Expression of human GITRL on myeloid dendritic cells enhances their immunostimulatory function but does not abrogate the suppressive effect of CD4+CD25+ regulatory T cells.
J Leukoc Biol
; 82(1): 93-105, 2007 Jul.
Article
em En
| MEDLINE
| ID: mdl-17449724
ABSTRACT
CD4(+)CD25(+) regulatory T cells (Treg) have been described as an important hurdle for immunotherapy. Engagement of glucocorticoid-induced TNF receptor-related protein (GITR) has emerged recently as an important mechanism to control the suppression of CD4(+)CD25(+) Treg. Furthermore, it has been documented extensively that GITR ligation is costimulatory for naive and activated T cells in the murine setting. However, little is known about the role of the human GITR ligand (huGITRL). We wanted to explore whether huGITRL could enhance antigen-specific T cell priming by dendritic cells (DC). First, we confirmed the endogenous expression of GITRL on HUVEC. We also detected GITRL expression on EBV-B cell lines, whereas no GITRL expression was observed on human monocyte-derived DC. Electroporation of GITRL mRNA in monocyte-derived DC resulted in a strong and long-lasting surface expression of GITRL. In contrast to data obtained in mice, no significant abrogation of Treg suppression by GITRL-expressing human DC was observed. Consistent with our mouse data, we showed that huGITRL is costimulatory for responder T cells. Furthermore, we found that GITRL-expressing DC primed increased numbers of Melan-A-specific CD8(+) T cells. We conclude that although huGITRL is not capable of alleviating Treg suppression of responder T cells, huGITRL overexpression on monocyte-derived DC enhances their capacity to induce antigen-specific T cell responses. Thus, GITRL incorporation in DC might improve the antitumor immune response after vaccination.
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Base de dados:
MEDLINE
Assunto principal:
Células Dendríticas
/
Linfócitos T Reguladores
/
Fatores de Necrose Tumoral
Limite:
Humans
Idioma:
En
Revista:
J Leukoc Biol
Ano de publicação:
2007
Tipo de documento:
Article
País de afiliação:
Bélgica