title: Leishmania promastigotes lack phosphatidylserine but bind annexin V upon permeabilization or miltefosine treatment.
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.
authors.affiliation: Institute of Biology, Humboldt-Universität zu Berlin, Berlin, Germany.
authors.forename: Adrien
authors.initials: A
authors.lastname: Weingärtner
authors.forename: Gerdi
authors.initials: G
authors.lastname: Kemmer
authors.forename: Frederic D
authors.initials: FD
authors.lastname: Müller
authors.forename: Ricardo Andrade
authors.initials: RA
authors.lastname: Zampieri
authors.forename: Marcos
authors.initials: M
authors.lastname: Gonzaga dos Santos
authors.forename: Jürgen
authors.initials: J
authors.lastname: Schiller
authors.forename: Thomas Günther
authors.initials: TG
authors.lastname: Pomorski
mesh_terms: D017304:Annexin A5 / Q000378:metabolism*; D000981:Antiprotozoal Agents / Q000494:pharmacology*; D002463:Cell Membrane Permeability / Q000187:drug effects*; D006801:Humans; D007891:Leishmania / Q000378:metabolism*; D010587:Phagocytosis / Q000187:drug effects; D010718:Phosphatidylserines; D010767:Phosphorylcholine / Q000031:analogs & derivatives* / Q000494:pharmacology
chemical_list: D017304:Annexin A5; D000981:Antiprotozoal Agents; D010718:Phosphatidylserines; D010767:Phosphorylcholine; C039128:miltefosine