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Williams WB, Wiehe K, Saunders KO, Haynes BF. Strategies for induction of HIV-1 envelope-reactive broadly neutralizing antibodies. J Int AIDS Soc 2021; 24 Suppl 7:e25831. [PMID: 34806332 PMCID: PMC8606870 DOI: 10.1002/jia2.25831] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Accepted: 09/23/2021] [Indexed: 12/30/2022] Open
Abstract
INTRODUCTION A primary focus of HIV-1 vaccine development is the activation of B cell receptors for naïve or precursor broadly neutralizing antibodies (bnAbs), followed by expansion and maturation of bnAb B cell lineage intermediates leading to highly affinity-matured bnAbs. HIV-1 envelope (Env) encodes epitopes for bnAbs of different specificities. Design of immunogens to induce bnAb precursors of different specificities and mature them into bnAb status is a goal for HIV-1 vaccine development. We review vaccine strategies for bnAb lineages development and highlight the immunological barriers that these strategies must overcome to generate bnAbs. METHODS We provide perspectives based on published research articles and reviews. DISCUSSION The recent Antibody Mediated Protection (AMP) trial that tested the protective efficacy of one HIV-1 Env bnAb specificity demonstrated that relatively high levels of long-lasting serum titers of multiple specificities of bnAbs will be required for protection from HIV-1 transmission. Current vaccine efforts for induction of bnAb lineages are focused on immunogens designed to expand naïve HIV-1 bnAb precursor B cells following the recent success of vaccine-induction of bnAb precursor B cells in macaques and humans. BnAb precursor B cells serve as templates for priming-immunogen design. However, design of boosting immunogens for bnAb maturation requires knowledge of the optimal immunogen design and immunological environment for bnAb B cell lineage affinity maturation. BnAb lineages acquire rare genetic changes as mutations during B cell maturation. Moreover, the immunological environment that supports bnAb development during HIV-1 infection is perturbed with an altered B cell repertoire and dysfunctional immunoregulatory controls, suggesting that in normal settings, bnAb development will be disfavoured. Thus, strategies for vaccine induction of bnAbs must circumvent immunological barriers for bnAb development that normally constrain bnAb B cell affinity maturation. CONCLUSIONS A fully protective HIV-1 vaccine needs to induce durable high titers of bnAbs that can be generated by a sequential set of Env immunogens for expansion and maturation of bnAb B cell lineages in a permitted immunological environment. Moreover, multiple specificities of bnAbs will be required to be sufficiently broad to prevent the escape of HIV-1 strains during transmission.
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Affiliation(s)
- Wilton B. Williams
- Human Vaccine InstituteDuke University School of MedicineDurhamNorth CarolinaUSA
- Department of SurgeryDuke University School of MedicineDurhamNorth CarolinaUSA
| | - Kevin Wiehe
- Human Vaccine InstituteDuke University School of MedicineDurhamNorth CarolinaUSA
- Department of MedicineDuke University School of MedicineDurhamNorth CarolinaUSA
| | - Kevin O. Saunders
- Human Vaccine InstituteDuke University School of MedicineDurhamNorth CarolinaUSA
- Department of SurgeryDuke University School of MedicineDurhamNorth CarolinaUSA
- Department of ImmunologyDuke University School of MedicineDurhamNorth CarolinaUSA
| | - Barton F. Haynes
- Human Vaccine InstituteDuke University School of MedicineDurhamNorth CarolinaUSA
- Department of MedicineDuke University School of MedicineDurhamNorth CarolinaUSA
- Department of ImmunologyDuke University School of MedicineDurhamNorth CarolinaUSA
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Requirements for Empirical Immunogenicity Trials, Rather than Structure-Based Design, for Developing an Effective HIV Vaccine. HIV/AIDS: IMMUNOCHEMISTRY, REDUCTIONISM AND VACCINE DESIGN 2019. [PMCID: PMC7122000 DOI: 10.1007/978-3-030-32459-9_14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
The claim that it is possible to rationally design a structure-based HIV-1 vaccine is based on misconceptions regarding the nature of protein epitopes and of immunological specificity. Attempts to use reverse vaccinology to generate an HIV-1 vaccine on the basis of the structure of viral epitopes bound to monoclonal neutralizing antibodies have failed so far because it was not possible to extrapolate from an observed antigenic structure to the immunogenic structure required in a vaccine. Vaccine immunogenicity depends on numerous extrinsic factors such as the host immunoglobulin gene repertoire, the presence of various cellular and regulatory mechanisms in the immunized host and the process of antibody affinity maturation. All these factors played a role in the appearance of the neutralizing antibody used to select the epitope to be investigated as potential vaccine immunogen, but they cannot be expected to be present in identical form in the host to be vaccinated. It is possible to rationally design and optimize an epitope to fit one particular antibody molecule or to improve the paratope binding efficacy of a monoclonal antibody intended for passive immunotherapy. What is not possible is to rationally design an HIV-1 vaccine immunogen that will elicit a protective polyclonal antibody response of predetermined efficacy. An effective vaccine immunogen can only be discovered by investigating experimentally the immunogenicity of a candidate molecule and demonstrating its ability to induce a protective immune response. It cannot be discovered by determining which epitopes of an engineered antigen molecule are recognized by a neutralizing monoclonal antibody. This means that empirical immunogenicity trials rather than structural analyses of antigens offer the best hope of discovering an HIV-1 vaccine.
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Induction of Heterologous Tier 2 HIV-1-Neutralizing and Cross-Reactive V1/V2-Specific Antibodies in Rabbits by Prime-Boost Immunization. J Virol 2016; 90:8644-60. [PMID: 27440894 DOI: 10.1128/jvi.00853-16] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Accepted: 07/13/2016] [Indexed: 12/29/2022] Open
Abstract
UNLABELLED Poxvirus prime-protein boost used in the RV144 trial remains the only immunization strategy shown to elicit a modest level of protection against HIV-1 acquisition in humans. Although neutralizing antibodies (NAb) were generated, they were against sensitive viruses, not the more resistant "tier 2" isolates that dominate circulating strains. Instead, risk reduction correlated with antibodies recognizing epitopes in the V1/V2 region of HIV-1 envelope glycoprotein (Env). Here, we examined whether tier 2 virus NAb and V1/V2-specific non-NAb could be elicited by a poxvirus prime-gp120 boost strategy in a rabbit model. We studied two clade B Envs that differ in multiple parameters, including tissue origin, neutralization sensitivity, and presence of the N197 (N7) glycan that was previously shown to modulate the exposure of conserved epitopes on Env. We demonstrate that immunized rabbits generated cross-reactive neutralizing activities against >50% of the tier 2 global HIV-1 isolates tested. Some of these activities were directed against the CD4 binding site (CD4bs). These rabbits also generated antibodies that recognized protein scaffolds bearing V1/V2 sequences from diverse HIV-1 isolates and mediated antibody-dependent cellular cytotoxicity. However, there are subtle differences in the specificities and the response rates of V1/V2-specific antibodies between animals immunized with different Envs, with or without the N7 glycan. These findings demonstrate that antibody responses that have been correlated with protection against HIV-1 acquisition in humans can be elicited in a preclinical model by a poxvirus prime-gp120 boost strategy and that improvements may be achievable by optimizing the nature of the priming and boosting immunogens. IMPORTANCE The only vaccine approach shown to elicit any protective efficacy against HIV-1 acquisition is based on a poxvirus prime-protein boost regimen (RV144 Thai trial). Reduction of risk was associated with nonneutralizing antibodies targeting the V1/V2 loops of the envelope protein gp120. However, the modest efficacy (31.2%) achieved in this trial highlights the need to examine approaches and factors that may improve vaccine-induced responses, including cross-reactive neutralizing activities. We show here that rabbits immunized with a novel recombinant vaccinia virus prime-gp120 protein boost regimen generated antibodies that recognize protein scaffolds bearing V1/V2 sequences from diverse HIV-1 isolates and mediated antibody-dependent cellular cytotoxicity. Importantly, immunized rabbits also showed neutralizing activities against heterologous tier 2 HIV-1 isolates. These findings may inform the design of prime-boost immunization approaches and help improve the protective efficacy of candidate HIV-1 vaccines.
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Shi Y, Feng Y, Ding X, Chen J, Xu J, Wan Y. Short Communication: The Distribution of Potential N-Linked Glycosylation Sites in Gp120 Differs Among Major HIV-1 Subtypes Circulating in China. AIDS Res Hum Retroviruses 2016; 32:101-8. [PMID: 26384088 DOI: 10.1089/aid.2015.0193] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
CRF01_AE shows an obvious sexual transmission advantage over other major HIV-1 subtypes circulating in China. Previous studies showed that the presence or absence of potential N-linked glycosylation sites (PNGSs) in variable loops might affect HIV-1 transmission; it is therefore of interest to compare the distribution of potential PNGSs on envelopes of different subtypes circulating in China. Compared to CRF07_BC, CRF08_BC, B, and B' subtypes isolated in China, CRF01_AE subtypes isolated from both China and outside China had significantly fewer PNGSs in total and in V2/V4, while they had significantly more PNGSs in V5. HIV-1 subtype CRF01_AE has a unique PNGS distribution pattern in Gp120, which may contribute to its advantage in sexual transmission in China.
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Affiliation(s)
- Yin Shi
- Shanghai Public Health Clinical Center, Fudan University, Shanghai, China
- Wenzhou Medical University, Wenzhou, China
| | - Yanmeng Feng
- Hubei Provincial Center for Disease Control and Prevention, Wuhan, China
| | - Xiangqing Ding
- Shanghai Public Health Clinical Center, Fudan University, Shanghai, China
| | - Jian Chen
- Shanghai Public Health Clinical Center, Fudan University, Shanghai, China
- Wenzhou Medical University, Wenzhou, China
| | - Jianqing Xu
- Shanghai Public Health Clinical Center, Fudan University, Shanghai, China
- Wenzhou Medical University, Wenzhou, China
| | - Yanmin Wan
- Shanghai Public Health Clinical Center, Fudan University, Shanghai, China
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5
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Qin Y, Shi H, Banerjee S, Agrawal A, Banasik M, Cho MW. Detailed characterization of antibody responses against HIV-1 group M consensus gp120 in rabbits. Retrovirology 2014; 11:125. [PMID: 25527085 PMCID: PMC4300834 DOI: 10.1186/s12977-014-0125-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Accepted: 12/04/2014] [Indexed: 11/10/2022] Open
Abstract
Background We recently reported induction of broadly neutralizing antibodies (bnAbs) against multiple HIV-1 (human immunodeficiency virus type 1) isolates in rabbits, albeit weak against tier 2 viruses, using a monomeric gp120 derived from an M group consensus sequence (MCON6). To better understand the nature of the neutralizing activity, detailed characterization of immunological properties of the protein was performed. Immunogenic linear epitopes were identified during the course of immunization, and spatial distribution of these epitopes was determined. Subdomain antibody target analyses were done using the gp120 outer domain (gp120-OD) and eOD-GT6, a protein based on a heterologous sequence. In addition, refined epitope mapping analyses were done by competition assays using several nAbs with known epitopes. Results Based on linear epitope mapping analyses, the V3 loop was most immunogenic, followed by C1 and C5 regions. The V1/V2 loop was surprisingly non-immunogenic. Many immunogenic epitopes were clustered together even when they were distantly separated in primary sequence, suggesting the presence of immunogenic hotspots on the protein surface. Although substantial antibody responses were directed against the outer domain, only about 0.1% of the antibodies bound eOD-GT6. Albeit weak, antibodies against peptides that corresponded to a part of the bnAb VRC01 binding site were detected. Although gp120-induced antibodies could not block VRC01 binding to eOD-GT6, they were able to inhibit VRC01 binding to both gp120 and trimeric BG505 SOSIP gp140. The immune sera also efficiently competed with CD4-IgG2, as well as nAbs 447-52D, PGT121 and PGT126, in binding to gp120. Conclusions The results suggest that some antibodies that bind at or near known bnAb epitopes could be partly responsible for the breadth of neutralizing activity induced by gp120 in our study. Immunization strategies that enhance induction of these antibodies relative to others (e.g. V3 loop), and increase their affinity, could improve protective efficacy of an HIV-1 vaccine.
