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Stabilizing the native trimer of HIV-1 Env by destabilizing the heterodimeric interface of the gp41 postfusion six-helix bundle. J Virol 2014; 88:9590-604. [PMID: 24920800 DOI: 10.1128/jvi.00494-14] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED The HIV-1 envelope glycoprotein (Env) is a trimer of gp120-gp41 heterodimers and is essential for viral entry. The gp41 subunit in native, prefusion trimeric Env exists in a metastable conformation and attains a stable six-helix bundle (6-HB) conformation comprised of a trimer of N-heptad repeat (NHR) and C-heptad repeat (CHR) heterodimers, that drives the fusion of viral and cellular membranes. We attempted to stabilize native Env trimers by incorporation of mutations at the NHR-CHR interface that disrupt the postfusion 6-HB of gp41. The mutations V570D and I573D stabilize native Env of the HIV-1 JRFL strain and occlude nonneutralizing epitopes to a greater extent than the previously identified I559P mutation that is at the interface of the NHR trimers in the 6-HB. The mutations prevent soluble-CD4 (sCD4)-induced gp120 shedding and 6-HB formation. In the context of cell surface-expressed JRFL Env, introduction of a previously reported additional disulfide between residues A501 and T605 perturbs the native conformation, though this effect is partially alleviated by furin coexpression. The data suggest that positions 570 and 573 are surface proximal in native Env and that the NHR homotrimeric coiled coil in native Env terminates before or close to residue 573. Aspartic acid substitutions at these positions stabilize native trimers through destabilization of the postfusion 6-HB conformation. These mutations can be used to stabilize Env in a DNA vaccine format. IMPORTANCE The major protein on the surface of HIV-1 is the envelope (Env) glycoprotein. Env is a trimer of gp120-gp41 heterodimers. gp120 is involved in receptor/coreceptor binding and gp41 in the fusion of viral and cellular membranes. Like many other viral fusion proteins, the gp41 subunit in native trimeric Env exists in a metastable conformation. gp41 readily forms a stable six-helix bundle (6-HB) conformation comprised of a trimer of N-heptad repeat (NHR) and C-heptad repeat (CHR) heterodimers that drives fusion of viral and cellular membranes. While it is expected that native Env is a good immunogen, its metastability results in exposure of immunodominant nonneutralizing epitopes. In the present study, we stabilize native Env trimers by incorporation of a number of different mutations at the NHR-CHR interface that disrupt the postfusion 6-HB of gp41. The stabilized constructs described here can be incorporated into DNA vaccine candidates.
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Immunogen design for HIV-1 and influenza. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2014; 1844:1891-1906. [PMID: 24892211 DOI: 10.1016/j.bbapap.2014.05.010] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Revised: 05/23/2014] [Accepted: 05/26/2014] [Indexed: 12/12/2022]
Abstract
Vaccines provide the most cost effective defense against pathogens. Although vaccines have been designed for a number of viral diseases, a vaccine against HIV-1 still remains elusive. In contrast, while there are excellent influenza vaccines, these need to be changed every few years because of antigenic drift and shift. The recent discovery of a large number of broadly neutralizing antibodies (bNAbs) and structural characterization of the conserved epitopes targeted by them presents an opportunity for structure based HIV-1 and influenza A vaccine design. We discuss strategies to design immunogens either targeting a particular antigenic region or focusing on native structure stabilization. This article is part of a Special Issue entitled: Recent advances in molecular engineering of antibody.
