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1.
Sci Total Environ ; 947: 174774, 2024 Jul 14.
Artículo en Inglés | MEDLINE | ID: mdl-39009144

RESUMEN

Exposure to hazardous chemicals in consumer products poses significant risks to personal health and the environment, and the combined effects may be negative even if each individual exposure is low. This necessitates informed and effective policies for risk reduction. This systematic review aims to identify and analyse existing evidence on how consumer preferences, product use, and product disposal are affected by information on harmful chemicals in consumer products and by price interventions. The review is conducted according to the PRISMA 2020 guidelines, synthesises forty-eight scientific articles on the relationship between information and consumer responses. No corresponding studies on the effects of price interventions were found. A large share of the identified articles focused on household chemicals, where warning labels are common, while less has been published on "everyday products" where the presence of hazardous chemicals is less clear to consumers. Effects of information on hazardous chemicals on consumer behaviour are highly contextual and dependent on the type of product, consumer behaviour and what kind of label is used. Warning symbols are effective in communicating a general warning of a potential danger, although consumers often misinterpret specifics regarding the exact nature of that danger or what means should be taken to minimise it. Informational texts are more informative but are also often missed or quickly forgotten. Consumer willingness to pay for safer products is generally positive but low. Additional research on how consumers react to information and price signals on chemical hazards is needed to improve policy design.

2.
Org Biomol Chem ; 13(22): 6203-16, 2015 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-25960177

RESUMEN

Class II major histocompatibility complex (MHC) proteins are involved in initiation of immune responses to foreign antigens via presentation of peptides to receptors of CD4(+) T-cells. An analogous presentation of self-peptides may lead to autoimmune diseases, such as rheumatoid arthritis (RA). The glycopeptide fragment CII259-273, derived from type II collagen, is presented by A(q) MHCII molecules in the mouse and has a key role in development of collagen induced arthritis (CIA), a validated model for RA. We have introduced hydroxyethylene amide bond isosteres at the Ala(261)-Gly(262) position of CII259-273. Biological evaluation showed that A(q) binding and T cell recognition were dramatically reduced for the modified glycopeptides, although static models predicted similar binding modes as the native type II collagen fragment. Molecular dynamics (MD) simulations demonstrated that introduction of the hydroxyethylene isosteres disturbed the entire hydrogen bond network between the glycopeptides and A(q). As a consequence the hydroxyethylene isosteric glycopeptides were prone to dissociation from A(q) and unfolding of the ß1-helix. Thus, the isostere induced adjustment of the hydrogen bond network altered the structure and dynamics of A(q)/glycopeptide complexes leading to the loss of A(q) affinity and subsequent T cell response.


Asunto(s)
Colágeno Tipo II/química , Etilenos/química , Glicopéptidos/química , Antígenos de Histocompatibilidad Clase II/química , Simulación de Dinámica Molecular , Enlace de Hidrógeno , Estructura Molecular , Estereoisomerismo
3.
Arthritis Res Ther ; 16(4): R143, 2014 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-25005029

RESUMEN

INTRODUCTION: Antibodies towards type II collagen (CII) are detected in patients with rheumatoid arthritis (RA) and in non-human primates and rodents with collagen induced arthritis (CIA). We have previously shown that antibodies specific for several CII-epitopes are pathogenic using monoclonal antibodies from arthritic mice, although the role of different anti-CII epitopes has not been investigated in detail in other species. We therefore performed an inter-species comparative study of the autoantibody response to CII in patients with RA versus monkeys and mice with CIA. METHODS: Analysis of the full epitope repertoire along the disease course of CIA was performed using a library of CII triple-helical peptides. The antibody responses to the major CII epitopes were analyzed in sera and synovial fluid from RA patients, and in sera from rhesus monkeys (Macaca mulatta), common marmosets (Callithrix jacchus) and mice. RESULTS: Many CII epitopes including the major C1, U1, and J1 were associated with established CIA and arginine residues played an important role in the anti-CII antibody interactions. The major epitopes were also recognized in RA patients, both in sera and even more pronounced in synovial fluid: 77% of the patients had antibodies to the U1 epitope. The anti-CII immune response was not restricted to the anti-citrulline protein antibodies (ACPA) positive RA group. CONCLUSION: CII conformational dependent antibody responses are common in RA and are likely to originate from rheumatoid joints but did not show a correlation with ACPA response. Importantly, the fine specificity of the anti-CII response is similar with CIA in monkeys and rodents where the recognized epitopes are conserved and have a major pathogenic role. Thus, anti-CII antibodies may both contribute to, as well as be the consequence of, local joint inflammation.