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Affiliation(s)
- Yali Qin
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, 1600 S 16th Street, Ames, IA, 50011-1250, USA. .,Center for Advanced Host Defenses, Immunobiotics and Translational Comparative Medicine, Iowa State University, Ames, IA, 50011, USA.
| | - Heliang Shi
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, 1600 S 16th Street, Ames, IA, 50011-1250, USA. .,Center for Advanced Host Defenses, Immunobiotics and Translational Comparative Medicine, Iowa State University, Ames, IA, 50011, USA.
| | - Saikat Banerjee
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, 1600 S 16th Street, Ames, IA, 50011-1250, USA. .,Center for Advanced Host Defenses, Immunobiotics and Translational Comparative Medicine, Iowa State University, Ames, IA, 50011, USA.
| | - Aditi Agrawal
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, 1600 S 16th Street, Ames, IA, 50011-1250, USA. .,Center for Advanced Host Defenses, Immunobiotics and Translational Comparative Medicine, Iowa State University, Ames, IA, 50011, USA.
| | - Marisa Banasik
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, 1600 S 16th Street, Ames, IA, 50011-1250, USA. .,Center for Advanced Host Defenses, Immunobiotics and Translational Comparative Medicine, Iowa State University, Ames, IA, 50011, USA.
| | - Michael W Cho
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, 1600 S 16th Street, Ames, IA, 50011-1250, USA. .,Center for Advanced Host Defenses, Immunobiotics and Translational Comparative Medicine, Iowa State University, Ames, IA, 50011, USA.
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Moscoso CG, Xing L, Hui J, Hu J, Kalkhoran MB, Yenigun OM, Sun Y, Paavolainen L, Martin L, Vahlne A, Zambonelli C, Barnett SW, Srivastava IK, Cheng RH. Trimeric HIV Env provides epitope occlusion mediated by hypervariable loops. Sci Rep 2014; 4:7025. [PMID: 25395053 PMCID: PMC4231788 DOI: 10.1038/srep07025] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Accepted: 08/26/2014] [Indexed: 12/17/2022] Open
Abstract
Hypervariable loops of HIV-1 Env protein gp120 are speculated to play roles in the conformational transition of Env to the receptor binding-induced metastable state. Structural analysis of full-length Env-based immunogens, containing the entire V2 loop, displayed tighter association between gp120 subunits, resulting in a smaller trimeric diameter than constructs lacking V2. A prominent basal quaternary location of V2 and V3′ that challenges previous reports would facilitate gp41-independent gp120-gp120 interactions and suggests a quaternary mechanism of epitope occlusion facilitated by hypervariable loops. Deletion of V2 resulted in dramatic exposure of basal, membrane-proximal gp41 epitopes, consistent with its predicted basal location. The structural features of HIV-1 Env characterized here provide grounds for a paradigm shift in loop exposure and epitope occlusion, while providing substantive rationale for epitope display required for elicitation of broadly neutralizing antibodies, as well as substantiating previous pertinent literature disregarded in recent reports.
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Affiliation(s)
- Carlos G Moscoso
- Department of Molecular and Cellular Biology, University of California, Davis, CA 95616
| | - Li Xing
- Department of Molecular and Cellular Biology, University of California, Davis, CA 95616
| | - Jinwen Hui
- Department of Molecular and Cellular Biology, University of California, Davis, CA 95616
| | - Jeffrey Hu
- Department of Molecular and Cellular Biology, University of California, Davis, CA 95616
| | | | - Onur M Yenigun
- Department of Molecular and Cellular Biology, University of California, Davis, CA 95616
| | - Yide Sun
- Novartis Vaccines and Diagnostics Inc., 45 Sydney Street, Cambridge, MA 02139
| | - Lassi Paavolainen
- Department of Biological and Environmental Science/Nanoscience Center, University of Jyväskylä, FI-40351 Jyväskylä, Finland
| | - Loïc Martin
- Commissariat à l'énergie atomique et aux énergies alternatives, Institut de Biologie et Technologies de Saclay, Service d'Ingénierie Moléculaire des Protéines, Gif-sur-Yvette F-91191, France
| | - Anders Vahlne
- Karolinska Institutet, Structural Virology, Clinical Microbiology/University Hospital, 171 77 Stockholm, Sweden
| | - Carlo Zambonelli
- Novartis Vaccines and Diagnostics Inc., 45 Sydney Street, Cambridge, MA 02139
| | - Susan W Barnett
- Novartis Vaccines and Diagnostics Inc., 45 Sydney Street, Cambridge, MA 02139
| | | | - R Holland Cheng
- 1] Department of Molecular and Cellular Biology, University of California, Davis, CA 95616 [2] Karolinska Institutet, Structural Virology, Clinical Microbiology/University Hospital, 171 77 Stockholm, Sweden
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Engineering, expression, purification, and characterization of stable clade A/B recombinant soluble heterotrimeric gp140 proteins. J Virol 2011; 86:128-42. [PMID: 22031951 DOI: 10.1128/jvi.06363-11] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The envelope glycoprotein (Env) of human immunodeficiency virus type 1 (HIV-1) is composed of two noncovalently associated subunits: an extracellular subunit (gp120) and a transmembrane subunit (gp41). The functional unit of Env on the surface of infectious virions is a trimer of gp120/gp41 heterodimers. Env is the target of anti-HIV neutralizing antibodies. A considerable effort has been invested in the engineering of recombinant soluble forms of the virion-associated Env trimer as vaccine candidates to elicit anti-HIV neutralizing antibody responses. These soluble constructs contain three gp120 subunits and the extracellular segments of the corresponding gp41 subunits. The individual gp120/gp41 protomers on these soluble trimers are identical in amino acid sequence (homotrimers). Here, we engineered novel soluble trimeric gp140 proteins that are formed by the association of gp140 protomers that differ in amino acid sequence and glycosylation patterns (heterotrimers). Specifically, we engineered soluble heterotrimeric proteins composed of clade A and clade B Env protomers. The clade A gp140 protomers were derived from viruses isolated during acute infection (Q168a2, Q259d2.17, and Q461e2), whereas the clade B gp140 protomers were derived from a virus isolated during chronic infection (SF162). The amino acid sequence divergence between the clade A and the clade B Envs is approximately 24%. Neutralization epitopes in the CD4 binding sites and coreceptor binding sites, as well as the membrane-proximal external region (MPER), were differentially expressed on the heterotrimeric and homotrimeric proteins. The heterotrimeric gp140s elicited broader anti-tier 1 isolate neutralizing antibody responses than did the homotrimeric gp140s.
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Van Regenmortel MHV. Requirements for empirical immunogenicity trials, rather than structure-based design, for developing an effective HIV vaccine. Arch Virol 2011; 157:1-20. [PMID: 22012269 PMCID: PMC7087187 DOI: 10.1007/s00705-011-1145-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2011] [Accepted: 10/07/2011] [Indexed: 11/29/2022]
Abstract
The claim that it is possible to rationally design a structure-based HIV-1 vaccine is based on misconceptions regarding the nature of protein epitopes and of immunological specificity. Attempts to use reverse vaccinology to generate an HIV-1 vaccine on the basis of the structure of viral epitopes bound to monoclonal neutralizing antibodies have failed so far because it was not possible to extrapolate from an observed antigenic structure to the immunogenic structure required in a vaccine. Vaccine immunogenicity depends on numerous extrinsic factors such as the host immunoglobulin gene repertoire, the presence of various cellular and regulatory mechanisms in the immunized host and the process of antibody affinity maturation. All these factors played a role in the appearance of the neutralizing antibody used to select the epitope to be investigated as potential vaccine immunogen, but they cannot be expected to be present in identical form in the host to be vaccinated. It is possible to rationally design and optimize an epitope to fit one particular antibody molecule or to improve the paratope binding efficacy of a monoclonal antibody intended for passive immunotherapy. What is not possible is to rationally design an HIV-1 vaccine immunogen that will elicit a protective polyclonal antibody response of predetermined efficacy. An effective vaccine immunogen can only be discovered by investigating experimentally the immunogenicity of a candidate molecule and demonstrating its ability to induce a protective immune response. It cannot be discovered by determining which epitopes of an engineered antigen molecule are recognized by a neutralizing monoclonal antibody. This means that empirical immunogenicity trials rather than structural analyses of antigens offer the best hope of discovering an HIV-1 vaccine.
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Affiliation(s)
- Marc H V Van Regenmortel
- Stellenbosch Institute of Advanced Study, Wallenberg Research Center at Stellenbosch University, Stellenbosch 7600, South Africa.
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Evolutionary and structural features of the C2, V3 and C3 envelope regions underlying the differences in HIV-1 and HIV-2 biology and infection. PLoS One 2011; 6:e14548. [PMID: 21283793 PMCID: PMC3024314 DOI: 10.1371/journal.pone.0014548] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2010] [Accepted: 12/10/2010] [Indexed: 11/21/2022] Open
Abstract
Background Unlike in HIV-1 infection, the majority of HIV-2 patients produce broadly reactive neutralizing antibodies, control viral replication and survive as elite controllers. The identification of the molecular, structural and evolutionary footprints underlying these very distinct immunological and clinical outcomes may lead to the development of new strategies for the prevention and treatment of HIV infection. Methodology/Principal Findings We performed a side-by-side molecular, evolutionary and structural comparison of the C2, V3 and C3 envelope regions from HIV-1 and HIV-2. These regions contain major antigenic targets and are important for receptor binding. In HIV-2, these regions also have immune modulatory properties. We found that these regions are significantly more variable in HIV-1 than in HIV-2. Within each virus, C3 is the most entropic region followed by either C2 (HIV-2) or V3 (HIV-1). The C3 region is well exposed in the HIV-2 envelope and is under strong diversifying selection suggesting that, like in HIV-1, it may harbour neutralizing epitopes. Notably, however, extreme diversification of C2 and C3 seems to be deleterious for HIV-2 and prevent its transmission. Computer modelling simulations showed that in HIV-2 the V3 loop is much less exposed than C2 and C3 and has a retractile conformation due to a physical interaction with both C2 and C3. The concealed and conserved nature of V3 in the HIV-2 is consistent with its lack of immunodominancy in vivo and with its role in preventing immune activation. In contrast, HIV-1 had an extended and accessible V3 loop that is consistent with its immunodominant and neutralizing nature. Conclusions/Significance We identify significant structural and functional constrains to the diversification and evolution of C2, V3 and C3 in the HIV-2 envelope but not in HIV-1. These studies highlight fundamental differences in the biology and infection of HIV-1 and HIV-2 and in their mode of interaction with the human immune system and may inform new vaccine and therapeutic interventions against these viruses.
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Khrustalev VV. Levels of HIV1 gp120 3D B-cell epitopes mutability and variability: searching for possible vaccine epitopes. Immunol Invest 2010; 39:551-69. [PMID: 20653424 DOI: 10.3109/08820131003706313] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
We used a DiscoTope 1.2 (http://www.cbs.dtu.dk/services/DiscoTope/), Epitopia (http://epitopia.tau.ac.il/) and EPCES (http://www.t38.physik.tu-muenchen.de/programs.htm) algorithms to map discontinuous B-cell epitopes in HIV1 gp120. The most mutable nucleotides in HIV genes are guanine (because of G to A hypermutagenesis) and cytosine (because of C to U and C to A mutations). The higher is the level of guanine and cytosine usage in third (neutral) codon positions and the lower is their level in first and second codon positions of the coding region, the more stable should be an epitope encoded by this region. We compared guanine and cytosine usage in regions coding for five predicted 3D B-cell epitopes of gp120. To make this comparison we used GenBank resource: 385 sequences of env gene obtained from ten HIV1-infected individuals were studied (http://www.barkovsky.hotmail.ru/Data/Seqgp120.htm). The most protected from nonsynonymous nucleotide mutations of guanine and cytosine 3D B-cell epitope is situated in the first conserved region of gp120 (it is mapped from 66th to 86th amino acid residue). We applied a test of variability to confirm this finding. Indeed, the less mutable predicted B-cell epitope is the less variable one. MEGA4 (standard PAM matrix) was used for the alignments and "VVK Consensus" algorithm (http://www.barkovsky.hotmail.ru) was used for the calculations.
