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Advances in methods for the production, purification, and characterization of HIV-1 Gag–Env pseudovirion vaccines. Vaccine 2007; 25:8036-48. [DOI: 10.1016/j.vaccine.2007.09.016] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2007] [Revised: 09/04/2007] [Accepted: 09/06/2007] [Indexed: 11/21/2022]
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Crooks ET, Moore PL, Franti M, Cayanan CS, Zhu P, Jiang P, de Vries RP, Wiley C, Zharkikh I, Schülke N, Roux KH, Montefiori DC, Burton DR, Binley JM. A comparative immunogenicity study of HIV-1 virus-like particles bearing various forms of envelope proteins, particles bearing no envelope and soluble monomeric gp120. Virology 2007; 366:245-62. [PMID: 17580087 PMCID: PMC2080857 DOI: 10.1016/j.virol.2007.04.033] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2007] [Revised: 03/08/2007] [Accepted: 04/24/2007] [Indexed: 10/23/2022]
Abstract
To assess the potential of native Envelope glycoprotein (Env) trimers as neutralizing antibody vaccines, we immunized guinea pigs with three types of VLPs and soluble gp120. Particles included "SOS-VLPs" (bearing disulfide-shackled functional trimers), "UNC-VLPs" (bearing uncleaved nonfunctional Env) and "naked VLPs" (bearing no Env). The SOS-VLPs were found to have a density of about 27 native trimers per particle, approximately twice that of live inactivated HIV-1 preparations. As immunogens, UNC- and SOS-VLP rapidly elicited anti-gp120 antibodies focused on the V3 loop and the gp120 coreceptor binding site. Reactivity to the gp41 immunodominant domain was absent in SOS-VLP sera, presumably because gp120-gp41 association is stabilized, effectively covering this epitope. Gp120-immune sera reacted with the receptor binding sites of gp120 and were less focused on the V3 loop. Some Env-VLP sera neutralized primary isolates at modest titers. The measurement of neutralization was found to be affected by the cell lines used. Depending on the assay particulars, non-Env specific antibodies in VLP sera could enhance infection, or nonspecifically neutralize. However, a neutralization assay using TZM-BL cells was essentially clear of these effects. We also describe a native trimer binding assay to confirm neutralization activity in a manner that completely eliminates nonspecific effects. Overall, our data suggests that Env-VLP sera were primarily focused on nonfunctional forms of Env on VLP surfaces, possibly gp120/gp41 monomers and not the trimers. Therefore, to make progress toward a more effective VLP-based vaccine, we will need to find ways to refocus the attention of B cells on native trimers.
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Affiliation(s)
- Emma T. Crooks
- Torrey Pines Institute for Molecular Studies, 3550 General Atomics Court, San Diego, CA 92121
| | - Penny L. Moore
- National Institute for Communicable Diseases, Sandringham, Johannesburg, South Africa
| | - Michael Franti
- Progenics Pharmaceuticals, 777 Old Saw Mill River Rd., Tarrytown, NY 10591
| | | | - Ping Zhu
- Department of Biological Science, and Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306
| | - Pengfei Jiang
- Torrey Pines Institute for Molecular Studies, 3550 General Atomics Court, San Diego, CA 92121
| | - Robbert P. de Vries
- Torrey Pines Institute for Molecular Studies, 3550 General Atomics Court, San Diego, CA 92121
- Department of Human Retrovirology, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands
| | - Cheryl Wiley
- The Scripps Research Institute, 10550 North Torrey Pines Rd., La Jolla CA 92037
| | - Irina Zharkikh
- The Scripps Research Institute, 10550 North Torrey Pines Rd., La Jolla CA 92037
| | - Norbert Schülke
- Millennium Pharmaceuticals, Inc., 35 Landsdowne Street, Cambridge, MA 02139
| | - Kenneth H. Roux
- Department of Biological Science, and Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306
| | - David C. Montefiori
- Duke University, Department of Surgery, La Salle Straight Extensions, Durham, NC 27710
| | - Dennis R. Burton
- The Scripps Research Institute, 10550 North Torrey Pines Rd., La Jolla CA 92037
| | - James M. Binley
- Torrey Pines Institute for Molecular Studies, 3550 General Atomics Court, San Diego, CA 92121
- *corresponding author: James M. Binley, Torrey Pines Institute for Molecular Studies, 3550 General Atomics Court, San Diego CA 92121. tel: (858) 909 5142. fax: (858) 455 3804.
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Ambrose Z, KewalRamani VN, Bieniasz PD, Hatziioannou T. HIV/AIDS: in search of an animal model. Trends Biotechnol 2007; 25:333-7. [PMID: 17574286 DOI: 10.1016/j.tibtech.2007.05.004] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2007] [Revised: 04/11/2007] [Accepted: 05/30/2007] [Indexed: 11/28/2022]
Abstract
AIDS is among the most devastating diseases of our time, claiming the lives of approximately 3 million people per year. The primary cause of AIDS, human immunodeficiency virus type 1 (HIV-1), is a pathogen that is highly specific for humans and generally does not infect or cause disease in other species. This property complicates the generation of animal models that are urgently needed to test new antiretroviral therapies and vaccines. The most practical animal models developed to date consist of infection of rhesus macaques with a simian immunodeficiency virus (SIV) or chimeric HIV/SIV viruses. Although these models are useful for particular applications, the fact that SIV is a distinct virus compared with HIV-1 represents a significant limitation to their use. Here, we discuss the uses and limitations of existing models and recent advances that might lead to better animal models for HIV/AIDS.
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Affiliation(s)
- Zandrea Ambrose
- HIV Drug Resistance Program, National Cancer Institute, Frederick, MD 21702, USA
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Amara RR, Patel K, Niedziela G, Nigam P, Sharma S, Staprans SI, Montefiori DC, Chenareddi L, Herndon JG, Robinson HL, McClure HM, Novembre FJ. A combination DNA and attenuated simian immunodeficiency virus vaccine strategy provides enhanced protection from simian/human immunodeficiency virus-induced disease. J Virol 2005; 79:15356-67. [PMID: 16306607 PMCID: PMC1315994 DOI: 10.1128/jvi.79.24.15356-15367.2005] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2005] [Accepted: 09/15/2005] [Indexed: 11/20/2022] Open
Abstract
Among the most effective vaccine candidates tested in the simian immunodeficiency virus (SIV)/macaque system, live attenuated viruses have been shown to provide the best protection from challenge. To investigate if preimmunization would increase the level of protection afforded by live attenuated SIVmac239Deltanef (Deltanef), macaques were given two priming immunizations of DNA encoding SIV Gag and Pol proteins, with control macaques receiving vector DNA immunizations. In macaques receiving the SIV DNA inoculation, SIV-specific cellular but not humoral responses were readily detectable 2 weeks after the second DNA inoculation. Following boosting with live attenuated virus, control of Deltanef replication was superior in SIV-DNA-primed macaques versus vector-DNA-primed macaques and was correlated with higher levels of CD8+/gamma-interferon-positive and/or interleukin-2-positive cells. Challenge with an intravenous inoculation of simian/human immunodeficiency virus (SHIV) strain SHIV89.6p resulted in infection of all animals. However, macaques receiving SIV DNA as the priming immunizations had statistically lower viral loads than control animals and did not develop signs of disease, whereas three of seven macaques receiving vector DNA showed severe CD4+ T-cell decline, with development of AIDS in one of these animals. No correlation of immune responses to protection from disease could be derived from our analyses. These results demonstrate that addition of a DNA prime to a live attenuated virus provided better protection from disease following challenge than live attenuated virus alone.
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Affiliation(s)
- Rama Rao Amara
- Divisions of Microbiology and Immunology, Yerkes National Primate Research Center, Emory University, 954 N. Gatewood Rd., Atlanta, GA 30329, USA
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5
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Abstract
Since the discovery of simian immunodeficiency viruses (SIV) causing AIDS-like diseases in Asian macaques, non-human primates (NHP) have played an important role in AIDS vaccine research. A multitude of vaccines and immunization approaches have been evaluated, including live attenuated viruses, DNA vaccines, viral and bacterial vectors, subunit proteins, and combinations thereof. Depending on the particular vaccine and model used, varying degrees of protection have been achieved, including prevention of infection, reduction of viral load, and amelioration of disease. In a few instances, potential safety concerns and vaccine-enhanced pathogenicity have also been noted. In the past decade, sophisticated methodologies have been developed to define the mechanisms of protective immunity. However, a clear road map for HIV vaccine development has yet to emerge. This is in part because of the intrinsic nature of the surrogate model and in part because of the improbability of any single model to fully capture the complex interactions of natural HIV infection in humans. The lack of standardization, the limited models available, and the incomplete understanding of the immunobiology of NHP contribute to the difficulty to extrapolate findings from such models to HIV vaccine development. Until efficacy data become available from studies of parallel vaccine concepts in humans and macaques, the predictive value of any NHP model remains unknown. Towards this end, greater appreciation of the utility and limitations of the NHP model and further developments to better mimic HIV infection in humans will likely help inform future AIDS vaccine efforts.
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Affiliation(s)
- Shiu-Lok Hu
- Department of Pharmaceutics and Washington National Primate Research Center, University of Washington, Seattle, 98121, USA.
