Background DNA vaccines are a promising approach to vaccination since they circumvent the problem of vector-induced immunity. DNA plasmid cytokine adjuvants have been shown to augment immune responses in small animals and in macaques. Methodology/Principal Findings We performed two first in human HIV vaccine trials in the US, Brazil and Thailand of an RNA-optimized truncated HIV-1 gag gene (p37) DNA derived from strain HXB2 administered either alone or in combination with dose-escalation of IL-12 or IL-15 plasmid cytokine adjuvants. Vaccinations with both the HIV immunogen and cytokine adjuvant were generally well-tolerated and no significant vaccine-related adverse events were identified. A small number of subjects developed asymptomatic low titer antibodies to IL-12 or IL-15. Cellular immunogenicity following 3 and 4 vaccinations was poor, with response rates to gag of 4.9%/8.7% among vaccinees receiving gag DNA alone, 0%/11.5% among those receiving gag DNA+IL-15, and no responders among those receiving DNA+high dose (1500 ug) IL-12 DNA. However, after three doses, 44.4% (4/9) of vaccinees receiving gag DNA and intermediate dose (500 ug) of IL-12 DNA demonstrated a detectable cellular immune response. Conclusions/Significance This combination of HIV gag DNA with plasmid cytokine adjuvants was well tolerated. There were minimal responses to HIV gag DNA alone, and no apparent augmentation with either IL-12 or IL-15 plasmid cytokine adjuvants. Despite the promise of DNA vaccines, newer formulations or methods of delivery will be required to increase their immunogenicity. Trial Registration Clinicaltrials.gov NCT00115960 NCT00111605
References
[1]
Kutzler MA, Weiner DB (2008) DNA vaccines: ready for prime time? Nat Rev Genet 9: 776–788.
[2]
Casimiro DR, Bett AJ, Fu TM, Davies ME, Tang A, et al. (2004) Heterologous human immunodeficiency virus type 1 priming-boosting immunization strategies involving replication-defective adenovirus and poxvirus vaccine vectors. J Virol 78: 11434–11438.
[3]
Liu J, O'Brien KL, Lynch DM, Simmons NL, La Porte A, et al. (2009) Immune control of an SIV challenge by a T-cell-based vaccine in rhesus monkeys. Nature 457: 87–91.
Wilson NA, Reed J, Napoe GS, Piaskowski S, Szymanski A, et al. (2006) Vaccine-induced cellular immune responses reduce plasma viral concentrations after repeated low-dose challenge with pathogenic simian immunodeficiency virus SIVmac239. J Virol 80: 5875–5885.
[6]
Chattergoon M, Boyer J, Weiner DB (1997) Genetic immunization: a new era in vaccines and immune therapeutics. FASEB J 11: 753–763.
[7]
Bansal A, Jackson B, West K, Wang S, Lu S, et al. (2008) Multifunctional T-cell characteristics induced by a polyvalent DNA prime/protein boost human immunodeficiency virus type 1 vaccine regimen given to healthy adults are dependent on the route and dose of administration. J Virol 82: 6458–6469.
[8]
Graham BS, Koup RA, Roederer M, Bailer RT, Enama ME, et al. (2006) Phase 1 safety and immunogenicity evaluation of a multiclade HIV-1 DNA candidate vaccine. J Infect Dis 194: 1650–1660.
[9]
Mwau M, Cebere I, Sutton J, Chikoti P, Winstone N, et al. (2004) A human immunodeficiency virus 1 (HIV-1) clade A vaccine in clinical trials: stimulation of HIV-specific T-cell responses by DNA and recombinant modified vaccinia virus Ankara (MVA) vaccines in humans. J Gen Virol 85: 911–919.
[10]
Tavel JA, Martin JE, Kelly GG, Enama ME, Shen JM, et al. (2007) Safety and immunogenicity of a Gag-Pol candidate HIV-1 DNA vaccine administered by a needle-free device in HIV-1-seronegative subjects. J Acquir Immune Defic Syndr 44: 601–605.
[11]
Donnelly JJ, Friedman A, Martinez D, Montgomery DL, Shiver JW, et al. (1995) Preclinical efficacy of a prototype DNA vaccine: enhanced protection against antigenic drift in influenza virus. Nat Med 1: 583–587.
[12]
Catanzaro AT, Koup RA, Roederer M, Bailer RT, Enama ME, et al. (2006) Phase 1 safety and immunogenicity evaluation of a multiclade HIV-1 candidate vaccine delivered by a replication-defective recombinant adenovirus vector. J Infect Dis 194: 1638–1649.