Asunto(s)
Artritis Experimental/inmunología , Artritis Reumatoide/inmunología , Colágeno Tipo II/inmunología , Epítopos de Linfocito B/inmunología , Adulto , Anciano , Anciano de 80 o más Años , Animales , Formación de Anticuerpos/inmunología , Autoanticuerpos/inmunología , Autoantígenos/inmunología , Callithrix , Femenino , Humanos , Macaca mulatta , Masculino , Ratones , Ratones Endogámicos BALB C , Persona de Mediana Edad , Líquido Sinovial/inmunología , Adulto Joven
4.
Arthritis Rheumatol ; 66(6): 1440-9, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24470447

RESUMEN

OBJECTIVE: To investigate type II collagen (CII) as a joint-specific target of the anti-citrullinated protein antibody (ACPA) response in rheumatoid arthritis (RA). METHODS: Potential citrullinated neoepitopes were identified by high-resolution tandem mass spectrometry (MS/MS) of in vitro peptidylarginine deiminase 2 (PAD-2)-treated CII, and the relationship between citrullination and CII conformation was investigated by circular dichroism and conformation-dependent antibodies. Based on the MS analyses, synthetic peptides were designed and analyzed for serum IgG reactivity in the Epidemiological Investigation of RA (EIRA) case-control cohort of 1,949 RA patients and 278 healthy controls. Peptide-specific antibodies were purified from RA patient serum and used to stain RA cartilage specimens. RESULTS: We described the conformation-dependent citrullination pattern of CII after PAD-2 treatment at room temperature and 37°C and showed that CII could be citrullinated in its native triple-helical conformation. Screening of Arg and Cit pairs of synthetic peptides revealed new citrullinated B cell epitopes on CII. Antibodies directed to 2 proximal epitopes close to the C-terminus of the CII triple helix were recognized by autoantibodies in 21% and 17% of RA patients, respectively. Affinity-purified antibodies from RA sera directed to these 2 epitopes, but not antibodies directed to citrullinated α-enolase peptide 1, bound to RA cartilage. CONCLUSION: These findings suggest that cartilage-directed anticitrulline immunity contributes to the induction of joint inflammation in RA.


Asunto(s)
Artritis Reumatoide/metabolismo , Autoanticuerpos/metabolismo , Cartílago Articular/metabolismo , Citrulina/inmunología , Colágeno Tipo II/metabolismo , Animales , Estudios de Casos y Controles , Colágeno Tipo II/efectos de los fármacos , Epítopos/inmunología , Humanos , Hidrolasas/farmacología , Inmunoglobulina G/metabolismo , Técnicas In Vitro , Desiminasas de la Arginina Proteica , Ratas , Espectrometría de Masas en Tándem
5.
Arthritis Rheum ; 64(8): 2482-8, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22392632

RESUMEN

OBJECTIVE: Type II collagen (CII) is a cartilage-specific protein to which a loss of immune tolerance may trigger autoimmune reactions and cause arthritis. The major T cell epitope on CII, amino acids 259-273, can be presented by several HLA-DRB1 04 alleles in its native or posttranslational glycosylated form. The present study was undertaken to functionally explore and compare CII-autoreactive T cells from blood and synovial fluid of patients with rheumatoid arthritis (RA). METHODS: Peripheral blood was obtained from HLA-DRB1 04-positive RA patients (n = 10) and control subjects (n = 10) and stimulated in vitro with several variants of the CII(259-273) epitope, i.e., unmodified, glycosylated on Lys-264, glycosylated on Lys-270, or glycosylated on both Lys-264 and Lys-270. Up-regulation of CD154 was used to identify responding T cells. These cells were further characterized by intracellular staining for interleukin-17 (IL-17), interferon-γ (IFNγ), and IL-2 by flow cytometry. Synovial T cells from RA patients were investigated in parallel. RESULTS: Multifunctional T cell responses toward all examined variants of the CII(259-273) peptide could be detected in RA patients and, to a lesser extent, also in healthy HLA-matched controls (P < 0.001). In RA patients, a comparison between blood- and joint-derived T cell function revealed a significant increase in levels of the proinflammatory cytokine IFNγ in synovial T cells (P = 0.027). Studies of longitudinally obtained samples showed that T cell responses were sustained over the course of disease, and even included epitope spreading. CONCLUSION: The identification of inflammatory T cell responses to both glycosylated and nonglycosylated variants of the major CII epitope in RA patients suggests that CII autoreactivity in RA may be more common than previously recognized.


