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1.
BMC Gastroenterol ; 21(1): 303, 2021 Jul 31.
Artículo en Inglés | MEDLINE | ID: mdl-34332529

RESUMEN

BACKGROUND: Epidemiological studies suggest an inverse association between H. pylori infection/exposure and inflammatory bowel disease prevalence/incidence, however, there are no reports of individual patients who developed a "non-transient" ulcerative colitis (UC) following H. pylori eradication. CASE PRESENTATION: We report a case of a 72-year-old female with an elderly-onset UC developed upon H. pylori eradication and a 3-year follow-up of the progression to steroid-dependent colitis complicated with enteropathic arthritis and final containment of the disease with golimumab. In our patient, H. pylori eradication was associated with the development of pancolitis that evolved into clinically, endoscopically, and pathohistologically confirmed UC. CONCLUSIONS: The case of our patient provides a unique clinical context for a growing body of literature suggesting molecular mechanisms involved in the interaction of genes, environment, and microbiota to be of critical importance in the etiopathogenesis of UC, and thus, provides a valuable set of complementary translational information for preclinical and epidemiological research on the topic.


Asunto(s)
Colitis Ulcerosa , Infecciones por Helicobacter , Helicobacter pylori , Enfermedades Inflamatorias del Intestino , Anciano , Colitis Ulcerosa/complicaciones , Colitis Ulcerosa/tratamiento farmacológico , Femenino , Estudios de Seguimiento , Infecciones por Helicobacter/complicaciones , Infecciones por Helicobacter/tratamiento farmacológico , Humanos
2.
Clin Otolaryngol ; 42(3): 544-549, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-27727523

RESUMEN

OBJECTIVE: The aim of this study was to investigate the diagnostic usefulness of combined multichannel intraluminal impedance-pH (MII-pH) monitoring in children with suspected laryngopharyngeal reflux (LPR). DESIGN, SETTING AND PARTICIPANTS: A prospective study including children in whom, due to LPR suggestive symptoms, MII-pH monitoring was performed at tertiary medical centre from February 2012 to July 2015. INTERVENTIONS: All included children underwent same diagnostic protocol which included examination by single pulmonologist and ENT specialist and underwent 24-hour MII-pH monitoring. MAIN OUTCOMES: Primary outcome was to determine MII-pH characteristics of the children in whom LPR was suspected based on symptoms and ENT examination. RESULTS: One hundred and four patients (mean age 8.9 years; range 0.4-17.9 years; male/female 57/47) participated in the study. In children with signs and symptoms suggestive of LPR, MII-pH monitoring found the median incidence of proximal gastro-oesophageal reflux (GER) of 15 (range 0-129), proximal acidic GER of 6.5 (range 0-66) and weakly acidic GER of 5 (range 0-102). There were significant positive correlations between the number of GER (proximal total, acidic and weakly acid) with Reflux Finding Score, Reflux Symptom Index and presence of eosinophils in nasal swabs. The only endoscopy ENT finding which significantly correlated with total proximal GER, acid proximal GER and weakly acidic proximal GER was arytenoid hyperaemia. CONCLUSION: Both acid and non-acid reflux seem to have a significant role in the pathogenesis of LPR.


Asunto(s)
Monitorización del pH Esofágico/métodos , Reflujo Laringofaríngeo/diagnóstico , Adolescente , Niño , Preescolar , Impedancia Eléctrica , Femenino , Estudios de Seguimiento , Humanos , Concentración de Iones de Hidrógeno , Lactante , Reflujo Laringofaríngeo/metabolismo , Reflujo Laringofaríngeo/fisiopatología , Masculino , Estudios Prospectivos , Reproducibilidad de los Resultados , Factores de Tiempo
3.
J Exp Med ; 179(5): 1713-7, 1994 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-8163949

RESUMEN

Virus shedding from the epithelial cells of the serous acini of salivary glands is a major source for the horizontal transmission of cytomegalovirus. These cells are, different to other tissues, exempt from CD8 T lymphocyte control. CD4 T lymphocytes are essential to terminate the productive infection. Here, we prove that T-B cooperation and the production of antibodies are not required for this process. For the infection with murine cytomegalovirus, mutant mice were used which do not produce antibodies because of a disrupted membrane exon of the immunoglobulin mu chain gene. Also, in these mice the virus clearance from salivary glands is a function of CD4 T lymphocytes. However, these mice clear the virus and establish viral latency with a kinetics that is distinguishable from normal mice. Reactivation from virus latency is the only stage at which the absence of antibodies alters the phenotype of infection. In immunoglobulin-deficient mice, virus recurrence results in higher virus titers. The adoptive serum transfer proved that antibody is the limited factor that prevents virus dissemination in the immunodeficient host.


