T-cell tolerance induced by repeated antigen stimulation: selective loss of Foxp3- conventional CD4 T cells and induction of CD4 T-cell anergy.
Eur J Immunol
; 39(4): 1078-87, 2009 Apr.
Article
em En
| MEDLINE
| ID: mdl-19283777
ABSTRACT
Repeated immunization of mice with bacterial superantigens induces extensive deletion and anergy of reactive CD4 T cells. Here we report that the in vitro proliferation anergy of CD4 T cells from TCR transgenic mice immunized three times with staphylococcal enterotoxin B (SEB) (3 x SEB) is partially due to an increased frequency of Foxp3(+) CD4 T cells. Importantly, reduced number of conventional CD25(-) Foxp3(-) cells, rather than conversion of such cells to Foxp3(+) cells, was the cause of that increase and was also seen in mice repeatedly immunized with OVA (3 x OVA) and OVA-peptide (OVAp) (3 x OVAp). Cell-transfer experiments revealed profound but transient anergy of CD4 T cells isolated from 3 x OVAp and 3x SEB mice. However, the in vivo anergy was CD4 T-cell autonomous and independent of Foxp3(+) Treg. Finally, proliferation of transferred CD4 T cells was inhibited in repeatedly immunized mice but inhibition was lost when transfer was delayed, despite the maintenance of elevated frequency of Foxp3(+) cells. These data provide important implications for Foxp3(+) cell-mediated tolerance in situations of repeated antigen exposure such as human persistent infections.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Linfócitos T CD4-Positivos
/
Linfócitos T Reguladores
/
Anergia Clonal
/
Fatores de Transcrição Forkhead
Limite:
Animals
Idioma:
En
Ano de publicação:
2009
Tipo de documento:
Article