SIRPA and bacterial infectious disease: The levels of immunosuppressive molecule PD-L1 and phagocytosis inhibitory molecule SIRPα are significantly elevated on WT exhausted neutrophils, which correlate closely with the immunosuppression phenotype favoring the augmentation of Th2 cells and depression of Th1 cells as well as the reduced neutrophil phagocytic potential to combat bacterial infection during the late stage of sepsis21,64,65.