184 research outputs found

    β-lactam hypersensitivity involves expansion of circulating and skin-resident Th22 cells

    Get PDF
    Background: β-lactam hypersensitivity has been classified according to the phenotype and function of drug-specific T-cells; however, new T-cell subsets have not been considered. Objective: The objective of this study was use piperacillin as a model of β-lactam hypersensitivity to study the nature of the drug-specific T-cell response induced in the blood and skin of hypersensitive patients and healthy volunteers. Methods: Drug-specific T-cells were cloned from blood and inflamed skin and cellular phenotype and function was explored. Naïve T cells from healthy volunteers were primed to piperacillin, cloned and subjected to the similar analyses. Results: PBMC and T-cell clones (n=570, 84% CD4+) from blood of piperacillin hypersensitive patients proliferated and secreted Th1/2 cytokines alongside IL-22 following drug stimulation. IL-17A secretion was not detected. Drug-specific clones from inflamed skin (n=96, 83% CD4+) secreted a similar profile of cytokines, but displayed greater cytolytic activity, secreting perforin, granzyme B and Fas L when activated. Blood- and skin-derived clones expressed high levels of skin-homing chemokine receptors and migrated in the presence of the ligands CCL17 and CCL27. Piperacillin-primed naïve T-cells from healthy volunteers also secreted IFN-γ, IL-13, IL-22 and cytolytic molecules. Aryl hydrocarbon (ArH) receptor blockade prevented differentiation of the naïve T-cells into antigen-specific Il-22 secreting cells. Conclusion: Together our results reveal that circulating and skin resident antigen-specific IL-22 secreting T-cells are detectable in patients with β-lactam hypersensitivity. Furthermore, differentiation of naïve T-cells into antigen-specific Th22 cells is dependent on ArH receptor signalling

    Measurement of CD4+ and CD8+ T-Lymphocyte Cytokine Secretion and Gene Expression Changes in p-Phenylenediamine Allergic Patients and Tolerant Individuals

    Get PDF
    Factors predisposing to individual susceptibility to contact allergic dermatitis are ill defined. This study was designed to characterize the response of allergic and tolerant individuals’ T-lymphocytes after exposure to p-phenylenediamine (PPD). Peripheral blood mononuclear cells (PBMCs) from allergic patients proliferated when treated with PPD and Bandrowski's base (BB) and secreted IL-1α, -1β, -4, -5, -6, -8, -10, and -13; IFN-γ; tumor necrosis factor-α; MIP-1α/β; MCP-1 (monocyte chemotactic protein-1); and RANTES. PBMCs from tolerant individuals were stimulated to proliferate only with BB, and they secreted significantly lower levels of Th2 cytokines. Principal component analysis showed that genes are differentially expressed between the patient groups. A network-based analysis of microarray data showed upregulation of T helper type 2 (Th2) gene pathways, including IL-9, in allergic patients, but a regulatory gene profile in tolerant individuals. Real-time PCR confirmed the observed increase in Th2 cytokine gene transcription in allergic patients. Purified CD4+ and CD8+ T cells from allergic patients were stimulated to proliferate and secrete Th2 cytokines following antigen exposure. Only CD4+ T cells from tolerant individuals were stimulated by BB, and levels of Th2 cytokines were 80% lower. The nature of the antigenic determinant stimulating PBMCs and levels of Th2 cytokines, including IL-9, was confirmed in a validation cohort. These studies show increased activity of Th2 cytokines in CD4+ and CD8+ T cells from individuals with allergic contact dermatitis

    Die Zukunft der bezahlten und unbezahlten Arbeit: drei Szenarien

    Get PDF
    Die in diesem Diskussionspapier zusammengefassten Beiträge von Carsten Stahmer (Halbtagsgesellschaft: konkrete Utopie für eine zukunftsfähige Grundsicherung), Ronald Schettkat (Dienstleistungen zwischen Eigenarbeit und Professionalisierung) und Gerhard Scherhorn (Demokratisierung des Wohlstands) beruhen auf einer Reihe von Veranstaltungen im Rahmen des Wirtschaftswissenschaftlichen Kolloquiums des Wuppertal Instituts. In dieser von Ronald Schettkat im Jahr 2007 organisierten Seminarreihe wurden am Wuppertal Institut ausgewählte Fragestellungen im Spannungsfeld von Wirtschaftswachstum und Nachhaltiger Entwicklung diskutiert. Mit der Präsentation seines Konzeptes einer Halbtagsgesellschaft, die einen radikalen Bruch mit konventionellen Arbeitsarrangements und eine drastische Ausweitung informeller Versorgungssysteme (informelle Arbeit, räumliche Substitution, Zeittauschringe) vorsieht, hatte Carsten Stahmer einen Stein ins Wasser geworfen. Die drei hier skizzierten Szenarien machen deutlich, dass verschiedene Zukünfte der Arbeit vorstellbar sind. Sie sind von unterschiedlichen Wertvorstellungen geprägt und mit verschiedenartigen Gestaltungsansätzen verbunden. Gesellschaft und Politik sind aufgerufen zu diskutieren, welche Entwicklungsrichtung wahrscheinlicher und welche zukunftsfähiger erscheint. Dazu wollen die drei Beiträge Impulse setzen. -- This discussion paper outlines articles from Carsten Stahmer (Halbtagsgesellschaft: konkrete Utopie für eine zukunftsfähige Grundsicherung / Part-time society: concrete utopia for a sustainable provision of basic social security), Ronald Schettkatt (Dienstleistungen zwischen Eigenarbeit und Professionalisierung / Supply of services between one's own work and professionalising) and Gerhard Scherhorn (Demokratisierung des Wohlstands / Democratisation of wealth), which are based on a series of events organised in the context of the Wuppertal Institute's scientific colloquium on economics. The lecture series organised by Ronald Schettkat at the Wuppertal Institute in 2007 dealt with discussions about selected questions in the conflicting fields of economic growth and sustainable development. The three scenarios, presented in this paper, demonstrate the possibility of different future work models. They are based on different moral concepts and on diverse conceptual approaches and want to give an impetus to society and policy to discuss which of the trends seems more likely and which of them seems more sustainable.

