摘要
白细胞介素２／白细胞介素２受体（ＩＬ－２／ＩＬ－２Ｒ）系统在免疫系统中起极重要作用，研究糖皮质激素对ＩＬ－２／ＩＬ－２Ｒ系统的影响有助于了解糖皮质激素免疫调节作用的分子机理。通过荧光素酶报告基因的表达及狭缝杂交，发现在Ｊｕｒｋａｔ细胞中地塞米松对ＩＬ－２Ｒα链基因ｍＲＮＡ的基础表达及ＰＨＡ的诱导表达均有直接促进作用，这种正调节作用与ＩＬ－２Ｒα链基因５＇上游一４８２ｂｐ以内近端已知的诱导转录元件无关，且与ＰＨＡ的活化机制不同，两者间具有协同效应。
Glucocorticoids have wide effects on the immune system,the mechanisms of these ef-fects have not been clearly defined,The interaction of interleukin-2(Il-2)with is receptor(IL-2R)is a critical control point in the T-cell mediated immune response.The effect of dex-amethasone,a synthetic glucocorticoid hormone, on IL-2R is unclear in comparison with itsinhibition on the accumulation of IL-2 mRNA.Our study shows that dexamethasone increas-es the basal and PHA-induced mRNA levels of IL-2R α gene in Jurkat cells,but it does notaffect the expression of reporter gene constructs containing 5'flanking sequences(一482bp/+16bp or -350bp/+16bp)of the IL-2R α gene in PHA activated Jurkat cells. These re-sults indicate that dexamethasone plays a positive regulatory role in the IL-2R a gene expres-sion,but the effect is not mediated by the previously identified proximal regulatory elementslocated between一482bp/+1bp. Meanwhile.our results also provide evidence that the acti-vation mechanism of dexamethasone is different from that of PHA,and that dexamethasoneand PHA show a synergistic effect in the induction of IL-2R α gene expression.
出处
《中国医学科学院学报》
CAS
CSCD
北大核心
1996年第2期89-94,共6页
Acta Academiae Medicinae Sinicae
基金
卫生部项目基金
