Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Resultados 1 - 20 de 21
Filtrar
1.
Nat Med ; 3(2): 218-21, 1997 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-9018242

RESUMEN

We describe a novel experimental approach to analyzing virus-host relationships and potential mechanisms of cytopathicity in vivo in simian immunodeficiency virus (SIV) infections. Progressive destruction of lymphoid tissue in the course of infection by SIV or human immunodeficiency virus (HIV) accompanies the loss of CD4+ T lymphocytes and sets the stage for AIDS. Because one of the important early events in this pathological process is lysis of follicular dendritic cells (FDCs), we investigated the controversial role of productive SIV infection in the destruction of FDCs. To differentiate productive infections from the known association of virus with FDCs as immune complexes trapped on cell surfaces, we used detection of spliced viral mRNAs in cells as evidence of productive infection. We found that spliced and unspliced viral RNAs could be detected by in situ hybridization (ISH) with specific antisense oligonucleotide probes in lymphocytes and macrophages with sensitivities of fewer than ten copies of spliced viral RNA per cell. We detected only unspliced RNA in germinal centers where FDCs reside. Thus, no productive infection of these cells can be detected in vivo by this assay, and their destruction likely occurs by indirect mechanisms that have yet to be determined.


Asunto(s)
Células Dendríticas/virología , Síndrome de Inmunodeficiencia Adquirida del Simio/virología , Virus de la Inmunodeficiencia de los Simios/fisiología , Animales , Efecto Citopatogénico Viral , Células Dendríticas/patología , Hibridación in Situ , Macaca mulatta , Empalme del ARN , ARN Viral/análisis , Síndrome de Inmunodeficiencia Adquirida del Simio/patología
2.
Science ; 286(5443): 1353-7, 1999 Nov 12.
Artículo en Inglés | MEDLINE | ID: mdl-10558989

RESUMEN

In sexual transmission of simian immunodeficiency virus, and early and later stages of human immunodeficiency virus-type 1 (HIV-1) infection, both viruses were found to replicate predominantly in CD4(+) T cells at the portal of entry and in lymphoid tissues. Infection was propagated not only in activated and proliferating T cells but also, surprisingly, in resting T cells. The infected proliferating cells correspond to the short-lived population that produces the bulk of HIV-1. Most of the HIV-1-infected resting T cells persisted after antiretroviral therapy. Latently and chronically infected cells that may be derived from this population pose challenges to eradicating infection and developing an effective vaccine.


Asunto(s)
Linfocitos T CD4-Positivos/virología , Infecciones por VIH/transmisión , VIH-1/fisiología , Activación de Linfocitos , Síndrome de Inmunodeficiencia Adquirida del Simio/transmisión , Virus de la Inmunodeficiencia de los Simios/fisiología , Animales , Fármacos Anti-VIH/uso terapéutico , Linfocitos T CD4-Positivos/citología , Linfocitos T CD4-Positivos/inmunología , Ciclo Celular , Cuello del Útero/virología , Células Epiteliales/virología , Femenino , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/virología , Ganglios Linfáticos/virología , Macaca mulatta , ARN Viral/análisis , Síndrome de Inmunodeficiencia Adquirida del Simio/virología , Factores de Tiempo , Replicación Viral
3.
AIDS Res Hum Retroviruses ; 16(17): 1895-908, 2000 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-11118075

RESUMEN

The effect of a mycobacterial infection on AIDS disease was studied in the simian model. Monkeys were infected with the primary virulent isolate SIV/DeltaB670 and inoculated 90 days later with BCG, an attenuated strain of Mycobacterium bovis. All monkeys experienced a dramatic transient increase in plasma viremia and CCR5 expression on T lymphocytes after BCG inoculation. Only two of the four SIV+ animals had substantial proliferative responses to PPD, with poor responders developing disseminated BCG during the course of the experiment. BCG inoculation of SIV-infected long-term nonprogressor (LTNP) monkeys was also performed. Similar to the acutely infected animals, two of three LTNPs experienced increases in plasma viral levels and CCR5 expression. In the majority of animals studied, there was no accelerated progression to AIDS despite the concomitant transient stimulation of virus replication and CCR5 expression on T lymphocytes.


