Deletion of a Single LeishIF4E-3 Allele by the CRISPR-Cas9 System Alters Cell Morphology and Infectivity of Leishmania

Abstract

Leishmania species are the causative agents of a spectrum of diseases. Available drug treatment is toxic and expensive, with drug resistance a growing concern. Leishmania parasites migrate between transmitting sand flies and mammalian hosts, experiencing unfavorable extreme conditions. The parasites therefore developed unique mechanisms for promoting a stage-specific program for gene expression, with translation playing a central role. There are six paralogs of the cap-binding protein eIF4E, which vary in their function, expression profiles, and assemblages. Using the CRISPR-Cas9 system for Leishmania , we deleted one of the two LeishIF4E-3 alleles. Expression of LeishIF4E-3 in the deletion mutant was low, leading to reduction in global translation and growth of the mutant cells. Cell morphology also changed, affecting flagellum growth, cell shape, and infectivity. The importance of this study is in highlighting that LeishIF4E-3 is essential for completion of the parasite life cycle. Our study gives new insight into how parasite virulence is determined.