Inhibition of caspase-8 activity reduces IFN-gamma expression by T cells from Leishmania major infection.
An Acad Bras Cienc
; 80(1): 129-36, 2008 Mar.
Article
en En
| MEDLINE
| ID: mdl-18345381
ABSTRACT
Following infection with Leishmania major, T cell activation and apoptosis can be detected in draining lymph nodes of C57BL/6-infected mice. We investigated the mechanisms involved in apoptosis and cytokine expression following T cell activation. After two weeks of infection, apoptotic T cells were not detected in draining lymph nodes but activation with anti-CD3 induced apoptosis in both CD4 and CD8 T cells. Treatment with anti-Fas Ligand, caspase-8 or caspase- 9 inhibitors did not block activation-induced T-cell death. We also investigated whether the blockade of caspase-8 activity would affect the expression of type-1 or type-2 cytokines. At early stages of infection, both CD4 and CD8 T cells expressed IFN-gamma upon activation. Treatment with the caspase-8 inhibitor zIETD-fmk (benzyl-oxycarbonyl-Ile- Glu(OMe)-Thr-Asp(OMe)-fluoromethyl ketone) reduced the proportion of CD8 T cells and IFN-gamma expression in both CD4 and CD8 T cells. We conclude that a non apoptotic role of caspase-8 activity may be required for T cell-mediated type-1 responses during L. major infection.
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Base de datos:
MEDLINE
Asunto principal:
Linfocitos T CD4-Positivos
/
Interferón gamma
/
Leishmaniasis Cutánea
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Apoptosis
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Leishmania major
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Linfocitos T CD8-positivos
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Inhibidores de Caspasas
Límite:
Animals
Idioma:
En
Revista:
An Acad Bras Cienc
Año:
2008
Tipo del documento:
Article
País de afiliación:
Brasil