Effects Of SB203580 On The Proliferation And Differentiation Of OT-â…¡ Cells Mediated By Splenic Dendritic Cells

Background:In recent years, emerging data was suggesting that the inflammatory and autoimmune diseases induced by the dysfunction of the CD4+ T cells were more and more, such as systemic lupus erythematosus(SLE), ulcerative bowel disease. There were many of factors inducing the dysfunction of the CD4+ T cells, but the main was antigen presenting cells(APC). As was known to all, the dendritic cell was the most important APC, whose primary function was to capture, process, and present antigens to T and B cells, as a result of activating immune reponse. The p38 MAPK signaling pathway had been an important branch of MAPK signaling pathway, which controlled the growth, activation, proliferation, apoptosis of the cells. While SB203580 could inhibit the p38 MAPK signaling transduction. We would investigate the effects of SB203580 on the phenotype and function of dendritic cel s and the mechanism. Objective:To investigate the effects of blocking p38mitogen-activated protein kinase(p38MAPK) pathway on the proliferation and differentiation of OT-Ⅱ cells mediated by splenic dendritic cel s(DCs). Methods:1 Spleen DCs of the C57BL/6 mice were purified with anti-CD11 c immunomagnetic beads.2 OT-Ⅱ cells were isolated from the spleen of C D4+-ovalbumin transgenic mice(OT-Ⅱ transgenic mice) by mouse CD4 T cell isolation kits.3 After being pretreated with SB203580, an inhibitor of p38 MAPK, DCs were stimulated with lipopolysaccharides(LPS). Then the expression levels of co-stimulatory molecules(C D80, CD86, CD40) and MHCⅡin DCs were measured by flow cytometry.4 Antigen-presenting ability of DCs treated with the 52-68 fragment of the E alpha-chain of I-E class Ⅱ molecules(Eα52-68 peptide) were detected by flow cytometry.5 The protein levels and the mRNA levels of tumer necrosis factor(TNF-α), IL-1α, IL-6, and transforming growth factor β(TGF-β) were measured by ELISA or real-time quantitative PCR(RT-qPCR).6 The proliferation of OT- Ⅱ cells which were co-cultured with OVA323-339-treated DCs and the percentage of Th1/Th2/Th17 cells and suppressing cel s was analyzed by flow cytometry. Resluts:1 The purity of DCs reached over 90% after isolation.2 The purity of OT-Ⅱ cel s reached over 90% after isolation.3 SB203580 downregulated the expressions of CD80, CD86, CD40 and MHCⅡ.4 SB203580 suppressed the antigen-presenting ability of DCs.5 TNF-α, IL-1α, IL-6 were down-regulated at mRNA and protein levels, while TGF-β was opposite.6 SB203580 suppressed DC-mediated proliferation of OT-Ⅱ cells, weaken the percentage of Th17 cel s, promoted the percentage of suppressing cel s. Conclusion:Blocking p38 MAPK pathway with SB203580 could inhibit DCs- mediated proliferation of OT- Ⅱ cells and differentiation to Th17 cells, and enhance differentiation to suppressing cells, which might be involved in modulating the expressions of CD80, CD86, CD40 and MHCⅡ, the antigen-presenting ability, as well as the expressions of pro-inflammatory and anti-inflammatory cytokines.