The Experts below are selected from a list of 13797 Experts worldwide ranked by ideXlab platform
Hameeda Sultana - One of the best experts on this subject based on the ideXlab platform.
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arthropod evs mediate dengue virus transmission through interaction with a tetraspanin domain containing glycoprotein tsp29fb
Proceedings of the National Academy of Sciences of the United States of America, 2018Co-Authors: Ashish Vora, Hameeda Sultana, Wenshuo Zhou, Berlin Londonorenteria, Michael Woodson, Michael B Sherman, Tonya M Colpitts, Girish NeelakantaAbstract:Dengue virus (DENV) is a mosquito-borne flavivirus that causes dengue fever in humans, worldwide. Using in vitro cell lines derived from Aedes albopictus and Aedes aegypti, the primary vectors of DENV, we report that DENV2/DENV3-infected cells secrete extracellular vesicles (EVs), including exosomes, containing infectious Viral RNA and proteins. A full-length DENV2 genome, detected in arthropod EVs, was infectious to naive mosquito and mammalian cells, including human-skin keratinocytes and blood endothelial cells. Cryo-electron microscopy showed mosquito EVs with a size range from 30 to 250 nm. Treatments with RNase A, Triton X-100, and 4G2 antibody-bead binding assays showed that infectious DENV2-RNA and proteins are contained inside EVs. Viral Plaque formation and dilution assays also showed securely contained infectious Viral RNA and proteins in EVs are transmitted to human cells. Up-regulated HSP70 upon DENV2 infection showed no role in Viral replication and transmission through EVs. In addition, qRT-PCR and immunoblotting results revealed that DENV2 up-regulates expression of a mosquito tetraspanin-domain–containing glycoprotein, designated as Tsp29Fb, in A. aegypti mosquitoes, cells, and EVs. RNAi-mediated silencing and antibody blocking of Tsp29Fb resulted in reduced DENV2 loads in both mosquito cells and EVs. Immunoprecipitation showed Tsp29Fb to directly interact with DENV2 E-protein. Furthermore, treatment with GW4869 (exosome-release inhibitor) affected Viral burden, direct interaction of Tsp29Fb with E-protein and EV-mediated transmission of Viral RNA and proteins to naive human cells. In summary, we report a very important finding on EV-mediated transmission of DENV2 from arthropod to mammalian cells through interactions with an arthropod EVs-enriched marker Tsp29Fb.
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Examination of West Nile Virus Neuroinvasion and Neuropathogenesis in the Central Nervous System of a Murine Model
Methods in molecular biology (Clifton N.J.), 2016Co-Authors: Hameeda SultanaAbstract:West Nile virus (WNV) is a neurotropic virus that causes inflammation and neuronal loss in the Central Nervous System leading to encephalitis and death. In this chapter, detailed methods to detect WNV in the murine brain tissue by quantitative real-time polymerase chain reaction and Viral Plaque assays are described. Determination of WNV neuropathogenesis by Hematoxylin and Eosin staining and immunohistochemical procedures are provided. In addition, TUNEL assays to determine neuronal loss during WNV neuropathogenesis are discussed in detail. Collectively, the methods mentioned in this chapter provide an overview to understand neuroinvasion and neuropathogenesis in a murine model of WNV infection.
Douglas S. Lyles - One of the best experts on this subject based on the ideXlab platform.
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variation in susceptibility of human malignant melanomas to oncolytic vesicular stomatitis virus
Surgery, 2013Co-Authors: Aaron U Blackham, Douglas S. Lyles, Scott A Northrup, Mark C Willingham, Ralph B Dagostino, John H StewartAbstract:Background Vesicular stomatitis virus (VSV) is a novel, anti-cancer therapy that targets cancer cells selectively with defective antiViral responses; however, not all malignant cells are sensitive to the oncolytic effects of VSV. Herein, we have explored the mechanistic determinants of mutant M protein VSV (M51R-VSV) susceptibility in malignant melanoma cells. Methods Cell viability after VSV infection was measured by the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) viability assay in a panel of melanoma cell lines. VSV infectability, Viral protein synthesis, and Viral progeny production were quantified by flow cytometry, 35S-methionine electrophoresis, and Viral Plaque assays, respectively. Interferon (IFN) responsiveness was determined using MTS assay after β-IFN pretreatment. Xenografts were established in athymic nude mice and treated with intratumoral M51R-VSV. Results Cell viability after M51R-VSV infection at a multiplicity of infection of 10 pfu/mL, 48 hours postinfection) ranged between 0 ± 1% and 59 ± 9% (mean ± standard deviation). Sensitive cell lines supported VSV infection, Viral protein synthesis, and Viral progeny production. In addition, when pretreated with β-IFN, sensitive cells became resistant to M51R-VSV, suggesting that IFN-mediated antiViral signaling is defective in these cells. In contrast, resistant melanoma cells do not support VSV infection, Viral protein synthesis, or Viral replication, indicating that antiViral defenses remain intact. In a murine xenograft model, intratumoral M51R-VSV treatment decreased tumor growth relative to controls after 26 days in SK-Mel 5 (−21 ± 19% vs 2,100 ± 770%; P Conclusion M51R-VSV is a viable anti-cancer therapy, but susceptibility varies among melanomas. Future work will exploit specific mechanisms of resistance to expand the therapeutic efficacy of M51R-VSV.
