Figure 4.

Apoptosis and Treg cell homeostasis and function. Apoptosis affects on Treg cell survival and function at multiple levels. Treg cell apoptosis susceptibility in response to GCs is decreased but increased in response to cytokine withdrawal, γ-irradiation, cyclophosphamide and Fas–FasL interaction, when compared with conventional CD4 T cells. In addition, Treg cells mediate their suppression of immune responses in part by induction of apoptosis (cytolysis, cytokine consumption or expression of DR-ligands)