bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structural Abnormalities in Neurons Are Sufficient To Explain the Clinical Disease and Fatal Outcome of Experimental Rabies in Yellow Fluorescent Protein-Expressing Transgenic Mice
Authors: Scott Courtney A. , Rossiter John P. , Andrew R. David , Jackson Alan C. 
Published: October 2007

ABSTRACT
Under natural conditions and in some experimental models, rabies virus infection of the central nervous system causes relatively mild histopathological changes, without prominent evidence of neuronal death despite its lethality. In this study, the effects of rabies virus infection on the structure of neurons were investigated with experimentally infected transgenic mice expressing yellow fluorescent protein (YFP) in neuronal subpopulations. Six-week-old mice were inoculated in the hind-limb footpad with the CVS strain of fixed virus or were mock infected with vehicle (phosphate-buffered saline). Brain regions were subsequently examined by light, epifluorescent, and electron microscopy. In moribund CVS-infected mice, histopathological changes were minimal in paraffin-embedded tissue sections, although mild inflammatory changes were present. Terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling and caspase-3 immunostaining showed only a few apoptotic cells in the cerebral cortex and hippocampus. Silver staining demonstrated the preservation of cytoskeletal integrity in the cerebral cortex. However, fluorescence microscopy revealed marked beading and fragmentation of the dendrites and axons of layer V pyramidal neurons in the cerebral cortex, cerebellar mossy fibers, and axons in brainstem tracts. At an earlier time point, when mice displayed hind-limb paralysis, beading was observed in a few axons in the cerebellar commissure. Toluidine blue-stained resin-embedded sections from moribund YFP-expressing animals revealed vacuoles within the perikarya and proximal dendrites of pyramidal neurons in the cerebral cortex and hippocampus. These vacuoles corresponded with swollen mitochondria under electron microscopy. Vacuolation was also observed ultrastructurally in axons and in presynaptic nerve endings. We conclude that the observed structural changes are sufficient to explain the severe clinical disease with a fatal outcome in this experimental model of rabies.
Identification of Hexon-Specific CD4 and CD8 T-Cell Epitopes for Vaccine and Immunotherapy
Authors: Leen Ann M. , Christin Anne , Khalil Mariam , Weiss Heidi , Gee Adrian P. , Brenner Malcolm K. , Heslop Helen E. , Rooney Cliona M. , Bollard Catherine M. 
Published: October 2007

ABSTRACTAdenoviral infections in the immunocompromised host are associated with significant morbidity and mortality. Although the adoptive transfer of adenovirus-specific T cells may prevent and treat such infections, the T-cell immune response to the multiplicity of adenovirus serotypes and subspecies that infect humans has not been well characterized, impeding the development of such approaches. We have, therefore, analyzed the specificities of T-cell responses to the viral capsid hexon antigen, since this structure is highly conserved in human pathogens. We screened 25 human cytotoxic T-cell lines with adenovirus specificity to extensively characterize their responses to adenoviral hexon and to identify a panel of novel CD4+and CD8+T-cell epitopes. Using a peptide library spanning the entire sequence of the hexon protein, we confirmed the responsiveness of these cytotoxic T-cell lines to seven peptides described previously and also identified 33 new CD4- or CD8-restricted hexon epitopes. Importantly, the majority of these epitopes were shared among different adenovirus subspecies, suggesting that T cells with such specificities could recognize and be protective against multiple serotypes, simplifying the task of effective adoptive transfer or vaccine-based immunotherapy for treating infection by this virus.
Heptad Repeat-Derived Peptides Block Protease-Mediated Direct Entry from the Cell Surface of Severe Acute Respiratory Syndrome Coronavirus but Not Entry via the Endosomal Pathway
Authors: Ujike Makoto , Nishikawa Hiroki , Otaka Akira , Yamamoto Naoki , Yamamoto Norio , Matsuoka Masao , Kodama Eiichi , Fujii Nobutaka , Taguchi Fumihiro 
Published: October 2007

