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Klasse PJ, Moore JP. Good CoP, bad CoP? Interrogating the immune responses to primate lentiviral vaccines. Retrovirology 2012; 9:80. [PMID: 23025660 PMCID: PMC3484039 DOI: 10.1186/1742-4690-9-80] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2012] [Accepted: 09/14/2012] [Indexed: 11/17/2022] Open
Abstract
Correlates of protection (CoPs) against infection by primate lentiviruses remain undefined. Modest protection against HIV-1 was observed in one human vaccine trial, whereas previous trials and vaccine-challenge experiments in non-human primates have yielded inconsistent but intriguing results. Although high levels of neutralizing antibodies are known to protect macaques from mucosal and intravenous viral challenges, antibody or other adaptive immune responses associated with protection might also be mere markers of innate immunity or susceptibility. Specific strategies for augmenting the design of both human trials and animal experiments could help to identify mechanistic correlates of protection and clarify the influences of confounding factors. Robust protection may, however, require the combined actions of immune responses and other host factors, thereby limiting what inferences can be drawn from statistical associations. Here, we discuss how to analyze immune protection against primate lentiviruses, and how host factors could influence both the elicitation and effectiveness of vaccine-induced responses.
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Affiliation(s)
- Per Johan Klasse
- Department of Microbiology and Immunology, Weill Cornell Medical College, Cornel University, 1300 York Avenue, Box 62, New York, NY 10065-4896, USA.
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Lindqvist M, van Lunzen J, Soghoian DZ, Kuhl BD, Ranasinghe S, Kranias G, Flanders MD, Cutler S, Yudanin N, Muller MI, Davis I, Farber D, Hartjen P, Haag F, Alter G, Schulze zur Wiesch J, Streeck H. Expansion of HIV-specific T follicular helper cells in chronic HIV infection. J Clin Invest 2012; 122:3271-80. [PMID: 22922259 DOI: 10.1172/jci64314] [Citation(s) in RCA: 342] [Impact Index Per Article: 28.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2012] [Accepted: 07/05/2012] [Indexed: 01/13/2023] Open
Abstract
HIV targets CD4 T cells, which are required for the induction of high-affinity antibody responses and the formation of long-lived B cell memory. The depletion of antigen-specific CD4 T cells during HIV infection is therefore believed to impede the development of protective B cell immunity. Although several different HIV-related B cell dysfunctions have been described, the role of CD4 T follicular helper (TFH) cells in HIV infection remains unknown. Here, we assessed HIV-specific TFH responses in the lymph nodes of treatment-naive and antiretroviral-treated HIV-infected individuals. Strikingly, both the bulk TFH and HIV-specific TFH cell populations were significantly expanded in chronic HIV infection and were highly associated with viremia. In particular, GAG-specific TFH cells were detected at significantly higher levels in the lymph nodes compared with those of GP120-specific TFH cells and showed preferential secretion of the helper cytokine IL-21. In addition, TFH cell expansion was associated with an increase of germinal center B cells and plasma cells as well as IgG1 hypersecretion. Thus, our study suggests that high levels of HIV viremia drive the expansion of TFH cells, which in turn leads to perturbations of B cell differentiation, resulting in dysregulated antibody production.
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Friis AMC, Akerlund B, Gyllensten K, Aleman A, Bratt G, Sandström E, Ernberg I. Epstein-Barr virus genome load is increased by therapeutic vaccination in HIV-l carriers, and further enhanced in patients with a history of symptomatic primary infection. Vaccine 2012; 30:6093-8. [PMID: 22863659 DOI: 10.1016/j.vaccine.2012.07.041] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2012] [Revised: 06/23/2012] [Accepted: 07/18/2012] [Indexed: 01/24/2023]
Abstract
OBJECTIVE Epstein-Barr virus (EBV) infection is an established risk factor for B-cell lymphomas in Human Immunodeficiency virus (HIV)-1 infected patients. A disturbed EBV-host relationship is seen in patient groups with a high risk for EBV-associated lymphomas. We have analysed this relationship by measuring EBV-DNA in the blood of HIV-1 carriers. METHOD EBV-DNA load in B-cells was monitored by PCR in non- or insufficiently antiretroviral treated and rgp160-vaccinated HIV-patients. RESULTS Both asymptomatic HIV-infected and AIDS-patients showed a 25-40-fold increase in the number of B cell associated EBV-DNA copies compared to healthy controls. Patients included in a vaccine trial with recombinant HIV gp160 showed a 5-fold increase of EBV load compared to non-immunised patients and a 50-fold increase compared to healthy controls. There was no difference whether they received vaccine or "placebo". Vaccinated patients with a history of symptomatic primary HIV-1 infection (PHI) had a 280-fold increase in median EBV load compared to healthy controls, thus suggesting a synergistic effect between the vaccination and PHI, which hypothetically could affect lymphoma risk. CONCLUSIONS We recommend analysis of EBV-load and long term follow up of lymphoma risk in all therapeutic HIV-1 vaccination trials.
