POS0432 MDSCs IN THE INFLAMMATORY JOINT OF SKG MICE HAVE BOTH T CELL SUPPRESSIVE ABILITY AND OSTEOCLAST DIFFERENTIATION POTENTIAL

Background Myeloid-derived suppressor cells (MDSCs) are heterogeneous immature myeloid with suppressive functions (1). It is known that MDSCs expanded in inflammatory sites after migrating from bone marrow (BM) or spleen. Rheumatoid arthritis (RA) an autoimmune disease characterized as polyarthritis. Although previous reports indicate increased BM and spleen of model mice, detailed analysis joints limited. Objectives The purpose this study to characterize the arthritis. Methods We isolated CD11b + Gr1 (Jo-MDSCs), (BM-MDSCs) (Sp-MDSCs) arthritis-induced SKG investigated differential expressed genes (DEGs) among three tissues by microarray expression analysis. Furthermore, we analyzed function each investigating effect them on T cell -proliferation osteoclast differentiation stimulated M-CSF RANKL. Results Microarray revealed Jo-MDSCs highly immunosuppressive DEGs ( Pdl1, Arg1, Egr2 Egr3 ) compared Sp MDSCs. In addition, Jo-MDCSs NF-κB non-canonical pathway Nfkb2 Relb ), which related differentiation. BM-MDSCs differentiated into osteoclasts but didn’t suppress cell-proliferation Sp-MDSCs suppressed differentiate osteoclasts. On other hand, was found have both functions: suppression potential. Conclusion a strong inhibitory proliferation ability References [1]Veglia F, Perego M, Gabrilovich D. coming age. Nat Immunol . 2018;19(2):108–19. Disclosure Interests None declared.