Activity: Talk or presentation › Oral presentation
Fish represent the first vertebrate group in evolution with well-developed adaptive immune responses comparable with those found in mammals, including diverse roles for immunoglobulin subtypes. Innate immune responses of fish may be relatively important and include important roles for natural antibodies, Toll-like receptors, phagocytic B cells and thrombocytes and polarized macrophages, among others. Fish typically live in highly diverse environments including fresh versus seawater and cold versus warm water with gut, skin, nose and gill as important organs for mucosal defense. Although fish are highly diverse with >30,000 different species including cartilaginous and bony representatives, zebrafish are considered an excellent vertebrate animal model species. In this lecture I will first summarize conserved aspects of the fish’ immune system, including characteristics of macrophage polarization and trained immunity and subsequently highlight a number of unique aspects. I will conclude with new insights in the function of fish gills, which not only are extremely important for a range of physiological processes including gas and nitrogenous waste exchange between blood and water, but have an associated large surface area and thin epithelial layer that makes fish gills highly vulnerable to infection, with organized lymphoid tissue within the mucosal linings of fish gills waiting to fight water-borne microorganisms.