Role of Innate Immunity in Host Defense

Abstract

Identification of Toll-like receptors (TLR) has led to elucidation of the mechanisms by which innate immunity senses invasion of pathogens and triggers host defense responses. In addition to TLRs, it has been revealed that cytoplasmic sensors such as NOD and RIG-I family of proteins are responsible for the recognition of pathogens in the cytoplasms. Innate immune responses, when in excess, have been shown to induce immune disorders such as chronic inflammatory bowel diseases. Therefore, activity of innate immune cells are finely regulated to prevent exaggerated inflammatory responses. As one of the mechanisms, IκBNS has been revealed to inhibit TLR-dependent induction of a subset of genes.