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1.
Sci Rep ; 11(1): 19713, 2021 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-34611200

RESUMO

The novel coronavirus disease 2019 (COVID-19) presents with non-specific clinical features. This may result in misdiagnosis or delayed diagnosis, and lead to further transmission in the community. We aimed to derive early predictors to differentiate COVID-19 from influenza and dengue. The study comprised 126 patients with COVID-19, 171 with influenza and 180 with dengue, who presented within 5 days of symptom onset. All cases were confirmed by reverse transcriptase polymerase chain reaction tests. We used logistic regression models to identify demographics, clinical characteristics and laboratory markers in classifying COVID-19 versus influenza, and COVID-19 versus dengue. The performance of each model was evaluated using receiver operating characteristic (ROC) curves. Shortness of breath was the strongest predictor in the models for differentiating between COVID-19 and influenza, followed by diarrhoea. Higher lymphocyte count was predictive of COVID-19 versus influenza and versus dengue. In the model for differentiating between COVID-19 and dengue, patients with cough and higher platelet count were at increased odds of COVID-19, while headache, joint pain, skin rash and vomiting/nausea were indicative of dengue. The cross-validated area under the ROC curve for all four models was above 0.85. Clinical features and simple laboratory markers for differentiating COVID-19 from influenza and dengue are identified in this study which can be used by primary care physicians in resource limited settings to determine if further investigations or referrals would be required.


Assuntos
COVID-19/patologia , Dengue/patologia , Influenza Humana/patologia , Adulto , Área Sob a Curva , COVID-19/complicações , COVID-19/virologia , Estudos de Coortes , Dengue/complicações , Dengue/virologia , Diagnóstico Diferencial , Diarreia/etiologia , Feminino , Febre/etiologia , Humanos , Influenza Humana/complicações , Influenza Humana/virologia , Contagem de Linfócitos , Masculino , Pessoa de Meia-Idade , Contagem de Plaquetas , RNA Viral/análise , RNA Viral/metabolismo , Curva ROC , SARS-CoV-2/genética , SARS-CoV-2/isolamento & purificação , Vômito/etiologia , Adulto Jovem
2.
Viruses ; 13(8)2021 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-34452505

RESUMO

Viral infection is a global public health threat causing millions of deaths. A suitable small animal model is essential for viral pathogenesis and host response studies that could be used in antiviral and vaccine development. The tree shrew (Tupaia belangeri or Tupaia belangeri chinenesis), a squirrel-like non-primate small mammal in the Tupaiidae family, has been reported to be susceptible to important human viral pathogens, including hepatitis viruses (e.g., HBV, HCV), respiratory viruses (influenza viruses, SARS-CoV-2, human adenovirus B), arboviruses (Zika virus and dengue virus), and other viruses (e.g., herpes simplex virus, etc.). The pathogenesis of these viruses is not fully understood due to the lack of an economically feasible suitable small animal model mimicking natural infection of human diseases. The tree shrew model significantly contributes towards a better understanding of the infection and pathogenesis of these important human pathogens, highlighting its potential to be used as a viable viral infection model of human viruses. Therefore, in this review, we summarize updates regarding human viral infection in the tree shrew model, which highlights the potential of the tree shrew to be utilized for human viral infection and pathogenesis studies.


Assuntos
Modelos Animais de Doenças , Tupaia , Viroses , Infecções por Adenoviridae/imunologia , Infecções por Adenoviridae/virologia , Animais , COVID-19/virologia , Dengue/imunologia , Dengue/patologia , Dengue/virologia , Infecções por HIV/virologia , Hepatite B/imunologia , Hepatite B/virologia , Hepatite C/imunologia , Hepatite C/patologia , Hepatite C/virologia , Herpes Simples/patologia , Herpes Simples/virologia , Humanos , Influenza Humana/imunologia , Influenza Humana/virologia , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/virologia , Infecção por Zika virus/imunologia , Infecção por Zika virus/patologia , Infecção por Zika virus/virologia
3.
J Gen Virol ; 102(8)2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34342561

