Humans ; Animals ; Culicidae ; Flavivirus ; Cell Line ; Spiramycin

Flavivirus ; Humans ; Immunity ; Vaccines ; Zika Virus ; Zika Virus Infection/prevention & control*

Zika virus (ZIKV) is a mosquito-borne flavivirus associated with severe neurological disorders including Guillain-Barré syndrome and microcephaly. The host innate immune responses against ZIKV infection are essential for protection; however, ZIKV has evolved strategies to evade and antagonize antiviral responses via its nonstructural (NS) proteins. Here, we demonstrated that ZIKV infection unexpectedly inhibits NLRP3-dependent inflammasome activation in bone marrow-derived macrophages and mixed glial cells from mouse brain. ZIKV infection led to increased transcript levels of proinflammatory cytokines such as IL-1β and IL-6 via activating NF-κB signaling. However, ZIKV infection failed to trigger the secretion of active caspase-1 and IL-1β from macrophages and glial cells even in the presence of LPS priming or ATP costimulation. Intriguingly, ZIKV infection significantly attenuated NLRP3-dependent, but not absent in melanoma 2-dependent caspase-1 activation and IL-1β secretion from both cells. ZIKV infection further blocked apoptosis-associated speck-like protein containing a caspase recruitment domain oligomerization in LPS/ATP-stimulated macrophages. Interestingly, expression of ZIKV NS3 protein reduced NLRP3-mediated caspase-1 activation and IL-1β secretion in macrophages, whereas NS1 and NS5 proteins showed no effects. Furthermore, NLRP3 was found to be degraded by the overexpression of ZIKV NS3 in 293T cells. Collectively, these results indicate that ZIKV evades host NLRP3 inflammasome-mediated innate immune responses in macrophages and glial cells; this may facilitate ZIKV's ability to enhance the replication and dissemination in these cells.
Adenosine Triphosphate ; Animals ; Brain ; Caspase 1 ; Cytokines ; Flavivirus ; Guillain-Barre Syndrome ; HEK293 Cells ; Immunity, Innate ; Inflammasomes ; Interleukin-6 ; Macrophages ; Melanoma ; Mice ; Microcephaly ; Nervous System Diseases ; Neuroglia ; Zika Virus

We developed a Rapid Diagnostic Test (RDT) kit for detecting IgG/IgM antibodies against Zika virus (ZIKV) using monoclonal antibodies to the envelope (E) and non-structural protein 1 (NS1) of ZIKV. These proteins were produced using baculovirus expression vector with Sf9 cells. Monoclonal antibodies J2G7 to NS1 and J5E1 to E protein were selected and conjugated with colloidal gold to produce the Zika IgG/IgM RDT kit (Zika RDT). Comparisons with ELISA, plaque reduction neutralization test (PRNT), and PCR were done to investigate the analytical sensitivity of Zika RDT, which resulted in 100% identical results. Sensitivity and specificity of Zika RDT in a field test was determined using positive and negative samples from Brazil and Korea. The diagnostic accuracy of Zika RDT was fairly high; sensitivity and specificity for IgG was 99.0 and 99.3%, respectively, while for IgM it was 96.7 and 98.7%, respectively. Cross reaction with dengue virus was evaluated using anti-Dengue Mixed Titer Performance Panel (PVD201), in which the Zika RDT showed cross-reactions with DENV in 16.7% and 5.6% in IgG and IgM, respectively. Cross reactions were not observed with West Nile, yellow fever, and hepatitis C virus infected sera. Zika RDT kit is very simple to use, rapid to assay, and very sensitive, and highly specific. Therefore, it would serve as a choice of method for point-of-care diagnosis and large scale surveys of ZIKV infection under clinical or field conditions worldwide in endemic areas.
Antibodies ; Antibodies, Monoclonal ; Baculoviridae ; Brazil ; Cross Reactions ; Dengue Virus ; Diagnosis ; Diagnostic Tests, Routine ; Enzyme-Linked Immunosorbent Assay ; Flavivirus ; Gold Colloid ; Hepacivirus ; Immunoglobulin G ; Immunoglobulin M ; Korea ; Methods ; Neutralization Tests ; Point-of-Care Systems ; Polymerase Chain Reaction ; Reagent Kits, Diagnostic ; Sensitivity and Specificity ; Sf9 Cells ; Yellow Fever ; Zika Virus

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.
Asian Continental Ancestry Group ; China ; Encephalitis Virus, Japanese ; Encephalitis, Japanese ; Encephalitis, Viral ; Flavivirus ; Genotype ; Humans ; Molecular Epidemiology ; Prevalence ; Spatio-Temporal Analysis ; Swine

Dengue fever is an acute febrile disease that is caused by a mosquito-borne flavivirus. It has become a major infectious disease threat in tropical and subtropical areas. In Korea, travel-associated dengue fever is increasing. Thirty-five Koreans went to Sri Lanka to do volunteer activities. Eight of the volunteers developed fever, myalgia, and rash; they were diagnosed with dengue fever. Two patients had macular hemorrhages and edema with no ophthalmic symptoms. The maculopathy caused by the dengue fever improved without specific treatment.
Communicable Diseases ; Dengue* ; Edema ; Exanthema ; Eye Manifestations ; Fever ; Flavivirus ; Hemorrhage ; Humans ; Korea ; Myalgia ; Sri Lanka* ; Volunteers*

