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Assessing ubiquitination of viral proteins: Lessons from flavivirus NS5.

Ubiquitin (Ub) conjugation to a substrate protein is a widely used cellular mechanism for control of protein stability and function, modulat … om Langat virus (LGTV), a member of the tick-borne encephalitis virus (TBEV) serocomplex within the Flavivirus genus. Using the protocols outlined here, we describe some of the pitfalls inherent in determination of Ub linkage and demonstrate that NS5 is modified by at least two distinct ubiquitination types, multiubiquitination and K48-linked polyubiquitin c …

Nuclear localization of flavivirus RNA synthesis in infected cells.

Flaviviral replication is believed to be exclusively cytoplasmic, occurring within virus-induced membrane-bound replication complexes in the … ggest an absolute requirement for both of the replicase proteins for nucleus-localized synthesis of flavivirus RNA. Thus, we conclusively demonstrate for the first time that the host cell nucleus functions as an additional site for the presence of functionally active flaviviral replicase complex.

Formalin-inactivated whole virus and recombinant subunit flavivirus vaccines.

The Flaviviridae is a family of arthropod-borne, enveloped, RNA viruses that contain important human pathogens such as yellow fever (YF), Ja … stic animals demonstrates the possibility of producing a similar vaccine for human use. Advances in flavivirus gene expression technology have led to the production of several recombinant subunit antigen vaccine candidates in a variety of expression systems. Some of these vaccines have shown sufficient promise in animal models to be considered as candidates …

Studies on serological cross-reaction in sequential flavivirus infections.

Acute- and convalescent-phase sera from patients with dengue (DEN) hemorrhagic fever (DHF) and Japanese encephalitis (JE) that contained pre-existing flavivirus antibodies were tested for cross-reacting antibodies to DEN, JE and yellow fever (YF) viruses by a neutralization (N) test. A fourfold or greater rise in N antibody titer in the convalescent-phase was considered significant. Of 39 DHF cases, obtained at Chiang Mai University Hospital, Thailand, 15 (38.5%) showed a rise in DEN antibody titer, while another 15 (38.5%) showed a significant rise in both DEN and JE N antibody titers. On the…

[Flavivirus: serological survey in horses from the Tandil area].

Sera from 282 equines from Tandil country and surroundings were investigated searching for hemagglutination inhibition (HI), Complement fixation (CF), and Neutralizing (NT) antibodies against three flavivirus:Ilheus, St. Louis Encephalitis, and Yellow Fever from the Togaviridae family. Sera were collected between 3-20-79 and 11-25-80 from 10 different places in Tandil and Ayacucho countries. Animals ranged from 45 days to 27 years old. Forty nine of them reacted with one or more flavivirus by HI and/or CF tes representing a prevalence of 17.4% for this antigenic complex. Twenty four of them ne…

[Protective effect of cellular immunity in experimental Flavivirus infections].

Experiments were conducted with the tick-borne encephalitis (TE) virus; confirmation of a protective action of cellular immunity in mice was obtained. Administration of sensitized splenocytes to the animals together with the virus was accompanied with an increase of their mean survival or with the reduction of mortality in comparison with control animals given nonimmune or destroyed cells. The protective action of the effector cells was not connected with the intensification of antibody formation in the recipients. A high specificity of cellular immunity was noted in experimental flaviviral in

Вирус Западного Нила, Anophels flavivirus, новичок флавивируса, а также Rhabdovirus Turchin, похожий на Merida, в полевых комарах, собранных из Фракии и Анатолии.

Москиты участвуют в передаче и лечении нескольких вирусных заболеваний, оказывающих значительное воздействие на здоровье. Усилия по биоразве … Aedes caspius (n=1) комаров, были описаны последовательности новых флавивирусов, далеко связанных с Flavivirus AV2011, которые ранее были выявлены в Испании и Турции. Кроме того, в двух бассейнах Ur. gungiculata были обнаружены формы нового аромата ДНК. Эти последовательности очень похожи на последовательности, усиленные вирусной РНК, с не нарушенными систем …

Identification of NECTIN1 as a novel restriction factor for flavivirus infection.

UNLABELLED: Nectin cell adhesion molecule 1 (NECTIN1) is a cell adhesion molecule that belongs to the immunoglobulin superfamily. It has been considered the most ubiquitous receptor for herpesviruses. However, in the context of flavivirus infection, its role was previously unknown. In this study, we described an arrayed siRNA screen mainly targeting Ig-like proteins that showed NECTIN1-restricted bovine viral diarrhea virus (BVDV) infection. We demonstrated that the depletion of NECTIN1 could significantly enhance the infection of both biotypes and multiple genotypes of BVDV, including BVDV-1a…

Acetylation of the NS3 helicase by KAT5γ is essential for flavivirus replication.

Direct targeting of essential viral enzymes such as proteases, polymerases, and helicases has long been the major focus of antiviral drug design. Although successful for some viral enzymes, targeting viral helicases is notoriously difficult to achieve, demanding alternative strategies. Here, we show that the NS3 helicase of Zika virus (ZIKV) undergoes acetylation in its RNA-binding tunnel. Regulation of the acetylated state of K389 in ZIKV NS3 modulates RNA binding and unwinding and is required for efficient viral replication. NS3 acetylation is mediated by a specific isoform of the host acety

Validation of a Reporter Cell Line for Flavivirus Inhibition Assays.