[13]
Casimiro DR, Chen L, Fu TM, Evans RK, Caulfield MJ, et al. (2003) Comparative immunogenicity in rhesus monkeys of DNA plasmid, recombinant vaccinia virus, and replication-defective adenovirus vectors expressing a human immunodeficiency virus type 1 gag gene. J Virol 77: 6305–6313.
[14]
Bett AJ, Dubey SA, Mehrotra DV, Guan L, Long R, et al. (2010) Comparison of T cell immune responses induced by vectored HIV vaccines in non-human primates and humans. Vaccine.
[15]
Cox KS, Clair JH, Prokop MT, Sykes KJ, Dubey SA, et al. (2008) DNA gag/adenovirus type 5 (Ad5) gag and Ad5 gag/Ad5 gag vaccines induce distinct T-cell response profiles. J Virol 82: 8161–8171.
[16]
Koup RA, Roederer M, Lamoreaux L, Fischer J, Novik L, et al. (2010) Priming immunization with DNA augments immunogenicity of recombinant adenoviral vectors for both HIV-1 specific antibody and T-cell responses. PLoS One 5: e9015.
[17]
Goepfert PAea (2010) Phase 1 safety and immunogenicity testing of DNA and recombinant modified vaccinia Ankara vaccines expressing HIV-1 Virus-Like Particles. J Infect Dis.
[18]
Barouch DH, Santra S, Schmitz JE, Kuroda MJ, Fu TM, et al. (2000) Control of viremia and prevention of clinical AIDS in rhesus monkeys by cytokine-augmented DNA vaccination. Science 290: 486–492.
[19]
Morrow MP, Pankhong P, Laddy DJ, Schoenly KA, Yan J, et al. (2009) Comparative ability of IL-12 and IL-28B to regulate Treg populations and enhance adaptive cellular immunity. Blood 113: 5868–5877.
[20]
Kraynyak KA, Kutzler MA, Cisper NJ, Laddy DJ, Morrow MP, et al. (2009) Plasmid-encoded interleukin-15 receptor alpha enhances specific immune responses induced by a DNA vaccine in vivo. Hum Gene Ther 20: 1143–1156.
[21]
Trinchieri G (1995) Interleukin-12: a proinflammatory cytokine with immunoregulatory functions that bridge innate resistance and antigen-specific adaptive immunity. Annu Rev Immunol 13: 251–276.
[22]
Wolf SF, Temple PA, Kobayashi M, Young D, Dicig M, et al. (1991) Cloning of cDNA for natural killer cell stimulatory factor, a heterodimeric cytokine with multiple biologic effects on T and natural killer cells. J Immunol 146: 3074–3081.
[23]
Sartori A, Ma X, Gri G, Showe L, Benjamin D, et al. (1997) Interleukin-12: an immunoregulatory cytokine produced by B cells and antigen-presenting cells. Methods 11: 116–127.
[24]
Freeman AF, Holland SM (2007) Persistent bacterial infections and primary immune disorders. Curr Opin Microbiol 10: 70–75.
[25]
Holland SM (2007) Interferon gamma, IL-12, IL-12R and STAT-1 immunodeficiency diseases: disorders of the interface of innate and adaptive immunity. Immunol Res 38: 342–346.
[26]
MacLennan C, Fieschi C, Lammas DA, Picard C, Dorman SE, et al. (2004) Interleukin (IL)-12 and IL-23 are key cytokines for immunity against Salmonella in humans. J Infect Dis 190: 1755–1757.
[27]
Giri JG, Anderson DM, Kumaki S, Park LS, Grabstein KH, et al. (1995) IL-15, a novel T cell growth factor that shares activities and receptor components with IL-2. J Leukoc Biol 57: 763–766.
[28]
Grabstein KH, Eisenman J, Shanebeck K, Rauch C, Srinivasan S, et al. (1994) Cloning of a T cell growth factor that interacts with the beta chain of the interleukin-2 receptor. Science 264: 965–968.
[29]
Rochman Y, Spolski R, Leonard WJ (2009) New insights into the regulation of T cells by gamma(c) family cytokines. Nat Rev Immunol 9: 480–490.
[30]
Becker TC, Wherry EJ, Boone D, Murali-Krishna K, Antia R, et al. (2002) Interleukin 15 is required for proliferative renewal of virus-specific memory CD8 T cells. J Exp Med 195: 1541–1548.
