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Ensoli B, Moretti S, Borsetti A, Maggiorella MT, Buttò S, Picconi O, Tripiciano A, Sgadari C, Monini P, Cafaro A. New insights into pathogenesis point to HIV-1 Tat as a key vaccine target. Arch Virol 2021; 166:2955-2974. [PMID: 34390393 PMCID: PMC8363864 DOI: 10.1007/s00705-021-05158-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Accepted: 05/09/2021] [Indexed: 02/07/2023]
Abstract
Despite over 30 years of enormous effort and progress in the field, no preventative and/or therapeutic vaccines against human immunodeficiency virus (HIV) are available. Here, we briefly summarize the vaccine strategies and vaccine candidates that in recent years advanced to efficacy trials with mostly unsatisfactory results. Next, we discuss a novel and somewhat contrarian approach based on biological and epidemiological evidence, which led us to choose the HIV protein Tat for the development of preventive and therapeutic HIV vaccines. Toward this goal, we review here the role of Tat in the virus life cycle as well as experimental and epidemiological evidence supporting its key role in the natural history of HIV infection and comorbidities. We then discuss the preclinical and clinical development of a Tat therapeutic vaccine, which, by improving the functionality and homeostasis of the immune system and by reducing the viral reservoir in virologically suppressed vaccinees, helps to establish key determinants for intensification of combination antiretroviral therapy (cART) and a functional cure. Future developments and potential applications of the Tat therapeutic vaccine are also discussed, as well as the rationale for its use in preventative strategies. We hope this contribution will lead to a reconsideration of the current paradigms for the development of HIV/AIDS vaccines, with a focus on targeting of viral proteins with key roles in HIV pathogenesis.
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Affiliation(s)
- Barbara Ensoli
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161, Rome, Italy.
| | - Sonia Moretti
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161, Rome, Italy
| | - Alessandra Borsetti
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161, Rome, Italy
| | - Maria Teresa Maggiorella
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161, Rome, Italy
| | - Stefano Buttò
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161, Rome, Italy
| | - Orietta Picconi
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161, Rome, Italy
| | - Antonella Tripiciano
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161, Rome, Italy
| | - Cecilia Sgadari
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161, Rome, Italy
| | - Paolo Monini
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161, Rome, Italy
| | - Aurelio Cafaro
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161, Rome, Italy
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Ng'uni T, Chasara C, Ndhlovu ZM. Major Scientific Hurdles in HIV Vaccine Development: Historical Perspective and Future Directions. Front Immunol 2020; 11:590780. [PMID: 33193428 PMCID: PMC7655734 DOI: 10.3389/fimmu.2020.590780] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 10/05/2020] [Indexed: 12/15/2022] Open
Abstract
Following the discovery of HIV as a causative agent of AIDS, the expectation was to rapidly develop a vaccine; but thirty years later, we still do not have a licensed vaccine. Progress has been hindered by the extensive genetic variability of HIV and our limited understanding of immune responses required to protect against HIV acquisition. Nonetheless, valuable knowledge accrued from numerous basic and translational science research studies and vaccine trials has provided insight into the structural biology of the virus, immunogen design and novel vaccine delivery systems that will likely constitute an effective vaccine. Furthermore, stakeholders now appreciate the daunting scientific challenges of developing an effective HIV vaccine, hence the increased advocacy for collaborative efforts among academic research scientists, governments, pharmaceutical industry, philanthropy, and regulatory entities. In this review, we highlight the history of HIV vaccine development efforts, highlighting major challenges and future directions.
