78 research outputs found

    Genetic Variation of Host Immune Response Genes and Their Effect on Hepatitis C Infection and Treatment Outcome

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    Effective control of pathogens is typically achieved by the timely interplay between the innate and adaptive immune response of an individual..

    Diagnosis, Management and Theragnostic Approach of Gastro-Entero-Pancreatic Neuroendocrine Neoplasms

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    Abstract: Gastro-entero-pancreatic neuroendocrine neoplasms (GEP-NENs) constitute an ideal target for radiolabeled somatostatin analogs. The theragnostic approach is able to combine diagnosis and therapy by the identification of a molecular target that can be diagnosed and treated with the same radiolabeled compound. During the last years, advances in functional imaging with the introduction of somatostatin analogs and peptide receptor radionuclide therapy, have improved the diagnosis and treatment of GEP-NENs. Moreover, PET/CT imaging with 18F-FDG represents a complementary tool for prognostic evaluation of patients with GEP-NENs. In the field of personalized medicine, the theragnostic approach has emerged as a promising tool in diagnosis and management of patients with GEP-NENs. The aim of this review is to summarize the current evidence on diagnosis and management of patients with GEP-NENs, focusing on the theragnostic approach

    HLA-Bw4 Homozygosity Is Associated with an Impaired CD4 T Cell Recovery after Initiation of Antiretroviral Therapy

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    We assessed the influence of human leukocyte antigen (HLA) alleles HLA-Bw4 and HLA-Bw6 on CD4 T cell recovery after starting successful combination antiretroviral therapy in 265 individuals. The median gains in the CD4 T cell count after 4 years were 258 cells/µL for HLA-Bw4 homozygotes, 321 cells/µL for HLA-Bw4/Bw6 heterozygotes, and 363 cells/µL for HLA-Bw6 homozygotes (P=.01, compared with HLA-Bw4 homozygotes). HLA-Bw4 homozygosity appears to predict an impaired CD4 T cell recovery after initiation of combination antiretroviral therap

    Molecular footprints reveal the impact of the protective HLA-A*03 allele in hepatitis C virus infection

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    Background and aims: CD8 T cells are central to the control of hepatitis C virus (HCV) although the key features of a successful CD8 T cell response remain to be defined. In a cohort of Irish women infected by a single source, a strong association between viral clearance and the human lecucocyte (HLA)-A*03 allele has been described, and the aim of this study was to define the protective nature of the associated CD8 T cell response. Methods: A sequence-led approach was used to identify HLA-A*03-restricted epitopes. We examine the CD8 T cell response associated with this gene and address the likely mechanism underpinning this protective effect in this special cohort, using viral sequencing, T cell assays and analysis of fitness of viral mutants. Results: A strong 'HLA footprint' in a novel NS3 epitope (TVYHGAGTK) was observed. A lysine (K) to arginine (R) substitution at position 9 (K1088R) was seen in a significant number of A*03-positive patients (9/12) compared with the control group (1/33, p=0.0003). Threonine (T) was also substituted with alanine (A) at position 8 (T1087A) more frequently in A*03-positive patients (6/12) compared with controls (2/33, p=0.01), and the double substitution of TK to AR was also observed predominantly in HLA-A*03- positive patients (p=0.004). Epitope-specific CD8 T cell responses were observed in 60% of patients three decades after exposure and the mutants selected in vivo impacted on recognition in vitro. Using HCV replicons matched to the viral sequences, viral fitness was found to be markedly reduced by the K1088R substitution but restored by the second substitution T1087A. Conclusions: It is proposed that at least part of the protective effect of HLA-A*03 results from targeting of this key epitope in a functional site: the requirement for two mutations to balance fitness and escape provides an initial host advantage. This study highlights the potential protective impact of common HLA-A alleles against persistent viruses, with important implications for HCV vaccine studies

