AB0030 THE BIOLOGICAL FUNCTION AND MECHANISM EXPLORATION OF TACI IN SJOGREN’S SYNDROME

Background primary Sjogren’s syndrome (pSS) is a chronic autoimmune disease that affects the lacrimal, salivary and other exocrine glands. More more studies have shown B cells play central role in pathogenesis of SS. Objectives We intended to explore expression transmembrane activator, calcium modulator cyclophilin ligand interactor (TACI) on cells, its pSS, possible signal transduction pathways. Methods included 34 naive pSS patients who visited rheumatology department Peking University First Hospital, 37 gender- age-distribution matched healthy controls (HCs). (1) To compare cell subsets, TACI relevant receptors patients, peripheral blood mononuclear were separated analyze ratio TACI, BAFF-R by flow cytometry; ELISA was applied detect serum BAFF soluble (sTACI) concentration. (2) As for functional research CD19+ magnetic sorting treated under vitro culture circumstances with raw knocked down siRNA, sTACI analog (telitacicept) intervention varing doses. The apoptosis, proliferation, differentiation regulatory capacity T analyzed cytometry, inflammatory cytokines immunoglobulin levels supernatants detected CBA. (3) TACI-associated signaling pathway exploration, based our previous miRNA data report high quality, associated significantly biased confirmed RT-qPCR. Screening target gene candidate miRNA, overexpression inhibition experiments conducted validate targeted relationship cells. And explored via overexpressing inhibiting gene. Results Compared HC, subsets exhibited significant bias, manifesting as increased proportion CD19+CD24hiCD38hi Breg decreased CD19+CD24+CD38- memory all down-regulated, while up-regulated. Both concentration significantly. setting group showed higher apoptosis rate than HC vitro, where (APRIL or BAFF) addition turned comparable; active impaired inducing Treg secrete IL-10. When 50%, performed less late differentiation, dysfunction itself induction While telitacicept early inhibited proliferation 500ng/mL ability Besides, telitacicept, IgG IgA observed. hsa-miR-30b-5p satisfactory correlation between both sTACI. could lead retard, secretion IL-10 SMAD1 screened database validated cell. After up- down-regulating transcription further, ID2 downstream TGF-β/Hippo changed accordingly. Conclusion deficient patients. deficiency closely downregulation hsa-miR-30b-5p, activating mediated taking part pSS. Disclosure Interests None declared