bluuebunny/crossref_metadata_2025_split huggingface dataset:
DC-SIGN and L-SIGN Are Attachment Factors That Promote Infection of Target Cells by Human Metapneumovirus in the Presence or Absence of Cellular Glycosaminoglycans
Authors: Gillespie Leah , Gerstenberg Kathleen , Ana-Sosa-Batiz Fernanda , Parsons Matthew S. , Farrukee Rubaiyea , Krabbe Mark , Spann Kirsten , Brooks Andrew G. , Londrigan Sarah L. , Reading Patrick C. 
Published: June 2016

ABSTRACTIt is well established that glycosaminoglycans (GAGs) function as attachment factors for human metapneumovirus (HMPV), concentrating virions at the cell surface to promote interaction with other receptors for virus entry and infection. There is increasing evidence to suggest that multiple receptors may exhibit the capacity to promote infectious entry of HMPV into host cells; however, definitive identification of specific transmembrane receptors for HMPV attachment and entry is complicated by the widespread expression of cell surface GAGs. pgsA745 Chinese hamster ovary (CHO) cells are deficient in the expression of cell surface GAGs and resistant to HMPV infection. Here, we demonstrate that the expression of the Ca2+-dependent C-type lectin receptor (CLR) DC-SIGN (CD209L) or L-SIGN (CD209L) rendered pgsA745 cells permissive to HMPV infection. Unlike infection of parental CHO cells, HMPV infection of pgsA745 cells expressing DC-SIGN or L-SIGN was dynamin dependent and inhibited by mannan but not by pretreatment with bacterial heparinase. Parental CHO cells expressing DC-SIGN/L-SIGN also showed enhanced susceptibility to dynamin-dependent HMPV infection, confirming that CLRs can promote HMPV infection in the presence or absence of GAGs. Comparison of pgsA745 cells expressing wild-type and endocytosis-defective mutants of DC-SIGN/L-SIGN indicated that the endocytic function of CLRs was not essential but could contribute to HMPV infection of GAG-deficient cells. Together, these studies confirm a role for CLRs as attachment factors and entry receptors for HMPV infection. Moreover, they define an experimental system that can be exploited to identify transmembrane receptors and entry pathways where permissivity to HMPV infection can be rescued following the expression of a single cell surface receptor.IMPORTANCEOn the surface of CHO cells, glycosaminoglycans (GAGs) function as the major attachment factor for human metapneumoviruses (HMPV), promoting dynamin-independent infection. Consistent with this, GAG-deficient pgaA745 CHO cells are resistant to HMPV. However, expression of DC-SIGN or L-SIGN rendered pgsA745 cells permissive to dynamin-dependent infection by HMPV, although the endocytic function of DC-SIGN/L-SIGN was not essential for, but could contribute to, enhanced infection. These studies provide direct evidence implicating DC-SIGN/L-SIGN as an alternate attachment factor for HMPV attachment, promoting dynamin-dependent infection via other unknown receptors in the absence of GAGs. Moreover, we describe a unique experimental system for the assessment of putative attachment and entry receptors for HMPV.
Analysis of
cis
and
trans
Requirements for DNA Replication at the Right-End Hairpin of the Human Bocavirus 1 Genome
Authors: Shen Weiran , Deng Xuefeng , Zou Wei , Engelhardt John F. , Yan Ziying , Qiu Jianming 
Published: June 2016

ABSTRACT

Parvoviruses are single-stranded DNA viruses that use the palindromic structures at the ends of the viral genome for their replication. The mechanism of parvovirus replication has been studied mostly in the dependoparvovirus adeno-associated virus 2 (AAV2) and the protoparvovirus minute virus of mice (MVM). Here, we used human bocavirus 1 (HBoV1) to understand the replication mechanism of bocaparvovirus. HBoV1 is pathogenic to humans, causing acute respiratory tract infections, especially in young children under 2 years old. By using the duplex replicative form of the HBoV1 genome in human embryonic kidney 293 (HEK293) cells, we identified the HBoV1 minimal replication origin at the right-end hairpin (OriR). Mutagenesis analyses confirmed the putative NS1 binding and nicking sites within the OriR. Of note, unlike the large nonstructural protein (Rep78/68 or NS1) of other parvoviruses, HBoV1 NS1 did not specifically bind OriR
in vitro
, indicating that other viral and cellular components or the oligomerization of NS1 is required for NS1 binding to the OriR.
In vivo
studies demonstrated that residues responsible for NS1 binding and nicking are within the origin-binding domain. Further analysis identified that the small nonstructural protein NP1 is required for HBoV1 DNA replication at OriR. NP1 and other viral nonstructural proteins (NS1 to NS4) colocalized within the viral DNA replication centers in both OriR-transfected cells and virus-infected cells, highlighting a direct involvement of NP1 in viral DNA replication at OriR. Overall, our study revealed the characteristics of HBoV1 DNA replication at OriR, suggesting novel characteristics of autonomous parvovirus DNA replication.

