Superoxide Anion Chemistry-Its Role at the Core of the Innate Immunity

Classically, superoxide anion O-2(center dot-) and reactive oxygen species ROS play a dual role. At the physiological balance level, they are a by-product of O-2 reduction, necessary for cell signalling, and at the pathological level they are considered harmful, as they can induce disease and apoptosis, necrosis, ferroptosis, pyroptosis and autophagic cell death. This revision focuses on understanding the main characteristics of the superoxide O-2(center dot-), its generation pathways, the biomolecules it oxidizes and how it may contribute to their modification and toxicity. The role of superoxide dismutase, the enzyme responsible for the removal of most of the superoxide produced in living organisms, is studied. At the same time, the toxicity induced by superoxide and derived radicals is beneficial in the oxidative death of microbial pathogens, which are subsequently engulfed by specialized immune cells, such as neutrophils or macrophages, during the activation of innate immunity. Ultimately, this review describes in some depth the chemistry related to O-2(center dot-) and how it is harnessed by the innate immune system to produce lysis of microbial agents.

Automated summary

This article mainly discusses the dual role of superoxide anion and reactive oxygen species (ROS) at the physiological and pathological levels, as well as the involvement of superoxide anion in cell signaling, diseases, and cell death. It focuses on the generation pathways of superoxide anion, the oxidation mechanism of biomolecules, and the role of superoxide dismutase in living organisms. It also explores the toxicity of superoxide and derived radicals in the oxidative death of microbial pathogens, and how they are utilized by the innate immune system to lyse microorganisms.