Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 48
Filtrar
1.
Surg Endosc ; 35(7): 3339-3353, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-32648038

RESUMEN

INTRODUCTION: Endoscopic full-thickness resection (eFTR) using the full-thickness resection device (FTRD®) is a novel minimally invasive procedure that allows the resection of various lesions in the gastrointestinal tract including the colorectum. Real-world data outside of published studies are limited. The aim of this study was a detailed analysis of the outcomes of colonoscopic eFTR in different hospitals from different care levels in correlation with the number of endoscopists performing eFTR. MATERIAL AND METHODS: In this case series, the data of all patients who underwent eFTR between November 2014 and June 2019 (performed by a total of 22 endoscopists) in 7 hospitals were analyzed retrospectively regarding rates of technical success, R0 resection, and procedure-related complications. RESULTS: Colonoscopic eFTR was performed in 229 patients (64.6% men; average age 69.3 ± 10.3 years) mainly on the basis of the following indication: 69.9% difficult adenomas, 21.0% gastrointestinal adenocarcinomas, and 7.9% subepithelial tumors. The average size of the lesions was 16.3 mm. Technical success rate of eFTR was achieved in 83.8% (binominal confidence interval 78.4-88.4%). Overall, histologically complete resection (R0) was achieved in 77.2% (CI 69.8-83.6%) while histologically proven full-wall excidate was confirmed in 90.0% (CI 85.1-93.7%). Of the resectates obtained (n = 210), 190 were resected en bloc (90.5%). We did not observe a clear improvement of technical success and R0 resection rate over time by the performing endoscopists. Altogether, procedure-related complications were observed in 17.5% (mostly moderate) including 2 cases of acute gangrenous appendicitis requiring operation. DISCUSSION: In this pooled analysis, eFTR represents a feasible, effective, and safe minimally invasive endoscopic technique.


Asunto(s)
Adenoma , Colonoscopía , Anciano , Femenino , Hospitales , Humanos , Masculino , Estudios Retrospectivos , Resultado del Tratamiento
3.
Eur J Gastroenterol Hepatol ; 28(2): 187-92, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26575158

RESUMEN

OBJECTIVE: Neuropsychiatric symptoms of hepatitis C virus (HCV) infection and during peginterferon α therapy have been investigated in the chronic stage of the infection, but have not been described during the acute phase of the disease so far. We therefore evaluated anxiety and depression in patients with acute hepatitis C by the Hospital Anxiety and Depression Scale (HADS) within a clinical trial. METHODS: Data were analysed from the German Hep-Net Acute HCV-III study. Anxiety and depression were characterized by an anxiety (HADS-A) and a depression subscale (HADS-D). More than eight points in each subscale were considered clinically relevant. Data were prospectively collected at baseline, end of treatment and at the end of the study. RESULTS: At baseline, a HADS-A above eight points was observed significantly more frequently than a HADS-D above eight points [n=23/103 (22%) vs. n=12/103 (12%); P=0.041].A pathological HADS-A or HADS-D score did not correlate with age, sex, IL28B genotype, the probable mode of infection, HCV genotype or severity of disease as investigated by alanine aminotransferase and bilirubin levels.Antiviral therapy did not influence anxiety as 12/50 (24%) of patients had HADS-A above 8 at the end of therapy. The proportion of patients with HADS-D above eight points increased from 12% at baseline to 24% (n=12/50) at the end of therapy (P=0.06). HADS results were not associated with lost to follow-up or sustained virological response rates. CONCLUSION: HADS data in acute HCV infection indicate that anxiety and depression do not correlate with severity of the disease, mode of acquisition, lost to follow-up and sustained virological response rates.


Asunto(s)
Ansiedad/epidemiología , Depresión/epidemiología , Hepatitis C/epidemiología , Enfermedad Aguda , Adulto , Antivirales/uso terapéutico , Ansiedad/diagnóstico , Ansiedad/psicología , Depresión/diagnóstico , Depresión/psicología , Femenino , Alemania/epidemiología , Hepatitis C/diagnóstico , Hepatitis C/tratamiento farmacológico , Hepatitis C/psicología , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Escalas de Valoración Psiquiátrica , Índice de Severidad de la Enfermedad , Encuestas y Cuestionarios , Resultado del Tratamiento , Adulto Joven
4.
J Exp Med ; 211(10): 2047-59, 2014 Sep 22.
Artículo en Inglés | MEDLINE | ID: mdl-25225458