RESUMO

Dengue virus (DENV) is the most prevalent pathogen of the Flaviviridae family. Due to the considerable increase in DENV incidence and spread, symptoms such as CNS involvement have increased. Heparan sulphate (HS) was the first molecule identified as an adhesion factor for DENV in mammalian cells. Viral phenotypes with different HS interactions are associated with various clinical symptoms, including neurological alterations. Here, using in silico analyses, in vitro studies, and the in vivo mouse model, we characterized two natural circulating DENV3 genotype I (GI) lineage 1 (L1) in Brazil-DENV3 MG-20 (from Minas Gerais) and DENV3 PV_BR (from Rondônia) that present divergent neurovirulent profiles and sensitivity to sulphated molecules. We identified substitutions at the viral envelope (E) in positions 62 and 123 as likely responsible for the differences in neurovirulence. The E62K and E123Q substitutions in DENV3 MG-20 and DENV3 PV_BR, respectively, greatly influenced in silico electrostatic density and heparin docking results. In vivo, mice inoculated with DENV3 MG-20 died, but not those infected with DENV3 PV_BR. The clinical symptoms, such as paralysis of the lower limbs and meningoencephalitis, and histopathology, also differed between the inoculated groups. In vitro heparin and heparinases assays further demonstrated the biological impact of these substitutions. Other characteristics that have been previously associated with alterations in cell tropism and neurovirulence, such as changes in the size of lysis plaques and differences in cytopathic effects in glioblastoma cells, were also observed.


Assuntos
Vírus da Dengue/classificação , Vírus da Dengue/genética , Dengue/virologia , Genótipo , Heparitina Sulfato/metabolismo , Proteínas do Envelope Viral/química , Animais , Sítios de Ligação , Encéfalo/patologia , Comunicação Celular , Linhagem Celular , Dengue/patologia , Vírus da Dengue/fisiologia , Modelos Animais de Doenças , Feminino , Heparina , Interações Hospedeiro-Patógeno/fisiologia , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Simulação de Acoplamento Molecular , Fenótipo , Filogenia , Conformação Proteica , Proteínas do Envelope Viral/classificação , Proteínas do Envelope Viral/genética , Virulência , Ligação Viral
4.
Front Immunol ; 12: 707287, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34394108

RESUMO

Background: The outbreak of Coronavirus disease 2019 (COVID-19) has become an international public health crisis, and the number of cases with dengue co-infection has raised concerns. Unfortunately, treatment options are currently limited or even unavailable. Thus, the aim of our study was to explore the underlying mechanisms and identify potential therapeutic targets for co-infection. Methods: To further understand the mechanisms underlying co-infection, we used a series of bioinformatics analyses to build host factor interaction networks and elucidate biological process and molecular function categories, pathway activity, tissue-specific enrichment, and potential therapeutic agents. Results: We explored the pathologic mechanisms of COVID-19 and dengue co-infection, including predisposing genes, significant pathways, biological functions, and possible drugs for intervention. In total, 460 shared host factors were collected; among them, CCL4 and AhR targets were important. To further analyze biological functions, we created a protein-protein interaction (PPI) network and performed Molecular Complex Detection (MCODE) analysis. In addition, common signaling pathways were acquired, and the toll-like receptor and NOD-like receptor signaling pathways exerted a significant effect on the interaction. Upregulated genes were identified based on the activity score of dysregulated genes, such as IL-1, Hippo, and TNF-α. We also conducted tissue-specific enrichment analysis and found ICAM-1 and CCL2 to be highly expressed in the lung. Finally, candidate drugs were screened, including resveratrol, genistein, and dexamethasone. Conclusions: This study probes host factor interaction networks for COVID-19 and dengue and provides potential drugs for clinical practice. Although the findings need to be verified, they contribute to the treatment of co-infection and the management of respiratory disease.


Assuntos
COVID-19/tratamento farmacológico , COVID-19/patologia , Biologia Computacional/métodos , Dengue/tratamento farmacológico , Dengue/patologia , Mapas de Interação de Proteínas/fisiologia , Antivirais/uso terapêutico , Quimiocina CCL2/metabolismo , Coinfecção , Vírus da Dengue/efeitos dos fármacos , Dexametasona/uso terapêutico , Regulação da Expressão Gênica/genética , Genisteína/uso terapêutico , Humanos , Molécula 1 de Adesão Intercelular/metabolismo , Pulmão/metabolismo , Resveratrol/uso terapêutico , SARS-CoV-2/efeitos dos fármacos , Transdução de Sinais
5.
Front Immunol ; 12: 599805, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34079535

