Ch'en, Irene L.Beisner, Daniel R.Degterev, AlexeiLynch, CandaceYuan, JunyingHoffmann, AlexanderHedrick, Stephen M.2019-10-052008Ch’en, I. L., D. R. Beisner, A. Degterev, C. Lynch, J. Yuan, A. Hoffmann, and S. M. Hedrick. 2008. “Antigen-Mediated T Cell Expansion Regulated by Parallel Pathways of Death.” Proceedings of the National Academy of Sciences 105 (45): 17463–68. https://doi.org/10.1073/pnas.0808043105.0027-84240744-28311091-6490http://nrs.harvard.edu/urn-3:HUL.InstRepos:41483459T cells enigmatically require caspase-8, an inducer of apoptosis, for antigen-driven expansion and effective antiviral responses, and yet the pathways responsible for this effect have been elusive. A defect in caspase-8 expression does not affect progression through the cell cycle but causes an abnormally high rate of cell death that is distinct from apoptosis and does not involve a loss of NF kappa B activation. Instead, antigen or mitogen activated Casp8-deficient T cells exhibit an alternative type of cell death similar to programmed necrosis that depends on receptor interacting protein (Ripk1). The selective genetic ablation of caspase-8, NF kappa B, and Ripk1, reveals two forms of cell death that can regulate virus-specific T cell expansion.en-USJournal Article2019-10-0510.1073/pnas.0808043105