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Affiliation(s)
- Anna M C Friis
- Department of Microbiology, Tumor and Cell Biology (MTC), Karolinska Institute, Box 280, SE-171 77, Stockholm, Sweden.
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Depetris RS, Julien JP, Khayat R, Lee JH, Pejchal R, Katpally U, Cocco N, Kachare M, Massi E, David KB, Cupo A, Marozsan AJ, Olson WC, Ward AB, Wilson IA, Sanders RW, Moore JP. Partial enzymatic deglycosylation preserves the structure of cleaved recombinant HIV-1 envelope glycoprotein trimers. J Biol Chem 2012; 287:24239-54. [PMID: 22645128 DOI: 10.1074/jbc.m112.371898] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The trimeric envelope glycoprotein complex (Env) is the focus of vaccine development programs aimed at generating protective humoral responses to human immunodeficiency virus type 1 (HIV-1). N-Linked glycans, which constitute almost half of the molecular mass of the external Env domains, produce considerable structural heterogeneity and are a major impediment to crystallization studies. Moreover, by shielding the peptide backbone, glycans can block attempts to generate neutralizing antibodies against a substantial subset of potential epitopes when Env proteins are used as immunogens. Here, we describe the partial deglycosylation of soluble, cleaved recombinant Env trimers by inhibition of the synthesis of complex N-glycans during Env production, followed by treatment with glycosidases under conditions that preserve Env trimer integrity. The partially deglycosylated trimers are stable, and neither abnormally sensitive to proteolytic digestion nor prone to aggregation. Moreover, the deglycosylated trimers retain or increase their ability to bind CD4 and antibodies that are directed to conformational epitopes, including the CD4-binding site and the V3 region. However, as expected, they do not react with glycan-dependent antibodies 2G12 and PGT123, or the C-type lectin receptor DC-SIGN. Electron microscopic analysis shows that partially deglycosylated trimers have a structure similar to fully glycosylated trimers, indicating that removal of glycans does not substantially perturb the structural integrity of the trimer. The glycan-depleted Env trimers should be useful for structural and immunogenicity studies.
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Affiliation(s)
- Rafael S Depetris
- Department of Microbiology and Immunology, Weill Medical College of Cornell University, New York, New York 10065, USA
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Rosales-Mendoza S, Rubio-Infante N, Govea-Alonso DO, Moreno-Fierros L. Current status and perspectives of plant-based candidate vaccines against the human immunodeficiency virus (HIV). PLANT CELL REPORTS 2012; 31:495-511. [PMID: 22159962 DOI: 10.1007/s00299-011-1194-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2011] [Revised: 11/03/2011] [Accepted: 11/18/2011] [Indexed: 05/31/2023]
Abstract
Genetically engineered plants are economical platforms for the large-scale production of recombinant proteins and have been used over the last 21 years as models for oral vaccines against a wide variety of human infectious and autoimmune diseases with promising results. The main inherent advantages of this approach consist in the absence of purification needs and easy production and administration. One relevant infectious agent is the human immunodeficiency virus (HIV), since AIDS evolved as an alarming public health problem implicating very high costs for government agencies in most African and developing countries. The design of an effective and inexpensive vaccine able to limit viral spread and neutralizing the viral entry is urgently needed. Due to the limited efficacy of the vaccines assessed in clinical trials, new HIV vaccines able to generate broad immune profiles are a priority in the field. This review discusses the current advances on the topic of using plants as alternative expression systems to produce functional vaccine components against HIV, including antigens from Env, Gag and early proteins such as Tat and Nef. Ongoing projects of our group based on the expression of chimeric proteins comprising C4 and V3 domains from gp120, as an approach to elicit broadly neutralizing antibodies are mentioned. The perspectives of the revised approaches, such as the great need of assessing the oral immunogenicity and a detailed immunological characterization of the elicited immune responses, are also discussed.
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Affiliation(s)
- Sergio Rosales-Mendoza
- Laboratorio de Biofarmacéuticos recombinantes, Universidad Autónoma de San Luis Potosí, Av. Dr. Manuel Nava 6, San Luis Potosí 78210, Mexico.
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56
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Influence of dendritic cells on B-cell responses during HIV infection. Clin Dev Immunol 2012; 2012:592187. [PMID: 22461837 PMCID: PMC3296217 DOI: 10.1155/2012/592187] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2011] [Revised: 12/11/2011] [Accepted: 12/12/2011] [Indexed: 12/23/2022]
Abstract
Dendritic cells (DCs) modulate B-cell differentiation, activation, and survival mainly through production of growth factors such as B lymphocyte stimulator (BLyS/BAFF). DC populations have been reported to be affected in number, phenotype and function during HIV infection and such alterations may contribute to the dysregulation of the B-cell compartment. Herein, we reflect on the potential impact of DC on the pathogenesis of HIV-related B cell disorders, and how DC status may modulate the outcome of mucosal B cell responses against HIV, which are pivotal to the control of disease. A concept that could be extrapolated to the overall outcome of HIV disease, whereby control versus progression may reside in the host's capacity to maintain DC homeostasis at mucosal sites, where DC populations present an inherent capacity of modulating the balance between tolerance and protection, and are amongst the earliest cell types to be exposed to the virus.
