Pathogen-Driven CRISPR Screens Identify TREX1 as a Regulator of DNA Self-Sensing During Influenza Virus Infection

Authors

Cason R King
Yiping Liu
Katherine A Amato
Grace A Schaack
Clayton Mickelson
Autumn E Sanders
Tony Hu
Srishti Gupta
Ryan A Langlois
Judith A Smith
Andrew Mehle

Publication Date

9-13-2023

Journal

Cell Host & Microbe

Abstract

Host:pathogen interactions dictate the outcome of infection, yet the limitations of current approaches leave large regions of this interface unexplored. Here, we develop a novel fitness-based screen that queries factors important during the middle to late stages of infection. This is achieved by engineering influenza virus to direct the screen by programming dCas9 to modulate host gene expression. Our genome-wide screen for pro-viral factors identifies the cytoplasmic DNA exonuclease TREX1. TREX1 degrades cytoplasmic DNA to prevent inappropriate innate immune activation by self-DNA. We reveal that this same process aids influenza virus replication. Infection triggers release of mitochondrial DNA into the cytoplasm, activating antiviral signaling via cGAS and STING. TREX1 metabolizes the DNA, preventing its sensing. Collectively, these data show that self-DNA is deployed to amplify innate immunity, a process tempered by TREX1. Moreover, they demonstrate the power and generality of pathogen-driven fitness-based screens to pinpoint key host regulators of infection.

Keywords

Humans, Influenza, Human, Clustered Regularly Interspaced Short Palindromic Repeats, DNA, Orthomyxoviridae Infections, Communicable Diseases, Exodeoxyribonucleases, Orthomyxoviridae

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Associated Data

PMID: 37652009