Fine particulate matter manipulates immune response to exacerbate microbial pathogenesis in the respiratory tract

Particulate matter with a diameter ⩽2.5 μm (PM_2.5) poses a substantial global challenge, with a growing recognition of pathogens contributing to diseases associated with exposure to PM_2.5. Recent studies have focused on PM_2.5, which impairs the immune cells in response to microbial infections and potentially contributes to the development of severe diseases in the respiratory tract. Accordingly, changes in the respiratory immune function and microecology mediated by PM_2.5 are important factors that enhance the risk of microbial pathogenesis. These factors have garnered significant interest. In this review, we summarise recent studies on the potential mechanisms involved in PM_2.5-mediated immune system disruption and exacerbation of microbial pathogenesis in the respiratory tract. We also discuss crucial areas for future research to address the gaps in our understanding and develop effective strategies to combat the adverse health effects of PM_2.5.