Asunto(s)
Anticuerpos Antivirales/inmunología , Infecciones por Citomegalovirus/inmunología , Citomegalovirus/inmunología , Animales , Citomegalovirus/fisiología , Infecciones por Citomegalovirus/transmisión , Femenino , Terapia de Inmunosupresión , Masculino , Ratones , Ratones Endogámicos C57BL , Recurrencia , Replicación Viral/inmunología , Esparcimiento de Virus
4.
J Exp Med ; 179(1): 185-93, 1994 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-8270864

RESUMEN

Recurrence of cytomegalovirus (CMV) from latency is a frequent cause of disease in immunocompromised patients. To date, there is no explanation for the diversity in the clinical manifestations. Primary infection can occur perinatally or later in life, and inevitably results in latent infection. Seropositivity for antibodies against CMV is indicative of latent infection, but is insufficient as a predictor for the risk of recurrence. As a model for this important medical problem, we compared the risks of murine CMV recurrence from latency established after neonatal primary infection and after infection at adult age. The risk of CMV recurrence was high only after neonatal infection. The copy number of latent viral genome in tissues was identified as the key parameter that determines the overall and organ-specific risks of recurrence. Latent CMV burden and risk of recurrence were related to the extent of virus multiplication during primary infection. The presence of latent CMV in multiple organs provides the molecular basis for stochastic events of recurrence in single organs or in any combination thereof. These findings are discussed as a concept of multifocal CMV latency and recurrence. It provides a rationale for the diversity in the clinical outcome of CMV disease.


Asunto(s)
Infecciones por Citomegalovirus/microbiología , Citomegalovirus/fisiología , ADN Viral/aislamiento & purificación , Latencia del Virus , Animales , Anticuerpos Antivirales/sangre , Citomegalovirus/genética , Citomegalovirus/aislamiento & purificación , Infecciones por Citomegalovirus/inmunología , Modelos Animales de Enfermedad , Femenino , Genoma Viral , Humanos , Pulmón/microbiología , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Pruebas de Neutralización , Recurrencia , Glándulas Salivales/microbiología , Bazo/microbiología
5.
J Exp Med ; 188(6): 1047-54, 1998 Sep 21.
Artículo en Inglés | MEDLINE | ID: mdl-9743523

RESUMEN

Reactivation from latent cytomegalovirus (CMV) infection is often associated with conditions of immunosuppression and can result in fatal disease. Whether the maintenance of systemic CMV latency is mainly governed by factors of the infected cell or by immune control functions is unknown. Likewise, the putative immune control mechanisms which could prevent the induction and spread of recurrent CMV infection are not clearly identified. We took advantage of latently infected B cell-deficient mice and a sensitive method for virus detection to study CMV reactivation after ablation of lymphocyte subsets. A crucial role of both T lymphocytes and natural killer (NK) cells was demonstrated. Within 5 d after depletion of lymphocytes, productive infection occurred in 50% of mice, and 14 d later 100% of mice exhibited recurrent infection. A hierarchy of immune control functions of CD8(+), NK, and CD4(+) cells was established. Reactivation was rare if only one of the lymphocyte subsets was depleted, but was evident after removal of a further subset, indicating a functional redundancy of control mechanisms. The salivary glands were identified as the site of most rapid virus shedding, followed by the detection of recurrent virus in the lungs, and eventually in the spleen. Our findings document a previously unknown propensity of latent CMV genomes to enter productive infection immediately and with a high frequency after immune cell depletion. The data indicate that only the sustained cellular immune control prevents CMV replication and restricts the viral genome to a systemic state of latency.


