Enhancement of immunogenicity of a therapeutic cervical cancer DNA-based vaccine by co-application of sequence-optimized genetic adjuvants

Int J Cancer. 2009 Jul 1;125(1):189-98. doi: 10.1002/ijc.24333.

Abstract

Treatment of patients with cervical cancer by conventional methods (mainly surgery, but also radiotherapy and chemotherapy) results in a significant loss in quality of life. A therapeutic DNA vaccine directed to tumor-specific antigens of the human papilloma virus (HPV) could be an attractive treatment option. We have developed a nontransforming HPV-16 E7-based DNA vaccine containing all putative T cell epitopes (HPV-16 E7SH). DNA vaccines, however, are less immunogenic than protein- or peptide-based vaccines in larger animals and humans. In this study, we have investigated an adjuvant gene support of the HPV-16 E7SH therapeutic cervical cancer vaccine. DNA encoded cytokines (IL-2, IL-12, GM-CSF, IFN-gamma) and the chemokine MIP1-alpha were co-applied either simultaneously or at different time points pre- or post-E7SH vaccination. In addition, sequence-optimized adjuvant genes were compared to wild type genes. Three combinations investigated lead to an enhanced IFN-gamma response of the induced T cells in mice. Interestingly, IFN-gamma secretion of splenocytes did not strictly correlate with tumor response in tumor regression experiments. Gene-encoded MIP-1alpha applied 5 days prior to E7SH-immunization combined with IFN-gamma or IL-12 (3 days) or IL-2 (5 days) postimmunization lead to a significantly enhanced tumor response that was clearly associated with granzyme B secretion and target cells lysis. Our results suggest that a conditioning application and combination with adjuvant genes may be a promising strategy to enhance synergistically immune responses by DNA immunization for the treatment of cervical cancer.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adjuvants, Immunologic
  • Animals
  • Chemokine CCL3 / genetics
  • Chemokine CCL3 / immunology*
  • Combined Modality Therapy
  • Cytokines / genetics
  • Cytokines / immunology*
  • Cytotoxicity, Immunologic
  • Epitopes, T-Lymphocyte / immunology
  • Female
  • Granulocyte-Macrophage Colony-Stimulating Factor
  • Interferon-gamma
  • Interleukin-12 / genetics
  • Interleukin-12 / immunology
  • Interleukin-2 / genetics
  • Interleukin-2 / immunology
  • Mice
  • Mice, Inbred C57BL
  • Oncogene Proteins, Viral / genetics
  • Oncogene Proteins, Viral / immunology*
  • Papillomavirus E7 Proteins
  • Spleen / immunology
  • Spleen / metabolism
  • T-Lymphocytes / immunology
  • T-Lymphocytes, Cytotoxic / immunology
  • Transduction, Genetic
  • Tumor Cells, Cultured
  • Uterine Cervical Neoplasms / genetics
  • Uterine Cervical Neoplasms / immunology
  • Uterine Cervical Neoplasms / prevention & control*
  • Vaccines, DNA / administration & dosage
  • Vaccines, DNA / genetics
  • Vaccines, DNA / immunology*
  • Viral Vaccines / genetics
  • Viral Vaccines / immunology*

Substances

  • Adjuvants, Immunologic
  • Chemokine CCL3
  • Cytokines
  • Epitopes, T-Lymphocyte
  • Interleukin-2
  • Oncogene Proteins, Viral
  • Papillomavirus E7 Proteins
  • Vaccines, DNA
  • Viral Vaccines
  • oncogene protein E7, Human papillomavirus type 16
  • Interleukin-12
  • Interferon-gamma
  • Granulocyte-Macrophage Colony-Stimulating Factor