Viral Encephalitis In Humans Research Articles

Cellular nuclear-localized U2AF2 protein is hijacked by the flavivirus 3’UTR for viral replication complex formation and RNA synthesis

Japanese encephalitis virus (JEV) is a zoonotic pathogen belonging to the Flavivirus genus, causing viral encephalitis in humans and reproductive failure in swine. The 3’ untranslated region (3’UTR) of JEV contains highly conservative secondary structures required for viral translation, RNA synthesis, and pathogenicity. Identification of host factors interacting with JEV 3’UTR is crucial for elucidating the underlying mechanism of flavivirus replication and pathogenesis. In this study, U2 snRNP auxiliary factor 2 (U2AF2) was identified as a novel cellular protein that interacts with the JEV genomic 3’UTR (the SL-I, SL-II, SL-III, and DB region) via its 1 to 148 amino acids. JEV infection or JEV 3’ UTR on its own triggered the nuclear-localized U2AF2 redistributed to the cytoplasm and colocalized with viral replication complex. U2AF2 also interacts with JEV NS3 and NS5 protein, the downregulation of U2AF2 nearly abolished the formation of flavivirus replication vesicles. The production of JEV protein, RNA, and viral titers were all increased by U2AF2 overexpression and decreased by knockdown. U2AF2 also functioned as a pro-viral factor for Zika virus (ZIKV) and West Nile virus (WNV), but not for vesicular stomatitis virus (VSV). Mechanically, U2AF2 facilitated the synthesis of both positive- and negative-strand flavivirus RNA without affecting viral attachment, internalization or release process. Collectively, our work paves the way for developing U2AF2 as a potential flavivirus therapeutic target.

CRISPR-Cas9-Mediated Cytosine Base Editing Screen for the Functional Assessment of CALR Intron Variants in Japanese Encephalitis Virus Replication.

The Japanese encephalitis virus (JEV) is a mosquito-borne flavivirus that causes viral encephalitis in humans, pigs and other mammals across Asia and the Western Pacific. Genetic screening tools such as CRISPR screening, DNA sequencing and RNA interference have greatly improved our understanding of JEV replication and its potential antiviral approaches. However, information on exon and intron mutations associated with JEV replication is still scanty. CRISPR-Cas9-mediated cytosine base editing can efficiently generate C: G-to-T: A conversion in the genome of living cells. One intriguing application of base editing is to screen pivotal variants for gene function that is yet to be achieved in pigs. Here, we illustrate that CRISPR-Cas9-mediated cytosine base editor, known as AncBE4max, can be used for the functional analysis of calreticulin (CALR) variants. We conducted a CRISPR-Cas9-mediated cytosine base editing screen using 457 single guide RNAs (sgRNAs) against all exons and introns of CALR to identify loss-of-function variants involved in JEV replication. We unexpectedly uncovered that two enriched sgRNAs targeted the same site in intron-2 of the CALR gene. We found that mutating four consecutive G bases in the intron-2 of the CALR gene to four A bases significantly inhibited JEV replication. Thus, we established a CRISPR-Cas9-mediated cytosine-base-editing point mutation screening technique in pigs. Our results suggest that CRISPR-mediated base editing is a powerful tool for identifying the antiviral functions of variants in the coding and noncoding regions of the CALR gene.

Detection of disease-associated microglia among various microglia phenotypes induced by West Nile virus infection in mice.

West Nile virus (WNV) has emerged as a significant cause of viral encephalitis in humans and horses. However, the pathogenesis of the West Nile encephalitis remains unclear. Microglia are activated by WNV infection, and the pathogenic involvement of their phenotypes is controversial. In this study, we examined the diversity of microglia phenotypes caused by WNV infection by assessing various microglia markers and identified disease-associated microglia in WNV-infected mouse brain tissue. Cells positive for general microglia markers such as Iba1, P2RY12, or TMEM119 were detected in the control and WNV-infected brain tissue. The morphology of the positive cells in brain tissue infected by WNV was different from that of control brain tissue, indicating that WNV infection induced activation of microglia. The activated microglia were classified into various phenotypes by investigation of specific marker expression. Among the activated microglia, disease-associated microglia that were positive for CD11c and weakly positive for TMEM119 were detected close to the WNV-infected cells. These results indicate that WNV infection induces activation of diverse microglia phenotypes and that disease-associated microglia may be associated with the pathogenicity of WNV infection in the mouse brain.

Recent Population Dynamics of Japanese Encephalitis Virus.

