Possibility of inhibiting arthritis and joint destruction by SSEA-3 positive cells derived from synovial tissue in rheumatoid arthritis

Aim Joint destruction progresses irreversibly once they occur in rheumatoid arthritis (RA), even with the recent development of anti-rheumatic drugs. Cells positive for stage-specific embryonic antigen-3 (SSEA-3), a marker of human embryonic stem cell, act as stem cells in the blood. The aim of this study is to investigate the effectiveness of SSEA-3 positive cells for the treatment for RA. Methods Synovial tissues were harvested at the time of joint surgery in RA patients. Cultured synovial cells were sorted by anti-SSEA-3 antibody using flow cytometry and were analyzed in in vitro. To investigate inhibitory effects on arthritis by SSEA-3 positive cells, collagen antibody-induced arthritis (CAIA) mice were used and transplanted with labeled cells intravenously. Results Presence of SSEA-3 positive cells was confirmed with approximately 1% in RA synovial cells. SSEA-3 positive cells were negative for CD34 and positive for CD44, CD90 and CD105. Multipotency of SSEA-3 positive cells was higher than that of SSEA-3 negative cells. Arthritis of the group transplanted with SSEA-3 positive cells in CAIA mice decreased over time. Conclusions SSEA-3 positive cells derived from RA synovial tissue might have the inhibitory effect on arthritis and would be one of cell source for new RA treatment.