Immunological aspects of infections part 6

Over the past decade, our knowledge of how we sense the microbial world (innate or adaptive) has fundamentally changed. It has been known for decades that microbial products such as lipopolysaccharides, lipoprotein or peptidoglycans have profound effects   on human cells. Although the structures of many  different pathogenic microbial compounds have been extensively studied, the molecular basis of their recognition by cells of the innate immune system remained elusive. Charles Janeway first developed the concept of microbial structures forming pathogen-associated molecular patterns (PAMPs), which would be recognized by pattern recognition receptors (toll refers to the toll gene of Drosophila, initially identified as an essential receptor controlling  dorsoventral polarization during embryonic development of the fly larvae) in species as diverse as Drosophila fly and humans and the recognition of their role in distinguishing molecular patterns that are common to microorganisms led to a renewed appreciation of the innate immune system.