title: In situ expression of a B7-like adhesion molecule on keratinocytes from human epidermis.
abstract: The B7 adhesion molecule, a member of the immunoglobulin superfamily, has previously been identified primarily on cells of hematopoietic origin. Because B7 has been shown to facilitate interactions with T cells and because cells of the epidermis are proficient at binding and activating T lymphocytes, studies were performed to determine whether B7 was expressed in human epidermis. A subpopulation of brightly staining B7-positive cells was observed in situ in normal human epidermis. Flow-cytometric examination of epidermal cell suspensions that had been cultured for 24 h or longer demonstrated that between 10 and 40% of cells expressed B7 or a closely related antigen. Immunoelectron microscopy, double-staining procedures, and examination of epidermal suspensions depleted of Langerhans cells all confirmed that the B7-positive cells were keratinocytes. These studies identify human epidermal keratinocytes, a non-hematopoietic cell population, as a cell type capable of expressing a B7-like adhesion molecule.
authors.affiliation: Department of Dermatology, Case Western Reserve University, Cleveland, Ohio.
authors.forename: T E
authors.initials: TE
authors.lastname: Fleming
authors.forename: W S
authors.initials: WS
authors.lastname: Mirando
authors.forename: U
authors.initials: U
authors.lastname: Trefzer
authors.forename: K A
authors.initials: KA
authors.lastname: Tubesing
authors.forename: C A
authors.initials: CA
authors.lastname: Elmets
mesh_terms: D000818:Animals; D018122:B7-1 Antigen / Q000032:analysis* / Q000502:physiology; D015815:Cell Adhesion Molecules / Q000032:analysis*; D000078404:Epidermal Cells; D006684:HLA-DR Antigens / Q000032:analysis; D006801:Humans; D015603:Keratinocytes / Q000737:chemistry*; D051379:Mice; D016253:Microscopy, Immunoelectron; D013535:Suspensions
chemical_list: D018122:B7-1 Antigen; D015815:Cell Adhesion Molecules; D006684:HLA-DR Antigens; D013535:Suspensions