Epigenetic changes in inflammatory arthritis monocytes contribute to disease and can be targeted by JAK inhibition.

OBJECTIVES: How the local inflammatory environment regulates epigenetic changes in the context of inflammatory arthritis remains unclear. Here we assessed the transcriptional and active enhancer profile of monocytes derived from the inflamed joints of JIA patients, a model well-suited for studying inflammatory arthritis. METHODS: RNA sequencing and H3K27me3 chromatin immunoprecipitation sequencing (ChIP-seq) were used to analyse the transcriptional and epigenetic profile, respectively, of JIA synovial fluid-derived monocytes. RESULTS: Synovial-derived monocytes display an activated phenotype, which is regulated on the epigenetic level. IFN signalling-associated genes are increased and epigenetically altered in synovial monocytes, indicating a driving role for IFN in establishing the local inflammatory phenotype. Treatment of synovial monocytes with the Janus-associated kinase (JAK) inhibitor ruxolitinib, which inhibits IFN signalling, transformed the activated enhancer landscape and reduced disease-associated gene expression, thereby inhibiting the inflammatory phenotype. CONCLUSION: This study provides novel insights into epigenetic regulation of inflammatory arthritis patient-derived monocytes and highlights the therapeutic potential of epigenetic modulation for the treatment of inflammatory rheumatic diseases.

Human TH17 cells engage gasdermin E pores to release IL-1α on NLRP3 inflammasome activation.

It has been shown that innate immune responses can adopt adaptive properties such as memory. Whether T cells utilize innate immune signaling pathways to diversify their repertoire of effector functions is unknown. Gasdermin E (GSDME) is a membrane pore-forming molecule that has been shown to execute pyroptotic cell death and thus to serve as a potential cancer checkpoint. In the present study, we show that human T cells express GSDME and, surprisingly, that this expression is associated with durable viability and repurposed for the release of the alarmin interleukin (IL)-1α. This property was restricted to a subset of human helper type 17 T cells with specificity for Candida albicans and regulated by a T cell-intrinsic NLRP3 inflammasome, and its engagement of a proteolytic cascade of successive caspase-8, caspase-3 and GSDME cleavage after T cell receptor stimulation and calcium-licensed calpain maturation of the pro-IL-1α form. Our results indicate that GSDME pore formation in T cells is a mechanism of unconventional cytokine release. This finding diversifies our understanding of the functional repertoire and mechanistic equipment of T cells and has implications for antifungal immunity.

Consensus-based recommendations for the management of juvenile localised scleroderma.

In 2012, a European initiative called Single Hub and Access point for paediatric Rheumatology in Europe (SHARE) was launched to optimise and disseminate diagnostic and management regimens in Europe for children and young adults with rheumatic diseases. Juvenile localised scleroderma (JLS) is a rare disease within the group of paediatric rheumatic diseases (PRD) and can lead to significant morbidity. Evidence-based guidelines are sparse and management is mostly based on physicians' experience. This study aims to provide recommendations for assessment and treatment of JLS. Recommendations were developed by an evidence-informed consensus process using the European League Against Rheumatism standard operating procedures. A committee was formed, mainly from Europe, and consisted of 15 experienced paediatric rheumatologists and two young fellows. Recommendations derived from a validated systematic literature review were evaluated by an online survey and subsequently discussed at two consensus meetings using a nominal group technique. Recommendations were accepted if ≥80% agreement was reached. In total, 1 overarching principle, 10 recommendations on assessment and 6 recommendations on therapy were accepted with ≥80% agreement among experts. Topics covered include assessment of skin and extracutaneous involvement and suggested treatment pathways. The SHARE initiative aims to identify best practices for treatment of patients suffering from PRDs. Within this remit, recommendations for the assessment and treatment of JLS have been formulated by an evidence-informed consensus process to produce a standard of care for patients with JLS throughout Europe.