LDL uptake by Leishmania amazonensis: Involvement of membrane lipid microdomains

• Published in: Experimental parasitology Vol. 130; no. 4; pp. 330 - 340
• Main Authors: De Cicco, Nuccia N.T., Pereira, Miria G., Corrêa, José R., Andrade-Neto, Valter V., Saraiva, Felipe B., Chagas-Lima, Alessandra C., Gondim, Katia C., Torres-Santos, Eduardo C., Folly, Evelize, Saraiva, Elvira M., Cunha-e-Silva, Narcisa L., Soares, Maurilio J., Atella, Georgia C.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.04.2012
• Subjects: Animals; beta-Cyclodextrins - pharmacology; Cattle; cholesterol; Cholesterol Esters - metabolism; Cholesterol uptake; dose response; Endocytosis - physiology; Esterification; Flow Cytometry; Fluorescein-5-isothiocyanate; Fluorescent Dyes; hosts; human diseases; Humans; LDL uptake; Leishmania; Leishmania amazonensis; Leishmania mexicana - drug effects; Leishmania mexicana - growth & development; Leishmania mexicana - metabolism; Lipid microdomains; Lipid rafts; Lipoproteins, HDL - blood; Lipoproteins, HDL - metabolism; Lipoproteins, LDL - blood; Lipoproteins, LDL - metabolism; low density lipoprotein; Membrane Lipids - metabolism; Membrane Microdomains - drug effects; Membrane Microdomains - metabolism; Mice; Mice, Inbred BALB C; parasites; parasitology; Receptors, LDL - metabolism; temperature; Cholesterol uptake; Lipid rafts; Lipid microdomains; LDL uptake; Leishmania
• ISSN: 0014-4894; 1090-2449
• DOI: 10.1016/j.exppara.2012.02.014

[Display omitted] ► Here we show that Leishmania amazonensis is able to acquire and internalize LDL. ► Furthermore free cholesterol from LDL particles is esterified by this parasite. ► Such pathway relies on detergent-resistant membrane lipid microdomains. Leishmania amazonensis lacks a de novo mechanism for cholesterol synthesis and therefore must scavenge this lipid from the host environment. In this study we show that the L. amazonensis takes up and metabolizes human LDL1Abbreviations: CHO, cholesterol; CHOE, cholesteryl ester; DRM, lipid microdomains or detergent-resistant membrane; LDL, low density lipoprotein; 125I-LDL, LDL labeled with 125I; 3H-CHO-LDL, LDL with 3H-Cholesterol incorporated; TR-LDL, LDL with Texas-Red-Phosphatidylethanolamine associated. FITC-LDL, LDL with fluorescein 5’-isothyocianate associated; MBCD, methyl-β-cyclodextrin.1 particles in both a time and dose-dependent manner. This mechanism implies the presence of a true LDL receptor because the uptake is blocked by both low temperature and by the excess of non-labelled LDL. This receptor is probably associated with specific microdomains in the membrane of the parasite, such as rafts, because this process is blocked by methyl-β-cyclodextrin (MCBD). Cholesteryl ester fluorescently-labeled LDL (BODIPY-cholesteryl-LDL) was used to follow the intracellular distribution of this lipid. After uptake it was localized in large compartments along the parasite body. The accumulation of LDL was analyzed by flow cytometry using FITC-labeled LDL particles. Together these data show for the first time that L. amazonensis is able to compensate for its lack of lipid synthesis through the use of a lipid importing machinery largely based on the uptake of LDL particles from the host. Understanding the details of the molecular events involved in this mechanism may lead to the identification of novel targets to block Leishmania infection in human hosts.