Inhibition of DAI-dependent necroptosis by the Z-DNA binding domain of the vaccinia virus innate immune evasion protein, E3

• Type of Material: Article
• Authors: Heather Koehler, Arizona State University; Samantha Cotsmire, Arizona State University; Jeffrey Langland, Arizona State University; Karen V. Kibler, Arizona State University; Daniel Kalman, Emory University; Jason W. Upton, University of Texas Austin; Edward S Mocarski, Emory University; Bertram L. Jacobs, Arizona State University
• Language: English
• Date: 2017-10-24
• Publisher: National Academy of Sciences
• Publication Version: Final Published Version
• Copyright Statement: Koehler et al.
• Final Published Version (URL): http://dx.doi.org/10.1073/pnas.1700999114
• Title of Journal or Parent Work: Proceedings of the National Academy of Sciences
• ISSN: 0027-8424
• Volume: 114
• Issue: 43
• Start Page: 11506
• End Page: 11511
• Grant/Funding Information: NIH Grants supported this work (R01 AI095394 to B.L.J. and R01 AI118853 to E.S.M.).
• Keywords: PROGRAMMED NECROSIS; necroptosis; N-TERMINAL DOMAIN; APOPTOSIS; MIXED LINEAGE KINASE; vaccinia; GENE; CELL-DEATH; type 1 interferon; KAPPA-B; PATHOGENESIS; Multidisciplinary Sciences; Science & Technology - Other Topics; RIPK3; CYTOMEGALOVIRUS; Science & Technology; RIP3; Z-DNA binding domain
• Research Categories: Health Sciences, Immunology; Biology, Virology; Biology, Genetics

Abstract

Vaccinia virus (VACV) encodes an innate immune evasion protein, E3, which contains an N-terminal Z-nucleic acid binding (Zα) domain that is critical for pathogenicity in mice. Here we demonstrate that the N terminus of E3 is necessary to inhibit an IFN-primed virusinduced necroptosis. VACV deleted of the Zα domain of E3 (VACVE3Lδ83N) induced rapid RIPK3-dependent cell death in IFN-treated L929 cells. Cell death was inhibited by the RIPK3 inhibitor, GSK872, and infection with this mutant virus led to phosphorylation and aggregation of MLKL, the executioner of necroptosis. In 293T cells, induction of necroptosis depended on expression of RIPK3 as well as the host-encoded Zα domain-containing DNA sensor, DAI. VACVE3Lδ83N is attenuated in vivo, and pathogenicity was restored in either RIPK3- or DAI-deficient mice. These data demonstrate that the N terminus of the VACV E3 protein prevents DAI-mediated induction of necroptosis.