title: Distinct mechanisms of neonatal tolerance induced by dendritic cells and thymic B cells.
abstract: To assess the role of different types of antigen-presenting cells (APC) in the induction of tolerance, we isolated B cells, macrophages, and dendritic cells from thymus and spleen, and injected these into neonatal BALB/c mice across an Mls-1 antigenic barrier. One week after injection of APC from Mls-1-incompatible mice or from control syngeneic mice, we measured the number of thymic, Mls-1a-reactive, V beta 6+ T cells and the capacity of thymocytes to induce a graft-vs.-host (GVH) reaction in popliteal lymph nodes of Mls-1a mice. Injection of thymic but not spleen B cells deleted thymic, Mls-1a-reactive V beta 6+ T cells and induced tolerance in the GVH assay. The thymic B cells were primarily of the CD5+ type, and fluorescence-activated cell sorter-purified CD5+ thymic B cells were active. Injection of dendritic cells from spleen or thymus also induced tolerance, but the V beta 6 cells were anergized rather than deleted. Macrophages from thymus did not induce tolerance. Dendritic cells and thymic B cells were also effective in inducing tolerance even when injected into Mls-, major histocompatibility complex-incompatible, I-E- mice, but only thymic B cells depleted V beta 6-expressing T cells. Therefore, different types of bone marrow-derived APC have different capacities for inducing tolerance, and the active cell types (dendritic cells and CD5+ thymic B cells) can act by distinct mechanisms.
authors.affiliation: Department of Pathology, Kansai Medical University, Osaka, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Inaba
authors.forename: K
authors.initials: K
authors.lastname: Inaba
authors.forename: M
authors.initials: M
authors.lastname: Hosono
authors.forename: T
authors.initials: T
authors.lastname: Kumamoto
authors.forename: T
authors.initials: T
authors.lastname: Ishida
authors.forename: S
authors.initials: S
authors.lastname: Muramatsu
authors.forename: T
authors.initials: T
authors.lastname: Masuda
authors.forename: S
authors.initials: S
authors.lastname: Ikehara
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D000911:Antibodies, Monoclonal; D000954:Antigens, Surface / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology*; D003713:Dendritic Cells / Q000276:immunology*; D007108:Immune Tolerance; D008213:Lymphocyte Activation; D008285:Major Histocompatibility Complex; D008562:Membrane Glycoproteins / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D008815:Mice, Inbred Strains; D016747:Minor Lymphocyte Stimulatory Antigens; D013601:T-Lymphocytes / Q000276:immunology; D013950:Thymus Gland / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D008562:Membrane Glycoproteins; D016747:Minor Lymphocyte Stimulatory Antigens