POS0098 LINC01871, IMPLICATED IN SJÖGREN’S DISEASE PATHOGENESIS, IS REGULATED BY INTERFERON-G AND CALCINEURIN SIGNALING

Background Sjögren’s disease (SjD) is an autoimmune characterized by exocrine gland dysfunction. Long non-coding RNAs (lncRNAs) are a functionally diverse class of non-protein coding that longer than 200 nucleotides. Our previous study using whole blood RNA-seq found lncRNA, LINC01871 , overexpressed in SjD relative to controls [1]. CRISPR-Cas9 targeting HSB2 T cells yielded -/- clone with altered expression many genes implicated immune regulation Objectives The goal this was analyze the gene perturbations resulting from loss and characterize both primary human response stimuli. Methods Flow cytometry LegendPlex bead assays were used compare surface secreted protein changes, respectively, parental cells. Parental cells, Kasumi-3 myeloid stimulated vitro changes measured over time qRT-PCR. Responses interferons (IFN) assessed universal type I IFN (IFNα) or IFNγ. TCR signaling responses PMA/Ionomycin (PMA/I) anti-CD3/CD28 stimulations presence absence calcineurin inhibitor, FK506. Results Previous analysis 1166 differentially expressed (DE) transcripts (log 2 FC ≥1 ≤-1; p adj ≤0.05) compared including prominent regulatory genes. Changes basal 7 proteins confirmed flow (significantly decreased: CD8a (p=0.0004), CD30 (p=0.0008), CXCR3 (p=0.037), T-Bet (p=0.0002), Aiolos (p=0.02); significantly increased: CD226 (p=0.0059) CD44 (p=0.024)). Analysis revealed growth inhibition (p=0.0014 at 72h), which multiple adhesion factors reduced: GM-CSF (p=2.0e-06), M-CSF (p=2.7e-09), IGBPF4 (p=1.2e-07), s-ICAM1 (p=0.015), MMP9 (p=3.0e-14), MMP2 (p=6e-08). In contrast, IL-6 cytokine family member, LIF, increased (p=1.2e-07). Because not responsive all IFNs, IFN-mediated examined cell line. While modulated stimulation, it robustly IFNγ treatment. Since pathways, pathways purified treated PMA/I. types, exhibited prolonged decrease abrogated concurrent treatment FK506, indicating regulated signaling. Treatment mimic true engagement resulted modest early points, followed increase stimulation (2d). Conclusion findings suggest potential mediator dysregulated inflammatory pathogenesis. influences important factors, inducible IFNγ, directly ligand engagement. Although functions still unknown, observed overexpression cases after suggests could be biomarker SjD. References [1]Joachims, et al. Annals Rheumatic Diseases 2020;79:90. Disclosure Interests Michelle L Joachims: None declared, Bhuwan Khatri: Chuang Li: Kandice Tessneer: John Ice: Anna M Stolarczyk: Nicolas Means: Kiely Grundahl: Stuart Glenn: Jennifer Kelly: David Lewis: Lida Radfar: Donald Stone: Joel Guthridge: Judith A. James: R Hal Scofield: Graham B Wiley: Jonathan Wren: Patrick Gaffney: Courtney Montgomery: Kathy Sivils Employee of: Current employee Janssen., Astrid Rasmussen: A Darise Farris: Indra Adrianto: Christopher Lessard: declared