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1.
J Psychiatr Ment Health Nurs ; 25(9-10): 546-557, 2018 Nov.
Article in English | MEDLINE | ID: mdl-30394636

ABSTRACT

WHAT IS KNOWN ON THE SUBJECT?: One-to-one observation uses continuous staff observation to safeguard patients judged likely to harm themselves or others. Policies increasingly mandate that staff engage therapeutically with patients during one-to-one observation. Yet not enough is known about factors facilitating or impeding such therapeutic engagement. WHAT DOES THIS PAPER ADD TO EXISTING KNOWLEDGE?: This study enriches existing literature on one-to-one observation through integrating the perspectives of staff of different levels of qualification, and patients of different diagnostic and risk profiles. Whilst previous research has highlighted the occurrence of counter-therapeutic staff-patient interactions, integration of patient and staff perspectives in the current study has demonstrated that patient and staff often attribute the causes differently, with each apportioning blame to the other, leading both parties to feel misunderstood, and staff lack confidence to overcome these challenges. A novel finding was that rapport-building via simple demonstrations of compassion and conversations about everyday things, was viewed as an essential prerequisite to encouraging patients to open up about their experiences of emotional distress, whilst implementation of techniques drawn from psychological interventions was viewed as less important than staff's core relational skills. WHAT ARE THE IMPLICATIONS FOR PRACTICE?: Therapeutic engagement during observation can enhance its risk management aims, providing thought is given to understanding and negotiating complex dynamics between staff and patients. Supervision for staff conducting observations should focus on building rapport in preference to emphasizing psychological intervention (e.g. DBT), and should enable staff to reflect on better understanding and managing their own emotions towards "hard-to-engage" patients. ABSTRACT: Introduction Policies increasingly focus on staff-patient interactions during one-to-one psychiatric nursing observations as an opportunity for therapeutic engagement - yet if and how this is feasible is unknown. Aim This study aimed to integrate staff and patient perspectives to determine what factors facilitate or impede therapeutic engagement during one-to-one observation. Method Thematic analysis of qualitative interviews with 31 psychiatric inpatient staff at different levels of seniority and 28 inpatients spanning a range of diagnoses and risk profiles. Results Negative experiences of observation were characterized by a reciprocal dynamic where both patients and staff withdrew from interactions, having felt the other did not want to engage with them. Staff and patients agreed that these difficulties could be overcome when staff showed patients that they cared, gradually building trust through simple demonstrations of compassion and 'normalizing' conversation about everyday things. This approach helped patients to feel safe enough to open up about their distress, which in turn helped staff to better understand their experiences and work with them to find solutions. Implications for practice Engagement during observation could be facilitated if staff receive more supervision in understanding difficult dynamics that impede rapport-building and in managing their emotions towards patients they experience as "hard-to-engage".


Subject(s)
Hospitals, Psychiatric , Inpatients , Mental Disorders/therapy , Personnel, Hospital , Professional-Patient Relations , Adolescent , Adult , Aged , Female , Humans , Male , Middle Aged , Young Adult
2.
J Lipid Res ; 59(6): 982-993, 2018 06.
Article in English | MEDLINE | ID: mdl-29559521

ABSTRACT

Obeticholic acid (OCA) is a selective farnesoid X receptor (FXR) agonist that regulates bile acid and lipid metabolism. FXR activation induces distinct changes in circulating cholesterol among animal models and humans. The mechanistic basis of these effects has been elusive because of difficulties in studying lipoprotein homeostasis in mice, which predominantly package circulating cholesterol in HDLs. Here, we tested the effects of OCA in chimeric mice whose livers are mostly composed (≥80%) of human hepatocytes. Chimeric mice exhibited a human-like ratio of serum LDL cholesterol (LDL-C) to HDL cholesterol (HDL-C) at baseline. OCA treatment in chimeric mice increased circulating LDL-C and decreased circulating HDL-C levels, demonstrating that these mice closely model the cholesterol effects of FXR activation in humans. Mechanistically, OCA treatment increased hepatic cholesterol in chimeric mice but not in control mice. This increase correlated with decreased SREBP-2 activity and target gene expression, including a significant reduction in LDL receptor protein. Cotreatment with atorvastatin reduced total cholesterol, rescued LDL receptor protein levels, and normalized serum LDL-C. Treatment with two clinically relevant nonsteroidal FXR agonists elicited similar lipoprotein and hepatic changes in chimeric mice, suggesting that the increase in circulating LDL-C is a class effect of FXR activation.


