251 research outputs found

    Defining the molecular role of gp91phox in the immune manifestation of acute allergic asthma using a preclinical murine model

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    <p>Abstract</p> <p>Objective</p> <p>The phenomena manifested during inflammation require interplay between circulating effector cells, local resident cells, soluble mediators and genetic host factors to establish, develop and maintain itself. Of the molecues involed in the initiation and perpetuation of acute allergic inflammation in asthma, the involvement of effector cells in redox reactions for producing O<sub>2</sub><sup>- </sup>(superoxide anion) through the mediation of NADPH oxidase is a critical step. Prior data suggest that reactive oxygen species (ROS) produced by NADPH oxidase homologues in non-phagocytic cells play an important role in the regulation of signal transduction, while macrophages use a membrane-associated NADPH oxidase to generate an array of oxidizing intermediates which inactivate MMPs on or near them.</p> <p>Materials and Methods and Treatment</p> <p>To clarify the role of gp91phox subunit of NADPH oxidase in the development and progression of an acute allergic asthma phenotype, we induced allergen dependent inflammation in a gp91<it><sup>phox</sup></it>-/- single knockout and a gp91phox-/-MMP-12-/- double knockout mouse models.</p> <p>Results</p> <p>In the knockout mice, both inflammation and airway hyperreactivity were more extensive than in wildtype mice post-OVA. Although OVA-specific IgE in plasma were comparable in wildtype and knockout mice, enhanced inflammatory cell recruitment from circulation and cytokine release in lung and BALf, accompanied by higher airway resistance as well as Penh in response to methacholine, indicate a regulatory role for NADPH oxidase in development of allergic asthma. While T cell mediated functions like Th2 cytokine secretion, and proliferation to OVA were upregulated synchronous with the overall robustness of the asthma phenotype, macrophage upregulation in functions such as proliferation, and mixed lymphocyte reaction indicate a regulatory role for gp91phox and an overall non-involvement or synergistic involvement of MMP12 in the response pathway (comparing data from gp91phox-/- and gp91phox-/-MMP-12-/- mice).</p

    Combating Cancer Through Public Health Practice in the United States: An In-Depth Look at the National Comprehensive Cancer Control Program

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    Cancer is the second leading cause of the death in the United States (U.S.). The National Comprehensive Cancer Control Program (NCCCP) is a national, public health practice program funded by the U.S. Centers for Disease Control and Prevention. The NCCCP has been planning and implementing interventions to reduce the burden of cancer since 1998. Interventions are implemented across three areas primary prevention, early detection, and survivorship using health systems and environmental changes to promote sustainable cancer control. The aim of this chapter is to provide a summary of the NCCCP, and highlight specific examples of interventions and successes to aid cancer planning in other countries. Cancer plan analyses show that all NCCCP participant cancer plans address reducing tobacco use for cancer prevention and 98% contain activities to increase colorectal cancer screening. The vast majority implement activities to improve the quality of life following a cancer diagnosis (94%). Relatively fewer cancer plans contain activities to reduce radon exposure (42%), promote human papilloma virus vaccination (62%), and incorporate the use of genomics in cancer control (56%). The examples of NCCCP activities demonstrate success in controlling cancer and other non-communicable diseases through public health practice

    Gene expression profiling in acute allograft rejection: challenging the immunologic constant of rejection hypothesis

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    In humans, the role and relationship between molecular pathways that lead to tissue destruction during acute allograft rejection are not fully understood. Based on studies conducted in humans, we recently hypothesized that different immune-mediated tissue destruction processes (i.e. cancer, infection, autoimmunity) share common convergent final mechanisms. We called this phenomenon the "Immunologic Constant of Rejection (ICR)." The elements of the ICR include molecular pathways that are consistently described through different immune-mediated tissue destruction processes and demonstrate the activation of interferon-stimulated genes (ISGs), the recruitment of cytotoxic immune cells (primarily through CXCR3/CCR5 ligand pathways), and the activation of immune effector function genes (IEF genes; granzymes A/B, perforin, etc.)

