Host Immune Response to H. pylori Infection

Neutrophils are the most abundant white blood cells in the blood and constitute a crucial part of innate immunity. As the first responders and key components of the innate immune response, neutrophils can function rapidly and diversely to combat invading pathogens and maintain tissue homeostasis [1, 2]. They destroy pathogens through phagocytosis, intracellular degradation, release of granules, and the formation of extracellular traps. In fact, neutrophils possess an impressive arsenal of antimicrobial peptides and defensins and deploy a range of oxidative mechanisms to eliminate pathogens [3, 4]. The activation of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase complex within neutrophils produces reactive oxygen species (ROS) with bactericidal properties, such as superoxide anion and hydrogen peroxide [5, 6]. Furthermore, neutrophils form neutrophil extracellular traps (NETs), which are web-like structures composed of chromatin and antimicrobial proteins used to capture and neutralize extracellular pathogens [7, 8].