scholarly journals Natural infection of cynomolgus monkeys with dengue virus occurs in epidemic cycles in the Philippines

2013 ◽  
Vol 94 (10) ◽  
pp. 2202-2207 ◽  
Author(s):  
Fumihiro Kato ◽  
Yuki Ishida ◽  
Takahiro Kawagishi ◽  
Takeshi Kobayashi ◽  
Takayuki Hishiki ◽  
...  
Keyword(s):  
Dengue Virus ◽  
Phylogenetic Analyses ◽  
Natural Infection ◽  
Denv Infection ◽  
Neutralization Assay ◽  
The Philippines ◽  
Cynomolgus Monkeys ◽  
Genomic Studies ◽  
Ns1 Gene

To investigate the potential role of non-human primates (NHPs) in a dengue virus (DENV) epidemic, we conducted serological and genomic studies using plasma samples collected from 100 cynomolgus monkeys (Macaca fascicularis) in an animal breeding facility in the Philippines. An ELISA revealed 21 monkeys with a positive IgM reaction and 19 positive for IgG. Five of the monkeys were positive for both IgM and IgG. Of the 21 IgM-positive samples, a neutralization assay identified seven containing DENV-specific antibodies. We amplified the viral non-structural 1 (NS1) gene in two and the envelope (E) gene in one of these seven samples by RT-PCR. Phylogenetic analyses revealed that these DENV genes belonged to the epidemic DENV-2 family, not the sylvatic DENV family. These results suggest that NHPs may serve as a reservoir of epidemic DENV; therefore, the ecology of the urban DENV infection cycle should be investigated in these animals in detail.

scholarly journals Dengue Virus-Infected Dendritic Cells, but Not Monocytes, Activate Natural Killer Cells through a Contact-Dependent Mechanism Involving Adhesion Molecules

mBio ◽  
2017 ◽  
Vol 8 (4) ◽  
Author(s):  
Vivian Vasconcelos Costa ◽  
Weijian Ye ◽  
Qingfeng Chen ◽  
Mauro Martins Teixeira ◽  
Peter Preiser ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Virus Infection ◽  
Dengue Virus ◽  
Nk Cells ◽  
Adhesion Molecules ◽  
Cell Activation ◽  
Nk Cell ◽  
Denv Infection ◽  
Ifn Γ

ABSTRACT Natural killer (NK) cells play a protective role against dengue virus (DENV) infection, but the cellular and molecular mechanisms are not fully understood. Using an optimized humanized mouse model, we show that human NK cells, through the secretion of gamma interferon (IFN-γ), are critical in the early defense against DENV infection. Depletion of NK cells or neutralization of IFN-γ leads to increased viremia and more severe thrombocytopenia and liver damage in humanized mice. In vitro studies using autologous human NK cells show that DENV-infected monocyte-derived dendritic cells (MDDCs), but not monocytes, activate NK cells in a contact-dependent manner, resulting in upregulation of CD69 and CD25 and secretion of IFN-γ. Blocking adhesion molecules (LFA-1, DNAM-1, CD2, and 2β4) on NK cells abolishes NK cell activation, IFN-γ secretion, and the control of DENV replication. NK cells activated by infected MDDCs also inhibit DENV infection in monocytes. These findings show the essential role of human NK cells in protection against acute DENV infection in vivo, identify adhesion molecules and dendritic cells required for NK cell activation, and delineate the sequence of events for NK cell activation and protection against DENV infection. IMPORTANCE Dengue is a mosquito-transmitted viral disease with a range of symptoms, from mild fever to life-threatening dengue hemorrhagic fever. The diverse disease manifestation is thought to result from a complex interplay between viral and host factors. Using mice engrafted with a human immune system, we show that human NK cells inhibit virus infection through secretion of the cytokine gamma interferon and reduce disease pathogenesis, including depletion of platelets and liver damage. During a natural infection, DENV initially infects dendritic cells in the skin. We find that NK cells interact with infected dendritic cells through physical contact mediated by adhesion molecules and become activated before they can control virus infection. These results show a critical role of human NK cells in controlling DENV infection in vivo and reveal the sequence of molecular and cellular events that activate NK cells to control dengue virus infection. IMPORTANCE Dengue is a mosquito-transmitted viral disease with a range of symptoms, from mild fever to life-threatening dengue hemorrhagic fever. The diverse disease manifestation is thought to result from a complex interplay between viral and host factors. Using mice engrafted with a human immune system, we show that human NK cells inhibit virus infection through secretion of the cytokine gamma interferon and reduce disease pathogenesis, including depletion of platelets and liver damage. During a natural infection, DENV initially infects dendritic cells in the skin. We find that NK cells interact with infected dendritic cells through physical contact mediated by adhesion molecules and become activated before they can control virus infection. These results show a critical role of human NK cells in controlling DENV infection in vivo and reveal the sequence of molecular and cellular events that activate NK cells to control dengue virus infection.

