The role of peptides in thymic positive selection of class II major histocompatibility complex-restricted T cells

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Peptide:MHC Tetramer-based Enrichment of Epitope-specific T cells
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Peptide:MHC Tetramer-based Enrichment of Epitope-specific T cells

Published on: October 22, 2012

R Wang1, A Nelson, K Kimachi

  • 1La Jolla Institute for Allergy and Immunology, Division of Immunochemistry, 10355 Science Center Drive, San Diego, CA 92121, USA.

Proceedings of the National Academy of Sciences of the United States of America
|May 9, 1998
PubMed

A thymic epithelial cell line transfected with I-Ek was used in reaggregate cultures to study the role of peptides in positive selection of T cell receptor transgenic thymocytes. In this system, positive selection of CD4 SP cells occurred only after the addition of exogenous peptide. Analysis of antigen analogs indicated an inverse relationship between the antigenicity for peripheral T cells and the concentration of peptide required for positive selection. These data are most consistent with an avidity (rather than an affinity) model of positive selection, in which ligand density and the affinity of T cell receptor act in concert to determine the fate of developing thymocytes.

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