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11
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Zhang C, Wan Y, Shi J, Zhou M, Meng Z, Yuan S, Qiu C, Zhang X, Xu X, Liu C, Xu J. Deglycosylation of HIV-1 AE Gp140 enhances the capacity to elicit neutralizing antibodies against the heterologous HIV-1 clade. AIDS Res Hum Retroviruses 2010; 26:569-75. [PMID: 20455767 DOI: 10.1089/aid.2009.0228] [Citation(s) in RCA: 4] [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 aim of this study was to test whether deglycosylation of an HIV-1 AE recombinant-derived gp140 could enhance the induction of neutralizing antibodies. N-to-Q mutations were introduced in the V1/V2 (m157/161) or V4 (m382/388) loops by using overlapping PCR. BALB/c mice were inoculated with different DNA vaccines at weeks 0, 2, 4, and 7. The Elispot assay was used to quantify Env-specific T-cell immunity, and the TZM-bl cell-based in vitro neutralizing assay with primary isolates was used to assess humoral immune responses. Our data showed that two mutant DNA vaccines, designated m157/161 and m382/388, mounted total T-cell responses that were at levels similar those of the unmutated vaccine. Although the levels of binding antibodies elicited by the two mutants were significantly lower than the levels elicited by the unmutated vaccine, cross-reactive neutralizing antibodies were observed only in the sera that received the mutant DNA vaccines. These data demonstrate that deglycosylation of HIV-1 Env could enhance the capacity to elicit cross-reactive neutralizing antibodies.
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Affiliation(s)
- Congyou Zhang
- Shanghai Public Health Clinical Center, Institutes of Biomedical Sciences, Fudan University, Shanghai, China
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12
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Chen W, Zhu Z, Liao H, Quinnan GV, Broder CC, Haynes BF, Dimitrov DS. Cross-Reactive Human IgM-Derived Monoclonal Antibodies that Bind to HIV-1 Envelope Glycoproteins. Viruses 2010; 2:547-565. [PMID: 21755021 PMCID: PMC3133461 DOI: 10.3390/v2020547] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Elicitation of antibodies with potent and broad neutralizing activity against HIV by immunization remains a challenge. Several monoclonal antibodies (mAbs) isolated from humans with HIV-1 infection exhibit such activity but vaccine immunogens based on structures containing their epitopes have not been successful for their elicitation. All known broadly neutralizing mAbs (bnmAbs) are immunoglobulin (Ig) Gs (IgGs) and highly somatically hypermutated which could impede their elicitation. Ig Ms (IgMs) are on average significantly less divergent from germline antibodies and are relevant for the development of vaccine immunogens but are underexplored compared to IgGs. Here we describe the identification and characterization of several human IgM-derived mAbs against HIV-1 which were selected from a large phage-displayed naive human antibody library constructed from blood, lymph nodes and spleens of 59 healthy donors. These antibodies bound with high affinity to recombinant envelope glycoproteins (gp140s, Envs) of HIV-1 isolates from different clades. They enhanced or did not neutralize infection by some of the HIV-1 primary isolates using CCR5 as a coreceptor but neutralized all CXCR4 isolates tested although weakly. One of these antibodies with relatively low degree of somatic hypermutation was more extensively characterized. It bound to a highly conserved region partially overlapping with the coreceptor binding site and close to but not overlapping with the CD4 binding site. These results suggest the existence of conserved structures that could direct the immune response to non-neutralizing or even enhancing antibodies which may represent a strategy used by the virus to escape neutralizing immune responses. Further studies will show whether such a strategy plays a role in HIV infection of humans, how important that role could be, and what the mechanisms of infection enhancement are. The newly identified mAbs could be used as reagents to further characterize conserved non-neutralizing, weakly neutralizing or enhancing epitopes and modify or remove them from candidate vaccine immunogens.
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Affiliation(s)
- Weizao Chen
- Protein Interactions Group, Center for Cancer Research Nanobiology Program, National Cancer Institute (NCI)-Frederick, National Institutes of Health (NIH), Frederick, MD 21702, USA
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +1-301-846-1770; Fax: +1-301-846-5598
| | - Zhongyu Zhu
- Protein Interactions Group, Center for Cancer Research Nanobiology Program, National Cancer Institute (NCI)-Frederick, National Institutes of Health (NIH), Frederick, MD 21702, USA
- Basic Research Program, Science Applications International Corporation-Frederick, Inc., NCI-Frederick, Frederick, MD 21702, USA
| | - Huaxin Liao
- Duke University Medical Center, Durham, NC 27710, USA
| | - Gerald V. Quinnan
- Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
| | | | | | - Dimiter S. Dimitrov
- Protein Interactions Group, Center for Cancer Research Nanobiology Program, National Cancer Institute (NCI)-Frederick, National Institutes of Health (NIH), Frederick, MD 21702, USA
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Vaine M, Lu S, Wang S. Progress on the induction of neutralizing antibodies against HIV type 1 (HIV-1). BioDrugs 2009; 23:137-53. [PMID: 19627166 DOI: 10.2165/00063030-200923030-00001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Infection with HIV type 1 (HIV-1), the causative agent of AIDS, is one of the most catastrophic pandemics to affect human healthcare in the latter 20th century. The best hope of controlling this pandemic is the development of a successful prophylactic vaccine. However, to date, this goal has proven to be exceptionally elusive. The recent failure of an experimental vaccine in a phase IIb study, named the STEP trial, intended solely to elicit cell-mediated immune responses against HIV-1, has highlighted the need for a balanced immune response consisting of not only cellular immunity but also a broad and potent humoral antibody response that can prevent infection with HIV-1. This article reviews the efforts made up to this point to elicit such antibody responses, especially with regard to the use of a DNA prime-protein boost regimen, which has been proven to be a highly effective platform for the induction of neutralizing antibodies in both animal and early-phase human studies.
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Affiliation(s)
- Michael Vaine
- Laboratory of Nucleic Acid Vaccines, Department of Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
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Wan Y, Liu L, Wu L, Huang X, Ma L, Xu J. Deglycosylation or partial removal of HIV-1 CN54 gp140 V1/V2 domain enhances env-specific T cells. AIDS Res Hum Retroviruses 2009; 25:607-17. [PMID: 19500018 DOI: 10.1089/aid.2008.0289] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
It remains a great challenge to develop an effective HIV vaccine against the most prevalent HIV-1 clade, B'/C recombinant, in China. Our objective was to test the influence of a new modification of the V1/V2 loops of HIV-1(CN54) gp140 on the immunogenicity of Env. HIV-1(CN54) gp140 was deglycosylated by replacing all six N residues in V1/V2 loops with six Q residues (gp140dG) or partially deleted on V1/V2 loops (gp140dV). gp140, gp140dG, and gp140dV were transferred into plasmid vector and recombinant Tiantan vaccinia (rTTV) vector to generate three DNA vaccines and three rTTV vaccines for vaccination of female BALB/c mice in a prime-boost regimen. An Elispot assay was used to read out the T cell immunity and ELISA and a poly-l-leucine (PLL) ELISA was employed to assess humoral immune responses. Surprisingly, gp140dV (1570 +/- 1569 SFCs/10(6) splenocytes) and gp140dG (731 +/- 471 SFCs/10(6) splenocytes) could elicit significantly higher Env-specific T cells than gp140 (224 +/- 140 SFCs/10(6) splenocytes). Three T cell epitopes were newly identified in BALB/c mice at the N terminus of C1, C terminus of C4, and N terminus of HR, respectively. Env-specific binding antibodies and linear antibodies elicited by gp140 tended to be higher than that stimulated by gp140dG and gp140dV but did not reach statistical difference. Our data demonstrated that the deglycosylation and partial deletion of V1/V2 loops of B'/C recombinant gp140 could lead to improvement of specific T cell immune responses.
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Affiliation(s)
- Yanmin Wan
- State Key Laboratory for Infectious Disease Prevention and Control, National Center for AIDS/STD Control and Prevention (NCAIDS), Chinese Center for Disease Control and Prevention (CDC), Beijing, China
- Scientific Research Center, Shanghai Public Health Clinical Center, Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Lianxing Liu
- State Key Laboratory for Infectious Disease Prevention and Control, National Center for AIDS/STD Control and Prevention (NCAIDS), Chinese Center for Disease Control and Prevention (CDC), Beijing, China
| | - Lan Wu
- State Key Laboratory for Infectious Disease Prevention and Control, National Center for AIDS/STD Control and Prevention (NCAIDS), Chinese Center for Disease Control and Prevention (CDC), Beijing, China
- Present address: Vaccine Research Center, National Institute of Allergy and Infectious Disease, National Institutes of Health, Bethesda, Maryland
| | - Xianggang Huang
- State Key Laboratory for Infectious Disease Prevention and Control, National Center for AIDS/STD Control and Prevention (NCAIDS), Chinese Center for Disease Control and Prevention (CDC), Beijing, China
| | - Liying Ma
- State Key Laboratory for Infectious Disease Prevention and Control, National Center for AIDS/STD Control and Prevention (NCAIDS), Chinese Center for Disease Control and Prevention (CDC), Beijing, China
| | - Jianqing Xu
- State Key Laboratory for Infectious Disease Prevention and Control, National Center for AIDS/STD Control and Prevention (NCAIDS), Chinese Center for Disease Control and Prevention (CDC), Beijing, China
- Scientific Research Center, Shanghai Public Health Clinical Center, Institutes of Biomedical Sciences, Fudan University, Shanghai, China
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Granados-González V, Piedrahita LD, Martínez M, Genin C, Riffard S, Urcuqui-Inchima S. [Role of the HIV-1 gp120 V1/V2 domains in the induction of neutralizing antibodies]. Enferm Infecc Microbiol Clin 2009; 27:523-30. [PMID: 19409660 DOI: 10.1016/j.eimc.2008.02.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2007] [Accepted: 02/11/2008] [Indexed: 11/25/2022]
Abstract
The development of a preventive vaccine against human immunodeficiency virus type-1 (HIV-1) provides hope for control of the pandemic over the coming years. Nevertheless, it is clear that one of the greatest difficulties in achieving this vaccine is the high mutation rate of the virus, which enables it to evade the host's immune response. The production of neutralizing antibodies (NAb) against the HIV-1 envelope proteins is believed to play an important role in controlling the infection and in providing effective protection following vaccination. Several studies have shown that the V1/V2 domain of the HIV-1 gp120 envelope protein is involved in viral tropism during infection, in masking conserved neutralizing epitopes, in the conformational changes occurring after coreceptor binding, and in NAb induction. Nonetheless, this domain has been poorly investigated. However, because the V1/V2 domain is highly glycosylated, numerous studies have determined the influence of carbohydrates on NAb production. The present review focuses on the importance of NAb directed against epitopes of the variable regions, mainly V1/V2, their importance in protecting against HIV-1 infection, and the role these regions play in evading the immune response. Lastly, we will discuss the importance of NAb in the search for an effective vaccine against HIV-1.
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Affiliation(s)
- Viviana Granados-González
- Groupe Immunité des Muqueuses et Agents Pathogènes, University of Saint Etienne, Saint Etienne, Francia.
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Tobin GJ, Trujillo JD, Bushnell RV, Lin G, Chaudhuri AR, Long J, Barrera J, Pena L, Grubman MJ, Nara PL. Deceptive imprinting and immune refocusing in vaccine design. Vaccine 2008; 26:6189-99. [PMID: 18852005 DOI: 10.1016/j.vaccine.2008.09.080] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2008] [Accepted: 09/18/2008] [Indexed: 10/21/2022]
Abstract
A large number of the world's most widespread and problematic pathogens evade host immune responses by inducing strain-specific immunity to immunodominant epitopes with high mutation rates capable of altering antigenic profiles. The immune system appears to be decoyed into reacting to these immunodominant epitopes that offer little cross protection between serotypes or subtypes. For example, during HIV-1 infection, the immune system reacts strongly to the V1, V2, and/or V3 loops of the surface envelope glycoprotein but not to epitopes that afford broad protection against strain variants. Similarly, the host mounts strain-specific immunity to immunodominant epitopes of the influenza hemagglutinin (HA) protein. A large number of pathogens appear to exploit this weakness in the host immune system by focusing antigenic attention upon highly variable epitopes while avoiding surveillance toward more highly conserved receptor binding sites or other essential functional domains. Because the propensity of the immune system to react against immunodominant strain-specific epitopes appears to be genetically hard-wired, the phenomenon has been termed "deceptive imprinting." In this review, the authors describe observations related to deceptive imprinting in multiple systems and propose strategies for overcoming this phenomenon in the design of vaccines capable of inducing protection against highly variable pathogens.
