Engineering neutrophils for enhanced function in host defense against S. aureus infections 3788

Abstract Description The rise of multidrug-resistant (MDR) microbes underscores the urgent need for novel treatments. Our research aims to develop genetically engineered murine myeloid progenitor cells that differentiate into mature neutrophils with enhanced antimicrobial functionality to combat MDR S. aureus. Neutrophils are critical to pathogen clearance, with the NADPH oxidase complex playing a significant role by generating reactive oxygen species (ROS). In the Lefort Lab, we have established a conditional neutrophil progenitor cell line (cNPs) that produces mature neutrophils equivalent to endogenous cells. Notably, cNPs have been shown to rescue mice with chronic granulomatous disease (CGD) from lethal infections, supporting their potential as a cell therapy to supply exogenous neutrophils. Therefore, we have genetically modified cNPs by overexpressing angiotensin-converting enzyme (ACE) and knock-out of Olfactomedin 4 (OLFM4). ACE boosts ROS production and microbial killing via the NADPH oxidase complex, while OLFM4 deficiency improves pathogen clearance by removing inhibitory effects on cathepsin C-dependent and independent mechanisms. By targeting oxidative and nonoxidative pathways, we aim to surpass wild-type neutrophil function, significantly enhancing bacterial clearance. This genetically modified cNP line offers a promising tool to combat antibiotic-resistant bacteria, complementing existing therapies and addressing the critical need for new strategies against MDR pathogens. Funding Sources Supported by Brown Respiratory Research Training Program (BRRTP), NIH T32HL134625; NIH/NIGMS R35GM124911 Topic Categories Microbial, Parasitic, and Fungal Immunology (MPF)