Project description:Here we investigated the effects of JAK/STAT pharmacological inhibition on cHL cell models using ruxolitinib, a JAK 1/2 inhibitor. We use five classical Hodgkin lymphoma cell lines: L428, L1236, L540, KMH2, L591
Project description:Toxic epidermal necrolysis (TEN) is a fatal cutaneous adverse drug reaction and an emerging public health issue 1-3. Triggered by common medications, patients suffer from fulminant epidermal detachment and long-term sequalae. Although molecular mechanisms driving keratinocyte cytotoxicity have been reported, no effective therapy exists4-6. In recent years, powerful omics technologies have expanded into spatial context and we reasoned that single cell spatial proteomics could uncover novel therapeutic targets in TEN. Applying Deep Visual Proteomics7,8 to formalin fixed paraffin embedded archived skin-tissue biopsies of three types of cutaneous drug reactions with varying severity quantified over 5,000 proteins in keratinocytes and skin-infiltrating immune cells. Most strikingly, this revealed a robust enrichment of Type-I- and -II interferon signature in the immune cell and keratinocyte compartment of TEN patients, along with a drastic activation of pSTAT1. Targeted inhibition with pan-JAK inhibitor (JAKi) Tofacitinib reduced keratinocyte-directed cytotoxicity in a novel live-cell imaging assay, using patient-derived keratinocytes and PBMCs. Furthermore, oral administration of pan-JAKi Tofacitinib or Baricitinib ameliorated clinical and histological disease severity in two distinct mouse models of TEN. This study uncovers the JAK-STAT and interferon signaling pathways as key pathogenic drivers of TEN and demonstrates the potential of targeted JAK inhibition as a curative therapy.
Project description:Immune cells need to sustain a state of constant alertness over a lifetime. Yet, little is known about the regulatory processes that control the fluent and fragile balance that is called homeostasis. Here we demonstrate that JAK-STAT signaling, beyond its role in immune responses, is a major regulator of immune cell homeostasis. We investigated JAK-STAT-mediated transcription and chromatin accessibility across 12 mouse models, including knockouts of all STAT transcription factors and of the TYK2 kinase. Baseline JAK-STAT signaling was detected in CD8+ T cells and macrophages of unperturbed mice – but abrogated in the knockouts and in unstimulated immune cells deprived of their normal tissue context. We observed diverse transcription-regulatory programs, including gene regulation by STAT2 and IRF9 independent of STAT1. In summary, our large-scale dataset and integrative analysis of JAK-STAT mutant and wildtype mice uncovered a crucial role of JAK-STAT signaling in unstimulated immune cells, where it contributes to a poised epigenetic and transcription-regulatory state and helps prepare these cells for rapid response to immune stimuli.
Project description:Immune cells need to sustain a state of constant alertness over a lifetime. Yet, little is known about the regulatory processes that control the fluent and fragile balance that is called homeostasis. Here we demonstrate that JAK-STAT signaling, beyond its role in immune responses, is a major regulator of immune cell homeostasis. We investigated JAK-STAT-mediated transcription and chromatin accessibility across 12 mouse models, including knockouts of all STAT transcription factors and of the TYK2 kinase. Baseline JAK-STAT signaling was detected in CD8+ T cells and macrophages of unperturbed mice – but abrogated in the knockouts and in unstimulated immune cells deprived of their normal tissue context. We observed diverse transcription-regulatory programs, including gene regulation by STAT2 and IRF9 independent of STAT1. In summary, our large-scale dataset and integrative analysis of JAK-STAT mutant and wildtype mice uncovered a crucial role of JAK-STAT signaling in unstimulated immune cells, where it contributes to a poised epigenetic and transcription-regulatory state and helps prepare these cells for rapid response to immune stimuli.
Project description:Immune cells need to sustain a state of constant alertness over a lifetime. Yet, little is known about the regulatory processes that control the fluent and fragile balance that is called homeostasis. Here we demonstrate that JAK-STAT signaling, beyond its role in immune responses, is a major regulator of immune cell homeostasis. We investigated JAK-STAT-mediated transcription and chromatin accessibility across 12 mouse models, including knockouts of all STAT transcription factors and of the TYK2 kinase. Baseline JAK-STAT signaling was detected in CD8+ T cells and macrophages of unperturbed mice – but abrogated in the knockouts and in unstimulated immune cells deprived of their normal tissue context. We observed diverse transcription-regulatory programs, including gene regulation by STAT2 and IRF9 independent of STAT1. In summary, our large-scale dataset and integrative analysis of JAK-STAT mutant and wildtype mice uncovered a crucial role of JAK-STAT signaling in unstimulated immune cells, where it contributes to a poised epigenetic and transcription-regulatory state and helps prepare these cells for rapid response to immune stimuli.
Project description:Multiple systemic vascular inflammatory disorders are associated with endothelial dysfunction and elevated levels of TNFα and IFNγ. Combined TNFα and IFNγ stimulation induces synergetic hyperinflammation in endothelial cells (ECs) through activation of the NFKB and JAK/STAT pathways. Here we assess how targeting these pathways affects EC inflammation. Using mass-spectrometry based proteomics, we investigate system-wide effects of TNFα- and IFNγ-stimulated Endothelial Colony Forming Cells (ECFCs) in combination with inhibitors targeting NFKB and JAK/STAT pathways. JAK1 inhibitor itacitinib blocked IFNγ-, but not TNFα-induced proteomic responses. IKK2/STAT3 inhibitor TPCA1 attenuated both responses. Most TNFα+IFNγ-induced proteins, such as pyroptosis mediators, chemokines and Weibel-Palade Body content, were inhibited by both inhibitors, highlighting their synergetic dependency on both pathways. Imaging of Von Willebrand Factor (VWF) revealed an extracellular VWF network induced by combined stimulation; a phenotype which was reverted by both inhibitors. This study provides a mechanistic basis for inhibiting endothelial inflammation in vascular inflammatory disorders.