title: Ultraviolet irradiation inhibits killer-target cell interaction.
abstract: The effects of ultraviolet (UV) irradiation on cell-mediated cytolysis were examined in order to clarify the inhibitory mechanisms of allosensitization by UV irradiation. UV-B-irradiated target cells (Sa; an Epstein-Barr virus-transformed B cell line) exhibited more resistance against alloreactive cytotoxic T lymphocytes (CTL) than mitomycin C (MMC)-treated target cells. In the conjugate formation assay, UV-B-irradiated target cells showed a considerably lower binding to alloreactive CTL than MMC-treated target cells. UV-B irradiation induced a reduction of HLA-class I, -DR, CD54 (ICAM-1) and CD58 (LFA-3) expression on target cells. However, it does not seem to contribute to the inhibition of cell adhesion induced by UV-B irradiation because a similar reduction of cell surface antigens was observed in MMC-treated target cells. Number of cells capped with anti-HLA-class I, -DR, CD54 or CD58 monoclonal antibody were markedly reduced by UV-B irradiation compared to that by MMC treatment. These findings suggest the possibility that the inhibition of cell adhesion between UV-B-irradiated Sa target cells and alloreactive CTL is due to the impaired mobility of cell surface antigens which will affect the early process of cell-mediated cytolysis.
authors.affiliation: Hokkaido Red Cross Blood Center, Sapporo, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Kobata
authors.forename: H
authors.initials: H
authors.lastname: Ikeda
authors.forename: Y
authors.initials: Y
authors.lastname: Ohnishi
authors.forename: N
authors.initials: N
authors.lastname: Urushibara
authors.forename: S O
authors.initials: SO
authors.lastname: Nakata
authors.forename: T A
authors.initials: TA
authors.lastname: Takahashi
authors.forename: S
authors.initials: S
authors.lastname: Sekiguchi
mesh_terms: D002450:Cell Communication / Q000528:radiation effects; D006801:Humans; D007519:Isoantigens / Q000528:radiation effects*; D008024:Ligands; D013602:T-Lymphocytes, Cytotoxic / Q000166:cytology / Q000528:radiation effects*; D014466:Ultraviolet Rays
chemical_list: D007519:Isoantigens; D008024:Ligands