Enebie Ramos Cáceres

1 Introduction Neutrophils are the most abundant circulating leukocyte and serve as one of the first lines of defense against invading pathogens and acute inflammation [1]. Morphologically defined by their multilobulated nuclei, neutrophils possess a versatile arsenal to neutralize their targets, including degranulation (i.e., the release of cytotoxic molecules from cytoplasmic granules), phagocytosis, and neutrophil extracellular trap (NET) formation [1, 2].

Abstract Myeloperoxidase (MPO) plays an important role in the immune response of human neutrophils and has been implicated in autoimmune conditions, cardiovascular disorders, and neurodegeneration. Current methods to detect MPO activity rely on the detection of HOCl using activatable probes or require challenging experimental procedures. Therefore, these tools provide limited information about the dynamics and localization of MPO in complex molecular processes such as NETosis in real time.