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1.
Nat Commun ; 10(1): 4155, 2019 09 13.
Artigo em Inglês | MEDLINE | ID: mdl-31519912

RESUMO

Zika virus (ZIKV) infection results in an increased risk of spontaneous abortion and poor intrauterine growth although the underlying mechanisms remain undetermined. Little is known about the impact of ZIKV infection during the earliest stages of pregnancy, at pre- and peri-implantation, because most current ZIKV pregnancy studies have focused on post-implantation stages. Here, we demonstrate that trophectoderm cells of pre-implantation human and mouse embryos can be infected with ZIKV, and propagate virus causing neural progenitor cell death. These findings are corroborated by the dose-dependent nature of ZIKV susceptibility of hESC-derived trophectoderm cells. Single blastocyst RNA-seq reveals key transcriptional changes upon ZIKV infection, including nervous system development, prior to commitment to the neural lineage. The pregnancy rate of mice is >50% lower in pre-implantation infection than infection at E4.5, demonstrating that pre-implantation ZIKV infection leads to miscarriage. Cumulatively, these data elucidate a previously unappreciated association of pre- and peri-implantation ZIKV infection and microcephaly.


Assuntos
Complicações Infecciosas na Gravidez/metabolismo , Infecção por Zika virus/complicações , Infecção por Zika virus/metabolismo , Zika virus/patogenicidade , Aborto Espontâneo/metabolismo , Aborto Espontâneo/fisiopatologia , Animais , Blastocisto/citologia , Blastocisto/metabolismo , Implantação do Embrião/fisiologia , Feminino , Desenvolvimento Fetal/genética , Desenvolvimento Fetal/fisiologia , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Gravidez , RNA Viral/genética , Pesquisa Médica Translacional/métodos , Trofoblastos/citologia , Trofoblastos/metabolismo
2.
Nat Commun ; 10(1): 4430, 2019 09 27.
Artigo em Inglês | MEDLINE | ID: mdl-31562326

RESUMO

Zika virus (ZIKV) invades and persists in the central nervous system (CNS), causing severe neurological diseases. However the virus journey, from the bloodstream to tissues through a mature endothelium, remains unclear. Here, we show that ZIKV-infected monocytes represent suitable carriers for viral dissemination to the CNS using human primary monocytes, cerebral organoids derived from embryonic stem cells, organotypic mouse cerebellar slices, a xenotypic human-zebrafish model, and human fetus brain samples. We find that ZIKV-exposed monocytes exhibit higher expression of adhesion molecules, and higher abilities to attach onto the vessel wall and transmigrate across endothelia. This phenotype is associated to enhanced monocyte-mediated ZIKV dissemination to neural cells. Together, our data show that ZIKV manipulates the monocyte adhesive properties and enhances monocyte transmigration and viral dissemination to neural cells. Monocyte transmigration may represent an important mechanism required for viral tissue invasion and persistence that could be specifically targeted for therapeutic intervention.


Assuntos
Moléculas de Adesão Celular/metabolismo , Monócitos/metabolismo , Monócitos/virologia , Neurônios/metabolismo , Migração Transendotelial e Transepitelial/fisiologia , Infecção por Zika virus/metabolismo , Zika virus/fisiologia , Zika virus/patogenicidade , Animais , Adesão Celular/fisiologia , Sobrevivência Celular , Sistema Nervoso Central/metabolismo , Sistema Nervoso Central/patologia , Sistema Nervoso Central/virologia , Cerebelo/patologia , Cerebelo/virologia , Modelos Animais de Doenças , Células-Tronco Embrionárias , Endotélio/virologia , Feminino , Humanos , Monócitos/patologia , Neurônios/patologia , Neurônios/virologia , Organoides/metabolismo , Organoides/patologia , Peixe-Zebra , Infecção por Zika virus/patologia , Infecção por Zika virus/virologia
3.
Nucleic Acids Res ; 47(18): 9789-9802, 2019 10 10.
Artigo em Inglês | MEDLINE | ID: mdl-31392996

RESUMO

Members of the Flaviviridae family, including dengue virus (DENV) and yellow fever virus, cause serious disease in humans, whilst maternal infection with Zika virus (ZIKV) can induce microcephaly in newborns. Following infection, flaviviral RNA genomes are translated to produce the viral replication machinery but must then serve as a template for the transcription of new genomes. However, the ribosome and viral polymerase proceed in opposite directions along the RNA, risking collisions and abortive replication. Whilst generally linear, flavivirus genomes can adopt a circular conformation facilitated by long-range RNA-RNA interactions, shown to be essential for replication. Using an in vitro reconstitution approach, we demonstrate that circularization inhibits de novo translation initiation on ZIKV and DENV RNA, whilst the linear conformation is translation-competent. Our results provide a mechanism to clear the viral RNA of ribosomes in order to promote efficient replication and, therefore, define opposing roles for linear and circular conformations of the flavivirus genome.