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6
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Lifson JD, Rossio JL, Piatak M, Bess J, Chertova E, Schneider DK, Coalter VJ, Poore B, Kiser RF, Imming RJ, Scarzello AJ, Henderson LE, Alvord WG, Hirsch VM, Benveniste RE, Arthur LO. Evaluation of the safety, immunogenicity, and protective efficacy of whole inactivated simian immunodeficiency virus (SIV) vaccines with conformationally and functionally intact envelope glycoproteins. AIDS Res Hum Retroviruses 2004; 20:772-87. [PMID: 15307924 DOI: 10.1089/0889222041524661] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
A novel, general approach to chemical inactivation of retroviruses was used to produce inactivated simian immunodeficiency virus (SIV) particles with functional envelope glycoproteins. Inactivated virions of three different virus isolates (SIVmne E11S, SIVmac239, and SIVmac239 g4,5), prepared by treatment with 2,2'-dithiodipyridine (aldrithol-2, AT-2), were not detectably infectious, in vitro or in vivo. Immunization of pigtailed macaques with inactivated SIVmne E11S particles, without adjuvant, induced both humoral and cellular immune responses. Four of six animals immunized with the inactivated particles did not show measurable SIV RNA in plasma (<100 copy Eq/ml) following intravenous challenge with pathogenic, homologous virus (SIVmne E11S), compared to peak values of > or =10(6) copy Eq/ml in challenged SIV-naive control animals (p = 0.0001). Despite the absence of measurable viral RNA in plasma in these animals, culturable virus and viral DNA were initially detectable in blood and lymph node specimens; in contrast to control animals, SIV DNA could no longer be detected in PBMC by 10 weeks postchallenge in five of six SIV-immunized animals (p = 0.0001). However, vaccines did not resist a sequential rechallenge with the heterologous pathogenic virus SIVsm E660. AT-2-inactivated virus with functional envelope glycoproteins is a novel class of vaccine immunogen and was noninfectious, under conditions of rigorous in vivo challenge, and induced both binding and neutralizing antibody responses, along with cellular immune responses. Results suggest that immunization facilitated effective containment of pathogenic homologous challenge virus. With further optimization, AT-2-inactivated viral particles may be a useful class of immunogen in the development of a vaccine to prevent AIDS.
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Affiliation(s)
- Jeffrey D Lifson
- AIDS Vaccine Program, SAIC Frederick, Inc., National Cancer Institute-Frederick, Frederick, Maryland 21702, USA.
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7
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Abstract
Development of a prophylactic human immunodeficiency virus type 1 (HIV-1) vaccine is a leading priority in biomedical research. Much of this work has been done with the nonhuman primate model of AIDS. In a historical context, vaccine studies, which use this model, are summarized and discussed.
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Affiliation(s)
- Stephen M Smith
- Saint Michael's Medical Center and The New Jersey Medical School - UMDNJ, Newark, NJ, USA.
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Ensoli B, Cafaro A. NOVEL STRATEGIES TOWARD THE DEVELOPMENT OF AN EFFECTIVE VACCINE TO PREVENT HUMAN IMMUNODEFICIENCY VIRUS INFECTION OR ACQUIRED IMMUNODEFICIENCY VIRUS*. ACTA ACUST UNITED AC 2001. [DOI: 10.1081/crp-100108179] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Wade-Evans AM, Stott J, Hanke T, Stebbings R, Berry N, Lines J, Sangster R, Silvera P, Walker B, MacManus S, Davis G, Cowie J, Arnold C, Hull R, Almond N. Specific proliferative T cell responses and antibodies elicited by vaccination with simian immunodeficiency virus Nef do not confer protection against virus challenge. AIDS Res Hum Retroviruses 2001; 17:1517-26. [PMID: 11709096 DOI: 10.1089/08892220152644223] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The efficacy of immunizing with a combination of simian immunodeficiency virus (SIV) Nef vaccines was evaluated. Four vaccinates received three intradermal immunizations with recombinant vaccinia virus that expressed SIV Nef, followed by three intramuscular immunizations with rDNA also expressing SIV Nef. Finally, the four vaccinates received two subcutaneous boosts with recombinant SIV Nef protein. This immunization protocol elicited anti-Nef antibodies in all of the vaccinates as well as specific proliferative responses. However, specific cytotoxic T cell responses were not detected before virus challenge. All vaccinates were challenged intravenously with 10 MID(50) of SIVmacJ5 along with four controls. All eight subjects became infected after SIV challenge and there were no group-specific differences in virus load as measured by virus titration and vRNA analysis. The results of this study support indirectly the report from Gallimore and colleagues (Nat Med 1995;1:1667) suggesting that CD8(+) T lymphocyte responses are required for Nef-based vaccines to restrict SIV infection. If Nef-based vaccines are to be beneficial in controlling infection with immunodeficiency viruses, then it will be necessary to develop more effective immunization protocols that elicit potent CD8(+) cell responses reproducibly.
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Affiliation(s)
- A M Wade-Evans
- Division of Retrovirology, National Institute for Biological Standards and Control, South Mimms, Potters Bar, EN6 3QG, UK
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10
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Abstract
Clinical investigation in humans and experimental lentivirus infection in nonhuman primates have advanced our understanding of immune responses that control HIV-1 disease. Recently, immunization approaches in macaques have shown that the immune response can control viremia and improve clinical outcome. When such vaccine strategies are formulated to be similarly immunogenic in humans, they could form the basis for the development of candidate AIDS vaccines that would prevent infection, suppress progression to disease or reduce HIV-1 transmission in humans.
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Affiliation(s)
- J R Mascola
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 40 Convent Drive, Bethesda, MD 20892, USA.
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11
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Crotty S, Miller CJ, Lohman BL, Neagu MR, Compton L, Lu D, Lü FX, Fritts L, Lifson JD, Andino R. Protection against simian immunodeficiency virus vaginal challenge by using Sabin poliovirus vectors. J Virol 2001; 75:7435-52. [PMID: 11462016 PMCID: PMC114979 DOI: 10.1128/jvi.75.16.7435-7452.2001] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Here we provide the first report of protection against a vaginal challenge with a highly virulent simian immunodeficiency virus (SIV) by using a vaccine vector. New poliovirus vectors based on Sabin 1 and 2 vaccine strain viruses were constructed, and these vectors were used to generate a series of new viruses containing SIV gag, pol, env, nef, and tat in overlapping fragments. Two cocktails of 20 transgenic polioviruses (SabRV1-SIV and SabRV2-SIV) were inoculated into seven cynomolgus macaques. All monkeys produced substantial anti-SIV serum and mucosal antibody responses. SIV-specific cytotoxic T-lymphocyte responses were detected in three of seven monkeys after vaccination. All 7 vaccinated macaques, as well as 12 control macaques, were challenged vaginally with pathogenic SIVmac251. Strikingly, four of the seven vaccinated animals exhibited substantial protection against the vaginal SIV challenge. All 12 control monkeys became SIV positive. In two of the seven SabRV-SIV-vaccinated monkeys we found no virological evidence of infection following challenge, indicating that these two monkeys were completely protected. Two additional SabRV-SIV-vaccinated monkeys exhibited a pronounced reduction in postacute viremia to <10(3) copies/ml, suggesting that the vaccine elicited an effective cellular immune response. Three of six control animals developed clinical AIDS by 48 weeks postchallenge. In contrast, all seven vaccinated monkeys remained healthy as judged by all clinical parameters. These results demonstrate the efficacy of SabRV as a potential human vaccine vector, and they show that the use of a vaccine vector cocktail expressing an array of defined antigenic sequences can be an effective vaccination strategy in an outbred population.
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Affiliation(s)
- S Crotty
- Department of Microbiology and Immunology, University of California, San Francisco, California 94143-0414, USA
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12
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Smith JM, Leung NJ, Torres JV. Preparation and induction of immune responses by a DNA AIDS vaccine. Viral Immunol 2001; 13:343-51. [PMID: 11016598 DOI: 10.1089/08828240050144662] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
In an effort to evaluate the feasibility of developing a safe DNA vaccine for acquired immunodeficiency syndrome (AIDS), we have prepared a plasmid-based immunogen modeled after a naturally occurring noninfectious mutant of the simian immunodeficiency virus (SIV). The mutant SIV genome produces defective virus particles that are noninfectious in vitro and nonpathogenic in vivo in rhesus macaques. Analysis of the mutant genome revealed a 1.6 kb deletion that is in frame and spans integrase, vif, vpx, and most of vpr and results in a pol/vpr gene fusion. This deletion was introduced into the parental pathogenic molecular clone and the U3 region of the 5' LTR was replaced with a cytomegalovirus promoter to produce a candidate DNA vaccine, pIV. After transfection with this plasmid, SIV gag and envelope proteins are expressed and properly processed in vitro. When injected into rabbits, pIV elicited an antibody response to SIV gp130 envelope glycoprotein with titers reaching 1:2048, and a strong lymphoproliferative response to SIV gp130 and whole SIV. The potential to produce defective virus particles in vivo without integrating into the host genome should result in both a strong humoral and cellular immune response in rhesus macaques. In addition, this approach offers a safe alternative to live attenuated vaccines and DNA vaccines that are capable of integration.
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Affiliation(s)
- J M Smith
- Department of Medical Microbiology and Immunology, School of Medicine, University of California, Davis 95616, USA
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13
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Cho MW. Assessment of HIV vaccine development: past, present, and future. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2001; 49:263-314. [PMID: 11013767 DOI: 10.1016/s1054-3589(00)49030-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Affiliation(s)
- M W Cho
- AIDS Vaccine Research and Development Unit, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
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14
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Kumar A, Lifson JD, Li Z, Jia F, Mukherjee S, Adany I, Liu Z, Piatak M, Sheffer D, McClure HM, Narayan O. Sequential immunization of macaques with two differentially attenuated vaccines induced long-term virus-specific immune responses and conferred protection against AIDS caused by heterologous simian human immunodeficiency Virus (SHIV(89.6)P). Virology 2001; 279:241-56. [PMID: 11145906 DOI: 10.1006/viro.2000.0695] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Four rhesus macaques were sequentially immunized with live vaccines DeltavpuDeltanefSHIV-4 (vaccine-I) and Deltavpu SHIV(PPC) (vaccine-II). The vaccine viruses did not replicate productively in the peripheral blood mononuclear cells (PBMCs) of the vaccinated animals. All four animals developed binding antibodies against both the vaccine-I and -II envelope glycoproteins but neutralizing antibodies only against vaccine-I. They developed vaccine virus-specific CTLs that also recognized homologous as well as heterologous pathogenic SHIVs. Thirty weeks after the last immunization, the vaccinated animals and three unvaccinated control animals were challenged iv with a highly virulent heterologous SHIV(89.6)P. As expected, the three unvaccinated control animals developed large numbers of infectious PBMCs, high plasma viremia, and precipitous loss of CD4(+) T cells. Two controls did not develop any immune response and succumbed to AIDS in about 6 months. The third control animal developed neutralizing antibodies and had a more chronic disease course, but eventually succumbed to AIDS-related complications 81 weeks after inoculation. The four vaccinated animals became infected with challenge virus as indicated by the presence of challenge virus-specific DNA in the PBMCs and RNA in plasma. However, virus in these animals replicated approximately 200- to 60,000-fold less efficiently than in control animals and eventually, plasma viral RNA became undetectable in three of the four vaccinates. The animals maintained normal CD4(+) T-cell levels throughout the observation period of 85 weeks after a transient drop at Week 3 postchallenge. They also maintained CTL responses throughout the observation period. These studies thus showed that the graded immunization schedule resulted in a safe and highly effective long-lasting immune response that was associated with protection against AIDS by highly pathogenic heterologous SHIV(89.6)P.
