Publications by authors named "Christof Straub"

People with pre-existing lung diseases such as chronic obstructive pulmonary disease (COPD) are more likely to get very sick from SARS-CoV-2 disease 2019 (COVID-19). Still, an interrogation of the immune response to COVID-19 infection, spatially throughout the lung structure, is lacking in patients with COPD. For this study, we characterized the immune microenvironment of the lung parenchyma, airways, and vessels of never- and ever-smokers with or without COPD, all of whom died of COVID-19, using spatial transcriptomic and proteomic profiling.

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The mechanisms contributing to persistent eosinophil activation and poor eosinopenic response to glucocorticoids in severe asthma are poorly defined. We examined the effect of cytokines typically overexpressed in the asthmatic airways on glucocorticoid signaling in in vitro activated eosinophils. An annexin V assay used to measure eosinophil apoptosis showed that cytokine combinations of IL-2 plus IL-4 as well as TNF-α plus IFN-γ, or IL-3, GM-CSF, and IL-5 alone significantly diminished the proapoptotic response to dexamethasone.

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Background Aims: Esophageal eosinophilia (EE) can be caused by gastroesophageal reflux disease (GERD), proton-pump inhibitor-responsive EE (PPI-REE) or eosinophilic esophagitis (EoE). This study quantified protein expression and S-nitrosylation (SNO) post-translational modifications in EE to elucidate potential disease biomarkers.

Methods: Proximal and distal esophageal (DE) biopsy proteins in patients with EE and in controls were assayed for protein content and fluorescence-labeled with and without ascorbate treatment.

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The mainstay of asthma therapy, glucocorticoids (GCs) exert their therapeutic effects through the inhibition of inflammatory signaling and induction of eosinophil apoptosis. However, laboratory and clinical observations of GC-resistant asthma suggest that GCs' effects on eosinophil viability may depend on the state of eosinophil activation. In the present study we demonstrate that eosinophils stimulated with IL-5 show impaired pro-apoptotic response to GCs.

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We used comparative proteomics to analyze eosinophils from a patient with hypereosinophilia due to fascioliasis. Using 2-dimensional electrophoresis and mass spectrometry, we demonstrated that the eosinophil proteome was significantly altered compared to those of healthy controls.

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The priming of eosinophils by cytokines leading to augmented response to chemoattractants and degranulating stimuli is a characteristic feature of eosinophils in the course of allergic inflammation and asthma. Actin reorganization and integrin activation are implicated in eosinophil priming by GM-CSF, but their molecular mechanism of action is unknown. In this regard, we investigated the role of L-plastin, an eosinophil phosphoprotein that we identified from eosinophil proteome analysis.

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Eosinophils are granular leukocytes that have significant roles in many inflammatory and immunoregulatory responses, especially asthma and allergic diseases. We have undertaken a fairly comprehensive proteomic analysis of purified peripheral blood eosinophils from normal human donors primarily employing 2-dimensional gel electrophoresis with protein spot identification by matrix-assisted laser desorption/ionization mass spectrometry. Protein subfractionation methods employed included isoelectric focusing (Zoom(®) Fractionator) and subcellular fractionation using differential protein solubilization.

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Reversal of eosinophilic inflammation has been an elusive therapeutic goal in the management of asthma pathogenesis. In this regard, GM-CSF is a primary candidate cytokine regulating eosinophil activation and survival in the lung; however, its molecular mechanism of propagation and maintenance of stimulated eosinophil activation is not well understood. In this study, we elucidate those late interactions occurring between the GM-CSF receptor and activated eosinophil signaling molecules.

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