title: Targeting of nucleoprotein to chemokine receptors by DNA vaccination results in increased CD8(+)-mediated cross protection against influenza.
abstract: Vaccination is at present the most efficient way of preventing influenza infections. Currently used inactivated influenza vaccines can induce virus-neutralizing antibodies that are protective against a particular influenza strain, but hamper the induction of cross-protective T-cell responses to later infections. Thus, influenza vaccines need to be updated annually in order to confer protection against circulating influenza strains. This study aims at developing an efficient vaccine that can induce broader protection against influenza. For this purpose, we have used the highly conserved nucleoprotein (NP) from an influenza A virus subtype H7N7 strain, and inserted it into a vaccine format that targets an antigen directly to relevant antigen presenting cells (APCs). The vaccine format consists of bivalent antigenic and targeting units, linked via an Ig-based dimerization unit. In this study, NP was linked to MIP-1α, a chemokine that targets the linked antigen to chemokine receptors 1, 3 and 5 expressed on various APCs. The vaccine protein was indirectly delivered by DNA. Mice were vaccinated intradermally with plasmids, in combination with electroporation to enhance cellular uptake of DNA. We found that a single DNA vaccination was sufficient for induction of both antibody and T cell responses in BALB/c mice. Targeting of nucleoprotein to chemokine receptors enhanced T cell responses but not antibody responses. Moreover, a single dose of MIP1α-NP conferred protection in BALB/c mice against a lethal challenge with an H1N1 influenza virus. The observed cross-protection was mediated by CD8(+) T cells.
authors.affiliation: K.G Jebsen Centre for Influenza Vaccine Research, Institute of Clinical Medicine, University of Oslo, Oslo, Norway; Institute of Immunology, Oslo University Hospital, Oslo, Norway.
authors.forename: Marta
authors.initials: M
authors.lastname: Baranowska
authors.affiliation: Department of Laboratory Services, Norwegian Veterinary Institute, Oslo, Norway; Division of Infectious Disease Control, Norwegian Institute of Public Health, Oslo, Norway.
authors.forename: Anna G
authors.initials: AG
authors.lastname: Hauge
authors.affiliation: K.G Jebsen Centre for Influenza Vaccine Research, Institute of Clinical Medicine, University of Oslo, Oslo, Norway; Institute of Immunology, Oslo University Hospital, Oslo, Norway.
authors.forename: Chloé
authors.initials: C
authors.lastname: Hoornaert
authors.affiliation: K.G Jebsen Centre for Influenza Vaccine Research, Institute of Clinical Medicine, University of Oslo, Oslo, Norway; Institute of Immunology, Oslo University Hospital, Oslo, Norway; Centre for Immune Regulation, Faculty of Medicine, University of Oslo, Oslo, Norway.
authors.forename: Bjarne
authors.initials: B
authors.lastname: Bogen
authors.affiliation: K.G Jebsen Centre for Influenza Vaccine Research, Institute of Clinical Medicine, University of Oslo, Oslo, Norway; Institute of Immunology, Oslo University Hospital, Oslo, Norway. Electronic address: gunnveig.grodeland@medisin.uio.no.
authors.forename: Gunnveig
authors.initials: G
authors.lastname: Grødeland
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D000917:Antibody Formation; D000938:Antigen-Presenting Cells / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D054405:Chemokine CCL3 / Q000276:immunology; D056738:Cross Protection; D005260:Female; D053118:Influenza A Virus, H1N1 Subtype; D053126:Influenza A Virus, H7N7 Subtype; D007252:Influenza Vaccines / Q000276:immunology*; D008807:Mice, Inbred BALB C; D009500:Neutralization Tests; D009698:Nucleoproteins / Q000276:immunology*; D009976:Orthomyxoviridae Infections / Q000276:immunology / Q000517:prevention & control*; D010957:Plasmids; D019707:Receptors, Chemokine / Q000276:immunology*; D019444:Vaccines, DNA / Q000276:immunology*
chemical_list: D000914:Antibodies, Viral; C496534:Ccl3 protein, mouse; D054405:Chemokine CCL3; D007252:Influenza Vaccines; D009698:Nucleoproteins; D019707:Receptors, Chemokine; D019444:Vaccines, DNA
keywords: APC-targeting; Antigen presenting cells; Cytotoxic; DNA vaccine; Influenza; Nucleoprotein; T cells; Vaccine