High-Throughput Screening to Develop a Biologically Relevant Netosis Induction Model

Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection (1). It is responsible for ~370,000 US deaths annually (2). Neutrophils are an integral part of the innate immune response and rapidly clear pathogens from circulation using neutrophil extracellular traps (NETs), which are released through a process called NETosis (3). NETs prevent dissemination of pathogens by entrapment in externalized chromatin containing deactivating enzymes. While we have learned much about the mechanisms underlying NETosis, we are yet to translate it to improved therapies or patient outcomes. This gap may be attributable to the models used to study NETosis. Current models used to investigate NETosis are limited and routinely employ unnatural triggers such as phorbol 12-myristate 13-acetate (PMA). PMA is not a physiological trigger present in the immune system and may bypass the natural pathways that regulate NETs production. Mouse models that use isolated neutrophils and neutrophil-like cells induced from immortalized cell lines do not completely reflect the complex cellular and molecular biology underlying neutrophil activation and NETosis, especially in a whole-blood environment. Therefore, it is crucial to study how specific factors, known to be upregulated in disease, interact and potentially induce NETosis. Here we use high-throughput screening and natural NETosis triggers to develop a more biologically relevant ex vivoNETosis (Synthetic-Sepsis™) model.