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1.
Genome Announc ; 6(12)2018 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-29567745

RESUMO

We report here the complete genome sequences for all three segments of the New York hantavirus (New York 1). This is the first reported L segment sequence for hantaviruses maintained in Peromyscus spp. endemic to the eastern United States and Canada.

2.
Exp Biol Med (Maywood) ; 228(6): 730-40, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12773706

RESUMO

Recent reports have indicated that norepinephrine (NE) enhances HIV replication in infected monocytes and promotes increased expression of select matrix metalloproteinases associated with dilated cardiomyopathy (DCM) in vitro in co-cultures of HIV-infected leukocytes and human cardiac microvascular endothelial cells (HMVEC-C). The influence of NE on HIV infection and leukocyte-endothelial interactions suggests a pathogenic role in AIDS-related cardiovascular disease. This study examined the effects of norepinephrine (NE) and HIV-1 infection on leukocyte adhesion to HMVEC-C. Both flow and static conditions were examined and the expression of selected adhesion molecules and cytokines were monitored in parallel. NE pretreatment resulted in a detectable, dose-dependent increase of leukocyte-endothelial adhesion (LEA) with both HIV-1-infected and -uninfected peripheral blood mononuclear cells (PBMCs) relative to media controls after 48 hr in co-culture with HMVEC-C in vitro. However, the combination of NE plus HIV infection resulted in a significant (P < 0.0001) 18-fold increase in LEA over uninfected media controls. Increased levels in both cell-associated and -soluble ICAM-1 and E-Selectin but not VCAM-1 correlated with increased LEA and with HIV-1 infection or NE pretreatment. Blocking antibodies specific for ICAM-1 or E-Selectin inhibited HIV-NE-induced LEA. These data suggest a model in which NE primes HIV-1-infected leukocytes for enhanced adhesion and localization in HMVEC-C where they can initiate and participate in vascular injury associated with AIDS-related cardiomyopathy.


Assuntos
Adesão Celular/efeitos dos fármacos , Endotélio Vascular/citologia , Infecções por HIV/patologia , HIV-1 , Leucócitos Mononucleares/citologia , Norepinefrina/farmacologia , Moléculas de Adesão Celular/análise , Moléculas de Adesão Celular/biossíntese , Moléculas de Adesão Celular/imunologia , Citocinas/análise , Citocinas/biossíntese , Relação Dose-Resposta a Droga , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/metabolismo , Infecções por HIV/metabolismo , Humanos , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/metabolismo , Leucócitos Mononucleares/virologia , Microcirculação , Fenótipo
3.
J Virol ; 75(22): 10651-62, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11602707

RESUMO

Isolates of bovine viral diarrhea virus (BVDV), the prototype pestivirus, are divided into cytopathic (cp) and noncytopathic (ncp) biotypes according to their effect on cultured cells. The cp viruses also differ from ncp viruses by the production of viral nonstructural protein NS3. However, the mechanism by which cp viruses induce cytopathic effect in cell culture remains unknown. Here we used a genetic approach to isolate ncp variants that arose from a cp virus at low frequency. A bicistronic BVDV (cp strain NADL) was created that expressed puromycin acetyltransferase as a dominant selectable marker. This bicistronic virus exhibited slightly slower growth kinetics and smaller plaques than NADL but remained cp. A number of independent ncp variants were isolated by puromycin selection. Remarkably, these ncp variants produced NS3 and viral RNA at levels comparable to those of the cp parent. Sequence analyses uncovered no change in NS3, but for all ncp variants a Y2441C substitution at residue 15 of NS4B was found. Introduction of the Y2441C substitution into the NADL or bicistronic cp viruses reconstituted the ncp phenotype. Y2441 is highly conserved among pestiviruses and is located in a region of NS4B predicted to be on the cytosolic side of the endoplasmic reticulum membrane. Other engineered substitutions for Y2441 also affected viral cytopathogenicity and viability, with Y2441V being cp, Y2441A being ncp, and Y2441D rendering the virus unable to replicate. The ncp substitutions for Y2441 resulted in slightly increased levels of NS2-3 relative to NS3. We also showed that NS3, NS4B, and NS5A could be chemically cross-linked in NADL-infected cells, indicating that they are associated as components of a multiprotein complex. Although the mechanism remains to be elucidated, these results demonstrate that mutations in NS4B can attenuate BVDV cytopathogenicity despite NS3 production.