scholarly journals Down Regulation Of IL-1β Secretion By Tgf-β1 In Macrophages Infected With Dengue Virus

2021 ◽  
Author(s):  
Brenda Ramírez-Aguero ◽  
Javier Serrato-Salas ◽  
José Luis Montiel-Hernández ◽  
Judith González-Christen
Keyword(s):  
Immune Response ◽  
Dengue Virus ◽  
Inflammatory Cytokines ◽  
Denv Infection ◽  
Inhibitory Effect ◽  
Microvascular Endothelium ◽  
Infected Cells ◽  
Tgf Β1 ◽  
Pro Inflammatory Cytokines

AbstractSeveral pathogenic mechanisms have been linked to the severity of dengue virus infection, like viral cytotoxicity, underlying host genetics and comorbidities such as diabetes and dyslipidemia. It has been observed that patients with severe manifestations develop an uncontrolled immune response, with an increase in pro-inflammatory cytokines such as TNF, IL-1β, IL-8, IL-6 and chemokines that damage the human microvascular endothelium, and also in anti-inflammatory cytokines IL-4, IL-10 and TGF-β1. The role of TGF-β1 on dengue is not clear; few studies have been published, and most of them from patient sera data, with both protective and pathological roles have described. The aim of this study was to evaluate the ability of TGF-β1 to regulate the secretion of IL-1β in macrophages infected by DENV using THP-1 cells treated with recombinant TGF-β1 before or after DENV infection. By RT-PCR we did not observe a difference in IL-1β expression between infected cells pretreated with TGF-β1 and those that were not. However, secretion of IL-1β was reduced only in cells stimulated with TGF-β1 before infection, and not in those treated 2 hours post-infection. TGF-β1 receptor blockage with SB505124 inhibitor, prior to the addition of TGF-β1 and infection, abrogated the inhibitory effect of TGF-β1. Our results suggest that DENV could regulate the function of TGF-β1 on macrophages. This negative regulation of the TGF-β1 pathway could be used by DENV to evade the immune response and could contribute to the immunopathology.

scholarly journals Dengue virus in humans and mosquitoes and their molecular characteristics in northeastern Thailand 2016-2018

PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0257460
Author(s):  
Patcharaporn Nonyong ◽  
Tipaya Ekalaksananan ◽  
Supranee Phanthanawiboon ◽  
Sirinart Aromseree ◽  
Juthamas Phadungsombat ◽  
...  
Keyword(s):  
Dengue Virus ◽  
Phylogenetic Analyses ◽  
Denv Infection ◽  
Urban Environments ◽  
Molecular Characteristics ◽  
Envelope Gene ◽  
Genotype I ◽  
Denv Serotypes ◽  
Epidemic Dynamics ◽  
Relationship Of

