A Synthetic Bioactive Peptide Derived from the Asian Medicinal Plant Acacia catechu Binds to Dengue Virus and Inhibits Cell Entry

Dengue virus (DENV) infection has become a critically important globally prevalent infectious disease, especially in tropical and subtropical countries. Since neither currently exists, there is an urgent need for an effective vaccine to prevent, and a specific drug to treat DENV infection. Therapeutic peptides represent an attractive alternative for development into anti-DENV drugs due to their safety and their diverse biological and chemical properties. We recently reported novel bioactive peptides extracted from the Asian medicinal plant Acacia catechu that efficiently inhibited all four DENV serotypes. In this study, we investigated the anti-DENV activity of a synthetic bioactive peptide derived from this plant. The most effective peptide (designated Pep-RTYM) inhibited DENV infection with a half-maximal inhibition concentration value of 7.9 μM. Time-of-addition study demonstrated that Pep-RTYM interacted with DENV particles and inhibited cellular entry. Pep-RTYM at 50 μM significantly reduced DENV production in Vero-kidney epithelial cells about 1000-fold, but it could decrease the virus production in Huh7 hepatocyte cells approximately 40-fold. Binding of Pep-RTYM to DENV particles may prevent virus interaction with cellular receptor and subsequent virus entry. This finding suggests a potential role of Pep-RTYM in the development of a novel anti-DENV drug.

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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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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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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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Demonstration of marmosets (Callithrix jacchus) as a non-human primate model for secondary dengue virus infection: high levels of viraemia and serotype cross-reactive antibody responses consistent with secondary infection of humans

Journal of General Virology ◽

10.1099/vir.0.060384-0 ◽

2014 ◽

Vol 95 (3) ◽

pp. 591-600 ◽

Cited By ~ 18

Author(s):

Meng Ling Moi ◽

Tomohiko Takasaki ◽

Tsutomu Omatsu ◽

Shinichiro Nakamura ◽

Yuko Katakai ◽

...

Keyword(s):

Dengue Virus ◽

Primary Infection ◽

Secondary Infection ◽

Denv Infection ◽

Callithrix Jacchus ◽

Antibody Responses ◽

Infection Model ◽

Primate Model ◽

Bhk Cells ◽

Denv Serotypes

There are four dengue virus (DENV) serotypes. Primary infection with one does not confer protective immunity against the others. We have reported previously that the marmoset (Callithrix jacchus) is a useful primary DENV infection model. It has been reported that secondary DENV infection with a heterotypic serotype induces viraemia kinetics and antibody responses that differ from those in primary infection. Thus, it is important to determine the utility of the marmoset as a model for secondary DENV infection. Marmosets were infected with heterologous DENV by secondary inoculation, and viraemia kinetics and antibody responses were analysed. The marmosets consistently developed high levels of viraemia after the secondary inoculation with heterologous DENV serotypes. IgM responses were lower compared with primary inoculation responses, whilst IgG responses were rapid and high. Neutralizing activities, which possessed serotype cross-reactive activities, were detected as early as 4 days after inoculation. In addition, infectious viraemia titres were higher when assayed with Fcγ receptor-expressing baby hamster kidney (BHK) cells than when assayed with conventional BHK cells, suggesting the presence of infectious virus–antibody immune complexes. After secondary infection with heterotypic DENV, the marmosets demonstrated viraemia kinetics, IgM and IgG responses, and high levels of serotype cross-reactive neutralizing antibody responses, all of which were consistent with secondary DENV infection in humans. The results indicate the marmoset as a useful animal for studying secondary, as well as primary, DENV infection.

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Complement-Mediated Neutralization of Dengue Virus Requires Mannose-Binding Lectin

mBio ◽

10.1128/mbio.00276-11 ◽

2011 ◽

Vol 2 (6) ◽

Cited By ~ 45

Author(s):

Panisadee Avirutnan ◽

Richard E. Hauhart ◽

Mary A. Marovich ◽

Peter Garred ◽

John P. Atkinson ◽

...

