The cell cycle of Leishmania: morphogenetic events and their implications for parasite biology

Abstract

The cell cycle is central to understanding fundamental biology of Leishmania, a group of human-infective protozoan parasites. Leishmania have two main life cycle morphologies: the intracellular amastigote in the mammalian host and the promastigote in the fly. We have produced the first comprehensive and quantitative description of a Leishmania promastigote cell cycle taking a morphometric approach to position any cell within the cell cycle based on its length and DNA content. We describe timings of cell cycle phases and rates of morphological changes; kinetoplast and nucleus S phase, division and position, cell body growth and morphology changes, flagellum growth and basal body duplication. We have shown that Leishmania mexicana undergoes large changes in morphology through the cell cycle and that the wide range of morphologies present in cultures during exponential growth represent different cell cycle stages. We also show promastigote flagellum growth occurs over multiple cell cycles. There are clear implications for the mechanisms of flagellum length regulation, life cycle stage differentiation and trypanosomatid division in general. This data set therefore provides a platform which will be of use for post-genomic analyses of Leishmania cell biology in relation to differentiation and infection.

Apoptotic-likeLeishmaniaexploit the host´s autophagy machinery to reduce T-cell-mediated parasite elimination

“…Cell cycle analysis was performed using propidium iodide staining, as described. 66 Human peripheral mononuclear cells Human peripheral mononuclear cells (PBMCs) were isolated from buffy coats (DRK-Blutspendedienst Hessen GmbH, 506838) by passage over a Leukocyte Separation Medium (PAA, J15-004) gradient. The donors were healthy German adults without known exposure to Leishmania parasites.…”

Cloning, expression, purification, crystallization and preliminary X-ray diffraction analysis of the mitochondrial tryparedoxin peroxidase fromLeishmania braziliensis

“…Leishmania parasites present two well defined forms in their life cycle: the promastigote in insects and the intracellular amastigote in the mammalian host (Wheeler et al, 2011). At the infection stage, a large amount of reactive oxygen or nitrogen intermediates are generated by the host cell to create unfavourable conditions for parasite development (Eslami et al, 2011).…”

Effect of Human Urine on Cell Cycle and Infectivity of Leismania Species Promastigotes In Vitro

“…Finally, the cell is reduced in length and retains the duplicated DNA content (G2 and mitosis) before cytokinesis returns the cell to start a new cell cycle. 39 However, Leishmania promastigote length shows a wide distribution (6-12 mm) and no significant difference between culture densities. Similarly, total DNA content has a two-fold range and no significant difference between culture densities during the cell cycle.…”

“…Similarly, total DNA content has a two-fold range and no significant difference between culture densities during the cell cycle. 39 On the basis of flow cytometry data, urine-containing culture media create differences in analysis of the cell cycle. Although a decrease in G0/G1 phases was observed compared with controls, there was an increase in G2/M, S phases and the proliferative index.…”