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Vesicular stomatitis virus as a treatment for colorectal cancer
Cancer Gene Therapy, 2011Co-Authors: J H Stewart, S A Northrup, M Willingham, M. Ahmed, Douglas S. LylesAbstract:M protein mutant vesicular stomatitis virus is an attractive candidate oncolytic virus for the treatment of metastatic colorectal cancer due to its ability to kill cancer cells that are defective in their antiViral responses. The oncolytic activity of recombinant wild-type and M protein mutant vesicular stomatitis viruses was determined in RKO, Hct116 and LoVo colorectal cancer cells, as well as in human fibroblast and hepatocyte primary cultures. RKO and Hct116 cells were sensitive to both viruses, whereas LoVo cells were resistant. [^35S]methionine labeling experiments and Viral Plaque assays showed that sensitive and resistant colorectal cancer cells supported Viral protein and progeny production after infection with either virus. Colorectal cancer cells were pretreated with β -interferon and infected with vesicular stomatitis virus to evaluate the extent to which interferon signaling is downregulated in colorectal cancer cells. Although colorectal cancer cells retained some degree of interferon signaling, this signaling did not negatively impact the oncolytic effects of either virus in sensitive cells. Murine xenografts of RKO cells were effectively treated by intratumoral injections with M protein mutant virus, whereas LoVo xenografts were resistant to treatment with this virus. These results suggest that M protein mutant vesicular stomatitis virus is a good candidate oncolytic virus for the treatment of selected metastatic colorectal cancers.
Paul Fornès - One of the best experts on this subject based on the ideXlab platform.
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Enterovirus Persistence in Cardiac Cells of Patients With Idiopathic Dilated Cardiomyopathy Is Linked to 5’ Terminal Genomic RNA-Deleted Viral Populations With Viral-Encoded Proteinase Activities
Circulation, 2019Co-Authors: Alexis Bouin, Paul-antoine Gretteau, Michel Wehbe, Fanny Renois, Yohan N’guyen, Nicolas Lévêque, Steven Tracy, Nora Chapman, Patrick Bruneval, Paul FornèsAbstract:BACKGROUND: Group B enteroviruses are common causes of acute myocarditis, which can be a precursor of chronic myocarditis and dilated cardiomyopathy, leading causes of heart transplantation. To date, the specific Viral functions involved in the development of dilated cardiomyopathy remain unclear. METHODS: Total RNA from cardiac tissue of patients with dilated cardiomyopathy was extracted, and sequences corresponding to the 5' termini of enterovirus RNAs were identified. After next-generation RNA sequencing, Viral cDNA clones mimicking the enterovirus RNA sequences found in patient tissues were generated in vitro, and their replication and impact on host cell functions were assessed on primary human cardiac cells in culture. RESULTS: Major enterovirus B populations characterized by 5' terminal genomic RNA deletions ranging from 17 to 50 nucleotides were identified either alone or associated with low proportions of intact 5' genomic termini. In situ hybridization and immunohistological assays detected these persistent genomes in clusters of cardiomyocytes. Transfection of Viral RNA into primary human cardiomyocytes demonstrated that deleted forms of genomic RNAs displayed early replication activities in the absence of detectable Viral Plaque formation, whereas mixed deleted and complete forms generated particles capable of inducing cytopathic effects at levels distinct from those observed with full-length forms alone. Moreover, deleted or full-length and mixed forms of Viral RNA were capable of directing translation and production of proteolytically active Viral proteinase 2A in human cardiomyocytes. CONCLUSIONS: We demonstrate that persistent Viral forms are composed of B-type enteroviruses harboring a 5' terminal deletion in their genomic RNAs and that these viruses alone or associated with full-length populations of helper RNAs could impair cardiomyocyte functions by the proteolytic activity of Viral proteinase 2A in cases of unexplained dilated cardiomyopathy. These results provide a better understanding of the molecular mechanisms that underlie the persistence of EV forms in human cardiac tissues and should stimulate the development of new therapeutic strategies based on specific inhibitors of the coxsackievirus B proteinase 2A activity for acute and chronic cardiac infections.
