bluuebunny/crossref_metadata_2025_split huggingface dataset:
Protein Interactions Targeting the Latency-Associated Nuclear Antigen of Kaposi's Sarcoma-Associated Herpesvirus to Cell Chromosomes
Authors: Krithivas Anita , Fujimuro Masahiro , Weidner Magdalena , Young David B. , Hayward S. Diane 
Published: October 2002

ABSTRACT

Maintenance of Kaposi's sarcoma-associated herpesvirus (KSHV) latent infection depends on the viral episomes in the nucleus being distributed to daughter cells following cell division. The latency-associated nuclear antigen (LANA) is constitutively expressed in all KSHV-infected cells. LANA binds sequences in the terminal repeat regions of the KSHV genome and tethers the viral episomes to chromosomes. To better understand the mechanism of chromosomal tethering, we performed glutathione
S
-transferase (GST) affinity and yeast two-hybrid assays to identify LANA-interacting proteins with known chromosomal association. Two of the interactors were the methyl CpG binding protein MeCP2 and the 43-kDa protein DEK. The interactions of MeCP2 and DEK with LANA were confirmed by coimmunoprecipitation. The MeCP2-interacting domain was mapped to the previously described chromatin binding site in the N terminus of LANA, while the DEK-interacting domain mapped to LANA amino acids 986 to 1043 in the C terminus. LANA was unable to associate with mouse chromosomes in chromosome spreads of transfected NIH 3T3 cells. However, LANA was capable of targeting to mouse chromosomes in the presence of human MeCP2 or DEK. The data indicate that LANA is tethered to chromosomes through two independent chromatin binding domains that interact with different protein partners.
Lack of an Immune Response against the Tetracycline-Dependent Transactivator Correlates with Long-Term Doxycycline-Regulated Transgene Expression in Nonhuman Primates after Intramuscular Injection of Recombinant Adeno-Associated Virus
Authors: Favre David , Blouin Véronique , Provost Nathalie , Spisek Radec , Porrot Françoise , Bohl Delphine , Marmé Frederic , Chérel Yan , Salvetti Anna , Hurtrel Bruno , Heard Jean-Michel , Rivière Yves , Moullier Philippe 
Published: October 2002

ABSTRACT

We previously documented persistent regulation of erythropoietin (Epo) secretion in mice after a single intramuscular (i.m.) injection of a recombinant adeno-associated virus (rAAV) vector harboring both the tetracycline-dependent transactivator (rtTA) and the Epo cDNA (D. Bohl, A. Salvetti, P. Moullier, and J. M. Heard, Blood
92:
1512-1517, 1998). Using the same vector harboring the cynomolgus macaque Epo cDNA instead, the present study evaluated the ability of the tetracycline-regulatable (tetR) system to establish long-term transgene regulation in nonhuman primates. The vector was administered i.m., after which 5-day induction pulses were performed monthly for up to 13 months by using doxycycline (DOX), a tetracycline analog. We show that initial inductions were successful in all individuals and that there was a tight regulation and a rapid deinduction pattern upon DOX withdrawal. For one macaque, regulation of Epo secretion was maintained during the entire experimental period; for the five remaining macaques, secreted Epo became indistinguishable from endogenous Epo upon repeated DOX inductions. We investigated the mechanism involved and showed that, except in the animal in which secretion persisted, delayed humoral and cellular immune responses were directed against the rtTA transactivator protein associated with the reduction of vector DNA in transduced muscles. This study provides some evidence that, when the immune system is not mobilized against the rtTA transactivator, the tetR-regulatable system is able to support long-term transgene regulation in the context of an rAAV in nonhuman primates. In addition, our results suggest potential improvements for vector design.
The Herpesvirus Saimiri Open Reading Frame 73 Gene Product Interacts with the Cellular Protein p32
Authors: Hall Kersten T. , Giles Mathew S. , Calderwood Michael A. , Goodwin Delyth J. , Matthews David A. , Whitehouse Adrian 
Published: October 2002

