Toxoplasma gondii resides in a vacuole that avoids fusion with host cell endocytic and exocytic vesicular trafficking pathways

Dana G. Mordue, Sebastian Håkansson, Ingrid Niesman, L. David Sibley

Research output: Contribution to journalArticlepeer-review

168 Scopus citations


Toxoplasma gondii actively penetrates its vertebrate host cell to establish a nonfusigenic compartment called the parasitophorous vacuole (PV) that has previously been characterized primarily in phagocytic cells. To determine the fate of this unique compartment in nonphagocytic cells, we examined the trafficking of host cell proteins and lipids in Toxoplasma- infected fibroblasts using quantitative immunofluorescence and immunoelectron microscopy. Toxoplasma-containing vacuoles remained segregated from all levels of the endocytic pathway, as shown by the absence of delivery of transferrin receptors, mannose phosphate receptors, and the lysosomal- associated protein LAMP1 to the vacuole. The PV was also inaccessible to lipids (DiIC16, and GM1) that were internalized from the plasma membrane via the endocytic system. In contrast, vacuoles containing dead parasites or zymosan sequentially acquired both endosomal and lysosomal protein markers and host lipids, reflecting the competency of fibroblasts to process phagocytic vacuoles. The mature PV often lies adjacent to the host cell Golgi, suggesting that it may intersect with vesicles from the exocytic pathway. Despite this proximity, the PV was inaccessible to nitrobenzadiazole-labeled sphingolipids exported from the Golgi and did not contain the host protein markers AP1 or β-COP. Our results demonstrate that Toxoplasma resides in a compartment that excludes delivery of protein and lipid components from the host cell endocytic and exocytic pathways.

Original languageEnglish
Pages (from-to)87-99
Number of pages13
JournalExperimental Parasitology
Issue number2
StatePublished - Jun 1999


  • Adaptor protein 1
  • Endocytosis
  • Exocytosis
  • Fusion
  • Intracellular parasite
  • Lipid traffic


Dive into the research topics of 'Toxoplasma gondii resides in a vacuole that avoids fusion with host cell endocytic and exocytic vesicular trafficking pathways'. Together they form a unique fingerprint.

Cite this