Japanese encephalitis virus (JEV) causes acute viral encephalitis in humans and reproductive disorders in pigs. JEV emerged during the 1870s in Japan, and since that time, JEV has been transmitted exclusively throughout Asia, according to known reporting and sequencing records. A recent JEV outbreak occurred in Australia, affecting commercial piggeries across different temperate southern Australian states, and causing confirmed infections in humans. A total of 47 human cases and 7 deaths were reported. The recent evolving situation of JEV needs to be reported due to its continuous circulation in endemic regions and spread to non-endemics areas. Here, we reconstructed the phylogeny and population dynamics of JEV using recent JEV isolates for the future perception of disease spread. Phylogenetic analysis shows the most recent common ancestor occurred about 2993 years ago (YA) (95% Highest posterior density (HPD), 2433 to 3569). Our results of the Bayesian skyline plot (BSP) demonstrates that JEV demography lacks fluctuations for the last two decades, but it shows that JEV genetic diversity has increased during the last ten years. This indicates the potential JEV replication in the reservoir host, which is helping it to maintain its genetic diversity and to continue its dispersal into non-endemic areas. The continuous spread in Asia and recent detection from Australia further support these findings. Therefore, an enhanced surveillance system is needed along with precautionary measures such as regular vaccination and mosquito control to avoid future JEV outbreaks.

Antiviral Activity of Luteolin against Pseudorabies Virus In Vitro and In Vivo

Pseudorabies virus (PRV) can cause acute swine disease leading to economic losses worldwide and is a potential causative agent of viral encephalitis in humans. Although effective vaccines are available, an increasing number of variants have emerged in China, and identifying effective antiviral agents against PRV to prevent latent infection is essential. In this study, we assessed the antiviral activity of luteolin against PRV in vitro and in vivo. Luteolin was found to significantly inhibit PRV at a noncytotoxic concentration (70 μM), with an IC50 of 26.24 μM and a selectivity index of 5.64. Luteolin inhibited the virus at the replication stage and decreased the expression of viral mRNA and gB protein. Luteolin reduced the apoptosis of PRV-infected cells, improved the survival rate of mice after lethal challenge, reduced the viral loads in the liver, kidney, heart, lung, and brain, reduced brain lesions, and slowed inflammation and oxidation reactions. Our results showed that luteolin has promise as a new alternative antiviral drug for PRV infection.

A Recombinant Genotype I Japanese Encephalitis Virus Expressing a Gaussia Luciferase Gene for Antiviral Drug Screening Assay and Neutralizing Antibodies Detection

Japanese encephalitis virus (JEV) is the major cause of viral encephalitis in humans throughout Asia. In the past twenty years, the emergence of the genotype I (GI) JEV as the dominant genotype in Asian countries has raised a significant threat to public health security. However, no clinically approved drug is available for the specific treatment of JEV infection, and the commercial vaccines derived from the genotype III JEV strains merely provided partial protection against the GI JEV. Thus, an easy-to-perform platform in high-throughput is urgently needed for the antiviral drug screening and assessment of neutralizing antibodies specific against the GI JEV. In this study, we established a reverse genetics system for the GI JEV strain (YZ-1) using a homologous recombination strategy. Using this reverse genetic system, a gaussia luciferase (Gluc) expression cassette was inserted into the JEV genome to generate a reporter virus (rGI-Gluc). The reporter virus exhibited similar growth kinetics to the parental virus and remained genetically stable for at least ten passages in vitro. Of note, the bioluminescence signal strength of Gluc in the culture supernatants was well correlated with the viral progenies determined by viral titration. Taking advantage of this reporter virus, we established Gluc readout-based assays for antiviral drug screening and neutralizing antibody detection against the GI JEV. These Gluc readout-based assays exhibited comparable performance to the assays using an actual virus and are less time consuming and are applicable for a high-throughput format. Taken together, we generated a GI JEV reporter virus expressing a Gluc gene that could be a valuable tool for an antiviral drug screening assay and neutralization assay.

B cells going viral in the CNS: Dynamics, complexities, and functions of B cells responding to viral encephalitis.

