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Le Infezioni in Medicina 2024Dengue is a vector-borne disease, especially important in tropical and subtropical areas. The first presentation of many arboviral diseases occurred mainly in animals,... (Review)
Review
INTRODUCTION
Dengue is a vector-borne disease, especially important in tropical and subtropical areas. The first presentation of many arboviral diseases occurred mainly in animals, including multiple and , such as dengue.
OBJECTIVE
To determine the serological and molecular frequency of the dengue virus in animals.
METHODS
A systematic literature review was carried out in five databases for the proportion of animals infected with dengue, defined by molecular and serological tests. A meta-analysis was performed using a random-effects model to calculate the pooled prevalence and 95% confidence intervals (CI). Cochran?s Q test and the I2 statistic were used to assess the heterogeneity between the two studies.
RESULTS
The presence of dengue in bats, primates, birds, sheep, horses, cattle, pigs, rodents and buffaloes, according to serological methods, had a prevalence of 10%, 29%, 8%, 1%, 11%, 0%, 49%, 2%, 7%, respectively. According to molecular methods, the presence of dengue in bats had a seroprevalence of 6.0%.
CONCLUSION
The present study confirms the presence of the Dengue virus in a large group of animal species, with potential implications as possible reservoirs of this virus, raising the possibility of zoonotic transmission.
PubMed: 38827825
DOI: 10.53854/liim-3202-7 -
Scientific Reports May 2024In flaviviruses such as Dengue or Zika, non-structural (NS) NS4A protein forms homo-oligomers, participates in membrane remodelling and is critical for virulence. In...
In flaviviruses such as Dengue or Zika, non-structural (NS) NS4A protein forms homo-oligomers, participates in membrane remodelling and is critical for virulence. In both viruses, mature NS4A has the same length and three predicted hydrophobic domains. The oligomers formed by Dengue NS4A are reported to be small (n = 2, 3), based on denaturing SDS gels, but no high-resolution structure of a flavivirus NS4A protein is available, and the size of the oligomer in lipid membranes is not known. Herein we show that crosslinking Zika NS4A protein in lipid membranes results in oligomers at least up to hexamers. Further, sedimentation velocity shows that NS4A in mild detergent C14-betaine appears to be in fast equilibrium between at least two species, where one is smaller, and the other larger, than a trimer or a tetramer. Consistently, sedimentation equilibrium data was best fitted to a model involving an equilibrium between dimers (n = 2) and hexamers (n = 6). Overall, the large, at least hexameric, oligomers obtained herein in liposomes and in mild detergent are more likely to represent the forms of NS4A present in cell membranes.
Topics: Liposomes; Viral Nonstructural Proteins; Detergents; Zika Virus; Protein Multimerization
PubMed: 38822066
DOI: 10.1038/s41598-024-63407-y -
Journal of Infection and Public Health Jul 2024We aimed to describe the landscape, including molecular, epidemiological, and clinical aspects of CHIKV infections in the Ribeirao Preto region, an area endemic to...
We aimed to describe the landscape, including molecular, epidemiological, and clinical aspects of CHIKV infections in the Ribeirao Preto region, an area endemic to dengue. We randomly screened 3744 plasma samples that had undergone DENV diagnosis to evaluate CHIKV-RNA using an in-house RT-PCR assay. Positive samples were followed clinically, and RNA samples were submitted to whole genome sequencing. Seventeen cases (0.5 %) were positive for CHIKV-RNA despite being negative for DENV-RNA. Notably, half of the patients experienced prolonged arthralgia lasting more than 90 days. Compared with the healthy control group, leukopenia and thrombocytopenia were observed in all CHIKV-positive individuals with statistically significant P values (P < 0.0001 and P = 0.0003, respectively). The genomic analysis revealed that the CHIKV strains being studied are classified within the East-Central-South-African (ECSA) genotype. This analysis identified new mutations, E1: K211E and E2: V264A, while the previously known mutation E1: A226V was not detected among these strains. This study highlights the need for epidemiological surveillance and preparedness for potential CHIKV epidemics in Brazil, particularly where other arboviruses co-circulate.
Topics: Humans; Brazil; Chikungunya Fever; Chikungunya virus; Dengue; Male; Female; Adult; Genotype; Middle Aged; RNA, Viral; Young Adult; Endemic Diseases; Adolescent; Whole Genome Sequencing; Aged; Child; Phylogeny; Mutation; Child, Preschool; Dengue Virus; Thrombocytopenia
PubMed: 38820892
DOI: 10.1016/j.jiph.2024.04.026 -
Cell Reports Jun 2024Flaviviruses such as dengue virus (DENV), Zika virus (ZIKV), and yellow fever virus (YFV) are spread by mosquitoes and cause human disease and mortality in tropical...