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Affiliation(s)
- A Kumar
- Laboratory of Viral Pathogenesis, University of Kansas Medical Center, Kansas City, Kansas, 66160, USA.
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15
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Abstract
Human immunodeficiency virus (HIV) continues to infect about 15,000 people every day, 90% of whom live in non-industrialised countries. So far, education programmes have only managed to slow, but not cease, the HIV spread, while powerful drug combinations are too costly and complex for the majority of HIV-infected people and in any case fail to clear HIV from the body. Under these circumstances, the best hope for controlling the HIV pandemic is the development of an effective prophylactic vaccine. With a series of new technologies and increased political and financial commitments, a growing momentum in the field of HIV-vaccine development promises exciting years ahead.
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Affiliation(s)
- T Hanke
- MRC Human Immunology Unit, Institute of Molecular Medicine, John Radcliffe Hospital, Oxford, UK
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16
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Kumar A, Lifson JD, Silverstein PS, Jia F, Sheffer D, Li Z, Narayan O. Evaluation of immune responses induced by HIV-1 gp120 in rhesus macaques: effect of vaccination on challenge with pathogenic strains of homologous and heterologous simian human immunodeficiency viruses. Virology 2000; 274:149-64. [PMID: 10936096 DOI: 10.1006/viro.2000.0444] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The simian human immunodeficiency virus (SHIV) macaque model of AIDS has provided a very useful system for evaluation of envelope-based candidate vaccines against HIV-1. Eight rhesus macaques were immunized with monomeric recombinant gp120 of HIV-1(LAI) (rgp120) and used to evaluate whether this vaccine conferred protection against challenge with pathogenic SHIVs (SHIV(KU-2) and SHIV(89.6)P). The vaccinated macaques developed high titers of antibodies against rgp120 that reacted efficiently with the envelope proteins of homologous SHIV (SHIV(KU-2)) and poorly with the SHIV(89.6)P envelope, a heterologous strain of SHIV. This vaccine also induced neutralizing antibodies but only against SHIV(KU-2). Vaccine-induced antibodies were of high avidity and predominantly against linear epitopes on the protein. Vaccinated macaques developed gp120-specific T-helper cells but no consistent cytotoxic T lymphocytes. However, cellular immune responses were short-lived in all eight vaccinates. At week 22 postimmunization, four vaccinates were challenged with SHIV(KU-2) and the other four with SHIV(89.6)P. Four unvaccinated control macaques were also infected: two with SHIV(KU-2) and two with SHIV(89.6)P. Vaccinated macaques generally showed anamnestic antibody and T-helper cell responses. However, T-helper responses were again short-lived. Upon challenge, the level of productive virus replication was indistinguishable between vaccine and control groups, suggesting that rgp120 did not confer protection against virus replication when animals were challenged with homologous or heterologous SHIV viruses.
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Affiliation(s)
- A Kumar
- Laboratory of Viral Pathogenesis, Department of Microbiology, MolecularGenetics, and Immunolgy, University of Kansas Medical Center, Kansas City, Kansas 66160, USA.
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Silvera P, Racz P, Racz K, Bischofberger N, Crabbs C, Yalley-Ogunro J, Greenhouse J, Jiang JB, Lewis MG. Effect of PMPA and PMEA on the kinetics of viral load in simian immunodeficiency virus-infected macaques. AIDS Res Hum Retroviruses 2000; 16:791-800. [PMID: 10826485 DOI: 10.1089/088922200308783] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
In this study we compared the effect of postexposure treatment of the acyclic nucleoside analogs 9-(2-phosphonylmethoxyethyl)-adenine (PMEA) and 9-(2-phosphonylmethoxypropyl)-adenine (PMPA) on the kinetics of viral load in the blood and lymph nodes of rhesus macaques chronically infected with SIVmac251 for 18 weeks. Two of the four macaques treated with PMPA (20 mg/kg per day) for 28 consecutive days had demonstrable reductions in viral loads of 1.5 and 3 logs. Three of four macaques given the same dosing regimen of PMEA had viral load reductions ranging from 1.25 to 2.8 logs. Furthermore, treatment with either drug caused a reduction in virus burden in the lymph nodes by 2 weeks posttreatment. However, in both PMEA- and PMPA-treated animals, viral loads rebounded to day of treatment levels by 2 weeks after termination of treatment. The extent to which viral load was suppressed was similar for both drugs. In contrast, viral loads in three of four mock-treated animals remained persistently high throughout the study. This study has demonstrated that postexposure treatment with these acyclic nucleoside analogs could modulate the kinetics of viral load reduction in some animals.
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Affiliation(s)
- P Silvera
- Henry Jackson Foundation, Rockville, Maryland 20850, USA.
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18
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Polacino PS, Stallard V, Klaniecki JE, Pennathur S, Montefiori DC, Langlois AJ, Richardson BA, Morton WR, Benveniste RE, Hu SL. Role of immune responses against the envelope and the core antigens of simian immunodeficiency virus SIVmne in protection against homologous cloned and uncloned virus challenge in Macaques. J Virol 1999; 73:8201-15. [PMID: 10482571 PMCID: PMC112838 DOI: 10.1128/jvi.73.10.8201-8215.1999] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We previously showed that envelope (gp160)-based vaccines, used in a live recombinant virus priming and subunit protein boosting regimen, protected macaques against intravenous and intrarectal challenges with the homologous simian immunodeficiency virus SIVmne clone E11S. However, the breadth of protection appears to be limited, since the vaccines were only partially effective against intravenous challenge by the uncloned SIVmne. To examine factors that could affect the breadth and the efficacy of this immunization approach, we studied (i) the effect of priming by recombinant vaccinia virus; (ii) the role of surface antigen gp130; and (iii) the role of core antigens (Gag and Pol) in eliciting protective immunity. Results indicate that (i) priming with recombinant vaccinia virus was more effective than subunit antigen in eliciting protective responses; (ii) while both gp130 and gp160 elicited similar levels of SIV-specific antibodies, gp130 was not as effective as gp160 in protection, indicating a possible role for the transmembrane protein in presenting functionally important epitopes; and (iii) although animals immunized with core antigens failed to generate any neutralizing antibody and were infected upon challenge, their virus load was 50- to 100-fold lower than that of the controls, suggesting the importance of cellular immunity or other core-specific immune responses in controlling acute infection. Complete protection against intravenous infection by the pathogenic uncloned SIVmne was achieved by immunization with both the envelope and the core antigens. These results indicate that immune responses to both antigens may contribute to protection and thus argue for the inclusion of multiple antigens in recombinant vaccine designs.
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Affiliation(s)
- P S Polacino
- Regional Primate Research Center, University of Washington, Seattle, USA
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19
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Ramsay AJ, Kent SJ, Strugnell RA, Suhrbier A, Thomson SA, Ramshaw IA. Genetic vaccination strategies for enhanced cellular, humoral and mucosal immunity. Immunol Rev 1999; 171:27-44. [PMID: 10582164 DOI: 10.1111/j.1600-065x.1999.tb01341.x] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
In this article, we describe several novel genetic vaccination strategies designed to facilitate the development of different types of immune responses. These include: i) the consecutive use of DNA and fowlpoxvirus vectors in "prime-boost" strategies which induce greatly enhanced and sustained levels of both cell-mediated immunity and humoral immunity, including mucosal responses; ii) the co-expression of genes encoding cytokines and cell-surface receptors, and the use of immunogenic carrier molecules, for immune modulation and/or improved targeting of vector-expressed vaccine antigens; and iii) the expression of minimal immunogenic amino acid sequences, particularly cytotoxic CD8+ T-cell determinants, in "polytope" vector vaccines. The capacity to modulate and enhance specific immune responses by the use of approaches such as these may underpin the development of vaccines against diseases for which no effective strategies are currently available.
