title: Generation of NK1.1+ T cell antigen receptor alpha/beta+ thymocytes associated with intact thymic structure.
abstract: The development of T cells within the thymus is largely dependent on intact cortical and medullary epithelial cells. However, it has been reported that positive selection of natural killer antigen 1.1+ (NK1.1+) T cell antigen receptor (TCR)-alpha/beta+ thymocytes recently identified among CD4+8- and CD4-8- subpopulations is attributable to major histocompatibility complex class Ib ligands expressed on bone marrow (BM)-derived components in the thymus. In the present study, we investigated generation of NK1.1+ TCR-alpha/beta+ cells in the thymus of the aly/aly mouse which lacks lymph nodes and Peyer's patches and shows abnormalities of thymic and splenic structure. We found that the proportion of the NK1.1+ TCR-alpha/beta+ thymocytes was extremely low in these mice as compared with aly/+ and normal C57BL/6 mice. Thymic reconstitution by BM cells from aly/+ mice that possess a normal population of NK1.1+ TCR-alpha/beta+ cell population did not restore the NK1.1+ TCR-alpha/beta+ cell population in the thymus of lethally irradiated aly/aly mouse. When deoxyguanosine-treated fetal thymi from (B6 x B10.G)F1 mice were transplanted to aly/aly mice that had been thymectomized and reconstituted with BM cells of aly/aly mice, normal proportions of the NK1.1+ TCR-alpha/beta+ thymocytes were present in the thymus grafts. These findings demonstrate that the development of NK1.1+ TCR-alpha/beta+ thymocytes is accomplished under the influence not only of BM-derived components, but also of irradiation-resistant or deoxyguanosine-resistant components and an intact microenvironment of the thymus.
authors.affiliation: Section of Pathology, Institute of Immunological Science, Hokkaido University, Sapporo, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Nakagawa
authors.forename: K
authors.initials: K
authors.lastname: Iwabuchi
authors.forename: K
authors.initials: K
authors.lastname: Ogasawara
authors.forename: M
authors.initials: M
authors.lastname: Ato
authors.forename: M
authors.initials: M
authors.lastname: Kajiwara
authors.forename: H
authors.initials: H
authors.lastname: Nishihori
authors.forename: C
authors.initials: C
authors.lastname: Iwabuchi
authors.forename: H
authors.initials: H
authors.lastname: Ishikura
authors.forename: R A
authors.initials: RA
authors.lastname: Good
authors.forename: K
authors.initials: K
authors.lastname: Onoé
mesh_terms: D000818:Animals; D016026:Bone Marrow Transplantation / Q000276:immunology*; D002478:Cells, Cultured; D002678:Chimera; D003433:Crosses, Genetic; D005434:Flow Cytometry; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D007376:Interleukin-2 / Q000494:pharmacology; D008214:Lymphocytes / Q000187:drug effects; D051379:Mice; D008810:Mice, Inbred C57BL; D008815:Mice, Inbred Strains; D008817:Mice, Mutant Strains; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000276:immunology*; D011994:Recombinant Proteins / Q000494:pharmacology; D013154:Spleen / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000276:immunology* / Q000528:radiation effects; D013934:Thymectomy; D013950:Thymus Gland / Q000276:immunology* / Q000528:radiation effects; D014184:Transplantation, Homologous
chemical_list: D007376:Interleukin-2; D016693:Receptors, Antigen, T-Cell, alpha-beta; D011994:Recombinant Proteins