Dynamic imaging of host–pathogen interactions in vivo

Recent advances in microscopic imaging methods, together with the development of genetically encoded fluorescent reporters, have made it possible to directly visualize host–pathogen interactions in living tissues.Time-lapse imaging studies have provided new insights into how immune cells function as sentinels for infection and tissue damage through active patrolling and sampling behaviour.Recent imaging studies have revealed how pathogens may use the neutrophil response to their own benefit and the role of neutrophils in tissue remodelling following infection.Dynamic imaging of Plasmodium spp. infection has provided important information regarding dissemination of the parasite from the site of infection, how Plasmodium spp. use Kupffer cells to access the liver and the strategies used by the parasite to avoid phagocytosis.The immune response to pathogens in the subcapsular sinus of the lymph node has been studied in some detail. These studies revealed the importance of subcapsular sinus macrophages in trapping lymph-borne pathogens and in presenting antigen to B and T cells. These studies also reveal how intracellular pathogens can invade macrophages and how T cell contacts with invaded macrophages may expose T cells to direct invasion by pathogens.T cell responses to pathogens in peripheral tissues have recently been imaged, revealing how T cells migrate within these tissues and interact with antigen-presenting cells.