Dans le but d'identifier de nouveaux inhibiteurs du chikungunya (CHIKV), de la dengue (DENV) et de la zika (ZIKV), une étude systématique portant sur 339 extraits d'Euphorbiaceae tropicales a été réalisée grâce à un test cellulaire d'inhibition du CHIKV et à des tests d'inhibition de l'ARN-polymérase de DENV et ZIKV.Sandwithia guyanensis et Sagotia racemosa, deux espèces provenant de Guyane française, dont les extraits d'écorce présentaient une forte activité anti-CHIKV importante, ont d'abord été étudiées. À la suite d'un processus d'isolement bioguidé classique, plus de 20 nouveaux diterpènes ont été caractérisés, mais aucun d'entre eux ne présentait une activité antivirale significative. Pour résoudre ce problème, des réseaux moléculaires (MN) ont été construits grâce aux données de LC-MS/MS obtenues à partir des fractions chromatographiques des deux extraits. L'annotation des MN, a permis l'identification d'analogues du phorbol, connus pour être de puissants inhibiteurs du CHIKV. Présents à l'état de traces, ces composés fournissent une explication plausible à l'activité anti-CHIKV des deux extraits.Dans une deuxième étude, une stratégie de priorisation des extraits de plantes basée sur la fusion de données taxonomiques et d'essais biologiques au sein d'un MN a conduit à l'isolement et à la caractérisation ciblée de plusieurs inhibiteurs doubles de Codiaeum peltatum. Les deux études illustrent comment les MN et les progrès récents en matière d'annotation des données de LC-MS/MS peuvent être mis en œuvre dans les études phytochimiques pour améliorer le processus découverte de composés bioactifs. / In order to identify new inhibitors of chikungunya (CHIKV), dengue fever (DENV) and zika (ZIKV), systematic study with 339 extracts from tropical Euphorbiaceae species was performed in a virus-cell-based assay for CHIKV and DENV and ZIKA NS5 inhibition assaysThe French Guianese species Sandwithia guyanensis and Sagotia racemosa, from which bark extracts exhibited significant anti-CHIKV activities, were first investigated. Following a classical bioguided isolation workflow, more than 20 new diterpenes were characterized but none of them showed significant antiviral activity. To adress this issue, molecular networks (MN) were built from the LC-MS/MS data acquired from the chromatographic fractions of both extracts. The annotation of the MNs led to the identification of phorbol analogues, known to be potent CHIKV inhibitors. Present at trace levels, these compounds provide a plausible explanation for the anti-CHIKV activity of both extracts.In a second study, a strategy to prioritize plant extracts based on the fusion of taxonomic data and bioassays within a MN led to the isolation and targeted characterization of several dual inhibitors from Codiaeum peltatum. Both studies illustrate how MN and recent advances in LC-MS/MS data annotation can be implemented in phytochemical studies to improve the bioactive compounds discovery process.