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Saha P, Bhattacharyya S, Kesavardhana S, Miranda ER, Ali PSS, Sharma D, Varadarajan R. Designed Cyclic Permutants of HIV-1 gp120: Implications for Envelope Trimer Structure and Immunogen Design. Biochemistry 2012; 51:1836-47. [DOI: 10.1021/bi300003v] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Piyali Saha
- Molecular
Biophysics Unit, Indian Institute of Science, Bangalore 560 012, India
| | | | - Sannula Kesavardhana
- Molecular
Biophysics Unit, Indian Institute of Science, Bangalore 560 012, India
| | | | - P. Shaik Syed Ali
- Molecular
Biophysics Unit, Indian Institute of Science, Bangalore 560 012, India
| | - Deepak Sharma
- Molecular
Biophysics Unit, Indian Institute of Science, Bangalore 560 012, India
| | - Raghavan Varadarajan
- Molecular
Biophysics Unit, Indian Institute of Science, Bangalore 560 012, India
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Huang X, Jin W, Hu K, Luo S, Du T, Griffin GE, Shattock RJ, Hu Q. Highly conserved HIV-1 gp120 glycans proximal to CD4-binding region affect viral infectivity and neutralizing antibody induction. Virology 2012; 423:97-106. [DOI: 10.1016/j.virol.2011.11.023] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2011] [Revised: 11/15/2011] [Accepted: 11/28/2011] [Indexed: 10/14/2022]
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5
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Agwale SM, Forbi JC, Notka F, Wrin T, Wild J, Wagner R, Wolf H. Broad antibody mediated cross-neutralization and preclinical immunogenicity of new codon-optimized HIV-1 clade CRF02_AG and G primary isolates. PLoS One 2011; 6:e23233. [PMID: 21829720 PMCID: PMC3150420 DOI: 10.1371/journal.pone.0023233] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2011] [Accepted: 07/10/2011] [Indexed: 02/05/2023] Open
Abstract
Creation of an effective vaccine for HIV has been an elusive goal of the scientific community for almost 30 years. Neutralizing antibodies are assumed to be pivotal to the success of a prophylactic vaccine but previous attempts to make an immunogen capable of generating neutralizing antibodies to primary “street strain” isolates have resulted in responses of very limited breadth and potency. The objective of the study was to determine the breadth and strength of neutralizing antibodies against autologous and heterologous primary isolates in a cohort of HIV-1 infected Nigerians and to characterize envelopes from subjects with particularly broad or strong immune responses for possible use as vaccine candidates in regions predominated by HIV-1 CRF02_AG and G subtypes. Envelope vectors from a panel of primary Nigerian isolates were constructed and tested with plasma/sera from the same cohort using the PhenoSense HIV neutralizing antibody assay (Monogram Biosciences Inc, USA) to assess the breadth and potency of neutralizing antibodies. The immediate goal of this study was realized by the recognition of three broadly cross-neutralizing sera: (NG2-clade CRF02_AG, NG3-clade CRF02_AG and NG9- clade G). Based on these findings, envelope gp140 sequences from NG2 and NG9, complemented with a gag sequence (Clade G) and consensus tat (CRF02_AG and G) antigens have been codon-optimized, synthesized, cloned and evaluated in BALB/c mice. The intramuscular administration of these plasmid DNA constructs, followed by two booster DNA immunizations, induced substantial specific humoral response against all constructs and strong cellular responses against the gag and tat constructs. These preclinical findings provide a framework for the design of candidate vaccine for use in regions where the HIV-1 epidemic is driven by clades CRF02_AG and G.
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Affiliation(s)
- Simon M Agwale
- Clinical Virology Laboratory, Innovative Biotech, Keffi/Abuja, Nigeria.
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6
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Abstract
Advances in vaccine technology are occurring in the molecular techniques used to develop vaccines and in the assessment of vaccine efficacy, allowing more complete characterization of vaccine-induced immunity correlating to protection. FIV vaccine development has closely mirrored and occasionally surpassed the development of HIV-1 vaccine, leading to first licensed technology. This review will discuss technological advances in vaccine designs, challenge infection assessment, and characterization of vaccine immunity in the context of the protection detected with prototype and commercial dual-subtype FIV vaccines and in relation to HIV-1.
