bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interaction of Rotavirus Polymerase VP1 with Nonstructural Protein NSP5 Is Stronger than That with NSP2
Authors: Arnoldi F. , Campagna M. , Eichwald C. , Desselberger U. , Burrone O. R. 
Published: December 2006

ABSTRACT
Rotavirus morphogenesis starts in intracellular inclusion bodies called viroplasms. RNA replication and packaging are mediated by several viral proteins, of which VP1, the RNA-dependent RNA polymerase, and VP2, the core scaffolding protein, were shown to be sufficient to provide replicase activity in vitro. In vivo, however, viral replication complexes also contain the nonstructural proteins NSP2 and NSP5, which were shown to be essential for replication, to interact with each other, and to form viroplasm-like structures (VLS) when coexpressed in uninfected cells. In order to gain a better understanding of the intermediates formed during viral replication, this work focused on the interactions of NSP5 with VP1, VP2, and NSP2. We demonstrated a strong interaction of VP1 with NSP5 but only a weak one with NSP2 in cotransfected cells in the absence of other viral proteins or viral RNA. By contrast, we failed to coimmunoprecipitate VP2 with anti-NSP5 antibodies or NSP5 with anti-VP2 antibodies. We constructed a tagged form of VP1, which was found to colocalize in viroplasms and in VLS formed by NSP5 and NSP2. The tagged VP1 was able to replace VP1 structurally by being incorporated into progeny viral particles. When applying anti-tag-VP1 or anti-NSP5 antibodies, coimmunoprecipitation of tagged VP1 with NSP5 was found. Using deletion mutants of NSP5 or different fragments of NSP5 fused to enhanced green fluorescent protein, we identified the 48 C-terminal amino acids as the region essential for interaction with VP1.
Exceptional Flexibility in the Sequence Requirements for Coronavirus Small Envelope Protein Function
Authors: Kuo Lili , Hurst Kelley R. , Masters Paul S. 
Published: December 2006

ABSTRACT
The small envelope protein (E) plays a role of central importance in the assembly of coronaviruses. This was initially established by studies demonstrating that cellular expression of only E protein and the membrane protein (M) was necessary and sufficient for the generation and release of virus-like particles. To investigate the role of E protein in the whole virus, we previously generated E gene mutants of mouse hepatitis virus (MHV) that were defective in viral growth and produced aberrantly assembled virions. Surprisingly, however, we were also able to isolate a viable MHV mutant (ΔE) in which the entire E gene, as well as the nonessential upstream genes 4 and 5a, were deleted. We have now constructed an E knockout mutant that confirms that the highly defective phenotype of the ΔE mutant is due to loss of the E gene. Additionally, we have created substitution mutants in which the MHV E gene was replaced by heterologous E genes from viruses spanning all three groups of the coronavirus family. Group 2 and 3 E proteins were readily exchangeable for that of MHV. However, the E protein of a group 1 coronavirus, transmissible gastroenteritis virus, became functional in MHV only after acquisition of particular mutations. Our results show that proteins encompassing a remarkably diverse range of primary amino acid sequences can provide E protein function in MHV. These findings suggest that E protein facilitates viral assembly in a manner that does not require E protein to make sequence-specific contacts with M protein.
Herpesvirus Saimiri STP-A Oncoprotein Utilizes Src Family Protein Tyrosine Kinase and Tumor Necrosis Factor Receptor-Associated Factors To Elicit Cellular Signal Transduction
Authors: Garcia Maria I. , Kaserman Joseph , Chung Young-Hwa , Jung Jae U. , Lee Sun-Hwa 
Published: December 2006