A diverse number of DNA and RNA viruses have the potential to invade the central nervous system (CNS), causing inflammation and injury to cells that have a limited capacity for repair and regeneration. While rare, viral encephalitis in humans is often fatal and survivors commonly suffer from permanent neurological sequelae including seizures. Established treatment options are extremely limited, predominantly relying on vaccines, antivirals, or supportive care. Many viral CNS infections are characterized by the presence of antiviral antibodies in the cerebral spinal fluid (CSF), indicating local maintenance of protective antibody secreting cells. However, the mechanisms maintaining these humoral responses are poorly characterized. Furthermore, while both viral and autoimmune encephalitis are associated with the recruitment of diverse B cell subsets to the CNS, their protective and pathogenic roles aside from antibody production are just beginning to be understood. This review will focus on the relevance of B cell responses to viral CNS infections, with an emphasis on the importance of intrathecal immunity and the potential contribution to autoimmunity. Specifically, it will summarize the newest data characterizing B cell activation, differentiation, migration, and localization in clinical samples as well as experimental models of acute and persistent viral encephalitis.

Novel reverse genetics of genotype I and III Japanese encephalitis viruses assembled through transformation associated recombination in yeast: The reporter viruses expressing a green fluorescent protein for the antiviral screening assay

Japanese encephalitis virus (JEV) belongs to a zoonotic flavivirus and is the main cause of viral encephalitis in humans throughout Asia. During the past two decades, both genotypes I (G) and III (GIII) JEVs co-existed in many Asian countries, and the prevalent strains have shifted from GIII to GI. Since all licensed JE vaccines are derived from GIII strains and no specific treatment is available, the development of novel vaccines and specific antiviral drugs against both genotypes is urgently required. To solve the unstable issue of the JEV infectious cDNA clone and establish a reliable antiviral screening assay, we established the yeast artificial chromosome (YAC)-based reverse genetics systems for GI and GIII JEV strains through transformation-associated recombination (TAR) technology in yeast. The YAC-based infectious clones of GI and GIII JEV exhibited high genetic stability both in yeast and E. coli. Using these reverse genetics systems, recombinant EGFP-reporter viruses were generated and remained stable for at least 10 passages in vitro. An image-based antiviral assay for JEV was developed with the EGFP-reporter viruses, and two drugs were identified to have a broad-spectrum inhibitory effect on GI and GIII JEV replication, which provide potential new therapeutic for the treatment of multiple genotypes JEV infection.

Sero-evidence of silent Japanese Encephalitis Virus infection among inhabitants of Ilorin, North-central Nigeria: a call for active surveillance

ABSTRACT Infection by Japanese Encephalitis Virus (JEV) causes viral encephalitis in humans. It is endemic in Asia and western Pacific regions with no reported case in Nigeria so far. This study aimed at detecting evidence of circulation and pattern of exposure of individuals in Ilorin, Nigeria to JEV. A total of 139 febrile patients attending outpatient departments of Sobi specialist hospital, Civil service hospital and University of Ilorin health center participated in the study. About 5 ml of venous blood was collected from each participant and the plasma tested for the presence of anti-JEV IgG antibody using Enzyme Linked Immunosorbent Assay (ELISA) technique. Anti-JEV IgG antibody was detected in 32% (45/139) of the participants. Males were more exposed (37%) than female participants (27.3%). Similarly, participants with travel history outside of the country were more exposed (44.4%) than those without travel history (29.5%). Further analysis on the basis of age, marital and working status showed no statistical association between these variables and anti-JEV positivity (p˃0.05). This study has provided serological evidence of the circulation of JEV among Ilorin inhabitants and therefore calls for active surveillance for the infection in order to forestall any future major outbreak.

Inhibition of Japanese encephalitis virus proliferation by long non-coding RNA SUSAJ1 in PK-15 cells

BackgroundJapanese encephalitis virus is a mosquito-borne neurotropic flavivirus that causes acute viral encephalitis in humans. Pigs are crucial amplifier host of JEV. Recently, increasing evidence has shown that long non-coding RNAs (lncRNAs) play important roles in virus infection.MethodsJEV proliferation was evaluated after overexpression or knockdown of lncRNA-SUSAJ1 using western blotting and reverse-transcription polymerase chain reaction (RT-PCR). C–C chemokine receptor type 1 (CCR1) was found to regulate the expression of lncRNA-SUSAJ1 by inhibitors screen. The expression of lncRNA-SUSAJ1 was detected using RT-PCR after overexpression or knockdown of transcription factor SP1. In addition, the enrichments of transcription factor SP1 on the promoter of lncRNA-SUSAJ1 were analyzed by chromatin immunoprecipitation.ResultsIn this study, we demonstrated that swine lncRNA-SUSAJ1 could suppress JEV proliferation in PK-15 cells. We also found that CCR1 inhibited the expression of lncRNA-SUSAJ1 via the transcription factor SP1. In addition, knockdown of CCR1 could upregulated the expression of SP1 and lncRNA-SUSAJ1, resulting in resistance to JEV proliferation.ConclusionsThese findings illustrate the importance of lncRNAs in virus proliferation, and reveal how this virus regulates lncRNAs in host cells to promote its proliferation.

