bluuebunny/crossref_metadata_2025_split huggingface dataset:
Single Antigen Detects both Immunoglobulin M (IgM) and IgG Antibodies Elicited by All Four Dengue Virus Serotypes
Authors: Hapugoda Menaka D. , Batra Gaurav , Abeyewickreme W. , Swaminathan S. , Khanna N. 
Published: September 2007

ABSTRACT

The resurgence of dengue (DEN) virus infections in the last few decades coupled with the lack of a preventive vaccine and specific antiviral drugs has jointly contributed to making this a significant global public health problem. Currently, symptomatic supportive treatment and fluid replacement therapy are the only means available to minimize DEN-induced mortality. As the clinical symptoms associated with DEN virus infections are indistinguishable from those of many other viral, bacterial, and parasitic infections, specific diagnostic tests assume critical importance in the unequivocal identification of DEN virus infections. We have designed a novel chimeric antigen based on envelope domain III (EDIII), a critical antigenic region of the major structural protein of DEN viruses. We fused EDIIIs corresponding to each of the four DEN virus serotypes using pentaglycyl linkers, overexpressed the resultant tetravalent chimeric protein in
Escherichia coli
, and affinity purified it in high yields, obtaining ∼30 mg protein of >95% purity per liter of culture. We show that this tetravalent antigen could specifically recognize anti-DEN virus antibodies of both the immunoglobulin M (IgM) and IgG classes. Using a large panel of IgM antibody capture-enzyme-linked immunosorbent assay- and hemagglutination inhibition-confirmed DEN virus-infected and uninfected patient sera (
n
= 289), we demonstrate that this tetravalent antigen can function as a diagnostic tool of high sensitivity and specificity.
Immunogenicity, Reactogenicity, and Safety of a P1.7b,4 Strain-Specific Serogroup B Meningococcal Vaccine Given to Preteens
Authors: Hosking Jamie , Rasanathan Kumanan , Mow Florina Chan , Jackson Catherine , Martin Diana , O'Hallahan Jane , Oster Philipp , Ypma Ellen , Reid Stewart , Aaberge Ingeborg , Crengle Sue , Stewart Joanna , Lennon Diana 
Published: September 2007

ABSTRACT

New Zealand (NZ) has experienced a
Neisseria meningitidis
serogroup B epidemic since 1991. MeNZB, a strain-specific outer membrane vesicle vaccine made using an NZ epidemic strain isolate, NZ98/254 (B:4:P1.7b,4), from two manufacturing sites, the Norwegian Institute of Public Health (NIPH) and Chiron Vaccines (CV; now Novartis), was evaluated for safety, immunogenicity, and reactogenicity in this observer-blind trial with 8- to 12-year-old children. In year 1, cohort A (
n
= 302) was randomized 4:1 for receipt of NIPH-MeNZB or MenBvac (Norwegian parent vaccine strain 44/76; B:15:P1.7,16). In year 2, cohort B (
n
= 313) was randomized 4:1 for receipt of CV-MeNZB or NIPH-MeNZB. Participants all received three vaccinations 6 weeks apart. Local and systemic reactions were monitored for 7 days. Seroresponse was defined as a fourfold or greater rise in the serum bactericidal antibody titer from the baseline titer as measured by a serum bactericidal assay. Those with baseline titers of <1:4 required titers of ≥1:8 to serorespond. Intention-to-treat (ITT) and per protocol (PP) analyses are presented. In cohort A, 74% (ITT) and 73% (PP) of NIPH-MeNZB recipients demonstrated seroresponses against NZ98/254 after three doses, versus 32% (ITT and PP) of MenBvac recipients. In cohort B, seroresponses against NZ98/254 after three doses occurred in 79% (ITT and PP) of CV-MeNZB versus 75% (ITT) and 76% (PP) of NIPH-MeNZB recipients. Vaccines were tolerable, with no vaccine-related serious adverse events. In conclusion, the NZ strain meningococcal B vaccine (MeNZB) from either manufacturing site was immunogenic against New Zealand epidemic vaccine strain meningococci with no safety concerns when given in three doses to these 8- to 12-year-old children.
Use of Protein Antigens for Early Serological Diagnosis of Leprosy
Authors: Duthie Malcolm S. , Goto Wakako , Ireton Greg C. , Reece Stephen T. , Cardoso Ludimila P. V. , Martelli Celina M. T. , Stefani Mariane M. A. , Nakatani Maria , de Jesus Robson Crusue , Netto Eduardo M. , Balagon Ma V. F. , Tan Esterlina , Gelber Robert H. , Maeda Yumi , Makino Masahiko , Hoft Dan , Reed Steven G. 
Published: September 2007

