title: Characterization of NK cells and extrathymic T cells generated in the liver of irradiated mice with a liver shield.
abstract: We previously reported that c-kit+ stem cells which give rise to extrathymic T cells are present in the liver of adult mice. Further characterization of extrathymic T cells in the liver of adult mice is conducted here. When mice with a liver shield were lethally (9.5 Gy) irradiated, all mice survived. All tested organs showed a distribution pattern of hepatic lymphocytes on day 7. The distribution pattern in the liver was characterized by an abundance of NK (CD3- IL-2Rbeta+) and extrathymic T cells (CD3int IL-2Rbeta+) before and after irradiation. To determine their function, post-irradiation allogeneic bone marrow transplantation (BMT) was performed in mice with or without a liver shield. Allogeneic BM cells were rejected in mice with a liver shield and specific activation of CD8+ CD3int IL-2Rbeta+ cells was induced. At that time, potent cytotoxicity of liver mononuclear cells (MNC) against allogeneic thymocytes was induced. Both NK1.1+ and NK1.1- subsets of CD3int cells expanded in these mice. An in vivo elimination experiment of the subsets indicated that the NK1.1+ subset of CD3int cells (i.e. NK T cells) was much more associated with the rejection of allogeneic BM cells. However, even after the elimination of NK T cells, allogeneic BM cells were rejected. In this case, granulocytes expanded in parallel with NK1.1- subsets. Granulocytes may also be associated with the rejection of allogeneic BM cells. These results suggest that the liver is an important haematopoietic organ even in adult life.
authors.affiliation: Department of Immunology, Niigata University School of Medicine, Niigata, Japan.
authors.forename: R C
authors.initials: RC
authors.lastname: Halder
authors.forename: S
authors.initials: S
authors.lastname: Seki
authors.forename: A
authors.initials: A
authors.lastname: Weerasinghe
authors.forename: T
authors.initials: T
authors.lastname: Kawamura
authors.forename: H
authors.initials: H
authors.lastname: Watanabe
authors.forename: T
authors.initials: T
authors.lastname: Abo
mesh_terms: D000818:Animals; D000941:Antigens / Q000032:analysis; D000950:Antigens, Ly; D000954:Antigens, Surface; D001854:Bone Marrow Cells; D017252:CD3 Complex / Q000032:analysis; D003602:Cytotoxicity, Immunologic; D005720:Gamma Rays; D006098:Granulocytes; D007694:Killer Cells, Natural / Q000276:immunology*; D037181:Lectins, C-Type; D008099:Liver / Q000166:cytology* / Q000528:radiation effects; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D055651:NK Cell Lectin-Like Receptor Subfamily B; D011506:Proteins / Q000032:analysis; D013154:Spleen / Q000166:cytology; D013601:T-Lymphocytes / Q000276:immunology*; D013950:Thymus Gland; D014916:Whole-Body Irradiation
chemical_list: D000941:Antigens; D000950:Antigens, Ly; D000954:Antigens, Surface; D017252:CD3 Complex; C527211:Klrb1c protein, mouse; D037181:Lectins, C-Type; D055651:NK Cell Lectin-Like Receptor Subfamily B; D011506:Proteins