    Current practices and challenges in adaptation of clinical guidelines : A qualitative study based on semistructured interviews

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    Funding YS is funded by China Scholarship Council (No 201707040103).Altres ajuts: CSC/201707040103Objective This study aims to better understand the current practice of clinical guideline adaptation and identify challenges raised in this process, given that published adapted clinical guidelines are generally of low quality, poorly reported and not based on published frameworks. Design A qualitative study based on semistructured interviews. We conducted a framework analysis for the adaptation process, and thematic analysis for participants' views and experiences about adaptation process. Setting Nine guideline development organisations from seven countries. Participants Guideline developers who have adapted clinical guidelines within the last 3 years. We identified potential participants through published adapted clinical guidelines, recommendations from experts, and a review of the Guideline International Network Conference attendees' list. Results We conducted ten interviews and identified nine adaptation methodologies. The reasons for adapting clinical guidelines include developing de novo clinical guidelines, implementing source clinical guidelines, and harmonising and updating existing clinical guidelines. We identified the following core steps of the adaptation process (1) selection of scope and source guideline(s), (2) assessment of source materials (guidelines, recommendations and evidence level), (3) decision-making process and (4) external review and follow-up process. Challenges on the adaptation of clinical guidelines include limitations from source clinical guidelines (poor quality or reporting), limitations from adaptation settings (lacking resources or skills), adaptation process intensity and complexity, and implementation barriers. We also described how participants address the complexities and implementation issues of the adaptation process. Conclusions Adaptation processes have been increasingly used to develop clinical guidelines, with the emergence of different purposes. The identification of core steps and assessment levels could help guideline adaptation developers streamline their processes. More methodological research is needed to develop rigorous international standards for adapting clinical guidelines

    GM-CSF/IL-3/IL-5 receptor common β chain (CD131) expression as a biomarker of antigen-stimulated CD8+ T cells

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    <p>Abstract</p> <p>Background</p> <p>Upon Ag-activation cytotoxic T cells (CTLs) produce IFN-γ GM-CSF and TNF-α, which deliver simultaneously pro-apoptotic and pro-inflammatory signals to the surrounding microenvironment. Whether this secretion affects in an autocrine loop the CTLs themselves is unknown.</p> <p>Methods</p> <p>Here, we compared the transcriptional profile of Ag-activated, Flu-specific CTL stimulated with the FLU M1:58-66 peptide to that of convivial CTLs expanded <it>in vitro </it>in the same culture. PBMCs from 6 HLA-A*0201 expressing donors were expanded for 7 days in culture following Flu M1:58-66 stimulation in the presence of 300 IU/ml of interleukin-2 and than sorted by high speed sorting to high purity CD8+ expressing T cells gated according to FluM1:58-66 tetrameric human leukocyte antigen complexes expression.</p> <p>Results</p> <p>Ag-activated CTLs displayed higher levels of IFN-γ, GM-CSF (CSF2) and GM-CSF/IL-3/IL-5 receptor common β- chain (CD131) but lacked completely expression of IFN-γ receptor-II and IFN-stimulated genes (ISGs). This observation suggested that Ag-activated CTLs in preparation for the release of IFN-γ and GM-CSF shield themselves from the potentially apoptotic effects of the former entrusting their survival to GM-SCF. <it>In vitro </it>phenotyping confirmed the selective surface expression of CD131 by Ag-activated CTLs and their increased proliferation upon exogenous administration of GM-CSF.</p> <p>Conclusion</p> <p>The selective responsiveness of Ag-activated CTLs to GM-CSF may provide an alternative explanation to the usefulness of this chemokine as an adjuvant for T cell aimed vaccines. Moreover, the selective expression of CD131 by Ag-activated CTLs proposes CD131 as a novel biomarker of Ag-dependent CTL activation.</p

    Modeling Parkinson’s disease neuropathology and symptoms by intranigral inoculation of preformed human α-synuclein oligomers

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    The accumulation of aggregated α-synuclein (αSyn) is a hallmark of Parkinson’s disease (PD). Current evidence indicates that small soluble αSyn oligomers (αSynOs) are the most toxic species among the forms of αSyn aggregates, and that size and topological structural properties are crucial factors for αSynOs-mediated toxicity, involving the interaction with either neurons or glial cells. We previously characterized a human αSynO (H-αSynO) with specific structural properties promoting toxicity against neuronal membranes. Here, we tested the neurotoxic potential of these H-αSynOs in vivo, in relation to the neuropathological and symptomatic features of PD. The H-αSynOs were unilaterally infused into the rat substantia nigra pars compacta (SNpc). Phosphorylated αSyn (p129-αSyn), reactive microglia, and cytokine levels were measured at progressive time points. Additionally, a phagocytosis assay in vitro was performed after microglia pre-exposure to αsynOs. Dopaminergic loss, motor, and cognitive performances were assessed. H-αSynOs triggered p129-αSyn deposition in SNpc neurons and microglia and spread to the striatum. Early and persistent neuroinflammatory responses were induced in the SNpc. In vitro, H-αSynOs inhibited the phagocytic function of microglia. H-αsynOs-infused rats displayed early mitochondrial loss and abnormalities in SNpc neurons, followed by a gradual nigrostriatal dopaminergic loss, associated with motor and cognitive impairment. The intracerebral inoculation of structurally characterized H-αSynOs provides a model of progressive PD neuropathology in rats, which will be helpful for testing neuroprotective therapies