Asunto(s)
Infecciones por Citomegalovirus/inmunología , Citomegalovirus/fisiología , Subgrupos Linfocitarios/inmunología , Latencia del Virus/fisiología , Replicación Viral/fisiología , Animales , Citomegalovirus/aislamiento & purificación , Infecciones por Citomegalovirus/genética , Infecciones por Citomegalovirus/virología , Síndromes de Inmunodeficiencia/genética , Síndromes de Inmunodeficiencia/virología , Interferón gamma/fisiología , Células Asesinas Naturales/inmunología , Depleción Linfocítica , Ratones , Ratones Endogámicos BALB C , Ratones Mutantes , Especificidad de Órganos , Recurrencia , Subgrupos de Linfocitos T/inmunología
6.
Euro Surveill ; 13(16)2008 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-18768116

RESUMEN

We report on three cases of symptomatic transmission of the L-Zagreb mumps vaccine virus from three vaccinated children to five adult contacts. The five contact cases were parents of the vaccinated children and presented with parotitis and in one case also with aseptic meningitis. The etiology of the contacts' illness was determined by viral culture, genomic sequencing, serology and epidemiological linking. Two of the vaccinated children developed vaccine associated parotitis as an adverse event three weeks following immunization. Symptoms in contact cases developed five to seven weeks after the vaccination of the children. The five contact cases, as well as the three children with adverse events recovered completely. The children had been vaccinated with MMR vaccine produced by the Institute of Immunology Zagreb, each of them with a different lot. One of the possible explanations for these adverse events is that the very low levels of wild mumps virus circulation in the last decade, combined with waning immunity in those who received one dose of vaccine or suffered from mumps in childhood, resulted in susceptible young adults and that this unique epidemiological situation allows us to detect horizontal transmission of mumps vaccine virus.


Asunto(s)
Transmisión de Enfermedad Infecciosa , Vacuna contra el Sarampión-Parotiditis-Rubéola/efectos adversos , Virus de la Parotiditis , Paperas/transmisión , Adulto , Trazado de Contacto , Croacia , Femenino , Humanos , Programas de Inmunización , Lactante , Masculino , Vacuna contra el Sarampión-Parotiditis-Rubéola/administración & dosificación , Meningitis/virología , Paperas/diagnóstico , Paperas/fisiopatología , Virus de la Parotiditis/inmunología , Parotiditis/virología
7.
Neurogastroenterol Motil ; 28(10): 1488-93, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-27137138

RESUMEN

BACKGROUND: The aim of this study was to determine the role of multichannel intraluminal impedance-pH (pH-MII) monitoring in the diagnosis of gastro-esophageal reflux disease (GERD) in children who presented with gastrointestinal (GI) symptoms in comparison with the results of pH-metry alone and endoscopy. METHODS: All children who underwent pH-MII monitoring due to GI symptoms, suggestive of GERD, from October 2013 to October 2015 in Children's Hospital Zagreb, were retrospectively enrolled in the study. The cohort was divided into three groups according to age - group 1: children <1 year of age; group 2: 1-9 years of age; and group 3: ≥9 years of age. KEY RESULTS: One hundred thirty-three patients met our inclusion criteria (73 female/60 male; mean age 9.2 years [0.19-18.0]). Gastro-esophageal reflux disease was determined in 44 of 133 patients (33.1%) by pH-MII and only in 21 of 133 patients (15.8%) by pH-metry alone. Endoscopy was performed in 77 (57.9%) children and esophagitis was found in 32/77 (41.6%). The finding of esophagitis significantly correlated with the number of total reflux episodes (coef. 0.42, p < 0.001), acidic (coef. 0.26, p = 0.02), weakly acidic (coef. 0.3, p = 0.008) and non-acidic (coef. 0.26, p = 0.02) reflux episodes detected by pH-MII; but, no correlation was found to reflux episodes detected by pH-metry alone (coef. 0.21, p = 0.07). CONCLUSIONS & INFERENCES: Compared with pH-metry alone, pH-MII performed significantly better in the detection of GERD in all age groups. On the basis of our data, pH-MII had a strong correlation with endoscopically confirmed esophagitis.


Asunto(s)
Impedancia Eléctrica , Monitorización del pH Esofágico/métodos , Esofagitis/fisiopatología , Reflujo Gastroesofágico/fisiopatología , Monitoreo Ambulatorio/métodos , Adolescente , Niño , Preescolar , Esofagitis/diagnóstico , Femenino , Reflujo Gastroesofágico/diagnóstico , Enfermedades Gastrointestinales/diagnóstico , Enfermedades Gastrointestinales/fisiopatología , Humanos , Lactante , Masculino , Estudios Retrospectivos
8.
Int J Tuberc Lung Dis ; 20(10): 1293-1299, 2016 10.
Artículo en Inglés | MEDLINE | ID: mdl-27725037