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Affiliation(s)
- Tiza Ng'uni
- KwaZulu-Natal Research Institute for Tuberculosis and HIV (K-RITH), Nelson R. Mandela School of Medicine, University of KwaZulu-Natal, Durban, South Africa
| | - Caroline Chasara
- KwaZulu-Natal Research Institute for Tuberculosis and HIV (K-RITH), Nelson R. Mandela School of Medicine, University of KwaZulu-Natal, Durban, South Africa
| | - Zaza M Ndhlovu
- KwaZulu-Natal Research Institute for Tuberculosis and HIV (K-RITH), Nelson R. Mandela School of Medicine, University of KwaZulu-Natal, Durban, South Africa.,Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology, and Harvard University, Cambridge, MA, United States
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3
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Phetsouphanh C, Zaunders JJ, Kelleher AD. Detecting Antigen-Specific T Cell Responses: From Bulk Populations to Single Cells. Int J Mol Sci 2015; 16:18878-93. [PMID: 26274954 PMCID: PMC4581277 DOI: 10.3390/ijms160818878] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 07/29/2015] [Accepted: 08/03/2015] [Indexed: 12/18/2022] Open
Abstract
A new generation of sensitive T cell-based assays facilitates the direct quantitation and characterization of antigen-specific T cell responses. Single-cell analyses have focused on measuring the quality and breadth of a response. Accumulating data from these studies demonstrate that there is considerable, previously-unrecognized, heterogeneity. Standard assays, such as the ICS, are often insufficient for characterization of rare subsets of cells. Enhanced flow cytometry with imaging capabilities enables the determination of cell morphology, as well as the spatial localization of the protein molecules within a single cell. Advances in both microfluidics and digital PCR have improved the efficiency of single-cell sorting and allowed multiplexed gene detection at the single-cell level. Delving further into the transcriptome of single-cells using RNA-seq is likely to reveal the fine-specificity of cellular events such as alternative splicing (i.e., splice variants) and allele-specific expression, and will also define the roles of new genes. Finally, detailed analysis of clonally related antigen-specific T cells using single-cell TCR RNA-seq will provide information on pathways of differentiation of memory T cells. With these state of the art technologies the transcriptomics and genomics of Ag-specific T cells can be more definitively elucidated.
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Affiliation(s)
| | - John James Zaunders
- Kirby Institute, University of New South Wales, 2031 Sydney, Australia.
- Centre for Applied Medical Research, St. Vincent's Hospital, 2010 Sydney, Australia.
| | - Anthony Dominic Kelleher
- Kirby Institute, University of New South Wales, 2031 Sydney, Australia.
- Centre for Applied Medical Research, St. Vincent's Hospital, 2010 Sydney, Australia.
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4
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Tongo M, Burgers WA. Challenges in the design of a T cell vaccine in the context of HIV-1 diversity. Viruses 2014; 6:3968-90. [PMID: 25341662 PMCID: PMC4213573 DOI: 10.3390/v6103968] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 10/15/2014] [Accepted: 10/18/2014] [Indexed: 12/27/2022] Open
Abstract
The extraordinary variability of HIV-1 poses a major obstacle to vaccine development. The effectiveness of a vaccine is likely to vary dramatically in different populations infected with different HIV-1 subtypes, unless innovative vaccine immunogens are developed to protect against the range of HIV-1 diversity. Immunogen design for stimulating neutralizing antibody responses focuses on “breadth” – the targeting of a handful of highly conserved neutralizing determinants on the HIV-1 Envelope protein that can recognize the majority of viruses across all HIV-1 subtypes. An effective vaccine will likely require the generation of both broadly cross-neutralizing antibodies and non-neutralizing antibodies, as well as broadly cross-reactive T cells. Several approaches have been taken to design such broadly-reactive and cross-protective T cell immunogens. Artificial sequences have been designed that reduce the genetic distance between a vaccine strain and contemporary circulating viruses; “mosaic” immunogens extend this concept to contain multiple potential T cell epitope (PTE) variants; and further efforts attempt to focus T cell immunity on highly conserved regions of the HIV-1 genome. Thus far, a number of pre-clinical and early clinical studies have been performed assessing these new immunogens. In this review, the potential use of these new immunogens is explored.