ABSTRACTThe saimiri transforming protein oncogene, called STP-A, of herpesvirus saimiri (HVS) subgroup A is not required for viral replication but is required for lymphoid cell immortalization in culture and lymphoma induction in primates. Here we report that STP-A interacts with cellular tumor necrosis factor receptor-associated factors (TRAF2 and TRAF6) and Src family protein tyrosine kinases (SF-PTKs) in a genetically and functionally separable manner and that each interaction constitutively elicits independent cellular signal transduction. The amino-terminal and central proline-rich motifs of STP-A were responsible for TRAF6 and TRAF2 interactions, respectively, and STP-A and TRAF6 interaction contributed to the majority of NF-κB activation, whereas STP-A and TRAF2 interaction played a minor role in NF-κB activation. On the other hand, interaction of STP-A with SF-PTKs through its SH2 binding motif effectively elicited AP-1 and NF-AT transcription factor activity. One cellular gene targeted by STP-A is intercellular adhesion molecule 1 (ICAM-1), which participates in a wide range of inflammatory and immune responses. Both TRAF and SF-PTK signal transductions induced by STP-A were required for the marked increase of ICAM-1 expression. These results demonstrate that the viral oncogene STP-A independently targets two vital cellular signaling molecules and that these activities likely contribute to HVS-mediated lymphoid cell immortalization in culture and lymphoma induction in primates.
Changes in Paracrine Interleukin-2 Requirement, CCR7 Expression, Frequency, and Cytokine Secretion of Human Immunodeficiency Virus-Specific CD4+T Cells Are a Consequence of Antigen Load
Authors: Tilton John C. , Luskin Marlise R. , Johnson Alison J. , Manion Maura , Hallahan Claire W. , Metcalf Julia A. , McLaughlin Mary , Davey Richard T. , Connors Mark 
Published: December 2006

ABSTRACTVirus-specific CD4+T-cell responses are thought to be required for the induction and maintenance of many effective CD8+T-cell and B-cell immune responses in experimental animals and humans. Although the presence of human immunodeficiency virus (HIV)-specific CD4+T cells has been documented in patients at all stages of HIV infection, many fundamental questions regarding their frequency and function remain. A 10-color, 12-parameter flow cytometric panel was utilized to examine the frequency, memory phenotype (CD27, CCR7, and CD45RA), and cytokine production (interleukin-2 [IL-2], gamma interferon, and tumor necrosis factor alpha) of CD4+T cells specific for HIV antigens as well as for adenovirus, Epstein-Barr virus (EBV), influenza H1N1 virus, influenza H3N2 virus, cytomegalovirus, varicella-zoster virus (VZV), and tetanus toxoid in normal controls, long-term nonprogressors (LTNP), and HIV-infected patients with progressive disease on or off therapy. The HIV-specific CD4+T-cell responses in LTNP and patients on therapy were similar in frequency, phenotype, and cytokine production to responses directed against adenovirus, EBV, influenza virus, and VZV. HIV-specific CD4+T cells from patients off antiretroviral therapy demonstrated a shift towards a CCR7−CD45RA−phenotype and a reduced percentage of IL-2-producing cells. The alterations in cytokine production during HIV viremia were found to be intrinsic to the HIV-specific CD4+T cells and caused a requirement for IL-2 supplied exogenously for proliferation to occur. These observations suggest that many previously described changes in HIV-specific CD4+T-cell function and phenotype are a consequence of high levels of antigen in viremic patients. In addition, defects in function and phenotype of HIV-specific CD4+T cells are not readily discernible in the context of antiretroviral therapy but rather are similar to responses to other viruses.
CD8 T-Cell Recognition of Multiple Epitopes within Specific Gag Regions Is Associated with Maintenance of a Low Steady-State Viremia in Human Immunodeficiency Virus Type 1-Seropositive Patients
Authors: Geldmacher Christof , Currier Jeffrey R. , Herrmann Eva , Haule Antelmo , Kuta Ellen , McCutchan Francine , Njovu Lilian , Geis Steffen , Hoffmann Oliver , Maboko Leonard , Williamson Carolyn , Birx Deborah , Meyerhans Andreas , Cox Josephine , Hoelscher Michael 
Published: December 2006

