Delivery of mengovirus-derived RNA replicons into tumoural liver enhances the anti-tumour efficacy of a peripheral peptide-based vaccine

Cancer Immunol Immunother. 2008 Aug;57(8):1161-71. doi: 10.1007/s00262-007-0448-3. Epub 2008 Feb 7.

Abstract

Hepatocellular carcinoma is a deadly cancer with growing incidence for which immunotherapy is one of the most promising therapeutic approach. Peptide-based vaccines designed to induce strong, sustained CD8+ T cell responses are effective in animal models and cancer patients. We demonstrated the efficacy of curative peptide-based immunisation against a unique epitope of SV40 tumour antigen, through the induction of a strong CD8+ T cell-specific response, in our liver tumour model. However, as in human clinical trials, most tumour antigen epitopes did not induce a therapeutic effect, despite inducing strong CD8+ T cell responses. We therefore modified the tumour environment to enhance peptide-based vaccine efficacy by delivering mengovirus (MV)-derived RNA autoreplicating sequences (MV-RNA replicons) into the liver. The injection of replication-competent RNA replicons into the liver converted partial tumour regression into tumour eradication, whereas non-replicating RNA had no such effect. Replicating RNA replicon injection induced local recruitment of innate immunity effectors (NK and NKT) to the tumour and did not affect specific CD8+ T cell populations or other myelolymphoid subsets. The local delivery of such RNA replicons into tumour stroma is therefore a promising strategy complementary to the use of peripheral peptide-based vaccines for treating liver tumours.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cancer Vaccines / administration & dosage*
  • Cancer Vaccines / immunology
  • Carcinoma, Hepatocellular / immunology
  • Carcinoma, Hepatocellular / pathology
  • Carcinoma, Hepatocellular / therapy*
  • Disease Models, Animal
  • Flow Cytometry
  • Histocompatibility Antigens Class I / immunology
  • Immunotherapy*
  • Liver Neoplasms / immunology
  • Liver Neoplasms / pathology
  • Liver Neoplasms / therapy*
  • Male
  • Mengovirus / immunology*
  • Mice
  • Mice, Inbred C57BL
  • Peptides / administration & dosage*
  • Peptides / immunology
  • RNA, Viral / immunology*
  • Replicon / immunology
  • Treatment Outcome

Substances

  • Cancer Vaccines
  • Histocompatibility Antigens Class I
  • Peptides
  • RNA, Viral