木瓜苷对环磷酰胺增强的小鼠接触性超敏反应的影响

摘要

AIM To investigate the roles of thymus T lymphocytes subsets in contact hypersensitivity (CHS) and effects of glucosides of Chaenomeles speciosa (GCS) on this response. METHODS CHS model induced by 2,4-dinitro-I-dinitrofluorobenzene (DNFB) and cyclophosphamide (Cy) potentiated CHS model were used. GCS(60,120 and 240 mg·kg-1) were given intragastrically (ig) once daily for 12 consecutive days. Concanavalin A (Con A)-induced lymphocytes proliferation was observed by MTT assay. CD4/CD8 T lymphocytes subsets were measured by flow cytometry and the levels of Con A-induced cytokines from thymocytes were measured by enzyme-linked immunosorbent asssay (ELISA). RESULTS Splenocyte proliferation stimulated by Con A was augmented and CD4+CD8+ T lymphocytes were increased in thymus of mice with CHS. The balance of CD4+Th subsets was changed to favor Th1 and Th3 as shown by the increased interleukin-2 (IL-2) and transforming growth factor β1 (TGF-β1) production and the decreased interleukin-4 (IL-4) production. GCS, similar as the control drug actarit (4-acetylaminophenylacetic acid), could elevate the percentage of CD4+CD8- T lymphocytes and CD4-CD8- T lymphocytes, and reduce the percentage of CD4+CD8+ T cells in Cy-potentiated CHS mice. GCS inhibited the production of IL-2 and TGF-β1, and increased the IL-4 level in cultures of thymocytes from mice with Cy-potentiated CHS. CONCLUSIONGCS inhibits Cy-potentiated mice CHS response and modulates the balance of CD4/CD8 or helper T cells subsets.%目的探讨胸腺在环磷酰胺(Cy)增强的小鼠接触性超敏反应(CHS)中的作用及木瓜苷(GCS)对胸腺T淋巴细胞亚型的影响.方法采用了2,4-二硝基氟苯(DNFB)诱导小鼠CHS模型及Cy诱导小鼠增强CHS模型,检测Con A诱导的小鼠脾脏T淋巴细胞增殖、胸腺T淋巴细胞亚型和Con A诱导的胸腺T淋巴细胞培养上清中TGF-β1,IL-4和IL-2水平.结果小鼠CHS模型中,Con A诱导的脾淋巴细胞增殖增强,CD4+CD8+双阳性胸腺T淋巴细胞比例增加,胸腺细胞产生的Th1和Th3型细胞因子IL-2和TGF-β1水平增高而Th2型细胞因子IL-4水平降低.DNFB初次致敏前3 d腹腔注射Cy(250 mg·kg-1)可以增强CHS反应.GCS(120和240 mg·kg-1)连续灌胃12 d可以提升Cy增强的小鼠CHS胸腺T淋巴细胞中CD4-CD8-和CD4+CD8-细胞比例,降低CD4+CD8+细胞比例;并提高胸腺淋巴细胞培养上清中IL-4水平,降低IL-2和TGF-β1水平.结论 GCS对Cy增强的小鼠CHS有明显抑制作用;可有效调节小鼠胸腺CD4/CD8和Th淋巴细胞亚群及细胞因子产生平衡.