雷公藤甲素的免疫抑制机理

雷公藤甲素(Triptolide,TL)为雷公藤主要有效对大剂量环磷酰胺所致DTH反应增高模型亦具显成分之一。在体外,0.5～10μg·L~(-1)的TL可抑制单向著抑制作用“0.25 mg·kg~(-1)的TL还可明显降低小鼠混合淋巴细胞培养(MLC).TL5和10μg·L~(-1)所诱导胸腺Th/Ts细胞比值.这些资料显示TL对小鼠细胞出的混合淋巴细胞经~(60)Co照射后可抑制第二次免疫功能具有显著抑制作用,其机理可能与抑制ThMLC.表明TL可以诱导抑制性T细胞(Ts)。体内给细胞和IL—2分泌活性及诱导Ts细胞有关。药.0.12～0.5 mg·kg~(-1)的TL可以显著抑制DNFB所致小鼠迟发性超敏反应(DTH).0.25和0.5 mg·kg~(-1)时,小鼠脾细胞的IL—2分泌活性亦明显受抑,

Mechanism of immunosuppressive effects of triptolide

Triptolide (TL) is a major active component extracted from Chinese traditional herb Tripteryginm wil-fordii Hook. In this article, the effects of TL on mixed lymphocyte culture (MLC),suppressor T cell(Ts) activity, delayed type hypersensitivity (DTH) reaction, IL - 2 secretion activity and Th/Ts ratio were evaluated, In vitro TL 0. 5~10 μg · L-1suppressed one-way MLC,Lymphocytes induced in first MLC with TL of 5,10 μg · L-1 suppressed the second MLC after irradiation with 3000 rad 60Co source. This suggests that TL may induce Ts cell-s. In vivo, DTH reaction sensitized to dinitrofluo-robenzene (DNFB) monitored by the increase in weight of the ears challenged with antigen was suppressed by TL at doses of 0. 12 to 0. 50 mg · kg-1(ip,qd×5) and the IL -2 activity secreted by spleen cells of these mice was inhibited at doses of 0. 25 and 0. 5 mg · kg-1. TL 0. 25, 0. 5 mg · kg-1(ip,qd×8) also had prominent suppres-sive effects on enhanced DTH reaction which was induced by cyclophosphamide(250 mg · kg-1,ip). Th/Ts ratio of mouse thymus cells were reduced after given 0. 25 mg · kg-1 of TL for 5 consecutive days. The above-mentioned data suggest that TL has suppressive effects on cellular immunity function and the suppressive mechanism may be related to the suppression of Th cells and IL-2 secretion activity and the induction of Ts cells.