Advances in infection-immunity mechanisms and molecular regulatory networks in severe pneumonia-associated lung injury.

Severe pneumonia-associated lung injury remains a critical focus in infection and immunology research due to its high lethality and complex immunopathology. Affected patients often present with cellular immune deficiency and an imbalanced interplay between pro-inflammatory and anti-inflammatory mediators, with infection-immunity disequilibrium driving disease progression. The initial infection triggers a defense-injury cascade: while inflammation facilitates pathogen clearance, persistent or excessive activation leads to progressive lung tissue damage. Recent advances have deepened our understanding of immune mechanisms and inflammatory regulation; however, key challenges persist in clinical translation. Here, we synthesize current evidence on the immunopathology of severe pneumonia-associated lung injury, dissect the hierarchical architecture of its molecular regulatory networks, and critically appraise existing therapeutic strategies and their limitations. We propose a translational framework-encompassing mechanistic research, network modelling, and precision intervention-to guide stage-specific regulation and targeted therapy. Finally, we outline the major challenges impeding the clinical application of basic immunological discoveries and highlight future directions for improving patient outcomes.