Search for the origin of the vertebrate immune system

Seniorforsker, PhD Niels Lorenzen, Danish Institute for Food and Veterinary Research, Århus

This project aims at chasing and characterising the evolutionary origin of the immune defence machanisms against infectious diseases in higher vertebrates. We hereby aim to create new knowledge of how the vertebrate immune system has developed in form and function and to relate this to the vertebrate immune system has developed in form and function and to relate this to the occurrence and evolution of disease-causing agents (pathogens). Fish comprise the greatest group of vertebrate species and they have adapted to many different habitats such as the Arctic, the tropics ant the deep sea. In the same time, fish represent the earliest class of vertebrates possessing the molecular key elements and functions of an adaptive immune system as known in higher vertebrates such as mammals, including man. By identification and characterisation of key molecules of the fish immune system in a variety of both the primitive and advanced fish species adapted to different life conditions, we will display the molecular spectrum of the immune system in this early class of vertebrates and hereby discover how the basic elements of the immune system known in mammals today have evolved. Since hosts and pathogens have developed hand in hand, we will also analyse the origin of the pathogens associated with the fish. The project will create scientific bachground for a better understanding of how the immune system is able to defend vertebrates against infections, and hereby provide valuable information for improvement of disease prophylaxis in cultured fish, terrestrial husbandry animals and man.