Chandipura Virus Research Articles

Cyclophilin A: a possible host modulator in Chandipura virus infection.

Chandipura virus (CHPV), belonging to the genus Vesiculovirus of the family Rhabdoviridae, has been identified as one of the causes of pediatric encephalitis in India. Currently, neither vaccines nor therapeutic drugs are available against this agent. Considering that the disease progresses very fast with a high mortality rate, working towards the development of potential therapeutics against it will have a public health impact. Although the use of viral inhibitors as antiviral agents is the most common way to curb virus replication, the mutation-prone nature of viruses results in the development of resistance to antiviral agents. The recent development of proteomic platforms for analysis of purified viral agents has allowed certain upregulated host proteins that are involved in the morphogenesis and replication of viruses to be identified. Thus, the alternative approach of inhibition of host proteins involved in the regulation of virus replication could be explored for their therapeutic effectiveness. In the current study, we have evaluated the effect of inhibition of cyclophilin A (CypA), an immunophilin with peptidyl-prolyl cis/trans-isomerase activity, on the replication of CHPV. Treatment with cyclosporin A, used in vitro for the inhibition of CypA, resulted in a 3-log reduction in CHPV titer and an undetectable level of CypA in comparison to an untreated control. An in silico analysis of the interaction of the CHPV nucleoprotein with the human CypA protein showed stable interaction in molecular docking and molecular dynamics simulations. Overall, the results of this study suggest a possible role of CypA in facilitating CHPV replication, thus making it one of the potential host factors to be explored in future antiviral studies.Supplementary informationThe online version contains supplementary material available at 10.1007/s00705-021-05237-1.

Chandipura virus dysregulates the expression of hsa-miR-21-5p to activate NF-\u03baB in human microglial cells

BackgroundChandipura virus (CHPV) is a negative single-stranded RNA virus of the Rhabdoviridae family. CHPV infection has been reported in Central and Western India. CHPV causes acute encephalitis with a case fatality rate of 70 % and mostly affects children below 15 years of age. CHPV infection in brain leads to neuronal apoptosis and activation of the microglial cells. The microRNAs (miRNAs) are small endogenous non-coding RNA that regulate the gene expression. Viral infections perturb the expression pattern of cellular miRNAs, which may in turn affect the expression pattern of downstream genes. This study aims to investigate hsa-miR-21-5p mediated regulation of PTEN, AKT, NF-ĸBp65, IL-6, TNF-α, and IL-1β, in human microglial cells during CHPV infection.MethodsTo understand the role of hsa-miR-21-5p in CHPV infection, the human microglial cells were infected with CHPV (MOI-0.1). Real-time PCR, western blotting, Luciferase assay, over-expression and knockdown techniques were used to understand the role of hsa-miR-21-5p in the regulation of PTEN, AKT and, NF-ĸBp65, IL-6, TNF-α, and IL-1β in this study.ResultsThe hsa-miR-21-5p was found to be upregulated during CHPV infection in human microglial cells. This led to the downregulation of PTEN which promoted the phosphorylation of AKT and NF-ĸBp65. Over-expression of hsa-miR-21-5p led to the decreased expression of PTEN and promoted further phosphorylation of AKT and NF-ĸBp65 in human microglial cells. However, the inhibition of hsa-miR-21-5p using hsa-miR-21-5p inhibitor restored the expression.ConclusionsThis study supports the role of hsa-miR-21-5p in the regulation of pro-inflammatory genes in CHPV infected human microglial cells.

