Biological Effects of Listeriolysin O: Implications for Vaccination

Figure 2

Innate and acquired immune response to LLO. (A) Pore forming activity of LLO induces cytosolic Ca²⁺ elevation in immune cells, which results in degranulation, activation, and release of proinflammatory molecules. (B) The binding of LLO on cell membranes induces lipid rafts aggregation, which is involved in cellular activation. (C) LLO has been described as a pathogen associated molecular pattern (PAMP), which is recognized by toll like receptor 4 (TLR-4), which results in NF-κB activation and gene modulation. As a recombinant antigen LLO traffics very efficiently to endosomal (D) or cytosolic compartments (E) promoting a highly efficient presentation to CD4+ and CD8+ T cells.