RESUMEN

The transcription factor T-bet regulates the production of interferon-γ and cytotoxic molecules in effector CD8 T cells, and its expression correlates with improved control of chronic viral infections. However, the role of T-bet in infections with differential outcome remains poorly defined. Here, we report that high expression of T-bet in virus-specific CD8 T cells during acute hepatitis B virus (HBV) and hepatitis C virus (HCV) infection was associated with spontaneous resolution, whereas T-bet deficiency was more characteristic of chronic evolving infection. T-bet strongly correlated with interferon-γ production and proliferation of virus-specific CD8 T cells, and its induction by antigen and IL-2 stimulation partially restored functionality in previously dysfunctional T-bet-deficient CD8 T cells. However, restoration of a strong interferon-γ response required additional stimulation with IL-12, which selectively induced the phosphorylation of STAT4 in T-bet(+) CD8 T cells. The observation that T-bet expression rendered CD8 T cells responsive to IL-12 suggests a stepwise mechanism of T cell activation in which T-bet facilitates the recruitment of additional transcription factors in the presence of key cytokines. These findings support a critical role of T-bet for viral clearance and suggest T-bet deficiency as an important mechanism behind chronic infection.


Asunto(s)
Linfocitos T CD8-positivos/inmunología , Hepatitis B/inmunología , Hepatitis C/inmunología , Proteínas de Dominio T Box/metabolismo , Linfocitos T CD8-positivos/citología , Citometría de Flujo , Humanos , Interferón gamma/inmunología , Interferón gamma/metabolismo , Interleucina-12/metabolismo , Fosforilación , Factor de Transcripción STAT4/metabolismo , Estadísticas no Paramétricas , Proteínas de Dominio T Box/inmunología
5.
PLoS One ; 9(8): e105703, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25144233

RESUMEN

BACKGROUND: T-cell exhaustion seems to play a critical role in CD8+ T-cell dysfunction during chronic viral infections. However, up to now little is known about the mechanisms underlying CD4+ T-cell dysfunction during chronic hepatitis B virus (CHB) infection and the role of inhibitory molecules such as programmed death 1 (PD-1) for CD4+ T-cell failure. METHODS: The expression of multiple inhibitory molecules such as PD-1, CTLA-4, TIM-3, CD244, KLRG1 and markers defining the grade of T-cell differentiation as CCR7, CD45RA, CD57 and CD127 were analyzed on virus-specific CD4+ T-cells from peripheral blood using a newly established DRB1*01-restricted MHC class II Tetramer. Effects of in vitro PD-L1/2 blockade were defined by investigating changes in CD4+ T-cell proliferation and cytokine production. RESULTS: CD4+ T-cell responses during chronic HBV infection was characterized by reduced Tetramer+CD4+ T-cell frequencies, effector memory phenotype, sustained PD-1 but low levels of CTLA-4, TIM-3, KLRG1 and CD244 expression. PD-1 blockade revealed individualized patterns of in vitro responsiveness with partly increased IFN-γ, IL-2 and TNF-α secretion as well as enhanced CD4+ T-cell expansion almost in treated patients with viral control. CONCLUSION: HBV-specific CD4+ T-cells are reliably detectable during different courses of HBV infection by MHC class II Tetramer technology. CD4+ T-cell dysfunction during chronic HBV is basically linked to strong PD-1 upregulation but absent coregulation of multiple inhibitory receptors. PD-L1/2 neutralization partly leads to enhanced CD4+ T-cell functionality with heterogeneous patterns of CD4+ T-cell rejunivation.


Asunto(s)
Linfocitos T CD4-Positivos/inmunología , Receptores Coestimuladores e Inhibidores de Linfocitos T/inmunología , Regulación de la Expresión Génica/inmunología , Hepatitis B Crónica/inmunología , Receptor de Muerte Celular Programada 1/inmunología , Adolescente , Adulto , Anciano , Linfocitos T CD4-Positivos/patología , Femenino , Hepatitis B Crónica/patología , Humanos , Masculino , Persona de Mediana Edad
7.
Virol J ; 10: 295, 2013 Sep 28.
Artículo en Inglés | MEDLINE | ID: mdl-24073713

RESUMEN

BACKGROUND: CTL escape mutations have been described during acute hepatitis C in patients who developed chronic disease later on. Our aim was to investigate the mutual relationship between HCV specific CD8+ T cells and evolution of the viral sequence during early acute HCV infection. RESULTS: We sequenced multiple clones of NS3 1406 epitope in 4 HLA-A*02 patients with acute hepatitis C genotype 1b infection. Pentamers specific for the variants were used to monitor the corresponding CD8+ T cell response. We observed outgrowth of mutations, which induced only a weak and thus potentially insufficient CD8+ T cell response. In one patient we observed outgrowth of variant epitopes with similarities to a different genotype rather than de novo mutations most probably due to a lack of responsiveness to these likely pre-existing variants. We could show that in acute hepatitis C CTL escape mutations occur much earlier than demonstrated in previous studies. CONCLUSIONS: The adaption of the virus to a new host is characterized by a high and rapid variability in epitopes under CD8+ T cell immune pressure. This adaption takes place during the very early phase of acute infection and strikingly some sequences were reduced below the limit of detection at some time points but were detected at high frequency again at later time points. Independent of the observed variability, HCV-specific CD8+ T cell responses decline and no adaption to different or new antigens during the course of infection could be detected.