Assuntos
Vírus da Dengue/genética , Flavivirus/genética , Biossíntese de Proteínas , Zika virus/genética , Vírus da Dengue/patogenicidade , Flavivirus/patogenicidade , Genoma Viral/genética , Genômica , Humanos , Recém-Nascido , RNA Viral/genética , Replicação Viral/genética , Vírus da Febre Amarela/genética , Vírus da Febre Amarela/patogenicidade , Zika virus/patogenicidade , Infecção por Zika virus/genética , Infecção por Zika virus/virologia
4.
Chin Med J (Engl) ; 132(14): 1645-1653, 2019 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-31268910

RESUMO

BACKGROUND: Zika virus (ZIKV) has emerged as a global pathogen causing significant public health concerns. China has reported several imported cases where ZIKV were carried by travelers who frequently travel between China and ZIKV-endemic regions. To fully characterize the ZIKV strains isolated from the cases reported in China and assess the risk of ZIKV transmission in China, comprehensive phylogenetic and genetic analyses were performed both on all ZIKV sequences of China and on a group of scientifically selected ZIKV sequences reported in some of the top interested destinations for Chinese travelers. METHODS: ZIKV genomic sequences were retrieved from the National Center for Biotechnology Information database through stratified sampling. Recombination event detection, maximum likelihood (ML) phylogenetic analysis, molecular clock analysis, selection pressure analysis, and amino acid substitution analysis were used to reconstruct the epidemiology and molecular transmission of ZIKV. RESULTS: The present study investigated 18 ZIKV sequences from China and 70 sequences from 16 selected countries. Recombination events rarely happens in all ZIKV Asian lineage. ZIKV genomes were generally undergone episodic positive selection (17 sites), and only one site was under pervasive positive selection. All ZIKV imported into China were Asian lineage and were assigned into two clusters: Venezuela-origin (cluster A) and Samoa-origin cluster (cluster B) with common ancestor from French Polynesia. The time of most recent common ancestors of Cluster A dated to approximately 2013/11 (95% highest posterior density [HPD] 2013/06, 2014/03) and cluster B dated to 2014/08 (95% HPD 2014/02, 2015/01). Cluster B is more variable than Cluster A in comparison with other clusters, but no varied site of biological significance was revealed. ZIKV strains in Southeast Asia countries are independent from strains in America epidemics. CONCLUSIONS: The genetic evolution of ZIKV is conservative. There are two independent introductions of ZIKV into China and China is in danger of autochthonous transmission of ZIKV because of high-risk surrounding areas. Southeast Asia areas have high risk of originating the next large-scale epidemic ZIKV strains.


Assuntos
Proteínas não Estruturais Virais/metabolismo , Infecção por Zika virus/genética , Zika virus/patogenicidade , China , Evolução Molecular , Genoma Viral/genética , Funções Verossimilhança , Filogenia , Estrutura Secundária de Proteína , Medição de Risco , Proteínas não Estruturais Virais/química , Proteínas não Estruturais Virais/genética , Zika virus/genética , Infecção por Zika virus/transmissão
5.
PLoS Negl Trop Dis ; 13(6): e0007387, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31170143

RESUMO

We investigated the growth properties and virulence in mice of three Zika virus (ZIKV) strains of Asian/American lineage, PRVABC59, ZIKV/Hu/Chiba/S36/2016 (ChibaS36), and ZIKV/Hu/NIID123/2016 (NIID123), belonging to the three distinct subtypes of this lineage. The American-subtype strain, PRVABC59, showed the highest growth potential in vitro, whereas the Southeast Asian-subtype strain, NIID123, showed the lowest proliferative capacity. Moreover, PRVABC59- and NIID123-infected mice showed the highest and lowest viremia levels and infectious virus levels in the testis, respectively, and the rate of damaged testis in PRVABC59-infected mice was higher than in mice infected with the other two strains. Lastly, ZIKV NS1 antigen was detected in the damaged testes of mice infected with PRVABC59 and the Pacific-subtype strain, ChibaS36, at 2 weeks post-inoculation and in the epididymides of PRVABC59-infected mice at 6 weeks post-inoculation. Our results indicate that PRVABC59 and ChibaS36 exhibit increased abilities to grow in vitro and in vivo and to induce testis damage in mice.


