bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Nuclear Inhibitor of NF-κB Encoded by a Poxvirus
Authors: Diel D. G. , Luo S. , Delhon G. , Peng Y. , Flores E. F. , Rock D. L. 
Published: October 2010

ABSTRACT

Poxviruses have evolved various strategies to inhibit cytoplasmic events leading to activation of the nuclear factor κB (NF-κB) signaling pathway, with individual viruses often encoding multiple NF-κB inhibitors. Here, the novel orf virus (ORFV)-encoded protein ORFV002 was shown to inhibit nuclear events regulating NF-κB transcriptional activity. ORFV002 expression in cell cultures significantly decreased wild-type-virus-, tumor necrosis factor alpha (TNF-α)-, and lipopolysaccharide (LPS)-induced NF-κB-mediated gene expression. Expression of ORFV002 in cells, while not affecting phosphorylation or nuclear translocation of NF-κB-p65, markedly decreased TNF-α- and wild-type-virus-induced acetylation of NF-κB-p65, a p300-mediated nuclear modification of NF-κB-p65 that regulates its transactivating activity. ORFV002 was shown to colocalize and interact with NF-κB-p65, and expression of ORFV002 in cell cultures resulted in a reduced interaction of NF-κB-p65 with p300, suggesting that ORFV002 interferes with NF-κB-p65/p300 association. Deletion of
ORFV002
from the OV-IA82 genome had no significant effect on ORFV pathogenesis in sheep, indicating that
ORFV002
is nonessential for virus virulence in the natural host. This represents the first description of a nuclear inhibitor of NF-κB encoded by a poxvirus.
Adenovirus Membrane Penetration Activates the NLRP3 Inflammasome
Authors: Barlan A. U. , Griffin T. M. , Mcguire K. A. , Wiethoff C. M. 
Published: October 2010

ABSTRACTAdenovirus type 5 (Ad5) infection of macrophages results in rapid secretion of interleukin-1β (IL-1β) and is dependent on the inflammasome components NLRP3 and ASC and the catalytic activity of caspase-1. Using lentivirus-expressed short hairpin RNA (shRNA) and competitive inhibitors, we show that Ad-induced IL-1β release is dependent upon Toll-like receptor 9 (TLR9) sensing of the Ad5 double-stranded DNA (dsDNA) genome in human cell lines and primary monocyte-derived macrophages but not in mouse macrophages. Additionally, a temperature-sensitive mutant of Ad5 unable to penetrate endosomal membranes,ts1, is unable to induce IL-1β release in TLR2-primed THP-1 cells, suggesting that penetration of endosomal membranes is required for IL-1β release. Disruption of lysosomal membranes and the release of cathepsin B into the cytoplasm are required for Ad-induced NLRP3 activation. Ad5 cell entry also induces reactive oxygen species (ROS) production, and inhibitors of ROS prevent Ad-induced IL-1β release. Ad5 activation of NLRP3 also induces necrotic cell death, resulting in the release of the proinflammatory molecule HMGB1. This work further defines the mechanisms of virally induced inflammasome activation.
Characterization of Cross-Reactive CD8
+
T-Cell Recognition of HLA-A2-Restricted HIV-Gag (SLYNTVATL) and HCV-NS5b (ALYDVVSKL) Epitopes in Individuals Infected with Human Immunodeficiency and Hepatitis C Viruses
Authors: Vali Bahareh , Tohn Robert , Cohen Michael J. , Sakhdari Ali , Sheth Prameet M. , Yue Feng Yun , Wong David , Kovacs Colin , Kaul Rupert , Ostrowski Mario A. 
Published: October 2010

