title: Cutaneous T-cell lymphoma: malignant proliferation of T-regulatory cells.
abstract: Studies in an in vitro model of cutaneous T-cell lymphoma (CTCL) demonstrated that CTCL cell proliferation is stimulated by direct contact with autologous, immature dendritic cells (DCs), suggesting that CD4(+) CTCL cell division is driven by antigens presented by DC major histocompatibility complex (MHC) class 2. We now report that the T-cell receptor (TCR) of the CD4(+) CTCL cells is triggered after interaction with DCs loaded with apoptotic CTCL cells, as shown by reduced membrane expression of CD3 and the TCR, up-regulation of cytotoxic T lymphocyte antigen-4 (CTLA-4), and calcium mobilization. CTCL cells adopt a T-regulatory (Treg) phenotype expressing CD25/CTLA-4 and FoxP3 and secreting interleukin-10 (IL-10) and transforming growth factor-beta (TGF-beta). Treg CTCL cells suppress normal T-cell antigen-driven secretion of IL-2 and interferon-gamma (IFN-gamma). Blocking DC MHC class 2 expression or transport inhibited CTCL cell adoption of a Treg phenotype. Allogeneic CTCL cells or normal CD4 T cells served as sources of apoptotic material for CTCL cell conversion to a Treg phenotype. Conversion of CTCL cells to Treg cells may explain the anergic, immunosuppressive nature of the malignancy.
authors.affiliation: Department of Dermatology, Yale University School of Medicine, 333 Cedar St, New Haven, CT 06520, USA. carole.berger@yale.edu
authors.forename: Carole L
authors.initials: CL
authors.lastname: Berger
authors.forename: Robert
authors.initials: R
authors.lastname: Tigelaar
authors.forename: Justine
authors.initials: J
authors.lastname: Cohen
authors.forename: Kavita
authors.initials: K
authors.lastname: Mariwalla
authors.forename: Jennifer
authors.initials: J
authors.lastname: Trinh
authors.forename: Nianci
authors.initials: N
authors.lastname: Wang
authors.forename: Richard L
authors.initials: RL
authors.lastname: Edelson
mesh_terms: D019138:Antibodies, Blocking / Q000494:pharmacology; D000941:Antigens / Q000494:pharmacology; D015703:Antigens, CD; D000943:Antigens, Differentiation / Q000096:biosynthesis / Q000378:metabolism; D017209:Apoptosis / Q000276:immunology; D060908:CTLA-4 Antigen; D002118:Calcium / Q000378:metabolism; D049109:Cell Proliferation; D002471:Cell Transformation, Neoplastic / Q000276:immunology* / Q000378:metabolism / Q000473:pathology*; D016207:Cytokines / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D003713:Dendritic Cells / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D004306:Dose-Response Relationship, Immunologic; D000949:Histocompatibility Antigens Class II / Q000276:immunology / Q000378:metabolism; D006801:Humans; D016130:Immunophenotyping; D016753:Interleukin-10 / Q000378:metabolism; D008213:Lymphocyte Activation / Q000276:immunology; D016410:Lymphoma, T-Cell, Cutaneous / Q000276:immunology* / Q000378:metabolism / Q000473:pathology*; D012878:Skin Neoplasms / Q000276:immunology* / Q000378:metabolism / Q000473:pathology*; D016176:T-Lymphocyte Subsets / Q000276:immunology / Q000378:metabolism; D050378:T-Lymphocytes, Regulatory / Q000276:immunology / Q000378:metabolism / Q000473:pathology*; D016212:Transforming Growth Factor beta / Q000378:metabolism; D014407:Tumor Cells, Cultured
chemical_list: D019138:Antibodies, Blocking; D000941:Antigens; D015703:Antigens, CD; D000943:Antigens, Differentiation; D060908:CTLA-4 Antigen; C556706:CTLA4 protein, human; D016207:Cytokines; D000949:Histocompatibility Antigens Class II; D016212:Transforming Growth Factor beta; D016753:Interleukin-10; D002118:Calcium