Analysis of the dark proteome of Chandipura virus reveals maximum propensity for intrinsic disorder in phosphoprotein

Chandipura virus (CHPV, a member of the Rhabdoviridae family) is an emerging pathogen that causes rapidly progressing influenza-like illness and acute encephalitis often leading to coma and death of the human host. Given several CHPV outbreaks in Indian sub-continent, recurring sporadic cases, neurological manifestation, and high mortality rate of this infection, CHPV is gaining global attention. The ‘dark proteome’ includes the whole proteome with special emphasis on intrinsically disordered proteins (IDP) and IDP regions (IDPR), which are proteins or protein regions that lack unique (or ordered) three-dimensional structures within the cellular milieu. These proteins/regions, however, play a number of vital roles in various biological processes, such as cell cycle regulation, control of signaling pathways, etc. and, therefore, are implicated in many human diseases. IDPs and IPPRs are also abundantly found in many viral proteins enabling their multifunctional roles in the viral life cycles and their capability to highjack various host systems. The unknown abundance of IDP and IDPR in CHPV, therefore, prompted us to analyze the dark proteome of this virus. Our analysis revealed a varying degree of disorder in all five CHPV proteins, with the maximum level of intrinsic disorder propensity being found in Phosphoprotein (P). We have also shown the flexibility of P protein using extensive molecular dynamics simulations up to 500 ns (ns). Furthermore, our analysis also showed the abundant presence of the disorder-based binding regions (also known as molecular recognition features, MoRFs) in CHPV proteins. The identification of IDPs/IDPRs in CHPV proteins suggests that their disordered regions may function as potential interacting domains and may also serve as novel targets for disorder-based drug designs.

N-protein-RNA interaction is a drug target in a negative strand RNA virus

The negative strand RNA virus family contains many human pathogens. Finding new antiviral drug targets against this class of human pathogens is one of the significant healthcare needs. Nucleocapsid proteins of negative strand RNA viruses wrap the viral genomic RNA and play essential roles in gene transcription and genome replication. Chandipura virus, a member of the Rhabdoviridae family, has a negative strand RNA genome. In addition to wrapping the genomic RNA, its nucleocapsid protein interacts with the positive strand leader RNA and plays a vital role in the virus life-cycle. We have designed a peptide, based on prior knowledge and demonstrated that the peptide is capable of binding specifically to the positive strand leader RNA. When the peptide was transported inside the cell, it inhibited viral growth with IC50 values in the low micromolar range. Given the widespread occurrence of leader RNAs in negative strand RNA viruses and its interaction with the nucleocapsid protein, it is likely that this interaction could be a valid drug target for other negative strand RNA viruses.

Obituary

Obituary

Overriding the complement barrier: The ups and downs in the Rhabdovirus's battle for survival

Background: Rhabdoviruses are non-segmented, negative sense RNA viruses and are potent pathogens causing infection in humans and animals, e.g., rabies virus, Chandipura virus. Vesicular stomatitis virus (VSV) is a prototypic rhabdovirus. The complement system is a potent barrier against an array of pathogens including VSV. Complement activation by VSV involves the classical pathway resulting in virus neutralization. However, VSV signature responsible for complement activation is unknown. Being the only surface glycoprotein, we investigated the role of G protein in complement activation. We also investigated the mechanism of modulation of human complement by VSV which included the recruitment of the host membrane associated regulators of complement activation (RCA). Methods and materials: Cell surface activation of complement by VSV was carried out by infecting Vero cells with wt-VSV or transfecting with VSV-G plasmid (pCAGGS-G) and treating with normal human serum followed by immunofluorescence microscopy and flow cytometry. G protein from the virion and infected cells was purified by affinity-chromatography and validated using silver staining. Complement binding and activation by the purified protein was tested using multiple biochemical approaches. The specificity of RCA modulation by VSV was assessed by performing time course experiments in VSV infected HeLa cells followed by western blotting and RT-PCR. RCA incorporation and their relative function in virion budding out at specific time points were validated by cofactor and decay accelerating activity. Results: Immunofluorescence and flow cytometric analysis of VSV infected and G transfected cells showed significant deposition of active complement proteins C3b and C4b suggesting a role for the G protein. Interaction of VSV-G with C3/C4 components of complement was further confirmed by ELISA. Fluid phase activation assays with purified G confirmed the role of G in binding to and activating complement proteins, further supported by SPR studies. Western blotting, FACS experiments with infected HeLa cells showed preference of CD55 over CD46 in complement modulation by VSV. The inactivation of C3b and decay acceleration of C3 convertase by the virion associated CD46 and CD55 conferred VSV with resistance against complement. Conclusion: The VSV-G protein plays a significant role in complement activation pathways. Acknowledgement: Effective modulation of complement neutralization is supported by the RCA CD55.

