Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 37
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Front Microbiol ; 12: 724345, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34566927

RESUMO

The Asian "tiger mosquito" Aedes albopictus is currently the most widely distributed disease-transmitting mosquito in the world. Its geographical expansion has also allowed the expansion of multiple arboviruses like dengue, Zika, and chikungunya, to higher latitudes. Due to the enormous risk to global public health caused by mosquitoes species vectors of human disease, and the challenges in slowing their expansion, it is necessary to develop new and environmentally friendly vector control strategies. Among these, host-associated microbiome-based strategies have emerged as promising options. In this study, we performed an RNA-seq analysis on dissected abdomens of Ae. albopictus females from Manhattan, KS, United States fed with sugar and human blood containing either normal or heat-inactivated serum, to evaluate the effect of heat inactivation on gene expression, the bacteriome transcripts and the RNA virome of this mosquito species. Our results showed at least 600 genes with modified expression profile when mosquitoes were fed with normal vs. heat-inactivated-containing blood. These genes were mainly involved in immunity, oxidative stress, lipid metabolism, and oogenesis. Also, we observed bacteriome changes with an increase in transcripts of Actinobacteria, Rhodospirillaceae, and Anaplasmataceae at 6 h post-feeding. We also found that feeding with normal blood seems to particularly influence Wolbachia metabolism, demonstrated by a significant increase in transcripts of this bacteria in mosquitoes fed with blood containing normal serum. However, no differences were observed in the virome core of this mosquito population. These results suggest that heat and further inactivation of complement proteins in human serum may have profound effect on mosquito and microbiome metabolism, which could influence interpretation of the pathogen-host interaction findings when using this type of reagents specially when measuring the effect of Wolbachia in vector competence.

2.
Viruses ; 13(7)2021 07 19.
Artigo em Inglês | MEDLINE | ID: mdl-34372606

RESUMO

As demonstrated with the novel coronavirus pandemic, rapid and accurate diagnosis is key to determine the clinical characteristic of a disease and to improve vaccine development. Once the infected person is identified, hematological findings may be used to predict disease outcome and offer the correct treatment. Rapid and accurate diagnosis and clinical parameters are pivotal to track infections during clinical trials and set protection status. This is also applicable for re-emerging diseases like dengue fever, which causes outbreaks in Asia and Latin America every 4 to 5 years. Some areas in the US are also endemic for the transmission of dengue virus (DENV), the causal agent of dengue fever. However, significant number of DENV infections in rural areas are diagnosed solely by clinical and hematological findings because of the lack of availability of ELISA or PCR-based tests or the infrastructure to implement them in the near future. Rapid diagnostic tests (RDT) are a less sensitive, yet they represent a timely way of detecting DENV infections. The purpose of this study was to determine whether there is an association between hematological findings and the probability for an NS1-based DENV RDT to detect the DENV NS1 antigen. We also aimed to describe the hematological parameters that are associated with the diagnosis through each test.


Assuntos
COVID-19/diagnóstico , COVID-19/epidemiologia , Dengue/diagnóstico , Adolescente , Adulto , Ásia/epidemiologia , Criança , Pré-Escolar , Colômbia/epidemiologia , Dengue/virologia , Vírus da Dengue/isolamento & purificação , Testes Diagnósticos de Rotina/métodos , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Lactente , Masculino , Pandemias , Reação em Cadeia da Polimerase , Kit de Reagentes para Diagnóstico , SARS-CoV-2/isolamento & purificação , Adulto Jovem
3.
Pathogens ; 10(7)2021 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-34209902

RESUMO

Culicoides sonorensis biting midges are biological vectors of vesicular stomatitis virus (VSV) in the U.S. Yet, little is known regarding the amount of ingested virus required to infect midges, nor how their feeding behavior or age affects viral replication and vector competence. We determined the minimum infectious dose of VSV-New Jersey for C. sonorensis midges and examined the effects of multiple blood-feeding cycles and age at the time of virus acquisition on infection dynamics. A minimum dose of 3.2 logs of virus/mL of blood resulted in midgut infections, and 5.2 logs/mL resulted in a disseminated infection to salivary glands. For blood-feeding behavior studies, ingestion of one or two non-infectious blood meals (BM) after a VSV infectious blood meal (VSV-BM) resulted in higher whole-body virus titers than midges receiving only the single infectious VSV-BM. Interestingly, this infection enhancement was not seen when a non-infectious BM preceded the infectious VSV-BM. Lastly, increased midge age at the time of infection correlated to increased whole-body virus titers. This research highlights the epidemiological implications of infectious doses, vector feeding behaviors, and vector age on VSV infection dynamics to estimate the risk of transmission by Culicoides midges more precisely.

