E3 Ubiquitin Ligase Cbl-b Regulates Thymic-Derived CD4+CD25+ Regulatory T Cell Development by Targeting Foxp3 for Ubiquitination.
J Immunol
; 194(4): 1639-45, 2015 Feb 15.
Article
en En
| MEDLINE
| ID: mdl-25560411
ABSTRACT
CD28 costimulation is essential for the development of thymic-derived CD4(+)CD25(+)Foxp3(+) regulatory T cells ("tTregs"). E3 ubiquitin ligase Cbl-b has been shown to regulate CD28 dependence of T cell activation. In this paper, we report that the loss of Cbl-b partially but significantly rescues the defective development of tTregs in Cd28(-/-) mice. This partial rescue is independent of IL-2. Mechanistically, Cbl-b binds to Foxp3 upon TCR stimulation and, together with Stub1, targets Foxp3 for ubiquitination and subsequently degradation in the proteasome. As Cbl-b self-ubiquitination and proteasomal degradation is impaired in Cd28(-/-) T cells, the defective development of tTregs in Cd28(-/-) mice may in part be due to increased Foxp3 ubiquitination and degradation targeted by Stub1 and Cbl-b. Treating Cd28(-/-) mice with a proteasome inhibitor completely rescues defective tTreg development in these mice. Therefore, Cbl-b, together with Stub1, ubiquitinate Foxp3, and regulate tTreg development.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Activación de Linfocitos
/
Linfocitos T Reguladores
/
Proteínas Adaptadoras Transductoras de Señales
/
Proteínas Proto-Oncogénicas c-cbl
/
Factores de Transcripción Forkhead
Límite:
Animals
Idioma:
En
Revista:
J Immunol
Año:
2015
Tipo del documento:
Article