bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pathogenesis of Herpes Simplex Virus Type 1-Induced Corneal Inflammation in Perforin-Deficient Mice
Authors: Chang Eddie , Galle Laurence , Maggs David , Estes D. Mark , Mitchell William J. 
Published: July 2002

ABSTRACTHerpetic stromal keratitis (HSK) is an inflammatory disease of the cornea that often results in blindness. It is mediated by a host immune response which is triggered by herpes simplex virus (HSV) infection. Immune effector mechanisms are hypothesized to be important in disease development. We investigated, in a mouse model, whether perforin-dependent cytotoxicity is an important effector mechanism in the production of HSK. Wild-type (C57BL/6) and perforin-deficient (PKO) mice were infected intracorneally with HSV-1 strain F. Clinical disease and histologic lesions of the cornea at 23 days postinfection (p.i.) were significantly less severe in HSV-1-infected PKO mice than in infected wild-type mice. mRNA for the chemokine macrophage inflammatory protein 1α (MIP-1α) was detected by reverse transcription-PCR in the corneas of infected wild-type mice but not in the corneas of infected PKO mice at 23 days p.i. Adoptive transfer of wild-type HSV-1 immune T-cell-enriched splenocytes into HSV-1-infected PKO mice restored the disease phenotype which was seen in infected wild-type mice. In contrast, mice carrying a null-function mutation in the Fas ligand, which is involved in an alternative cytotoxic mechanism, developed clinical disease and histologic lesions which were comparable to those in wild-type mice. Viral clearance from the eyes of PKO mice was not impaired. There was no significant difference between the infectious viral titers isolated from the eyes of PKO and wild-type mice. Our findings show that perforin is important in the pathogenesis of HSK.
Effects of Point Mutations in the Readthrough Domain of the Beet Western Yellows Virus Minor Capsid Protein on Virus Accumulation In Planta and on Transmission by Aphids
Authors: Brault V. , Mutterer J. , Scheidecker D. , Simonis M. T. , Herrbach E. , Richards K. , Ziegler-Graff V. 
Published: July 2002

ABSTRACT

Point mutations were introduced into or near five conserved sequence motifs of the readthrough domain of the beet western yellows virus minor capsid protein P74. The mutant virus was tested for its ability to accumulate efficiently in agroinfected plants and to be transmitted by its aphid vector,
Myzus persicae
. The stability of the mutants in the agroinfected and aphid-infected plants was followed by sequence analysis of the progeny virus. Only the mutation Y201D was found to strongly inhibit virus accumulation in planta following agroinfection, but high accumulation levels were restored by reversion or pseudoreversion at this site. Four of the five mutants were poorly aphid transmissible, but in three cases successful transmission was restored by pseudoreversion or second-site mutations. The same second-site mutations in the nonconserved motif PVT(32-34) were shown to compensate for two distinct primary mutations (R24A and E59A/D60A), one on each side of the PVT sequence. In the latter case, a second-site mutation in the PVT motif restored the ability of the virus to move from the hemocoel through the accessory salivary gland following microinjection of mutant virus into the aphid hemocoel but did not permit virus movement across the epithelium separating the intestine from the hemocoel. Successful movement of the mutant virus across both barriers was accompanied by conversion of A59 to E or T, indicating that distinct features of the readthrough domain in this region operate at different stages of the transmission process.
Chimeric Bovine Respiratory Syncytial Virus with Glycoprotein Gene Substitutions from Human Respiratory Syncytial Virus (HRSV): Effects on Host Range and Evaluation as a Live-Attenuated HRSV Vaccine
Authors: Buchholz Ursula J. , Granzow Harald , Schuldt Kathrin , Whitehead Stephen S. , Murphy Brian R. , Collins Peter L. 
Published: July 2002