Asunto(s)
Artritis Reumatoide/inmunología , Artritis Reumatoide/patología , Colágeno Tipo II/inmunología , Epítopos de Linfocito T/inmunología , Linfocitos T/inmunología , Linfocitos T/patología , Artritis Reumatoide/metabolismo , Células Sanguíneas/patología , Estudios de Casos y Controles , Progresión de la Enfermedad , Glicosilación , Cadenas HLA-DRB1/metabolismo , Humanos , Interferón gamma/metabolismo , Interleucina-17/metabolismo , Interleucina-2/metabolismo , Estudios Longitudinales , Líquido Sinovial/citología , Linfocitos T/metabolismo
6.
Scand J Caring Sci ; 26(2): 262-70, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-21967678

RESUMEN

AIM: The aim of this study was to investigate how women who have experienced one or more miscarriages manage their feelings when they become pregnant again. METHOD: Individual qualitative interviews were conducted with 16 women who were pregnant again after experiencing one or more miscarriages. The interviews were analysed using qualitative content analysis with an inductive approach. RESULTS: The analysis of the material ended up in five categories: distancing herself from her pregnancy, focusing on her pregnancy symptoms, searching for confirming information, asking for ultrasound examination and asking for professional and social support. Because of their past experience with miscarriage, it could be painful to have another pregnancy terminate in disappointment. Therefore, the women manage their feelings by distancing themselves from their pregnancies. Simultaneously, they are managing their emotions by seeking affirmation that their current pregnancy is normal. CONCLUSION: Generally speaking, women manage their emotions by themselves. They feel isolated with their worries and concerns, and they are in need of the support provided from their intimate circle of friends and family as well as from the staff of the maternity health care ward. Unfortunately, the women do not feel that they get the support they need from the staff, instead they have to rely on their friends, family and partners to help them manage their emotions.


Asunto(s)
Aborto Espontáneo/psicología , Emociones , Embarazo/psicología , Femenino , Humanos , Entrevistas como Asunto
7.
J Am Chem Soc ; 133(36): 14368-78, 2011 Sep 14.
Artículo en Inglés | MEDLINE | ID: mdl-21766871

RESUMEN

The structural basis for antigen presentation by class II major histocompatibility complex (MHC) proteins to CD4(+) T-cells is important for understanding and possibly treating autoimmune diseases. In the work described in this paper, (E)-alkene and ethylene amide-bond isosteres were used to investigate the effect of removing hydrogen-bonding possibilities from the CII259-270 glycopeptide, which is bound by the arthritis-associated murine A(q) class II MHC protein. The isostere-modified glycopeptides showed varying and unexpectedly large losses of A(q) binding that could be linked to the dynamics of the system. Molecular dynamics (MD) simulations revealed that the backbone of CII259-270 and the A(q) protein are able to form up to 11 hydrogen bonds, but fewer than this number are present at any one time. Most of the strong hydrogen-bond interactions were formed by the N-terminal part of the glycopeptide, i.e., in the region where the isosteric replacements were made. The structural dynamics also revealed that hydrogen bonds were strongly coupled to each other; the loss of one hydrogen-bond interaction had a profound effect on the entire hydrogen-bonding network. The A(q) binding data revealed that an ethylene isostere glycopeptide unexpectedly bound more strongly to A(q) than the corresponding (E)-alkene, which is in contrast to the trend observed for the other isosteres. Analysis of the MD trajectories revealed that the complex conformation of this ethylene isostere was structurally different and had an altered molecular interaction pattern compared to the other A(q)/glycopeptide complexes. The introduced amide-bond isosteres also affected the interactions of the glycopeptide/A(q) complexes with T-cell receptors. The dynamic variation of the patterns and strengths of the hydrogen-bond interactions in the class II MHC system is of critical importance for the class II MHC/peptide/TCR signaling system.


