A role for c-FLIP(L) in the regulation of apoptosis, autophagy, and necroptosis in T lymphocytes.

Published

Journal Article

Caspase 8 plays a dual role in the survival of T lymphocytes. Although active caspase 8 mediates apoptosis upon death receptor signaling, the loss of caspase 8 activity leads to receptor-interacting protein (RIP)-1/RIP-3-dependent necrotic cell death (necroptosis) upon TCR activation. The anti-apoptotic protein c-FLIP (cellular caspase 8 (FLICE)-like inhibitory protein) suppresses death receptor-induced caspase 8 activation. Moreover, recent findings suggest that c-FLIP is also involved in inhibiting necroptosis and autophagy. It remains unclear whether c-FLIP protects primary T lymphocytes from necroptosis or regulates the threshold at which autophagy occurs. Here, we used a c-FLIP isoform-specific conditional deletion model to show that c-FLIP(L)-deficient T cells underwent RIP-1-dependent necroptosis upon TCR stimulation. Interestingly, although previous studies have only described necroptosis in the absence of caspase 8 activity, we found that pro-apoptotic caspase 8 activity and apoptosis were also enhanced in c-FLIP(L)-deficient T lymphocytes. Furthermore, c-FLIP(L)-deficient T cells exhibited enhanced autophagy, which served a cytoprotective function. Together, these findings indicate that c-FLIP(L) plays an important antinecroptotic role and is a key regulator of apoptosis, autophagy, and necroptosis in T lymphocytes.

Full Text

Duke Authors

Cited Authors

  • He, M-X; He, Y-W

Published Date

  • February 2013

Published In

Volume / Issue

  • 20 / 2

Start / End Page

  • 188 - 197

PubMed ID

  • 23175183

Pubmed Central ID

  • 23175183

Electronic International Standard Serial Number (EISSN)

  • 1476-5403

Digital Object Identifier (DOI)

  • 10.1038/cdd.2012.148

Language

  • eng

Conference Location

  • England