ABSTRACT
We recently developed a system for the generation of infectious bovine respiratory syncytial virus (BRSV) from cDNA. Here, we report the recovery of fully viable chimeric recombinant BRSVs (rBRSVs) that carry human respiratory syncytial virus (HRSV) glycoproteins in place of their BRSV counterparts, thus combining the replication machinery of BRSV with the major antigenic determinants of HRSV. A cDNA encoding the BRSV antigenome was modified so that the complete G and F genes, including the gene start and gene end signals, were replaced by their HRSV A2 counterparts. Alternatively, the BRSV F gene alone was replaced by that of HRSV Long. Each antigenomic cDNA directed the successful recovery of recombinant virus, yielding rBRSV/A2 and rBRSV/LongF, respectively. The HRSV G and F proteins or the HRSV F in combination with BRSV G were expressed efficiently in cells infected with the appropriate chimeric virus and were efficiently incorporated into recombinant virions. Whereas BRSV and HRSV grew more efficiently in bovine and human cells, respectively, the chimeric rBRSV/A2 exhibited intermediate growth characteristics in a human cell line and grew better than either parent in a bovine line. The cytopathology induced by the chimera more closely resembled that of BRSV. BRSV was confirmed to be highly restricted for replication in the respiratory tract of chimpanzees, a host that is highly permissive for HRSV. Interestingly, the rBRSV/A2 chimeric virus was somewhat more competent than BRSV for replication in chimpanzees but remained highly restricted compared to HRSV. This showed that the substitution of the G and F glycoproteins alone was not sufficient to induce efficient replication in chimpanzees. Thus, the F and G proteins contribute to the host range restriction of BRSV but are not the major determinants of this phenotype. Although rBRSV/A2 expresses the major neutralization and protective antigens of HRSV, chimpanzees infected with this chimeric virus were not significantly protected against subsequent challenge with wild-type HRSV. This suggests that the growth restriction of rBRSV/A2 was too great to provide adequate antigen expression and that the capacity of this chimeric vaccine candidate for replication in primates will need to be increased by the importation of additional HRSV genes.
Multiepitopic B- and T-Cell Responses Induced in Humans by a Human Immunodeficiency Virus Type 1 Lipopeptide Vaccine
Authors: Gahéry-Ségard Hanne , Pialoux Gilles , Charmeteau Bénédicte , Sermet Sandrine , Poncelet Hubert , Raux Maurice , Tartar André , Lévy Jean-Paul , Gras-Masse Helene , Guillet Jean-Gérard 
Published: July 2002

ABSTRACTWe have attempted to develop an anti-human immunodeficiency virus (HIV) lipopeptide vaccine with several HIV-specific long peptides modified by C-terminal addition of a single palmitoyl chain. A mixture of six lipopeptides derived from regulatory or structural HIV-1 proteins (Nef, Gag, and Env) was prepared. A phase I study was conducted to evaluate immunogenicity and tolerance in lipopeptide vaccination of HIV-1-seronegative volunteers given three injections of either 100, 250, or 500 μg of each lipopeptide, with or without immunoadjuvant (QS21). This report analyzes in detail B- and T-cell responses induced by vaccination. The lipopeptide vaccine elicited strong and multiepitopic B- and T-cell responses. Vaccinated subjects produced specific immunoglobulin G antibodies that recognized the Nef and Gag proteins. After the third injection, helper CD4+-T-cell responses as well as specific cytotoxic CD8+T cells were also obtained. These CD8+T cells were able to recognize naturally processed viral proteins. Finally, specific gamma interferon-secreting CD8+T cells were also detected ex vivo.
Evolutionary Relationships of Endemic/Epidemic and Sylvatic Dengue Viruses
Authors: Wang Eryu , Ni Haolin , Xu Renling , Barrett Alan D. T. , Watowich Stanley J. , Gubler Duane J. , Weaver Scott C. 
Published: July 2002

ABSTRACT

Endemic/epidemic dengue viruses (DEN) that are transmitted among humans by the mosquito vectors
Aedes aegypti
and
Aedes albopictus
are hypothesized to have evolved from sylvatic DEN strains that are transmitted among nonhuman primates in West Africa and Malaysia by other
Aedes
mosquitoes. We tested this hypothesis with phylogenetic studies using envelope protein gene sequences of both endemic/epidemic and sylvatic strains. The basal position of sylvatic lineages of DEN-1, -2, and -4 suggested that the endemic/epidemic lineages of these three DEN serotypes evolved independently from sylvatic progenitors. Time estimates for evolution of the endemic/epidemic forms ranged from 100 to 1,500 years ago, and the evolution of endemic/epidemic forms represents relatively recent events in the history of DEN evolution. Analysis of envelope protein amino acid changes predicted to have accompanied endemic/epidemic emergence suggested a role for domain III in adaptation to new mosquito and/or human hosts.
The Hinge of the Human Papillomavirus Type 11 E2 Protein Contains Major Determinants for Nuclear Localization and Nuclear Matrix Association
Authors: Zou Nianxiang , Lin Biing Yuan , Duan Fenghai , Lee Kyung-Yeol , Jin Ge , Guan Ran , Yao Guang , Lefkowitz Elliot J. , Broker Thomas R. , Chow Louise T. 
Published: July 2002