Asunto(s)
Linfocitos T CD8-positivos/inmunología , Hepacivirus/genética , Hepacivirus/inmunología , Hepatitis C/inmunología , Hepatitis C/virología , Evasión Inmune , Adaptación Biológica , Adulto , Antígenos Virales/genética , Antígenos Virales/inmunología , Análisis Mutacional de ADN , Femenino , Hepacivirus/aislamiento & purificación , Humanos , Masculino , Persona de Mediana Edad , Mutación , Análisis de Secuencia de ADN
8.
Mol Ther ; 21(9): 1796-805, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23752314

RESUMEN

Clearance of infections caused by the hepatitis C virus (HCV) correlates with HCV-specific T cell function. We therefore evaluated therapeutic vaccination in 12 patients with chronic HCV infection. Eight patients also underwent a subsequent standard-of-care (SOC) therapy with pegylated interferon (IFN) and ribavirin. The phase I/IIa clinical trial was performed in treatment naive HCV genotype 1 patients, receiving four monthly vaccinations in the deltoid muscles with 167, 500, or 1,500 µg codon-optimized HCV nonstructural (NS) 3/4A-expressing DNA vaccine delivered by in vivo electroporation (EP). Enrollment was done with 2 weeks interval between patients for safety reasons. Treatment was safe and well tolerated. The vaccinations significantly improved IFN-γ-producing responses to HCV NS3 during the first 6 weeks of therapy. Five patients experienced 2-10 weeks 0.6-2.4 log10 reduction in serum HCV RNA. Six out of eight patients starting SOC therapy within 1-30 months after the last vaccine dose were cured. This first-in-man therapeutic HCV DNA vaccine study with the vaccine delivered by in vivo EP shows transient effects in patients with chronic HCV genotype 1 infection. The interesting result noted after SOC therapy suggests that therapeutic vaccination can be explored in a combination with SOC treatment.


Asunto(s)
Antivirales/uso terapéutico , Hepatitis C Crónica/terapia , Interferón-alfa/uso terapéutico , Polietilenglicoles/uso terapéutico , Ribavirina/uso terapéutico , Vacunas de ADN/uso terapéutico , Vacunas contra Hepatitis Viral/uso terapéutico , Adulto , Antivirales/administración & dosificación , Antivirales/efectos adversos , Terapia Combinada , Electroporación , Femenino , Hepacivirus/genética , Hepacivirus/inmunología , Hepacivirus/fisiología , Hepatitis C Crónica/genética , Hepatitis C Crónica/virología , Humanos , Interferón-alfa/administración & dosificación , Interferón-alfa/efectos adversos , Interferones , Interleucinas/genética , Activación de Linfocitos , Masculino , Persona de Mediana Edad , Polietilenglicoles/administración & dosificación , Polietilenglicoles/efectos adversos , ARN Viral/sangre , Proteínas Recombinantes/administración & dosificación , Proteínas Recombinantes/efectos adversos , Proteínas Recombinantes/uso terapéutico , Ribavirina/administración & dosificación , Ribavirina/efectos adversos , Nivel de Atención , Linfocitos T/inmunología , Vacunas de ADN/administración & dosificación , Vacunas de ADN/efectos adversos , Vacunas de ADN/inmunología , Vacunas contra Hepatitis Viral/administración & dosificación , Vacunas contra Hepatitis Viral/efectos adversos , Carga Viral
9.
Lancet Infect Dis ; 13(6): 497-506, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23523674

