Whole-genome CRISPR screen identifies RAVER1 as a key regulator of RIPK1-mediated inflammatory cell death, PANoptosis

R K Subbarao Malireddi; Ratnakar R Bynigeri; Raghvendra Mall; Eswar Kumar Nadendla; Jon P Connelly; Shondra M Pruett-Miller; Thirumala-Devi Kanneganti

doi:10.1016/j.isci.2023.106938

Whole-genome CRISPR screen identifies RAVER1 as a key regulator of RIPK1-mediated inflammatory cell death, PANoptosis

iScience. 2023 May 22;26(6):106938. doi: 10.1016/j.isci.2023.106938. eCollection 2023 Jun 16.

Authors

R K Subbarao Malireddi¹, Ratnakar R Bynigeri¹, Raghvendra Mall¹, Eswar Kumar Nadendla¹, Jon P Connelly², Shondra M Pruett-Miller², Thirumala-Devi Kanneganti¹

Affiliations

¹ Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA.
² Center for Advanced Genome Engineering (CAGE), St. Jude Children's Research Hospital, Memphis, TN 38105, USA.

Abstract

Transforming growth factor-β-activated kinase 1 (TAK1) is a central regulator of innate immunity, cell death, inflammation, and cellular homeostasis. Therefore, many pathogens carry TAK1 inhibitors (TAK1i). As a host strategy to counteract this, inhibition or deletion of TAK1 induces spontaneous inflammatory cell death, PANoptosis, through the RIPK1-PANoptosome complex, containing the NLRP3 inflammasome and caspase-8/FADD/RIPK3 as integral components; however, PANoptosis also promotes pathological inflammation. Therefore, understanding molecular mechanisms that regulate TAK1i-induced cell death is essential. Here, we report a genome-wide CRISPR screen in macrophages that identified TAK1i-induced cell death regulators, including polypyrimidine tract-binding (PTB) protein 1 (PTBP1), a known regulator of RIPK1, and a previously unknown regulator RAVER1. RAVER1 blocked alternative splicing of Ripk1, and its genetic depletion inhibited TAK1i-induced, RIPK1-mediated inflammasome activation and PANoptosis. Overall, our CRISPR screen identified several positive regulators of PANoptosis. Moreover, our study highlights the utility of genome-wide CRISPR-Cas9 screens in myeloid cells for comprehensive characterization of complex cell death pathways to discover therapeutic targets.

Keywords: Biological sciences; Cell biology; Immunology; Molecular biology.