抄録
Poor induction of interferon-induced 2', 5'-oligoadenylate synthetase (2-5AS) activity has been demonstrated in cells persistently infected with the mumps virus or human T-lymphotropic virus type-I (HTLV-I). The suppression of 2-5AS induction is the result of the repression of 2-5AS gene expression at the transcription level. In a general way, after the binding of interferon-α (IFN-α) to cell surface-specific receptors, expression of 2-5AS gene is thought to be regulated by some transacting factors, IFN-regulatory factors (IRF-1 and IRF-2) and the IFN-stimulated gene factor (ISGF-3, a complex consisting of STAT 1α, STAT-2 and p48). To clarify the cause of the suppression mechanism(s), fluctuation in the number of IFN receptors and the levels of mRNAs in both IRF-1 and IRF-2 were examined in cells persistently infected with the mumps virus (FLMT and KBMT). There were few defferences in the number of IFN receptors and the level of IRF-2 mRNA between persistently infected cells and uninfected control cells. After the treatment of cells with INF, a slight reduction of IRF-1 mRNA was found in persistently infected cells as compared with that of the uninfected control cells.