RESUMO

Background: Dengue virus (DENV) infection has a global impact on public health. The clinical outcomes (of DENV) can vary from a flu-like illness called dengue fever (DF), to a more severe form, known as dengue hemorrhagic fever (DHF). The underlying innate immune mechanisms leading to protective or detrimental outcomes have not been fully elucidated. Helper innate lymphoid cells (hILCs), an innate lymphocyte recently discovered, functionally resemble T-helper cells and are important in inflammation and homeostasis. However, the role of hILCs in DENV infection had been unexplored. Methods: We performed flow cytometry to investigate the frequency and phenotype of hILCs in peripheral blood mononuclear cells from DENV-infected patients of different disease severities (DF and DHF), and at different phases (febrile and convalescence) of infection. Intracellular cytokine staining of hILCs from DF and DHF were also evaluated by flow cytometry after ex vivo stimulation. Further, the hILCs were sorted and subjected to transcriptome analysis using RNA sequencing. Differential gene expression analysis was performed to compare the febrile and convalescent phase samples in DF and DHF. Selected differentially expressed genes were then validated by quantitative PCR. Results: Phenotypic analysis showed marked activation of all three hILC subsets during the febrile phase as shown by higher CD69 expression when compared to paired convalescent samples, although the frequency of hILCs remained unchanged. Upon ex vivo stimulation, hILCs from febrile phase DHF produced significantly higher IFN-γ and IL-4 when compared to those of DF. Transcriptomic analysis showed unique hILCs gene expression in DF and DHF, suggesting that divergent functions of hILCs may be associated with different disease severities. Differential gene expression analysis indicated that hILCs function both in cytokine secretion and cytotoxicity during the febrile phase of DENV infection. Conclusions: Helper ILCs are activated in the febrile phase of DENV infection and display unique transcriptomic changes as well as cytokine production that correlate with severity. Targeting hILCs during early innate response to DENV might help shape subsequent immune responses and potentially lessen the disease severity in the future.


Assuntos
Vírus da Dengue/imunologia , Dengue/imunologia , Imunidade Inata , Linfócitos T Auxiliares-Indutores/imunologia , Transcriptoma/imunologia , Dengue/patologia , Feminino , Humanos , Interferon gama/imunologia , Interleucina-4/imunologia , Masculino , Pessoa de Meia-Idade , RNA-Seq , Linfócitos T Auxiliares-Indutores/patologia
6.
BMC Infect Dis ; 21(1): 470, 2021 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-34030658

RESUMO

BACKGROUND: In 2017, New Caledonia experienced an outbreak of severe dengue causing high hospital burden (4379 cases, 416 hospital admissions, 15 deaths). We decided to build a local operational model predictive of dengue severity, which was needed to ease the healthcare circuit. METHODS: We retrospectively analyzed clinical and biological parameters associated with severe dengue in the cohort of patients hospitalized at the Territorial Hospital between January and July 2017 with confirmed dengue, in order to elaborate a comprehensive patient's score. Patients were compared in univariate and multivariate analyses. Predictive models for severity were built using a descending step-wise method. RESULTS: Out of 383 included patients, 130 (34%) developed severe dengue and 13 (3.4%) died. Major risk factors identified in univariate analysis were: age, comorbidities, presence of at least one alert sign, platelets count < 30 × 109/L, prothrombin time < 60%, AST and/or ALT > 10 N, and previous dengue infection. Severity was not influenced by the infecting dengue serotype nor by previous Zika infection. Two models to predict dengue severity were built according to sex. Best models for females and males had respectively a median Area Under the Curve = 0.80 and 0.88, a sensitivity = 84.5 and 84.5%, a specificity = 78.6 and 95.5%, a positive predictive value = 63.3 and 92.9%, a negative predictive value = 92.8 and 91.3%. Models were secondarily validated on 130 patients hospitalized for dengue in 2018. CONCLUSION: We built robust and efficient models to calculate a bedside score able to predict dengue severity in our setting. We propose the spreadsheet for dengue severity score calculations to health practitioners facing dengue outbreaks of enhanced severity in order to improve patients' medical management and hospitalization flow.


Assuntos
Dengue/classificação , Dengue/diagnóstico , Dengue/epidemiologia , Dengue/patologia , Feminino , Hospitalização , Humanos , Masculino , Modelos Teóricos , Nova Caledônia/epidemiologia , Valor Preditivo dos Testes , Prognóstico , Estudos Retrospectivos , Fatores de Risco , Triagem
7.
J Virol ; 95(13): e0220320, 2021 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-33853965

RESUMO

Recent field trials have demonstrated that dengue incidence can be substantially reduced by introgressing strains of the endosymbiotic bacterium Wolbachia into Aedes aegypti mosquito populations. This strategy relies on Wolbachia reducing the susceptibility of Ae. aegypti to disseminated infection by positive-sense RNA viruses like dengue. However, RNA viruses are well known to adapt to antiviral pressures. Here, we review the viral infection stages where selection for Wolbachia-resistant virus variants could occur. We also consider the genetic constraints imposed on viruses that alternate between vertebrate and invertebrate hosts, and the likely selection pressures to which dengue virus might adapt in order to be effectively transmitted by Ae. aegypti that carry Wolbachia. While there are hurdles to dengue viruses developing resistance to Wolbachia, we suggest that long-term surveillance for resistant viruses should be an integral component of Wolbachia-introgression biocontrol programs.


