Differential expression and function of α-mannosidase I in stimulated naive and memory CD4+ T cells.
J Immunother
; 34(5): 428-37, 2011 Jun.
Article
en En
| MEDLINE
| ID: mdl-21577142
ABSTRACT
N-linked protein glycosylation represents an important cellular process for modifying protein properties. It resembles a cascade of various enzymatic reactions, in which class I α-mannosidases play a central role. We and others have recently shown that N-glycosylation plays a major role for immune functions. We now analyzed the expression and function of α-mannosidase I in CD4(+) naive and memory T cells studying human and murine T cells. Alpha-mannosidase I function was altered by (i) treatment with Kifunensine, a specific inhibitor class I α-mannosidases, (ii) synthetic inhibitory RNA, and (iii) overexpression by retroviral gene transfer. T-cell activation was evaluated by CD69 expression, cytokine production and proliferation. Our results demonstrate (i) that α-mannosidase I transcription is transiently downregulated after T-cell activation with either polyclonal anti-CD3/CD28 antibodies or allogeneic CD19(+) B cells, and (ii) that α-mannosidase I exerts an inhibitory effect on T-cell activation. It is interesting to note that the inhibitory effect was restricted to naive CD4(+) T cells in both systems, human T cells and murine transgenic CD4(+)OT-II cells, whereas human memory T cells and primed CD4(+)OT-II cells remained unaffected. Alpha-mannosidase I inhibition reduced the activation threshold for naive but not already primed CD4(+)OT-II cells as the cells were able to respond to lower ovalbumin peptide concentrations and increased the rejection potential of alloreactive T cells in vivo. Thus, complex N-glycans generated by enzymes such as α-mannosidase I inhibit the activation of naive T cells. These findings could be used to improve the ex vivo priming of naive T cells for adaptive T-cell therapies.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Linfocitos T CD4-Positivos
/
Alfa-Manosidasa
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Memoria Inmunológica
Límite:
Animals
/
Humans
Idioma:
En
Revista:
J Immunother
Asunto de la revista:
ALERGIA E IMUNOLOGIA
/
NEOPLASIAS
/
TERAPEUTICA
Año:
2011
Tipo del documento:
Article
País de afiliación:
Alemania