title: Enhancement of immunotherapeutic effects of HPV16E7 on cervical cancer by fusion with CTLA4 extracellular region.
abstract: Cervical cancer is caused by infection by high-risk human papillomavirus (HPV), especially HPV16. Limitations in current treatments of cervical cancers call for the development of new and improved immunotherapies. This study aims at investigating the efficacy of a novel vaccine consisting of modified HPV 16E7 fused with human cytotoxic T-lymphocyte antigen 4 (CTLA4). The regions in HPV16 E7 gene associated with its transformation and CTL-enhanced response were modified; the resultant HPV16mE7 was fused with extracellular region of CTLA4 to generate HPVml6E7-eCTLA4 fusion protein. Binding of this fusion protein to B7 molecules expressed on antigen presenting-cells (APCs) was demonstrated. C57BL/6 (H-2b) mice immunized with low dose of the fusion protein (10 microg) produced higher titer antibody and stronger specific CTL response, and expressed higher levels of IFN-gamma and IL-12, compared with those immunized with HPVml6E7 only or admixture of HPVml6E7 and CTLA4, or PBS; and were protected from lethal dose tumor challenge. Tumor growth was retarded and survival prolonged in mouse models with the fusion protein treatment. Our results demonstrate that fusion of HPV16 E7 with eCTLA4 targeting APCs resulted in enhanced immunity, and that this fusion protein may be useful for improving the efficacy of immunotherapeutic treatments of cervical cancer and other HPV16 infection-associated tumors.
authors.affiliation: The Shenzhen Key Lab of Gene and Antibody Therapy, Center for Biotech and BioMedicine and Division of Life Sciences, Graduate School at Shenzhen, Tsinghua University, Shenzhen, Guangdong, 518055, P. R. China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Zheng
authors.forename: Yijuan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Yuandong
authors.initials: Y
authors.lastname: Ma
authors.forename: Jun
authors.initials: J
authors.lastname: Wan
authors.forename: Chaofan
authors.initials: C
authors.lastname: Shi
authors.forename: Laiqiang
authors.initials: L
authors.lastname: Huang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood*; D015703:Antigens, CD / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D060908:CTLA-4 Antigen; D005110:Extracellular Space; D005260:Female; D052162:Human papillomavirus 16 / Q000276:immunology; D006801:Humans; D007167:Immunotherapy; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D009374:Neoplasms, Experimental / Q000276:immunology / Q000401:mortality / Q000517:prevention & control / Q000628:therapy*; D009856:Oncogene Proteins, Viral / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D050725:Papillomavirus E7 Proteins; D053918:Papillomavirus Vaccines / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D002583:Uterine Cervical Neoplasms / Q000276:immunology / Q000401:mortality / Q000517:prevention & control / Q000628:therapy*
chemical_list: D000914:Antibodies, Viral; D015703:Antigens, CD; D060908:CTLA-4 Antigen; C556706:CTLA4 protein, human; C556707:Ctla4 protein, mouse; D009856:Oncogene Proteins, Viral; D050725:Papillomavirus E7 Proteins; D053918:Papillomavirus Vaccines; D011993:Recombinant Fusion Proteins; C059731:oncogene protein E7, Human papillomavirus type 16