Squalene-based emulsion adjuvant-mediated immune activation (null)

Squalene-based emulsion adjuvants, such as MF59 and AS03, are oil-in-water formulations used in vaccines to boost immune responses. They function by enhancing antigen uptake and presentation by local innate immune cells (dendritic cells, monocytes, macrophages), increasing recruitment of immune cells to the injection site and draining lymph nodes, and stimulating local cytokine production. This results in a stronger and broader adaptive immune response, notably improved antibody and CD8 T cell responses, compared to non-adjuvanted vaccines. The action involves RIPK3-dependent necroptosis of lymph node-resident macrophages for CD8 T cell activation and diverse pathways for antibody enhancement. Squalene adjuvants have an extensive safety record in seasonal and pandemic influenza vaccines and are being applied to new vaccine candidates, including for COVID-19, especially where strong or broader immune responses are needed[1][2][3][4][5][6][7].

Other names

Squalene emulsion adjuvantoil-in-water emulsion adjuvantMF59AS03

Enhancement of antigen uptake and presentation by dendritic cells (DCs), monocytes, and macrophages Recruitment of neutrophils, monocytes, and other granulocytes to the injection site and draining lymph nodes Activation of local cytokine and chemokine responses Promotion of cross-presentation to CD8 T cells via RIPK3-dependent necroptosis of lymph node-resident macrophages Depot formation (sustained antigen release)[1][2][3][4][5][6][7]