ABSTRACT
The inherent capability of the innate immune system to respond to a vast number of pathogens is mediated by its ability to recognize highly conserved motifs shared by diverse pathogens.[1-3] Examples of these motifscommonly referred to as pathogen-associated molecular patterns (PAMPs)—include the bacterial cell wall components, lipopolysaccharide (LPS), peptidoglycan (PGN), and lipoteichoic acid (LTA), as well as unmethylated cytosine phosphate guanine (CpG) residues present in the DNA of lower microorganisms.[2] Because these PAMPs are commonly expressed by pathogenic organisms, but not by the host, the innate immune system is capable of differentiating self from nonself. Further, the ability to recognize common PAMPs on distinct pathogens enables the innate immune system to respond to vast numbers of infectious agents with only a limited repertoire of host recognition elements.
