Successful induction of severe destructive arthritis by the transfer of in vitro-activated synovial fluid T cells from patients with rheumatoid arthritis (RA) in severe combined immunodeficient (SCID) mice

In order to investigate the role of pathogenic T cells in RA, the establishment of an RA model using patients' T cells is thought to be essential. In this study, multiple and severe destructive arthritis was established by transferring in vitro-stimulated synovial fluid T (SFT) cells from patients with RA through simultaneous injection into knee joint and peritoneal cavity of SCID mice without causing xenogeneic graft-versus-host disease (GVHD). Neither the transfer of unstimulated SFT cells nor sole i.p. injection was sufficient to induce severe arthritis. Interestingly, in contrast with SFT cells, in vitro-activated peripheral blood lymphocytes from RA patients failed to trigger such arthritis, suggesting that pathogenic T cells might be concentrated in synovial fluid of RA patients. This, the first severe arthritis model mimicking RA induced by RA patients' T cells, is expected to provide important information about RA pathogenesis and a possible therapeutic approach.