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1.
Nurs Educ Perspect ; 45(5): 271-275, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39159250

RESUMEN

AIM: This research aimed to uncover elements of a comprehensive, trauma-informed (TI) multidisciplinary health professions simulation framework to improve the delivery of care to traumatized patients. BACKGROUND: Trauma is a pervasive public health problem requiring a TI approach. Simulation is an evidence-based teaching strategy that advances knowledge and clinical reasoning. There is a lack of scientifically based simulation education models addressing the delivery of TI care for the health professions. METHOD: A Delphi study utilizing a panel of experts was conducted to identify the most critical elements of a simulation framework. RESULTS: Phase one identified 10 content areas and 111 subcontent areas. Phase two analysis revealed 99 percent of the 111 subcontent areas achieved expert consensus. CONCLUSION: This Delphi study provides the first scientifically based framework to guide the development of a comprehensive, TI, multidisciplinary simulation framework to recognize trauma survivors and subsequently display concern and respect.


Asunto(s)
Curriculum , Técnica Delphi , Entrenamiento Simulado , Humanos , Heridas y Lesiones/enfermería , Femenino , Masculino , Adulto
2.
PLoS Pathog ; 20(2): e1012037, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38394338

RESUMEN

Mammalian orthoreovirus (MRV) is a prototypic member of the Spinareoviridae family and has ten double-stranded RNA segments. One copy of each segment must be faithfully packaged into the mature virion, and prior literature suggests that nucleotides (nts) at the terminal ends of each gene likely facilitate their packaging. However, little is known about the precise packaging sequences required or how the packaging process is coordinated. Using a novel approach, we have determined that 200 nts at each terminus, inclusive of untranslated regions (UTR) and parts of the open reading frame (ORF), are sufficient for packaging S gene segments (S1-S4) individually and together into replicating virus. Further, we mapped the minimal sequences required for packaging the S1 gene segment into a replicating virus to 25 5' nts and 50 3' nts. The S1 UTRs, while not sufficient, were necessary for efficient packaging, as mutations of the 5' or 3' UTRs led to a complete loss of virus recovery. Using a second novel assay, we determined that 50 5' nts and 50 3' nts of S1 are sufficient to package a non-viral gene segment into MRV. The 5' and 3' termini of the S1 gene are predicted to form a panhandle structure and specific mutations within the stem of the predicted panhandle region led to a significant decrease in viral recovery. Additionally, mutation of six nts that are conserved across the three major serotypes of MRV that are predicted to form an unpaired loop in the S1 3' UTR, led to a complete loss of viral recovery. Overall, our data provide strong experimental proof that MRV packaging signals lie at the terminal ends of the S gene segments and offer support that the sequence requirements for efficient packaging of the S1 segment include a predicted panhandle structure and specific sequences within an unpaired loop in the 3' UTR.


Asunto(s)
Orthoreovirus de los Mamíferos , Animales , Orthoreovirus de los Mamíferos/genética , Regiones no Traducidas 3'/genética , Sistemas de Lectura Abierta/genética , ARN Viral/genética , Mutación , Genoma Viral , Mamíferos
3.
Virology ; 587: 109871, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37634292

RESUMEN

Mammalian orthoreovirus (MRV) is an oncolytic virus that has been tested in over 30 clinical trials. Increased clinical success has been achieved when MRV is used in combination with other onco-immunotherapies. This has led the field to explore the creation of recombinant MRVs which incorporate immunotherapeutic sequences into the virus genome. This work focuses on creation and characterization of a recombinant MRV, S1/HER2nhd, which encodes a truncated σ1 protein fused in frame with three human epidermal growth factor receptor 2 (HER2) peptides (E75, AE36, and GP2) known to induce HER2 specific CD8+ and CD4+ T cells. We show S1/HER2nhd expresses the σ1 fusion protein containing HER2 peptides in infected cells and on the virion, and infects, replicates in, and reduces survival of HER2+ breast cancer cells. The oncolytic properties of MRV combined with HER2 peptide expression holds potential as a vaccine to prevent recurrences of HER2 expressing cancers.