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Affiliation(s)
- A J Ramsay
- Division of Immunology and Cell Biology, John Curtin School of Medical Research, Australian National University, Canberra, Australia
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20
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Almond N, Jenkins A, Jones S, Arnold C, Silvera P, Kent K, Mills KHG, Stott EJ. The appearance of escape variants in vivo does not account for the failure of recombinant envelope vaccines to protect against simian immunodeficiency virus. J Gen Virol 1999; 80 ( Pt 9):2375-2382. [PMID: 10501490 DOI: 10.1099/0022-1317-80-9-2375] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The presence or evolution of immune escape variants has been proposed to account for the failure of recombinant envelope vaccines to protect macaques against challenge with simian immunodeficiency virus (SIVmac). To address this issue, two groups of three cynomolgus macaques were immunized with recombinant SIV Env vaccines using two different vaccine schedules. One group of macaques received four injections of recombinant SIV gp120 in SAF-1 containing threonyl muramyl dipeptide as adjuvant. A second group were primed twice with recombinant vaccinia virus expressing SIV gp160 and then boosted twice with recombinant SIV gp120. Both vaccine schedules elicited neutralizing antibodies to Env. However, on the day of challenge, titres of anti-Env antibodies measured by ELISA were higher in macaques primed with recombinant vaccinia virus. Following intravenous challenge with 10 monkey infectious doses of the SIVmac J5M challenge stock, five of the six immunized macaques and all four naive controls became infected. The virus burdens in PBMC of macaques that were primed with recombinant vaccinia virus were lower than those of naive controls, as determined by virus titration and quantitative DNA PCR. Sequence analysis was performed on SIV env amplified from the blood of immunized and naive infected macaques. No variation of SIV env sequence was observed, even in macaques with a reduced virus load, suggesting that the appearance of immune escape variants does not account for the incomplete protection observed. In addition, this study indicates that the measurement of serum neutralizing antibodies may not provide a useful correlate for protection elicited by recombinant envelope vaccines.
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Affiliation(s)
- N Almond
- Division of Retrovirology, National Institute for Biological Standards and Control, Blanche Lane, South Mimms, Potters Bar, Herts EN6 3QG, UK1
| | - A Jenkins
- Division of Retrovirology, National Institute for Biological Standards and Control, Blanche Lane, South Mimms, Potters Bar, Herts EN6 3QG, UK1
| | - S Jones
- Division of Retrovirology, National Institute for Biological Standards and Control, Blanche Lane, South Mimms, Potters Bar, Herts EN6 3QG, UK1
| | - C Arnold
- Division of Retrovirology, National Institute for Biological Standards and Control, Blanche Lane, South Mimms, Potters Bar, Herts EN6 3QG, UK1
| | - P Silvera
- Division of Retrovirology, National Institute for Biological Standards and Control, Blanche Lane, South Mimms, Potters Bar, Herts EN6 3QG, UK1
| | - K Kent
- Division of Retrovirology, National Institute for Biological Standards and Control, Blanche Lane, South Mimms, Potters Bar, Herts EN6 3QG, UK1
| | - K H G Mills
- Division of Retrovirology, National Institute for Biological Standards and Control, Blanche Lane, South Mimms, Potters Bar, Herts EN6 3QG, UK1
| | - E J Stott
- Division of Retrovirology, National Institute for Biological Standards and Control, Blanche Lane, South Mimms, Potters Bar, Herts EN6 3QG, UK1
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21
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Israel ZR, Gettie A, Ishizaka ST, Mishkin EM, Staas J, Gilley R, Montefiori D, Marx PA, Eldridge JH. Combined systemic and mucosal immunization with microsphere-encapsulated inactivated simian immunodeficiency virus elicits serum, vaginal, and tracheal antibody responses in female rhesus macaques. AIDS Res Hum Retroviruses 1999; 15:1121-36. [PMID: 10461832 DOI: 10.1089/088922299310412] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
We determined the efficacy of immunization with microsphere-encapsulated whole inactivated simian immunodeficiency virus (SIV) by combined systemic and mucosal administration to protect female rhesus macaques against vaginal challenge with homologous rhesus PBMC-grown SIVmac251. Animals in one group were primed and boosted intramuscularly. Two groups were primed intramuscularly and boosted either intratracheally or orally. A final group was primed by vaccinia/rgp140 scarification and subdivided for either intratracheal or oral boosting. Strong ELISA titers of circulating SIV-specific IgG and modest IgA responses were elicited in the animals primed intramuscularly. Intratracheal boosting in the intramuscularly primed macaques resulted in high bronchial alveolar wash (BAW) IgG and less pronounced IgA. SIV-specific vaginal wash (VW) IgG was also present in the intramuscular/intramuscular and intramuscular/intratracheal groups. Vaccinia/rgp140 priming gave low ELISA titers to whole SIV, and failed to elicit mucosal antibody regardless of the booster route. No animal in any group developed serum neutralizing antibody to homologous SIVmac251. On vaginal challenge none of the immunized groups was infected at a lesser frequency than the unimmunized controls. These data suggest that the use of microspheres in a combined parenteral and mucosal regimen is an effective method of eliciting IgG and IgA antibody at mucosal surfaces.
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Affiliation(s)
- Z R Israel
- Wyeth-Lederle Vaccines, Viral Vaccine Immunology, Pearl River, New York 10965, USA.
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22
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Johnson RP, Lifson JD, Czajak SC, Cole KS, Manson KH, Glickman R, Yang J, Montefiori DC, Montelaro R, Wyand MS, Desrosiers RC. Highly attenuated vaccine strains of simian immunodeficiency virus protect against vaginal challenge: inverse relationship of degree of protection with level of attenuation. J Virol 1999; 73:4952-61. [PMID: 10233957 PMCID: PMC112539 DOI: 10.1128/jvi.73.6.4952-4961.1999] [Citation(s) in RCA: 184] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Three different deletion mutants of simian immunodeficiency virus (SIV) that vary in their levels of attenuation were tested for the ability to protect against mucosal challenge with pathogenic SIV. Four female rhesus monkeys were vaccinated by intravenous inoculation with SIVmac239Delta3, four with SIVmac239Delta3X, and four with SIVmac239Delta4. These three vaccine strains exhibit increasing levels of attenuation: Delta3 < Delta3X <Delta4. The vaccinated monkeys were challenged by vaginal exposure to uncloned, pathogenic SIVmac251 at 61 weeks after the time of vaccination. On the basis of viral RNA loads in plasma, cell-associated virus loads in peripheral blood, and CD4 cell counts, strong protective effects were observed in all three groups of vaccinated monkeys. However, the degree of protection correlated inversely with the level of attenuation; the least-attenuated strain, SIVmac239Delta3, gave the greatest protection. One monkey in the Delta3X group and two in the Delta4 group clearly became superinfected by the challenge virus, but these animals had levels of SIV RNA in plasma that were considerably lower than those of naive animals that were challenged in parallel. Protection against vaginal challenge appears easier to achieve than protection against intravenous challenge, since four other SIVmac239Delta4-vaccinated monkeys showed no protection when challenged intravenously with a much lower inoculum of the same challenge virus stock. Protection against vaginal challenge in the Delta4-vaccinated group occurred in the absence of detectable serum neutralizing activities and appeared to be associated with the development of an early SIV-specific cytotoxic-T-lymphocyte response. Our results demonstrate that mucosal protection can be achieved by systemic immunization with the highly attenuated SIVmac239Delta4 more than 1 year prior to the time of challenge.
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Affiliation(s)
- R P Johnson
- New England Regional Primate Research Center, Harvard Medical School, Southborough, Massachusetts 01772-9102, USA
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23
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Hanke T, Neumann VC, Blanchard TJ, Sweeney P, Hill AV, Smith GL, McMichael A. Effective induction of HIV-specific CTL by multi-epitope using gene gun in a combined vaccination regime. Vaccine 1999; 17:589-96. [PMID: 10075166 DOI: 10.1016/s0264-410x(98)00238-2] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Reliable and effective induction of cytotoxic T-lymphocytes (CTL) is one of the prime objectives of vaccine research. Previously, novel HIV vaccine candidates were constructed as a string of CTL epitopes (20 human, 3 macaque and 1 mouse) delivered using a DNA vector [Hanke T, Schneider J, Gilbert SG, Hill AVS, McMichael A. DNA multi-CTL epitope vaccines for HIV and Plasmodium falciparum: immunogenicity in mice. Vaccine 1998;16:426-435.] or modified vaccinia Ankara (MVA [Hanke T, Blanchard TJ, Schneider J, Ogg GS, Tan R, Becker MSC, Gilbert SG, Hill AVS, Smith GL, McMichael A. Immunogenicities of intravenous and intramuscular administrations of MVA-based multi-CTL epitope vaccine for HIV in mice. J Gen Virol 1998;79:83-90.]), i.e. vaccine vehicles acceptable for use in humans. In mice, a single intramuscular (i.m.) needle injection of either vaccine alone elicited good CTL responses. Here, it is demonstrated that the multi-epitope DNA also induced CTL when delivered intradermally using the Accell gene gun. The CTL responses increased after re-immunization and after three deliveries were comparable to those induced by a single i.m. injection. Recent evidence indicates that combining routes and vaccine vehicles enhances the immunogenicity of vaccine-delivered or -encoded antigens. Here, it is shown that administration of DNA by an i.m. priming/gene gun boosting more efficiently induced CTL than gene gun priming/i.m. boosting. A similar increment was obtained by sequential vaccinations using a gene gun-delivered DNA followed by recombinant MVA. Thus particular sequences of routes or vaccine vehicles rather than simple prime-boost delivery of a single vaccine is critical for an effective elicitation of CTL.
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Affiliation(s)
- T Hanke
- Molecular Immunology Group, Institute of Molecular Medicine, University of Oxford, The John Radcliffe Hospital, Headington, UK.
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24
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Polacino P, Stallard V, Klaniecki JE, Montefiori DC, Langlois AJ, Richardson BA, Overbaugh J, Morton WR, Benveniste RE, Hu SL. Limited breadth of the protective immunity elicited by simian immunodeficiency virus SIVmne gp160 vaccines in a combination immunization regimen. J Virol 1999; 73:618-30. [PMID: 9847367 PMCID: PMC103868 DOI: 10.1128/jvi.73.1.618-630.1999] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We previously reported that immunization with recombinant simian immunodeficiency virus SIVmne envelope (gp160) vaccines protected macaques against an intravenous challenge by the cloned homologous virus, E11S. In this study, we confirmed this observation and found that the vaccines were effective not only against virus grown on human T-cell lines but also against virus grown on macaque peripheral blood mononuclear cells (PBMC). The breadth of protection, however, was limited. In three experiments, 3 of 10 animals challenged with the parental uncloned SIVmne were completely protected. Of the remaining animals, three were transiently virus positive and four were persistently positive after challenge, as were 10 nonimmunized control animals. Protection was not correlated with levels of serum-neutralizing antibodies against the homologous SIVmne or a related virus, SIVmac251. To gain further insight into the protective mechanism, we analyzed nucleotide sequences in the envelope region of the uncloned challenge virus and compared them with those present in the PBMC of infected animals. The majority (85%) of the uncloned challenge virus was homologous to the molecular clone from which the vaccines were made (E11S type). The remaining 15% contained conserved changes in the V1 region (variant types). Control animals infected with this uncloned virus had different proportions of the two genotypes, whereas three of four immunized but persistently infected animals had >99% of the variant types early after infection. These results indicate that the protective immunity elicited by recombinant gp160 vaccines is restricted primarily to the homologous virus and suggest the possibility that immune responses directed to the V1 region of the envelope protein play a role in protection.
