Search results for "Virus disease"
showing 10 items of 1907 documents
The interplay between the host microbiome and pathogenic viral infections
2021
The microorganisms associated with an organism, the microbiome, have a strong and wide impact in their host biology. In particular, the microbiome modulates both the host defense responses and immunity, thus influencing the fate of infections by pathogens. Indeed, this immune modulation and/or interaction with pathogenic viruses can be essential to define the outcome of viral infections. Understanding the interplay between the microbiome and pathogenic viruses opens future venues to fight viral infections and enhance the efficacy of antiviral therapies. An increasing number of researchers are focusing on microbiome-virus interactions, studying diverse combinations of microbial communities, …
Generation and Applications of HPV Pseudovirions Using Vaccinia Virus
2005
This chapter outlines the generation and application of human papillomavirus type 33 (HPV 33) pseudovirions. These pseudovirions are structurally indistinguishable from native virions and are therefore valuable tools for the study of papillomavirus/cell interactions. The method describes (1) the construction of vaccinia viruses recombinant for the major and minor HPV capsid proteins, L1 and L2, respectively, (2) the transfection of Cos7 cells with a marker plasmid replicating to high copy numbers, (3) the expression of L1 and L2 using the vaccinia virus expression system, (4) the extraction, purification, and analysis of HPV-33 pseudovirions, (5) pseudoinfection assays, (6) pre- and post-at…
CVB3 VP1 interacts with MAT1 to inhibit cell proliferation by interfering with Cdk-activating kinase complex activity in CVB3-induced acute pancreati…
2021
Coxsackievirus B3 (CVB3) belongs to the genus Enterovirus of the family Picornaviridae and can cause acute acinar pancreatitis in adults. However, the molecular mechanisms of pathogenesis underlying CVB3-induced acute pancreatitis have remained unclear. In this study, we discovered that CVB3 capsid protein VP1 inhibited pancreatic cell proliferation and exerted strong cytopathic effects on HPAC cells. Through yeast two-hybrid, co-immunoprecipitation, and confocal microscopy, we show that Menage a trois 1 (MAT1), a subunit of the Cdk-Activating Kinase (CAK) complex involved in cell proliferation and transcription, is a novel interaction protein with CVB3 VP1. Moreover, CVB3 VP1 inhibited MAT…
Mouse models of cytomegalovirus latency: overview.
2002
Abstract Background: The molecular regulation of viral latency and reactivation is a central unsolved issue in the understanding of cytomegalovirus (CMV) biology. Like human CMV (hCMV), murine CMV (mCMV) can establish a latent infection in cells of the myeloid lineage. Since mCMV genome remains present in various organs after its clearance from hematopoietic cells first in bone marrow and much later in blood, there must exist one or more widely distributed cell type(s) representing the cellular site(s) of enduring mCMV latency in host tissues. Endothelial cells and histiocytes are candidates, but the question is not yet settled. Another long debated problem appears to be solved: mCMV establ…
Modulation of Hepatitis C Virus NS5A Hyperphosphorylation by Nonstructural Proteins NS3, NS4A, and NS4B
1999
NS5A of the hepatitis C virus (HCV) is a highly phosphorylated protein involved in resistance against interferon and required most likely for replication of the viral genome. Phosphorylation of this protein is mediated by a cellular kinase(s) generating multiple proteins with different electrophoretic mobilities. In the case of the genotype 1b isolate HCV-J, in addition to the basal phosphorylated NS5A (designated pp56), a hyperphosphorylated form (pp58) was found on coexpression of NS4A (T. Kaneko, Y. Tanji, S. Satoh, M. Hijikata, S. Asabe, K. Kimura, and K. Shimotohno, Biochem. Biophys. Res. Commun. 205:320‐326, 1994). Using a comparative analysis of two full-length genomes of genotype 1b…
Functional properties of a monoclonal antibody inhibiting the hepatitis C virus RNA-dependent RNA polymerase.
2001
The hepatitis C virus (HCV) RNA-dependent RNA polymerase (RdRp), represented by nonstructural protein 5B (NS5B), has recently emerged as a promising target for antiviral intervention. Here, we describe the isolation, functional characterization, and molecular cloning of a monoclonal antibody (mAb) inhibiting the HCV RdRp. This mAb, designated 5B-12B7, binds with high affinity to a conformational epitope in the palm subdomain of the HCV RdRp and recognizes native NS5B expressed in the context of the entire HCV polyprotein or subgenomic replicons. Complete inhibition of RdRp activity in vitro was observed at equimolar concentrations of NS5B and mAb 5B-12B7, whereas RdRp activities of classica…
Binding and internalization of human papillomavirus type 33 virus-like particles by eukaryotic cells
1995
Infection of cells by human papillomaviruses (HPVs) associated with malignant genital lesions has not been studied because of the lack of an in vitro system and the unavailability of virions. We have now used virus-like particles (VLPs) of HPV type 33 to analyze the initial events in the interaction of the HPV capsid with cell lines. Binding of VLPs to HeLa cells was observed in biochemical assays and by immunofluorescence. VLP binding was inhibited by antisera raised against VLPs but not by monoclonal antibodies recognizing either L1 or L2 epitopes accessible on VLPs. Under saturating conditions, approximately 2 x 10(4) VLPs were bound per cell, with a dissociation constant of about 100 pM…
Nuclear localization but not PML protein is required for incorporation of the papillomavirus minor capsid protein L2 into virus-like particles.
2004
ABSTRACT Recent reports suggest that nuclear domain(s) 10 (ND10) is the site of papillomavirus morphogenesis. The viral genome replicates in or close to ND10. In addition, the minor capsid protein, L2, accumulates in these subnuclear structures and recruits the major capsid protein, L1. We have now used cell lines deficient for promyelocytic leukemia (PML) protein, the main structural component of ND10, to study the role of this nuclear protein for L2 incorporation into virus-like particles (VLPs). L2 expressed in PML protein knockout (PML −/− ) cells accumulated in nuclear dots, which resemble L2 aggregates forming at ND10 in PML protein-containing cells. These L2 assemblies also attracted…
Generation and neutralization of pseudovirions of human papillomavirus type 33
1997
Since human papillomaviruses (HPV) cannot be propagated in cell culture, the generation of infectious virions in vitro is a highly desirable goal. Here we report that pseudovirions can be generated by the assembly of virus-like particles (VLPs) in COS-7 cells containing multiple copies of a marker plasmid. Using recombinant vaccinia viruses, we have obtained spherical VLPs of HPV type 33 (HPV-33) which fractionate into heavy and light VLPs in cesium chloride density gradients. VLPs in the heavy fraction (1.31 g/cm3) carry the plasmid in DNase-resistant form and are capable of transferring the genetic marker located on the plasmid to COS-7 cells in a DNase-resistant way (pseudoinfection). Th…
Human Papillomavirus Types 16, 18, and 31 Share Similar Endocytic Requirements for Entry
2013
ABSTRACT Human papillomavirus type 18 (HPV18), one of the HPVs with malignant potential, enters cells by an unknown endocytic mechanism. The key cellular requirements for HPV18 endocytosis were tested in comparison to those for HPV16 and -31 endocytoses. HPV18 (like HPV16 and -31) entry was independent of clathrin, caveolin, dynamin, and lipid rafts but required actin polymerization and tetraspanin CD151, and the viruses were routed to the same LAMP-1-positive compartment. Hence, the viruses shared similar cellular requirements for endocytic entry.