title: FoxP3+ regulatory T cells are distinct from leukemia cells in HTLV-1-associated adult T-cell leukemia.
abstract: Human T-lymphotropic virus type 1 (HTLV-1) is the causative agent of adult T-cell leukemia/lymphoma (ATLL). It has been postulated that ATLL cells might act as regulatory T cells (T(regs)) which, in common with ATLL cells, express both CD25 and FoxP3, and so contribute to the severe immune suppression typical of ATLL. We report here that the frequency of CD25(+) cells varied independently of the frequency of FoxP3(+) cells in both a cross-sectional study and in a longitudinal study of 2 patients with chronic ATLL. Furthermore, the capacity of ATLL cells to suppress proliferation of heterologous CD4(+)CD25(-) cells correlated with the frequency of CD4(+) FoxP3(+) cells but was independent of CD25 expression. Finally, the frequency of CD4(+)FoxP3(+) cells was inversely correlated with the lytic activity of HTLV-1-specific CTLs in patients with ATLL. We conclude that ATLL is not a tumor of FoxP3(+) regulatory T cells, and that a population of FoxP3(+) cells distinct from ATLL cells has regulatory functions and may impair the cell-mediated immune response to HTLV-1 in patients with ATLL.
authors: Department of Immunology, Imperial College, London, United Kingdom. f.toulza@imperial.ac.uk
authors: Frederic
authors: F
authors: Toulza
authors: Kisato
authors: K
authors: Nosaka
authors: Masafumi
authors: M
authors: Takiguchi
authors: Tony
authors: T
authors: Pagliuca
authors: Hiroaki
authors: H
authors: Mitsuya
authors: Yuetsu
authors: Y
authors: Tanaka
authors: Graham P
authors: GP
authors: Taylor
authors: Charles R M
authors: CR
authors: Bangham
mesh_terms: D000328:Adult; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D049109:Cell Proliferation; D002908:Chronic Disease; D005260:Female; D005434:Flow Cytometry; D005500:Follow-Up Studies; D051858:Forkhead Transcription Factors / Q000378:metabolism*; D015490:HTLV-I Infections / Q000150:complications / Q000235:genetics / Q000276:immunology*; D015368:Human T-lymphotropic virus 1 / Q000235:genetics / Q000276:immunology*; D006801:Humans; D015459:Leukemia-Lymphoma, Adult T-Cell / Q000235:genetics / Q000276:immunology* / Q000473:pathology; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D015996:Survival Rate; D050378:T-Lymphocytes, Regulatory / Q000276:immunology* / Q000378:metabolism / Q000473:pathology
chemical_list: C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors