scholarly journals Dengue Virus Non-Structural Protein 5 as a Versatile, Multi-Functional Effector in Host–Pathogen Interactions

2021 ◽  
Vol 11 ◽  
Author(s):  
Priya Bhatnagar ◽  
Gopinathan Pillai Sreekanth ◽  
Kaja Murali-Krishna ◽  
Anmol Chandele ◽  
Ramakrishnan Sitaraman
Keyword(s):  
Immune Responses ◽  
Dengue Virus ◽  
Structural Proteins ◽  
Structural Protein ◽  
Human Virus ◽  
Human Host ◽  
Adaptive Immune ◽  
Interferon Signalling ◽  
Rna Capping ◽  
Stat Pathway

Dengue is emerging as one of the most prevalent mosquito-borne viral diseases of humans. The 11kb RNA genome of the dengue virus encodes three structural proteins (envelope, pre-membrane, capsid) and seven non-structural proteins (NS1, NS2A, NS2B, NS3, NS4A, NS4B, and NS5), all of which are translated as a single polyprotein that is subsequently cleaved by viral and host cellular proteases at specific sites. Non-structural protein 5 (NS5) is the largest of the non-structural proteins, functioning as both an RNA-dependent RNA polymerase (RdRp) that replicates the viral RNA and an RNA methyltransferase enzyme (MTase) that protects the viral genome by RNA capping, facilitating polyprotein translation. Within the human host, NS5 interacts with several proteins such as those in the JAK-STAT pathway, thereby interfering with anti-viral interferon signalling. This mini-review presents annotated, consolidated lists of known and potential NS5 interactors in the human host as determined by experimental and computational approaches respectively. The most significant protein interactors and the biological pathways they participate in are also highlighted and their implications discussed, along with the specific serotype of dengue virus as appropriate. This information can potentially stimulate and inform further research efforts towards providing an integrative understanding of the mechanisms by which NS5 manipulates the human-virus interface in general and the innate and adaptive immune responses in particular.

scholarly journals The Role of Non-Structural Protein NSs in the Pathogenesis of Severe Fever with Thrombocytopenia Syndrome

Viruses ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 876
Author(s):  
Jumana Khalil ◽  
Hiroki Kato ◽  
Takashi Fujita
Keyword(s):  
Immune Responses ◽  
Antiviral Therapy ◽  
Virulence Factors ◽  
Viral Pathogenesis ◽  
Structural Proteins ◽  
Structural Protein ◽  
Therapy Development ◽  
The Many ◽  
Severe Fever

Viral non-structural proteins, such as NSs of the newly emerging severe fever with thrombocytopenia syndrome virus, are well established virulence factors, mediating viral pathogenesis and disease progression through various mechanisms. NSs has been described as a potent interferon antagonist and NF-κB agonist, two divergent signaling pathways in many immune responses upon a viral encounter. In this review, we highlight the many mechanisms used by NSs on the host that promote viral replication and hyper-inflammation. Understanding these host-pathogen interactions is crucial for antiviral therapy development.

scholarly journals Immunogenicity of Recombinant DNA Vaccine Encoding Non-Structural Protein-1 Dengue Virus Serotype-2 in Balb/c Mice

2021 ◽  
Vol 15 (2) ◽  
pp. 4
Author(s):  
Elitha Pulungan
Keyword(s):  
Immune Response ◽  
Dengue Virus ◽  
Dna Vaccine ◽  
Humoral Immune Response ◽  
Structural Proteins ◽  
Ns1 Protein ◽  
Structural Protein ◽  
Humoral Immune ◽  
Virus Serotype ◽  
Positive Strand Rna

Background: Dengue Hemorrhagic Fever (DHF) is an infectious disease caused by the dengue virus (DENV) which spread widely in tropical and subtropical regions of the world. DENV is a single-positive strand RNA virus with a genome size of ± 11kb which encodes three structural proteins, seven non-structural proteins, and two untranslated regions (UTR). The non-structural protein-1 (NS1) of DENV is known to have important role in dengue pathogenesis also promising to be developed as dengue vaccine. Lately, novel vaccine approach by DNA immunization have given new perspective for a safe, stable, and immunogenic vaccine platform. Previously, we have successfully construct DNA vaccine encoding NS1 protein of DENV2 (pUNS1) which express recombinant NS1 protein in-vitro. Thus, in this current study the ability of pUNS1 to induce humoral immune response will be further analyzed by in mice immunization. Methods: Sixteen BALB/c mice aged of 4 weeks were immunized 3 times with 100 µg of pUNS1 or pUMVC4a on 2 week time interval. Blood sampling was carried out just before immunization and termination was done 2 week after last immunization. Titer from individual mice sera against DENV-2 were measure with in-house ELISA. Results: IgG against NS1 protein of DENV2 titer from mice group immunized with recombinant pUNS1 shown high ELISA absorbancies, 5 times higher than pUMVC4a group. This result suggest the ability of pUNS1 to induce humoral immune response against NS1 DENV-2 in-vivo. Conclusion: Recombinant pUNS1 can induce humoral immune response in mice.