Keyword(s):

Dengue Virus ◽

Human Serum ◽

Complement Activation ◽

Insect Cell ◽

Denv Infection ◽

Mannose Binding Lectin ◽

Lectin Pathway ◽

Denv Serotypes ◽

Mannose Binding ◽

Binding Lectin

ABSTRACTMannose-binding lectin (MBL) is a key soluble pathogen recognition protein of the innate immune system that binds specific mannose-containing glycans on the surfaces of microbial agents and initiates complement activation via the lectin pathway. Prior studies showed that MBL-dependent activation of the complement cascade neutralized insect cell-derived West Nile virus (WNV) in cell culture and restricted pathogenesis in mice. Here, we investigated the antiviral activity of MBL in infection by dengue virus (DENV), a related flavivirus. Using a panel of naïve sera from mouse strains deficient in different complement components, we showed that inhibition of infection by insect cell- and mammalian cell-derived DENV was primarily dependent on the lectin pathway. Human MBL also bound to DENV and neutralized infection of all four DENV serotypes through complement activation-dependent and -independent pathways. Experiments with human serum from naïve individuals with inherent variation in the levels of MBL in blood showed a direct correlation between the concentration of MBL and neutralization of DENV; samples with high levels of MBL in blood neutralized DENV more efficiently than those with lower levels. Our studies suggest that allelic variation of MBL in humans may impact complement-dependent control of DENV pathogenesis.IMPORTANCEDengue virus (DENV) is a mosquito-transmitted virus that causes a spectrum of clinical disease in humans ranging from subclinical infection to dengue hemorrhagic fever and dengue shock syndrome. Four serotypes of DENV exist, and severe illness is usually associated with secondary infection by a different serotype. Here, we show that mannose-binding lectin (MBL), a pattern recognition molecule that initiates the lectin pathway of complement activation, neutralized infection of all four DENV serotypes through complement activation-dependent and -independent pathways. Moreover, we observed a direct correlation with the concentration of MBL in human serum and neutralization of DENV infection. Our studies suggest that common genetic polymorphisms that result in disparate levels and function of MBL in humans may impact DENV infection, pathogenesis, and disease severity.

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Development of a Dengue Virus Serotype-Specific Non-Structural Protein 1 Capture Immunochromatography Method

Sensors ◽

10.3390/s21237809 ◽

2021 ◽

Vol 21 (23) ◽

pp. 7809

Author(s):

Kanaporn Poltep ◽

Emi E. Nakayama ◽

Tadahiro Sasaki ◽

Takeshi Kurosu ◽

Yoshiki Takashima ◽

...

Keyword(s):

Dengue Virus ◽

Pcr Amplification ◽

Denv Infection ◽

Epidemiologic Studies ◽

Cross Reaction ◽

Structural Protein ◽

Current Standard ◽

Denv Serotypes ◽

Detection Systems ◽

Virus Serotype

Four serotypes of dengue virus (DENV), type 1 to 4 (DENV-1 to DENV-4), exhibit approximately 25–40% of the difference in the encoded amino acid residues of viral proteins. Reverse transcription of RNA extracted from specimens followed by PCR amplification is the current standard method of DENV serotype determination. However, since this method is time-consuming, rapid detection systems are desirable. We established several mouse monoclonal antibodies directed against DENV non-structural protein 1 and integrated them into rapid DENV detection systems. We successfully developed serotype-specific immunochromatography systems for all four DENV serotypes. Each system can detect 104 copies/mL in 15 min using laboratory and clinical isolates of DENV. No cross-reaction between DENV serotypes was observed in these DENV isolates. We also confirmed that there was no cross-reaction with chikungunya, Japanese encephalitis, Sindbis, and Zika viruses. Evaluation of these systems using serum from DENV-infected individuals indicated a serotype specificity of almost 100%. These assay systems could accelerate both DENV infection diagnosis and epidemiologic studies in DENV-endemic areas.

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

PLoS ONE ◽

10.1371/journal.pone.0257460 ◽

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.

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Receptor-activated human α2-macroglobulin interacts with the envelope protein of dengue virus and protects virions from temperature-induced inactivation through multivalent binding

Journal of General Virology ◽

10.1099/vir.0.068544-0 ◽

2014 ◽

Vol 95 (12) ◽

pp. 2668-2676 ◽

Cited By ~ 9

Author(s):

Vivian Huerta ◽

Patricia Toledo ◽

Noralvis Fleitas ◽

Alejandro Martín ◽

Dianne Pupo ◽

...

