131 research outputs found

    Promoting self-disclosure from prison inmates

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    This study examined the effects of interviewer self-disclosure on the self-disclosure of 40 male prison inmates and 40 male university students. A four-point scale was used for rating the intimacy of selfdisclosure, the number of statements were counted for scoring the breadth of self-disclosure, and a stop watch was used to time the duration of self-disclosure. The three measures correlated highly with each others indicating all were good measures of self-disclosure. The self-disclosure reciprocity effect was demonstrated with both prison inmates and university students. It was also found that overall, prison inmates self-disclosed significantly less < .05) than university students. The personality variables of extroversion and neuroticism, as measured by the Eysenck Personality Inventory, were also examined. Prison inmates were significantly lower than university students on extroversion < .001) and no different than university students on neuroticism. It was also found that extroversion was positively related to self-disclosure. However, neuroticism was not related to either self-disclosure or to extroversion

    Persistent Replication of a Chikungunya Virus Replicon in Human Cells is Associated with Presence of Stable Cytoplasmic Granules Containing Non-structural Protein 3

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    Chikungunya virus (CHIKV), a mosquito-borne human pathogen, causes a disabling disease characterized by severe joint pain that can persist for weeks, months or even years in patients. The non-structural protein 3 (nsP3) plays essential roles during acute infection, but little is known about the function of nsP3 during chronic disease. Here, we used sub-diffraction multi-color microscopy for spatial and temporal analysis of CHIKV nsP3 within human cells that persistently replicate replicon RNA. Round cytoplasmic granules of various sizes (i) contained nsP3 and stress granule assembly factors 1 and 2 (G3BP1/2); (ii) were next to double-stranded RNA foci and nsP1-positive structures; and (iii) were close to the nuclear membrane and the nuclear pore complex protein Nup98. Analysis of protein turnover and mobility by live-cell microscopy revealed that granules could persist for hours to days, accumulated newly synthesized protein, and moved through the cytoplasm at varying speeds. Granules also had a static internal architecture and were stable in cell lysates. Refractory cells that had cleared the non-cytotoxic replicon regained the ability to respond to arsenite-induced stress. In summary, nsP3 can form uniquely stable granular structures that persist long-term within the host cell. This continued presence of viral and cellular protein-complexes has implications for the study of the pathogenic consequences of lingering CHIKV infection and the development of strategies to mitigate the burden of chronic musculoskeletal disease brought about by a medically important arthropod-borne virus (arbovirus).ImportanceChikungunya virus (CHIKV) is a re-emerging alphavirus transmitted by mosquitos and causes transient sickness but also chronic disease affecting muscles and joints. No approved vaccines or antivirals are available. Thus, a better understanding of the viral life cycle and the role of viral proteins can aid in identifying new therapeutic targets. Advances in microscopy and development of non-cytotoxic replicons (Utt, Das, Varjak, Lulla, Lulla, Merits, J Virol 89:3145-62, 2015, doi:10.1128/JVI.03213-14) have allowed researchers to study viral proteins within controlled laboratory environments over extended durations. Here we established human cells that stably replicate replicon RNA and express tagged non-structural protein 3. The ability to track nsP3 within the host cell and during persistent replication can benefit fundamental research efforts to better understand long-term consequences of the persistence of viral protein complexes and thereby provide the foundation for new therapeutic targets to control CHIKV infection and treat chronic disease symptoms

    Host Inflammatory Response to Mosquito Bites Enhances the Severity of Arbovirus Infection

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    Aedes aegypti mosquitoes are responsible for trans- mitting many medically important viruses such as those that cause Zika and dengue. The inoculation of viruses into mosquito bite sites is an important and common stage of all mosquito-borne virus infec- tions. We show, using Semliki Forest virus and Bunyamwera virus, that these viruses use this inflam- matory niche to aid their replication and dissemina- tion in vivo. Mosquito bites were characterized by an edema that retained virus at the inoculation site and an inflammatory influx of neutrophils that coordi- nated a localized innate immune program that inad- vertently facilitated virus infection by encouraging the entry and infection of virus-permissive myeloid cells. Neutrophil depletion and therapeutic blockade of inflammasome activity suppressed inflammation and abrogated the ability of the bite to promote infec- tion. This study identifies facets of mosquito bite inflammation that are important determinants of the subsequent systemic course and clinical outcome of virus infection

    Is the ADP ribose site of the Chikungunya virus NSP3 Macro domain a target for antiviral approaches?

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    Chikungunya virus (CHIKV) is a mosquito-transmitted virus of special concern as it causes Chikungunya fever, characterized by an acute febrile illness, rash, and arthralgia that can progress to chronic and debilitating arthritic symptoms. The effects of climate change on the geographic distribution of the mosquito vector has the potential to expose more of the globe to this virus. No antiviral agents or vaccines are currently available against CHIKV infection and the development of novel therapies that may lead to a future treatment is therefore necessary. In this context, the ADP-ribose binding site of the CHIKV nsP3 macro domain has been reported as a potential target for the development of antivirals. Mutations in the ADP-ribose binding site demonstrated decreased viral replication in cell culture and reduced virulence. In this study, 48,750 small molecules were screened in silico for their ability to bind to the ADP-ribose binding site of the CHIKV nsP3 macro domain. From this in silico analysis, 12 molecules were selected for in vitro analysis using a CHIKV subgenomic replicon in Huh-7 cells. Cell viability and CHIKV replication were evaluated and molecules C5 and C13 demonstrated 53 and 66% inhibition of CHIKV replication, respectively. By using a CHIKV-Dual luciferase replicon contain two reporter genes, we also demonstrated that the treatment with either compounds are probably interfering in the early replication rather than after RNA replication has occurred