IMPORTANCE
Human bocavirus 1 (HBoV1) causes acute respiratory tract infections in young children. The duplex HBoV1 genome replicates in HEK293 cells and produces progeny virions that are infectious in well-differentiated airway epithelial cells. A recombinant AAV2 vector pseudotyped with an HBoV1 capsid has been developed to efficiently deliver the cystic fibrosis transmembrane conductance regulator gene to human airway epithelia. Here, we identified both
cis
-acting elements and
trans
-acting proteins that are required for HBoV1 DNA replication at the right-end hairpin in HEK293 cells. We localized the minimal replication origin, which contains both NS1 nicking and binding sites, to a 46-nucleotide sequence in the right-end hairpin. The identification of these essential elements of HBoV1 DNA replication acting both in
cis
and in
trans
will provide guidance to develop antiviral strategies targeting viral DNA replication at the right-end hairpin and to design next-generation recombinant HBoV1 vectors, a promising tool for gene therapy of lung diseases.
ICAM-1 Binding Rhinoviruses A89 and B14 Uncoat in Different Endosomal Compartments
Authors: Conzemius Rick , Ganjian Haleh , Blaas Dieter , Fuchs Renate 
Published: June 2016

ABSTRACT
Human rhinovirus A89 (HRV-A89) and HRV-B14 bind to and are internalized by intercellular adhesion molecule 1 (ICAM-1); as demonstrated earlier, the RNA genome of HRV-B14 penetrates into the cytoplasm from endosomal compartments of the lysosomal pathway. Here, we show by immunofluorescence microscopy that HRV-A89 but not HRV-B14 colocalizes with transferrin in the endocytic recycling compartment (ERC). Applying drugs differentially interfering with endosomal recycling and with the pathway to lysosomes, we demonstrate that these two major-group HRVs productively uncoat in distinct endosomal compartments. Overexpression of constitutively active (Rab11-GTP) and dominant negative (Rab11-GDP) mutants revealed that uncoating of HRV-A89 depends on functional Rab11. Thus, two ICAM-1 binding HRVs are routed into distinct endosomal compartments for productive uncoating.

IMPORTANCE
Based on similarity of their RNA genomic sequences, the more than 150 currently known common cold virus serotypes were classified as species A, B, and C. The majority of HRV-A viruses and all HRV-B viruses use ICAM-1 for cell attachment and entry. Our results highlight important differences of two ICAM-1 binding HRVs with respect to their intracellular trafficking and productive uncoating; they demonstrate that serotypes belonging to species A and B, but entering the cell via the same receptors, direct the endocytosis machinery to ferry them along distinct pathways toward different endocytic compartments for uncoating.
Mutagenesis of Paramyxovirus Hemagglutinin-Neuraminidase Membrane-Proximal Stalk Region Influences Stability, Receptor Binding, and Neuraminidase Activity
Authors: Adu-Gyamfi Emmanuel , Kim Lori S. , Jardetzky Theodore S. , Lamb Robert A. 
Published: June 2016

ABSTRACT

Paramyxoviridae
consist of a large family of enveloped, negative-sense, nonsegmented single-stranded RNA viruses that account for a significant number of human and animal diseases. The fusion process for nearly all paramyxoviruses involves the mixing of the host cell plasma membrane and the virus envelope in a pH-independent fashion. Fusion is orchestrated via the concerted action of two surface glycoproteins: an attachment protein called hemagglutinin-neuraminidase (HN [also called H or G depending on virus type and substrate]), which acts as a receptor binding protein, and a fusion (F) protein, which undergoes a major irreversible refolding process to merge the two membranes. Recent biochemical evidence suggests that receptor binding by HN is dispensable for cell-cell fusion. However, factors that influence the stability and/or conformation of the HN 4-helix bundle (4HB) stalk have not been studied. Here, we used oxidative cross-linking as well as functional assays to investigate the role of the structurally unresolved membrane-proximal stalk region (MPSR) (residues 37 to 58) of HN in the context of headless and full-length HN membrane fusion promotion. Our data suggest that the receptor binding head serves to stabilize the stalk to regulate fusion. Moreover, we found that the MPSR of HN modulates receptor binding and neuraminidase activity without a corresponding regulation of F triggering.