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Affiliation(s)
- Gregory J Tobin
- Biological Mimetics, Inc., 124 Byte Drive Frederick, MD 21702, USA.
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17
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Comparison of the immunogenicities of HIV-1 mutants based on structural modification of env. Virol Sin 2008. [DOI: 10.1007/s12250-008-2949-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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18
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The membrane-proximal external region of the human immunodeficiency virus type 1 envelope: dominant site of antibody neutralization and target for vaccine design. Microbiol Mol Biol Rev 2008; 72:54-84, table of contents. [PMID: 18322034 DOI: 10.1128/mmbr.00020-07] [Citation(s) in RCA: 202] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Enormous efforts have been made to produce a protective vaccine against human immunodeficiency virus type 1; there has been little success. However, the identification of broadly neutralizing antibodies against epitopes on the highly conserved membrane-proximal external region (MPER) of the gp41 envelope protein has delineated this region as an attractive vaccine target. Furthermore, emerging structural information on the MPER has provided vaccine designers with new insights for building relevant immunogens. This review describes the current state of the field regarding (i) the structure and function of the gp41 MPER; (ii) the structure and binding mechanisms of the broadly neutralizing antibodies 2F5, 4E10, and Z13; and (iii) the development of an MPER-targeting vaccine. In addition, emerging approaches to vaccine design are presented.
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19
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Nelson JD, Kinkead H, Brunel FM, Leaman D, Jensen R, Louis JM, Maruyama T, Bewley CA, Bowdish K, Clore GM, Dawson PE, Frederickson S, Mage RG, Richman DD, Burton DR, Zwick MB. Antibody elicited against the gp41 N-heptad repeat (NHR) coiled-coil can neutralize HIV-1 with modest potency but non-neutralizing antibodies also bind to NHR mimetics. Virology 2008; 377:170-83. [PMID: 18499210 DOI: 10.1016/j.virol.2008.04.005] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2008] [Revised: 03/11/2008] [Accepted: 04/09/2008] [Indexed: 11/28/2022]
Abstract
Following CD4 receptor binding to the HIV-1 envelope spike (Env), the conserved N-heptad repeat (NHR) region of gp41 forms a coiled-coil that is a precursor to the fusion reaction. Although it has been a target of drug and vaccine design, there are few monoclonal antibody (mAb) tools with which to probe the antigenicity and immunogenicity specifically of the NHR coiled-coil. Here, we have rescued HIV-1-neutralizing anti-NHR mAbs from immune phage display libraries that were prepared (i) from b9 rabbits immunized with a previously described mimetic of the NHR coiled-coil, N35(CCG)-N13, and (ii) from an HIV-1 infected individual. We describe a rabbit single-chain Fv fragment (scFv), 8K8, and a human Fab, DN9, which specifically recognize NHR coiled-coils that are unoccupied by peptide corresponding to the C-heptad repeat or CHR region of gp41 (e.g. C34). The epitopes of 8K8 and DN9 were found to partially overlap with that of a previously described anti-NHR mAb, IgG D5; however, 8K8 and DN9 were much more specific than D5 for unoccupied NHR trimers. The mAbs, including a whole IgG 8K8 molecule, neutralized primary HIV-1 of clades B and C in a pseudotyped virus assay with comparable, albeit relatively modest potency. Finally, a human Fab T3 and a rabbit serum (both non-neutralizing) were able to block binding of D5 and 8K8 to a gp41 NHR mimetic, respectively, but not the neutralizing activity of these mAbs. We conclude from these results that NHR coiled-coil analogs of HIV-1 gp41 elicit many Abs during natural infection and through immunization, but that due to limited accessibility to the corresponding region on fusogenic gp41 few can neutralize. Caution is therefore required in targeting the NHR for vaccine design. Nevertheless, the mAb panel may be useful as tools for elucidating access restrictions to the NHR of gp41 and in designing potential improvements to mimetics of receptor-activated Env.
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Affiliation(s)
- Josh D Nelson
- Department of Immunology, The Scripps Research Institute, La Jolla, CA 92037, USA
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20
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Penn-Nicholson A, Han DP, Kim SJ, Park H, Ansari R, Montefiori DC, Cho MW. Assessment of antibody responses against gp41 in HIV-1-infected patients using soluble gp41 fusion proteins and peptides derived from M group consensus envelope. Virology 2008; 372:442-56. [PMID: 18068750 PMCID: PMC2293309 DOI: 10.1016/j.virol.2007.11.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2007] [Revised: 10/29/2007] [Accepted: 11/08/2007] [Indexed: 11/18/2022]
Abstract
Human immunodeficiency virus type 1 (HIV-1) transmembrane glycoprotein gp41 is targeted by broadly-reactive neutralizing antibodies 2F5 and 4E10, making it an attractive target for vaccine development. To better assess immunogenic properties of gp41, we generated five soluble glutathione S-transferase fusion proteins encompassing C-terminal 30, 64, 100, 142, or 172 (full-length) amino acids of gp41 ectodomain from M group consensus envelope sequence. Antibody responses in HIV-1-infected patients were evaluated using these proteins and overlapping peptides. We found (i) antibody responses against different regions of gp41 varied tremendously among individual patients, (ii) patients with stronger antibody responses against membrane-proximal external region exhibit broader and more potent neutralizing activity, and (iii) several patients mounted antibodies against epitopes that are near, or overlap with, those targeted by 2F5 or 4E10. These soluble gp41 fusion proteins could be an important source of antigens for future vaccine development efforts.
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Affiliation(s)
- Adam Penn-Nicholson
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
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21
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Selvarajah S, Puffer BA, Lee FH, Zhu P, Li Y, Wyatt R, Roux KH, Doms RW, Burton DR. Focused dampening of antibody response to the immunodominant variable loops by engineered soluble gp140. AIDS Res Hum Retroviruses 2008; 24:301-14. [PMID: 18284327 DOI: 10.1089/aid.2007.0158] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Immunization studies with modified gp120 monomers using a hyperglycosylation strategy, in which undesired epitopes are masked by the selective incorporation of N-linked glycans, were described in a previous paper (Selvarajah S, et al., J Virol 2000;79:12148-12163). In this report, we applied the hyperglycosylation strategy to soluble uncleaved gp140 trimers to improve the antigenic and immunogenic profile in the context of a trimeric conformation of the immunogen. The JR-FL gp140 gene was added upstream of a soluble trimerization domain of chicken cartilage matrix (CART) protein and expressed predominantly as a trimer and called gp140-CART wild-type. In the hyperglycosylated gp140-CART mCHO(V) mutant, four extra sugar attachment motifs on the variable loops helped mask epitope recognition by monoclonal antibodies specific to the variable loops. The gp140-CART mCHO(V) mutant and gp140-CART wild-type soluble trimer protein were used to immunize rabbits. The gp140-CART mCHO(V) immune sera had reduced antibody response to the variable loops compared to gp140-CART wild-type immune sera as shown by peptide reactivity, competition assays, and the reduced ability of sera to neutralize SF162 virus (a variable loop neutralization-sensitive virus). The antibody response to the CD4 binding site was retained in the gp140-CART mCHO(V) mutant immune sera similar to gp140-CART wild-type immune sera. The results demonstrate that the strategy of hyperglycosylation is clearly useful in the context of a compact form of Env immunogen such as the soluble gp140 trimer in dampening responses to variable loops while maintaining responses to an important epitope, the CD4 binding site. However, the results also show that in order to elicit broadly neutralizing antibodies that target conserved epitopes, the soluble gp140 trimer immunogen template will require further modifications.
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Affiliation(s)
- Suganya Selvarajah
- Departments of Immunology and Molecular Biology, The Scripps Research Institute, La Jolla, California 92037
| | - Bridget A. Puffer
- Department of Microbiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Fang-Hua Lee
- Department of Microbiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Ping Zhu
- Department of Biological Science and Institute of Molecular Biophysics, Florida State University, Tallahassee, Florida 32306
| | - Yuxing Li
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892
| | - Richard Wyatt
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892
| | - Kenneth H. Roux
- Department of Biological Science and Institute of Molecular Biophysics, Florida State University, Tallahassee, Florida 32306
| | - Robert W. Doms
- Department of Microbiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Dennis R. Burton
- Departments of Immunology and Molecular Biology, The Scripps Research Institute, La Jolla, California 92037
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22
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Perspectives for a protective HIV-1 vaccine. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2008; 56:423-52. [PMID: 18086420 DOI: 10.1016/s1054-3589(07)56014-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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Kim M, Qiao Z, Yu J, Montefiori D, Reinherz EL. Immunogenicity of recombinant human immunodeficiency virus type 1-like particles expressing gp41 derivatives in a pre-fusion state. Vaccine 2007; 25:5102-14. [PMID: 17055621 PMCID: PMC2705924 DOI: 10.1016/j.vaccine.2006.09.071] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2006] [Revised: 09/13/2006] [Accepted: 09/15/2006] [Indexed: 11/22/2022]
Abstract
The conserved membrane proximal external region (MPER) of the ectodomain of human immunodeficiency virus type 1 (HIV-1) gp41 is the target of two broadly neutralizing antibodies, 2F5 and 4E10. However, no neutralizing antibodies have been elicited against immunogens bearing these epitopes. Given that structural and biochemical studies suggest that the lipid membrane of the virion is involved in their proper configuration, HIV-1 gp41 derivatives in a pre-fusion state were expressed on the surface of immature virus like particles (VLP) derived from Sf9 cells. Guinea pigs were immunized with three doses of VLPs or Sf9 cells presenting gp41 derivatives with or without E. coli heat-labile enterotoxin (LT) as an adjuvant. While immune sera contained high titer anti-VLP antibodies, the specific anti-gp41 antibody responses were low with no neutralizing antibodies detected. An explanation for this absence may be the low level of gp41 expression relative to the many other proteins derived from host cells which are incorporated onto the VLP surface. In addition, the anti-gp41 immune response was preferentially directed to the C-helical domain, away from the MPER. Future vaccine design needs to contend with the complexity of epitope display as well as immunodominance.
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Affiliation(s)
- Mikyung Kim
- Laboratory of Immunobiology and Department of Medical Oncology, Dana-Farber Cancer Institute, Massachusetts 02115
- Department of Medicine, Harvard Medical School, Boston, Massachusetts 02115
| | - Zhisong Qiao
- Laboratory of Immunobiology and Department of Medical Oncology, Dana-Farber Cancer Institute, Massachusetts 02115
- Department of Medicine, Harvard Medical School, Boston, Massachusetts 02115
| | - Jessica Yu
- Laboratory of Immunobiology and Department of Medical Oncology, Dana-Farber Cancer Institute, Massachusetts 02115
| | - David Montefiori
- Department of Surgery, Duke University, Medical Center, Durham, North Carolina 27710
| | - Ellis L. Reinherz
- Laboratory of Immunobiology and Department of Medical Oncology, Dana-Farber Cancer Institute, Massachusetts 02115
- Department of Medicine, Harvard Medical School, Boston, Massachusetts 02115
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Wan Y, Wu L, Liu L, Xu J, Liu Y, Liu Y, Shao Y. Comparison of immunogenicity between codon optimized HIV-1 Thailand subtype B gp140 and gp145 vaccines. Vaccine 2007; 25:4949-59. [PMID: 17350736 PMCID: PMC1961633 DOI: 10.1016/j.vaccine.2007.01.118] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2006] [Revised: 01/23/2007] [Accepted: 01/30/2007] [Indexed: 01/06/2023]
Abstract
HIV-1 pandemic posed an unprecedented challenge to the global health and it is believed that an effective vaccine will be the final solution against HIV-1. HIV-1 envelope is the primary immunogen in developing neutralization antibody based HIV vaccine. To define the suitable Env derived immunogen, we systemically compared the immunogenicity of gp140 and gp145 in a DNA vaccination alone and a prime-boost modalities. Two DNA vaccines and two recombinant Tiantan vaccinia vaccines (rTTV) were constructed for vaccination of female Balb/c mice. Elispot assay was used to read out the T cell immunity and ELISA assay was used to quantify antibody immunity. PLL (poly-L-leucine)-ELISA assay was used in linear antibody epitope mapping. Mice primed with gp145 tended to elicit more Env-specific T cells responses than those primed with gp140, significant difference was observed in DNA immunization alone. The ultimate T cell responses in prime-boost regimen tend to be determined mainly by the priming efficacy. Linear antibody epitope mapping displayed that sera raised by gp145 priming were vigorously reactive to more peptides than that by gp140. Our data demonstrated HIV-1 Thailand B-derived gp145 may raise higher T-cell responses and broader linear peptide-specific antibody responses than gp140 does. However, it remains to be determined that how these observations are relevant to the neutralization of antibody activities.