Assuntos
Infecção por Zika virus/virologia , Zika virus/crescimento & desenvolvimento , Animais , Sangue/virologia , Modelos Animais de Doenças , Epididimo/virologia , Masculino , Camundongos Endogâmicos C57BL , Testículo/virologia , Carga Viral , Virulência , Zika virus/isolamento & purificação , Zika virus/patogenicidade
6.
J Assist Reprod Genet ; 36(7): 1339-1349, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31147867

RESUMO

Zika virus (ZIKV) is mainly transmitted through Aedes mosquito bites, but sexual and post-transfusion transmissions have been reported. During acute infection, ZIKV is detectable in most organs and body fluids including human semen. Although it is not currently epidemic, there is a concern that the virus can still reemerge since the male genital tract might harbor persistent reservoirs that could facilitate viral transmission over extended periods, raising concerns among public health and assisted reproductive technologies (ART) experts and professionals. So far, the consensus is that ZIKV infection in the testes or epididymis might affect sperm development and, consequently, male fertility. Still, diagnostic tests have not yet been adapted to resource-restricted countries. This manuscript provides an updated overview of the cellular and molecular mechanisms of ZIKV infection and reviews data on ZIKV persistence in semen and associated risks to the male reproductive system described in human and animal models studies. We provide an updated summary of the impact of the recent ZIKV outbreak on human-ART, weighing on current recommendations and diagnostic approaches, both available and prospective, with special emphasis on mass spectrometry-based biomarker discovery. In the light of the identified gaps in our accumulated knowledge on the subject, we highlight the importance for couples seeking ART to follow the constantly revised guidelines and the need of specific ZIKV diagnosis tools for semen screening to contain ZIKV virus spread and make ART safer.


Assuntos
Biomarcadores , Genitália Masculina/fisiopatologia , Infecção por Zika virus/fisiopatologia , Zika virus/patogenicidade , Animais , Feminino , Genitália Masculina/virologia , Humanos , Masculino , Espectrometria de Massas , Modelos Animais , Sêmen/metabolismo , Infecção por Zika virus/virologia
7.
Int J Mol Sci ; 20(12)2019 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-31234341

RESUMO

Zika virus (ZIKV) transmission can cause serious fetal neurological abnormalities. ZIKV persistence in various human cells and tissues can serve as infectious reservoirs and post serious threats to public health. The human embryonic kidney (HEK293) cell line with known neuronal developmental properties was readily infected by ZIKV in a strain-dependent fashion. Significant cytopathic effect in HEK293 cells infected by the prototype MR 766 strain of ZIKV resulted in complete loss of cells, while small numbers of HEK293 cells infected by contemporary ZIKV isolates (PRV or FLR strain) continued to survive and regrow to confluency in the culture around two months after initial infection. Most, if not all, of the cells in the two resulting persistently ZIKV-infected HEK293 cell lines tested positive for ZIKV antigen. Compared to HEK293 control cells, the persistently ZIKV-infected HEK293 cells had slower growth rates with some cells undergoing apoptosis in culture. The "persistent ZIKVs" produced constitutively by both PRV and FLR strains ZIKV-infected HEK293 cells had significantly attenuated cell infectivity and/or cytopathogenicity. Comparative genome sequence analyses between the persistent ZIKVs and the original inoculum ZIKVs showed no clonal selection with specific gene mutations in the prolonged process of establishing persistently PRV strain ZIKV-infected HEK293 cells; while selection of ZIKV subclones with mutations in the envelope, protein pr and multiple NS genes was evident in developing persistently FLR strain ZIKV-infected HEK293 cell line. Our study provides molecular insights into the complex interplays of ZIKV and human host cells in establishing ZIKV persistence.


