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Background Japanese encephalitis (JE) is a serious infection and disease in southern and eastern Asia. The design and development of safer and more efficacious vaccines against Japanese encephalitis virus (JEV) is a high-priority target in the world. Recently, baculovirus pseudotyped with vesicular stomatitis virus glycoprotein (VSVG) was described as an attractive gene delivery vehicle in mammalian cells and a potential vector for vaccine development. In the present study, we constructed a recombinant pseudotype baculovirus encoding the JEV envelope (E) protein and demonstrated that it could elicit high protective immunity in mice. Methods Recombinant pseudotype baculovirus (BV-G-E) was generated by inserting JEV E gene fragment into pFastBac-VSV/G vector. BALB/c mice were immunized with BV-G-E and challenged with JEV wild-type strain. The neutralization antibody, interferon (IFN)-γ expression and release, and survival rate were analysed and compared with the group of immunized with inactivated vaccine and DNA vaccine (pc-E) encoding the same gene of JEV. Results We demonstrated that intramuscular injections of BV-G-E at various doses into mice produced higher levels of JEV-specific neutralizing antibodies, IFN-γ and better protective efficacy against a lethal challenge with JEV than that of pc-E. Furthermore, BV-G-E could elicit a higher level of cellular immunity response and provide equal protective efficacy against JEV challenge compared to inactivated vaccine. Conclusions Our data demonstrate that BV-G-E elicited higher levels of protective immunity compared to DNA vaccine and that pseudotype baculovirus-mediated gene delivery can be utilized as an alternative strategy to develop new generations of vaccines against JEV infection. Copyright © 2008 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Flaviviruses, such as Zika virus (ZIKV), Japanese encephalitis virus (JEV), Dengue virus (DENV), and West Nile virus (WNV), are important arthropod-borne pathogens that present an immense global health problem. Their unpredictable disease severity, unusual clinical features, and severe neurological manifestations underscore an urgent need for antiviral interventions. Furin, a host proprotein convertase, is a key contender in processing flavivirus prM protein to M protein, turning the inert virus to an infectious particle. For this reason, the current study was planned to evaluate the antiviral activity of decanoyl-Arg-Val-Lys-Arg-chloromethylketone, a specific furin inhibitor, against flaviviruses, including ZIKV and JEV. Analysis of viral proteins revealed a significant increase in the prM/E index of ZIKV or JEV in dec-RVKR-cmk-treated Vero cells compared to DMSO-treated control cells, indicating dec-RVKR-cmk inhibits prM cleavage. Plaque assay, qRT-PCR, and immunofluorescence assay revealed a strong antiviral activity of dec-RVKR-cmk against ZIKV and JEV in terms of the reduction in virus progeny titer and in viral RNA and protein production in both mammalian cells and mosquito cells. Time-of-drug addition assay revealed that the maximum reduction of virus titer was observed in post-infection treatment. Furthermore, our results showed that dec-RVKR-cmk exerts its inhibitory action on the virus release and next round infectivity but not on viral RNA replication. Taken together, our study highlights an interesting antiviral activity of dec-RVKR-cmk against flaviviruses. [ABSTRACT FROM AUTHOR]

The cDNA fragment of JEV prME gene was cloned into the baculovirus shuttle vector (bacmid) to construct a recombinant baculovirus vector, defined as AcBac-prME. Then the recombinant baculovirus Ac-prME was obtained by transfecting Sf9 cells with AcBac-prME. Western blot analysis and immunofluorescence results indicated that both prM and E proteins were efficiently expressed in Sf9 cells. Electron microscopy suggested that prME was assembled into JEV-VLPs. To further evaluate the potential of JEV-VLPs as vaccine, the mice were immunized with JEV-VLPs and then challenged with lethal JEV. The results of mice survival and pathological changes demonstrated that the JEV-VLPs performed complete protection against JEV-P3 strain and relieved pathological changes in the mice brain significant. This study suggest that JEV-VLPs would be a potential vaccine for Japanese encephalitis virus.

Ubiquitination, also denoted ubiquitylation, is a posttranslational modification that has been implicated in the regulation of both innate and adaptive immune responses. Ubiquitination plays crucial roles in innate immune signaling by ensuring the proper orchestration of several signaling mediators that constitute a functional immune response. Herein, we briefly summarize the latest discoveries concerning the molecular ubiquitination-related machinery that senses, assembles, and disassembles innate immune signaling mediators.

Unlabelled: Dendritic cells (DCs) are the most efficient antigen-presenting cells, playing a key role in the adaptive immune responses to viral infections. Our studies demonstrate that wild-type (wt) rabies virus (RABV) does not activate DCs. Adoptive transfer of DCs primed with wt RABV did not activate DCs, stimulate virus neutralizing antibodies (VNA), or protect recipients against challenge. However, adoptive transfer of DCs primed with laboratory-attenuated RABV resulted in DC activation, production of VNA, and protection against challenge. In vitro studies with recombinant RABV (laboratory-attenuated RABV expressing the glycoprotein or the phosphoprotein from wt RABV) demonstrate that DC activation is dependent on the glycoprotein and involves the IPS-1 pathway. Furthermore, binding to and entry into DCs by wt RABV is severely blocked, and the copy number of de novo-synthesized leader RNA was two logs lower in DCs infected with the wt than in DCs treated with laboratory-attenuated RABV. However, transient transfection of DCs with synthesized leader RNA from either wt or attenuated RABV is capable of activating DCs in a dose-dependent manner. Thus, the inability of wt RABV to activate DCs correlates with its low level of the de novo-synthesized leader RNA., Importance: Rabies remains a public health threat, with more than 55,000 fatalities each year around the world. Since DCs play a key role in the adaptive immune responses to viral infections, we investigated the ability of rabies virus (RABV) to activate DCs. It was found that the adoptive transfer of DCs primed with wt RABV did not activate DCs, stimulate VNA, or protect mice against lethal challenge. However, laboratory-attenuated RABV mediates the activation of DCs via the IPS-1 pathway and is glycoprotein dependent. We further show that wt RABV evades DC-mediated immune activation by inefficient binding/entry into DCs and as a result of a reduced level of de novo-synthesized leader RNA. These findings may have important implications in the development of efficient rabies vaccines., (Copyright © 2015, American Society for Microbiology. All Rights Reserved.)