Dengue is hyperendemic in most Southeast Asian countries including Thailand, where all four dengue virus serotypes (DENV-1 to -4) have circulated over different periods and regions. Despite dengue cases being annually reported in all regions of Thailand, there is limited data on the relationship of epidemic DENV infection between humans and mosquitoes, and about the dynamics of DENV during outbreaks in the northeastern region. The present study was conducted in this region to investigate the molecular epidemiology of DENV and explore the relationships of DENV infection in humans and in mosquitoes during 2016–2018. A total of 292 dengue suspected patients from 11 hospitals and 902 individual mosquitoes (at patient’s houses and neighboring houses) were recruited and investigated for DENV serotypes infection using PCR. A total of 103 patients and 149 individual mosquitoes were DENV -positive. Among patients, the predominant DENV serotypes in 2016 and 2018 were DENV-4 (74%) and DENV-3 (53%) respectively, whereas in 2017, DENV-1, -3 and -4 had similar prevalence (38%). Additionally, only 19% of DENV infections in humans and mosquitoes at surrounding houses were serotypically matched, while 81% of infections were serotypically mismatched, suggesting that mosquitoes outside the residence may be an important factor of endemic dengue transmission. Phylogenetic analyses based on envelope gene sequences showed the genotype I of both DENV-1 and DENV-4, and co-circulation of the Cosmopolitan and Asian I genotypes of DENV-2. These strains were closely related to concurrent strains in other parts of Thailand and also similar to strains in previous epidemiological profiles in Thailand and elsewhere in Southeast Asia. These findings highlight genomic data of DENV in this region and suggest that people’s movement in urban environments may result in mosquitoes far away from the residential area being key determinants of DENV epidemic dynamics.

scholarly journals Time elapsed between Zika and dengue virus infections affects antibody and T cell responses

2019 ◽  
Author(s):  
Erick X. Pérez-Guzmán ◽  
Petraleigh Pantoja ◽  
Crisanta Serrano-Collazo ◽  
Mariah A. Hassert ◽  
Alexandra Ortiz-Rosa ◽  
...  
Keyword(s):  
T Cell ◽  
Dengue Virus ◽  
Rhesus Macaques ◽  
T Cell Responses ◽  
Denv Infection ◽  
Virus Infections ◽  
Zikv Infection ◽  
Cell Responses ◽  
Inflammatory Status

AbstractThe role of Zika virus (ZIKV) immunity on subsequent dengue virus (DENV) infections is relevant to anticipate the dynamics of forthcoming DENV epidemics in areas with previous ZIKV exposure. We study the effect of ZIKV infection with various strains on subsequent DENV immune response after 10 and 2 months of ZIKV infection in rhesus macaques. Our results show that a subsequent DENV infection in animals with early- and middle-convalescent periods to ZIKV do not promote an increase in DENV viremia nor pro-inflammatory status. Previous ZIKV exposure increases the magnitude of the antibody and T cell responses against DENV, and different time intervals between infections alter the magnitude and durability of such responses—more after longer ZIKV pre-exposure. Collectively, we find no evidence of a detrimental effect of ZIKV immunity in a subsequent DENV infection. This supports the implementation of ZIKV vaccines that could also boost immunity against future DENV epidemics.

scholarly journals Individual-based dengue virus surveillance in Aedes aegypti mosquitoes collected concurrently with suspected patients in Tarlac City, Philippines

2020 ◽  
Author(s):  
Jean Claude Balingit ◽  
Thaddeus M. Carvajal ◽  
Mariko Saito-Obata ◽  
Maribet Gamboa ◽  
Amalea Dulcene Nicolasora ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Dengue Virus ◽  
Phylogenetic Analyses ◽  
Simultaneous Detection ◽  
Denv Infection ◽  
Health Concern ◽  
Effective Control ◽  
Entomological Surveillance ◽  
Mosquito Abundance ◽  
Virus Surveillance

