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Updated: Jun 3, 2026
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Peptide:MHC Tetramer-based Enrichment of Epitope-specific T cells
Published on: October 22, 2012
Redox regulation facilitates optimal peptide selection by MHC class I during antigen processing.
Boyoun Park1, Sungwook Lee, Eunkyung Kim
1Department of Biological Sciences, National Creative Research Center for Antigen Presentation, Seoul National University, Seoul 151-747, South Korea.
Cell
|October 24, 2006
Summary
Protein disulfide isomerase (PDI) stabilizes MHC class I molecules, enabling T cells to recognize infected cells. Human cytomegalovirus inhibits this process by degrading PDI, highlighting PDI
Area of Science:
- Immunology
- Molecular Biology
- Biochemistry
Background:
- CD8(+) T cells identify abnormal cells via MHC class I-bound peptides.
- The mechanism of peptide selection by MHC class I in the endoplasmic reticulum (ER) was unclear.
Purpose of the Study:
- To elucidate the mechanism of peptide selection by MHC class I molecules.
- To identify factors involved in stabilizing peptide-receptive MHC class I molecules.
Main Methods:
- Co-immunoprecipitation to identify components of the peptide-loading complex.
- In vitro assays to assess PDI's effect on MHC class I peptide binding.
- Analysis of human cytomegalovirus (CMV) US3 protein's effect on PDI and T cell recognition.
Main Results:
- Protein disulfide isomerase (PDI) was identified as a component of the peptide-loading complex.
- PDI stabilizes the peptide-binding groove of MHC class I molecules, regulating peptide selection.
- Human cytomegalovirus US3 protein degrades PDI, impairing CD8(+) T cell recognition.
Conclusions:
- PDI plays a crucial role in antigen processing by facilitating optimal peptide selection for MHC class I.
- PDI-catalyzed peptide editing is essential for T cell-mediated immunity against intracellular pathogens.
- Thiol-based redox regulation is linked to antigen processing and immune surveillance.
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