Assuntos
Infecção por Zika virus/patologia , Zika virus/fisiologia , Animais , Apoptose , Efeito Citopatogênico Viral , Genoma Viral , Genômica , Células HEK293 , Humanos , Mutação , Células Vero , Zika virus/genética , Zika virus/patogenicidade , Infecção por Zika virus/virologia
8.
BMC Res Notes ; 12(1): 326, 2019 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-31182146

RESUMO

OBJECTIVE: Increase in the evidence of global occurrence of Zika viral infection suggests that in Africa the circulation of the virus which causes 80% of asymptomatic infection could be undetected and/or overlooked. We sought to serologically detect Zika virus infection in febrile patients at Greater Accra Regional Hospital, Ghana. RESULTS: Of the 160 patient serum samples analyzed, 33 were found to have antibodies against Zika virus infection. Among the sero-positives 30 (91%) of the cases were anti-Zika virus IgM with the 21-30-year age group recording the highest number of 8 (26%) and 2 (7%) cases being the least for the 61 years and above age group. All sero-positive febrile patients developed at least one symptom consistent with Zika virus infection: 33 (100%) fever, 25 (76%) muscle pain, 24 (73%) joint pain, and conjunctivitis 2 (6%). Digestive symptoms recorded include 16 (49%) nausea, 12 (36%) vomiting and diarrhea 18 (55%). In addition, 28 (85%) loss of appetite, 14 (75%) rapid respiration and chest pain 15 (42%) were reported by seropositive febrile patients. Our data indicates exposure to Zika virus which suggests the possible circulation of the virus among febrile patients in Ghana with a sero-prevalence rate of 20.6%.


Assuntos
Anticorpos Antivirais/sangue , Artralgia/imunologia , Febre/imunologia , Mialgia/imunologia , Infecção por Zika virus/imunologia , Zika virus/imunologia , Adolescente , Adulto , Idoso , Artralgia/diagnóstico , Artralgia/epidemiologia , Artralgia/fisiopatologia , Criança , Pré-Escolar , Conjuntivite Viral/diagnóstico , Conjuntivite Viral/epidemiologia , Conjuntivite Viral/imunologia , Conjuntivite Viral/fisiopatologia , Estudos Transversais , Diarreia/diagnóstico , Diarreia/epidemiologia , Diarreia/imunologia , Diarreia/fisiopatologia , Feminino , Febre/diagnóstico , Febre/epidemiologia , Febre/fisiopatologia , Gana/epidemiologia , Humanos , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Masculino , Pessoa de Meia-Idade , Mialgia/diagnóstico , Mialgia/epidemiologia , Mialgia/fisiopatologia , Náusea/diagnóstico , Náusea/epidemiologia , Náusea/imunologia , Náusea/fisiopatologia , Estudos Soroepidemiológicos , Vômito/diagnóstico , Vômito/epidemiologia , Vômito/imunologia , Vômito/fisiopatologia , Zika virus/crescimento & desenvolvimento , Zika virus/patogenicidade , Infecção por Zika virus/diagnóstico , Infecção por Zika virus/epidemiologia , Infecção por Zika virus/fisiopatologia
9.
Matern Child Health J ; 23(8): 1140-1145, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31209616

RESUMO

OBJECTIVES: This study sought to describe the knowledge and perceptions of pregnant women in Miami-Dade County concerning Zika virus (ZIKV) in their community, to characterize their testing behaviors, and to identify any barriers that would keep them from seeking testing. METHODS: The Florida Department of Health in Miami-Dade County partnered with the Healthy Start Coalition of Miami-Dade to administer an assessment survey in eight OBGYN clinics from June to August 2017. The survey captured past ZIKV testing practices, attitudes towards testing, barriers to testing, risk perception of ZIKV in the participants' community, and ZIKV-related knowledge. Descriptive analyses were performed on variables of interest. Chi squared tests examined associations between categorical variables. RESULTS: A total of 363 participants were included in the analysis. Of these, 203 (55.9%) thought they should be tested for ZIKV, and less than half of the participants reported having been previously tested (152, 41.9%). Participants with some high school education were significantly more likely than those with higher education levels to see ZIKV as a "big problem" in the community (p = 0.0026). There was a significant association (p ≤ 0.0001) between women who thought that they should be tested, and those who perceived ZIKV to be a medium or big problem in their community. CONCLUSIONS FOR PRACTICE: Health interventions that focus on increasing ZIKV knowledge should also place greater emphasis on risk communication when targeting the pregnant population. Having a higher risk perception may be more predictive of testing behaviors than having a lack of barriers or a high level of ZIKV-related knowledge.


