A genome-wide CRISPR knockout screen identified host genes essential for Brucella invasion and intracellular survival

For Brucella spp., the ability to invade and survive within host macrophages is essential for causing chronic infections in their mammalian hosts. In this study, a genome-wide CRISPR knockout screen was performed for the first time in human THP-1 macrophages to identify host genes mediating resistance to Brucella invasion and intracellular survival. Results showed that the screening identified 35 candidate genes, 11 of which were selected to generate monoclonal knockout cell lines for functional validation. This study demonstrated that knockout of WDR4, ZNF532, or MTHFD1 significantly restricted Brucella invasion and early intracellular survival. In addition, TRAPPC2 knockout restricted Brucella invasion and, crucially, its intracellular survival throughout infection, exerting the most potent antibacterial effect. Mechanistically, TRAPPC2 deficiency suppresses Brucella infection by inhibiting autophagosome formation in macrophages. Furthermore, TRAPPC2 knockout decreases macrophage apoptosis and improves host cell viability following Brucella infection. These results provide therapeutic targets for combating Brucella infection and offer novel insights into the molecular mechanisms associated with Brucella-induced chronic infections.