Sakamoto S, Nie J, Taniguchi T
Laboratory of Molecular Biology, Medical Research Center, Kochi Medical School, Japan.
J Immunol. 1999 Apr 15;162(8):4381-4.
We observed that IFN-gamma-inducible expression of the DR alpha gene was enhanced when THP-1 cells are differentiated into macrophage-like cells by phorbol ester treatment. Here, we observed that class II MHC trans-activator and STAT1 alpha mRNA, mediators of the signaling cascade from the IFN-gamma receptor to the DR alpha induction, were markedly increased by IFN-gamma stimulation in phorbol ester-activated THP-1 cells; however, both mRNAs were not increased by phorbol ester treatment alone. Then, we demonstrated that the mRNA and proteins of the IFN-gamma receptor alpha- and beta-chains were amplified by phorbol ester treatment in THP-1 cells. Consequently, these results indicate that the enhancement of DR alpha gene expression by IFN-gamma treatment in phorbol ester-activated THP-1 cells is due to the phorbol ester-induced up-regulation of IFN-gamma receptor alpha- and beta-chains. As a result, the amplification of STAT1 alpha and the increment of class II MHC trans-activator results in enhancement of DR alpha expression.
我们观察到，当用佛波酯处理将THP-1细胞分化为巨噬细胞样细胞时，DRα基因的IFN-γ诱导型表达增强。在此，我们观察到，在佛波酯激活的THP-1细胞中，IFN-γ刺激显著增加了II类MHC反式激活因子和STAT1α mRNA，它们是从IFN-γ受体到DRα诱导的信号级联反应的介质；然而，单独用佛波酯处理时，这两种mRNA均未增加。然后，我们证明了在THP-1细胞中，佛波酯处理可扩增IFN-γ受体α链和β链的mRNA及蛋白质。因此，这些结果表明，在佛波酯激活的THP-1细胞中，IFN-γ处理增强DRα基因表达是由于佛波酯诱导的IFN-γ受体α链和β链上调。结果，STAT1α的扩增和II类MHC反式激活因子的增加导致DRα表达增强。
