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Results 451 - 500 of 1520
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Tremblay Douglas - - 2005
The Red clover necrotic mosaic virus movement protein (MP) is essential for cell-to-cell movement. Eight previously characterized alanine-scanning mutants of the MP were fused to the green fluorescent protein (GFP) and expressed from viral infectious transcripts. Inoculated plants were assayed for movement and intracellular accumulation of MP by confocal laser-scanning ...
Borkow G - - 2005
The multistep nature of HIV-1 entry provides multisite targeting at the entrance door of HIV-1 to cells. Blocking HIV-1 entry to its host cells has clear advantages over blocking subsequent stages in the life cycle of the virus. Indeed, potent cooperative and synergistic inhibition of HIV-1 proliferation has been observed ...
Cooper Arik - - 2005
Delivery of oligonucleotides (ON) into cells is a technical challenge. In this study, we utilized the capsid of the hepatitis B virus (HBV) to meet this goal. A single and short open reading frame of the virus programs efficient capsid production in bacteria. We show that these capsids can encapsulate ...
Yamaguchi Ryoji - - 2005
Canine distemper virus (CDV) growth and the morphological characterization were examined in a cell line established from a canine malignant histiocytosis (CCT cell line). The susceptibility of the CCT cells to 3 CDV strains, FXNO, YSA-TC and MD-77 was shown by detection of the antigen in the indirect fluorescent assay. ...
Mustafa Farah - - 2005
The feline immunodeficiency virus (FIV) long terminal repeat (LTR), compared with some primate lentiviral LTRs, is quite a strong basal promoter. However, it seems to be highly species-specific in function and generally not very efficient in cells of non-feline origin. This study systematically explored the function of the FIV LTR ...
Topliff Christina L - - 2005
We determined the in vitro and in vivo translational efficiency mediated by the internal ribosomal entry site (IRES) from eight BVDV2 field isolates varying in virulence using a bicistronic reporter vector in rabbit reticulocyte lysates (RRL), and in primate and bovine cell lines. Using a T7-promoter system, the high virulence ...
Deffrasnes Céline - - 2005
Human metapneumovirus (hMPV) is associated with acute respiratory tract disease especially in young children. Using a quantitative real-time TaqMan PCR, we analyzed the replication kinetics of hMPV in different cell lines. Our results indicate that hMPV replicates slightly more efficiently in LLC-MK2 than in Vero cells and poorly in HEp-2 ...
Yeung Man Lung - - 2005
MicroRNAs (miRNAs) are small RNAs of 18-25 nucleotides (nt) in length that play important roles in regulating a variety of biological processes. Recent studies suggest that cellular miRNAs may serve to control the replication of viruses in cells. If such is the case, viruses might be expected to evolve the ...
Emmett Stevan R - - 2005
A number of different viruses interact with the cell cycle in order to subvert host-cell function and increase the efficiency of virus replication; examples can be found from DNA, retro, and RNA viruses. The majority of studies have been conducted on DNA and retroviruses whose primary site of replication is ...
Shackelford Julia - - 2005
The ability of viruses to co-opt cell signalling pathways has, over millions of years of co-evolution, come to pervade nearly every facet of cellular functions. Recognition of the extent to which the ubiquitin-proteasome system can be directed or subverted by viruses is relatively recent. Viral products interact with, and adjust, ...
De Bolle L - - 2005
Although HHV-6A and -6B are known to replicate preferably in human T-lymphocytes, in vitro infection of several other cell types has been described. Also, the finding that both variants use the ubiquitous molecule CD46 as a membrane receptor fully supports the possibility of a broad cellular tropism. However, productive infection, ...
Mavoungou Donatien - - 2005
BACKGROUND: Immunor (IM28), an analog of dehydroepiandrosterone (DHEA), inhibits human immunodeficiency virus type-1 (HIV-1) by inhibiting reverse transcriptase. We assessed the ability of IM28 to inhibit the cell-cell fusion mediated by HIV envelope glycoprotein in an in vitro system. For this purpose, we co-cultured TF228.1.16, a T-cell line expressing stably ...
Hyde Robyn M - - 2005
Previous work has shown that novel amphipalhic oligo and polyribonucleotides are potent inhibitors of HIV. It was hypothesized that the mechanism(s) of action for these compounds might be inhibition of retroviral reverse transcriptase (RT) and/or viral uptake by cells. A fluorescent oligonucleotide analog was prepared, and confocal microscopy studies were ...
