bluuebunny/crossref_metadata_2025_split huggingface dataset:
HIV Load Testing with Small Samples of Whole Blood
Authors: Steinmetzer Katrin , Seidel Thomas , Stallmach Andreas , Ermantraut Eugen 
Published: June 2010

ABSTRACTAccess to human immunodeficiency virus (HIV) viral load (VL) testing is of paramount importance for the success of antiretroviral therapy treatment campaigns throughout the world. In many countries, limited laboratory infrastructure and transport capacities preclude a substantial number of people infected with HIV from accessing the necessary testing. Point-of-care diagnostic testing methods for those with HIV infection provide a compelling solution to addressing this challenge. To facilitate ease of use in such tests, finger-stick whole blood (WB) would constitute an ideal sample type if test performance equivalent to laboratory testing could be ensured. To determine the diagnostic sensitivity of a VL assay based on small volumes of WB, we analyzed 1,094 sample pairs of 1 ml of plasma and 10 μl of WB from donors confirmed to be HIV positive. The probability of detecting HIV nucleic acids in 10 μl of blood was 59.3% (95% confidence interval, 54.9 to 63.6%), 85.1% (80.0 to 90.2%), 91.5% (88.1 to 95%), and 100% when the corresponding plasma samples had an undetectable VL, a detectable VL less than 40 viral copies/ml (cp/ml), a VL between 40 and 4,000 cp/ml, and a VL greater than 4,000 cp/ml, respectively. Capillary blood and venous blood yielded comparable diagnostic sensitivities. Furthermore, our data indicate that WB could be used to monitor VL changes after highly active antiretroviral therapy (HAART) started. Thus, we have demonstrated the feasibility of small volumes of venous and finger-stick WB as valid samples for VL testing. This approach should facilitate the development of robust point-of-care HIV VL tests.
Isolation and Detection of
Campylobacter concisus
from Saliva of Healthy Individuals and Patients with Inflammatory Bowel Disease
Authors: Zhang Li , Budiman Vanna , Day Andrew S. , Mitchell Hazel , Lemberg Daniel A. , Riordan Stephen M. , Grimm Michael , Leach Steven T. , Ismail Yazan 
Published: June 2010

ABSTRACT

The presence of
Campylobacter concisus
in the saliva of healthy individuals and patients with inflammatory bowel disease (IBD) was examined.
C
.
concisus
was detected in 97% of the healthy individuals and 100% of the patients with IBD tested. The
C
.
concisus
culture positivity rate in younger children was significantly lower than that in the other age groups.
Receptor Specificity of Influenza A H3N2 Viruses Isolated in Mammalian Cells and Embryonated Chicken Eggs
Authors: Stevens James , Chen Li-Mei , Carney Paul J. , Garten Rebecca , Foust Angie , Le Jianhua , Pokorny Barbara A. , Manojkumar Ramanunninair , Silverman Jeanmarie , Devis Rene , Rhea Karen , Xu Xiyan , Bucher Doris J. , Paulson James , Cox Nancy J. , Klimov Alexander , Donis Ruben O. 
Published: June 2010

ABSTRACTIsolation of human subtype H3N2 influenza viruses in embryonated chicken eggs yields viruses with amino acid substitutions in the hemagglutinin (HA) that often affect binding to sialic acid receptors. We used a glycan array approach to analyze the repertoire of sialylated glycans recognized by viruses from the same clinical specimen isolated in eggs or cell cultures. The binding profiles of whole virions to 85 sialoglycans on the microarray allowed the categorization of cell isolates into two groups. Group 1 cell isolates displayed binding to a restricted set of α2-6 and α2-3 sialoglycans, whereas group 2 cell isolates revealed receptor specificity broader than that of their egg counterparts. Egg isolates from group 1 showed binding specificities similar to those of cell isolates, whereas group 2 egg isolates showed a significantly reduced binding to α2-6- and α2-3-type receptors but retained substantial binding to specific O- and N-linked α2-3 glycans, including α2-3GalNAc and fucosylated α2-3 glycans (including sialyl Lewis x), both of which may be important receptors for H3N2 virus replication in eggs. These results revealed an unexpected diversity in receptor binding specificities among recent H3N2 viruses, with distinct patterns of amino acid substitution in the HA occurring upon isolation and/or propagation in eggs. These findings also suggest that clinical specimens containing viruses with group 1-like receptor binding profiles would be less prone to undergoing receptor binding or antigenic changes upon isolation in eggs. Screening cell isolates for appropriate receptor binding properties might help focus efforts to isolate the most suitable viruses in eggs for production of antigenically well-matched influenza vaccines.
Development of a Regulatable Oncolytic Herpes Simplex Virus Type 1 Recombinant Virus for Tumor Therapy
Authors: Yao Feng , Murakami Nao , Bleiziffer Oliver , Zhang Pengwei , Akhrameyeva Natali V. , Xu Ximing , Brans Richard 
Published: June 2010