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Affiliation(s)
- P Polacino
- Regional Primate Research Center, University of Washington, Seattle, USA
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25
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Kent SJ, Zhao A, Best SJ, Chandler JD, Boyle DB, Ramshaw IA. Enhanced T-cell immunogenicity and protective efficacy of a human immunodeficiency virus type 1 vaccine regimen consisting of consecutive priming with DNA and boosting with recombinant fowlpox virus. J Virol 1998; 72:10180-8. [PMID: 9811759 PMCID: PMC110562 DOI: 10.1128/jvi.72.12.10180-10188.1998] [Citation(s) in RCA: 268] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The induction of human immunodeficiency virus (HIV)-specific T-cell responses is widely seen as critical to the development of effective immunity to HIV type 1 (HIV-1). Plasmid DNA and recombinant fowlpox virus (rFPV) vaccines are among the most promising safe HIV-1 vaccine candidates. However, the immunity induced by either vaccine alone may be insufficient to provide durable protection against HIV-1 infection. We evaluated a consecutive immunization strategy involving priming with DNA and boosting with rFPV vaccines encoding common HIV-1 antigens. In mice, this approach induced greater HIV-1-specific immunity than either vector alone and protected mice from challenge with a recombinant vaccinia virus expressing HIV-1 antigens. In macaques, a dramatic boosting effect on DNA vaccine-primed HIV-1-specific helper and cytotoxic T-lymphocyte responses, but a decline in HIV-1 antibody titers, was observed following rFPV immunization. The vaccine regimen protected macaques from an intravenous HIV-1 challenge, with the resistance most likely mediated by T-cell responses. These studies suggest a safe strategy for the enhanced generation of T-cell-mediated protective immunity to HIV-1.
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Affiliation(s)
- S J Kent
- AIDS Pathogenesis Research Unit, Macfarlane Burnet Centre for Medical Research, Fairfield 3078, Victoria, Australia.
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26
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Hasenkrug KJ, Brooks DM, Robertson MN, Srinivas RV, Chesebro B. Immunoprotective determinants in friend murine leukemia virus envelope protein. Virology 1998; 248:66-73. [PMID: 9705256 DOI: 10.1006/viro.1998.9264] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Several immunological epitopes are known to be located within the Friend murine leukemia virus (F-MuLV) envelope protein, but their relative contributions to protection from Friend virus-induced disease are not known. To determine how expression of various immunological determinants affected protection, mice were immunized with recombinant vaccinia viruses expressing different portions of the F-MuLV envelope protein, and they were then challenged with a lethal dose of Friend virus complex. The disease parameters that were followed in the mice were early viremia, early splenomegaly, and late splenomegaly. Both the N-terminal and C-terminal portions of the F-MuLV gp70 were found to protect against late splenomegaly, the primary clinical sign associated with virus-induced erythroleukemia. However, neither region alone protected against early splenomegaly and early viremia, indicating poor immunological control over early virus replication and spread through the spleen and blood. In contrast, mice immunized with a vaccine expressing the entire F-MuLV envelope protein were protected against all three disease parameters. The results indicated that expression of multiple immunological determinants including both T-helper and B cell epitopes was necessary for full protection.
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Affiliation(s)
- K J Hasenkrug
- Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institute of Health, 903 South 4th Street, Hamilton, Montana, 59840, USA
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27
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Johnson RP, Desrosiers RC. Protective immunity induced by live attenuated simian immunodeficiency virus. Curr Opin Immunol 1998; 10:436-43. [PMID: 9722920 DOI: 10.1016/s0952-7915(98)80118-0] [Citation(s) in RCA: 111] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Lack of information on the mechanisms of protective immunity to AIDS virus infection represents a major obstacle to the development of a rational strategy for an effective HIV vaccine. In macaques, immunization with live attenuated simian immunodeficiency viruses has induced the most potent protective immunity and continued study promises a better understanding of the nature of protective immune responses. Recent evidence supports involvement of both cytotoxic T lymphocytes and neutralizing antibodies in protective immunity against infection by simian immunodeficiency virus, but more detailed studies are needed to document their relative importance.
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Affiliation(s)
- R P Johnson
- Division of Immunology, New England Regional Primate Research Center, Harvard Medical School, Southborough, MA 01772, USA.
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28
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Dittmer U, Brooks DM, Hasenkrug KJ. Characterization of a live-attenuated retroviral vaccine demonstrates protection via immune mechanisms. J Virol 1998; 72:6554-8. [PMID: 9658099 PMCID: PMC109828 DOI: 10.1128/jvi.72.8.6554-6558.1998] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Live-attenuated retroviruses have been shown to be effective retroviral vaccines, but currently little is known regarding the mechanisms of protection. In the present studies, we used Friend virus as a model to analyze characteristics of a live-attenuated vaccine in protection against virus-induced disease. Highly susceptible mice were immunized with nonpathogenic Friend murine leukemia helper virus (F-MuLV), which replicates poorly in adult mice. Further attenuation of the vaccine virus was achieved by crossing the Fv-1 genetic resistance barrier. The minimum dose of vaccine virus required to protect 100% of the mice against challenge with pathogenic Friend virus complex was determined to be 10(3) focus-forming units of attenuated virus. Live vaccine virus was necessary for induction of immunity, since inactivated F-MuLV did not induce protection. To determine whether immune cells mediated protection, spleen cells from vaccinated donor mice were adoptively transferred into syngeneic recipients. The results indicated that immune mechanisms rather than viral interference mediated protection.
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Affiliation(s)
- U Dittmer
- Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, Hamilton, Montana 59840, USA.
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29
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Meyer D, Anderson DE, Gardner MB, Torres JV. Hypervariable epitope constructs representing variability in envelope glycoprotein of SIV induce a broad humoral immune response in rabbits and rhesus macaques. AIDS Res Hum Retroviruses 1998; 14:751-60. [PMID: 9643375 DOI: 10.1089/aid.1998.14.751] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Using synthetic peptides, we developed an approach to account for protein epitope variability. We have prepared, in a single synthesis, a cocktail of peptides we have designated a hypervariable epitope construct (HEC), which collectively represents much of the in vivo variability seen in an epitope. Eight HECs representing the in vivo variability seen throughout the envelope glycoprotein of the simian immunodeficiency virus (SIV) were designed and synthesized. The constructs were collectively conjugated to KLH (HEC-KLH) or recombinant gp130 (HEC-rgp130) and used to immunize rabbits and rhesus macaques, respectively. Using sera collected from rabbits immunized with HEC-KLH, we demonstrated that individual components of the immunogen were recognized as antigen in ELISAs, and that the induced antibodies cross-reacted with several strains of SIV as well as with a strain of HIV-2. Following immunization of macaques with HEC-rgp130 antiviral antibodies were induced. These antibodies were still present 9.5 months after the last boost and were also capable of recognizing several different strains of SIV, including SIVmac239, SIVmac251, and SIVsmH3, as well as a strain of HIV-2 (HIV-2ROD). In addition, the antibodies were also capable of neutralizing SIV viral infectivity in vitro. Peripheral blood lymphocytes (PBLs) from immunized macaques proliferated in response to whole proteins and virus. Finally, sera from monkeys immunized with SIV, rgp130, and HIV-2 as well as sera from HIV-2-positive humans recognized HECs in ELISAs, demonstrating the relevance of these epitopes in vivo. This approach can be used as an effective method for generating a strong, broadly cross-reactive humoral response against HIV and can serve as an important component of combination vaccines against HIV and AIDS.
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Affiliation(s)
- D Meyer
- Department of Medical Microbiology and Immunology, School of Medicine, University of California Davis, 95616, USA
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30
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Benson J, Chougnet C, Robert-Guroff M, Montefiori D, Markham P, Shearer G, Gallo RC, Cranage M, Paoletti E, Limbach K, Venzon D, Tartaglia J, Franchini G. Recombinant vaccine-induced protection against the highly pathogenic simian immunodeficiency virus SIV(mac251): dependence on route of challenge exposure. J Virol 1998; 72:4170-82. [PMID: 9557706 PMCID: PMC109646 DOI: 10.1128/jvi.72.5.4170-4182.1998] [Citation(s) in RCA: 130] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/1997] [Accepted: 02/06/1998] [Indexed: 02/07/2023] Open
Abstract
Vaccine protection from infection and/or disease induced by highly pathogenic simian immunodeficiency virus (SIV) strain SIV(mac251) in the rhesus macaque model is a challenging task. Thus far, the only approach that has been reported to protect a fraction of macaques from infection following intravenous challenge with SIV(mac251) was the use of a live attenuated SIV vaccine. In the present study, the gag, pol, and env genes of SIV(K6W) were expressed in the NYVAC vector, a genetically engineered derivative of the vaccinia virus Copenhagen strain that displays a highly attenuated phenotype in humans. In addition, the genes for the alpha and beta chains of interleukin-12 (IL-12), as well as the IL-2 gene, were expressed in separate NYVAC vectors and inoculated intramuscularly, in conjunction with or separate from the NYVAC-SIV vaccine, in 40 macaques. The overall cytotoxic T-lymphocyte (CTL) response was greater, at the expense of proliferative and humoral responses, in animals immunized with NYVAC-SIV and NYVAC-IL-12 than in animals immunized with the NYVAC-SIV vaccine alone. At the end of the immunization regimen, half of the animals were challenged with SIV(mac251) by the intravenous route and the other half were exposed to SIV(mac251) intrarectally. Significantly, five of the eleven vaccinees exposed mucosally to SIV(mac251) showed a transient peak of viremia 1 week after viral challenge and subsequently appeared to clear viral infection. In contrast, all 12 animals inoculated intravenously became infected, but 5 to 6 months after viral challenge, 4 animals were able to control viral expression and appeared to progress to disease more slowly than control animals. Protection did not appear to be associated with any of the measured immunological parameters. Further modulation of immune responses by coadministration of NYVAC-cytokine recombinants did not appear to influence the outcome of viral challenge. The fact that the NYVAC-SIV recombinant vaccine appears to be effective per se in the animal model that best mirrors human AIDS supports the idea that the development of a highly attenuated poxvirus-based vaccine candidate can be a valuable approach to significantly decrease the spread of human immunodeficiency virus (HIV) infection by the mucosal route.
