title: Radioresistance of intermediate TCR cells and their localization in the body of mice revealed by irradiation.
abstract: Extrathymic generation of T cells in the liver and in the intestine was recently demonstrated. We investigated herein whether such T cells, especially those in the liver, are present in other organs of mice. This investigation is possible employing our recently introduced method with which even a minor proportion of extrathymic, intermediate TCR cells in organs other than the liver can be identified. Intermediate TCR cells expressed higher levels of IL-2R beta and LFA-1 than bright TCR cells (i.e., T cells of thymic origin) as revealed by two-color staining. Although intermediate TCR cells were present at a small proportion in the spleen and thymus, they predominated in these organs after irradiation (9 Gy) and bone marrow reconstitution, or after low dose irradiation (6 Gy). This was due to that intermediate TCR cells were relatively radioresistant, whereas bright TCR cells were radiosensitive. Microscopic observation and immunochemical staining showed that intermediate TCR cells in the spleen localized in the red pulp and those in the thymus localized in the medulla. These intermediate TCR cells displayed a large light scatter, similar to such cells in the liver. The present results suggest that intermediate TCR cells may proliferate at multiple sites in the body.
authors.affiliation: Department of Immunology, Niigata University School of Medicine, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Kimura
authors.forename: H
authors.initials: H
authors.lastname: Watanabe
authors.forename: K
authors.initials: K
authors.lastname: Ohtsuka
authors.forename: T
authors.initials: T
authors.lastname: Iiai
authors.forename: M
authors.initials: M
authors.lastname: Tsuchida
authors.forename: S
authors.initials: S
authors.lastname: Sato
authors.forename: T
authors.initials: T
authors.lastname: Abo
mesh_terms: D000818:Animals; D016026:Bone Marrow Transplantation; D017252:CD3 Complex / Q000032:analysis; D002454:Cell Differentiation; D005434:Flow Cytometry; D007958:Leukocyte Count; D008099:Liver / Q000473:pathology*; D016169:Lymphocyte Function-Associated Antigen-1 / Q000032:analysis; D051379:Mice / Q000276:immunology*; D008809:Mice, Inbred C3H / Q000276:immunology; D009928:Organ Specificity; D011828:Radiation Chimera; D011833:Radiation Injuries, Experimental / Q000473:pathology*; D011836:Radiation Tolerance; D011948:Receptors, Antigen, T-Cell / Q000032:analysis*; D015375:Receptors, Interleukin-2 / Q000032:analysis; D013047:Specific Pathogen-Free Organisms; D013154:Spleen / Q000473:pathology; D016176:T-Lymphocyte Subsets / Q000166:cytology / Q000528:radiation effects*; D013950:Thymus Gland / Q000473:pathology; D014916:Whole-Body Irradiation
chemical_list: D017252:CD3 Complex; D016169:Lymphocyte Function-Associated Antigen-1; D011948:Receptors, Antigen, T-Cell; D015375:Receptors, Interleukin-2