Assuntos
Programas de Rastreamento/psicologia , Percepção , Gestantes/psicologia , Risco Ajustado/normas , Infecção por Zika virus/diagnóstico , Adolescente , Adulto , Feminino , Florida , Humanos , Programas de Rastreamento/métodos , Programas de Rastreamento/estatística & dados numéricos , Gravidez , Risco Ajustado/métodos , Medição de Risco/métodos , Inquéritos e Questionários , Zika virus/patogenicidade , Infecção por Zika virus/psicologia
10.
mSphere ; 4(3)2019 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-31068433

RESUMO

Zika virus (ZIKV) infection during pregnancy leads to devastating fetal outcomes, including neurological (microcephaly) and ocular pathologies such as retinal lesions, optic nerve abnormalities, chorioretinal atrophy, and congenital glaucoma. Only clinical case reports have linked ZIKV infection to causing glaucoma, a major blinding eye disease. In the present study, we have investigated the role of ZIKV in glaucoma pathophysiology using in vitro and in vivo experimental models. We showed that human primary trabecular meshwork (Pr. TM) cells, as well as a human GTM3 cell line, were permissive to ZIKV infection. ZIKV induced the transcription of various genes expressing pattern recognition receptors (TLR2, TLR3, and RIG-I), cytokines/chemokines (TNF-α, IL-1ß, CCL5, and CXCL10), interferons (IFN-α2, IFN-ß1, and IFN-γ), and interferon-stimulated genes (ISG15 and OAS2) in Pr. TM cells. ZIKV infection in IFNAR1-/- and wild-type (WT) mouse eyes resulted in increased intraocular pressure (IOP) and the development of chorioretinal atrophy. Anterior chamber (AC) inoculation of ZIKV caused infectivity in iridocorneal angle and TM, leading to the death of TM cells in the mouse eyes. Moreover, anterior segment tissue of infected eyes exhibited increased expression of inflammatory mediators and interferons. Furthermore, ZIKV infection in IFNAR1-/- mice resulted in retinal ganglion cell (RGC) death and loss, coinciding with optic nerve infectivity and disruption of anterograde axonal transport. Because of similarity in glaucomatous pathologies in our study and other experimental glaucoma models, ZIKV infection can be used to study infectious triggers of glaucoma, currently an understudied area of investigation.IMPORTANCE Ocular complications due to ZIKV infection remains a major public health concern because of their ability to cause visual impairment or blindness. Most of the previous studies have shown ZIKV-induced ocular pathology in the posterior segment (i.e., retina) of the eye. However, some recent clinical reports from affected countries highlighted the importance of ZIKV in affecting the anterior segment of the eye and causing congenital glaucoma. Because glaucoma is the second leading cause of blindness worldwide, it is imperative to study ZIKV infection in causing glaucoma to identify potential targets for therapeutic intervention. In this study, we discovered that ZIKV permissively infects human TM cells and evokes inflammatory responses causing trabeculitis. Using a mouse model, we demonstrated that ZIKV infection resulted in higher IOP, increased RGC loss, and optic nerve abnormalities, the classical hallmarks of glaucoma. Collectively, our study provides new insights into ocular ZIKV infection resulting in glaucomatous pathology.


Assuntos
Olho/patologia , Olho/virologia , Glaucoma/virologia , Malha Trabecular/virologia , Infecção por Zika virus/complicações , Zika virus/patogenicidade , Animais , Morte Celular , Linhagem Celular , Quimiocinas/genética , Citocinas/genética , Modelos Animais de Doenças , Feminino , Glaucoma/fisiopatologia , Humanos , Interferons/genética , Pressão Intraocular , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Células Ganglionares da Retina/patologia , Células Ganglionares da Retina/virologia , Malha Trabecular/patologia , Transcriptoma , Infecção por Zika virus/patologia
11.
Gene ; 708: 57-62, 2019 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-31128224

RESUMO

Zika virus (ZIKV) has spread globally and has been linked to the onset of microcephaly and other brain abnormalities. The ZIKV genome consists of an ~10.7 kb positive-stranded RNA molecule that encodes three structural (C, prM and E) and seven nonstructural (5'-NS1-NS2A-NS2B-NS3- NS4A/2K-NS4B-NS5-3') proteins. In this work, we looked for genetic variants in 485 ZIKV complete genomes from GenBank (NCBI) and performed a computational systematic approach using MAESTROweb server to assess the impact of nonsynonymous mutations in ZIKV proteins (C, M, E, NS1, NS2A, NS2B-NS3 protease, NS3 helicase and NS5). Then, we merged the data and correlated it with the phenotypic reports of ZIKV circulating strains. The sensitivity profile of the proteins showed 96 mutational hotspots. We found 22 relevant mutations in proteins C (I80T), NS2A (I34M/T/V, I45V, I80T/V, L113F, A117V, I118V, L128P, V143A, T151A, M199I/V, R207K and L208I) and NS3 helicase (D436G, Y498H, R525K, Q528R and R583K) of the circulating strains. Our analysis exploited the impact of nonsynonymous mutations on ZIKV proteins, their structural and functional insights. The results presented here could advance our current understanding on ZIKV proteins functions and pathogenesis.