ABSTRACT
Oncolytic viruses are genetically modified viruses that preferentially replicate in host cancer cells, leading to the production of new viruses and, ultimately, cell death. Currently, no oncolytic viruses that are able to kill only tumor cells while leaving normal cells intact are available. Using T-REx (Invitrogen, Carlsbad, CA) gene switch technology and a self-cleaving ribozyme, we have constructed a novel oncolytic HSV-1 recombinant, KTR27, whose replication can be tightly controlled and regulated by tetracycline in a dose-dependent manner. Infection of normal replicating cells as well as multiple human cancer cell types with KTR27 in the presence of tetracycline led to 1,000- to 250,000-fold-higher progeny virus production than in the absence of tetracycline, while little viral replication and virus-associated cytotoxicity was observed in infected growth-arrested normal human cells. We show that intratumoral inoculation with KTR27 markedly inhibits tumor growth in a xenograft model of human non-small-cell lung cancer in nude mice. It is shown further that replication of KTR27 in the inoculated tumors can be efficiently controlled by local codelivery of tetracycline to the target tumors at the time of KTR27 inoculation. Collectively, KTR27 possesses a unique pharmacological feature that can limit its replication to the targeted tumor microenvironment with localized tetracycline delivery, thus minimizing unwanted viral replication in distant tissues following local virotherapy. This regulatory mechanism would also allow the replication of the virus to be quickly shut down should adverse effects be detected.
Influence of
HLA
Class I and
HLA-KIR
Compound Genotypes on HIV-2 Infection and Markers of Disease Progression in a Manjako Community in West Africa
Authors: Yindom Louis-Marie , Leligdowicz Aleksandra , Martin Maureen P. , Gao Xiaojiang , Qi Ying , Zaman Syed M. A. , van der Loeff Maarten Schim , van Tienen Carla , Jaye Assan , Aveika Akum , Worwui Archibald , Diatta Mathurin , Vincent Tim , Whittle Hilton C. , Rowland-Jones Sarah L. , Walton Robert , Carrington Mary 
Published: June 2010

ABSTRACT

Overall, the time to AIDS after HIV-2 infection is longer than with HIV-1, and many individuals infected with HIV-2 virus remain healthy throughout their lives. Multiple
HLA
and
KIR
gene products have been implicated in the control of HIV-1, but the effect of variation at these loci on HIV-2 disease is unknown. We show here for the first time that
HLA-B*1503
is associated significantly with poor prognosis after HIV-2 infection and that
HLA-B*0801
is associated with susceptibility to infection. Interestingly, previous data indicate that
HLA-B*1503
is associated with low viral loads in HIV-1 clade B infection but has no significant effect on viral load in clade C infection. In general, alleles strongly associated with HIV-1 disease showed no effect in HIV-2 disease. These data emphasize the unique nature of the effects of
HLA
and
HLA/KIR
combinations on HIV-2 immune responses relative to HIV-1, which could be related to their distinct clinical course.
Multiple DNA Damage Signaling and Repair Pathways Deregulated by Simian Virus 40 Large T Antigen
Authors: Boichuk Sergei , Hu Liang , Hein Jennifer , Gjoerup Ole V. 
Published: June 2010

ABSTRACT

We demonstrated previously that expression of simian virus 40 (SV40) large T antigen (LT), without a viral origin, is sufficient to induce the hallmarks of a cellular DNA damage response (DDR), such as focal accumulation of γ-H2AX and 53BP1, via Bub1 binding. Here we expand our characterization of LT effects on the DDR. Using comet assays, we demonstrate that LT induces overt DNA damage. The Fanconi anemia pathway, associated with replication stress, becomes activated, since FancD2 accumulates in foci, and monoubiquitinated FancD2 is detected on chromatin. LT also induces a distinct set of foci of the homologous recombination repair protein Rad51 that are colocalized with Nbs1 and PML. The FancD2 and Rad51 foci require neither Bub1 nor retinoblastoma protein binding. Strikingly, wild-type LT is localized on chromatin at, or near, the Rad51/PML foci, but the LT mutant in Bub1 binding is not localized there. SV40 infection was previously shown to trigger ATM activation, which facilitates viral replication. We demonstrate that productive infection also triggers ATR-dependent Chk1 activation and that Rad51 and FancD2 colocalize with LT in viral replication centers. Using small interfering RNA (siRNA)-mediated knockdown, we demonstrate that Rad51 and, to a lesser extent, FancD2 are required for efficient viral replication
in vivo
, suggesting that homologous recombination is important for high-level extrachromosomal replication. Taken together, the interplay of LT with the DDR is more complex than anticipated, with individual domains of LT being connected to different subcomponents of the DDR and repair machinery.
Accessory Protein 5a Is a Major Antagonist of the Antiviral Action of Interferon against Murine Coronavirus
Authors: Koetzner Cheri A. , Kuo Lili , Goebel Scott J. , Dean Amy B. , Parker Monica M. , Masters Paul S. 
Published: June 2010

