mqPCR)...
This study aimed to investigate the prevalence of viral agents causing reproductive failure in pigs in Korea. In addition, two types of multiplex real-time PCR (mqPCR) were developed for the simultaneous detection of Aujeszky's disease virus (ADV) and porcine parvovirus (PPV) in mqPCR and encephalomyocarditis virus (EMCV) and Japanese encephalitis virus (JEV) in reverse transcription mqPCR (mRT-qPCR). A total of 150 aborted fetus samples collected from 2020 to 2022 were analyzed. Porcine reproductive and respiratory syndrome virus was the most prevalent (49/150 32.7%), followed by porcine circovirus type 2 (31/150, 20.7%), and PPV1 (7/150, 4.7%), whereas ADV, EMCV, and JEV were not detected. The newly developed mqPCR and mRT-qPCR could simultaneously detect and differentiate with high sensitivities and specificities. When applied to aborted fetuses, the newly developed mqPCR for PPV was 33.3% more sensitivities than the previously established diagnostic method. Amino acid analysis of the VP2 sequences of PPV isolates revealed considerable similarity to the highly pathogenic Kresse strain. This study successfully evaluated the prevalence of viral agents causing reproductive failure among swine in Korea, the developed mqPCR and mRT-qPCR methods could be utilized as effective and accurate diagnostic methods for the epidemiological surveillance of ADV, PPV, EMCV, and JEV.
Topics: Animals; Swine; Republic of Korea; Swine Diseases; Multiplex Polymerase Chain Reaction; Real-Time Polymerase Chain Reaction; Prevalence; Female; Reverse Transcriptase Polymerase Chain Reaction; Pregnancy; Parvovirus, Porcine; Abortion, Veterinary; Virus Diseases
PubMed: 38641502
DOI: 10.1016/j.biologicals.2024.101763 -
Journal of Virology May 2024The role of mosquitoes in the transmission of Japanese encephalitis virus (JEV) is crucial, yet the mechanisms of JEV infection in these vectors remain unclear....
The role of mosquitoes in the transmission of Japanese encephalitis virus (JEV) is crucial, yet the mechanisms of JEV infection in these vectors remain unclear. Previous research has indicated that various host factors participate in JEV infection. Herein, we present evidence that mosquito sialic acids enhance JEV infection both and . By treating mosquitoes and C6/36 cells with neuraminidase or lectin, the function of sialic acids is effectively blocked, resulting in significant inhibition of JEV infection. Furthermore, knockdown of the sialic acid biosynthesis genes in mosquitoes also leads to a reduction in JEV infection. Moreover, our research revealed that sialic acids play a role in the attachment of JEV to mosquito cells, but not in its internalization. To further explore the mechanisms underlying the promotion of JEV attachment by sialic acids, we conducted immunoprecipitation experiments to confirm the direct binding of sialic acids to the last α-helix in JEV envelope protein domain III. Overall, our study contributes to a molecular comprehension of the interaction between mosquitoes and JEV and offers potential strategies for preventing the dissemination of flavivirus in natural environments.IMPORTANCEIn this study, we aimed to investigate the impact of glycoconjugate sialic acids on mosquito infection with Japanese encephalitis virus (JEV). Our findings demonstrate that sialic acids play a crucial role in enhancing JEV infection by facilitating the attachment of the virus to the cell membrane. Furthermore, our investigation revealed that sialic acids directly bind to the final α-helix in the JEV envelope protein domain III, thereby accelerating virus adsorption. Collectively, our results highlight the significance of mosquito sialic acids in JEV infection within vectors, contributing to a better understanding of the interaction between mosquitoes and JEV.
Topics: Animals; Mice; Cell Line; Culex; Encephalitis Virus, Japanese; Encephalitis, Japanese; Mosquito Vectors; Neuraminidase; Sialic Acids; Viral Envelope Proteins; Virus Attachment; Virus Internalization
PubMed: 38634598
DOI: 10.1128/jvi.01959-23 -
Vector Borne and Zoonotic Diseases... Apr 2024Widespread transmission of Japanese encephalitis virus (JEV) genotype four (GIV) occurred across mainland Australia in 2022. This resulted in forty-five human cases,...
Widespread transmission of Japanese encephalitis virus (JEV) genotype four (GIV) occurred across mainland Australia in 2022. This resulted in forty-five human cases, including seven deaths, and the identification of JEV infection in over 80 commercial piggeries. We collected mosquitoes which were trapped using CO-baited light traps deployed near piggeries reporting disease or in regions linked to human cases in the Wide Bay region in the state of Queensland. Mosquitoes from four traps yielded JEV RNA by real-time RT-PCR. Pools containing RNA positive mosquitoes were inoculated onto mosquito cell monolayers. A single isolate of JEV was obtained from a pool of mixed mosquito species. Near whole genome sequencing and phylogenetic analysis of the JEV isolate demonstrated its high genomic relatedness with JEV GIV pig sequences sampled from Queensland and the state of New South Wales in 2022. We report the first isolation of JEV GIV from mosquitoes collected in Australia. With only a few JEV GIV isolates available globally, the isolate we report will be essential for future research of JEV host interactions, evolution and disease markers, and development of effective therapies, vaccines, diagnostic assays, and mosquito control strategies.
