13 results on '"Rajendra Raut"'
Search Results
2. Erratum for Markmann et al., 'Sex Disparities and Neutralizing-Antibody Durability to SARS-CoV-2 Infection in Convalescent Individuals'
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Terri Wrin, Caleb Cornaby, David R. Martinez, David M. Margolis, Susan R. Weiss, Luther A. Bartelt, Alena J. Markmann, Aaron Lerner, Rajendra Raut, Sonia Napravnik, David van Duin, Quique Guerra, John L. Schmitz, Yixuan J. Hou, Heather Root, Aravinda M. de Silva, Natasa Giallourou, D Ryan Bhowmik, Yara A. Park, Christos J. Petropoulos, Lakshmanane Premkumar, Ralph S. Baric, Stephen D Graham, and Joann D. Kuruc
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2019-20 coronavirus outbreak ,Coronavirus disease 2019 (COVID-19) ,biology ,SARS-CoV-2 ,business.industry ,Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ,Microbiology ,Virology ,QR1-502 ,immunology ,neutralizing ,biology.protein ,antibodies ,Medicine ,neutralizing antibodies ,business ,Neutralizing antibody ,Molecular Biology ,Research Article - Abstract
The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) has now caused over 2 million deaths worldwide and continues to expand. Currently, much is unknown about functionally neutralizing human antibody responses and durability to SARS-CoV-2 months after infection or the reason for the discrepancy in COVID-19 disease and sex. Using convalescent-phase sera collected from 101 COVID-19-recovered individuals 21 to 212 days after symptom onset with 48 additional longitudinal samples, we measured functionality and durability of serum antibodies. We also evaluated associations of individual demographic and clinical parameters with functional neutralizing antibody responses to COVID-19. We found robust antibody durability out to 6 months, as well as significant positive associations with the magnitude of the neutralizing antibody response and male sex and in individuals with cardiometabolic comorbidities. IMPORTANCE In this study, we found that neutralizing antibody responses in COVID-19-convalescent individuals vary in magnitude but are durable and correlate well with receptor binding domain (RBD) Ig binding antibody levels compared to other SARS-CoV-2 antigen responses. In our cohort, higher neutralizing antibody titers are independently and significantly associated with male sex compared to female sex. We also show for the first time that higher convalescent antibody titers in male donors are associated with increased age and symptom grade. Furthermore, cardiometabolic comorbidities are associated with higher antibody titers independently of sex. Here, we present an in-depth evaluation of serologic, demographic, and clinical correlates of functional antibody responses and durability to SARS-CoV-2 which supports the growing literature on sex discrepancies regarding COVID-19 disease morbidity and mortality, as well as functional neutralizing antibody responses to SARS-CoV-2.
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- 2021
3. Sex Disparities and Neutralizing-Antibody Durability to SARS-CoV-2 Infection in Convalescent Individuals
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Terri Wrin, Caleb Cornaby, Ralph S. Baric, Lakshmanane Premkumar, Susan R. Weiss, David M. Margolis, Aaron Lerner, Alena J. Markmann, David van Duin, Yixuan J. Hou, Natasa Giallourou, Yara A. Park, Stephen D Graham, Christos J. Petropoulos, D Ryan Bhowmik, Heather Root, Aravinda M. de Silva, Rajendra Raut, Luther A. Bartelt, Joann D. Kuruc, Sonia Napravnik, John L. Schmitz, Quique Guerra, and David R. Martinez
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Adult ,Male ,Adolescent ,Antibodies, Viral ,medicine.disease_cause ,Microbiology ,Serology ,Cohort Studies ,Young Adult ,Antigen ,Humans ,Medicine ,Young adult ,Neutralizing antibody ,Pandemics ,Molecular Biology ,Aged ,Coronavirus ,Aged, 80 and over ,biology ,SARS-CoV-2 ,business.industry ,Immunization, Passive ,Antibody titer ,COVID-19 ,Middle Aged ,Antibodies, Neutralizing ,QR1-502 ,Antibody Formation ,Spike Glycoprotein, Coronavirus ,Cohort ,Immunology ,biology.protein ,Female ,Erratum ,Antibody ,business - Abstract
