Innate immune cells (AS03-engaged)

The innate immune cells engaged by the AS03 adjuvant system represent a coordinated cellular response at the injection site and draining lymph nodes (dLNs) rather than a single molecular target. AS03 is an oil-in-water emulsion adjuvant composed of alpha-tocopherol, squalene, and polysorbate 80, which functions by creating a transient 'immunocompetent environment' (Morel et al., 2011). Upon injection, it triggers the rapid production of chemokines such as CCL2 and CXCL10, which recruit monocytes, macrophages, and granulocytes to the site of administration (Garçon et al., 2012). These recruited cells internalize the vaccine antigen and migrate to the dLNs, where they facilitate the activation of the adaptive immune system, specifically enhancing B-cell and T-cell responses. The presence of alpha-tocopherol is a distinguishing feature of AS03, as it significantly modulates the magnitude of the innate response and subsequent antibody titers compared to squalene-only emulsions (Morel et al., 2011; Cohet et al., 2019).

Other names

AS03-responsive innate immune cellsInjection site immune infiltrateDraining lymph node innate cellsAS03-activated antigen-presenting cells

AS03 induces a transient local innate immune response at the injection site, characterized by the release of cytokines and chemokines that recruit and activate antigen-presenting cells for migration to draining lymph nodes (Morel et al., 2011).