Improved innate and adaptive immunostimulation by genetically modified HIV-1 protein expressing NYVAC vectors

• Published in: PloS one 2011-02, Vol.6 (2), p.e16819
• Main Authors: Quakkelaar, Esther D, Redeker, Anke, Haddad, Elias K, Harari, Alexandre, McCaughey, Stella Mayo, Duhen, Thomas, Filali-Mouhim, Abdelali, Goulet, Jean-Philippe, Loof, Nikki M, Ossendorp, Ferry, Perdiguero, Beatriz, Heinen, Paul, Gomez, Carmen E, Kibler, Karen V, Koelle, David M, Sékaly, Rafick P, Sallusto, Federica, Lanzavecchia, Antonio, Pantaleo, Giuseppe, Esteban, Mariano, Tartaglia, Jim, Jacobs, Bertram L, Melief, Cornelis J M
• Format: Article
• Language: English
• Subjects: Adaptive immunity; Adaptive Immunity - genetics; AIDS vaccines; Animals; Antigen presentation; Antigen Presentation - genetics; Antigen processing; Antigens; Attenuation; B7-2 Antigen - metabolism; Binding; Biological response modifiers; Biology; Blood transfusions; CD8 antigen; Cell Proliferation; Clonal deletion; Cricetinae; Cross Reactions - genetics; Dendritic cells; Dendritic Cells - immunology; Dendritic Cells - metabolism; Dendritic Cells - virology; Deoxyribonucleic acid; DNA; gag Gene Products, Human Immunodeficiency Virus - genetics; Gene Deletion; Gene Expression; Gene Expression Regulation - genetics; Gene Expression Regulation - immunology; Gene therapy; Genes; Genetic Engineering - methods; Genetic modification; Genetic Vectors - genetics; Genetically modified organisms; HeLa Cells; HIV; HIV-1 - genetics; HIV-1 - physiology; Human immunodeficiency virus; Humans; Immune response; Immune system; Immunity, Innate - genetics; Immunization - methods; Immunogenicity; Immunological memory; Immunology; Immunostimulation; Infectious diseases; Interferon; Interferon-alpha - biosynthesis; Leukocytes (mononuclear); Lymphocytes; Lymphocytes T; Medical research; Medicine; Memory cells; Mutants; Nef protein; Poxviridae - genetics; Poxviridae - physiology; Protein binding; Proteins; Replication; Restoration; Ribonucleic acid; RNA; Signal Transduction - genetics; Signal Transduction - immunology; T cell receptors; T cells; T-Lymphocytes - cytology; T-Lymphocytes - immunology; T-Lymphocytes - virology; Vaccination; Vaccines; Vectors; Veterinary medicine; Viral Proteins - genetics; Viruses
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0016819

Attenuated poxviruses are safe and capable of expressing foreign antigens. Poxviruses are applied in veterinary vaccination and explored as candidate vaccines for humans. However, poxviruses express multiple genes encoding proteins that interfere with components of the innate and adaptive immune response. This manuscript describes two strategies aimed to improve the immunogenicity of the highly attenuated, host-range restricted poxvirus NYVAC: deletion of the viral gene encoding type-I interferon-binding protein and development of attenuated replication-competent NYVAC. We evaluated these newly generated NYVAC mutants, encoding HIV-1 env, gag, pol and nef, for their ability to stimulate HIV-specific CD8 T-cell responses in vitro from blood mononuclear cells of HIV-infected subjects. The new vectors were evaluated and compared to the parental NYVAC vector in dendritic cells (DCs), RNA expression arrays, HIV gag expression and cross-presentation assays in vitro. Deletion of type-I interferon-binding protein enhanced expression of interferon and interferon-induced genes in DCs, and increased maturation of infected DCs. Restoration of replication competence induced activation of pathways involving antigen processing and presentation. Also, replication-competent NYVAC showed increased Gag expression in infected cells, permitting enhanced cross-presentation to HIV-specific CD8 T cells and proliferation of HIV-specific memory CD8 T-cells in vitro. The recombinant NYVAC combining both modifications induced interferon-induced genes and genes involved in antigen processing and presentation, as well as increased Gag expression. This combined replication-competent NYVAC is a promising candidate for the next generation of HIV vaccines.