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Affiliation(s)
- Elizabeth W Uhl
- Department of Veterinary Pathology, College of Veterinary Medicine, University of Georgia, 501 DW Brooks Drive, Athens, GA 30602-7388, USA
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7
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Parker SD, Rottinghaus ST, Zajac AJ, Yue L, Hunter E, Whitley RJ, Parker JN. HIV-1(89.6) Gag expressed from a replication competent HSV-1 vector elicits persistent cellular immune responses in mice. Vaccine 2007; 25:6764-73. [PMID: 17706843 PMCID: PMC2084203 DOI: 10.1016/j.vaccine.2007.06.064] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2006] [Revised: 06/19/2007] [Accepted: 06/26/2007] [Indexed: 01/11/2023]
Abstract
We have constructed a replication competent, gamma(1)34.5-deleted herpes simplex virus type-1 (HSV-1) vector (J200) that expresses the gag gene from human immunodeficiency virus type-1, primary isolate 89.6 (HIV-1(89.6)), as a candidate vaccine for HIV-1. J200 replicates in vitro, resulting in abundant Gag protein production and accumulation in the extracellular media. Immunization of Balb/c mice with a single intraperitoneal injection of J200 elicited strong Gag-specific CD8 responses, as measured by intracellular IFN-gamma staining and flow cytometry analysis. Responses were highest between 6 weeks and 4 months, but persisted at 9 months post-immunization, the last time-point evaluated. These data highlight the potential utility of neuroattenuated, replication competent HSV-1 vectors for delivery of HIV-1 immunogens.
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Affiliation(s)
- Scott D. Parker
- Department of Medicine, The University of Alabama at Birmingham, Birmingham, AL 35294
| | - Scott T. Rottinghaus
- Department of Medicine, The University of Alabama at Birmingham, Birmingham, AL 35294
| | - Allan J. Zajac
- Department of Microbiology, The University of Alabama at Birmingham, Birmingham, AL 35294
| | - Ling Yue
- Emory Vaccine Center, Emory University, Atlanta, Georgia, 30329
| | - Eric Hunter
- Emory Vaccine Center, Emory University, Atlanta, Georgia, 30329
| | - Richard J. Whitley
- Department of Medicine, The University of Alabama at Birmingham, Birmingham, AL 35294
- Department of Microbiology, The University of Alabama at Birmingham, Birmingham, AL 35294
- Department of Pediatrics, The University of Alabama at Birmingham, Birmingham, AL 35294
| | - Jacqueline N. Parker
- Department of Pediatrics, The University of Alabama at Birmingham, Birmingham, AL 35294
- Corresponding author: Jacqueline N. Parker, Ph.D., Department of Pediatrics, Division of Infectious Diseases, University of Alabama at Birmingham, CHB 118B, 1600 6 Avenue South, Birmingham, AL 35233, Phone: 205-996-7881, FAX: 205-975-6549, E-mail:
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Tatsis N, Fitzgerald JC, Reyes-Sandoval A, Harris-McCoy KC, Hensley SE, Zhou D, Lin SW, Bian A, Xiang ZQ, Iparraguirre A, Lopez-Camacho C, Wherry EJ, Ertl HCJ. Adenoviral vectors persist in vivo and maintain activated CD8+ T cells: implications for their use as vaccines. Blood 2007; 110:1916-23. [PMID: 17510320 PMCID: PMC1976365 DOI: 10.1182/blood-2007-02-062117] [Citation(s) in RCA: 176] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
CD8(+) T cell-numbers rapidly expand and then contract after exposure to their cognate antigen. Here we show that the sustained frequencies of transgene product-specific CD8(+) T cells elicited by replication-defective adenovirus vectors are linked to persistence of low levels of transcriptionally active adenovirus vector genomes at the site of inoculation, in liver, and lymphatic tissues. Continuously produced small amounts of antigen maintain fully active effector CD8(+) T cells, while also allowing for their differentiation into central memory cells. The long-term persistence of adenoviral vectors may be highly advantageous for their use as vaccines against pathogens for which T-cell-mediated protection requires both fully activated T cells for immediate control of virus-infected cells and central memory CD8(+) T cells that, because of their higher proliferative capacity, may be suited best to eliminate cells infected by pathogens that escaped the initial wave of effector T cells.