The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) has now caused over 2 million deaths worldwide and continues to expand. Currently, much is unknown about functionally neutralizing human antibody responses and durability to SARS-CoV-2 months after infection or the reason for the discrepancy in COVID-19 disease and sex. Using convalescent-phase sera collected from 101 COVID-19-recovered individuals 21 to 212 days after symptom onset with 48 additional longitudinal samples, we measured functionality and durability of serum antibodies. We also evaluated associations of individual demographic and clinical parameters with functional neutralizing antibody responses to COVID-19. We found robust antibody durability out to 6 months, as well as significant positive associations with the magnitude of the neutralizing antibody response and male sex and in individuals with cardiometabolic comorbidities. IMPORTANCE In this study, we found that neutralizing antibody responses in COVID-19-convalescent individuals vary in magnitude but are durable and correlate well with receptor binding domain (RBD) Ig binding antibody levels compared to other SARS-CoV-2 antigen responses. In our cohort, higher neutralizing antibody titers are independently and significantly associated with male sex compared to female sex. We also show for the first time that higher convalescent antibody titers in male donors are associated with increased age and symptom grade. Furthermore, cardiometabolic comorbidities are associated with higher antibody titers independently of sex. Here, we present an in-depth evaluation of serologic, demographic, and clinical correlates of functional antibody responses and durability to SARS-CoV-2 which supports the growing literature on sex discrepancies regarding COVID-19 disease morbidity and mortality, as well as functional neutralizing antibody responses to SARS-CoV-2.
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- 2021
4. Dengue type 1 viruses circulating in humans are highly infectious and poorly neutralized by human antibodies
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Gregory D. Ebel, De Silva Ad, Sunil Premawansa, Kizzmekia S. Corbett, Rashika N. Tennekoon, Rajendra Raut, Gayani Premawansa, de Silva Am, Piotr A. Mieczkowski, Ananda Wijewickrama, and Claudia Rückert
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0301 basic medicine ,Vaccine evaluation ,viruses ,030106 microbiology ,Genome, Viral ,Cross Reactions ,Dengue virus ,Biology ,Antibodies, Viral ,medicine.disease_cause ,Polymerase Chain Reaction ,Neutralization ,Dengue fever ,Dengue ,03 medical and health sciences ,Commentaries ,Chlorocebus aethiops ,medicine ,Animals ,Humans ,Vero Cells ,Cells, Cultured ,Dengue vaccine ,Sri Lanka ,Multidisciplinary ,virus diseases ,Dengue Virus ,biochemical phenomena, metabolism, and nutrition ,medicine.disease ,Antibodies, Neutralizing ,Virology ,030104 developmental biology ,Vero cell ,biology.protein ,Antibody ,Vaccine failure - Abstract
The four dengue virus (DENV) serotypes are mosquito-borne flaviviruses of humans. The interactions between DENVs and the human host that lead to asymptomatic, mild, or severe disease are poorly understood, in part, because laboratory models are poor surrogates for human DENV disease. Virologists are interested in how the properties of DENVs replicating in people compare with virions propagated on laboratory cell lines, which are widely used for research and vaccine development. Using clinical samples from a DENV type 1 epidemic in Sri Lanka and new ultrasensitive assays, we compared the properties of DENVs in human plasma and after one passage on laboratory cell lines. DENVs in plasma were 50- to 700-fold more infectious than cell culture-grown viruses. DENVs produced by laboratory cell lines were structurally immature and hypersensitive to neutralization by human antibodies compared with DENVs circulating in people. Human plasma and cell culture-derived virions had identical genome sequences, indicating that these phenotypic differences were due to the mature state of plasma virions. Several dengue vaccines are under development. Recent studies indicate that vaccine-induced antibodies that neutralized DENVs in cell culture assays were not sufficient for protecting people from DENV infections. Our results about structural differences between DENVs produced in humans versus cell lines may be key to understanding vaccine failure and developing better models for vaccine evaluation.
