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A High Throughput MHC II Binding Assay for Quantitative Analysis of Peptide Epitopes
Published on: March 25, 2014
The functional half-life of H-2Kd-restricted T cell epitopes on living cells
G Eberl1, C Widmann, G Corradin
1Institute of Biochemistry, University of Lausanne, Switzerland.
Insights
The functional half-life of peptide/MHC complexes on target cells is 5-10 hours. This duration is determined solely by the unfolding of these complexes, not by target cell type or proteases.
Area of Science:
- Immunology
- Molecular Biology
- Cell Biology
Background:
- Major histocompatibility complex (MHC) class I molecules present antigens to cytotoxic T lymphocytes (CTLs).
- The stability and presentation of peptide/MHC complexes influence T cell recognition and immune response.
- Understanding the functional half-life of these complexes is crucial for immunology.
Purpose of the Study:
- To determine the functional half-life (t1/2) of peptide/MHC class I complexes on target cells.
- To investigate factors influencing the stability and presentation of these complexes.
- To correlate functional half-life with CTL epitope stability.
Main Methods:
- Utilized specific cytotoxic T lymphocyte (CTL) clones.
- Employed cytolysis assays.
- Measured interferon-gamma production and Ca(2+)-mobilization assays.
Main Results:
- Functional half-life (t1/2) of peptide/MHC complexes was measured to be 5-10 hours.
- Results were consistent across different target cell types and fixation methods.
- Half-life remained consistent even in the presence of proteases that degrade peptides.
Conclusions:
- The functional half-life of CTL epitopes is primarily determined by the intrinsic unfolding of peptide/MHC complexes at the cell surface.
- External factors like target cell type or proteases do not significantly alter the functional half-life.
- This finding provides insights into the stability and duration of T cell recognition.
Abstract:
The functional half-life (t1/2) of different complexes formed by major histocompatibility complex (MHC) class I molecules and antigen on the surface of target cells was measured using specific cytotoxic T lymphocyte (CTL) clones in cytolysis, and interferon-gamma-production and Ca(2+)-mobilization assays. Functional t1/2 values of 5-10 h were obtained, which are in accordance with some previous estimations obtained from biochemical and immunochemical measurements. Moreover, these values were independent of the type of target cell, fixation of the target cells, or proteases able to degrade the peptides, suggesting that the unfolding of the peptide/MHC complexes at the cell surface alone determines the functional t1/2 of the CTL epitopes.
