A functional recombinant single-chain T cell receptor fragment capable of selectively targeting antigen-presenting cells

Cancer Immunol Immunother. 2002 Nov;51(10):565-73. doi: 10.1007/s00262-002-0312-4. Epub 2002 Sep 13.


Specificity in the immune system is dictated and regulated by specific recognition of peptide/major histocompatibility complexes (MHC) by the T cell receptor (TCR). Such peptide/MHC complexes are a desirable target for novel approaches in immunotherapy because of their highly restricted fine specificity. Recently a potent anti-human p53 CD8(+) cytotoxic T lymphocyte (CTL) response has been developed in HLA-A2 transgenic mice after immunization with peptides corresponding to HLA-A2 motifs from human p53. An alpha/beta T-cell receptor was cloned from such CTL which exhibited a moderately high affinity to the human p53(149-157) peptide. In this report, we investigated the possibility of using a recombinant tumor-specific TCR for antigen-specific elimination of cells that express the specific MHC-peptide complex. To this end, we constructed a functional single-chain Fv fragment from the cloned TCR and fused it to a very potent cytotoxic molecule, a truncated form of Pseudomonas exotoxin A (PE38). The p53 TCR scFv-P38 fusion protein was generated by in vitro refolding from bacterially-expressed inclusion bodies, and was found to be functional by its ability to bind antigen-presenting cells (APC) which express the specific p53-derived peptide. Moreover, we have shown that the p53-specific TCR scFv-PE38 molecule specifically kills APC in a peptide-dependent manner. These results represent the first time that a TCR-derived recombinant single-chain Fv fragment has been used as a targeting moiety to deliver a cytotoxic effector molecule to cells and has been able to mediate the efficient killing of the particular cell population that expresses the specific MHC/peptide complex. Similarly to antibody-based targeting approaches, TCR with tumor cell specificity represent attractive candidates for generating new, very specific targeting moieties for various modes of cancer immunotherapy.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Antigen-Presenting Cells / drug effects*
  • Antigen-Presenting Cells / immunology
  • Cell Line
  • Cell Line, Transformed
  • Drug Delivery Systems
  • Humans
  • Immunoglobulin Variable Region / chemistry
  • Mice
  • Molecular Sequence Data
  • Peptides / immunology
  • Protein Folding
  • Receptors, Antigen, T-Cell, alpha-beta / chemistry
  • Receptors, Antigen, T-Cell, alpha-beta / genetics*
  • Recombinant Fusion Proteins / chemistry
  • Recombinant Fusion Proteins / genetics*
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / toxicity
  • Single-Chain Antibodies
  • Tumor Suppressor Protein p53 / chemistry
  • Tumor Suppressor Protein p53 / immunology


  • Immunoglobulin Variable Region
  • Peptides
  • Receptors, Antigen, T-Cell, alpha-beta
  • Recombinant Fusion Proteins
  • Recombinant Proteins
  • Single-Chain Antibodies
  • Tumor Suppressor Protein p53
  • p53 TCR scFv-P38 fusion protein, recombinant