ABSTRACT

The type I interferon (IFN) response plays an essential role in the control of
in vivo
infection by the coronavirus mouse hepatitis virus (MHV). However,
in vitro
, most strains of MHV are largely resistant to the action of this cytokine, suggesting that MHV encodes one or more functions that antagonize or evade the IFN system. A particular strain of MHV, MHV-S, exhibited orders-of-magnitude higher sensitivity to IFN than prototype strain MHV-A59. Through construction of interstrain chimeric recombinants, the basis for the enhanced IFN sensitivity of MHV-S was found to map entirely to the region downstream of the spike gene, at the 3′ end of the genome. Sequence analysis revealed that the major difference between the two strains in this region is the absence of gene 5a from MHV-S. Creation of a gene 5a knockout mutant of MHV-A59 demonstrated that a major component of IFN resistance maps to gene 5a. Conversely, insertion of gene 5a, or its homologs from related group 2 coronaviruses, at an upstream genomic position in an MHV-A59/S chimera restored IFN resistance. This is the first demonstration of a coronavirus gene product that can protect that same virus from the antiviral state induced by IFN. Neither protein kinase R, which phosphorylates eukaryotic initiation factor 2, nor oligoadenylate synthetase, which activates RNase L, was differentially activated in IFN-treated cells infected with MHV-A59 or MHV-S. Thus, the major IFN-induced antiviral activities that are specifically inhibited by MHV, and possibly by other coronaviruses, remain to be identified.
Insertion of a Multibasic Cleavage Motif into the Hemagglutinin of a Low-Pathogenic Avian Influenza H6N1 Virus Induces a Highly Pathogenic Phenotype
Authors: Munster Vincent J. , Schrauwen Eefje J. A. , de Wit Emmie , van den Brand Judith M. A. , Bestebroer Theo M. , Herfst Sander , Rimmelzwaan Guus F. , Osterhaus Albert D. M. E. , Fouchier Ron A. M. 
Published: June 2010

ABSTRACT

The highly pathogenic avian influenza (HPAI) virus phenotype is restricted to influenza A viruses of the H5 and H7 hemagglutinin (HA) subtypes. To obtain more information on the apparent subtype-specific nature of the HPAI virus phenotype, a low-pathogenic avian influenza (LPAI) H6N1 virus was generated, containing an HPAI H5 RRRKKR↓G multibasic cleavage site (MBCS) motif in HA (the downward arrow indicates the site of cleavage). This insertion converted the LPAI virus phenotype into an HPAI virus phenotype
in vitro
and
in vivo
. The H6N1 virus with an MBCS displayed
in vitro
characteristics similar to those of HPAI H5 viruses, such as cleavage of HA
0
(the HA protein of influenza A virus initially synthesized as a single polypeptide precursor) and virus replication in the absence of exogenous trypsin. Studies of chickens confirmed the HPAI phenotype of the H6N1 virus with an MBCS, with an intravenous pathogenicity index of 1.4 and systemic virus replication upon intranasal inoculation, the hallmarks of HPAI viruses. This study provides evidence that the subtype-specific nature of the emergence of HPAI viruses is not at the molecular, structural, or functional level, since the introduction of an MBCS resulted in a fully functional virus with an HPAI virus genotype and phenotype.
Sphingosine 1-Phosphate-Metabolizing Enzymes Control Influenza Virus Propagation and Viral Cytopathogenicity
Authors: Seo Young-Jin , Blake Celeste , Alexander Stephen , Hahm Bumsuk 
Published: June 2010

