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MHC restriction is imposed on a diverse T cell receptor repertoire by CD4 and CD8 co-receptors during thymic

François Van Laethem1, Anastasia N Tikhonova, Alfred Singer

  • 1Experimental Immunology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.

Trends in Immunology
|July 10, 2012
PubMed

Mature αβ T cells recognize foreign antigenic peptides presented by MHC molecules but do not recognize native antigenic proteins; features known as MHC restriction. How MHC restriction is imposed on αβ T cells has intrigued immunologists for several decades. One model proposes that germline-encoded elements in the T cell receptor (TCR) variable regions are evolutionarily conserved to only recognize MHC. However, we propose an alternative model that posits that MHC restriction is imposed by CD4 and CD8 co-receptors during thymic selection. Thus, we think that TCRs are structurally able to recognize a huge diversity of ligands but only TCRs with MHC specificity survive thymic selection.

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