scholarly journals Dengue Outbreak is a Global Recurrent Crisis: Review of the Literature

2020 ◽  
Author(s):  
Yusha Araf ◽  
Md. Asad Ullah ◽  
Nairita Ahsan Faruqui ◽  
Sadrina Afrin Mowna ◽  
Durdana Hossain Prium ◽  
...  
Keyword(s):  
Immune Responses ◽  
Dengue Virus ◽  
Preventive Measures ◽  
Vaccine Development ◽  
Secondary Infection ◽  
Detection Methods ◽  
Adaptive Immune ◽  
Worldwide Distribution ◽  
Dengue Outbreaks ◽  
Life Threatening

Purpose: This review features a generalized overview of dengue outbreaks, dengue pathogenesis, symptoms, immune response, diagnosis methods and preventive measures which facilitates the better understanding of the global expansion and concerns relating to the disease. Recent Findings: A recent study showed that natural killer cells of the infected person become activated soon after the infection which may help in treatment and vaccine development. A research team has also produced synthetically engineered mosquitoes that can prevent the transmission and dissemination of the dengue virus by the activation of an antibody. Furthermore, a mutation in the protein envelope of the dengue virus leads to variation in shapes, developing resistance towards the vaccine. Summary: The increasing number of reported cases indicated the worldwide distribution of the mosquito vectors, which was further facilitated by the growth in the shipping and commerce industries. The immune system, through activation of the innate and adaptive immune responses, facilitates the recruitment of an array of leukocytes which help neutralize the virus. However, the 4 different viral serotypes increases the risk of a life-threatening secondary infection due to the varying serotypes. Apart from the laboratory standard PRNT method, several other dengue detection methods such as ELISA, RT-LAMP and several optical, microfluidic and electrochemical methods have been developed. Since Dengvaxia® (CYD-TDV) has its own set of drawbacks and limitations, several companies have been investing for the production of more potential vaccines that are currently in trial.

scholarly journals Dengue Virus Non-structural Protein 1 Modulates Infectious Particle Production via Interaction with the Structural Proteins

2015 ◽  
Vol 11 (11) ◽  
pp. e1005277 ◽  
Author(s):  
Pietro Scaturro ◽  
Mirko Cortese ◽  
Laurent Chatel-Chaix ◽  
Wolfgang Fischl ◽  
Ralf Bartenschlager
Keyword(s):  
Dengue Virus ◽  
Particle Production ◽  
Structural Proteins ◽  
Structural Protein ◽  
Infectious Particle

scholarly journals Dengue Epidemic Is a Global Recurrent Crisis: Review of the Literature

2020 ◽  
Author(s):  
Yusha Araf ◽  
Md. Asad Ullah ◽  
Nairita Ahsan Faruqui ◽  
Sadrina Afrin Mowna ◽  
Durdana Hossain Prium ◽  
...  
Keyword(s):  
Immune Responses ◽  
Dengue Virus ◽  
Vaccine Development ◽  
Secondary Infection ◽  
Detection Methods ◽  
Adaptive Immune ◽  
Worldwide Distribution ◽  
Dengue Outbreaks ◽  
Life Threatening ◽  
Dengue Epidemic

Purpose: This review highlights the global scenario of dengue outbreaks, dengue pathogenesis, symptoms, immune response, diagnosis methods and preventive measures which facilitates the better understanding of the global expansion and concerns relating to the disease. Recent Findings: A recent study showed that natural killer cells of the infected person become activated soon after the infection which may help in treatment and vaccine development. A research team has also produced synthetically engineered mosquitoes that can prevent the transmission and dissemination of the dengue virus by the activation of an antibody. Furthermore, a mutation in the protein envelope of the dengue virus leads to variation in shapes, developing resistance towards the vaccine. Summary: The mosquito vectors marked their worldwide distribution through an increasing number of reported cases which was further facilitated by the growth in the shipping and commerce industries. The immune system, through activation of the innate and adaptive immune responses, facilitates the recruitment of an array of leukocytes which help neutralize the virus. Apart from the laboratory standard PRNT method, several other dengue detection methods such as ELISA, RT-LAMP and several optical, microfluidic and electrochemical methods have been developed. The existence of the 4 different viral serotypes makes the secondary infection life-threatening and also leads to difficulties in vaccine development. Since Dengvaxia® (CYD-TDV) has its own set of drawbacks and limitations, several companies have been investing for the production of more potential vaccines that are currently in trial.