J H Stewart - One of the best experts on this subject based on the ideXlab platform.
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Vesicular stomatitis virus as a treatment for colorectal cancer
Cancer Gene Therapy, 2011Co-Authors: J H Stewart, S A Northrup, M Willingham, M. Ahmed, Douglas S. LylesAbstract:M protein mutant vesicular stomatitis virus is an attractive candidate oncolytic virus for the treatment of metastatic colorectal cancer due to its ability to kill cancer cells that are defective in their antiViral responses. The oncolytic activity of recombinant wild-type and M protein mutant vesicular stomatitis viruses was determined in RKO, Hct116 and LoVo colorectal cancer cells, as well as in human fibroblast and hepatocyte primary cultures. RKO and Hct116 cells were sensitive to both viruses, whereas LoVo cells were resistant. [^35S]methionine labeling experiments and Viral Plaque assays showed that sensitive and resistant colorectal cancer cells supported Viral protein and progeny production after infection with either virus. Colorectal cancer cells were pretreated with β -interferon and infected with vesicular stomatitis virus to evaluate the extent to which interferon signaling is downregulated in colorectal cancer cells. Although colorectal cancer cells retained some degree of interferon signaling, this signaling did not negatively impact the oncolytic effects of either virus in sensitive cells. Murine xenografts of RKO cells were effectively treated by intratumoral injections with M protein mutant virus, whereas LoVo xenografts were resistant to treatment with this virus. These results suggest that M protein mutant vesicular stomatitis virus is a good candidate oncolytic virus for the treatment of selected metastatic colorectal cancers.
Alexis Bouin - One of the best experts on this subject based on the ideXlab platform.
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Enterovirus Persistence in Cardiac Cells of Patients With Idiopathic Dilated Cardiomyopathy Is Linked to 5’ Terminal Genomic RNA-Deleted Viral Populations With Viral-Encoded Proteinase Activities
Circulation, 2019Co-Authors: Alexis Bouin, Paul-antoine Gretteau, Michel Wehbe, Fanny Renois, Yohan N’guyen, Nicolas Lévêque, Steven Tracy, Nora Chapman, Patrick Bruneval, Paul FornèsAbstract:BACKGROUND: Group B enteroviruses are common causes of acute myocarditis, which can be a precursor of chronic myocarditis and dilated cardiomyopathy, leading causes of heart transplantation. To date, the specific Viral functions involved in the development of dilated cardiomyopathy remain unclear. METHODS: Total RNA from cardiac tissue of patients with dilated cardiomyopathy was extracted, and sequences corresponding to the 5' termini of enterovirus RNAs were identified. After next-generation RNA sequencing, Viral cDNA clones mimicking the enterovirus RNA sequences found in patient tissues were generated in vitro, and their replication and impact on host cell functions were assessed on primary human cardiac cells in culture. RESULTS: Major enterovirus B populations characterized by 5' terminal genomic RNA deletions ranging from 17 to 50 nucleotides were identified either alone or associated with low proportions of intact 5' genomic termini. In situ hybridization and immunohistological assays detected these persistent genomes in clusters of cardiomyocytes. Transfection of Viral RNA into primary human cardiomyocytes demonstrated that deleted forms of genomic RNAs displayed early replication activities in the absence of detectable Viral Plaque formation, whereas mixed deleted and complete forms generated particles capable of inducing cytopathic effects at levels distinct from those observed with full-length forms alone. Moreover, deleted or full-length and mixed forms of Viral RNA were capable of directing translation and production of proteolytically active Viral proteinase 2A in human cardiomyocytes. CONCLUSIONS: We demonstrate that persistent Viral forms are composed of B-type enteroviruses harboring a 5' terminal deletion in their genomic RNAs and that these viruses alone or associated with full-length populations of helper RNAs could impair cardiomyocyte functions by the proteolytic activity of Viral proteinase 2A in cases of unexplained dilated cardiomyopathy. These results provide a better understanding of the molecular mechanisms that underlie the persistence of EV forms in human cardiac tissues and should stimulate the development of new therapeutic strategies based on specific inhibitors of the coxsackievirus B proteinase 2A activity for acute and chronic cardiac infections.