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Affiliation(s)
- Nia Tatsis
- Wistar Institute, Philadelphia, PA 19104, USA
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9
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Abstract
The glycoprotein (gp) 120 subunit is an important part of the envelope spikes that decorate the surface of HIV-1 and a major target for neutralizing antibodies. However, immunization with recombinant gp120 does not elicit neutralizing antibodies against multiple HIV-1 isolates (broadly neutralizing antibodies), and gp120 failed to demonstrate vaccine efficacy in recent clinical trials. Ongoing crystallographic studies of gp120 molecules from HIV-1 and SIV increasingly reveal how conserved regions, which are the targets of broadly neutralizing antibodies, are concealed from immune recognition. Based on this structural insight and that from studies of antibody structures, a number of strategies are being pursued to design immunogens that can elicit broadly neutralizing antibodies to gp120. These include (a) the construction of mimics of the viral envelope spike and (b) the design of antigens specifically tailored to induce broadly neutralizing antibodies.
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Affiliation(s)
- Ralph Pantophlet
- Department of Immunology, The Scripps Research Institute, La Jolla, California 92037, USA.
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10
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Vandhuick O, Guias B, De Saint Martin L, Bressollette L. Traitement antirétroviral et risque cardio-vasculaire. ACTA ACUST UNITED AC 2004; 29:192-9. [PMID: 15529082 DOI: 10.1016/s0398-0499(04)96747-9] [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: 11/16/2022]
Abstract
Current antiretroviral therapy protocols enable long-term survival of HIV-infected patients, decreasing the risk of infectious complications. Three classes of anti-HIV treatments are available. With longer survival, unusual cardiovascular complications related to iatrogenic biological anomalies (dyslipidemia and impaired glucose tolerance) have appeared among this young population which is exposed to usual risk factors of atherosclerosis. Antiretroviral therapies are suspected to cause these complications, inducing maturity-onset diabetes in 4 to 20% of patients, impaired glucose tolerance in 15 to 60%, hypertriglyceridemia in 15 to 74% depending on the survey, and hypercholesterolemia in 20 to 60%, especially in case of associated lipodystrophia. A lipid battery including total cholesterol, HDL, and triglycerides, and 12-h fasting blood glucose should be obtained before initiating antiretroviral therapy. Any anomalous finding should be followed carefully with regular surveillance every 3 to 6 months and search for other causes of secondary dyslipidemia. In the event of casual and persisting elevation of LDL-cholesterol levels, a statin treatment can be introduced. For secondary prevention, irrespective of the context, recommendations currently merge with the consensus applying to the general population. These patients require careful surveillance of cardiovascular risk factors and a specific care in addition to treatment of their immunodeficiency.
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Affiliation(s)
- O Vandhuick
- Unité d'Echo-Doppler et de Médecine Vasculaire, CHU La Cavale Blanche, 29609 Brest
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11
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Abstract
Since the beginning of the AIDS epidemic in 1981, HIV-1 has demonstrated an amazing ability to mutate. HIV-1 was introduced into the human population in the early to mid twentieth century in central Africa. During ensuing decades, this extraordinary mutational capacity has resulted in the circulation of HIV-1 strains that are quite different from one another, yet still remarkably pathogenic. The potential impact of this viral diversity on treatment, monitoring,and vaccine development is discussed.