Asunto(s)
Neoplasias , Orthoreovirus de los Mamíferos , Animales , Humanos , Orthoreovirus de los Mamíferos/genética , Proteínas Recombinantes de Fusión/genética , Péptidos , Mamíferos
4.
Bioact Mater ; 30: 116-128, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37560199

RESUMEN

Effective oral drugs and vaccines require high delivery efficiency across the gastrointestinal epithelia and protection of medically effective payloads (i.e., immunogens) against gastric damage. In this study, hollowed nanocarriers (NCs: silica nanospheres and gold nanocages) with poly-l-lysine (PLL) coating and mammalian orthoreovirus cell attachment protein σ1 functionalization (NC-PLL-σ1) were explored as functional oral drug delivery vehicles (ODDVs). The transport of these ODDVs to mucosal lymphoid tissues could be facilitated by microfold cells (M-cells) mediated transcytosis (via σ1-α2-3-linked sialic acids adherence) across gastrointestinal epithelia. PLL coating provided protection and slow-release of rhodamine 6 G (R6G), a model payload. The transport effectiveness of these ODDVs was tested on intestinal organoid monolayers in vitro. When compared with other experimental groups, the fully functionalized ODDV system (with PLL-σ1) demonstrated two significant advantages: a significantly higher transport efficiency (198% over blank control at 48 h); and protection of payloads which led to both better transport efficiency and extended-release of payloads (61% over uncoated carriers at 48 h). In addition, it was shown that the M cell presence in intestinal organoid monolayers (modulated by Rank L stimulation) was a determining factor on the transport efficiency of the ODDVs: more M-cells (induced by higher Rank L) in the organoid monolayers led to higher transport efficiency for ODDV-delivered model payload (R6G). The fully functionalized ODDVs showed great potential as effective oral delivery vehicles for drugs and vaccines.

5.
bioRxiv ; 2023 May 26.
Artículo en Inglés | MEDLINE | ID: mdl-37292944

RESUMEN

Mammalian orthoreovirus (MRV) is a prototypic member of the Spinareoviridae family and has ten double-stranded RNA segments. One copy of each segment must be faithfully packaged into the mature virion, and prior literature suggests that nucleotides (nts) at the terminal ends of each gene likely facilitate their packaging. However, little is known about the precise packaging sequences required or how the packaging process is coordinated. Using a novel approach, we have determined that 200 nts at each terminus, inclusive of untranslated regions (UTR) and parts of the open reading frame (ORF), are sufficient for packaging each S gene segment (S1-S4) individually and together into replicating virus. Further, we mapped the minimal sequences required for packaging the S1 gene segment to 25 5' nts and 50 3' nts. The S1 UTRs alone are not sufficient, but are necessary for packaging, as mutations of the 5' or 3' UTRs led to a complete loss of virus recovery. Using a second novel assay, we determined that 50 5'nts and 50 3' nts of S1 are sufficient to package a non-viral gene segment into MRV. The 5' and 3' termini of the S1 gene are predicted to form a panhandle structure and specific mutations within the predicted stem of the panhandle region led to a significant decrease in viral recovery. Additionally, mutation of six nts that are conserved in the three major serotypes of MRV and are predicted to form an unpaired loop in the S1 3'UTR, led to a complete loss of viral recovery. Overall, our data provide strong experimental proof that MRV packaging signals lie at the terminal ends of the S gene segments and offer support that the sequence requirements for efficient packaging of the S1 segment include a predicted panhandle structure and specific sequences within an unpaired loop in the 3' UTR.

