Sialic Acid Expression in the MosquitoAedes aegyptiand Its Possible Role in Dengue Virus-Vector Interactions

Dengue fever (DF) is the most prevalent arthropod-borne viral disease which affects humans. DF is caused by the four dengue virus (DENV) serotypes, which are transmitted to the host by the mosquitoAedes aegyptithat has key roles in DENV infection, replication, and viral transmission (vector competence). Mosquito saliva also plays an important role during DENV transmission. In this study, we detected the presence of sialic acid (Sia) inAedes aegyptitissues, which may have an important role during DENV-vector competence. We also identified genome sequences encoding enzymes involved in Sia pathways. The cDNA forAedes aegyptiCMP-Sia synthase (CSAS) was amplified, cloned, and functionally evaluated via the complementation of LEC29.Lec32 CSAS-deficient CHO cells.AedesCSAS-transfected LEC29.Lec32 cells were able to express Sia moieties on the cell surface. Sequences related toα-2,6-sialyltransferase were detected in theAedes aegyptigenome. Likewise, we identified Sia-α-2,6-DENV interactions in different mosquito tissues. In addition, we evaluated the possible role of sialylated molecules in a salivary gland extract during DENV internalization in mammalian cells. The knowledge of early DENV-host interactions could facilitate a better understanding of viral tropism and pathogenesis to allow the development of new strategies for controlling DENV transmission.

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Determining vector competence of Aedes aegypti from Ghana in transmitting dengue virus serotypes 1 and 2

Parasites & Vectors ◽

10.1186/s13071-021-04728-z ◽

2021 ◽

Vol 14 (1) ◽

Author(s):

Michael Amoa-Bosompem ◽

Daisuke Kobayashi ◽

Kentaro Itokawa ◽

Katsunori Murota ◽

Astri Nur Faizah ◽

...

Keyword(s):

Aedes Aegypti ◽

Dengue Virus ◽

Urban Areas ◽

Vector Competence ◽

Denv Infection ◽

West African ◽

Control Group ◽

African Countries ◽

Denv Serotypes ◽

Serotype 1

Abstract Background Dengue virus (DENV) is a mosquito-borne arbovirus transmitted by Aedes mosquitoes, but is not endemic in all areas where this vector is found. For example, the relatively sparse distribution of cases in West Africa is generally attributed to the refractory nature of West African Aedes aegypti (Ae. aegypti) to DENV infection, and particularly the forest-dwelling Ae. aegypti formosus. However, recent studies have shown these mosquitoes to be competent vectors within some West African countries that have suffered outbreaks in the past, such as Senegal. There is however little information on the vector competence of the Ae. aegypti in West African countries such as Ghana with no reported outbreaks. Methods This study examined the vector competence of 4 Ae. aegypti colonies from urban, semi-urban, and two rural locations in Ghana in transmitting DENV serotypes 1 and 2, using a single colony from Vietnam as control. Midgut infection and virus dissemination were determined by quantitative reverse transcription polymerase chain reaction (qRT-PCR), while the presence and concentration of DENV in the saliva of infectious mosquitoes was determined by the focus forming assay. Results There were significant differences in the colonies’ susceptibility to virus infection, dissemination, and transmission. All examined Ghanaian mosquitoes were refractory to infection by DENV serotype 2, while some colonies exhibited potential to transmit DENV serotype 1. None of the tested colonies were as competent as the control group colony. Conclusions These findings give insight into the possible risk of outbreaks, particularly in the urban areas in the south of Ghana, and highlight the need for continuous surveillance to determine the transmission status and outbreak risk. This study also highlights the need to prevent importation of different DENV strains and potential invasion of new highly vector-competent Ae. aegypti strains, particularly around the ports of entry. Graphic Abstract

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

The Journal of Infection in Developing Countries ◽

10.3855/jidc.3978 ◽

2014 ◽

Vol 8 (07) ◽

pp. 876-884 ◽

Cited By ~ 8

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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Virus-Like Particles With FLAG-Tagged Envelope Protein as A Tetravalent Dengue Vaccine Candidate

10.21203/rs.3.rs-590302/v1 ◽

2021 ◽

Author(s):

Toshifumi Imagawa ◽

Masahiko Ito ◽

Mami Matsuda ◽

Kenji Nakashima ◽

Yuhei Tokunaga ◽

...

Keyword(s):

Dengue Virus ◽

Mammalian Cells ◽

Vaccine Development ◽

Secondary Infection ◽

Denv Infection ◽

Vaccine Platform ◽

Virus Like Particles ◽

Denv Serotypes ◽

One Step ◽

Characteristic Features

Abstract The global incidence of dengue, which is caused by dengue virus (DENV) infection, has grown dramatically in recent decades and secondary infection with heterologous serotype of the virus may cause severe symptoms. Efficacious dengue vaccines should be able to provide long-lasting immunity against all four DENV serotypes simultaneously. In this study, we constructed a novel vaccine platform based on tetravalent dengue virus-like particles (DENV-LPs) in which envelope (E) protein carried a FLAG tag sequence at the position located not only in the exterior loop on the protruding domain but outside of dimerization interface of the protein. We demonstrated an effective strategy to produce the DENV-LPs by transient transfection with expression plasmids for pre-membrane and E proteins of DENV-1 to DENV-4 in mammalian cells and to concentrate and purify them with one-step affinity chromatography. Characteristic features of VLPs such as particle size, shape and density were comparable to flavivirus-like particles reported. The neutralizing activity against all four DENV serotypes was successfully induced by immunization with the purified tetravalent VLPs in mice. Simple, one-step purification systems for VLP vaccine platforms using epitope-tagging strategy should be advantageous for vaccine development not only for dengue but for emerging pandemics in the future.