Assuntos
Genoma Viral/genética , Proteínas Virais/genética , Zika virus/genética , Sequência de Aminoácidos/genética , Mutação , Conformação Proteica , Zika virus/patogenicidade
12.
PLoS Pathog ; 15(4): e1007640, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30998804

RESUMO

Zika virus (ZIKV) has been known for decades to circulate in Africa and Asia. However, major complications of a ZIKV infection have recently become apparent for reasons that are still not fully elucidated. One of the hypotheses for the seemingly increased pathogenicity of ZIKV is that cross-reactive dengue antibodies can enhance a ZIKV infection through the principle of antibody-dependent enhancement (ADE). Recently, ADE in ZIKV infection has been studied, but conclusive evidence for the clinical importance of this principle in a ZIKV infection is lacking. Conversely, the widespread circulation of ZIKV in dengue virus (DENV)-endemic regions raises new questions about the potential contribution of ZIKV antibodies to DENV ADE. In this review, we summarize the results of the evidence to date and elaborate on other possible detrimental effects of cross-reactive flavivirus antibodies, both for ZIKV infection and the risk of ZIKV-related congenital anomalies, DENV infection, and dengue hemorrhagic fever.


Assuntos
Anticorpos Antivirais/imunologia , Anticorpos Facilitadores/imunologia , Reações Cruzadas/imunologia , Efeito Citopatogênico Viral/imunologia , Dengue/imunologia , Infecção por Zika virus/imunologia , Zika virus/patogenicidade , Dengue/virologia , Humanos , Infecção por Zika virus/prevenção & controle , Infecção por Zika virus/virologia
13.
Int J Mol Sci ; 20(8)2019 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-31003530

RESUMO

The mosquito-borne viral disease caused by the Dengue virus is an expanding global threat. Diagnosis in low-resource-settings and epidemiological surveillance urgently requires new immunoprobes for serological tests. Structure-based epitope prediction is an efficient method to design diagnostic peptidic probes able to reveal specific antibodies elicited in response to infections in patients' sera. In this study, we focused on the Dengue viral envelope protein (E); computational analyses ranging from extensive Molecular Dynamics (MD) simulations and energy-decomposition-based prediction of potentially immunoreactive regions identified putative epitope sequences. Interestingly, one such epitope showed internal dynamic and energetic properties markedly different from those of other predicted sequences. The epitope was thus synthesized as a linear peptide, modified for chemoselective immobilization on microarrays and used in a serological assay to discriminate Dengue-infected individuals from healthy controls. The synthetic epitope probe showed a diagnostic performance comparable to that of the full antigen in terms of specificity and sensitivity. Given the high level of sequence identity among different flaviviruses, the epitope was immune-reactive towards Zika-infected sera as well. The results are discussed in the context of the quest for new possible structure-dynamics-based rules for the prediction of the immunoreactivity of selected antigenic regions with potential pan-flavivirus immunodiagnostic capacity.


Assuntos
Vírus da Dengue/imunologia , Dengue/imunologia , Epitopos/imunologia , Proteínas do Envelope Viral/imunologia , Anticorpos Antivirais , Biologia Computacional , Reações Cruzadas/imunologia , Dengue/sangue , Dengue/virologia , Vírus da Dengue/patogenicidade , Mapeamento de Epitopos , Humanos , Simulação de Dinâmica Molecular , Peptídeos/imunologia , Zika virus/imunologia , Zika virus/patogenicidade , Infecção por Zika virus/sangue , Infecção por Zika virus/imunologia , Infecção por Zika virus/virologia
14.
PLoS Negl Trop Dis ; 13(4): e0007281, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30946747

