Assuntos
Fatores de Transcrição Forkhead/imunologia , Regulação da Expressão Gênica/imunologia , Transtornos Linfoproliferativos/imunologia , Linfócitos T Reguladores/imunologia , Animais , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/patologia , Antígeno CTLA-4/genética , Antígeno CTLA-4/imunologia , Fatores de Transcrição Forkhead/genética , Proteína Relacionada a TNFR Induzida por Glucocorticoide/genética , Proteína Relacionada a TNFR Induzida por Glucocorticoide/imunologia , Transtornos Linfoproliferativos/genética , Transtornos Linfoproliferativos/patologia , Camundongos , Linfócitos T Reguladores/patologiaRESUMO
The molecular properties that characterize CD4+CD25+ regulatory T cells (TR cells) remain elusive. Absence of the transcription factor Scurfin (also known as forkhead box P3 and encoded by Foxp3) causes a rapidly fatal lymphoproliferative disease, similar to that seen in mice lacking cytolytic T lymphocyte-associated antigen 4 (CTLA-4). Here we show that Foxp3 is highly expressed by T(R) cells and is associated with T(R) cell activity and phenotype. Scurfin-deficient mice lack T(R) cells, whereas mice that overexpress Foxp3 possess more T(R) cells. In Foxp3-overexpressing mice, both CD4+CD25- and CD4-CD8+ T cells show suppressive activity and CD4+CD25- cells express glucocorticoid-induced tumor-necrosis factor receptor-related (GITR) protein. The forced expression of Foxp3 also delays disease in CTLA-4-/- mice, indicating that the Scurfin and CTLA-4 pathways may intersect and providing further insight into the T(R) cell lineage.