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Affiliation(s)
- J Benson
- Basic Research Laboratory, National Cancer Institute, Bethesda, Maryland 20892, USA
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31
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Richardson J, Moraillon A, Crespeau F, Baud S, Sonigo P, Pancino G. Delayed infection after immunization with a peptide from the transmembrane glycoprotein of the feline immunodeficiency virus. J Virol 1998; 72:2406-15. [PMID: 9499101 PMCID: PMC109540 DOI: 10.1128/jvi.72.3.2406-2415.1998] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Recent advances in the quantitative assessment of viral burden, by permitting the extension of criteria applied to assess the efficacy of vaccines from all-or-none protection to diminution of the viral burden, may allow the identification of original immunogens of value in combined vaccines. Peptides corresponding to three domains of the envelope glycoproteins of feline immunodeficiency virus that are recognized during natural infection were used to immunize cats. After challenge with a primary isolate of feline immunodeficiency virus, the development of acute infection was monitored by quantitative assessment of the viral burden in plasma and tissues by competitive reverse transcription-PCR, by measurement of the humoral response developed to viral components, and by lymphocyte subset analysis. Whereas immunization with two peptides derived from the surface glycoprotein had no effect on the early course of infection, immunization with a peptide derived from the transmembrane glycoprotein delayed infection, as reflected by a diminished viral burden in the early phase of primary infection and delayed seroconversion. This peptide, located in the membrane-proximal region of the extracellular domain, has homology to an epitope of human immunodeficiency virus type 1 recognized by a broadly neutralizing monoclonal antibody. These results suggest that lentivirus transmembrane glycoproteins share a determinant in the juxtamembrane ectodomain which could be of importance in the design of vaccines against AIDS.
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Affiliation(s)
- J Richardson
- Génétique des Virus (ICGM-CNRS UPR 0415), Institut Cochin de Génétique Moléculaire, Paris, France
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32
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Affiliation(s)
- S Lu
- Department of Medicine, University of Massachusetts Medical Center, Worcester 01655, USA
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33
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Desrosiers RC, Lifson JD, Gibbs JS, Czajak SC, Howe AY, Arthur LO, Johnson RP. Identification of highly attenuated mutants of simian immunodeficiency virus. J Virol 1998; 72:1431-7. [PMID: 9445045 PMCID: PMC124623 DOI: 10.1128/jvi.72.2.1431-1437.1998] [Citation(s) in RCA: 190] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Deletion mutants of the pathogenic clone of simian immunodeficiency virus isolate 239 (SIVmac239) were derived that are missing nef, vpr, and upstream sequences (US) in the U3 region of the LTR (SIVmac239 delta3), nef, vpx, and US (SIVmac239 delta3x), and nef, vpr, vpx, and US (SIVmac239 delta4). These multiply deleted derivatives replicated well in the continuously growing CEMx174 cell line and were infectious for rhesus monkeys. However, on the basis of virus load measurements, strength of antibody responses, and lack of disease progression, these mutants were highly attenuated. Measurements of cell-associated viral load agreed well with assays of plasma viral RNA load and with the strengths of the antibody responses; thus, these measurements likely reflected the extent of viral replication in vivo. A derivative of SIVmac239 lacking vif sequences (SIVmac239 delta vif) could be consistently grown only in a vif-complementing cell line. This delta vif virus appeared to be very weakly infectious for rhesus monkeys on the basis of sensitive antibody tests only. The weak antibody responses elicited by SIVmac239 delta vif were apparently in response to low levels of replicating virus since they were not elicited by heat-inactivated virus and the anti-SIV antibody responses persisted for greater than 1 year. These results, and the results of previous studies, allow a rank ordering of the relative virulence of nine mutant strains of SIVmac according to the following order: delta vpr > delta vpx > delta vpr delta vpx approximately delta nef > delta3 > delta3x > or = delta4 > delta vif > delta5. The results also demonstrate that almost any desired level of attenuation can be achieved, ranging from still pathogenic in a significant proportion of animals (delta vpr and delta vpx) to not detectably infectious (delta5), simply by varying the number and location of deletions in these five loci.
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Affiliation(s)
- R C Desrosiers
- New England Regional Primate Research Center, Harvard Medical School, Southborough, Massachusetts 01772-9102, USA.
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Connor RI, Korber BT, Graham BS, Hahn BH, Ho DD, Walker BD, Neumann AU, Vermund SH, Mestecky J, Jackson S, Fenamore E, Cao Y, Gao F, Kalams S, Kunstman KJ, McDonald D, McWilliams N, Trkola A, Moore JP, Wolinsky SM. Immunological and virological analyses of persons infected by human immunodeficiency virus type 1 while participating in trials of recombinant gp120 subunit vaccines. J Virol 1998; 72:1552-76. [PMID: 9445059 PMCID: PMC124637 DOI: 10.1128/jvi.72.2.1552-1576.1998] [Citation(s) in RCA: 167] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/1997] [Accepted: 11/04/1997] [Indexed: 02/05/2023] Open
Abstract
We have studied 18 participants in phase I/II clinical trials of recombinant gp120 (rgp120) subunit vaccines (MN and SF-2) who became infected with human immunodeficiency virus type 1 (HIV-1) during the course of the trials. Of the 18 individuals, 2 had received a placebo vaccine, 9 had been immunized with MN rgp120, and seven had been immunized with SF-2 rgp120. Thirteen of the 18 infected vaccinees had received three or four immunizations prior to becoming infected. Of these, two were placebo recipients, six had received MN rgp120, and five had received SF-2 rgp120. Only 1 of the 11 rgp120 recipients who had multiple immunizations failed to develop a strong immunoglobulin G antibody response to the immunogen. However, the antibody response to rgp120 was transient, typically having a half-life of 40 to 60 days. No significant neutralizing activity against the infecting strain was detected in any of the infected individuals at any time prior to infection. Antibody titers in subjects infected despite vaccination and in noninfected subjects were not significantly different. Envelope-specific cytotoxic T-lymphocyte responses measured after infection were infrequent and weak in the nine vaccinees who were tested. HIV-1 was isolated successfully from all 18 individuals. Sixteen of these strains had a non-syncytium-inducing (NSI) phenotype, while two had a syncytium-inducing (SI) phenotype. NSI strains used the CCR5 coreceptor to enter CD4+ cells, while an SI strain from one of the vaccinees also used CXCR4. Viruses isolated from the blood of rgp120 vaccinees were indistinguishable from viruses isolated from control individuals in terms of their inherent sensitivity to neutralization by specific monoclonal antibodies and their replication rates in vitro. Furthermore, genetic sequencing of the env genes of strains infecting the vaccinees did not reveal any features that clearly distinguished these viruses from contemporary clade B viruses circulating in the United States. Thus, despite rigorous genetic analyses, using various breakdowns of the data sets, we could find no evidence that rgp120 vaccination exerted selection pressure on the infecting HIV-1 strains. The viral burdens in the infected rgp120 vaccine recipients were also determined, and they were found to be not significantly different from those in cohorts of placebo-vaccinated and nonvaccinated individuals. In summary, we conclude that vaccination with rgp120 has had,to date, no obvious beneficial or adverse effects on the individuals we have studied.
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Affiliation(s)
- R I Connor
- The Aaron Diamond AIDS Research Center, The Rockefeller University, New York, New York 10016, USA
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35
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Shibata R, Siemon C, Czajak SC, Desrosiers RC, Martin MA. Live, attenuated simian immunodeficiency virus vaccines elicit potent resistance against a challenge with a human immunodeficiency virus type 1 chimeric virus. J Virol 1997; 71:8141-8. [PMID: 9343164 PMCID: PMC192270 DOI: 10.1128/jvi.71.11.8141-8148.1997] [Citation(s) in RCA: 97] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Three rhesus macaques, previously immunized with SIVdelta3 or SIVdelta2, each an attenuated derivative of SIVmac239, and two naive monkeys were challenged with 30,000 50% tissue culture infective doses of SHIV, an SIV/human immunodeficiency virus type 1 (HIV-1) chimeric virus bearing the dual-tropic envelope of HIV-1DH12. By several criteria, including virus isolation, serological assays, and PCR (both DNA and reverse transcriptase), SHIV levels were reduced to barely detectable levels in the circulating blood of vaccinated animals. The resistant SIV-vaccinated macaques had no preexisting neutralizing antibodies directed against SHIV, nor did they produce neutralizing antibodies at any time over a 14-month observation period following SHIV challenge. Interestingly, SIV sequences, derived from the vaccine, could be amplified from numerous tissue samples collected at the conclusion of the experiment, 60 weeks postchallenge, but SHIV-specific sequences (viz., HIV-1 env) could not. These results demonstrate that live attenuated SIV vaccines provide strong long-term protection even against challenge strains with highly divergent envelope sequences.
