bluuebunny/crossref_metadata_2025_split huggingface dataset:
ANTIOXIDANT ACTIVITY OF ALMOND SEED EXTRACT AND ITS FRACTIONS
Authors: AMAROWICZ RYSZARD , TROSZYŃSKA AGNIESZKA , SHAHIDI FEREIDOON 
Published: November 2005

ABSTRACT Phenolic compounds were extracted from defatted almond seeds using 80% aqueous acetone. Crude extract was applied onto a Sephadex LH‐20 column. Fraction I consisting of low‐molecular‐weight phenolics was eluted from the column by ethanol. Fraction II consisting of tannins was obtained using water‐acetone (1:1, v/v) as the mobile phases. Phenolic compounds present in the crude extract and its fractions showed antioxidant and antiradical properties as revealed following studies using a β‐carotene‐linoleate model system, total antioxidant activity (TAA) method, 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical scavenging activity and reducing power evaluation. Results of these assays showed highest values when tannins (fraction II) were tested. For example, TAA of tannin fraction was 3.93 mmol Trolox/g, whereas the crude extract and fraction I showed values of only 0.24 and 0.09 μmol Trolox/mg, respectively. The content of total phenolics in fraction II was the highest (80.4 mg/g). The content of tannins in this fraction determined using the vanillin method and expressed as absorbance units at 500 nm per 1 g was 2436. The high‐performance liquid chromatography (HPLC) analysis of almond seed crude extract showed the presence of phenolic compounds, namely vanillic, caffeic, p‐coumaric, ferulic acids (after basic hydrolysis), quercetin, kaempferol and isorhamnetin (after acidic hydrolysis), delphinidin and cyanidin (after n‐butanol‐HCl hydrolysis) and procyanidin B2 and B3.
PREPARATION AND ANTIOXIDANT ACTIVITY OF EPIGALLOCATECHIN GALLATE OCTADECANOATE
Authors: DU QIZHEN , SHEN LIANQING 
Published: November 2005

ABSTRACT To prepare a liposoluble antioxidant, the esterification reaction between octadecanoyl chloride and epigallocatechin‐3‐O‐gallate (EGCG) from green tea was conducted. The main reaction product, EGCG–octadecanoate (EGCGO), was isolated from the reaction mixture; and its antioxidant activity was assayed using 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical scavenging and inhibition of peroxide formation in soybean oil. The solubility of EGCGO in soybean oil was 11.7 g/L. The relative antioxidant power of EGCGO was 78% of that of the EGCG's and 278% of that of the butylated hydroxytoluene's based on DPPH radical scavenging activity. The relative antioxidant activity was 2.4 times that of vitamin E's on the basis of inhibiting peroxide formation in soybean oil. The results show that it was feasible to prepare a liposoluble antioxidant through the esterification of EGCG.
Endocytosis and a Low-pH Step Are Required for Productive Entry of Equine Infectious Anemia Virus
Authors: Brindley Melinda A. , Maury Wendy 
Published: November 2005

ABSTRACT
Recently, it has become evident that entry of some retroviruses into host cells is dependent upon a vesicle-localized, low-pH step. The entry mechanism of equine infectious anemia virus (EIAV) has yet to be examined. Here, we demonstrate that wild-type strains of EIAV require a low-pH step for productive entry. Lysosomotropic agents that inhibit the acidification of internal vesicles inhibited productive entry of EIAV. The presence of ammonium chloride (30 mM), monensin (30 μM), or bafilomycin A (50 nM) in the medium dramatically decreased the number of EIAV antigen-positive cells. We found that a low-pH step was required for EIAV infection of tissue culture cell lines as well as primary cells, such as endothelial cells and monocyte-derived macrophages. The ammonium chloride treatment did not reduce virion stability, nor did the treatment prevent virion binding to cells. Consistent with a requirement for a low-pH step, virion infectivity was enhanced more than threefold by brief low-pH treatment following binding of viral particles to permissive cells. A superinfecting variant strain of EIAV, vMA-1c, did not require a low-pH step for productive infection of fibroblasts. However, lysosomotropic agents were inhibitory to vMA-1c infection in the other cell types that vMA-1c infected but did not superinfect, indicating that the entry pathway used by vMA-1c for superinfection abrogates the need for the low-pH step.
Receptor-Mediated Entry by Equine Infectious Anemia Virus Utilizes a pH-Dependent Endocytic Pathway
Authors: Jin Sha , Zhang Baoshan , Weisz Ora A. , Montelaro Ronald C. 
Published: November 2005