Asunto(s)
Alquenos/química , Linfocitos T CD4-Positivos/inmunología , Etilenos/química , Glicopéptidos/inmunología , Antígenos de Histocompatibilidad Clase II/inmunología , Animales , Presentación de Antígeno , Línea Celular , Glicopéptidos/química , Antígenos de Histocompatibilidad Clase II/química , Hibridomas , Enlace de Hidrógeno , Ratones , Estructura Secundaria de Proteína
8.
PLoS One ; 6(3): e17881, 2011 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-21423632

RESUMEN

The glycopeptide fragment CII259-273 from type II collagen (CII) binds to the murine A(q) and human DR4 class II Major Histocompatibility Complex (MHC II) proteins, which are associated with development of murine collagen-induced arthritis (CIA) and rheumatoid arthritis (RA), respectively. It has been shown that CII259-273 can be used in therapeutic vaccination of CIA. This glycopeptide also elicits responses from T-cells obtained from RA patients, which indicates that it has an important role in RA as well. We now present a methodology for studies of (glyco)peptide-receptor interactions based on a combination of structure-based virtual screening, ligand-based statistical molecular design and biological evaluations. This methodology included the design of a CII259-273 glycopeptide library in which two anchor positions crucial for binding in pockets of A(q) and DR4 were varied. Synthesis and biological evaluation of the designed glycopeptides provided novel structure-activity relationship (SAR) understanding of binding to A(q) and DR4. Glycopeptides that retained high affinities for these MHC II proteins and induced strong responses in panels of T-cell hybridomas were also identified. An analysis of all the responses revealed groups of glycopeptides with different response patterns that are of high interest for vaccination studies in CIA. Moreover, the SAR understanding obtained in this study provides a platform for the design of second-generation glycopeptides with tuned MHC affinities and T-cell responses.


Asunto(s)
Artritis Experimental/inmunología , Artritis Reumatoide/inmunología , Glicopéptidos/síntesis química , Antígenos de Histocompatibilidad Clase II/metabolismo , Linfocitos T/inmunología , Secuencia de Aminoácidos , Animales , Unión Competitiva , Biotinilación , Evaluación Preclínica de Medicamentos , Glicopéptidos/análisis , Glicopéptidos/química , Antígeno HLA-DR4/química , Antígeno HLA-DR4/metabolismo , Antígenos de Histocompatibilidad Clase II/química , Humanos , Hibridomas , Análisis de los Mínimos Cuadrados , Ligandos , Ratones , Modelos Moleculares , Simulación de Dinámica Molecular , Datos de Secuencia Molecular , Análisis de Componente Principal , Unión Proteica , Interfaz Usuario-Computador
9.
J Chem Inf Model ; 51(2): 267-82, 2011 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-21309544

RESUMEN

Molecular docking plays an important role in drug discovery as a tool for the structure-based design of small organic ligands for macromolecules. Possible applications of docking are identification of the bioactive conformation of a protein-ligand complex and the ranking of different ligands with respect to their strength of binding to a particular target. We have investigated the effect of implicit water on the postprocessing of binding poses generated by molecular docking using MM-PB/GB-SA (molecular mechanics Poisson-Boltzmann and generalized Born surface area) methodology. The investigation was divided into three parts: geometry optimization, pose selection, and estimation of the relative binding energies of docked protein-ligand complexes. Appropriate geometry optimization afforded more accurate binding poses for 20% of the complexes investigated. The time required for this step was greatly reduced by minimizing the energy of the binding site using GB solvation models rather than minimizing the entire complex using the PB model. By optimizing the geometries of docking poses using the GB(HCT+SA) model then calculating their free energies of binding using the PB implicit solvent model, binding poses similar to those observed in crystal structures were obtained. Rescoring of these poses according to their calculated binding energies resulted in improved correlations with experimental binding data. These correlations could be further improved by applying the postprocessing to several of the most highly ranked poses rather than focusing exclusively on the top-scored pose. The postprocessing protocol was successfully applied to the analysis of a set of Factor Xa inhibitors and a set of glycopeptide ligands for the class II major histocompatibility complex (MHC) A(q) protein. These results indicate that the protocol for the postprocessing of docked protein-ligand complexes developed in this paper may be generally useful for structure-based design in drug discovery.