ABSTRACT
The peptides derived from the heptad repeat (HRP) of severe acute respiratory syndrome coronavirus (SCoV) spike protein (sHRPs) are known to inhibit SCoV infection, yet their efficacies are fairly low. Recently our research showed that some proteases facilitated SCoV's direct entry from the cell surface, resulting in a more efficient infection than the previously known infection via endosomal entry. To compare the inhibitory effect of the sHRP in each pathway, we selected two sHRPs, which showed a strong inhibitory effect on the interaction of two heptad repeats in a rapid and virus-free in vitro assay system. We found that they efficiently inhibited SCoV infection of the protease-mediated cell surface pathway but had little effect on the endosomal pathway. This finding suggests that sHRPs may effectively prevent infection in the lungs, where SCoV infection could be enhanced by proteases produced in this organ. This is the first observation that HRP exhibits different effects on virus that takes the endosomal pathway and virus that enters directly from the cell surface.
Altered Pathogenesis of Porcine Respiratory Coronavirus in Pigs due to Immunosuppressive Effects of Dexamethasone: Implications for Corticosteroid Use in Treatment of Severe Acute Respiratory Syndrome Coronavirus
Authors: Jung Kwonil , Alekseev Konstantin P. , Zhang Xinsheng , Cheon Doo-Sung , Vlasova Anastasia N. , Saif Linda J. 
Published: October 2007

ABSTRACTThe pathogenesis and optimal treatments for severe acute respiratory syndrome (SARS) are unclear, although corticosteroids were used to reduce lung and systemic inflammation. Because the pulmonary pathology of porcine respiratory coronavirus (PRCV) in pigs resembles SARS, we used PRCV as a model to clarify the effects of the corticosteroid dexamethasone (DEX) on coronavirus (CoV)-induced pneumonia. Conventional weaned pigs (n= 130) in one of four groups (PRCV/phosphate-buffered saline [PBS] [n= 41], PRCV/DEX [n= 41], mock/PBS [n= 23], and mock/DEX [n= 25]) were inoculated intranasally and intratracheally with the ISU-1 strain of PRCV (1 × 107PFU) or cell culture medium. DEX was administered (once daily, 2 mg/kg of body weight/day, intramuscularly) from postinoculation day (PID) 1 to 6. In PRCV/DEX pigs, significantly milder pneumonia, fewer PRCV-positive cells, and lower viral RNA titers were present in lungs early at PID 2; however, at PID 4, 10, and 21, severe bronchointerstitial pneumonia, significantly higher numbers of PRCV-positive cells, and higher viral RNA titers were observed compared to results for PRCV/PBS pigs. Significantly lower numbers of CD2+, CD3+, CD4+, and CD8+T cells were also observed in lungs of PRCV/DEX pigs than in those of PRCV/PBS pigs at PID 8 and 10, coincident with fewer gamma interferon (IFN-γ)-secreting cells in the tracheobronchial lymph nodes as determined by enzyme-linked immunospot assay. Our results confirm that DEX treatment alleviates PRCV pneumonia early (PID 2) in the infection but continued use through PID 6 exacerbates later stages of infection (PID 4, 10, and 21), possibly by decreasing cellular immune responses in the lungs (IFN-γ-secreting T cells), thereby creating an environment for more-extensive viral replication. These data have potential implications for corticosteroid use with SARS-CoV patients and suggest a precaution against prolonged use based on their unproven efficacy in humans, including possible detrimental secondary effects.
Antiretroviral Activity and Vif Sensitivity of Rhesus Macaque APOBEC3 Proteins
Authors: Virgen Cesar A. , Hatziioannou Theodora 
Published: October 2007

