Upregulation of CD4 expression during MHC class II-specific positive selection is essential for error-free lineage choice.
Immunity
; 31(3): 480-90, 2009 Sep 18.
Article
em En
| MEDLINE
| ID: mdl-19747858
ABSTRACT
The lineage fate of developing thymocytes is determined by the persistence or cessation of T cell receptor (TCR) signaling during positive selection, with persistent TCR signaling required for CD4 lineage choice. We show here that transcriptional upregulation of CD4 expression is essential for error-free lineage choice during major histocompatibility complex class II (MHC II)-specific positive selection and is critical for error-free lineage choice in TCR-transgenic mice whose thymocytes compete for the identical selecting ligand. CD4 upregulation occurred for endogenously encoded CD4 coreceptors, but CD4 transgenes were downregulated during positive selection, disrupting MHC II-specific TCR signaling and causing lineage errors regardless of the absolute number or signaling strength of transgenic CD4 proteins. Thus, the kinetics of CD4 coreceptor expression during MHC II-specific positive selection determines the integrity of CD4 lineage choice, revealing an elegant symmetry between coreceptor kinetics and lineage choice.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Linfócitos T CD4-Positivos
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Antígenos de Histocompatibilidade Classe II
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Antígenos CD4
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Regulação para Cima
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Linhagem da Célula
Limite:
Animals
Idioma:
En
Ano de publicação:
2009
Tipo de documento:
Article