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Peptide-MHC class I tetrameric complexes display exquisite ligand specificity
S R Burrows1, N Kienzle, A Winterhalter
1Division of Infectious Diseases and Immunology, Queensland Institute of Medical Research and University of Queensland Joint Oncology Program, The Bancroft Centre, Brisbane, Australia. scott@qimr.edu.au
Journal of Immunology (Baltimore, Md. : 1950)
|November 22, 2000
Summary
MHC-peptide tetramers accurately identify specific T cells. High avidity binding correlates with functional activity, confirming their specificity for detecting pathogen-specific CD8(+) T cells in cellular immunology research.
Area of Science:
- Cellular Immunology
- Immunogenetics
Background:
- Synthetic MHC-peptide tetramers reveal pathogen-specific CD8(+) T cell expansions.
- High avidity binding of tetramers is crucial for T cell staining.
- Potential for tetramer avidity to cause cross-reactivity and overestimate T cell numbers.
Purpose of the Study:
- Investigate the fine specificity of CTL staining using MHC-peptide tetramers.
- Compare tetramer staining with functional data (cytotoxicity assays).
- Assess the accuracy of tetramers in quantifying epitope-specific T cells.
Main Methods:
- Utilized CTL clones with varying fine specificity for EBV epitope analogs.
- Employed HLA-B8 tetramers incorporating these peptide analogs.
- Correlated tetramer staining intensity with peptide activity in cytotoxicity assays.
- Examined EBV-specific T cell expansion in EBV-exposed individuals.
Main Results:
- Demonstrated a strong correlation between tetramer staining and cytotoxicity assay results.
- Observed significant staining only with strong agonist peptides, not weak agonists.
- Tetramer staining intensity decreased proportionally with reduced peptide activity (>10-fold).
- Confirmed similar fine specificity in tetramer staining of fresh peripheral T cells from EBV-exposed individuals.
Conclusions:
- Class I MHC-peptide tetramers exhibit exquisite specificity.
- Tetramers accurately quantify T cells recognizing low levels of endogenous antigen.
- Validated tetramer staining as a reliable method for assessing T cell responses.