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Published on: December 7, 2019
TCR affinity promotes CD8+ T cell expansion by regulating survival.
Mirja Hommel1, Philip D Hodgkin
1Immunology Division, Walter and Eliza Hall Institute, Parkville, Victoria, Australia. hommel@wehi.edu.au
Journal of Immunology (Baltimore, Md. : 1950)
|August 7, 2007
Summary
T-cell receptor (TCR) affinity and peptide concentration significantly impact T cell proliferation and survival. Higher affinity ligands promote T cell growth and dominance, while lower affinity ligands result in incomplete responses and increased cell death.
Area of Science:
- Immunology
- Cellular Biology
- T cell activation
Background:
- T lymphocytes activation is crucial for adaptive immunity.
- Ligand affinity influences T cell response magnitude and kinetics.
- Understanding T cell receptor (TCR) affinity is key to modulating immune responses.
Purpose of the Study:
- To investigate the quantitative effects of varying peptide concentrations and T cell receptor (TCR) affinities on CD8(+) T cell proliferation.
- To determine how TCR affinity influences T cell division times and cell death.
- To elucidate the role of TCR affinity in regulating T cell clonal dominance.
Main Methods:
- Utilized the mouse OT-I model to study CD8(+) T cell responses.
- Administered peptides with diverse TCR affinities at various concentrations.
- Quantitatively analyzed T cell frequency, division times, and cell death rates.
Main Results:
- Both peptide concentration and affinity affected T cell response frequency and initial division timing.
- Subsequent T cell division times were largely independent of these variables.
- TCR affinity was identified as the primary regulator of cell death in later divisions.
Conclusions:
- TCR affinity modulates T cell proliferation rates and survival.
- Higher affinity T cell clones are favored, ensuring their dominance over time.
- This mechanism allows for fine-tuning of immune responses based on antigen recognition strength.
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