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Affiliation(s)
- Cristian Apetrei
- Tulane National Primate Research Center and Department of Tropical Medicine, Tulane University Health Sciences Center, Covington, LA 70433, USA
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12
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Sanders RW, Busser E, Moore JP, Lu M, Berkhout B. Evolutionary repair of HIV type 1 gp41 with a kink in the N-terminal helix leads to restoration of the six-helix bundle structure. AIDS Res Hum Retroviruses 2004; 20:742-9. [PMID: 15307920 DOI: 10.1089/0889222041524544] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The HIV-1 envelope glycoprotein complex (Env) can be stabilized by the introduction of a disulfide bond between the gp120 and gp41 subunits. The resulting protein is monomeric, but trimerization can be improved by the introduction of a single helix-breaking residue at the conserved Ile559 site in the N-terminal heptad repeat region of gp41. To provide more insight into how such a substitution in gp41 affects Env structure and function, we evaluated the effect on the wild-type Env in the context of replicating virus. The Ile559Gly and Ile559Pro mutations adversely affect Env biosynthesis and Env incorporation into virions. Biophysical studies show that the Ile559Pro mutation essentially disrupts the folding of a recombinant gp41 ectodomain core into a six-helix bundle structure. Viruses containing the Ile559Gly and Ile559Pro substitutions replicate poorly, but an evolutionary route is described that restores replication competence. In the escape virus, which contains a Pro559Leu first-site pseudoreversion, the local helical structure and, as a consequence, Env biosynthesis and function are restored.
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Affiliation(s)
- Rogier W Sanders
- Department of Human Retrovirology, Academic Medical Center, University of Amsterdam, 1100 DE Amsterdam, the Netherlands
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13
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Das AT, Verhoef K, Berkhout B. A Conditionally Replicating Virus as a Novel Approach Toward an HIV Vaccine. Methods Enzymol 2004; 388:359-79. [PMID: 15289083 DOI: 10.1016/s0076-6879(04)88028-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- Atze T Das
- Department of Human Retrovirology, Academic Medical Center, Amsterdam, The Netherlands
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14
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Buge SL, Ma HL, Amara RR, Wyatt LS, Earl PL, Villinger F, Montefiori DC, Staprans SI, Xu Y, Carter E, O'Neil SP, Herndon JG, Hill E, Moss B, Robinson HL, McNicholl JM. Gp120-alum boosting of a Gag-Pol-Env DNA/MVA AIDS vaccine: poorer control of a pathogenic viral challenge. AIDS Res Hum Retroviruses 2003; 19:891-900. [PMID: 14585221 DOI: 10.1089/088922203322493067] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Envelope protein immunogens may improve DNA or live-vectored HIV vaccines by complementing antiviral cellular responses with Env antibodies. We tested this concept by administering two immunizations of alum-adjuvanted HIV-1 89.6 gp120 to macaques being primed at weeks 0 and 8 with SHIV 89.6 Gag-Pol-Env DNA and boosted at week 24 with SHIV-89.6 Gag-Pol-Env recombinant modified vaccinia Ankara (MVA). Three hundred micrograms of gp120 was delivered with the second DNA prime and the MVA booster. Eight months after vaccination, all animals were challenged intrarectally with the related, yet serologically distinct, SHIV-89.6P. The gp120 immunizations raised binding, but not neutralizing antibody for the challenge virus, and allowed testing of whether gp120 vaccines that fail to raise neutralizing antibody can improve protection. Following the second gp120 immunization, the plus-gp120 group showed >10 times higher levels of binding antibody than the minus-gp120 group. These levels fell and were overall similar in both groups at the time of challenge. Following the second challenge, both groups had similar temporal patterns and heights of binding and neutralizing antibodies. However, the plus-gp120 group had less consistent control of viremia and higher levels of plasma viral RNA for the first year postchallenge. Assays for complement-dependent enhancing antibody revealed a trend toward higher levels of activity in the plus-gp120 group. This trend did not reach significance in our animal groups of 8. We conclude that gp120 inoculations that fail to raise neutralizing antibody do not improve the efficacy of Gag-Pol-Env DNA/MVA vaccines.
