A pan-immune panorama of bacterial pneumonia revealed by a large-scale single-cell transcriptome atlas

T cell function, potentially reflecting a compensatory mechanism. Dysregulated neutrophil and macrophage responses contributed significantly to the pathogenesis of severe disease. Immature neutrophils promote excessive inflammation and suppress T cell activation, while a specific macrophage subset (Macro_03_M1) displaying features akin to myeloid-derived suppressor cells (M-MDSCs) suppress T cells and promote inflammation. Together, these findings highlight potential therapeutic targets for modulating immune responses and improving clinical outcomes in bacterial pneumonia.