bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of the Clinical Performance of PapilloCheck Human Papillomavirus Detection with That of the GP5+/6+-PCR-Enzyme Immunoassay in Population-Based Cervical Screening
Authors: Hesselink A. T. , Heideman D. A. M. , Berkhof J. , Topal F. , Pol R. P. , Meijer C. J. L. M. , Snijders P. J. F. 
Published: December 2009

ABSTRACT

We compared the clinical performance of the PapilloCheck human papillomavirus (HPV) assay with that of the GP5+/6+-PCR method with an enzyme immunoassay readout (GP5+/6+-PCR-EIA) for the detection of high-risk HPV (hrHPV) types by the use of cervical samples originating from women in a population-based by the use of cervical screening cohort tested by combined cytology and GP5+/6+-PCR-EIA (POBASCAM trial). Specimens from a random sample of 1,437 controls (women ages 40 to 60 years with normal cytological findings and without evidence of cervical intraepithelial neoplasia grade 2 or higher [≥CIN2] within up to 8 years of follow-up) and 192 cases (women ages 30 to 60 years in whom ≥CIN3 was detected within up to 3 years of follow-up) were subjected to analysis by the PapilloCheck method. When all 17 (probably) hrHPV types were taken into account, the PapilloCheck assay had a clinical sensitivity for the detection of ≥CIN3 of 96.4% (185/192 samples; 95% confidence interval [CI], 93.7 to 99.7) and a clinical specificity for the detection of ≥CIN2 of 96.3% (95% CI, 95.3 to 97.3). After restriction of the analysis by the PapilloCheck assay to the 14 hrHPV types targeted by GP5+/6+-PCR-EIA, the clinical sensitivity and clinical specificity values were 95.8% (95% CI, 92.8 to 98.8) and 96.7% (95% CI, 95.7 to 97.7), respectively. By comparison, these values were 96.4% (95% CI, 93.9 to 98.9) and 97.7% (95% CI, 96.9 to 98.5), respectively, for the GP5+/6+-PCR-EIA. When all 17 (probably) hrHPV types were included in the analysis, noninferiority score testing revealed that the clinical sensitivity of the PapilloCheck assay for the detection of ≥CIN3 was noninferior to that of the GP5+/6+-PCR-EIA (
P
< 0.0001), but the clinical specificity of the PapilloCheck assay for the detection of ≥CIN2 was inferior to that of the GP5+/6+-PCR-EIA (
P
= 0.08) when lower bounds of 90% for sensitivity and 98% for specificity were used. When the analysis was restricted to the 14 hrHPV types targeted by the GP5+/6+-PCR-EIA, both the clinical sensitivity and the clinical specificity of the PapilloCheck assay were noninferior to those of the GP5+/6+-PCR-EIA (noninferiority score test;
P
< 0.0001 and
P
= 0.007, respectively). Thus, when the findings obtained for the 14 hrHPV types detectable by the GP5+/6+-PCR-EIA are considered, the PapilloCheck assay is clinically compatible with the GP5+/6+-PCR-EIA.
Sodium Polyanethole Sulfonate as an Inhibitor of Activation of Complement Function in Blood Culture Systems
Authors: Palarasah Yaseelan , Skjoedt Mikkel-Ole , Vitved Lars , Andersen Thomas Emil , Skjoedt Karsten , Koch Claus 
Published: December 2009

ABSTRACT
Sodium polyanethole sulfonate (SPS; trade name, Liquoid) is a constituent in culture media used to grow bacteria from blood samples from patients suspected of bacteremia. SPS prevents the killing of bacteria by innate cellular and humoral factors. We analyzed the effect of SPS on the three complement activation pathways: the classical, alternative, and lectin pathways, respectively. Inhibition of complement activity by SPS is caused by a blocking of complement activation and is not a result of complement consumption. The classical pathway is inhibited at SPS concentrations greater than 0.1 mg/ml, and complete inhibition is seen at 0.4 mg/ml. An SPS concentration of 0.5 mg/ml completely inhibits the binding of C1q and subsequent incorporation of C3, C4, and C9. The same was observed for the alternative pathway with an inhibition at SPS concentrations from 0.1 mg/ml and a complete inhibition from 0.4 mg/ml. Here, properdin binding was completely absent, and no incorporation of C3 and C9 was observed. In contrast, the lectin complement pathway remains unaffected at these SPS concentrations, and inhibition is first observed from 0.7 mg/ml. A complete inhibition required concentrations greater than 1 mg/ml. SPS is used in growth media (e.g., BACTEC and BacT/Alert) at concentrations from 0.3 to 0.5 mg/ml. The well-known finding that certain bacteria are growth inhibited by blood factors could therefore be a consequence of the lectin pathway, which is not inhibited at these concentrations. In addition, our findings also open up the possibility of a new assay for the assessment of the functional capacity of the lectin complement pathway.
GLTSCR2/PICT-1, a Putative Tumor Suppressor Gene Product, Induces the Nucleolar Targeting of the Kaposi's Sarcoma-Associated Herpesvirus KS-Bcl-2 Protein
Authors: Kalt Inna , Borodianskiy-Shteinberg Tatyana , Schachor Adi , Sarid Ronit 
Published: December 2009