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- 2018
5. The RBD Of The Spike Protein Of SARS-Group Coronaviruses Is A Highly Specific Target Of SARS-CoV-2 Antibodies But Not Other Pathogenic Human and Animal Coronavirus Antibodies
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Bruno Segovia-Chumbez, Longping V. Tse, Caitlin E. Edwards, Aravinda M. de Silva, Erin M. Scherer, Caleb Cornaby, Ralph S. Baric, David J. Margolis, Yixuan J. Hou, Lakshmanane Premkumar, Sri Edupuganti, Alena J. Markmann, Matthew H. Collins, John L. Schmitz, Rajendra Raut, Nadine Roupael, Eric T. Weimer, Susan R. Weiss, Alessandro Sette, Ramesh Jadi, Yara A. Park, Daniela Weiskopf, David R. Martinez, and Luther A. Bartelt
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viruses ,medicine.disease_cause ,Virus ,Serology ,law.invention ,Antigen ,law ,Pandemic ,Medicine ,Neutralizing antibody ,skin and connective tissue diseases ,Research Articles ,Coronavirus ,biology ,business.industry ,R-Articles ,fungi ,virus diseases ,food and beverages ,Virology ,respiratory tract diseases ,body regions ,biology.protein ,Recombinant DNA ,Antibody ,business - Abstract
The serum level of RBD-binding antibodies correlates with SARS-CoV-2 neutralization and can be used for population-level surveillance., The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that first emerged in late 2019 is responsible for a pandemic of severe respiratory illness. People infected with this highly contagious virus can present with clinically inapparent, mild, or severe disease. Currently, the virus infection in individuals and at the population level is being monitored by PCR testing of symptomatic patients for the presence of viral RNA. There is an urgent need for SARS-CoV-2 serologic tests to identify all infected individuals, irrespective of clinical symptoms, to conduct surveillance and implement strategies to contain spread. As the receptor binding domain (RBD) of the spike protein is poorly conserved between SARS-CoVs and other pathogenic human coronaviruses, the RBD represents a promising antigen for detecting CoV-specific antibodies in people. Here we use a large panel of human sera (63 SARS-CoV-2 patients and 71 control subjects) and hyperimmune sera from animals exposed to zoonotic CoVs to evaluate RBD's performance as an antigen for reliable detection of SARS-CoV-2-specific antibodies. By day 9 after the onset of symptoms, the recombinant SARS-CoV-2 RBD antigen was highly sensitive (98%) and specific (100%) for antibodies induced by SARS-CoVs. We observed a strong correlation between levels of RBD binding antibodies and SARS-CoV-2 neutralizing antibodies in patients. Our results, which reveal the early kinetics of SARS-CoV-2 antibody responses, support using the RBD antigen in serological diagnostic assays and RBD-specific antibody levels as a correlate of SARS-CoV-2 neutralizing antibodies in people.