    Checkpoint Inhibition Reduces the Threshold for Drug-Specific T-Cell Priming and Increases the Incidence of Sulfasalazine Hypersensitivity

    Get PDF
    An emerging clinical issue associated with immune-oncology agents is the collateral effects on the tolerability of concomitant medications. One report of this phenomenon was the increased incidence of hypersensitivity reactions observed in patients receiving concurrent immune checkpoint inhibitors (ICIs) and sulfasalazine (SLZ). Thus, the aim of this study was to characterize the T cells involved in the pathogenesis of such reactions, and recapitulate the effects of inhibitory checkpoint blockade on de-novo priming responses to compounds within in vitro platforms. A regulatory competent human dendritic cell/T-cell coculture assay was used to model the effects of ICIs on de novo nitroso sulfamethoxazole- and sulfapyridine (SP) (the sulfonamide component of SLZ) hydroxylamine-specific priming responses. The role of T cells in the pathogenesis of the observed reactions was explored in 3 patients through phenotypic characterization of SP/sulfapyridine hydroxylamine (SPHA)-responsive T-cell clones (TCC), and assessment of cross-reactivity and pathways of T-cell activation. Augmentation of the frequency of responding drug-specific T cells and intensity of the T-cell response was observed with PD-1/PD-L1 blockade. Monoclonal populations of SP- and SPHA-responsive T cells were isolated from all 3 patients. A core secretory effector molecule profile (IFN-Îł, IL-13, granzyme B, and perforin) was identified for SP and SPHA-responsive TCC, which proceeded through Pi and hapten mechanisms, respectively. Data presented herein provides evidence that drug-responsive T cells are effectors of hypersensitivity reactions observed in oncology patients administered ICIs and SLZ. Perturbation of drug-specific T-cell priming is a plausible explanation for clinical observations of how an increased incidence of these adverse events is occurring

    Detection of Hepatic Drug Metabolite-Specific T-Cell Responses Using a Human Hepatocyte, Immune Cell Coculture System

    Get PDF
    Drug-responsive T-cells are activated with the parent compound or metabolites, often via different pathways (pharmacological interaction and hapten). An obstacle to the investigation of drug hypersensitivity is the scarcity of reactive metabolites for functional studies and the absence of coculture systems to generate metabolites in situ. Thus, the aim of this study was to utilize dapsone metabolite-responsive T-cells from hypersensitive patients, alongside primary human hepatocytes to drive metabolite formation, and subsequent drug-specific T-cell responses. Nitroso dapsone-responsive T-cell clones were generated from hypersensitive patients and characterized in terms of cross-reactivity and pathways of T-cell activation. Primary human hepatocytes, antigen-presenting cells, and T-cell cocultures were established in various formats with the liver and immune cells separated to avoid cell contact. Cultures were exposed to dapsone, and metabolite formation and T-cell activation were measured by LC-MS and proliferation assessment, respectively. Nitroso dapsone-responsive CD4+ T-cell clones from hypersensitive patients were found to proliferate and secrete cytokines in a dose-dependent manner when exposed to the drug metabolite. Clones were activated with nitroso dapsone-pulsed antigen-presenting cells, while fixation of antigen-presenting cells or omission of antigen-presenting cells from the assay abrogated the nitroso dapsone-specific T-cell response. Importantly, clones displayed no cross-reactivity with the parent drug. Nitroso dapsone glutathione conjugates were detected in the supernatant of hepatocyte immune cell cocultures, indicating that hepatocyte-derived metabolites are formed and transferred to the immune cell compartment. Similarly, nitroso dapsone-responsive clones were stimulated to proliferate with dapsone, when hepatocytes were added to the coculture system. Collectively, our study demonstrates the use of hepatocyte immune cell coculture systems to detect in situ metabolite formation and metabolite-specific T-cell responses. Similar systems should be used in future diagnostic and predictive assays to detect metabolite-specific T-cell responses when synthetic metabolites are not available
    • …
    corecore