ABSTRACT
KS-Bcl-2, encoded by Kaposi's sarcoma-associated herpesvirus (KSHV), is a structural and functional homologue of the Bcl-2 family of apoptosis regulators. Like several other Bcl-2 family members, KS-Bcl-2 protects cells from apoptosis and autophagy. Using a yeast two-hybrid screen and coimmunoprecipitation assays, we identified a novel KS-Bcl-2-interacting protein, referred to as protein interacting with carboxyl terminus 1 (PICT-1), encoded by a candidate tumor suppressor gene, GLTSCR2. Confocal laser scanning microscopy revealed nucleolar localization of PICT-1, whereas KS-Bcl-2 was located mostly at the mitochondrial membranes with a small fraction in the nucleoli. Ectopic expression of PICT-1 resulted in a large increase in the nucleolar fraction of KS-Bcl-2, and only a minor fraction remained in the cytoplasm. Furthermore, knockdown of endogenous PICT-1 abolished the nucleolar localization of KS-Bcl-2. However, ectopically expressed PICT-1 did not alter the cellular distribution of human Bcl-2. Subsequent analysis mapped the crucial amino acid sequences of both KS-Bcl-2 and PICT-1 required for their interaction and for KS-Bcl-2 targeting to the nucleolus. Functional studies suggest a correlation between nucleolar targeting of KS-Bcl-2 by PICT-1 and reduction of the antiapoptotic activity of KS-Bcl-2. Thus, these studies demonstrate a cellular mechanism to sequester KS-Bcl-2 from the mitochondria and to downregulate its virally encoded antiapoptotic activity. Additional characterization of the interaction of KS-Bcl-2 and PICT-1 is likely to shed light on the functions of both proteins.
Inability of Plasmacytoid Dendritic Cells To Directly Lyse HIV-Infected Autologous CD4
+
T Cells despite Induction of Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand
Authors: Chehimi Jihed , Papasavvas Emmanouil , Tomescu Costin , Gekonge Bethsebah , Abdulhaqq Shaheed , Raymond Andrea , Hancock Aidan , Vinekar Kavita , Carty Craig , Reynolds Griffin , Pistilli Maxwell , Mounzer Karam , Kostman Jay , Montaner Luis J. 
Published: December 2009

ABSTRACT

The function of plasmacytoid dendritic cells (PDC) in chronic human immunodeficiency virus type 1 (HIV-1) infection remains controversial with regard to its potential for sustained alpha interferon (IFN-α) production and induction of PDC-dependent tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL)-mediated cytotoxicity of HIV-infected cells. We address these areas by a study of chronically HIV-1-infected subjects followed through antiretroviral therapy (ART) interruption and by testing PDC cytolytic function against autologous HIV-infected CD4
+
T cells. Rebound in viremia induced by therapy interruption showed a positive association between TRAIL and viral load or T-cell activation, but comparable levels of plasma IFN-α/β were found in viremic ART-treated and control subjects. While PDC from HIV-infected subjects expressed less interferon regulator factor 7 (IRF-7) and produced significantly less IFN-α upon Toll-like receptor 7/9 (TLR7/9) engagement than controls, membrane TRAIL expression in PDC from HIV
+
subjects was increased. Moreover, no significant increase in death receptor 5 (DR5) expression was seen in CD4
+
T cells from viremic HIV
+
subjects compared to controls or following
in vitro
infection/exposure to infectious and noninfectious virus or exogenous IFN-α, respectively. Although activated PDC killed the DR5-expressing HIV-infected Sup-T1 cell line, PDC did not lyse primary autologous HIV
+
CD4
+
T cells yet could provide accessory help for NK cells in killing HIV-infected autologous CD4
+
T cells. Taken together, our data show a lack of sustained high levels of soluble IFN-α in chronic HIV-1 infection
in vivo
and document a lack of direct PDC cytolytic activity against autologous infected or uninfected CD4
+
T cells.
Measles Virus Infection of Alveolar Macrophages and Dendritic Cells Precedes Spread to Lymphatic Organs in Transgenic Mice Expressing Human Signaling Lymphocytic Activation Molecule (SLAM, CD150)
Authors: Ferreira Claudia S. Antunes , Frenzke Marie , Leonard Vincent H. J. , Welstead G. Grant , Richardson Christopher D. , Cattaneo Roberto 
Published: December 2009