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Affiliation(s)
- Yanmin Wan
- State Key Laboratory for Infectious Diseases Prevention and Control, National Center for AIDS/STD Control and Prevention (NCAIDS), China CDC, Beijing, China
| | - Lan Wu
- State Key Laboratory for Infectious Diseases Prevention and Control, National Center for AIDS/STD Control and Prevention (NCAIDS), China CDC, Beijing, China
| | - Lianxing Liu
- State Key Laboratory for Infectious Diseases Prevention and Control, National Center for AIDS/STD Control and Prevention (NCAIDS), China CDC, Beijing, China
- Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
- Graduate University of the Chinese Academy of Sciences, Beijing, China
| | - Jianqing Xu
- State Key Laboratory for Infectious Diseases Prevention and Control, National Center for AIDS/STD Control and Prevention (NCAIDS), China CDC, Beijing, China
| | - Ying Liu
- State Key Laboratory for Infectious Diseases Prevention and Control, National Center for AIDS/STD Control and Prevention (NCAIDS), China CDC, Beijing, China
| | | | - Yiming Shao
- State Key Laboratory for Infectious Diseases Prevention and Control, National Center for AIDS/STD Control and Prevention (NCAIDS), China CDC, Beijing, China
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25
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Law M, Cardoso RMF, Wilson IA, Burton DR. Antigenic and immunogenic study of membrane-proximal external region-grafted gp120 antigens by a DNA prime-protein boost immunization strategy. J Virol 2007; 81:4272-85. [PMID: 17267498 PMCID: PMC1866136 DOI: 10.1128/jvi.02536-06] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The membrane-proximal external region (MPER) of human immunodeficiency virus type 1 (HIV-1) gp41 is a target of broadly neutralizing monoclonal antibodies (MAbs) 2F5, 4E10, and Z13. Here we engrafted the MPER into the V1/2 region of HIV-1 gp120 to investigate the ability of the engineered antigens to elicit virus-neutralizing antibodies (NAbs). To promote the correct folding and presentation of the helical 4E10 epitope, we flanked the epitope with helical domains and manipulated the helix by sequential deletion of residues preceding the epitope. Binding of the recombinant proteins to MAb 4E10 increased four- to fivefold with the deletion of one or two residues, but it returned to the wild-type level when three residues were deleted, suggesting rotation of the 4E10 epitope along the helix. Immunization of mice and rabbits by electroporation-mediated DNA priming and protein boosting with these constructs elicited high levels of gp120-specific antibodies. A consistent NAb response against the neutralization-resistant, homologous JR-FL virus was detected in rabbits but not in mice. Analysis of the neutralizing activity revealed that the NAbs do not target the MPER or the V1, V2, or V3 region. Through this study, we learned the following. (i) The 4E10 epitope can be manipulated using a "rotate-the-helix" strategy that alters the helix register. However, presentation of this epitope in the immunogenic V1/2 region did not render it immunogenic in mice or rabbits. (ii) DNA vaccination with monomeric gp120-based antigens can elicit a consistent NAb response against the homologous neutralization-resistant virus by targeting epitopes outside the V1, V2, and V3 regions.
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Affiliation(s)
- Mansun Law
- The Scripps Research Institute, Department of Immunology (IMM-2), 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
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26
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Immunogenicity of a polyvalent HIV-1 candidate vaccine based on fourteen wild type gp120 proteins in golden hamsters. BMC Immunol 2006; 7:25. [PMID: 17076905 PMCID: PMC1636068 DOI: 10.1186/1471-2172-7-25] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2006] [Accepted: 10/31/2006] [Indexed: 11/10/2022] Open
Abstract
Background One of the major obstacles in the design of an effective vaccine against HIV-1 is the hypervariability of the HIV-1 envelope glycoprotein. Most HIV-1 vaccine candidates have utilized envelope glycoprotein from a single virus isolate, but to date, none of them elicited broadly reactive humoral immunity. Herein, we hypothesised that a cocktail of HIV-1 gp120 proteins containing multiple epitopes may increase the breadth of immune responses against HIV-1. We compared and evaluated the immunogenicity of HIV-1 vaccines containing either gp120 protein alone or in combinations of four or fourteen gp120s from different primary HIV-1 isolates in immunized hamsters. Results We amplified and characterized 14 different gp120s from primary subtype B isolates with both syncytium and non-syncytium inducing properties, and expressed the proteins in Chinese Hamster Ovary (CHO) cell lines. Purified proteins were used either alone or in combinations of four or fourteen different gp120s to vaccinate golden hamsters. The polyvalent vaccine showed higher antibody titers to HIV-1 subtype B isolates MN and SF162 compared to the groups that received one or four gp120 proteins. However, the polyvalent vaccine was not able to show higher neutralizing antibody responses against HIV-1 primary isolates. Interestingly, the polyvalent vaccine group had the highest proliferative immune responses and showed a substantial proportion of cross-subtype CD4 reactivity to HIV-1 subtypes B, C, and A/E Conclusion Although the polyvalent approach achieved only a modest increase in the breadth of humoral and cellular immunity, the qualitative change in the vaccine (14 vs. 1 gp120) resulted in a quantitative improvement in vaccine-induced immunity.
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27
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Haynes BF, Montefiori DC. Aiming to induce broadly reactive neutralizing antibody responses with HIV-1 vaccine candidates. Expert Rev Vaccines 2006; 5:579-95. [PMID: 16989638 DOI: 10.1586/14760584.5.4.579] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Neutralizing antibody induction is a key feature of many effective vaccines and is the only immune response that has proven to be capable of completely blocking AIDS virus infection in animal models. Unfortunately, the extensive genetic variability and complex immune-evasion strategies of HIV-1 have thwarted all attempts to date at eliciting an effective neutralizing antibody response with candidate HIV-1 vaccine immunogens. Recent advances in our understanding of how these evasion strategies operate, coupled with growing progress in unravelling the structure and immunobiology of the viral envelope glycoproteins, are contributing to novel immunogen designs to overcome the many barriers to inducing protective antibodies against HIV-1.
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28
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Liao HX, Sutherland LL, Xia SM, Brock ME, Scearce RM, Vanleeuwen S, Alam SM, McAdams M, Weaver EA, Camacho Z, Ma BJ, Li Y, Decker JM, Nabel GJ, Montefiori DC, Hahn BH, Korber BT, Gao F, Haynes BF. A group M consensus envelope glycoprotein induces antibodies that neutralize subsets of subtype B and C HIV-1 primary viruses. Virology 2006; 353:268-82. [PMID: 17039602 PMCID: PMC1762135 DOI: 10.1016/j.virol.2006.04.043] [Citation(s) in RCA: 166] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
HIV-1 subtype C is the most common HIV-1 group M subtype in Africa and many parts of Asia. However, to date HIV-1 vaccine candidate immunogens have not induced potent and broadly neutralizing antibodies against subtype C primary isolates. We have used a centralized gene strategy to address HIV-1 diversity and generated a group M consensus envelope gene with shortened consensus variable loops (CON-S) for comparative studies with wild-type (WT) Env immunogens. Our results indicate that the consensus HIV-1 group M CON-S Env elicited cross-subtype neutralizing antibodies of similar or greater breadth and titer than the WT Envs tested, indicating the utility of a centralized gene strategy. Our study also shows the feasibility of iterative improvements in Env immunogenicity by rational design of centralized genes.
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Affiliation(s)
- Hua-Xin Liao
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA.
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29
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Derby NR, Kraft Z, Kan E, Crooks ET, Barnett SW, Srivastava IK, Binley JM, Stamatatos L. Antibody responses elicited in macaques immunized with human immunodeficiency virus type 1 (HIV-1) SF162-derived gp140 envelope immunogens: comparison with those elicited during homologous simian/human immunodeficiency virus SHIVSF162P4 and heterologous HIV-1 infection. J Virol 2006; 80:8745-62. [PMID: 16912322 PMCID: PMC1563892 DOI: 10.1128/jvi.00956-06] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The antibody responses elicited in rhesus macaques immunized with soluble human immunodeficiency virus (HIV) Env gp140 proteins derived from the R5-tropic HIV-1 SF162 virus were analyzed and compared to the broadly reactive neutralizing antibody responses elicited during chronic infection of a macaque with a simian/human immunodeficiency virus (SHIV) expressing the HIV-1 SF162 Env, SHIV(SF162P4), and humans infected with heterologous HIV-1 isolates. Four gp140 immunogens were evaluated: SF162gp140, DeltaV2gp140 (lacking the crown of the V2 loop), DeltaV3gp140 (lacking the crown of the V3 loop), and DeltaV2DeltaV3gp140 (lacking both the V2 and V3 loop crowns). SF162gp140 and DeltaV2gp140 have been previously evaluated by our group in a pilot study, but here, a more comprehensive analysis of their immunogenic properties was performed. All four gp140 immunogens elicited stronger anti-gp120 than anti-gp41 antibodies and potent homologous neutralizing antibodies (NAbs) that primarily targeted the first hypervariable region (V1 loop) of gp120, although SF162gp140 also elicited anti-V3 NAbs. Heterologous NAbs were elicited by SF162gp140 and DeltaV2gp140 but were weak in potency and narrow in specificity. No heterologous NAbs were elicited by DeltaV3gp140 or DeltaV2DeltaV3gp140. In contrast, the SHIV(SF162P4)-infected macaque and HIV-infected humans generated similar titers of anti-gp120 and anti-gp41 antibodies and NAbs of significant breadth against primary HIV-1 isolates, which did not target the V1 loop. The difference in V1 loop immunogenicity between soluble gp140 and virion-associated gp160 Env proteins derived from SF162 may be the basis for the observed difference in the breadth of neutralization in sera from the immunized and infected animals studied here.
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Affiliation(s)
- Nina R Derby
- Seattle Biomedical Research Institute, WA 98109, USA
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30
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Burke B, Derby NR, Kraft Z, Saunders CJ, Dai C, Llewellyn N, Zharkikh I, Vojtech L, Zhu T, Srivastava IK, Barnett SW, Stamatatos L. Viral evolution in macaques coinfected with CCR5- and CXCR4-tropic SHIVs in the presence or absence of vaccine-elicited anti-CCR5 SHIV neutralizing antibodies. Virology 2006; 355:138-51. [PMID: 16920175 DOI: 10.1016/j.virol.2006.07.026] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2006] [Revised: 06/08/2006] [Accepted: 07/11/2006] [Indexed: 11/21/2022]
Abstract
Macaques were immunized with SF162 Env-based gp140 immunogens and challenged simultaneously with the CCR5-tropic homologous SHIV(SF162P4) and the CXCR4-tropic heterologous SHIV(SF33A) viruses. Both mock-immunized and immunized animals became dually infected. Prior immunization preferentially reduced the viral replication of the homologous virus during primary infection but the relative replication of the two coinfecting viruses during chronic infection was unaffected by prior immunization, despite the fact that five of six immunized animals maintained a significantly lower overall viral replication that the control animals. Neutralizing antibodies participated in controlling the replication of SHIV(SF162P4), but not that of SHIV(SF33A). Dual infection resulted in the emergence and predominance within the circulating CCR5 virus pool, of a variant with a distinct neutralization phenotype. The signature of this variant was the presence of three amino acid changes in gp120, two of which were located in the receptor and coreceptor binding sites. Also, a significant fraction of the viruses circulating in the blood, as early as two weeks post-infection, was recombinants and prior immunization did not prevent their emergence. These findings provide new insights into the dynamic interaction of CCR5- and CXCR4-tropic HIV isolates that are potentially relevant in better understanding HIV-mediated pathogenesis.