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Affiliation(s)
- Marcel Tongo
- Institute of Infectious Disease and Molecular Medicine, Division of Medical Virology, University of Cape Town, Anzio Road, Observatory 7925, Cape Town, South Africa.
| | - Wendy A Burgers
- Institute of Infectious Disease and Molecular Medicine, Division of Medical Virology, University of Cape Town, Anzio Road, Observatory 7925, Cape Town, South Africa.
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5
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A brief history of the global effort to develop a preventive HIV vaccine. Vaccine 2013; 31:3502-18. [PMID: 23707164 DOI: 10.1016/j.vaccine.2013.05.018] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2013] [Revised: 05/01/2013] [Accepted: 05/07/2013] [Indexed: 01/09/2023]
Abstract
Soon after HIV was discovered as the cause of AIDS in 1983-1984, there was an expectation that a preventive vaccine would be rapidly developed. In trying to achieve that goal, three successive scientific paradigms have been explored: induction of neutralizing antibodies, induction of cell mediated immunity, and exploration of combination approaches and novel concepts. Although major progress has been made in understanding the scientific basis for HIV vaccine development, efficacy trials have been critical in moving the field forward. In 2009, the field was reinvigorated with the modest results obtained from the RV144 trial conducted in Thailand. Here, we review those vaccine development efforts, with an emphasis on events that occurred during the earlier years. The goal is to provide younger generations of scientists with information and inspiration to continue the search for an HIV vaccine.
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Abstract
A detailed understanding of the cellular response to human immunodeficiency virus (HIV-1) infection is needed to inform prevention and therapeutic strategies that aim to contain the AIDS pandemic. The cellular immune response plays a critical role in reducing viral load in HIV-1 infection and in the nonhuman primate model of SIV infection. Much of this virus suppressive activity has been ascribed to CD8(+)T-cell-directed cytolysis of infected CD4(+)T cells. However, emerging evidence suggests that CD8(+)T cells can maintain a lowered viral burden through multiple mechanisms. A thorough understanding of the CD8(+)T-cell functions in HIV-1 infection that correlate with viral control, the populations responsible for these functions, and the elicitation and maintenance of these responses can provide guidance for vaccine design and potentially the development of new classes of antiretroviral therapies. In this review, we discuss the CD8(+)T-cell correlates of protection in HIV-1 and SIV infection and recent advances in this field.
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Affiliation(s)
- Stephanie A Freel
- Department of Surgery, Duke Human Vaccine Institute, Duke University Medical Center, Rm 113 SORF Building MSRBII, LaSalle St. Ext., Durham, NC 27710, USA
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7
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Keckler MS, Hodara VL, Parodi LM, Giavedoni LD. Novel application of nonhuman primate tethering system for evaluation of acute phase SIVmac251 infection in rhesus macaques (Macaca mulatta). Viral Immunol 2008; 20:623-34. [PMID: 18158735 DOI: 10.1089/vim.2007.0068] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Infection of rhesus macaques with simian immunodeficiency virus (SIV) is the preferred animal model for the development and testing of human immunodeficiency virus (HIV) vaccines, and animals protected from SIV challenge by live attenuated vaccines are an invaluable tool for determining immune correlates of protection. The acute phase of SIV infection, in which immune responses are most critical for slowing disease progression, occurs within the first 4 weeks of exposure. The small window of time available for observing critical immune responses makes obtaining adequate blood samples with sufficient frequency difficult. This study is the first to apply a previously reported nonhuman primate (NHP) tether system to study viral immunology. The use of the tether allows for frequent blood sampling without using restraints or sedation, thereby reducing the potentially confounding physiological changes induced by stress. We performed comparative analysis of acute phase immune responses in vaccinated and unvaccinated animals challenged with SIV-mac251. Our results demonstrate live attenuated vaccine-induced protection, which is associated with small increases in the cytotoxic T-cell (CTL) response to immunodominant epitopes, but not with increases in antibody titers. Additionally, vaccination was shown to establish a pool of antigen-specific CD8+ memory cells available for expansion after challenge. The confirmatory nature of these data indicates the validity of using the tether system for evaluation of acute phase anti-SIV responses and can be applied to the study of immune responses in other viral infections in which frequent sampling in small windows of time would be useful.
