Selection of antigen-specific T cells by a single IEk peptide combination.
J Exp Med
; 186(9): 1441-50, 1997 Nov 03.
Article
em En
| MEDLINE
| ID: mdl-9348301
ABSTRACT
In normal mice, major histocompatibility complex (MHC) proteins are bound to many different peptides, derived from the proteins of their host. In the thymus, the diversity of this collection of MHC + peptide ligands allows thymocytes bearing many different T cell receptors (TCRs) to mature by low avidity reactions between the MHC + peptide ligands and the thymocyte TCRs. To investigate this problem, the selection of T cells specific for a well-studied combination of MHC + peptide, IEk + moth cytochrome c 88-103 (MCC), was investigated. Mice were created that expressed IEk bound to a single peptide, either a variant of MCC in which a critical TCR contact residue, 99K, was changed to A, or a variant of a mouse hemoglobin 64-76 (Hb) peptide, 72A. IEk bound to the MCC variant caused the clonal deletion of some T cells specific for the IEk + MCC ligand; nevertheless, it also positively selected many T cells that could react with this ligand. Some of the TCRs on the selected T cells were related to those on cells from normal mice and some were not. IEk bound to the Hb variant, on the other hand, did not select any T cells which could react with IEk + MCC. These results demonstrate that although positive selection is a partially degenerate event, the sequence of the peptide involved in positive selection controls the selected repertoire.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fragmentos de Peptídeos
/
Antígenos de Histocompatibilidade Classe II
/
Subpopulações de Linfócitos T
/
Epitopos de Linfócito T
Limite:
Animals
Idioma:
En
Revista:
J Exp Med
Ano de publicação:
1997
Tipo de documento:
Article
País de afiliação:
Estados Unidos