ABSTRACT
The inability of human immunodeficiency virus type 1(HIV-1) to replicate in rhesus macaque cells is in part due to the failure of HIV-1 Vif to counteract the restriction factor APOBEC3G. However, in this study we demonstrate that several rhesus macaque APOBEC3 (rhAPOBEC3) proteins are capable of inhibiting HIV-1 infectivity. There was considerable variation in the ability of a panel of Vif proteins to induce degradation of rhAPOBEC3 proteins, and mutations within HIV-1 Vif that render it capable of degrading rhAPOBEC3G did not confer activity against other antiviral rhAPOBEC3 proteins. These findings suggest that multiple APOBEC3 proteins can contribute to primate lentivirus species tropism.
Binding of Human Papillomavirus Type 16 E6 to E6AP Is Not Required for Activation of hTERT
Authors: Sekaric Pedja , Cherry Jonathan J. , Androphy Elliot J. 
Published: October 2007

ABSTRACT
The human papillomavirus (HPV) type 16 (HPV16) E6 protein stimulates transcription of the catalytic subunit of telomerase, hTERT, in epithelial cells. It has been reported that binding to the ubiquitin ligase E6AP is required for this E6 activity, with E6 directing E6AP to the hTERT promoter. We previously reported two E6AP binding-defective HPV16 E6 mutations that induced immortalization of human mammary epithelial cells. Because activation of hTERT is proposed to be necessary for epithelial cell immortalization, we sought to further characterize the relationship between E6/E6AP association and telomerase induction. We demonstrate that while these E6 mutants do not bind E6AP, they retain the capability to stimulate the expression of hTERT. Chromatin immunoprecipitation assays confirmed the presence of Myc, wild-type E6, and the E6AP binding-defective E6 mutants, but not E6AP itself, at the endogenous hTERT promoter. Interestingly, an immortalization-defective E6 mutant localized to the hTERT promoter but failed to increase transcription. We conclude that binding to E6AP is not necessary for E6 localization to or activation of the hTERT promoter and that another activity of E6 is involved in hTERT activation.
Crystal Structure of the NS3 Protease-Helicase from Dengue Virus
Authors: Luo Dahai , Xu Ting , Hunke Cornelia , Grüber Gerhard , Vasudevan Subhash G. , Lescar Julien 
Published: October 2007

ABSTRACTSeveral flaviviruses are important human pathogens, including dengue virus, a disease against which neither a vaccine nor specific antiviral therapies currently exist. During infection, the flavivirus RNA genome is translated into a polyprotein, which is cleaved into several components. Nonstructural protein 3 (NS3) carries out enzymatic reactions essential for viral replication, including proteolysis of the polyprotein through its serine protease N-terminal domain, with a segment of 40 residues from the NS2B protein acting as a cofactor. The ATPase/helicase domain is located at the C terminus of NS3. Atomic structures are available for these domains separately, but a molecular view of the full-length flavivirus NS3 polypeptide is still lacking. We report a crystallographic structure of a complete NS3 molecule fused to 18 residues of the NS2B cofactor at a resolution of 3.15 Å. The relative orientation between the protease and helicase domains is drastically different than the single-chain NS3-NS4A molecule from hepatitis C virus, which was caught in the act ofciscleavage at the NS3-NS4A junction. Here, the protease domain sits beneath the ATP binding site, giving the molecule an elongated shape. The domain arrangement found in the crystal structure fits nicely into an envelope determined ab initio using small-angle X-ray scattering experiments in solution, suggesting a stable molecular conformation. We propose that a basic patch located at the surface of the protease domain increases the affinity for nucleotides and could also participate in RNA binding, explaining the higher unwinding activity of the full-length enzyme compared to that of the isolated helicase domain.
The Human T-Cell Leukemia Virus Type 1 Tax Oncoprotein Requires the Ubiquitin-Conjugating Enzyme Ubc13 for NF-κB Activation
Authors: Shembade Noula , Harhaj Nicole S. , Yamamoto Masahiro , Akira Shizuo , Harhaj Edward W. 
Published: October 2007