ABSTRACTRecent studies of primate models suggest that wild-type measles virus (MV) infects immune cells located in the airways before spreading systemically, but the identity of these cells is unknown. To identify cells supporting primary MV infection, we took advantage of mice expressing the MV receptor human signaling lymphocyte activation molecule (SLAM, CD150) with human-like tissue specificity. We infected these mice intranasally (IN) with a wild-type MV expressing green fluorescent protein. One, two, or three days after inoculation, nasal-associated lymphoid tissue (NALT), the lungs, several lymph nodes (LNs), the spleen, and the thymus were collected and analyzed by microscopy and flow cytometry, and virus isolation was attempted. One day after inoculation, MV replication was documented only in the airways, in about 2.5% of alveolar macrophages (AM) and 0.5% of dendritic cells (DC). These cells expressed human SLAM, and it was observed that MV infection temporarily enhanced SLAM expression. Later, MV infected other immune cell types, including B and T lymphocytes. Virus was isolated from lymphatic tissue as early as 2 days post-IN inoculation; the mediastinal lymph node was an early site of replication and supported high levels of infection. Three days after intraperitoneal inoculation, 1 to 8% of the mediastinal LN cells were infected. Thus, MV infection of alveolar macrophages and subepithelial dendritic cells in the airways precedes infection of lymphocytes in lymphatic organs of mice expressing human SLAM with human-like tissue specificity.
Epstein-Barr Virus-Encoded Bcl-2 Homologue Functions as a Survival Factor in Wp-Restricted Burkitt Lymphoma Cell Line P3HR-1
Authors: Watanabe Ami , Maruo Seiji , Ito Taku , Ito Miho , Katsumura Koichi Ricardo , Takada Kenzo 
Published: December 2009

ABSTRACT
Burkitt lymphoma (BL) is etiologically associated with Epstein-Barr virus (EBV). EBV-positive BL tumors display two latent forms of infection. One is referred to as latency I infection, in which EBV expresses the virus genome maintenance protein EBNA1 as the only viral protein. The other is referred to as Wp-restricted latency and was recently identified in a subset of BL tumors. In these tumors, EBV expresses EBNA1, EBNA3A, EBNA3B, EBNA3C, a truncated form of EBNA-LP, and the viral Bcl-2 homologue BHRF1, all of which are driven by the BamHI W promoter (Wp). To investigate the role of EBV in Wp-restricted BL, we conditionally expressed a dominant-negative EBNA1 (dnEBNA1) mutant which interrupts the virus genome maintenance function of EBNA1 in the P3HR-1 BL cell line. Induction of dnEBNA1 expression caused loss of the EBV genome and resulted in apoptosis of P3HR-1 cells in the absence of exogenous apoptosis inducers, indicating that P3HR-1 cells cannot survive without EBV. Stable transfection of the BHRF1 gene into P3HR-1 cells rescued the cells from the apoptosis induced by dnEBNA1 expression, whereas stable transfection of truncated EBNA-LP, EBNA3A, or EBNA3C did not. Moreover, knockdown of BHRF1 expression in P3HR-1 cells resulted in increased cell death. These results indicate that EBV is essential for the survival of P3HR-1 cells and that BHRF1 functions as a survival factor. Our finding implies a critical contribution of BHRF1 to the pathogenesis of Wp-restricted BLs.
Effect of Mutations in the Human Immunodeficiency Virus Type 1 Protease on Cleavage of the gp41 Cytoplasmic Tail
Authors: Waheed Abdul A. , Ablan Sherimay D. , Sowder Raymond C. , Roser James D. , Schaffner Carl P. , Chertova Elena , Freed Eric O. 
Published: December 2009