ABSTRACT

Previous studies of human and nonhuman primate lentiviral entry mechanisms indicate a predominant use of pH-independent pathways, although more recent studies of human immunodeficiency virus type 1 entry appear to reveal the use of a low-pH-dependent entry pathway in certain target cells. To expand the characterization of the specificity of lentiviral entry mechanisms, we have in the current study examined the entry pathway of equine infectious anemia virus (EIAV) during infection of its natural target, equine macrophages, permissive equine fibroblastic cell lines, and an engineered mouse cell line expressing the recently defined equine lentivirus receptor-1. The specificity of EIAV entry into these various cells was determined by assaying the effects of specific drug treatments on the level of virus entry as measured by quantitative real-time PCR assay of early reverse transcripts or by measurements of virion production. The results of these studies demonstrated that EIAV entry into all cell types was substantially inhibited in a dose-dependent manner by treatment with the vacuolar H
+
-ATPase inhibitors concanamycin A and bafilomycin A1 or the lysosomotropic weak base ammonium chloride. In contrast, treatments with sucrose to block clathrin-mediated endocytosis or with chloroquine to block organelle acidification failed to inhibit EIAV entry into the same target cells. The observed inhibition of EIAV entry was shown not to be related to cytotoxicity. Taken together, these experiments reveal for the first time that EIAV receptor-mediated entry into target cells is via a low-pH-dependent endocytic pathway.
Akt/Protein Kinase B Activation by Adenovirus Vectors Contributes to NFκB-Dependent CXCL10 Expression
Authors: Liu Qiang , White Lindsay R. , Clark Sharon A. , Heffner Daniel J. , Winston Brent W. , Tibbles Lee Anne , Muruve Daniel A. 
Published: November 2005

ABSTRACT

In gene therapy, the innate immune system is a significant barrier to the effective application of adenovirus (Ad) vectors. In kidney epithelium-derived (REC) cells, serotype 5 Ad vectors induce the expression of the chemokine CXCL10 (IP-10), a response that is dependent on NFκB. Compared to the parental vector AdLuc, transduction with the RGD-deleted vector AdL.PB resulted in reduced CXCL10 activation despite increasing titers, implying that RGD-α
V
integrin interactions contribute to adenovirus induction of inflammatory genes. Akt, a downstream effector of integrin signaling, was activated within 10 min of transduction with Ad vectors in a dose-dependent manner. Akt activation was not present following transduction with AdL.PB, confirming the importance of capsid-α
V
integrin interactions in Ad vector Akt activation. Inhibition of the phosphoinositide-3-OH kinase/Akt pathway by Wortmannin or Ly294002 compounds decreased Ad vector induction of CXCL10 mRNA. Similarly, adenovirus-mediated overexpression of the dominant negative AktAAA decreased CXCL10 mRNA expression compared to the reporter vector AdLacZ alone. The effect of Akt on CXCL10 mRNA expression occurred via NFκB-dependent transcriptional activation, since AktAAA overexpression and Ly294002 both inhibited CXCL10 and NFκB promoter activation in luciferase reporter experiments. These results show that Akt plays a role in the Ad vector activation of NFκB and CXCL10 expression. Understanding the mechanism underlying the regulation of host immunomodulatory genes by adenovirus vectors will lead to strategies that will improve the efficacy and safety of these agents for clinical use.
Interaction of Rotavirus with Human Myeloid Dendritic Cells
Authors: Narváez Carlos F. , Angel Juana , Franco Manuel A. 
Published: November 2005

ABSTRACTWe have previously shown that very few rotavirus (RV)-specific T cells that secrete gamma interferon circulate in recently infected and seropositive adults and children. Here, we have studied the interaction of RV with myeloid immature (IDC) and mature dendritic cells (MDC) in vitro. RV did not induce cell death of IDC or MDC and induced maturation of between 12 and 48% of IDC. Nonetheless, RV did not inhibit the maturation of IDC or change the expression of maturation markers on MDC. After treatment with RV, few IDC expressed the nonstructural viral protein NSP4. In contrast, a discrete productive viral infection was shown in MDC of a subset of volunteers, and between 3 and 46% of these cells expressed NSP4. RV-treated IDC secreted interleukin 6 (IL-6) (but not IL-1β, IL-8, IL-10, IL-12, tumor necrosis factor alpha, or transforming growth factor beta), and MDC released IL-6 and small amounts of IL-10 and IL-12p70. The patterns of cytokines secreted by T cells stimulated by staphylococcal enterotoxin B presented by MDC infected with RV or uninfected were comparable. The frequencies and patterns of cytokines secreted by memory RV-specific T cells evidenced after stimulation of peripheral blood mononuclear cells (PBMC) with RV were similar to those evidenced after stimulation of PBMC with RV-infected MDC. Finally, IDC treated with RV strongly stimulated naive allogeneic CD4+T cells to secrete Th1 cytokines. Thus, although RV does not seem to be a strong maturing stimulus for DC, it promotes their capacity to prime Th1 cells.
Envelope Is a Major Viral Determinant of the Distinct In Vitro Cellular Transformation Tropism of Human T-Cell Leukemia Virus Type 1 (HTLV-1) and HTLV-2
Authors: Xie Li , Green Patrick L. 
Published: November 2005

