Figure 2.

Generation of innate immune memory using microbial ligands. Initial challenge with microbial ligands such as lipopolysaccharide, monophosphoryl lipid A, CpG, β-glucan potently stimulates host innate effector immune responses in cells such as neutrophils, monocytes, and macrophages, leading to the reprogramming of their metabolic and epigenetic status. Upon re-exposure of the initially primed host with a secondary inflammatory stimulus or infectious challenge, there occurs a heightened innate immune response against invading microbes via increased immune cell recruitment leading to improved microbial clearance and survival. This phenomenon is termed as innate immune memory.