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Affiliation(s)
- R Shibata
- Laboratory of Molecular Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
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36
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Fuller DH, Simpson L, Cole KS, Clements JE, Panicali DL, Montelaro RC, Murphey-Corb M, Haynes JR. Gene gun-based nucleic acid immunization alone or in combination with recombinant vaccinia vectors suppresses virus burden in rhesus macaques challenged with a heterologous SIV. Immunol Cell Biol 1997; 75:389-96. [PMID: 9315483 DOI: 10.1038/icb.1997.61] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Gene gun-based DNA immunization alone or in combination with recombinant vaccinia vectors was evaluated for the ability to elicit protective immune responses in rhesus macaques challenged with a pathogenic, heterologous simian immunodeficiency virus (SIV). Six monkeys primed with seven consecutive doses of DNA encoding SIVmac239 gp120 and gp160 (DNA + DNA) were divided into two groups. Three of these animals received another DNA booster immunization and the remaining three received a booster immunization containing a homologous, live recombinant vaccinia virus expressing SIVmac251 gp160 (DNA + VAC). In addition, a group of 15 animals primed with recombinant vaccinia vectors were divided into two groups. One group of six monkeys received another immunization of vaccinia (VAC + VAC) and the other nine animals received a DNA (mac239) booster immunization (VAC + DNA). Geometric mean end-point IgG titres in the DNA + VAC and VAC + DNA groups were substantially higher than the responses seen in the VAC + VAC and DNA + DNA groups, demonstrating a synergistic relationship between DNA-based vaccines and recombinant vaccinia virus-based vaccines. All vaccinates and five naive controls were challenged 19 weeks after the final booster immunization with 10 animal infectious doses of SIVDelta/B670. The vaccines did not prevent infection. However, all vaccine groups showed significant virus load reductions from seven to 56 days post challenge when compared to controls. Although the DNA + DNA group developed the lowest prechallenge antibody responses, the most significant reduction (200-fold) in virus load was associated with this group. In addition, a significant delay in CD4+ T cell loss relative to controls was observed in the DNA + DNA group. These results demonstrate that a gene gun-based DNA vaccine provided some attenuation of infection and CD4+ T cell loss after a heterologous challenge.
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37
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Cole KS, Rowles JL, Murphey-Corb M, Clements JE, Robinson J, Montelaro RC. A model for the maturation of protective antibody responses to SIV envelope proteins in experimentally immunized monkeys. J Med Primatol 1997; 26:51-8. [PMID: 9271189 DOI: 10.1111/j.1600-0684.1997.tb00319.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Studies using live attenuated virus vaccines in the simian immunodeficiency virus (SIV) rhesus macaque model have demonstrated broad protection against experimental challenge. Protection in these studies was found to be critically dependent on the length of time postvaccination, suggesting that protective immunity involves a necessary maturation of immune responses. The current study characterizes the evolution of protective envelope-specific antibody responses from monkeys inoculated with the highly attenuated SIV/17E-Cl virus vaccine. For comparison, the same antibody assays were used to characterize the properties of SIV envelope-specific antibodies elicited by inactivated whole virus and envelope subunit vaccines that failed to provide protection from experimental virus challenge. Results of these studies identify a continuous and complex maturation of envelope-specific antibody responses during the first six to eight months postinfection. Furthermore, the time required for maturation of SIV envelope-specific antibodies parallels the time required for the development of protective immunity against experimental challenge with heterologous strains of SIV. While no single immune correlate of protection has been identified, we suggest that a combination of antibody parameters may serve as prognostic indicators in the development of candidate AIDS vaccines.
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Affiliation(s)
- K S Cole
- Department Molecular Genetics and Biochemisry, University of Pittsburgh School of Medicine, PA 15261, USA
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38
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Wyand MS, Manson KH, Lackner AA, Desrosiers RC. Resistance of neonatal monkeys to live attenuated vaccine strains of simian immunodeficiency virus. Nat Med 1997; 3:32-6. [PMID: 8986737 DOI: 10.1038/nm0197-32] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
A major safety concern of using live-attenuated vaccine strategies against AIDS is the potential exposure of neonates or fetuses to vaccine virus from the mother. Here we report that high viral loads and disease were observed in only 2 of 18 neonatal monkeys infected with gene-deleted vaccine strains of simian immunodeficiency virus. Pathogenicity was restricted to neonates born to unvaccinated mothers, that is, lacking maternal immunity, and that received extremely high doses of vaccine virus orally. No in utero transmission of vaccine virus was observed in four neonates born to mothers vaccinated during the second trimester. Our results suggest that the live attenuated vaccine approach should remain a viable option for preventing HIV infection and disease in high-risk human populations.
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Affiliation(s)
- M S Wyand
- TSI Mason Laboratories, Worcester, Massachusetts 01608, USA
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39
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Affiliation(s)
- MI Johnston
- The International AIDS Vaccine Initiative, c/o The Rockefeller Foundation, 420 Fifth Avenue, New York, NY 10018-2702, USA
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40
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Abstract
Recent vaccine trials utilizing the simian immunodeficiency virus/macaque model of AIDS are beginning to yield clues regarding mechanisms of protective immunity. Although cytotoxic T lymphocyte responses to SIV may play a role in mediating protection against infection, protective immunity appears to correlate best with the development of antibodies able to neutralize primary or heterologous pathogenic viruses. Protection against disease or persistent infection may be achieved in the absence of sterilizing immunity, suggesting that new benchmarks for AIDS vaccines may be in order.
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Affiliation(s)
- R P Johnson
- New England Regional Primate Research Center, Harvard Medical School, PO Box 9102, One Pine Hill Drive, Southborough, MA 01772, USA.
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41
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Myagkikh M, Alipanah S, Markham PD, Tartaglia J, Paoletti E, Gallo RC, Franchini G, Robert-Guroff M. Multiple immunizations with attenuated poxvirus HIV type 2 recombinants and subunit boosts required for protection of rhesus macaques. AIDS Res Hum Retroviruses 1996; 12:985-92. [PMID: 8827214 DOI: 10.1089/aid.1996.12.985] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Vaccine protocols involving multiple immunizations with molecularly attenuated vaccinia virus (NYVAC) or naturally attenuated canarypox virus (ALVAC) HIV-2 recombinants and subunit boosts have conferred longlasting protection against HIV-2 infection of macaques. Similar complex protocols using HIV-1 NYVAC and ALVAC recombinants and subunit boosts have provided cross-protection against HIV-2 challenge. Here a simplified three-immunization regimen over 24 weeks was tested in 18 juvenile rhesus macaques. Twelve macaques were immunized twice with NYVAC or ALVAC recombinants carrying HIV-2 env, gag, and pol genes. Subsequently, macaques in groups of three received either an additional recombinant immunization or an HIV-2 gp160 boost. Six control macaques received three immunizations of NYVAC or ALVAC vector alone and additionally alum at the third immunization. Macaques primed with ALVAC recombinant exhibited sporadic T cell proliferative activity, and all but one failed to develop neutralizing antibodies. In contrast, macaques primed with NYVAC recombinants had no T cell proliferative activity but exhibited neutralizing antibody titers (highest in the three recombinant group) that declined by the time of challenge. None of the macaques exhibited significant cytotoxic T lymphocyte activity. Following challenge at 32 weeks with HIV-2SBL6669 all macaques became infected. Thus, the three-immunization regimen is not sufficient to confer protective immunity in the HIV-2 rhesus macaque model. However, delayed infection in macaques immunized with the NYVAC-HIV-2 recombinant may have been associated with the development of memory B cells capable of providing a neutralizing antibody response on challenge.
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Affiliation(s)
- M Myagkikh
- Laboratory of Tumor Cell Biology, DBS, NCI, NIH, Bethesda, Maryland 20892-4255, USA
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42
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Wyand MS, Manson KH, Garcia-Moll M, Montefiori D, Desrosiers RC. Vaccine protection by a triple deletion mutant of simian immunodeficiency virus. J Virol 1996; 70:3724-33. [PMID: 8648707 PMCID: PMC190248 DOI: 10.1128/jvi.70.6.3724-3733.1996] [Citation(s) in RCA: 269] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Twelve rhesus monkeys were vaccinated with SIVmac316 delta nef (lacking nef sequences), and 12 were vaccinated with SIVmac239 delta3 (lacking nef, vpr, and upstream sequences in U3). SIVmac316 and SIVmac239 differ by only eight amino acids in the envelope; these changes render SIVmac316 highly competent for replication in macrophages. Seventeen of the animals developed persistent infections with the vaccine viruses. Seven of the 24 vaccinated animals, however, developed infections that were apparently transient in nature. Six of these seven yielded virus from peripheral blood when tested at weeks 2 and/or 3, three of the seven had transient antibody responses, but none of the seven had persisting antibody responses. The 24 monkeys were challenged in groups of four with 10 rhesus monkey infectious doses of wild-type, pathogenic SIVmac251 at weeks 8, 20, and 79 following receipt of vaccine. None of the seven with apparently transient infections with vaccine virus were protected upon subsequent challenge. Analysis of cell-associated viral loads, CD4+ cell counts, and viral gene sequences present in peripheral blood in the remainder of the monkeys following challenge allowed a number of conclusions. (i) There was a trend toward increased protection with length of time of vaccination. (ii) Solid vaccine protection was achieved by 79 weeks with the highly attenuated SIV239 delta3. (iii) Solid long-term protection was achieved in at least two animals in the absence of complete sterilizing immunity. (iv) Genetic backbone appeared to influence protective capacity; animals vaccinated with SIV239 delta3 were better protected than animals receiving SIV316 delta nef. This better protection correlated with increased levels of the replicating vaccine strain. (v) The titer of virus-neutralizing activity in serum on the day of challenge correlated with protection when measured against a primary stock of SIVmac251 but not when measured against a laboratory-passaged stock. The level of binding antibodies to whole virus by enzyme-linked immunosorbent assay also correlated with protection.
