Innate immune sensing pathways engaged by aluminium adjuvant

Innate immune sensing pathways engaged by aluminium adjuvant refer to the complex molecular mechanisms through which aluminum salts (alum) enhance the body's immune response to vaccine antigens. Alum acts as a potent activator of the innate immune system by triggering several distinct pathways, most notably the NLRP3 inflammasome. Upon phagocytosis, alum particles cause lysosomal destabilization and the release of cathepsin B, which leads to the assembly of the NLRP3 inflammasome, activation of caspase-1, and the secretion of pro-inflammatory cytokines IL-1β and IL-18. Additionally, alum induces the release of damage-associated molecular patterns (DAMPs) such as host DNA and uric acid, which are sensed by the cGAS-STING pathway and contribute to dendritic cell maturation and Th2-biased adaptive immunity. Alum also interacts directly with cell membrane lipid rafts to activate Syk and PI3K signaling pathways, further promoting antigen uptake and presentation. While highly effective for enhancing antibody production, these pathways are also associated with local inflammation and rare systemic safety concerns.

Other names

Alum-induced innate immune pathwaysAluminium adjuvant sensingNLRP3 inflammasome activation by alumSyk-dependent alum sensingDAMP-mediated alum sensing

Activation of the NLRP3 inflammasome via lysosomal destabilization; induction of DAMP release (DNA, uric acid); activation of Syk kinase and PI3K signaling.