ABSTRACT

The immunologic mechanisms underlying the faster progression of hepatitis C virus (HCV) disease in the presence of human immunodeficiency virus (HIV) coinfection are not clearly understood. T-cell cross-reactivity between HCV and influenza virus-specific epitopes has been associated with rapid progression of HCV disease (S. Urbani, B. Amadei, P. Fisicaro, M. Pilli, G. Missale, A. Bertoletti, and C. Ferrari, J. Exp. Med. 201:675-680, 2005). We asked whether T-cell cross-reactivity between HCV and HIV could exist during HCV/HIV coinfection and affect pathogenesis. Our search for amino acid sequence homology between the HCV and HIV proteomes revealed two similar HLA-A2-restricted epitopes, HIV-Gag (SLYNTVATL [HIV-SL9]) and HCV-NS5b (ALYDVVSKL [HCV-AL9]). We found that 4 out of 20 HLA-A2-positive (HLA-A2
+
) HIV-infected individuals had CD8
+
T cells that recognized both the HIV-SL9 and HCV-AL9 epitopes. However, the AL9 epitope was generally shown to be a weak agonist. Although HCV-monoinfected individuals in our study did not show AL9-specific responses, we found that about half of HCV/HIV-coinfected individuals had dual responses to both epitopes. High dual T-cell recognition among coinfected subjects was usually due to separate T-cell populations targeting each epitope, as determined by pentamer staining. The one individual demonstrating cross-reactive T cells to both epitopes showed the most advanced degree of liver disease. In coinfected individuals, we observed a positive correlation between the magnitudes of T-cell responses to both the SL9 and the AL9 epitopes, which was also positively associated with the clinical parameter of liver damage. Thus, we find that HIV infection induces T cells that can cross-react to heterologous viruses or prime for T cells that are closely related in sequence. However, the induction of cross-reactive T cells may not be associated with control of disease caused by the heterologous virus. This demonstrates that degeneracy of HIV-specific T cells may play a role in the immunopathology of HCV/HIV coinfection.
Template Recognition Mechanisms by Replicase Proteins Differ between Bipartite Positive-Strand Genomic RNAs of a Plant Virus
Authors: Iwakawa Hiro-oki , Mine Akira , Hyodo Kiwamu , An Mengnan , Kaido Masanori , Mise Kazuyuki , Okuno Tetsuro 
Published: October 2010

ABSTRACTRecognition of RNA templates by viral replicase proteins is one of the key steps in the replication process of all RNA viruses. However, the mechanisms underlying this phenomenon, including primary RNA elements that are recognized by the viral replicase proteins, are not well understood. Here, we used aptamer pulldown assays with membrane fractionation and protein-RNA coimmunoprecipitation in a cell-free viral translation/replication system to investigate how viral replicase proteins recognize the bipartite genomic RNAs of theRed clover necrotic mosaic virus(RCNMV). RCNMV replicase proteins bound specifically to a Y-shaped RNA element (YRE) located in the 3′ untranslated region (UTR) of RNA2, which also interacted with the 480-kDa replicase complexes that contain viral and host proteins. The replicase-YRE interaction recruited RNA2 to the membrane fraction. Conversely, RNA1 fragments failed to interact with the replicase proteins supplied intrans. The results of protein-RNA coimmunoprecipitation assays suggest that RNA1 interacts with the replicase proteins coupled with their translation. Thus, the initial template recognition mechanisms employed by the replicase differ between RCNMV bipartite genomic RNAs and RNA elements are primary determinants of the differential replication mechanism.
Serine-Threonine Ubiquitination Mediates Downregulation of BST-2/Tetherin and Relief of Restricted Virion Release by HIV-1 Vpu
Authors: Tokarev Andrey A. , Munguia Jason , Guatelli John C. 
Published: October 2010

ABSTRACT
The HIV-1 protein Vpu counteracts the antiviral activity of the innate restriction factor BST-2/tetherin by a mechanism that partly depends on its interaction with β-TrCP, a substrate adaptor for an SCF (Skp-Cullin 1-F box) E3 ubiquitin ligase complex. This suggests that Vpu stimulates the ubiquitination of BST-2 and that this underlies the relief of restriction. Here, we show that Vpu stimulates ubiquitination of BST-2. Mutation of all potential ubiquitination sites in the cytoplasmic domain of BST-2, including lysines, cysteines, serines, and threonines, abrogates Vpu-mediated ubiquitination. However, a serine-threonine-serine sequence specifically mediates the downregulation of BST-2 from the cell surface and the optimal relief of restricted virion release. Serine-threonine ubiquitination of BST-2 is likely part of the mechanism by which Vpu counteracts innate defenses.
Association of TRIM22 with the Type 1 Interferon Response and Viral Control during Primary HIV-1 Infection
Authors: Singh Ravesh , Gaiha Gaurav , Werner Lise , McKim Kevin , Mlisana Koleka , Luban Jeremy , Walker Bruce D. , Karim Salim S. Abdool , Brass Abraham L. , Ndung'u Thumbi 
Published: October 2010