Asunto(s)
Mycobacterium bovis/inmunología , ARN Viral/sangre , Síndrome de Inmunodeficiencia Adquirida del Simio/fisiopatología , Virus de la Inmunodeficiencia de los Simios/fisiología , Tuberculosis/inmunología , Infecciones Oportunistas Relacionadas con el SIDA/inmunología , Infecciones Oportunistas Relacionadas con el SIDA/microbiología , Animales , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Humanos , Hibridación in Situ , Ganglios Linfáticos/virología , Activación de Linfocitos , Macaca mulatta , Receptores CCR5/metabolismo , Síndrome de Inmunodeficiencia Adquirida del Simio/complicaciones , Bazo/virología , Sobrevivientes , Linfocitos T/inmunología , Tuberculosis/microbiología , Tuberculosis/fisiopatología , Carga Viral
4.
Arch Pathol Lab Med ; 122(6): 523-33, 1998 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-9625420

RESUMEN

OBJECTIVE: To assess disease progression in baboons (Papio cynocephalus) that were infected with two human immunodeficiency virus-2 (HIV-2) isolates. METHODS: Eight baboons were inoculated intravenously with either HIV-2UC2 or HIV-2UC14 and were followed for a 2- to 7-year period of observation. RESULTS: Six of 8 baboons showed lymphadenopathy and other signs of HIV-related disease, 3 of 8 baboons had an acute phase CD4+ T-cell decline, and 2 of 5 baboons infected with the HIV-2UC2 isolate progressed to an acquired immunodeficiency syndrome-like disease. Human immunodeficiency virus-2-specific pathology in lymphatic tissues included follicular lysis, vascular proliferation, and lymphoid depletion. Both neutralizing antibodies and a CD8+ T-cell antiviral response were associated with resistance to disease. CONCLUSIONS: Disease progression and the development of acquired immunodeficiency syndrome in HIV-2-infected baboons have similarities to human HIV infections.


Asunto(s)
Infecciones por VIH/etiología , VIH-2 , Síndrome de Inmunodeficiencia Adquirida/patología , Animales , Anticuerpos Antivirales/análisis , Recuento de Linfocito CD4 , Linfocitos T CD8-positivos/inmunología , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Femenino , Fibroma/patología , Infecciones por VIH/patología , Infecciones por VIH/fisiopatología , VIH-2/inmunología , VIH-2/aislamiento & purificación , VIH-2/patogenicidad , Humanos , Hibridación in Situ , Enfermedades Linfáticas/patología , Masculino , Pruebas de Neutralización , Papio/virología , ARN Viral/análisis , Sarcoma de Kaposi/patología , Replicación Viral/inmunología
5.
Placenta ; 34(3): 248-55, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23332415

RESUMEN

Leukocyte-associated immunoglobulin-like receptor 2 (LAIR2) was identified on a global gene expression microarray analysis of surplus chorionic villus sampling (CVS) tissues as down-regulated in the first trimester of preeclampsia pregnancies. LAIR2 is the soluble receptor counterpart to LAIR1, an inhibitory receptor found on multiple immune cell subsets. In situ and immunohistochemical studies have previously shown that placental expression of LAIR2 expression is highly restricted, confined to the more distal portions of extravillous trophoblast (EVT) cell columns. This study examines LAIR2 expression in deeper layers of trophoblasts in the placental implantation site, maternal decidua and maternal spiral arterioles. Immunohistochemical staining detected LAIR2 expression on a subset of EVT within the implantation site. This trophoblast included the invasive EVT infiltrating the maternal decidual vessels and the EVT forming the endovascular trophoblastic plugs. More specifically, LAIR2-positive EVT showed a striking predilection for maternal decidual arterioles and the immediately surrounding decidua. Moreover, the appearance of EVT expressing LAIR2 in these areas was contemporaneous with the process of spiral arteriole remodeling. Based on these findings, we suggest that LAIR2-expressing EVT may play an important role in the remodeling of maternal spiral arterioles.


Asunto(s)
Arteriolas/fisiología , Decidua/irrigación sanguínea , Neovascularización Fisiológica/fisiología , Receptores Inmunológicos/metabolismo , Trofoblastos/metabolismo , Adulto , Arteriolas/citología , Diferenciación Celular , Decidua/citología , Femenino , Regulación del Desarrollo de la Expresión Génica , Humanos , Hibridación in Situ , Placenta/citología , Embarazo , Receptores Inmunológicos/genética , Regeneración
6.
Mucosal Immunol ; 6(5): 972-84, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23299616

RESUMEN

The variable efficacy of tuberculosis (TB) vaccines and the emergence of drug-resistant strains of Mycobacterium tuberculosis (Mtb) emphasize the urgency for not only generating new and more effective vaccines against TB but also understanding the underlying mechanisms that mediate vaccine-induced protection. We demonstrate that mucosal adjuvants, such as type II heat labile enterotoxin (LT-IIb), delivered through the mucosal route induce pulmonary Mtb-specific T helper type 17 (Th17) responses and provide vaccine-induced protection against Mtb infection. Importantly, protection is interferon-γ (IFNγ)-independent but interleukin-17 (IL-17)-dependent. Our data show that IL-17 mediates C-X-C motif chemokine ligand 13 (CXCL13) induction in the lung for strategic localization of proinflammatory cytokine-producing CXCR5+ (C-X-C motif chemokine receptor 5-positive) T cells within lymphoid structures, thereby promoting early and efficient macrophage activation and the control of Mtb. Our studies highlight the potential value of targeting the IL-17-CXCL13 pathway rather than the IFNγ pathway as a new strategy to improve mucosal vaccines against TB.