6.
bioRxiv ; 2023 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-37214868

RESUMEN

Mammalian orthoreovirus (MRV) is a clinically benign oncolytic virus which has been investigated for use in multiple cancer types, including breast cancer (BC). In human clinical trials, MRV has been shown to be safe, and multiple BC patients have shown partial responses to intratumoral and intravenous virus delivery. Combination therapies inclusive of MRV and current FDA approved BC chemotherapies are being investigated to target metastatic, early BC, and triple negative BC. Though MRV is being tested clinically, we still do not fully understand the highly variable patient responses to MRV therapy. One of the most aggressive BC subtypes is HER2+ BC, in which human epidermal growth factor receptor 2 (HER2) is dysregulated, resulting in increased growth, survival, and metastasis of cancer cells. FDA approved therapies, trastuzumab and pertuzumab, target HER2 to prevent signaling of the phosphoinositide 3-kinase (PI3K) pathway. However, recent findings show that accumulation of hypoxia inducible factor-1 alpha (HIF-1α) in HER2+ BC cells contributes to trastuzumab resistance. In this work, we provide evidence that MRV infects, replicates in, and kills HER2 overexpressing cells. MRV infection is also found to have variable effects on signaling pathways that activate or are activated by HER2 expression. Finally, we show that MRV reduces HIF-1α accumulation in all the cell lines tested, including a HER2+ BC cell line. These studies provide further evidence that MRV holds promise for use in conjunction with trastuzumab to treat HER2+ BC patients.

7.
Virology ; 558: 38-48, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33721728

RESUMEN

Mammalian orthoreovirus (MRV) is a safe and effective cancer killing virus that has completed Phase I-III clinical trials against numerous cancer types. While many patients experience benefit from MRV therapy, pre-defined set points necessary for FDA approval have not been reached. Therefore, additional research into MRV biology and the effect of viral therapy on different tumor genetic subtypes and microenvironments is necessary to identify tumors most amenable to MRV virotherapy. In this work we analyzed the stage of viral infection necessary to inhibit HIF-1α, an aggressive cancer activator induced by hypoxia. We demonstrated that two viral capsid proteins were not necessary and that a step parallel with virus core movement across the endosomal membrane was required for this inhibition. Altogether, this work clarifies the mechanisms of MRV-induced HIF-1α inhibition and provides biological relevance for using MRV to inhibit the devastating effects of tumor hypoxia.


Asunto(s)
Subunidad alfa del Factor 1 Inducible por Hipoxia/antagonistas & inhibidores , Viroterapia Oncolítica , Orthoreovirus de los Mamíferos/fisiología , Neoplasias de la Próstata , Microambiente Tumoral/fisiología , Línea Celular Tumoral , Humanos , Subunidad alfa del Factor 1 Inducible por Hipoxia/análisis , Masculino , Hipoxia Tumoral
8.
Viruses ; 13(2)2021 01 28.
Artículo en Inglés | MEDLINE | ID: mdl-33525628

RESUMEN

Cells are continually exposed to stressful events, which are overcome by the activation of a number of genetic pathways. The integrated stress response (ISR) is a large component of the overall cellular response to stress, which ultimately functions through the phosphorylation of the alpha subunit of eukaryotic initiation factor-2 (eIF2α) to inhibit the energy-taxing process of translation. This response is instrumental in the inhibition of viral infection and contributes to evolution in viruses. Mammalian orthoreovirus (MRV), an oncolytic virus that has shown promise in over 30 phase I-III clinical trials, has been shown to induce multiple arms within the ISR pathway, but it successfully evades, modulates, or subverts each cellular attempt to inhibit viral translation. MRV has not yet received Food and Drug Administration (FDA) approval for general use in the clinic; therefore, researchers continue to study virus interactions with host cells to identify circumstances where MRV effectiveness in tumor killing can be improved. In this review, we will discuss the ISR, MRV modulation of the ISR, and discuss ways in which MRV interaction with the ISR may increase the effectiveness of cancer therapeutics whose modes of action are altered by the ISR.