Chandipura virus evades human complement by recruiting host complement regulatory proteins

Chandipura virus evades human complement by recruiting host complement regulatory proteins

Design of a multi-epitope peptide vaccine candidate against chandipura virus: an immuno-informatics study

Chandipura virus (CHPV) is an emerging pathogen responsible for acute encephalitic syndrome (AES) in pediatric population in India. Several outbreaks of CHPV have been reported from different states of India since the year 2003. At present there is no vaccine or therapeutic measures available to curtail the disease. In this study, we have identified both T-cell and B-cell epitopes of different antigenic proteins of CHPV like Nucleoprotein (N), Phosphoprotein (P) and Matrix protein (M) along with the immuno-dominant glycoprotein (G) and conducted in silico characterization for the same. The idea is to design a multi-epitope peptide construct using the epitopes, which were found to be non-toxic, non-allergenic and possessing high immunogenicity. The final multi-epitope construct named as: MEC-CHPV, comprised of β-defensin adjuvant at N-terminal for enhancement of immunogenicity followed by fourteen B-cell epitopes, four Helper T-cell epitopes and six Cytotoxic T-cell epitopes. The characterization of designed construct was carried out in terms of physicochemical parameters, antigenicity and allergenicity. The 3D structure prediction was performed. Molecular docking and molecular-dynamics simulation of MEC-CHPV with Toll like receptors (TLR-3 and TLR-8) showed stable interactions. In silico cloning of MEC-CHPV in pET30a(+) expression vector was also conducted using codon optimization. The in silico immune-simulation indicated a typical immune response against MEC-CHPV when used as a potential vaccine. This study provides a cost-effective and time-saving way to design a peptide vaccine candidate against CHPV using immuno-informatics approach. Development of the MEC-CHPV construct may pave the way for future laboratory experiments. Communicated by Ramaswamy H. Sarma

Ribavirin inhibits Chandipura virus replication in Vero cells.

Chandipura virus (CHPV) is an emerging tropical pathogen in India. The virus has been reported to be associated with an acute encephalitis syndrome in young children with a case fatality rate of 55% to 75%. Clinical management with symptomatic treatment is the only option available to treat infected patients. No vaccines are available for prophylaxis. In light of the prophylactic limitations, antiviral therapy would play an important role in control of CHPV infection. In the present study, ribavirin (RBV), an antiviral drug widely accepted for human use and having an antiviral effect on many RNA and DNA viruses, was tested against the CHPV. A screening assay that scores for the virus-mediated plaque formation in the cultured Vero cells was used. RBV exhibited 50% inhibitory concentration (IC50 ) at 89.84 ± 1.8 µM. The drug was very effective when the cells were treated either within an hour postinfection or 4 to 6 hours before infection. The plaque morphology was different in RBV treated cells; the plaques were smaller in size as compared with the plaques in the virus infected cells. The study reports the antiviral activity of RBV against CHPV, and hence, suggests the possible utility of RBV in CHPV infected patients to mitigate the disease. A further clinical trial is needed before introducing the drug for human use against CHPV infection.

Modified Alphavirus-Vesiculovirus Hybrid Vaccine Vectors for Homologous Prime-Boost Immunotherapy of Chronic Hepatitis B.