Asunto(s)
Quimiocina CXCL13/metabolismo , Mycobacterium tuberculosis/inmunología , Células Th17/inmunología , Vacunas contra la Tuberculosis , Tuberculosis/inmunología , Animales , Enterotoxinas/genética , Humanos , Interleucina-17/metabolismo , Activación de Macrófagos , Ratones , Ratones Endogámicos C57BL , Terapia Molecular Dirigida , Receptores CXCR5/metabolismo , Transducción de Señal , Tuberculosis/prevención & control
7.
Placenta ; 31(10): 880-5, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-20692035

RESUMEN

PURPOSE: A global gene expression microarray analysis of surplus chorionic villus sampling (CVS) tissues identified leukocyte-associated immunoglobulin-like receptor 2 (LAIR2) as down-regulated in the first trimester of pregnancies destined for preeclampsia. Neither the localization nor the function of LAIR2 has been examined in the placenta. Localization studies were conducted in placental tissues to determine the precise sites of LAIR2 mRNA production and protein binding. RESULTS: Quantitative real time polymerase chain reaction (qRT-PCR) indicated LAIR2 expression in CVS, but none in breast, lymph node, kidney, skin, uterus, or third trimester placentas. In situ hybridization (ISH) revealed a highly restricted LAIR2 localization. LAIR2 mRNA was found only in the more distal portions of trophoblast anchoring cell columns, adjacent to the invading extravillous trophoblast (EVT). Immunohistochemistry (IHC) detected intracellular LAIR2 staining in these same cells. Extracellular staining of this soluble receptor was found in the acellular material between invasive EVT cells distal to the anchoring cell columns. CONCLUSIONS: ISH and IHC staining for LAIR2 detected specific, highly localized expression at the leading edge of EVT anchoring cell columns in first trimester placentas. This staining likely identifies the site of production for this soluble receptor. Following secretion, the receptor appears to bind extracellular material among the invasive EVT. The precise restriction of this protein only to the sites of EVT invasion strongly suggests that it functions to regulate this invasion. The decreased LAIR2 expression noted in first trimester placentas that ultimately developed preeclampsia further suggests that alterations in LAIR2 may play an etiologic role in preeclampsia.


Asunto(s)
Vellosidades Coriónicas/metabolismo , Preeclampsia/metabolismo , Primer Trimestre del Embarazo/metabolismo , Receptores Inmunológicos/metabolismo , Trofoblastos/metabolismo , Femenino , Humanos , Inmunohistoquímica , Hibridación in Situ , Preeclampsia/etiología , Embarazo , ARN/química , ARN/genética , Receptores Inmunológicos/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
8.
Virology ; 224(1): 338-44, 1996 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-8862432

RESUMEN

Alternative splicing of the full-length, primary transcript into numerous subgenomic mRNAs is one way that lentiviral gene expression is regulated. Because the behaviors of different viral isolates might reflect in part differences in splicing, we Investigated the patterns of splice site utilization by simian immunodeficiency viruses (SIVs)-originally isolated from sooty mangabey monkeys (Cercocebus atys) We used reverse transcription-polymerase chain reaction (RT-PCR), molecular cloning, and DNA sequencing approaches to characterize SIVdeltaB670, a pathogenic and neurovirulent isolate, and SIVsmmH4, a related molecular clone. The majority of randomly selected SIVdeltaB670 and SIVsmmH4 partial cDNAs contained tat, rev, nef, and long terminal repeat (LTR) intron splice donor and acceptor sites positioned as expected based on the proviral sequence of SIVsmmH4. Nearly all (87%) of the partial cDNAs analyzed contained a spliced LTR intron. A greater number of partial cDNAs derived from SIVdeltaB670-infected cells contained putative alternatively spliced introns In comparison to SIVsmmH4, including two previously undocumented splice junctions involving the LTR intron splice donor. These data provide the first comprehensive analysis of splice site utilization by an isolate of SIV in comparison to a related molecular clone and the first characterization of SIVsmm splice site utilization.


