Induction of CD4+ T-cell anergy and apoptosis by activated human B cells.
Blood
; 112(12): 4555-64, 2008 Dec 01.
Article
en En
| MEDLINE
| ID: mdl-18802006
ABSTRACT
B cells are well-known mediators of humoral immunity and serve as costimulators in the generation of T cell-mediated responses. In several mouse models, however, it was observed that B cells can also down-regulate immune reactions, suggesting a dual role for B cells. Due to this discrepancy and so far limited data, we directly tested the effects of primary human B cells on activated CD4(+) T helper cells in vitro. We found that under optimal costimulation large, activated CD25(+) B cells but not small CD25(-) B cells induced temporary T-cell anergy, determined by cell division arrest and down-regulation of cytokine production. In addition, large CD25(+) B cells directly induced CD95-independent apoptosis in a subpopulation of activated T cells. Suppression required direct B-T-cell contact and was not transferable from T to T cell, excluding potential involvement of regulatory T cells. Moreover, inhibitory effects involved an IL-2-dependent mechanism, since decreasing concentrations of IL-2 led to a shift from inhibitory toward costimulatory effects triggered by B cells. We conclude that activated CD25(+) B cells are able to costimulate or down-regulate T-cell responses, depending on activation status and environmental conditions that might also influence their pathophysiological impact.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Linfocitos B
/
Activación de Linfocitos
/
Linfocitos T CD4-Positivos
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Apoptosis
/
Anergia Clonal
Tipo de estudio:
Prognostic_studies
Límite:
Humans
Idioma:
En
Revista:
Blood
Año:
2008
Tipo del documento:
Article
País de afiliación:
Alemania