Orientador: Ana Cláudia Figueiredo Frizzo / Resumo: Introdução: O Zica vírus tornou-se uma epidemia no Brasil a partir do início de 2015, tendo os primeiros casos de microcefalia com suspeita de causa pelo Zica Virus confirmados nos estados do Rio Grande do Norte e Pernambuco. Desde então, pesquisas evidenciam a necessidade de maiores investigações acerca da fisiologia dos indivíduos afetados pela doença, sintomas e prognósticos a fim de aprimorar o tratamento das crianças com a chamada “síndrome congênita do zica vírus”. Desta forma, para estudar e minimizar os impactos que uma possível alteração no córtex auditivo possa acarretar no desenvolvimento comunicativo destas crianças, este estudo tem como objetivo principal descrever os valores do potencial cortical auditivo de crianças que provavelmente foram infectadas pela síndrome congênita do Zica vírus. Métodos: Trata-se de um estudo multicêntrico, transversal descritivo, o qual foi desenvolvido no Setor de Audiologia do Centro de Estudos da Educação e da Saúde (CEES), da Universidade Estadual Paulista (UNESP), e na Universidade Estadual de Ciências da Saúde de Alagoas – UNCISAL, Laboratório de Audiologia do Centro Especializado em Reabilitação (CER III), com aprovação no comitê de ética CAAE nº 68684117.8.1001.5406. Participaram do estudo 30 crianças, de ambos os gêneros, de seis a 38 meses de vida, compondo o grupo estudo, com microcefalia e provável síndrome congênita do zica vírus e grupo controle, nos quais foram realizados exames de potencial evocado auditivo cortical e... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Introduction: The Zika virus became an epidemic in Brazil from the beginning of 2015, with the first cases of microcephaly with suspected cause by Zika Virus confirmed in the states of Rio Grande do Norte and Pernambuco. Since then, research has shown the need for further research into the physiology of individuals affected by the disease, symptoms and prognosis in order to improve the treatment of children with the so-called congenital zygote virus syndrome. Thus, in order to study and minimize the impacts that a possible alteration in the auditory cortex may have on the communicative development of these children, this study has as main objective to describe the cortical auditory potential values of children who were probably infected by the congenital syndrome of Zika virus. Methods: This is a multicenter, cross-sectional descriptive study, which was developed in the Audiology Sector of the Center for Education and Health Studies (CEES), Universidade Estadual Paulista (UNESP), and at the State University of Health Sciences of Alagoas - UNCISAL, Audiology Laboratory of the Specialized Center for Rehabilitation (CER III), with approval in the ethics committee CAAE nº 68684117.8.1001.5406. The study consisted of 30 children of both genders, from six to 38 months of age, making up the study group, with microcephaly and probable congenital syndrome of the virus zika and control group, in which cortical auditory evoked potential tests were performed in children with development.... (Complete abstract click electronic access below) / Mestre

Orientador: Virgínia Bodelão Richini-Pereira / Resumo: O Zika virus (ZIKV) é um flavivírus transmitido por mosquito que causa Febre Zika e está associado às Malformações Congênitas e Síndrome de Guillain-Barré integrando a lista de agentes etiológicos que são um problema de saúde pública internacional. Apresentamos uma investigação sorológica e molecular do ZIKV em amostras humanas na região de Bauru do estado de São Paulo, Brasil a fim de contribuir na determinação dos primeiros casos de infecção de ZIKV nos locais do estudo. Foi realizada a investigação sorológica por técnica de imunocromatografia em 2000 amostras Dengue virus negativas referentes aos anos de 2014-2016, sendo 159 (7,9%) positivas para ZIKV, evidenciando que a circularização do ZIKV na região de estudo teve início em 2014. Foi investigado pela técnica de Reação em Cadeia da Polimerase quantitativa por transcrição reversa a presença de ácido ribonucleico (RNA) do ZIKV nas 159 amostras positivas a nível sorológico. Porém o RNA viral não foi detectável. Esse resultado negativo quanto a molecular a partir de soro reforça a possibilidade de aderência do ZIKV em eritrócitos. Esses achados levantam o questionamento se outros membros do gênero Flavivirus possuem o mesmo potencial. Para complementar os dados realizamos uma análise filogenética da espécie ZIKV. Com o propósito de geração de hipóteses referentes a sua dinâmica de distribuição no Brasil. Para tal utilizamos os bancos de dados, algoritmos e parâmetros presentes nos softwares Virus Pathogen Resource e MEGA7. ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Zika virus (ZIKV) is a mosquito-borne flavivirus that causes Zika Fever and is associated with Congenital Malformations and Guillain-Barré Syndrome, which has been declared an international public health problem by the World Health Organization. We conduct a serological and molecular investigation of ZIKV in human samples in the Bauru region of the state of São Paulo, Brazil, in order to contribute to the determination of the first cases of ZIKV infection in the study sites. Serological investigation was made by immunochromatography technique performed in 2000 Dengue virus negative samples referring to the years 2014-2016, 159 (7.9%) was positive for ZIKV, evidencing that the circularization of ZIKV in the region of study began in 2014. The presence of ZIKV ribonucleic acid (RNA) in the 159 serologically positive samples was investigated by the Quantitative Reverse Polymerase Chain Reaction technique. All did not show detectable RNA. This molecular negative result from serum enhances the possibility of ZIKV adhesion in erythrocytes. These findings raise the question of whether other flaviviruses have the same potential. We also performed a phylogenetic analysis of the ZIKV species. With the purpose of generating hypotheses referring to its distribution dynamics. For this we use the databases, algorithms and parameters present in the software Virus Pathogen Resource and MEGA7. Our evidence allows us to infer that the ZIKV presents a possible adaptation in the Northeast Region ... (Complete abstract click electronic access below) / Mestre