Asunto(s)
Virus Oncolíticos/fisiología , Orthoreovirus de los Mamíferos/fisiología , Infecciones por Reoviridae/virología , Estrés Fisiológico , Factor 2 Eucariótico de Iniciación/metabolismo , Humanos , Viroterapia Oncolítica , Fosforilación , Biosíntesis de Proteínas , Caperuzas de ARN/metabolismo , Infecciones por Reoviridae/metabolismo
9.
Nanoscale ; 12(30): 16339-16347, 2020 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-32725029

RESUMEN

Compared with subcutaneous or intramuscular routes for vaccination, vaccine delivery via the gastrointestinal mucosa has tremendous potential as it is easy to administer and pain-free. Robust immune responses can be triggered successfully once the vaccine carrying an antigen reaches the mucosal associated lymphoid sites (e.g., Peyer's patches). However, the absence of an efficient delivery method has always been an issue for successful oral vaccine development. In our study, inspired by mammalian orthoreovirus (MRV) transport into the gut mucosal lymphoid tissue via Microfold cells (M cells), artificial virus-like nanocarriers (AVNs), consisting of gold nanocages functionalized with the σ1 protein from mammalian reovirus (MRV), were tested as an effective oral vaccine delivery vehicle targeting M cells. AVNs were shown to have a significantly higher transport compared to other experimental groups across mouse organoid monolayers containing M cells. These findings suggest that AVNs have the potential to be an M cell-specific oral vaccine/drug delivery vehicle.


Asunto(s)
Ganglios Linfáticos Agregados , Vacunas , Animales , Antígenos , Mucosa Intestinal , Ratones
10.
Pathogens ; 8(1)2019 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-30823456

RESUMEN

Many plant viral RNA genomes lack a 5' cap, and instead are translated via a cap-independent translation element (CITE) in the 3' untranslated region (UTR). The panicum mosaic virus-like CITE (PTE), found in many plant viral RNAs, binds and requires the cap-binding translation initiation factor eIF4E to facilitate translation. eIF4E is structurally conserved between plants and animals, so we tested cap-independent translation efficiency of PTEs of nine plant viruses in plant and mammalian systems. The PTE from thin paspalum asymptomatic virus (TPAV) facilitated efficient cap-independent translation in wheat germ extract, rabbit reticulocyte lysate, HeLa cell lysate, and in oat and mammalian (BHK) cells. Human eIF4E bound the TPAV PTE but not a PTE that did not stimulate cap-independent translation in mammalian extracts or cells. Selective 2'-hydroxyl acylation analyzed by primer extension (SHAPE) footprinting revealed that both human and wheat eIF4E protected the conserved guanosine (G)-rich domain in the TPAV PTE pseudoknot. The central G plays a key role, as it was found to be required for translation and protection from SHAPE modification by eIF4E. These results provide insight on how plant viruses gain access to the host's translational machinery, an essential step in infection, and raise the possibility that similar PTE-like mechanisms may exist in mRNAs of mammals or their viruses.

11.
Nat Microbiol ; 3(4): 400-401, 2018 04.
Artículo en Inglés | MEDLINE | ID: mdl-29588535
12.
J Virol ; 91(22)2017 11 15.
Artículo en Inglés | MEDLINE | ID: mdl-28878073

