Analysis of the Zika and Japanese Encephalitis Virus NS5 Interactomes.

Mosquito-borne flaviviruses, including dengue virus (DENV), Japanese encephalitis virus (JEV), and Zika virus (ZIKV), are major human pathogens. Among the flaviviral proteins, the nonstructural protein 5 (NS5) is the largest, most conserved, and major enzymatic component of the viral replication complex. Disruption of the common key NS5-host protein-protein interactions critical for viral replication could aid in the development of broad-spectrum antiflaviviral therapeutics. Hundreds of NS5 interactors have been identified, but these are mostly DENV-NS5 interactors. To this end, we sought to investigate the JEV- and ZIKV-NS5 interactomes using EGFP immunoprecipitation with label-free quantitative mass spectrometry analysis. We report here a total of 137 NS5 interactors with a significant enrichment of spliceosomal and spliceosomal-associated proteins. The transcription complex Paf1C and phosphatase 6 were identified as common NS5-associated complexes. PAF1 was shown to play opposite roles in JEV and ZIKV infections. Additionally, we validated several NS5 targets and proposed their possible roles in infection. These include lipid-shuttling proteins OSBPL9 and OSBPL11, component of RNAP3 transcription factor TFIIIC, minichromosome maintenance, and cochaperone PAQosome. Mining this data set, our study expands the current interaction landscape of NS5 and uncovers several NS5 targets that are new to flavivirus biology.

Cytokines Interleukin 4 (IL-4) and Interleukin 10 (IL-10) Gene Polymorphisms as Potential Host Susceptibility Factors in Virus-Induced Encephalitis.

BACKGROUND This study aimed to analyze and explore the relationship between the cytokines IL-4 and IL-10 in relation to gene polymorphism and their respective effects on the susceptibility to virus-induced encephalitis. MATERIAL AND METHODS From January 2012 to June 2013, 112 patients with virus-induced encephalitis (the case group and 109 healthy individuals (the control group) were recruited for the purposes of this study. The functional variations that IL-4 and IL-10 genes exhibit were detected through the use of a function analysis and selection tool for single-nucleotide polymorphisms (FASTSNP). The genotypes of IL-4 were rs2227283 and IL-4 rs2227288, and the genotypes of IL-10 were rs1800871 and IL-10 rs1800872. These genotypes were respectively assessed using direct sequencing. RESULTS IL-4 rs2227283 and IL-10 rs1800871 have no correlation in with risk of virus-induced encephalitis (both P>0.05) GA and AA genotypes were related to IL-4 rs2227288 and GT, while TT and GT + TT genotypes were related to IL-10 rs1800872. These were highlighted as being risk factors in virus-induced encephalitis (all P<0.05). However, the duration of fever, white blood cell (WBC) count, C-reactive protein (CRP), neutrophils, and lymphocytes and monocytes of virus-induced encephalitis patients with IL-4 rs2227288 and IL-10 rs1800872 all displayed significant differences (all P<0.05). Frequencies of GAGT and CAGT haplotypes were evaluated and deemed to be of statistical significance and subsequently were highlighted as being risk factors in virus-induced encephalitis (all P<0.05). CONCLUSIONS IL-4 rs2227288 and IL-10 rs1800872 may contribute to an increased risk for virus-induced encephalitis. Through use of direct sequencing, we showed that genotypes of IL-4 rs2227288 and IL-10 rs1800872 may have particular host susceptibility to virus-induced encephalitis.

CD11c(hi) Dendritic Cells Regulate Ly-6C(hi) Monocyte Differentiation to Preserve Immune-privileged CNS in Lethal Neuroinflammation.