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Affiliation(s)
- Suzan L Buge
- Center for Infectious Diseases, Centers for Disease Control and Prevention, 1600 Clifton Road NE, Atlanta, GA 30333, USA
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15
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Zhan X, Slobod KS, Surman S, Brown SA, Lockey TD, Coleclough C, Doherty PC, Hurwitz JL. Limited breadth of a T-helper cell response to a human immunodeficiency virus envelope protein. J Virol 2003; 77:4231-6. [PMID: 12634380 PMCID: PMC150625 DOI: 10.1128/jvi.77.7.4231-4236.2003] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Single-envelope human immunodeficiency virus (HIV) vaccines have been studied for more than a decade, with some successes in homologous challenge experiments in nonhuman primates but with no clear successes in clinical trials. To gain insight into the breadth of the immunity elicited by such vaccines, we have dissected the T-helper cell response of C57BL/6 mice to an individual, molecularly cloned envelope protein. Here, we report that T-helper cells responsive to HIV type 1 1035 envelope are very highly restricted in C57BL/6 animals: seven different hybridomas recovered from five separate mice recognized the same peptide, PKVSFEPIPIHYCAP, located in the C2 region of gp120. Three of these hybridomas were tested on a natural variant of the peptide but failed to respond. A more extensive analysis of whole splenic populations from other C57BL/6 mice immunized with the 1035 envelope reproducibly confirmed that the gp120-specific T-helper response was almost exclusively focused on a single epitope. We conclude that single-envelope vaccines may frequently fail to provoke an immune response sufficiently diverse to recognize variant sequences among circulating HIV. The results encourage the inclusion of more than one envelope in future vaccines to enhance the potential diversity and respective surveillance capacities of responding T-helper cell populations.
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Affiliation(s)
- X Zhan
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38105-2794, USA
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16
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Hu DJ, Vitek CR, Bartholow B, Mastro TD. Key issues for a potential human immunodeficiency virus vaccine. Clin Infect Dis 2003; 36:638-44. [PMID: 12594646 DOI: 10.1086/367891] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2002] [Revised: 11/18/2002] [Indexed: 11/04/2022] Open
Abstract
A safe, effective, and affordable vaccine remains the best long-term hope for bringing the global human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) epidemic under control. Recent scientific developments have suggested that the first generation of HIV vaccines available for public health care use will likely be of low to moderate efficacy, compared with currently licensed vaccines for other diseases. Nevertheless, such "partially effective" HIV vaccines could provide considerable individual and public health benefits. A consultation was held in January 2002 to advise the Centers for Disease Control and Prevention (Atlanta, Georgia) about critical issues that need to be addressed in anticipation of the eventual licensure and availability of an HIV vaccine in the United States. The present article summarizes the major issues discussed at the consultation with regard to the potential use of a partially effective vaccine in HIV prevention programs in the United States and the activities that are needed to prepare for vaccine availability.
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Affiliation(s)
- Dale J Hu
- HIV Vaccine Section, Epidemiology Branch, Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA.
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17
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Thomson MM, Pérez-Alvarez L, Nájera R. Molecular epidemiology of HIV-1 genetic forms and its significance for vaccine development and therapy. THE LANCET. INFECTIOUS DISEASES 2002; 2:461-71. [PMID: 12150845 DOI: 10.1016/s1473-3099(02)00343-2] [Citation(s) in RCA: 144] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Since their initial expansion in human beings roughly seven decades ago in central Africa, the HIV-1 pandemic strains have diversified extensively through mutation and recombination. 24 circulating genetic forms of the main HIV-1 group are presently recognised, including 11 subtypes or sub-subtypes and 13 circulating recombinant forms. New genetic forms are being introduced in different areas of the world, changing the molecular epidemiology of the infection. It is generally agreed that the control of the HIV-1 pandemic requires the development of vaccines that efficiently protect against the range of HIV-1 genetic forms. The introduction of effective antiretroviral therapies in areas of high HIV-1 prevalence may also contribute to the control of the pandemic, as has been documented in developed countries. Efficient targeting of the extensive genetic diversity of HIV-1 constitutes one of the major challenges in present efforts against the pandemic, although the significance of HIV-1 genetic forms for vaccine development and therapy remains to be defined.