RESUMEN

BACKGROUND: Early treatment of acute hepatitis C virus (HCV) infection with interferon alfa monotherapy is very effective, with cure rates of greater than 85%. However, spontaneous clearance of HCV occurs in 10-50% of cases. We aimed to assess an alternative treatment strategy of delayed antiviral therapy in patients who do not eliminate the virus spontaneously compared with immediate treatment. METHODS: In our open-label phase 3 non-inferiority trial, we enrolled adults (≥18 years) with acute hepatitis C but no HIV or hepatitis B co-infection at 72 centres in Germany. We randomly allocated patients with symptomatic acute hepatitis C (1:1) to receive immediate pegylated interferon alfa-2b treatment for 24 weeks or delayed treatment with pegylated interferon alfa-2b plus ribavirin (for 24 weeks) starting 12 weeks after randomisation if HCV RNA remained positive. We used a computer-generated randomisation sequence and block sizes of eight, stratified by bilirubin concentration. We assigned all asymptomatic patients to immediate treatment with pegylated interferon alfa-2b for 24 weeks. The primary endpoint was sustained HCV RNA negativity in all randomly allocated participants who completed screening (intention-to-treat analysis), with a non-inferiority margin of 10%. For the primary analysis, we calculated the virological response of patients in the immediate and delayed treatment groups and an absolute risk difference stratified by bilirubin status. The trial was stopped early on advice from the study advisory committee because of slow recruitment of participants. This study is registered, number ISRCTN88729946. FINDINGS: Between April, 2004, and February, 2010, we recruited 107 symptomatic and 25 asymptomatic patients. 37 (67%) of 55 symptomatic patients randomly allocated to receive immediate treatment and 28 (54%) of 52 symptomatic patients randomly allocated to receive delayed treatment had a sustained virological response (difference 13·7%, 95% CI -4·6 to 32·0; p=0·071). 18 (72%) of 25 asymptomatic patients had a sustained virological response. 22 (42%) of 52 symptomatic patients allocated to receive delayed treatment did not complete follow-up compared with 20 (25%) of 80 symptomatic or asymptomatic patients assigned immediate treatment (p=0·037). 11 symptomatic patients (21%) assigned delayed treatment had spontaneous HCV clearance. 14 patients who received delayed pegylated interferon alfa-2b plus ribavirin treatment and completed follow-up achieved sustained virological response. INTERPRETATION: Delayed treatment is effective although not of equal efficacy to immediate treatment; coupled with the rate of spontaneous clearance it can reduce unnecessary treatment in closely monitored populations. Immediate treatment seems preferable in populations where loss to follow-up is great. FUNDING: German Network of Competence on Viral Hepatitis (HepNet, funded by the German Federal Ministry of Education and Research, grants 01KI0102, 01KI0401, and 01KI0601), MSD, Schering-Plough.


Asunto(s)
Antivirales/uso terapéutico , Hepatitis C/tratamiento farmacológico , Enfermedad Aguda , Adulto , Anciano , Coinfección/diagnóstico , Coinfección/virología , Esquema de Medicación , Femenino , Estudios de Seguimiento , Infecciones por VIH/diagnóstico , Hepacivirus/aislamiento & purificación , Hepatitis C/virología , Humanos , Interferón alfa-2 , Interferón-alfa/uso terapéutico , Masculino , Persona de Mediana Edad , Polietilenglicoles/uso terapéutico , ARN Viral , Proteínas Recombinantes/uso terapéutico , Ribavirina/uso terapéutico , Adulto Joven
10.
PLoS One ; 8(1): e54793, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23358556

RESUMEN

BACKGROUND: Genetic variation in the IL28B gene has been strongly associated with treatment outcomes, spontaneous clearance and progression of the hepatitis C virus infection (HCV). The aim of the present study was to investigate the role of polymorphisms at this locus with progression and outcome of HCV infection in a Moroccan population. METHODS: We analyzed a cohort of 438 individuals among them 232 patients with persistent HCV infection, of whom 115 patients had mild chronic hepatitis and 117 had advanced liver disease (cirrhosis and hepatocellular carcinoma), 68 individuals who had naturally cleared HCV and 138 healthy subjects. The IL28B SNPs rs12979860 and rs8099917 were genotyped using a TaqMan 5' allelic discrimination assay. RESULTS: The protective rs12979860-C and rs8099917-T alleles were more common in subjects with spontaneous clearance (77.9% vs 55.2%; p = 0.00001 and 95.6% vs 83.2%; p = 0.0025, respectively). Individuals with clearance were 4.69 (95% CI, 1.99-11.07) times more likely to have the C/C genotype for rs12979860 polymorphism (p = 0.0017) and 3.55 (95% CI, 0.19-66.89) times more likely to have the T/T genotype at rs8099917. Patients with advanced liver disease carried the rs12979860-T/T genotype more frequently than patients with mild chronic hepatitis C (OR = 1.89; 95% CI, 0.99-3.61; p = 0.0532) and this risk was even more pronounced when we compared them with healthy controls (OR = 4.27; 95% CI, 2.08-8.76; p = 0.0005). The rs8099917-G allele was also associated with advanced liver disease (OR = 2.34; 95% CI, 1.40-3.93; p = 0.0100). CONCLUSIONS: In the Moroccan population, polymorphisms near the IL28B gene play a role both in spontaneous clearance and progression of HCV infection.