4.
Vaccines (Basel) ; 9(4)2021 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-33916367

RESUMO

The saliva of hematophagous arthropods contains a group of active proteins to counteract host responses against injury and to facilitate the success of a bloodmeal. These salivary proteins have significant impacts on modulating pathogen transmission, immunogenicity expression, the establishment of infection, and even disease severity. Recent studies have shown that several salivary proteins are immunogenic and antibodies against them may block infection, thereby suggesting potential vaccine candidates. Here, we discuss the most relevant salivary proteins currently studied for their therapeutic potential as vaccine candidates or to control the transmission of human vector-borne pathogens and immune responses against different arthropod salivary proteins.

5.
Int J Mol Sci ; 21(18)2020 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-32916828

RESUMO

Aedes aegypti is the primary mosquito vector of several human arboviruses, including the dengue virus (DENV). Vector control is the principal intervention to decrease the transmission of these viruses. The characterization of molecules involved in the mosquito physiological responses to blood-feeding may help identify novel targets useful in designing effective control strategies. In this study, we evaluated the in vivo effect of feeding adult female mosquitoes with human red blood cells reconstituted with either heat-inactivated (IB) or normal plasma (NB). The RNA-seq based transcript expression of IB and NB mosquitoes was compared against sugar-fed (SF) mosquitoes. In in vitro experiments, we treated Aag2 cells with a recombinant version of complement proteins (hC3 or hC5a) and compared transcript expression to untreated control cells after 24 h. The transcript expression analysis revealed that human complement proteins modulate approximately 2300 transcripts involved in multiple biological functions, including immunity. We also found 161 upregulated and 168 downregulated transcripts differentially expressed when human complement protein C3 (hC3) and human complement protein C5a (hC5a) treated cells were compared to the control untreated cells. We conclude that active human complement induces significant changes to the transcriptome of Ae. aegypti mosquitoes, which may influence the physiology of these arthropods.


Assuntos
Aedes/metabolismo , Mosquitos Vetores/metabolismo , Transcriptoma , Aedes/imunologia , Animais , Complemento C3 , Complemento C5a , Feminino , Humanos , Mosquitos Vetores/imunologia
6.
Artigo em Inglês | MEDLINE | ID: mdl-32984076

RESUMO

Introduction: Malaria is still an important vector-borne disease in the New World tropics. Despite the recent decline in malaria due to Plasmodium falciparum infection in Africa, a rise in Plasmodium infections has been detected in several low malaria transmission areas in Latin America. One of the main obstacles in the battle against malaria is the lack of innovative tools to assess malaria transmission risk, and the behavioral plasticity of one of the main malaria vectors in Latin America, Anopheles darlingi. Methods: We used human IgG antibodies against mosquito salivary gland proteins as a measure of disease risk. Whole salivary gland antigen (SGA) from Anopheles darlingi mosquitoes was used as antigen in Western blot experiments, in which a ~65 kDa protein was visualized as the main immunogenic band and sent for sequencing by mass spectrometry. Apyrase and peroxidase peptides were designed and used as antigens in an ELISA-based test to measure human IgG antibody responses in people with different clinical presentations of malaria. Results: Liquid chromatography-mass spectrometry revealed 17 proteins contained in the ~65 kDa band, with an apyrase and a peroxidase as the two most abundant proteins. Detection of IgG antibodies against salivary antigens by ELISA revealed a significant higher antibody levels in people with malaria infection when compared to uninfected volunteers using the AnDar_Apy1 and AnDar_Apy2 peptides. We also detected a significant positive correlation between the anti-peptides IgG levels and antibodies against the Plasmodium vivax and P. falciparum antigens PvMSP1 and PfMSP1. Odd ratios suggest that people with higher IgG antibodies against the apyrase peptides were up to five times more likely to have a malaria infection. Conclusion: Antibodies against salivary peptides from An. darlingi salivary gland proteins may be used as biomarkers for malaria risk.