ABSTRACTThe role of the gamma-2 herpesvirus open reading frame (ORF) 73 gene product has become the focus of considerable interest. It has recently been shown that the Kaposi's sarcoma-associated herpesvirus (KSHV) latency-associated nuclear antigen (LANA) is expressed during a latent infection and can modulate both viral and cellular gene expression. The herpesvirus saimiri (HVS) ORF 73 gene product has some sequence homology to LANA; however, the role of HVS ORF 73 is unknown. We have previously demonstrated that HVS ORF73 is expressed in a stably transduced human carcinoma cell line, where HVS genomes persist as nonintegrated circular episomes. This implies that there may be some functional homology between these proteins. To further investigate the role of the HVS ORF 73 protein, the yeast two-hybrid system was employed to identify interacting cellular proteins. We demonstrate that ORF 73 interacts with the cellular protein p32 and triggers the accumulation of p32 in the nucleus. Using reporter gene-based transient-transfection assays, we demonstrate that ORF 73 can transactivate a number of heterologous promoter constructs and also upregulate its own promoter. Moreover, ORF 73 and p32 act synergistically to transactivate these promoters. The binding of ORF 73 to p32 is mediated by an amino-terminal arginine-rich domain, which contains two functionally distinct nuclear localization signals. The p32 binding domains are required for ORF 73 transactivating abilities and for ORF 73 to induce nuclear accumulation of p32. These results suggest that ORF 73 can function as a regulator of gene expression and that p32 is involved in ORF 73-dependent transcriptional activation.
Both Mucosal and Systemic Routes of Immunization with the Live, Attenuated NYVAC/Simian Immunodeficiency Virus SIVgpeRecombinant Vaccine Result in Gag-Specific CD8+T-Cell Responses in Mucosal Tissues of Macaques
Authors: Stevceva Liljana , Alvarez Xavier , Lackner Andrew A. , Tryniszewska Elzbieta , Kelsall Brian , Nacsa Janos , Tartaglia Jim , Strober Warren , Franchini Genoveffa 
Published: October 2002

ABSTRACTAs most human immunodeficiency virus (HIV) infection occurs via mucosal surfaces, an important goal of vaccination may be the induction of virus-specific immune responses at mucosal sites to contain viral infection early on. Here we designed a study in macaques carrying the major histocompatibility complex class I Mamu-A∗01 molecule to assess the capacity of the highly attenuated poxvirus NYVAC/simian immunodeficiency virus (SIV) SIVgpevaccine candidate administered by the intranasal, intramuscular, or intrarectal route to induce mucosal immunity. All macaques, including one naive macaque, were exposed to SIVmac251by the intrarectal route and sacrificed 48 h after infection. The kinetics of immune response at various time points following immunization with NYVAC/SIVgpeand the anamnestic response to SIVmac251at 48 h after challenge were assessed in blood, in serial rectal and vaginal biopsy samples, and in tissues at euthanasia with an SIVmacGag-specific tetramer. In addition, at euthanasia, antigen-specific cells producing gamma interferon or tumor necrosis factor alpha from the jejunum lamina propria were quantified in all macaques. Surprisingly, antigen-specific CD8+T cells were found in the mucosal tissues of all immunized macaques regardless of whether the vaccine was administered by a mucosal route (intranasal or intrarectal) or systemically. In addition, following mucosal SIVmac251challenge, antigen-specific responses were mainly confined to mucosal tissues, again regardless of the route of immunization. We conclude that immunization with a live vector vaccine results in the appearance of CD8+T-cell responses at mucosal sites even when the vaccine is delivered by nonmucosal routes.
Age-Dependent Resistance to Lethal Alphavirus Encephalitis in Mice: Analysis of Gene Expression in the Central Nervous System and Identification of a Novel Interferon-Inducible Protective Gene, MouseISG12
Authors: Labrada Lucia , Liang Xiao Huan , Zheng Wei , Johnston Christine , Levine Beth 
Published: October 2002