Subject(s)
Chenodeoxycholic Acid/analogs & derivatives , Chimera , Cholesterol/metabolism , Lipoproteins/metabolism , Liver/drug effects , Liver/metabolism , Receptors, Cytoplasmic and Nuclear/metabolism , Animals , Atorvastatin/pharmacology , Chenodeoxycholic Acid/pharmacology , Cholesterol/blood , Humans , Lipoproteins/blood , Liver/cytology , Male , Mice
3.
Cell Rep ; 21(6): 1600-1612, 2017 Nov 07.
Article in English | MEDLINE | ID: mdl-29117564

ABSTRACT

Interferon-regulatory factors (IRFs) are a family of transcription factors (TFs) that translate viral recognition into antiviral responses, including type I interferon (IFN) production. Dengue virus (DENV) and other clinically important flaviviruses are suppressed by type I IFN. While mice lacking the type I IFN receptor (Ifnar1-/-) succumb to DENV infection, we found that mice deficient in three transcription factors controlling type I IFN production (Irf3-/-Irf5-/-Irf7-/- triple knockout [TKO]) survive DENV challenge. DENV infection of TKO mice resulted in minimal type I IFN production but a robust type II IFN (IFN-γ) response. Using loss-of-function approaches for various molecules, we demonstrate that the IRF-3-, IRF-5-, IRF-7-independent pathway predominantly utilizes IFN-γ and, to a lesser degree, type I IFNs. This pathway signals via IRF-1 to stimulate interleukin-12 (IL-12) production and IFN-γ response. These results reveal a key antiviral role for IRF-1 by activating both type I and II IFN responses during DENV infection.


Subject(s)
Antiviral Agents/pharmacology , Dengue Virus/drug effects , Dengue/pathology , Drug Resistance, Viral , Interferon Regulatory Factor-1/metabolism , Interferon Type I/metabolism , Interferon-gamma/metabolism , Animals , Antibodies/immunology , Antiviral Agents/therapeutic use , Cells, Cultured , Dengue/mortality , Dengue/veterinary , Dengue/virology , Dengue Virus/genetics , Dengue Virus/physiology , Down-Regulation , Interferon Regulatory Factors/deficiency , Interferon Regulatory Factors/genetics , Interferon Regulatory Factors/metabolism , Mice , Mice, Inbred C57BL , Mice, Knockout , Receptor, Interferon alpha-beta/deficiency , Receptor, Interferon alpha-beta/genetics , Receptor, Interferon alpha-beta/immunology , Signal Transduction , Spleen/cytology , Spleen/metabolism , Spleen/virology , Up-Regulation , Virus Replication/drug effects
4.
Soc Psychiatry Psychiatr Epidemiol ; 52(4): 473-483, 2017 04.
Article in English | MEDLINE | ID: mdl-28161766

ABSTRACT

PURPOSE: Continuous observation of psychiatric inpatients aims to protect those who pose an acute risk of harm to self or others, but involves intrusive privacy restrictions. Initiating, conducting and ending continuous observation requires complex decision-making about keeping patients safe whilst protecting their privacy. There is little published guidance about how to balance privacy and safety concerns, and how staff and patients negotiate this in practice is unknown. To inform best practice, the present study, therefore, aimed to understand how staff and patients experience negotiating the balance between privacy and safety during decision-making about continuous observation. METHODS: Thematic analysis of qualitative interviews with thirty-one inpatient psychiatric staff and twenty-eight inpatients. RESULTS: Most patients struggled with the lack of privacy but valued feeling safe during continuous observation. Staff and patients linked good decision-making to using continuous observation for short periods and taking positive risks, understanding and collaborating with the patient, and working together as a supportive staff team. Poor decision-making was linked to insufficient consideration of observation's iatrogenic potential, insufficient collaboration with patients, and the stressful impact on staff of conducting observations and managing risk. CONCLUSIONS: Best practice in decision-making about continuous observation may be facilitated by making decisions in collaboration with patients, and by staff supporting each-other in positive risk-taking. To achieve truly patient-centred decision-making, decisions about observation should not be influenced by staff's own stress levels. To address the negative impact of staff stress on decision-making, it may be helpful to improve staff training, education and support structures.


