Peptide contributes to the specificity of positive selection of CD8+ T cells in the thymus

Cell. 1993 Jun 4;73(5):1041-9. doi: 10.1016/0092-8674(93)90281-t.


Mice deficient in the gene encoding the peptide transporter associated with antigen processing (TAP1) have drastically reduced levels of surface expression of MHC class I molecules and few CD8+ T cells. Addition of class I binding peptides to cultured fetal thymi from TAP1 mutant mice invariably allowed the rescue of class I expression, while only some of these peptides promoted the positive selection of CD8+ T cells, which were polyclonal and specific for the peptide-MHC complex. A nonselecting peptide was converted to a mixture of selecting peptides when the residues involved in the interaction with TCRs were altered. A mixture of self-peptides derived from C57BL/6 thymi induced positive selection of CD8+ T cells at concentrations that gave relatively low class I surface expression. The implication of these observations is that self-peptides determine, in part, the repertoire of specificities exhibited by CD8+ T cells.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • ATP Binding Cassette Transporter, Subfamily B, Member 2
  • ATP-Binding Cassette Transporters*
  • Amino Acid Sequence
  • Animals
  • CD8 Antigens
  • Carrier Proteins / genetics
  • Histocompatibility Antigens Class I / biosynthesis*
  • Histocompatibility Antigens Class II / genetics
  • Mice
  • Mice, Inbred C57BL
  • Mice, Mutant Strains
  • Molecular Sequence Data
  • Organ Culture Techniques
  • Peptides / immunology*
  • T-Lymphocytes / immunology*
  • Thymus Gland / cytology*


  • ATP Binding Cassette Transporter, Subfamily B, Member 2
  • ATP-Binding Cassette Transporters
  • CD8 Antigens
  • Carrier Proteins
  • Histocompatibility Antigens Class I
  • Histocompatibility Antigens Class II
  • Peptides
  • TAP1 protein, human
  • Tap1 protein, mouse