Cytokine secretion pathway

The cytokine secretion pathway refers to the tightly regulated cellular processes by which cytokines—small signaling proteins crucial for immune regulation—are packaged, trafficked, and released from immune cells and other cell types[1][3][4][5][7]. In immune cells, there are two main routes: Classical (constitutive) secretion: Cytokines are synthesized in the endoplasmic reticulum, trafficked via vesicles to the Golgi apparatus, and then directed to the cell surface for release. This is common in macrophages and other immune cells that lack storage granules[1][3][4]. Regulated (granule-mediated) secretion: Certain cells, such as eosinophils and mast cells, store cytokines in secretory granules for rapid release upon activation[1][3][5]. Key molecular machinery includes Rab and Rho family GTPases (regulate trafficking), SNARE proteins (mediate vesicle fusion and release), and other intracellular membrane transporters. Some cytokines (e.g., IL-1β, IL-18) utilize nonclassical secretion pathways that do not rely on the canonical ER-Golgi route[1][3][4]. Disruption or excessive activation of the cytokine secretion pathway is implicated in pathological conditions such as cytokine release syndrome, inflammation, autoimmune diseases, and cancer[4]. In summary: This entry does not describe a single molecule, receptor, or enzyme and is thus technically incorrect as a "therapeutic target," but the pathway’s components are individually relevant for drug targeting in immune and inflammatory diseases[4][5][7].

Other names

Cytokine release pathwayCytokine exocytosis pathway