ABSTRACTThe importance of HLA class I-restricted CD8 T-cell responses in the control of human immunodeficiency virus (HIV) infection is generally accepted. While several studies have shown an association of certain HLA class I alleles with slower disease progression, it is not fully established whether this effect is mediated by HIV-specific CD8 T-cell responses restricted by these alleles. In order to study the influence of the HLA class I alleles on the HIV-specific CD8 T-cell response and on viral control, we have assessed HIV-specific epitope recognition, plasma viral load, and expression of HLA class I alleles in a cohort of HIV-seropositive bar workers. Possession of the HLA class I alleles B5801, B8101, and B0702 was associated with a low median viral load and simultaneously with a broader median recognition of Gag epitopes compared to all other HLA alleles (twofold increase) (P= 0.0035). We further found an inverse linear relationship between the number of Gag epitopes recognized and the plasma viral load (R= −0.36;P= 0.0016). Particularly, recognition of multiple epitopes within two regions of Gag (amino acids [aa] 1 to 75 and aa 248 to 500) was associated with the maintenance of a low steady-state viremia, even years after acute infection.
NS1 Proteins of Avian Influenza A Viruses Can Act as Antagonists of the Human Alpha/Beta Interferon Response
Authors: Hayman A. , Comely S. , Lackenby A. , Hartgroves L. C. S. , Goodbourn S. , McCauley J. W. , Barclay W. S. 
Published: December 2006

ABSTRACT
Many viruses, including human influenza A virus, have developed strategies for counteracting the host type I interferon (IFN) response. We have explored whether avian influenza viruses were less capable of combating the type I IFN response in mammalian cells, as this might be a determinant of host range restriction. A panel of avian influenza viruses isolated between 1927 and 1997 was assembled. The selected viruses showed variation in their ability to activate the expression of a reporter gene under the control of the IFN-β promoter and in the levels of IFN induced in mammalian cells. Surprisingly, the avian NS1 proteins expressed alone or in the genetic background of a human influenza virus controlled IFN-β induction in a manner similar to the NS1 protein of human strains. There was no direct correlation between the IFN-β induction and replication of avian influenza viruses in human A549 cells. Nevertheless, human cells deficient in the type I IFN system showed enhanced replication of the avian viruses studied, implying that the human type I IFN response limits avian influenza viruses and can contribute to host range restriction.
Synergy of Small Molecular Inhibitors of Hepatitis C Virus Replication Directed at Multiple Viral Targets
Authors: Wyles David L. , Kaihara Kelly A. , Vaida Florin , Schooley Robert T. 
Published: December 2006

ABSTRACT
Chronic hepatitis C virus (HCV) infection is a significant worldwide health problem with limited therapeutic options. A number of novel, small molecular inhibitors of HCV replication are now entering early clinical trials in humans. Resistance to small molecular inhibitors is likely to be a significant hurdle to their use in patients. A systematic assessment of combinations of interferon and/or novel anti-hepatitis C virus agents from several different mechanistic classes was performed in vitro. Combinations of inhibitors with different mechanisms of action consistently demonstrated more synergy than did compounds with similar mechanisms of action. These results suggest that combinations of inhibitors with different mechanisms of action should be prioritized for assessment in clinical trials for chronic hepatitis C virus infection.
Multiple Amino Acid Substitutions in Hemagglutinin Are Necessary for Wild-Type MeaslesVirus To Acquire the Ability To Use Receptor CD46 Efficiently
Authors: Tahara Maino , Takeda Makoto , Seki Fumio , Hashiguchi Takao , Yanagi Yusuke 
Published: December 2006

ABSTRACTMeasles virus (MV) possesses two envelope glycoproteins, namely, the receptor-binding hemagglutinin (H) and fusion proteins. Wild-type MV strains isolated in B-lymphoid cell lines use signaling lymphocyte activation molecule (SLAM), but not CD46, as a cellular receptor, whereas MV vaccine strains of the Edmonston lineage use both SLAM and CD46 as receptors. Studies have shown that the residue at position 481 of the H protein is critical in determining the use of CD46 as a receptor. However, the wild-type IC-B strain with a single N481Y substitution in the H protein utilizes CD46 rather inefficiently. In this study, a number of chimeric and mutant H proteins, and recombinant viruses harboring them, were generated to determine which residues of the Edmonston H protein are responsible for its efficient use of CD46. Our results show that three substitutions (N390I and E492G plus N416D or T446S), in addition to N481Y, are necessary for the IC-B H protein to use CD46 efficiently as a receptor. The N390I, N416D, and T446S substitutions are present in the H proteins of all strains of the Edmonston lineage, whereas the E492G substitution is found only in the H protein of the Edmonston tag strain generated from cDNAs. The T484N substitution, found in some of the Edmonston-lineage strains, resulted in a similar effect on the use of CD46 to that caused by the E492G substitution. Thus, multiple residues in the H protein that have not previously been implicated have important roles in the interaction with CD46.
Group B streptococcus prevalence in pregnant women from North-Eastern Italy: advantages of a screening strategy based on direct plating plus broth enrichment
Authors: Busetti Marina , D’Agaro Pierlanfranco , Campello Cesare 
Published: December 2006