Assuntos
Anopheles , Plasmodium , África , Animais , Formação de Anticorpos , Humanos , Mosquitos Vetores , Plasmodium falciparum , Proteínas e Peptídeos Salivares
7.
Int J Mol Sci ; 21(18)2020 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-32927629

RESUMO

Dengue is the most burdensome vector-borne viral disease in the world. Dengue virus (DENV), the etiological cause of dengue, is transmitted primarily by the Aedes aegypti mosquito. Like any arbovirus, the transmission cycle of dengue involves the complex interactions of a multitude of human and mosquito factors. One point during this transmission cycle that is rich in these interactions is the biting event by the mosquito, upon which its saliva is injected into the host. A number of components in mosquito saliva have been shown to play a pivotal role in the transmission of dengue, however one such component that is not as well characterized is extracellular vesicles. Here, using high-performance liquid chromatography in tandem with mass spectrometry, we show that dengue infection altered the protein cargo of Aedes aegypti extracellular vesicles, resulting in the packaging of proteins with infection-enhancing ability. Our results support the presence of an infection-dependent pro-viral protein packaging strategy that uses the differential packaging of pro-viral proteins in extracellular vesicles of Ae. aegypti saliva to promote transmission. These studies represent the first investigation into the function of Ae. aegypti extracellular vesicle cargo during dengue infection.


Assuntos
Aedes/metabolismo , Dengue/transmissão , Vesículas Extracelulares/metabolismo , Proteínas de Insetos/metabolismo , Mosquitos Vetores/metabolismo , Aedes/virologia , Animais , Células Cultivadas , Dengue/virologia , Vírus da Dengue , Feminino , Humanos , Mosquitos Vetores/virologia
8.
Pathogens ; 9(4)2020 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-32344602

RESUMO

Culicoides sonorensis biting midges are well-known agricultural pests and transmission vectors of arboviruses such as vesicular stomatitis virus (VSV). The epidemiology of VSV is complex and encompasses a broad range of vertebrate hosts, multiple routes of transmission, and diverse vector species. In temperate regions, viruses can overwinter in the absence of infected animals through unknown mechanisms, to reoccur the next year. Non-conventional routes for VSV vector transmission may help explain viral maintenance in midge populations during inter-epidemic periods and times of adverse conditions for bite transmission. In this study, we examined whether VSV could be transmitted venereally between male and female midges. Our results showed that VSV-infected females could venereally transmit virus to uninfected naïve males at a rate as high as 76.3% (RT-qPCR), 31.6% (virus isolation) during the third gonotrophic cycle. Additionally, VSV-infected males could venereally transmit virus to uninfected naïve females at a rate as high as 76.6% (RT-qPCR), 49.2% (virus isolation). Immunofluorescent staining of micro-dissected reproductive organs, immunochemical staining of midge histological sections, examination of internal reproductive organ morphology, and observations of mating behaviors were used to determine relevant anatomical sites for virus location and to hypothesize the potential mechanism for VSV transmission in C. sonorensis midges through copulation.