RESUMEN

Within infected host cells, mammalian orthoreovirus (MRV) forms viral factories (VFs), which are sites of viral transcription, translation, assembly, and replication. The MRV nonstructural protein µNS comprises the structural matrix of VFs and is involved in recruiting other viral proteins to VF structures. Previous attempts have been made to visualize VF dynamics in live cells, but due to current limitations in recovery of replicating reoviruses carrying large fluorescent protein tags, researchers have been unable to directly assess VF dynamics from virus-produced µNS. We set out to develop a method to overcome this obstacle by utilizing the 6-amino-acid (CCPGCC) tetracysteine (TC) tag and FlAsH-EDT2 reagent. The TC tag was introduced into eight sites throughout µNS, and the capacity of the TC-µNS fusion proteins to form virus factory-like (VFL) structures and colocalize with virus proteins was characterized. Insertion of the TC tag interfered with recombinant virus rescue in six of the eight mutants, likely as a result of loss of VF formation or important virus protein interactions. However, two recombinant (r)TC-µNS viruses were rescued and VF formation, colocalization with associating virus proteins, and characterization of virus replication were subsequently examined. Furthermore, the rTC-µNS viruses were utilized to infect cells and examine VF dynamics using live-cell microscopy. These experiments demonstrate active VF movement with fusion events as well as transient interactions between individual VFs and demonstrate the importance of microtubule stability for VF fusion during MRV infection. This work provides important groundwork for future in-depth studies of VF dynamics and host cell interactions.IMPORTANCE MRV has historically been used as a model to study the double-stranded RNA (dsRNA) Reoviridae family, the members of which infect and cause disease in humans, animals, and plants. During infection, MRV forms VFs that play a critical role in virus infection but remain to be fully characterized. To study VFs, researchers have focused on visualizing the nonstructural protein µNS, which forms the VF matrix. This work provides the first evidence of recovery of replicating reoviruses in which VFs can be labeled in live cells via introduction of a TC tag into the µNS open reading frame. Characterization of each recombinant reovirus sheds light on µNS interactions with viral proteins. Moreover, utilizing the TC-labeling FlAsH-EDT2 biarsenical reagent to visualize VFs, evidence is provided of dynamic VF movement and interactions at least partially dependent on intact microtubules.


Asunto(s)
Proteínas de la Cápside/metabolismo , Exosomas/virología , Orthoreovirus de los Mamíferos/fisiología , ARN Viral/metabolismo , Replicación Viral/fisiología , Anticuerpos Monoclonales de Origen Murino/química , Anticuerpos Antivirales/química , Proteínas de la Cápside/genética , Línea Celular , Exosomas/genética , Exosomas/metabolismo , Humanos , ARN Viral/genética
13.
J Virol ; 91(21)2017 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-28794026

RESUMEN

Mammalian orthoreovirus (MRV) infection induces phosphorylation of translation initiation factor eIF2α, which promotes the formation of discrete cytoplasmic inclusions, termed stress granules (SGs). SGs are emerging as a component of the innate immune response to virus infection, and modulation of SG assembly is a common mechanism employed by viruses to counter this antiviral response. We previously showed that MRV infection induces SGs early and then interferes with SG formation as infection proceeds. In this work, we found that SG-associated proteins localized to the periphery of virus-encoded cytoplasmic structures, termed virus factories (VFs), where viral transcription, translation, and replication occur. The localization of SG proteins to VFs was dependent on polysome dissociation and occurred via association of the SG effector protein, Ras-GAP SH3-binding protein 1 (G3BP1), with the MRV nonstructural protein σNS, which localizes to VFs via association with VF nucleating protein, µNS. Deletion analysis of the σNS RNA binding domain and G3BP1 RNA (RRM) and ribosomal (RGG) binding domains showed that σNS association and VF localization phenotypes of G3BP1 do not occur solely through RNA or ribosomal binding but require both the RRM and RGG domains of G3BP1 for maximal viral-factory-like structure (VFL) localization and σNS association. Coexpression of σNS and µNS resulted in disruption of normal SG puncta, and in cells lacking G3BP1, MRV replication was enhanced in a manner correlating with strain-dependent induction of host translation shutoff. These results suggest that σNS association with G3BP1 and relocalization of G3BP1 to the VF periphery play roles in SG disruption to facilitate MRV replication in the host translational shutoff environment.IMPORTANCE SGs and SG effector proteins have emerged as important, yet poorly understood, players in the host's innate immune response to virus infection. MRV infection induces SGs early during infection that are dispersed and/or prevented from forming during late stages of infection despite continued activation of the eIF2α signaling pathway. Cellular and viral components involved in disruption of SGs during late stages of MRV infection remain to be elucidated. This work provides evidence that MRV disruption of SGs may be facilitated by association of the MRV nonstructural protein σNS with the major SG effector protein G3BP1 and subsequent localization of G3BP1 and other SG-associated proteins around the peripheries of virus-encoded factories, interrupting the normal formation of SGs. Our findings also reveal the importance of G3BP1 as an inhibitor of MRV replication during infection for the first time.

