title: Role of T cell competition in the induction of cytotoxic T lymphocyte activity during viral vector-based immunization regimens.
abstract: T cell competition between antigen- and vector-specific T cells may determine the outcome of viral vector-based immunization regimens, as we previously proposed. Here, we unravelled the interplay between antigen- and vector-specific immunity, using recombinant Semliki Forest virus (rSFV). Priming of mice with rSFV, encoding LacZ (SFVLacZ), or with empty rSFV strongly suppressed subsequent induction of ovalbumin or Human Papilloma virus (HPV) E6/E7-specific CTL activity by a booster with SFVeOVA or SFVeE6,7, respectively. Yet, priming with irradiated, i.e. replication-defective, SFVLacZ did not affect subsequent CTL induction, indicating that the interfering vector-specific immunity was directed against the viral replicase. However, immune responses against the strongly immunogenic nucleoprotein of influenza virus encoded by SFV were less severely affected by priming with SFVLacZ. Thus the outcome of heterologous prime-boost immunizations appears to depend on the immunogenicity of the respective antigens.
authors.affiliation: Department of Medical Microbiology, Molecular Virology Section, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
authors.forename: Annechien J A
authors.initials: AJ
authors.lastname: Lambeck
authors.forename: Hans W
authors.initials: HW
authors.lastname: Nijman
authors.forename: Baukje Nynke
authors.initials: BN
authors.lastname: Hoogeboom
authors.forename: Joke
authors.initials: J
authors.lastname: Regts
authors.forename: Arjan
authors.initials: A
authors.lastname: de Mare
authors.forename: Jan
authors.initials: J
authors.lastname: Wilschut
authors.forename: Toos
authors.initials: T
authors.lastname: Daemen
mesh_terms: D000818:Animals; D000918:Antibody Specificity; D002460:Cell Line; D006224:Cricetinae; D000939:Epitopes / Q000276:immunology*; D005260:Female; D007111:Immunity, Cellular; D007117:Immunization, Secondary; D008213:Lymphocyte Activation; D051379:Mice; D008810:Mice, Inbred C57BL; D009975:Orthomyxoviridae / Q000276:immunology; D027383:Papillomaviridae / Q000276:immunology; D012324:RNA-Dependent RNA Polymerase / Q000276:immunology; D012672:Semliki forest virus / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D019076:Transgenes / Q000276:immunology
chemical_list: D000939:Epitopes; D012324:RNA-Dependent RNA Polymerase