Flaviviruses such as dengue virus (DENV), Zika virus (ZIKV), and yellow fever virus (YFV) are spread by mosquitoes and cause human disease and mortality in tropical areas. In contrast, Powassan virus (POWV), which causes severe neurologic illness, is a flavivirus transmitted by ticks in temperate regions of the Northern hemisphere. We find serologic neutralizing activity against POWV in individuals living in Mexico and Brazil. Monoclonal antibodies P002 and P003, which were derived from a resident of Mexico (where POWV is not reported), neutralize POWV lineage I by recognizing an epitope on the virus envelope domain III (EDIII) that is shared with a broad range of tick- and mosquito-borne flaviviruses. Our findings raise the possibility that POWV, or a flavivirus closely related to it, infects humans in the tropics.
Topics: Humans; Brazil; Antibodies, Neutralizing; Mexico; Antibodies, Viral; Animals; Encephalitis Viruses, Tick-Borne; Flavivirus; Epitopes; Antibodies, Monoclonal; Ticks; Female; Male
PubMed: 38819991
DOI: 10.1016/j.celrep.2024.114298 -
New Microbes and New Infections 2024
PubMed: 38818244
DOI: 10.1016/j.nmni.2024.101431 -
Heliyon May 2024The roles of antibodies secreted by subsets of B cells in dengue virus (DENV) infection have been extensively studied, yet, the contribution of tissue-homing B cells to...
The roles of antibodies secreted by subsets of B cells in dengue virus (DENV) infection have been extensively studied, yet, the contribution of tissue-homing B cells to antiviral immunity remains unclear. In this study, we performed a comprehensive analysis of B cell subpopulations in peripheral blood samples from DENV-infected patients using single-cell RNA-sequencing (scRNA-seq) datasets and flow cytometry. We showed that plasma cells (PCs) and plasmablasts (PBs) were the predominant B cell populations during the acute phase of secondary natural DENV infection, but not in convalescent phase nor in healthy controls. Interestingly, these cells expressed proliferation, adhesion, and tissue-homing genes, including , a homing marker of the skin, the initial infected site of DENV. Flow cytometry analysis confirmed a significant upregulation of cell surface expression of a cutaneous lymphocyte-associated antigen (CLA) encoded by in PCs and PBs, compared to naive and memory B cells from the same patients. The analysis of an independent single-cell B-cell receptor sequencing (scBCR-seq) dataset of DENV-infected patients revealed that the peripheral blood PCs and PBs exhibited the highest clonal expansion in secondary DENV infection compared to other B cell subsets. These clonally expanded cells also expressed the highest levels of tissue-homing genes, including In addition, by utilizing a public scRNA-seq dataset of SARS-CoV2 infection, we demonstrated the upregulation of several tissue-homing genes in PCs and PBs. Our study provides evidence for the potential roles of tissue-homing B cell subsets in the context of immune responses against viral infections in humans.
PubMed: 38818157
DOI: 10.1016/j.heliyon.2024.e30314 -
PNAS Nexus May 2024C-type lectins (CTLs) are a family of carbohydrate-binding proteins and an important component of mosquito saliva. Although CTLs play key roles in immune activation and...
C-type lectins (CTLs) are a family of carbohydrate-binding proteins and an important component of mosquito saliva. Although CTLs play key roles in immune activation and viral pathogenesis, little is known about their role in regulating dengue virus (DENV) infection and transmission. In this study, we established a homozygous knockout mutant line using CRISPR/Cas9 to study the interaction between and viruses in mosquito vectors. Furthermore, mouse experiments were conducted to confirm the transmission of DENV by mutants. We found that was mainly expressed in the medial lobe of the salivary glands (SGs) in female . knockout increased DENV replication and accumulation in the SGs of female , suggesting that plays an important role in DENV transmission. We also found a reduced expression of immunodeficiency and Janus kinase/signal transducer and activator of transcription pathway components correlated with increased DENV viral titer, infection rate, and transmission efficiency in the mutant strain. The findings of this study provide insights not only for guiding future investigations on the influence of CTLs on immune responses in mosquitoes but also for developing novel mutants that can be used as vector control tools.
PubMed: 38813522
DOI: 10.1093/pnasnexus/pgae188 -
Health Science Reports Jun 2024Epidemics of the dengue virus can trigger widespread morbidity and mortality along with no specific treatment. Examining the spatial autocorrelation and variability of...
BACKGROUND
Epidemics of the dengue virus can trigger widespread morbidity and mortality along with no specific treatment. Examining the spatial autocorrelation and variability of dengue prevalence throughout Bangladesh's 64 districts was the focus of this study.
METHODS
The spatial autocorrelation is evaluated with the help of Moran and Geary . Local Moran was used to detect hotspots and cold spots, whereas local Getis Ord was used to identify only spatial hotspots. The spatial heterogeneity has been detected using various conventional and spatial models, including the Poisson-Gamma model, the Poisson-Lognormal Model, the Conditional Autoregressive (CAR) model, the Convolution model, and the BYM2 model, respectively. These models are implemented using Gibbs sampling and other Bayesian hierarchical approaches to analyze the posterior distribution effectively, enabling inference within a Bayesian context.