[31]
Wherry EJ, Becker TC, Boone D, Kaja MK, Ma A, et al. (2002) Homeostatic proliferation but not the generation of virus specific memory CD8 T cells is impaired in the absence of IL-15 or IL-15Ralpha. Adv Exp Med Biol 512: 165–175.
[32]
Wherry EJ, Teichgraber V, Becker TC, Masopust D, Kaech SM, et al. (2003) Lineage relationship and protective immunity of memory CD8 T cell subsets. Nat Immunol 4: 225–234.
[33]
Schneider R, Campbell M, Nasioulas G, Felber BK, Pavlakis GN (1997) Inactivation of the human immunodeficiency virus type 1 inhibitory elements allows Rev-independent expression of Gag and Gag/protease and particle formation. J Virol 71: 4892–4903.
[34]
Schwartz S, Campbell M, Nasioulas G, Harrison J, Felber BK, et al. (1992) Mutational inactivation of an inhibitory sequence in human immunodeficiency virus type 1 results in Rev-independent gag expression. J Virol 66: 7176–7182.
[35]
Schwartz S, Felber BK, Pavlakis GN (1992) Distinct RNA sequences in the gag region of human immunodeficiency virus type 1 decrease RNA stability and inhibit expression in the absence of Rev protein. J Virol 66: 150–159.
[36]
Moodie Z, Price L, Gouttefangeas C, Mander A, Janetzki S, et al. (2010) Response definition criteria for ELISPOT assays revisited. Cancer Immunol Immunother 59: 1489–1501.
[37]
Agresti A, Coull BA (1996) Order-restricted tests for stratified comparisons of binomial proportions. Biometrics 52: 1103–1111.
[38]
Abrams D, Levy Y, Losso MH, Babiker A, Collins G, et al. (2009) Interleukin-2 therapy in patients with HIV infection. N Engl J Med 361: 1548–1559.
[39]
Rodolfo M, Colombo MP (1999) Interleukin-12 as an adjuvant for cancer immunotherapy. Methods 19: 114–120.
[40]
Atkins MB, Robertson MJ, Gordon M, Lotze MT, DeCoste M, et al. (1997) Phase I evaluation of intravenous recombinant human interleukin 12 in patients with advanced malignancies. Clin Cancer Res 3: 409–417.
[41]
Leonard JP, Sherman ML, Fisher GL, Buchanan LJ, Larsen G, et al. (1997) Effects of single-dose interleukin-12 exposure on interleukin-12-associated toxicity and interferon-gamma production. Blood 90: 2541–2548.
[42]
Schadeck EB, Sidhu M, Egan MA, Chong SY, Piacente P, et al. (2006) A dose sparing effect by plasmid encoded IL-12 adjuvant on a SIVgag-plasmid DNA vaccine in rhesus macaques. Vaccine 24: 4677–4687.
[43]
Chong SY, Egan MA, Kutzler MA, Megati S, Masood A, et al. (2007) Comparative ability of plasmid IL-12 and IL-15 to enhance cellular and humoral immune responses elicited by a SIVgag plasmid DNA vaccine and alter disease progression following SHIV(89.6P) challenge in rhesus macaques. Vaccine 25: 4967–4982.
[44]
Boyer JD, Robinson TM, Kutzler MA, Vansant G, Hokey DA, et al. (2007) Protection against simian/human immunodeficiency virus (SHIV) 89.6P in macaques after coimmunization with SHIV antigen and IL-15 plasmid. Proc Natl Acad Sci U S A 104: 18648–18653.
[45]
Frahm N, Korber BT, Adams CM, Szinger JJ, Draenert R, et al. (2004) Consistent cytotoxic-T-lymphocyte targeting of immunodominant regions in human immunodeficiency virus across multiple ethnicities. J Virol 78: 2187–2200.
[46]
Hirao LA, Wu L, Khan AS, Hokey DA, Yan J, et al. (2008) Combined effects of IL-12 and electroporation enhances the potency of DNA vaccination in macaques. Vaccine 26: 3112–3120.
[47]
Luckay A, Sidhu MK, Kjeken R, Megati S, Chong SY, et al. (2007) Effect of plasmid DNA vaccine design and in vivo electroporation on the resulting vaccine-specific immune responses in rhesus macaques. J Virol 81: 5257–5269.
[48]
Hirao LA, Wu L, Satishchandran A, Khan AS, Draghia-Akli R, et al. (2010) Comparative Analysis of Immune Responses Induced by Vaccination With SIV Antigens by Recombinant Ad5 Vector or Plasmid DNA in Rhesus Macaques. Mol Ther 18: 1568–1576.