ABSTRACTSeveral different mammalian neurotropic viruses produce an age-dependent encephalitis characterized by more severe disease in younger hosts. To elucidate potential factors that contribute to age-dependent resistance to lethal viral encephalitis, we compared central nervous system (CNS) gene expression in neonatal and weanling mice that were either mock infected or infected intracerebrally with a recombinant strain, dsTE12Q, of the prototype alphavirus Sindbis virus. In 1-day-old mice, infection with dsTE12Q resulted in rapidly fatal disease associated with high CNS viral titers and extensive CNS apoptosis, whereas in 4-week-old mice, dsTE12Q infection resulted in asymptomatic infection with lower CNS virus titers and undetectable CNS apoptosis. GeneChip expression comparisons of mock-infected neonatal and weanling mouse brains revealed developmental regulation of the mRNA expression of numerous genes, including some apoptosis regulatory genes, such as the proapoptotic molecules caspase-3 and TRAF4, which are downregulated during development, and the neuroprotective chemokine, fractalkine, which is upregulated during postnatal development. In parallel with increased neurovirulence and increased viral replication, Sindbis virus infection in 1-day-old mice resulted in both a greater number of host inflammatory genes with altered expression and greater changes in levels of host inflammatory gene expression than infection in 4-week-old mice. Only one inflammatory response gene, an expressed sequence tag similar to humanISG12, increased by a greater magnitude in infected 4-week-old mouse brains than in infected 1-day-old mouse brains. Furthermore, we found that enforced neuronal ISG12 expression results in a significant delay in Sindbis virus-induced death in neonatal mice. Together, our data identify genes that are developmentally regulated in the CNS and genes that are differentially regulated in the brains of different aged mice in response to Sindbis virus infection.
Elevated Levels of Tumor Necrosis Factor Alpha (TNF-α) in Human Immunodeficiency Virus Type 1-Transgenic Mice: Prevention of Death by Antibody to TNF-α
Authors: De Swapan K. , Devadas Krishnakumar , Notkins Abner Louis 
Published: October 2002

ABSTRACTHomozygous human immunodeficiency virus type 1 (HIV-1)-transgenic mice (Tg26) appear normal at birth but die within 3 to 4 weeks. The skin of these animals shows diffuse scaling and high-level expression of both HIV-1 mRNA and gp120. Previous experiments showed that treatment with human chorionic gonadatropin (hCG) prevented death and the expression of HIV-1 mRNA and gp120. The present experiments were initiated to study the role of tumor necrosis factor alpha (TNF-α) in HIV-1-induced pathology. Examination of the sera of Tg26 mice revealed a 50-fold increase in TNF-α levels compared to those in nontransgenic mice. Treatment with antibody to TNF-α prevented death, resulted in near normal growth, and produced a marked decrease in skin lesions and a profound reduction in the expression of HIV-1 mRNA and gp120. Both TNF-α antibody and hCG reduced TNF-α levels in sera by approximately 75%. We conclude that TNF-α contributes in a major way to HIV-1-induced pathology in transgenic mice and that both hCG and antibody to TNF-α prevent the development of pathology by suppressing the level of TNF-α.
Immune-Mediated Positive Selection Drives Human Immunodeficiency Virus Type 1 Molecular Variation and Predicts Disease Duration
Authors: Ross Howard A. , Rodrigo Allen G. 
Published: October 2002

ABSTRACT

Using likelihood-based evolutionary methods, we demonstrate that the broad genetic diversity of human immunodeficiency virus type 1 (HIV-1) in an infected individual is a consequence of site-specific positive selection for diversity, a likely consequence of immune recognition. In particular, the extent of positive selection appears to be a good predictor of disease duration. Positively selected sites along HIV-1 partial
env
sequences are numerous but not distributed uniformly. In a sample of eight patients studied longitudinally, the proportion of sites per sample under positive selection was a statistically significant predictor of disease duration. Among long-term progressors, positive selection persisted at sites over time and appears to be associated with helper T-cell epitopes. In contrast, sites under positive selection shifted from one longitudinal sample to the next in short-term progressors. Our study is consistent with the hypothesis that a broad and persistent immunologic response is associated with a slower rate of disease progression. In contrast, narrow, shifting immune responses characterize short-term progressors.
Reversible Binding of Recombinant Human Immunodeficiency Virus Type 1 Gag Protein to Nucleic Acids in Virus-Like Particle Assembly In Vitro
Authors: Feng Ya-Xiong , Li Tong , Campbell Stephen , Rein Alan 
Published: October 2002