Grill Jacques - - 2005
OBJECTIVE: To evaluate the efficacy of the conditionally replicating adenovirus (Ad) Ad.d24 for oncolysis of benign and malignant meningiomas. METHODS: Primary meningioma cells and organotypic spheroids were cultured from tumor biopsies of 12 consecutive unselected patients. Four different Ads were constructed and tested on meningioma cells and spheroids: a replication-deficient ...
Byrum Jennifer - - 2005
Lentivirus vector systems have been developed for the safe delivery of foreign genes to target tissues. However, the use of these systems for delivering specific proteins to target cells has been largely unexplored. To test this concept, the lentivirus expression plasmid pLenti was utilized to overexpress in producer cells a ...
Van Hoeven Neal S - - 2005
Enzootic nasal tumor virus (ENTV) and jaagsiekte sheep retrovirus (JSRV) are closely related retroviruses that cause epithelial cancers of the respiratory tract in sheep and goats. Both viruses use the glycosylphosphatidylinositol (GPI)-anchored cell surface protein hyaluronidase 2 (Hyal2) as a receptor for cell entry, and entry is mediated by the ...
McCoubrie Joanne E - - 2004
HIV integrates into the host cell genome where it persists for the life of the cell. One approach to reducing viral burden is to selectively eliminate cells containing integrated provirus early following infection. We have used the HIV LTR promoter to selectively express transgenes in human cells positive for the ...
Argyris Elias G - - 2004
Cell surface heparan sulfate proteoglycans (HSPGs) mediate internalization of HIV-1 Tat. Herein, we report that human WiDr cells, which express perlecan but no other HSPGs, can internalize 125I-labeled Tat with minimal lysosomal degradation. Pre-treatment of cells with heparitinase almost completely abolished 125I-Tat surface binding, while the use of an HIV-1 ...
Srivastava Pratibha - - 2004
A combinatorial chemistry approach was employed to prepare a restricted library of N-substituted S-acyl-2-mercaptobenzamide thioesters. It was shown that many members of this chemotype display anti-HIV activity via their ability to interact with HIV-1, HIV-2, SIV-infected cells, cell-free virus, and chronically and latently infected cells in a manner consistent with ...
Rivera A A - - 2004
Oncolytic adenoviruses constitute a new and promising tool for cancer treatment that has been rapidly translated into clinical trials. However, minimal or absent expression of the adenovirus serotype 5 (Ad5) receptor CAR (coxsackievirus and adenovirus receptor) on cancer cells represents a major limitation for Ad5-based oncolysis. Here, we report on ...
Li Xinhui - - 2004
Marek's disease virus (MDV), a highly cell-associated alphaherpesvirus, can be isolated and propagated in chicken kidney cells (CKC) and chicken or duck embryo fibroblast cells (CEF or DEF, respectively). Two recently developed cell lines, CU447 and CU453, developed from methylcholanthrene-induced tumors in Japanese quail, were examined for their suitability to ...
Zhou N - - 2004
RNA interference (RNAi) is an evolutionarily conserved process by which plants and animals protect their genomes utilizing small, double-stranded RNAs to degrade target RNAs in a sequence-specific manner. Post-transcriptional gene silencing by these moieties can lead to degradation of both cellular and viral RNAs. It has recently been shown that ...
Mannioui Abdelkrim - - 2004
We examined the influence of mitosis on the kinetics of human immunodeficiency virus type 1 integration in T cells. Single-round infection of cells arrested in G1b or allowed to synchronously proceed through division showed that mitosis delays virus integration until 18-24 h postinfection, whereas integration reaches maximum levels by 15 ...
Agbottah Emmanuel - - 2005
There are currently 40 million individuals in the world infected with human immunodeficiency virus (HIV). The introduction of highly active antiretroviral therapy (HAART) has led to a significant reduction in AIDS-related morbidity and mortality. Unfortunately, up to 25% of patients discontinue their initial HAART regimen. Current HIV-1 inhibitors target the ...
