title: Encapsulation of Living Leishmania Promastigotes in Artificial Lipid Vacuoles.
abstract: After phagocytosis by mammalian macrophages, promastigote forms of Leishmania parasites settle inside intracellular parasitophorous vacuoles (PVs) in which they transform into amastigote forms and replicate. Here, using a variant of the 'inverted emulsion' method, we succeeded in encapsulating living L. amazonensis parasites in giant artificial liposomes that serve as model PVs. We were able to control the size of liposomes, the pH and the composition of their internal volume, and the number of internalized parasites per liposome. L. amazonensis promastigotes encapsulated in liposomes filled with RPMI-Dextran solution at pH 7.5 or 6.5 survived up to 96 h at 24°C. At 37°C and pH 5.5, parasites survived 48h. This method paves the way to identifying certain effectors secreted by the parasite and to unraveling specific mechanisms of fusion between the PV and intracellular vesicles of the host cell. This method will also facilitate the study of the temporal evolution of biophysical properties of the PV during its maturation.
authors.affiliation: Centro de Pesquisas Gonçalo Moniz, Fiocruz, Laboratório de Patologia e Biointervenção, Rua Waldemar Falcão, 121, Candeal, Salvador, Bahia, Brazil.
authors.forename: Carlos E S
authors.initials: CE
authors.lastname: Guedes
authors.affiliation: Centro de Pesquisas Gonçalo Moniz, Fiocruz, Laboratório de Patologia e Biointervenção, Rua Waldemar Falcão, 121, Candeal, Salvador, Bahia, Brazil.
authors.forename: Jose G B
authors.initials: JG
authors.lastname: Lima
authors.affiliation: Aix-Marseille Université, CNRS, CINaM UMR 7325, 13288, Marseille, France.
authors.forename: Emmanuèle
authors.initials: E
authors.lastname: Helfer
authors.affiliation: Centro de Pesquisas Gonçalo Moniz, Fiocruz, Laboratório de Patologia e Biointervenção, Rua Waldemar Falcão, 121, Candeal, Salvador, Bahia, Brazil.
authors.forename: Patricia S T
authors.initials: PS
authors.lastname: Veras
authors.affiliation: Aix-Marseille Université, CNRS, CINaM UMR 7325, 13288, Marseille, France.
authors.forename: Annie
authors.initials: A
authors.lastname: Viallat
mesh_terms: D055598:Chemical Phenomena; D003911:Dextrans; D004655:Emulsions; D007894:Leishmania mexicana / Q000254:growth & development* / Q000502:physiology; D008081:Liposomes; D008899:Mineral Oil; D010274:Parasitology / Q000379:methods*; D010587:Phagocytosis; D010743:Phospholipids; D012996:Solutions; D013535:Suspensions; D014617:Vacuoles / Q000469:parasitology*
chemical_list: D003911:Dextrans; D004655:Emulsions; D008081:Liposomes; D010743:Phospholipids; D012996:Solutions; D013535:Suspensions; D008899:Mineral Oil