ABSTRACT

The E2 protein of papillomaviruses is a site-specific DNA binding nuclear protein. It functions as the primary replication origin recognition protein and assists in the assembly of the preinitiation complex. It also helps regulate transcription from the native viral promoter. The E2 protein consists of an amino-terminal (N)
trans
-acting domain, a central hinge (H) domain, and a carboxyl-terminal (C) protein dimerization and DNA binding domain. The hinge is highly divergent among papillomaviruses, and little is known about its functions. We fused the enhanced green fluorescent protein (GFP) with the full-length human papillomavirus type 11 (HPV-11) E2 protein and showed that the resultant fusion, called gfpE2, maintained transcription and replication functions of the wild-type protein and formed similar subnuclear foci. Using a series of GFP fusion proteins, we showed that the hinge conferred strong nuclear localization, whereas the N or C domain was present in both cytoplasm and nucleus. Biochemical fractionation demonstrated that the N domain and hinge, but not the C domain, independently associated with the nuclear matrix. Mutational analyses showed that a cluster of basic amino acid residues, which is conserved among many mucosotropic papillomaviruses, was required for efficient nuclear localization and nuclear matrix association. This mutation no longer repressed the HPV-11 upstream regulatory region-controlled reporter expression. However, a very small fraction of this mutant colocalized with E1 in the nucleus, perhaps by a piggyback mechanism, and was able to support transient replication. We propose that the hinge is critical for the diverse regulatory functions of the HPV-11 E2 protein during mRNA transcription and viral DNA replication.
Transient Mobilization of Human Immunodeficiency Virus (HIV)-Specific CD4 T-Helper Cells Fails To Control Virus Rebounds during Intermittent Antiretroviral Therapy in Chronic HIV Type 1 Infection
Authors: Carcelain Guislaine , Tubiana Roland , Samri Assia , Calvez Vincent , Delaugerre Constance , Agut Henri , Katlama Christine , Autran Brigitte 
Published: July 2002

ABSTRACTImmune control of human immunodeficiency virus (HIV) is not restored by highly active antiretroviral therapies (HAART) during chronic infection. We examined the capacity of repeated structured therapeutic interruptions (STI) to restore HIV-specific CD4 and CD8 T-cell responses that controlled virus production. Eleven STI (median duration, 7 days; ranges, 4 to 24 days) were performed in three chronically HIV-infected patients with CD4 counts above 400/mm3and less than 200 HIV RNA copies/ml after 18 to 21 months of HAART; treatment resumed after 1 week or when virus became detectable. HIV-specific T-cell responses were analyzed by proliferation, gamma interferon (IFN-γ) production, and enzyme-linked immunospot assays. Seven virus rebounds were observed (median, 4,712 HIV-1 RNA copies/ml) with a median of 7 days during which CD4 and CD8 counts did not significantly change. After treatment resumed, the viral load returned below 200 copies/ml within 3 weeks. Significant CD4 T-cell proliferation and IFN-γ production against HIV p24 appeared simultaneously with or even before the virus rebounds in all patients. These CD4 responses lasted for less than 3 weeks and disappeared before therapeutic control of the virus had occurred. Increases in the numbers of HIV-specific CD8 T cells were delayed compared to changes in HIV-specific CD4 T-cell responses. No delay or increase in virus doubling time was observed after repeated STI. Iterative reexposure to HIV during short STI in chronically infected patients only transiently mobilized HIV-specific CD4 T1-helper cells, which might be rapidly altered by virus replication. Such kinetics might explain the failure at delaying subsequent virus rebounds and raises concerns about strategies based on STI to restore durable HIV-specific T-cell responses in chronic HIV infection.
Calpain Inhibition Protects against Virus-Induced Apoptotic Myocardial Injury
Authors: DeBiasi Roberta L. , Edelstein Charles L. , Sherry Barbara , Tyler Kenneth L. 
Published: July 2002