ABSTRACTHuman T-cell leukemia virus type 1 (HTLV-1) and HTLV-2 are related deltaretroviruses but are distinct in their disease-inducing capacity. These viruses can infect a variety of cell types, but only T lymphocytes become transformed, which is defined in vitro as showing indefinite interleukin-2-independent growth. Studies have indicated that HTLV-1 has a preferential tropism for CD4+T cells in vivo and is associated with the development of leukemia and neurological disease. Conversely, the in vivo T-cell tropism of HTLV-2 is less clear, although it appears that CD8+T cells preferentially harbor the provirus, with only a few cases of disease association. The difference in T-cell transformation tropism has been confirmed in vitro as shown by the preferential transformation of CD4+T cells by HTLV-1 versus the transformation of CD8+T cells by HTLV-2. Our previous studies showed that Tax and overlapping Rex do not confer the distinct T-cell transformation tropisms between HTLV-1 and HTLV-2. Therefore, for this study HTLV-1 and HTLV-2 recombinants were generated to assess the contribution of LTR andenvsequences in T-cell transformation tropism. Both sets of proviral recombinants expressed p19 Gag following transfection into cells. Furthermore, recombinant viruses were replication competent and had the capacity to transform T lymphocytes. Our data showed that exchange of theenvgene resulted in altered T-cell transformation tropism compared to wild-type virus, while exchange of long terminal repeat sequences had no significant effect. HTLV-2/Env1 preferentially transformed CD4+Tcells similarly to wild-type HTLV-1 (wtHTLV-1), whereas HTLV-1/Env2 had a transformation tropism similar to that of wtHTLV-2 (CD8+T cells). These results indicate thatenvis a major viral determinant for HTLV T-cell transformation tropism in vitro and provides strong evidence implicating its contribution to the distinct pathogenesis resulting from HTLV-1 versus HTLV-2 infections.
Clearance of Herpes Simplex Virus Type 2 by CD8+T Cells Requires Gamma Interferon and either Perforin- or Fas-Mediated Cytolytic Mechanisms
Authors: Dobbs Melanie E. , Strasser Jane E. , Chu Chin-Fun , Chalk Claudia , Milligan Gregg N. 
Published: November 2005

ABSTRACTThe T-cell-mediated resolution of herpes simplex virus type 2 (HSV-2) genital infections is not fully understood. In these studies, the mechanisms by which CD8+T cells clear virus from the genital epithelium were examined. Ovalbumin (OVA)-specific CD8+T cells from OT-I transgenic mice cleared a thymidine kinase-deficient, ovalbumin-expressing HSV-2 virus (HSV-2 tk−OVA) from the genital epithelium of recipient mice, and clearance was abrogated by in vivo neutralization of gamma interferon (IFN-γ). Further, CD8+OT-I T cells deficient in IFN-γ were unable to clear HSV-2 tk−OVA from the vaginal epithelium. The requirement for cytolytic mechanisms in HSV-2 tk−OVA clearance was tested in radiation chimeras by adoptive transfer of wild-type or perforin-deficient OT-I T cells to irradiated Fas-defective or wild-type recipients. Although a dramatic decrease in viral load was observed early after challenge with HSV-2 tk−OVA, full resolution of the infection was not achieved in recipients lacking both perforin- and Fas-mediated cytolytic pathways. These results suggest that IFN-γ was responsible for an early rapid decrease in HSV-2 virus titer. However, either perforin- or Fas-mediated cytolytic mechanisms were required to achieve complete clearance of HSV-2 from the genital epithelium.
Protection from Interferon-Induced Apoptosis by Epstein-Barr Virus Small RNAs Is Not Mediated by Inhibition of PKR
Authors: Ruf Ingrid K. , Lackey Kristen A. , Warudkar Swati , Sample Jeffery T. 
Published: November 2005