ABSTRACT
Ubiquitination of the human T-cell leukemia virus 1 Tax oncoprotein provides an important regulatory mechanism that promotes the Tax-mediated activation of NF-κB. However, the type of polyubiquitin chain linkages and the host factors that are required for Tax ubiquitination have not been identified. Here, we demonstrate that Tax polyubiquitin chains are composed predominantly of lysine 63-linked chains. Furthermore, the ubiquitination of Tax is critically dependent on the E2 ubiquitin-conjugating enzyme Ubc13. Tax interacts with Ubc13, and small interfering RNA-mediated knockdown of Ubc13 expression abrogates Tax ubiquitination and the activation of NF-κB. Mouse fibroblasts lacking Ubc13 exhibit impaired Tax activation of NF-κB despite normal tumor necrosis factor- and interleukin-1-mediated NF-κB activation. Finally, the interaction of Tax with NEMO is disrupted in the absence of Tax ubiquitination and Ubc13 expression, suggesting that Tax ubiquitination is critical for NEMO binding. Collectively, our results reveal that Ubc13 is essential for Tax ubiquitination, its interaction with NEMO, and Tax-mediated NF-κB activation.
Characterization of the Human Cytomegalovirus gH/gL/UL128-131 Complex That Mediates Entry into Epithelial and Endothelial Cells
Authors: Ryckman Brent J. , Rainish Barb L. , Chase Marie C. , Borton Jamie A. , Nelson Jay A. , Jarvis Michael A. , Johnson David C. 
Published: October 2007

ABSTRACT
The entry of human cytomegalovirus (HCMV) into biologically relevant epithelial and endothelial cells involves endocytosis followed by low-pH-dependent fusion. This entry pathway is facilitated by the HCMV UL128, UL130, and UL131 proteins, which form one or more complexes with the virion envelope glycoprotein gH/gL. gH/gL/UL128-131 complexes appear to be distinct from the gH/gL/gO complex, which likely facilitates entry into fibroblasts. In order to better understand the assembly and protein-protein interactions of gH/gL/UL128-131 complexes, we generated HCMV mutants lacking UL128-131 proteins and nonreplicating adenovirus vectors expressing gH, gL, UL128, UL130, and UL131. Our results demonstrate that UL128, UL130, and UL131 can each independently assemble onto gH/gL scaffolds. However, the binding of individual UL128-131 proteins onto gH/gL can significantly affect the binding of other proteins; for example, UL128 increased the binding of both UL130 and UL131 to gH/gL. Direct interactions between gH/UL130, UL130/UL131, gL/UL128, and UL128/UL130 were also observed. The export of gH/gL complexes from the endoplasmic reticulum (ER) to the Golgi apparatus and cell surface was dramatically increased when all of UL128, UL130, and UL131 were coexpressed with gH/gL (with or without gO expression). Incorporation of gH/gL complexes into the virion envelope requires transport beyond the ER. Thus, we concluded that UL128, UL130, and UL131 must all bind simultaneously onto gH/gL for the production of complexes that can function in entry into epithelial and endothelial cells.
Hyperdiploidy Is a Common Finding in Monoclonal Gammopathy of Undetermined Significance and Monosomy 13 Is Restricted to These Hyperdiploid Patients
Authors: Brousseau Maud , Leleu Xavier , Gerard Jérémie , Gastinne Thomas , Godon Alban , Genevieve Franck , Dib Mamoun , Lai Jean-Luc , Facon Thierry , Zandecki Marc ,   for the Intergroupe Francophone du Myélome
Published: October 2007