Virus-like vesicles (VLV) are hybrid vectors based on an evolved Semliki Forest virus (SFV) RNA replicon and the envelope glycoprotein (G) from vesicular stomatitis virus (VSV). Previously, we showed that VLV can be used to express protein antigens and generate protective antigen-specific CD8+ T cells. This report describes VLV vectors designed for enhanced protein expression and immunogenicity. Expressing hepatitis B virus (HBV) middle S antigen (MHBs) from VLV using a dual subgenomic promoter significantly increased MHBs-specific CD8+ T cell and antibody production in mice. Furthermore, envelope glycoprotein switch from VSV Indiana to the glycoprotein of Chandipura virus enabled prime-boost immunization and further increased responses to MHBs. Therapeutic efficacy was evaluated in a mouse model of chronic HBV infection initiated by HBV delivery with adeno-associated virus. Mice with lower or intermediate HBV antigen levels demonstrated a significant and sustained reduction of HBV replication following VLV prime-boost immunization. However, mice with higher HBV antigen levels showed no changes in HBV replication, emphasizing the importance of HBV antigenemia for implementing immunotherapies. This report highlights the potential of VLV dual promoter vectors to induce effective antigen-specific immune responses and informs the further development and evaluation of hybrid viral vaccine platforms for preventative and therapeutic purposes.

Role of cell surface vimentin in Chandipura virus replication in Neuro-2a cells

The neurotropic behavior of Chandipura virus (CHPV) is partly understood in experimental animals. Under in vitro conditions, neuronal cells could be a useful tool to study the CHPV interaction with neuronal proteins. The information gathered from such studies will help to design the new therapeutics for CHPV infection. This study identified the surface vimentin protein involved in adsorption of CHPV on Neuro-2a cell line (mouse neuroblastoma cells). The decrease in CHPV infectivity to Neuro-2a cells was observed in the presence of recombinant vimentin or anti-vimentin antibody. Vimentin mRNA expression remains unaltered in CHPV infected Neuro-2a cells. Furthermore, in silico analysis predicted the residues in vimentin and CHPV glycoprotein (G); probably involved in cell-virus interactions. Overall, we conclude that surface vimentin in Neuro-2a cells interact with CHPV and facilitate the binding of CHPV to the cells; it could be acting as a co-receptor for the CHPV. Further investigation is necessary to confirm the exact role of vimentin in CHPV infection in neuronal cells.

Human Tibroviruses: Commensals or Lethal Pathogens?

Rhabdoviruses are a large and ecologically diverse family of negative-sense RNA viruses (Mononegavirales: Rhabdoviridae). These viruses are capable of infecting an unexpectedly wide variety of plants, vertebrates, and invertebrates distributed over all human-inhabited continents. However, only a few rhabdoviruses are known to infect humans: a ledantevirus (Le Dantec virus), several lyssaviruses (in particular, rabies virus), and several vesiculoviruses (e.g., Chandipura virus, vesicular stomatitis Indiana virus). Recently, several novel rhabdoviruses have been discovered in the blood of both healthy and severely ill individuals living in Central and Western Africa. These viruses—Bas-Congo virus, Ekpoma virus 1, and Ekpoma virus 2—are members of the little-understood rhabdoviral genus Tibrovirus. Other than the basic genomic architecture, tibroviruses bear little resemblance to well-studied rhabdoviruses such as rabies virus and vesicular stomatitis Indiana virus. These three human tibroviruses are quite divergent from each other, and each of them clusters closely with tibroviruses currently known only from biting midges or healthy cattle. Seroprevalence studies suggest that human tibrovirus infections may be common but are almost entirely unrecognized. The pathogenic potential of this diverse group of viruses remains unknown. Although certain tibroviruses may be benign and well-adapted to humans, others could be newly emerging and produce serious disease. Here, we review the current knowledge of tibroviruses and argue that assessing their impact on human health should be an urgent priority.

Determination of Etiology and Epidemiology of Viral Central Nervous System Infections by Quantitative Real-Time Polymerase Chain Reaction in Central India Population.