RESULTS
The study's findings show that Moran and Geary analysis provides a substantial clustering pattern of positive spatial autocorrelation of dengue fever (DF) rates between surrounding districts at a 90% confidence interval. The Local Indicators of Spatial Autocorrelation cluster mapped spatial clusters and outliers based on prevalence rates, while the local Getis-Ord displayed a thorough breakdown of high or low rates, omitting outliers. Although Chattogram had the most dengue cases (15,752), Khulna district had a higher prevalence rate (133.636) than Chattogram (104.796). The BYM2 model, determined to be well-fitted based on the lowest Deviance Information Criterion value (527.340), explains a significant association between spatial heterogeneity and prevalence rates.
CONCLUSION
This research pinpoints the district with the highest prevalence rate for dengue and the neighboring districts that also have high risk, allowing government agencies and communities to take the necessary precautions to mollify the risk effect of DF.
PubMed: 38812714
DOI: 10.1002/hsr2.2154 -
ACS Infectious Diseases Jun 2024Dengue virus (DENV) nonstructural protein 5 (NS5), consisting of methyltransferase and RNA-dependent RNA polymerase (RdRp) domains, is critical for viral RNA synthesis...
Dengue virus (DENV) nonstructural protein 5 (NS5), consisting of methyltransferase and RNA-dependent RNA polymerase (RdRp) domains, is critical for viral RNA synthesis within endoplasmic reticulum-derived replication complexes in the cytoplasm. However, a significant proportion of NS5 is localized to the nucleus of infected cells for DENV2, 3, and 4, whereas DENV1 NS5 is localized diffusely in the cytoplasm. We still have an incomplete understanding of how the DENV NS5 subcellular localization is regulated. Within NS5, two putative nuclear localization signal (NLS) sequences have been identified: NLS residing in the palm of the RdRp domain as well as the recently discovered NLS residing in the flexible region at the C-terminal of the RdRp domain. We have previously shown that DENV2 NS5 nuclear localization can be significantly reduced by single-point mutations to the NLS. Here, we present biochemical, virological, and structural data demonstrating that the relative importance of either NLS in NS5 nuclear localization is unique to each of the four DENV serotypes. DENV1 NS5's cytoplasmic localization appears to be due to a functionally weak interaction between its NLS and importin-α (IMPα), while DENV2 NS5 is almost exclusively nuclear through its NLS's strong interaction with IMPα. Both NLSs of DENV3 NS5 appear to contribute to directing its nuclear localization. Lastly, in the case of DENV4, the regulation of its NS5 nuclear localization remains an enigma but appears to be associated with its NLS.
Topics: Viral Nonstructural Proteins; Dengue Virus; Nuclear Localization Signals; Cell Nucleus; Humans; Serogroup; Cytoplasm; Virus Replication; RNA-Dependent RNA Polymerase; Animals; Dengue; Protein Transport
PubMed: 38811007
DOI: 10.1021/acsinfecdis.4c00054 -
Open Veterinary Journal Apr 2024Dengue infection can trigger an immunological response that results in an inflammatory reaction, which acts as a defensive mechanism to protect the host. Dengue...
BACKGROUND
Dengue infection can trigger an immunological response that results in an inflammatory reaction, which acts as a defensive mechanism to protect the host. Dengue infection leads to an elevation in the release of pro-inflammatory cytokines, including tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6). These three cytokines have been shown to correlate with the development of thrombocytopenia and plasma leakage, which is related to the severity of the disease.
AIM
This study aims to investigate the effect of faloak ( R. Br) stem bark on TNF-α, IL-1β, and IL-6 levels in Wistar rats infected with dengue, specifically DENV-3.
METHODS
A group of 27 male Wistar rats () aged 2-3 months and weighting 200-300 g were divided into three distinct groups: healthy, dengue, and treatment (dengue infection and extract) groups. The rats in both the dengue and treatment groups were administered an injection of DENV-3 with a titer of 105 pfu at a dosage of 0.8 cc via the intraperitoneal route. The propagation of DENV-3 was initiated using C6/36 cells, and it underwent four passages. The extract was administered orally via a nasogastric tube at a dosage of 1,500 mg/kg body weight once daily for 7 days. The healthy group underwent blood sampling on the first day, whereas the dengue and therapy groups underwent blood sampling on the fifth and eighth, respectively.
RESULTS
Compared with the healthy group, TNF-α levels in the dengue and treatment groups showed significant differences on day 5 post-infection. The analysis revealed a statistically significant difference between the dengue-treatment and dengue-healthy groups. The IL-1β levels in the dengue and healthy groups significantly differed on days 5 and 8 post-infection compared to the healthy group. The treatment group had less of a decrease in IL-6 levels on days 5 and 8 than the dengue group. However, no statistically significant differences were observed.
CONCLUSION
The stem bark of shows potential as an anti-inflammatory agent in dengue infections, particularly in its ability to decrease levels of TNF-α and IL-1β.
Topics: Animals; Rats, Wistar; Male; Rats; Plant Bark; Tumor Necrosis Factor-alpha; Dengue; Plant Extracts; Interleukin-6; Anti-Inflammatory Agents; Interleukin-1beta; Dengue Virus
PubMed: 38808285
DOI: 10.5455/OVJ.2024.v14.i4.11