Here, we report the validation of a new reporter cell line, Hec1a-IFNB-Luc, for use in inhibition studies of various flaviviruses relevant to human pathology. The reporter system allows the detection of viral replication after luciferase gene activation driven by an interferon beta (IFN-β) promoter. We found the reporter cell line to be highly responsive to all 10 flaviviruses tested, including the 4 dengue virus serotypes. The applicability of the Hec1a-IFNB-Luc reporter cell line for serodiagnostic purposes in neutralizing antibody assays was confirmed by comparison of its sensitivity and sp…

A Perspective on Current Flavivirus Vaccine Development: A Brief Review.

The flavivirus genus contains several clinically important pathogens that account for tremendous global suffering. Primarily transmitted by mosquitos or ticks, these viruses can cause severe and potentially fatal diseases ranging from hemorrhagic fevers to encephalitis. The extensive global burden is predominantly caused by six flaviviruses: dengue, Zika, West Nile, yellow fever, Japanese encephalitis and tick-borne encephalitis. Several vaccines have been developed, and many more are currently being tested in clinical trials. However, flavivirus vaccine development is still confronted with ma…

Structure and function of cis-acting RNA elements of flavivirus.

The genus Flavivirus is a group of single-stranded, positive-sense RNA viruses that includes numerous human pathogens with global impact, such as dengue virus (DENV), yellow fever virus (YFV), West Nile virus (WNV), and Zika virus (ZIKV). The approximately 11-kilobase genome is flanked by highly structured untranslated regions (UTRs), which contain various cis-acting RNA elements with unique structures and functions. Moreover, local RNA elements circularize the genome non-covalently through long-range interactions. Interestingly, many flavivirus cis-acting RNA elements contain group-specific m…

Flavivirus infection-A review of immunopathogenesis, immunological response, and immunodiagnosis.

Flaviviruses are group of single stranded RNA viruses that cause severe endemic infection and epidemics on a global scale. It presents a significant health impact worldwide and the viruses have the potential to emerge and outbreak in a non-endemic geographical region. Effective vaccines for prophylaxis are only available for several flaviviruses such as Yellow Fever virus, Tick-borne Encephalitis Virus, Dengue Virus and Japanese Encephalitis Virus and there is no antiflaviviral agent being marketed. This review discusses the flavivirus genome, replication cycle, epidemiology, clinical presenta…

A novel mechanism of antibody-mediated enhancement of flavivirus infection.

Antibody-dependent enhancement of viral infection is a well-described phenomenon that is based on the cellular uptake of infectious virus-antibody complexes following their interaction with Fcγ receptors expressed on myeloid cells. Here we describe a novel mechanism of antibody-mediated enhancement of infection by a flavivirus (tick-borne encephalitis virus) in transformed and primary human cells, which is independent of the presence of Fcγ receptors. Using chemical cross-linking and immunoassays, we demonstrate that the monoclonal antibody (mab) A5, recognizing an epitope at the interface of …

Pathophysiological mechanisms of Flavivirus infection of the central nervous system.

Flaviviruses are important human pathogens. Transmitted by the bite of infected mosquitoes, Flaviviruses such as West Nile and Japanese encephalitis may reach the central nervous system where they can elicit severe diseases. Their ability to cross the blood-brain-barrier is still poorly understood. The newly emerging Zika Flavivirus on the other hand very rarely reaches the brain of adults, but can infect neural progenitors in the developing central nervous system of fetuses, eliciting devastating congenital malformations including microcephaly. This short review focuses on selected aspects of…

The mysterious Zika virus: Adding to the tropical flavivirus mayhem.

Until now, known as the demure cousin of dengue virus (DENV) inhabiting Africa, Zika virus (ZIKV) has reinvented itself to cause explosive e … ratory confirmation mandatory for definitive diagnosis. The serological cross-reactivity with other Flavivirus, particularly with DENV makes laboratory confirmation challenging and will place additional burden on health systems to establish molecular diagnostic facilities. The evidence of additional nonvector modes of transmission, such as perinatal, sexual …

Patterns of Flavivirus Seroprevalence in the Human Population of Northern Laos.

A total of 1,136 samples from 289 households in four provinces in northern Laos were subjected to Japanese encephalitis virus (JEV) and deng … f which 7, 1, and 0, respectively, had HI activity against DENV1-3 only. JEV was the most prevalent Flavivirus in Oudomxay, Luangprabang, and Huaphan provinces and DENV4 was the most prevalent in Xiengkhouang province. Seroprevalence for JEV increased with increasing age and wealth and was higher in villages where rice was cultivated in paddy fields and high …

Ортомиксо-, парамиксо- и ароматические инфекции в дикой водоплавающей птице в Финляндии.

СОСТОЯНИЕ: Все более важное значение приобретает проверка диких птиц на наличие вирусных патогенов. Мы проверили подход к отбору на основе крови и калакальных и трахеальных мазков, собранных охотниками для изучения распространенности гриппа А, парамиксо, флави и альфавирусов в финской дикой водоплавающей птице, которые ранее не были известны. В 2006 году мы изучили 310 образцов крови и 115 смешанных трахеальных и клаковых мазков, собранных из охотничьей водоплавающей птицы. Пробы проверялись с помощью РТ-ПКР и серологически с помощью теста на ингибирование гемаглютинации (HI) или анализа иммун

Совпадение в аннотации оригинала
BACKGROUND: Screening wild birds for viral pathogens has become increasingly important. We tested a screening approach based on blood and cl … were isolated, while two blood samples were antibody positive. None of the birds were positive for flavivirus RNA but three birds had flavivirus antibodies by HI test. No antibodies to SINV were detected. CONCLUSION: We conclude that circulation of both influenza A virus and avian paramyxovirus-1 in Finnish wild waterfowl was documented. The FLUAV and APMV …