Related Experiment Video
Updated: Jun 14, 2026
14:29
Examination of Thymic Positive and Negative Selection by Flow Cytometry
Published on: October 8, 2012
Preselection CD4+CD8+ thymocytes modulate TCR responsiveness following TCRβ selection.
Esther Jeong Yoon Kim1, Dominik A Aylard1, Zoë Steier2,3,4
1Division of Immunology and Molecular Medicine, Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, United States.
Journal of Immunology (Baltimore, Md. : 1950)
|June 12, 2026
Summary
T cell receptor (TCR) sensitivity decreases in preselection thymocytes, a process linked to gene expression changes. This modulation guides T cell development and prevents unwanted cell death during T cell selection.
Area of Science:
- Immunology
- Cell Biology
- Developmental Biology
Background:
- T cell receptor (TCR) sensitivity modulation is crucial for T cell development.
- Positive selection directs thymocytes into appropriate lineages while avoiding negative selection.
- Preselection thymocytes were considered homogeneous, with TCR modulation uncharacterized.
Purpose of the Study:
- To investigate TCR sensitivity changes in preselection double-positive thymocytes.
- To identify gene expression dynamics during T cell selection.
- To understand the link between TCR modulation and T cell lineage commitment.
Main Methods:
- Analysis of gene expression in preselection double-positive thymocytes.
- Assessment of TCR responsiveness.
- Correlation of gene expression with TCR signaling pathways.
Main Results:
- Progressive gene expression changes observed in preselection thymocytes.
- Gradual reduction in TCR responsiveness correlated with these changes.
- Reduced upregulation of TCR target genes linked to CD4 lineage commitment.
Conclusions:
- Preselection thymocytes are not homogeneous and undergo TCR modulation.
- TCR sensitivity reduction is a progressive event during T cell selection.
- These findings link TCR modulation to T cell lineage commitment and positive selection.
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