Influence of age on the proliferation and peripheralization of thymic T cells

Journal Article · Fri Jan 01 04:00:00 EST 1988 · Arch. Pathol.; (United States)

OSTI ID:5407235

Hirokawa, K; Utsuyama, M; Katsura, Y; Sado, T

Bone marrow cells obtained from B10.Thy-1.1 mice (H-2b, Thy-1.1) were injected directly into the thymus of C57BL/6 mice (H-2b,Thy 1.2) of various ages. Thymocyte precursors in the injected donor-bone marrow cells could proliferate in the thymic microenvironment in the following manner: first, preferentially proliferating into the subcapsular cortex; and second, spreading to the whole layer of the cortex, a portion of them gradually moving into the medulla. The proliferation of donor-type thymocytes was most pronounced when intrathymic injection of bone marrow cells (ITB) was performed in newborn mice and especially prominent in week-old mice; it took approximately ten weeks for donor-type thymocytes to finish the whole course of proliferation, differentiation, and emigration to the periphery. When ITB was performed in mice 4 weeks of age and older, the proliferation of donor-type thymocytes was retarded at onset, less pronounced in magnitude, and disappeared earlier. Emigration of donor-type T cells from the thymus to the peripheral lymphoid tissues occurred most rapidly when ITB was performed in newborn mice, and these T cells continued to reside thereafter in the peripheral lymphoid tissues. However, when ITB was performed in mice 4 weeks of age and older, the number of emigrated T cells in the spleen decreased (about a tenth of that in newborn mice) and, moreover, these T cells resided only transiently in the spleen. It was suggested that T cells emigrating from the thymus of mice from newborn to 2 weeks of age are long-lived, whereas those from the thymus in mice 4 weeks of age and older are short-lived. However, when 4-week-old young adult mice were treated by irradiation or hydrocortisone, the thymic capacity was enhanced in terms of proliferation and peripheralization of thymocytes, and emigrated T cells became long-lived.

• Research Organization: Tokyo Metropolitan Institute of Gerontology, Japan
• OSTI ID: 5407235
• Journal Information: Arch. Pathol.; (United States), Journal Name: Arch. Pathol.; (United States) Vol. 112:1; ISSN ARPAA
• Country of Publication: United States
• Language: English

Related Subjects

560152* -- Radiation Effects on Animals-- Animals
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AGE DEPENDENCE
ANIMAL CELLS
ANIMALS
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
BODY
BONE MARROW CELLS
CELL PROLIFERATION
CONNECTIVE TISSUE CELLS
LYMPHATIC SYSTEM
MAMMALS
MICE
NEONATES
ORGANS
RADIATION EFFECTS
RODENTS
SOMATIC CELLS
THYMOCYTES
THYMUS
VERTEBRATES