Subject(s)
Clinical Decision-Making , Hospitals, Psychiatric/standards , Inpatients/psychology , Patient Rights/standards , Patient Safety/standards , Privacy , Adolescent , Adult , Aged , Clinical Decision-Making/ethics , Female , Hospitals, Psychiatric/ethics , Humans , Male , Medical Staff, Hospital , Middle Aged , Nursing Staff, Hospital , Patient Rights/ethics , Young Adult
5.
Antiviral Res ; 129: 93-98, 2016 May.
Article in English | MEDLINE | ID: mdl-26946111

ABSTRACT

The antiviral activity of UV-4 was previously demonstrated against dengue virus serotype 2 (DENV2) in multiple mouse models. Herein, step-wise minimal effective dose and therapeutic window of efficacy studies of UV-4B (UV-4 hydrochloride salt) were conducted in an antibody-dependent enhancement (ADE) mouse model of severe DENV2 infection in AG129 mice lacking types I and II interferon receptors. Significant survival benefit was demonstrated with 10-20 mg/kg of UV-4B administered thrice daily (TID) for seven days with initiation of treatment up to 48 h after infection. UV-4B also reduced infectious virus production in in vitro antiviral activity assays against all four DENV serotypes, including clinical isolates. A set of purified enzyme, in vitro, and in vivo studies demonstrated that inhibition of endoplasmic reticulum (ER) α-glucosidases and not the glycosphingolipid pathway appears to be responsible for the antiviral activity of UV-4B against DENV. Along with a comprehensive safety package, these and previously published data provided support for an Investigational New Drug (IND) filing and Phases 1 and 2 clinical trials for UV-4B with an indication of acute dengue disease.


Subject(s)
1-Deoxynojirimycin/analogs & derivatives , Antiviral Agents/pharmacology , Dengue Virus/drug effects , Glycoside Hydrolase Inhibitors/pharmacology , Severe Dengue/drug therapy , alpha-Glucosidases/metabolism , 1-Deoxynojirimycin/administration & dosage , 1-Deoxynojirimycin/pharmacology , 1-Deoxynojirimycin/therapeutic use , Animals , Antibodies, Viral/blood , Antibody-Dependent Enhancement/drug effects , Antiviral Agents/administration & dosage , Antiviral Agents/therapeutic use , Cells, Cultured , Chlorocebus aethiops , Clinical Trials as Topic , Disease Models, Animal , Drugs, Investigational , Endoplasmic Reticulum/drug effects , Endoplasmic Reticulum/enzymology , Glycoside Hydrolase Inhibitors/administration & dosage , Glycoside Hydrolase Inhibitors/chemistry , Glycoside Hydrolase Inhibitors/therapeutic use , Humans , Inhibitory Concentration 50 , Mice , Monocytes/virology , Receptors, Interferon/deficiency , Serogroup , Severe Dengue/virology , Vero Cells
6.
Sci Rep ; 5: 12616, 2015 Jul 29.
Article in English | MEDLINE | ID: mdl-26220099

ABSTRACT

Dengue virus (DENV) is the most important mosquito-borne viral infection in humans. In recent years, the number of cases and outbreaks has dramatically increased worldwide. While vaccines are being developed, none are currently available that provide balanced protection against all DENV serotypes. Advances in human antibody isolation have uncovered DENV neutralizing antibodies (nAbs) that are capable of preventing infection from multiple serotypes. Yet delivering monoclonal antibodies using conventional methods is impractical due to high costs. Engineering novel methods of delivering monoclonal antibodies could tip the scale in the fight against DENV. Here we demonstrate that simple intramuscular delivery by electroporation of synthetic DNA plasmids engineered to express modified human nAbs against multiple DENV serotypes confers protection against DENV disease and prevents antibody-dependent enhancement (ADE) of disease in mice. This synthetic nucleic acid antibody prophylaxis/immunotherapy approach may have important applications in the fight against infectious disease.


