The Diverse and Dynamic Nature of Leishmania Parasitophorous Vacuoles Studied by Multidimensional Imaging

Abstract

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 Leishmania major or L. amazonensis. While tight-fitting PVs are housing one or two L. major amastigotes, giant PVs are housing many L. amazonensis 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 L. major or L. amazonensis and ii) loaded with Lysotracker, a lysosomotropic fluorescent probe. Three dynamic features of Leishmania amastigote-hosting PVs are documented: they range from i) entry of Lysotracker transients within tight-fitting, fission-prone L. major amastigote-housing PVs; ii) the decrease in the number of macrophage acidic vesicles during the L. major PV fission or L. amazonensis PV enlargement; to iii) the L. amazonensis PV remodeling after homotypic fusion. The high content information of multidimensional images allowed the updating of our understanding of the Leishmania species-specific differences in PV biogenesis/remodeling and could be useful for the study of other intracellular microorganisms.

Trypanosoma cruzi Differentiates and Multiplies within Chimeric Parasitophorous Vacuoles in Macrophages Coinfected with Leishmania amazonensis

“…4; also see Movie S4). Rab7 is a marker of late endosomes and phagolysosomes, which can be observed in the membrane of PVs formed by L. amazonensis or T. cruzi in the first few hours postinfection in vitro (47,73). At the beginning of our recordings, MT forms could be seen surrounded by Rab7; a flagellum also could be inferred from Rab7 contours (Fig.…”

“…T. cruzi resides in a transient parasitophorous vacuole (PV) from which the parasite escapes into the host cell cytosol, where it then multiplies (72). L. amazonensis develops in spacious PVs containing dozens, even hundreds, of multiplying parasites that remain in these vacuoles until their transfer to other host cells (73,74). Due to the morphology of large L. amazonensis PVs, it is possible to study coinfection between L. amazonensis and T. cruzi forms.…”

Drug Delivery: Lessons to Be Learnt From Leishmania Studies

“…Once at the site of infection, any drug must first permeate the infected macrophage membrane before crossing the membrane of the PV and finally cross the plasma membrane of the parasite (Figure 1). Studies using live imaging of immunolabeled parasites and lysotracker dyes have shown the dynamic nature of PV [3]. These studies showed that the increase in size of L. amazonensis PVs was associated with a decrease in acidic vesicles within infected macrophages.…”

“…The form and size of the PV varies for different Leishmania species. L. mexicana and L. amazonesis live in large communal PV that contain several parasites within the one membrane whereas PVs of L. donovani and L. major are relatively small and contain fewer amastigotes [3,4]. The parasites maintain an acidic pH in the PV to favor their intracellular survival and they have access to nutrients brought by new endosomes or can take in substances via their posterior pole, which has tight contact future science group Review Shaw & Carter with the PV membrane.…”

Cyclopalladated Compound 7a Induces Apoptosis- and Autophagy-Like Mechanisms in Paracoccidioides and Is a Candidate for Paracoccidioidomycosis Treatment

“…Four different microscopic fields of each sample were recorded. Live-cell serial images were processed by Imaris software (Bitplane) as follows on the basis of methods previously established (19). Isosurfaces were constructed on the basis of the calcofluor signal, which allowed the assessment of several morphological parameters, such as volume, area, and relative fluorescence intensity.…”