title: Effect of phosphatidylcholine-cholesterol liposomes on Entamoeba histolytica virulence.
abstract: Trophozoites of Entamoeba histolytica HM-1:IMSS become less virulent after long-term maintenance in axenic cultures. The factors responsible for the loss of virulence during in vitro cultivation remain unclear. However, it is known that in vitro cultivation of amoeba in culture medium supplemented with cholesterol restores their virulence. In this study, we analyzed the effect of adding phosphatidylcholine-cholesterol (PC-Chol) liposomes to the culture medium and evaluated the effect of this lipid on various biochemical and biological functions of E. histolytica HM-1:IMSS in terms of its virulence. The addition of PC-Chol liposomes to the culture medium maintained the virulence of these parasites against hamster liver at the same level as the original virulent E. histolytica strain, even though these amoebae were maintained without passage through hamster liver for 18 months. The trophozoites also showed increased endocytosis, erythrophagocytosis, and carbohydrate residue expression on the amoebic surface. Protease activities were also modified by the presence of cholesterol in the culture medium. These findings indicate the capacity of cholesterol to preserve amoeba virulence and provide an alternative method for the maintenance of virulent E. histolytica trophozoites without the need for in vivo procedures.
authors.affiliation: Department of Cell Biology, Center for Research and Advanced Studies, Av. Instituto Politécnico Nacional 2508, Zacatenco 07360, México D.F., City 07360, México. serranolunajesus@yahoo.com.mx
authors.forename: Jesús
authors.initials: J
authors.lastname: Serrano-Luna
authors.forename: Manuel
authors.initials: M
authors.lastname: Gutiérrez-Meza
authors.forename: Ricardo
authors.initials: R
authors.lastname: Mejía-Zepeda
authors.forename: Silvia
authors.initials: S
authors.lastname: Galindo-Gómez
authors.forename: Víctor
authors.initials: V
authors.lastname: Tsutsumi
authors.forename: Mineko
authors.initials: M
authors.lastname: Shibayama
mesh_terms: D000818:Animals; D002784:Cholesterol / Q000032:analysis / Q000494:pharmacology*; D003208:Concanavalin A / Q000032:analysis; D006224:Cricetinae; D003470:Culture Media / Q000737:chemistry; D004705:Endocytosis / Q000187:drug effects; D004748:Entamoeba histolytica / Q000187:drug effects* / Q000201:enzymology / Q000254:growth & development / Q000472:pathogenicity*; D004912:Erythrocytes / Q000187:drug effects; D008081:Liposomes / Q000494:pharmacology; D008101:Liver Abscess, Amebic / Q000469:parasitology*; D008297:Male; D010447:Peptide Hydrolases / Q000378:metabolism; D010587:Phagocytosis / Q000187:drug effects; D010713:Phosphatidylcholines / Q000494:pharmacology*; D053058:Trophozoites / Q000187:drug effects / Q000201:enzymology / Q000254:growth & development; D014774:Virulence / Q000187:drug effects; D037521:Virulence Factors / Q000378:metabolism
chemical_list: D003470:Culture Media; D008081:Liposomes; D010713:Phosphatidylcholines; D037521:Virulence Factors; D003208:Concanavalin A; D002784:Cholesterol; D010447:Peptide Hydrolases