Asunto(s)
Modelos Moleculares , Proteínas/metabolismo , Solventes/química , Cristalografía por Rayos X , Entropía , Factor Xa/metabolismo , Inhibidores del Factor Xa , Glicoproteínas/química , Glicoproteínas/metabolismo , Antígenos HLA/metabolismo , Ligandos , Peptidomiméticos/metabolismo , Unión Proteica , Proteínas/química
10.
Org Biomol Chem ; 8(13): 2931-40, 2010 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-20485848

RESUMEN

The glycopeptide CII259-273, a fragment from type II collagen (CII), can induce tolerance in mice susceptible to collagen-induced arthritis (CIA), which is a validated disease model for rheumatoid arthritis (RA). Here, we describe the design and synthesis of a small series of modified CII259-273 glycopeptides with oxazole heterocycles replacing three potentially labile peptide bonds. These glycopeptidomimetics were evaluated for binding to murine CIA-associated A(q) and human RA-associated DR4 class II major histocompatibility complex (MHC) proteins. The oxazole modifications drastically reduced or completely abolished binding to A(q). Two of the glycopeptidomimetics were, however, well tolerated in binding to DR4 and they also induced strong responses by one or two DR4-restricted T-cell hybridomas. This work contributes to the development of an altered glycopeptide for inducing immunological tolerance in CIA, with the long-term goal of developing a therapeutic vaccine for treatment of RA.


Asunto(s)
Artritis Reumatoide/metabolismo , Glicopéptidos/química , Glicopéptidos/metabolismo , Antígenos de Histocompatibilidad Clase II/metabolismo , Oxazoles/química , Receptores del Ligando Inductor de Apoptosis Relacionado con TNF/metabolismo , Amidas/química , Secuencia de Aminoácidos , Animales , Artritis Reumatoide/inducido químicamente , Artritis Reumatoide/inmunología , Colágeno/farmacología , Dipéptidos/química , Diseño de Fármacos , Glicopéptidos/síntesis química , Glicopéptidos/inmunología , Antígenos de Histocompatibilidad Clase II/química , Humanos , Ratones , Modelos Moleculares , Conformación Molecular , Datos de Secuencia Molecular , Receptores del Ligando Inductor de Apoptosis Relacionado con TNF/química , Linfocitos T/inmunología
11.
J Med Virol ; 80(8): 1397-404, 2008 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-18551619

RESUMEN

As a first line of defence against virus infection, mammalian cells elicit an innate immune response, characterized by secretion of type I interferons and the up-regulation of interferon stimulated genes. Many viruses down-regulate the innate immune responses in order to enhance their virulence. Crimean-Congo hemorrhagic fever virus (CCHFV), a Nairovirus of the family Bunyaviridae is the causative agent of severe hemorrhagic fever in humans with high mortality. Knowledge regarding the innate immune response against CCHFV is most limited. Interestingly, in this study it is shown that replicating CCHFV delays substantially the IFN response, possibly by interfering with the activation pathway of IRF-3. In addition, it is demonstrated that CCHFV replication is almost insensitive to subsequent treatment with interferon-alpha. Once the virus is replicating, virus replication is more or less insensitive to the antiviral effects induced by the interferon. By using an interferon bioassay, it is shown that infected cells secrete interferon relatively late after infection, that is, 48 hr post-infection. In summary, the results suggest the presence of a virulence factor encoded by CCHFV that delays the host defence in order to allow rapid viral spread in the host.


Asunto(s)
Antivirales , Virus de la Fiebre Hemorrágica de Crimea-Congo/patogenicidad , Inmunidad Innata , Interferón-alfa , Interferón beta , Animales , Antivirales/metabolismo , Antivirales/farmacología , Línea Celular , Chlorocebus aethiops , Virus de la Fiebre Hemorrágica de Crimea-Congo/fisiología , Humanos , Interferón-alfa/metabolismo , Interferón-alfa/farmacología , Interferón beta/metabolismo , Interferón beta/farmacología , Factores de Tiempo , Células Vero , Factores de Virulencia/metabolismo , Replicación Viral/efectos de los fármacos
12.
PLoS One ; 3(4): e2032, 2008 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-18446221