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Infection rate of Aedes aegypti mosquitoes with dengue virus depends on the interaction between temperature and mosquito genotype

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2017.1506 ◽

2017 ◽

Vol 284 (1864) ◽

pp. 20171506 ◽

Cited By ~ 21

Author(s):

A. Gloria-Soria ◽

P. M. Armstrong ◽

J. R. Powell ◽

P. E. Turner

Keyword(s):

Aedes Aegypti ◽

Dengue Virus ◽

Infection Rate ◽

Incubation Temperature ◽

Disease Risk ◽

Vector Competence ◽

Dengue Infection ◽

Denv Infection ◽

Environment Interaction ◽

Virus Genotype

Dengue fever is the most prevalent arthropod-transmitted viral disease worldwide, with endemic transmission restricted to tropical and subtropical regions of different temperature profiles. Temperature is epidemiologically relevant because it affects dengue infection rates in Aedes aegypti mosquitoes, the major vector of the dengue virus (DENV). Aedes aegypti populations are also known to vary in competence for different DENV genotypes. We assessed the effects of mosquito and virus genotype on DENV infection in the context of temperature by challenging Ae. aegypti from two locations in Vietnam, which differ in temperature regimes, with two isolates of DENV-2 collected from the same two localities, followed by incubation at 25, 27 or 32°C for 10 days. Genotyping of the mosquito populations and virus isolates confirmed that each group was genetically distinct. Extrinsic incubation temperature (EIT) and DENV-2 genotype had a direct effect on the infection rate, consistent with previous studies. However, our results show that the EIT impacts the infection rate differently in each mosquito population, indicating a genotype by environment interaction. These results suggest that the magnitude of DENV epidemics may not only depend on the virus and mosquito genotypes present, but also on how they interact with local temperature. This information should be considered when estimating vector competence of local and introduced mosquito populations during disease risk evaluation.

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Virus-like particles with FLAG-tagged envelope protein as a tetravalent dengue vaccine candidate

Scientific Reports ◽

10.1038/s41598-021-97038-4 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Toshifumi Imagawa ◽

Masahiko Ito ◽

Mami Matsuda ◽

Kenji Nakashima ◽

Yuhei Tokunaga ◽

...

Keyword(s):

Dengue Virus ◽

Mammalian Cells ◽

Vaccine Development ◽

Secondary Infection ◽

Denv Infection ◽

Vaccine Platform ◽

Virus Like Particles ◽

Denv Serotypes ◽

One Step ◽

Characteristic Features

AbstractThe global incidence of dengue, which is caused by dengue virus (DENV) infection, has grown dramatically in recent decades and secondary infection with heterologous serotype of the virus may cause severe symptoms. Efficacious dengue vaccines should be able to provide long-lasting immunity against all four DENV serotypes simultaneously. In this study, we constructed a novel vaccine platform based on tetravalent dengue virus-like particles (DENV-LPs) in which envelope (E) protein carried a FLAG tag sequence at the position located not only in the exterior loop on the protruding domain but outside of dimerization interface of the protein. We demonstrated an effective strategy to produce the DENV-LPs by transient transfection with expression plasmids for pre-membrane and E proteins of DENV-1 to DENV-4 in mammalian cells and to concentrate and purify them with one-step affinity chromatography. Characteristic features of VLPs such as particle size, shape and density were comparable to flavivirus-like particles reported. The neutralizing activity against all four DENV serotypes was successfully induced by immunization with the purified tetravalent VLPs in mice. Simple, one-step purification systems for VLP vaccine platforms using epitope-tagging strategy should be advantageous for vaccine development not only for dengue but for emerging pandemics in the future.

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Use of immunodot blot and multiplex reverse transcriptase-polymerase chain reaction in dengue virus detection in macerates of Aedes aegypti larvae

Microbiology Research ◽

10.4081/mr.2012.e13 ◽

2012 ◽

Vol 3 (1) ◽

pp. 13

Author(s):

Aline T.A. Chagas ◽

Michelle D. Oliveira ◽

Jose M.S. Mezencio ◽

Eduardo A.M. Silva ◽

Leandro L. Oliveira ◽

...