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- 2020
6. Structural differences between dengue viruses circulating in humans and viruses used for vaccine research
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Aravinda M. de Silva and Rajendra Raut
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Vaccine research ,Virology ,medicine ,Biology ,medicine.disease ,Dengue fever - Published
- 2019
7. Placental thickness and its correlation to gestational age in Nepalese woman: a hospital based study
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Kedar Prasad Baral, Jessica Shrestha, Rajendra Raut, and Ranjan Prasad Devbhandari
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Correlation ,Menstruation ,Hospital based study ,medicine.medical_specialty ,Correlation coefficient ,Singleton ,Cross-sectional study ,business.industry ,Obstetrics ,Statistical significance ,Medicine ,Gestational age ,business - Abstract
Introductions: Gestational age is estimated on the basis of last normal menstrual period and the measurement of foetal growth parameters by ultrasonography. The lack of accurate recollection of the last menstrual period and dependence of growth parameters on intra-uterine environment, physical and mental well-being of the mother, maternal nutrition and genetic factors leads to the over or under estimation of gestational age. The aim of this study was to investigate the correlation between placental thicknesses (PT) in normal singleton Nepalese foetuses. Methods: This was a cross sectional study of ultrasound measurement of placental thickness during 2 nd and 3 rd trimester pregnancy from April 2015 to October 2015 at Department of Radiology, Suraksha Hospital, Biratnagar, Nepal. All viable singleton uncomplicated pregnancies, history of regular menstruation with known LNMP were included. Microsoft Excel and SPSS 17 were used for data analysis. Pearson’s correlation analysis was used for correlation between placental thickness and gestational age. Statistical tests were two-tailed with p
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- 2017
8. A tetravalent virus-like particle vaccine designed to display domain III of dengue envelope proteins induces multi-serotype neutralizing antibodies in mice and macaques which confer protection against antibody dependent enhancement in AG129 mice
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Aravinda M. de Silva, Navin Khanna, Rafi Ahmed, Melissa M. Mattocks, Rajgokul K. Shanmugam, Siddhartha Kumar Bhaumik, Ankur Poddar, Rajendra Raut, Rahul Shukla, Poornima Tyagi, Viswanathan Ramasamy, Robert E. Johnston, Sathyamangalam Swaminathan, Murali Krishna Kaja, Francois Villinger, Upasana Arora, Laura J. White, and Ashiya Perween
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0301 basic medicine ,RNA viruses ,Viral Diseases ,Immunogen ,Physiology ,viruses ,Dengue virus ,Monkeys ,medicine.disease_cause ,Antibodies, Viral ,Pathology and Laboratory Medicine ,Biochemistry ,Epitope ,Pichia ,Mice ,Virus-like particle ,Viral Envelope Proteins ,Immune Physiology ,Medicine and Health Sciences ,Enzyme-Linked Immunoassays ,Neutralizing antibody ,Mammals ,Vaccines ,Immune System Proteins ,biology ,lcsh:Public aspects of medicine ,virus diseases ,Eukaryota ,Recombinant Proteins ,3. Good health ,Body Fluids ,Blood ,Infectious Diseases ,Medical Microbiology ,Viral Pathogens ,Vertebrates ,Viruses ,Anatomy ,Pathogens ,Macaque ,Research Article ,Primates ,lcsh:Arctic medicine. Tropical medicine ,Infectious Disease Control ,medicine.drug_class ,lcsh:RC955-962 ,030106 microbiology ,Immunology ,Monoclonal antibody ,Serogroup ,Research and Analysis Methods ,Microbiology ,Antibodies ,03 medical and health sciences ,Old World monkeys ,medicine ,Animals ,Antibody-dependent enhancement ,Severe Dengue ,Vaccines, Virus-Like Particle ,Viremia ,Antigens ,Immunoassays ,Microbial Pathogens ,Dengue vaccine ,Flaviviruses ,Public Health, Environmental and Occupational Health ,Organisms ,Biology and Life Sciences ,Proteins ,lcsh:RA1-1270 ,Dengue Virus ,Blood Serum ,Virology ,Antibodies, Neutralizing ,Antibody-Dependent Enhancement ,Survival Analysis ,Disease Models, Animal ,030104 developmental biology ,Amniotes ,biology.protein ,Immunologic Techniques ,Macaca ,Immune Serum - Abstract