Keyword(s):

Dengue Virus ◽

Specific Binding ◽

Interaction Network ◽

Denv Infection ◽

Virus Binding ◽

Denv Serotypes ◽

Α2 Macroglobulin ◽

Multivalent Binding ◽

Domain Iii ◽

Amyloid P

Based on the hypothesis that interactions between virions and serum components may influence the outcome of dengue virus (DENV) infections, we decided to use affinity chromatography with domain III from the envelope (E) protein of DENV2 (DIIIE2) as a ligand to isolate virus-binding proteins from human plasma. This approach yielded serum amyloid P (SAP) and α2-macroglobulin (α2M) as novel viral interactors. After confirming the specific binding of both SAP and α2M to DIIIE2 by ELISA, the latter interaction was examined in greater detail. We obtain evidence suggesting that the binding species was actually the receptor-activated form of α2M (α2M*), that α2M* could bind monovalently to recombinant domain III from all four DENV serotypes with affinities in the micromolar range ranking as DENV4>DENV1~DENV2>DENV3 and that this interaction exhibited a strong avidity effect when multivalent binding was favoured (K D 8×10−8 M for DIIIE2). We also showed that α2M* bound to DENV virions of the four serotypes, protecting the virus from temperature-induced inactivation in the absence of serum and enhancing infectivity. The latter effect exhibited an ED50 of 2.9×10−8 M, also suggesting an avidity effect due to multivalent binding. These results will further contribute to the characterization of the virus–host factor interaction network during human DENV infection.

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Crocetin Improves Dengue Virus-Induced Liver Injury

Viruses ◽

10.3390/v12080825 ◽

2020 ◽

Vol 12 (8) ◽

pp. 825

Author(s):

Gopinathan Pillai Sreekanth ◽

Aporn Chuncharunee ◽

Pa-thai Yenchitsomanus ◽

Thawornchai Limjindaporn

Keyword(s):

Polymerase Chain Reaction ◽

Liver Injury ◽

Dengue Virus ◽

Real Time ◽

Nuclear Translocation ◽

Virus Production ◽

Denv Infection ◽

Chain Reaction ◽

Gene Expressions ◽

Polymerase Chain

Dengue virus (DENV) infection is one of the most widespread mosquito-borne viral infections. Liver injury is commonly observed in severe DENV infection, and the present study aimed to examine the efficacy of crocetin treatment in an immunocompetent mouse model of DENV infection exhibiting liver injury. The efficacy of crocetin treatment in DENV-induced liver injury was assessed via both transaminase levels and histopathology analysis. A real-time polymerase chain reaction array was then used to describe the expression of 84 apoptosis-related genes. Using real-time RT-PCR and Western blot analysis, the gene expressions of host factors were investigated. Additionally, the effect of crocetin in NF-kB signaling during DENV infection was studied. We did not observe any significant reduction in virus production when DENV-infected mice were treated with crocetin. However, DENV-infected mice treated with crocetin showed reduced DENV-induced apoptosis. The real-time polymerase chain reaction array revealed pro-inflammatory cytokine expressions to be significantly reduced in the crocetin-treated DENV-infected mice. We also found that crocetin could effectively modulate antioxidant status in DENV-infected mice. Moreover, crocetin demonstrated the ability to reduce the nuclear translocation of NF-kB in DENV-infected mice. Our results suggest that crocetin treatment does not inhibit DENV replication in the liver of DENV-infected mice; however, we did find that crocetin improves host responses that reduce liver injury.

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

BioMed Research International ◽

10.1155/2015/504187 ◽

2015 ◽

Vol 2015 ◽

pp. 1-16 ◽

Cited By ~ 11

Author(s):

Jorge Cime-Castillo ◽

Philippe Delannoy ◽

Guillermo Mendoza-Hernández ◽

Verónica Monroy-Martínez ◽

Anne Harduin-Lepers ◽

...

Keyword(s):

Sialic Acid ◽

Aedes Aegypti ◽

Dengue Virus ◽

Mammalian Cells ◽

Vector Competence ◽

Denv Infection ◽

Viral Disease ◽

Salivary Gland Extract ◽

Denv Serotypes ◽

Mosquito Saliva

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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