title: Regulation gone wrong: a subset of Sézary patients have malignant regulatory T cells.
abstract: Cutaneous T-cell lymphomas (CTCLs) are non-Hodgkin's lymphomas derived from T cells that home to and inhabit the skin. There are conflicting reports as to whether CTCLs represent a malignancy of regulatory T cells (Tregs), a T-cell subset that can suppress local immune reactions. In this issue, Heid et al. present convincing evidence that the malignant T cells in a subgroup of Sézary patients are FOXP3(+) regulatory T cells. Clonal malignant T cells showed increased expression of the Treg-associated transcription factor FOXP3 and demethylation of the FOXP3 gene locus, and T cells from at least some of these patients suppressed T-cell proliferation in vitro.
authors.affiliation: Harvard Skin Disease Research Center and the Department of Dermatology, Brigham and Women's Hospital, EBRC Room 505A, 221 Longwood Avenue, Boston, Massachusetts 02115, USA. rclark1@partners.org
authors.forename: Rachael A
authors.initials: RA
authors.lastname: Clark
mesh_terms: D006801:Humans; D007108:Immune Tolerance / Q000276:immunology; D012751:Sezary Syndrome / Q000276:immunology*; D012878:Skin Neoplasms / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*