ABSTRACT

Leprosy is a chronic and debilitating human disease caused by infection with the
Mycobacterium leprae
bacillus. Despite the marked reduction in the number of registered worldwide leprosy cases as a result of the widespread use of multidrug therapy, the number of new cases detected each year remains relatively stable. This indicates that
M. leprae
is still being transmitted and that, without earlier diagnosis,
M. leprae
infection will continue to pose a health problem. Current diagnostic techniques, based on the appearance of clinical symptoms or of immunoglobulin M (IgM) antibodies that recognize the bacterial phenolic glycolipid I, are unable to reliably identify early-stage leprosy. In this study we examine the ability of IgG within leprosy patient sera to bind several
M. leprae
protein antigens. As expected, multibacillary leprosy patients provided stronger responses than paucibacillary leprosy patients. We demonstrate that the geographic locations of the patients can influence the antigens they recognize but that ML0405 and ML2331 are recognized by sera from diverse regions (the Philippines, coastal and central Brazil, and Japan). A fusion construct of these two proteins (designated leprosy IDRI diagnostic 1 [LID-1]) retained the diagnostic activity of the component antigens. Upon testing against a panel of prospective sera from individuals who developed leprosy, we determined that LID-1 was capable of diagnosing leprosy 6 to 8 months before the onset of clinical symptoms. A serological diagnostic test capable of identifying and allowing treatment of early-stage leprosy could reduce transmission, prevent functional disabilities and stigmatizing deformities, and facilitate leprosy eradication.
Anaplasma phagocytophilum
-
Borrelia burgdorferi
Coinfection Enhances Chemokine, Cytokine, and Matrix Metalloprotease Expression by Human Brain Microvascular Endothelial Cells
Authors: Grab Dennis J. , Nyarko Elvis , Barat Nicole C. , Nikolskaia Olga V. , Dumler J. Stephen 
Published: September 2007

ABSTRACT

Borrelia burgdorferi
and
Anaplasma phagocytophilum
coinfect and are transmitted by
Ixodes
species ticks. Clinical indicators suggest that
A. phagocytophilum
coinfection contributes to the severity, dissemination, and, possibly, sequelae of Lyme disease. Previous in vitro studies showed that spirochete penetration through human brain microvascular endothelial cells of the blood-brain barrier is facilitated by endothelial cell-derived matrix metalloproteases (MMPs).
A. phagocytophilum
-infected neutrophils continuously release MMPs and other vasoactive biomediators. We examined
B. burgdorferi
infection of brain microvascular barriers during
A. phagocytophilum
coinfection and showed that coinfection enhanced reductions in transendothelial electrical resistance and enhanced or synergistically increased production of MMPs (MMP-1, -3, -7, -8, and -9), cytokines (interleukin 6 [IL-6], IL-10, and tumor necrosis factor alpha), and chemokines (IL-8 and macrophage inflammatory protein 1α) known to affect vascular permeability and inflammatory responses.
Confirmatory Real-Time PCR Assay for Human Papillomavirus (HPV) Type 52 Infection in Anogenital Specimens Screened for HPV Infection with the Linear Array HPV Genotyping Test
Authors: Coutlée François , Rouleau Danielle , Ghattas Georges , Hankins Catherine , Vézina Sylvie , Coté Pierre , Macleod John , de Pokomandy Alexandra , Money Deborah , Walmsley Sharon , Voyer Hélène , Brassard Paul , Franco Eduardo 
Published: September 2007

ABSTRACT
A novel real-time PCR assay for detection of human papillomavirus type 52 (HPV-52) DNA (RT-52) was evaluated on 265 anogenital samples. RT-52 had a sensitivity of 98.4% and a specificity of 100% compared to conventional HPV-52 typing assays, including hybridization of PGMY products with an HPV-52-specific probe and PCR sequencing of HPV-52 E6.
Improved COBAS TaqMan Hepatitis C Virus Test (Version 2.0) for Use with the High Pure System: Enhanced Genotype Inclusivity and Performance Characteristics in a Multisite Study
Authors: Colucci G. , Ferguson J. , Harkleroad C. , Lee S. , Romo D. , Soviero S. , Thompson J. , Velez M. , Wang A. , Miyahara Y. , Young S. , Sarrazin C. 
Published: September 2007

