title: Graft-versus-Tax response in adult T-cell leukemia patients after hematopoietic stem cell transplantation.
abstract: Adult T-cell leukemia (ATL) caused by human T-cell leukemia virus type I (HTLV-I) is characterized by poor prognosis after chemotherapy. Recent clinical trials have indicated, however, that allogeneic but not autologous hematopoietic stem cell transplantation (HSCT) for ATL can yield better clinical outcomes. In the present study, we investigated cellular immune responses of ATL patients who obtained complete remission after nonmyeloablative allogeneic peripheral blood HSCT from HLA-identical sibling donors. In the culture of peripheral blood mononuclear cells (PBMCs) from a post-HSCT but not pre-HSCT ATL patient, CD8(+) CTLs proliferated vigorously in response to stimulation with autologous HTLV-I-infected T cells that had been established before HSCT in vitro. These CTLs contained a large number of monospecific CTL population directed to a HLA-A2-restricted HTLV-I Tax 11-19 epitope. The frequency of Tax 11-19-specific CD8+ CTLs in this patient markedly increased also in vivo after HSCT, as determined by staining with HLA-A2/Tax 11-19 tetramers. Similar clonal expansion of HTLV-I Tax-specific CTLs exclusively directed to a HLA-A24-restricted Tax 301-309 epitope was observed in the PBMCs from another ATL patient after HSCT from a HTLV-I-negative donor. Among four post-HSCT ATL patients tested, HTLV-I-specific CTLs were induced in the PBMC culture from three patients but not from the remaining one who had later recurrence of ATL. These observations suggested that reconstituted immunity against antigen presentation in ATL patients after HSCT resulted in strong and selective graft-versus-HTLV-I response, which might contribute to graft-versus-leukemia effects.
authors.affiliation: Department of Immunotherapeutics, Tokyo Medical and Dental University, Medical Research Division, Tokyo, Japan.
authors.forename: Nanae
authors.initials: N
authors.lastname: Harashima
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Kurihara
authors.forename: Atae
authors.initials: A
authors.lastname: Utsunomiya
authors.forename: Ryuji
authors.initials: R
authors.lastname: Tanosaki
authors.forename: Shino
authors.initials: S
authors.lastname: Hanabuchi
authors.forename: Masato
authors.initials: M
authors.lastname: Masuda
authors.forename: Takashi
authors.initials: T
authors.lastname: Ohashi
authors.forename: Fumiyo
authors.initials: F
authors.lastname: Fukui
authors.forename: Atsuhiko
authors.initials: A
authors.lastname: Hasegawa
authors.forename: Takao
authors.initials: T
authors.lastname: Masuda
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Takaue
authors.forename: Jun
authors.initials: J
authors.lastname: Okamura
authors.forename: Mari
authors.initials: M
authors.lastname: Kannagi
mesh_terms: D000368:Aged; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D016356:Gene Products, tax / Q000276:immunology*; D006650:Histocompatibility Testing; D015368:Human T-lymphotropic virus 1 / Q000276:immunology* / Q000302:isolation & purification; D006801:Humans; D015459:Leukemia-Lymphoma, Adult T-Cell / Q000276:immunology* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D011533:Proviruses / Q000302:isolation & purification; D035781:Siblings; D033581:Stem Cell Transplantation; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D014184:Transplantation, Homologous / Q000276:immunology*; D016896:Treatment Outcome
chemical_list: D016356:Gene Products, tax