Susceptibility of retinal vascular endothelium to infection witn Toxoplasma gondii tachyzoites

Justine R. Smith, Daniel T. Franc, Nicola Carter, David Zamora, Stephen Planck, James (Jim) Rosenbaum

Research output: Contribution to journalArticle

26 Citations (Scopus)

Abstract

PURPOSE. Retinochoroidal infection with the protozoan parasite Toxoplasma gondii is the most common cause of posterior uveitis worldwide. Tachyzoites spread throughout the body through the blood stream and lymphatics, but preferentially encyst in the eye and other parts of the central nervous system (CNS). It is unknown whether T. gondii penetrates the CNS selectively or whether these sites of immune privilege have limited capacity to eradicate the parasite. METHODS. Human vascular endothelial cell lines, including retinal (three lines from three different donors), aortic, umbilical vein, and dermal microvascular endothelium, as well as human foreskin fibroblasts, were grown to confluence in 24-well plates. Cells were incubated with RH-strain T. gondii tachyzoites in the presence of [3H]-uracil. Trichloroacetic acid-insoluble radioactivity was measured as an index of T. gondii proliferation, because tachyzoites, but not human cells, incorporate uracil directly through pyrimidine salvage. RESULTS. Tachyzoites showed higher [ 3H]-uracil incorporation after incubation with retinal vascular endothelial cells in comparison with aortic (55% more), umbilical vein (33% more) and dermal (34% more) endothelial cells. In eight separate assays, significantly greater radioactivity was measured for tachyzoites cultured with retinal versus other cell subtypes (P <0.05), except for one assay in which differences reached only borderline significance (P ≤ 0.07). In contrast, experiments comparing different retinal endothelial lines revealed no difference between any pair. Growth of the tachyzoites was approximately 2.8-fold higher in retinal endothelium than in foreskin fibroblasts, the cell subtype often used to investigate processes of T. gondii infection. CONCLUSIONS. Enhanced susceptibility of retinal vascular endothelium to infection by T. gondii tachyzoites may explain, at least in part, preferential localization of T. gondii to the retina. Susceptibility may relate to preferential binding of tachyzoites to the retinal vascular endothelial surface, relative ease of penetration into the cell, rate of replication within the cell and/or cell response to infection.

Original languageEnglish (US)
Pages (from-to)1157-1161
Number of pages5
JournalInvestigative Ophthalmology and Visual Science
Volume45
Issue number4
DOIs
StatePublished - Apr 2004

Fingerprint

Retinal Vessels
Toxoplasmosis
Vascular Endothelium
Toxoplasma
Uracil
Foreskin
Umbilical Veins
Endothelial Cells
Radioactivity
Endothelium
Parasites
Central Nervous System
Fibroblasts
Posterior Uveitis
Protozoan Infections
Trichloroacetic Acid
Skin
Retina
Cell Line
Growth

ASJC Scopus subject areas

  • Ophthalmology

Cite this

Susceptibility of retinal vascular endothelium to infection witn Toxoplasma gondii tachyzoites. / Smith, Justine R.; Franc, Daniel T.; Carter, Nicola; Zamora, David; Planck, Stephen; Rosenbaum, James (Jim).

In: Investigative Ophthalmology and Visual Science, Vol. 45, No. 4, 04.2004, p. 1157-1161.

Research output: Contribution to journalArticle

@article{0291bfe7fc6b47e89094389f66c4310e,
title = "Susceptibility of retinal vascular endothelium to infection witn Toxoplasma gondii tachyzoites",
abstract = "PURPOSE. Retinochoroidal infection with the protozoan parasite Toxoplasma gondii is the most common cause of posterior uveitis worldwide. Tachyzoites spread throughout the body through the blood stream and lymphatics, but preferentially encyst in the eye and other parts of the central nervous system (CNS). It is unknown whether T. gondii penetrates the CNS selectively or whether these sites of immune privilege have limited capacity to eradicate the parasite. METHODS. Human vascular endothelial cell lines, including retinal (three lines from three different donors), aortic, umbilical vein, and dermal microvascular endothelium, as well as human foreskin fibroblasts, were grown to confluence in 24-well plates. Cells were incubated with RH-strain T. gondii tachyzoites in the presence of [3H]-uracil. Trichloroacetic acid-insoluble radioactivity was measured as an index of T. gondii proliferation, because tachyzoites, but not human cells, incorporate uracil directly through pyrimidine salvage. RESULTS. Tachyzoites showed higher [ 3H]-uracil incorporation after incubation with retinal vascular endothelial cells in comparison with aortic (55{\%} more), umbilical vein (33{\%} more) and dermal (34{\%} more) endothelial cells. In eight separate assays, significantly greater radioactivity was measured for tachyzoites cultured with retinal versus other cell subtypes (P <0.05), except for one assay in which differences reached only borderline significance (P ≤ 0.07). In contrast, experiments comparing different retinal endothelial lines revealed no difference between any pair. Growth of the tachyzoites was approximately 2.8-fold higher in retinal endothelium than in foreskin fibroblasts, the cell subtype often used to investigate processes of T. gondii infection. CONCLUSIONS. Enhanced susceptibility of retinal vascular endothelium to infection by T. gondii tachyzoites may explain, at least in part, preferential localization of T. gondii to the retina. Susceptibility may relate to preferential binding of tachyzoites to the retinal vascular endothelial surface, relative ease of penetration into the cell, rate of replication within the cell and/or cell response to infection.",
author = "Smith, {Justine R.} and Franc, {Daniel T.} and Nicola Carter and David Zamora and Stephen Planck and Rosenbaum, {James (Jim)}",
year = "2004",
month = "4",
doi = "10.1167/iovs.03-1105",
language = "English (US)",
volume = "45",
pages = "1157--1161",
journal = "Investigative Ophthalmology and Visual Science",
issn = "0146-0404",
publisher = "Association for Research in Vision and Ophthalmology Inc.",
number = "4",

}

TY - JOUR

T1 - Susceptibility of retinal vascular endothelium to infection witn Toxoplasma gondii tachyzoites

AU - Smith, Justine R.

