Sequential analysis of distributions of donor-derived thymocytes bearing T-cell antigen receptor (TCR) and donor-derived Ia+ cells in thymuses of fully allogeneic bone marrow chimera in mice.
Lethally irradiated SJL/J mice were reconstituted with B10 bone marrow cells, and the process of thymic reconstitution by donor-derived cells positive for I-A or V beta 8 molecules was investigated. The donor-derived Ia+ cells appeared in the medulla on day 7 after reconstitution. The Ia+ cells became confluent up to day 14, and the cellularity in the medulla on day 17 was almost the same as that in the normal thymus. Dull V beta 8+ thymocytes were first recognized in the cortex on day 10 and were identifiable in the medulla by day 14. The V beta 8+ cells seemed to be mainly CD4+8+ double-positive. Furthermore, most of the V beta 8+ cells in the medulla of chimeras given cyclosporin A for 3 weeks after reconstitution appeared to be CD4+8+ thymocytes which bear a low concentration of TCR exist in the thymic medulla at a relatively early stage when donor-derived Ia+ cells have already settled there. The coincidental appearance and coexistence of Ia+ cells and TCR+ thymocytes in the medulla suggest that these histological characteristics may be related to the selection of thymocytes in this area.
Hatakeyama
S
S
Section of Pathology, Hokkaido University, Sapporo, Japan.
Ogasawara
K
K
Fukushi
N
N
Iwabuchi
C
C
Iwabuchi
K
K
Wang
B Y
BY
Kajiwara
M
M
Good
R A
RA
Onoé
K
K
D000818:Animals; D000943:Antigens, Differentiation / Q000032:analysis; D016026:Bone Marrow Transplantation / Q000276:immunology*; D003524:Cyclosporins / Q000494:pharmacology; D005260:Female; D000949:Histocompatibility Antigens Class II / Q000032:analysis*; D007150:Immunohistochemistry; D051379:Mice; D008810:Mice, Inbred C57BL; D011828:Radiation Chimera / Q000276:immunology*; D011948:Receptors, Antigen, T-Cell / Q000032:analysis*; D013950:Thymus Gland / Q000166:cytology / Q000276:immunology*; D014019:Tissue Donors; D014184:Transplantation, Homologous
D000943:Antigens, Differentiation; D003524:Cyclosporins; D000949:Histocompatibility Antigens Class II; D011948:Receptors, Antigen, T-Cell