Asunto(s)
Empalme del ARN , ARN Viral , Virus de la Inmunodeficiencia de los Simios/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Sitios de Unión , Línea Celular , Cercocebus atys/virología , Datos de Secuencia Molecular , ARN Viral/metabolismo
9.
J Virol ; 67(9): 5153-62, 1993 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-8394443

RESUMEN

Cell killing by cytopathic retroviruses is often associated with a delay or failure in the establishment of superinfection interference. Superinfection has been observed during T-cell killing and fatal immunodeficiency disease induction by the feline leukemia virus (FeLV) chimera FeLV-FAIDS-EECC, containing the surface envelope glycoprotein (SU) of FeLV-FAIDS clone 61C. We demonstrate here that 61C SU has a defect that results in a nearly complete failure to establish superinfection interference against homologous virus challenge. This failure was evident only in feline T (FeT) cell clones expressing envelope protein, not in the rare cells that have survived cytopathic infection to become chronically infected. The regions of SU responsible for this defect were the same as those previously identified as responsible for T-cell killing. The superinfection interference properties of a noncytophatic molecular clone, FeLV-FAIDS-61E, were different in that 61E established interference to homologous virus challenge, both in SU-expressing cell clones and in chronically infected cells. Neither 61E nor EECC established interference against heterologous virus challenge. Viruses expressing chimeric SU proteins displayed varied and intermediate interference properties. Purified 61E and 61C SU competed for binding sites on FeT cell surfaces, and purified 61E SU blocked infection of virus bearing 61E or 61C SU. In addition, purified 61E and 61C SU each coprecipitated 70-kDa FeT cell surface proteins. Our data are consistent with the hypothesis that there are multiple cellular components necessary for 61E and 61C attachment to and penetration of FeT cells, a primary receptor that is utilized by both 61E and 61C, and secondary receptors that are likely to be virus specific.


Asunto(s)
Virus de la Leucemia Felina/genética , Virus de la Leucemia Felina/fisiología , Linfocitos T/inmunología , Proteínas del Envoltorio Viral/biosíntesis , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Células CHO , Gatos , Quimera , Células Clonales , Clonación Molecular , Cricetinae , Genes env , Genes gag , Genes pol , Virus de la Inmunodeficiencia Felina/genética , Virus de la Leucemia Felina/patogenicidad , Datos de Secuencia Molecular , Mutagénesis Sitio-Dirigida , Oligodesoxirribonucleótidos , Plásmidos , Reacción en Cadena de la Polimerasa , Secuencias Repetitivas de Ácidos Nucleicos , Mapeo Restrictivo , Transfección , Proteínas del Envoltorio Viral/genética
10.
J Virol ; 67(7): 4142-53, 1993 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-8389921

RESUMEN

The functions of the surface glycoproteins (SU) of feline leukemia viruses (FeLVs) are of interest since these proteins mediate virus infection and interference and are critical determinants of disease specificity. In this study, we examined the biochemical and genetic determinants of SU important to virus entry and cell killing. In particular, we developed and used vesicular stomatitis virus (VSV)/FeLV pseudotype virus interference assays to determine interference subgroupings and assess mechanisms of host cell restriction. We also assessed roles of SU in virus growth kinetics and in the inhibition of cell killing caused by superinfection with cytopathic virus. Subgroup classification by VSV/FeLV pseudotype assay was in agreement with that defined previously by focus interference assay and was found to be determined by changes near the N terminus of SU for FeLV subgroups A (FeLV-A) and C. Virus host range restriction was found to be mediated at the level of virus entry in most cases, although postentry events mediated restriction in the failure of a subgroup A-like, T-cell cytopathic and immunodeficiency-inducing clone (FeLV-FAIDS-EECC) to replicate in feline fibroblasts. FeLV-FAIDS-EECC-induced cell killing was also inhibited by prior infection with one of two FeLV-A isolates. This inhibition could be conveyed by as few as four amino acid changes near the N terminus of the FeLV-A SU and also appeared to be mediated at a postentry level. Lastly, the SU-coding sequence was also found to determine differences in growth kinetics of viruses within the same subgroup. These studies demonstrate that subtle alterations in the FeLV SU, particularly in the N-terminal region, impart multiple significant functional differences which distinguish virus variants.