Background Dengue is one of the fastest spreading vector-borne diseases, caused by four antigenically distinct dengue viruses (DENVs). Antibodies against DENVs are responsible for both protection as well as pathogenesis. A vaccine that is safe for and efficacious in all people irrespective of their age and domicile is still an unmet need. It is becoming increasingly apparent that vaccine design must eliminate epitopes implicated in the induction of infection-enhancing antibodies. Methodology/principal findings We report a Pichia pastoris-expressed dengue immunogen, DSV4, based on DENV envelope protein domain III (EDIII), which contains well-characterized serotype-specific and cross-reactive epitopes. In natural infection, Author summary Dengue is mosquito-borne viral disease which is currently a global public health problem. It is caused by four different types of dengue viruses. Nearly a 100 million people a year suffer from overt sickness, which may range from mild fever to potentially fatal disease. A virus-based dengue vaccine was launched for the first time in late 2015. Unexpectedly, this vaccine mimics the dengue viruses in that it appears to elicit disease-enhancing antibodies. To reduce such risk, safer vaccines that eliminate viral proteins responsible for undesirable antibodies are needed. We focused our attention on a small domain of the dengue virus surface protein known as envelope domain III (EDIII). Humans make only a small amount of antibodies against EDIII, but these antibodies are effective in blocking dengue virus from entering cells. We used a yeast expression system to display EDIIIs of all four types of dengue viruses on the surface of non-infectious virus-like particles (VLPs). These VLPs elicited antibodies, in mice and monkeys, which blocked all four dengue virus types and their variants from entering cells in culture. Importantly, these antibodies did not enhance dengue infection in a mouse model.
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- 2017
9. Pichia pastoris-expressed dengue virus type 2 envelope domain III elicits virus-neutralizing antibodies
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Rajendra Raut, Gaurav Batra, Satinder Dahiya, Sathyamangalam Swaminathan, Neha Kamran, and Navin Khanna
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Molecular Sequence Data ,Dengue Vaccines ,Oleic Acids ,Viral Plaque Assay ,Biology ,Dengue virus ,Antibodies, Viral ,medicine.disease_cause ,Pichia ,Virus ,Epitope ,Dengue fever ,Pichia pastoris ,Mice ,Plaque reduction neutralization test ,Adjuvants, Immunologic ,Viral Envelope Proteins ,Antigen ,Neutralization Tests ,Virology ,medicine ,Animals ,Mannitol ,Dengue vaccine ,Mice, Inbred BALB C ,Vaccines, Synthetic ,Sequence Analysis, DNA ,Dengue Virus ,medicine.disease ,biology.organism_classification ,Antibodies, Neutralizing ,Vaccines, Subunit ,Alum Compounds - Abstract
A tetravalent dengue vaccine that can protect against all four serotypes of dengue viruses is a global priority. The host-receptor binding, multiple neutralizing epitope-containing carboxy-terminal region of the dengue envelope protein, known as domain III (EDIII), has emerged as a promising subunit vaccine antigen. One strategy to develop a tetravalent dengue subunit vaccine envisages mixing recombinant EDIIIs, corresponding to the four dengue virus serotypes. Towards this objective, a recombinant clone of the methylotrophic yeast Pichia pastoris, harboring the EDIII gene of dengue virus type 2 (EDIII-2) for its intracellular expression, was created. Recombinant EDIII-2 protein, expressed by this clone was purified to near homogeneity by affinity chromatography, with final yields of >50 mg/l culture. Groups of Balb/c mice were immunized with this protein, separately formulated in two adjuvants, alum and montanide ISA 720. The EDIII-2 antigen, formulated in either adjuvant, elicited high levels of neutralizing antibodies to dengue virus type 2 in mice as analyzed by Plaque Reduction Neutralization Test (PRNT). This study demonstrates the feasibility of using P. pastoris to produce EDIII antigens capable of eliciting potent virus-neutralizing antibodies.