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Affiliation(s)
- M S Wyand
- TSI Mason Laboratory, Worcester, Massachusetts, USA
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43
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Lu S, Arthos J, Montefiori DC, Yasutomi Y, Manson K, Mustafa F, Johnson E, Santoro JC, Wissink J, Mullins JI, Haynes JR, Letvin NL, Wyand M, Robinson HL. Simian immunodeficiency virus DNA vaccine trial in macaques. J Virol 1996; 70:3978-91. [PMID: 8648735 PMCID: PMC190276 DOI: 10.1128/jvi.70.6.3978-3991.1996] [Citation(s) in RCA: 187] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
An experimental vaccine consisting of five DNA plasmids expressing different combinations and forms of simian immunodeficiency virus-macaque (SIVmac) proteins has been evaluated for the ability to protect against a highly pathogenic uncloned SIVmac251 challenge. One vaccine plasmid encoded nonreplicating SIVmac239 virus particles. The other four plasmids encoded secreted forms of the envelope glycoproteins of two T-cell-tropic relatives (SIVmac239 and SIVmac251) and one monocyte/macrophage-tropic relative (SIVmac316) of the uncloned challenge virus. Rhesus macaques were inoculated with DNA at 1 and 3, 11 and 13, and 21 and 23 weeks. Four macaques were inoculated intravenously, intramuscularly, and by gene gun inoculations. Three received only gene gun inoculations. Two control monkeys were inoculated with control plasmids by all three routes of inoculation. Neutralizing antibody titers of 1:216 to 1:768 were present in all of the vaccinated monkeys after the second cluster of inoculations. These titers were transient, were not boosted by the third cluster of inoculations, and had fallen to 1:24 to 1:72 by the time of challenge. Cytotoxic T-cell activity for Env was also raised in all of the vaccinated animals. The temporal appearance of cytotoxic T cells was similar to that of antibody. However, while antibody responses fell with time, cytotoxic T-cell responses persisted. The SIVmac251 challenge was administered intravenously at 2 weeks following the last immunization. The DNA immunizations did not prevent infection or protect against CD4+ cell loss. Long-term chronic levels of infection were similar in the vaccinated and control animals, with 1 in 10,000 to 1 in 100,000 peripheral blood cells carrying infectious virus. However, viral loads were reduced to the chronic level over a shorter period of time in the vaccinated groups (6 weeks) than in the control group (12 weeks). Thus, the DNA vaccine raised both neutralizing antibody and cytotoxic T-lymphocyte responses and provided some attenuation of the acute phase of infection, but it did not prevent the loss of CD4+ cells.
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Affiliation(s)
- S Lu
- Department of Pathology, University of Massachusetts Medical Center, Worcester 01655, USA
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44
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Fenyö EM, Putkonen P. Broad cross-neutralizing activity in serum is associated with slow progression and low risk of transmission in primate lentivirus infections. Immunol Lett 1996; 51:95-9. [PMID: 8811351 DOI: 10.1016/0165-2478(96)02561-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Sera from human immunodeficiency virus type 1 and type 2 (HIV-1 and HIV-2)-infected humans were tested with autologous (from the same individual) and heterologous (from other individuals) virus isolates in a neutralization assay. Similarly, sera from experimentally simian immunodeficiency virus (SIVsm from sooty mangabey) or HIV-2SBL6669-infected cynomolgus macaques were tested for neutralizing activity against autologous and heterologous reisolates. In the neutralization assay, the virus dose ranged between 10-75 50% infectious dose (ID50), sera were used in five 2- or 4-fold dilutions, beginning with 1:20, and human peripheral blood mononuclear cells (PBMCs) served as target cells. The readout of the 7-day assay was a HIV-1 or HIV-2 antigen enzyme-linked immunosorbent assay (ELISA). Our results show that SIVsm-inoculated monkeys who develop early immunodeficiency lack serum neutralizing activity or develop a neutralizing antibody response with narrow specificity. Long survival is associated with the ability to neutralize several autologous and heterologous SIVsm reisolates. Infection of macaques with HIV-2SBL6669 did not cause disease within the 5 years observation time and elicited a broadly cross-reactive neutralizing antibody response, including neutralization of other, independently obtained, HIV-2 isolates. In HIV-1-infected humans, neutralizing antibodies can only be detected in up to 50% of cases. Neutralizing activity, whenever present, may show a broad specificity, that is, neutralization may occur across genetic subtypes. Presence of broadly cross-reactive neutralizing antibodies is associated with a lower risk of HIV-1 (subtype B) transmission both from mother to child and sexually from male to female. Unlike HIV-1 infection, serum neutralizing activity is regularly present in HIV-2 infection. In view of the differences between HIV-1 and HIV-2 pathogenesis, we suggest that an effective neutralizing antibody response may contribute to a delay in disease progression and to a decrease in risk of transmission.
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Affiliation(s)
- E M Fenyö
- Microbiology and Tumorbiology Center, Karolinska Institute, Stockholm, Sweden
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45
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Montelaro RC, Grund C, Raabe M, Woodson B, Cook RF, Cook S, Issel CJ. Characterization of protective and enhancing immune responses to equine infectious anemia virus resulting from experimental vaccines. AIDS Res Hum Retroviruses 1996; 12:413-5. [PMID: 8882322 DOI: 10.1089/aid.1996.12.413] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Affiliation(s)
- R C Montelaro
- Department of Molecular Genetics and Biochemistry, University of Pittsburgh School of Medicine, Pennsylvania 15261, USA
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46
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Affiliation(s)
- S L Hu
- Bristol-Myers Squibb Pharmaceutical Research Institute, Seattle, Washington 98121, USA
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47
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Mossman SP, Bex F, Berglund P, Arthos J, O'Neil SP, Riley D, Maul DH, Bruck C, Momin P, Burny A, Fultz PN, Mullins JI, Liljeström P, Hoover EA. Protection against lethal simian immunodeficiency virus SIVsmmPBj14 disease by a recombinant Semliki Forest virus gp160 vaccine and by a gp120 subunit vaccine. J Virol 1996; 70:1953-60. [PMID: 8627721 PMCID: PMC190024 DOI: 10.1128/jvi.70.3.1953-1960.1996] [Citation(s) in RCA: 128] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Infection of pigtail macaques with SIVsmmPBj14, biological clone 3 (SIV-PBj14-bc13), produces an acute and usually fatal shock-like syndrome 7 to 14 days after infection. We used this simian immunodeficiency virus (SIV) model as a rapid and rigorous challenge to evaluate the efficacy of two SIV Env vaccine strategies. Groups of four pigtail macaques were immunized four times over a 25-week span with either a recombinant Semliki Forest virus expressing the SIV-PBj14 Env gp160 (SFV-SIVgp160) or purified recombinant SIV-PBj14 gp120 (rgp120) in SBN-1 adjuvant. Antibody titers to SIV Env developed in all immunized animals (mean peak titers prior to challenge, 1:1,700 for SFV-SIV gp 160 and 1:10,500 for rgp120), but neither neutralizing antibodies nor SIV-specific T-cell proliferative responses were detectable in any of the vaccinees. All macaques were challenged with a 100% infectious, 75% fatal dose of SIV-PBj14-bc13 at week 26. Three of four control animals died of acute SIV-PBj14 syndrome on days 12 and 13. By contrast, all four SFV-SIVgp160-immunized animals and three of the four rgp120-immunized animals were protected from lethal disease. While all virus-challenged animals became infected, symptoms of the SIV-PBj14 syndrome were more severe in controls than in vaccinees. Mean virus titers in plasma at 13 days postchallenge were approximately 10-fold lower in vaccinated than control animals. However, there was no apparent correlation between survival and levels of peripheral blood mononuclear cell-associated culturable virus, provirus load, or any antiviral immunologic parameter examined. The results indicate that while immunization with SFV-SIVgp160 and rgp120 did not protect against virus infection, these Env vaccines did lower the virus load in plasma and protect against the lethal SIV-PBj14 challenge.
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Affiliation(s)
- S P Mossman
- Department of Pathology, Colorado State University, Fort Collins 80523, USA
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48
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Yasutomi Y, Robinson HL, Lu S, Mustafa F, Lekutis C, Arthos J, Mullins JI, Voss G, Manson K, Wyand M, Letvin NL. Simian immunodeficiency virus-specific cytotoxic T-lymphocyte induction through DNA vaccination of rhesus monkeys. J Virol 1996; 70:678-81. [PMID: 8523593 PMCID: PMC189866 DOI: 10.1128/jvi.70.1.678-681.1996] [Citation(s) in RCA: 109] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
In view of the growing evidence that virus-specific cytotoxic T lymphocytes (CTL) play an important role in containing the early spread of human immunodeficiency virus type 1 (HIV-1) in infected individuals, novel vaccine strategies capable of eliciting HIV-1-specific CTL are being pursued in attempts to create an effective AIDS vaccine. We have used the simian immunodeficiency virus of macaques (SIVmac)/rhesus monkey model to explore the induction of AIDS virus-specific CTL responses by DNA vaccination. We found that the inoculation of rhesus monkeys with plasmid DNA encoding SIVmac Env and Gag elicited a persisting SIVmac-specific memory CTL response. These CTL were CD8+ and major histocompatibility complex class I restricted. These studies provide evidence for the potential utility of DNA inoculation as an approach to an HIV-1 vaccine.
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Affiliation(s)
- Y Yasutomi
- Division of Viral Pathogenesis, Beth Israel Hospital, Harvard Medical School, Boston, Massachusetts 02215, USA
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49
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Warren JT, Levinson MA. Fourth annual survey of worldwide HIV, SIV, and SHIV challenge studies in vaccinated nonhuman primates. J Med Primatol 1995; 24:150-68. [PMID: 8751055 DOI: 10.1111/j.1600-0684.1995.tb00161.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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