Asunto(s)
Productos del Gen env/fisiología , Virus de la Leucemia Felina/crecimiento & desarrollo , Virus de la Leucemia Felina/patogenicidad , Proteínas del Envoltorio Viral/fisiología , Secuencia de Aminoácidos , Antígenos de Superficie/fisiología , Secuencia de Bases , Línea Celular , Quimera , Clonación Molecular , Efecto Citopatogénico Viral , ADN Recombinante , Técnicas In Vitro , Datos de Secuencia Molecular , Oligodesoxirribonucleótidos/química , Receptores Virales/metabolismo , Alineación de Secuencia , Especificidad de la Especie , Interferencia Viral , Ensayo de Placa Viral , Replicación Viral
11.
Virology ; 283(1): 148-58, 2001 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-11312671

RESUMEN

In this study Nef proteins derived from simian immunodeficiency virus (SIV) and human immunodeficiency virus (HIV) were compared to assess their abilities to down-modulate the cell surface levels of the T-cell costimulatory molecule CD28. We demonstrate that in addition to Nef derived from the prototypic SIVmac239, Nef proteins encoded by the pathogenic SIVsmmPBj molecular clone and the SIVsmmB670 isolate also down-modulate cell surface CD28. In contrast, Nef proteins derived from HIV failed to down-modulate CD28. We have also identified H196 as a critical residue which influences the capacity of SIVmac Nef to down-modulate CD28. Nef derived from SIVmacJ5 failed to down-modulate cell surface CD28, whereas a Q196H substitution mutant of SIVmacJ5 Nef was able to down-modulate cell surface CD28. Conversely, substitution of H196 to Q196 in SIVmac239 Nef resulted in a mutant that had minimal effect on cell surface CD28 expression, despite retaining the capacity to down-modulate cell surface CD3epsilon. H196 lies immediately adjacent to a documented di-leucine endocytic motif and mutation of this motif also abrogated the ability of SIVmac239 Nef to down-modulate CD28. These findings demonstrate that down-modulation of the costimulatory molecule, CD28, and clonotypic TCR/CD3 complex are conserved attributes of SIV Nef.


Asunto(s)
Antígenos CD28/metabolismo , Complejo CD3 , Regulación hacia Abajo , Productos del Gen nef/genética , Productos del Gen nef/metabolismo , Virus de la Inmunodeficiencia de los Simios/metabolismo , Animales , Productos del Gen nef/química , Genes nef/genética , VIH-1/genética , VIH-1/metabolismo , Histidina , Humanos , Células Jurkat , Pruebas de Precipitina , Receptores de Antígenos de Linfocitos T/metabolismo , Virus de la Inmunodeficiencia de los Simios/genética , Transfección , Técnicas del Sistema de Dos Híbridos , Productos del Gen nef del Virus de la Inmunodeficiencia Humana
12.
J Virol ; 74(7): 3273-83, 2000 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-10708444

RESUMEN

We have recently demonstrated that simian immunodeficiency virus (SIV) Nef binds to the zeta chain of the T-cell receptor (TCR), leading to its down-modulation from T-cell surfaces (I. Bell, C. Ashman, J. Maughan, E. Hooker, F. Cook, and T. A. Reinhart, J. Gen. Virol. 79:2717-2727, 1998). Using a panel of human as well as rhesus macaque TCR zeta cytoplasmic domain mutants, we have identified in this report two linear peptides in the cytoplasmic domain of TCR zeta which independently interact with SIV Nef. Each SIV Nef interaction domain was sufficient in the absence of the other for interaction with SIV Nef in a yeast two-hybrid assay. In parallel, we demonstrated that Nef down-modulation of CD8-TCR zeta fusion proteins containing full-length or truncated portions of the TCR zeta cytoplasmic domain occurs in transiently transfected 293T cells. Furthermore, using proteins expressed in Escherichia coli, a glutathione S-transferase-Nef fusion protein coprecipitated histidine-tagged portions of the TCR zeta cytoplasmic domain which contained SNID-1 or SNID-2. The peptides targeted by SIV Nef, YNELNL and YSEIGMKGERRR, are portions of the first and second of three immunoreceptor tyrosine-based activation motifs which are important in signal transduction, thymocyte development, and TCR biogenesis. These results demonstrate that SIV Nef binds to two distinct domains on TCR zeta in the absence of other T-cell-specific factors, and that interaction with either domain is sufficient to cause down-modulation of TCR zeta.