Subject(s)
Antibodies, Monoclonal/immunology , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , Dengue/immunology , Nucleic Acids/immunology , Animals , Antigens, Viral/immunology , Cell Line , Chlorocebus aethiops , Cross Reactions/immunology , Dengue/virology , Dengue Virus/immunology , Humans , Immunotherapy/methods , K562 Cells , Mice , Mice, Inbred C57BL , Neutralization Tests/methods , Vero Cells , Viral Envelope Proteins/immunology
7.
Viruses ; 7(5): 2404-27, 2015 May 13.
Article in English | MEDLINE | ID: mdl-25984714

ABSTRACT

Iminosugars are capable of targeting the life cycles of multiple viruses by blocking host endoplasmic reticulum α-glucosidase enzymes that are required for competent replication of a variety of enveloped, glycosylated viruses. Iminosugars as a class are approved for use in humans with diseases such as diabetes and Gaucher's disease, providing evidence for safety of this class of compounds. The in vitro antiviral activity of iminosugars has been described in several publications with a subset of these demonstrating in vivo activity against flaviviruses, herpesviruses, retroviruses and filoviruses. Although there is compelling non-clinical in vivo evidence of antiviral efficacy, the efficacy of iminosugars as antivirals has yet to be demonstrated in humans. In the current study, we report a novel iminosugar, UV-12, which has efficacy against dengue and influenza in mouse models. UV-12 exhibits drug-like properties including oral bioavailability and good safety profile in mice and guinea pigs. UV-12 is an example of an iminosugar with activity against multiple virus families that should be investigated in further safety and efficacy studies and demonstrates potential value of this drug class as antiviral therapeutics.


Subject(s)
Antiviral Agents/therapeutic use , Dengue/drug therapy , Imino Sugars/therapeutic use , Orthomyxoviridae Infections/drug therapy , Animals , Antiviral Agents/pharmacology , Dengue Virus/drug effects , Disease Models, Animal , Female , Guinea Pigs , Imino Sugars/pharmacology , Male , Mice , Microbial Sensitivity Tests , Orthomyxoviridae/drug effects , Treatment Outcome
8.
J Virol ; 89(10): 5592-601, 2015 May.
Article in English | MEDLINE | ID: mdl-25762732

ABSTRACT

UNLABELLED: The host-targeted antiviral drug UV-4B reduces viral replication and promotes survival in a mouse model of experimental dengue virus (DENV) infection. UV-4B is an iminosugar that inhibits the α-glucosidase family of enzymes and subsequently the folding of glycosylated proteins, both viral and host. Here, we utilized next-generation sequencing to investigate evolution of a flavivirus under selective pressure by a host-targeted antiviral in vivo. In viral populations recovered from UV-4B-treated mice, there was a significant increase in the number of single-nucleotide polymorphisms (SNPs) and the ratio of nonsynonymous to synonymous SNPs compared to findings in viral populations from vehicle-treated mice. The strongest evidence of positive selection was in the glycosylated membrane protein, thereby providing in vivo validation of the mechanism of action of an iminosugar. In addition, mutations in glycosylated proteins were present only in drug-treated mice after a single passage. However, the bulk of the other mutations were present in both populations, indicating nonspecific selective pressure. Together with the continued control of viremia by UV-4B, these findings are consistent with the previously predicted high genetic barrier to escape mutations in host-targeted antivirals. IMPORTANCE: Although hundreds of millions of people are infected with DENV every year, there is currently no approved vaccine or antiviral therapy. UV-4B has demonstrated antiviral activity against DENV and is expected to enter clinical trials soon. Therefore, it is important to understand the mechanisms of DENV resistance to UV-4B. Host-targeted antivirals are thought to have a higher genetic barrier to escape mutants than directly acting antivirals, yet there are very few published studies of viral evolution under host-targeted antivirals. No study to date has described flavivirus evolution in vivo under selective pressure by a host-based antiviral drug. We present the first in vivo study of the sequential progression of viral evolution under selective pressure by a host-targeted antiviral compound. This study bolsters support for the clinical development of UV-4B as an antiviral drug against DENV, and it provides a framework to compare how treatment with other host-targeted antiflaviviral drugs in humans and different animal models influence viral genetic diversity.


