The Zα2 domain of ZBP1 is a molecular switch regulating influenza-induced PANoptosis and perinatal lethality during development

Shaina N Porter,Thirumala-Devi Kanneganti,Amanda R Burton,Sannula Kesavardhana,R K Subbarao Malireddi,Shondra M Pruett-Miller,Peter Vogel

doi:10.1074/jbc.ra120.013752

Shaina N Porter, Thirumala-Devi Kanneganti + Show 5 more

Open Access

https://doi.org/10.1074/jbc.ra120.013752

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Abstract

Z-DNA-binding protein 1 (ZBP1) is an innate immune sensor of nucleic acids that regulates host defense responses and development. ZBP1 activation triggers inflammation and pyroptosis, necroptosis, and apoptosis (PANoptosis) by activating receptor-interacting Ser/Thr kinase 3 (RIPK3), caspase-8, and the NLRP3 inflammasome. ZBP1 is unique among innate immune sensors because of its N-terminal Zα1 and Zα2 domains, which bind to nucleic acids in the Z-conformation. However, the specific role of these Zα domains in orchestrating ZBP1 activation and subsequent inflammation and cell death is not clear. Here we generated Zbp1ΔZα2/ΔZα2 mice that express ZBP1 lacking the Zα2 domain and demonstrate that this domain is critical for influenza A virus-induced PANoptosis and underlies perinatal lethality in mice in which the RIP homotypic interaction motif domain of RIPK1 has been mutated (Ripk1mRHIM/mRHIM). Deletion of the Zα2 domain in ZBP1 abolished influenza A virus-induced PANoptosis and NLRP3 inflammasome activation. Furthermore, deletion of the Zα2 domain of ZBP1 was sufficient to rescue Ripk1mRHIM/mRHIM mice from perinatal lethality caused by ZBP1-driven cell death and inflammation. Our findings identify the essential role of the Zα2 domain of ZBP1 in several physiological functions and establish a link between Z-RNA sensing via the Zα2 domain and promotion of influenza-induced PANoptosis and perinatal lethality.

Highlights

Z-DNA-binding protein 1 (ZBP1) is an innate immune sensor of nucleic acids that regulates host defense responses and development
influenza A virus (IAV) infection did not induce cell death in Ripk1mRHIM/mRHIMZbp1⌬Z␣2/⌬Z␣2 or Ripk1mRHIM/mRHIMZbp1Ϫ/Ϫ bone marrow– derived macrophage (BMDM) (Fig. S2D). These results suggest that deletion of the Z␣2 domain of ZBP1 prevents cell death and perinatal lethality in Ripk1mRHIM/mRHIM mice and facilitates normal immune cell development in these mice, with a mild increase in circulating neutrophils
Several recent studies unraveled an important role of ZBP1 in regulating cell death and inflammation and uncovered its role as an innate immune sensor

Summary

Introduction

Z-DNA-binding protein 1 (ZBP1) is an innate immune sensor of nucleic acids that regulates host defense responses and development. We identify the critical role of the Z␣2 domain of ZBP1 in regulating IAV-induced NLRP3 inflammasome activation, cell death, and perinatal lethality during mouse development. We generated ZBP1 mutant mice with deletion of the Z␣2 domain, which contains critical residues essential for Z-nucleic acid recognition, in the C57BL/6 background using CRISPR/Cas9 technology (hereafter referred to as Zbp1⌬Z␣2/⌬Z␣2 mice) (Fig. 1A and Table S1).

Results

Conclusion