Asunto(s)
Regulación hacia Abajo , Productos del Gen nef/metabolismo , Proteínas de la Membrana/metabolismo , Receptores de Antígenos de Linfocitos T/metabolismo , Virus de la Inmunodeficiencia de los Simios/metabolismo , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Sitios de Unión , Línea Celular , Cartilla de ADN , Macaca mulatta , Proteínas de la Membrana/química , Datos de Secuencia Molecular , Mutagénesis , Receptores de Antígenos de Linfocitos T/química , Homología de Secuencia de Aminoácido
13.
J Virol ; 70(1): 359-67, 1996 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-8523548

RESUMEN

Cytopathic feline leukemia virus (FeLV) infections of feline T-cell line (FeT-cell) cultures led to the accumulation and maintenance of threefold more proviruses with deletions within the polymerase gene (pol) than minimally cytopathic FeLV infections. Over 60% of the viral DNA from cytopathic infections bore deletions in pol. Characterization of DNA sequences adjoining the deletions revealed that the junctions were most often flanked by RNA splice donor and acceptor consensus motifs. A thymidine-to-cytidine mutation introduced at the +2 position of one RNA splice donor-like motif inhibited formation of the two most prevalent viral DNA species with deletions, confirming the origin of many proviruses with deletions from reverse transcription of aberrantly spliced viral RNA species. An example of deletion by misalignment was also characterized. Viral inocula obtained from cells recovered after cytopathic infections were attenuated in their ability to cause cytopathic effects (CPE) and were able to confer superinfection resistance to naïve FeT-cells, despite maintaining envelope gene (env) sequences with full cytopathic potential. This suggested that viral genomes with deletions, rather than being required for cytopathicity, play a role in protecting cells from CPE. Indeed, expression of a molecularly cloned provirus bearing one of the characterized deletions attenuated CPE in FeT-cells caused by superinfecting cytopathic virus.


Asunto(s)
Virus Defectuosos/fisiología , Virus de la Leucemia Felina/fisiología , Provirus/fisiología , Animales , Secuencia de Bases , Gatos , Línea Celular , ADN Viral , Virus Defectuosos/genética , Virus Defectuosos/aislamiento & purificación , Genes Virales , Genes pol , Virus de la Leucemia Felina/genética , Virus de la Leucemia Felina/aislamiento & purificación , Datos de Secuencia Molecular , Provirus/aislamiento & purificación , Eliminación de Secuencia , Replicación Viral
14.
J Gen Virol ; 79 ( Pt 11): 2717-27, 1998 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-9820147

RESUMEN

The Nef protein of simian immunodeficiency virus (SIV) is dispensable for replication in established T-cell lines but essential for high level virus replication in the adult host, though the mechanism by which Nef contributes to this has remained unclear. We demonstrate here that SIV Nef binds to the zeta chain of the T-cell receptor (TCR). SIV Nef proteins that interact with TCR zeta in a yeast two-hybrid system also reduce T-cell surface expression levels of TCR alphabeta, CD3 and CD4. These findings are the first demonstration that Nef can bind directly to a component of the TCR-CD3 complex and modulate its surface expression.


Asunto(s)
Productos del Gen nef/inmunología , Proteínas de la Membrana/inmunología , Receptores de Antígenos de Linfocitos T/inmunología , Virus de la Inmunodeficiencia de los Simios/fisiología , Linfocitos T/inmunología , Animales , Productos del Gen nef/metabolismo , Activación de Linfocitos , Proteínas de la Membrana/metabolismo , Unión Proteica , Receptores de Antígenos de Linfocitos T/metabolismo , Linfocitos T/virología , Replicación Viral
15.
J Infect Dis ; 176(5): 1198-208, 1997 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-9359719

RESUMEN

In the course of human immunodeficiency virus infection or of the related simian immunodeficiency virus (SIV), progression to AIDS is associated with high virus burdens in blood. How virus burden in the bloodstream is related to virus burden in tissue reservoirs was addressed in an animal model of rhesus macaques infected with SIV. In situ hybridization and quantitative image analysis were used to quantitate virus burden. Animals who developed AIDS had high levels of virus production and storage in lymphoid tissue reservoirs and evidence of productive infection of macrophages in the nervous system. With the quantitative approach described, it should be possible to design and assess the impact of treatment and shed light on the outstanding issues in pathogenesis.


Asunto(s)
Síndrome de Inmunodeficiencia Adquirida del Simio/virología , Virus de la Inmunodeficiencia de los Simios/aislamiento & purificación , Latencia del Virus , Animales , Tejido Linfoide/virología , Macaca mulatta
16.
Ann Neurol ; 40(1): 84-90, 1996 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-8687197

RESUMEN

Infection by human T-lymphotropic virus type I (HTLV-I) is associated with adult T-cell leukemia and a slowly progressive disease of the central nervous system (CNS), HTLV-I-associated myelopathy/tropical spastic paraparesis, characterized pathologically by inflammation and white matter degeneration in the spinal cord. One of the explanations for the tissue destruction is that HTLV-I infects cells in the CNS, or HTLV-I-infected CD4+ T lymphocytes enter the CNS, and this drives local expansion of virus-specific CD8+ cytotoxic T lymphocytes, which along with cytokines cause the pathological changes. Because both in the circulation and in the cerebrospinal fluid, CD8+ cytotoxic T lymphocytes are primarily reactive to the product of the HTLV-I tax gene, we sought evidence of expression of this gene within cells in the inflammatory lesions. After using double-label in situ hybridization techniques, we now report definitive localization of HTLV-I tax gene expression in CD4+ T lymphocytes in areas of inflammation and white matter destruction. These findings lend support to a hypothetical scheme of neuropathogenesis in which HTLV-I tax gene expression provokes and sustains an immunopathological process that progressively destroys myelin and axons in the spinal cord.