Subject(s)
Antiviral Agents/pharmacology , Dengue Virus/drug effects , Dengue Virus/genetics , Dengue/drug therapy , Dengue/virology , Animals , Dengue Virus/physiology , Disease Models, Animal , Evolution, Molecular , Genetic Variation , Host-Pathogen Interactions/drug effects , Humans , Imino Sugars/pharmacology , Mice , Mice, 129 Strain , Mice, Knockout , Mutation , Polymorphism, Single Nucleotide , Selection, Genetic , Viral Proteins/genetics , Virus Replication/drug effects
9.
Methods Mol Biol ; 1138: 377-90, 2014.
Article in English | MEDLINE | ID: mdl-24696349

ABSTRACT

Validation of a mouse model of dengue virus (DENV) infection relies on verification of viremia and productive replication in mouse tissues following infection. Here, we describe a quantitative assay for determining viral RNA levels in mouse serum and tissues. For the purpose of confirming DENV replication, we outline a fluorescence immunohistochemistry (FIHC) protocol for staining a nonstructural protein of DENV.


Subject(s)
Dengue/virology , Disease Models, Animal , Animals , Dengue Virus/genetics , Fluorescence , Immunohistochemistry , Mice , RNA/isolation & purification , RNA Helicases/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Serine Endopeptidases/metabolism , Spleen/virology , Viral Nonstructural Proteins/metabolism
10.
J Immunol Methods ; 410: 34-8, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24440090

ABSTRACT

Dengue virus (DENV) has substantial global impact, with an estimated 390million people infected each year. In spite of this, there is currently no approved DENV-specific vaccine or antiviral. One reason for this is the difficulty involved with development of an adequate animal model. While non-human primates support viral replication, they do not exhibit signs of clinical disease. A mouse model is an ideal alternative; however, wild-type mice are resistant to DENV-induced disease. Infection of interferon receptor-deficient mice results in disease that recapitulates key features of severe dengue disease in humans. For the development of vaccines, interferon receptor-deficient mice provide a stringent model for testing vaccine-induced immune components from vaccinated wild-type mice.


Subject(s)
Dengue Vaccines/immunology , Dengue Virus/physiology , Dengue/immunology , Dengue/prevention & control , Disease Models, Animal , Virus Replication/immunology , Animals , Dengue/genetics , Dengue Vaccines/genetics , Humans , Interferon-gamma/genetics , Interferon-gamma/immunology , Mice , Mice, Mutant Strains , Virus Replication/genetics
11.
Antiviral Res ; 98(1): 35-43, 2013 Apr.
Article in English | MEDLINE | ID: mdl-23376501

ABSTRACT

The aim of the present study was to evaluate the ability of the iminosugar drug UV-4 to provide in vivo protection from lethal dengue virus (DENV) challenge. This study utilized a well-described model of dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS)-like lethal disease in AG129 mice lacking the type I and II interferon receptors. Herein, we present UV-4 as a potent iminosugar for controlling DENV infection and disease in this mouse model. Specifically, administration of UV-4 reduced mortality, as well as viremia and viral RNA in key tissues, and cytokine storm. In addition, UV-4 treatment can be delayed, and it does not alter the anti-DENV antibody response. These results have set the foundation for development of UV-4 as a DENV-specific antiviral in phase I human clinical trials.


Subject(s)
Antiviral Agents/pharmacology , Dengue Virus/drug effects , Dengue/drug therapy , Dengue/virology , Imino Sugars/pharmacology , Animals , Antiviral Agents/chemistry , Cytokines , Dengue/immunology , Dengue Virus/physiology , Humans , Imino Sugars/chemistry , Mice , Mice, Inbred Strains , Structure-Activity Relationship
12.
Mol Pharm ; 10(1): 26-32, 2013 Jan 07.
Article in English | MEDLINE | ID: mdl-22905759

ABSTRACT

Cowpea mosaic virus (CPMV) has been used as a nanoparticle platform for biomedical applications including vaccine development, in vivo vascular imaging, and tissue-targeted delivery. A better understanding of the mechanisms of CPMV targeting and cell internalization would enable enhanced targeting and more effective delivery. Previous studies showed that, following binding and internalization by mammalian cells, CPMV localizes in a perinuclear late-endosome compartment where it remains for as long as several days. To further investigate endocytic trafficking of CPMV within the cell, we used multiple approaches including pharmacologic inhibition of pathways and colocalization with endocytic vesicle compartments. CPMV internalization was clathrin-independent and utilized a combination of caveolar endocytosis and macropinocytosis pathways for entry. CPMV particles colocalized with Rab5(+) early endosomes to traffic ultimately to a lysosomal compartment. These studies facilitate the further development of effective intracellular drug-delivery strategies using CPMV.


