Expression of T cell antigen receptor genes in the thymus of irradiated mice after bone marrow transplantation.
Sequential appearance of the expression of T cell antigen receptor genes was investigated in the thymus of irradiated mice at the early stage after transplantation of Thy-1 congeneic H-2 compatible allogeneic bone marrow cells. The first cells to repopulate the thymus on day 7 after bone marrow transplantation were intrathymic radioresistant T cell precursors, which expanded mainly to CD4+CD8+ host-type thymocytes by day 14. A high level of gamma gene expression but a much reduced level of alpha and beta gene expression were detected in the host-type thymocytes on day 7. During regeneration of these cells, gamma-chain messages fell to low level and alpha and beta mRNA levels increased. The thymus of the recipients began to be repopulated by donor-derived T cells about 2 wk after bone marrow transplantation and was almost completely replaced by the third week. An ordered expression of gamma then beta and alpha-chain gene transcript was also observed in the donor-type thymocytes at the early stage after bone marrow transplantation. The use of thymocytes at early stage in whole-body irradiated bone marrow chimera provides a pertinent source for investigating the molecular mechanism of T cell differentiation in adult thymus.
Matsuzaki
G
G
Department of Immunology, Kyushu University, Fukuoka, Japan.
Yoshikai
Y
Y
Kishihara
K
K
Nomoto
K
K
D000818:Animals; D016026:Bone Marrow Transplantation; D005786:Gene Expression Regulation / Q000528:radiation effects*; D051379:Mice; D008806:Mice, Inbred AKR; D008808:Mice, Inbred CBA; D012333:RNA, Messenger / Q000378:metabolism; D011828:Radiation Chimera; D011948:Receptors, Antigen, T-Cell / Q000235:genetics*; D013154:Spleen / Q000378:metabolism; D013601:T-Lymphocytes / Q000378:metabolism; D013950:Thymus Gland / Q000378:metabolism*; D014916:Whole-Body Irradiation
D012333:RNA, Messenger; D011948:Receptors, Antigen, T-Cell