Assuntos
Adaptação Fisiológica/fisiologia , Aedes/microbiologia , Vírus da Dengue/crescimento & desenvolvimento , Dengue/prevenção & controle , Wolbachia/metabolismo , Aedes/efeitos dos fármacos , Animais , Dengue/patologia , Dengue/transmissão , Drosophila/microbiologia , Evolução Molecular , Humanos , Resistência a Inseticidas/fisiologia , Mosquitos Vetores/microbiologia , Seleção Genética/genética
8.
J Virol ; 95(13): e0197420, 2021 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-33827950

RESUMO

Dengue is a mosquito-borne infectious disease that is highly endemic in tropical and subtropical countries. Symptomatic patients can rapidly progress to severe conditions of hemorrhage, plasma extravasation, and hypovolemic shock, which leads to death. The blood tests of patients with severe dengue typically reveal low levels of high-density lipoprotein (HDL), which is responsible for reverse cholesterol transport (RCT) and regulation of the lipid composition in peripheral tissues. It is well known that dengue virus (DENV) depends on membrane cholesterol rafts to infect and to replicate in mammalian cells. Here, we describe the interaction of DENV nonstructural protein 1 (NS1) with apolipoprotein A1 (ApoA1), which is the major protein component of HDL. NS1 is secreted by infected cells and can be found circulating in the serum of patients with the onset of symptoms. NS1 concentrations in plasma are related to dengue severity, which is attributed to immune evasion and an acute inflammatory response. Our data show that the DENV NS1 protein induces an increase of lipid rafts in noninfected cell membranes and enhances further DENV infection. We also show that ApoA1-mediated lipid raft depletion inhibits DENV attachment to the cell surface. In addition, ApoA1 is able to neutralize NS1-induced cell activation and to prevent NS1-mediated enhancement of DENV infection. Furthermore, we demonstrate that the ApoA1 mimetic peptide 4F is also capable of mediating lipid raft depletion to control DENV infection. Taken together, our results suggest the potential of RCT-based therapies for dengue treatment. These results should motivate studies to assess the importance of RCT in DENV infection in vivo. IMPORTANCE DENV is one of the most relevant mosquito-transmitted viruses worldwide, infecting more than 390 million people every year and leading to more than 20 thousand deaths. Although a DENV vaccine has already been approved, its potential side effects have hampered its use in large-scale immunizations. Therefore, new treatment options are urgently needed to prevent disease worsening or to improve current clinical management of severe cases. In this study, we describe a new interaction of the NS1 protein, one of the major viral components, with a key component of HDL, ApoA1. This interaction seems to alter membrane susceptibility to virus infection and modulates the mechanisms triggered by DENV to evade the immune response. We also propose the use of a mimetic peptide named 4F, which was originally developed for atherosclerosis, as a potential therapy for relieving DENV symptoms.


Assuntos
Apolipoproteína A-I/imunologia , Vírus da Dengue/metabolismo , Evasão da Resposta Imune/imunologia , Microdomínios da Membrana/metabolismo , Proteínas não Estruturais Virais/imunologia , Animais , Antivirais/farmacologia , Linhagem Celular , Colesterol/metabolismo , Dengue/patologia , Humanos , Inflamação/prevenção & controle , Camundongos , Peptídeos/farmacologia , Células RAW 264.7 , Ligação Viral/efeitos dos fármacos
9.
Int J Mol Sci ; 22(6)2021 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-33809042

RESUMO

Clinical presentations of dengue fever (DF) are diverse and non-specific, causing unpredictable progression and outcomes. Its progression and severity have been associated with cytokine levels alteration. In this study, dengue patients were classified into groups following the 2009 WHO dengue classification scheme to investigate the cytokine signature at different severity of the disease: dengue without warning sign symptoms (A); dengue with warning signs (B); severe dengue (C); other fever (OF) and healthy (Healthy). We analyzed 23 different cytokines simultaneously, namely IL-1b, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p70, IL-17A, IL-33, CD14, CD54, CD62E, CD62L, CD62p, CD106, CD121b, CD154, CD178, GM-CSF, IFN-g, MIF, ST2 and TNF from patients admitted to National Cheng Kung University Hospital during the 2015 Taiwan dengue outbreak. Cytokines TNF, CD54, CD62E, CD62L, CD62P, GM-CSF, IL-1b, IL-2, IL-6, IL-8, IL-10, IL-12p70, IL-17A, INF-g and MIF were elevated while CD106, CD154, IL-4 and L-33 were decreased when compared to the control. IL-10 demonstrated to be a potential diagnostic marker for DF (H and A group; AUC = 0.944, H and OF group; AUC = 0.969). CD121b demonstrated to be predictive of the SD (A and B group; AUC = 0.744, B and C group; AUC = 0.775). Our results demonstrate the cytokine profile changes during the progression of dengue and highlight possible biomarkers for optimizing effective intervention strategies.