Although the roles of dendritic cells (DCs) in adaptive defense have been defined well, the contribution of DCs to T cell-independent innate defense and subsequent neuroimmunopathology in immune-privileged CNS upon infection with neurotropic viruses has not been completely defined. Notably, DC roles in regulating innate CD11b(+)Ly-6C(hi) monocyte functions during neuroinflammation have not yet been addressed. Using selective ablation of CD11c(hi)PDCA-1(int/lo) DCs without alteration in CD11c(int)PDCA-1(hi) plasmacytoid DC number, we found that CD11c(hi) DCs are essential to control neuroinflammation caused by infection with neurotropic Japanese encephalitis virus, through early and increased infiltration of CD11b(+)Ly-6C(hi) monocytes and higher expression of CC chemokines. More interestingly, selective CD11c(hi) DC ablation provided altered differentiation and function of infiltrated CD11b(+)Ly-6C(hi) monocytes in the CNS through Flt3-L and GM-CSF, which was closely associated with severely enhanced neuroinflammation. Furthermore, CD11b(+)Ly-6C(hi) monocytes generated in CD11c(hi) DC-ablated environment had a deleterious rather than protective role during neuroinflammation, and were more quickly recruited into inflamed CNS, depending on CCR2, thereby exacerbating neuroinflammation via enhanced supply of virus from the periphery. Therefore, our data demonstrate that CD11c(hi) DCs provide a critical and unexpected role to preserve the immune-privileged CNS in lethal neuroinflammation via regulating the differentiation, function, and trafficking of CD11b(+)Ly-6C(hi) monocytes.

Arboviral encephalitis and RNAi treatment.

Encephalitis refers to an acute, usually diffuse, inflammatory process affecting the brain. The clinical hallmark of acute encephalitis is the triad of fever, headache, and altered mental status. The most common and important cause of encephalitis is the infection by a virus although other organisms can cause the disease. This article is a general overview of the most common viral encephalitides, divided into two families, Flavivirus and Alphavirus, and provides details about virus and RNA interference. More detailed descriptions of each viral family are provided below.

Genetically determined resistance to flavivirus infection in wild Mus musculus domesticus and other taxonomic groups in the genus Mus.

Inherited resistance to flaviviruses in laboratory mice is a rare trait conferred by an autosomal dominant gene (Flvr). To provide information on genetic resistance to flaviviruses in wild mice, we analysed (i) wild M. m. domesticus trapped in Australia, and (ii) mice representing other species and subspecies in the genus Mus. Mice were screened for resistance relative to C3H/HeJ mice by intracerebral challenge with Murray Valley encephalitis virus or yellow fever virus, and breeding studies were undertaken to identify inherited resistance factors. Widespread flavivirus resistance was demonstrated in Australian M. m. domesticus. A single, autosomal dominant Flvr-like gene appeared to be primarily responsible, but there was some evidence for additional inherited resistance factors. Flavivirus resistance was also identified in other taxonomic groups, and a genetic basis for this resistance was demonstrated in M. m. musculus (Skive), M. spretus, and M. spicilegus. Interestingly, M. m. musculus (CZI-O) were more susceptible than C3H/HeJ mice. Our findings show that genetic resistance to flaviviruses is common in divergent taxonomic groups in the genus Mus, suggesting that the trait has an ancient evolutionary origin, but whether flavivirus resistance genes have an anti-viral role or serve some other function is unknown.

Human and viral gene detection in routine paraffin embedded tissue by in situ hybridisation with biotinylated probes: viral localisation in herpes encephalitis.

A simple reproducible protocol for detecting multiple copy human genes and viral DNA in routine formalin fixed paraffin embedded tonsil and brain, by in situ hybridisation with biotinylated probes, is described. The protocol consists of digestion of formalin fixed paraffin sections, with 0.4% pepsin in 0.01 M hydrochloric acid for one hour at 37 degrees C, followed by hybridisation with biotinylated probes. The biotinylated probes used for establishing the conditions for in situ localisation of DNA were total placental DNA (TG1), pHY 2.1 (a Y chromosome probe), and herpes simplex virus I and II. In human male tonsil TG1 labelled all nuclei and pHY 2.1 reacted only with nuclear Y bodies. In herpes encephalitis the virus was detected in some glial cells and neurones.

Para-infectious encephalopathies in childhood. EEG-aspects and familial occurrence.

The authors report on infectious-allergic encephalopathy, occurring in a nine-year old boy. The clinical picture is that of a generalized myoclonic epileptic state. The EEG shows bilaterally occurring stereotyped rhythmic complexes with a short interval. The child recovered completely. The diagnostic value of periodically occurring EEG-features and the familial occurrence of para-infectious encephalopathies are discussed.