ABSTRACT
Sphingosine 1-phosphate (S1P)-metabolizing enzymes regulate the level of sphingolipids and have important biological functions. However, the effects of S1P-metabolizing enzymes on host defense against invading viruses remain unknown. In this study, we investigated the role of S1P-metabolizing enzymes in modulating cellular responses to influenza virus infection. Overexpression of S1P lyase (SPL), which induces the degradation of S1P, interfered with the amplification of infectious influenza virus. Accordingly, SPL-overexpressing cells were much more resistant than control cells to the cytopathic effects caused by influenza virus infection. SPL-mediated inhibition of virus-induced cell death was supported by impairment of the upregulation of the proapoptotic protein Bax, a critical factor for influenza virus cytopathogenicity. Importantly, influenza virus infection of SPL-overexpressing cells induced rapid activation of extracellular signal-regulated kinase (ERK) and STAT1 but not of p38 mitogen-activated protein kinase (MAPK), Akt, or c-Jun N-terminal kinase (JNK). Blockade of STAT1 expression or inhibition of Janus kinase (JAK) activity elevated the level of influenza virus replication in the cells, indicating that SPL protects cells from influenza virus via the activation of JAK/STAT signaling. In contrast to that of SPL, the overexpression of S1P-producing sphingosine kinase 1 heightened the cells' susceptibility to influenza virus infection, an effect that was reversed by the inhibition of its kinase activity, representing opposed enzymatic activity. These findings indicate that the modulation of S1P-metabolizing enzymes is crucial for controlling the host defense against infection with influenza virus. Thus, S1P-metabolizing enzymes are novel potential targets for the treatment of diseases caused by influenza virus infection.
A Single Immunization with CoVaccine HT-Adjuvanted H5N1 Influenza Virus Vaccine Induces Protective Cellular and Humoral Immune Responses in Ferrets
Authors: Bodewes R. , Kreijtz J. H. C. M. , van Amerongen G. , Geelhoed-Mieras M. M. , Verburgh R. J. , Heldens J. G. M. , Bedwell J. , van den Brand J. M. A. , Kuiken T. , van Baalen C. A. , Fouchier R. A. M. , Osterhaus A. D. M. E. , Rimmelzwaan G. F. 
Published: June 2010

ABSTRACT
Highly pathogenic avian influenza A viruses of the H5N1 subtype continue to circulate in poultry, and zoonotic transmissions are reported frequently. Since a pandemic caused by these highly pathogenic viruses is still feared, there is interest in the development of influenza A/H5N1 virus vaccines that can protect humans against infection, preferably after a single vaccination with a low dose of antigen. Here we describe the induction of humoral and cellular immune responses in ferrets after vaccination with a cell culture-derived whole inactivated influenza A virus vaccine in combination with the novel adjuvant CoVaccine HT. The addition of CoVaccine HT to the influenza A virus vaccine increased antibody responses to homologous and heterologous influenza A/H5N1 viruses and increased virus-specific cell-mediated immune responses. Ferrets vaccinated once with a whole-virus equivalent of 3.8 μg hemagglutinin (HA) and CoVaccine HT were protected against homologous challenge infection with influenza virus A/VN/1194/04. Furthermore, ferrets vaccinated once with the same vaccine/adjuvant combination were partially protected against infection with a heterologous virus derived from clade 2.1 of H5N1 influenza viruses. Thus, the use of the novel adjuvant CoVaccine HT with cell culture-derived inactivated influenza A/H5N1 virus antigen is a promising and dose-sparing vaccine approach warranting further clinical evaluation.
Identification of Wild-Derived Inbred Mouse Strains Highly Susceptible to Monkeypox Virus Infection for Use as Small Animal Models
Authors: Americo Jeffrey L. , Moss Bernard , Earl Patricia L. 
Published: June 2010

ABSTRACT

Infection with monkeypox virus (MPXV) causes disease manifestations in humans that are similar, although usually less severe, than those of smallpox. Since routine vaccination for smallpox ceased more than 30 years ago, there is concern that MPXV could be used for bioterrorism. Thus, there is a need to develop animal models to study MPXV infection. Accordingly, we screened 38 inbred mouse strains for susceptibility to MPXV. Three highly susceptible wild-derived inbred strains were identified, of which CAST/EiJ was further developed as a model. Using an intranasal route of infection with an isolate of the Congo Basin clade of MPXV, CAST/EiJ mice exhibited weight loss, morbidity, and death in a dose-dependent manner with a calculated 50% lethal dose (LD
50
) of 680 PFU, whereas there were no deaths of BALB/c mice at a 10,000-fold higher dose. CAST/EiJ mice exhibited greater MPXV sensitivity when infected via the intraperitoneal route, with an LD
50
of 14 PFU. Both routes resulted in MPXV replication in the lung, spleen, and liver. Intranasal infection with an isolate of the less-pathogenic West African clade yielded an LD
50
of 7,600 PFU. The immune competence of CAST/EiJ mice was established by immunization with vaccinia virus, which induced antigen-specific T- and B-lymphocyte responses and fully protected mice from lethal doses of MPXV. The new mouse model has the following advantages for studying pathogenesis of MPXV, as well as for evaluation of potential vaccines and therapeutics: relative sensitivity to MPXV through multiple routes, genetic homogeneity, available immunological reagents, and commercial production.
The ESCRT-Associated Protein Alix Recruits the Ubiquitin Ligase Nedd4-1 To Facilitate HIV-1 Release through the LYPX
n
L L Domain Motif
Authors: Sette Paola , Jadwin Joshua A. , Dussupt Vincent , Bello Nana F. , Bouamr Fadila 
Published: June 2010

