title: 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.
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.
authors.affiliation: Laboratory of Cellular and Molecular Biology, Cancer Institute & Hospital, Peking Union Medical College, Beijing, PR China.
authors.forename: Yuanzhi
authors.initials: Y
authors.lastname: Lu
authors.forename: Zhixin
authors.initials: Z
authors.lastname: Zhang
authors.forename: Qiao
authors.initials: Q
authors.lastname: Liu
authors.forename: Bo
authors.initials: B
authors.lastname: Liu
authors.forename: Xinxin
authors.initials: X
authors.lastname: Song
authors.forename: Mingrong
authors.initials: M
authors.lastname: Wang
authors.forename: Xinhua
authors.initials: X
authors.lastname: Zhao
authors.forename: Qingzheng
authors.initials: Q
authors.lastname: Zhao
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000276:immunology; D001426:Bacterial Proteins / Q000235:genetics / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D019496:Cancer Vaccines / Q000276:immunology*; D045744:Cell Line, Tumor; D004938:Esophageal Neoplasms / Q000276:immunology* / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D053804:Granzymes / Q000378:metabolism; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics / Q000276:immunology*; D006801:Humans; D016233:Immunotherapy, Active; D007371:Interferon-gamma / Q000378:metabolism; D016246:Lymphocytes, Tumor-Infiltrating / Q000276:immunology; D008562:Membrane Glycoproteins / Q000378:metabolism; D051379:Mice; D016513:Mice, SCID; D009856:Oncogene Proteins, Viral / Q000235:genetics / Q000276:immunology*; D050725:Papillomavirus E7 Proteins; D053918:Papillomavirus Vaccines / Q000276:immunology*; D054353:Perforin; D052899:Pore Forming Cytotoxic Proteins / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000276:immunology; D012097:Repressor Proteins / Q000235:genetics / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D013997:Time Factors; D014162:Transfection; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D023041:Xenograft Model Antitumor Assays
chemical_list: D001426:Bacterial Proteins; D019496:Cancer Vaccines; C068651:E6 protein, Human papillomavirus type 16; D018840:HSP70 Heat-Shock Proteins; C444642:HSP70 protein, Mycobacterium tuberculosis; D008562:Membrane Glycoproteins; D009856:Oncogene Proteins, Viral; D050725:Papillomavirus E7 Proteins; D053918:Papillomavirus Vaccines; D052899:Pore Forming Cytotoxic Proteins; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; D014409:Tumor Necrosis Factor-alpha; C059731:oncogene protein E7, Human papillomavirus type 16; D054353:Perforin; D007371:Interferon-gamma; D053804:Granzymes