The innate immune response

•The innate immune response is described in an evolutionary perspective.•The cellular and humoral branches of the innate immune response are discussed.•Regulation of the immune response by the neuronal system is reviewed.

The innate immune response is of prime importance in the immediate recognition and elimination of invading micro-organisms. However, deregulation of this system is clearly associated with the pathogenesis of a wide range of inflammatory diseases. Innate immunity consists of a humoral and a cellular branch, which are closely interacting. An additional level of control is found at the level of neuronal reflexes that can fine-tune these immunological mechanisms.