This literature review will discuss Zika virus and the salient research on antibody dependent enhancement and how this mechanism may lead to congenital defects. Specific objectives include: the mechanism of antibody dependent enhancement, Zika and dengue virus pathogenesis, placenta pathophysiology, and how changes in viral virulence may play a role the pathogenesis of neurologic congenital defects seen in infants infected with Zika virus in utero. While some cohort studies have examined the relationship between prior dengue immunity, Zika virus infection in pregnancy, and effects on neonatal outcomes further prospective studies using large cohorts and more detailed lab testing and imaging is essential to better understand this relationship. A proposed study enrolling a large cohort of women in the 6th- 8th week of pregnancy from Northeastern Brazil will seek to further describe what additional risk dengue immunity may pose in the context of Zika virus. This risk is essential to understand, as Zika and Dengue viruses co-circulate in many regions of the world. Furthermore, participants in the proposed study will undergo bi-weekly screening for Zika virus through laboratory and ultrasound testing until their delivery. Infants will then have full neurologic testing and MRI scanning for the following year after birth to characterize any congenital defects. Neonates born to mothers with prior dengue immunity who contract Zika virus during pregnancy will be compared to neonates not exposed to Zika virus in utero. This experiment will illuminate the associated risk and evidence of ADE occurring with prior dengue immunity and Zika virus infection during pregnancy. Results from this study will not only help define risks of congenital defects with Zika virus, it will inform vaccine research and elucidate challenges in the administration of the current tetravalent dengue vaccine.

Cartas al editor

Arboviruses are blood-borne pathogens that threaten half of the world’s population. The recent outbreak of Zika virus (ZIKV) in Brazil has highlighted the importance of developing new strategies to limit virus spread. While vaccines are in development, one way to immediately suppress viral transmission is through biocontrol of mosquito vector. Novel biocontrol strategies utilize microbe – mosquito interactions to inhibit the transmission of pathogens. A powerful tool under investigation is the intracellular bacteria, Wolbachia pipientis, which are maintained in insect populations through maternal transmission. The Wolbachia strain wMel can be trans-infected into mosquitos limiting ZIKV transmission. However, thermal stress can hinder maternal transmission of the wMel strain of Wolbachia. For Wolbachia-based technologies of vector control, it is important to have additional strains with viral suppression capabilities available. We characterized alternative Wolbachia strains in A. albopictus mosquito cell lines and the underlying mechanisms of these interactions. We identified two novel Wolbachia strains with robust arbovirus repression. wAlbB, native to mosquitos blocked 90% of ZIKV growth. More strikingly, wStri, a nonnative symbiont, ablated ZIKV growth in A. albopictus cells below the limit of detection. After showing that ZIKV growth is rescued in wStri infected A. albopictus cells by the pharmacological removal of Wolbachia, we established these cells as an in vitro model for mechanistic studies. Using novel labeling and reporter techniques, we isolate a block in virus growth by Wolbachia at two stages of viral growth, entry and translation. We further show that cholesterol, which can partially rescue viral growth in Wolbachia wStri infected cells, aids in viral entry but does not promote viral growth post entry. Beyond our Wolbachia studies, we further investigated the limited arbovirus growth observed in many A. aegypti cell lines and identified two insect–specific viruses which interfere with arbovirus growth. To address the limited biocontrol tools in C. pipiens mosquitos, we characterized commensal microbiota that may be used as a direct competitor of viruses or as a tool to genetically enhance an antiviral response in the mosquito gut. Together this work expands our understanding of Wolbachia-mediated biocontrol strategies and offers novel resources to suppress arbovirus transmission. / 2020-07-18T00:00:00Z

