Masahiro Fujii

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Using Vero cells, we isolated a virus (NII561-2000) from a cerebrospinal fluid specimen of a 1-year-old girl with Reye syndrome. The determined amino acid sequence of the virus indicated that the isolate was a human parechovirus (HPeV), a member of Picornaviridae. Neutralization test showed that the NII561-2000 virus had distinct antigenicity to HPeV-1,(More)
While human T-cell leukemia virus type 1 (HTLV-1) is associated with the development of adult T-cell leukemia (ATL), HTLV-2 has not been reported to be associated with such malignant leukemias. HTLV-1 Tax1 oncoprotein transforms a rat fibroblast cell line (Rat-1) to form multiple large colonies in soft agar, and this activity is much greater than that of(More)
Human T-lymphotropic virus type 1 (HTLV-1) infection is associated with the clonal expansion and transformation of mature T lymphocytes. While the mechanisms involved are incompletely understood the viral regulatory protein Tax plays a central role in these processes. Recent studies employing genomic and proteomic approaches have demonstrated the marked(More)
Upon exposure to various environmental stresses such as arsenite, hypoxia, and heat shock, cells inhibit their translation and apoptosis and then repair stress-induced alterations, such as DNA damage and the accumulation of misfolded proteins. These types of stresses induce the formation of cytoplasmic RNA granules called stress granules (SGs). SGs are(More)
Human T-cell leukemia virus type I (HTLV-I) is the causative agent of an aggressive form of leukemia designated adult T-cell leukemia (ATL). We have previously demonstrated that all T-cell lines infected with HTLV-I and primary leukemic cells from ATL patients display constitutively high activity of transcription factor NF-kappaB. In this study we showed(More)
Adult T-cell leukemia (ATL) is a highly aggressive T-cell malignancy caused by human T-cell leukemia virus type 1 (HTLV-1). The activation of NF-kappaB by Tax has been reported to play a crucial role in HTLV-1-induced transformation. The HTLV-1 bZIP factor (HBZ), which is encoded by an mRNA of the opposite polarity of the viral genomic RNA, is involved in(More)
Human T-cell leukemia virus type 1 (HTLV-1) is the etiologic agent for adult T-cell leukemia/lymphoma (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis. Tax(1) is a 40-kDa phosphoprotein, predominantly localized in the nucleus of the host cell, which functions to transactivate both viral and cellular promoters. It seems likely that HTLV-1,(More)
Human T-cell leukemia virus type I (HTLV-I) is an etiologic agent of adult T-cell leukemia (ATL). The viral protein Tax induces the activation and nuclear translocalization of transcription factor NF-kB, which is proposed to play a crucial role in the transformation of T cells by HTLV-I. However, the HTLV-I genes including Tax are not expressed(More)
While the human T-cell leukemia virus type 1 (HTLV-1) is the etiologic agent of adult T-cell leukemia/lymphoma (ATL), to date, its close relative HTLV-2 is not associated with ATL or other types of malignancies. Accumulating evidence shows that HTLV-1 Tax1 and HTLV-2 Tax2 have many shared activities, but the two proteins have a limited number of(More)
Human T-cell leukemia virus type 1 (HTLV-1) but not HTLV-2 is associated with adult T-cell leukemia, and the distinct pathogenicity of these two closely related viruses is thought to stem from the distinct biological functions of the respective transforming proteins, HTLV-1 Tax1 and HTLV-2 Tax2. In this study, we demonstrate that Tax1 but not Tax2 interacts(More)