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Affiliation(s)
- M Shannon Keckler
- University of Texas Health Science Center at San Antonio, Texas., Department of Virology and Immunology, San Antonio, Texas, USA
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9
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Maris CH, Chappell CP, Jacob J. Interleukin-10 plays an early role in generating virus-specific T cell anergy. BMC Immunol 2007; 8:8. [PMID: 17570849 PMCID: PMC1903364 DOI: 10.1186/1471-2172-8-8] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2006] [Accepted: 06/14/2007] [Indexed: 11/14/2022] Open
Abstract
Background Infection of mice with the Armstrong strain of lymphocytic choriomeningitis virus (LCMVARM) leads to a robust immune response and efficient viral clearance. This is in contrast to infection with the variant strain LCMVClone13, which causes functional inactivation of effector T cells and viral persistence. The mechanism by which LCMVClone13 suppresses the antiviral immune response and persists in its host is unknown. Results Here we demonstrate that infection with LCMVClone13, but not with LCMVARM, resulted in a steady increase in the serum levels of the immuno-inhibitory cytokine, IL-10. Blockade of IL-10 using neutralizing monoclonal antibody injections in LCMVClone13-infected mice led to dramatically enhanced effector T cell responses at 8 days post-infection. Even though IL-10 blockade resulted in decreased viral titers, the generation and maintenance of memory T cells was still compromised. The functional inactivation of CD8+ T cells in IL-10-blocked, chronically infected mice 30 days post-infection was incomplete as potent CTL (cytotoxic T lymphocytes) could be generated by in vitro re-stimulation. IL-10 knockout mice showed a similar pattern of antiviral CD8 T cell responses: early antiviral T cells were dramatically increased and viral levels were decreased; however, CD8 T cells in IL-10 knockout mice were also eventually anergized and these mice became persistently infected. Conclusion Our data suggest that IL-10 plays an early role in LCMVClone13-induced tolerance, although other factors collaborate with IL-10 to induce virus-specific tolerance.
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Affiliation(s)
- Charles H Maris
- Sidney Kimmel Comprehensive Cancer Center at The Johns Hopkins University, 1650 Orleans Street CRB-1 424, Baltimore, MD 21231, USA
| | - Craig P Chappell
- Department of Microbiology and Immunology and the Emory Vaccine Center, Emory University, 954 N. Gatewood Rd, Atlanta, GA 30329, USA
| | - Joshy Jacob
- Department of Microbiology and Immunology and the Emory Vaccine Center, Emory University, 954 N. Gatewood Rd, Atlanta, GA 30329, USA
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10
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Regoes RR, Barber DL, Ahmed R, Antia R. Estimation of the rate of killing by cytotoxic T lymphocytes in vivo. Proc Natl Acad Sci U S A 2007; 104:1599-603. [PMID: 17242364 PMCID: PMC1785271 DOI: 10.1073/pnas.0508830104] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Cytotoxic T lymphocytes (CTL) help control virus infections by killing virus-infected (target) cells. How fast do CTL find and kill target cells in vivo? Experiments allow us to follow populations of labeled target cells after their transfer into immune mice where they are killed by CTL. Here, we develop models of the migration and killing processes involved in these experiments and use them to quantitatively analyze the in vivo killing data. These models allow us to estimate the rate constant for killing of target cells by CTL.