    A gestão estratégica de pessoas do tribunal de contas do Rio Grande do Sul

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    Neste presente estudo, objetiva-se identificar como a Gestão Estratégica de Pessoas do Tribunal de Contas do Rio Grande do Sul se articula para resolver e minimizar as dificuldades do órgão, no que diz respeito à implantação e a solução de problemas de gestão de pessoas. Somado a isso, também foi investigado quais são os principais desafios e dificuldades na gestão de pessoas e na aplicação da gestão estratégica de pessoas no serviço público, e como o Tribunal de Contas se articula para superá-los. A administração pública, em diversos países, passou por reformas significativas a partir da década de 1980. Práticas gerenciais da iniciativa privada foram adotadas como referência para transposição para o setor público, visando à geração de maior eficiência e foco em resultado (BRESSER PEREIRA apud FONSECA et al., 2013). Dentre as atividades que deveriam ser modernizadas encontra-se a gestão de recursos humanos (RH), até então voltada, no Governo como um todo, para sua função clássica de registro e controle de custos de funcionários. A sociedade vem exigindo do poder público uma atuação cada vez mais voltada para o alcance de resultados, isto é, além da eficiência tão perseguida pelas organizações nos últimos tempos, atualmente a eficácia e a efetividade da ação governamental são as palavras de ordem. Para tanto, foi elaborado um estudo de caso no Tribunal de Contas do Rio Grande do Sul, mostrando as práticas de gestão estratégica de pessoas implementadas pelo órgão. Assim sendo, o estudo reúne as práticas de gestão estratégica de pessoas, que obtiveram êxito no Tribunal de Contas, assim como as especificidades e os limites que delimitam a implantação desse tipo de estratégias, políticas e ações/

    Genetic Variations in IL28B and Allergic Disease in Children

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    Environmental changes affecting the relationship between the developing immune system and microbial exposure have been implicated in the epidemic rise of allergic disease in developed countries. While early developmental differences in T cell function are well-recognised, there is now emerging evidence that this is related to developmental differences in innate immune function. In this study we sought to examine if differences associated with innate immunity contribute to the altered immune programming recognised in allergic children. Here, we describe for the first time, the association of carriage of the T allele of the tagging single nucleotide polymorphism rs12979860 3 kb upstream of IL28B, encoding the potent innate immune modulator type III interferon lambda (IFN-λ3), and allergy in children (p = 0.004; OR 4.56). Strikingly, the association between rs12979860 genotype and allergic disease is enhanced in girls. Furthermore, carriage of the T allele at rs12979860 correlates with differences in the pro-inflammatory profile during the first five years of life suggesting this contributes to the key differences in subsequent innate immune development in children who develop allergic disease. In the context of rising rates of disease, these immunologic differences already present at birth imply very early interaction between genetic predisposition and prenatal environmental influences

    Analysis of FOXP3+ Regulatory T Cells That Display Apparent Viral Antigen Specificity during Chronic Hepatitis C Virus Infection

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    We reported previously that a proportion of natural CD25+ cells isolated from the PBMC of HCV patients can further upregulate CD25 expression in response to HCV peptide stimulation in vitro, and proposed that virus-specific regulatory T cells (Treg) were primed and expanded during the disease. Here we describe epigenetic analysis of the FOXP3 locus in HCV-responsive natural CD25+ cells and show that these cells are not activated conventional T cells expressing FOXP3, but hard-wired Treg with a stable FOXP3 phenotype and function. Of ∼46,000 genes analyzed in genome wide transcription profiling, about 1% were differentially expressed between HCV-responsive Treg, HCV-non-responsive natural CD25+ cells and conventional T cells. Expression profiles, including cell death, activation, proliferation and transcriptional regulation, suggest a survival advantage of HCV-responsive Treg over the other cell populations. Since no Treg-specific activation marker is known, we tested 97 NS3-derived peptides for their ability to elicit CD25 response (assuming it is a surrogate marker), accompanied by high resolution HLA typing of the patients. Some reactive peptides overlapped with previously described effector T cell epitopes. Our data offers new insights into HCV immune evasion and tolerance, and highlights the non-self specific nature of Treg during infection

    Tracking Virus-Specific CD4+ T Cells during and after Acute Hepatitis C Virus Infection

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    CD4+ T cell help is critical in maintaining antiviral immune responses and such help has been shown to be sustained in acute resolving hepatitis C. In contrast, in evolving chronic hepatitis C CD4+ T cell helper responses appear to be absent or short-lived, using functional assays. Here we used a novel HLA-DR1 tetramer containing a highly targeted CD4+ T cell epitope from the hepatitis C virus non-structural protein 4 to track number and phenotype of hepatitis C virus specific CD4+ T cells in a cohort of seven HLA-DR1 positive patients with acute hepatitis C in comparison to patients with chronic or resolved hepatitis C. We observed peptide-specific T cells in all seven patients with acute hepatitis C regardless of outcome at frequencies up to 0.65% of CD4+ T cells. Among patients who transiently controlled virus replication we observed loss of function, and/or physical deletion of tetramer+ CD4+ T cells before viral recrudescence. In some patients with chronic hepatitis C very low numbers of tetramer+ cells were detectable in peripheral blood, compared to robust responses detected in spontaneous resolvers. Importantly we did not observe escape mutations in this key CD4+ T cell epitope in patients with evolving chronic hepatitis C. During acute hepatitis C a CD4+ T cell response against this epitope is readily induced in most, if not all, HLA-DR1+ patients. This antiviral T cell population becomes functionally impaired or is deleted early in the course of disease in those where viremia persists
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