Lee Cheonghoon - - 2004
Viral contamination in environmental samples can be underestimated because a single cell line might reproduce only some enteric viruses and some enteric viruses do not exhibit apparent cytopathic effects in cell culture. To overcome this problem, we evaluated a cell culture-PCR assay based on a combination of A549 and Buffalo ...
Jeffers Scott A - - 2004
Angiotensin-converting enzyme 2 (ACE2) is a receptor for SARS-CoV, the novel coronavirus that causes severe acute respiratory syndrome [Li, W. Moore, M. J., Vasilieva, N., Sui, J., Wong, S. K., Berne, M. A., Somasundaran, M., Sullivan, J. L., Luzuriaga, K., Greenough, T. C., et al. (2003) Nature 426, 450-454]. We ...
Cavrois Marielle - - 2004
We recently described a sensitive and specific assay that detects the fusion of HIV-1 virions to a broad range of target cells, including primary CD4 cells. This assay involves the use of virions containing beta-lactamase-Vpr (BlaM-Vpr) and the loading of target cells with CCF2, a fluorogenic substrate of beta-lactamase. Since ...
Llano Manuel - - 2004
The transcriptional coactivator lens epithelium-derived growth factor (LEDGF)/p75 acts as a chromatin tethering factor for human immunodeficiency virus type 1 (HIV-1) integrase protein, determining its nuclear localization and its tight association with nuclear DNA. Here we identify a second function for the LEDGF/p75-integrase interaction. We observed that stable introduction of ...
Robertson Christopher M - - 2004
Avian reoviruses (ARV) are economically important pathogens, especially in the poultry industry, where they cause viral arthritis and tenosynovitis. Mycophenolic acid (MPA) is an inhibitor of inosine monophosphate dehydrogenase (mainly used clinically for immunosuppression) that inhibits the replication of several viruses. We demonstrate in this study that MPA also is ...
Doms Robert W - - 2004
HIV entry to host cells begins with binding of the viral envelope protein to CD4 molecules on the host cell surface. This binding initiates conformational changes in the envelope protein that result in binding to a coreceptor (CCR5 or CXCR4), exposure of a previously hidden domain in the viral protein, ...
Drobni Peter - - 2004
Lactoferrin (LF), a member of the transferrin family, is a bi-globular protein secreted in milk, saliva, tears, seminal fluid, endocervix and vaginal secretions. LF is an important player in the defence against pathogenic microorganisms and has also been shown to have activity against several viruses including herpesvirus, adenovirus, rotavirus and ...
Andersen Jeanette H - - 2004
Lactoferrin (LF) is a multifunctional glycoprotein, which plays an important role in immune regulation and defense mechanisms against bacteria, fungi, and viruses. Lactoferricin (Lfcin) is a potent antimicrobial peptide generated from the N-terminal part of LF by pepsin cleavage. In this study, we investigated the mechanisms of the anti-herpes simplex ...
Gatto Dominique - - 2004
Marginal zone (MZ) B cells are thought to be responsible for the first wave of Abs against bacterial Ags. In this study, we assessed the in vivo response of MZ B cells in mice immunized with viral particles derived from the RNA phage Qbeta. We found that both follicular (FO) ...
Cosenza M A - - 2004
Macrophages and microglia are the predominant cells infected with HIV-1 in the brain, yet the effects of productive HIV infection on the fate of these cells are poorly understood. In this study, we tested the hypothesis that HIV-1 expression influences cell death in infected macrophages and microglial cells. We detected ...
Kimata Jason T - - 2004
Human and simian immunodeficiency virus (HIV and SIV) may co-opt antigen capture and presentation functions of antigen presenting cells (APCs) to facilitate infection of CD4+ T-cells. To address whether the replicative capacity of SIV in the host may be associated with the extent of viral replication in response to APC-T-cell ...
Sauthoff Harald H Division of Pulmonary & Critical Care Medicine, New York University School of Medicine, New York, NY 10016, - - 2004
Replicating adenoviral vectors are capable of multiplying up to a thousandfold in the target cell, a property that might prove to be of tremendous potential for cancer therapy. However, restricting viral replication and toxicity to cancer cells is essential to optimize safety. It has been proposed that modifications of the ...
Derse David - - 2004
Retrovirus infection proceeds by attachment of the envelope glycoprotein to a cell surface receptor, followed by fusion of the viral and cellular membranes. Once in the cell, the viral enzymes and structural proteins form a replication complex that converts the single-stranded viral genomic RNA into a double-stranded DNA, which is ...
