Leishmania promastigotes lack phosphatidylserine but bind annexin V upon permeabilization or miltefosine treatment

PLoS One. 2012;7(8):e42070. doi: 10.1371/journal.pone.0042070. Epub 2012 Aug 1.

Abstract

The protozoan parasite Leishmania is an intracellular pathogen infecting and replicating inside vertebrate host macrophages. A recent model suggests that promastigote and amastigote forms of the parasite mimic mammalian apoptotic cells by exposing phosphatidylserine (PS) at the cell surface to trigger their phagocytic uptake into host macrophages. PS presentation at the cell surface is typically analyzed using fluorescence-labeled annexin V. Here we show that Leishmania promastigotes can be stained by fluorescence-labeled annexin V upon permeabilization or miltefosine treatment. However, combined lipid analysis by thin-layer chromatography, mass spectrometry and (31)P nuclear magnetic resonance (NMR) spectroscopy revealed that Leishmania promastigotes lack any detectable amount of PS. Instead, we identified several other phospholipid classes such phosphatidic acid, phosphatidylethanolamine; phosphatidylglycerol and phosphatidylinositol as candidate lipids enabling annexin V staining.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Annexin A5 / metabolism*
  • Antiprotozoal Agents / pharmacology*
  • Cell Membrane Permeability / drug effects*
  • Humans
  • Leishmania / metabolism*
  • Phagocytosis / drug effects
  • Phosphatidylserines*
  • Phosphorylcholine / analogs & derivatives*
  • Phosphorylcholine / pharmacology

Substances

  • Annexin A5
  • Antiprotozoal Agents
  • Phosphatidylserines
  • Phosphorylcholine
  • miltefosine

Grants and funding

This work was supported by FAZIT (AW), Research Training Group 1121 of the German Research Foundation (AW, TGP), and the Carlsberg Foundation (TGP). TGP and GK gratefully acknowledge financial support from “Center for Synthetic Biology” at Copenhagen University funded by the UNIK research initiative of the Danish Ministry of Science, Technology and Innovation. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.