title: High-dose UV-B radiation alters human dendritic cell costimulatory activity but does not allow dendritic cells to tolerize T lymphocytes to alloantigen in vitro.
abstract: Human blood dendritic cells require UV-B radiation (290 to 320 nm) in excess of 1,000 J/m2 to inhibit their stimulation of primary T-cell responses to alloantigen by 60% to 70% or more. The effect is twofold to threefold greater in the allogeneic mixed leukocyte reaction (MLR) than in polyclonal mitogenesis using comparable numbers of dendritic cells and doses of UV-B radiation. UV-B radiation does not significantly alter dendritic cell viability at the doses administered. Dendritic cell expression of important costimulatory ligands, eg, B7/BB1 and ICAM-1/CD54, is reduced in proportion to the dose of UV-B light administered. UV-B irradiated dendritic cells nevertheless initiate stable contacts with primary alloreactive T lymphocytes that are sufficient to prime T-cell responsiveness to interleukin-2 (IL-2). Subsequent proliferation is severely abrogated without supplemental lymphokine, while T-cell alloreactivity is preserved in a secondary response, irrespective of primary exposure to UV-B irradiated dendritic cells.
authors.affiliation: Laboratory of Cellular Physiology and Immunology, Rockefeller University, New York, NY 10021.
authors.forename: J W
authors.initials: JW
authors.lastname: Young
authors.forename: J
authors.initials: J
authors.lastname: Baggers
authors.forename: S A
authors.initials: SA
authors.lastname: Soergel
mesh_terms: D000938:Antigen-Presenting Cells / Q000528:radiation effects*; D000954:Antigens, Surface / Q000378:metabolism; D015815:Cell Adhesion Molecules / Q000378:metabolism; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000528:radiation effects*; D004306:Dose-Response Relationship, Immunologic; D006801:Humans; D007108:Immune Tolerance; D066298:In Vitro Techniques; D018799:Intercellular Adhesion Molecule-1; D007519:Isoantigens / Q000276:immunology; D008213:Lymphocyte Activation; D007959:Lymphocyte Culture Test, Mixed; D015375:Receptors, Interleukin-2 / Q000378:metabolism; D013601:T-Lymphocytes / Q000276:immunology*; D014466:Ultraviolet Rays
chemical_list: D000954:Antigens, Surface; D015815:Cell Adhesion Molecules; D007519:Isoantigens; D015375:Receptors, Interleukin-2; D018799:Intercellular Adhesion Molecule-1