title: Autoimmune disease as a consequence of developmental abnormality of a T cell subpopulation.
abstract: Neonatal thymectomy (NTx), especially around day 3 after birth, causes various organ-specific autoimmune diseases in mice. This report shows that: (a) T cells expressing the interleukin 2 receptor alpha chains (CD25) ontogenically begin to appear in the normal periphery immediately after day 3, rapidly increasing within 2 wk to nearly adult levels (approximately 10% of CD3+ cells, especially of CD4+ cells); (b) NTx on day 3 eliminates CD25+ T cells from the periphery for several days; inoculation immediately after NTx of CD25+ splenic T cells from syngeneic non-Tx adult mice prevents autoimmune development, whereas inoculation of CD25- T cells even at a larger dose does not; and furthermore, (c) similar autoimmune diseases can be produced in adult athymic nu/nu mice by inoculating either spleen cell suspensions from 3-d-old euthymic nu/+ mice or CD25+ cell-depleted spleen cell suspensions from older, even 1-yr-old, nu/+ mice. The CD25- populations from neonates or adults are also similar in the profile of cytokine formation. These results, taken together, indicate that one aspect of peripheral self-tolerance is maintained by CD25+ T cells that sustain potentially pathogenic self-reactive T cells in a CD25- dormant state; the thymic production of the former is developmentally programmed to begin on day 3 after birth in mice. Thus, NTx on day 3 can, at least transiently, eliminate/reduce the autoimmune-preventive CD25+ T cells, thereby leading to activation of the self-reactive T cells that have been produced before NTx.
authors: Department of Immunopathology, Tokyo Metropolitan Institute of Geromology, Japan.
authors: M
authors: M
authors: Asano
authors: M
authors: M
authors: Toda
authors: N
authors: N
authors: Sakaguchi
authors: S
authors: S
authors: Sakaguchi
mesh_terms: D000367:Age Factors; D000818:Animals; D001324:Autoantigens / Q000276:immunology; D001327:Autoimmune Diseases / Q000276:immunology*; D001483:Base Sequence; D017637:Clonal Deletion; D017931:DNA Primers / Q000737:chemistry; D005260:Female; D006410:Hematopoiesis; D007108:Immune Tolerance; D007116:Immunization, Passive; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D008969:Molecular Sequence Data; D015375:Receptors, Interleukin-2 / Q000032:analysis; D016176:T-Lymphocyte Subsets / Q000166:cytology*; D013934:Thymectomy; D013950:Thymus Gland / Q000254:growth & development
chemical_list: D001324:Autoantigens; D017931:DNA Primers; D015375:Receptors, Interleukin-2