ABSTRACT
The Epstein-Barr virus (EBV) EBER transcripts are small, highly structured RNAs able to bind to and inhibit activation of the double-stranded RNA-dependent protein kinase PKR in cell-free systems, and within latently infected B-cell lines they inhibit alpha interferon-induced apoptosis that is believed to be mediated through PKR. Here, we address the consequences of EBER expression for PKR activation in vivo in response to alpha interferon. In agreement with published findings, either EBV infection or the EBERs alone protected Burkitt lymphoma cells from alpha-interferon-induced apoptosis. However, utilizing multiple phosphorylation state-specific antibodies to monitor PKR activation within cells in response to interferon, we demonstrate that the EBERs are unable to inhibit phosphorylation of either cytoplasmic or nuclear PKR. Concordantly, a direct substrate of PKR, the α subunit of eukaryotic initiation factor 2 (eIF-2α), was equally phosphorylated in EBV-positive and EBV-negative cells following interferon treatment. Therefore, EBER inhibition of alpha-interferon-induced apoptosis, and potentially other PKR-mediated events, is unlikely to be mediated through direct inhibition of PKR, as previously thought.
Effect of Mutations in the Mouse Hepatitis Virus 3′(+)42 Protein Binding Element on RNA Replication
Authors: Johnson Reed F. , Feng Min , Liu Pinghua , Millership Jason J. , Yount Boyd , Baric Ralph S. , Leibowitz Julian L. 
Published: November 2005

ABSTRACT

The mouse hepatitis virus (MHV) genome's 3′ untranslated region contains
cis
-acting sequences necessary for replication. Studies of MHV and other coronaviruses have indicated a role for RNA secondary and tertiary elements in replication. Previous work in our laboratory has identified four proteins which form ribonucleoprotein complexes with the 3′-terminal 42 nucleotides [3′(+)42] of the MHV genome. Defective interfering (DI) RNA replication assays have demonstrated a role for the 3′(+)42 host protein binding element in the MHV life cycle. Using gel mobility shift RNase T
1
protection assays and secondary structure modeling, we have characterized a possible role for RNA secondary structure in host protein binding to the 3′-terminal 42-nucleotide element. Additionally we have identified a role for the 3′-terminal 42-nucleotide host protein binding element in RNA replication and transcription using DI RNA replication assays and targeted recombination and by directly constructing mutants in this protein binding element using a recently described MHV reverse genetic system. DI RNA replication assays demonstrated that mutations in the 3′(+)42 host protein binding element had a deleterious effect on the accumulation of DI RNA. When the identical mutations were directly inserted into the MHV genome, most mutant genomes were viable but formed smaller plaques than the wild-type parent virus. One mutant was not viable. This mutant directed the synthesis of genome-sized negative-sense RNA approximately as efficiently as the wild type did but had a defect in subgenomic mRNA synthesis. These results point to a potential role for sequences at the extreme 3′ end of the MHV genome in subgenomic RNA synthesis.
Frequency, Proliferation, and Activation of Human Memory T Cells Induced by a Nonhuman Adenovirus
Authors: Perreau Matthieu , Kremer Eric J. 
Published: November 2005

ABSTRACT

Multiple human adenovirus (HAd) infections during childhood generate a memory T-cell (T
M
) response, which is the primary defense against HAd-induced morbidity. This cellular memory creates a conundrum for the potential clinical use of HAd-derived vectors: vector-mediated gene transfer is efficient in immunologically naïve mammals but will be compromised by memory immunity when using vectors derived from ubiquitous human pathogens. The potential lack of cellular and humoral memory is one reason we developed vectors from canine adenovirus serotype 2 (CAV-2). Here, we assayed human peripheral blood mononuclear cells for a T
M
response that could be stimulated by CAV-2 virion and individual capsid proteins. We found that less than half of the donors harbored a proliferating T
M
response directed against the CAV-2 virion (versus >85% against HAd5) in spite of a conserved antigenic
Adenoviridae
epitope in the CAV-2 hexon. When CAV-2 induced proliferation, it was 2.3- to >10-fold lower than HAd5 depending on the assay. The primary proliferating cells appeared to be memory (CD45RO
+
) CD4
+
lymphocytes, differentiated into Th1 gamma interferon-producing cells, with a frequency that was up to 66-fold lower than that obtained for HAd5. We also compared CAV-2 to prototype HAd from five of the six human species and found that CAV-2-induced cellular proliferation was similar to that found with rare HAd serotypes. Individual CAV-2 capsid proteins also induced less proliferation than their HAd5 homologues. Our data suggest that CAV-2 vectors may be safer (i.e., less immunogenic) for gene transfer but are not without a theoretical risk in a subset of potential patients.
The Cotton Rat Provides a Novel Model To Study Genital Herpes Infection and To Evaluate Preventive Strategies
Authors: Yim Kevin C. , Carroll Clifford J. , Tuyama Ana , Cheshenko Natalia , Carlucci Maria Josefina , Porter David D. , Prince Gregory A. , Herold Betsy C. 
Published: November 2005

