Genome-wide screen ofMycobacterium tuberculosis-infected macrophages identified the GID/CTLH complex as a determinant of intracellular bacterial growth

Abstract

SummaryThe eukaryotic GID/CTLH complex is a highly conserved E3 ubiquitin ligase involved in a broad range of biological processes. However, a role of this complex in host antimicrobial defenses has not been described. We exploitedMycobacterium tuberculosis(Mtb) induced cytotoxicity in macrophages in a FACS based CRISPR genetic screen to identify host determinants of intracellularMtbgrowth restriction. Our screen identified 5 (GID8,YPEL5,WDR26,UBE2H,MAEA) of the 10 predicted members of the GID/CTLH complex as determinants of intracellular growth of bothMtbandSalmonellaserovar Typhimurium. We show that the antimicrobial properties of the GID/CTLH complex knockdown macrophages are mediated by enhanced GABAergic signaling, activated AMPK, increased autophagic flux and resistance to cell death. Meanwhile,Mtbisolated from GID/CTLH knockdown macrophages are nutritionally starved and oxidatively stressed. Our study identifies the GID/CTLH complex activity as broadly suppressive of host antimicrobial responses against intracellular bacterial infections.Graphical abstract