title: In cutaneous T-cell lymphoma, class II MHC molecules on CD1+ antigen-presenting cells are upregulated in involved compared with uninvolved epidermis.
abstract: CD1+ antigen-presenting cells in involved epidermis of patients with cutaneous T-cell lymphoma exhibit and enhanced functional capacity to activate autologous CD4+ T cells compared with CD1+ antigen-presenting cells from uninvolved and normal epidermis. Class II major histocompatibility complex molecules are involved in antigen presentation, and their expression on CD1+ Langerhans cells is known to vary. The expression of all three class II (HLA-DR, -DQ, -DP) molecules was therefore determined on CD1+ epidermal cells from both involved and uninvolved epidermis, using flow cytometry. The involved CD1+ epidermal cells exhibited a 1.5-1.6-fold, statistically significant increase in fluorescence intensity after staining of the class II molecules (HLA-DR, -DQ, -DP) compared with CD1+ epidermal cells from uninvolved epidermis. The autologous CD4+ T cells, activation was almost completely blocked by anti-HLA-DR, and partly by anti-HLA-DQ and anti-HLA-DP. In contrast, an antibody against class I, and an irrelevant control antibody, had no blocking effect. In a pokeweed mitogen assay it was demonstrated that autologous CD4+ T cells, activated by involved epidermal cells, demonstrated suppressor activity rather than helper activity. The suppressor activity was dependent on the presence of HLA-DR-positive epidermal cells. Thus, in cutaneous T-cell lymphoma, class II molecules on the individual CD1+ antigen-presenting cell are upregulated in clinically involved compared with uninvolved epidermis, and these molecules are crucially involved in activation of CD4+ T cells.
authors.affiliation: Finsen Laboratory, Rigshospitalet, Department of Dermatology, Gentofte Hospital, Denmark.
authors.forename: E R
authors.initials: ER
authors.lastname: Hansen
authors.forename: B
authors.initials: B
authors.lastname: Bang
authors.forename: J K
authors.initials: JK
authors.lastname: Larsen
authors.forename: G L
authors.initials: GL
authors.lastname: Vejlsgaard
authors.forename: O
authors.initials: O
authors.lastname: Baadsgaard
mesh_terms: D000938:Antigen-Presenting Cells / Q000276:immunology* / Q000378:metabolism; D015703:Antigens, CD / Q000276:immunology* / Q000378:metabolism; D018949:Antigens, CD1; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D004817:Epidermis / Q000276:immunology; D005434:Flow Cytometry; D006681:HLA-D Antigens / Q000276:immunology* / Q000378:metabolism; D006682:HLA-DP Antigens / Q000276:immunology; D006683:HLA-DQ Antigens / Q000276:immunology; D006684:HLA-DR Antigens / Q000276:immunology; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology; D008213:Lymphocyte Activation; D016410:Lymphoma, T-Cell, Cutaneous / Q000276:immunology*; D012878:Skin Neoplasms / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology; D015854:Up-Regulation
chemical_list: D015703:Antigens, CD; D018949:Antigens, CD1; D006681:HLA-D Antigens; D006682:HLA-DP Antigens; D006683:HLA-DQ Antigens; D006684:HLA-DR Antigens; D007074:Immunoglobulin G