CTL response and protection against P815 tumor challenge in mice immunized with DNA expressing the tumor-specific antigen P815A

Hum Gene Ther. 1997 Aug 10;8(12):1451-8. doi: 10.1089/hum.1997.8.12-1451.


A DNA immunization approach was used to induce an immune response against the tumor-specific antigen P815A in DBA/2 mice. The P1A gene, which encodes the P815A antigen, was modified by the addition of a short sequence coding for a tag epitope recognized by the monoclonal antibody AU1, and cloned into the eukaryotic expression vector pBKCMV, resulting in plasmid pBKCMV-P1A. L1210 cells stably transfected with pBKCMV-P1A expressed P1A mRNA and were lysed by the syngeneic P815A-specific cytotoxic clone CTL-P1:5, thus confirming that the tag-modified P1A protein underwent correct processing and presentation. A single intramuscular injection of 100 microg of pBKCMV-P1A induced the expression of P1A mRNA for at least 4 months. Eighty percent of DBA/2 mice injected three times with 100 microg of pBKCMV-P1A generated cytotoxic T lymphocytes (CTL) that lysed P815 tumor cells, whereas mock-inoculated animals failed to show any cytotoxicity. Moreover, experiments designed to evaluate the protection of pBKCMV-P1A-immunized mice against a lethal challenge with P815 tumor cells showed that 6 of 10 immunized mice rejected the tumor, and 2 mice showed prolonged survival compared to control animals.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigens, Neoplasm / genetics*
  • Antigens, Neoplasm / immunology*
  • Cell Transplantation
  • Female
  • Humans
  • Immunization / methods*
  • Mice
  • Mice, Inbred DBA
  • Neoplasms / genetics
  • Neoplasms / immunology
  • Neoplasms / prevention & control*
  • Plasmids / genetics
  • Plasmids / pharmacology
  • T-Lymphocytes, Cytotoxic / immunology*
  • Tumor Cells, Cultured


  • Antigens, Neoplasm
  • tumor rejection antigen P815A, mouse