title: Induction of Fas-dependent apoptosis in synovial infiltrating cells in rheumatoid arthritis.
abstract: Apoptosis is a feature of the synovium of rheumatoid arthritis (RA). We have recently shown that RA synoviocytes were susceptible to anti-Fas mAb and undergo apoptosis in vitro. To investigate whether infiltrating mononuclear cells also undergo Fas-dependent apoptosis, double-labeling techniques combined with immunohistochemical examination with anti-CD3 mAb and the TdT-mediated dUTP-blotin nick end labeling (TUNEL) method to detect apoptotic cells, or in situ RT assay to detect Fas mRNA, were performed using frozen tissue sections. We also examined the in vitro induction of Fas-dependent apoptosis in freshly isolated synovium infiltrating mononuclear cells (SIM), synovial stromal cells (SSC) and peripheral blood lymphocytes (PBL) using tissues from nine patients with RA and three with osteoarthritis (OA). The results showed expression of Fas antigen and apoptotic cells in a number of CD3-bearing cells in RA synovial tissues. In vitro treatment with anti-Fas mAb produced a significant apoptosis of RA SIM and SSC, while none of PBL, and neither SIM nor SSC from OA exhibited apoptosis. Moreover, approximately 50% of CD4+, CD3+ and CD45RO+ cells, and > 90% of Fas-expressing cells of RA SIM underwent apoptosis in response to anti-Fas mAb, as detected by flow cytometry. Our results suggest that RA synovial infiltrating lymphocytes acquire high susceptibility to anti-Fas mAb and undergo apoptosis. Such a phenomenon of infiltrating T cells in RA synovium may play an important pathophysiological role and suggest a possible therapeutic effect for anti-Fas mAb in RA.
authors.affiliation: Division of Rheumatology and Immunology, St Marianna University School of Medicine, Kawasaki, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Hasunuma
authors.forename: T T
authors.initials: TT
authors.lastname: Hoa
authors.forename: H
authors.initials: H
authors.lastname: Aono
authors.forename: H
authors.initials: H
authors.lastname: Asahara
authors.forename: S
authors.initials: S
authors.lastname: Yonehara
authors.forename: K
authors.initials: K
authors.lastname: Yamamoto
authors.forename: T
authors.initials: T
authors.lastname: Sumida
authors.forename: S
authors.initials: S
authors.lastname: Gay
authors.forename: K
authors.initials: K
authors.lastname: Nishioka
mesh_terms: D000368:Aged; D000911:Antibodies, Monoclonal / Q000276:immunology* / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D001172:Arthritis, Rheumatoid / Q000188:drug therapy*; D017252:CD3 Complex / Q000276:immunology; D015704:CD4 Antigens / Q000276:immunology; D002634:Chemotaxis, Leukocyte / Q000187:drug effects*; D004253:DNA Nucleotidylexotransferase; D005260:Female; D006801:Humans; D007075:Immunoglobulin M / Q000276:immunology / Q000494:pharmacology; D017403:In Situ Hybridization / Q000379:methods; D017493:Leukocyte Common Antigens / Q000276:immunology; D008875:Middle Aged; D010003:Osteoarthritis / Q000188:drug therapy; D013583:Synovial Membrane / Q000187:drug effects* / Q000473:pathology*; D013601:T-Lymphocytes / Q000187:drug effects* / Q000378:metabolism; D019014:fas Receptor / Q000096:biosynthesis / Q000276:immunology* / Q000494:pharmacology*
chemical_list: D000911:Antibodies, Monoclonal; D017252:CD3 Complex; D015704:CD4 Antigens; D007075:Immunoglobulin M; D019014:fas Receptor; D004253:DNA Nucleotidylexotransferase; D017493:Leukocyte Common Antigens