RESUMO

BACKGROUND: Recent epidemics of Zika virus (ZIKV) in the Pacific and the Americas have highlighted its potential as an emerging pathogen of global importance. Both Aedes (Ae.) aegypti and Ae. albopictus are known to transmit ZIKV but variable vector competence has been observed between mosquito populations from different geographical regions and different virus strains. Since Australia remains at risk of ZIKV introduction, we evaluated the vector competence of local Ae. aegypti and Ae. albopictus for a Brazilian epidemic ZIKV strain. In addition, we evaluated the impact of daily temperature fluctuations around a mean of 28°C on ZIKV transmission and extrinsic incubation period. METHODOLOGY/PRINCIPAL FINDINGS: Mosquitoes were orally challenged with a Brazilian ZIKV strain (8.8 log CCID50/ml) and maintained at either 28°C constant or fluctuating temperature conditions. At 3, 7 and 14 days post-infection (dpi), ZIKV RNA copies were quantified in mosquito bodies, as well as wings and legs, using qRT-PCR, while virus antigen in saliva (a proxy for transmission) was detected using a cell culture ELISA. Despite high body and disseminated infection rates in both vectors, the transmission rates of ZIKV in saliva of Ae. aegypti (50-60%) were significantly higher than in Ae. albopictus (10%) at 14 dpi. Both species supported a high viral load in bodies, with no significant differences between constant and fluctuating temperature conditions. However, a significant difference in viral load in wings and legs between species was observed, with higher titres in Ae. aegypti maintained at constant temperature conditions. For ZIKV transmission to occur in Ae. aegypti, a disseminated virus load threshold of 7.59 log10 copies had to be reached. CONCLUSIONS/SIGNIFICANCE: Australian Ae. aegypti are better able to transmit a Brazilian ZIKV strain than Ae. albopictus. The results are in agreement with the global consensus that Ae. aegypti is the major vector of ZIKV.


Assuntos
Aedes/virologia , Mosquitos Vetores/virologia , Infecção por Zika virus/transmissão , Animais , Austrália/epidemiologia , Brasil , RNA Viral/análise , Saliva/virologia , Temperatura Ambiente , Carga Viral , Asas de Animais/virologia , Zika virus/genética , Zika virus/patogenicidade
16.
Viruses ; 11(3)2019 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-30875715

RESUMO

Zika virus (ZIKV) is an emerging mosquito-borne member of the Flaviviridae family that has historically been known to cause sporadic outbreaks, associated with a mild febrile illness, in Africa and Southeast Asia [...].


Assuntos
Interações entre Hospedeiro e Microrganismos , Pesquisa/tendências , Infecção por Zika virus/epidemiologia , Surtos de Doenças , Feminino , Humanos , Mosquitos Vetores/virologia , Gravidez , Complicações Infecciosas na Gravidez/virologia , Zika virus/patogenicidade , Infecção por Zika virus/complicações
17.
PLoS Negl Trop Dis ; 13(3): e0007212, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30845254

RESUMO

Zika virus (ZIKV) is a mosquito-borne positive sense RNA virus. Recently, ZIKV emerged into the Western hemisphere as a human health threat, with severe disease associated with developmental and neurological complications. The structural envelope protein of ZIKV and other neurotropic flaviviruses contains an extended CD-loop relative to non-neurotropic flaviviruses, and has been shown to augment ZIKV stability and pathogenesis. Here we show that shortening the CD-loop in ZIKV attenuates the virus in mice, by reducing the ability to invade and replicate in the central nervous system. The CD-loop mutation was genetically stable following infection in mice, though secondary site mutations arise adjacent to the CD-loop. Importantly, while shortening of the CD-loop attenuates the virus, the CD-loop mutant maintains antigenicity in immunocompetent mice, eliciting an antibody response that similarly neutralizes both the mutant and wildtype ZIKV. These findings suggest that the extended CD-loop in ZIKV is a determinant of neurotropism and may be a target in live-attenuated vaccine design, for not only ZIKV, but for other neurotropic flaviviruses.


Assuntos
Sistema Nervoso Central/virologia , Proteínas do Envelope Viral/imunologia , Vacinas Virais/imunologia , Infecção por Zika virus/prevenção & controle , Zika virus/imunologia , Zika virus/patogenicidade , Animais , Anticorpos Antivirais/imunologia , Humanos , Camundongos , Camundongos Knockout , Mutação , Proteínas do Envelope Viral/química , Proteínas do Envelope Viral/genética , Virulência , Replicação Viral/genética , Zika virus/genética
18.
Int J Mol Sci ; 20(5)2019 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-30836648

RESUMO

Emerging mosquito-transmitted RNA viruses, such as Zika virus (ZIKV) and Chikungunya represent human pathogens of an immense global health problem. In particular, ZIKV has emerged explosively since 2007 to cause a series of epidemics in the South Pacific and most recently in the Americas. Although typical ZIKV infections are asymptomatic, ZIKV infection during pregnancy is increasingly associated with microcephaly and other fetal developmental abnormalities. In the last few years, genomic and molecular investigations have established a remarkable progress on the pathogenic mechanisms of ZIKV infection using in vitro and in vivo models. Here, we highlight recent advances in ZIKV-host cell interaction studies, including cellular targets of ZIKV, ZIKV-mediated cell death mechanisms, host cell restriction factors that limit ZIKV replication, and immune evasion mechanisms utilized by ZIKV. Understanding of the mechanisms of ZIKV⁻host interaction at the cellular level will contribute crucial insights into the development of ZIKV therapeutics and vaccines.