ABSTRACT

Prevention of genital herpes and other sexually transmitted infections (STI) is a critical health priority because of the overwhelming impact on women and infants and the epidemiological association with human immunodeficiency virus (HIV)/AIDS. Small animal models are essential for evaluating strategies for prevention or treatment of STI. Neither the murine nor the guinea pig model of genital herpes fully recapitulates human disease. We demonstrate that herpes simplex virus type 2 (HSV-2) readily infects inbred cotton rats (
Sigmodon hispidus
). Consistent infection does not require pretreatment with medroxyprogesterone, and primary disease resembles that observed in humans. The animals develop genital lesions and fully recover. During primary infection, viral DNA is also detected in liver, lungs, brain, and kidneys. Clinical self-limited recurrences occur spontaneously but may also be induced by dexamethasone. Pretreatment of cotton rats with PRO 2000 gel, a candidate vaginal microbicide being evaluated in clinical trials to prevent HSV and HIV, protects cotton rats from HSV. Together, these studies suggest that the cotton rat may provide an excellent model to study genital herpes and to evaluate preventive strategies.
Central Nervous System Pathology Caused by Autoreactive CD8+T-Cell Clones following Virus Infection
Authors: Tsunoda Ikuo , Kuang Li-Qing , Kobayashi-Warren Mikako , Fujinami Robert S. 
Published: November 2005

ABSTRACTTheiler's murine encephalomyelitis virus (TMEV) causes a demyelinating disease in infected mice which has similarities to multiple sclerosis. Spleen cells from TMEV-infected SJL/J mice stimulated with antigen-presenting cells infected with TMEV resulted in a population of autoreactive CD8+cytotoxic T cells that kill uninfected syngeneic cells. We established CD8+T cell clones that could kill both TMEV-infected and uninfected syngeneic targets, although infected target cells were killed more efficiently. The CD8+T-cell clones produced gamma interferon when incubated with either infected or uninfected syngeneic target cells. Intracerebral injection of the clones into naïve mice induced degeneration, not only in the brain, but also in the spinal cord. This suggests that CD8+Tc1 cells could play a pathogenic role in central nervous system inflammation.
Murine Gammaherpesvirus 68 Infection Is Associated with Lymphoproliferative Disease and Lymphoma in BALB β2 Microglobulin-Deficient Mice
Authors: Tarakanova Vera L. , Suarez Felipe , Tibbetts Scott A. , Jacoby Meagan A. , Weck Karen E. , Hess Jay L. , Speck Samuel H. , Virgin Herbert W. 
Published: November 2005

ABSTRACTHuman gammaherpesvirus infections are associated with development of lymphoproliferative disease. Understanding of the mechanisms of gammaherpesvirus lymphomagenesis during chronic infection in a natural host has been limited by the exquisite species specificity of human gammaherpesviruses and the expense of primates. Murine gammaherpesvirus γHV68 is genetically and biologically related to human gammaherpesviruses and herpesvirus saimiri and has been reported to be associated with lymphoproliferative disease in mice (N. P. Sunil-Chandra, J. Arno, J. Fazakerley, and A. A. Nash, Am. J. Pathol.145:818-826, 1994). We report the development of an animal model of γHV68 lymphomagenesis in BALB/c β2 microglobulin-deficient mice (BALB β2m−/−). γHV68 infection induced two lymphoproliferative lesions: B-cell lymphoma and atypical lymphoid hyperplasia (ALH). ALH lesion histology resembled lesions of Epstein-Barr virus-associated posttransplant lymphoproliferative disease and was characterized by the abnormal infiltration of the white pulp with cells expressing the plasma cell marker CD138. Lymphomas observed in γHV68-infected animals were B220+/CD3−large-cell lymphomas. γHV68-infected cells were common in ALH lesions as measured by in situ hybridization with a probe specific for viral tRNAs (vtRNAs), but they were scarce in γHV68-infected spleens with normal histology. Unlike ALH lesions, γHV68 vtRNA-positive cells were rare in lymphomas. γHV68 infection of BALB β2m−/−mice results in lymphoproliferation and lymphoma, providing a valuable tool for identifying viral and host genes involved in gammaherpesvirus-associated malignancies. Our findings suggest that γHV68 induces lymphomas via hit-and-run oncogenesis, paracrine effects, or stimulation of chronic inflammation.