Viral infections of the central nervous system (CNS) are the most common cause of hospital admission in worldwide and remain a challenging disease for diagnosis and treatment. The most common infectious agents associated with viral CNS infections are cytomegalovirus (CMV), Epstein-Barr virus (EBV), varicella zoster virus (VZV), Japanese encephalitis virus (JEV), Dengue virus (DENV),West Nile virus(WNV), and Chandipura virus(CHPV). The aim of the present work was to find the etiology of CNS viral infection in the Central India population by transcriptase PCR (RT-PCR) comparing real-time polymerase chain reaction (PCR) method [one-step and two-step reverse transcriptase (RT-PCR)] in cerebrospinal fluid (CSF) and blood samples of CNS viral infections patients. One-step and two-step real-time PCR assays were evaluated in CSF and parallel blood samples from patients with viral CNS infections for detection of DNA and RNA viruses. A comparative analysis was also done between gDNA, gRNA, cDNA, and plasmid-based real-time PCR methods for an efficient quantitation of viral particles in clinical samples for determination of viral etiology. On evaluation of 150 CSF and 50 parallel blood samples from suspected cases of viral CNS infections, a viral etiology was confirmed in 21 (14%) cases, including 3% for EBV, 1% of CMV, and 5% for VZV and JEV. The one-step RT-PCR has a higher detection limit for detection and quantitation of viral RNA in comparison to two-step RT-PCR. Our result reveals that VZV and JEV are the most usual cases of CNS viral infection in hospitalized patients in the Central India population and one-step RT-PCR shows higher viral load detection limits for quantitation of viral genome and more sensitivity in comparison to two-step RT-PCR.

Alternative pathway of complement activation has a beneficial role against Chandipura virus infection.

The complement system is a critical component of both innate and adaptive immune responses. It has both protective and pathogenic roles in viral infections. There are no studies regarding the role of complement system in Chandipura virus (CHPV) infection. The current study has investigated the role of complement pathways in the in vitro neutralization of CHPV in Vero E6 cells. Using normal human serum (NHS), heat-inactivated serum (HIS), human serum deficient of complement factor, respective reconstituted serum, assays like in vitro neutralization, real-time PCR, and flow cytometry-based tissue culture-based limited dose assay (TC-LDA) were carried out for assessing the activation of different complement pathways. NHS from 9/10 donors showed complement dependent neutralization, reduction in viral load and decrease in percentage of CHPV-positive cells compared to their HIS counterparts. EGTA or EDTA pretreatment experiments indicated that CHPV neutralization proceeds through the alternative pathway of the complement activation. Our data showed a strong dependence on C3 for the in vitro neutralization of CHPV. Disparity in CHPV neutralization levels between factor B-deficient and reconstituted sera could be attributed to amplification loop/“tick-over” mechanism. Assays using C3, C5, and C8 deficient sera indicated that complement-mediated CHPV neutralization and suppression of CHPV infectivity are primarily through C3 and C5, and not dependent on downstream complement factor C8. With no specific anti-viral treatment/vaccine against Chandipura, the current data, elucidating role of human complement system in the neutralization of CHPV, may help in designing effective therapeutics.

Vesiculopolins, a New Class of Anti-Vesiculoviral Compounds, Inhibit Transcription Initiation of Vesiculoviruses

Vesicular stomatitis virus (VSV) represents a promising platform for developing oncolytic viruses, as well as vaccines against significant human pathogens. To safely control VSV infection in humans, small-molecule drugs that selectively inhibit VSV infection may be needed. Here, using a cell-based high-throughput screening assay followed by an in vitro transcription assay, compounds with a 7-hydroxy-6-methyl-3,4-dihydroquinolin-2(1H)-one structure and an aromatic group at position 4 (named vesiculopolins, VPIs) were identified as VSV RNA polymerase inhibitors. The most effective compound, VPI A, inhibited VSV-induced cytopathic effects and in vitro mRNA synthesis with micromolar to submicromolar 50% inhibitory concentrations. VPI A was found to inhibit terminal de novo initiation rather than elongation for leader RNA synthesis, but not mRNA capping, with the VSV L protein, suggesting that VPI A is targeted to the polymerase domain in the L protein. VPI A inhibited transcription of Chandipura virus, but not of human parainfluenza virus 3, suggesting that it specifically acts on vesiculoviral L proteins. These results suggest that VPIs may serve not only as molecular probes to elucidate the mechanisms of transcription of vesiculoviruses, but also as lead compounds to develop antiviral drugs against vesiculoviruses and other related rhabdoviruses.