9.
Parasit Vectors ; 13(1): 128, 2020 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-32171303

RESUMO

BACKGROUND: Zika virus (ZIKV) is transmitted to humans during the bite of an infected mosquito. In a scenario of globalization and climate change, the frequency of outbreaks has and will increase in areas with competent vectors, revealing a need for continuous improvement of ZIKV detection tools in vector populations. A simple, rapid and sensitive assay for viral detection is quantitative reverse transcription polymerase chain reaction (qRT-PCR), yet oligos optimized for ZIKV detection in mammalian cells and samples have repeatedly shown high background when used on mosquito ribonucleic acid (RNA). In this paper, we present a one-step qRT-PCR protocol that allows for the detection of ZIKV in mosquitoes and for the evaluation of gene expression from the same mosquito sample and RNA. This assay is a less expensive qRT-PCR approach than that most frequently used in the literature and has a much lower background, allowing confident detection. METHODS: Our new oligo design to detect ZIKV RNA included in silico analysis of both viral and mosquito (Ae. aegypti and Ae. albopictus) genomes, targeting sequences conserved between Asian and African ZIKV lineages, but not matching Aedes genomes. This assay will allow researchers to avoid nonspecific amplification in insect samples due to viral integration into the mosquito genome, a phenomenon known to happen in wild and colonized populations of mosquitoes. Standard curves constructed with in vitro transcribed ZIKV RNA were used to optimize the sensitivity, efficiency and reproducibility of the assay. RESULTS: Finally, the assay was used with success to detect both ZIKV RNA in infected mosquitoes and to detect expression of the Defensin A gene, an antimicrobial peptide (AMP) involved in Aedes aegypti immune response to virus infection. CONCLUSIONS: The experimental approach to detect ZIKV RNA in Aedes aegypti presented here has demonstrated to be specific, sensitive and reliable, and additionally it allows for the analysis of mosquito gene expression during ZIKV infection.


Assuntos
Aedes/virologia , Regulação Viral da Expressão Gênica , Mosquitos Vetores/virologia , RNA Viral/isolamento & purificação , Reação em Cadeia da Polimerase em Tempo Real/métodos , Infecção por Zika virus/diagnóstico , Zika virus/genética , Zika virus/isolamento & purificação , Aedes/genética , Animais , Chlorocebus aethiops , Culicidae/virologia , RNA Viral/genética , Reprodutibilidade dos Testes , Alinhamento de Sequência , Células Vero , Proteínas não Estruturais Virais/genética , Infecção por Zika virus/virologia
10.
Malar J ; 19(1): 42, 2020 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-31973737

RESUMO

BACKGROUND: The humoral immune response against Anopheles salivary glands proteins in the vertebrate host can reflect the intensity of exposure to Anopheles bites and the risk of Plasmodium infection. In Colombia, the identification of exposure biomarkers is necessary due to the several Anopheles species circulating. The purpose of this study was to evaluate risk of malaria infection by measuring antibody responses against salivary glands extracts from Anopheles (Nyssorhynchus) albimanus and Anopheles (Nys.) darlingi and also against the gSG6-P1 peptide of Anopheles gambiae in people residing in a malaria endemic area in the Colombian Pacific coast. METHODS: Dried blood spots samples were eluted to measure the IgG antibodies against salivary gland extracts of An. albimanus strains STECLA (STE) and Cartagena (CTG) and An. darlingi and the gSG6-P1 peptide by ELISA in uninfected people and microscopic and submicroscopic Plasmodium carriers from the Colombia Pacific Coast. A multiple linear mixed regression model, Spearman correlation, and Mann-Whitney U-test were used to analyse IgG data. RESULTS: Significant differences in specific IgG levels were detected between infected and uninfected groups for salivary glands extracts from An. albimanus and for gSG6-P1, also IgG response to CTG and gSG6-P1 peptide were positively associated with the IgG response to Plasmodium falciparum in the mixed model. CONCLUSION: The CTG and STE An. albimanus salivary glands extracts are a potential source of new Anopheles salivary biomarkers to identify exposure to the main malaria vector and to calculate risk of disease in the Colombian Pacific coast. Also, the gSG6-P1 peptide has the potential to quantify human exposure to the subgenus Anopheles vectors in the same area.


Assuntos
Anopheles/imunologia , Imunoglobulina G/biossíntese , Malária/epidemiologia , Mosquitos Vetores/imunologia , Proteínas e Peptídeos Salivares/imunologia , Adolescente , Animais , Infecções Assintomáticas/epidemiologia , Criança , Pré-Escolar , Colômbia/epidemiologia , Estudos Transversais , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Imunoglobulina G/sangue , Estudos Longitudinais , Malária/imunologia , Malária/transmissão , Masculino , Razão de Chances , Oceano Pacífico , Fatores de Risco
11.
Int J Mol Sci ; 21(3)2020 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-31973044