Aims:To assess the sensitivity of a combined selective broth enrichment technique plus selective plating for the detection of group B streptococcus (GBS) colonisation in a large cohort of pregnant women from North-Eastern Italy.Methods:During 2002–2005, 5020 pregnant women were screened between the 35th and the 37th week of gestation. A lower vaginal sample and a rectal sample were collected and inoculated onto LIM broth and a selective colistin aztreonam blood agar plate (CAP). Direct agar plates were examined after 18–24 hours and, if negative, after 48 hours. LIM broth was subcultured after 18–24 hours onto a Columbia blood agar plate. All colonies suggestive for GBS were submitted to phenotypic identification.Results:901 Women (17.9%) were positive for GBS. On 728 positive samples, corresponding to patients enrolled between 2003 and 2005, the results of selective direct plating and selective broth enrichment were compared. A total of 561 (77.1% of positive samples, corresponding to 13.9% of patients) were positive on direct selective agar; an additional 167 isolates (22.9% of samples, 4.1% of patients) were recovered from the LIM broth subculture.Conclusions:The prevalence of GBS carriage in this population-based study is a reliable estimate considering the sensitivity of the microbiological methods used, the rate of attendance of pregnant women to clinical and laboratory settings and the compliance to the protocol. Results confirm that the combination of selective enrichment broth and selective direct plating is a time-saving and sensitive method.
Selecting immunohistochemical cut-off scores for novel biomarkers of progression and survival in colorectal cancer
Authors: Zlobec Inti , Steele Russell , Terracciano Luigi , Jass Jeremy R , Lugli Alessandro 
Published: December 2006

Background:Cut-off scores for determining positivity of biomarkers detected by immunohistochemistry are often set arbitrarily and vary between reports.Aims:To evaluate the performance of receiver operating characteristic (ROC) curve analysis in determining clinically important cut-off scores for a novel tumour marker, the receptor for hyaluronic acid mediated motility (RHAMM), and show the reproducibility of the selected cut-off scores in 1197 mismatch-repair (MMR) proficient colorectal cancers (CRC).Methods:Immunohistochemistry for RHAMM was performed using a tissue microarray of 1197 MMR-proficient CRC. Immunoreactivity was scored using a semi-quantitative scoring method by evaluating the percentage of positive tumour cells. ROC curve analysis was performed for T stage, N stage, tumour grade, vascular invasion and survival. The score with the shortest distance from the curve to the point with both maximum sensitivity and specificity, i.e. the point (0.0, 1.0), was selected as the cut-off score leading to the greatest number of tumours correctly classified as having or not having the clinical outcome. In order to determine the reliability of the selected cut-off scores, 100 bootstrapped replications were performed to resample the data.Results:The cut-off score for T stage, N stage, tumour grade and vascular invasion was 100% and that for survival 90%. The most frequently selected cut-off score from the 100 resamples was also 100% for T stage, N stage, tumour grade, and vascular invasion and 90% for survival.Conclusions:ROC curve analysis can be used as an alternative method in the selection and validation of cut-off scores for determining the clinically relevant threshold for immunohistochemical tumour positivity.
Assessment of exposure to mercury from industrial emissions: comparing “distance as a proxy” and dispersion modelling approaches
Authors: Hodgson Susan , Nieuwenhuijsen Mark J , Colvile Roy , Jarup Lars 
Published: December 2006