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Affiliation(s)
- Brian Burke
- Seattle Biomedical Research Institute, Seattle, WA 98109, USA
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31
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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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32
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Haynes BF, Montefiori DC. Aiming to induce broadly reactive neutralizing antibody responses with HIV-1 vaccine candidates. Expert Rev Vaccines 2006; 5:347-63. [PMID: 16827619 PMCID: PMC2716009 DOI: 10.1586/14760584.5.3.347] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Neutralizing antibody induction is a key feature of many effective vaccines and is the only immune response that has proven to be capable of completely blocking AIDS virus infection in animal models. Unfortunately, the extensive genetic variability and complex immune-evasion strategies of HIV-1 have thwarted all attempts to date at eliciting an effective neutralizing antibody response with candidate HIV-1 vaccine immunogens. Recent advances in our understanding of how these evasion strategies operate, coupled with growing progress in unravelling the structure and immunobiology of the viral envelope glycoproteins, are contributing to novel immunogen designs to overcome the many barriers to inducing protective antibodies against HIV-1.
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Affiliation(s)
- Barton F Haynes
- Box 3258, RP-1 Building, Building 107, Circuit Drive, Duke University Medical Center, Durham, NC 27710, USA, Tel: +1919 684 5279, Fax: +1 919 684 5230,
| | - David C Montefiori
- Department of Surgery, Box 2926, Duke University Medical Center, Durham, NC 27710, USA, Tel: +1 919 684 5278, Fax: +1 919 684 4288,
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33
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Rodriguez-Chavez IR, Allen M, Hill EL, Sheets RL, Pensiero M, Bradac JA, D'Souza MP. Current advances and challenges in HIV-1 vaccines. Curr HIV/AIDS Rep 2006; 3:39-47. [PMID: 16522258 DOI: 10.1007/s11904-006-0007-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Recent advances in science, which have aided HIV-1 vaccine development, include an improved understanding of HIV-1 envelope structure and function, expansion of the pipeline with innovative vaccine strategies, promising multi-gene and multi-clade vaccines that elicit cellular immunity, conduct of clinical trials in a global network, and development of validated techniques that enable simultaneous measurement of multiple T cell vaccine-induced immune responses in humans. A common feature of several preventive vaccine strategies now in early clinical trials is their ability in nonhuman primates to attenuate clinical disease rather than completely prevent HIV-1 infection. One vaccine concept has been tested in large-scale clinical trials, two are currently in efficacy trials, and one more is poised to enter efficacy trial in the next few years. Simultaneously, expanded efforts continue to identify new designs that induce mucosal immunity as well as broadly neutralizing antibodies.
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Affiliation(s)
- Isaac R Rodriguez-Chavez
- Division of AIDS, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
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34
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Li Y, Svehla K, Mathy NL, Voss G, Mascola JR, Wyatt R. Characterization of antibody responses elicited by human immunodeficiency virus type 1 primary isolate trimeric and monomeric envelope glycoproteins in selected adjuvants. J Virol 2006; 80:1414-26. [PMID: 16415019 PMCID: PMC1346938 DOI: 10.1128/jvi.80.3.1414-1426.2006] [Citation(s) in RCA: 140] [Impact Index Per Article: 7.8] [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 soluble, stable YU2 gp140 trimeric human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein immunogens could elicit improved breadth of neutralization against HIV-1 isolates compared to monomeric YU2 gp120 proteins. In this guinea pig immunization study, we sought to extend these data and determine if adjuvant could quantitatively or qualitatively alter the neutralizing response elicited by trimeric or monomeric immunogens. Consistent with our earlier studies, the YU2 gp140 immunogens elicited higher-titer neutralizing antibodies against homologous and heterologous isolates than those elicited by monomeric YU2 gp120. Additionally, the GlaxoSmithKline family of adjuvants AS01B, AS02A, and AS03 induced higher levels of neutralizing antibodies compared to emulsification of the same immunogens in Ribi adjuvant. Further analysis of vaccine sera indicated that homologous virus neutralization was not mediated by antibodies to the V3 loop, although V3 loop-directed neutralization could be detected for some heterologous isolates. In most gp120-inoculated animals, the homologous YU2 neutralization activity was inhibited by a peptide derived from the YU2 V1 loop, whereas the neutralizing activity elicited by YU2 gp140 trimers was much less sensitive to V1 peptide inhibition. Consistent with a less V1-focused antibody response, sera from the gp140-immunized animals more efficiently neutralized heterologous HIV-1 isolates, as determined by two distinct neutralization formats. Thus, there appear to be qualitative differences in the neutralizing antibody response elicited by YU2 gp140 compared to YU2 monomeric gp120. Further mapping analysis of more conserved regions of gp120/gp41 may be required to determine the neutralizing specificity elicited by the trimeric immunogens.
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Affiliation(s)
- Y Li
- Vaccine Research Center, National Institutes of Health, 40 Convent Drive, Rm 4512, Bethesda, MD 20892, USA
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35
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Selvarajah S, Puffer B, Pantophlet R, Law M, Doms RW, Burton DR. Comparing antigenicity and immunogenicity of engineered gp120. J Virol 2005; 79:12148-63. [PMID: 16160142 PMCID: PMC1211546 DOI: 10.1128/jvi.79.19.12148-12163.2005] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We have engineered monomeric gp120 in such a way as to favorably present the conserved epitope for the broadly neutralizing antibody b12 while lowering the exposure of epitopes recognized by some weakly neutralizing and nonneutralizing antibodies. The work presented here describes the immune response in rabbits immunized with two prototype, engineered gp120s to explore the relationship between antigenicity and immunogenicity for these mutants. The GDMR gp120 mutant (residues 473 to 476 on gp120 altered from GDMR to AAAA) has a series of substitutions on the edge of the CD4 binding site (CD4bs), and the mCHO gp120 mutant has seven extra glycans relative to the wild-type protein. Importantly, serum mapping showed that both mutants did not elicit antibodies against a number of epitopes that had been targeted for dampening. The sera from rabbits immunized with the GDMR gp120 mutant neutralized some primary viruses at levels somewhat better than the wild-type gp120 immune sera as a result of an increased elicitation of anti-V3 antibodies. Unlike wild-type gp120 immune sera, GDMR gp120 immune sera failed to neutralize HXBc2, a T-cell line adapted (TCLA) virus. This was associated with loss of CD4bs/CD4-induced antibodies that neutralize TCLA but not primary viruses. The mCHO gp120 immune sera did not neutralize primary viruses to any significant degree, reflecting the masking of epitopes of even weakly neutralizing antibodies without eliciting b12-like antibodies. These results show that antibody responses to multiple epitopes on gp120 can be dampened. More precise focusing to a neutralizing epitope will likely require several iterations comparing antigenicity and immunogenicity of engineered proteins.
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Affiliation(s)
- Suganya Selvarajah
- The Scripps Research Institute, Department of Immunology, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
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36
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Lorin C, Combredet C, Labrousse V, Mollet L, Desprès P, Tangy F. A paediatric vaccination vector based on live attenuated measles vaccine. Therapie 2005; 60:227-33. [PMID: 16128264 DOI: 10.2515/therapie:2005029] [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: 12/18/2022]
Abstract
Live attenuated RNA viruses make highly efficient vaccines. Among them, measles virus (MV) vaccine has been given to a very large number of children and shown to be highly effective and safe. MV vaccine induces a life-long immunity after a single or two low-dose injections. It is easily produced on a large scale in most countries and can be distributed at low cost. Reversion to pathogenicity has never been observed with this vaccine. Because of all these characteristics, MV vaccine might be a very promising vector to immunise children against both measles and other infectious agents, such as HIV or flaviviruses, in the developing world. In this article, we describe recent data that we obtained showing the capacity of recombinant Schwarz MVs to express proteins from human immunodeficiency or West Nile viruses, and to induce specific immune responses able, in the case of West Nile virus, to protect from an experimental challenge.
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Affiliation(s)
- Clarisse Lorin
- Unité des Virus Lents, CNRS URA 1930, Institut Pasteur, Paris, France
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37
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Poon B, Hsu JF, Gudeman V, Chen ISY, Grovit-Ferbas K. Formaldehyde-treated, heat-inactivated virions with increased human immunodeficiency virus type 1 env can be used to induce high-titer neutralizing antibody responses. J Virol 2005; 79:10210-7. [PMID: 16051814 PMCID: PMC1182614 DOI: 10.1128/jvi.79.16.10210-10217.2005] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The lack of success of subunit human immunodeficiency virus (HIV) type 1 vaccines to date suggests that multiple components or a complex virion structure may be required. We hypothesized that the failure of current vaccine strategies to induce protective antibodies is linked to the inability of native envelope structures to readily elicit these types of antibodies. We have previously reported on the ability of a formaldehyde-treated, heat-inactivated vaccine to induce modest antibody responses in animal vaccine models. We investigated here whether immunization for HIV with an envelope-modified, formaldehyde-stabilized, heat-inactivated virion vaccine could produce higher-titer and/or broader neutralizing antibody responses. Thus, a clade B vaccine which contains a single point mutation in gp41 (Y706C) that results in increased incorporation of oligomeric Env into virions was constructed. This vaccine was capable of inducing high-titer antibodies that could neutralize heterologous viruses, including those of clades A and C. These results further support the development of HIV vaccines with modifications in native Env structures for the induction of neutralizing antibody responses.
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Affiliation(s)
- B Poon
- Department of Medicine, David Geffen School of Medicine at UCLA, 11-934 Factor Building, Los Angeles, CA 90095, USA
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38
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Pan Y, Ma B, Nussinov R. CD4 binding partially locks the bridging sheet in gp120 but leaves the beta2/3 strands flexible. J Mol Biol 2005; 350:514-27. [PMID: 15946678 DOI: 10.1016/j.jmb.2005.05.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2005] [Revised: 04/22/2005] [Accepted: 05/04/2005] [Indexed: 11/20/2022]
Abstract
The structure of the free form HIV gp120, critical for therapeutic agent development, is unavailable due to its high flexibility. Previous thermodynamic data, structural analysis and simulation results have suggested a large conformational change in the core domain upon CD4 binding. The bridging sheet, which consists of four beta-strands with beta20/21 nestling against the inner/outer domains and beta2/3 facing outward, more exposed to the solvent, was proposed to be unfolded in the native state. In order to test this proposition and to characterize the native conformations, we performed potential mean force (PMF) molecular dynamics (MD) simulations on the CD4-bound crystal structure. We pushed the bridging sheet away from the inner and outer domain to explore the accessible conformational space for the bridging sheet. In addition, we performed conventional MD simulations on structures with the bridging sheet partially unfolded to investigate the stability of the association between the inner and outer domains. Based on the free energy profiles, we find that the whole bridging sheet is unlikely to unfold without other concurrent conformational changes. On the other hand, the partial bridging sheet, beta strands 2/3, can switch its conformation from the folded to the unfolded state. Furthermore, relaxation of conformation with partially unfolded bridging sheet through MD simulations leads to a conformation with beta strands 20/21 quickly re-anchoring against the inner and outer domains. Such a conformation, although lacking some of the hydrophobic interactions present in the CD4-bound structure, displayed high stability as further indicated by other restrained MD simulations. The relevance of this conformation to the free form structure and the pathway for conformational change from the free form to the CD4-bound structure is discussed in detail in light of the available unliganded SIV gp120 crystal structure.
