The Diverse and Dynamic Nature of <em>Leishmania</em> Parasitophorous Vacuoles Studied by Multidimensional Imaging

<div><p>An important area in the cell biology of intracellular parasitism is the customization of parasitophorous vacuoles (PVs) by prokaryotic or eukaryotic intracellular microorganisms. We were curious to compare PV biogenesis in primary mouse bone marrow-derived macrophages exposed to carefully prepared amastigotes of either <em>Leishmania major</em> or <em>L. amazonensis</em>. While tight-fitting PVs are housing one or two <em>L. major</em> amastigotes, giant PVs are housing many <em>L. amazonensis</em> amastigotes. In this study, using multidimensional imaging of live cells, we compare and characterize the PV biogenesis/remodeling of macrophages i) hosting amastigotes of either <em>L. major</em> or <em>L. amazonensis</em> and ii) loaded with Lysotracker, a lysosomotropic fluorescent probe. Three dynamic features of <em>Leishmania</em> amastigote-hosting PVs are documented: they range from i) entry of Lysotracker transients within tight-fitting, fission-prone <em>L. major</em> amastigote-housing PVs; ii) the decrease in the number of macrophage acidic vesicles during the <em>L. major</em> PV fission or <em>L. amazonensis</em> PV enlargement; to iii) the <em>L. amazonensis</em> PV remodeling after homotypic fusion. The high content information of multidimensional images allowed the updating of our understanding of the <em>Leishmania</em> species-specific differences in PV biogenesis/remodeling and could be useful for the study of other intracellular microorganisms.</p>