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Affiliation(s)
- Roland R. Regoes
- *Department of Biology and
- To whom correspondence may be addressed. E-mail:
or
| | | | - Rafi Ahmed
- Emory Vaccine Center, Emory University, Atlanta, GA 30322
| | - Rustom Antia
- *Department of Biology and
- To whom correspondence may be addressed. E-mail:
or
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12
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Omori M, Pu R, Tanabe T, Hou W, Coleman JK, Arai M, Yamamoto JK. Cellular immune responses to feline immunodeficiency virus (FIV) induced by dual-subtype FIV vaccine. Vaccine 2004; 23:386-98. [PMID: 15530685 DOI: 10.1016/j.vaccine.2004.05.032] [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: 11/07/2003] [Revised: 05/10/2004] [Accepted: 05/13/2004] [Indexed: 10/26/2022]
Abstract
Vaccine-induced T cell responses to FIV were assessed by measuring FIV-specific cytokine and cytotoxic-effector molecule production. A total of 22 cats at 10-12 weeks of age received either dual-subtype FIV vaccine (n=12), uninfected cell lysate (n=5) consisting of cells used to produce vaccine viruses, or no immunization (n=5). Significant increases in mRNA and protein production of T-helper 1 (Th1) cytokines (IL-2, IFNgamma), mRNA production of a cytotoxic-effector molecule (perforin), and lymphoproliferation response were observed in peripheral blood mononuclear cells (PBMC) from dual-subtype FIV-vaccinated cats after in vitro stimulation with inactivated FIV. In contrast, no statistically significant increase in FIV-stimulated mRNA production of Th2 cytokines (IL-4, IL-6) or other cytotoxic-effector molecules (TNFalpha, FasL) was observed in the PBMC from dual-subtype vaccinated cats. Moreover, no FIV-specific increases in the IFNgamma, IL-2, and perforin mRNA productions and in the IFNgamma bioactivity and lymphoproliferation responses were observed in the PBMC from cell-immunized cats. These observations suggest that IFNgamma induction, lymphoproliferation, and significant portion of IL-2 and perforin productions in the PBMC from dual-subtype vaccinated cats are clearly specific for viral antigens. Overall, dual-subtype FIV vaccine elicited strong Th1 response (IFN(, IL-2), which may contribute to the vaccine protection by enhancing the perforin-mediated cytotoxic-cell activity against FIV.
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Affiliation(s)
- M Omori
- Department of Pathobiology, College of Veterinary Medicine, University of Florida, P.O. Box 110880, Gainesville, FL 32611, USA
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Yu XG, Addo MM, Perkins BA, Wej F, Rathod A, Geer SC, Parta M, Cohen D, Stone DR, Russell CJ, Tanzi G, Mei S, Wurcel AG, Frahm N, Lichterfeld M, Heath L, Mullins JI, Marincola F, Goulder PJR, Brander C, Allen T, Cao Y, Walker BD, Altfeld M. Differences in the expressed HLA class I alleles effect the differential clustering of HIV type 1-specific T cell responses in infected Chinese and caucasians. AIDS Res Hum Retroviruses 2004; 20:557-64. [PMID: 15186531 DOI: 10.1089/088922204323087813] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
China is a region of the world with a rapidly spreading HIV-1 epidemic. Studies providing insights into HIV-1 pathogenesis in infected Chinese are urgently needed to support the design and testing of an effective HIV-1 vaccine for this population. HIV-1-specific T cell responses were characterized in 32 HIV-1-infected individuals of Chinese origin and compared to 34 infected caucasians using 410 overlapping peptides spanning the entire HIV-1 clade B consensus sequence in an IFN-gamma ELISpot assay. All HIV-1 proteins were targeted with similar frequency in both populations and all study subjects recognized at least one overlapping peptide. HIV-1-specific T cell responses clustered in seven different regions of the HIV-1 genome in the Chinese cohort and in nine different regions in the caucasian cohort. The dominant HLA class I alleles expressed in the two populations differed significantly, and differences in epitope clustering pattern were shown to be influenced by differences in class I alleles that restrict immunodominant epitopes. These studies demonstrate that the clustering of HIV-1-specific T cell responses is influenced by the genetic HLA class I background in the study populations. The design and testing of candidate vaccines to fight the rapidly growing HIV-1 epidemic must therefore take the HLA genetics of the population into account as specific regions of the virus can be expected to be differentially targeted in ethnically diverse populations.