Complement-Mediated Neutralization of a Potent Neurotropic Human Pathogen, Chandipura Virus, Is Dependent on C1q.

Among the innate immune sentinels, the complement system is a formidable first line of defense against pathogens, including viruses. Chandipura virus (CHPV), a neurotropic vesiculovirus of the family Rhabdoviridae, is a deadly human pathogen known to cause fatal encephalitis, especially among children. The nature of interaction and the effect of human complement on CHPV are unknown. Here, we report that CHPV is a potent activator of complement and, thus, is highly sensitive to complement proteins in normal human serum (NHS). Utilizing a panel of specific complement component depleted/reconstituted human serum, we have demonstrated that CHPV neutralization is C3, C4, and C1q dependent and independent of factor B, suggesting the importance of the classical pathway in limiting CHPV. Employing a range of biochemical approaches, we showed (i) a direct association of C1q to CHPV, (ii) deposition of complement proteins C3b, C4b, and C1q on CHPV, and (iii) virus aggregation. Depletion of C8, an important component of the pore-forming complex of complement, had no effect on CHPV, further supporting the finding that aggregation and not virolysis is the mechanism of virus neutralization. With no approved vaccines or treatment modalities in place against CHPV, insights into such interactions can be exploited to develop potent vaccines or therapeutics targeting CHPV.IMPORTANCE Chandipura virus is a clinically important human pathogen of the Indian subcontinent. The rapidity of death associated with CHPV infection in addition to the absence of an effective vaccine or therapeutics results in poor clinical prognosis. The biology of the virus and its interaction with the host immune system, including the complement system, are understudied. Our investigation reveals the susceptibility of CHPV to fluid phase complement and also dissects the pathway involved and the mechanism of virus neutralization. Direct binding of C1q, an important upstream component of the classical pathway of complement to CHPV, and the strong dependency on C1q for virus neutralization highlight the significance of identifying such interactions to better understand CHPV pathogenesis and devise strategies to target this deadly pathogen.

Chandipura Virus Utilizes the Prosurvival Function of RelA NF-κB for Its Propagation.

Chandipura virus (CHPV), a cytoplasmic RNA virus, has been implicated in several outbreaks of acute encephalitis in India. Despite the relevance of CHPV to human health, how the virus interacts with the host signaling machinery remains obscure. In response to viral infections, mammalian cells activate RelA/NF-κB heterodimers, which induce genes encoding interferon beta (IFN-β) and other immune mediators. Therefore, RelA is generally considered to be an antiviral transcription factor. However, RelA activates a wide spectrum of genes in physiological settings, and there is a paucity of direct genetic evidence substantiating antiviral RelA functions. Using mouse embryonic fibroblasts, we genetically dissected the role of RelA in CHPV pathogenesis. We found that CHPV indeed activated RelA and that RelA deficiency abrogated the expression of IFN-β in response to virus infections. Unexpectedly, infection of Rela-/- fibroblasts led to a decreased CHPV yield. Our investigation clarified that RelA-dependent synthesis of prosurvival factors restrained infection-inflicted cell death and that exacerbated cell death processes prevented multiplication of CHPV in RelA-deficient cells. Chikungunya virus, a cytopathic RNA virus associated also with epidemics, required RelA, and Japanese encephalitis virus, which produced relatively minor cytopathic effects in fibroblasts, circumvented the need of RelA for their propagation. In sum, we documented a proviral function of the pleiotropic factor RelA linked to its prosurvival properties. RelA promoted the growth of cytopathic RNA viruses by extending the life span of infected cells, which serve as the replicative niche of intracellular pathogens. We argue that our finding bears significance for understanding host-virus interactions and may have implications for antiviral therapeutic regimes.IMPORTANCE RelA/NF-κB participates in a wide spectrum of physiological processes, including shaping immune responses against invading pathogens. In virus-infected cells, RelA typically induces the expression of IFN-β, which restrains viral propagation in neighboring cells involving paracrine mechanisms. Our study suggested that RelA might also play a proviral role. A cell-autonomous RelA activity amplified the yield of Chandipura virus, a cytopathic RNA virus associated with human epidemics, by extending the life span of infected cells. Our finding necessitates a substantial revision of our understanding of host-virus interactions and indicates a dual role of NF-κB signaling during the course of RNA virus infections. Our study also bears significance for therapeutic regimes which alter NF-κB activities while alleviating the viral load.