Assuntos
Interações Hospedeiro-Patógeno/genética , Replicação Viral/genética , Infecção por Zika virus/genética , Zika virus/genética , Animais , Culicidae/patogenicidade , Culicidae/virologia , Humanos , Microcefalia , Vacinas Virais/genética , Vacinas Virais/uso terapêutico , Zika virus/patogenicidade , Infecção por Zika virus/transmissão , Infecção por Zika virus/virologia
19.
Biosens Bioelectron ; 131: 149-155, 2019 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-30831416

RESUMO

Seventy years after its discovery, the zika virus emerged in Brazil and spread rapidly throughout the Americas, bringing unusual complications such as microcephaly. The World Health Organization classifies zika as the most harmful viral disease today and considers the development of new diagnostic methods for zika and related diseases, such as dengue, urgent. Although there are tests to identify both infections, current diagnostic methods are slow, nonspecific, and costly. This study describes an impedimetric electrochemical DNA biosensor for label-free detection of zika virus. Disposable electrodes were fabricated by thermal evaporation on polyethylene terephthalate substrates covered with a nanometric gold layer manufactured in three-contact configurations. The disposable, evaporated electrodes were morphologically characterized by atomic force microscopy and scanning electron microscopy. The electrode surface was characterized by electroanalytical techniques. Genetic sequences of primers and complementary capture probes were designed based on analysis of the zika and dengue virus genomes. The biosensor used a three-contact electrode to identify DNA sequences in a drop of sample, and for detection of zika virus sequences, it allowed for direct reading of the hybridization event without labeling on disposable electrodes and with a 1.5 h response time. In this system, impedance measurements indicated a limit of detection of 25.0 ±â€¯1.7 nM. The developed biosensors showed selectivity for zika in the synthetic DNA assays, and therefore, are promising for clinical analysis.


Assuntos
Técnicas Biossensoriais , Técnicas Eletroquímicas , Infecção por Zika virus/diagnóstico , Zika virus/isolamento & purificação , Sondas de DNA/química , Sondas de DNA/genética , DNA Viral/genética , DNA Viral/isolamento & purificação , Ouro/química , Humanos , Limite de Detecção , Microscopia de Força Atômica , Zika virus/patogenicidade , Infecção por Zika virus/virologia
20.
Biosens Bioelectron ; 131: 46-52, 2019 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-30822687

RESUMO

Detection of viral infection is commonly performed using serological techniques like the enzyme-linked immunosorbent assay (ELISA) to detect antibody responses. Such assays may also be used to determine the infection phase based on isotype prevalence. However, ELISAs demonstrate limited sensitivity and are difficult to perform at the point of care. Here, we present a novel technique for label-free, rapid detection of ultra-low concentrations of virus specific antibodies. We have developed a simple, robust capacitive biosensor using microwires coated with Zika or Chikungunya virus envelope antigen. With little discernable nonspecific binding, the sensor can detect as few as 10 antibody molecules in a small volume (10 molecules/30 µL) within minutes. It can also be used to rapidly, specifically, and accurately determine the isotype of antigen-specific antibodies. Finally, we demonstrate that anti-Zika virus antibody can be sensitively and specifically detected in dilute mouse serum and can be isotyped using the sensor. Overall, our findings suggest that our microwire sensor platform has the potential to be used as a reliable, sensitive, and inexpensive diagnostic tool to detect immune responses at the point of care.


Assuntos
Anticorpos Antivirais/isolamento & purificação , Técnicas Biossensoriais , Infecção por Zika virus/diagnóstico , Zika virus/isolamento & purificação , Anticorpos Antivirais/sangue , Formação de Anticorpos/imunologia , Humanos , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Proteínas do Envelope Viral/sangue , Proteínas do Envelope Viral/isolamento & purificação , Zika virus/patogenicidade , Infecção por Zika virus/virologia
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