Keyword(s):

Polymerase Chain Reaction ◽

Aedes Aegypti ◽

Dengue Virus ◽

Reverse Transcriptase ◽

Epidemiological Surveillance ◽

Rt Pcr ◽

Chain Reaction ◽

Denv Serotypes ◽

Polymerase Chain ◽

Pcr Techniques

The <em>Dengue virus</em> is the main arbovirus that affects man in terms of morbidity and mortality. The detection of the virus is very important for epidemiological surveillance, so here we propose to standardize and compare the immunodot blot (IDB) and multiplex reverse transcriptase-polymerase chain reaction (M-RT-PCR) techniques to detect and characterize the dengue virus (DENV) serotypes in samples of <em>Aedes aegypti</em> larvae. Thus, the IDB and M-RT-PCR techniques were standardized using macerated samples of larvae collected in nature. The use of monoclonal antibodies in IDB has not shown great results, but DENV detection through this method was possible using polyclonal antibodies. The distinction of serotypes 1, 2 and 3 was carried out by M-RT-PCR.

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Boosting can explain patterns of fluctuations of ratios of inapparent to symptomatic dengue virus infections

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2013941118 ◽

2021 ◽

Vol 118 (14) ◽

pp. e2013941118

Author(s):

Laura W. Alexander ◽

Rotem Ben-Shachar ◽

Leah C. Katzelnick ◽

Guillermina Kuan ◽

Angel Balmaseda ◽

...

Keyword(s):

Dengue Virus ◽

Denv Infection ◽

Protective Effects ◽

Virus Infections ◽

Denv Serotypes ◽

Symptomatic Disease ◽

Large Fluctuations ◽

Antibody Titers ◽

Dengue Control ◽

Arboviral Disease

Dengue is the most prevalent arboviral disease worldwide, and the four dengue virus (DENV) serotypes circulate endemically in many tropical and subtropical regions. Numerous studies have shown that the majority of DENV infections are inapparent, and that the ratio of inapparent to symptomatic infections (I/S) fluctuates substantially year-to-year. For example, in the ongoing Pediatric Dengue Cohort Study (PDCS) in Nicaragua, which was established in 2004, the I/S ratio has varied from 16.5:1 in 2006–2007 to 1.2:1 in 2009–2010. However, the mechanisms explaining these large fluctuations are not well understood. We hypothesized that in dengue-endemic areas, frequent boosting (i.e., exposures to DENV that do not lead to extensive viremia and result in a less than fourfold rise in antibody titers) of the immune response can be protective against symptomatic disease, and this can explain fluctuating I/S ratios. We formulate mechanistic epidemiologic models to examine the epidemiologic effects of protective homologous and heterologous boosting of the antibody response in preventing subsequent symptomatic DENV infection. We show that models that include frequent boosts that protect against symptomatic disease can recover the fluctuations in the I/S ratio that we observe, whereas a classic model without boosting cannot. Furthermore, we show that a boosting model can recover the inverse relationship between the number of symptomatic cases and the I/S ratio observed in the PDCS. These results highlight the importance of robust dengue control efforts, as intermediate dengue control may have the potential to decrease the protective effects of boosting.

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

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1715788115 ◽

2017 ◽

Vol 115 (2) ◽

pp. 361-366 ◽

Cited By ~ 51

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.

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

Journal of General Virology ◽

10.1099/jgv.0.001694 ◽

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.

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Doratoxylon apetalum, an Indigenous Medicinal Plant from Mascarene Islands, Is a Potent Inhibitor of Zika and Dengue Virus Infection in Human Cells

International Journal of Molecular Sciences ◽

10.3390/ijms20102382 ◽

2019 ◽

Vol 20 (10) ◽

pp. 2382 ◽

Cited By ~ 8

Author(s):

Juliano G. Haddad ◽

Andrea Cristine Koishi ◽

Arnaud Gaudry ◽

Claudia Nunes Duarte dos Santos ◽

Wildriss Viranaicken ◽

...

Keyword(s):

Antiviral Activity ◽

Medicinal Plant ◽

Dengue Virus ◽

Denv Infection ◽

Antiviral Drugs ◽

Human Cells ◽

Host Cells ◽

Global Public Health ◽

Denv Serotypes ◽

Mascarene Islands

Zika virus (ZIKV) and Dengue virus (DENV) are mosquito-borne viruses of the Flavivirus genus that could cause congenital microcephaly and hemorrhage, respectively, in humans, and thus present a risk to global public health. A preventive vaccine against ZIKV remains unavailable, and no specific antiviral drugs against ZIKV and DENV are licensed. Medicinal plants may be a source of natural antiviral drugs which mostly target viral entry. In this study, we evaluate the antiviral activity of Doratoxylum apetalum, an indigenous medicinal plant from the Mascarene Islands, against ZIKV and DENV infection. Our data indicated that D. apetalum exhibited potent antiviral activity against a contemporary epidemic strain of ZIKV and clinical isolates of four DENV serotypes at non-cytotoxic concentrations in human cells. Time-of-drug-addition assays revealed that D. apetalum extract acts on ZIKV entry by preventing the internalisation of virus particles into the host cells. Our data suggest that D. apetalum-mediated ZIKV inhibition relates to virus particle inactivation. We suggest that D. apetalum could be a promising natural source for the development of potential antivirals against medically important flaviviruses.

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