Zika virus (ZIKV) was spread to both eastward and westward from Uganda where the virus was identified approximately in 1947 by a group of arbovirus researchers. In 2015, ZIKV reached Americas with major outbreaks in Brazil. Most countries with mosquito transmitted ZIKV infection are located in tropical and subtropical areas, where ZIKV is endemic with other flaviviruses, including JEV, dengue and yellow fever virus. Approximately 40 countries in Central and South Americas and territories in South Pacific Islands and South East Asia show autochthonous ZIKV endemics. American lineage of ZIKV is known significantly to be mutated in susceptibility to host and in pathogenicity from Asian and Asian lineages approximately since 2014. Early and specific identification of ZIKV infection is very important for the effective management of patients. First of all, optimal collection of specimens for the laboratory diagnosis is required for both nucleic acid testing (NAT) and serological tests. Specimens for NAT tests and serological tests should be determined by the available laboratory resources, work-flow in each laboratory and the geographic areas of specimen collected in addition to days after showing symptoms. Testing strategy for specific differentiation among flaviviruses will vary depending on the prevalence of viruses known to be circulating in the area where the patients were exposed. NAT will be employed for the patients presenting with onset of symptoms less than 7 days. Advanced diagnostic technologies should be continuously developed for the increase of specificity and sensitivity of ZIKV diagnosis.
Americas ; Arboviruses ; Asian Continental Ancestry Group ; Biology* ; Brazil ; Clinical Laboratory Techniques* ; Culicidae ; Dengue ; Diagnosis ; Disease Outbreaks ; Epidemiology* ; Far East ; Flavivirus ; Humans ; Pacific Islands ; Prevalence ; Sensitivity and Specificity ; Serologic Tests ; South America ; Uganda ; Virulence ; Yellow fever virus ; Zika Virus*

Since its discovery in 1989, hepatitis C virus (HCV) has been intensively investigated to understand its biology and develop effective antiviral therapies. The efforts of the previous 25 years have resulted in a better understanding of the virus, and this was facilitated by the development of in vitro cell culture systems for HCV replication. Antiviral treatments and sustained virological responses have also improved from the early interferon monotherapy to the current all-oral regimens using direct-acting antivirals. However, antiviral resistance has become a critical issue in the treatment of chronic hepatitis C, similar to other chronic viral infections, and retreatment options following treatment failure have become important questions. Despite the clinical challenges in the management of chronic hepatitis C, substantial progress has been made in understanding HCV, which may facilitate the investigation of other closely related flaviviruses and lead to the development of antiviral agents against these human pathogens.
Antiviral Agents ; Biology ; Cell Culture Techniques ; Drug Resistance ; Drug Resistance, Viral* ; Flavivirus ; Hepacivirus* ; Hepatitis C* ; Hepatitis C, Chronic ; Hepatitis* ; Humans ; In Vitro Techniques ; Interferons ; Retreatment ; Treatment Failure

Since its discovery in 1989, hepatitis C virus (HCV) has been intensively investigated to understand its biology and develop effective antiviral therapies. The efforts of the previous 25 years have resulted in a better understanding of the virus, and this was facilitated by the development of in vitro cell culture systems for HCV replication. Antiviral treatments and sustained virological responses have also improved from the early interferon monotherapy to the current all-oral regimens using direct-acting antivirals. However, antiviral resistance has become a critical issue in the treatment of chronic hepatitis C, similar to other chronic viral infections, and retreatment options following treatment failure have become important questions. Despite the clinical challenges in the management of chronic hepatitis C, substantial progress has been made in understanding HCV, which may facilitate the investigation of other closely related flaviviruses and lead to the development of antiviral agents against these human pathogens.
Antiviral Agents ; Biology ; Cell Culture Techniques ; Drug Resistance ; Drug Resistance, Viral* ; Flavivirus ; Hepacivirus* ; Hepatitis C* ; Hepatitis C, Chronic ; Hepatitis* ; Humans ; In Vitro Techniques ; Interferons ; Retreatment ; Treatment Failure

Zika virus (ZIKV) is a mosquito borne pathogen, belongs to Flaviviridae family having a positive-sense single-stranded RNA genome, currently known for causing large epidemics in Brazil. Its infection can cause microcephaly, a serious birth defect during pregnancy. The recent outbreak of ZIKV in February 2016 in Brazil realized it as a major health risk, demands an enhanced surveillance and a need to develop novel drugs against ZIKV. Amodiaquine, prochlorperazine, quinacrine, and berberine are few promising drugs approved by Food and Drug Administration against dengue virus which also belong to Flaviviridae family. In this study, we performed molecular docking analysis of these drugs against nonstructural 3 (NS3) protein of ZIKV. The protease activity of NS3 is necessary for viral replication and its prohibition could be considered as a strategy for treatment of ZIKV infection. Amongst these four drugs, berberine has shown highest binding affinity of –5.8 kcal/mol and it is binding around the active site region of the receptor. Based on the properties of berberine, more similar compounds were retrieved from ZINC database and a structure-based virtual screening was carried out by AutoDock Vina in PyRx 0.8. Best 10 novel drug-like compounds were identified and amongst them ZINC53047591 (2-(benzylsulfanyl)-3-cyclohexyl-3H-spiro[benzo[h]quinazoline-5,1'-cyclopentan]-4(6H)-one) was found to interact with NS3 protein with binding energy of –7.1 kcal/mol and formed H-bonds with Ser135 and Asn152 amino acid residues. Observations made in this study may extend an assuring platform for developing anti-viral competitive inhibitors against ZIKV infection.
Amodiaquine ; Berberine ; Brazil ; Catalytic Domain ; Congenital Abnormalities ; Culicidae ; Dengue Virus ; Drug Design ; Flaviviridae ; Flavivirus ; Genome ; High-Throughput Screening Assays ; Humans ; Mass Screening* ; Microcephaly ; Molecular Docking Simulation ; Pregnancy ; Prochlorperazine ; Quinacrine ; RNA ; United States Food and Drug Administration ; Zika Virus* ; Zinc