Utilizing a TLR5-Adjuvanted Cytomegalovirus as a Lentiviral Vaccine in the Nonhuman Primate Model for AIDS

• Published in: PloS one 2016-05, Vol.11 (5), p.e0155629-e0155629
• Main Authors: Deere, Jesse D, Chang, W L William, Castillo, Luis D, Schmidt, Kim A, Kieu, Hung T, Renzette, Nicholas, Kowalik, Timothy, Barthold, Stephen W, Shacklett, Barbara L, Barry, Peter A, Sparger, Ellen E
• Format: Article
• Language: English
• Subjects: Acquired immune deficiency syndrome; Adjuvants, Immunologic; AIDS; AIDS (Disease); AIDS Vaccines - immunology; Animals; Biology and Life Sciences; Cell culture; Cytomegalovirus; Cytomegalovirus - genetics; Cytomegalovirus - immunology; Diagnosis; Female; Flagellin; Fusion protein; Gag protein; Gene Expression Regulation; Gene Order; Gene Products, gag - genetics; Gene Products, gag - immunology; Genetic aspects; Genetic vectors; Genetic Vectors - genetics; Genetic Vectors - immunology; Genomes; Health aspects; HIV; Human immunodeficiency virus; In vivo methods and tests; Infections; Inflammation; Inflammatory response; Inoculation; Lentivirus - immunology; Lysates; Macaca mulatta; Macrophages; Medicine and Health Sciences; Monoclonal antibodies; Mutation; Physiological aspects; Protein Interaction Domains and Motifs; Recombinant Fusion Proteins - genetics; Recombinant Fusion Proteins - immunology; Replication; Research and analysis methods; Salmonella; Simian Acquired Immunodeficiency Syndrome - immunology; Simian Acquired Immunodeficiency Syndrome - prevention & control; Simian immunodeficiency virus; Simian Immunodeficiency Virus - immunology; Swine influenza virus; TLR5; TLR5 protein; Toll-Like Receptor 5 - chemistry; Toll-Like Receptor 5 - genetics; Toll-Like Receptor 5 - metabolism; Toll-like receptors; Transfection; Tumor Necrosis Factor-alpha - genetics; Tumor necrosis factor-TNF; Tumor necrosis factor-α; Vaccine efficacy; Vaccines; Veterinary colleges; Viral vaccines; Viruses
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0155629

Despite tremendous progress in our understanding of human immunodeficiency virus (HIV) natural history and advances in HIV treatment, there is neither an approved vaccine nor a cure for infection. Here, we describe the development and characterization of a novel replicating vaccine vector utilizing Cytomegalovirus (CMV) and a TLR5 adjuvant. After partial truncation of the central, immunodominant hypervariable domain, flagellin (fliC) from Salmonella was cloned downstream of a codon optimized gag gene from simian immunodeficiency virus (SIV) and transiently expressed in telomerized rhesus fibroblast (TeloRF) cells in culture. Lysates generated from these transfected cells induced the tumor necrosis factor alpha (TNF-α), in a mouse macrophage cell line, in a TLR5-dependent manner. The Gag/FliC expression construct was cloned into a bacterial artificial chromosome encoding the rhesus CMV (RhCMV) genome, and infectious RhCMV was generated following transfection of TeloRF cells. This virus stably expressed an SIV Gag/FliC fusion protein through four serial passages. Lysates generated from infected cells induced TNF-α in a TLR5-dependent manner. Western blot analysis of infected cell lysates verified expression of a Gag/FliC fusion protein using a SIV p27 capsid monoclonal antibody. Lastly, rhesus macaques inoculated with this novel RhCMV virus demonstrated increased inflammatory responses at the site of inoculation seven days post-infection when compared to the parental RhCMV. These results demonstrate that an artificially constructed replicating RhCMV expressing an SIV Gag/FliC fusion protein is capable of activating TLR5 in a macrophage cell line in vitro and induction of an altered inflammatory response in vivo. Ongoing animals studies are aimed at determining vaccine efficacy, including subsequent challenge with pathogenic SIV.