title: T cells affect thymic involution during puberty by inducing regression of the adrenal reticularis.
abstract: The thymus involutes after puberty, although the mechanism by which this process occurs remains poorly understood. The profile of thymic involution, which is inversely correlated with an increase in peripheral T cells, may indicate that the accumulation of T cells in the periphery is related to thymic atrophy. In this study, it was shown that the prevention of T cell generation delayed the initiation of thymic involution. The activation of T cells increased the serum concentration of glucocorticoid (GC) and thymic involution, which was completely prevented by adrenalectomy. In the adrenals of growing mice, the activity of the zona fasciculata, which produces GC, increased and plateaued by the weaning period; however, the zona reticularis (ZR), which produces dehydroepiandrosterone (DHEA) that has anti-GC actions, started to decline just before puberty. Thymic atrophy was preceded by the infiltration of activated T cells into the ZR and by the loss of ZR cells. Thus, T cells are involved in thymic involution, a process which was retarded by DHEA administration, through an increase in GC activity due to ZR cell-killing.
authors.affiliation: Laboratory of Immunobiology, Department of Life Science, Graduate School of Science and Technology, Niigata University, 8050 Ikarashi 2-no-cho, Niigata 950-2181, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Kushida
authors.forename: Sayaka
authors.initials: S
authors.lastname: Kumagai
authors.forename: Ken
authors.initials: K
authors.lastname: Gotoh
authors.forename: Masato
authors.initials: M
authors.lastname: Fujii
authors.forename: Maki
authors.initials: M
authors.lastname: Touma
authors.forename: Masamichi
authors.initials: M
authors.lastname: Hosono
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D001284:Atrophy; D017252:CD3 Complex / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000502:physiology; D003687:Dehydroepiandrosterone / Q000502:physiology; D005938:Glucocorticoids / Q000502:physiology; D051379:Mice; D008807:Mice, Inbred BALB C; D011627:Puberty / Q000502:physiology*; D013601:T-Lymphocytes / Q000502:physiology*; D013950:Thymus Gland / Q000473:pathology* / Q000502:physiology; D015385:Zona Reticularis / Q000473:pathology / Q000502:physiology*
chemical_list: D000911:Antibodies, Monoclonal; D017252:CD3 Complex; D005938:Glucocorticoids; D003687:Dehydroepiandrosterone