Immunological protection against HPV16 E7-expressing human esophageal cancer cell challenge by a novel HPV16-E6/E7 fusion protein based-vaccine in a Hu-PBL-SCID mouse model

Biol Pharm Bull. 2007 Jan;30(1):150-6. doi: 10.1248/bpb.30.150.

Abstract

Increasing evidence has suggested that infection with high-risk human papillomavirus (HPVs) is closely associated with esophageal squamous cell carcinoma (ESCC) in China. The E6 and E7 oncoproteins expressed in ESCC are considered as attractive tumor-specific antigen targets for immunotherapy. We have reported that the HPV16 mE6delta/mE7/TBhsp70delta fusion protein vaccination induced powerful anti-tumor immunity against TC-1 tumor cells in a C57BL/6 mouse model. In the present study, we further evaluate the protective efficacy of this fusion protein vaccine using an HPV E7-expressing human ESCC cell line (EC9706) and a Hu-PBL-SCID mouse model. We demonstrated that immunization with the fusion protein vaccine caused significant inhibition of tumor growth with the delay time to tumor detection (tests vs. controls, 16 d vs. 9 d, p<0.01) and much smaller tumor size (p<0.01) in vivo. The inhibitory rate was ca. 69.6%, and 25% of the fusion protein vaccinated-mice remained tumor free by the end of the experiment (42 d). Furthermore, the activated lymphocytes (CD8+) were capable of infiltrating into the tumor site, and much more apoptotic cells along with activation of caspase-3 were observed in the tumors from vaccinated-mice. Also, high expression levels of human IFN-gamma, TNF-alpha, granzyme B and perforin were detected in the tumors from vaccinated-mice. Therefore, we concluded that the HPV16 mE6delta/mE7/TBhsp70delta fusion protein vaccine is able to stimulate cellular-mediated immune response against E7-containing ESCC cells through CD8+-dependent CTL-induced apoptosis in Hu-PBL-SCID mice. These findings provide a scientific basis for HPV E7-expressing ESCC active immunotherapy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis / immunology
  • Bacterial Proteins / genetics
  • Bacterial Proteins / immunology*
  • CD8-Positive T-Lymphocytes / immunology
  • Cancer Vaccines / immunology*
  • Cell Line, Tumor
  • Esophageal Neoplasms / immunology*
  • Esophageal Neoplasms / metabolism
  • Esophageal Neoplasms / pathology
  • Esophageal Neoplasms / prevention & control*
  • Granzymes / metabolism
  • HSP70 Heat-Shock Proteins / genetics
  • HSP70 Heat-Shock Proteins / immunology*
  • Humans
  • Immunotherapy, Active
  • Interferon-gamma / metabolism
  • Lymphocytes, Tumor-Infiltrating / immunology
  • Membrane Glycoproteins / metabolism
  • Mice
  • Mice, SCID
  • Oncogene Proteins, Viral / genetics
  • Oncogene Proteins, Viral / immunology*
  • Papillomavirus E7 Proteins
  • Papillomavirus Vaccines / immunology*
  • Perforin
  • Pore Forming Cytotoxic Proteins / metabolism
  • Recombinant Fusion Proteins / immunology
  • Repressor Proteins / genetics
  • Repressor Proteins / immunology*
  • T-Lymphocytes, Cytotoxic / immunology
  • Time Factors
  • Transfection
  • Tumor Necrosis Factor-alpha / metabolism
  • Xenograft Model Antitumor Assays

Substances

  • Bacterial Proteins
  • Cancer Vaccines
  • E6 protein, Human papillomavirus type 16
  • HSP70 Heat-Shock Proteins
  • HSP70 protein, Mycobacterium tuberculosis
  • Membrane Glycoproteins
  • Oncogene Proteins, Viral
  • Papillomavirus E7 Proteins
  • Papillomavirus Vaccines
  • Pore Forming Cytotoxic Proteins
  • Recombinant Fusion Proteins
  • Repressor Proteins
  • Tumor Necrosis Factor-alpha
  • oncogene protein E7, Human papillomavirus type 16
  • Perforin
  • Interferon-gamma
  • Granzymes