Abstract
Purpose: Two pathways, hyperdiploid and nonhyperdiploid, are proposed for progression to plasma cell neoplasia. Implication of monosomy 13 (Δ13) is unclear in monoclonal gammopathy of undetermined significance (MGUS), and data on DNA content of plasma cells [DNA index (DI)] are rare.
Experimental Design: We ascertained DI in 169 multiple myeloma (MM) and 96 MGUS patients. Interphase fluorescence in situ hybridization (FISH) coupled to cytoplasmic staining of specific Ig (cIg-FISH) was done to look for trisomies and to ascertain Δ13.
Results: Hyperdiploidy and hypodiploidy were found in 54% and 11.5% of MGUS patients and in 59.5% and 25% of MM patients, respectively. In MGUS patients tested using probes for odd chromosomes, cIg-FISH showed association between trisomies for chromosomes 3, 7, 9, 11, or 15 and hyperdiploidy. Δ13 was found in 45.3% and 24.6% of MM and MGUS patients, respectively. Most Δ13 cases observed in MGUS were found within hyperdiploid clones, 38% versus 11% in hypodiploid cases, in sharp contrast with the occurrence of Δ13 in MM patients, 31.9% and 76.3%, respectively. That peculiar distribution of Δ13 according to DI persisted with other thresholds used to ascertain hyperdiploidy, such as DI ≥ 1.05. A strong relationship between IgA peak and hypodiploidy (P = 0.007) was only observed in MM, whereas λ light chain was significantly associated with hypodiploidy in MGUS (P = 0.001) and MM (P = 0.05). Hyperdiploidy shows similar pattern in MGUS and MM.
Conclusion: This fits well a hyperdiploid pathway leading to MM after a preceding MGUS stage. Yet-to-be-determined secondary event(s) needs to occur for the transition to MM, unrelated to changes in chromosome number or to loss of chromosome 13. In contrast, the “nonhyperdiploid” pathway needs to be clarified further because hypodiploidy is less common in MGUS than in MM and Δ13 is rare in hypodiploid MGUS patients compared with hypodiploid MM patients.
Identification of a Met-Binding Peptide from a Phage Display Library
Authors: Zhao Ping , Grabinski Tessa , Gao Chongfeng , Skinner R. Scot , Giambernardi Troy , Su Yanli , Hudson Eric , Resau James , Gross Milton , Vande Woude George F. , Hay Rick , Cao Brian 
Published: October 2007

AbstractPurpose: Aberrant c-Met expression has been implicated in most types of human cancer. We are developing Met-directed imaging and therapeutic agents.Experimental Design: To seek peptides that bind specifically to receptor Met, the Met-expressing cell lines S114 and SK-LMS-1 were used for biopanning with a random peptide phage display library. Competition ELISA, fluorescence-activated cell sorting analysis, an internalization assay, and a cell proliferation assay were used to characterize a Met-binding peptide in vitro. To evaluate the utility of the peptide as a diagnostic agent in vivo, 125I-labeled peptide was injected i.v. into nude mice bearing s.c. xenografts of the Met-expressing and hepatocyte growth factor (HGF)/scatter factor–expressing SK-LMS-1/HGF, and total body scintigrams were obtained between 1 and 24 h postinjection.Results: One Met-binding peptide (YLFSVHWPPLKA), designated Met-pep1, reacts with Met on the cell surface and competes with HGF/scatter factor binding to Met in a dose-dependent manner. Met-pep1 is internalized by Met-expressing cells after receptor binding. Met-pep1 inhibits human leiomyosarcoma SK-LMS-1 cell proliferation in vitro. In SK-LMS-1 mouse xenografts, tumor-associated activity was imaged as early as 1 h postinjection and remained visible in some animals as late as 24 h postinjection.Conclusions: Met-pep1 specifically interacts with Met: it is internalized by Met-expressing cells and inhibits tumor cell proliferation in vitro; it is a potential diagnostic agent for tumor imaging.
Canonical Nuclear Factor κB Pathway Inhibition Blocks Myeloma Cell Growth and Induces Apoptosis in Strong Synergy with TRAIL
Authors: Romagnoli Mathilde , Desplanques Grégoire , Maïga Sophie , Legouill Steven , Dreano Michel , Bataille Régis , Barillé-Nion Sophie 
Published: October 2007

