Human pluripotent stem cell-derived macrophages host Mycobacterium abscessus infection

Human macrophages are a natural host of many mycobacterium species, including Mycobacterium abscessus (M. abscessus), an emerging pathogen affecting patients with lung diseases and immunocompromised individuals. There are few available treatments and the search for effective antibiotics against M. abscessus has been hindered by the lack of a tractable in vitro intracellular model of infection. Here, we established a reliable model for M. abscessus infection using human pluripotent stem cell-derived macrophages (hPSC-macrophages). hPSC differentiation permitted a reproducible generation of functional human macrophages that were highly susceptible to M. abscessus infection. Electron microscopy demonstrated that M. abscessus was present in the vacuoles of hPSC-macrophages. RNA-sequencing analysis revealed a time dependent host cell response to M. abscessus, with differing gene and protein expression patterns observed at 3-hours, 24-hours and 48-hours post-infection. Culture of engineered tdTOMATO-expressing hPSC-macrophages with GFP-expressing M. abscessus enabled rapid and image-based high-throughput analysis of intracellular infection and quantitative assessment of antibiotic resistance and efficacy. Our study describes the first hPSC-based model for M. abscessus infection, which represents a novel platform for studying M. abscessus-host interaction and an accessible tool for drug discovery. The hPSC line PB1 (PB001) (Vlahos et al., 2019) was differentiated into macrophages, which were inoculated with M. abscessus-GFP. RNA-sequencing were performed at 3 hours, 24 hours and 48 hours post-infection, with uninfected samples used as controls collected at 3 hours post-infection (3h_un).