TY - JOUR T1 - Distinct stromal and immune cell interactions shape the pathogenesis of rheumatoid and psoriatic arthritis JF - Annals of the Rheumatic Diseases JO - Ann Rheum Dis SP - 1224 LP - 1242 DO - 10.1136/annrheumdis-2021-221761 VL - 81 IS - 9 AU - Achilleas Floudas AU - Conor M Smith AU - Orla Tynan AU - Nuno Neto AU - Vinod Krishna AU - Sarah M Wade AU - Megan Hanlon AU - Clare Cunningham AU - Viviana Marzaioli AU - Mary Canavan AU - Jean M Fletcher AU - Ronan H Mullan AU - Suzanne Cole AU - Ling-Yang Hao AU - Michael G Monaghan AU - Sunil Nagpal AU - Douglas J Veale AU - Ursula Fearon Y1 - 2022/09/01 UR - http://ard.bmj.com/content/81/9/1224.abstract N2 - Objectives Immune and stromal cell communication is central in the pathogenesis of rheumatoid arthritis (RA) and psoriatic arthritis (PsA), however, the nature of these interactions in the synovial pathology of the two pathotypes can differ. Identifying immune-stromal cell crosstalk at the site of inflammation in RA and PsA is challenging. This study creates the first global transcriptomic analysis of the RA and PsA inflamed joint and investigates immune-stromal cell interactions in the pathogenesis of synovial inflammation.Methods Single cell transcriptomic profiling of 178 000 synovial tissue cells from five patients with PsA and four patients with RA, importantly, without prior sorting of immune and stromal cells. This approach enabled the transcriptomic analysis of the intact synovial tissue and identification of immune and stromal cell interactions. State of the art data integration and annotation techniques identified and characterised 18 stromal and 14 immune cell clusters.Results Global transcriptomic analysis of synovial cell subsets identifies actively proliferating synovial T cells and indicates that due to differential λ and κ immunoglobulin light chain usage, synovial plasma cells are potentially not derived from the local memory B cell pool. Importantly, we report distinct fibroblast and endothelial cell transcriptomes indicating abundant subpopulations in RA and PsA characterised by differential transcription factor usage. Using receptor–ligand interactions and downstream target characterisation, we identify RA-specific synovial T cell-derived transforming growth factor (TGF)-β and macrophage interleukin (IL)-1β synergy in driving the transcriptional profile of FAPα+THY1+ invasive synovial fibroblasts, expanded in RA compared with PsA. In vitro characterisation of patient with RA synovial fibroblasts showed metabolic switch to glycolysis, increased adhesion intercellular adhesion molecules 1 expression and IL-6 secretion in response to combined TGF-β and IL-1β treatment. Disrupting specific immune and stromal cell interactions offers novel opportunities for targeted therapeutic intervention in RA and PsA.Data are available in a public, open access repository. Data are available upon reasonable request. All raw and processed files as well clinical information for each sample are deposited on national center for biotechnology information (NCBI), ascension number GSE200815 and are publically available without any restrictions of their subsequent use. Additionally, while detailed vignettes and base code is available on the bioinformatics platform GitHubgithub (as indicated in methods) for all packages used in the analysis, if specific parts of the code are needed, they will become available upon reasonable request. ER -