Phosphorylated peptides can be transported by TAP molecules, presented by class I MHC molecules, and recognized by phosphopeptide-specific CTL

J Immunol. 1999 Oct 1;163(7):3812-8.


CTL recognize short peptide fragments presented by class I MHC molecules. In this study, we examined the effect of phosphorylation on TAP transport, binding to class I MHC molecules, and recognition by CTL of peptide fragments from known phosphorylated oncogene proteins or virus phosphoproteins. We show that phosphopeptides can be efficiently transported from the cytosol to the endoplasmic reticulum by the TAP. Furthermore, we show that phosphorylation can have a neutral, negative, or even a positive effect on peptide binding to class I MHC. Finally, we have generated phosphopeptide-specific CTL that discriminate between the phosphorylated and the nonphosphorylated versions of the peptide. We conclude that phosphopeptide-specific CTL responses are likely to constitute a subset of the class I MHC-restricted CTL repertoire in vivo.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ATP Binding Cassette Transporter, Subfamily B, Member 2
  • ATP-Binding Cassette Transporters / immunology
  • ATP-Binding Cassette Transporters / metabolism*
  • Animals
  • Antigen Presentation*
  • Cell Line, Transformed
  • Cytotoxicity Tests, Immunologic
  • Epitopes, T-Lymphocyte / metabolism*
  • H-2 Antigens / metabolism
  • HLA Antigens / metabolism
  • Histocompatibility Antigens Class I / metabolism*
  • Humans
  • Mice
  • Mice, Inbred C57BL
  • Oligopeptides / immunology
  • Oligopeptides / metabolism*
  • Phosphopeptides / immunology
  • Phosphopeptides / metabolism*
  • Phosphorylation
  • Protein Binding / immunology
  • T-Lymphocytes, Cytotoxic / immunology
  • T-Lymphocytes, Cytotoxic / metabolism*
  • Tumor Cells, Cultured


  • ATP Binding Cassette Transporter, Subfamily B, Member 2
  • ATP-Binding Cassette Transporters
  • Epitopes, T-Lymphocyte
  • H-2 Antigens
  • HLA Antigens
  • Histocompatibility Antigens Class I
  • Oligopeptides
  • Phosphopeptides
  • TAP1 protein, human
  • Tap1 protein, mouse