Asunto(s)
Hepatitis C/patología , Interleucinas/genética , Polimorfismo de Nucleótido Simple , Anciano , Alelos , Secuencia de Bases , Estudios de Cohortes , Cartilla de ADN , Femenino , Hepatitis C/genética , Humanos , Interferones , Masculino , Persona de Mediana Edad , Marruecos , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
11.
Gastroenterology ; 141(4): 1422-31, 1431.e1-6, 2011 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21763239

RESUMEN

BACKGROUND & AIMS: Inhibitory receptors such as programmed death 1 (PD-1) and cytotoxic T lymphocyte-associated antigen (CTLA)-4 mediate CD8+ T-cell exhaustion during chronic viral infection, but little is known about roles in dysfunction of CD4+ T cells. METHODS: We investigated the functions of inhibitory molecules on hepatitis C virus (HCV)-, influenza-, and Epstein-Barr virus (EBV)-specific CD4+ T cells in patients with chronic infections compared with patients with resolved HCV infection and healthy donors. Expression of PD-1, CTLA-4, CD305, and CD200R were analyzed on HCV-specific CD4+ T cells, isolated from peripheral blood using major histocompatibility complex class II tetramers. We investigated the effects of in vitro inhibition of various inhibitory pathways on proliferation and cytokine production by CD4+ T cells, and we compared these effects with those from inhibition of interleukin (IL)-10 and transforming growth factor (TGF)-ß1. RESULTS: PD-1 and CTLA-4 were up-regulated on virus-specific CD4+ T cells from patients with chronic HCV infections. PD-1 expression was lower on influenza- than on HCV-specific CD4+ T cells from subjects with chronic HCV infection, whereas CTLA-4 was expressed at similar levels, independent of their specificity. CD305 and CD200R were up-regulated in HCV resolvers. Blockade of PD-L1/2, IL-10, and TGF-ß1 increased expansion of CD4+ T cells in patients with chronic HCV, whereas inhibition of IL-10 and TGF-ß1 was most effective in restoring HCV-specific production of interferon gamma, IL-2, and tumor necrosis factor α. CONCLUSIONS: We characterized expression of inhibitory molecules on HCV-, influenza-, and EBV-specific CD4+ T cells and the effects of in vitro blockade on CD4+ T-cell expansion and cytokine production. Inhibition of PD-1, IL-10, and TGF-ß1 is most efficient in restoration of HCV-specific CD4+ T cells.


Asunto(s)
Antígenos CD/metabolismo , Linfocitos T CD4-Positivos/inmunología , Proliferación Celular , Hepacivirus/inmunología , Hepatitis C Crónica/inmunología , Activación de Linfocitos , Anticuerpos Neutralizantes , Antígenos CD/inmunología , Antígenos de Superficie/metabolismo , Linfocitos T CD4-Positivos/virología , Antígeno CTLA-4/metabolismo , Estudios de Casos y Controles , Células Cultivadas , Femenino , Alemania , Hepacivirus/genética , Hepatitis C Crónica/diagnóstico , Herpesvirus Humano 4/inmunología , Humanos , Interferón gamma/metabolismo , Interleucina-10/inmunología , Interleucina-10/metabolismo , Interleucina-2/metabolismo , Masculino , Persona de Mediana Edad , Receptores de Orexina , Orthomyxoviridae/inmunología , Receptor de Muerte Celular Programada 1/metabolismo , ARN Viral/sangre , Receptores de Superficie Celular/metabolismo , Factor de Crecimiento Transformador beta1/inmunología , Factor de Crecimiento Transformador beta1/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo , Carga Viral
12.
PLoS One ; 6(2): e16797, 2011 Feb 08.
Artículo en Inglés | MEDLINE | ID: mdl-21347433

RESUMEN

Cellular immune responses during acute Hepatitis C virus (HCV) and HIV infection are a known correlate of infection outcome. Viral adaptation to these responses via mutation(s) within CD8+ T-cell epitopes allows these viruses to subvert host immune control. This study examined HCV evolution in 21 HCV genotype 1-infected subjects to characterise the level of viral adaptation during acute and early HCV infection. Of the total mutations observed 25% were within described CD8+ T-cell epitopes or at viral adaptation sites. Most mutations were maintained into the chronic phase of HCV infection (75%). The lack of reversion of adaptations and high proportion of silent substitutions suggests that HCV has structural and functional limitations that constrain evolution. These results were compared to the pattern of viral evolution observed in 98 subjects during a similar phase in HIV infection from a previous study. In contrast to HCV, evolution during acute HIV infection is marked by high levels of amino acid change relative to silent substitutions, including a higher proportion of adaptations, likely reflecting strong and continued CD8+ T-cell pressure combined with greater plasticity of the virus. Understanding viral escape dynamics for these two viruses is important for effective T cell vaccine design.