Subject(s)
Comovirus/metabolism , Endocytosis/physiology , Nanoparticles/administration & dosage , Animals , Biological Transport , Cells, Cultured , Drug Delivery Systems/methods , Endosomes/metabolism , Endosomes/physiology , Endosomes/virology , HeLa Cells , Humans , Macrophages/metabolism , Macrophages/virology , Mice , Pinocytosis/physiology
13.
J Mater Chem B ; 1(39): 5256-5263, 2013 Oct 21.
Article in English | MEDLINE | ID: mdl-32263328

ABSTRACT

Contrast-enhanced magnetic resonance imaging (MRI) allows rapid non-invasive diagnosis of central nervous system (CNS) pathologies such as multiple sclerosis (MS). Current gadolinium-based contrast agents must be administered at high doses, are excreted by the kidney, and some formulations are associated with toxicity in patients with renal insufficiency. The development of nanoparticle carriers for targeted delivery of gadolinium to sites of disease would increase specificity, as well as decrease the dose of gadolinium required to obtain sufficient contrast for disease diagnosis. The plant virus, cowpea mosaic virus (CPMV), is a biocompatible nanoparticle platform for imaging applications. Gadolinium is rapidly incorporated into the interior of the CPMV capsid without disrupting particle integrity, and CPMV-Gd particles have relaxivity comparable to gadolinium chelates used clinically. Here we examine the ability of gadolinium-loaded CPMV particles (CPMV-Gd) to localize to lesions in the CNS in an animal model of MS, experimental autoimmune encephalomyelitis (EAE). The in vivo distribution of gadolinium-loaded CPMV (CPMV-Gd) was examined within the periphery and central nervous system (CNS). CPMV accumulated in inflammatory lesions within the brain and spinal cord, and specifically associated with CD11b+ and CD11c+ cells. These results demonstrate that CPMV is an attractive nanoparticle chelate for gadolinium for in vivo applications and may have clinical utility as a contrast agent for the detection of autoimmune demyelinating diseases of the CNS.

14.
J Virol ; 86(22): 12138-47, 2012 Nov.
Article in English | MEDLINE | ID: mdl-22933295

ABSTRACT

Human postmortem studies of natural dengue virus (DENV) infection have reported systemically distributed viral antigen. Although it is widely accepted that DENV infects mononuclear phagocytes, the sequence in which specific tissues and cell types are targeted remains uncharacterized. We previously reported that mice lacking alpha/beta and gamma interferon receptors permit high levels of DENV replication and show signs of systemic disease (T. R. Prestwood et al., J. Virol. 82:8411-8421, 2008). Here we demonstrate that within 6 h, DENV traffics to and replicates in both CD169(+) and SIGN-R1(+) macrophages of the splenic marginal zone or draining lymph node, respectively, following intravenous or intrafootpad inoculation. Subsequently, high levels of replication are detected in F4/80(+) splenic red pulp macrophages and in the bone marrow, lymph nodes, and Peyer's patches. Intravenously inoculated mice begin to succumb to dengue disease 72 h after infection, at which time viral replication occurs systemically, except in lymphoid tissues. In particular, high levels of replication occur in CD68(+) macrophages of the kidneys, heart, thymus, and gastrointestinal tract. Over the course of infection, proportionately large quantities of DENV traffic to the liver and spleen. However, late during infection, viral trafficking to the spleen decreases, while trafficking to the liver, thymus, and kidneys increases. The present study demonstrates that macrophage populations, initially in the spleen and other lymphoid tissues and later in nonlymphoid tissues, are major targets of DENV infection in vivo.


