title: DNA prime Listeria boost induces a cellular immune response to SIV antigens in the rhesus macaque model that is capable of limited suppression of SIV239 viral replication.
abstract: DNA vaccines and recombinant Listeria monocytogenes that express and secrete SIV Gag and Env antigens were combined in a nonhuman primate prime-boost immunogenicity study followed by a challenge with SIV239. We report that recombinant DNA vaccine delivered intramuscularly, and recombinant L. monocytogenes delivered orally each individually have the ability to induce CD8+ and CD4+ T cell immune responses in a nonhuman primate. Four rhesus monkeys were immunized at weeks 0, 4, 8, and 12 with the pCSIVgag and pCSIVenv DNA plasmids and boosted with SIV expressing L. monocytogenes vaccines at weeks 16, 20, and 28. Four rhesus monkeys received only the L. monocytogenes vaccines at weeks 16, 20, and 28. A final group of monkeys served as a control group. Blood samples were taken before vaccination and 2 weeks post each injection and analyzed by ELISPOT for CD4+ and CD8+ T cell responses. Moderate vaccine induced SIV-specific cellular immune responses were observed following immunization with either DNA or L. monocytogenes vectors. However, the SIV antigen-specific immune responses were significantly increased when Rhesus macaques were primed with SIV DNA vaccines and boosted with the SIV expressing L. monocytogenes vectors. In addition, the combined vaccine was able to impact SIV239 viral replication following an intrarectal challenge. This study demonstrates for the first time that oral L. monocytogenes can induce a cellular immune response in a nonhuman primate and is able to enhance the efficacy of a DNA vaccine as well as provide modest protection against SIV239 challenge.
authors.affiliation: Department of Pathology and Laboratory Medicine, Philadelphia, PA, USA.
authors.forename: Jean D
authors.initials: JD
authors.lastname: Boyer
authors.forename: Tara M
authors.initials: TM
authors.lastname: Robinson
authors.forename: Paulo C
authors.initials: PC
authors.lastname: Maciag
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Peng
authors.forename: Ross S
authors.initials: RS
authors.lastname: Johnson
authors.forename: George
authors.initials: G
authors.lastname: Pavlakis
authors.forename: Mark G
authors.initials: MG
authors.lastname: Lewis
authors.forename: Anding
authors.initials: A
authors.lastname: Shen
authors.forename: Robert
authors.initials: R
authors.lastname: Siliciano
authors.forename: Charles R
authors.initials: CR
authors.lastname: Brown
authors.forename: David B
authors.initials: DB
authors.lastname: Weiner
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Paterson
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D000956:Antigens, Viral / Q000276:immunology*; D004279:DNA, Viral; D005260:Female; D015683:Gene Products, gag / Q000276:immunology; D005822:Genetic Vectors; D007111:Immunity, Cellular / Q000276:immunology*; D007117:Immunization, Secondary; D008089:Listeria monocytogenes / Q000235:genetics / Q000276:immunology*; D008198:Lymph Nodes / Q000821:virology; D008253:Macaca mulatta; D008297:Male; D030781:Organisms, Genetically Modified; D018449:SAIDS Vaccines / Q000008:administration & dosage / Q000276:immunology*; D015302:Simian Immunodeficiency Virus / Q000276:immunology*; D013997:Time Factors; D019444:Vaccines, DNA / Q000008:administration & dosage / Q000276:immunology; D014614:Vaccines, Synthetic / Q000276:immunology; D014759:Viral Envelope Proteins / Q000276:immunology; D019562:Viral Load
chemical_list: D000914:Antibodies, Viral; D000956:Antigens, Viral; D004279:DNA, Viral; D015683:Gene Products, gag; D018449:SAIDS Vaccines; D019444:Vaccines, DNA; D014614:Vaccines, Synthetic; D014759:Viral Envelope Proteins