RESUMO

Insect saliva induces significant antibody responses associated with the intensity of exposure to bites and the risk of disease in humans. Several salivary biomarkers have been characterized to determine exposure intensity to Old World Anopheles mosquito species. However, new tools are needed to quantify the intensity of human exposure to Anopheles bites and understand the risk of malaria in low-transmission areas in the Americas. To address this need, we conducted proteomic and bioinformatic analyses of immunogenic candidate proteins present in the saliva of uninfected Anopheles albimanus from two separate colonies-one originating from Central America (STECLA strain) and one originating from South America (Cartagena strain). A ~65 kDa band was identified by IgG antibodies in serum samples from healthy volunteers living in a malaria endemic area in Colombia, and a total of five peptides were designed from the sequences of two immunogenic candidate proteins that were shared by both strains. ELISA-based testing of human IgG antibody levels against the peptides revealed that the transferrin-derived peptides, TRANS-P1, TRANS-P2 and a salivary peroxidase peptide (PEROX-P3) were able to distinguish between malaria-infected and uninfected groups. Interestingly, IgG antibody levels against PEROX-P3 were significantly lower in people that have never experienced malaria, suggesting that it may be a good marker for mosquito bite exposure in naïve populations such as travelers and deployed military personnel. In addition, the strength of the differences in the IgG levels against the peptides varied according to location, suggesting that the peptides may able to detect differences in intensities of bite exposure according to the mosquito population density. Thus, the An. albimanus salivary peptides TRANS-P1, TRANS-P2, and PEROX-P3 are promising biomarkers that could be exploited in a quantitative immunoassay for determination of human-vector contact and calculation of disease risk.


Assuntos
Anopheles/metabolismo , Malária/imunologia , Proteínas e Peptídeos Salivares/imunologia , Proteínas e Peptídeos Salivares/isolamento & purificação , Animais , Formação de Anticorpos , Antígenos , Biomarcadores/sangue , Colômbia , Humanos , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Mordeduras e Picadas de Insetos , Proteínas de Insetos/imunologia , Mosquitos Vetores , Projetos Piloto , Proteômica , Saliva/química
12.
Front Immunol ; 10: 1996, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31555263

RESUMO

Ticks are a growing concern to human and animal health worldwide and they are leading vectors of arthropod-borne pathogens in the United States. Ticks are pool blood feeders that can attach to the host skin for days to weeks using their saliva to counteract the host defenses. Tick saliva, as in other hematophagous arthropods, contains pharmacological and immunological active compounds, which modulate local and systemic immune responses and induce antibody production. In the present study, we explore differences in the salivary gland extract (SGE) protein content of Amblyomma americanum ticks raised in a laboratory colony (CT) vs. those collected in the field (FT). First, we measured the IgG antibody levels against SGE in healthy volunteers residing in Kansas. ELISA test showed higher IgG antibody levels when using the SGE from CT as antigen. Interestingly, antibody levels against both, CT-SGE and FT-SGE, were high in the warm months (May-June) and decreased in the cold months (September-November). Immunoblot testing revealed a set of different immunogenic bands for each group of ticks and mass spectrometry data revealed differences in at 19 proteins specifically identified in the CT-SGE group and 20 from the FT-SGE group. Our results suggest that differences in the salivary proteins between CT-SGE and FT-SGE may explain the differential immune responses observed in this study.


Assuntos
Interações Hospedeiro-Parasita/imunologia , Proteínas de Insetos/imunologia , Proteínas e Peptídeos Salivares/imunologia , Infestações por Carrapato/imunologia , Carrapatos/imunologia , Adulto , Animais , Antígenos/imunologia , Linhagem Celular , Citocinas/genética , Citocinas/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Glândulas Salivares/imunologia , Infestações por Carrapato/genética , Adulto Jovem
13.
Sci Rep ; 9(1): 6352, 2019 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-31015516

