CFLAR/c-FLIPL: a star in the autophagy, apoptosis and necroptosis alliance.

Necroptosis, a caspase-independent, receptor (TNFRSF)-interacting serine-threonine kinase 1 (RIPK1)/RIPK3-dependent necrotic cell death, occurs in cells when apoptosis is blocked. A high level of macroautophagy (herein referred to as autophagy) is usually detected in necroptotic cells, although it is still controversial as to whether excessive autophagy leads to cell death or is cytoprotective. In a recently published paper, we show that the anti-apoptotic protein CFLAR (CASP8 and FADD-like apoptosis regulator) long isoform (CFLARL) plays a critical role in all three fundamental intracellular processes: autophagy, necroptosis, and apoptosis in T lymphocytes. CFLARL-deficient T cells suffer from severe cell death upon T cell receptor stimulation, in which both apoptosis and necroptosis are involved. Autophagy is enhanced in both naïve and activated CFLARL-deficient T cells and plays a cytoprotective function. Here, we summarize our findings and discuss the future direction in the study of the interplay of autophagy, apoptosis and necroptosis in T lymphocytes.