Cellular microRNA-155 Regulates Virus-Induced Inflammatory Response and Protects against Lethal West Nile Virus Infection.

West Nile virus (WNV) is a flavivirus that has disseminated globally as a significant cause of viral encephalitis in humans. MircoRNA-155 (miR-155) regulates various aspects of innate and adaptive immune responses. We previously reported that WNV infection induces upregulation of miR-155 in mice brains. In the current study, we demonstrate the critical role of miR-155 in restricting the pathogenesis of WNV infection in mice. Compared to wild-type (WT) mice, miR-155 knockout mice exhibited significantly higher morbidity and mortality after infection with either a lethal strain, WNV NY99, or a non-lethal strain, WNV Eg101. Increased mortality in miR-155−/− mice was associated with significantly high WNV burden in the serum and brains. Protein levels of interferon (IFN)-α in the serum and brains were higher in miR-155−/− mice. However, miR-155−/− mice exhibited significantly lower protein levels of anti-viral interleukin (IL)-1β, IL-12, IL-6, IL-15, and GM-CSF despite the high viral load. Primary mouse cells lacking miR-155 were more susceptible to infection with WNV compared to cells derived from WT mice. Besides, overexpression of miR-155 in human neuronal cells modulated anti-viral cytokine response and resulted in significantly lower WNV replication. These data collectively indicate that miR-155 restricts WNV production in mouse and human cells and protects against lethal WNV infection in mice.

Development and application of a monoclonal-antibody-based blocking ELISA for detection of Japanese encephalitis virus NS1 antibodies in swine.

Japanese encephalitis virus (JEV) is a zoonotic pathogen transmitted by Culex mosquitoes and is the leading cause of viral encephalitis in humans. JEV infection of swine, which are the main amplifying hosts for JEV, can cause reproductive failure in sows; in boars it can cause testitis and infertility. The prevalence of JEV in swine is a continuous threat to human health. A practical diagnostic method for monitoring JEV infection in swine herds is essential for control of the disease in both swine and humans. Here, we have identified a high-affinity anti-JEV NS1 monoclonal antibody (mAb) by indirect ELISA and utilized it for the development of a blocking ELISA (bELISA). The optimal NS1 protein coating concentration (2 μg/mL) and mAb working concentration (1 μg/mL) were determined by checkerboard titration. One hundred ten JEV-antibody-negative serum samples were used to establish 34.03% inhibition as the cutoff value for a negative result. By the bELISA, seroconversion in 80% of newly JEV-vaccinated pigs was detected by 7 days post-immunization, while by the commercial envelope-protein-based iELISA, seroconversion was detected in 20% of the newly vaccinated pigs. We found 98.7% agreement between the bELISA and the commercial iELISA when we tested 157 field samples using both methods. From an epidemiological survey of swine serum collected between 2014 and 2016, we found that the average JEV seropositive rate in unvaccinated commodity pigs was 8.1%, and in vaccinated boars and sows, it was 67.6%.

Aerosol and Contact Transmission Following Intranasal Infection of Mice with Japanese Encephalitis Virus.

The Japanese encephalitis virus (JEV), a causative agent of severe viral encephalitis in humans, has a biological cycle fluctuating between transmission in mosquitoes and avian species and amplification in pigs. Contact transmission of JEV was recently shown in pigs in the absence of arthropod vectors. Here, we show JEV transmission between infected and contact mice and further demonstrate that JEV transmission occurs between animals via aerosols, as both viral RNA and infectious JEV were detected in direct contact- and aerosol-exposed contact animals. The results of this study change our understanding of JEV transmission in densely populated regions and may help to explain JEV outbreaks without the presence of arthropod vectors.

Targeting of the Nasal Mucosa by Japanese Encephalitis Virus for Non-Vector-Borne Transmission.