RESUMO

Aedes aegypti is the primary vector of a number of viruses pathogenic to humans including dengue virus (DENV). DENV infection leads to widespread transcriptomic and proteomic alterations in mosquito cells. Here we identified alterations to the mosquito cell secretome during DENV infection by performing liquid chromatography tandem mass spectrometry. We found that an extracellular fragment of low-density lipoprotein receptor-related protein 1 (LRP-1) was present during infection. Previous literature suggests that LRP-1 regulates cholesterol homeostasis. Therefore, we hypothesized that DENV modifies LRP-1 protein expression to maintain host-derived intracellular cholesterol, which would facilitate virus replication within membrane-associated replication compartments. Accordingly, stimuli that are present during flavivirus infection reduced LRP-1 protein expression. We also found that dsRNA knockdown of LRP-1 increased intracellular cholesterol and DENV viral RNA. Further, depletion of intracellular lipids reduced infection. Together, these data suggest that DENV reduces LRP-1 protein expression, possibly through regulated intramembrane proteolysis (RIP), to increase intracellular cholesterol and facilitate replication in Ae. aegypti.


Assuntos
Aedes/virologia , Vírus da Dengue/fisiologia , Proteína-1 Relacionada a Receptor de Lipoproteína de Baixa Densidade/metabolismo , Replicação Viral/fisiologia , Animais , Linhagem Celular , Colesterol/metabolismo , Dengue/virologia , Proteínas de Insetos/metabolismo , Peptídeos/metabolismo , RNA Viral/metabolismo
14.
J Vis Exp ; (143)2019 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-30735189

RESUMO

The recent emergence of the flavivirus Zika and neurological complications, such as Guillain-Barré syndrome and microcephaly in infants, has brought serious public safety concerns. Among the risk factors, antibody-dependent enhancement (ADE) poses the most significant threat, as the recent re-emergence of the Zika virus (ZIKV) is primarily in areas where the population has been exposed and is in a state of pre-immunity to other closely related flaviviruses, especially dengue virus (DENV). Here, we describe a protocol for quantifying the effect of human serum antibodies against DENV on ZIKV infection in primary human cells or cell lines.


Assuntos
Anticorpos Antivirais/imunologia , Anticorpos Facilitadores/imunologia , Zika virus/imunologia , Dengue/imunologia , Dengue/virologia , Vírus da Dengue/imunologia , Humanos , Soros Imunes , Macrófagos/virologia , Temperatura , Células U937 , Infecção por Zika virus/sangue , Infecção por Zika virus/imunologia , Infecção por Zika virus/virologia
15.
Insects ; 10(2)2019 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-30717390

RESUMO

Dengue virus (DENV) is transmitted by mosquitoes and is a major public health concern. The study of innate mosquito defense mechanisms against DENV have revealed crucial roles for the Toll, Imd, JAK-STAT, and RNAi pathways in mediating DENV in the mosquito. Often overlooked in such studies is the role of intrinsic cellular defense mechanisms that we hypothesize to work in concert with the classical immune pathways to affect organismal defense. Our understanding of the molecular interaction of DENV with mosquito host cells is limited, and we propose to expand upon the recent results from a genome-scale, small interfering RNA (siRNA)-based study that identified mammalian host proteins associated with resistance to dengue/West Nile virus (DENV/WNV) infection. The study identified 22 human DENV/WNV resistance genes (DVR), and we hypothesized that a subset would be functionally conserved in Aedes aegypti mosquitoes, imparting cellular defense against flaviviruses in this species. We identified 12 homologs of 22 human DVR genes in the Ae. aegypti genome. To evaluate their possible role in cellular resistance/antiviral defense against DENV, we used siRNA silencing targeted against each of the 12 homologs in an Ae. aegypti cell line (Aag2) infected with DENV2 and identified that silencing of the two candidates, AeFKBP1 and AeATCAY, homologs of human FKBP1B and ATCAY, were associated with a viral increase. We then used dsRNA to silence each of the two genes in adult mosquitoes to validate the observed antiviral functions in vivo. Depletion of AeFKBP1 or AeATCAY increased viral dissemination through the mosquito at 14 days post-infection. Our results demonstrated that AeFKBP1 and AeATCAY mediate resistance to DENV akin to what has been described for their homologs in humans. AeFKBP1 and AeATCAY provide a rare opportunity to elucidate a DENV-resistance mechanism that may be evolutionarily conserved between humans and Ae. aegypti.