RESUMEN

SETTING: In June 2014, we became aware that shortages of purified protein derivative (PPD), the test substance used for the tuberculin skin test (TST), had occurred in several European health care institutions providing care for children with tuberculosis (TB). OBJECTIVE: To establish the extent of the shortage, a survey was performed. DESIGN: Survey conducted over a 1-month period (June-July 2014) among members of the Paediatric Tuberculosis Network European Trials Group (ptbnet). RESULTS: Thirty-five physicians from 23 European countries contributed data. The most commonly used PPD product was RT23 (Statens Serum Institut; n = 22, 63%). Twenty-one (60%) participants reported that their institution was experiencing a PPD shortage. The majority (n = 17, 81%) of those reporting a shortage were using RT23. Thirteen (37%) participants reported changes in screening practices resulting from the shortage, including sourcing PPD from alternative manufacturers, restricting remaining supplies to patients at greatest risk or replacing TST by an interferon-gamma release assay. CONCLUSIONS: The data show that a PPD shortage occurred in 2014, affecting multiple European countries. The shortage resulted in changes in TB screening capabilities and practices, potentially compromising both patient care as well as public health efforts. Appropriate actions to prevent future PPD shortages should be explored urgently by public health agencies and key stakeholders.


Asunto(s)
Necesidades y Demandas de Servicios de Salud , Tamizaje Masivo , Prueba de Tuberculina , Tuberculina , Tuberculosis/diagnóstico , Europa (Continente) , Humanos , Ensayos de Liberación de Interferón gamma , Prevalencia
9.
Antiviral Res ; 36(1): 35-42, 1997 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-9330759

RESUMEN

We used recombinant vaccinia viruses (rVV) containing the UL97 open reading frame (ORF) of the human cytomegalovirus (HCMV) to investigate the UL97-dependent phosphorylation of different nucleoside analogs. The rVV T1 expressed the wild-type UL97 protein whereas rVV A5 contained a 12 bp deletion in the UL97 which had been known to be responsible for resistance of HCMV to ganciclovir (GCV). The rVV T1opal was generated which contained a stop codon at position 1089 of the UL97 ORF and which expressed a truncated UL97 protein. We quantitatively analyzed the capability of these rVVs to phosphorylate GCV, penciclovir (PCV), aciclovir (ACV) and 2-amino-7-[(1,3-dihydroxy-2-propoxy)methyl] purine (S2242) as well as the natural nucleosides deoxycytidine and deoxythymidine. Moreover, we compared their phosphorylating capability with that of herpes simplex virus type 1 strains. In thymidine kinase (TK)-deficient 143B cells infected with rVV T1, the three compounds GCV, ACV and PCV were phosphorylated with different efficiency whereas in cells infected with the rVV A5 a markedly reduced but not completely abolished phosphorylation of these compounds was observed. In rVV T1opal-infected cells no specific phosphorylation of the compounds was detectable at all. Neither S2242 nor the natural substrates of TKs were phosphorylated by any of the vaccinia recombinants. The rVVs proved to be a suitable tool for analysis of UL97-dependent phosphorylation of nucleoside analogs and also allowed to quantitatively study the influence of UL97 mutations on drug phosphorylation.


Asunto(s)
Aciclovir/análogos & derivados , Aciclovir/metabolismo , Ganciclovir/metabolismo , Fosfotransferasas (Aceptor de Grupo Alcohol)/metabolismo , Purinas/metabolismo , Antivirales/metabolismo , Células Cultivadas , Guanina , Humanos , Fosforilación , Recombinación Genética , Virus Vaccinia/genética
10.
J Gen Virol ; 74 ( Pt 10): 2215-23, 1993 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-8105025

RESUMEN

Interferon gamma (IFN gamma) represents an essential cytokine involved in murine cytomegalovirus (MCMV) clearance from the salivary gland and the control of horizontal transmission. Because IFN gamma cannot be responsible for all cytokine effects during recovery from MCMV infection we have now tested the potential participation of tumour necrosis factor alpha (TNF alpha) in the antiviral defence. Neutralization of endogenous TNF alpha abolished the antiviral activity of CD4 T cells in immunocompetent as well as in CD8 subset-deficient mice. These data suggest that the antiviral effect of the CD4 subset requires the presence of at least two cytokines, namely IFN gamma and TNF alpha. Depletion of endogenous TNF alpha in adoptive cell transfer recipients diminished the antiviral function of CD8 T lymphocytes suggesting that TNF alpha also participates in CD8 T cell effector functions. Furthermore, endogenous cytokines were found to be required for survival after infection with lethal doses of MCMV, whereas immunotherapy with recombinant TNF alpha and IFN gamma could not limit virus replication in vivo. The results suggest that, similar to IFN gamma, TNF alpha is an integral part of the protective mechanisms involved in cytomegalovirus clearance.


