Defective Th1 and Th2 cytokine synthesis in the T-T cell presentation model for lack of CD40/CD40 ligand interaction.
Eur J Immunol
; 28(11): 3552-63, 1998 11.
Article
em En
| MEDLINE
| ID: mdl-9842898
ABSTRACT
In this study, T or NK cell clones used as antigen-presenting cells (T- or NK-APC) were shown to be significantly less efficient than professional APC in inducing Th1 and Th2 cytokines by antigen-specific T cell clones. This phenomenon was not related to a limited engagement of TCR by T-APC, since comparable thresholds of TCR down-regulation were shown when antigen was presented by either T-APC or professional APC. Rather, the stimulatory T-APC weakness was due to their inability, because they are CD40-, to provide the appropriate co-stimuli to responder T cells both indirectly via IL-12, and partially via direct CD40L triggering on T cells. Indeed, the simultaneous addition of IL-12 and reagents directly engaging CD40L on responder T cells restored T cell cytokine synthesis when antigen was presented by T-APC. In addition, either IL-12 production or blocking of T cell cytokine synthesis by anti-IL-12 p75 antibodies was evident only when professional APC were used in our antigen-specific system. The down-regulation of cytokine synthesis in the system of T-T cell presentation could represent a novel mechanism of immune regulation, which may intervene to switch off detrimental Th1- or Th2-mediated responses induced by antigen presentation among activated T cells infiltrating inflamed tissues.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Glicoproteínas de Membrana
/
Ativação Linfocitária
/
Citocinas
/
Células Th2
/
Células Th1
/
Antígenos CD40
/
Células Apresentadoras de Antígenos
Tipo de estudo:
Prognostic_studies
Limite:
Humans
Idioma:
En
Ano de publicação:
1998
Tipo de documento:
Article