title: Epidermal cells in activation of suppressor lymphocytes: further characterization.
abstract: Intravenous administration of hapten-coupled, high-density (density greater than 1.077) epidermal cells (HD-EC) to mice results in the appearance of transferable splenic T suppressor (Ts) cells as assayed in adoptive transfer experiments. Depletion of I-A bearing cells from the HD-EC population before hapten coupling prevents these cells from inducing Ts cell formation, whereas depletion of Thy-1-bearing cells from the HD-EC cell preparation has no effect. When HD-EC are adhered to glass for 2 hr, the ability to induce Ts cell formation resides in the adherent population. Exposure of HD-EC to a dose of ultraviolet radiation (UVR) that largely abrogates the ability of hapten-coupled EC to immunize mice for a DTH response does not affect the ability of these cells to activate Ts cells. Treatment of mice with i.p. administration of 20 mg/kg of cyclophosphamide 2 days before EC harvesting abrogates the ability of HD-EC from these mice to induce Ts cell formation. HD-EC from B10.A(3R) (I-Jb) but not B10.A(5R) (I-Jk) mice induce Ts cell formation in B10.A(3R) mice, demonstrating that the ability to do so is restricted by the I-J locus. Transmission electron microscopy of adherent HD-EC populations demonstrated that two cell types were present. One type had the characteristics of keratinocytes; the other was monocyte-like and resembled Langerhans cells or indeterminate cells in many aspects. Immunoelectron microscopy revealed this second cell type to bear I-A/I-E antigen. These cells were T-200 positive and Mac-1 negative by immunoperoxidase staining. Extensive examination by light and electron microscopy failed to reveal any dermal components in the EC populations; however, a very small degree of dermal contamination cannot be excluded. Thus, EC that activate afferent-acting Ts cells are high-density, I-A+, Thy-1-, I-J restricted, glass adherent, and functionally UVR resistant and cyclophosphamide sensitive.
mesh_terms: D000818:Animals; D000954:Antigens, Surface / Q000276:immunology; D003520:Cyclophosphamide / Q000494:pharmacology; D000078404:Epidermal Cells; D004817:Epidermis / Q000276:immunology*; D005260:Female; D006241:Haptens / Q000008:administration & dosage; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D007108:Immune Tolerance / Q000187:drug effects / Q000528:radiation effects; D007116:Immunization, Passive; D008213:Lymphocyte Activation; D051379:Mice; D008805:Mice, Inbred A / Q000276:immunology; D008807:Mice, Inbred BALB C / Q000276:immunology; D008815:Mice, Inbred Strains / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*; D018800:Thy-1 Antigens; D014466:Ultraviolet Rays
chemical_list: D000954:Antigens, Surface; D006241:Haptens; D000949:Histocompatibility Antigens Class II; C043911:I-J-antigen; D018800:Thy-1 Antigens; D003520:Cyclophosphamide