IMPORTANCE
Paramyxoviruses require two viral membrane glycoproteins, the attachment protein variously called HN, H, or G and the fusion protein (F), to couple host receptor recognition to virus-cell fusion. The HN protein has a globular head that is attached to a membrane-anchored flexible stalk of ∼80 residues and has three activities: receptor binding, neuraminidase, and fusion activation. In this report, we have identified the functional significance of the membrane-proximal stalk region (MPSR) (HN, residues 37 to 56) of the paramyxovirus parainfluenza virus (PIV5), a region of the HN stalk that has not had its structure determined by X-ray crystallography. Our data suggest that the MPSR influences receptor binding and neuraminidase activity via an indirect mechanism. Moreover, the receptor binding head group stabilizes the 4HB stalk as part of the general mechanism to fine-tune F-activation.
Herpes Simplex Virus 2 Virion Host Shutoff Endoribonuclease Activity Is Required To Disrupt Stress Granule Formation
Authors: Finnen Renée L. , Zhu Mingzhao , Li Jing , Romo Daniel , Banfield Bruce W. 
Published: June 2016

ABSTRACT
We previously established that cells infected with herpes simplex virus 2 (HSV-2) are disrupted in their ability to form stress granules (SGs) in response to oxidative stress and that this disruption is mediated by virion host shutoff protein (vhs), a virion-associated endoribonuclease. Here, we test the requirement for vhs endoribonuclease activity in disruption of SG formation. We analyzed the ability of HSV-2 vhs carrying the point mutation D215N, which ablates its endoribonuclease activity, to disrupt SG formation in both transfected and infected cells. We present evidence that ablation of vhs endoribonuclease activity results in defects in vhs-mediated disruption of SG formation. Furthermore, we demonstrate that preformed SGs can be disassembled by HSV-2 infection in a manner that requires vhs endoribonuclease activity and that, befitting this ability to promote SG disassembly, vhs is able to localize to SGs. Together these data indicate that endoribonuclease activity must be maintained in order for vhs to disrupt SG formation. We propose a model whereby vhs-mediated destruction of SG mRNA promotes SG disassembly and may also prevent SG assembly.

IMPORTANCE
Stress granules (SGs) are transient cytoplasmic structures that form when a cell is exposed to stress. SGs are emerging as potential barriers to viral infection, necessitating a more thorough understanding of their basic biology. We identified virion host shutoff protein (vhs) as a herpes simplex virus 2 (HSV-2) protein capable of disrupting SG formation. As mRNA is a central component of SGs and the best-characterized activity of vhs is as an endoribonuclease specific for mRNA
in vivo
, we investigated the requirement for vhs endoribonuclease activity in disruption of SG formation. Our studies demonstrate that endoribonuclease activity is required for vhs to disrupt SG formation and, more specifically, that SG disassembly can be driven by vhs endoribonuclease activity. Notably, during the course of these studies we discovered that there is an ordered departure of SG components during their disassembly and, furthermore, that vhs itself has the capacity to localize to SGs.
Adeno-associated Virus Vectors Efficiently Transduce Mouse and Rabbit Sensory Neurons Coinfected with Herpes Simplex Virus 1 following Peripheral Inoculation
Authors: Watson Zachary L. , Ertel Monica K. , Lewin Alfred S. , Tuli Sonal S. , Schultz Gregory S. , Neumann Donna M. , Bloom David C. 
Published: June 2016

