For a long time the existence in mammals of complex pathogen recognition and control mechanisms outside the domain of the classical lymphocyte-based immune system was not seriously considered. Now it is clear that the classical immune system, for all its virtuosity, depends for its effectiveness on the successful functioning of a raft of other mechanisms which operate on entirely different principles. Novel receptor systems have been described which recognise, not the unpredictable foreign structures seen by the classical immune system, but rather recurrent molecular patterns characteristic of pathogens, while novel effector systems are emerging which restrain and destroy pathogens in ways previously not thought of. Our own programme is concentrated on a group of dedicated GTPases which are essential for the survival of mice after infection with certain intracellular pathogens. We are trying to find out what they do and how they do it.

Jonathan Howard received his PhD in Oxford in 1969, where he investigated the cellular origin of antibody forming cells in rats under the supervision of J. L. Gowans in the Sir William Dunn School of Pathology. For his post-doctoral work he studied lymphocytes reactive against major histocompatibility antigens with Darcy Wilson at the University of Pennsylvania. After 20 years in his own laboratory at the Department of Immunology, The Babraham Institute, Cambridge, working on monoclonal antibodies and MHC immunogenetics, he joined the Institute for Genetics in Cologne in 1994. Since then his work has concentrated increasingly on the study of novel mechanisms in natural immunity. He is a fellow of the Royal Society and member of the EMBO and serves as editor for Genome Biology.