ABSTRACTWe have evaluated the COBAS TaqMan hepatitis C virus (HCV) test (version 2.0) for use with the High Pure system (HCVHPS V2), a new, revised real-time reverse transcription-PCR assay developed to improve the genotype quantitation of version 1.0 (HCVHPS V1). Revisions were made in the wash buffer and in the reverse transcription temperature. The genotype inclusivity of HCVHPS V2 was evaluated at three different sites, using HCVHPS V2, HCVHPS V1, and the COBAS AMPLICOR HCV MONITOR test (version 2.0) (CAHCM). The fully automated COBAS Ampliprep/COBAS TaqMan HCV test was also used in one of the participating laboratories. The mean differences in HCV RNA values between HCVHPS V2 and CAHCM and between HCVHPS V2 and HCVHPS V1 ranged from −0.21 to 0.13 log and from 0.24 to 1.27 log, respectively, with >0.5-log differences for genotypes 2, 3, 4, and 5. With a NIBSC panel of HCV genotypes 1 through 6, the measured HCVHPS V2 values were within 0.25 log of the nominal values for all 6 genotypes. When serial dilutions of genotype-specific clinical HCV specimens were tested, the assay showed a limit of detection between 10 and 20 IU/ml and a linear range of 25 IU/ml to 3.91 × 108IU/ml. Clinical and analytical specificities of 100% were demonstrated with 100 HCV-seronegative specimens as well as with 12 non-HCV members ofFlaviviridaeand 22 additional microorganisms. These data indicate that HCVHPS V2 is a robust and accurate test for the quantitation of all six HCV genotypes and useful in monitoring viral load in all clinical HCV specimens.
Discovery of a Novel
Mycobacterium tuberculosis
Lineage That Is a Major Cause of Tuberculosis in Rio de Janeiro, Brazil
Authors: Lazzarini Luiz Claudio Oliveira , Huard Richard C. , Boechat Neio L. , Gomes Harrison M. , Oelemann Maranibia C. , Kurepina Natalia , Shashkina Elena , Mello Fernanda C. Q. , Gibson Andrea L. , Virginio Milena J. , Marsico Ana Grazia , Butler W. Ray , Kreiswirth Barry N. , Suffys Philip N. , Lapa e Silva Jose Roberto , Ho John L. 
Published: September 2007

ABSTRACT

The current study evaluated
Mycobacterium tuberculosis
isolates from Rio de Janeiro, Brazil, for genomic deletions. One locus in our panel of PCR targets failed to amplify in ∼30% of strains. A single novel long sequence polymorphism (>26.3 kb) was characterized and designated RD
Rio
. Homologous recombination between two similar protein-coding genes is proposed as the mechanism for deleting or modifying 10 genes, including two potentially immunogenic PPE proteins. The flanking regions of the RD
Rio
locus were identical in all strains bearing the deletion. Genetic testing by principal genetic group, spoligotyping, variable-number tandem repeats of mycobacterial interspersed repetitive units (MIRU-VNTR), and IS
6110
-based restriction fragment length polymorphism analysis cumulatively support the idea that RD
Rio
strains are derived from a common ancestor belonging solely to the Latin American-Mediterranean spoligotype family. The RD
Rio
lineage is therefore the predominant clade causing tuberculosis (TB) in Rio de Janeiro and, as indicated by genotypic clustering in MIRU-VNTR analysis, the most significant source of recent transmission. Limited retrospective reviews of bacteriological and patient records showed a lack of association with multidrug resistance or specific risk factors for TB. However, trends in the data did suggest that RD
Rio
strains may cause a form of TB with a distinct clinical presentation. Overall, the high prevalence of this genotype may be related to enhanced virulence, transmissibility, and/or specific adaptation to a Euro-Latin American host population. The identification of RD
Rio
strains outside of Brazil points to the ongoing intercontinental dissemination of this important genotype. Further studies are needed to determine the differential strain-specific features, pathobiology, and worldwide prevalence of RD
Rio
M. tuberculosis
.
Cell-Cell Fusion Induced by Measles Virus Amplifies the Type I Interferon Response
Authors: Herschke F. , Plumet S. , Duhen T. , Azocar O. , Druelle J. , Laine D. , Wild T. F. , Rabourdin-Combe C. , Gerlier D. , Valentin H. 
Published: September 2007

