biostudies-literatureLi XNational Natural Science Foundation of China1500-1512https://www.ebi.ac.uk/biostudies/studies/S-EPMC9345959biostudies-literatureUnknown29(8)Caspase-8 is an initiator of death receptor-induced apoptosis and an inhibitor of RIPK3-MLKL-dependent necroptosis. In addition, caspase-8 has been implicated in diseases such as lymphoproliferation, immunodeficiency, and autoimmunity in humans. Although auto-cleavage is indispensable for caspase-8 activation, its physiological functions remain poorly understood. Here, we generated a caspase-8 mutant lacking E385 in auto-cleavage site knock-in mouse (Casp8^{ΔE385/ΔE385}). Casp8^{ΔE385/ΔE385} cells were expectedly resistant to Fas-induced apoptosis, however, Casp8^{ΔE385/ΔE385} cells could switch TNF-α-induced apoptosis to necroptosis by attenuating RIPK1 cleavage. More importantly, CASP8(ΔE385) sensitized cells to RIPK3-MLKL-dependent necroptosis through promoting cCell death and differentiationCaspase-8 auto-cleavage regulates programmed cell death and collaborates with RIPK3/MLKL to prevent lymphopenia.PMC9345959317715378200168431970688Liu JLi JLi FZhang HDeng JLi MZhao YWang LLi XXing MZhao QZhang YZhang XOu YLuo YWang XWu XfalseCaspase-8 auto-cleavage regulates programmed cell death and collaborates with RIPK3/MLKL to prevent lymphopenia.Caspase-8 is an initiator of death receptor-induced apoptosis and an inhibitor of RIPK3-MLKL-dependent necroptosis. In addition, caspase-8 has been implicated in diseases such as lymphoproliferation, immunodeficiency, and autoimmunity in humans. Although auto-cleavage is indispensable for caspase-8 activation, its physiological functions remain poorly understood. Here, we generated a caspase-8 mutant lacking E385 in auto-cleavage site knock-in mouse (Casp8^{ΔE385/ΔE385}). Casp8^{ΔE385/ΔE385} cells were expectedly resistant to Fas-induced apoptosis, however, Casp8^{ΔE385/ΔE385} cells could switch TNF-α-induced apoptosis to necroptosis by attenuating RIPK1 cleavage. More importantly, CASP8(ΔE385) sensitized cells to RIPK3-MLKL-dependent necroptosis through promoting c2022-01-01T00:00:00Z2022 Aug2025-04-26T11:57:09.635Z2025-02-19T05:06:14.828ZS-EPMC93459593506421310.1038/s41418-022-00938-9