Asunto(s)
Infecciones por Citomegalovirus/inmunología , Linfocitos T/inmunología , Factor de Necrosis Tumoral alfa/inmunología , Animales , Linfocitos T CD4-Positivos/inmunología , Antígenos CD8 , Citomegalovirus/inmunología , Modelos Animales de Enfermedad , Inmunidad Innata/inmunología , Interferón gamma/inmunología , Ratones , Ratones Endogámicos BALB C , Bazo/citología , Bazo/inmunología , Replicación Viral/inmunología
11.
J Virol ; 66(4): 1977-84, 1992 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-1312614

RESUMEN

Cytomegalovirus (CMV), similar to other members of the Herpesviridae family, can establish both persistent and latent infections. Each of the CMVs that are found in many animal species replicates in the salivary gland, and oral secretion represents a source of horizontal transmission. Locally restricted replication characterizes the immunocompetent individual, whereas in the immunocompromised host, protean disease manifestations occur due to virus dissemination. The virus is cleared by immune surveillance, and CD8+ T lymphocytes play a major role. Remarkably, certain cell types of salivary gland tissues are exempt from CD8+ T-lymphocyte control of murine CMV infection and require the activity of CD4+ T lymphocytes. The results presented here suggest that this activity is a function of Th1 cells. Neutralization of endogenous gamma interferon abrogated the antiviral activity of Th1 cells but not that of CD8+ T lymphocytes in other tissues. Neutralization of endogenous gamma interferon did not interfere with the induction of the cellular and humoral immune response but acted during the effector phase. Recombinant gamma interferon could not replace the function of Th1 cells in vivo and had limited direct antiviral activity in vitro. The results therefore suggest that gamma interferon represents one, but not the only, essential factor involved in salivary gland clearance, establishment of CMV latency, and, eventually, the control of horizontal transmission.


Asunto(s)
Infecciones por Citomegalovirus/inmunología , Interferón gamma/fisiología , Glándulas Salivales/inmunología , Subgrupos de Linfocitos T/inmunología , Animales , Antígenos CD4/metabolismo , Antígenos CD8/metabolismo , Citomegalovirus/inmunología , Infecciones por Citomegalovirus/microbiología , Femenino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos CBA , Pruebas de Neutralización
12.
Antimicrob Agents Chemother ; 41(12): 2686-92, 1997 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-9420039

RESUMEN

We established a quantitative flow cytometric method for determination of herpes simplex virus type 1 (HSV-1) susceptibility to acyclovir (ACV), ganciclovir, and foscarnet in vitro. Susceptibility was defined in terms of the drug concentration which reduced the number of cells expressing HSV-1 glycoprotein C (gpC) with a fluorescence intensity of > or =10(2) by 50% (IC50). Flow cytometry allowed us to use a high (1.0) as well as a low (0.005) multiplicity of infection, and determination of the IC50 was possible after one or more viral replicative cycles. IC50s were dependent on virus input and on time postinfection. In mixture experiments, 1 to 2% resistant viruses added to a sensitive strain could be detected. The results obtained by flow cytometry showed a good qualitative correlation with those achieved by cytopathic effect inhibitory assay. However, flow cytometry might detect more quantitative differences in drug susceptibility, especially among resistant strains, as confirmed also by determination of intracellular drug phosphorylation. The mean IC50s for ACV-sensitive strains were 0.45 to 1.47 microM, and those for ACV-resistant strains were between 140 and 3,134 microM. Flow cytometric analysis was fast and accurate, automatizable, and highly reproducible. Flow cytometry may be a more powerful tool than standard cytopathic effect-based assays and could have advantages for the detection of low levels of drug resistance or mixtures of sensitive and resistant virus strains.