ABSTRACT
We previously reported that human immunodeficiency virus type 1 (HIV-1) develops resistance to the cholesterol-binding compound amphotericin B methyl ester (AME) by acquiring mutations (P203L and S205L) in the cytoplasmic tail of the transmembrane envelope glycoprotein gp41 that create cleavage sites for the viral protease (PR). In the present study, we observed that a PR inhibitor-resistant (PIR) HIV-1 mutant is unable to efficiently cleave the gp41 cytoplasmic tail in P203L and S205L virions, resulting in loss of AME resistance. To define the pathway to AME resistance in the context of the PIR PR, we selected for resistance with an HIV-1 isolate expressing the mutant enzyme. We identified a new gp41 mutation, R236L, that results in cleavage of the gp41 tail by the PIR PR. These results highlight the central role of gp41 cleavage as the primary mechanism of AME resistance.
Identification of an ICP27-Responsive Element in the Coding Region of a Herpes Simplex Virus Type 1 Late Gene
Authors: Sedlackova Lenka , Perkins Keith D. , Meyer Julia , Strain Anna K. , Goldman Oksana , Rice Stephen A. 
Published: December 2009

ABSTRACT

During productive herpes simplex virus type 1 (HSV-1) infection, a subset of viral delayed-early (DE) and late (L) genes require the immediate-early (IE) protein ICP27 for their expression. However, the
cis
-acting regulatory sequences in DE and L genes that mediate their specific induction by ICP27 are unknown. One viral L gene that is highly dependent on ICP27 is that encoding glycoprotein C (gC). We previously demonstrated that this gene is posttranscriptionally transactivated by ICP27 in a plasmid cotransfection assay. Based on our past results, we hypothesized that the gC gene possesses a
cis
-acting inhibitory sequence and that ICP27 overcomes the effects of this sequence to enable efficient gC expression. To test this model, we systematically deleted sequences from the body of the gC gene and tested the resulting constructs for expression. In so doing, we identified a 258-bp “silencing element” (SE) in the 5′ portion of the gC coding region. When present, the SE inhibits gC mRNA accumulation from a transiently transfected gC gene, unless ICP27 is present. Moreover, the SE can be transferred to another HSV-1 gene, where it inhibits mRNA accumulation in the absence of ICP27 and confers high-level expression in the presence of ICP27. Thus, for the first time, an ICP27-responsive sequence has been identified in a physiologically relevant ICP27 target gene. To see if the SE functions during viral infection, we engineered HSV-1 recombinants that lack the SE, either in a wild-type (WT) or ICP27-null genetic background. In an ICP27-null background, deletion of the SE led to ICP27-independent expression of the gC gene, demonstrating that the SE functions during viral infection. Surprisingly, the ICP27-independent gC expression seen with the mutant occurred even in the absence of viral DNA synthesis, indicating that the SE helps to regulate the tight DNA replication-dependent expression of gC.
Interaction Domains of the UL16 and UL21 Tegument Proteins of Herpes Simplex Virus
Authors: Harper Amy L. , Meckes David G. , Marsh Jacob A. , Ward Michael D. , Yeh Pei-Chun , Baird Nicholas L. , Wilson Carol B. , Semmes O. John , Wills John W. 
Published: December 2009

ABSTRACT

The UL16 protein of herpes simplex virus is capsid associated and was previously identified as a binding partner of the membrane-associated UL11 tegument protein (J. S. Loomis, R. J. Courtney, and J. W. Wills, J. Virol. 77:11417-11424, 2003). In those studies, a less-prominent, ∼65-kDa binding partner of unknown identity was also observed. Mass spectrometry studies have now revealed this species to be UL21, a tegument protein that has been implicated in the transport of capsids in the cytoplasm. The validity of the mass spectrometry results was tested in a variety of coimmunoprecipitation and glutathione
S
-transferase pull-down experiments. The data revealed that UL21 and UL16 can form a complex in the absence of other viral proteins, even when the assays used proteins purified from
Escherichia coli
. Moreover, UL11 was able to pull down UL21 only when UL16 was present, suggesting that all three proteins can form a complex. Deletion analyses revealed that the second half of UL21 (residues 268 to 535) is sufficient for the UL16 interaction and packaging into virions; however, attempts to map a subdomain of UL16 were largely unsuccessful, with only the first 40 (of 373) residues being found to be dispensable. Nevertheless, it is clear that UL16 must have two distinct binding sites, because covalent modification of its free cysteines with
N
-ethylmaleimide blocked binding to UL11 but not UL21. These findings should prove useful for elucidating the molecular machinery used to transmit a signal into a virion when it attaches to cells, a recently discovered mechanism in which UL16 is a central player.
Proteasome Subunits Relocalize during Human Cytomegalovirus Infection, and Proteasome Activity Is Necessary for Efficient Viral Gene Transcription
Authors: Tran Karen , Mahr Jeffrey A. , Spector Deborah H. 
Published: December 2009