PubMed: 38621176
DOI: 10.1089/vbz.2024.0017 -
Emerging Microbes & Infections Dec 2024Japanese encephalitis (JE), caused by the Japanese encephalitis virus (JEV), is a highly threatening disease with no specific treatment. Fortunately, the development of...
Japanese encephalitis (JE), caused by the Japanese encephalitis virus (JEV), is a highly threatening disease with no specific treatment. Fortunately, the development of vaccines has enabled effective defense against JE. However, re-emerging genotype V (GV) JEV poses a challenge as current vaccines are genotype III (GIII)-based and provide suboptimal protection. Given the isolation of GV JEVs from Malaysia, China, and the Republic of Korea, there is a concern about the potential for a broader outbreak. Under the hypothesis that a GV-based vaccine is necessary for effective defense against GV JEV, we developed a pentameric recombinant antigen using cholera toxin B as a scaffold and mucosal adjuvant, which was conjugated with the E protein domain III of GV by genetic fusion. This GV-based vaccine antigen induced a more effective immune response in mice against GV JEV isolates compared to GIII-based antigen and efficiently protected animals from lethal challenges. Furthermore, a bivalent vaccine approach, inoculating simultaneously with GIII- and GV-based antigens, showed protective efficacy against both GIII and GV JEVs. This strategy presents a promising avenue for comprehensive protection in regions facing the threat of diverse JEV genotypes, including both prevalent GIII and GI as well as emerging GV strains.
Topics: Encephalitis Virus, Japanese; Animals; Genotype; Encephalitis, Japanese; Japanese Encephalitis Vaccines; Mice; Antibodies, Viral; Humans; Mice, Inbred BALB C; Female; Antigens, Viral; Vaccine Efficacy; Cholera Toxin
PubMed: 38618740
DOI: 10.1080/22221751.2024.2343910 -
Vaccine May 2024Tick-borne encephalitis (TBE) virus infects the central nervous system and may lead to severe neurological complications or death. This study assessed immunogenicity,...
BACKGROUND
Tick-borne encephalitis (TBE) virus infects the central nervous system and may lead to severe neurological complications or death. This study assessed immunogenicity, safety, and tolerability of TBE vaccine in Japanese participants 1 year of age and older.
METHODS
This phase 3, multicenter, single-arm, open-label study was conducted in Japanese adult (≥ 16 years) and pediatric (1-< 16 years) populations. Participants received a single 0.5-mL (adult) or 0.25-mL (pediatric) dose of TBE vaccine at each of 3 visits. The primary endpoint was the proportion of participants who were seropositive (neutralization test [NT] titer ≥ 1:10) 4 weeks after Dose 3. Secondary and exploratory endpoints included NT seropositivity rates 4 weeks after Dose 2, immunoglobulin G (IgG) seropositivity 4 weeks after Doses 2 and 3, NT geometric mean titers (GMTs), IgG geometric mean concentrations (GMCs), and geometric mean fold rises. Primary safety endpoints were frequencies of local reactions, systemic events, adverse events (AEs), and serious AEs.
RESULTS
Among 100 adult and 65 pediatric participants, 99.0 % and 100.0 % completed the study, respectively. NT seropositivity was achieved in 98.0 % adult and 100.0 % pediatric participants after Dose 3; seropositivity after Dose 2 was 93.0 % and 92.3 %, respectively. In both age groups, IgG seropositivity was ≥ 90.0 % and ≥ 96.0 % after Doses 2 and 3, respectively; GMTs and GMCs were highest 4 weeks after Dose 3. Reactogenicity events were generally mild to moderate in severity and short-lived. AEs were reported by 15.0 % (adult) and 43.1 % (pediatric) of participants. No life-threatening AEs, AEs leading to discontinuation, immediate AEs, related AEs, or deaths were reported. No serious AEs were considered related to TBE vaccine.
CONCLUSIONS
TBE vaccine elicited robust immune responses in Japanese participants 1 year of age and older. The 3-dose regimen was safe and well tolerated, and findings were consistent with the known safety profile of this TBE vaccine.
CLINICALTRIALS
gov: NCT04648241.
Topics: Adolescent; Adult; Aged; Child; Child, Preschool; Female; Humans; Infant; Male; Middle Aged; Young Adult; Antibodies, Neutralizing; Antibodies, Viral; East Asian People; Encephalitis Viruses, Tick-Borne; Encephalitis, Tick-Borne; Healthy Volunteers; Immunogenicity, Vaccine; Immunoglobulin G; Japan; Neutralization Tests; Viral Vaccines; Aged, 80 and over
PubMed: 38614954
DOI: 10.1016/j.vaccine.2024.03.071