14.
Vet Microbiol ; 191: 35-43, 2016 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-27374905

RESUMEN

The increasing diversity of influenza strains circulating in swine herds escalates the potential for the emergence of novel pandemic viruses and highlights the need for swift development of new vaccines. Baculovirus has proven to be a flexible platform for the generation of recombinant forms of hemagglutinin (HA) including subunit, VLP-displayed, and baculovirus-displayed antigens. These presentations have been shown to be efficacious in mouse, chicken, and ferret models but little is known about their immunogenicity in pigs. To assess the utility of these HA presentations in swine, Baculovirus constructs expressing HA fused to swine IgG2a Fc, displayed in a FeLV gag VLP, or displayed in the baculoviral envelope were generated. Vaccines formulated with these antigens wer The e administered to groups of pigs who were subsequently challenged with H1α cluster H1N1 swine influenza virus (SIV) A/Swine/Indiana/1726/88. Our results demonstrate that vaccination with any of these three vaccines elicits robust hemagglutinin inhibition titers in the serum and decreased the severity of SIV-associated lung lesions after challenge when compared to placebo-vaccinated controls. In addition, the number of pigs with virus detected in the lungs and nasal passages was reduced. Taken together, the results demonstrate that these recombinant approaches expressed with the baculovirus expression vector system may be viable options for development of SIV vaccines for swine.


Asunto(s)
Glicoproteínas Hemaglutininas del Virus de la Influenza/inmunología , Subtipo H1N1 del Virus de la Influenza A , Vacunas contra la Influenza/normas , Infecciones por Orthomyxoviridae/veterinaria , Enfermedades de los Porcinos/prevención & control , Animales , Anticuerpos Antivirales/sangre , Baculoviridae/genética , Baculoviridae/inmunología , Línea Celular , Subtipo H1N1 del Virus de la Influenza A/inmunología , Vacunas contra la Influenza/inmunología , Pulmón/virología , Nariz/virología , Infecciones por Orthomyxoviridae/inmunología , Infecciones por Orthomyxoviridae/patología , Infecciones por Orthomyxoviridae/prevención & control , Distribución Aleatoria , Porcinos , Enfermedades de los Porcinos/patología , Enfermedades de los Porcinos/virología , Vacunas de Subunidad/normas , Vacunas Sintéticas/normas
15.
Virology ; 485: 153-61, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26264969

RESUMEN

As prostate tumor cell growth depends on hormones, androgen ablation is an effective therapy for prostate cancer (PCa). However, progression of PCa cells to androgen independent growth (castrate resistant prostate cancer, CRPC) results in relapse and mortality. Hypoxia, a microenvironment of low oxygen that modifies the activity of PCa regulatory proteins including the androgen receptor (AR), plays a critical role in progression to CRPC. Therapies targeting hypoxia and the AR may lengthen the time to CRPC progression thereby increasing survival time of PCa patients. Mammalian Orthoreovirus (MRV) has shown promise for the treatment of prostate tumors in vitro and in vivo. In this study, we found that MRV infection induces downregulation of proteins implicated in CRPC progression, interferes with hypoxia-induced AR activity, and induces apoptosis in androgen dependent cells. This suggests MRV possesses traits that could be exploited to create novel therapies for the inhibition of progression to CRPC.