    Bortezomib decreases Rb phosphorylation and induces caspase-dependent apoptosis in Imatinib-sensitive and -resistant Bcr-Abl1-expressing cells

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    The use of c-abl-specific inhibitors such as Imatinib (IM) or Dasatinib has revolutionized the treatment of chronic myeloid leukemia (CML). However, a significant percentage of patients become resistant to IM. In this report, we have analyzed the possibility of using the proteasome as a molecular target in CML. Our results show that cells that express Bcr-Abl1 are more sensitive to the inhibition of the proteasome with Bortezomib (Btz) than control cells. This treatment reduces the proliferation of Bcr-Abl1- expressing cells, by inactivating NF-jB2 and decreasing the phosphorylation of Rb, eventually leading to an increase in caspase-dependent apoptosis. Furthermore, we show that Btz also induces cell-cycle arrest and apoptosis in cells expressing Bcr-Abl1 mutants that are resistant to IM. These results unravel a new molecular target of Btz, that is the Rb pathway, and open new possibilities in the treatment of CML especially for patients that become resistant to IM because of the presence of the T315I mutation

    An immunologic portrait of cancer

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    The advent of high-throughput technology challenges the traditional histopathological classification of cancer, and proposes new taxonomies derived from global transcriptional patterns. Although most of these molecular re-classifications did not endure the test of time, they provided bulk of new information that can reframe our understanding of human cancer biology. Here, we focus on an immunologic interpretation of cancer that segregates oncogenic processes independent from their tissue derivation into at least two categories of which one bears the footprints of immune activation. Several observations describe a cancer phenotype where the expression of interferon stimulated genes and immune effector mechanisms reflect patterns commonly observed during the inflammatory response against pathogens, which leads to elimination of infected cells. As these signatures are observed in growing cancers, they are not sufficient to entirely clear the organism of neoplastic cells but they sustain, as in chronic infections, a self-perpetuating inflammatory process. Yet, several studies determined an association between this inflammatory status and a favorable natural history of the disease or a better responsiveness to cancer immune therapy. Moreover, these signatures overlap with those observed during immune-mediated cancer rejection and, more broadly, immune-mediated tissue-specific destruction in other immune pathologies. Thus, a discussion concerning this cancer phenotype is warranted as it remains unknown why it occurs in immune competent hosts. It also remains uncertain whether a genetically determined response of the host to its own cancer, the genetic makeup of the neoplastic process or a combination of both drives the inflammatory process. Here we reflect on commonalities and discrepancies among studies and on the genetic or somatic conditions that may cause this schism in cancer behavior

    The stable traits of melanoma genetics: an alternate approach to target discovery

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    <p>Abstract</p> <p>Background</p> <p>The weight that gene copy number plays in transcription remains controversial; although in specific cases gene expression correlates with copy number, the relationship cannot be inferred at the global level. We hypothesized that genes steadily expressed by 15 melanoma cell lines (CMs) and their parental tissues (TMs) should be critical for oncogenesis and their expression most frequently influenced by their respective copy number.</p> <p>Results</p> <p>Functional interpretation of 3,030 transcripts concordantly expressed (Pearson's correlation coefficient p-value < 0.05) by CMs and TMs confirmed an enrichment of functions crucial to oncogenesis. Among them, 968 were expressed according to the transcriptional efficiency predicted by copy number analysis (Pearson's correlation coefficient p-value < 0.05). We named these genes, "genomic delegates" as they represent at the transcriptional level the genetic footprint of individual cancers. We then tested whether the genes could categorize 112 melanoma metastases. Two divergent phenotypes were observed: one with prevalent expression of cancer testis antigens, enhanced cyclin activity, WNT signaling, and a Th17 immune phenotype (Class A). This phenotype expressed, therefore, transcripts previously associated to more aggressive cancer. The second class (B) prevalently expressed genes associated with melanoma signaling including <it>MITF</it>, melanoma differentiation antigens, and displayed a Th1 immune phenotype associated with better prognosis and likelihood to respond to immunotherapy. An intermediate third class (C) was further identified. The three phenotypes were confirmed by unsupervised principal component analysis.</p> <p>Conclusions</p> <p>This study suggests that clinically relevant phenotypes of melanoma can be retraced to stable oncogenic properties of cancer cells linked to their genetic back bone, and offers a roadmap for uncovering novel targets for tailored anti-cancer therapy.</p
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