The CD7(-) subset of CD4(+) memory T cells is prone to accelerated apoptosis that is prevented by interleukin-15 (IL-15).
Cell Death Differ
; 8(4): 395-402, 2001 Apr.
Article
em En
| MEDLINE
| ID: mdl-11550091
ABSTRACT
The CD7(-) subset of CD4(+) T cells reflects a stable differentiation state of post-thymic helper T cells with CD45R0(+)CD45RA(-) 'memory' phenotype. Here we report that CD4(+)CD7(-) T cells are prone to increased spontaneous apoptosis in vitro compared to CD4(+)CD7(+) T cells. Spontaneous apoptosis is prevented by IL-15, but not by IL-2. Moreover, IL-15 increases Bcl-2 and decreases CD95/Fas expression of CD7(-), but not of CD7(+) T cells. Because IL-15 is physiologically not secreted but expressed in a membrane-bound form, we cocultured T cells with TNF-alpha stimulated fibroblasts that expose membrane IL-15. TNF-alpha stimulated fibroblasts rescue CD4(+)CD7(-) T cells from apoptosis whereas unstimulated fibroblasts do not. Rescue from apoptosis requires cell-cell contact and is abolished by addition of neutralizing antibodies to IL-15. We conclude that membrane IL-15 prevents accelerated apoptosis of CD4(+)CD7(-) T cells. This mechanism may contribute to accumulation of CD7(-) T cells in chronic inflammatory skin lesions.
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Base de dados:
MEDLINE
Assunto principal:
Linfócitos T CD4-Positivos
/
Subpopulações de Linfócitos T
/
Apoptose
/
Antígenos CD7
/
Interleucina-15
/
Dermatite
Limite:
Humans
Idioma:
En
Revista:
Cell Death Differ
Ano de publicação:
2001
Tipo de documento:
Article