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- 2010
10. Casamino acids facilitate the secretion of recombinant dengue virus serotype-3 envelope domain III in Pichia pastoris
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Gaurav Batra, Navin Khanna, Urpo Lamminmäki, Deepak Rohila, Neha Kaushik, Rajendra Raut, and Upasana Arora
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0106 biological sciences ,0301 basic medicine ,Envelope domain III ,Dengue virus ,Biology ,medicine.disease_cause ,01 natural sciences ,Pichia Pastoris ,Pichia ,Microbiology ,Pichia pastoris ,law.invention ,Dengue fever ,03 medical and health sciences ,Mice ,Antigen ,Viral Envelope Proteins ,law ,010608 biotechnology ,medicine ,Animals ,Secretion ,Amino Acids ,Mice, Inbred BALB C ,Dengue Virus ,biology.organism_classification ,medicine.disease ,Casamino acids ,Virology ,Recombinant Proteins ,Culture Media ,Titer ,030104 developmental biology ,Recombinant DNA ,Biotechnology ,Research Article - Abstract
Background Dengue is a viral disease spread to humans by mosquitoes. Notably, there are four serotypes of dengue viruses (DENV) that places ~40 % of the global population at risk of infection. However, lack of a suitable drug or a preventive vaccine exacerbates the matter further. Envelope domain-III (EDIII) antigen of dengue virus (DENV) has garnered much attention as a promising vaccine candidate for dengue, in addition to its use as a diagnostic intermediate. Hence developing a method for efficient production of high quality recombinant EDIII is important for research and industrial purpose. Results In this work, a Pichia pastoris system was optimized for the secretory over-expression of DENV serotype-3 EDIII under the control of methanol inducible AOX1 promoter. Temperature alone had a significant impact upon the amount of secretory EDIII, with 2.5-fold increase upon reducing the induction temperature from 30 to 20 °C. However surprisingly, supplementation of culture media with Casamino acids (CA), further augmented secretory EDIII titer, with a concomitant drop of intracellular EDIII levels at both temperatures. Though, reduction in intracellular retention of EDIII was more prominent at 20 °C than 30 °C. This suggests that CA supplementation facilitates overexpressing P. pastoris cells to secrete more EDIII by reducing the proportion retained intracellularly. Moreover, a bell-shaped correlation was observed between CA concentration and secretory EDIII titer. The maximum EDIII expression level of 187 mg/L was achieved under shake flask conditions with induction at 20 °C in the presence of 1 % CA. The overall increase in EDIII titer was ~9-fold compared to un-optimized conditions. Notably, mouse immune-sera, generated using this purified EDIII antigen, efficiently neutralized the DENV. Conclusions The strategy described herein could enable fulfilling the mounting demand for recombinant EDIII as well as lay direction to future studies on secretory expression of recombinant proteins in P. pastoris with CA as a media supplement. Electronic supplementary material The online version of this article (doi:10.1186/s12896-016-0243-3) contains supplementary material, which is available to authorized users.
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- 2015
11. Cissampelos pareira Linn: Natural Source of Potent Antiviral Activity against All Four Dengue Virus Serotypes
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Chandra Kant Katiyar, Ruchi Sood, Navin Kumar Sharma, Tarani Kanta Barman, Raj Kumar Shirumalla, Pradip Kumar Bhatnagar, Smita Singhal, Vijay Kanoje, Anil Kanaujia, Yogendra Kumar Gupta, Dilip J. Upadhyay, Gyanesh Shukla, Ravisankar Rajerethinam, Rajendra Raut, Sathyamangalam Swaminathan, Pawan Kumar Pareek, Ramesh Subbarayan, Poornima Tyagi, and Navin Khanna
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Gene Expression Regulation, Viral ,Male ,lcsh:Arctic medicine. Tropical medicine ,lcsh:RC955-962 ,India ,Context (language use) ,Dengue virus ,medicine.disease_cause ,Serogroup ,Virus Replication ,Antiviral Agents ,Dengue fever ,Cell Line ,Dengue ,Mice ,medicine ,Animals ,Humans ,Vector (molecular biology) ,Rats, Wistar ,Antigens, Viral ,Cissampelos ,biology ,Traditional medicine ,business.industry ,Plant Extracts ,lcsh:Public aspects of medicine ,Public Health, Environmental and Occupational Health ,lcsh:RA1-1270 ,Dengue Virus ,Viral Load ,biology.organism_classification ,medicine.disease ,Rats ,Infectious Diseases ,Cissampelos pareira ,Immunology ,Biological Assay ,Female ,Viral disease ,business ,Viral load ,Research Article - Abstract
