The past, present, and future of Leishmania genomics and transcriptomics

Abstract

It has been nearly 10 years since the completion of the first entire genome sequence of a Leishmania parasite. Genomic and transcriptomic analyses have advanced our understanding of the biology of Leishmania, and shed new light on the complex interactions occurring within the parasite-host-vector triangle. Here, we review these advances and examine potential avenues for translation of these discoveries into treatment and control programs. In addition, we argue for a strong need to explore how disease in dogs relates to that in humans, and how an improved understanding in line with the 'One Health' concept may open new avenues for the control of these devastating diseases.

Keywords: Leishmania infantum; One Health; bioinformatics; genome; high-throughput sequencing; host-parasite interactions; leishmaniases; metazoonosis; sand fly; transcriptome.

Figure 1

Life cycle of Leishmania spp. and examples of molecules putatively involved in parasite infectivity and visceralisation of infection. Phlebotominae sand flies release Leishmania infective stages (i.e., metacyclic promastigotes) to the mammalian hosts during blood feeding (1); the parasites invade macrophages and granulocytes (2 and 3) and develop to amastigotes inside the phagolysosome (4); the amastigote stages replicate within the phagolysosome by simple division (5); then, amastigote-containing macrophages are ingested by susceptible sand flies during the blood meal (6); the parasites are released from the infected macrophages within the sand fly midgut (7), where they transform into procyclic promastigotes and divide. Then, the parasites migrate towards the stomodeal valve (anterior midgut) and transform into different promastigote subtypes that ultimately form metacyclic promastigotes (8). These infective stages are then released into a new mammalian host during a subsequent blood meal (9) . Abbreviation: Cox2, prostaglandin-endoperoxide synthase 2.