Mumps Virus Can Suppress the Effective Augmentation of HPC‐Induced Apoptosis by IFN‐γ through Disruption of IFN Signaling in U937 Cells

Y Hariya, N Yokosawa, N Yonekura… - Microbiology and …, 2000 - Wiley Online Library
Y Hariya, N Yokosawa, N Yonekura, G Kohama, N Fujii
Microbiology and immunology, 2000Wiley Online Library
Cells of the human promonocytic cell line U937 were found to be sensitive to
hexadeeylphosphocholine (HPC), which is a potential anticancer drug. Induction of
apoptosis was found in U937 cells after treatment with HPC for 24 to 48 hr. The apoptosis in
U937 cells exposed to HPC was increased significantly in the presence of interferon‐
gamma (IFN‐γ). The augmentation of HPC‐induced apoptosis by IFN‐γ is repressed in cells
(U937‐MP) persistently infected with mumps virus. A persistently infected cell line, U937 …
Abstract
Cells of the human promonocytic cell line U937 were found to be sensitive to hexadeeylphosphocholine (HPC), which is a potential anticancer drug. Induction of apoptosis was found in U937 cells after treatment with HPC for 24 to 48 hr. The apoptosis in U937 cells exposed to HPC was increased significantly in the presence of interferon‐gamma (IFN‐γ). The augmentation of HPC‐induced apoptosis by IFN‐γ is repressed in cells (U937‐MP) persistently infected with mumps virus. A persistently infected cell line, U937‐MP, showed poor induction of signal transducers and activators of transcription‐1α (STAT‐1α), STAT‐2, p48 and IFN‐regulatory factor‐1 (IRF‐1), which are closely correlated with interferon‐α (IFN‐α) and IFN‐γ signaling pathways. Expression of MHC class‐I or class‐II was augmented by IFN‐α or IFN‐γ in U937 cells, but not in persistently infected cells. Therefore, it is suggested that the IFN‐γ signaling pathway plays an important role in the augmentation of HPC‐induced apoptosis. Mumps virus can suppress the IFN‐γ signaling pathway and subsequent development of apoptosis.
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