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Affiliation(s)
- Xu G Yu
- Partners AIDS Research Center and Infectious Disease Division, Massachusetts General Hospital and Division of AIDS, Harvard Medical School, Boston, Massachusetts 02129, USA
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McDermott AB, Mitchen J, Piaskowski S, De Souza I, Yant LJ, Stephany J, Furlott J, Watkins DI. Repeated low-dose mucosal simian immunodeficiency virus SIVmac239 challenge results in the same viral and immunological kinetics as high-dose challenge: a model for the evaluation of vaccine efficacy in nonhuman primates. J Virol 2004; 78:3140-4. [PMID: 14990733 PMCID: PMC353751 DOI: 10.1128/jvi.78.6.3140-3144.2004] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Simian immunodeficiency virus (SIV) challenge of rhesus macaques provides a relevant model for the assessment of human immunodeficiency virus (HIV) vaccine strategies. To ensure that all macaques become infected, the vaccinees and controls are exposed to large doses of pathogenic SIV. These nonphysiological high-dose challenges may adversely affect vaccine evaluation by overwhelming potentially efficacious vaccine responses. To determine whether a more physiologically relevant low-dose challenge can initiate infection and cause disease in Indian rhesus macaques, we used a repeated low-dose challenge strategy designed to reduce the viral inoculum to more physiologically relevant doses. In an attempt to more closely mimic challenge with HIV, we administered repeated mucosal challenges with 30, 300, and 3,000 50% tissue culture infective doses (TCID(50)) of pathogenic SIVmac239 to six animals in three groups. Infection was assessed by sensitive quantitative reverse transcription-PCR and was achieved following a mean of 8, 5.5, and 1 challenge(s) in the 30, 300, and 3,000 TCID(50) groups, respectively. Mortality, humoral immune responses, and peak plasma viral kinetics were similar in five of six animals, regardless of challenge dose. Interestingly, macaques challenged with lower doses of SIVmac239 developed broad T-cell immune responses as assessed by ELISPOT assay. This low-dose repeated challenge may be a valuable tool in the evaluation of potential vaccine regimes and offers a more physiologically relevant regimen for pathogenic SIVmac239 challenge experiments.
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Affiliation(s)
- Adrian B McDermott
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
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15
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Izumi Y, Ami Y, Matsuo K, Someya K, Sata T, Yamamoto N, Honda M. Intravenous inoculation of replication-deficient recombinant vaccinia virus DIs expressing simian immunodeficiency virus gag controls highly pathogenic simian-human immunodeficiency virus in monkeys. J Virol 2004; 77:13248-56. [PMID: 14645581 PMCID: PMC296093 DOI: 10.1128/jvi.77.24.13248-13256.2003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
To be effective, a vaccine against human immunodeficiency virus type 1 (HIV-1) must induce virus-specific T-cell responses and it must be safe for use in humans. To address these issues, we developed a recombinant vaccinia virus DIs vaccine (rDIsSIVGag), which is nonreplicative in mammalian cells and expresses the full-length gag gene of simian immunodeficiency virus (SIV). Intravenous inoculation of 10(6) PFU of rDIsSIVGag in cynomologus macaques induced significant levels of gamma interferon (IFN-gamma) spot-forming cells (SFC) specific for SIV Gag. Antigen-specific lymphocyte proliferative responses were also induced and were temporally associated with the peak of IFN-gamma SFC activity in each macaque. In contrast, macaques immunized with a vector control (rDIsLacZ) showed no significant induction of antigen-specific immune responses. After challenge with a highly pathogenic simian-human immunodeficiency virus (SHIV), CD4(+) T lymphocytes were maintained in the peripheral blood and lymphoid tissues of the immunized macaques. The viral set point in plasma was also reduced in these animals, which may be related to the enhancement of virus-specific intracellular IFN-gamma(+) CD8(+) cell numbers and increased antibody titers after SHIV challenge. These results demonstrate that recombinant DIs has potential for use as an HIV/AIDS vaccine.