Abstract Background Dengue virus (DENV) infection continues to be a major public health concern throughout tropical and subtropical regions of the world where Aedes aegypti mosquitoes, its primary vector, dwell. In the context of DENV transmission, effective control is reliant not only on knowledge of mosquito abundance, but also on mosquito infection. In the 2015 dengue season, we conducted a one-month entomological surveillance of adult Aedes aegypti mosquitoes around households of suspected dengue patients in Tarlac City, Philippines to assess the DENV infection rate in the local mosquito population, and to identify the DENV genotypes and serotypes concurrently co-circulating in mosquitoes and patients. Methods We performed a one-step multiplex real-time RT-PCR assay for the simultaneous detection and serotyping of DENV in patients and in individual female Aedes aegypti mosquito. Consequently, we performed sequencing and phylogenetic analyses to further characterize the detected DENVs in mosquitoes and patients at the genotype level. Results We collected a total of 583 adult Aedes aegypti mosquitoes, of which we tested 359 female mosquitoes individually for the presence of the DENV. Ten mosquitoes (2.8%) from amongst 359 female mosquitoes were confirmed to be positive for the presence of the DENV. We detected DENV-1, DENV-2, and DENV-4 in the field-collected mosquitoes, which were consistent with the serotypes concurrently infecting patients. Sequencing and phylogenetic analyses of the detected DENVs based on the partial envelope ( E ) gene revealed three genotypes concurrently present in the sampled mosquitoes and patients during the study period, namely: DENV-1 genotype IV, DENV-2 Cosmopolitan genotype and DENV-4 genotype II. Notably, we observed a random geographic distribution of DENVs in the study area suggesting the occurrence of active DENV transmission within and outside the vicinities of Tarlac City. Conclusions In this study, we demonstrate the utility of an individual-based DENV surveillance in field-collected mosquitoes and the importance of incorporating mosquito virus data in phylogenetic studies. Analyzing virus sequences from vector and host could potentially improve our understanding of the dynamics of DENV transmission.

scholarly journals Changes in complement alternative pathway components, factor B and factor H during dengue virus infection in the AG129 mouse

2021 ◽  
Author(s):  
Sheila Cabezas-Falcon ◽  
Aidan J. Norbury ◽  
Jarrod Hulme-Jones ◽  
Sonja Klebe ◽  
Penelope Adamson ◽  
...  
Keyword(s):  
Dengue Virus ◽  
Alternative Pathway ◽  
Severe Disease ◽  
Denv Infection ◽  
Factor H ◽  
Severe Dengue ◽  
Complement Alternative Pathway ◽  
Factor B ◽  
Dengue Disease

The complement alternative pathway (AP) is tightly regulated and changes in two important AP components, factor B (FB) and factor H (FH) are linked to severe dengue in humans. Here, a mouse model of dengue was investigated to define the changes in FB and FH and assess the utility of this model to study the role of the AP in severe dengue. Throughout the period of viremia in the AG129 IFN signalling-deficient mouse, an increase in FB and a decrease in FH was observed following dengue virus (DENV) infection, with the former only seen in a model of more severe disease associated with antibody-dependent enhancement (ADE). Terminal disease was associated with a decrease in FB and FH, with greater changes during ADE, and accompanied by increased C3 degradation consistent with complement activation. In silico analysis of NFκΒ, signal transducer and activator of transcription (STAT) and IFN-driven FB and FH promoter elements to reflect the likely impact of the lack of IFN-responses in AG129 mice, demonstrated that these elements differed markedly between human and mouse, notably with mouse FH lacking NFκΒ and key IFN-stimulated response elements (ISRE), and FB with many more NFκΒ and STAT-responsive elements than human FB. Thus, the AG129 mouse offers utility in demonstrating changes in FB and FH that, similar to humans, are associated with severe disease, but lack predicted important human-specific and IFN-dependent responses of FB and FH to DENV-infection that are likely to regulate the subtleties of the overall AP response during dengue disease in humans.

scholarly journals Dengue Virus Dysregulates Master Transcription Factors and PI3K/AKT/mTOR Signaling Pathway in Megakaryocytes

