title: Expression of the CD1a molecule in B- and T-lymphoproliferative skin conditions.
abstract: The skin immune system is characterized by the presence of two types of CD1a expressing cells: langerhans cells and dermal dendritic cells, which are professional antigen processing and presenting cells. It is well established that several dermatoses are associated with T-cell mediated immune responses. In these pathological skin conditions, T-cells are activated by professional antigen presenting cells and dendritic cells are the most potent antigen presenting cells for both T-helper cells and T-cytotoxic cells. Therefore, it is plausible that dendritic cells are crucially involved in the pathogenesis of lymphoproliferative skin conditions characterized by the presence of a T-cell infiltrate. In this study, we examined the frequency and distribution of CD1a expressing cells and CD3+ cells in both the dermal and epidermal compartment in a wide range of lymphoproliferative dermatoses with a T-lymphoid infiltrate. In the skin conditions investigated, the CD1a molecule was highly expressed in mycosis fungoides, T-cutaneous lymphoid hyperplasia, lymphomatoid papulosis and parapsoriasis, whereas few CD1a-positive cells were observed in cutaneous B-cell lymphomas. Our study demonstrates a distinct pattern of CD1a staining in the infiltrates of cutaneous lympho-proliferative disorders which may reflect different immunoregulatory events involving T-lymphocytes and CD1a-positive dermal and epidermal dendritic cells.
authors.affiliation: Unit of Dermatology, University of Padua, Via C. Battisti 206, I-35128 Padova, Italy.
authors.forename: Barbara
authors.initials: B
authors.lastname: Pigozzi
authors.forename: Matteo
authors.initials: M
authors.lastname: Bordignon
authors.forename: Anna
authors.initials: A
authors.lastname: Belloni Fortina
authors.forename: Giorgio
authors.initials: G
authors.lastname: Michelotto
authors.forename: Mauro
authors.initials: M
authors.lastname: Alaibac
mesh_terms: D018949:Antigens, CD1 / Q000276:immunology / Q000378:metabolism; D014408:Biomarkers, Tumor / Q000032:analysis; D017252:CD3 Complex / Q000276:immunology / Q000378:metabolism; D003713:Dendritic Cells / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D016393:Lymphoma, B-Cell / Q000276:immunology / Q000378:metabolism*; D016410:Lymphoma, T-Cell, Cutaneous / Q000276:immunology / Q000378:metabolism*; D012871:Skin Diseases / Q000276:immunology / Q000378:metabolism; D012878:Skin Neoplasms / Q000276:immunology / Q000378:metabolism*
chemical_list: D018949:Antigens, CD1; D014408:Biomarkers, Tumor; C419393:CD1a antigen; D017252:CD3 Complex