title: Preferential contribution of B7-H1 to programmed death-1-mediated regulation of hapten-specific allergic inflammatory responses.
abstract: Programmed death-1 (PD-1) and its ligands, B7-H1/PD-L1 and B7-DC/PD-L2, are new CD28-B7 family members that may be involved in the regulation of immune responses. We examined the roles of these molecules in mouse hapten-induced contact hypersensitivity (CH). Administration of anti-PD-1 mAb at sensitization significantly enhanced and prolonged ear swelling. Treatment with anti-B7-H1 mAb, but not anti-B7-DC mAb, also enhanced CH reactions. The anti-PD-1 mAb treatment at sensitization significantly increased the T cell number of draining lymph nodes (DLN). B7-H1 was induced on activated T cells and antigen-presenting cells (APC) in the skin and the DLN, whereas B7-DC expression was restricted to dendritic cells (DC) in the dermis and the DLN. A particular subset of DC, B7-H1(+)B7-DC(-)CD86(low), was found in sensitized DLN. The blockade of B7-H1, but not B7-DC, dramatically enhanced the initial T cell proliferative responses against hapten-pulsed DLN APC, suggesting the preferential contribution of B7-H1 to the T cell-APC interaction. Our results demonstrate the regulatory role of PD-1 and the differential roles of B7-H1 and B7-DC in hapten-induced immune responses. The PD-1-B7-H1 pathway may play a unique role in regulating inflammatory responses.
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000938:Antigen-Presenting Cells / Q000737:chemistry / Q000502:physiology; D015703:Antigens, CD; D000943:Antigens, Differentiation / Q000502:physiology; D000954:Antigens, Surface; D051017:Apoptosis Regulatory Proteins; D018122:B7-1 Antigen / Q000032:analysis / Q000502:physiology*; D060890:B7-H1 Antigen; D001798:Blood Proteins; D060908:CTLA-4 Antigen; D003877:Dermatitis, Contact / Q000209:etiology*; D005260:Female; D006241:Haptens / Q000276:immunology; D008562:Membrane Glycoproteins; D051379:Mice; D008807:Mice, Inbred BALB C; D010455:Peptides; D061027:Programmed Cell Death 1 Ligand 2 Protein; D061026:Programmed Cell Death 1 Receptor; D011506:Proteins / Q000502:physiology*
chemical_list: D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D000943:Antigens, Differentiation; D000954:Antigens, Surface; D051017:Apoptosis Regulatory Proteins; D018122:B7-1 Antigen; D060890:B7-H1 Antigen; D001798:Blood Proteins; D060908:CTLA-4 Antigen; C498919:Cd274 protein, mouse; C556707:Ctla4 protein, mouse; D006241:Haptens; D008562:Membrane Glycoproteins; C491383:Pdcd1 protein, mouse; C556978:Pdcd1lg2 protein, mouse; D010455:Peptides; D061027:Programmed Cell Death 1 Ligand 2 Protein; D061026:Programmed Cell Death 1 Receptor; D011506:Proteins