CCR7 expression in developing thymocytes is linked to the CD4 versus CD8 lineage decision.
J Immunol
; 179(11): 7358-64, 2007 Dec 01.
Article
em En
| MEDLINE
| ID: mdl-18025179
ABSTRACT
During thymic development, T cell progenitors undergo positive selection based on the ability of their T cell Ag receptors (TCR) to bind MHC ligands on thymic epithelial cells. Positive selection determines T cell fate, in that thymocytes whose TCR bind MHC class I (MHC-I) develop as CD8-lineage T cells, whereas those that bind MHC class II (MHC-II) develop as CD4 T cells. Positive selection also induces migration from the cortex to the medulla driven by the chemokine receptor CCR7. In this study, we show that CCR7 is up-regulated in a larger proportion of CD4(+)CD8(+) thymocytes undergoing positive selection on MHC-I compared with MHC-II. Mice bearing a mutation of Th-POK, a key CD4/CD8-lineage regulator, display increased expression of CCR7 among MHC-II-specific CD4(+)CD8(+) thymocytes. In addition, overexpression of CCR7 results in increased development of CD8 T cells bearing MHC-II-specific TCR. These findings suggest that the timing of CCR7 expression relative to coreceptor down-regulation is regulated by lineage commitment signals.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Timo
/
Linfócitos T CD4-Positivos
/
Linfócitos T CD8-Positivos
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Linhagem da Célula
/
Receptores CCR7
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
J Immunol
Ano de publicação:
2007
Tipo de documento:
Article
País de afiliação:
Estados Unidos