Asunto(s)
Linfocitos T CD4-Positivos/metabolismo , Genes pX , Paraparesia Espástica Tropical/virología , Adulto , Anciano , Secuencia de Bases , Encéfalo/patología , Encéfalo/virología , Linfocitos T CD4-Positivos/virología , Células Cultivadas , Técnicas de Cultivo , Femenino , Expresión Génica , Humanos , Inmunohistoquímica , Hibridación in Situ , Leucemia de Células T/genética , Leucemia de Células T/patología , Leucemia de Células T/virología , Masculino , Datos de Secuencia Molecular , Paraparesia Espástica Tropical/genética , Paraparesia Espástica Tropical/patología , ARN Mensajero/análisis , ARN Viral/análisis , Médula Espinal/patología , Médula Espinal/virología
17.
Virology ; 206(1): 16-27, 1995 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-7831771

RESUMEN

In the lymph nodes of individuals infected with human immunodeficiency virus (HIV), there is evidence that points to three kinds of virus-cell relationships. Virions may be associated with CD4+ lymphocytes that are actively producing virus or may be bound at the surfaces of follicular dendritic cells like other antigens. HIV is also harbored in CD4+ lymphocytes and monocytes/macrophages in a latent form as transcriptionally silenced provirus. To ultimately investigate in vivo these and other HIV-cell interactions that play such critical roles in the persistence of virus, immune dysregulation, and depletion, we have developed an in situ hybridization method that discriminates multiply spliced from singly or unspliced viral transcripts. In this report we describe the method and the results obtained with it in an analysis of the switch from latent to productive infection of chronically infected T lymphocytes in culture. We found with this single-cell technique that there are two subpopulations in the culture, a minor one of productively infected cells and a major one of latently infected cells in which only low levels of viral transcripts terminated close to the 5' end of the viral genome were detected. Shortly after activation of viral gene expression with phorbol ester, transcripts encoding Tat and Rev increase in abundancy in individual latently infected cells and this is followed by increases in and cytoplasmic export of singly or unspliced mRNAs encoding structural proteins. These studies provide insights into the regulation of HIV gene expression from a single-cell perspective and, from that perspective, transcript profiles of productively infected cells as a frame of reference for defining HIV-cell relationships in individual cells in tissue sections.


Asunto(s)
Regulación Viral de la Expresión Génica , VIH/fisiología , ARN Viral/metabolismo , Activación Viral , VIH/genética , Humanos , ARN Mensajero/análisis , Células Tumorales Cultivadas , Latencia del Virus
18.
J Hum Virol ; 2(3): 139-45, 1999.
Artículo en Inglés | MEDLINE | ID: mdl-10413365

RESUMEN

OBJECTIVES: Widespread dendritic injury may be one mechanism involved in the neurologic impairment that occurs in HIV-1 infection. The objectives of this study were to quantitate the extent of dendritic injury in a primate model of central nervous system (CNS) infection, investigate the role of nitric oxide (NO) as a mediator of neuropathologic changes, and evaluate the relation of these changes to cognitive and motor function. STUDY DESIGN/METHODS: Cognitive and motor function was assessed in rhesus macaque monkeys infected with simian immunodeficiency virus (SIV). In situ hybridization, immunohistochemistry, and quantitative image analysis were employed to assess the relations among productive infection, NO synthase (iNOS), and dendritic injury. RESULTS: Productive infection of cells of the macrophage lineage in CNS is associated with inflammation, increased expression of iNOS, and dendritic injury. The tests of cognitive and motor function employed were abnormal in both animals that had evidence of productive infection and those that did not. CONCLUSIONS: Increased NO accompanying productive infection and encephalitis may be one cause of neuronal injury in lentivirus infections of the CNS. Extension of tests of cognitive and motor function to late-stage AIDS in rhesus monkeys is needed to assess the potential role of NO-induced dendritic damage in lentiviral encephalopathy/AIDS dementia complex.