Background Dengue, a mosquito-borne viral disease, poses a significant global public health risk. In tropical countries such as India where periodic dengue outbreaks can be correlated to the high prevalence of the mosquito vector, circulation of all four dengue viruses (DENVs) and the high population density, a drug for dengue is being increasingly recognized as an unmet public health need. Methodology/Principal findings Using the knowledge of traditional Indian medicine, Ayurveda, we developed a systematic bioassay-guided screening approach to explore the indigenous herbal bio-resource to identify plants with pan-DENV inhibitory activity. Our results show that the alcoholic extract of Cissampelos pariera Linn (Cipa extract) was a potent inhibitor of all four DENVs in cell-based assays, assessed in terms of viral NS1 antigen secretion using ELISA, as well as viral replication, based on plaque assays. Virus yield reduction assays showed that Cipa extract could decrease viral titers by an order of magnitude. The extract conferred statistically significant protection against DENV infection using the AG129 mouse model. A preliminary evaluation of the clinical relevance of Cipa extract showed that it had no adverse effects on platelet counts and RBC viability. In addition to inherent antipyretic activity in Wistar rats, it possessed the ability to down-regulate the production of TNF-α, a cytokine implicated in severe dengue disease. Importantly, it showed no evidence of toxicity in Wistar rats, when administered at doses as high as 2g/Kg body weight for up to 1 week. Conclusions/Significance Our findings above, taken in the context of the human safety of Cipa, based on its use in Indian traditional medicine, warrant further work to explore Cipa as a source for the development of an inexpensive herbal formulation for dengue therapy. This may be of practical relevance to a dengue-endemic resource-poor country such as India., Author Summary India represents ~50% of the global population estimated to be at risk of dengue. Severe dengue, which is potentially fatal, correlates with very high virus load, reduction in platelet counts and haemorrhage. Antiviral therapy to reduce high virus load may be beneficial in attenuating disease severity. We have explored Indian traditional medicine, Ayurveda, to identify plants that could be a source of dengue inhibitory activity. We show that an alcoholic extract prepared from Cissampelos pareira Linn inhibited the replication of dengue viruses in living cells in culture and protected mice against dengue infection. It also showed antipyretic and anti-inflammatory effects. Importantly, this extract did not show any toxic effects in rats and did not affect platelets and red blood cells. This observation is critical as dengue fever is commonly treated with antipyretics. In a dengue-endemic resource-poor country as India, the C. pareira plant may serve as a source for the development of an inexpensive herbal formulation against dengue.
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- 2015
12. A small molecule inhibitor of dengue virus type 2 protease inhibits the replication of all four dengue virus serotypes in cell culture
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Rajendra Raut, Dharmarajan Sriram, Hemalatha Beesetti, Sathyamangalam Swaminathan, Poornima Tyagi, Perumal Yogeeswari, Swatantra Kumar Jain, Ira Khanna, and Variam Ullas Jeankumar
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Cell Survival ,medicine.drug_class ,medicine.medical_treatment ,Drug Evaluation, Preclinical ,Antiviral therapy ,Biology ,Dengue virus ,Serogroup ,Virus Replication ,medicine.disease_cause ,Antiviral Agents ,Virus ,Dengue fever ,Virology ,Chlorocebus aethiops ,NS2b-NS3 protease ,medicine ,Animals ,Protease Inhibitors ,Antibody-dependent enhancement ,Vero Cells ,Protease ,Research ,Serine Endopeptidases ,Dengue Virus ,medicine.disease ,Molecular Docking Simulation ,Dengue protease inhibitor ,Kinetics ,Infectious Diseases ,Viral replication ,Proteolysis ,Vero cell ,Benzimidazoles ,Antiviral drug - Abstract