Subject(s)
Dengue Virus/metabolism , Dengue/virology , Macrophages/cytology , Spleen/cytology , Animals , Biological Transport , Bone Marrow/virology , CD58 Antigens/biosynthesis , Cell Adhesion Molecules/biosynthesis , Dengue/metabolism , Immunohistochemistry/methods , Kinetics , Lectins, C-Type/biosynthesis , Lymph Nodes/virology , Macrophages/virology , Mice , Peyer's Patches/virology , Receptors, Cell Surface/biosynthesis , Sialic Acid Binding Ig-like Lectin 1/biosynthesis , Spleen/virology , Tissue Distribution , Virus Replication
15.
Nanomedicine (Lond) ; 7(6): 877-88, 2012 Jun.
Article in English | MEDLINE | ID: mdl-22394183

ABSTRACT

AIMS: Detection of atherosclerosis has generally been limited to the late stages of development, after cardiovascular symptoms present or a clinical event occurs. One possibility for early detection is the use of functionalized nanoparticles. The aim of this study was the early imaging of atherosclerosis using nanoparticles with a natural affinity for inflammatory cells in the lesion. MATERIALS & METHODS: We investigated uptake of cowpea mosaic virus by macrophages and foam cells in vitro and correlated this with vimentin expression. We also examined the ability of cowpea mosaic virus to interact with atherosclerotic lesions in a murine model of atherosclerosis. RESULTS & CONCLUSION: We found that uptake of cowpea mosaic virus is increased in areas of atherosclerotic lesion. This correlated with increased surface vimentin in the lesion compared with nonlesion vasculature. In conclusion, cowpea mosaic virus and its vimentin-binding region holds potential for use as a targeting ligand for early atherosclerotic lesions, and as a probe for detecting upregulation of surface vimentin during inflammation.


Subject(s)
Atherosclerosis/diagnosis , Comovirus/immunology , Nanoparticles , Vimentin/immunology , Animals , Arteries/immunology , Arteries/pathology , Atherosclerosis/immunology , Atherosclerosis/pathology , Cell Line , Cells, Cultured , Comovirus/chemistry , Endothelial Cells/immunology , Endothelial Cells/pathology , Foam Cells/immunology , Foam Cells/pathology , Lipoproteins, LDL/immunology , Macrophages/immunology , Macrophages/pathology , Male , Mice , Mice, Inbred C57BL , Nanoparticles/chemistry , Plaque, Atherosclerotic/diagnosis , Plaque, Atherosclerotic/immunology , Plaque, Atherosclerotic/pathology
16.
Article in English | MEDLINE | ID: mdl-20872839

ABSTRACT

Current vaccines that provide protection against infectious diseases have primarily relied on attenuated or inactivated pathogens. Virus-like particles (VLPs), comprised of capsid proteins that can initiate an immune response but do not include the genetic material required for replication, promote immunogenicity and have been developed and approved as vaccines in some cases. In addition, many of these VLPs can be used as molecular platforms for genetic fusion or chemical attachment of heterologous antigenic epitopes. This approach has been shown to provide protective immunity against the foreign epitopes in many cases. A variety of VLPs and virus-based nanoparticles are being developed for use as vaccines and epitope platforms. These particles have the potential to increase efficacy of current vaccines as well as treat diseases for which no effective vaccines are available.


Subject(s)
Nanomedicine/methods , Nanoparticles/chemistry , Viral Vaccines/chemistry , Viral Vaccines/immunology , Virion/immunology , Viruses/immunology , Animals , Humans , Virion/chemistry , Viruses/chemistry
17.
PLoS One ; 4(11): e7981, 2009 Nov 23.
Article in English | MEDLINE | ID: mdl-19956734

ABSTRACT

BACKGROUND: Plant viruses such as Cowpea mosaic virus (CPMV) are increasingly being developed for applications in nanobiotechnology including vaccine development because of their potential for producing large quantities of antigenic material in plant hosts. In order to improve efficacy of viral nanoparticles in these types of roles, an investigation of the individual cell types that interact with the particles is critical. In particular, it is important to understand the interactions of a potential vaccine with antigen presenting cells (APCs) of the immune system. CPMV was previously shown to interact with vimentin displayed on cell surfaces to mediate cell entry, but the expression of surface vimentin on APCs has not been characterized. METHODOLOGY: The binding and internalization of CPMV by several populations of APCs was investigated both in vitro and in vivo by flow cytometry and fluorescence confocal microscopy. The association of the particles with mouse gastrointestinal epithelium and Peyer's patches was also examined by confocal microscopy. The expression of surface vimentin on APCs was also measured. CONCLUSIONS: We found that CPMV is bound and internalized by subsets of several populations of APCs both in vitro and in vivo following intravenous, intraperitoneal, and oral administration, and also by cells isolated from the Peyer's patch following gastrointestinal delivery. Surface vimentin was also expressed on APC populations that could internalize CPMV. These experiments demonstrate that APCs capture CPMV particles in vivo, and that further tuning the interaction with surface vimentin may facilitate increased uptake by APCs and priming of antibody responses. These studies also indicate that CPMV particles likely access the systemic circulation following oral delivery via the Peyer's patch.