2021 ◽  
Vol 11 ◽  
Author(s):  
Anismrita Lahon ◽  
Ravi P. Arya ◽  
Akhil C. Banerjea
Keyword(s):  
Transcription Factors ◽  
Dengue Virus ◽  
Dengue Fever ◽  
Denv Infection ◽  
Mtor Pathway ◽  
Mtor Signaling Pathway ◽  
Low Platelet Count ◽  
Pharmacologic Inhibition ◽  
Specific Inhibitors

Dengue virus (DENV) infection can cause either self-limited dengue fever or hemorrhagic complications. Low platelet count is one of the manifestations of dengue fever. Megakaryocytes are the sole producers of platelets. However, the role of both host and viral factors in megakaryocyte development, maturation, and platelet production is largely unknown in DENV infection. PI3K/AKT/mTOR pathway plays a significant role in cell survival, maturation, and megakaryocyte development. We were interested to check whether pathogenic insult can impact this pathway. We observed decreased expression of most of the major key molecules associated with the PI3K/AKT/mTOR pathway in DENV infected MEG-01 cells. In this study, the involvement of PI3K/AKT/mTOR pathway in megakaryocyte development and maturation was confirmed with the use of specific inhibitors in infected MEG-01 cells. Our results showed that direct pharmacologic inhibition of this pathway greatly impacted megakaryopoiesis associated molecule CD61 and some essential transcription factors (GATA-1, GATA-2, and NF-E2). Additionally, we observed apoptosis in megakaryocytes due to DENV infection. Our results may suggest that DENV impairs PI3K/AKT/mTOR axis and molecules involved in the development and maturation of megakaryocytes. It is imperative to investigate the role of these molecules in the context of megakaryopoiesis during DENV infection to better understand the pathways and mechanisms, which in turn might provide insights into the development of antiviral strategies.

scholarly journals USP18 Mediates Interferon Resistance of Dengue Virus Infection

2021 ◽  
Vol 12 ◽  
Author(s):  
Haiyan Ye ◽  
Xiaoqiong Duan ◽  
Min Yao ◽  
Lan Kang ◽  
Yujia Li ◽  
...  
Keyword(s):  
Dengue Virus ◽  
Western Blot ◽  
Signaling Pathway ◽  
Hela Cells ◽  
Denv Infection ◽  
Luciferase Assay ◽  
Type I ◽  
Qrt Pcr ◽  
Stat Signaling

Previous studies demonstrated that dengue virus (DENV) infection developed resistance to type-I interferons (IFNα/β). The underlying mechanism remains unclear. USP18 is a negative regulator of IFNα/β signaling, and its expression level is significantly increased following DENV infection in cell lines and patients’ blood. Our previous study revealed that increased USP18 expression contributed to the IFN-α resistance of Hepatitis C Virus (HCV). However, the role of USP18 in DENV replication and resistance to IFN-α is elusive. In this current study, we aimed to explore the role of USP18 in DENV-2 replication and resistance to IFN-α. The level of USP18 was up-regulated by plasmid transfection and down-regulated by siRNA transfection in Hela cells. USP18, IFN-α, IFN-β expression, and DENV-2 replication were monitored by qRT-PCR and Western blot. The activation of the Jak/STAT signaling pathway was assessed at three levels: p-STAT1/p-STAT2 (Western blot), interferon-stimulated response element (ISRE) activity (Dual-luciferase assay), and interferon-stimulated genes (ISGs) expression (qRT-PCR). Our data showed that DENV-2 infection increased USP18 expression in Hela cells. USP18 overexpression promoted DENV-2 replication, while USP18 silence inhibited DENV-2 replication. Silence of USP18 potentiated the anti-DENV-2 activity of IFN-α through activation of the IFN-α-mediated Jak/STAT signaling pathway as shown by increased expression of p-STAT1/p-STAT2, enhanced ISRE activity, and elevated expression of some ISGs. Our data indicated that USP18 induced by DENV-2 infection is a critical host factor utilized by DENV-2 to confer antagonism on IFN-α.

