Imaging Leishmania development in their host cells.

The interactions between the Leishmania parasite and its mammalian host cells are strongly regulated dynamic processes that take place at the molecular, cellular and organ level. Several different interaction models have been developed to take advantage of the development of imaging technologies. Here, we first review how conventional imaging techniques have been applied to fixed Leishmania-loaded tissue and cell samples. Then, we show how transgenic Leishmania expressing fluorescent or bioluminescent reporters allowed characterization of their tissue and cell host niches. Most notably, the use of whole-body imaging or intravital microscopy techniques has allowed accurate real-time monitoring of parasites in their environment. Finally, we discuss how innovative imaging technologies will allow further refinement of our understanding of the interplay between Leishmania and its hosts.