AU - Franc, Daniel T.

AU - Carter, Nicola

AU - Zamora, David

AU - Planck, Stephen

AU - Rosenbaum, James (Jim)

PY - 2004/4

Y1 - 2004/4

N2 - PURPOSE. Retinochoroidal infection with the protozoan parasite Toxoplasma gondii is the most common cause of posterior uveitis worldwide. Tachyzoites spread throughout the body through the blood stream and lymphatics, but preferentially encyst in the eye and other parts of the central nervous system (CNS). It is unknown whether T. gondii penetrates the CNS selectively or whether these sites of immune privilege have limited capacity to eradicate the parasite. METHODS. Human vascular endothelial cell lines, including retinal (three lines from three different donors), aortic, umbilical vein, and dermal microvascular endothelium, as well as human foreskin fibroblasts, were grown to confluence in 24-well plates. Cells were incubated with RH-strain T. gondii tachyzoites in the presence of [3H]-uracil. Trichloroacetic acid-insoluble radioactivity was measured as an index of T. gondii proliferation, because tachyzoites, but not human cells, incorporate uracil directly through pyrimidine salvage. RESULTS. Tachyzoites showed higher [ 3H]-uracil incorporation after incubation with retinal vascular endothelial cells in comparison with aortic (55% more), umbilical vein (33% more) and dermal (34% more) endothelial cells. In eight separate assays, significantly greater radioactivity was measured for tachyzoites cultured with retinal versus other cell subtypes (P <0.05), except for one assay in which differences reached only borderline significance (P ≤ 0.07). In contrast, experiments comparing different retinal endothelial lines revealed no difference between any pair. Growth of the tachyzoites was approximately 2.8-fold higher in retinal endothelium than in foreskin fibroblasts, the cell subtype often used to investigate processes of T. gondii infection. CONCLUSIONS. Enhanced susceptibility of retinal vascular endothelium to infection by T. gondii tachyzoites may explain, at least in part, preferential localization of T. gondii to the retina. Susceptibility may relate to preferential binding of tachyzoites to the retinal vascular endothelial surface, relative ease of penetration into the cell, rate of replication within the cell and/or cell response to infection.

AB - PURPOSE. Retinochoroidal infection with the protozoan parasite Toxoplasma gondii is the most common cause of posterior uveitis worldwide. Tachyzoites spread throughout the body through the blood stream and lymphatics, but preferentially encyst in the eye and other parts of the central nervous system (CNS). It is unknown whether T. gondii penetrates the CNS selectively or whether these sites of immune privilege have limited capacity to eradicate the parasite. METHODS. Human vascular endothelial cell lines, including retinal (three lines from three different donors), aortic, umbilical vein, and dermal microvascular endothelium, as well as human foreskin fibroblasts, were grown to confluence in 24-well plates. Cells were incubated with RH-strain T. gondii tachyzoites in the presence of [3H]-uracil. Trichloroacetic acid-insoluble radioactivity was measured as an index of T. gondii proliferation, because tachyzoites, but not human cells, incorporate uracil directly through pyrimidine salvage. RESULTS. Tachyzoites showed higher [ 3H]-uracil incorporation after incubation with retinal vascular endothelial cells in comparison with aortic (55% more), umbilical vein (33% more) and dermal (34% more) endothelial cells. In eight separate assays, significantly greater radioactivity was measured for tachyzoites cultured with retinal versus other cell subtypes (P <0.05), except for one assay in which differences reached only borderline significance (P ≤ 0.07). In contrast, experiments comparing different retinal endothelial lines revealed no difference between any pair. Growth of the tachyzoites was approximately 2.8-fold higher in retinal endothelium than in foreskin fibroblasts, the cell subtype often used to investigate processes of T. gondii infection. CONCLUSIONS. Enhanced susceptibility of retinal vascular endothelium to infection by T. gondii tachyzoites may explain, at least in part, preferential localization of T. gondii to the retina. Susceptibility may relate to preferential binding of tachyzoites to the retinal vascular endothelial surface, relative ease of penetration into the cell, rate of replication within the cell and/or cell response to infection.

UR - http://www.scopus.com/inward/record.url?scp=2142647266&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=2142647266&partnerID=8YFLogxK

U2 - 10.1167/iovs.03-1105

DO - 10.1167/iovs.03-1105

M3 - Article

C2 - 15037582

AN - SCOPUS:2142647266

VL - 45

SP - 1157

EP - 1161

JO - Investigative Ophthalmology and Visual Science

JF - Investigative Ophthalmology and Visual Science

SN - 0146-0404

IS - 4

ER -