Asunto(s)
Antivirales/farmacología , Herpesvirus Humano 1/efectos de los fármacos , Aciclovir/metabolismo , Aciclovir/farmacología , Antivirales/metabolismo , Fibroblastos/metabolismo , Fibroblastos/virología , Citometría de Flujo , Foscarnet/metabolismo , Foscarnet/farmacología , Ganciclovir/metabolismo , Ganciclovir/farmacología , Herpes Simple/metabolismo , Humanos , Cinética , Pruebas de Sensibilidad Microbiana , Fosforilación , Proteínas del Envoltorio Viral/biosíntesis
13.
J Virol ; 70(9): 6340-6, 1996 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-8709262

RESUMEN

The temporal expression of the UL97 gene product during human cytomegalovirus (HCMV) infection of human foreskin fibroblasts (HFF) and subcellular localization of this protein were analyzed by using a polyclonal antiserum raised against a truncated UL97 protein of 47 kDa. The UL97 protein was detectable 16 h after infection by Western blot (immunoblot) analysis. Since only reduced UL97 expression occurred in the presence of two inhibitors of DNA replication, phosphonoacetic acid and ganciclovir, we conclude that UL97 is an early-late gene, requiring DNA replication for maximum expression. By indirect immunofluorescence, the protein could be visualized in the nuclei of virus-infected HFF 22 h after infection. Nuclear localization of the UL97 protein was also detected in thymidine kinase-deficient 143B cells infected with a recombinant vaccinia virus containing the entire UL97 open reading frame (ORF), as well as in HFF transiently expressing the entire UL97 ORF under the control of HCMV major immediate-early promoter. However, transiently expressed 5'-terminal deletion mutants of the UL97 ORF in addition showed a cytoplasmic localization of the UL97 protein, confirming the presence of a nuclear localization site in the N-terminal region of the protein. Our high-pressure liquid chromatography analyses confirmed the ganciclovir phosphorylation by the UL97 protein, but no specific phosphorylation of natural nucleosides was observed, indicating that the UL97 protein is not a nucleoside kinase. During plaque purification of recombinant UL97-deficient HCMV, this virus was growth defective; hence, we presume that UL97 may be essential for the viral life cycle.


Asunto(s)
Núcleo Celular/metabolismo , Citomegalovirus/metabolismo , Fosfotransferasas (Aceptor de Grupo Alcohol)/metabolismo , Secuencia de Aminoácidos , Anticuerpos Monoclonales , Secuencia de Bases , Western Blotting , Núcleo Celular/virología , Células Cultivadas , Citomegalovirus/genética , Cartilla de ADN , Replicación del ADN , Fibroblastos , Técnica del Anticuerpo Fluorescente Indirecta , Genes Virales , Humanos , Cinética , Masculino , Datos de Secuencia Molecular , Sistemas de Lectura Abierta , Fosfotransferasas/metabolismo , Fosfotransferasas (Aceptor de Grupo Alcohol)/biosíntesis , Reacción en Cadena de la Polimerasa , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/metabolismo , Mapeo Restrictivo , Eliminación de Secuencia , Homología de Secuencia de Aminoácido , Piel , Transfección
14.
J Virol ; 64(11): 5457-64, 1990 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-1976821

RESUMEN

Although the relative contribution of different immune effector functions to clearing tissues of cytomegalovirus is controversial, the contribution of CD8+ T lymphocytes has generally been accepted as essential. In this report, we show that under certain conditions the CD8+ T-lymphocyte subset can be dispensable for clearance of cytomegalovirus. Mice depleted of the CD8+ T-lymphocyte subset eliminated infectious virus with a clearance kinetics similar to that of normal mice. Adoptive transfer studies revealed that the limitation of virus spread required the cooperation between the CD4+ subset and other cells. Comparison between protective functions generated in fully immunocompetent and in CD8- mice demonstrated that elimination of the CD8+ subset before infection altered the quality of the antiviral immune response. The compensatory protective activity gained by CD4+ cells in CD8- mice was absent in normal mice recovering from virus infection.