Assuntos
Vírus da Dengue/isolamento & purificação , Dengue/diagnóstico , Interleucina-10/genética , Receptores Tipo II de Interleucina-1/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/metabolismo , Citocinas/classificação , Citocinas/genética , Dengue/genética , Dengue/patologia , Dengue/virologia , Vírus da Dengue/genética , Vírus da Dengue/patogenicidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença , Transcriptoma/genética , Adulto Jovem
10.
Animal Model Exp Med ; 4(1): 16-26, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33738433

RESUMO

Dengue is a significant public health concern across tropical and subtropical regions worldwide, principally causing disease in children. Very young children are at increased risk of severe manifestations of dengue infection. The mechanism of dengue disease in this population is not fully understood. In this study, we present a murine model of dengue virus primary infection in suckling C57BL/6 and BALB/c mice in order to investigate disease pathogenesis. Three-day-old C57BL/6 mice intraperitoneally infected with DENV-2 NGC were more susceptible to infection than BALB/c mice, showing increased liver enzymes, extended viremia, dissemination to organs and histological alterations in liver and small intestine. Furthermore, the immune response in DENV-infected C57BL/6 mice exhibited a marked Th1 bias compared to BALB/c mice. These findings highlight the possibility of establishing an immunocompetent mouse model of DENV-2 infection in suckling mice that reproduces certain signs of disease observed in humans and that could be used to further study age-related mechanisms of dengue pathogenesis.


Assuntos
Dengue/imunologia , Dengue/patologia , Modelos Animais de Doenças , Animais , Animais Lactentes , Diferenciação Celular , Dengue/virologia , Vírus da Dengue/patogenicidade , Vírus da Dengue/fisiologia , Intestino Delgado/patologia , Fígado/enzimologia , Fígado/patologia , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Células Th1 , Viremia
11.
Front Immunol ; 12: 599345, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33659001

RESUMO

Exposure to environmental hormones such as di(2-ethylhexyl) phthalate (DEHP) has become a critical human health issue globally. This study aimed to investigate the correlations between DEHP/mono-(2-ethylhexyl) phthalate (MEHP) levels and macrophage-associated immune responses and clinical manifestations in dengue virus (DV)-infected patients. Among 89 DV-infected patients, those with DV infection-related gastrointestinal (GI) bleeding (n = 13, 15% of patients) had significantly higher DEHP exposure than those without GI bleeding (n = 76, 85% of patients), which were 114.2 ng/ml versus 52.5 ng/ml ΣDEHP in urine; p = 0.023). In an in vitro study using cultured human monocyte-derived macrophages (MDMs) to investigate the effects of MEHP, treatment increased IL-1ß and TNF-α release but decreased IL-23 release, with negative correlations observed between urine ΣDEHP and serum IL-23 levels in patients. MEHP-treated MDMs had lower antiviral Th17 response induction activity in mixed T-cell response tests. The in vitro data showed that MEHP increased DV viral load and decreased IL-23 release dose-dependently, and adding IL-23 to MEHP-exposed MDMs significantly reduced the DV viral load. MEHP also suppressed IL-23 expression via the peroxisome proliferator-activated receptor-gamma (PPAR-γ) pathway. Further, the PPAR-γ antagonist GW9662 significantly reversed MEHP-induced IL-23 suppression and reduced the DV viral load. These study findings help to explain the associations between high MEHP levels and the high global burden of dengue disease.


Assuntos
Antivirais , Vírus da Dengue/imunologia , Dengue/imunologia , Dietilexilftalato/análogos & derivados , Interleucina-23/imunologia , Macrófagos/imunologia , Adulto , Idoso , Antivirais/efeitos adversos , Antivirais/farmacologia , Dengue/tratamento farmacológico , Dengue/patologia , Dietilexilftalato/efeitos adversos , Dietilexilftalato/farmacologia , Feminino , Humanos , Interleucina-1beta/imunologia , Macrófagos/fisiologia , Macrófagos/virologia , Masculino , Pessoa de Meia-Idade , Fator de Necrose Tumoral alfa/imunologia
12.
PLoS Negl Trop Dis ; 15(2): e0008861, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33566822

