THU0268 Decreased Expression of MIR-130A and MIR-708 in Type-1 Classical Dendritic Cells of Sjögren's Syndrome Patients Indicates Their Dysregulation

BackgroundPrimary Sjögren's syndrome (pSS) is a systemic autoimmune disease characterized by lymphocytic infiltration of the salivary and lachrymal exocrine glands that leads to dryness of mouth and eyes. Type-1 classical dendritic cells (cDCs) are very potent antigen presenting cells known to induce strong T-cell proliferation and cytokine production. Despite the fact that especially cDC1s are candidate key players in the activation of local T and B-cells in pSS, they have rarely been studied in pSS.ObjectivesConsidering the critical role of micro-RNAs (miRNAs) in regulation of gene expression, we investigated miRNA expression in isolated cDC1s of pSS patients.MethodsTwo independent cohorts (discovery and validation) were established including a total of 29 pSS patients. 17 healthy controls (HC) were included as control group. cD1c+CD19- cells were isolated from peripheral blood using MACS and we performed miRNA profiling of 758 miRNA targets using the OpenArray platform in the donors included in the discovery cohort. A selection of the miRNAs found to be differentially expressed in pSS versus HC was measured in the validation cohort. We performed pathway enrichment with the experimentally supported targets of the validated miRNAs.ResultsA total of 24 miRNAs were downregulated in pSS patients versus HC in the discovery cohort (all at least p