Low-dose antigen promotes induction of FOXP3 in human CD4+ T cells.
J Immunol
; 187(7): 3511-20, 2011 Oct 01.
Article
em En
| MEDLINE
| ID: mdl-21865550
ABSTRACT
Low Ag dose promotes induction and persistence of regulatory T cells (Tregs) in mice, yet few studies have addressed the role of Ag dose in the induction of adaptive CD4(+)FOXP3(+) Tregs in humans. To this end, we examined the level of FOXP3 expression in human CD4(+)CD25(-) T cells upon activation with autologous APCs and varying doses of peptide. Ag-specific T cells expressing FOXP3 were identified by flow cytometry using MHC class II tetramer (Tmr). We found an inverse relationship between Ag dose and the frequency of FOXP3(+) cells for both foreign Ag-specific and self Ag-specific T cells. Through studies of FOXP3 locus demethylation and helios expression, we determined that variation in the frequency of Tmr(+)FOXP3(+) T cells was not due to expansion of natural Tregs, but instead, we found that induction, proliferation, and persistence of FOXP3(+) cells was similar in high- and low-dose cultures, whereas proliferation of FOXP3(-) T cells was favored in high Ag dose cultures. The frequency of FOXP3(+) cells positively correlated with suppressive function, indicative of adaptive Treg generation. The frequency of FOXP3(+) cells was maintained with IL-2, but not upon restimulation with Ag. Together, these data suggest that low Ag dose favors the transient generation of human Ag-specific adaptive Tregs over the proliferation of Ag-specific FOXP3(-) effector T cells. These adaptive Tregs could function to reduce ongoing inflammatory responses and promote low-dose tolerance in humans, especially when Ag exposure and tolerance is transient.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Ativação Linfocitária
/
Linfócitos T CD4-Positivos
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Subpopulações de Linfócitos T
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Fatores de Transcrição Forkhead
/
Antígenos
Tipo de estudo:
Prognostic_studies
Limite:
Animals
/
Humans
Idioma:
En
Revista:
J Immunol
Ano de publicação:
2011
Tipo de documento:
Article
País de afiliação:
Estados Unidos