scholarly journals Regulation of midgut cell proliferation impacts Aedes aegypti susceptibility to dengue virus

2018 ◽  
Author(s):  
Mabel L. Taracena ◽  
Vanessa Bottino-Rojas ◽  
Octavio A.C. Talyuli ◽  
Ana Beatriz Walter-Nuno ◽  
José Henrique M. Oliveira ◽  
...  
Keyword(s):  
Virus Infection ◽  
Aedes Aegypti ◽  
Dengue Virus ◽  
Denv Infection ◽  
Pathogen Transmission ◽  
Intestinal Lumen ◽  
Midgut Cell ◽  
Vector Borne Diseases ◽  
Cellular Processes ◽  
Vector Borne

AbstractAedes aegypti is the vector of some of the most important vector-borne diseases like Dengue, Chikungunya, Zika and Yellow fever, affecting millions of people worldwide. The cellular processes that follow a blood meal in the mosquito midgut are directly associated with pathogen transmission. We studied the homeostatic response of the midgut against oxidative stress, as well as bacterial and dengue virus (DENV) infections, focusing on the proliferative ability of the intestinal stem cells (ISC). Inhibition of the peritrophic matrix (PM) formation led to an increase in ROS production by the epithelial cells in response to contact with the resident microbiota, suggesting that maintenance of low levels of ROS in the intestinal lumen is key to keep ISCs division in balance. We show that dengue virus infection induces midgut cell division in both DENV susceptible (Rockefeller) and refractory (Orlando) mosquito strains. However, the susceptible strain delays the activation of the regeneration process compared with the refractory strain. Impairment of the Delta/Notch signaling, by silencing the Notch ligand Delta using RNAi, significantly increased the susceptibility of the refractory strains to DENV infection of the midgut. We propose that this cell replenishment is essential to control viral infection in the mosquito. Our study demonstrates that the intestinal epithelium of the blood fed mosquito is able to respond and defend against different challenges, including virus infection. In addition, we provide unprecedented evidence that the activation of a cellular regenerative program in the midgut is important for the determination of the mosquito vectorial competence.

scholarly journals Autochthonous dengue in two Dutch tourists visiting Département Var, southern France, July 2020

2020 ◽  
Vol 25 (39) ◽  
Author(s):  
Tom D Vermeulen ◽  
Johan Reimerink ◽  
Chantal Reusken ◽  
Sandra Giron ◽  
Peter J de Vries
Keyword(s):  
Public Health ◽  
Dengue Virus ◽  
Denv Infection ◽  
Diagnosis And Treatment ◽  
Southern Europe ◽  
Southern France ◽  
Delay In Diagnosis ◽  
Vector Borne Diseases ◽  
Vector Borne ◽  
Health Experts

We report dengue virus (DENV) infection in two Dutch tourists who visited Département Var, southern France, in July and August 2020. As some autochthonous dengue cases have occurred in Europe in recent years, awareness among physicians and public health experts about possible intermittent presence of DENV in southern Europe is important to minimise delay in diagnosis and treatment. Quick diagnosis can lead to timely action to contain the spread of vector-borne diseases and minimise transmission.

scholarly journals Urban Populations of Aedes aegypti (Diptera: Culicidae) From Central Argentina: Dispersal Patterns Assessed by Bayesian and Multivariate Methods

2020 ◽  
Vol 57 (4) ◽  
pp. 1069-1076
Author(s):  
Ana María Ayala ◽  
Noelia Soledad Vera ◽  
Marina Beatriz Chiappero ◽  
Walter Ricardo Almirón ◽  
Cristina Noemí Gardenal
Keyword(s):  
Aedes Aegypti ◽  
Isolation By Distance ◽  
Pathogen Transmission ◽  
Dispersal Pattern ◽  
Dispersal Patterns ◽  
Population Genetic Analysis ◽  
Vector Borne Diseases ◽  
High Q ◽  
Control Programs ◽  
Vector Borne