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Affiliation(s)
- Yasuyuki Izumi
- AIDS Research Center. Division of Experimental Animal Research. Department of Pathology, National Institute of Infectious Diseases, Shinjuku-ku, Tokyo 162-8640. Japan
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16
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Emeny RT, Wheeler CM, Jansen KU, Hunt WC, Fu TM, Smith JF, MacMullen S, Esser MT, Paliard X. Priming of human papillomavirus type 11-specific humoral and cellular immune responses in college-aged women with a virus-like particle vaccine. J Virol 2002; 76:7832-42. [PMID: 12097595 PMCID: PMC136358 DOI: 10.1128/jvi.76.15.7832-7842.2002] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In this study, we evaluated the potency of a human papillomavirus (HPV) virus-like particle (VLP)-based vaccine at generating HPV type 11 (HPV-11)-specific cellular and humoral immune responses in seronegative women. The vaccine was administered by intramuscular immunizations at months 0, 2, and 6. A fourth immunization was administered to approximately half of the women at month 12. All vaccine recipients had positive HPV-11 VLP-specific lymphoproliferative responses at month 3 following the second immunization (geometric mean lymphoproliferative stimulation index [SI] = 28.4; 95% confidence interval [CI] = 16.9 to 48.0) and HPV-11 VLP-specific antibody titers following the first immunization at month 1 (geometric mean antibody titer = 53.9 milli-Merck units/ml, 95% CI, 34.8 to 83.7). In contrast, lymphoproliferative and antibody titer responses were never detected in the participants who received placebo. Relatively homogeneous lymphoproliferative responses were observed in all vaccinated women. The mean lymphoproliferative SI of the vaccinated group over the first 12 months of the study was 7.6-fold greater than that of the placebo group following the initial immunization. The cellular immune responses generated by VLP immunization were both Th1 and Th2, since peripheral blood mononuclear cells from vaccinees, but not placebo recipients, secreted interleukin 2 (IL-2), IL-5, and gamma interferon (IFN-gamma) in response to in vitro stimulation with HPV-11 VLP. The proliferation-based SI was moderately correlated with IFN-gamma production and significantly correlated with IL-2 production after the third immunization (P = 0.078 and 0.002, respectively). The robust lymphoproliferative responses were specific for HPV-11, since SIs generated against bovine papillomavirus and HPV-16 VLPs were not generally observed and when detected were similar pre- and postimmunization.
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Affiliation(s)
- Rebecca T Emeny
- Molecular Genetics and Microbiology, University of New Mexico School of Medicine, Albuquerque, New Mexico 87131-5276, USA
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Koesters S, Rutherford W, Fowke KR. Development of a novel allo-independent HIV-1 virus preparation for use in immunoassays. J Immunol Methods 2002; 264:69-76. [PMID: 12191511 DOI: 10.1016/s0022-1759(02)00085-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The study of the immunologic response to whole human immunodeficiency virus type 1 (HIV-1) antigen is limited by the presence of highly immunogenic human leukocyte antigen (HLA) alloantigens on the envelope of wild type virus. This paper outlines the production of HIV-1 infectious virions free of HLA for use as whole viral antigens in immunoassays. An infectious molecular clone of HIV-1 was transfected into the K-562 cell line, which does not express HLA on the cell surface. After a 30-day selection period, to ensure stable transfection, cells and culture supernatants were analyzed for productive HIV-1 infection and virion infectivity. An enzyme-linked immunosorbent assay (ELISA) confirmed the presence of p24 in the culture supernatants. Molecular confirmation of HIV-1 transfection was achieved by gene amplification. Flow cytometric analysis was used to identify gp120 on the surface of the infected cells. Viral supernatants were tested for HIV infectivity in peripheral blood mononuclear cells (PBMCs). The usefulness of this viral preparation as whole virus antigens was validated using PBMCs from HIV-infected individuals. These results indicate the successful production of HIV-1 infectious virions, which do not have HLA molecules on their viral envelope, and demonstrate their utility for immunoassays.