RESUMO

BACKGROUND: In Africa, information on dengue is limited to outbreak reports and focused on some countries with continuing transmission in West and East Africa. To estimate the proportion of dengue-positive cases among febrile patients and identify clinical indicators of dengue cases, we conducted passive facility-based fever surveillance in a catchment area population of 70,000 residents of Lambaréné and its surroundings in Gabon. METHODS: Non-malarial febrile patients with current fever or history of fever (≤7 days) between 1 and 55 years of age, were enrolled at Albert Schweitzer Hospital (ASH). Acute (visit 1, day of enrollment) and convalescent blood samples were collected between 10 and 21 days after enrollment. Acute/convalescent samples were tested with IgM/IgG ELISA, and a selected subset of acute samples with RT-PCR. RESULTS: Among 682 non-malarial febrile patients enrolled, 119 (17.4%) were identified as dengue-positive (94 dengue-confirmed and 25 dengue-probable cases). Of these dengue-positive cases, 14 were confirmed with PCR, and based on serotyping, two infections were identified to be DENV-2 and two were DENV-3. The majority of our enrolled patients were <25 years of age and close to 80% of our dengue-positive cases were <15 years of age. In adjusted analyses, retro-orbital pain and abdominal pain were 2.7 and 1.6 times more frequently found among dengue-positive cases, compared to non-dengue cases. CONCLUSION: Lambaréné is not considered dengue-endemic. However, one in six non-malarial febrile episodes was found to be dengue-positive in the study period. Dengue should be considered more frequently in clinicians' diagnosis among non-malarial febrile patients in Lambaréné. Given the lack of data on dengue in Gabon, additional prospective and longitudinal studies would help to further define the burden and patterns of dengue for improved case detection.


Assuntos
Dengue/epidemiologia , Dengue/patologia , Surtos de Doenças , Febre/epidemiologia , Febre/etiologia , Instalações de Saúde , Adolescente , Adulto , Anticorpos Antivirais/sangue , Criança , Pré-Escolar , Vírus da Dengue/classificação , Vírus da Dengue/genética , Vírus da Dengue/isolamento & purificação , Ensaio de Imunoadsorção Enzimática , Monitoramento Epidemiológico , Feminino , Gabão/epidemiologia , Humanos , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Lactente , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Estudos Prospectivos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Adulto Jovem
14.
J Virol ; 95(4)2021 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-33257477

RESUMO

Positive-strand RNA viruses have been the etiological agents in several major disease outbreaks over the last few decades. Examples of this include flaviviruses, such as dengue virus and Zika virus, which cause millions of yearly infections around the globe, and coronaviruses, such as SARS-CoV-2, the source of the current pandemic. The severity of outbreaks caused by these viruses stresses the importance of research aimed at determining methods to limit virus spread and to curb disease severity. Such studies require molecular tools to decipher virus-host interactions and to develop effective treatments. Here, we describe the generation and characterization of a reporter system that can be used to visualize and identify cells infected with dengue virus or SARS-CoV-2. This system is based on viral protease activity that mediates cleavage and nuclear translocation of an engineered fluorescent protein stably expressed in cells. We show the suitability of this system for live cell imaging, for visualization of single infected cells, and for screening and testing of antiviral compounds. With the integrated modular building blocks, this system is easy to manipulate and can be adapted to any virus encoding a protease, thus offering a high degree of flexibility.IMPORTANCE Reporter systems are useful tools for fast and quantitative visualization of virus-infected cells within a host cell population. Here, we describe a reporter system that takes advantage of virus-encoded proteases expressed in infected cells to cleave an ER-anchored fluorescent protein fused to a nuclear localization sequence. Upon cleavage, the GFP moiety translocates to the nucleus, allowing for rapid detection of the infected cells. Using this system, we demonstrate reliable reporting activity for two major human pathogens from the Flaviviridae and the Coronaviridae families: dengue virus and SARS-CoV-2. We apply this reporter system to live cell imaging and use it for proof-of-concept to validate antiviral activity of a nucleoside analogue. This reporter system is not only an invaluable tool for the characterization of viral replication, but also for the discovery and development of antivirals that are urgently needed to halt the spread of these viruses.


Assuntos
COVID-19/virologia , Vírus da Dengue/isolamento & purificação , Dengue/virologia , SARS-CoV-2/isolamento & purificação , Células A549 , Animais , COVID-19/diagnóstico , COVID-19/metabolismo , COVID-19/patologia , Linhagem Celular , Chlorocebus aethiops , Dengue/diagnóstico , Dengue/metabolismo , Dengue/patologia , Vírus da Dengue/genética , Vírus da Dengue/metabolismo , Genes Reporter , Proteínas de Fluorescência Verde/metabolismo , Células HEK293 , Humanos , Sinais de Localização Nuclear/metabolismo , SARS-CoV-2/genética , SARS-CoV-2/metabolismo , Células Vero , Proteínas não Estruturais Virais/metabolismo , Replicação Viral
15.
Am J Trop Med Hyg ; 104(1): 52-59, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33200725