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Affiliation(s)
- Yongping Pan
- Basic Research Program, SAIC-Frederick, Inc. Laboratory of Experimental and Computational Biology, NCI-Frederick, Frederick, MD 21702, USA
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39
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Li M, Gao F, Mascola JR, Stamatatos L, Polonis VR, Koutsoukos M, Voss G, Goepfert P, Gilbert P, Greene KM, Bilska M, Kothe DL, Salazar-Gonzalez JF, Wei X, Decker JM, Hahn BH, Montefiori DC. Human immunodeficiency virus type 1 env clones from acute and early subtype B infections for standardized assessments of vaccine-elicited neutralizing antibodies. J Virol 2005; 79:10108-25. [PMID: 16051804 PMCID: PMC1182643 DOI: 10.1128/jvi.79.16.10108-10125.2005] [Citation(s) in RCA: 946] [Impact Index Per Article: 49.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2005] [Accepted: 05/09/2005] [Indexed: 01/16/2023] Open
Abstract
Induction of broadly cross-reactive neutralizing antibodies is a high priority for AIDS vaccine development but one that has proven difficult to be achieved. While most immunogens generate antibodies that neutralize a subset of T-cell-line-adapted strains of human immunodeficiency virus type 1 (HIV-1), none so far have generated a potent, broadly cross-reactive response against primary isolates of the virus. Even small increments in immunogen improvement leading to increases in neutralizing antibody titers and cross-neutralizing activity would accelerate vaccine development; however, a lack of uniformity in target strains used by different investigators to assess cross-neutralization has made the comparison of vaccine-induced antibody responses difficult. Thus, there is an urgent need to establish standard panels of HIV-1 reference strains for wide distribution. To facilitate this, full-length gp160 genes were cloned from acute and early subtype B infections and characterized for use as reference reagents to assess neutralizing antibodies against clade B HIV-1. Individual gp160 clones were screened for infectivity as Env-pseudotyped viruses in a luciferase reporter gene assay in JC53-BL (TZM-bl) cells. Functional env clones were sequenced and their neutralization phenotypes characterized by using soluble CD4, monoclonal antibodies, and serum samples from infected individuals and noninfected recipients of a recombinant gp120 vaccine. Env clones from 12 R5 primary HIV-1 isolates were selected that were not unusually sensitive or resistant to neutralization and comprised a wide spectrum of genetic, antigenic, and geographic diversity. These reference reagents will facilitate proficiency testing and other validation efforts aimed at improving assay performance across laboratories and can be used for standardized assessments of vaccine-elicited neutralizing antibodies.
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Affiliation(s)
- Ming Li
- Department of Surgery, Duke University Medical Center, Durham, NC 27710, USA
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40
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Brown BK, Darden JM, Tovanabutra S, Oblander T, Frost J, Sanders-Buell E, de Souza MS, Birx DL, McCutchan FE, Polonis VR. Biologic and genetic characterization of a panel of 60 human immunodeficiency virus type 1 isolates, representing clades A, B, C, D, CRF01_AE, and CRF02_AG, for the development and assessment of candidate vaccines. J Virol 2005; 79:6089-101. [PMID: 15857994 PMCID: PMC1091694 DOI: 10.1128/jvi.79.10.6089-6101.2005] [Citation(s) in RCA: 114] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A critical priority for human immunodeficiency virus type 1 (HIV-1) vaccine development is standardization of reagents and assays for evaluation of immune responses elicited by candidate vaccines. To provide a panel of viral reagents from multiple vaccine trial sites, 60 international HIV-1 isolates were expanded in peripheral blood mononuclear cells and characterized both genetically and biologically. Ten isolates each from clades A, B, C, and D and 10 isolates each from CRF01_AE and CRF02_AG were prepared from individuals whose HIV-1 infection was evaluated by complete genome sequencing. The main criterion for selection was that the candidate isolate was pure clade or pure circulating recombinant. After expansion in culture, the complete envelope (gp160) of each isolate was verified by sequencing. The 50% tissue culture infectious dose and p24 antigen concentration for each viral stock were determined; no correlation between these two biologic parameters was found. Syncytium formation in MT-2 cells and CCR5 or CXCR4 coreceptor usage were determined for all isolates. Isolates were also screened for neutralization by soluble CD4, a cocktail of monoclonal antibodies, and a pool of HIV-1-positive patient sera. The panel consists of 49 nonsyncytium-inducing isolates that use CCR5 as a major coreceptor and 11 syncytium-inducing isolates that use only CXCR4 or both coreceptors. Neutralization profiles suggest that the panel contains both neutralization-sensitive and -resistant isolates. This collection of HIV-1 isolates represents the six major globally prevalent strains, is exceptionally large and well characterized, and provides an important resource for standardization of immunogenicity assessment in HIV-1 vaccine trials.
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Affiliation(s)
- Bruce K Brown
- The Henry M. Jackson Foundation, 13 Taft Court, Suite 200, Rockville, MD 20850, USA.
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41
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Poon B, Safrit JT, McClure H, Kitchen C, Hsu JF, Gudeman V, Petropoulos C, Wrin T, Chen ISY, Grovit-Ferbas K. Induction of humoral immune responses following vaccination with envelope-containing, formaldehyde-treated, thermally inactivated human immunodeficiency virus type 1. J Virol 2005; 79:4927-35. [PMID: 15795278 PMCID: PMC1069531 DOI: 10.1128/jvi.79.8.4927-4935.2005] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The lack of success of subunit human immunodeficiency virus type 1 (HIV-1) vaccines to date suggests that multiple components or a complex virion structure may be required. We previously demonstrated retention of the major conformational epitopes of HIV-1 envelope following thermal treatment of virions. Moreover, antibody binding to some of these epitopes was significantly enhanced following thermal treatment. These included the neutralizing epitopes identified by monoclonal antibodies 1b12, 2G12, and 17b, some of which have been postulated to be partially occluded or cryptic in native virions. Based upon this finding, we hypothesized that a killed HIV vaccine could be derived to elicit protective humoral immune responses. Shedding of HIV-1 envelope has been described for some strains of HIV-1 and has been cited as one of the major impediments to developing an inactivated HIV-1 vaccine. In the present study, we demonstrate that treatment of virions with low-dose formaldehyde prior to thermal inactivation retains the association of viral envelope with virions. Moreover, mice and nonhuman primates vaccinated with formaldehyde-treated, thermally inactivated virions produce antibodies capable of neutralizing heterologous strains of HIV in peripheral blood mononuclear cell-, MAGI cell-, and U87-based infectivity assays. These data indicate that it is possible to create an immunogen by using formaldehyde-treated, thermally inactivated HIV-1 virions to induce neutralizing antibodies. These findings have broad implications for vaccine development.
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Affiliation(s)
- B Poon
- Department of Medicine, UCLA, Los Angeles, CA 90095, USA
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42
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Kang SM, Quan FS, Huang C, Guo L, Ye L, Yang C, Compans RW. Modified HIV envelope proteins with enhanced binding to neutralizing monoclonal antibodies. Virology 2005; 331:20-32. [PMID: 15582650 DOI: 10.1016/j.virol.2004.10.005] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The target for neutralizing antibodies against human immunodeficiency virus (HIV) is the trimeric Env protein on the native virion. Conserved neutralizing epitopes of receptor binding sites are located in the recessed core of the Env protein, partially masked by glycosylations and variable loops. In this study, we have investigated the effects of modifications of the HIV Env protein by glycosylation site mutations, deletions of variable loops, or combinations of both types of mutations on their protein functions and reactivities with neutralizing antibodies. Modified Env proteins were expressed in insect or mammalian cells, and their reactivity with epitope-specific broadly neutralizing monoclonal antibodies (Mabs) was determined by flow cytometry. A unique mutant designated 3G with mutations in three glycosylation motifs within the V3/C3 domains surrounding the CD4 binding site showed higher levels of binding to most broadly neutralizing Mabs (b12 and 2F5) in both insect and mammalian expression systems. Mutants with a deletion of both V1 and V2 loop domains or with a unique combination of both types of mutations also bound to most neutralizing Mabs at higher levels compared to the wild-type control. Most mutants maintained the ability to bind CD4 and to induce syncytium formation at similar or higher levels as compared to that of the wild-type Env protein, except for a mutant with a combination of variable loop deletions and deglycosylation mutations. Our study suggests that modified HIV Env proteins with reduced glycosylation in domains surrounding the CD4 binding site or variable loop-deleted mutants expose important neutralizing epitopes at higher levels than wild type and may provide novel vaccine immunogens.
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Affiliation(s)
- Sang-Moo Kang
- Department of Microbiology and Immunology, Emory University School of Medicine, 1510 Clifton Road, RRC 3086, Atlanta, GA 30322, USA.
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43
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Trujillo JD, Kumpula-McWhirter NM, Hötzel KJ, Gonzalez M, Cheevers WP. Glycosylation of immunodominant linear epitopes in the carboxy-terminal region of the caprine arthritis-encephalitis virus surface envelope enhances vaccine-induced type-specific and cross-reactive neutralizing antibody responses. J Virol 2004; 78:9190-202. [PMID: 15308714 PMCID: PMC506968 DOI: 10.1128/jvi.78.17.9190-9202.2004] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
This study evaluated type-specific and cross-reactive neutralizing antibodies induced by immunization with modified surface glycoproteins (SU) of the 63 isolate of caprine arthritis-encephalitis lentivirus (CAEV-63). Epitope mapping of sera from CAEV-infected goats localized immunodominant linear epitopes in the carboxy terminus of SU. Two modified SU (SU-M and SU-T) and wild-type CAEV-63 SU (SU-W) were produced in vaccinia virus and utilized to evaluate the effects of glycosylation or the deletion of immunodominant linear epitopes on neutralizing antibody responses induced by immunization. SU-M contained two N-linked glycosylation sites inserted into the target epitopes by R539S and E542N mutations. SU-T was truncated at 518A, upstream from the target epitopes, by introduction of termination codons at 519Y and 521Y. Six yearling Saanen goats were immunized subcutaneously with 30 microg of SU-W, SU-M, or SU-T in Quil A adjuvant and boosted at 3, 7, and 16 weeks. SU antibody titers determined by indirect enzyme-linked immunosorbent assay demonstrated anamnestic responses after each boost. Wild-type and modified SU-induced type-specific CAEV-63 neutralizing antibodies and cross-reactive neutralizing antibodies against CAEV-Co, a virus isolate closely related to CAEV-63, and CAEV-1g5, an isolate geographically distinct from CAEV-63, were determined. Immunization with SU-T resulted in altered recognition of SU linear epitopes and a 2.8- to 4.6-fold decrease in neutralizing antibody titers against CAEV-63, CAEV-Co, and CAEV-1g5 compared to titers of SU-W-immunized goats. In contrast, immunization with SU-M resulted in reduced recognition of glycosylated epitopes and a 2.4- to 2.7-fold increase in neutralizing antibody titers compared to titers of SU-W-immunized goats. Thus, the glycosylation of linear immunodominant nonneutralization epitopes, but not epitope deletion, is an effective strategy to enhance neutralizing antibody responses by immunization.
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Affiliation(s)
- J D Trujillo
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington 99164-7040, USA.