Chandipura virus changes cellular miRNome in human microglial cells.

Chandipura virus (CHPV) is a neurotropic virus, known to cause encephalitis in humans. The microRNAs (miRNA/miR) play an important rolein the pathogenesis of viral infection. The present study is focused on the role of miRNAs during CHPV (strain 1653514) infection in human microglial cells. The deep sequencing of CHPV-infected human microglial cells identified a total of 12 differentially expressed miRNA (DEMs). To elucidate the role of DEMs, the target gene prediction, Gene Ontology term (GO Term), pathway enrichment analysis, and miRNA-messenger RNA (mRNA) interaction network analysis was performed. The GO terms and pathway enrichment analysis provided 146 enriched genes; which were involved in interferon response, cytokine and chemokine signaling. Further, the WGCNA (weighted gene coexpression network analysis) of the enriched genes were discretely categorized into three modules (blue, brown, and turquoise). The hub genes in the blue module may correlate to CHPV induced neuroinflammation. Altogether, the miRNA-mRNA interaction network and WGCNA study revealed the following pairs, hsa-miR-542-3p and FAF1, hsa-miR-92a-1-5p and MYD88, and hsa-miR-3187-3p and TNFRSF21, which may contribute to neuroinflammation during CHPV infection in human microglial cells.

Investigating the role of Ebp1 in Chandipura virus infection

ErbB-3 binding protein 1 (Ebp1) is a host protein which binds ErbB-3 receptor to induce signalling events for cell growth regulation. In addition, Ebp1 also interacts with ribonucleoprotein complexes. In recent times, Ebp1 was found to play an antagonistic role in viral infections caused by Influenza and Rinderpest viruses. In our present work we have tried to understand the role of Ebp1 in Chandipura virus (CHPV) infection. We have observed an induction in Ebp1 expression upon CHPV infection similar to other viruses. However, unlike other viruses an overexpressed Ebp1 only reduces viral protein expression, but does not affect its progeny formation. Additionally, this effect is being carried out in an indirect manner, as there is no interaction between Ebp1 and viral proteins. This is despite Ebp1's presence in viral inclusion bodies.

Temperature sensitivity and environmental stability of Chandipura virus.

Chandipura virus (CHPV), a negative-stranded RNA virus of family Rhabdoviridae is endemic in Central India since 1965. The virus gained public health importance when it was held responsible for massive outbreak in 2003-2004 in Maharashtra, Telengana and Gujarat with case fatality rates ranging from 55 to 75% among children. We studied the stability of the virus as well as RNA persistence in samples stored at different temperatures for different periods. CHPV remained infective in sand flies and cell culture supernatants at 4°C for 8weeks. At 37°C CHPV remained viable for 18days when stored in infected cell supernatant (Minimum essential medium supplemented with 10% fetal bovine serum). However, in infected sand flies stored at 37°C, the virus lost virulence within a week. CHPV RNA, though lost virulence, could be detected in virus exposed sand flies stored at 37°C for 13weeks by real time RT-PCR. Retaining virulence at 37°C for 18days in serum containing medium is a matter of concern for laboratories and hospital settings where clinical samples are handled. RNA persistence for prolonged periods in dead sand flies might help in surveillance studies of CHPV in sand flies and will help in resource constraint nations where cold chain management is a concern.