Asunto(s)
Regulación Neoplásica de la Expresión Génica , Virus Oncolíticos/genética , Orthoreovirus de los Mamíferos/genética , Próstata/virología , Receptores Androgénicos/genética , Andrógenos/metabolismo , Apoptosis/genética , Hipoxia de la Célula , Línea Celular Tumoral , Humanos , Calicreínas/genética , Calicreínas/metabolismo , Masculino , Viroterapia Oncolítica/métodos , Virus Oncolíticos/metabolismo , Orthoreovirus de los Mamíferos/metabolismo , Próstata/metabolismo , Próstata/patología , Antígeno Prostático Específico/genética , Antígeno Prostático Específico/metabolismo , Proteínas Proto-Oncogénicas c-akt/genética , Proteínas Proto-Oncogénicas c-akt/metabolismo , Receptores Androgénicos/metabolismo , Transducción de Señal
16.
Virology ; 481: 51-62, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25768891

RESUMEN

The membrane insertion and topology of nonstructural protein 2 (nsp2) of porcine reproductive and respiratory syndrome virus (PRRSV) strain VR-2332 was assessed using a cell free translation system in the presence or absence of artificial membranes. Expression of PRRSV nsp2 in the absence of all other viral factors resulted in the genesis of both full-length nsp2 as well as a select number of C-terminal nsp2 isoforms. Addition of membranes to the translation stabilized the translation reaction, resulting in predominantly full-length nsp2 as assessed by immunoprecipitation. Analysis further showed full-length nsp2 strongly associates with membranes, along with two additional large nsp2 isoforms. Membrane integration of full-length nsp2 was confirmed through high-speed density fractionation, protection from protease digestion, and immunoprecipitation. The results demonstrated that nsp2 integrated into the membranes with an unexpected topology, where the amino (N)-terminal (cytoplasmic) and C-terminal (luminal) domains were orientated on opposite sides of the membrane surface.


Asunto(s)
Membrana Celular/virología , Síndrome Respiratorio y de la Reproducción Porcina/virología , Virus del Síndrome Respiratorio y Reproductivo Porcino/metabolismo , Proteínas no Estructurales Virales/química , Proteínas no Estructurales Virales/metabolismo , Animales , Línea Celular , Virus del Síndrome Respiratorio y Reproductivo Porcino/química , Virus del Síndrome Respiratorio y Reproductivo Porcino/genética , Isoformas de Proteínas/química , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Estructura Terciaria de Proteína , Porcinos , Proteínas no Estructurales Virales/genética
17.
Oncotarget ; 5(2): 561-74, 2014 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-24504474

RESUMEN

Hypoxia has emerged as one of the most important drivers of tumor aggression, metastasis, and poor clinical outcome in many cancers.In prostate cancer (PCa), hypoxia has been strongly correlated to biochemical failure and local recurrence. However, current PCa treatment options do not address hypoxic cells highlighting a critical gap in existing therapies and the need for development of therapies that target hypoxic prostate tumor cells. Mammalian orthoreovirus (MRV) is an oncolytic virus that targets tumor cells over normal cells which has been shown to be safe and effective against many cancers in vitro, in animal models, and in human clinical trials. We found that MRVinfects and replicates in hypoxic prostate tumor cells to levels comparable to normoxic cells leading to apoptosis and cell death. In addition, the regulatory subunit (HIF-1α) of the master transcriptional regulator of hypoxia, HIF-1, was significantly downregulated in infected cells. HIF-1α downregulation was found to occur via ubiquitin-dependent proteasome-mediated degradation and translational inhibition. Virus-mediated HIF-1α degradation required the HIF-1α PAS domain and expression of the receptor for activated kinase C (RACK1) protein. These data provide evidence that MRV may be a viable therapeutic option for targeting hypoxic cells and HIF-1α in PCa.


Asunto(s)
Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Neoplasias de la Próstata/metabolismo , Neoplasias de la Próstata/virología , Infecciones por Reoviridae/metabolismo , Factores de Transcripción/genética , Apoptosis/fisiología , Hipoxia de la Célula/fisiología , Progresión de la Enfermedad , Regulación hacia Abajo , Humanos , Masculino , Recurrencia Local de Neoplasia/metabolismo , Recurrencia Local de Neoplasia/patología , Recurrencia Local de Neoplasia/virología , Orthoreovirus de los Mamíferos , Neoplasias de la Próstata/patología , Infecciones por Reoviridae/patología , Transfección
18.
Virology ; 448: 133-45, 2014 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-24314644