RESUMEN

Innate immunity is critically dependent on the rapid production of interferon in response to intruding viruses. The intracellular pathogen recognition receptors RIG-I and MDA5 are essential for interferon induction by viral RNAs containing 5' triphosphates or double-stranded structures, respectively. Viruses with a negative-stranded RNA genome are an important group of pathogens causing emerging and re-emerging diseases. We investigated the ability of genomic RNAs from substantial representatives of this virus group to induce interferon via RIG-I or MDA5. RNAs isolated from particles of Ebola virus, Nipah virus, Lassa virus, and Rift Valley fever virus strongly activated the interferon-beta promoter. Knockdown experiments demonstrated that interferon induction depended on RIG-I, but not MDA5, and phosphatase treatment revealed a requirement for the RNA 5' triphosphate group. In contrast, genomic RNAs of Hantaan virus, Crimean-Congo hemorrhagic fever virus and Borna disease virus did not trigger interferon induction. Sensitivity of these RNAs to a 5' monophosphate-specific exonuclease indicates that the RIG-I-activating 5' triphosphate group was removed post-transcriptionally by a viral function. Consequently, RIG-I is unable to bind the RNAs of Hantaan virus, Crimean-Congo hemorrhagic fever virus and Borna disease virus. These results establish RIG-I as a major intracellular recognition receptor for the genome of most negative-strand RNA viruses and define the cleavage of triphosphates at the RNA 5' end as a strategy of viruses to evade the innate immune response.


Asunto(s)
ARN Helicasas DEAD-box/inmunología , Genoma Viral/genética , Interferones/inmunología , Virus ARN/genética , Línea Celular , Proteína 58 DEAD Box , Humanos , Fosfatos , Virus ARN/patogenicidad , ARN Viral/genética , Receptores Inmunológicos , Virulencia
13.
J Med Chem ; 50(23): 5627-43, 2007 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-17944452

RESUMEN

T cells obtained in a mouse model for rheumatoid arthritis are activated by a glycopeptide fragment from rat type II collagen (CII) bound to the class II major histocompatibility complex Aq molecule. We report a comparative model of Aq in complex with the glycopeptide CII260-267. This model was used in a structure-based design approach where the amide bond between Ala261 and Gly262 in the glycopeptide was selected for replacement with psi[COCH2], psi[CH2NH2+], and psi[(E)-CH=CH] isosteres. Ala-Gly isostere building blocks were then synthesized and introduced in CII260-267 and CII259-273 glycopeptides. The modified glycopeptides were evaluated for binding to the Aq molecule, and the results were interpreted in view of the Aq/glycopeptide model. Moreover, recognition by a panel of T-cell hybridomas revealed high sensitivity for the backbone modifications. These studies contribute to the understanding of the interactions in the ternary Aq/glycopeptide/T-cell receptor complexes that activate T cells in autoimmune arthritis and suggest possibilities for new vaccination approaches.


Asunto(s)
Artritis Experimental/inmunología , Colágeno Tipo II/química , Glicopéptidos/química , Antígenos de Histocompatibilidad Clase II/química , Fragmentos de Péptidos/química , Receptores de Antígenos de Linfocitos T/metabolismo , Alanina/química , Animales , Células Presentadoras de Antígenos/metabolismo , Artritis Experimental/inducido químicamente , Unión Competitiva , Técnicas de Cocultivo , Glicina/química , Glicopéptidos/síntesis química , Glicopéptidos/metabolismo , Antígenos de Histocompatibilidad Clase II/metabolismo , Hibridomas , Interleucina-2/metabolismo , Ratones , Modelos Moleculares , Estructura Molecular , Fragmentos de Péptidos/síntesis química , Fragmentos de Péptidos/metabolismo , Unión Proteica , Ratas , Bazo/citología , Estereoisomerismo , Relación Estructura-Actividad , Linfocitos T/metabolismo
14.
J Med Virol ; 78(2): 216-22, 2006 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-16372299

RESUMEN

Crimean-Congo hemorrhagic fever virus (CCHFV) is a causative agent of severe hemorrhagic fever occurring sporadically in parts of Africa, Asia, Southeast Europe, and the Middle East. Its recent recognition as a potential agent of bioterrorism/biowarfare highlights the need for effective antiviral therapy. In this study, it is shown that human endothelial cells are permissive to CCHFV. It is also shown that interferon-alpha inhibits the growth of CCHFV in human endothelial and hepatoma cells, reducing virus yields by a factor of 100-1,000. By using a siRNA approach, it was demonstrated that the interferon-induced MxA GTPase is a major factor mediating the antiviral effect against CCHFV, in agreement with previous findings showing that recombinant MxA inhibits CCHFV replication by interacting with the viral nucleocapsid protein. The identification of intrinsic cellular resistance factors that block CCHFV replication may help in designing novel antiviral agents.


