Open AccessTumor immunity against adult T‐cell leukemia
Author(s) -
Kannagi Mari,
Harashima Nanae,
Kurihara Kiyoshi,
Ohashi Takashi,
Utsunomiya Atae,
Tanosaki Ryuji,
Masuda Masato,
Tomonaga Masao,
Okamura Jun
Publication year - 2005
Publication title -
cancer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.035
H-Index - 141
eISSN - 1349-7006
pISSN - 1347-9032
DOI - 10.1111/j.1349-7006.2005.00050.x
Subject(s) - ctl* , immunology , leukemia , t cell leukemia , biology , cytotoxic t cell , immune system , immunity , population , stem cell , virology , t cell , cancer , transplantation , cancer research , medicine , cd8 , in vitro , microbiology and biotechnology , biochemistry , environmental health , genetics
Human T‐cell leukemia virus type‐I (HTLV‐I) causes adult T‐cell leukemia (ATL) in a small population of infected individuals after a long incubation period. Although the process of clonal evolution of ATL cells may involve multiple steps, ATL cells from half of the ATL cases still retain the ability to express HTLV‐I Tax, a key molecule of HTLV‐I leukemogenesis. A recent finding of reactivation of Tax‐specific cytotoxic T lymphocytes (CTL) in ATL patients after hematopoietic stem cell transplantation suggests the presence of Tax expression in vivo and potential contribution of the CTL to antitumor immunity. This is consistent with the results of a series of animal experiments indicating that Tax‐specific CTL limit the growth of HTLV‐I‐infected cells in vivo , although the animal model mimics only an early phase of HTLV‐I infection and leukemogenesis. Establishment of an insufficient HTLV‐I‐specific T‐cell response and an increased viral load in orally HTLV‐I‐infected rats suggests that host HTLV‐I‐specific T‐cell response at a primary HTLV‐I infection can be a critical determinant of persistent HTLV‐I levels thereafter. These findings indicate that Tax‐targeted vaccines may be effective for prophylaxis of ATL in a high‐risk group, and also for therapy of ATL in at least half the cases. ( Cancer Sci 2005; 96: 249 –255)