Abstract Aedes aegypti (L.), the main vector of dengue and other arboviruses, was declared eradicated from Argentina in 1964; however, in 1987, it was detected again and nowadays it occurs in most of the country territory. To understand the transmission of vector-borne diseases, knowledge of the dispersal of vector populations is essential to evaluate the risk of pathogen transmission. We conducted a population genetic analysis of Ae. aegypti in 20 neighborhoods from Córdoba, the second largest city in Argentina, using 10 microsatellite loci. High genetic differentiation and the absence of an isolation by distance pattern was found using Weir and Cockerham’s θ. Bayesian and multivariate clustering analyses showed that the studied sites included individuals with high membership coefficients (Q) in their populations, individuals with membership in another cluster, and admixed individuals. Individuals with high Q in clusters different from the population in which they were collected strongly suggests that passive transport is important in shaping the Ae. aegypti dispersal pattern in Córdoba city. Knowing the genetic structure of Ae. aegypti populations and their dispersal patterns would contribute to the implementation of vector control programs.

scholarly journals Molecular determinants of dengue virus infection in Aedes aegypti midgut

2019 ◽  
Vol 1 (10) ◽  
Author(s):  
Tanamas Siriphanitchakorn ◽  
Milly M. Choy ◽  
Wy Ching Ng ◽  
Dorothy Ng ◽  
Hwee Cheng Tan ◽  
...  
Keyword(s):  
Virus Infection ◽  
Aedes Aegypti ◽  
Dengue Virus ◽  
Dengue Virus Infection ◽  
Molecular Determinants

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 Field- and clinically derived estimates of Wolbachia-mediated blocking of dengue virus transmission potential in Aedes aegypti mosquitoes

2017 ◽  
Vol 115 (2) ◽  
pp. 361-366 ◽  
Author(s):  
Lauren B. Carrington ◽  
Bich Chau Nguyen Tran ◽  
Nhat Thanh Hoang Le ◽  
Tai Thi Hue Luong ◽  
Truong Thanh Nguyen ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Dengue Virus ◽  
Virus Transmission ◽  
Field Testing ◽  
Denv Infection ◽  
Ho Chi Minh City ◽  
Wild Type ◽  
Transmission Potential ◽  
Blood Meals ◽  
Increased Susceptibility

The wMel strain of Wolbachia can reduce the permissiveness of Aedes aegypti mosquitoes to disseminated arboviral infections. Here, we report that wMel-infected Ae. aegypti (Ho Chi Minh City background), when directly blood-fed on 141 viremic dengue patients, have lower dengue virus (DENV) transmission potential and have a longer extrinsic incubation period than their wild-type counterparts. The wMel-infected mosquitoes that are field-reared have even greater relative resistance to DENV infection when fed on patient-derived viremic blood meals. This is explained by an increased susceptibility of field-reared wild-type mosquitoes to infection than laboratory-reared counterparts. Collectively, these field- and clinically relevant findings support the continued careful field-testing of wMel introgression for the biocontrol of Ae. aegypti-born arboviruses.

Transcriptional response of Wolbachia-transinfected Aedes aegypti mosquito cells to dengue virus at early stages of infection

2022 ◽  
Vol 103 (1) ◽  
Author(s):  
Michael Leitner ◽  
Kayvan Etebari ◽  
Sassan Asgari
Keyword(s):  
Aedes Aegypti ◽  
Dengue Virus ◽  
Viral Infections ◽  
Transcriptional Response ◽  
Denv Infection ◽  
Content Type ◽  
Public Health Burden ◽  
Immune Genes ◽  
Link Type ◽  
Early Stages