Asunto(s)
Adaptación Fisiológica/genética , Evolución Molecular , Hepacivirus/genética , Hepacivirus/fisiología , Hepatitis C/virología , Enfermedad Aguda , Alelos , Epítopos/inmunología , Genotipo , Antígenos HLA/inmunología , Hepacivirus/patogenicidad , Hepatitis C/diagnóstico , Hepatitis C/inmunología , Hepatitis C Crónica/diagnóstico , Hepatitis C Crónica/inmunología , Hepatitis C Crónica/virología , Humanos , Mutación , Pronóstico , Linfocitos T/inmunología , Linfocitos T/virología
13.
PLoS One ; 5(12): e15200, 2010 Dec 08.
Artículo en Inglés | MEDLINE | ID: mdl-21170333

RESUMEN

BACKGROUND: Specific differences in signaling and antiviral properties between the different Lambda-interferons, a novel group of interferons composed of IL-28A, IL-28B and IL-29, are currently unknown. This is the first study comparatively investigating the transcriptome and the antiviral properties of the Lambda-interferons IL-28A and IL-29. METHODOLOGY/PRINCIPAL FINDINGS: Expression studies were performed by microarray analysis, quantitative PCR (qPCR), reporter gene assays and immunoluminometric assays. Signaling was analyzed by Western blot. HCV replication was measured in Huh-7 cells expressing subgenomic HCV replicon. All hepatic cell lines investigated as well as primary hepatocytes expressed both IFN-λ receptor subunits IL-10R2 and IFN-λR1. Both, IL-28A and IL-29 activated STAT1 signaling. As revealed by microarray analysis, similar genes were induced by both cytokines in Huh-7 cells (IL-28A: 117 genes; IL-29: 111 genes), many of them playing a role in antiviral immunity. However, only IL-28A was able to significantly down-regulate gene expression (n = 272 down-regulated genes). Both cytokines significantly decreased HCV replication in Huh-7 cells. In comparison to liver biopsies of patients with non-viral liver disease, liver biopsies of patients with HCV showed significantly increased mRNA expression of IL-28A and IL-29. Moreover, IL-28A serum protein levels were elevated in HCV patients. In a murine model of viral hepatitis, IL-28 expression was significantly increased. CONCLUSIONS/SIGNIFICANCE: IL-28A and IL-29 are up-regulated in HCV patients and are similarly effective in inducing antiviral genes and inhibiting HCV replication. In contrast to IL-29, IL-28A is a potent gene repressor. Both IFN-λs may have therapeutic potential in the treatment of chronic HCV.


Asunto(s)
Antivirales/farmacología , Regulación de la Expresión Génica , Hepacivirus/genética , Interleucinas/química , Transcripción Genética , Animales , Granulocitos/citología , Hepatitis C/metabolismo , Humanos , Interferones , Interleucinas/genética , Leucocitos Mononucleares/citología , Hígado/metabolismo , Ratones , Muromegalovirus/genética , Fosforilación , Factor de Transcripción STAT3/genética , Transducción de Señal
14.
Hepatology ; 52(6): 1934-47, 2010 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21064032

RESUMEN

UNLABELLED: Multiple inhibitory receptors may play a role in the weak or absent CD8+ T-cell response in chronic hepatitis B virus (HBV) infection. Yet few receptors have been characterized in detail and little is known about their complex regulation. In the present study, we investigated the role of the signaling lymphocyte activation molecule (SLAM)-related receptor CD244 and of programmed death 1 (PD-1) in HBV infection in 15 acutely and 66 chronically infected patients as well as 9 resolvers and 21 healthy controls. The expression of CD244, PD-1, and T-cell immunoglobulin domain and mucin domain 3 (TIM-3) was analyzed in virus-specific CD8+ T-cells derived from peripheral blood or liver using major histocompatibility complex class I pentamers targeting immunodominant epitopes of HBV, Epstein-Barr-virus (EBV), or influenza virus (Flu). In chronic HBV infection, virus-specific CD8+ T-cells expressed higher levels of CD244 both in the peripheral blood and liver in comparison to the acute phase of infection or following resolution. CD244 was expressed at similarly high levels in EBV infection, but was low on Flu-specific CD8+ T-cells. In chronic HBV infection, high-level CD244 expression coincided with an increased expression of PD-1. The inhibition of the CD244 signaling pathway by antibodies directed against either CD244 or its ligand CD48 resulted in an increased virus-specific proliferation and cytotoxicity as measured by the expression of CD107a, interferon-γ, and tumor necrosis factor-α in CD8+ T-cells. CONCLUSION: CD244 and PD-1 are highly coexpressed on virus-specific CD8+ T-cells in chronic HBV infection and blocking CD244 or its ligand CD48 may restore T-cell function independent of the PD-1 pathway. CD244 may thus be another potential target for immunotherapy in chronic viral infections.