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Affiliation(s)
- Sandra Koesters
- Department of Medical Microbiology, University of Manitoba, 539-730 William Avenue, Winnipeg, MB, Canada
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Abstract
The twenty-first century has begun with considerable success for new AIDS vaccines in macaque models. A common feature of these vaccines is their ability to induce high-frequency CD8+ T-cell responses that control, rather than prevent, infection with HIV. The new vaccines, which include DNA vaccines and live viral vectors, are based on technologies that have been developed since the start of the AIDS epidemic. The ultimate promise of these vaccines will be realized only when efficacy trials in humans are conducted.
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McMichael A, Hanke T. The quest for an AIDS vaccine: is the CD8+ T-cell approach feasible? Nat Rev Immunol 2002; 2:283-91. [PMID: 12001999 DOI: 10.1038/nri779] [Citation(s) in RCA: 104] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The rationale for developing anti-HIV vaccines that stimulate cytotoxic T-lymphocyte responses is given. We argue that such vaccines will work, provided that attention is paid to the development of memory T-cell responses that are strong and preferably activated. Furthermore, the vaccine should match the prevailing virus clade as closely as possible. Vaccines will have to stimulate a wide range of responses, but it is not clear how this can be achieved.
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Affiliation(s)
- Andrew McMichael
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, Oxford, UK.
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Cheng LE, Ohlén C, Nelson BH, Greenberg PD. Enhanced signaling through the IL-2 receptor in CD8+ T cells regulated by antigen recognition results in preferential proliferation and expansion of responding CD8+ T cells rather than promotion of cell death. Proc Natl Acad Sci U S A 2002; 99:3001-6. [PMID: 11867736 PMCID: PMC122462 DOI: 10.1073/pnas.052676899] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Multiple cytokines, including IL-2, can affect T cell proliferation and survival. However, IL-2 can lead to apoptosis as well as proliferation, making unclear whether IL-2 receptor (IL-2R) signals ultimately have a predominantly positive or negative effect. To address this issue, we examined the effect of enhancing IL-2R signals in CD8(+) T cells after antigen stimulation by engineering a transgenic (Tg) mouse strain with CD8(+) T cells capable of augmented, regulated, autocrine IL-2R signaling after target recognition by means of expression of a chimeric granulocyte-macrophage colony-stimulating factor (GM-CSF)/IL-2R. The Tg CD8(+) T cells can bind the granulocyte-macrophage colony-stimulating GM-CSF produced by antigen stimulation, but the GM-CSF binding results in delivery of an IL-2R signal. After antigen stimulation in vivo, the Tg T cells demonstrated marked increases in the initial proliferative response and cell expansion and displayed continued increases in cell expansion after repeated antigen exposure. These data suggest that the predominant role of IL-2R signals delivered to responding CD8(+) T cells is to set the size of the initial response to antigen by promoting T cell proliferation and survival and not cell death.
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Affiliation(s)
- Laurence E Cheng
- Department of Immunology, University of Washington, Seattle, WA 98195, USA
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Biggar RJ, Broadhead R, Janes M, Kumwenda N, Taha TE, Cassol S. Viral levels in newborn African infants undergoing primary HIV-1 infection. AIDS 2001; 15:1311-3. [PMID: 11426078 DOI: 10.1097/00002030-200107060-00015] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
We examined weekly changes in viral levels in seven untreated infants infected with HIV at birth. Viral levels spiked immediately but reverted quickly to plateau levels typical of infant HIV infection within 2 weeks of first detected viraemia. We speculated that the depletion of naive, susceptible cells is responsible for the rapid decrease in spike levels and that the rapid replacement of lymphocytes in infants causes the high plateau viral levels (10(5) copies/ml) to be sustained.
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Affiliation(s)
- R J Biggar
- Viral Epidemiology Branch, NCI, Bethesda, Maryland, USA
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