Asunto(s)
Dendritas/patología , Encefalitis Viral/enzimología , Óxido Nítrico Sintasa/biosíntesis , Síndrome de Inmunodeficiencia Adquirida del Simio/enzimología , Virus de la Inmunodeficiencia de los Simios , Animales , Sistema Nervioso Central/virología , Trastornos del Conocimiento , Encefalitis Viral/patología , Macaca mulatta , Actividad Motora , Neuronas , Óxido Nítrico Sintasa de Tipo II , Síndrome de Inmunodeficiencia Adquirida del Simio/patología , Replicación Viral
19.
J Virol ; 72(1): 113-20, 1998 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-9420206

RESUMEN

Genetically distinct lentiviruses constitute a quasispecies population that can evolve in response to selective forces. To move beyond characterization of the population as a whole to the behavior of individual members, we devised an in situ hybridization approach that uses genotype-specific probes. We used probes that detect simian immunodeficiency viruses (SIV) that differ in sequence in the V1 region of the surface envelope glycoprotein (env) gene to investigate the replication and cellular tropisms of four viral variants in the tissues of infected rhesus macaques. We found that the V1 genotypic variants replicated in spatially defined patterns and to different extents at each anatomic site. The two variants that replicated most extensively in animals with AIDS were detected in both macrophages and T lymphocytes in tissues. By extension of this approach, it will be possible to investigate the role of individual lentiviruses in a quasispecies in pathogenesis and to evaluate the effects of antiviral or immunotherapeutic treatment on select members of a quasispecies.


Asunto(s)
Síndrome de Inmunodeficiencia Adquirida del Simio/virología , Virus de la Inmunodeficiencia de los Simios/genética , Virus de la Inmunodeficiencia de los Simios/aislamiento & purificación , Animales , Secuencia de Bases , Células COS , Clonación Molecular , Sondas de ADN/genética , Genes env , Variación Genética , Genotipo , Hibridación in Situ , Técnicas In Vitro , Macaca mulatta , Especificidad de Órganos , Virus de la Inmunodeficiencia de los Simios/fisiología , Transfección , Replicación Viral/genética
20.
J Virol ; 75(21): 10281-9, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11581396

RESUMEN

DC-SIGN, a type II membrane protein with a C-type lectin binding domain that is highly expressed on mucosal dendritic cells (DCs) and certain macrophages in vivo, binds to ICAM-3, ICAM-2, and human and simian immunodeficiency viruses (HIV and SIV). Virus captured by DC-SIGN can be presented to T cells, resulting in efficient virus infection, perhaps representing a mechanism by which virus can be ferried via normal DC trafficking from mucosal tissues to lymphoid organs in vivo. To develop reagents needed to characterize the expression and in vivo functions of DC-SIGN, we cloned, expressed, and analyzed rhesus macaque, pigtailed macaque, and murine DC-SIGN and made a panel of monoclonal antibodies (MAbs) to human DC-SIGN. Rhesus and pigtailed macaque DC-SIGN proteins were highly similar to human DC-SIGN and bound and transmitted HIV type 1 (HIV-1), HIV-2, and SIV to receptor-positive cells. In contrast, while competent to bind virus, murine DC-SIGN did not transmit virus to receptor-positive cells under the conditions tested. Thus, mere binding of virus to a C-type lectin does not necessarily mean that transmission will occur. The murine and macaque DC-SIGN molecules all bound ICAM-3. We mapped the determinants recognized by a panel of 16 MAbs to the repeat region, the lectin binding domain, and the extreme C terminus of DC-SIGN. One MAb was specific for DC-SIGN, failing to cross-react with DC-SIGNR. Most MAbs cross-reacted with rhesus and pigtailed macaque DC-SIGN, although none recognized murine DC-SIGN. Fifteen of the MAbs recognized DC-SIGN on DCs, with MAbs to the repeat region generally reacting most strongly. We conclude that rhesus and pigtailed macaque DC-SIGN proteins are structurally and functionally similar to human DC-SIGN and that the reagents that we have developed will make it possible to study the expression and function of this molecule in vivo.


Asunto(s)
Moléculas de Adhesión Celular , Lectinas Tipo C , Lectinas/fisiología , Receptores de Superficie Celular/fisiología , Secuencia de Aminoácidos , Animales , Anticuerpos Monoclonales/inmunología , Mapeo Epitopo , Humanos , Lectinas/química , Lectinas/inmunología , Lectinas/metabolismo , Macaca mulatta , Macaca nemestrina , Ratones , Ratones Endogámicos BALB C , Datos de Secuencia Molecular , Conejos , Receptores de Superficie Celular/química , Receptores de Superficie Celular/inmunología
SELECCIÓN DE REFERENCIAS
Detalles de la búsqueda