Overexpression of IL-21 promotes massive CD8+ memory T cell accumulation.
Eur J Immunol
; 37(11): 3069-77, 2007 Nov.
Article
em En
| MEDLINE
| ID: mdl-17918202
ABSTRACT
The ability of IL-21 to promote in vitro T cell survival led us to investigate its biological activity in vivo. We report that overexpression of IL-21 in transgenic mice drives CD8(+) memory T cell accumulation with a concomitant reduction in naive T cell numbers. These memory T cells are functional, given their ability to rapidly produce IFN-gamma and proliferate following stimulation. Since the homeostasis of naive and memory T cells is controlled by cytokines, we evaluated whether IL-21 influences cytokine receptor expression. We show that IL-21 inhibits IL-7R expression on naive T cells in vitro, suggesting impaired IL-7-mediated naive T cell survival in IL-21-transgenic mice. In contrast, IL-7R expression on CD4(+) memory T cells is not affected, allowing their IL-7-dependent survival in IL-21-transgenic mice. Although IL-21 decreases IL-7R expression on CD8(+) memory T cells, this has no impact on their survival since their maintenance in the T cell pool is IL-7-independent. Rather, we demonstrate that CD8(+) memory T cells are receptive to IL-21 survival signals allowing for their accumulation in IL-21-transgenic mice. This study identifies new roles for IL-21 in T cell homeostasis and in the regulation of T cell responses to cytokines.
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Base de dados:
MEDLINE
Assunto principal:
Subpopulações de Linfócitos T
/
Interleucinas
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Linfócitos T CD8-Positivos
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Memória Imunológica
Idioma:
En
Ano de publicação:
2007
Tipo de documento:
Article