Research Publications


Ptpn6 inhibits caspase-8- and Ripk3/Mlkl-dependent inflammation

Speir, M; Nowell, CJ; Chen, AA; O'Donnell, JA; Shamie, IS; Lakin, PR; D'Cruz, AA; Braun, RO; Babon, JJ; Lewis, RS; Bliss-Moreau, M; Shlomovitz, I; Wang, S; Cengia, LH; Stoica, AI; Hakem, R; Kelliher, MA; O'Reilly, LA; Patsiouras, H; Lawlor, KE; Weller, E; Lewis, NE; Roberts, AW; Gerlic, M; Croker, BA
Nature Immunology
Journal Article in press
Ptpn6 is a cytoplasmic phosphatase that functions to prevent autoimmune and interleukin-1 (IL-1) receptor-dependent, caspase-1-independent inflammatory disease. Conditional deletion of Ptpn6 in neutrophils (Ptpn6(PMN)) is sufficient to initiate IL-1 receptor-dependent cutaneous inflammatory disease, but the source of IL-1 and the mechanisms behind IL-1 release remain unclear. Here, we investigate the mechanisms controlling IL-1alpha/beta release from neutrophils by inhibiting caspase-8-dependent apoptosis and Ripk1-Ripk3-Mlkl-regulated necroptosis. Loss of Ripk1 accelerated disease onset, whereas combined deletion of caspase-8 and either Ripk3 or Mlkl strongly protected Ptpn6(PMN) mice. Ptpn6(PMN) neutrophils displayed increased p38 mitogen-activated protein kinase-dependent Ripk1-independent IL-1 and tumor necrosis factor production, and were prone to cell death. Together, these data emphasize dual functions for Ptpn6 in the negative regulation of p38 mitogen-activated protein kinase activation to control tumor necrosis factor and IL-1alpha/beta expression, and in maintaining Ripk1 function to prevent caspase-8- and Ripk3-Mlkl-dependent cell death and concomitant IL-1alpha/beta release.
Springer Nature
Structural Biology; Inflammation; Blood Cells and Blood Cancer
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Creation Date 2019-12-16 02:49:02 Last Modified 2019-12-16 03:01:02