ABSTRACT

Type 1 interferons (IFNs) induce the expression of the tripartite interaction motif (TRIM) family of E3 ligases, but the contribution of these antiviral factors to HIV pathogenesis is not completely understood. We hypothesized that the increased expression of select type 1 IFN and TRIM isoforms is associated with a significantly lower likelihood of HIV-1 acquisition and viral control during primary HIV-1 infection. We measured IFN-α, IFN-β, myxovirus resistance protein A (MxA), human TRIM5α (huTRIM5α), and TRIM22 mRNA levels in peripheral blood mononuclear cells (PBMCs) of high-risk, HIV-1-uninfected participants and HIV-1-positive study participants. Samples were available for 32 uninfected subjects and 28 infected persons, all within 1 year of infection. HIV-1-positive participants had higher levels of IFN-β (
P
= 0.0005), MxA (
P
= 0.007), and TRIM22 (
P
= 0.01) and lower levels of huTRIM5α (
P
< 0.001) than did HIV-1-negative participants. TRIM22 but not huTRIM5α correlated positively with type 1 IFN (IFN-α, IFN-β, and MxA) (all
P
< 0.0001). In a multivariate model, increased MxA expression showed a significant positive association with viral load (
P
= 0.0418). Furthermore, TRIM22 but not huTRIM5α, IFN-α, IFN-β, or MxA showed a negative correlation with plasma viral load (
P
= 0.0307) and a positive correlation with CD4
+
T-cell counts (
P
= 0.0281).
In vitro
studies revealed that HIV infection induced TRIM22 expression in PBMCs obtained from HIV-negative donors. Stable TRIM22 knockdown resulted in increased HIV-1 particle release and replication in Jurkat reporter cells. Collectively, these data suggest concordance between type 1 IFN and TRIM22 but not huTRIM5α expression in PBMCs and that TRIM22 likely acts as an antiviral effector
in vivo
.
T Cell-Mediated Protection against Lethal 2009 Pandemic H1N1 Influenza Virus Infection in a Mouse Model
Authors: Guo Hailong , Santiago Félix , Lambert Kris , Takimoto Toru , Topham David J. 
Published: October 2010

ABSTRACTGenetic mutation and reassortment of influenza virus gene segments, in particular those of hemagglutinin (HA) and neuraminidase (NA), that lead to antigenic drift and shift are the major strategies for influenza virus to escape preexisting immunity. The most recent example of such phenomena is the first pandemic of H1N1 influenza of the 21st century, which started in 2009. Cross-reactive antibodies raised against H1N1 viruses circulating before 1930 show protective activity against the 2009 pandemic virus. Cross-reactive T-cell responses can also contribute to protection, butin vivosupport of this view is lacking. To explore the protection mechanismsin vivo, we primed mice with H1 and H3 influenza virus isolates and rechallenged them with a virus derived from the 2009 H1N1 A/CA/04/09 virus, named CA/E3/09. We found that priming with influenza viruses of both H1 and H3 homo- and heterosubtypes protected against lethal CA/E3/09 virus challenge. Convalescent-phase sera from these primed mice conferred no neutralization activityin vitroand no protectionin vivo. However, T-cell depletion studies suggested that both CD4 and CD8 T cells contributed to the protection. Taken together, these results indicate that cross-reactive T cells established after initial priming with distally related viruses can be a vital component for prevention of disease and control of pandemic H1N1 influenza virus infection. Our results highlight the importance of establishing cross-reactive T-cell responses for protecting against existing or newly emerging pandemic influenza viruses.
Upregulation of CXCL10 in Human Dorsal Root Ganglia during Experimental and Natural Varicella-Zoster Virus Infection
Authors: Steain Megan , Gowrishankar Kavitha , Rodriguez Michael , Slobedman Barry , Abendroth Allison 
Published: October 2010

ABSTRACT

Varicella-zoster virus (VZV) reactivation causes herpes zoster, which is accompanied by an influx of lymphocytes into affected ganglia, but the stimulus for this infiltrate is not known. We report that VZV infection of ganglia leads to increased CXCL10 production
in vitro
, in an explant ganglion model and in naturally infected dorsal root ganglia (DRG) during herpes zoster. Lymphocytes expressing the receptor for CXCL10, CXCR3, were also observed throughout naturally infected ganglia during herpes zoster, including immediately adjacent to neurons. This study identifies VZV-induced CXCL10 as a potential driver of T lymphocyte recruitment into DRG during herpes zoster.
An In-Depth Analysis of Original Antigenic Sin in Dengue Virus Infection
Authors: Midgley Claire M. , Bajwa-Joseph Martha , Vasanawathana Sirijitt , Limpitikul Wannee , Wills Bridget , Flanagan Aleksandra , Waiyaiya Emily , Tran Hai Bac , Cowper Alison E. , Chotiyarnwon Pojchong , Grimes Jonathan M. , Yoksan Sutee , Malasit Prida , Simmons Cameron P. , Mongkolsapaya Juthathip , Screaton Gavin R. 
Published: October 2010