ABSTRACT

Recombinant human immunodeficiency virus type 1 (HIV-1) Gag protein can assemble into virus-like particles (VLPs) in suitable buffer conditions with nucleic acid. We have explored the role of nucleic acid in this assembly process. HIV-1 nucleocapsid protein, a domain of Gag, can bind to oligodeoxynucleotides with the sequence d(TG)
n
with more salt resistance than to d(A)
n
oligonucleotides. We found that assembly of VLPs on d(TG)
n
oligonucleotides was more salt resistant than assembly on d(A)
n
; thus, the oligonucleotides do not simply neutralize basic residues in Gag but provide a binding surface upon which Gag molecules assemble into VLPs. We also found that Gag molecules could be “trapped” on internal d(TG)
n
sequences within 40-base oligonucleotides, rendering them unable to take part in assembly. Thus, assembly on oligonucleotides requires that Gag proteins bind near the ends of the nucleic acid, and binding of Gag to internal d(TG)
n
sequences is apparently cooperative. Finally, we showed that nucleic acids in VLPs can exchange with nucleic acids in solution; there is a hierarchy of preferences in these exchange reactions. The results are consistent with an equilibrium model of in vitro assembly and may help to explain how Gag molecules in vivo select genomic RNA despite the presence in the cell of a vast excess of cellular mRNA molecules.
Deletion of Epstein-Barr Virus Regulatory Sequences Upstream of the EBNA Gene Promoter Wp1 Is Unfavorable for B-Cell Immortalization
Authors: Yoo Lina I. , Woloszynek Josh , Templeton Steven , Speck Samuel H. 
Published: October 2002

ABSTRACT

Transcription of the six Epstein-Barr virus (EBV) EBNA genes is coordinately regulated, being driven by either the Cp promoter, which is encoded within the unique region just upstream of the EBV major internal repeat (IR-1), or by the Wp promoter, which is encoded within the IR-1 repeat and thus present in multiple copies. Previous analyses of Cp- and Wp-initiated transcription have identified a shared
cis
-regulatory element mapping to the region extending from −169 to −369 bp upstream of the Wp transcription initiation site (M. T. Puglielli, N. Desai, and S. H. Speck, J. Virol. 71:120-128, 1997). To assess the impact of this regulatory region on Cp and Wp activity in the context of the viral genome, we attempted to delete this regulatory region upstream of the first copy of Wp (Wp1). While 10 recombinant viruses were obtained in which this deletion was incorporated in the interior of the IR-1 repeat, only a single lymphoblastoid cell line (LCL) immortalized by a recombinant EBV harboring the deletion upstream of Wp1 was recovered. In contrast, using a control targeting vector in which the Wp regulatory sequences were intact but which contained a sequence tag within the W0 exon, we demonstrated that of the five recombinant viruses analyzed in which the crossover event had occurred upstream of the Wp sequence tag, four had incorporated the tagged sequences into Wp1 of the virus. Taken together, these results indicate that deletion of the regulatory sequences from −369 to −169 bp upstream of Wp1 is unfavorable for EBV-driven B-cell immortalization but is tolerated within the interior of the IR-1 repeat. Analysis of promoter usage in the clone 9-60 LCL, in which the W enhancer sequences were deleted upstream of Wp1, revealed the following: (i) the level of Cp-initiated transcription was significantly diminished compared to that of wild-type LCLs; (ii) the decreased Cp-initiated transcription was not efficiently compensated by transcription initiation from Wp1; and (iii) transcription initiation from downstream Wp promoters was detectable. This is the first report of an LCL in which transcription initiation from a Wp downstream of Wp1 has been documented.
Altered DNA Mutation Spectrum in Aflatoxin B1-Treated Transgenic Mice That Express the Hepatitis B Virus X Protein
Authors: Madden Charles R. , Finegold Milton J. , Slagle Betty L. 
Published: October 2002

