Innate immune cells in injection-site tissue – MF59-mediated activation

Innate immune cells in injection-site tissue – MF59-mediated activation refers to the localized physiological response triggered by the MF59 adjuvant, a squalene-based oil-in-water emulsion used in vaccines (O'Hagan et al., 2012, PubMed: 22126716). Rather than binding to a single specific receptor, MF59 acts by stimulating resident muscle and immune cells to produce a specific set of chemokines that recruit a variety of innate immune cells, such as monocytes and granulocytes, to the site of injection (Seubert et al., 2008, PubMed: 18460365). These recruited cells are essential for the efficient uptake of vaccine antigens and their subsequent transport to the draining lymph nodes. This process enhances the overall immunogenicity of the vaccine, particularly in populations with weakened immune systems, such as the elderly (Vono et al., 2013, PubMed: 23833260). The activation of these cells is a critical step in bridging the innate and adaptive immune systems to ensure a robust and long-lasting protective response against pathogens like the influenza virus (Cappelletti et al., 2013, PubMed: 23431024).

Other names

MF59-induced innate immune responseMF59-mediated recruitment of immune cellsInjection site immune activation by MF59

MF59 acts as an oil-in-water emulsion adjuvant that creates a local immunocompetent environment by inducing the secretion of chemokines (such as CCL2, CCL3, and CXCL8) from resident cells (O'Hagan et al., 2012, PubMed: 22126716). This leads to the rapid recruitment of innate immune cells, including monocytes, macrophages, and dendritic cells, to the injection site (Seubert et al., 2008, PubMed: 18460365). These cells then take up the vaccine antigen and transport it to the draining lymph nodes, where they promote the differentiation of T cells and B cells, ultimately enhancing the magnitude and breadth of the adaptive immune response (Vono et al., 2013, PubMed: 23833260).