Asunto(s)
Antígenos CD/inmunología , Proteínas Reguladoras de la Apoptosis/inmunología , Linfocitos T CD8-positivos/inmunología , Hepatitis B Crónica/inmunología , Receptores Inmunológicos/inmunología , Adulto , Antígenos CD/biosíntesis , Linfocitos T CD8-positivos/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Infecciones por Virus de Epstein-Barr/inmunología , Femenino , Antígenos HLA-DR/biosíntesis , Virus de la Hepatitis B/inmunología , Humanos , Interferón gamma/metabolismo , Proteína 1 de la Membrana Asociada a los Lisosomas/biosíntesis , Masculino , Receptor de Muerte Celular Programada 1 , Receptores Inmunológicos/antagonistas & inhibidores , Receptores Inmunológicos/biosíntesis , Familia de Moléculas Señalizadoras de la Activación Linfocitaria , Factor de Necrosis Tumoral alfa/biosíntesis , Carga Viral
16.
Expert Rev Vaccines ; 9(3): 243-7, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-20218851

RESUMEN

Antigen-specific downregulation of T-cell effector function is critical for maintaining self-tolerance but it can promote pathogen persistence in chronic infections; consequently, the restoration of T-cell effector functions is a major goal of therapeutic vaccines against chronic viral infections and malignancies. Recently, a number of T-cell inhibitory receptors, most prominently programmed death-1 (PD-1) and cytotoxic T-lymphocyte antigen-4, have been described that are associated with T-cell exhaustion and tolerance. Blocking these receptors can restore T-cell function and, depending on the model, lead to autoimmune disease or successful viral elimination. Antibodies to PD-1 and cytotoxic T-lymphocyte antigen-4 are currently being tested in clinical trials in several malignant diseases and chronic hepatitis C as they are promising candidates for combination with both prophylactic and therapeutic vaccines. Given the central role of T-cell inhibitory receptors in the regulation of immune responses, understanding their molecular mode of action is of major importance. In the report from Fife and colleagues, two-photon laser scanning microscopy of mouse lymphoid and peripheral tissue has been employed to study the interaction of tolerized PD-1-expressing T cells with antigen-bearing dendritic cells in vivo. While tolerized T cells moved freely and did not make prolonged contacts with dendritic cells, addition of an antibody that blocked the interaction between PD-1 and its ligand PD-L1 lowered T-cell motility, enhanced T-cell-dendritic cell contacts and caused autoimmune disease in the nonobese diabetic mouse model of autoimmune diabetes. The authors conclude that PD-1-PD-L1 interactions mediate peripheral tolerance by inhibiting T-cell receptor-induced stop signals.

17.
Gastroenterology ; 137(4): 1280-8.e1-6, 2009 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19596013

RESUMEN

BACKGROUND & AIMS: Down-regulation of hepatitis C virus (HCV)-specific CD4(+) T-cell responses is a hallmark of chronic viral persistence in acute hepatitis C. FOXP3(+)CD25(+)CD4(+) regulatory T cells can modulate HCV-specific immune responses in vitro, but the role of virus-specific regulatory T cells in the pathogenesis of chronic viral persistence is unknown. METHODS: Two novel HLA-DR15 tetramers were synthesized to study the kinetics and phenotype of FOXP3(+)-expressing HCV-specific CD4(+) T cells from 10 patients with acute hepatitis C and 15 patients with chronic hepatitis C. RESULTS: In acute hepatitis C, generally only a low percentage of HCV-specific CD4(+) T cells expressed FOXP3(+) (mean of 2.5% in patients with self-limited acute hepatitis C vs 2.4% in patients with evolving chronic hepatitis C). Although distinct but short-lived increases in virus-specific FOXP3(+)CD4(+) T cells occurred in 3 patients (30%, 26%, and 7% of tet(+) CD4(+) T cells, respectively), these did not correlate with the evolution of chronic hepatitis C. HCV-specific FOXP3(+)CD4(+) T cells displayed a distinct phenotype, with only 10% expressing CD25 and 40% being CD127low. Interestingly, this phenotype of FOXP3(+)CD4(+) T cells was already expanded in bulk CD4(+) T cells in patients with chronic hepatitis C. CONCLUSIONS: Although short-lived increases in HCV-specific FOXP3(+)CD4(+) T cells occur during the course of acute hepatitis C, we could not demonstrate an association of HCV-specific regulatory T cells and persistent viremia.