16.
PLoS One ; 14(1): e0208455, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30601814

RESUMO

Dengue virus (DENV) is an arbovirus responsible for a significant number of deaths in Latin America. This virus is transmitted through the bite of Aedes aegypti, the main mosquito vector, and Ae. albopictus. During blood uptake, the mosquito injects its saliva into the host to facilitate the feeding process. Mosquito saliva contains potent immunogens capable of inducing antibody production directly related to mosquito bite exposure intensity and disease risk. In this study, we first determined the DENV infection status by two different DENV non-structural protein 1 (NS1) based rapid tests and qRT-PCR, then measured the levels of IgG1 and IgG4 antibodies against salivary proteins of Ae. aegypti female mosquitoes in volunteers living in a dengue endemic area. Our results show that people with a positive DENV diagnosis present higher levels of IgG4 antibodies than people with a negative diagnostic test, and that these antibody levels were higher in people with secondary DENV infections. With this study, we show that detection of IgG4 antibodies against mosquito saliva may be a reliable method to evaluate the risk of dengue infection.


Assuntos
Aedes/imunologia , Dengue/epidemiologia , Imunoglobulina G/imunologia , Proteínas e Peptídeos Salivares/imunologia , Adolescente , Adulto , Animais , Formação de Anticorpos/imunologia , Antígenos Virais/imunologia , Criança , Pré-Escolar , Colômbia/epidemiologia , Feminino , Humanos , Lactente , Pessoa de Meia-Idade , Fatores de Risco , Glândulas Salivares/metabolismo , Proteínas não Estruturais Virais/metabolismo , Adulto Jovem
17.
Insects ; 9(4)2018 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-30544935

RESUMO

Vesicular stomatitis (VS) is a viral disease of veterinary importance, enzootic in tropical and subtropical regions of the Americas. In the U.S., VS produces devastating economic losses, particularly in the southwestern states where the outbreaks display an occurrence pattern of 10-year intervals. To date, the mechanisms of the geographic spread and maintenance cycles during epizootics remain unclear. This is due, in part, to the fact that VS epidemiology has a complex of variables to consider, including a broad range of vertebrate hosts, multiple routes of transmission, and an extensive diversity of suspected vector species acting as both mechanical and biological vectors. Infection and viral progression within vector species are highly influenced by virus serotype, as well as environmental factors, including temperature and seasonality; however, the mechanisms of viral transmission, including non-conventional pathways, are yet to be fully studied. Here, we review VS epidemiology and transmission mechanisms, with comparisons of transmission evidence for the four most incriminated hematophagous dipteran taxa: Aedes mosquitoes, Lutzomyia sand flies, Simulium black flies, and Culicoides biting midges.

18.
Front Public Health ; 6: 111, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29868532

RESUMO

Background: Dengue is one of the most geographically significant mosquito-borne viral diseases transmitted by Aedes mosquitoes. During blood feeding, mosquitoes deposit salivary proteins that induce antibody responses. These can be related to the intensity of exposure to bites. Some mosquito salivary proteins, such as D7 proteins, are known as potent allergens. The antibody response to D7 proteins can be used as a marker to evaluate the risk of exposure and disease transmission and provide critical information for understanding the dynamics of vector-host interactions. Methods: The study was conducted at the Los Patios Hospital, Cucuta, Norte de Santander, Colombia. A total of 63 participants were enrolled in the study. Participants were categorized into three disease status groups, age groups, and socioeconomic strata. The level of IgG antibodies against D7 Aedes proteins was determined by ELISA. We used a statistical approach to determine if there is an association between antibody levels and factors such as age, living conditions, and dengue virus (DENV) infection. Results: We found that IgG antibodies against D7 proteins were higher in non-DENV infected individuals in comparison to DENV-infected participants. Also, the age factor showed a significant positive correlation with IgG antibodies against D7 proteins, and the living conditions (socioeconomic stratification), in people aged 20 years or older, are a statistically significant factor in the variability of IgG antibodies against D7 proteins. Conclusion: This pilot study represents the first approximation to elucidate any correlation between the antibody response against mosquito D7 salivary proteins and its correlation with age, living conditions, and DENV infection in a dengue endemic area.

