González-Alvaro I, Ortiz AM, Domínguez-Jiménez C, Aragón-Bodi A, Díaz Sánchez B, Sánchez-Madrid F. Inhibition of tumour necrosis factor and IL-17 production by leflunomide involves the JAK/STAT pathway.
Ann Rheum Dis 2008;
68:1644-50. [PMID:
18957484 PMCID:
PMC2946060 DOI:
10.1136/ard.2008.096743]
[Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Objective:
To study the effects of different disease-modifying antirheumatic drugs (DMARD) on different events mediated by IL-15-activated lymphocytes.
Methods:
Peripheral blood lymphocytes (PBL) were isolated from healthy donors and activated with IL-15 after exposure to different DMARD: leflunomide, cyclosporin A, methotrexate, mycophenolic acid, FK-506, sulphasalazine and sodium aurothiomalate. The expression of different surface molecules on the PBL was then determined by flow cytometry. Cells were also co-cultured with the monocytic cell line THP-1 and the tumour necrosis factor (TNF) concentration in the supernatant was measured after 24 h using an immunoenzyme assay. The effect of the aforementioned drugs on IL-17 production by IL-15-activated PBL was also studied.
Results:
Treatment of PBL with leflunomide, cyclosporin A and FK-506 inhibited the IL-15-induced expression of both CD54 and CD69 by PBL, as well as TNF production in co-cultures of activated PBL and THP-1 cells. The downregulation of CD54 and CD69 in PBL was correlated with the inhibition of TNF production. Likewise, leflunomide, cyclosporin A and FK-506 all inhibited IL-17 production in IL-15-activated PBL. Interestingly, the effect of leflunomide was not reverted by the presence of uridine in the medium. In addition, leflunomide inhibited the phosphorylation of STAT6 in vitro.
Conclusion:
Inhibition of the JAK/STAT pathway may represent an additional effect of leflunomide in chronic polyarthritis because it impairs certain events that control proinflammatory TNF and IL-17 cytokine production.
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