Pulmonary Epithelial Injury Impairs Innate Defense and Reprograms Macrophage Function, Reducing Early Mycobacterium tuberculosis Clearance

Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb), remains a significant global health burden, characterized by complex host–pathogen interactions that drive heterogeneous clinical outcomes. While pulmonary epithelial cells are increasingly recognized as active participants in innate immunity during Mtb infection, how host defences are altered when the epithelial barrier is compromised remains unclear . In this study, we developed a murine model combining naphthalene-induced airway epithelial injury with Mtb infection, and found a pronounced impairment in pulmonary bacterial clearance. Through single-cell RNA sequencing (scRNA-seq), we mapped the pulmonary cells landscape and identified widespread suppression of epithelial immune functions. Notably, we observed macrophages transition from an antimicrobial to an antigen-presenting phenotype, indicating waning pulmonary innate defenses and heightened adaptive immune activation. These findings highlight the pivotal role of pulmonary epithelial integrity in shaping host immunity against Mtb and offer new insights into potential therapeutic strategies targeting barrier–immune crosstalk.