ABSTRACT

Measles virus (MeV) infection is characterized by the formation of multinuclear giant cells (MGC). We report that beta interferon (IFN-β) production is amplified in vitro by the formation of virus-induced MGC derived from human epithelial cells or mature conventional dendritic cells. Both fusion and IFN-β response amplification were inhibited in a dose-dependent way by a fusion-inhibitory peptide after MeV infection of epithelial cells. This effect was observed at both low and high multiplicities of infection. While in the absence of virus replication, the cell-cell fusion mediated by MeV H/F glycoproteins did not activate any IFN-α/β production, an amplified IFN-β response was observed when H/F-induced MGC were infected with a nonfusogenic recombinant chimerical virus. Time lapse microscopy studies revealed that MeV-infected MGC from epithelial cells have a highly dynamic behavior and an unexpected long life span. Following cell-cell fusion, both of the RIG-I and IFN-β gene deficiencies were
trans
complemented to induce IFN-β production. Production of IFN-β and IFN-α was also observed in MeV-infected immature dendritic cells (iDC) and mature dendritic cells (mDC). In contrast to iDC, MeV infection of mDC induced MGC, which produced enhanced amounts of IFN-α/β. The amplification of IFN-β production was associated with a sustained nuclear localization of IFN regulatory factor 3 (IRF-3) in MeV-induced MGC derived from both epithelial cells and mDC, while the IRF-7 up-regulation was poorly sensitive to the fusion process. Therefore, MeV-induced cell-cell fusion amplifies IFN-α/β production in infected cells, and this indicates that MGC contribute to the antiviral immune response.
Distribution of Fitness and Virulence Effects Caused by Single-Nucleotide Substitutions inTobacco Etch Virus
Authors: Carrasco Purificación , de la Iglesia Francisca , Elena Santiago F. 
Published: September 2007

ABSTRACTLittle is known about the fitness and virulence consequences of single-nucleotide substitutions in RNA viral genomes, and most information comes from the analysis of nonrandom sets of mutations with strong phenotypic effect or which have been assessed in vitro, with their relevance in vivo being unclear. Here we used site-directed mutagenesis to create a collection of 66 clones ofTobacco etch potyvirus, each carrying a different, randomly chosen, single-nucleotide substitution. Competition experiments between each mutant and the ancestral nonmutated clone were performed in planta to quantitatively assess the relative fitness of each mutant genotype. Among all mutations, 40.9% were lethal, and among the viable ones, 36.4% were significantly deleterious and 22.7% neutral. Not a single case of beneficial effects was observed within the level of resolution of our measures. On average, the fitness of a genotype carrying a deleterious but viable mutation was 49% smaller than that for its unmutated progenitor. Deleterious mutational effects conformed to a beta probability distribution. The virulence of a subset of viable mutants was assessed as the reduction in the number of viable seeds produced by infected plants. Mutational effects on virulence ranged between 17% reductions and 24.4% increases. Interestingly, the only mutations showing a significant effect on virulence were hypervirulent. Competitive fitness and virulence were uncorrelated traits.
Biochemical and Genetic Analyses of Murine Hepatitis Virus Nsp15 Endoribonuclease
Authors: Kang Hyojeung , Bhardwaj Kanchan , Li Yi , Palaninathan Satheesh , Sacchettini James , Guarino Linda , Leibowitz Julian L. , Kao C. Cheng 
Published: September 2007

ABSTRACT

The goal of this project was to better define the relationship between the endoribonuclease activity of murine hepatitis virus (MHV) Nsp15 (mNsp15) and its role in virus infection. Molecular modeling demonstrated that the catalytic residues of mNsp15 are superimposable with its severe acute respiratory syndrome coronavirus ortholog. Alanine substitutions at three key residues in the mNsp15 catalytic pocket (H262, H277, and G275) and a double-mutant version (H262P and H277A) generated proteins with greatly reduced but detectable endoribonuclease activities. Furthermore, these mutant proteins demonstrated lower cleavage specificities for uridylate than wild-type (WT) mNsp15. These mutations were successfully incorporated into viruses named vH262A, vH277A, vG275A, and vH262P+H277A. All four mutant viruses formed plaques with diameters similar to that of MHV-A59 1000 (WT virus) on several different cell lines. Interestingly, viruses with a mutation at a noncatalytic residue, D324A, could not be recovered despite repeated attempts, and expression of mNsp15 containing the D324A mutation in
Escherichia coli
resulted in an insoluble protein. Plaques derived from vH262A produced approximately 6- to 13-fold fewer PFU than those from WT virus. Cells infected with mNsp15 mutant viruses accumulated lesser amounts of plus- and minus-sense subgenomic RNAs and spike protein than WT virus. The expression of mNsp15 in
trans
by transient transfection partially restored RNA synthesis by vH262A. These results demonstrate that mNsp15 is required for optimal infection by MHV.
Phylogenetic Surveillance of Viral Genetic Diversity and the Evolving Molecular Epidemiology of Human Immunodeficiency Virus Type 1
Authors: Gifford Robert J. , de Oliveira Tulio , Rambaut Andrew , Pybus Oliver G. , Dunn David , Vandamme Anne-Mieke , Kellam Paul , Pillay Deenan 
Published: September 2007