    Semliki Forest virus strongly reduces mosquito host defence signaling

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    The Alphavirus genus within the Togaviridae family contains several important mosquito-borne arboviruses. Other than the antiviral activity of RNAi, relatively little is known about alphavirus interactions with insect cell defences. Here we show that Semliki Forest virus (SFV) infection of Aedes albopictus-derived U4.4 mosquito cells reduces cellular gene expression. Activation prior to SFV infection of pathways involving STAT/IMD, but not Toll signaling reduced subsequent virus gene expression and RNA levels. These pathways are therefore not only able to mediate protective responses against bacteria but also arboviruses. However, SFV infection of mosquito cells did not result in activation of any of these pathways and suppressed their subsequent activation by other stimuli

    LDL receptor in alphavirus entry: structural analysis and implications for antiviral therapy

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    Various low-density lipoprotein receptors (LPRs) have been identified as entry factors for alphaviruses, and structures of the corresponding virion-receptor complexes have been determined. Here, we analyze the similarities and differences in the receptor binding modes of multiple alphaviruses to understand their ability to infect a wide range of hosts. We further discuss the challenges associated with the development of broad-spectrum treatment strategies against a diverse range of alphaviruses

    Structural and phenotypic analysis of Chikungunya virus RNA replication elements

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    Chikungunya virus (CHIKV) is a re-emerging, pathogenic Alphavirus transmitted to humans by Aedes spp. mosquitoes. We have mapped the RNA structure of the 5′ region of the CHIKV genome using selective 2′-hydroxyl acylation analysed by primer extension (SHAPE) to investigate intramolecular base-pairing at single-nucleotide resolution. Taking a structure-led reverse genetic approach, in both infectious virus and sub-genomic replicon systems, we identified six RNA replication elements essential to efficient CHIKV genome replication - including novel elements, either not previously analysed in other alphaviruses or specific to CHIKV. Importantly, through a reverse genetic approach we demonstrate that the replication elements function within the positive-strand genomic copy of the virus genome, in predominantly structure-dependent mechanisms during efficient replication of the CHIKV genome. Comparative analysis in human and mosquito-derived cell lines reveal that a novel element within the 5′UTR is essential for efficient replication in both host systems, while those in the adjacent nsP1 encoding region are specific to either vertebrate or invertebrate host cells. In addition to furthering our knowledge of fundamental aspects of the molecular virology of this important human pathogen, we foresee that results from this study will be important for rational design of a genetically stable attenuated vaccine

    Antiviral activity of silymarin against chikungunya virus

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    Citation: Lani, R., Hassandarvish, P., Chiam, C. W., Moghaddam, E., Chu, J. J. H., Rausalu, K., . . . Zandi, K. (2015). Antiviral activity of silymarin against chikungunya virus. Scientific Reports, 5, 10. doi:10.1038/srep11421The mosquito-borne chikungunya virus (CHIKV) causes chikungunya fever, with clinical presentations such as severe back and small joint pain, and debilitating arthritis associated with crippling pains that persist for weeks and even years. Although there are several studies to evaluate the efficacy of drugs against CHIKV, the treatment for chikungunya fever is mainly symptom-based and no effective licensed vaccine or antiviral are available. Here, we investigated the antiviral activity of three types of flavonoids against CHIKV in vitro replication. Three compounds: silymarin, quercetin and kaempferol were evaluated for their in vitro antiviral activities against CHIKV using a CHIKV replicon cell line and clinical isolate of CHIKV of Central/East African genotype. A cytopathic effect inhibition assay was used to determine their activities on CHIKV viral replication and quantitative reverse transcription PCR was used to calculate virus yield. Antiviral activity of effective compound was further investigated by evaluation of CHIKV protein expression using western blotting for CHIKV nsP1, nsP3, and E2E1 proteins. Briefly, silymarin exhibited significant antiviral activity against CHIKV, reducing both CHIKV replication efficiency and down-regulating production of viral proteins involved in replication. This study may have important consequence for broaden the chance of getting the effective antiviral for CHIKV infection

    Evidence of differences in cellular regulation of Wolbachia-mediated viral inhibition between alphaviruses and flaviviruses

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    The intracellular bacterium Wolbachia is increasingly being utilised in control programs to limit the spread of arboviruses by Aedes mosquitoes. Achieving a better understanding of how Wolbachia strains can reduce viral replication/spread could be important for the long-term success of such programs. Previous studies have indicated that for some strains of Wolbachia, perturbations in lipid metabolism and cholesterol storage are vital in Wolbachia-mediated antiviral activity against the flaviviruses dengue and Zika; however, it has not yet been examined whether arboviruses in the alphavirus group are affected in the same way. Here, using the reporters for the alphavirus Semliki Forest virus (SFV) in Aedes albopictus cells, we found that Wolbachia strains wMel, wAu and wAlbB blocked viral replication/translation early in infection and that storage of cholesterol in lipid droplets is not key to this inhibition. Another alphavirus, o’nyong nyong virus (ONNV), was tested in both Aedes albopictus cells and in vivo in stable, transinfected Aedes aegypti mosquito lines. The strains wMel, wAu and wAlbB show strong antiviral activity against ONNV both in vitro and in vivo. Again, 2-hydroxypropyl-β-cyclodextrin (2HPCD) was not able to rescue ONNV replication in cell lines, suggesting that the release of stored cholesterol caused by wMel is not able to rescue blockage of ONNV. Taken together, this study shows that alphaviruses appear to be inhibited early in replication/translation and that there may be differences in how alphaviruses are inhibited by Wolbachia in comparison to flaviviruses
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