title: Rheumatoid arthritis synovial fluid enhances T cell effector functions.
abstract: Rheumatoid arthritis is a chronic autoimmune joint disease of unknown etiology. T cells are believed to be important in the pathogenesis of rheumatoid arthritis since they infiltrate the joints and express several activation markers, such as MHC class II and IL-2R. In this study we have elucidated the effect on freshly isolated T cells of rheumatoid arthritis synovial fluid (RA-SF), which contains in vivo produced cytokines and enzymes. The mouse mixed lymphocyte culture (MLC) has been used as a model and specific cytotoxicity was evaluated against 51Cr-labelled sensitive target cells. Studies have shown that RA-SF contains a B cell differentiation activity that can cross-react between the human and murine species. Here we have shown that the addition of RA-SF strongly potentiates cytotoxic activity as well as lymphokine production by allogeneic activated effector T cells. The enhanced cytotoxicity induced by RA-SF was found to be due to a combined effect of increased cytotoxic T lymphocyte (CTL) precursor frequency, measured by limiting dilution analysis, and a more efficient killing on a per cell basis. Kinetic studies show that RA-SF must be added within 48 h after initiation of the MLC, otherwise the effect is lost. The target cell specificity of RA-SF was studied, using enriched CD4+ or CD8+ responder cells in the MLC. It was found that RA-SF could act directly on the CD8+ cells and potentiate their development to cytotoxic effector cells: this activity was not found when CD4+ responder cells were used instead. RA-SF could, on the other hand, greatly enhance IL-2 production by CD4+ responder cells. We suggest that B and T cell activity in RA-SF is important in the propagation of chronic inflammation in the joints of patients with rheumatoid arthritis.
authors.affiliation: Department of Immunology, Arrhenius Laboratories for Natural Sciences, University of Stockholm, Sweden.
authors.forename: A
authors.initials: A
authors.lastname: Ridderstad
authors.forename: M
authors.initials: M
authors.lastname: Abedi-Valugerdi
authors.forename: H
authors.initials: H
authors.lastname: Ström
authors.forename: E
authors.initials: E
authors.lastname: Möller
mesh_terms: D000818:Animals; D001172:Arthritis, Rheumatoid / Q000276:immunology*; D001327:Autoimmune Diseases / Q000276:immunology*; D001402:B-Lymphocytes / Q000187:drug effects / Q000276:immunology; D016207:Cytokines / Q000494:pharmacology; D003602:Cytotoxicity, Immunologic / Q000187:drug effects; D004798:Enzymes / Q000494:pharmacology; D006801:Humans; D007376:Interleukin-2 / Q000096:biosynthesis; D008213:Lymphocyte Activation / Q000187:drug effects; D007959:Lymphocyte Culture Test, Mixed; D051379:Mice; D008807:Mice, Inbred BALB C / Q000276:immunology; D008810:Mice, Inbred C57BL / Q000276:immunology; D013582:Synovial Fluid / Q000737:chemistry / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism
chemical_list: D016207:Cytokines; D004798:Enzymes; D007376:Interleukin-2