ABSTRACT

Humans chronically infected with hepatitis B virus (HBV) are at further risk of liver cancer upon exposure to dietary aflatoxin B1 (AFB1), a carcinogenic product of the mold
Aspergillus flavus.
For the present study, we utilized double-transgenic mice (ATX mice) that express the HBV X protein (HBx) and possess a bacteriophage lambda transgene to evaluate the in vivo effect of HBx expression on AFB1-induced DNA mutations. The expression of HBx correlated with a 24% increase in mutation frequency overall and an approximately twofold increase in the incidence of G/C-to-T/A transversion mutations following AFB1 exposure. These results are consistent with a model in which expression of HBx during chronic HBV infection may contribute to the development of hepatocellular carcinoma following exposure to environmental carcinogens.
Diverging Effects of Human Recombinant Anti-Hepatitis C Virus (HCV) Antibody Fragments Derived from a Single Patient on the Infectivity of a Vesicular Stomatitis Virus/HCV Pseudotype
Authors: Burioni Roberto , Matsuura Yoshiharu , Mancini Nicasio , Tani Hideki , Miyamura Tatsuo , Varaldo Pietro E. , Clementi Massimo 
Published: October 2002

ABSTRACT
Hepatitis C virus (HCV) is the major causative agent of blood-borne non-A, non-B hepatitis. Although a strong humoral response is detectable within a few weeks of primary infection and during viral persistence, the role played by antibodies against HCV envelope glycoproteins in controlling viral replication is still unclear. We describe how human monoclonal anti-HCV E2 antibody fragments isolated from a chronically HCV-infected patient differ sharply in their abilities to neutralize infection of HepG2 cells by a vesicular stomatitis virus pseudotype bearing HCV envelope glycoproteins. Two clones were able to neutralize the pseudotype virus at a concentration of 10 μg/ml, while three other clones completely lacked this activity. These data can explain the lack of protection and the possibility of reinfection that occur even in the presence of a strong antiviral antibody response.
The Evolution of an Energy Analyst: Some Personal Reflections
Authors: Reddy Amulya K. N. 
Published: October 2002

[Figure: see text]▪ Abstract  The evolution from an electrochemist was motivated by a growing conviction that Indian science and technology should be reoriented. A cell was created in the Indian Institute of Science in 1974 to initiate and promote work of rural relevance as a weapon against poverty. Surveys led to a detailed empirical study of energy consumption patterns in villages and to the design and construction of rural energy centers. The lessons from this village work are described.The principal outcome of the collaboration with J. Goldemberg (Brazil), T.B. Johansson (Sweden), and R.H. Williams (United States) was the book Energy for a Sustainable World that contributed significantly to the new paradigm for energy. The application of this paradigm resulted in a detailed electricity demand scenario for the South Indian state of Karnataka. Following mandatory retirement from the Indian Institute of Science, the International Energy Initiative (IEI) was set up in 1991 as a Southern-conceived, Southern-led, Southern-located South-North partnership. Persisting personal concerns about the ethical implications of science resurfaced through opposition to India's nuclear tests in 1998 and a visit to the concentration camps at Auschwitz. The associated human dimensions of energy were emphasized in the acceptance speech at Göteborg of the Volvo Environment Prize 2000. The penultimate endgame involved retirement.
Neural Correlates of British Sign Language Comprehension: Spatial Processing Demands of Topographic Language
Authors: MacSweeney Mairéad , Woll Bencie , Campbell Ruth , Calvert Gemma A. , McGuire Philip K. , David Anthony S. , Simmons Andrew , Brammer Michael J. 
Published: October 2002

Abstract
In all signed languages used by deaf people, signs are executed in “sign space” in front of the body. Some signed sentences use this space to map detailed “real-world” spatial relationships directly. Such sentences can be considered to exploit sign space “topographically.” Using functional magnetic resonance imaging, we explored the extent to which increasing the topographic processing demands of signed sentences was reflected in the differential recruitment of brain regions in deaf and hearing native signers of the British Sign Language. When BSL signers performed a sentence anomaly judgement task, the occipito-temporal junction was activated bilaterally to a greater extent for topographic than nontopo-graphic processing. The differential role of movement in the processing of the two sentence types may account for this finding. In addition, enhanced activation was observed in the left inferior and superior parietal lobules during processing of topographic BSL sentences. We argue that the left parietal lobe is specifically involved in processing the precise configuration and location of hands in space to represent objects, agents, and actions. Importantly, no differences in these regions were observed when hearing people heard and saw English translations of these sentences. Despite the high degree of similarity in the neural systems underlying signed and spoken languages, exploring the linguistic features which are unique to each of these broadens our understanding of the systems involved in language comprehension.