TIM-4 expressed on APCs induces T cell expansion and survival.
J Immunol
; 180(7): 4706-13, 2008 Apr 01.
Article
em En
| MEDLINE
| ID: mdl-18354194
ABSTRACT
TIM (T cell, Ig, mucin) proteins can regulate T cell immune responses. Tim-4 mRNA is not expressed in T cells, but exclusively in APCs. Tim-4 is a ligand for Tim-1 and Tim-4.Ig fusion protein was shown to either inhibit or expand T cells. However, the molecular basis for such opposite effects was not defined. By generating mAbs, we show that expression of Tim-4 protein is restricted to CD11c(+) and CD11b(+) cells and is up-regulated upon activation. We show that Tim-4 specifically phosphorylates Tim-1 and induces T cell expansion by enhancing cell division and reducing apoptosis. Tim-4 also induces the phosphorylation of signaling molecules LAT, Akt, and ERK1/2 in T cells. Tim-4, expressed on APCs, is a costimulatory molecule that promotes T cell expansion and survival by cross-linking Tim-1 on T cells.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Linfócitos T
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Diferenciação Celular
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Proteínas de Membrana
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Células Apresentadoras de Antígenos
Idioma:
En
Ano de publicação:
2008
Tipo de documento:
Article