RESUMO

Dengue infections are increasing globally and account for significant morbidity and mortality. Severe dengue results in microvascular changes and coagulopathy that may make surgical intervention risky and the overall surgical management challenging. We outline the potential surgical manifestations and complications following dengue infections and describe the clinical, pathogenetic, diagnostic, and treatment aspects of dengue and surgical patients. The main surgical presentations were acute cholecystitis, acute pancreatitis, acute appendicitis, splenic rupture, bowel perforation, gastrointestinal bleeding, and hematomas. Dengue may also mimic an acute abdomen without any true surgical complications. A majority were treated nonoperatively. Misdiagnosis and unnecessary surgical intervention resulted in poor outcomes. Better knowledge of the potential surgical complications would help in early diagnosis, treatment, and referral to specialized centers and thus improve outcomes. A high degree of suspicion of dengue fever is necessary when patients in a dengue-epidemic area present with acute abdomen or bleeding manifestations. In endemic areas, early dengue antigen testing and abdominal imaging before surgical intervention may help in the diagnoses. Multidisciplinary team involvement with case-by-case decision-making is needed for optimal care.


Assuntos
Dengue/complicações , Dengue/patologia , Procedimentos Cirúrgicos Operatórios/efeitos adversos , Abdome Agudo/cirurgia , Humanos
16.
Int J Mol Sci ; 21(24)2020 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-33352639

RESUMO

Dengue virus (DENV) infection is a significant public health threat in tropical and subtropical regions; however, there is no specific antiviral drug. Accumulated studies have revealed that DENV infection induces several cellular responses, including autophagy and apoptosis. The crosstalk between autophagy and apoptosis is associated with the interactions among components of these two pathways, such as apoptotic caspase-mediated cleavage of autophagy-related proteins. Here, we show that DENV-induced autophagy inhibits early cell apoptosis and hence enhances DENV replication. Later, the apoptotic activities are elevated to suppress autophagy through cleavage of Beclin-1, an essential autophagy-related protein. Inhibition of cleavage of Beclin-1 by a pan-caspase inhibitor, Z-VAD, increases both autophagy and viral replication. Regarding the mechanism, we further found that DENV nonstructural protein 1 (NS1) is able to interact with Beclin-1 during DENV infection. The interaction between Beclin-1 and NS1 attenuates Beclin-1 cleavage and facilitates autophagy to prevent cell apoptosis. Our study suggests a novel mechanism whereby NS1 preserves Beclin-1 for maintaining autophagy to antagonize early cell apoptosis; however, elevated caspases trigger apoptosis by degrading Beclin-1 in the late stage of infection. These findings suggest implications for anti-DENV drug design.


Assuntos
Proteína Beclina-1/metabolismo , Caspases/metabolismo , Vírus da Dengue/isolamento & purificação , Dengue/patologia , Dengue/virologia , Proteínas não Estruturais Virais/metabolismo , Células A549 , Aedes , Animais , Autofagia , Dengue/metabolismo , Humanos
17.
Biomolecules ; 11(1)2020 12 24.
Artigo em Inglês | MEDLINE | ID: mdl-33374457

RESUMO

Phenolic compounds have been related to multiple biological activities, and the antiviral effect of these compounds has been demonstrated in several viral models of public health concern. In this review, we show the antiviral role of phenolic compounds against dengue virus (DENV), the most widespread arbovirus globally that, after its re-emergence, has caused multiple epidemic outbreaks, especially in the last two years. Twenty phenolic compounds with anti-DENV activity are discussed, including the multiple mechanisms of action, such as those directed against viral particles or viral proteins, host proteins or pathways related to the productive replication viral cycle and the spread of the infection.


Assuntos
Antivirais/uso terapêutico , Dengue/tratamento farmacológico , Fenóis/uso terapêutico , Replicação Viral/efeitos dos fármacos , Animais , Chlorocebus aethiops , Dengue/genética , Dengue/patologia , Dengue/virologia , Vírus da Dengue/efeitos dos fármacos , Vírus da Dengue/genética , Vírus da Dengue/patogenicidade , Humanos , Extratos Vegetais/química , Extratos Vegetais/uso terapêutico , Células Vero/efeitos dos fármacos , Proteínas Virais/antagonistas & inibidores , Proteínas Virais/genética
18.
Front Immunol ; 11: 538240, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33193307