Asunto(s)
Infecciones por Citomegalovirus/inmunología , Inmunidad Celular , Subgrupos de Linfocitos T/inmunología , Animales , Antígenos de Diferenciación de Linfocitos T/análisis , Antígenos Virales/inmunología , Linfocitos T CD4-Positivos/inmunología , Antígenos CD8 , Citomegalovirus/inmunología , Citotoxicidad Inmunológica , Ratones , Ratones Endogámicos BALB C , Trasplante de Piel/inmunología , Linfocitos T Citotóxicos/inmunología
15.
J Gen Virol ; 77 ( Pt 2 ): 217-25, 1996 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-8627225

RESUMEN

It has been claimed that MHC class I proteins serve as receptors for murine cytomegalovirus (MCMV) and that this interaction is the most important mechanism for virus entry in most cells. This claim is based on the observation that the MHC haplotype contributes to the susceptibility to cytomegalovirus (CMV) infection in vivo. Results from in vitro studies support the concept that stable expression of correctly folded MHC class I molecules contributes to infection, since the individual properties of MHC class I alleles, the availability of beta 2-microglobulin (beta 2m) and also the degree of peptide charging of the MHC class I heavy chain beta 2m heterodimers determined the infection phenotype of cell lines. To assess the biological relevance of proper MHC class I expression we investigated CMV infection in beta 2m-deficient mice which fail to express ternary MHC class I complexes and lack peripheral CD8+ T lymphocytes. We found that organ virus titres and virus clearance kinetics were not altered in beta 2m mutant mice. In addition, there was no indication of diminished virus propagation in beta 2m-/- embryonic fibroblasts. beta 2m-/- mice suffered from the lack of CD8+ T lymphocytes that was partially compensated for by the function of CD4+ T lymphocytes. An organ-specific anti-virus function of natural killer (NK) cells was observed, independent from the beta 2m deletion. The immune control unique for salivary gland infection was maintained. From the data presented here, we confirm the role of MHC class I molecules in the immune surveillance of CMV infection but question the biological impact of correct MHC class I complexes for productive infection.


Asunto(s)
Infecciones por Citomegalovirus/inmunología , Antígenos de Histocompatibilidad Clase I/fisiología , Animales , Linfocitos T CD8-positivos/fisiología , Ratones , Ratones Endogámicos C57BL , Ratas , Microglobulina beta-2/deficiencia
16.
J Gen Virol ; 79 ( Pt 9): 2105-12, 1998 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-9747718

RESUMEN

In order to identify functional regions of the human cytomegalovirus protein pUL97 (i) different 5' fragments of the UL97 open reading frame (ORF) were fused to the coding region of the green fluorescent protein and (ii) recombinant vaccinia viruses (rVV) were generated carrying two full-length and 11 mutated UL97 ORFs. The results indicated the presence of an N-terminal region within pUL97 which changed the intracellular distribution of the fusion proteins. pUL97 was localized in the nucleus, but not in the nucleoli, and was detected in the nuclear matrix fraction. Expression of all pUL97 mutants could be confirmed by Western blot analysis. pUL97-associated ganciclovir (GCV) phosphorylation in rVV-infected cells, determined quantitatively by HPLC analysis, was abolished completely using individual UL97 deletion mutants. Phosphorylation of full-length and some of the mutated pUL97 was detected in cells infected with the rVVs. The UL97 constructs carrying point mutations from GCV-resistant HCMV isolates at positions 460M, 520H, 594V, and the 4 aa deletion 590AACR593, also resulted in decreased but not abolished phosphorylation of GCV in the rVV system, whereas the phosphorylation of pUL97 itself was not influenced. The rVV system is a suitable method for quantitatively testing the functional relevance of pUL97 mutations.


Asunto(s)
Antivirales/metabolismo , Antivirales/farmacocinética , Citomegalovirus/metabolismo , Ganciclovir/metabolismo , Ganciclovir/farmacocinética , Fosfotransferasas (Aceptor de Grupo Alcohol)/química , Fosfotransferasas (Aceptor de Grupo Alcohol)/metabolismo , Secuencia de Aminoácidos , Secuencia de Bases , Sitios de Unión , Transporte Biológico Activo , Línea Celular , Núcleo Celular/metabolismo , Citomegalovirus/genética , Cartilla de ADN/genética , Genes Virales , Proteínas Fluorescentes Verdes , Humanos , Proteínas Luminiscentes/química , Proteínas Luminiscentes/genética , Proteínas Luminiscentes/metabolismo , Datos de Secuencia Molecular , Matriz Nuclear/metabolismo , Sistemas de Lectura Abierta , Fosforilación , Fosfotransferasas (Aceptor de Grupo Alcohol)/genética , Mutación Puntual , Reacción en Cadena de la Polimerasa , Proteínas Recombinantes de Fusión/química , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Eliminación de Secuencia , Virus Vaccinia/genética
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