ABSTRACTViral myocarditis is an important cause of human morbidity and mortality for which reliable and effective therapy is lacking. Using reovirus strain 8B infection of neonatal mice, a well-characterized experimental model of direct virus-induced myocarditis, we now demonstrate that myocardial injury results from apoptosis. Proteases play a critical role as effectors of apoptosis. The activity of the cysteine protease calpain increases in reovirus-infected myocardiocytes and can be inhibited by the dipeptide alpha-ketoamide calpain inhibitorZ-Leu-aminobutyric acid-CONH(CH2)3-morpholine (CX295). Treatment of reovirus-infected neonatal mice with CX295 protects them against reovirus myocarditis as documented by (i) a dramatic reduction in histopathologic evidence of myocardial injury, (ii) complete inhibition of apoptotic myocardial cell death as identified by terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling, (iii) a reduction in serum creatine phosphokinase, and (iv) improved weight gain. These findings are the first evidence for the importance of a calpain-associated pathway of apoptotic cell death in viral disease. Inhibition of apoptotic signaling pathways may be an effective strategy for the treatment of viral disease in general and viral myocarditis in particular.
Heterogeneous Nuclear Ribonucleoprotein A1 Binds to the 3′-Untranslated Region and Mediates Potential 5′-3′-End Cross Talks of Mouse Hepatitis Virus RNA
Authors: Huang Peiyong , Lai Michael M. C. 
Published: July 2002

ABSTRACTThe 3′-untranslated region (3′-UTR) of mouse hepatitis virus (MHV) RNA regulates the replication of and transcription from the viral RNA. Several host cell proteins have previously been shown to interact with this regulatory region. By immunoprecipitation of UV-cross-linked cellular proteins and in vitro binding of the recombinant protein, we have identified the major RNA-binding protein species as heterogeneous nuclear ribonucleoprotein A1 (hnRNP A1). A strong hnRNP A1-binding site was located 90 to 170 nucleotides from the 3′ end of MHV RNA, and a weak binding site was mapped at nucleotides 260 to 350 from the 3′ end. These binding sites are complementary to the sites on the negative-strand RNA that bind another cellular protein, polypyrimidine tract-binding protein (PTB). Mutations that affect PTB binding to the negative strand of the 3′-UTR also inhibited hnRNP A1 binding on the positive strand, indicating a possible relationship between these two proteins. Defective-interfering RNAs containing a mutated hnRNP A1-binding site have reduced RNA transcription and replication activities. Furthermore, hnRNP A1 and PTB, both of which also bind to the complementary strands at the 5′ end of MHV RNA, together mediate the formation of an RNP complex involving the 5′- and 3′-end fragments of MHV RNA in vitro. These studies suggest that hnRNP A1-PTB interactions provide a molecular mechanism for potential 5′-3′ cross talks in MHV RNA, which may be important for RNA replication and transcription.
DNA Binding by Kaposi's Sarcoma-Associated Herpesvirus Lytic Switch Protein Is Necessary for Transcriptional Activation of Two Viral Delayed Early Promoters
Authors: Lukac David M. , Garibyan Lilit , Kirshner Jessica R. , Palmeri Diana , Ganem Don 
Published: July 2002

ABSTRACT
Kaposi's sarcoma-associated herpesvirus (KSHV; also known as human herpesvirus-8) establishes latent and lytic infections in both lymphoid and endothelial cells and has been associated with diseases of both cell types. The KSHV open reading frame 50 (ORF50) protein is a transcriptional activator that plays a central role in the reactivation of lytic viral replication from latency. Here we identify and characterize a DNA binding site for the ORF50 protein that is shared by the promoters of two delayed early genes (ORF57 and K-bZIP). Transfer of this element to heterologous promoters confers on them high-level responsiveness to ORF50, indicating that the element is both necessary and sufficient for activation. The element consists of a conserved 12-bp palindromic sequence and less conserved sequences immediately 3′ to it. Mutational analysis reveals that sequences within the palindrome are critical for binding and activation by ORF50, but the presence of a palindrome itself is not absolutely required. The 3′ flanking sequences also play a critical role in DNA binding and transactivation. The strong concordance of DNA binding in vitro with transcriptional activation in vivo strongly implies that sequence-specific DNA binding is necessary for ORF50-mediated activation through this element. Expression of truncated versions of the ORF50 protein reveals that DNA binding is mediated by the amino-terminal 272 amino acids of the polypeptide.
Host Range of Small-Ruminant Lentivirus Cytopathic Variants Determined with a Selectable Caprine Arthritis- Encephalitis Virus Pseudotype System
Authors: Hötzel Isidro , Cheevers William P. 
Published: July 2002