Mosquito-borne flaviviruses are responsible for viral infections and represent a considerable public health burden. Aedes aegypti is the principal vector of dengue virus (DENV), therefore understanding the intrinsic virus–host interactions is vital, particularly in the presence of the endosymbiont Wolbachia, which blocks virus replication in mosquitoes. Here, we examined the transcriptional response of Wolbachia -transinfected Ae. aegypti Aag2 cells to DENV infection. We identified differentially expressed immune genes that play a key role in the activation of anti-viral defence such as the Toll and immune deficiency pathways. Further, genes encoding cytosine and N6-adenosine methyltransferases and SUMOylation, involved in post-transcriptional modifications, an antioxidant enzyme, and heat-shock response were up-regulated at the early stages of DENV infection and are reported here for the first time. Additionally, several long non-coding RNAs were among the differentially regulated genes. Our results provide insight into Wolbachia -transinfected Ae. aegypti’s initial virus recognition and transcriptional response to DENV infection.

scholarly journals The relationship between entomological indicators of Aedes aegypti abundance and dengue virus infection

2017 ◽  
Vol 11 (3) ◽  
pp. e0005429 ◽  
Author(s):  
Elizabeth A. Cromwell ◽  
Steven T. Stoddard ◽  
Christopher M. Barker ◽  
Annelies Van Rie ◽  
William B. Messer ◽  
...  
Keyword(s):  
Virus Infection ◽  
Aedes Aegypti ◽  
Dengue Virus ◽  
Dengue Virus Infection ◽  
The Relationship

scholarly journals Aedes aegypti salivary protein “aegyptin” co-inoculation modulates dengue virus infection in the vertebrate host

Virology ◽  
2014 ◽  
Vol 468-470 ◽  
pp. 133-139 ◽  
Author(s):  
M.K. McCracken ◽  
R.C. Christofferson ◽  
B.J. Grasperge ◽  
E. Calvo ◽  
D.M. Chisenhall ◽  
...  
Keyword(s):  
Virus Infection ◽  
Aedes Aegypti ◽  
Dengue Virus ◽  
Salivary Protein ◽  
Vertebrate Host ◽  
Dengue Virus Infection

scholarly journals Differential replication of dengue virus serotypes 2 and 3 in coinfections of C6/36 cells and Aedes aegypti mosquitoes

2014 ◽  
Vol 8 (07) ◽  
pp. 876-884 ◽  
Author(s):  
Diana Carolina Quintero-Gil ◽  
Marta Ospina ◽  
Jorge Emilio Osorio-Benitez ◽  
Marlen Martinez-Gutierrez
Keyword(s):  
Aedes Aegypti ◽  
Dengue Virus ◽  
Cell Viability ◽  
Denv Infection ◽  
Replication Capacity ◽  
Denv Serotypes ◽  
Viral Genomes ◽  
Diphenyltetrazolium Bromide

Introduction: Different dengue virus (DENV) serotypes have been associated with greater epidemic potential. In turn, the increased frequency in cases of severe forms of dengue has been associated with the cocirculation of several serotypes. Because Colombia is a country with an endemic presence of all four DENV serotypes, the aim of this study was to evaluate the in vivo and in vitro replication of the DENV-2 and DENV-3 strains under individual infection and coinfection conditions. Methodology: C6/36HT cells were infected with the two strains individually or simultaneously (coinfection). Replication capacity was evaluated by RT-qPCR, and the effects on cell viability were assessed with an MTT (3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. Additionally, Aedes aegypti mosquitoes were artificially fed the two strains of each serotype individually or simultaneously. The viral genomes were quantified by RT-qPCR and the survival of the infected mosquitoes was compared to that of uninfected controls. Results: In single infections, three strains significantly affected C6/36HT cell viability, but no significant differences were found in the replication capacities of the strains of the same serotype. In the in vivo infections, mosquito survival was not affected, and no significant differences in replication between strains of the same serotype were found. Finally, in coinfections, serotype 2 replicated with a thousandfold greater efficiency than serotype 3 did both in vitro and in vivo. Conclusions: Due to the cocirculation of serotypes in endemic regions, further studies of coinfections in a natural environment would further an understanding of the transmission dynamics that affect DENV infection epidemiology.

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