Leishmania-host interactions: what has imaging taught us?

Leishmania parasites are well adapted to initiate infection, resist the onslaught of innate immunity and achieve a state of long-lived persistence. In recent years, the tools available to study these interactions have developed enormously and have become much more widely available. Confocal microscopy, live cell imaging, whole animal imaging and intra-vital 2-photon now complement and extend the classical light and electron microscopical techniques. Coupled with approaches to generate transgenic parasites that express imaging friendly reporter proteins, these tools are making the full breadth of the life cycle accessible to imaging studies. New insights into the life history of these highly successful parasites are emerging with increasing frequency, and often with startling clarity and visual drama. In this short review, we focus on how this new generation of imaging-based research tools has augmented our understanding of the complex interplay that occurs between Leishmania and the cells that it infects in mammalian hosts.