scholarly journals A Dengue Virus Serotype 1 mRNA-LNP Vaccine Elicits Protective Immune Responses

2021 ◽  
Author(s):  
Clayton J. Wollner ◽  
Michelle Richner ◽  
Mariah A. Hassert ◽  
Amelia K. Pinto ◽  
James D. Brien ◽  
...  
Keyword(s):  
Immune Responses ◽  
Dengue Virus ◽  
Viral Infection ◽  
Neutralizing Antibody ◽  
Viral Disease ◽  
Structural Proteins ◽  
Severe Dengue ◽  
Antibody Dependent Enhancement ◽  
Virus Serotype ◽  
Serotype 1

Dengue virus (DENV) is the most common vector-borne viral disease with nearly 400 million worldwide infections each year concentrated in the tropical and subtropical regions of the world. Severe dengue complications are often associated with a secondary heterotypic infection of one of the four circulating serotypes. In this scenario, humoral immune responses targeting cross-reactive, poorly-neutralizing epitopes can lead to increased infectivity of susceptible cells via antibody-dependent enhancement (ADE). In this way, antibodies produced in response to infection or vaccination are capable of contributing to enhanced disease in subsequent infections. Currently, there are no available therapeutics to combat DENV disease, and there is an urgent need for a safe and efficacious vaccine. Here, we developed a nucleotide-modified mRNA vaccine encoding for the membrane and envelope structural proteins from DENV serotype 1 encapsulated into lipid nanoparticles (prM/E mRNA-LNP). Vaccination of mice elicited robust antiviral immune responses comparable to viral infection with high levels of neutralizing antibody titers and antiviral CD4+ and CD8+ T cells. Immunocompromised AG129 mice vaccinated with the prM/E mRNA-LNP vaccine were protected from a lethal DENV challenge. Vaccination with either a wild-type vaccine, or a vaccine with mutations in the immunodominant fusion-loop epitope, elicited equivalent humoral and cell mediated immune responses. Neutralizing antibodies elicited by the vaccine were sufficient to protect against a lethal challenge. Both vaccine constructs demonstrated serotype specific immunity with minimal serum cross-reactivity and reduced ADE compared to a live DENV1 viral infection. IMPORTANCE With 400 million worldwide infections each year, dengue is the most common vector-born viral disease. 40% of the world's population is at risk with dengue experiencing consistent geographic spread over the years. With no therapeutics available and vaccines performing sub optimally, the need for an effective dengue vaccine is urgent. Here we develop and characterize a novel mRNA vaccine encoding for the dengue serotype 1 envelope and premembrane structural proteins that is delivered via a lipid nanoparticle. Our DENV1 prM/E mRNA-LNP vaccine induces neutralizing antibody and cellular immune responses in immunocompetent mice and protects an immunocompromised mouse from a lethal DENV challenge. Existing antibodies against dengue can enhance subsequent infections via antibody-dependent enhancement. Importantly our vaccine only induced serotype specific immune responses and did not induce ADE.

scholarly journals A mRNA-LNP vaccine against Dengue Virus elicits robust, serotype-specific immunity

2021 ◽  
Author(s):  
Clayton J. Wollner ◽  
Michelle Richner ◽  
Mariah A. Hassert ◽  
Amelia K. Pinto ◽  
James D. Brien ◽  
...  
Keyword(s):  
Immune Responses ◽  
Dengue Virus ◽  
Viral Infection ◽  
Neutralizing Antibody ◽  
Viral Disease ◽  
Structural Proteins ◽  
Severe Dengue ◽  
Antibody Dependent Enhancement ◽  
Specific Immunity ◽  
Serotype 1

ABSTRACTDengue virus (DENV) is the most common vector-borne viral disease with nearly 400 million worldwide infections each year concentrated in the tropical and subtropical regions of the world. Severe dengue complications are often associated with a secondary heterotypic infection of one of the four circulating serotypes. In this scenario, humoral immune responses targeting cross-reactive, poorly-neutralizing epitopes can lead to increased infectivity of susceptible cells via antibody-dependent enhancement (ADE). In this way, antibodies produced in response to infection or vaccination are capable of contributing to enhanced disease in subsequent infections. Currently, there are no available therapeutics to combat DENV disease, and there is an urgent need for a safe and efficacious vaccine. Here, we developed a nucleotide-modified mRNA vaccine encoding for the membrane and envelope structural proteins from DENV serotype 1 encapsulated into lipid nanoparticles (prM/E mRNA-LNP). Vaccination of mice elicited robust antiviral immune responses comparable to viral infection with high levels of neutralizing antibody titers and antiviral CD4+ and CD8+ T cells. Immunocompromised AG129 mice vaccinated with the prM/E mRNA-LNP vaccine were protected from a lethal DENV challenge. Vaccination with either a wild-type vaccine, or a vaccine with mutations in the immunodominant fusion-loop epitope, elicited equivalent humoral and cell mediated immune responses. Neutralizing antibodies elicited by the vaccine were sufficient to protect against a lethal challenge. Both vaccine constructs demonstrated serotype specific immunity with minimal serum cross-reactivity and reduced ADE compared to a live DENV1 viral infection.IMPORTANCEWith 400 million worldwide infections each year, dengue is the most common vector-born viral disease. 40% of the world’s population is at risk with dengue experiencing consistent geographic spread over the years. With no therapeutics available and vaccines performing sub optimally, the need for an effective dengue vaccine is urgent. Here we develop and characterize a novel mRNA vaccine encoding for the dengue serotype 1 envelope and premembrane structural proteins that is delivered via a lipid nanoparticle. Our DENV1 prM/E mRNA-LNP vaccine induces neutralizing antibody and cellular immune responses in immunocompetent mice and protects an immunocompromised mouse from a lethal DENV challenge. Existing antibodies against dengue can enhance subsequent infections via antibody-dependent enhancement. Importantly our vaccine only induced serotype specific immune responses and did not induce ADE.

