A Phenotypic Assay to Identify Chikungunya Virus Inhibitors Targeting the Nonstructural Protein nsP2
ABSTRACT Chikungunya virus (CHIKV) is a mosquito-transmitted pathogen responsible for an acute infection of abrupt onset, characterized by high fever, polyarthralgia, myalgia, headaches, chills, and rash. In 2006, CHIKV was responsible for an epidemic outbreak of unprecedented magnitude in the Indian Ocean, stressing the need for therapeutic approaches. Since then, we have acquired a better understanding of CHIKV biology, but we are still missing active molecules against this reemerging pathogen. We recently reported that the nonstructural nsP2 protein of CHIKV induces a transcriptional shutoff that allows the virus to block cellular antiviral response. This was demonstrated using various luciferase-based reporter gene assays, including a trans-reporter system where Gal4 DNA binding domain is fused to Fos transcription factor. Here, we turned this assay into a high-throughput screening system to identify small molecules targeting nsP2-mediated shutoff. Among 3040 molecules tested, we identified one natural compound that partially blocks nsP2 activity and inhibits CHIKV replication in vitro. This proof of concept suggests that similar functional assays could be developed to target other viral proteins mediating a cellular shutoff and identify innovative therapeutic molecules.
Full-textDOI: · Available from: Frederic Tangy, Sep 29, 2015
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- "Recently, cell-based high throughput assays have been developed to identify potential CHIKV inhibitors. One study reported a focus screen of 356 natural compounds and clinically approved drugs using a CHIKV replicon and a concomitant screen with SFV surrogate infection model , while another study screened 3,040 small molecules for inhibitors of CHIKV nsP2 using a novel target-based phenotypic assay approach . Cruz et al.  used a cell-based high throughput screening assay using resazurin against a kinase inhibitor library combined with the image-based high content assay approach to identify compounds against CHIKV having novel antiviral activity. "
ABSTRACT: Chikungunya virus (CHIKV) is a mosquito-borne pathogen that has a major health impact in humans and causes acute febrile illness in humans accompanied by joint pains and, in many cases, persistent arthralgia lasting for weeks to years. CHIKV reemerged in 2005-2006 in several parts of the Indian Ocean islands and India after a gap of 32 years, causing millions of cases. The re-emergence of CHIKV has also resulted in numerous outbreaks in several countries in the eastern hemisphere, with a threat to further expand in the near future. However, there is no vaccine against CHIKV infection licensed for human use, and therapy for CHIKV infection is still mainly limited to supportive care as antiviral agents are yet in different stages of testing or development. In this review we explore the different perspectives for chikungunya treatment and the effectiveness of these treatment regimens and discuss the scope for future directions.BioMed Research International 05/2014; 2014(5):631642. DOI:10.1155/2014/631642 · 3.17 Impact Factor
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ABSTRACT: Chikungunya virus (CHIKV) has re-emerged as a significant public health threat since the 2005 chikungunya fever epidemic in La Réunion. Driven by the medical importance of this virus, as well as the lack of approved antivirals, research into the field of CHIKV antivirals has recently intensified. Potential therapeutics that have been reported to show anti-CHIKV activity in vitro range from known broad-spectrum antivirals like chloroquine to novel strategies involving RNA silencing technology. Although most of the earlier efforts focused on compounds that target host components, some recent studies have reported viral targets such as nonstructural proteins. This article examines the reported in vitro and in vivo efficacies, as well as the therapeutic potential of these antiviral compounds.Drug discovery today 05/2013; 18(19). DOI:10.1016/j.drudis.2013.05.002 · 6.69 Impact Factor
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ABSTRACT: Chikungunya virus (CHIKV) is the aetiological agent of the mosquito-borne disease chikungunya fever, a debilitating arthritic disease that, during the past seven years, has caused immeasurable morbidity and some mortality in humans, including newborn babies, following its emergence and dispersal out of Africa to the Indian Ocean islands and Asia. Since the first reports of its existence in Africa in the 1950s, more than 1500 scientific publications on the different aspects of the disease and its causative agent have been produced. Analysis of these publications shows that, following a number of studies in the 1960s and 70s, and in the absence of autochthonous cases in developed countries, the interest of the scientific community remained low. However, in 2005 chikungunya fever unexpectedly re-emerged in the form of devastating epidemics in and around the Indian Ocean. These outbreaks were associated with mutations in the viral genome that facilitated the replication of the virus in Aedes albopictus mosquitoes. Since then, nearly 1000 publications on chikungunya fever have been referenced in the PubMed database. This article provides a comprehensive review of chikungunya fever and CHIKV, including clinical data, epidemiological reports, therapeutic aspects and data relating to animal models for in vivo laboratory studies. It includes supplementary tables of all WHO outbreak bulletins, ProMED Mail alerts, viral sequences available on GenBank, and PubMed reports of clinical cases and seroprevalence studies.Antiviral research 06/2013; 99(3). DOI:10.1016/j.antiviral.2013.06.009 · 3.94 Impact Factor