title: Changes to cholesterol trafficking in macrophages by Leishmania parasites infection.
abstract: Leishmania spp. are protozoan parasites that are transmitted by sandfly vectors during blood sucking to vertebrate hosts and cause a spectrum of diseases called leishmaniases. It has been demonstrated that host cholesterol plays an important role during Leishmania infection. Nevertheless, little is known about the intracellular distribution of this lipid early after internalization of the parasite. Here, pulse-chase experiments with radiolabeled cholesteryl esterified to fatty acids bound to low-density lipoproteins indicated that retention of this source of cholesterol is increased in parasite-containing subcellular fractions, while uptake is unaffected. This is correlated with a reduction or absence of detectable NPC1 (Niemann-Pick disease, type C1), a protein responsible for cholesterol efflux from endocytic compartments, in the Leishmania mexicana habitat and infected cells. Filipin staining revealed a halo around parasites within parasitophorous vacuoles (PV) likely representing free cholesterol accumulation. Labeling of host cell membranous cholesterol by fluorescent cholesterol species before infection revealed that this pool is also trafficked to the PV but becomes incorporated into the parasites' membranes and seems not to contribute to the halo detected by filipin. This cholesterol sequestration happened early after infection and was functionally significant as it correlated with the upregulation of mRNA-encoding proteins required for cholesterol biosynthesis. Thus, sequestration of cholesterol by Leishmania amastigotes early after infection provides a basis to understand perturbation of cholesterol-dependent processes in macrophages that were shown previously by others to be necessary for their proper function in innate and adaptive immune responses.
authors.affiliation: Mycotic and Parasitic Agents and Mycobacteria, Department of Infectious Diseases, Robert Koch-Institute, Berlin, Germany.
authors.forename: Geo
authors.identifier: 0000-0001-9815-4718
authors.initials: G
authors.lastname: Semini
authors.affiliation: Institute of Immunology and Infection Research, The University of Edinburgh, Edinburgh, UK.
authors.forename: Daniel
authors.initials: D
authors.lastname: Paape
authors.affiliation: Institute of Immunology and Infection Research, The University of Edinburgh, Edinburgh, UK.
authors.forename: Athina
authors.initials: A
authors.lastname: Paterou
authors.affiliation: Institute of Immunology and Infection Research, The University of Edinburgh, Edinburgh, UK.
authors.forename: Juliane
authors.initials: J
authors.lastname: Schroeder
authors.affiliation: Institute of Immunology and Infection Research, The University of Edinburgh, Edinburgh, UK.
authors.forename: Martin
authors.initials: M
authors.lastname: Barrios-Llerena
authors.affiliation: Mycotic and Parasitic Agents and Mycobacteria, Department of Infectious Diseases, Robert Koch-Institute, Berlin, Germany.|Institute of Immunology and Infection Research, The University of Edinburgh, Edinburgh, UK.
authors.forename: Toni
authors.initials: T
authors.lastname: Aebischer
mesh_terms: D000818:Animals; D001692:Biological Transport; D002462:Cell Membrane / Q000378:metabolism; D002784:Cholesterol / Q000378:metabolism*; D004195:Disease Models, Animal; D007894:Leishmania mexicana / Q000254:growth & development* / Q000378:metabolism*; D007896:Leishmaniasis / Q000469:parasitology / Q000473:pathology; D008264:Macrophages / Q000378:metabolism* / Q000469:parasitology*; D008808:Mice, Inbred CBA; D014617:Vacuoles / Q000378:metabolism* / Q000469:parasitology*
chemical_list: D002784:Cholesterol
keywords: 
  Leishmania
  ; Niemann-Pick C1 (NPC1); cholesterol; filipin staining; macrophages; parasitophorous vacuole