+ 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

The role of phospholipase in host cell penetration by Toxoplasma gondii

The role of phospholipase in host cell penetration by Toxoplasma gondii

American Journal of Tropical Medicine and Hygiene 40(2): 145-149

Phospholipase A2 (PLA2) plays an important pathogenic role in infections caused by several microorganisms and has been implicated in host cell invasion. The mechanism of host cell penetration by the intracellular protozoan Toxoplasma gondii involves several steps; we have investigated the role of PLA2 in cellular invasion by the tachyzoite stage of this parasite. We assayed T. gondii invasion of human fibroblast monolayers by measurement of the selective incorporation of 3H-uracil into growing intracellular parasites. Exogenous PLA2 from snake venom (Naja naja) increased the penetration of fibroblasts by T. gondii, while horse antiserum to Naja hannah venom inhibited penetration. An irreversible PLA2 inhibitor, p-bromophenacyl bromide, blocked penetration without metabolically disabling the parasite. When host fibroblasts were preincubated with this drug, penetration was not affected, supporting a role for parasite rather than host cell PLA2 in the penetration process. Another PLA2 inhibitor, nordihydroguaiaretic acid, also inhibited penetration. we assayed extracellular T. gondii tachyzoites, purified from host cell debris, for PLA2 activity by radiometric detection of fatty acid release from labeled Escherichia coli membranes. Sonically disrupted parasites contained a low level of calcium-dependent PLA2 with maximum activity at pH 8.5 - 9.0. These experiments suggest that a phospholipase is implicated in T. gondii host cell invasion.

Please choose payment method:

(PDF emailed within 1 workday: $29.90)

Accession: 007932812

Download citation: RISBibTeXText

PMID: 2919724

Related references

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

Characterization of the phospholipase involved in toxoplasma gondii host cell penetration. Journal of Cellular Biochemistry Suppl. (13 Part E): 148, 1989

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

Eicosanoid production by mouse peritoneal macrophages during Toxoplasma gondii penetration: role of parasite and host cell phospholipases. Infection and Immunity 61(4): 1432-1441, 1993

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

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

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

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

Immunological Study on the Host Cell Penetration Factor of Toxoplasma gondii. Infection and Immunity 3(2): 278-286, 1971

Invasion of Toxoplasma gondii occurs by active penetration of the host cell. Journal of Cell Science 108: 2457-2464, 1995

Localization of a Toxoplasma gondii rhoptry protein by immunoelectron microscopy during and after host cell penetration. Journal of Protozoology 394: 526-530, 1992

Sialic acid residues of host cell are involved in the process of Toxoplasma gondii penetration. Memorias do Instituto Oswaldo Cruz 92(Suppl. 1): 79, 1997

Toxoplasma gondii - host cell interaction. Ultrastructural aspects of the parasite penetration mechanism. Archives Roumaines de Pathologie Experimentale et de Microbiologie 35(3): 223-230, 1976

A Toxoplasma gondii rhoptry protein associated with host cell penetration has unusual charge asymmetry. Molecular and Biochemical Parasitology 501: 1-16, 1992

Quinine inhibition of host cell penetration by Toxoplasma gondii, Besnoitia jellisoni, and Sarcocystis sp. in vitro. Journal of Parasitology 58(3): 595-599, 1972