title: Accessory cell-dependent selection of specific T-cell functions.
abstract: Activation of many T-cell functions depends on their interaction with antigen-presenting accessory cells which express I region associated (Ia) products. Cells expressing accessory cell function include those of the monocyte/macrophage lineage and dendritic cells. More recently, B cells and a number of tumour cell lines of macrophage or B-cell origin were shown to act as accessory cells in certain assays. We showed previously that normal peritoneal exudate macrophages (PEC) induced both T-cell proliferation as well as T-cell help, whereas various Ia+ tumour lines of macrophage or B-cell origin, although stimulating antigen-specific T-cell proliferation, did not significantly activate T-cell help. We report here that during the initial T-cell activation in vitro accessory cells (PEC or Ia+ tumour cells) select particular T cells to express previously determined functions. Moreover, some tumour cell lines induce suppressor T cells which inhibit helper activity.
mesh_terms: D000818:Animals; D000941:Antigens; D002460:Cell Line; D002478:Cells, Cultured; D006433:Hemocyanins; D008213:Lymphocyte Activation; D051379:Mice; D008808:Mice, Inbred CBA; D013601:T-Lymphocytes / Q000276:immunology*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology
chemical_list: D000941:Antigens; D006433:Hemocyanins; C032808:keyhole-limpet hemocyanin