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Peculiarities of Host Cholesterol Transport to the Unique Intracellular Vacuole Containing Toxoplasma
Author(s) -
Sehgal Alfica,
Bettiol Silvana,
Pypaert Marc,
Wenk Markus R.,
Kaasch Achim,
Blader Ira J.,
Joiner Keith A.,
Coppens Isabelle
Publication year - 2005
Publication title -
traffic
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.677
H-Index - 130
eISSN - 1600-0854
pISSN - 1398-9219
DOI - 10.1111/j.1600-0854.2005.00348.x
Subject(s) - biology , microbiology and biotechnology , toxoplasma gondii , vacuole , golgi apparatus , endoplasmic reticulum , intracellular , vesicular transport protein , endosome , endocytosis , organelle , intracellular parasite , transport protein , vesicle , biochemistry , membrane , cytoplasm , immunology , cell , antibody
The intracellular protozoan Toxoplasma gondii is auxotrophic for low‐density lipoprotein (LDL)‐derived cholesterol (C). We previously showed that T . gondii scavenges this essential lipid from host endolysosomal compartments and that C delivery to the parasitophorous vacuole (PV) does not require transit through host Golgi or endoplasmic reticulum. In this study, we explore the itinerary of C from the host endolysosomes to the PV. Labeled C incorporated into LDL is rapidly detected in intravacuolar parasites and partially esterified by the parasites. In contrast to diverse mammalian organelles, the post‐endolysosomal transfer of C to the PV does not involve the host plasma membrane as an intermediate. Nevertheless, the PV membrane is accessible to extracellular sterol acceptors, suggesting C trafficking from intracellular parasites to host plasma membrane. C movement to the PV requires temperatures permissive for vesicular transport, metabolic energy and functional microtubules. Host caveolae vesicles and the sterol carrier protein‐2 do not participate in this process. Proteolytic treatment of purified PV or free parasites abolishes C acquisition by the parasites. Altogether, these results support a vesicular transport system from host endolysosomes to the PV, and a requirement for PV membrane and parasite plasma membrane proteins in C delivery to T. gondii .