ABSTRACT
Following infection of epithelial tissues, herpes simplex virus 1 (HSV-1) virions travel via axonal transport to sensory ganglia and establish a lifelong latent infection within neurons. Recent studies have revealed that, following intraganglionic or intrathecal injection, recombinant adeno-associated virus (rAAV) vectors can also infect sensory neurons and are capable of stable, long-term transgene expression. We sought to determine if application of rAAV to peripheral nerve termini at the epithelial surface would allow rAAV to traffic to sensory ganglia in a manner similar to that seen with HSV. We hypothesized that footpad or ocular inoculation with rAAV8 would result in transduction of dorsal root ganglia (DRG) or trigeminal ganglia (TG), respectively. To test this, we inoculated the footpads of mice with various amounts of rAAV as well as rAAV capsid mutants. We demonstrated that this method of inoculation can achieve a transduction rate of >90% of the sensory neurons in the DRG that innervate the footpad. Similarly, we showed that corneal inoculation with rAAV vectors in the rabbit efficiently transduced >70% of the TG neurons in the optic tract. Finally, we demonstrated that coinfection of mouse footpads or rabbit eyes with rAAV vectors and HSV-1 resulted in colocalization in nearly all of the HSV-1-positive neurons. These results suggest that rAAV is a useful tool for the study of HSV-1 infection and may provide a means to deliver therapeutic cargos for the treatment of HSV infections or of dysfunctions of sensory ganglia.

IMPORTANCE
Adeno-associated virus (AAV) has been shown to transduce dorsal root ganglion sensory neurons following direct intraganglionic sciatic nerve injection and intraperitoneal and intravenous injection as well as intrathecal injection. We sought to determine if rAAV vectors would be delivered to the same sensory neurons that herpes simplex virus (HSV-1) infects when applied peripherally at an epithelial surface that had been treated to expose the underlying sensory nerve termini. For this study, we chose two well-established HSV-1 infection models: mouse footpad infection and rabbit ocular infection. The results presented here provide the first description of AAV vectors transducing neurons following delivery at the skin/epithelium/eye. The ability of AAV to cotransduce HSV-1-infected neurons in both the mouse and the rabbit provides an opportunity to experimentally explore and disrupt host and viral proteins that are integral to the establishment of HSV-1 latency, to the maintenance of latency, and to reactivation from latency
in vivo
.
Human T
h
17 Cells Lack HIV-Inhibitory RNases and Are Highly Permissive to Productive HIV Infection
Authors: Christensen-Quick Aaron , Lafferty Mark , Sun Lingling , Marchionni Luigi , DeVico Anthony , Garzino-Demo Alfredo 
Published: June 2016

ABSTRACT

Human immunodeficiency virus (HIV) infects and depletes CD4
+
T cells, but subsets of CD4
+
T cells vary in their susceptibility and permissiveness to infection. For example, HIV preferentially depletes interleukin-17 (IL-17)-producing T helper 17 (T
h
17) cells and T follicular helper (T
fh
) cells. The preferential loss of T
h
17 cells during the acute phase of infection impairs the integrity of the gut mucosal barrier, which drives chronic immune activation—a key determinant of disease progression. The preferential loss of T
h
17 cells has been attributed to high CD4, CCR5, and CXCR4 expression. Here, we show that T
h
17 cells also exhibit heightened permissiveness to productive HIV infection. Primary human CD4
+
T cells were sorted, activated under T
h
17- or T
h
0-polarizing conditions and infected, and then analyzed by flow cytometry. T
h
17-polarizing cytokines increased HIV infection, and HIV infection was disproportionately higher among T
h
17 cells than among IL-17
−
or gamma interferon-positive (IFN-γ
+
) cells, even upon infection with a replication-defective HIV vector with a pseudotype envelope. Further, T
h
17-polarized cells produced more viral capsid protein. Our data also reveal that T
h
17-polarized cells have diminished expression of RNase A superfamily proteins, and we report for the first time that RNase 6 inhibits HIV. Thus, our findings link T
h
17 polarization to increased HIV replication.