Zika virus (ZIKV) is a sexually transmitted viral infection most frequently transmitted by mosquitoes. The source of infectious virions in the male reproductive tract has yet to be elucidated. The goals of the studies included developing and characterizing two mouse models for reproductive transmission studies and demonstration of sexual transmission of virus via artificial insemination. The mouse strains used in the study lacked receptors to interferon molecules, key signaling proteins of the host immune response. Inflammation severity was assessed during acute disease, 5-11 days after infection using a novel histopathology grading system. ZIKV proteins and genome were initially detected in epididymal epithelial cells in males. Inflammation was first observed in the epididymis and progressed to the testicle in both AG129 and Ifnar-/- males. Infection of Ifnar-/- mice may better recapitulate Zika virus pathology in humans due to milder histopathologic lesions, the presence of histologically normal sperm in epididymal tubules, and an ability to survive the acute phase of disease. In further studies, male Ifnar-/- mice were challenged subcutaneously with ZIKV. Artificial insemination fluid derived from experimentally infected males showed positive sexual transmission at 7 days post infection (DPI) but not 35 or 70 DPI. These studies show passage of virus from epididymal flush and seminal plasma to females via insemination during acute ZIKV disease in males and provides a model for sexual transmission of ZIKV.

In recent years, Zika virus (ZIKV) has garnered worldwide attention due to its epidemic spread throughout the Americas and due to the newly recognized link between ZIKV infection and neurological diseases, including microcephaly and Guillain-Barré syndrome. ZIKV is a mosquito-borne member of the genus Flavivirus, which includes the other prominent human pathogens Japanese encephalitis virus, West Nile virus, dengue virus, and yellow fever virus. Many questions about the biology of ZIKV and how it causes disease remain unanswered. Furthermore, there currently are no vaccines or licensed antiviral drugs available to treat ZIKV infection. The goal of this study was to create new tools to aid in ZIKV research and in the creation of new therapies for ZIKV infection. To accomplish this, we created two recombinant ZIKVs–one expressing a green fluorescent protein reporter gene and the other expressing a luciferase reporter gene. These additional genes will allow us to easily visualize infected cells and to precisely track levels of viral replication over time, thereby facilitating new experimental approaches and providing a means to gain insights about ZIKV. We believe that these two new versions of ZIKV will prove to be useful tools in the urgent task of better understanding how ZIKV causes disease and its links to other complications, as well as in the process of developing and testing new treatments to combat ZIKV infection.

Zika virus (ZIKV) has emerged in many regions of the world, with infection outcomes spanning from no apparent illness to crippling nervous system disease. ZIKV and its close relatives, West Nile virus, Japanese encephalitis virus, dengue virus, and yellow fever virus are primarily transmitted by mosquitoes. Three ZIKVs were selected: MR-766 (Uganda, 1947), P6-740 (Malaysia, 1966), and PRVABC-59 (Puerto Rico, 2015), whose place of origin and time of isolation differ substantially. Stable, complementary DNA (cDNA) copies of the three ZIKV RNA genomes were cloned to examine the significance of viral and host genetic variations in directing ZIKV infection outcomes. Using a new toolbox for ZIKV genome engineering and protein analysis, combined with various cell culture and mouse infection model systems, the following were determined: (1) Genome-wide landscape of viral gene products and their related species, with several immuno-reactive gene products identified in the case of all three cloned ZIKVs. (2) Viral replicability in cultured cells, varied significantly depending on the virus strain and host cell type, with one cow cell line being resistant to ZIKV infection. (3) Virus induced neurological disease in mice, differed dramatically depending on the virus dose and strain, mouse age and strain, route of infection, and presence or absence of immune system components. Overall, the findings demonstrate the impact of the viral and host genetic backgrounds on the ability of ZIKV to replicate and cause disease. The ZIKV strain-specific characterizations and molecular instruments described will provide multiple avenues for developing and testing medical countermeasures.

