TGF-β suppresses RasGRP1 expression and supports regulatory T cell resistance against p53-induced CD28-dependent T-cell apoptosis.

ABSTRACT: Thymus-derived regulatory T cells (tTregs) play pivotal roles in immunological self-tolerance and homeostasis. A majority of tTregs are reactive to self-antigens and are constantly exposed to antigenic stimulation. Despite this continuous stimulation, tTreg and conventional T-cell populations remain balanced during homeostasis, but the mechanisms controlling this balance are unknown. We previously reported a form of activation-induced cell death, which is dependent on p53 (p53-induced CD28-dependent T-cell apoptosis, PICA). Under PICA-inducing conditions, tTregs survive while a majority of conventional T cells undergo apoptosis, suggesting there is a survival mechanism that protects tTregs. Here, we report that the expression of RasGRP1 (Ras guanyl-releasing protein 1) is required for PICA

SUBMITTER: Takami M 

PROVIDER: S-EPMC6368088 | biostudies-literature | 2018 Dec

REPOSITORIES: biostudies-literature