scholarly journals The role of different serotypes and dengue virus concentration in the prognosis of dengue shock syndrome in children

2019 ◽  
Vol 10 (3) ◽  
Author(s):  
Tram Van Ta ◽  
Hai Thanh Tran ◽  
Quyen Nguyen Than Ha ◽  
Xuong Tuyet Nguyen ◽  
Vu Kien Tran ◽  
...  
Keyword(s):  
Dengue Virus ◽  
Dengue Infection ◽  
Dengue Shock Syndrome ◽  
Denv Infection ◽  
Virus Concentration ◽  
Denv Serotypes ◽  
Significant Difference ◽  
Almost All ◽  
The Relationship

Dengue haemorrhagic fever (DHF) is a burden of disease in tropical countries, caused by any one of four-dengue virus (DENV) serotypes (DENV-1 to DENV-4). Although there have been many studies on patients with DHF, many things remain unclear, including the role of DENV serotypes and DENV concentration. The objective of this study was to determine the role of different serotypes and DENV concentration in the prognosis of dengue shock syndrome. This was a prospective cohort study, conducted to show information relating to patients’ conditions, such as hematocrit, platelet, leukocytes, and DENV concentration and the differences between DENV serotypes. The study also expressed the relationship between two groups, DHF without shock and DHF with shock, in terms of immune status, different DENV serotypes, and DENV concentration. Two-hundred and thirty-four patients were serologically confirmed as having a DENV infection. On hospital admission day (fever within 72 hours), results showed that almost all patients had a secondary dengue infection (76.5 %). DENV-1 accounted for the highest number of cases (61.11%), and DENV-4 accounted for the lowest (0.43%). No statistically significant difference was found when comparing the two groups (DHF with shock and DHF without shock) or when comparing the groups of different DENV serotypes. The study concluded that different DENV serotypes or DENV concentration in the first day of hospitalization (fever within 72 hours) cannot be used for prognostic of DSS.

scholarly journals Dengue Virus Infection Causes the Activation of Distinct NF-κB Pathways for Inducible Nitric Oxide Synthase and TNF-αExpression in RAW264.7 Cells

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Yi-Lin Cheng ◽  
Yee-Shin Lin ◽  
Chia-Ling Chen ◽  
Shu-Wen Wan ◽  
Yi-Dan Ou ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Dengue Virus ◽  
Inflammatory Responses ◽  
Denv Infection ◽  
Raw264.7 Cells ◽  
Inflammatory Activation ◽  
Proinflammatory Responses ◽  
Oxide Synthase ◽  
Inducible Nitric Oxide

Infection with dengue virus (DENV) causes an increase in proinflammatory responses, such as nitric oxide (NO) generation and TNF-αexpression; however, the molecular mechanism underlying this inflammatory activation remains undefined, although the activation of the transcription factor NF-κB is generally involved. In addition to TNF-αproduction in DENV-infected murine macrophage RAW264.7 cells, inducible NO synthase was transcriptionally and posttranslationally elevated and accompanied by NO generation. NF-κB is known to be activated by DENV infection. Pharmacologically inhibiting NF-κB activation abolishes iNOS/NO biosynthesis and TNF-αproduction. With inhibition, the potential role of NF-κB in oxidative signaling regulation was prevented during DENV infection. Heat-inactivated DENV failed to cause the identified inflammatory responses. Pharmacological inhibition of TLR3 partly decreased NF-κB activation; however, it effectively abolished inducible iNOS/NO biosynthesis but did not inhibit TNF-αproduction. In contrast to TLR3, viral protein NS2B3 also independently contributed to NF-κB activation to regulate TNF-αproduction. These results show the distinct pathways for NF-κB activation caused by DENV infection individually for the regulation of iNOS/NO and TNF-αexpression.

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