ABSTRACT

The small-ruminant lentiviruses ovine maedi-visna virus (MVV) and caprine arthritis-encephalitis virus (CAEV) cause encephalitis, progressive pneumonia, arthritis, and mastitis in sheep and goats. Icelandic MVV strains, which are lytic in tissue culture, have a wide species distribution of functional receptors, which includes human cells. In contrast, functional receptors for the nonlytic CAEV CO are absent from human cells. To determine if the wide species distribution of functional receptors is a common property of MVV strains or related to cytopathic phenotype, we tested the infectivity of viruses pseudotyped with the envelope glycoproteins of MVV K1514, CAEV CO, and lytic and nonlytic North American MVV strains to cells of different species. Replication-defective CAEV proviral constructs lacking the
env
,
tat
, and
vif
genes and carrying the neomycin phosphotransferase gene in the
vif
-
tat
region were developed for the infectivity assays. Cotransfection of human 293T cells with these proviral constructs and plasmids expressing CAEV, MVV, or vesicular stomatitis virus envelope glycoproteins produced infectious pseudotyped virus which induced resistance of infected cells to G418. Using these pseudotypes, we confirmed the wide species distribution of Icelandic MVV receptors and the narrow host range of CAEV. However, functional receptors for the two North American MVV strains tested, unlike the Icelandic MVV and similar to CAEV, were limited to cells of ruminant species, regardless of cytopathic phenotype. The results indicate a differential receptor recognition by MVV strains which is unrelated to cytopathic phenotype.
Chimeric Plant Virus Particles as Immunogens for Inducing Murine and Human Immune Responses against Human Immunodeficiency Virus Type 1
Authors: Marusic Carla , Rizza Paola , Lattanzi Laura , Mancini Camillo , Spada Massimo , Belardelli Filippo , Benvenuto Eugenio , Capone Imerio 
Published: July 2002

ABSTRACT
The high-yield expression of a neutralizing epitope from human immunodeficiency virus type 1 (HIV-1) on the surface of a plant virus and its immunogenicity are presented. The highly conserved ELDKWA epitope from glycoprotein (gp) 41 was expressed as an N-terminal translational fusion with the potato virus X (PVX) coat protein. The resulting chimeric virus particles (CVPs), purified and used to immunize mice intraperitoneally or intranasally, were able to elicit high levels of HIV-1-specific immunoglobulin G (IgG) and IgA antibodies. Furthermore, the human immune response to CVPs was studied with severe combined immunodeficient mice reconstituted with human peripheral blood lymphocytes (hu-PBL-SCID). hu-PBL-SCID mice immunized with CVP-pulsed autologous dendritic cells were able to mount a specific human primary antibody response against the gp41-derived epitope. Notably, sera from both normal and hu-PBL-SCID mice showed an anti-HIV-1-neutralizing activity. Thus, PVX-based CVPs carrying neutralizing epitopes can offer novel perspectives for the development of effective vaccines against HIV and, more generally, for the design of new vaccination strategies in humans.
Human Herpesvirus 8 (HHV-8)-Encoded Cytokines Induce Expression of and Autocrine Signaling by Vascular Endothelial Growth Factor (VEGF) in HHV-8-Infected Primary-Effusion Lymphoma Cell Lines and Mediate VEGF-Independent Antiapoptotic Effects
Authors: Liu Chaoqi , Okruzhnov Yury , Li Hong , Nicholas John 
Published: July 2002

ABSTRACT

The potential roles of human herpesvirus 8 (HHV-8) cytokines in HHV-8 pathogenesis were investigated by determining the expression of the HHV-8 chemokines viral macrophage inflammatory protein 1A (vMIP-1A) and vMIP-1B in primary effusion lymphoma (PEL)-derived cell lines and examining the signaling activities of these chemokines and HHV-8-encoded vIL-6 in these cells. Secreted vMIP-1A and vMIP-1B were detected in biologically significant concentrations following tetradecanoyl phorbol acetate treatment, which induces productive replication. vIL-6 and vMIP-1A, added exogenously to cultures of four different PEL cell lines, induced the expression of vascular endothelial growth factor type B (VEGF-B) and VEGF-A, respectively. These cells were found to express VEGF receptor 1 (Flt-1) protein, and signaling by recombinant VEGF-A
165
was demonstrated for two of the PEL cell lines, indicating the potential for autocrine, as well as paracrine, effects of viral cytokine-induced VEGF. In addition, vMIP-1A and vMIP-1B, but not VEGF-A
165
, were found to inhibit chemically induced apoptosis in PEL cells. Our data suggest that vIL-6 and vMIP-1A may influence PEL through VEGF autocrine and paracrine signaling that promotes PEL cell growth and extravascular effusion and that vMIP-1A and vMIP-1B can act independently of VEGF as antiapoptotic factors.