Annelida: Hirudinea (Leeches): Heterogeneity in leech immune responses

Abstract

This chapter provides a comprehensive picture of some of the most significant information on the type of cells and mechanisms involved in the regulation of the inflammation, immune response, and tissue regeneration processes in the medicinal leech. This annelid represents a useful experimental model for investigating the immune system, being cost effective, easily manipulable, and devoid of significant ethical considerations and regulatory restrictions in relation to its use. Moreover, this invertebrate model shows an innate immune response and a wound healing process characterized by the same responses as observed in vertebrates, involving the same cellular mechanisms and also the same types of molecules-as specific growth factors-playing a pivotal role in guiding, controlling, and regulating the angiogenesis and innate immune response.