Immuno-detection of Immature and Bioactive Forms of the Inflammatory Cytokine IL-18

Gastric cancer (GC) is the third most lethal cancer worldwide, and like many other types of cancers, it is associated with precursory chronic inflammatory responses. In the context of many inflammation-associated cancers such as GC, activation of the innate immune response by infectious microbes and/or host-derived molecules is often characterized by production of the cytokines interleukin (IL)-1β and IL-18, which can often have divergent and opposing (i.e., pro or anti) roles in inflammation and oncogenesis. The processing of these mature bioactive cytokines from their inactive precursor polypeptides is dependent upon the enzyme Caspase-1, which is part of multiprotein complexes called "inflammasomes." Considering the recent mounting evidence for the role of IL-18 in the pathogenesis of GC, here, we describe a Western blotting technique used on genetic mouse models for GC to detect and characterize both pro-Il-18 and mature IL-18 proteins.