Asunto(s)
Antivirales/farmacología , Virus de la Fiebre Hemorrágica de Crimea-Congo/efectos de los fármacos , Interferón-alfa/farmacología , Células Cultivadas , Relación Dosis-Respuesta a Droga , Proteínas de Unión al GTP/fisiología , Virus de la Fiebre Hemorrágica de Crimea-Congo/crecimiento & desarrollo , Fiebre Hemorrágica de Crimea/virología , Humanos , Proteínas de Resistencia a Mixovirus , Interferencia de ARN , ARN Viral/genética
15.
J Virol ; 78(8): 4323-9, 2004 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-15047845

RESUMEN

Crimean-Congo hemorrhagic fever virus (CCHFV) belongs to the genus Nairovirus within the family Bunyaviridae and is the causative agent of severe hemorrhagic fever. Despite increasing knowledge about hemorrhagic fever viruses, the factors determining their pathogenicity are still poorly understood. The interferon-induced MxA protein has been shown to have an inhibitory effect on several members of the Bunyaviridae family, but the effect of MxA against CCHFV has not previously been studied. Here, we report that human MxA has antiviral activity against CCHFV. The yield of progeny virus in cells constitutively expressing MxA was reduced up to 1,000-fold compared with control cells, and accumulation of viral genomes was blocked. Confocal microscopy revealed that MxA colocalizes with the nucleocapsid protein (NP) of CCHFV in the perinuclear regions of infected cells. Furthermore, we found that MxA interacted with NP by using a coimmunoprecipitation assay. We also found that an amino acid substitution (E645R) within the C-terminal domain of MxA resulted in a loss of MxA antiviral activity and, concomitantly, in the capacity to interact with CCHFV NP. These results suggest that MxA, by interacting with a component of the nucleocapsid, prevents replication of CCHFV viral RNA and thereby inhibits the production of new infectious virus particles.


Asunto(s)
Proteínas de Unión al GTP/fisiología , Virus de la Fiebre Hemorrágica de Crimea-Congo/fisiología , Sustitución de Aminoácidos , Animales , Antivirales/metabolismo , Secuencia de Bases , Chlorocebus aethiops , ADN Viral/genética , Proteínas de Unión al GTP/genética , Virus de la Fiebre Hemorrágica de Crimea-Congo/patogenicidad , Humanos , Proteínas de Resistencia a Mixovirus , Proteínas de la Nucleocápside/fisiología , ARN Viral/biosíntesis , ARN Viral/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Transfección , Células Vero , Virulencia , Replicación Viral/fisiología
16.
J Med Virol ; 72(1): 83-93, 2004 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-14635015

RESUMEN

Crimean-Congo hemorrhagic fever virus is the causative agent of a severe disease throughout Africa, Europe, and Asia. Like other members of the genus Nairovirus, the Crimean-Congo hemorrhagic fever virus contains three genomic RNA segments, the small (S), medium (M), and large (L) segments. The S segment encodes the viral nucleocapsid protein (NP), while the M and L segments encode the glycoproteins and the RNA-dependent RNA polymerase, respectively. In this study, the site of expression and assembly of Crimean-Congo hemorrhagic fever virus NP in mammalian cells have been investigated. It was found that the NP is localized in the perinuclear region of infected cells. By using the Semliki forest virus expression system, it was shown that the Crimean-Congo hemorrhagic fever virus NP is targeted to the perinuclear region of cells in the absence of native RNA segments and virally encoded glycoproteins. It was also demonstrated that the Crimean-Congo hemorrhagic fever virus NP was not expressed as a Golgi-membrane associated protein. By using Cytochalasin D, an agent that disrupts actin filaments, it was found that actin filaments are involved in targeting the viral NP to perinuclear regions. We also demonstrated that disruption of actin filaments reduced the assembly of infectious Crimean-Congo hemorrhagic fever virus up to 97%. Furthermore, we showed that the NP of Crimean-Congo hemorrhagic fever virus NP interacts with actin.


Asunto(s)
Citoesqueleto de Actina/metabolismo , Citoplasma/metabolismo , Virus de la Fiebre Hemorrágica de Crimea-Congo/fisiología , Proteínas de la Nucleocápside/metabolismo , Ensamble de Virus , Animales , Línea Celular , Chlorocebus aethiops , Cricetinae , Aparato de Golgi/metabolismo , Proteínas de la Nucleocápside/genética , Virus de los Bosques Semliki/genética , Virus de los Bosques Semliki/metabolismo , Células Vero
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