Netome: The Molecular Characterization of Neutrophil Extracellular Traps (NETs)

Abstract

Neutrophils are the most abundant type of white blood cells in humans with biological roles relevant to inflammation and fighting infections. The release of neutrophil extracellular DNA aims to control invasion by bacteria, viruses, fungi, and tissue damage. Neutrophil Extracellular Traps (NETs) act as antimicrobial agents triggering immune signaling through the release of the nuclear content into the extracellular space. Although intense investigations have elucidated the pathways preceding NET formation, the exact molecular composition of released NETs has not been mapped. We aimed to decode the sequences of DNA and proteins from NETs. With emerging needs to understand neutrophil functions precisely, we open the field of NETOMIC studies through isolation of NETs in combination with omics approaches including shotgun genomics and proteomics. Our in vitro NET isolation methodology allowed for unprecedented replicability with induction in a sterile inflammation model system. Enrichment of mitochondrial DNA and telomere sequences are significantly expressed in NET genomes. This study revealed that the genomic sequence released in the extracellular milieu is not stochastically serving as a scaffold for a repertoire of proteins involved in neutrophil protective functions. Collectively, we established the gene and protein signatures exclusive to the extracellular NETs in comparison to undifferentiated and differentiated neutrophil states, further guiding future detection of specific regions needed for diagnostics and targeted therapies of NET related conditions.