ABSTRACTThe evolution of dengue viruses has resulted in four antigenically similar yet distinct serotypes. Infection with one serotype likely elicits lifelong immunity to that serotype, but generally not against the other three. Secondary or sequential infections are common, as multiple viral serotypes frequently cocirculate. Dengue infection, although frequently mild, can lead to dengue hemorrhagic fever (DHF) which can be life threatening. DHF is more common in secondary dengue infections, implying a role for the adaptive immune response in the disease. There is currently much effort toward the design and implementation of a dengue vaccine but these efforts are made more difficult by the challenge of inducing durable neutralizing immunity to all four viruses. Domain 3 of the dengue virus envelope protein (ED3) has been suggested as one such candidate because it contains neutralizing epitopes and it was originally thought that relatively few cross-reactive antibodies are directed to this domain. In this study, we performed a detailed analysis of the anti-ED3 response in a cohort of patients suffering either primary or secondary dengue infections. The results show dramatic evidence of original antigenic sin in secondary infections both in terms of binding and enhancement activity. This has important implications for dengue vaccine design because heterologous boosting is likely to maintain the immunological footprint of the first vaccination. On the basis of these findings, we propose a simplein vitroenzyme-linked immunosorbent assay (ELISA) to diagnose the original dengue infection in secondary dengue cases.
Reverse Genetics Generation of Chimeric Infectious Junin/Lassa Virus Is Dependent on Interaction of Homologous Glycoprotein Stable Signal Peptide and G2 Cytoplasmic Domains
Authors: Albariño César G. , Bird Brian H. , Chakrabarti Ayan K. , Dodd Kimberly A. , White David M. , Bergeron Éric , Shrivastava-Ranjan Punya , Nichol Stuart T. 
Published: October 2010

ABSTRACT

The
Arenaviridae
are a diverse and globally distributed collection of viruses that are maintained primarily by rodent reservoirs. Junin virus (JUNV) and Lassa virus (LASV) can both cause significant outbreaks of severe and often fatal human disease throughout their respective areas of endemicity. In an effort to improve upon the existing live attenuated JUNV Candid1 vaccine, we generated a genetically homogenous stock of this virus from cDNA copies of the virus S and L segments by using a reverse genetics system. Further, these cDNAs were used in combination with LASV cDNAs to successfully generate two recombinant Candid1 JUNV/LASV chimeric viruses (via envelope glycoprotein [GPC] exchange). It was found that while the GPC extravirion domains were readily exchangeable, homologous stable signal peptide (SSP) and G2 transmembrane and cytoplasmic tail domains were essential for correct GPC maturation and production of infectious chimeric viruses. The switching of the JUNV and LASV G1/G2 ectodomains within the Candid1 vaccine background did not alter the attenuated phenotype of the vaccine strain in a lethal mouse model. These recombinant chimeric viruses shed light on the fundamental requirements of arenavirus GPC maturation and may serve as a strategy for the development of bivalent JUNV and LASV vaccine candidates.
R5 HIV
env
and Vesicular Stomatitis Virus G Protein Cooperate To Mediate Fusion to Naïve CD4
+
T Cells
Authors: Pace Matthew J. , Agosto Luis , O'Doherty Una 
Published: October 2010

ABSTRACT

Naïve CD4
4
T cells are resistant to both HIV R5
env
and vesicular stomatitis virus G protein (VSV-G)-mediated fusion. However, viral particles carrying both HIV R5
env
and VSV-G infect naïve cells by an unexplained mechanism. We show that VSV-G-pseudotyped virus cannot fuse to unstimulated cells because the viral particles cannot be endocytosed. However, virions carrying both HIV R5
env
and VSV-G can fuse because CD4 binding allows viral uptake. Our findings reveal a unique mechanism by which R5 HIV
env
and VSV-G cooperate to allow entry to naïve CD4
+
T cells, providing a tool to target naïve CD4
+
T cells with R5 HIV to study HIV coreceptor signaling and latency.
Assembly and Immunological Properties of Newcastle Disease Virus-Like Particles Containing the Respiratory Syncytial Virus F and G Proteins
Authors: McGinnes Lori W. , Gravel Kathryn A. , Finberg Robert W. , Kurt-Jones Evelyn A. , Massare Michael J. , Smith Gale , Schmidt Madelyn R. , Morrison Trudy G. 
Published: October 2010