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Zhang MY, Xiao X, Sidorov IA, Choudhry V, Cham F, Zhang PF, Bouma P, Zwick M, Choudhary A, Montefiori DC, Broder CC, Burton DR, Quinnan GV, Dimitrov DS. Identification and characterization of a new cross-reactive human immunodeficiency virus type 1-neutralizing human monoclonal antibody. J Virol 2004; 78:9233-42. [PMID: 15308718 PMCID: PMC506938 DOI: 10.1128/jvi.78.17.9233-9242.2004] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2004] [Accepted: 04/23/2004] [Indexed: 11/20/2022] Open
Abstract
The identification and characterization of new human monoclonal antibodies (hMAbs) able to neutralize primary human immunodeficiency virus type 1 (HIV-1) isolates from different subtypes may help in our understanding of the mechanisms of virus entry and neutralization and in the development of entry inhibitors and vaccines. For enhanced selection of broadly cross-reactive antibodies, soluble HIV-1 envelope glycoproteins (Envs proteins) from two isolates complexed with two-domain soluble CD4 (sCD4) were alternated during panning of a phage-displayed human antibody library; these two Env proteins (89.6 and IIIB gp140s), and one additional Env (JR-FL gp120) alone and complexed with sCD4 were used for screening. An antibody with relatively long HCDR3 (17 residues), designated m14, was identified that bound to all antigens and neutralized heterologous HIV-1 isolates in multiple assay formats. Fab m14 potently neutralized selected well-characterized subtype B isolates, including JRCSF, 89.6, IIIB, and Yu2. Immunoglobulin G1 (IgG1) m14 was more potent than Fab m14 and neutralized 7 of 10 other clade B isolates; notably, although the potency was on average significantly lower than that of IgG1 b12, IgG1 m14 neutralized two of the isolates with significantly lower 50% inhibitory concentrations than did IgG1 b12. IgG1 m14 neutralized four of four selected clade C isolates with potency higher than that of IgG1 b12. It also neutralized 7 of 17 clade C isolates from southern Africa that were difficult to neutralize with other hMAbs and sCD4. IgG1 m14 neutralized four of seven primary HIV-1 isolates from other clades (A, D, E, and F) much more efficiently than did IgG1 b12; for the other three isolates, IgG b12 was much more potent. Fab m14 bound with high (nanomolar range) affinity to gp120 and gp140 from various isolates; its binding was reduced by soluble CD4 and antibodies recognizing the CD4 binding site (CD4bs) on gp120, and its footprint as defined by alanine-scanning mutagenesis overlaps that of b12. These results suggest that m14 is a novel CD4bs cross-reactive HIV-1-neutralizing antibody that exhibits a different inhibitory profile compared to the only known potent broadly neutralizing CD4bs human antibody, b12, and may have implications for our understanding of the mechanisms of immune evasion and for the development of inhibitors and vaccines.
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Affiliation(s)
- Mei-Yun Zhang
- Human Immunovirology Group, Laboratory of Experimental and Computational Biology, Center for Cancer Research, National Cancer Institute-Frederick, NIH, Frederick, Maryland 21702-1201, USA
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Sreepian A, Srisurapanon S, Horthongkham N, Tunsupasawasdikul S, Kaoriangudom S, Khusmith S, Sutthent R. Conserved neutralizing epitopes of HIV type 1 CRF01_AE against primary isolates in long-term nonprogressors. AIDS Res Hum Retroviruses 2004; 20:531-42. [PMID: 15186528 DOI: 10.1089/088922204323087787] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Linear conserved B cell epitopes in envelope glycoprotein of long-term nonprogressors (LTNPs) HIV-1 CRF01_AE were determined. The envelope sequences of HIV-1 subtype E from Thailand were aligned to define consensus sequences. Then the peptides corresponding to these predicted regions were synthesized as peptides represent C1, C2, C3, C5, V2, V3, and gp41 regions. After that, the neutralizing B cell epitopes were determined by neutralized competitive assay with pool sera of typical progressor and LTNP HIV-1 CRF01_AE patients against HIV-1 CRF01_AE 24 primary isolates (PI) and laboratory strains (TCLA). We found that the strength and breadth of neutralization were greater for sera from LTNPs compared with sera from typical progressors. Peptides C1E and C2E could inhibit primary isolates but not the TCLA strain in LTNP sera. The new B cell epitopes, which were located in the C1 and C2 regions of CRF01_AE against primary HIV-1 isolates, were identified in HIV-1 CRF01_AE LTNPs. This may be important in HIV-1 vaccine development and trial.
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Affiliation(s)
- Apichai Sreepian
- Department of Microbiology, Mahidol University, Bangkok, Thailand 10700
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Gzyl J, Bolesta E, Wierzbicki A, Kmieciak D, Naito T, Honda M, Komuro K, Kaneko Y, Kozbor D. Effect of partial and complete variable loop deletions of the human immunodeficiency virus type 1 envelope glycoprotein on the breadth of gp160-specific immune responses. Virology 2004; 318:493-506. [PMID: 14972518 DOI: 10.1016/j.virol.2003.10.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2003] [Revised: 09/23/2003] [Accepted: 10/09/2003] [Indexed: 11/28/2022]
Abstract
Induction of cross-reactive cellular and humoral responses to the HIV-1 envelope (env) glycoprotein was examined after DNA immunization of BALB/c mice with gp140(89.6)-derived constructs exhibiting partial or complete deletions of the V1, V2, and V3 domains. It was demonstrated that specific modification of the V3 loop (mV3) in combination with the V2-modified (mV2) or V1/V2-deleted (DeltaV1/V2) region elicited increased levels of cross-reactive CD8(+) T cell responses. Mice immunized with the mV2/mV3 or DeltaV1/V2/mV3 gp140(89.6) plasmid DNA were greater than 50-fold more resistant to challenge with recombinant vaccinia virus (rVV) expressing heterologous env gene products than animals immunized with the wild-type (WT) counterpart. Sera from mV2/mV3- and DeltaV1/V2/mV3-immunized mice exhibited the highest cross-neutralizing activity and displayed intermediate antibody avidity values which were further enhanced by challenge with rVV expressing the homologous gp160 glycoprotein. In contrast, complete deletion of the variable regions had little or no effect on the cross-reactive antibody responses. The results of these experiments indicate that the breadth of antibody responses to the HIV-1 env glycoprotein may not be increased by removal of the variable domains. Instead, partial deletions within these regions may redirect specific responses toward conserved epitopes and facilitate approaches for boosting cross-reactive cellular and antibody responses to the env glycoprotein.
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Affiliation(s)
- Jaroslaw Gzyl
- Department of Immunology, Roswell Park Cancer Institute, Elm and Carlton Streets, Buffalo, NY 14263, USA
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Center RJ, Lebowitz J, Leapman RD, Moss B. Promoting trimerization of soluble human immunodeficiency virus type 1 (HIV-1) Env through the use of HIV-1/simian immunodeficiency virus chimeras. J Virol 2004; 78:2265-76. [PMID: 14963123 PMCID: PMC369220 DOI: 10.1128/jvi.78.5.2265-2276.2004] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The envelope proteins (Env) of human immunodeficiency virus type 1 (HIV-1) and simian immunodeficiency virus (SIV) form homo-oligomers in the endoplasmic reticulum. The oligomeric structure of Env is maintained, but is less stable, after cleavage in a Golgi compartment and transport to the surface of infected cells. Functional, virion-associated HIV-1 and SIV Env have an almost exclusively trimeric structure. In addition, a soluble form of SIV Env (gp140) forms a nearly homogeneous population of trimers. Here, we describe the oligomeric structure of soluble, uncleaved HIV-1 gp140 and modifications that promote a stable trimeric structure. Biochemical and biophysical analyses, including sedimentation equilibrium and scanning transmission electron microscopy, revealed that unmodified HIV-1 gp140 purified as a heterogeneous range of oligomeric species, including dimers and aggregates. Deletion of the V2 domain alone or, especially, both the V1 and V2 domains reduced dimer formation but promoted aggregation rather than trimerization. Expressing gp140 with mannose-only oligosaccharides did not eliminate heterogeneity. Replacement of the entire gp41 segment of HIV-1 gp140 or just the N-terminal half (85 amino acids) of this segment with the corresponding region of SIV was sufficient to confer efficient trimerization for gp140 derived from clade B and C isolates. Importantly, the relatively small segment of the HIV Env replaced by SIV sequences contains no known targets of neutralizing antibody. The soluble trimeric form of HIV-1 Env should prove useful for assessment of antigenic structure and immunogenicity.
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MESH Headings
- Chromatography, Gel
- Dimerization
- Gene Products, env/chemistry
- Gene Products, env/genetics
- Gene Products, env/metabolism
- Gene Products, env/ultrastructure
- HIV Envelope Protein gp41/chemistry
- HIV Envelope Protein gp41/genetics
- HIV Envelope Protein gp41/metabolism
- HIV-1/chemistry
- Mannose/analysis
- Microscopy, Electron, Scanning Transmission
- Molecular Weight
- Protein Structure, Quaternary
- Protein Structure, Tertiary
- Recombinant Fusion Proteins/chemistry
- Recombinant Fusion Proteins/genetics
- Recombinant Fusion Proteins/metabolism
- Sequence Deletion
- Simian Immunodeficiency Virus/chemistry
- Solubility
- env Gene Products, Human Immunodeficiency Virus
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Affiliation(s)
- Rob J Center
- Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA.
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Lorin C, Mollet L, Delebecque F, Combredet C, Hurtrel B, Charneau P, Brahic M, Tangy F. A single injection of recombinant measles virus vaccines expressing human immunodeficiency virus (HIV) type 1 clade B envelope glycoproteins induces neutralizing antibodies and cellular immune responses to HIV. J Virol 2004; 78:146-57. [PMID: 14671096 PMCID: PMC303376 DOI: 10.1128/jvi.78.1.146-157.2004] [Citation(s) in RCA: 110] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The anchored and secreted forms of the human immunodeficiency virus type 1 (HIV-1) 89.6 envelope glycoprotein, either complete or after deletion of the V3 loop, were expressed in a cloned attenuated measles virus (MV) vector. The recombinant viruses grew as efficiently as the parental virus and expressed high levels of the HIV protein. Expression was stable during serial passages. The immunogenicity of these recombinant vectors was tested in mice susceptible to MV and in macaques. High titers of antibodies to both MV and HIV-Env were obtained after a single injection in susceptible mice. These antibodies neutralized homologous SHIV89.6p virus, as well as several heterologous HIV-1 primary isolates. A gp160 mutant in which the V3 loop was deleted induced antibodies that neutralized heterologous viruses more efficiently than antibodies induced by the native envelope protein. A high level of CD8+ and CD4+ cells specific for HIV gp120 was also detected in MV-susceptible mice. Furthermore, recombinant MV was able to raise immune responses against HIV in mice and macaques with a preexisting anti-MV immunity. Therefore, recombinant MV vaccines inducing anti-HIV neutralizing antibodies and specific T lymphocytes responses deserve to be tested as a candidate AIDS vaccine.
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Affiliation(s)
- Clarisse Lorin
- Unité des Virus Lents, CNRS URA 1930, Unité de Physiopathologie des Infections Lentivirales, Groupe de Virologie Moléculaire et de Vectorologie, Institut Pasteur, Paris, France
| | - Lucile Mollet
- Unité des Virus Lents, CNRS URA 1930, Unité de Physiopathologie des Infections Lentivirales, Groupe de Virologie Moléculaire et de Vectorologie, Institut Pasteur, Paris, France
| | - Frédéric Delebecque
- Unité des Virus Lents, CNRS URA 1930, Unité de Physiopathologie des Infections Lentivirales, Groupe de Virologie Moléculaire et de Vectorologie, Institut Pasteur, Paris, France
| | - Chantal Combredet
- Unité des Virus Lents, CNRS URA 1930, Unité de Physiopathologie des Infections Lentivirales, Groupe de Virologie Moléculaire et de Vectorologie, Institut Pasteur, Paris, France
| | - Bruno Hurtrel
- Unité des Virus Lents, CNRS URA 1930, Unité de Physiopathologie des Infections Lentivirales, Groupe de Virologie Moléculaire et de Vectorologie, Institut Pasteur, Paris, France
| | - Pierre Charneau
- Unité des Virus Lents, CNRS URA 1930, Unité de Physiopathologie des Infections Lentivirales, Groupe de Virologie Moléculaire et de Vectorologie, Institut Pasteur, Paris, France
| | - Michel Brahic
- Unité des Virus Lents, CNRS URA 1930, Unité de Physiopathologie des Infections Lentivirales, Groupe de Virologie Moléculaire et de Vectorologie, Institut Pasteur, Paris, France
| | - Frédéric Tangy
- Unité des Virus Lents, CNRS URA 1930, Unité de Physiopathologie des Infections Lentivirales, Groupe de Virologie Moléculaire et de Vectorologie, Institut Pasteur, Paris, France
- Corresponding author. Mailing address: Unité des Virus Lents, Institut Pasteur, 28 rue du Dr Roux, 75015 Paris, France. Phone: (33) 1-45-68-87-73. Fax: (33) 1-40-61-31-67. E-mail:
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