Development of a cost-effective Alveolus-on-Chip for studying Mycobacterium tuberculosis infection

Abstract We developed a cost-effective human alveolus-on-chip based on 3D printing molds (3DP-μLung) to study early events of Mycobacterium tuberculosis ( Mtb ) infection in a physiologically human relevant microenvironment. This organ-on-chip platform is compatible with advanced imaging and recreates the alveolar–capillary interface by co-culturing primary human alveolar epithelial cells, endothelial cells and macrophages. We show that epithelial-only models display limited susceptibility to Mtb infection, whereas the integration of macrophages significantly enhances infection levels of the alveolar barrier and supports intracellular bacterial replication. Quantitative imaging reveals that macrophages act as a permissive niche, promoting Mtb infection of both epithelial and endothelial compartments. This accessible organ-on-chip platform enables robust modeling of early events of host–respiratory pathogen interactions and provides a valuable tool for studying tuberculosis pathogenesis in human-relevant conditions. More broadly, it lowers technical and economic barriers to accelerate the adoption of organ-on-chip technologies for studying human specific infection. Summary A cost-effective human alveolus-on-chip enables physiologically relevant modeling of early host pathogen interaction and revealing a key role of macrophages in Mycobacterium tuberculosis infection