ABSTRACT

With ongoing generation of viral genetic diversity and increasing levels of migration, the global human immunodeficiency virus type 1 (HIV-1) epidemic is becoming increasingly heterogeneous. In this study, we investigate the epidemiological characteristics of 5,675 HIV-1
pol
gene sequences sampled from distinct infections in the United Kingdom. These sequences were phylogenetically analyzed in conjunction with 976 complete-genome and 3,201
pol
gene reference sequences sampled globally and representing the broad range of HIV-1 genetic diversity, allowing us to estimate the probable geographic origins of the various strains present in the United Kingdom. A statistical analysis of phylogenetic clustering in this data set identified several independent transmission chains within the United Kingdom involving recently introduced strains and indicated that strains more commonly associated with infections acquired heterosexually in East Africa are spreading among men who have sex with men. Coalescent approaches were also used and indicated that the transmission chains that we identify originated in the late 1980s to early 1990s. Similar changes in the epidemiological structuring of HIV epidemics are likely to be taking in place in other industrialized nations with large immigrant populations. The framework implemented here takes advantage of the vast amount of routinely generated HIV-1 sequence data and can provide epidemiological insights not readily obtainable through standard surveillance methods.
Human Papillomavirus E6 Proteins Mediate Resistance to Interferon-Induced Growth Arrest through Inhibition of p53 Acetylation
Authors: Hebner Christy , Beglin Melanie , Laimins Laimonis A. 
Published: September 2007

ABSTRACT
The high-risk human papillomavirus (HPV) E6 and E7 proteins act cooperatively to mediate multiple activities in viral pathogenesis. For instance, E7 acts to increase p53 levels while E6 accelerates its rate of turnover through the binding of the cellular ubiquitin ligase E6AP. Interferons are important antiviral agents that modulate both the initial and persistent phases of viral infection. The expression of HPV type 16 E7 was found to sensitize keratinocytes to the growth-inhibitory effects of interferon, while coexpression of E6 abrogates this inhibition. Treatment of E7-expressing cells with interferon ultimately resulted in cellular senescence through a process that is dependent upon acetylation of p53 by p300/CBP at lysine 382. Cells expressing mutant forms of E6 that are unable to bind p300/CBP or bind p53 failed to block acetylation of p53 at lysine 382 and were sensitive to growth arrest by interferon. In contrast, mutant forms of E6 that are unable to bind E6AP remain resistant to the effects of interferon, demonstrating that the absolute levels of p53 are not the major determinants of this activity. Finally, p53 acetylation at lysine 382 was found not to be an essential determinant of other types of senescence such as that induced by overexpression of Ras in human fibroblasts. This study identifies an important physiological role for E6 binding to p300/CBP in blocking growth arrest of human keratinocytes in the presence of interferon and so contributes to the persistence of HPV-infected cells.
A Monoclonal Fab Derived from a Human Nonimmune Phage Library Reveals a New Epitope on gp41 and Neutralizes Diverse Human Immunodeficiency Virus Type 1 Strains
Authors: Gustchina Elena , Louis John M. , Lam Son N. , Bewley Carole A. , Clore G. Marius 
Published: September 2007

ABSTRACT

A monoclonal Fab (Fab 3674) selected from a human nonimmune phage library by panning against the chimeric construct N
CCG
-gp41 (which comprises an exposed coiled-coil trimer of gp41 N helices fused in the helical phase onto the minimal thermostable ectodomain of gp41) is described. Fab 3674 is shown to neutralize diverse laboratory-adapted B strains of human immunodeficiency virus type 1 (HIV-1) and primary isolates of subtypes A, B, and C in an Env-pseudotyped-virus neutralization assay, albeit with reduced potency (approximately 25-fold) compared to that of 2F5 and 4E10. Alanine scanning mutagenesis maps a novel epitope to a shallow groove on the N helices of gp41 that is exposed between two C helices in the fusogenic six-helix bundle conformation of gp41. Bivalent Fab 3674 and the C34 peptide (a potent fusion inhibitor derived from the C helix of gp41) are shown to act at similar stages of the fusion reaction and to neutralize HIV-1 synergistically, providing additional evidence that the epitope of Fab 3674 is new and distinct from the binding site of C34.