Asunto(s)
Factores de Transcripción Forkhead/metabolismo , Hepacivirus/inmunología , Hepatitis C Crónica/inmunología , Hepatitis C/inmunología , Linfocitos T Reguladores/inmunología , Enfermedad Aguda , Adulto , Anciano , Proliferación Celular , Células Cultivadas , Progresión de la Enfermedad , Femenino , Antígenos HLA-DR/inmunología , Cadenas HLA-DRB1 , Hepatitis C/diagnóstico , Anticuerpos contra la Hepatitis C/sangre , Hepatitis C Crónica/diagnóstico , Humanos , Inmunofenotipificación , Subunidad alfa del Receptor de Interleucina-2/metabolismo , Subunidad alfa del Receptor de Interleucina-7/metabolismo , Cinética , Masculino , Persona de Mediana Edad , Linfocitos T Reguladores/virología , Viremia/inmunología
18.
Antiviral Res ; 82(3): 103-9, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19428600

RESUMEN

Despite the high propensity of hepatitis C virus to establish chronic viral persistence, immune-mediated viral clearance occurs in some patients, fostering hopes that therapeutic induction of specific antiviral immune responses might be able to contribute to viral clearance in chronically infected patients. Indeed, recent clinical trials of therapeutic vaccination have provided clear proof of concept that specific immunotherapy can reduce the viral load in some patients. Further improvement of these strategies will depend on a detailed analysis of the immunopathogenesis of chronic hepatitis C. Recent advances in our understanding of the mechanisms of down-regulation of virus-specific immune responses during chronic infection, including the role of regulatory T cells and inhibitory molecules such as programmed death receptor 1, may open up new avenues for second-generation immunotherapeutic interventions.


Asunto(s)
Hepacivirus/inmunología , Hepatitis C Crónica/inmunología , Hepatitis C Crónica/patología , Ensayos Clínicos como Asunto , Hepatitis C Crónica/tratamiento farmacológico , Humanos , Inmunoterapia/métodos , Linfocitos T Reguladores/inmunología
20.
Eur J Gastroenterol Hepatol ; 20(8): 778-83, 2008 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-18617783

RESUMEN

OBJECTIVES: Recurrent hepatitis C virus (HCV) infection after liver transplantation (LT) is a major cause of transplant failure in HCV-positive patients. We retrospectively assessed the efficacy and safety of antiviral therapy and determined the factors influencing sustained virologic response (SVR) in LT recipients. METHODS: Between 1998 and 2007, we treated 36 LT recipients for hepatitis C cirrhosis and subsequent HCV recurrence (27 genotype 1 and 9 genotypes 2/3) with pegylated interferon alpha-2a (180 microg/week), pegylated interferon alpha-2b (1.5 microg/kg per week), or standard interferon alpha-2b (3 MIU 3X/week) plus ribavirin (600-1200 mg/day) for 48 weeks. RESULTS: SVR was achieved in seven of 27 (26%) of genotype 1 patients versus nine of nine (100%) genotype 2/3 patients (P=0.0001). Early virologic response at week 12 was associated with permanent viral clearance. Side effects included cytopenia and acute hearing loss, but rate of therapy withdrawal and dose reduction was low. CONCLUSION: Combination therapy in patients with HCV reinfection after LT yields an excellent SVR rate in genotype 2/3 patients, but remains unsatisfactory in genotype 1 patients. Virologic response at week 12 (early virologic response) can determine whether therapy should be continued or not.


Asunto(s)
Antivirales/uso terapéutico , Hepacivirus/genética , Hepatitis C/tratamiento farmacológico , Trasplante de Hígado , Adulto , Antivirales/efectos adversos , Esquema de Medicación , Quimioterapia Combinada , Femenino , Genotipo , Supervivencia de Injerto , Hepacivirus/efectos de los fármacos , Hepatitis C/cirugía , Humanos , Inmunosupresores/uso terapéutico , Interferón-alfa/efectos adversos , Interferón-alfa/uso terapéutico , Masculino , Persona de Mediana Edad , Recurrencia , Estudios Retrospectivos , Ribavirina/efectos adversos , Ribavirina/uso terapéutico , Análisis de Supervivencia , Resultado del Tratamiento
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...