Orientador: Paula Rahal / Coorientador: / Banca: / Resumo: O ZIKV é um vírus de RNA, não segmentado, de fita simples e sentido positivo membro da família Flaviviridae. O genoma viral possui uma arquitetura típica de flavivírus, com cerca de 11kb de comprimento, que codifica três proteínas estruturais (Capsídeo, precursor-Membrana, Envelope) e sete proteínas não-estruturais (NS1, NS2A, NS2B, NS3, NS4A, NS4B, NS5). Nas Américas, emergiu rapidamente após surto na ilha da Páscoa, Chile. No Brasil, o surto iniciou em 2015, aumentando consideravelmente casos de microcefalia em recém-nascidos. Aliada a esses casos, também foi observada a ocorrência de síndrome neurológica de Guillain-Barré. Essas associações transformaram o impacto da transmissão e infecções por ZIKV em uma preocupação de saúde pública global. O vírus é transmitido principalmente pelos mosquitos do gênero Aedes, que possuem ampla distribuição e apresentam grandes adaptações a ambientes urbanos. Além de transmissão vetorial, pode ser transmitido via sexual e materno-fetal. O objetivo deste trabalho foi comparar as infecções por uma cepa contemporânea de ZIKV com DENV2 em modelo de explantes de placenta humana a termo, bem como quantificar expressão de citocinas, interferons do tipo I, II e III e marcadores de apoptose induzida via infecção viral. Os resultados demonstram que os explantes da placenta a termo são permissivos e apoiam a infecção por ZIKV. A quantificação da carga viral entre infecções ZIKV e DENV2 foram similares. No entanto, DENV2 apresentou decréscimo na... / Abstract: ZIKV is a non-segmented, single-stranded, positive-sense RNA virus and a member of the Flaviviridae family. Its genome has a typical 11 kB-long flavivirus architecture that encodes three structural proteins (Capsid, PrecursorMembrane, Envelop) and seven non-structural proteins (NS1, NS2A, NS2B, NS3, NS4A, NS4B and NS5). In the Americas, the viruses emerged rapidly after outbreak on Pascoa Island, Chile. The outbreak reached Brazil in 2015, substantially increasing cases of microcephaly in newborns. In addition to microcephaly, cases associated with neurological diseases such as GuillainBarré syndrome have made ZIKV a global public health concern. The virus is mainly transmitted by mosquitoes of the genus Aedes, which are widely distributed and which have adapted well great to urban environments. In addition to vector transmission, ZIKV can be transmitted via sexual and maternal-fetal routes, the virus has been isolated is from sperm, amniotic fluid and central nervous systems of stillborn fetuses. The goal of this report was compare ZIKV-infected to DENV2 in full-term human placenta explant model. Quantify expression of cytokines, type I, II and III interferons and markers of induced-apoptosis by viral infection. The results demonstrated that full-term placenta explants are permissive and support ZIKV infection. Viral loads in ZIKV and DENV2 infections were similar. However, DENV2 presented a decrease in viral load release at 24 hours post infection (h.p.i). The kinetics of viral replication coincided with the expression of proinflammatory cytokines and the increase of apoptosis in the infected tissue. Apoptosis was partially dependent on TNF-α. Anti-TNF-α treatment significantly decreased the activated-caspase 3 mediated viral infection. Cumulatively, this model demonstrates that human placental tissues are targets of ZIKV-infection and that the infection is pathogenic to ... / Doutor