title: Enhancing cellular immunogenicity of MVA-vectored vaccines by utilizing the F11L endogenous promoter.
abstract: Modified vaccinia virus Ankara (MVA)-vectored vaccines against malaria, influenza, tuberculosis and recently Ebola virus are in clinical development. Although this vector is safe and immunogenic in humans, efforts remain on-going to enhance immunogenicity through various approaches such as using stronger promoters to boost transgene expression. We previously reported that endogenous MVA promoters such as pB8 and pF11 increased transgene expression and immunogenicity, as compared to the conventional p7.5 promoter. Here, we show that both promoters also rivalled the mH5 promoter in enhancing MVA immunogenicity. We investigated the mechanisms behind this improved immunogenicity and show that it was a result of strong early transgene expression in vivo, rather than in vitro as would normally be assessed. Moreover, keeping the TK gene intact resulted in a modest improvement in immunogenicity. Utilizing pB8 or pF11 as ectopic promoters at the TK locus instead of their natural loci also increased transgene expression and immunogenicity. In addition to a reporter antigen, the pF11 promoter was tested with the expression of two vaccine antigens for which cellular immunogenicity was significantly increased as compared to the p7.5 promoter. Our data support the use of the pF11 and pB8 promoters for improved immunogenicity in future MVA-vectored candidate vaccines.
authors.affiliation: The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK; King Abdullah International Medical Research Center, Riyadh, Saudi Arabia. Electronic address: naif.alharbi@ndm.ox.ac.uk.
authors.forename: Naif Khalaf
authors.initials: NK
authors.lastname: Alharbi
authors.affiliation: The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK.
authors.forename: Alexandra J
authors.initials: AJ
authors.lastname: Spencer
authors.affiliation: The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK.
authors.forename: Ahmed M
authors.initials: AM
authors.lastname: Salman
authors.affiliation: The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK.
authors.forename: Claire M
authors.initials: CM
authors.lastname: Tully
authors.affiliation: The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK.
authors.forename: Senthil K
authors.initials: SK
authors.lastname: Chinnakannan
authors.affiliation: The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK.
authors.forename: Teresa
authors.initials: T
authors.lastname: Lambe
authors.affiliation: The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Yamaguchi
authors.affiliation: The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK.
authors.forename: Susan J
authors.initials: SJ
authors.lastname: Morris
authors.affiliation: The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK.
authors.forename: Toritse
authors.initials: T
authors.lastname: Orubu
authors.affiliation: The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK.
authors.forename: Simon J
authors.initials: SJ
authors.lastname: Draper
authors.affiliation: The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK.
authors.forename: Adrian V S
authors.initials: AV
authors.lastname: Hill
authors.affiliation: The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK.
authors.forename: Sarah C
authors.initials: SC
authors.lastname: Gilbert
mesh_terms: D000818:Animals; D004337:Drug Carriers; D058501:Enzyme-Linked Immunospot Assay; D005260:Female; D015870:Gene Expression; D005822:Genetic Vectors; D007252:Influenza Vaccines / Q000235:genetics / Q000276:immunology; D007371:Interferon-gamma / Q000378:metabolism; D007963:Leukocytes, Mononuclear / Q000276:immunology; D017780:Malaria Vaccines / Q000235:genetics / Q000276:immunology; D008807:Mice, Inbred BALB C; D011401:Promoter Regions, Genetic; D019076:Transgenes; D016896:Treatment Outcome; D014614:Vaccines, Synthetic / Q000235:genetics* / Q000276:immunology*; D014616:Vaccinia virus / Q000235:genetics*
chemical_list: D004337:Drug Carriers; D007252:Influenza Vaccines; D017780:Malaria Vaccines; D014614:Vaccines, Synthetic; D007371:Interferon-gamma
keywords: Immunogenicity; MVA; Promoter; Transgene expression; Vaccine development; Viral vector