IMPORTANCE
Our study compares the intracellular replicative capacities of several different HIV isolates among different T cell subsets, providing a link between the differentiation of T
h
17 cells and HIV replication. T
h
17 cells are of key importance in mucosal integrity and in the immune response to certain pathogens. Based on our findings and the work of others, we propose a model in which HIV replication is favored by the intracellular environment of two CD4
+
T cell subsets that share several requirements for their differentiation: T
h
17 and T
fh
cells. Characterizing cells that support high levels of viral replication (rather than becoming latently infected or undergoing cell death) informs the search for new therapeutics aimed at manipulating intracellular signaling pathways and/or transcriptional factors that affect HIV replication.
Perceptions and culture of safety among helicopter emergency medical service personnel in the UK
Authors: Chesters Adam , Grieve Philip H , Hodgetts Timothy J 
Published: June 2016

BackgroundThe use of helicopter emergency medical services (HEMS) has increased significantly in the UK since 1987. To date there has been no research that addresses HEMS pilots and medical crews' own ideas on the risks that they view as inherent in their line of work and how to mitigate these risks. The aim of this survey is to describe and compare the attitudes and perceptions towards risk in HEMS operations of these staff.MethodsA questionnaire was administered electronically to a representative selection of HEMS doctors, paramedics and pilots in the UK. A number of questions were grouped into common themes, and presented as Likert scales and ranking where appropriate. Descriptive and comparative results were presented and statistically analysed.ResultsThe target sample of 100 consecutive respondents was achieved. All questionnaires were entirely completed. Respondents attributed the most risk to night HEMS operations without the use of night vision goggles, commercial pressure and mechanical aircraft failure. There was no statistical difference in overall perception of safety and years of experience (p=0.58) or between professions (p=0.08). Those who had experienced a crash were more likely to believe that HEMS operations are not inherently safe (p=0.05).ConclusionsWe have surveyed a cross-section of the HEMS operational community in the UK in order to describe their perceptions of safety and risk within their professional life. Two-thirds of respondents believed that HEMS operations were inherently safe. Those who did not seemed to be influenced by personal experience of a crash or serious incident. We support increased operational training for clinical crewmembers, an increased emphasis on incident reporting and a culture of safety, and careful attention to minimum training and equipment requirements for all HEMS missions.
STRATEGIC GIVENS IN NEW PRODUCT DEVELOPMENT: UNDERSTANDING CURVILINEAR EFFECTS ON NEW PRODUCT PERFORMANCE
Authors: ZACHARIAS NICOLAS A. , STOCK RUTH MARIA , IM SUBIN 
Published: June 2016

Although top managers’ direct influence on new product development (NPD) projects may not be evident, managers frame the conditions surrounding such projects by determining the strategic directions and managing the context for a firm’s innovation activities. Drawing on strategic leadership theory and effectuation logic, this study proposes nonlinear effects of three important strategic givens determined by top managers that represent key levers to frame firms’ NPD: customer orientation, encouragement to take risks, and autonomy. Multi-informant data from top-level marketing managers and project managers in multiple U.S. high-tech industries indicate optimal levels for each strategic given. A moderate level of customer orientation is optimal for new product performance (inverted U-shaped relationship); new products also perform best when managers support very low or high levels of autonomy (U-shaped relationship). In contrast with a predicted curvilinear effect, managers’ encouragement of risk taking actually exerts a positive linear effect on new product performance.
Novel Anticancer Agents Based on Targeting the Trimer Interface of the PRL Phosphatase
Authors: Bai Yunpeng , Yu Zhi-Hong , Liu Sijiu , Zhang Lujuan , Zhang Ruo-Yu , Zeng Li-Fan , Zhang Sheng , Zhang Zhong-Yin 
Published: June 2016

Abstract
Phosphatase of regenerating liver (PRL) oncoproteins are phosphatases overexpressed in numerous types of human cancer. Elevated levels of PRL associate with metastasis and poor clinical outcomes. In principle, PRL phosphatases offer appealing therapeutic targets, but they remain underexplored due to the lack of specific chemical probes. In this study, we address this issue by exploiting a unique property of PRL phosphatases, namely, that they may function as homotrimers. Starting from a sequential structure-based virtual screening and medicinal chemistry strategy, we identified Cmpd-43 and several analogs that disrupt PRL1 trimerization. Biochemical and structural analyses demonstrate that Cmpd-43 and its close analogs directly bind the PRL1 trimer interface and obstruct PRL1 trimerization. Cmpd-43 also specifically blocks the PRL1-induced cell proliferation and migration through attenuation of both ERK1/2 and Akt activity. Importantly, Cmpd-43 exerted potent anticancer activity both in vitro and in vivo in a murine xenograft model of melanoma. Our results validate a trimerization-dependent signaling mechanism for PRL and offer proof of concept for trimerization inhibitors as candidate therapeutics to treat PRL-driven cancers. Cancer Res; 76(16); 4805–15. ©2016 AACR.