Modification of CEA with both CRT and TAT PTD induces potent anti-tumor immune responses in RNA-pulsed DC vaccination

Vaccine. 2008 Nov 25;26(50):6433-40. doi: 10.1016/j.vaccine.2008.08.072. Epub 2008 Sep 21.

Abstract

Carcinoembryonic antigen (CEA) is expressed on human colon carcinomas, is well characterized, and continues to be a promising target for cancer immunotherapy in humans. To enhance the immunogenecity of CEA, we developed a fusion gene (CRT-TAT-DeltaCEA) of the TAT protein transduction domain (PTD) and calreticulin (CRT) with human CEA devoid of its signal sequences (DeltaCEA) and evaluated anti-tumor immunity using RNA-pulsed dendritic cell (DC) vaccination. Mice vaccinated with DC by electroporation with mRNA encoding TAT-DeltaCEA (DC/TAT-DeltaCEA) and CRT-DeltaCEA (DC/CRT-DeltaCEA) had enhanced induction of tumor-specific cytotoxic T lymphocyte (CTL) and increased numbers of IFN-gamma-secreting T cells by ELISPOT, as compared to mice vaccinated with DC/DeltaCEA. DC/CRT-DeltaCEA and DC/TAT-DeltaCEA vaccines preferentially stimulated CD4+ and CD8+ T cells, respectively. The DC vaccine by electroporation with mRNA encoding CRT-TAT-DeltaCEA (DC/CRT-TAT-DeltaCEA) enhanced both CD4+ and CD8+ T cells. DC/CRT-TAT-DeltaCEA had the additional effects of CRT and TAT PTD and enhanced the anti-tumor effect against CEA-expressing tumors compared to DC/CRT-DeltaCEA or DC/TAT-DeltaCEA. These findings suggest that modification of CEA with both CRT and TAT PTD induces potent anti-tumor immune responses in RNA-pulsed DC vaccination and may be a useful approach for DC-based immunotherapy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenocarcinoma / immunology*
  • Adenocarcinoma / therapy
  • Animals
  • CD4-Positive T-Lymphocytes / immunology
  • CD8-Positive T-Lymphocytes / immunology
  • Calreticulin* / genetics
  • Calreticulin* / immunology
  • Calreticulin* / metabolism
  • Cancer Vaccines*
  • Carcinoembryonic Antigen* / genetics
  • Carcinoembryonic Antigen* / immunology
  • Carcinoembryonic Antigen* / metabolism
  • Cell Line, Tumor
  • Colonic Neoplasms / immunology*
  • Colonic Neoplasms / therapy
  • Dendritic Cells / immunology*
  • Dendritic Cells / transplantation
  • Electroporation
  • Gene Products, tat* / genetics
  • Gene Products, tat* / immunology
  • Gene Products, tat* / metabolism
  • Humans
  • Mice
  • Mice, Inbred C57BL
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / immunology
  • Recombinant Fusion Proteins / metabolism
  • Vaccination

Substances

  • Calreticulin
  • Cancer Vaccines
  • Carcinoembryonic Antigen
  • Gene Products, tat
  • RNA, Messenger
  • Recombinant Fusion Proteins