title: UVB-irradiated dendritic cells are impaired in their APC function and tolerize primed Th1 cells but not naive CD4+ T cells.
abstract: We have shown that low-dose UVB radiation converts Langerhans cells (LC) from immunogenic to tolerogenic APC. Therefore, we questioned whether low-dose UVB irradiation of bone marrow-derived dendritic cells (DC) alters their APC function, thereby inducing tolerance in T cells. To address this issue, cocultures of DC; and naive, allogeneic T cells; naïve, OVA-specific TCR-transgenic T cells from DO11.10 mice; or primed, antigen-specific T cells using the Th1 clone AE7 were analyzed. First, we found low-dose UVB-irradiated DC (UVB-DC) to dose-dependently (50-200 J/m2) inhibit T-cell proliferation of naive and primed T cells. In addition, supernatants harvested from cocultures of UVB-DC and naive T cells showed markedly reduced levels of IL-2 and IFN-gamma and to a lesser degree of IL-4 and IL-10, suggesting a preferential down-regulation of Th1 responses by UVB-DC. FACS analysis of UVB-DC revealed no changes in surface expression of MHC, costimulatory, and adhesion molecules. To test tolerance induction, allo- or antigen-specific T cells isolated from cocultures with unirradiated DC and UVB-DC were restimulated with unirradiated DC or IL-2. It is interesting that UVB-DC induced antigen-specific tolerance in the Th1 clone AE7. In contrast, UVB-DC induced a partial inhibition of allogeneic T-cell proliferation but no tolerance with similar unresponsiveness to restimulation with IL-2 and unirradiated DC irrespective of their haplotype. Similar observations were made when naive, TCR-transgenic T cells from DO11.10 mice were used. In conclusion, UVB-DC are impaired in their APC function and tolerize the primed antigen-specific Th1 clone AE7 but not naive allo- or OVA-specific T cells.
authors: Department of Dermatology, Albert-Ludwigs-Universität, Freiburg, Germany. denfeld@haut.ukl.uni-freiburg.de
authors: R W
authors: RW
authors: Denfeld
authors: H
authors: H
authors: Hara
authors: J P
authors: JP
authors: Tesmann
authors: S
authors: S
authors: Martin
authors: J C
authors: JC
authors: Simon
mesh_terms: D000818:Animals; D017951:Antigen Presentation / Q000528:radiation effects*; D015703:Antigens, CD / Q000096:biosynthesis; D018122:B7-1 Antigen / Q000096:biosynthesis; D051940:B7-2 Antigen; D001854:Bone Marrow Cells / Q000528:radiation effects; D018106:CD28 Antigens / Q000096:biosynthesis; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D015815:Cell Adhesion Molecules / Q000096:biosynthesis; D017635:Clonal Anergy; D018920:Coculture Techniques; D003713:Dendritic Cells / Q000187:drug effects / Q000276:immunology / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D005260:Female; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D000949:Histocompatibility Antigens Class II / Q000096:biosynthesis; D015847:Interleukin-4 / Q000494:pharmacology; D007801:Langerhans Cells / Q000528:radiation effects; D008562:Membrane Glycoproteins / Q000096:biosynthesis; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D010047:Ovalbumin / Q000276:immunology; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000235:genetics; D018417:Th1 Cells / Q000276:immunology*; D014466:Ultraviolet Rays / Q000009:adverse effects*
chemical_list: D015703:Antigens, CD; D018122:B7-1 Antigen; D051940:B7-2 Antigen; D018106:CD28 Antigens; C497965:Cd86 protein, mouse; D015815:Cell Adhesion Molecules; D000949:Histocompatibility Antigens Class II; D008562:Membrane Glycoproteins; D016693:Receptors, Antigen, T-Cell, alpha-beta; D015847:Interleukin-4; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D010047:Ovalbumin