title: Synovial fluid T cells from patients with rheumatoid arthritis are refractory to the T helper type 2 differentiation-inducing effects of interleukin-4.
abstract: The balance between T helper type 1 (Th1) and Th2 cytokines is thought to be important in the initiation and outcome of autoimmune diseases. The goal of the present study was to compare the production of interferon-gamma (IFN-gamma) and interleukin-4 (IL-4) by synovial fluid (SF) and peripheral blood (PB) CD4+ and CD8+ cells from patients with rheumatoid arthritis (RA) using three-colour immunofluorescence staining and flow cytometry, and to investigate the capacity of IL-4, IL-10 and IL-12 to modify the cytokine production profile of SF T cells. The frequency of IFN-gamma-producing CD4+ and CD8+ cells was significantly increased in SF when compared with PB. In contrast to IFN-gamma, the expression of IL-4 in SF and PB T cells was comparable. The majority of IL-4-producing cells in SF belonged to Th0/T cytotoxic (Tc) type 0 phenotype, whereas there were significantly more Th2/Tc2 cells in PB than in SF. Interestingly, IL-4 was unable to induce differentiation of non-adherent SF mononuclear cells (SFMC) into Th2 cells, whereas PB mononuclear cells (PBMC) under similar culture conditions differentiated into cells producing high levels of IL-4, IL-10 and IL-13. In contrast, there were no major differences in the effects of IL-10 and IL-12 on the cytokine production profile of SFMC when compared with PBMC. Taken together, the present results suggest that SF T cells from patients with RA are terminally differentiated into Th1/Tc1-like phenotype, and Th2/Tc2 differentiation-inducing agents, such as IL-4, may not be able to reverse the inflammatory process occurring in the joints.
authors.affiliation: Department of Medical Microbiology, Turku University, Turku, Finland.
authors.forename: P
authors.initials: P
authors.lastname: Isomäki
authors.forename: R
authors.initials: R
authors.lastname: Luukkainen
authors.forename: O
authors.initials: O
authors.lastname: Lassila
authors.forename: P
authors.initials: P
authors.lastname: Toivanen
authors.forename: J
authors.initials: J
authors.lastname: Punnonen
mesh_terms: D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000276:immunology*; D001327:Autoimmune Diseases / Q000276:immunology*; D002454:Cell Differentiation / Q000276:immunology; D016207:Cytokines / Q000096:biosynthesis; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007371:Interferon-gamma / Q000276:immunology; D016753:Interleukin-10 / Q000276:immunology; D018664:Interleukin-12 / Q000276:immunology; D015847:Interleukin-4 / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D013582:Synovial Fluid / Q000276:immunology*; D016176:T-Lymphocyte Subsets / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology; D018418:Th2 Cells / Q000276:immunology*
chemical_list: D016207:Cytokines; D016753:Interleukin-10; D018664:Interleukin-12; D015847:Interleukin-4; D007371:Interferon-gamma