Innate immune cells and pattern-recognition pathways activated by AS03 adjuvant

The innate immune cells and pattern-recognition pathways activated by the AS03 adjuvant represent a complex physiological response designed to enhance vaccine efficacy. AS03 is an oil-in-water emulsion consisting of squalene, alpha-tocopherol, and polysorbate 80, which acts by creating a transient immunocompetent environment at the injection site (Morel et al., 2011, PubMed: 21296405). It triggers the endoplasmic reticulum (ER) stress response and the NF-kappaB signaling pathway, rather than directly stimulating Toll-like receptors (Givestein et al., 2016). This activation results in the localized production of cytokines and chemokines, such as IL-6, CCL2, and CXCL10, which recruit monocytes and dendritic cells to the site of injection (Garçon et al., 2012, Expert Review of Vaccines). These recruited cells then transport vaccine antigens to the draining lymph nodes, promoting a robust and long-lasting adaptive immune response. AS03 has been successfully utilized in pandemic influenza vaccines to achieve significant dose-sparing and high seroconversion rates (Burny et al., 2017, Journal of Infectious Diseases).

Other names

AS03-induced innate immune responseAS03-mediated signalingAdjuvant System 03 activationAS03-triggered innate pathways

Induction of a transient local innate immune response via activation of the endoplasmic reticulum (ER) stress response and NF-kappaB pathway, leading to cytokine production and recruitment of antigen-presenting cells (Morel et al., 2011).