Clonal deletion of self-Mls-reactive thymocytes at the early stage in H-2-compatible but Mls-disparate radiation chimeras.
Clonal deletion of T cells capable of recognizing both host-type Mls and donor-type Mls occurred in the peripheral mature T-cell pool in radiation bone marrow chimeras of two H-2-compatible Mls-disparate strain combinations of AKR/J(H-2k,Thy-1.1,Mls-1a) and C3H/He(H-2k,Thy-1.2,Mls-1b). In order to determine further the stage at which the clonal deletion occurs in thymus, we examined the kinetics of thymocytes bearing V beta 6 capable of recognizing Mls-1a in both C3H/He----AKR/J and AKR/J----C3H/He chimeras. An almost complete replacement from host-derived cells to donor-derived cells occurred by Day 21 after reconstitution in both chimeras. At this stage, CD4+CD8+ double-positive thymocytes contained an appreciable number of cells that expressed V beta 6 on their surface, albeit at low intensity, whereas CD4 or CD8 single-positive thymocytes which expressed a high density of V beta 6 were virtually abolished in both C3H----AKR and AKR----C3H chimeras on Day 21. These results suggest that clonal deletion of self-Mls-reactive T cells begins at an early stage when the thymocytes interact with the early appearing donor-derived haemotopoietic cells and relatively radio-resistant host-derived cells in thymus of radiation bone marrow chimeras.
Ogimoto
M
M
Department of Immunology, Kyushu University, Fukuoka, Japan.
Yoshikai
Y
Y
Matsuzaki
G
G
Ohga
S
S
Matsumoto
K
K
Nomoto
K
K
D000483:Alleles; D000818:Animals; D002999:Clone Cells; D006183:H-2 Antigens / Q000235:genetics*; D007108:Immune Tolerance / Q000235:genetics; D007958:Leukocyte Count; D051379:Mice; D008806:Mice, Inbred AKR; D008809:Mice, Inbred C3H; D011828:Radiation Chimera / Q000276:immunology*; D011948:Receptors, Antigen, T-Cell / Q000032:analysis; D013601:T-Lymphocytes; D013950:Thymus Gland / Q000276:immunology
D006183:H-2 Antigens; D011948:Receptors, Antigen, T-Cell