Meeting Abstract
Innate immunity is an ancient defense mechanism that operates in multicellular organisms to detect and eliminate pathogens and distinguish self from non-self. Animal immune cells deploy diverse behaviors during pathogen detection and elimination, including phagocytosis, secretion of inflammatory cytokines, and expulsion of nuclear material – the casting of extracellular DNA “traps” (e.g. ETosis). While cells capable of mammalian neutrophil-like ETosis behavior were recently described in several bilaterian invertebrate taxa, the cellular immune system of the non-bilaterian clade Ctenophora remains almost completely undescribed. We have developed and deployed microscopy and biochemical approaches to explore and compare immune cell behaviors in model ctenophore (Mnemiopsis leidyi) stellate cells and oyster (Crassostrea gigas) hemocytes. Our findings suggest a variety of cell types may be competent for a range of anti-microbial responses, including ETosis. We also find that some immune cell type behaviors may be activated by non-canonical signaling pathways. This data provides an opportunity to explore both conserved and novel aspects of pathogen defense mechanisms associated with the evolution of the animal innate immunity.