Subject(s)
Antigen-Presenting Cells/metabolism , Antigen-Presenting Cells/virology , Biotechnology/methods , Comovirus/metabolism , Nanoparticles , Nanotechnology/methods , Animals , Cell Membrane/metabolism , Cell Separation , Fibroblasts/metabolism , Hydrogen-Ion Concentration , In Vitro Techniques , Mice , Mice, Inbred C57BL , Microscopy, Confocal/methods , Protein Binding , Vimentin/chemistry , Vimentin/metabolism
18.
PLoS Pathog ; 5(5): e1000417, 2009 May.
Article in English | MEDLINE | ID: mdl-19412526

ABSTRACT

Cowpea mosaic virus (CPMV) is a plant comovirus in the picornavirus superfamily, and is used for a wide variety of biomedical and material science applications. Although its replication is restricted to plants, CPMV binds to and enters mammalian cells, including endothelial cells and particularly tumor neovascular endothelium in vivo. This natural capacity has lead to the use of CPMV as a sensor for intravital imaging of vascular development. Binding of CPMV to endothelial cells occurs via interaction with a 54 kD cell-surface protein, but this protein has not previously been identified. Here we identify the CPMV binding protein as a cell-surface form of the intermediate filament vimentin. The CPMV-vimentin interaction was established using proteomic screens and confirmed by direct interaction of CPMV with purified vimentin, as well as inhibition in a vimentin-knockout cell line. Vimentin and CPMV were also co-localized in vascular endothelium of mouse and rat in vivo. Together these studies indicate that surface vimentin mediates binding and may lead to internalization of CPMV in vivo, establishing surface vimentin as an important vascular endothelial ligand for nanoparticle targeting to tumors. These results also establish vimentin as a ligand for picornaviruses in both the plant and animal kingdoms of life. Since bacterial pathogens and several other classes of viruses also bind to surface vimentin, these studies suggest a common role for surface vimentin in pathogen transmission.


Subject(s)
Comovirus/metabolism , Endothelium, Vascular/metabolism , Endothelium, Vascular/virology , Vimentin/metabolism , Animals , Aorta/metabolism , Cell Line , Cell Membrane/metabolism , Chromatography, Liquid , HeLa Cells , Humans , Male , Mice , Protein Binding , Proteomics , Rats , Rats, Sprague-Dawley , Tandem Mass Spectrometry , Virion/metabolism
19.
J Exp Biol ; 211(Pt 1): 66-78, 2008 Jan.
Article in English | MEDLINE | ID: mdl-18083734

ABSTRACT

Song of the zebra finch (Taeniopygia guttata) is a complex temporal sequence generated by a drastic change to the regular oscillations of the normal respiratory pattern. It is not known how respiratory functions, such as supply of air volume and gas exchange, are controlled during song. To understand the integration between respiration and song, we manipulated respiration during song by injecting inert dental medium into the air sacs. Increased respiratory rate after injections indicates that the reduction of air affected quiet respiration and that birds compensated for the reduced air volume. During song, air sac pressure, tracheal airflow and sound amplitude decreased substantially with each injection. This decrease was consistently present during each expiratory pulse of the song motif irrespective of the air volume used. Few changes to the temporal pattern of song were noted, such as the increased duration of a minibreath in one bird and the decrease in duration of a long syllable in another bird. Despite the drastic reduction in air sac pressure, airflow and sound amplitude, no increase in abdominal muscle activity was seen. This suggests that during song, birds do not compensate for the reduced physiological or acoustic parameters. Neither somatosensory nor auditory feedback mechanisms appear to effect a correction in expiratory effort to compensate for reduced air sac pressure and sound amplitude.


Subject(s)
Air Sacs/physiology , Finches/physiology , Pulmonary Ventilation/physiology , Sound , Vocalization, Animal/physiology , Acoustics , Animals , Apnea/physiopathology , Electromyography , Injections , Muscles , Pressure
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