Age-related propensity to peripheral expansion of Vgamma3+ gammadelta+ T lymphocytes after irradiation and bone marrow transplantation.
The age-related decline in T cell functions is generally considered to be due to changes in the responding alphabeta T cell populations as a result of impairment of T cell differentiation in the thymus. T cells bearing the gammadelta TCR are normally a minor subset of circulating T cells, but often the major T cell type among lymphocytes in epithelial tissues. In this paper we show that gammadelta T cells are expanded in lymph nodes of irradiated mice after syngenic bone marrow transplantation. Interestingly, these gammadelta T cells express mainly the Vgamma3 TCR, which is characteristic of dendritic epithelial T cells that can develop in athymic nude mice and may recognize self antigens. Since the peripheral expansion of Vgamma3 T lymphocytes is closely related to bone marrow age, these observations indicate that the age-related propensity to extrathymic development of Vgamma3+ gammadelta+ T lymphocytes is mainly due to stem cell dysregulation in aging. This phenomenon may contribute to T cell impairment and to the increased natural cytotoxic activity of lymphoid cells in aged mice.
Poccia
F
F
Department of Biology, University of Rome Tor Vergata, Italy.
Cicconi
R
R
Frasca
D
D
Mancini
C
C
Colizzi
V
V
Doria
G
G
D000375:Aging / Q000276:immunology*; D000818:Animals; D016026:Bone Marrow Transplantation / Q000276:immunology*; D007135:Immunoglobulin Variable Region / Q000276:immunology; D008198:Lymph Nodes / Q000166:cytology / Q000528:radiation effects; D008213:Lymphocyte Activation / Q000276:immunology; D051379:Mice; D008819:Mice, Nude; D011828:Radiation Chimera; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology* / Q000528:radiation effects*; D013950:Thymus Gland / Q000166:cytology / Q000276:immunology
D007135:Immunoglobulin Variable Region; D016692:Receptors, Antigen, T-Cell, gamma-delta