+ Site Statistics
+ Search Articles
+ PDF Full Text Service
How our service works
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ Translate
+ Recently Requested

Invasion of Toxoplasma gondii occurs by active penetration of the host cell

Invasion of Toxoplasma gondii occurs by active penetration of the host cell

Journal of Cell Science 108: 2457-2464

Toxoplasma gondii is an obligate intracellular parasite that infects a wide variety of vertebrate cells including macrophages. We have used a combination of video microscopy and fluorescence localization to examine the entry of Toxoplasma into macrophages and nonphagocytic host cells. Toxoplasma actively invaded host cells without inducing host cell membrane ruffling, actin microfilament reorganization, or tyrosine phosphorylation of host proteins. Invasion occurred rapidly and within 25-40 seconds the parasite penetrated into a tight-fitting vacuole formed by invagination of the plasma membrane. In contrast, during phagocytosis of Toxoplasma, extensive membrane ruffling captured the parasite in a loose-fitting phagosome that formed over a period of 2-4 minutes. Phagocytosis involved both reorganization of the host cytoskeleton and tyrosine phosphorylation of host proteins. In some cases, parasites that were first internalized by phagocytosis, were able to escape from the phagosome by a process analogous to invasion. These studies reveal that active penetration of the host cell by Toxoplasma is fundamentally different from phagocytosis or induced endocytic uptake. The novel ability to penetrate the host cell likely contributes to the capability of Toxoplasma-containing vacuoles to avoid endocytic processing.

Please choose payment method:

(PDF emailed within 1 workday: $29.90)

Accession: 002643557

Download citation: RISBibTeXText

PMID: 7673360

Related references

Lysosomes of Toxoplasma gondii and their possible relation to the host-cell penetration of toxoplasma parasites. Journal of Bacteriology 96(4): 916-919, 1968

Polycationic polypeptides: a possible model for the penetration-enhancing factor in the invasion of host cells by Toxoplasma gondii. Journal of General Microbiology 130(4): 927-933, 1984

Penetration of mouse peritoneal macrophages by the protozoan toxoplasma gondii new evidence for active invasion and phagocytosis. Laboratory Investigation 44(4): 324-335, 1981

Host Cell Penetration of Toxoplasma gondii. Infection and Immunity 2(3): 250-255, 1970

Host cell penetration of toxoplasma gondii. Journal of Protozoology 19(Suppl.): 14, 1972

Toxoplasma gondii: membrane properties of active energy-dependent invasion of host cells. Tropenmedizin und Parasitologie 31(4): 417-420, 1980

Carbohydrate-containing molecules found in rhoptries are released during active penetration of tachyzoites of Toxoplasma gondii into host cells. Biocell 21(2): 129-135, 1997

Host cell invasion by Toxoplasma gondii is temporally regulated by the host microtubule cytoskeleton. Eukaryotic Cell 9(11): 1680-1689, 2010

Host cell invasion by Toxoplasma gondii. Trends in Microbiology 6(1): 27-30, 1998

Molecular partitioning during host cell penetration by Toxoplasma gondii. Traffic 5(11): 855-867, 2004

A soluble phospholipase of Toxoplasma gondii associated with host cell penetration. Journal of Protozoology 385: 454-460, 1991

Factors enhancing the host-cell penetration of Toxoplasma gondii. Journal of Bacteriology 93(1): 53-58, 1967

The role of phospholipase in host cell penetration by Toxoplasma gondii. American Journal of Tropical Medicine and Hygiene 40(2): 145-149, 1989

Active invasion of host cells by Toxoplasma gondii is mediated by a parasite actin-based mechanism. Molecular Biology of the Cell 5(Suppl. ): 373A, 1994

Biology of Toxoplasma gondii host cell entry: the role of recognition and attachment for invasion of host cells. Intracellular parasitism: 259-269, 1989