CD8+ T cells induce medullary thymic epithelium and CD4+CD8+CD25+ TCRbeta- thymocytes in SCID mice.
During T-cell development the transition in the thymus of CD4-CD8- double negative (DN) progenitor T cells into CD4+CD8+ double positive (DP) cells is dependent on the expression of a T-cell receptor (TCR)-beta-chain protein. In this study purified peripheral CD4+ and CD8+ T lymphocytes from the C.B-17 strain of mice were adoptively transferred into syngeneic, neonatal SCID mice, where donor cells resided at constant numbers in thymus from 2 weeks until 10 weeks post cell transfer. In the recipient thymus the CD8+ donor cells outnumbered the CD4+ cells by a factor of three to five and both subsets contained a large fraction of activated cells. During the late phase of treatment, CD8+ T cells induced high numbers of DP thymocytes in the SCID mice, a process accompanied by the maturation of medullary epithelial cells. Such thymic development in the SCID mouse was inhibited by coresiding CD4+ donor T cells. These results indicate a regulatory role by mature peripheral T cells on medullary epithelial growth and thymocyte development in the treated SCID mice.
Pettersson
F E
FE
Department of Vaccine Research, National Veterinary Institute, Uppsala University, S-751 89 Uppsala, Sweden.
Schneider
M K
MK
Andersson
J
J
Grönvik
K O
KO
D019264:Adoptive Transfer; D000818:Animals; D000831:Animals, Newborn; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D002465:Cell Movement; D004848:Epithelium / Q000254:growth & development / Q000276:immunology; D008213:Lymphocyte Activation; D051379:Mice; D016513:Mice, SCID; D010641:Phenotype; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D013950:Thymus Gland / Q000254:growth & development* / Q000276:immunology*