ABSTRACT

Human respiratory syncytial virus (RSV) is a serious respiratory pathogen in infants and young children as well as elderly and immunocompromised populations. However, no RSV vaccines are available. We have explored the potential of virus-like particles (VLPs) as an RSV vaccine candidate. VLPs composed entirely of RSV proteins were produced at levels inadequate for their preparation as immunogens. However, VLPs composed of the Newcastle disease virus (NDV) nucleocapsid and membrane proteins and chimera proteins containing the ectodomains of RSV F and G proteins fused to the transmembrane and cytoplasmic domains of NDV F and HN proteins, respectively, were quantitatively prepared from avian cells. Immunization of mice with these VLPs, without adjuvant, stimulated robust, anti-RSV F and G protein antibody responses. IgG2a/IgG1 ratios were very high, suggesting predominantly T
H
1 responses. In contrast to infectious RSV immunization, neutralization antibody titers were robust and stable for 4 months. Immunization with a single dose of VLPs resulted in the complete protection of mice from RSV replication in lungs. Upon RSV intranasal challenge of VLP-immunized mice, no enhanced lung pathology was observed, in contrast to the pathology observed in mice immunized with formalin-inactivated RSV. These results suggest that these VLPs are effective RSV vaccines in mice, in contrast to other nonreplicating RSV vaccine candidates.
Cytomegalovirus MicroRNA Expression Is Tissue Specific and Is Associated with Persistence
Authors: Meyer Christine , Grey Finn , Kreklywich Craig N. , Andoh Takeshi F. , Tirabassi Rebecca S. , Orloff Susan L. , Streblow Daniel N. 
Published: October 2010

ABSTRACTMicroRNAs (miRNAs) are a class of small noncoding RNAs involved in posttranscriptional regulation. miRNAs are utilized in organisms ranging from plants to higher mammals, and data have shown that DNA viruses also use this method for host and viral gene regulation. Here, we report the sequencing of the small RNAs in rat cytomegalovirus (RCMV)-infected fibroblasts and persistently infected salivary glands. We identified 24 unique miRNAs that mapped to hairpin structures found within the viral genome. While most miRNAs were detected in both samples, four were detected exclusively in the infected fibroblasts and two were specific for the infected salivary glands. The RCMV miRNAs are distributed across the viral genome on both the positive and negative strands, with clusters of miRNAs at a number of locations, including near viral genesr1andr111. The RCMV miRNAs have a genomic positional orientation similar to that of the miRNAs described for mouse cytomegalovirus, but they do not share any substantial sequence conservation. Similar to other reported miRNAs, the RCMV miRNAs had considerable variation at their 3′ and 5′ ends. Interestingly, we found a number of specific examples of differential isoform usage between the fibroblast and salivary gland samples. We determined by real-time PCR that expression of the RCMV miRNA miR-r111.1-2 is highly expressed in the salivary glands and that miR-R87-1 is expressed in most tissues during the acute infection phase. Our study identified the miRNAs expressed by RCMVin vitroandin vivoand demonstrated that expression is tissue specific and associated with a stage of viral infection.
Reovirus Infection or Ectopic Expression of Outer Capsid Protein μ1 Induces Apoptosis Independently of the Cellular Proapoptotic Proteins Bax and Bak
Authors: Wisniewski Meagan L. , Werner Brenda G. , Hom Louis G. , Anguish Lynne J. , Coffey Caroline M. , Parker John S. L. 
Published: October 2010

ABSTRACT

Mammalian orthoreoviruses induce apoptosis
in vivo
and
in vitro
; however, the specific mechanism by which apoptosis is induced is not fully understood. Recent studies have indicated that the reovirus outer capsid protein μ1 is the primary determinant of reovirus-induced apoptosis. Ectopically expressed μ1 induces apoptosis and localizes to intracellular membranes. Here we report that ectopic expression of μ1 activated both the extrinsic and intrinsic apoptotic pathways with activation of initiator caspases-8 and -9 and downstream effector caspase-3. Activation of both pathways was required for μ1-induced apoptosis, as specific inhibition of either caspase-8 or caspase-9 abolished downstream effector caspase-3 activation. Similar to reovirus infection, ectopic expression of μ1 caused release into the cytosol of cytochrome
c
and smac/DIABLO from the mitochondrial intermembrane space. Pancaspase inhibitors did not prevent cytochrome
c
release from cells expressing μ1, indicating that caspases were not required. Additionally, μ1- or reovirus-induced release of cytochrome
c
occurred efficiently in Bax
−/−
Bak
−/−
mouse embryonic fibroblasts (MEFs). Finally, we found that reovirus-induced apoptosis occurred in Bax
−/−
Bak
−/−
MEFs, indicating that reovirus-induced apoptosis occurs independently of the proapoptotic Bcl-2 family members Bax and Bak.