RESUMO

Dengue virus infection (DENV-2) is transmitted by infected mosquitoes via the skin, where many dermal and epidermal cells are potentially susceptible to infection. Most of the cells in an area of infection will establish an antiviral microenvironment to control viral replication. Although cumulative studies report permissive DENV-2 infection in dendritic cells, keratinocytes, and fibroblasts, among other cells also infected, little information is available regarding cell-to-cell crosstalk and the effect of this on the outcome of the infection. Therefore, our study focused on understanding the contribution of fibroblast and dendritic cell crosstalk to the control or promotion of dengue. Our results suggest that dendritic cells promote an antiviral state over fibroblasts by enhancing the production of type I interferon, but not proinflammatory cytokines. Infected and non-infected fibroblasts promoted partial dendritic cell maturation, and the fibroblast-matured cells were less permissive to infection and showed enhanced type I interferon production. We also observed that the soluble mediators produced by non-infected or Poly (I:C) transfected fibroblasts induced allogenic T cell proliferation, but mediators produced by DENV-2 infected fibroblasts inhibited this phenomenon. Additionally, the effects of fibroblast soluble mediators on CD14+ monocytes were analyzed to assess whether they affected the differentiation of monocyte derived dendritic cells (moDC). Our data showed that mediators produced by infected fibroblasts induced variable levels of monocyte differentiation into dendritic cells, even in the presence of recombinant GM-CSF and IL-4. Cells with dendritic cell-like morphology appeared in the culture; however, flow cytometry analysis showed that the mediators did not fully downregulate CD14 nor did they upregulate CD1a. Our data revealed that fibroblast-dendritic cell crosstalk promoted an antiviral response mediated manly by type I interferons over fibroblasts. Furthermore, the maturation of dendritic cells and T cell proliferation were promoted, which was inhibited by DENV-2-induced mediators. Together, our results suggest that activation of the adaptive immune response is influenced by the crosstalk of skin resident cells and the intensity of innate immune responses established in the microenvironment of the infected skin.


Assuntos
Comunicação Celular/imunologia , Células Dendríticas/imunologia , Vírus da Dengue/imunologia , Dengue/imunologia , Derme/imunologia , Fibroblastos/imunologia , Adulto , Antígenos CD1/imunologia , Células Dendríticas/patologia , Células Dendríticas/virologia , Dengue/patologia , Derme/patologia , Derme/virologia , Feminino , Fibroblastos/patologia , Fibroblastos/virologia , Fator Estimulador de Colônias de Granulócitos e Macrófagos/imunologia , Humanos , Interferon Tipo I/imunologia , Interleucina-4/imunologia , Receptores de Lipopolissacarídeos/imunologia , Masculino , Pessoa de Meia-Idade
19.
PLoS Negl Trop Dis ; 14(11): e0008835, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33216752

RESUMO

Suitable cell models are essential to advance our understanding of the pathogenesis of liver diseases and the development of therapeutic strategies. Primary human hepatocytes (PHHs), the most ideal hepatic model, are commercially available, but they are expensive and vary from lot-to-lot which confounds their utility. We have recently developed an immortalized hepatocyte-like cell line (imHC) from human mesenchymal stem cells, and tested it for use as a substitute model for hepatotropic infectious diseases. With a special interest in liver pathogenesis of viral infection, herein we determined the suitability of imHC as a host cell target for dengue virus (DENV) and as a model for anti-viral drug testing. We characterized the kinetics of DENV production, cellular responses to DENV infection (apoptosis, cytokine production and lipid droplet metabolism), and examined anti-viral drug effects in imHC cells with comparisons to the commonly used hepatoma cell lines (HepG2 and Huh-7) and PHHs. Our results showed that imHC cells had higher efficiencies in DENV replication and NS1 secretion as compared to HepG2 and Huh-7 cells. The kinetics of DENV infection in imHC cells showed a slower rate of apoptosis than the hepatoma cell lines and a certain similarity of cytokine profiles to PHHs. In imHC, DENV-induced alterations in levels of lipid droplets and triacylglycerols, a major component of lipid droplets, were more apparent than in hepatoma cell lines, suggesting active lipid metabolism in imHC. Significantly, responses to drugs with DENV inhibitory effects were greater in imHC cells than in HepG2 and Huh-7 cells. In conclusion, our findings suggest superior suitability of imHC as a new hepatocyte model for studying mechanisms underlying viral pathogenesis, liver diseases and drug effects.


Assuntos
Vírus da Dengue/crescimento & desenvolvimento , Dengue/patologia , Hepatócitos/patologia , Hepatopatias/patologia , Fígado/virologia , Aedes , Animais , Antivirais/farmacologia , Apoptose/imunologia , Linhagem Celular Tumoral , Chlorocebus aethiops , Citocinas/metabolismo , Dengue/tratamento farmacológico , Vírus da Dengue/efeitos dos fármacos , Células Hep G2 , Hepatócitos/virologia , Humanos , Gotículas Lipídicas/metabolismo , Metabolismo dos Lipídeos , Fígado/patologia , Hepatopatias/tratamento farmacológico , Hepatopatias/virologia , Receptores Virais/metabolismo , Triglicerídeos/análise , Células Vero , Replicação Viral/fisiologia
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