Editorial overview: Innate immunity - cross-talk with adaptive immunity through pattern recognition receptors and cytokines

摘要

For many years, the molecular and cellular basis of adaptive immune responses has been the focus of immunological research worldwide. The increasing knowledge of the role of MHC molecules and T-cell receptors in antigen presentation and recognition led to refined models of how tolerance is generated and maintained on the basis of the immune system's capacity to discriminate between 'self and 'non-self . Another (not mutually exclusive) view of the function of the immune system has been proposed by Polly Matzinger. She postulated that the immune system's primary task is to sense any kind of 'danger', which might come not only from outside (e.g. infectious microorganisms) but also from inside the body (e.g. tissue damage) . The discovery of pattern recognition receptors that recognize conserved molecular patterns that are shared by many bacteria (e.g. lipopetides, peptidoglycan, lipopolsaccharide and bacterial DNA) or viruses (e.g. single-stranded or double-stranded RNA) has greatly advanced the concept of pattern recognition as a prime task of the innate immune system. Whereas such pattern recognition receptors generally recognize non-self microbial ligands (and thus mediate selfon-self discrimination), some also recognize endogenous ligands that can be generated under abnormal conditions or as an indirect result of infection.