title: Accessory and alloantigen-presenting cell functions of A431 keratinocytes that stably express the B7 antigen.
abstract: Because keratinocytes are tolerogenic antigen-presenting cells (APC), we investigated the role of B7/BB-1 in reconstituting defective accessory cell (AC) and APC functions by such nonlymphoid cells. KC were induced to stably express B7/BB-1 by DNA-mediated gene transfection. This single-transformed B7/BB-1+ A431 cell line (but not control A431) functioned as AC for lectin-induced T-cell proliferation, as well as oxidative mitogenesis. This costimulation was dependent on B7/BB-1 expression since the monoclonal antibody BB-1 blocked costimulation of PHA mitogenesis by 75%. After the induction of class II MHC antigen expression by interferon-gamma, B7/BB-1+ KC but not control KC presented alloantigens to resting T-cells in the primary mixed lymphocyte reaction. These data indicate that the stable expression of B7/BB-1 antigen by KC reconstitutes defective AC and alloantigen-presenting activity. The lack of expression of such second signal by normal KC may be responsible for their ability to induce clonal anergy in vitro and in vivo.
authors.affiliation: Department of Dermatology, University of Rochester School of Medicine and Dentistry, New York 14627.
authors.forename: A A
authors.initials: AA
authors.lastname: Gaspari
authors.forename: B
authors.initials: B
authors.lastname: Ferbel
authors.forename: Z
authors.initials: Z
authors.lastname: Chen
authors.forename: F
authors.initials: F
authors.lastname: Razvi
authors.forename: R
authors.initials: R
authors.lastname: Polakowska
mesh_terms: D000938:Antigen-Presenting Cells / Q000276:immunology*; D000954:Antigens, Surface / Q000276:immunology*; D018122:B7-1 Antigen; D001483:Base Sequence; D002460:Cell Line / Q000276:immunology; D006801:Humans; D007108:Immune Tolerance; D007519:Isoantigens / Q000276:immunology*; D015603:Keratinocytes / Q000276:immunology*; D008969:Molecular Sequence Data
chemical_list: D000954:Antigens, Surface; D018122:B7-1 Antigen; D007519:Isoantigens