AbstractPurpose: Intrinsic activation of nuclear factor κB (NF-κB) characterizes various hematologic malignancies. In this study, we specifically address the role of NF-κB blockade in mediated antimyeloma activity using the IκB kinase-2 pharmacologic inhibitor, AS602868.Experimental Design: Human myeloma cell lines (n = 16) and primary myeloma cells (n = 10) were tested for their sensitivity to AS602868 in terms of proliferation and apoptosis. Both in vitro and in vivo experiments were conducted. Functional mechanisms regarding the apoptotic pathways triggered by AS602868 were studied. The potential proapoptotic synergy between AS602868 and tumor necrosis factor–related apoptosis-inducing ligand (TRAIL) was also evaluated.Results: Our results show that AS602868 efficiently targeted the canonical NF-κB pathway in myeloma cells and potently inhibited their growth in inducing apoptosis through Bax and caspase-3 activation. AS602868 also induced apoptosis in primary myeloma cells even in the presence of bone marrow mononuclear cells. Moreover, the IκB kinase-2 inhibitor targeted the paracrine effect on the bone marrow environment. Indeed, it decreased the intrinsic and myeloma-induced secretion of interleukin-6 from bone marrow stromal cells. In addition, AS602868 inhibited myeloma cell growth in the MM.1S xenograft myeloma model. Of particular interest, AS602868 strongly increased myeloma sensitivity to TRAIL in blocking TRAIL-induced NF-κB activation and in decreasing the expression of antiapoptotic proteins such as cFLIP and cIAP-1/2.Conclusions: Taken together, our data point out the interest to inhibit the canonical NF-κB pathway in myeloma and clearly encourage clinical evaluation of novel therapies based on targeting NF-κB, especially in combination with TRAIL.
Evaluation of an 111In-Radiolabeled Peptide as a Targeting and Imaging Agent for ErbB-2 Receptor–Expressing Breast Carcinomas
Authors: Kumar Senthil R. , Quinn Thomas P. , Deutscher Susan L. 
Published: October 2007

Abstract
Purpose: The cellular targeting and tumor imaging properties of a novel ErbB-2-avid peptide, discovered from bacteriophage display, were evaluated in human breast carcinoma cells and in breast carcinoma–xenografted mice.
Experimental Design: The affinity of the ErbB-2 targeting peptide KCCYSL and its alanine substituted counterparts for the extracellular domain (ECD) of purified recombinant ErbB-2 (ErbB-2-ECD) was assessed by fluorescence titration. Binding of the KCCYSL peptide to breast and prostate carcinoma cells was analyzed by confocal microscopy. A DOTA(GSG)-KCCYSL peptide conjugate was radiolabeled with 111In, and stability, target binding, and internalization were analyzed in vitro. In vivo biodistribution and single-photon emission computed tomography imaging studies were done with the radiolabeled peptide in MDA-MB-435 human breast tumor–bearing severe combined immunodeficient mice.
Results: KCCYSL peptide exhibited high affinity (295 ± 56 nmol/L) to ErbB-2-ECD. Substitution of alanine for lysine, tryptophan, and cysteine reduced the peptide affinity ∼ 1- to 2.4-fold, whereas replacing leucine completely abolished binding. Both biotin-KCCYSL and 111In-DOTA(GSG)-KCCYSL were capable of binding ErbB-2–expressing human breast carcinoma cells in vitro. Approximately 11% of the total bound radioactivity was internalized in the carcinoma cells. Competitive binding studies indicated that the radiolabeled peptide exhibited an IC50 value of 42.5 ± 2.76 nmol/L for the breast carcinoma cells. 111In-DOTA(GSG)-KCCYSL was stable in serum and exhibited rapid tumor uptake (2.12 ± 0.32 %ID/g) at 15 min postinjection and extended retention coupled with rapid whole body disappearance, as observed by biodistribution and single-photon emission computed tomography imaging studies, respectively.
Conclusions: The DOTA(GSG)-KCCYSL peptide has the potential to be used as a tumor-imaging agent and a vehicle for specific delivery of radionuclide or cytotoxic agents for tumors overexpressing ErbB-2.