100 research outputs found

    Hepatic fibrosis and immune phenotype vary by HCV viremia in HCV/HIV co-infected subjects: A Women\u27s interagency HIV study.

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    HCV and HIV independently lead to immune dysregulation. The mechanisms leading to advanced liver disease progression in HCV/HIV coinfected subjects remain unclear. In this cross-sectional study, we assessed the association of HCV viremia, liver fibrosis, and immune response patterns in well-characterized HIV phenotypes: Elite controllers (Elites), HIV controlled (ARTc), and HIV uncontrolled (ARTuc) matched by age and race. Groups were stratified by HCV RNA status. Regulatory T-cell frequencies, T-cell activation (HLADR+CD38+), apoptosis (Caspase-3+), and intracellular cytokines (interferon-γ, IL-2, IL-17) were assessed using multiparametric flow-cytometry. Liver fibrosis was scored by AST to platelet ratio index (APRI). We found liver fibrosis (APRI) was 50% lower in Elites and ARTc compared to ARTuc. Higher liver fibrosis was associated with significantly low CD4+ T cell counts (P \u3c 0.001, coefficient r = −0.463). Immune activation varied by HIV phenotype but was not modified by HCV viremia. HCV viremia was associated with elevated CD8 T-cell Caspase-3 in Elites, ARTuc, and HIV− except ARTc. CD8 T-cell Caspase-3 levels were significantly higher in HCV RNA+ Elites (P = 0.04) and ARTuc (P = 0.001) and HIV− groups (P = 0.02) than ARTc. Importantly, ARTuc HCV RNA+ had significantly higher CD4 T-cell interleukin-17 levels than ARTuc HCV RNA− (P = 0.005). HIV control was associated with lower liver fibrosis in HCV/HIV co-infected women. HCV viremia is associated with an inflammatory CD4 TH-17 phenotype in absence of HIV control and higher frequency of pro-apoptosis CD8 T-cells critical to avert progression of HIV and HCV disease that is attenuated in ART controllers. Elite controllers with HCV viremia are more prone to CD8 T-cell apoptosis than ART controllers, which could have negative consequences over time, highlighting the importance of ART control in HCV/HIV coinfected individuals

    LISP Machine Progress Report

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    This informal paper introduces the LISP Machine, describes the goals and current status of the project, and explicates some of the key ideas. It covers the LISP machine implementation, LISP as a system language, input/output, representation of data, representation of programs, control structures, storage organization, garbage collection, the editor, and the current status of the work

    p53 modulates homologous recombination by transcriptional regulation of the RAD51 gene

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    DNA repair by homologous recombination is involved in maintaining genome stability. Previous data report that wild-type p53 suppresses homologous recombination and physically interacts with Rad51. Here, we show the in vivo binding of wild-type p53 to a p53 response element in the promoter of Rad51 and the downregulation of Rad51 messenger RNA and protein by wild-type p53, favoured by DNA damage. Moreover, wild-type p53 inhibits Rad51 foci formation in response to double-strand breaks, whereas p53 contact mutant R280K fails to repress Rad51 mRNA and protein expression and Rad51 foci formation. We propose that transcriptional repression of Rad51 by p53 participates in regulating homologous recombination, and impaired Rad51 repression by p53 mutants may contribute to malignant transformation
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