Piguet Vincent - - 2004
Cell-to-cell viral transmission facilitates the propagation of HIV-1 and human T cell leukemia virus type 1. Mechanisms of cell-to-cell transmission by retroviruses were not well understood until the recent description of virological synapses (VSs). VSs function as specialized sites of immune cell-to-cell contact that direct virus infection. Deciphering the molecular ...
Mocé-Llivina Laura - - 2004
This paper describes a method for the temporary storage of cultured cells. Cells from recently completed cell monolayers were trypsinized and then centrifuged. After centrifugation, the supernatant and pellet were kept at 4 degrees C for one week. After storage, the supernatant was discarded, the cells were resuspended and used ...
Youil R - - 2004
The choice of a cell line for the production of influenza vaccines is determined by how well the virus is able to replicate and how easily the cell line can be maintained. Madin-Darby canine kidney (MDCK) cells have long been known to successfully support influenza growth. Vero cells are also ...
Oomens A G P - - 2004
Human respiratory syncytial virus (HRSV) expresses three transmembrane glycoproteins: small hydrophobic protein SH, attachment protein G, and fusion protein F. The genes encoding SH and G can be deleted from the HRSV genome and infectious virus recovered. In contrast, HRSVs lacking the F gene or a functional replacement thereof have ...
Campbell Grant R - - 2004
Human immunodeficiency virus (HIV) infection and the progression to AIDS are characterized by the depletion of CD4(+) T-cells. HIV-1 infection leads to apoptosis of uninfected bystander cells and the direct killing of HIV-infected cells. This is mediated, in part, by the HIV-1 Tat protein, which is secreted by virally infected ...
del Real Gustavo - - 2004
Human immunodeficiency virus (HIV)-1 infectivity requires actin-dependent clustering of host lipid raft-associated receptors, a process that might be linked to Rho guanosine triphosphatase (GTPase) activation. Rho GTPase activity can be negatively regulated by statins, a family of drugs used to treat hypercholesterolemia in man. Statins mediate inhibition of Rho GTPases ...
Moloney M - - 2004
Since its invention, the atomic force microscope has been used to image a wide variety of biological samples, including viruses. Viral entry into, and egress from, cultured cells has been extensively studied using numerous scientific techniques and to a limited extent using atomic force microscopy. One of the main structural ...
Scavia G - - 2004
During the epidemic of bluetongue (BT) in Lazio and Tuscany between 2001 and 2003, the distribution pattern of Culicoides imicola did not always correspond either geographically or seasonally, with virus circulation. Culicoides obsoletus was observed to be abundant, ubiquitous and active throughout the year. The geographical and seasonal distribution of ...
McNees Adrienne L - - 2004
Detection of adenovirus DNA in human tonsillar T cells in the absence of active virus replication suggests that T cells may be a site of latency or of attenuated virus replication in persistently infected individuals. The lytic replication cycle of Ad5 in permissive epithelial cells (A549) was compared to the ...
Lyengar Sujatha - - 2004
HIV faces the challenge of identifying and entering suitable host cells (i.e. activated and viable) among a wide array of receptor-positive but unsuitable targets. Lymph nodes contain resting cells, activated cells destined for apoptosis within 24 h, and cell fragments, all of which represent replicative dead ends. We postulate that ...
López Susana - - 2004
Rotavirus entry into a cell is a complex multistep process in which different domains of the rotavirus surface proteins interact with different cell surface molecules, which act as attachment and entry receptors. These recently described molecules include several integrins and a heat shock protein, which have been found to be ...
Yang Zhi-Yong - - 2004
The severe acute respiratory syndrome coronavirus (SARS-CoV) synthesizes several putative viral envelope proteins, including the spike (S), membrane (M), and small envelope (E) glycoproteins. Although these proteins likely are essential for viral replication, their specific roles in SARS-CoV entry have not been defined. In this report, we show that the ...
Quinn Gary - - 2004
Galactose alpha1-3 galactose (Gal) trisaccharides are present on the surface of wild-type pig cells, as well as on viruses particles produced from such cells. The recognition of Gal sugars by natural anti-Gal antibodies (NAb) in human and Old World primate serum can cause the lysis of the particles via complement-dependent ...
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