Background Dengue has emerged as the most significant of arboviral diseases in the 21st century. It is endemic to >100 tropical and sub-tropical countries around the world placing an estimated 3.6 billion people at risk. It is caused by four genetically similar but antigenically distinct, serotypes of dengue viruses. There is neither a vaccine to prevent nor a drug to treat dengue infections, at the present time. The major objective of this work was to explore the possibility of identifying a small molecule inhibitor of the dengue virus protease and assessing its ability to suppress viral replication in cultured cells. Methods We cloned, expressed and purified recombinant dengue virus type 2 protease. Using an optimized and validated fluorogenic peptide substrate cleavage assay to monitor the activity of this cloned dengue protease we randomly screened ~1000 small molecules from an ‘in-house’ library to identify potential dengue protease inhibitors. Results A benzimidazole derivative, named MB21, was found to be the most potent in inhibiting the cloned protease (IC50 = 5.95 μM). In silico docking analysis indicated that MB21 binds to the protease in the vicinity of the active site. Analysis of kinetic parameters of the enzyme reaction suggested that MB21 presumably functions as a mixed type inhibitor. Significantly, this molecule identified as an inhibitor of dengue type 2 protease was also effective in inhibiting each one of the four serotypes of dengue viruses in infected cells in culture, based on analysis of viral antigen synthesis and infectious virus production. Interestingly, MB21 did not manifest any discernible cytotoxicity. Conclusions This work strengthens the notion that a single drug molecule can be effective against all four dengue virus serotypes. The molecule MB21 could be a potential candidate for ‘hit-to-lead’ optimization, and may pave the way towards developing a pan-dengue virus antiviral drug. Electronic supplementary material The online version of this article (doi:10.1186/s12985-015-0248-x) contains supplementary material, which is available to authorized users.
- Published
- 2015
13. An envelope domain III-based chimeric antigen produced in Pichia pastoris elicits neutralizing antibodies against all four dengue virus serotypes
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Saima Khanam, Navin Khanna, Behzad Etemad, Gaurav Batra, Sathyamangalam Swaminathan, Rajendra Raut, and Satinder Dahiya
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viruses ,Recombinant Fusion Proteins ,T-Lymphocytes ,Dose-Response Relationship, Immunologic ,Dengue Vaccines ,Biology ,Dengue virus ,medicine.disease_cause ,Antibodies, Viral ,digestive system ,complex mixtures ,Neutralization ,Virus ,Pichia ,Microbiology ,Dengue fever ,Pichia pastoris ,Cell Line ,Dengue ,Mice ,fluids and secretions ,Viral Envelope Proteins ,Virology ,Cricetinae ,medicine ,Animals ,Serotyping ,Antigens, Viral ,Infectivity ,Mice, Inbred BALB C ,Haplorhini ,Dengue Virus ,medicine.disease ,biology.organism_classification ,Fusion protein ,digestive system diseases ,Flavivirus ,Infectious Diseases ,Culicidae ,Parasitology ,Genetic Engineering ,Spleen - Abstract
There is currently no vaccine to prevent dengue (DEN) virus infection, which is caused by any one of four closely related serotypes, DEN-1, DEN-2, DEN-3, or DEN-4. A DEN vaccine must be tetravalent, because immunity to a single serotype does not offer cross-protection against the other serotypes. We have developed a novel tetravalent chimeric protein by fusing the receptor-binding envelope domain III (EDIII) of the four DEN virus serotypes. This protein was expressed in the yeast, Pichia pastoris, and purified to near homogeneity in high yields. Antibodies induced in mice by the tetravalent protein, formulated in different adjuvants, neutralized the infectivity of all four serotypes. This, coupled with the high expression potential of the P. pastoris system and easy one-step purification, makes the EDIII-based recombinant protein a potentially promising candidate for the development of a safe, efficacious, and inexpensive, tetravalent DEN vaccine.
- Published
- 2008
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