The mosquito-borne Japanese encephalitis virus (JEV) causes severe central nervous system diseases and cycles between Culex mosquitoes and different vertebrates. For JEV and some other flaviviruses, oronasal transmission is described, but the mode of infection is unknown. Using nasal mucosal tissue explants and primary porcine nasal epithelial cells (NEC) at the air-liquid interface (ALI) and macrophages as ex vivo and in vitro models, we determined that the nasal epithelium could represent the route of entry and exit for JEV in pigs. Porcine NEC at the ALI exposed to with JEV resulted in apical and basolateral virus shedding and release of monocyte recruiting chemokines, indicating infection and replication in macrophages. Moreover, macrophages stimulated by alarmins, including interleukin-25, interleukin-33, and thymic stromal lymphopoietin, were more permissive to the JEV infection. Altogether, our data are important to understand the mechanism of non-vector-borne direct transmission of Japanese encephalitis virus in pigs.IMPORTANCE JEV, a main cause of severe viral encephalitis in humans, has a complex ecology composed of a mosquito-waterbird cycle and a cycle involving pigs, which amplifies virus transmission to mosquitoes, leading to increased human cases. JEV can be transmitted between pigs by contact in the absence of arthropod vectors. Moreover, virus or viral RNA is found in oronasal secretions and the nasal epithelium. Using nasal mucosa tissue explants and three-dimensional porcine nasal epithelial cells cultures and macrophages as ex vivo and in vitro models, we determined that the nasal epithelium could be a route of entry as well as exit for the virus. Infection of nasal epithelial cells resulted in apical and basolateral virus shedding and release of monocyte recruiting chemokines and therefore infection and replication in macrophages, which is favored by epithelial-cell-derived cytokines. The results are relevant to understand the mechanism of non-vector-borne direct transmission of JEV.

Increased serum microRNA-29b expression and bad recovery in Japanese encephalitis virus infected patients; A new component to improve the disease recovery

BackgroundJapanese encephalitis virus (JEV) is a neurotropic mosquito-borne Flavivirus, mainly prevalent in Asia. It is the most important causative agent of acute viral encephalitis in humans. Recently, micro RNAs are discovered as a key regulator of inflammatory and immune responses in various diseases including neurological and viral infections. Thus, this study was proposed to check whether changes in cellular miRNA expression due to JE virus infection, can be detected in circulation which would be helpful in diagnosis and treatment. MethodsmiRNAs (miR-29b and miR-146a) were analyzed in the serum of JEV infected patients using quantitative reverse transcription polymerase chain reaction (RT-qPCR). ResultsmiR-146a was found significantly decreased (p = 0.0008) in JEV infected patients as compared to healthy controls whereas miR-29b was significantly increased (p = 0.001) in JEV patients recovered with neurological sequelae when compared to those recovered without sequelae. ConclusionIn conclusion, miRNA can be measured in serum. Studying microRNAs will provide novel information and help us to identify the components that can serve as biomarkers and can lead to new discovery in controlling disease recovery.

Serological and molecular epidemiology of Japanese encephalitis virus infections in swine herds in China, 2006-2012.

Japanese encephalitis virus (JEV) is a mosquito-borne, zoonotic flavivirus causing viral encephalitis in humans and reproductive disorder in swine. JEV is prevalent throughout China in human; however, spatiotemporal analysis of JEV in Chinese swine herds has not been reported previously. Herein, we present serological and molecular epidemiological results and estimates of prevalence of JEV infections among swine herds in various regions of China. The results suggest that JEV infections are widespread and genotype I and III strains co-exist in the same regions. Therefore, there is an urgent need to monitor JEV infection status among swine herds in China.

Screening of FDA-Approved Drugs for Inhibitors of Japanese Encephalitis Virus Infection.

ABSTRACTJapanese encephalitis virus (JEV), an arthropod-borne flavivirus, is a major cause of acute viral encephalitis in humans. No approved drug is available for the specific treatment of JEV infections, and the available vaccines are not effective against all clinical JEV isolates. In the study described here, a high-throughput screening of an FDA-approved drug library for inhibitors of JEV was performed. Five hit drugs that inhibited JEV infection with a selective index of >10 were identified. The antiviral activities of these five hit drugs against other flavivirus, including Zika virus, were also validated. As three of the five hit drugs were calcium inhibitors, additional types of calcium inhibitors that confirmed that calcium is essential for JEV infection, most likely during viral replication, were utilized. Adaptive mutant analysis uncovered that replacement of Q130, located in transmembrane domain 3 of the nonstructural NS4B protein, which is relatively conserved in flaviviruses, with R or K conferred JEV resistance to manidipine, a voltage-gated Ca2+ channel (VGCC) inhibitor, without an apparent loss of the viral growth profile. Furthermore, manidipine was indicated to protect mice against JEV-induced lethality by decreasing the viral load in the brain, while it abrogated the histopathological changes associated with JEV infection. This study provides five antiflavivirus candidates and identifies cytoplasmic calcium to be a novel antiviral target for the treatment of JEV infection. The findings reported here provide therapeutic possibilities for combating infections caused by flaviviruses.IMPORTANCE No approved therapy for the treatment of Japanese encephalitis virus infection is currently available. Repurposing of approved drugs would accelerate the development of a therapeutic stratagem. In this study, we screened a library of FDA-approved drugs and identified five hit drugs, especially calcium inhibitors, exerting antiflavivirus activity that blocked viral replication. The in vivo efficacy and toxicity of manidipine were investigated with a mouse model of JEV infection, and the viral target was identified by generating an adaptive mutant.