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Affiliation(s)
- Michael M Thomson
- Department of Viral Pathogenesis, Centro Nacional de Microbiologia, Instituto de Salud Carlos III, Ctra Majadahonda-Pozuelo, 28220, Madrid, Majadahonda, Spain
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18
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Warren J. Preclinical AIDS vaccine research: survey of SIV, SHIV, and HIV challenge studies in vaccinated nonhuman primates. J Med Primatol 2002; 31:237-56. [PMID: 12390546 DOI: 10.1034/j.1600-0684.2002.02010.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
This current supplementary and systematic survey of 237 preclinical AIDS vaccine challenge/protection studies in nonhuman primates enumerates and broadly describes the recent status of different vaccine strategies in macaque and chimpanzee experimental models. Published studies since the previous survey were compiled and categorized by their vaccine types, challenge parameters, and challenge results. These models have supportively verified that some prophylactic vaccine approaches, though rarely preventing infection (which is observed in these models with some passively administered antibody-based vaccines), can control to some degree primate lentivirus replication and disease development, and this is encouraging because it places more potentially effective immunogens on the precipice for early clinical studies. Many of these promising approaches may benefit from more testing in mucosal challenge models, and resources will be needed to follow more of these partially protected vaccinees for longer periods.
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Affiliation(s)
- Jon Warren
- Division of AIDS, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892-7628, USA.
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19
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Abstract
Increased support from the global HIV/AIDS community is driving advances in HIV treatment and vaccine development in the developing world. Care of patients with AIDS includes many biomedical, nutritional, psychosocial, and behavioural interventions. In resource-poor settings, antiretroviral drugs should be given with use of standardised treatment regimens and streamlined algorithms for monitoring use. A safe and effective HIV vaccine will supplement prevention efforts to protect uninfected people against infection, or might possibly be able to modify the course of HIV infection. Advances have been made in understanding the immune response and immunisation to HIV, and new ideas for candidate vaccines have been developed, including several based on HIV-1 strains prevalent in Africa. HIV vaccine efficacy trials are needed in Africa to determine whether these advances can be translated into clinical and public health benefits. In this review, we discuss the prospects for use of treatment and vaccines in resource-poor settings.
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Affiliation(s)
- Paul J Weidle
- Division of HIV/AIDS Prevention, National Center for HIV, STD, and TB Prevention, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA.
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20
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Gaschen B, Taylor J, Yusim K, Foley B, Gao F, Lang D, Novitsky V, Haynes B, Hahn BH, Bhattacharya T, Korber B. Diversity considerations in HIV-1 vaccine selection. Science 2002; 296:2354-60. [PMID: 12089434 DOI: 10.1126/science.1070441] [Citation(s) in RCA: 606] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Globally, human immunodeficiency virus-type 1 (HIV-1) is extraordinarily variable, and this diversity poses a major obstacle to AIDS vaccine development. Currently, candidate vaccines are derived from isolates, with the hope that they will be sufficiently cross-reactive to protect against circulating viruses. This may be overly optimistic, however, given that HIV-1 envelope proteins can differ in more than 30% of their amino acids. To contend with the diversity, country-specific vaccines are being considered, but evolutionary relationships may be more useful than regional considerations. Consensus or ancestor sequences could be used in vaccine design to minimize the genetic differences between vaccine strains and contemporary isolates, effectively reducing the extent of diversity by half.
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Affiliation(s)
- Brian Gaschen
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA
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Abstract
In this review, we address recent advances in the understanding of the pathogenesis of human immunodeficiency type 1 virus infection, which have provided the rationale for present trials of therapeutic vaccines. We shall relate this work to lessons of the past few years both in the use of highly active antiretroviral therapy to attempt eradication of the HIV virus, and in the study of treatment interruptions.
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Affiliation(s)
- S Kinloch-de Loes
- Department of HIV/Thoracic Medicine, Department of Medicine, The Royal Free Centre for HIV Medicine, Royal Free Campus, Royal Free and University College Medical School, London, NW3 2PF, UK.
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