Search results for " culture"
showing 10 items of 5779 documents
Occlusion-derived baculovirus: interaction with human cells and evaluation of the envelope protein P74 as a surface display platform.
2008
To develop complementary baculovirus-based tools for gene delivery and display technologies, the interaction of occlusion-derived baculovirus (ODV) with human cells, and the functionality of the P74 ODV envelope protein for display of the IgG-binding Z domains (ZZP74) were evaluated. The cellular binding of ODV was concentration-dependent and saturable. Only minority of the bound virions were internalized at both 37 and 4 degrees C, suggesting usage of direct membrane fusion as the entry mode. The intracellular transport of ODV was confined in vesicular structures peripheral to the plasma membrane, impeding subsequent nuclear entry and transgene expression. Transduction of ODV was not rescu…
Transfection of lipoma cells with papilloma bovine virus subgenomic fragment.
1991
Abstract Lipoma cells with consistent chromosomal aberration have been transfected with plasmids carrying papilloma bovine virus subgenomic fragment (PBV 69). The succesful transformation of the cells was ascerted on the changed growth pattern of the cells in liquid medium, colony formation in soft agar and modified cell appearrance in electron microscopy; transfection with PBV 69 has not been, however, sufficient to immortalize lipoma cells.
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…
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…
Assembly and Translocation of Papillomavirus Capsid Proteins
2002
ABSTRACT The major and minor capsid proteins of polyomavirus are preassembled in the cytoplasm and translocated to the nucleus only as a VP1-VP2/VP3 complex. In this study, we describe independent nuclear translocation of the L1 major protein and the L2 minor capsid protein of human papillomavirus type 33 by several approaches. First, we observed that expression and nuclear translocation of L2 in natural lesions precede expression of L1. Second, using a cell culture system for coexpression, we found that accumulation of L2 in nuclear domain 10 (ND10) subnuclear structures precedes L1 by several hours. In contrast, complexes of L2 and mutants of L1 forced to assemble in the cytoplasm are tra…
Enhancement of hepatitis C virus RNA replication by cell culture-adaptive mutations.
2001
ABSTRACT Studies of the Hepatitis C virus (HCV) replication cycle have been made possible with the development of subgenomic selectable RNAs that replicate autonomously in cultured cells. In these replicons the region encoding the HCV structural proteins was replaced by the neomycin phosphotransferase gene, allowing the selection of transfected cells that support high-level replication of these RNAs. Subsequent analyses revealed that, within selected cells, HCV RNAs had acquired adaptive mutations that increased the efficiency of colony formation by an unknown mechanism. Using a panel of replicons that differed in their degrees of cell culture adaptation, in this study we show that adaptive…
Viral and cellular determinants of hepatitis C virus RNA replication in cell culture.
2003
Studies on the replication of hepatitis C virus (HCV) have been facilitated by the development of selectable subgenomic replicons replicating in the human hepatoma cell line Huh-7 at a surprisingly high level. Analysis of the replicon population in selected cells revealed the occurrence of cell culture-adaptive mutations that enhance RNA replication substantially. To gain a better understanding of HCV cell culture adaptation, we characterized conserved mutations identified by sequence analysis of 26 independent replicon cell clones for their effect on RNA replication. Mutations enhancing replication were found in nearly every nonstructural (NS) protein, and they could be subdivided into at …
Translocation of the nuclear autoantigen La to the cell surface of herpes simplex virus type 1 infected cells.
1992
Recently we developed a procedure to translocalize one of the extractable nuclear antigens (ENAs), the La protein, to the cell surface of CV-1 cells. Here we report that herpes simplex virus type 1 infection can also induce a translocation of the autoantigen to the cell surface. On the cell surface we detected La protein assembled with large protrusions. Within these protrusions La protein colocalized with virus particles. These protrusions are known to be released from the cell after virus infections. Such complexes consisting of self and virus could provide helper determinants for an anti-self response, and therefore be important in generation of autoimmunity.
The human autoantigen La/SS-B accelerates herpes simplex virus type 1 replication in transfected mouse 3T3 cells.
1998
SUMMARY Permanently transfected mouse cell lines which expressed different levels of the human autoantigen La/SS-B were infected with different strains of herpes simplex virus type 1, including the strains ANG, HSZP, 17syn+ and HFEM. During infection the localization of the human La protein was followed using an anti-La MoAb, which recognized only the human La protein but did not cross-react with either the endogenous mouse La protein or any viral encoded protein. After infection La protein was transported from the nucleus to the cytoplasm. The time course of translocation was dependent on the amount of human La protein expressed in the respective cell line. Moreover, acceleration of viral …
Rapid and sensitive detection of metapneumovirus in clinical specimens by indirect fluorescence assay using a monoclonal antibody.
2008
Human metapneumovirus, with two known genotypes named A and B, is associated with mild respiratory symptoms to severe LRTI in children, high-risk adults and the elderly. Rapid and reliable methods of hMPV detection in clinical samples are essential to implement appropriate care, to better understand the pathology of hMPV and to determine its epidemiology. Respiratory samples from 1,386 patients collected during 2 consecutive years were screened for hMPV using indirect immunofluorescence (IFA) assay with a monoclonal antibody. Forty-three patients tested positive for hMPV by the IFA method. In parallel, the samples were examined with RT-PCR on the F gene. Of these, 41 specimens were RT-PCR p…