title: The roles of acquired and innate immunity in human T-cell leukemia virus type 1-mediated diseases.
abstract: Human T-cell leukemia virus type 1 (HTLV-1) causes adult T-cell leukemia (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis in small subsets of HTLV-1 carriers. HTLV-1-specific T-cell responses play critical roles in anti-viral and anti-tumor host defense during HTLV-1 infections. Some HTLV-1 carriers exhibit selective loss or anergy of HTLV-1-specific T-cells at an asymptomatic stage. This is also observed in ATL patients and may therefore be an underlying risk factor of ATL in combination with elevated proviral loads. HTLV-1-specific T-cells often recognize the viral oncoprotein Tax, indicating expression of Tax protein in vivo, although levels of HTLV-1 gene expression are known to be very low. A type-I interferon (IFN) response can be induced by HTLV-1-infected cells and suppresses HTLV-1 expression in vitro, suggesting a role of type-I IFN response in viral suppression and pathogenesis in vivo. Both acquired and innate immune responses control the status of HTLV-1-infected cells and could be the important determinants in the development of HTLV-1-mediated malignant and inflammatory diseases.
authors.affiliation: Department of Immunotherapeutics, Graduate School, Tokyo Medical and Dental University Tokyo, Japan.
authors.forename: Mari
authors.initials: M
authors.lastname: Kannagi
authors.forename: Atsuhiko
authors.initials: A
authors.lastname: Hasegawa
authors.forename: Ayako
authors.initials: A
authors.lastname: Takamori
authors.forename: Shuichi
authors.initials: S
authors.lastname: Kinpara
authors.forename: Atae
authors.initials: A
authors.lastname: Utsunomiya