Assuntos
Vírus da Diarreia Viral Bovina/patogenicidade , Proteínas não Estruturais Virais/fisiologia , Sequência de Aminoácidos , Sequência de Bases , Efeito Citopatogênico Viral , Vírus da Diarreia Viral Bovina/química , Vírus da Diarreia Viral Bovina/efeitos dos fármacos , Dados de Sequência Molecular , Mutação , Puromicina/farmacologia , RNA Helicases , RNA Viral/biossíntese , Serina Endopeptidases , Proteínas não Estruturais Virais/química
4.
J Virol ; 75(13): 6070-85, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11390609

RESUMO

Sin Nombre virus (SNV) and Hantaan virus (HTN) infect endothelial cells and are associated with different patterns of increased vascular permeability during human disease. It is thought that such patterns of increased vascular permeability are a consequence of endothelial activation and subsequent dysfunction mediated by differential immune responses to hantavirus infection. In this study, the ability of hantavirus to directly induce activation of human lung microvascular endothelial cells (HMVEC-Ls) was examined. No virus-specific modulation in the constitutive or cytokine-induced expression of cellular adhesion molecules (CD40, CD54, CD61, CD62E, CD62P, CD106, and major histocompatibility complex classes I and II) or in cytokines and chemokines (eotaxin, tumor necrosis factor alpha, interleukin 1beta [IL-1beta], IL-6, IL-8, MCP-1, MIP-1alpha, and MIP-1beta) was detected at either the protein or message level in hantavirus-infected HMVEC-Ls. Furthermore, no virus-specific enhancement of paracellular or transcellular permeability or changes in the organization and distribution of endothelial intercellular junctional proteins was observed. However, infection with either HTN or SNV resulted in detectable levels of the chemokines RANTES and IP-10 (the 10-kDa interferon-inducible protein) in HMVEC-Ls within 72 h and was associated with nuclear translocation of interferon regulatory factor 3 (IRF-3) and IRF-7. Gamma interferon (IFN-gamma)-induced expression of RANTES and IP-10 could also be detected in uninfected HMVEC-Ls and was associated with nuclear translocation of IRF-1 and IRF-3. Treatment of hantavirus-infected HMVEC-Ls with IFN-gamma for 24 h resulted in a synergistic enhancement in the expression of both RANTES and IP-10 and was associated with nuclear translocation of IRF-1, IRF-3, IRF-7, and NF-kappaB p65. These results reveal a possible mechanism by which hantavirus infection and a TH1 immune response can cooperate to synergistically enhance chemokine expression by HMVEC-Ls and trigger immune-mediated increases in vascular permeability.


Assuntos
Permeabilidade Capilar , Quimiocina CCL5/biossíntese , Quimiocinas CXC/biossíntese , Endotélio Vascular/metabolismo , Orthohantavírus/fisiologia , Animais , Células Cultivadas , Quimiocina CCL2/biossíntese , Quimiocina CCL3 , Quimiocina CCL4 , Quimiocina CXCL10 , Proteínas de Ligação a DNA/genética , Endotélio Vascular/citologia , Endotélio Vascular/ultraestrutura , Humanos , Junções Intercelulares/metabolismo , Junções Intercelulares/ultraestrutura , Fator Regulador 7 de Interferon , Interferon gama/farmacologia , Pulmão/irrigação sanguínea , Proteínas Inflamatórias de Macrófagos/biossíntese , Camundongos , Coelhos , Fator de Necrose Tumoral alfa/farmacologia
5.
J Clin Microbiol ; 38(7): 2670-7, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10878062

RESUMO

The Lassa virus (an arenavirus) is found in West Africa, where it sometimes causes a severe hemorrhagic illness called Lassa fever. Laboratory diagnosis has traditionally been by the indirect fluorescent-antibody (IFA) test. However, enzyme-linked immunosorbent assays (ELISAs) for Lassa virus antigen and immunoglobulin M (IgM) and G (IgG) antibodies have been developed that are thought to be more sensitive and specific. We compared ELISA and IFA testing on sera from 305 suspected cases of Lassa fever by using virus isolation with a positive reverse transcription-PCR (RT-PCR) test as the "gold standard." Virus isolation and RT-PCR were positive on 50 (16%) of the 305 suspected cases. Taken together, Lassa virus antigen and IgM ELISAs were 88% (95% confidence interval [CI], 77 to 95%) sensitive and 90% (95% CI, 88 to 91%) specific for acute infection. Due to the stringent gold standard used, these likely represent underestimates. Diagnosis could often be made on a single serum specimen. Antigen detection was particularly useful in providing early diagnosis as well as prognostic information. Level of antigenemia varied inversely with survival. Detection by ELISA of IgG antibody early in the course of illness helped rule out acute Lassa virus infection. The presence of IFA during both acute and convalescent stages of infection, as well as significant interobserver variation in reading the slides, made interpretation difficult. However, the assay provided useful prognostic information, the presence of IFA early in the course of illness correlating with death. The high sensitivity and specificity, capability for early diagnosis, and prognostic value of the ELISAs make them the diagnostic tests of choice for the detection of Lassa fever.


Assuntos
Ensaio de Imunoadsorção Enzimática/métodos , Técnica Indireta de Fluorescência para Anticorpo , Febre Lassa/diagnóstico , Vírus Lassa/imunologia , Vírus Lassa/isolamento & purificação , Anticorpos Antivirais/sangue , Antígenos Virais/sangue , Humanos , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Febre Lassa/virologia , Prognóstico , RNA Viral/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sensibilidade e Especificidade
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