Human T cell activation results in extracellular signal-regulated kinase (ERK)-calcineurin-dependent exposure of Tn antigen on the cell surface and binding of the macrophage galactose-type lectin (MGL).
J Biol Chem
; 288(38): 27519-27532, 2013 Sep 20.
Article
en En
| MEDLINE
| ID: mdl-23918927
ABSTRACT
The C-type lectin macrophage galactose-type lectin (MGL) exerts an immunosuppressive role reflected by its interaction with terminal GalNAc moieties, such as the Tn antigen, on CD45 of effector T cells, thereby down-regulating T cell receptor signaling, cytokine responses, and induction of T cell death. Here, we provide evidence for the pathways that control the specific expression of GalNAc moieties on human CD4(+) T cells. GalNAc epitopes were readily detectable on the cell surface after T cell activation and required de novo protein synthesis. Expression of GalNAc-containing MGL ligands was completely dependent on PKC and did not involve NF-κB. Instead, activation of the downstream ERK MAPK pathway led to decreased mRNA levels and activity of the core 1 ß3GalT enzyme and its chaperone Cosmc, favoring the expression of Tn antigen. In conclusion, expression of GalNAc moieties mirrors the T cell activation status, and thus only highly stimulated T cells are prone to the suppressive action of MGL.
Palabras clave
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Activación de Linfocitos
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Antígenos de Carbohidratos Asociados a Tumores
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Linfocitos T CD4-Positivos
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Calcineurina
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Sistema de Señalización de MAP Quinasas
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Lectinas Tipo C
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Quinasas MAP Reguladas por Señal Extracelular
Límite:
Humans
Idioma:
En
Año:
2013
Tipo del documento:
Article