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Alloreactive cytotoxic T cells recognize MHC class I antigen without peptide specificity
A Müllbacher1, A B Hill, R V Blanden
1Division of Cell Biology, John Curtin School of Medical Research, Australian National University, Canberra.
Journal of Immunology (Baltimore, Md. : 1950)
|September 15, 1991
Summary
This study investigated how cytotoxic T (Tc) cells recognize class I MHC molecules. Findings suggest most Tc cells recognize MHC without specific peptides, supporting a non-specific peptide model.
Area of Science:
- Immunology
- Molecular Biology
- Cellular Biology
Background:
- Class I MHC molecules present peptides to T cells.
- Allorecognition, T cell response to foreign MHC, is crucial in transplantation.
- Three models exist for class I MHC allorecognition: peptide-free, peptide-specific, and non-specific peptide recognition.
Purpose of the Study:
- To differentiate between three models of class I MHC allorecognition.
- To investigate the role of peptides in T cell receptor (TCR) interaction with MHC.
Main Methods:
- Utilized nucleoprotein peptide (NPP) with high affinity for Kd class I MHC molecules.
- Assessed target cell lysis by cytotoxic T (Tc) cells.
- Employed limiting dilution split clone experiments.
- Used vaccinia virus recombinant for MHC antigen expression.
Main Results:
- Kd-NPP complexes remained on target cells for over 72 hours.
- Kd-specific alloreactive Tc cells lysed Kd-bearing targets despite NPP presence.
- NPP-modified stimulator cells induced potent Kd-NPP-specific self-restricted Tc cells.
- Kd-NPP stimulator cells did not generate Kd-NPP specific alloreactive Tc cells.
- Reemergence rates of alloreactive and self-restricted Tc cell epitopes were identical after MHC removal.
Conclusions:
- The majority of T cell precursor and effector cells recognize class I MHC antigens without peptide specificity.
- Results support a model of peptide-MHC-nonspecific recognition for class I MHC allorecognition.