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Immunodominance: intramolecular competition between T cell epitopes
D L Perkins1, G Berriz, T Kamradt
1Laboratory of Immunogenetics and Transplantation, Brigham and Women's Hospital, Boston, MA.
Journal of Immunology (Baltimore, Md. : 1950)
|April 1, 1991
Summary
Immunodominance is determined by peptide conformation, not just amino acid sequence. Synthetic peptides reveal that epitope context within a protein influences T cell recognition and immune response.
Area of Science:
- Immunology
- Molecular Biology
Background:
- Immunodominance dictates the magnitude of T cell responses to antigens.
- Understanding immunodominance mechanisms is crucial for vaccine design and immunotherapy.
Purpose of the Study:
- To investigate the mechanisms underlying T cell epitope immunodominance.
- To determine factors influencing the selection of dominant T cell epitopes from complex peptides.
Main Methods:
- Constructed synthetic peptides by linking known T cell epitopes.
- Immunized mice with lambda repressor (cI) protein and cI:NP peptide.
- Assessed T cell recognition using fixed antigen-presenting cells (APCs).
- Evaluated MHC binding affinities using in vitro competition assays.
Main Results:
- A previously dominant epitope (cI12-26) became minor in the cI:NP peptide context.
- A novel junctional epitope emerged as dominant in response to the cI:NP peptide.
- Ag processing minimally affected T cell recognition of cI:NP.
- MHC binding affinities did not explain the observed immunodominance hierarchy.
Conclusions:
- Immunodominance is influenced by peptide conformation and its interaction with MHC.
- Epitope context within a protein, not just sequence, determines immunodominance.
- Peptide conformation affects T cell recognition, impacting immune responses.