Immune responses and therapeutic antitumor effects of an experimental DNA vaccine encoding human papillomavirus type 16 oncoproteins genetically fused to herpesvirus glycoprotein D

Clin Vaccine Immunol. 2010 Oct;17(10):1576-83. doi: 10.1128/CVI.00264-10. Epub 2010 Aug 25.

Abstract

Recombinant adenovirus or DNA vaccines encoding herpes simplex virus type 1 (HSV-1) glycoprotein D (gD) genetically fused to human papillomavirus type 16 (HPV-16) oncoproteins (E5, E6, and E7) induce antigen-specific CD8(+) T-cell responses and confer preventive resistance to transplantable murine tumor cells (TC-1 cells). In the present report, we characterized some previously uncovered aspects concerning the induction of CD8(+) T-cell responses and the therapeutic anticancer effects achieved in C57BL/6 mice immunized with pgD-E7E6E5 previously challenged with TC-1 cells. Concerning the characterization of the immune responses elicited in mice vaccinated with pgD-E7E6E5, we determined the effect of the CD4(+) T-cell requirement, longevity, and dose-dependent activation on the E7-specific CD8(+) T-cell responses. In addition, we determined the priming/boosting properties of pgD-E7E6E5 when used in combination with a recombinant serotype 68 adenovirus (AdC68) vector encoding the same chimeric antigen. Mice challenged with TC-1 cells and then immunized with three doses of pgD-E7E6E5 elicited CD8(+) T-cell responses, measured by intracellular gamma interferon (IFN-γ) and CD107a accumulation, to the three HPV-16 oncoproteins and displayed in vivo antigen-specific cytolytic activity, as demonstrated with carboxyfluorescein diacetate succinimidyl ester (CFSE)-labeled target cells pulsed with oligopeptides corresponding to the H-2D(b)-restricted immunodominant epitopes of the E7, E6, or E5 oncoprotein. Up to 70% of the mice challenged with 5 × 10(5) TC-1 cells and immunized with pgD-E7E6E5 controlled tumor development even after 3 days of tumor cell challenge. In addition, coadministration of pgD-E7E6E5 with DNA vectors encoding pGM-CSF or interleukin-12 (IL-12) enhanced the therapeutic antitumor effects for all mice challenged with TC-1 cells. In conclusion, the present results expand our previous knowledge on the immune modulation properties of the pgD-E7E6E5 vector and demonstrate, for the first time, the strong antitumor effects of the DNA vaccine, raising promising perspectives regarding the development of immunotherapeutic reagents for the control of HPV-16-associated tumors.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • CD4-Positive T-Lymphocytes / immunology
  • CD8-Positive T-Lymphocytes / immunology
  • Cancer Vaccines / administration & dosage
  • Cancer Vaccines / immunology*
  • Dose-Response Relationship, Immunologic
  • Female
  • Human papillomavirus 16 / genetics
  • Human papillomavirus 16 / immunology*
  • Immunization, Secondary / methods
  • Interferon-gamma / metabolism
  • Leukocytes, Mononuclear / immunology
  • Mice
  • Mice, Inbred C57BL
  • Neoplasms, Experimental / immunology
  • Neoplasms, Experimental / prevention & control*
  • Oncogene Proteins, Viral / genetics
  • Oncogene Proteins, Viral / immunology*
  • Papillomavirus Vaccines / genetics
  • Papillomavirus Vaccines / immunology*
  • Recombinant Fusion Proteins / administration & dosage
  • Recombinant Fusion Proteins / immunology
  • Time Factors
  • Vaccination / methods
  • Vaccines, DNA / administration & dosage
  • Vaccines, DNA / immunology*
  • Viral Envelope Proteins / genetics
  • Viral Envelope Proteins / immunology*

Substances

  • Cancer Vaccines
  • Oncogene Proteins, Viral
  • Papillomavirus Vaccines
  • Recombinant Fusion Proteins
  • Vaccines, DNA
  • Viral Envelope Proteins
  • glycoprotein D, Human herpesvirus 1
  • Interferon-gamma