Tamm-Horsfall蛋白对细胞因子与受体结合能力的影响

THE EFFECT OF TAMM-HORSFALL PROTEIN ON BINDING OF CYTOKINES TO THEIR RECEPTORS

近年在体外试验中证实,Tamm-Horsfall蛋白(THP)能以高度亲和力与IL-1、IL-2和TNF结合,故有作者提出,THP可能竞争与细胞因子结合,影响后者与受体的相互作用而发挥免疫抑制效应。我们用放射性配体——受体结合分析法证实,THP对^(125)I-IL-I、^(125)I-IL-2和^(125)I-TNF与各自靶细胞结合的放射活性无明显影响,即便在浓度超过放射性配体100倍时亦然,THP也不影响细胞表面IL-1、IL-2和TNF受体的数目及亲和力。这一结论对阐明这种重要蛋白质与机体免疫系统的关系,探讨其病理生理作用具有重要意义。

Tamm-Horsfall protein (THP) has been considered as an inhibitor of some cyto-kines since it has been shown to be a high affinity ligand for IL-1, IL-2 and TNF. By using radio-receptor assay, we demonstrated that THP failed to block the binding of 126-labeled IL-1, rIL-2 and rTNF to their receptors on cell surface, even the concentration of THP was 100 times more than that of the radioligands. THP also did not affect the numbers of the membrane IL-1K,IL-2R and TNFR and their equlibrium dissociation constant. These findings would be important in illustrating the relationship between THP and immune system,and might be helpful to understand the pathophysio-Iogic effect of this important protein.