scholarly journals The dengue virus non-structural protein 1 (NS1) is secreted from mosquito cells in association with the intracellular cholesterol transporter chaperone caveolin complex

2018 ◽  
Author(s):  
Romel Rosales Ramirez ◽  
Juan E. Ludert
Keyword(s):  
Dengue Virus ◽  
Brefeldin A ◽  
Structural Proteins ◽  
Infected Mosquito ◽  
Dependent Manner ◽  
Structural Protein ◽  
Caveolin 1 ◽  
Virion Release ◽  
Mosquito Cells ◽  
Infected Cells

ABSTRACTDengue virus (DENV) is a mosquito-borne virus of the familyFlaviviridae.The RNA viral genome encodes for a polyprotein that is co-translationally processed into three structural proteins and seven non-structural proteins. The non-structural protein 1 (NS1) is a multifunctional viral protein actively secreted in vertebrate and mosquito cells during DENV infection. In mosquito cells, NS1 is secreted in a caveolin-1 (CAV-1) dependent manner by an unconventional pathway. The caveolin chaperone complex (CCC) is a cytoplasmic complex formed by caveolin-1 and the chaperones FKBP52, Cy40 and CyA which is responsible for cholesterol traffic inside the cell. In this work, we demonstrate that in infected mosquito cells, DENV NS1 is secreted by an early and unconventional route that bypasses the Golgi apparatus in close association with the CCC. Treatment of mosquito cells with classic secretion inhibitors such as brefeldin A, golgicide A and Fli-06 showed no effect on NS1 secretion, but significant reductions in recombinant luciferase secretion and virion release. Silencing the expression of CAV1, FKBP52 with siRNAs or the inhibition of CyA by cyclosporine A resulted in significant decrease in NS1 secretion without affecting virion release. Using co-localization, co-inmunoprecipitation and proximity ligation assays, NS1 was found to co-localize and interact with all the protein components of the CCC in mosquito infected cells. In addition, CAV-1 and FKBP52 expression was found augmented in DENV infected cells. Finally, the treatment of ZIKV infected mosquito cells with brefeldin A and golgicide A showed no effect on NS1 secretion, while affecting virion release. ZIKV NS1 was also found to co-localize with CAV-1 in infected mosquito cells. These results suggest that in mosquito cells, ZIKV NS1 follows the same secretory pathway observed for DENV NS1. The association of NS1 with the cholesterol transporter CCC agrees with the lipoprotein nature of secreted hexameric NS1.AUTHOR SUMMARYDengue protein NS1 is secreted in infected mosquito and vertebrate cells. In humans, secreted NS1 have been associated with pathogenesis. In mosquito cells, NS1 follows an unconventional secretion pathway that is dependent on Caveolin-1. This work shows that in mosquito cells, NS1 secretion is associated to the chaperone caveolin complex, a complex formed by caveolin-1 and several chaperones, in charge of cholesterol transport within the cells. Reduction of the expression or the activity of chaperone caveolin complex in mosquito infected cells, diminished the secretion of NS1 without affecting virion release. Direct interaction between NS1 and the chaperone caveolin complex proteins was demonstrated by several assays. Moreover, increased expression of the caveolin-1 and co-chaperone FKBP52 during dengue infection was found, presumably in response to the higher requirements of these proteins during dengue virus infection. Results obtained with ZIKV infected mosquito cells suggest that also ZIKV NS1 is released following an unconventional secretory route in association with the chaperone caveolin complex. The functions of secreted NS1 within mosquito are unclear. However, giving the importance of the soluble NS1 in the vertebrate host, manipulation of the NS1 secretory route may prove a valuable strategy for dengue mosquito control and patient treatment.

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