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Updated: Aug 11, 2026
3-D Imaging and Analysis of Neurons Infected In Vivo with Toxoplasma gondii
Published on: December 9, 2014
A rapid flow cytometric method to explore cellular immunity against Toxoplasma gondii in humans
S Kahi1, G J Cozon, T Greenland
1Université Claude Bernard Lyon I, JE 1947, Lyon, France.
Insights
Flow cytometry detected CD25 expression on T cells, indicating cell-mediated immunity to Toxoplasma gondii. This method shows promise for diagnosing congenital toxoplasmosis.
Area of Science:
- Immunology
- Infectious Diseases
Background:
- Toxoplasma gondii infection triggers cell-mediated immunity.
- Assessing this immunity is crucial for diagnosis, especially in congenital cases.
Purpose of the Study:
- To evaluate activation antigens (CD69, CD71, CD25) on T lymphocytes for assessing cell-mediated immunity to Toxoplasma gondii.
- To determine the diagnostic potential of these markers for T. gondii infection.
Main Methods:
- Flow cytometry was used to analyze T lymphocyte activation antigens.
- Whole blood from 127 T. gondii-positive and 63 T. gondii-negative individuals was stimulated with T. gondii antigens.
- Expression of CD69, CD71, and CD25 was measured post-stimulation.
Main Results:
- CD69 expression was not consistently detected at 24 hours post-stimulation.
- CD71 and CD25 were detectable on T cells from seropositive individuals 7 days after stimulation.
- CD25 detection on total T cells demonstrated high sensitivity (98%) and specificity (97%) for prior T. gondii infection.
- CD25 was primarily expressed on stimulated CD4(+) T cells.
Conclusions:
- Flow cytometric detection of CD25 is a sensitive and specific indicator of prior Toxoplasma gondii infection.
- CD25 expression serves as a valuable marker for screening cell-mediated immunity to T. gondii in vitro.
- This method holds potential for diagnosing congenital toxoplasmosis.
Abstract:
To assess cell-mediated immunity to Toxoplasma gondii, we evaluated the expression of the activation antigens CD69, CD71, and CD25 on T lymphocytes by flow cytometry after specific in vitro stimulation of whole blood from 127 T. gondii-positive and 63 T. gondii-negative patients. T lymphocytes from many seropositive individuals did not express CD69 at 24 h after T. gondii antigen stimulation, but CD71 and CD25 were easily detectable on T cells from seropositive individuals 7 days after specific activation. CD25 was mainly expressed by stimulated CD4(+) T cells, and its detection on total T cells was both a sensitive (98%) and a specific (97%) indicator of prior T. gondii infection. These results make flow cytometric detection of CD25 an excellent candidate for screening cell-mediated immunity to T. gondii in vitro and an interesting tool for the diagnosis of congenital infection.
