title: Efficiency of HPV 16 L1/E7 DNA immunization: influence of cellular localization and capsid assembly.
abstract: Infections by human papillomaviruses (HPV) are the major cause of uterine cancer in women worldwide. Aiming to develop a combined prophylactic and therapeutic vaccine we have previously demonstrated immunogenicity of chimeric virus-like particles consisting of a C-terminally truncated HPV 16 L1 capsid protein fused to an E7 portion. Here we show that genetic vaccination with a corresponding DNA was inefficient in the induction of a L1-specific prophylactic immune response. DNA immunization with C-terminally truncated HPV 16 L1 genes of different lengths revealed that only short deletions (L1(1-498)) were tolerated for eliciting a humoral immune response against viral capsids. This correlates with the observation that the C-terminal sequences are critical for nuclear localization, capsomere and capsid assembly. However, only the ability of L1 protein to form capsomeres or capsids showed a direct influence on the outcome of the immune response. C-terminal insertion of 60 amino acids of E7 was tolerated in fusion constructs, whereas insertion of full-length E7(1-98) or shuffled E7 (149 aa) completely abolished the humoral immune response. The L1(1-498)/E7(1-60) fusion construct not only induced L1-specific antibodies but also L1- and E7-specific CTL responses after DNA vaccination.
authors.affiliation: German Cancer Research Center, Programme Infection and Cancer, 69120 Heidelberg, Germany.
authors.forename: Dirk
authors.initials: D
authors.lastname: Kuck
authors.forename: Christoph
authors.initials: C
authors.lastname: Leder
authors.forename: Andrea
authors.initials: A
authors.lastname: Kern
authors.forename: Martin
authors.initials: M
authors.lastname: Müller
authors.forename: Konrad
authors.initials: K
authors.lastname: Piuko
authors.forename: Lutz
authors.initials: L
authors.lastname: Gissmann
authors.forename: Jürgen A
authors.initials: JA
authors.lastname: Kleinschmidt
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D002213:Capsid / Q000276:immunology; D036022:Capsid Proteins / Q000235:genetics / Q000276:immunology*; D002467:Cell Nucleus; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006367:HeLa Cells; D052162:Human papillomavirus 16 / Q000235:genetics / Q000276:immunology*; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL; D019913:Nuclear Localization Signals; D009856:Oncogene Proteins, Viral / Q000235:genetics / Q000276:immunology*; D050725:Papillomavirus E7 Proteins; D017434:Protein Structure, Tertiary; D017384:Sequence Deletion; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D019444:Vaccines, DNA / Q000235:genetics / Q000276:immunology*; D014614:Vaccines, Synthetic / Q000235:genetics / Q000276:immunology; D014765:Viral Vaccines / Q000235:genetics / Q000276:immunology*
chemical_list: D000914:Antibodies, Viral; D036022:Capsid Proteins; D019913:Nuclear Localization Signals; D009856:Oncogene Proteins, Viral; D050725:Papillomavirus E7 Proteins; D019444:Vaccines, DNA; D014614:Vaccines, Synthetic; D014765:Viral Vaccines; C059731:oncogene protein E7, Human papillomavirus type 16; C063317:L1 protein, Human papillomavirus type 16