ABSTRACTWe have continued studies to further understand the role of the ubiquitin-proteasome system (UPS) in human cytomegalovirus (HCMV) infection. With specific inhibitors of the proteasome, we show that ongoing proteasome activity is necessary for facilitating the various stages of the infection. Immediate-early protein 2 expression is modestly reduced with addition of proteasome inhibitors at the onset of infection; however, both early and late gene expression are significantly delayed, even if the inhibitor is removed at 12 h postinfection. Adding the inhibitor at later times during the infection blocks the further accumulation of viral early and late gene products, the severity of which is dependent on when the proteasome is inhibited. This can be attributed primarily to a block in viral RNA transcription, although DNA synthesis is also partially inhibited. Proteasome activity and expression increase as the infection progresses, and this coincides with the relocalization of active proteasomes to the periphery of the viral DNA replication center, where there is active RNA transcription. Interestingly, one 19S subunit, Rpn2, is specifically recruited into the viral DNA replication center. The relocalization of the subunits requires viral DNA replication, but their maintenance around or within the replication center is not dependent on continued viral DNA synthesis or the proteolytic activity of the proteasome. These studies highlight the importance of the UPS at all stages of the HCMV infection and support further studies into this pathway as a potential antiviral target.
Relationship between Antibody 2F5 Neutralization of HIV-1 and Hydrophobicity of Its Heavy Chain Third Complementarity-Determining Region
Authors: Ofek Gilad , McKee Krisha , Yang Yongping , Yang Zhi-Yong , Skinner Jeff , Guenaga F. Javier , Wyatt Richard , Zwick Michael B. , Nabel Gary J. , Mascola John R. , Kwong Peter D. 
Published: December 2009

ABSTRACT

The membrane-proximal external region (MPER) of the HIV-1 gp41 transmembrane glycoprotein is the target of the broadly neutralizing antibody 2F5. Prior studies have suggested a two-component mechanism for 2F5-mediated neutralization involving both structure-specific recognition of a gp41 protein epitope and nonspecific interaction with the viral lipid membrane. Here, we mutationally alter a hydrophobic patch on the third complementarity-determining region of the heavy chain (CDR H3) of the 2F5 antibody and assess the abilities of altered 2F5 variants to bind gp41 and to neutralize diverse strains of HIV-1. CDR H3 alterations had little effect on the affinity of 2F5 variants for a peptide corresponding to its gp41 epitope. In contrast, strong effects and a high degree of correlation (
P
< 0.0001) were found between virus neutralization and CDR H3 hydrophobicity, as defined by predicted free energies of transfer from water to a lipid bilayer interface or to octanol. The effect of CDR H3 hydrophobicity on neutralization was independent of isolate sensitivity to 2F5, and CDR H3 variants with tryptophan substitutions were able to neutralize HIV-1 ∼10-fold more potently than unmodified 2F5. A threshold was observed for increased hydrophobicity of the 2F5 CDR H3 loop beyond which effects on 2F5-mediated neutralization leveled off. Together, the results provide a more complete understanding of the 2F5 mechanism of HIV-1 neutralization and indicate ways to enhance the potency of MPER-directed antibodies.
Gamma Interferon Signaling in Oligodendrocytes Is Critical for Protection from Neurotropic Coronavirus Infection
Authors: Parra Gabriel I. , Bergmann Cornelia C. , Phares Timothy W. , Hinton David R. , Atkinson Roscoe , Stohlman Stephen A. 
Published: December 2009

ABSTRACTNeurotropic coronavirus induces acute encephalomyelitis and demyelination in mice. Infection of BALB/c (H-2d) mice expressing a dominant negative gamma interferon (IFN-γ) receptor specifically in oligodendrocytes was examined to determine the influence of IFN-γ signaling on pathogenesis. Inhibition of IFN-γ signaling in oligodendrocytes increased viral load, infection of oligodendrocytes, oligodendrocyte loss, demyelination, and axonal damage resulting in increased mortality. IFN-γ levels and the inflammatory response were not altered, although the level of tumor necrosis factor (TNF) mRNA was increased. These data indicate that IFN-γ signaling by oligodendroglia reduces viral replication but affects both demyelination and tissue destruction in a host-specific manner.