Secreted Phospholipase PLA2G5 Acts as a Self-Venom in Sepsis by Mediating Hemolysis

Sepsis is a systemic response to infection with life-threatening consequences such as hemolysis, a predictor of mortality risks for the disease. Here, by measuring organism-wide changes in gene expression, we discovered that the secreted phospholipase PLA2G5 is induced in colon cell types during sepsis. The genetic deletion and antibody blockade of PLA2G5 abrogated the lethal effects of sepsis. PLA2G5 blockade during sepsis led to an increase in splenic red pulp macrophages and iron homeostasis, linking PLA2G5 to red blood cell homeostasis during sepsis. Mechanistically, bloodborne PLA2G5 led to intravascular hemolysis through its lipolytic activity on red blood cell membranes. In humans with sepsis, the plasma level of PLA2G5 was elevated and predictive of disease severity and mortality. We conclude that sepsis corrupts PLA2G5 from the gut into becoming a systemic self-venom which is toxic for host red blood cells. We performed the experiment and 1 dataset was generated from the following experiments and samples: (1) Pla2g5 neutralizing antibody.