Background:The Runcorn area, north-west England, contains many pollution sources, the health effects of which have been under discussion for over 100 years. Preliminary investigations revealed an excess risk of mortality from kidney disease in people living nearest to several point sources of pollution, using distance as a proxy for exposure. Ongoing epidemiological investigations into the effect of ambient mercury exposure on dose and renal effect required a more refined assessment of exposure.Methods:Atmospheric dispersion modelling was used to assess mercury dispersion from three mercury-emitting sources (including a large chlor alkali plant), based on knowledge of emissions, local meteorology and topography.Results:The model was sensitive to various input parameters, with different dispersion patterns and ground-level concentrations, and therefore different exposed populations identified when different input parameters were defined. The different approaches to exposure assessment also had an impact on the epidemiological findings. The model output correlated well with weekly monitoring data collected in the local area, although the model underestimated concentrations in close proximity to the chlor alkali plant. The model identified that one point source did not contribute significantly to ground-level mercury concentrations, so that inclusion of this source when using the “distance as a proxy” approach led to significant exposure misclassification.Conclusions:The model output indicates that assessment of ambient exposure should give consideration to the magnitude of emissions, point source characteristics, local meteorology and topography to ensure that the most appropriate exposure classification is reached. Even if dispersion modelling cannot be undertaken, these data can be used to inform and improve the distance as a proxy approach, and improve the interpretability of the epidemiological findings.
Causes of death among lead smelters in relation to the glucose-6-phosphate dehydrogenase polymorphism: Table 1
Authors: Cocco Pierluigi , Fadda Domenica , Atzeri Sergio , Avataneo Giuseppe , Meloni Michele , Flore Costantino 
Published: December 2006

Objective:To assess, by updating a follow-up mortality study of a lead smelters cohort in Sardinia, Italy, the adverse health effects following occupational lead exposure in relation to the glucose-6-phosphate dehydrogenase (G6PD) polymorphism.Method:The 1973–2003 mortality of 1017 male lead smelters were followed-up, divided into two subcohorts according to the G6PD phenotype: whether G6PD deficient (G6PD−) or wild-type (wtG6PD). Deaths observed in the overall cohort and the two subcohorts were compared with those expected, on the basis of the age-, sex- and calendar year-specific mortality in the general male population of the island. Directly standardised mortality rates (sr) in the two subcohorts were also compared.Results:Cardiovascular mortality was strongly reduced among production and maintenance workers, which is most related to the healthy worker effect. However, the sr for cardiovascular diseases was substantially lower among the G6PD− subcohort (5.0×10−4) than among the wtG6PD subcohort (33.6×10−4; χ2 = 1.10; p = NS). Neoplasms of the haemopoietic system exceeded the expectation in the G6PD− subcohort (SMR = 388; 95% CI 111 to 1108). No other cancer sites showed any excess in the overall cohort or in the two subcohorts. No death from haemolytic anaemia occurred in the G6PD− subcohort.Conclusion:With due consideration of the limited statistical power of our study, previous results suggesting that in workplaces where exposure is under careful control, expressing the G6PD− phenotype does not convey increased susceptibility to lead toxicity are confirmed. The observed excess risk of haematopoietic malignancies seems to have most likely resulted from chance.
Air pollution and inflammation in type 2 diabetes: a mechanism for susceptibility
Authors: O’Neill M S , Veves A , Sarnat J A , Zanobetti A , Gold D R , Economides P A , Horton E S , Schwartz J 
Published: December 2006

Background:Particulate air pollution has been associated with several adverse cardiovascular health outcomes, and people with diabetes may be especially vulnerable. One potential pathway is inflammation and endothelial dysfunction—processes in which cell adhesion molecules and inflammatory markers play important roles.Aim:To examine whether plasma levels of soluble intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1) and von Willebrand factor (vWF) were associated with particle exposure in 92 Boston area residents with type 2 diabetes.Methods:Daily average ambient levels of air pollution (fine particles (PM2.5), black carbon (BC) and sulphates) were measured approximately 500 m from the patient examination site and evaluated for associations with ICAM-1, VCAM-1 and vWF. Linear regressions were fit to plasma levels of ICAM-1, VCAM-1 and vWF, with the particulate pollutant index, apparent temperature, season, age, race, sex, glycosylated haemoglobin, cholesterol, smoking history and body mass index as predictors.Results:Air pollutant exposure measures showed consistently positive point estimates of association with the inflammatory markers. Among participants not taking statins and those with a history of smoking, associations between PM2.5, BC and VCAM-1 were particularly strong.Conclusions:These results corroborate evidence suggesting that inflammatory mechanisms may explain the increased risk of air pollution-associated cardiovascular events among those with diabetes.