Isolation and full-genome sequences of Japanese encephalitis virus genotype I strains from Cambodian human patients, mosquitoes and pigs.

Japanese encephalitis remains the most important cause of viral encephalitis in humans in several southeast Asian countries, including Cambodia, causing at least 65 000 cases of encephalitis per year. This vector-borne viral zoonosis - caused by Japanese encephalitis virus (JEV) - is considered to be a rural disease and is transmitted by mosquitoes, with birds and pigs being the natural reservoirs, while humans are accidental hosts. In this study we report the first two JEV isolations in Cambodia from human encephalitis cases from two studies on the aetiology of central nervous system disease, conducted at the two major paediatric hospitals in the country. We also report JEV isolation from Culextritaeniorhynchus mosquitoes and from pig samples collected in two farms, located in peri-urban and rural areas. Out of 11 reverse-transcription polymerase chain reaction-positive original samples, we generated full-genome sequences from 5 JEV isolates. Five additional partial sequences of the JEV NS3 gene from viruses detected in five pigs and one complete coding sequence of the envelope gene of a strain identified in a pig were generated. Phylogenetic analyses revealed that JEV detected in Cambodia belonged to genotype I and clustered in two clades: genotype I-a, mainly comprising strains from Thailand, and genotype I-b, comprising strains from Vietnam that dispersed northwards to China. Finally, in this study, we provide proof that the sequenced JEV strains circulate between pigs, Culex tritaeniorhynchus and humans in the Phnom Penh vicinity.

MiR-124 attenuates Japanese encephalitis virus replication by targeting DNM2

BackgroundJapanese encephalitis virus (JEV) is a mosquito-borne flavivirus that causes acute viral encephalitis in humans. Pigs are important amplifier hosts of JEV. Emerging evidence indicates that host microRNAs (miRNAs) play key roles in modulating viral infection and pathogenesis. However, mechanistic studies delineating the roles of miRNAs in regulating host-JEV interactions remain scarce.ResultsIn this study, we demonstrated that miR-124 inhibited JEV replication in porcine kidney epithelial PK15 cells. Furthermore, using bioinformatics tools, we identified dynamin2 (DNM2), a GTPase responsible for vesicle scission, as a target of miR-124. Small interfering RNA (siRNA) depletion studies inicated that dynamin2 was required for efficient JEV replication. We also demonstrated that upregulation of miR-124 expression corresponded to decreased expression of its target, DNM2, in the JEV-infected PK15 cells.ConclusionsOverall, these results suggest the importance of miR-124 in modulating JEV replication and provide a scientific basis for using cellular miRNAs in anti-JEV therapies.Electronic supplementary materialThe online version of this article (doi:10.1186/s12985-016-0562-y) contains supplementary material, which is available to authorized users.

The effect of cyclin-dependent kinases inhibitor treatment on experimental herpes simplex encephalitis mice

Herpes simplex encephalitis(HSE) is the most common and serious viral encephalitis in humans. There is a lack of effective medication to date for HSE. A better understanding of the mediators of tissue damage is essential for finding new targets for therapeutic intervention. In this project, we explored the effect of cyclin-dependent kinases inhibitor olomoucine treatment on experimental HSE mice. The following results were obtained: (1) olomoucine increased survival in HSE mice; (2) olomoucine inhibited microglial activation and reduced HSV-1-induced cytokines release; (3) olomoucine prevented neural cells apoptosis and attenuated brain tissue pathological changes following HSV-1 infection; (4) olomoucine reduced brain edema and improved neurological function in HSE. Overall, olomoucine can induce a blunted inflammatory response, maintain the blood vessel wall intact, improve neurological function and increase survival in HSE mice.