RESUMEN
Homeostatic proliferation of T cells leads to the generation of effector/memory cells, which have the potential to cause harm to the host. The role of Tregs in the control of homeostatic proliferation is unclear. In this study we utilized mice that either harbor or lack Tregs as recipients of monoclonal or polyclonal T cells. We observed that while Tregs completely prevented cell division of T cells displaying low affinity for self ligands, they had a less marked, albeit significant, effect on cell cycle entry of T cells displaying higher affinity. The presence of Tregs resulted in a lower accumulation of T cells, enhanced apoptosis, and impaired differentiation to a cytokine-producing state. We conclude that Tregs play a major role in the control of homeostatic proliferation.
Asunto(s)
Linfocitos T Reguladores/citología , Animales , Anticuerpos/química , Anticuerpos Monoclonales/química , Apoptosis , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD4-Positivos/metabolismo , Antígenos CD5/biosíntesis , Proliferación Celular , Separación Celular , Citometría de Flujo , Genes RAG-1 , Heterocigoto , Receptores de Hialuranos/metabolismo , Memoria Inmunológica , Etiquetado Corte-Fin in Situ , Ligandos , Ganglios Linfáticos/patología , Activación de Linfocitos , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Proteína Básica de Mielina/genética , Receptores de Antígenos de Linfocitos T/metabolismo , Bazo/citología , Linfocitos T/metabolismo , Factores de Tiempo , TransgenesRESUMEN
The control of peripheral lymphocyte numbers is a fundamental aspect of the immune system. Regulatory T cells are involved in the suppression of autoimmune, antitumor, allergic, and other inflammatory responses, as well as in facilitating graft acceptance. In this paper, we discuss whether the control of homeostatic proliferation is another facet of the immune system that is controlled by regulatory T cells. A review of the published data connecting regulatory T cells with the control of homeostatic proliferation indicates that several key questions remain open. One of these relates to the stage at which regulatory T cells could play a role (i.e., T-cell proliferation vs. survival).