19.
Proc Natl Acad Sci U S A ; 115(28): E6604-E6613, 2018 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-29946031

RESUMO

Dengue virus (DENV) is a mosquito-borne flavivirus that causes dengue fever in humans, worldwide. Using in vitro cell lines derived from Aedes albopictus and Aedes aegypti, the primary vectors of DENV, we report that DENV2/DENV3-infected cells secrete extracellular vesicles (EVs), including exosomes, containing infectious viral RNA and proteins. A full-length DENV2 genome, detected in arthropod EVs, was infectious to naïve mosquito and mammalian cells, including human-skin keratinocytes and blood endothelial cells. Cryo-electron microscopy showed mosquito EVs with a size range from 30 to 250 nm. Treatments with RNase A, Triton X-100, and 4G2 antibody-bead binding assays showed that infectious DENV2-RNA and proteins are contained inside EVs. Viral plaque formation and dilution assays also showed securely contained infectious viral RNA and proteins in EVs are transmitted to human cells. Up-regulated HSP70 upon DENV2 infection showed no role in viral replication and transmission through EVs. In addition, qRT-PCR and immunoblotting results revealed that DENV2 up-regulates expression of a mosquito tetraspanin-domain-containing glycoprotein, designated as Tsp29Fb, in A. aegypti mosquitoes, cells, and EVs. RNAi-mediated silencing and antibody blocking of Tsp29Fb resulted in reduced DENV2 loads in both mosquito cells and EVs. Immunoprecipitation showed Tsp29Fb to directly interact with DENV2 E-protein. Furthermore, treatment with GW4869 (exosome-release inhibitor) affected viral burden, direct interaction of Tsp29Fb with E-protein and EV-mediated transmission of viral RNA and proteins to naïve human cells. In summary, we report a very important finding on EV-mediated transmission of DENV2 from arthropod to mammalian cells through interactions with an arthropod EVs-enriched marker Tsp29Fb.


Assuntos
Vírus da Dengue , Dengue , Vesículas Extracelulares , Proteínas de Insetos , Proteínas do Envelope Viral , Aedes , Animais , Linhagem Celular , Dengue/genética , Dengue/metabolismo , Dengue/transmissão , Vírus da Dengue/genética , Vírus da Dengue/metabolismo , Vírus da Dengue/patogenicidade , Vesículas Extracelulares/genética , Vesículas Extracelulares/metabolismo , Vesículas Extracelulares/virologia , Células Endoteliais da Veia Umbilical Humana , Humanos , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Camundongos , Domínios Proteicos , Proteínas do Envelope Viral/genética , Proteínas do Envelope Viral/metabolismo
20.
J Gen Virol ; 98(7): 1702-1712, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28691657

RESUMO

Zika virus (ZIKV) is a mosquito-borne flavivirus that has recently been responsible for a serious outbreak of disease in South and Central America. Infection with ZIKV has been associated with severe neurological symptoms and the development of microcephaly in unborn fetuses. Many of the regions involved in the current outbreak are known to be endemic for another flavivirus, dengue virus (DENV), which indicates that a large percentage of the population may have pre-existing DENV immunity. Thus, it is vital to investigate what impact pre-existing DENV immunity has on ZIKV infection. Here, we use primary human myeloid cells as a model for ZIKV enhancement in the presence of DENV antibodies. We show that sera containing DENV antibodies from individuals living in a DENV-endemic area are able to enhance ZIKV infection in a human macrophage-derived cell line and primary human macrophages. We also demonstrate altered pro-inflammatory cytokine production in macrophages with enhanced ZIKV infection. Our study indicates an important role for pre-existing DENV immunity on ZIKV infection in primary human immune cells and establishes a relevant in vitro model to study ZIKV antibody-dependent enhancement.


Assuntos
Anticorpos Antivirais/imunologia , Anticorpos Facilitadores/imunologia , Vírus da Dengue/imunologia , Macrófagos/imunologia , Infecção por Zika virus/patologia , Zika virus/imunologia , Adulto , Linhagem Celular Tumoral , Criança , Pré-Escolar , Reações Cruzadas/imunologia , Citocinas/biossíntese , Dengue/imunologia , Dengue/virologia , Surtos de Doenças , Feminino , Humanos , Lactente , Masculino , Células U937 , Infecção por Zika virus/imunologia , Infecção por Zika virus/virologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...