Stochastic coreceptor shut-off is restricted to the CD4 lineage maturation pathway.
J Exp Med
; 181(5): 1623-33, 1995 May 01.
Article
en En
| MEDLINE
| ID: mdl-7722442
ABSTRACT
Kinetics of mature T cell generation in the thymus of normal or major histocompatibility complex (MHC) class I- or II-deficient mice were studied by the bromodeoxyuridine pulse labeling method. As previously described, the early activation and final maturation phases were found to be synchronous for the two T cell lineages, but CD4+8- cells were generated faster than CD4-8+ cells in MHC class I- and II-deficient mice, respectively. CD8 downregulation started on day 2 after cell proliferation even in the absence of MHC class II expression. CD8 downregulation thus appears to be stochastic at its beginning. By contrast, CD4 shut-off was found totally instructive, as the generation of CD4lo8+ cells with a high TCR density was not observed in class I-deficient mice. The analysis of the V beta 14 TCR frequencies in CD4/8 subsets in normal and MHC-deficient mice confirmed that CD4 and CD8 generation pathways are not symmetrical. These findings show that commitment towards the CD4+8- or CD4-8+ phenotype is controlled at the CD8lo step for the former and at the CD4+8+ double-positive stage for the latter.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Linfocitos T CD4-Positivos
/
Receptores de Antígenos de Linfocitos T alfa-beta
/
Linfocitos T CD8-positivos
Límite:
Animals
Idioma:
En
Revista:
J Exp Med
Año:
1995
Tipo del documento:
Article
País de afiliación:
Francia