RESUMEN

At early times in Mammalian Orthoreovirus (MRV) infection, cytoplasmic inclusions termed stress granules (SGs) are formed as a component of the innate immune response, however, at later times they are no longer present despite continued immune signaling. To investigate the roles of MRV proteins in SG modulation we examined non-structural protein µNS localization relative to SGs in infected and transfected cells. Using a series of mutant plasmids, we mapped the necessary µNS residues for SG localization to amino acids 78 and 79. We examined the capacity of a µNS(78-79) mutant to associate with known viral protein binding partners of µNS and found that it loses association with viral core protein λ2. Finally, we show that while this mutant cannot support de novo viral replication, it is able to rescue replication following siRNA knockdown of µNS. These data suggest that µNS association with SGs, λ2, or both play roles in MRV replication.


Asunto(s)
Gránulos Citoplasmáticos/virología , Orthoreovirus Mamífero 3/metabolismo , Infecciones por Reoviridae/virología , Proteínas del Núcleo Viral/metabolismo , Proteínas no Estructurales Virales/administración & dosificación , Proteínas no Estructurales Virales/química , Replicación Viral , Secuencias de Aminoácidos , Animales , Línea Celular , Humanos , Orthoreovirus Mamífero 3/química , Orthoreovirus Mamífero 3/genética , Unión Proteica , Proteínas del Núcleo Viral/genética , Proteínas no Estructurales Virales/genética
19.
J Virol ; 87(24): 13456-65, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24089566

RESUMEN

Viral structural proteins form the critical intermediary between viral infection cycles within and between hosts, function to initiate entry, participate in immediate early viral replication steps, and are major targets for the host adaptive immune response. We report the identification of nonstructural protein 2 (nsp2) as a novel structural component of the porcine reproductive and respiratory syndrome virus (PRRSV) particle. A set of custom α-nsp2 antibodies targeting conserved epitopes within four distinct regions of nsp2 (the PLP2 protease domain [OTU], the hypervariable domain [HV], the putative transmembrane domain [TM], and the C-terminal region [C]) were obtained commercially and validated in PRRSV-infected cells. Highly purified cell-free virions of several PRRSV strains were isolated through multiple rounds of differential density gradient centrifugation and analyzed by immunoelectron microscopy (IEM) and Western blot assays using the α-nsp2 antibodies. Purified viral preparations were found to contain pleomorphic, predominantly spherical virions of uniform size (57.9 nm ± 8.1 nm diameter; n = 50), consistent with the expected size of PRRSV particles. Analysis by IEM indicated the presence of nsp2 associated with the viral particle of diverse strains of PRRSV. Western blot analysis confirmed the presence of nsp2 in purified viral samples and revealed that multiple nsp2 isoforms were associated with the virion. Finally, a recombinant PRRSV genome containing a myc-tagged nsp2 was used to generate purified virus, and these particles were also shown to harbor myc-tagged nsp2 isoforms. Together, these data identify nsp2 as a virion-associated structural PRRSV protein and reveal that nsp2 exists in or on viral particles as multiple isoforms.


Asunto(s)
Evolución Molecular , Síndrome Respiratorio y de la Reproducción Porcina/virología , Virus del Síndrome Respiratorio y Reproductivo Porcino/metabolismo , Proteínas no Estructurales Virales/metabolismo , Virión/metabolismo , Secuencia de Aminoácidos , Animales , Datos de Secuencia Molecular , Virus del Síndrome Respiratorio y Reproductivo Porcino/química , Virus del Síndrome Respiratorio y Reproductivo Porcino/clasificación , Virus del Síndrome Respiratorio y Reproductivo Porcino/genética , Isoformas de Proteínas/química , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Alineación de Secuencia , Porcinos , Proteínas no Estructurales Virales/química , Proteínas no Estructurales Virales/genética , Virión/química , Virión/clasificación , Virión/genética
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