ABSTRACT

The p6 region of HIV-1 Gag contains two late (L) domains, PTAP and LYPX
n
L, that bind Tsg101 and Alix, respectively. Interactions with these two cellular proteins recruit members of the host's fission machinery (ESCRT) to facilitate HIV-1 release. Other retroviruses gain access to the host ESCRT components by utilizing a PPXY-type L domain that interacts with cellular Nedd4-like ubiquitin ligases. Despite the absence of a PPXY motif in HIV-1 Gag, interaction with the ubiquitin ligase Nedd4-2 was recently shown to stimulate HIV-1 release. We show here that another Nedd4-like ubiquitin ligase, Nedd4-1, corrected release defects resulting from the disruption of PTAP (PTAP
−
), suggesting that HIV-1 Gag also recruits Nedd4-1 to facilitate virus release. Notably, Nedd4-1 remediation of HIV-1 PTAP
−
budding defects is independent of cellular Tsg101, implying that Nedd4-1's function in HIV-1 release does not involve ESCRT-I components and is therefore distinct from that of Nedd4-2. Consistent with this finding, deletion of the p6 region decreased Nedd4-1-Gag interaction, and disruption of the LYPX
n
L motif eliminated Nedd4-1-mediated restoration of HIV-1 PTAP
−
. This result indicated that both Nedd4-1 interaction with Gag and function in virus release occur through the Alix-binding LYPX
n
L motif. Mutations of basic residues located in the NC domain of Gag that are critical for Alix's facilitation of HIV-1 release, also disrupted release mediated by Nedd4-1, further confirming a Nedd4-1-Alix functional interdependence. In fact we found that Nedd4-1 binds Alix in both immunoprecipitation and yeast-two-hybrid assays. In addition, Nedd4-1 requires its catalytic activity to promote virus release. Remarkably, RNAi knockdown of cellular Nedd4-1 eliminated Alix ubiquitination in the cell and impeded its ability to function in HIV-1 release. Together our data support a model in which Alix recruits Nedd4-1 to facilitate HIV-1 release mediated through the LYPX
n
L/Alix budding pathway via a mechanism that involves Alix ubiquitination.
Lentiviral Vif Degrades the APOBEC3Z3/APOBEC3H Protein of Its Mammalian Host and Is Capable of Cross-Species Activity
Authors: LaRue Rebecca S. , Lengyel Joy , Jónsson Stefán R. , Andrésdóttir Valgerdur , Harris Reuben S. 
Published: June 2010

ABSTRACT

All lentiviruses except equine infectious anemia virus (EIAV) use the small accessory protein Vif to counteract the restriction activity of the relevant APOBEC3 (A3) proteins of their host species. Prior studies have suggested that the Vif-A3 interaction is species specific. Here, using the APOBEC3H (Z3)-type proteins from five distinct mammals, we report that this is generally not the case: some lentiviral Vif proteins are capable of triggering the degradation of both the A3Z3-type protein of their normal host species and those of several other mammals. For instance, SIV
mac
Vif can mediate the degradation of the human, macaque, and cow A3Z3-type proteins but not of the sheep or cat A3Z3-type proteins. Maedi-visna virus (MVV) Vif is similarly promiscuous, degrading not only sheep A3Z3 but also the A3Z3-type proteins of humans, macaques, cows, and cats. In contrast to the neutralization capacity of these Vif proteins, human immunodeficiency virus (HIV), bovine immunodeficiency virus (BIV), and feline immunodeficiency virus (FIV) Vif appear specific to the A3Z3-type protein of their hosts. We conclude, first, that the Vif-A3Z3 interaction can be promiscuous and, second, despite this tendency, that each lentiviral Vif protein is optimized to degrade the A3Z3 protein of its mammalian host. Our results thereby suggest that the Vif-A3Z3 interaction is relevant to lentivirus biology.