Cow Interleukin 18 (IL18) Protein

Background

IL18 is a pro-inflammatory cytokine and a member of the interleukin-1 (IL-1) family, playing a critical role in innate and adaptive immunity. IL18 is produced as an inactive precursor (pro-IL18) and activated by caspase-1 following inflammasome activation. It signals through the IL18 receptor complex, comprising IL18R1 and IL18RAP, leading to the activation of NF-κB, MAPK, and JNK pathways, which promote IFN-γ production, cytokine release, and immune cell activation. IL18 is primarily produced by macrophages, dendritic cells, and epithelial cells in response to infections, tissue damage, and inflammatory stimuli. It plays a pivotal role in enhancing Th1 immune responses, promoting NK cell activation, and inducing IFN-γ-dependent pathogen clearance. Additionally, IL18 supports Th2 and Th17 responses under specific conditions, contributing to allergic inflammation and autoimmunity. Dysregulation of IL18 is associated with chronic inflammation, autoimmune diseases (e.g., rheumatoid arthritis, lupus), and tumor progression, where excessive IL18 signaling exacerbates tissue damage and immune imbalance. Knockout studies show impaired IFN-γ production, defective NK and Th1 responses, and increased susceptibility to infections, underscoring IL18's essential role in immune regulation and host defense.