title: The development of NK cell activity in thymectomized bone marrow chimaeras.
abstract: Most of the natural killer (NK) cells, recently derived from the bone marrow (14 days after injection of bone marrow cells into lethally irradiated mice), express the Thy-1 antigen; after some period of time (by day 28) a normal proportion (50%) of Thy-1+ NK cells is found. This study demonstrates that the shift of these Thy-1+ NK cells to Thy-1- NK cells is influenced by the thymus: NK cells developing in the total absence of the thymus--bone marrow (bm) cells from adult thymectomized (Tx) or nude (nu) mice injected into thymectomized recipients, (Tx) bm----(Tx) or nu bm----(Tx)--remain Thy-1+, while the presence of the thymus at some stage of the NK cell maturation--bone marrow cells injected into thymectomized recipients, bm----(Tx), or normal recipients reconstituted with bone marrow cells from thymectomized or nude mice, (Tx) bm----or nu bm----normal recipients--is sufficient for the development of normal ratio of Thy-1+ and Thy-1- NK cells.
mesh_terms: D000818:Animals; D000954:Antigens, Surface / Q000032:analysis; D001853:Bone Marrow / Q000276:immunology*; D016026:Bone Marrow Transplantation; D003602:Cytotoxicity, Immunologic; D007694:Killer Cells, Natural / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D011828:Radiation Chimera; D013154:Spleen / Q000276:immunology; D018800:Thy-1 Antigens; D013934:Thymectomy; D013950:Thymus Gland / Q000276:immunology*
chemical_list: D000954:Antigens, Surface; D018800:Thy-1 Antigens