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Banerjee K, Michael E, Eggink D, van Montfort T, Lasnik AB, Palmer KE, Sanders RW, Moore JP, Klasse PJ. Occluding the mannose moieties on human immunodeficiency virus type 1 gp120 with griffithsin improves the antibody responses to both proteins in mice. AIDS Res Hum Retroviruses 2012; 28:206-14. [PMID: 21793733 DOI: 10.1089/aid.2011.0101] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
To assess the influence of mannosylated glycans on the immunogenicity of human immunodeficiency virus type 1 (HIV-1) Env proteins, we immunized mice with monomeric gp120 in the presence and absence of the mannose-binding protein, griffithsin (GRFT). For comparison, other groups of mice received the nonglycosylated HIV-1 Gag protein, with and without GRFT. Coimmunization with GRFT increased the anti-gp120 IgG reactivity significantly, but had no effect on the anti-Gag response. We also investigated the IgG response to GRFT and found that gp120, but not Gag, enhanced its immunogenicity. For both proteins, IgG1 antibodies dominated the IgG response, with IgG2b as the next most prevalent subclass. We conclude that gp120-GRFT complexes are more immunogenic than the free proteins, for both components, and that occluding the mannose moieties on monomeric gp120 can improve the humoral immune response to this protein.
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Affiliation(s)
- Kaustuv Banerjee
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, New York
| | - Elizabeth Michael
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, New York
| | - Dirk Eggink
- Laboratory of Experimental Virology, Department of Medical Microbiology, Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center of the University of Amsterdam, Amsterdam, The Netherlands
| | - Thijs van Montfort
- Laboratory of Experimental Virology, Department of Medical Microbiology, Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center of the University of Amsterdam, Amsterdam, The Netherlands
| | - Amanda B. Lasnik
- James Graham Brown Cancer Center, Owensboro Cancer Research Program and Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, Kentucky
| | - Kenneth E. Palmer
- James Graham Brown Cancer Center, Owensboro Cancer Research Program and Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, Kentucky
| | - Rogier W. Sanders
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, New York
- Laboratory of Experimental Virology, Department of Medical Microbiology, Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center of the University of Amsterdam, Amsterdam, The Netherlands
| | - John P. Moore
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, New York
| | - Per Johan Klasse
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, New York
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Targeting HIV-1 envelope glycoprotein trimers to B cells by using APRIL improves antibody responses. J Virol 2011; 86:2488-500. [PMID: 22205734 DOI: 10.1128/jvi.06259-11] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
An HIV-1 vaccine remains elusive, in part because various factors limit the quantity and quality of the antibodies raised against the viral envelope glycoprotein complex (Env). We hypothesized that targeting Env vaccines directly to B cells, by fusing them to molecules that bind and activate these cells, would improve Env-specific antibody responses. Therefore, we fused trimeric Env gp140 to A PRoliferation-Inducing Ligand (APRIL), B-cell Activating Factor (BAFF), and CD40 Ligand (CD40L). The Env-APRIL, Env-BAFF, and Env-CD40L gp140 trimers all enhanced the expression of activation-induced cytidine deaminase (AID), the enzyme responsible for inducing somatic hypermutation, antibody affinity maturation, and antibody class switching. They also triggered IgM, IgG, and IgA secretion from human B cells in vitro. The Env-APRIL trimers induced higher anti-Env antibody responses in rabbits, including neutralizing antibodies against tier 1 viruses. The enhanced Env-specific responses were not associated with a general increase in total plasma antibody concentrations, indicating that the effect of APRIL was specific for Env. All the rabbit sera raised against gp140 trimers, irrespective of the presence of CD40L, BAFF, or APRIL, recognized trimeric Env efficiently, whereas sera raised against gp120 monomers did not. The levels of trimer-binding and virus-neutralizing antibodies were strongly correlated, suggesting that gp140 trimers are superior to gp120 monomers as immunogens. Targeting and activating B cells with a trimeric HIV-1 Env-APRIL fusion protein may therefore improve the induction of humoral immunity against HIV-1.
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59
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Bilello JP, Manrique JM, Shin YC, Lauer W, Li W, Lifson JD, Mansfield KG, Johnson RP, Desrosiers RC. Vaccine protection against simian immunodeficiency virus in monkeys using recombinant gamma-2 herpesvirus. J Virol 2011; 85:12708-20. [PMID: 21900170 PMCID: PMC3209374 DOI: 10.1128/jvi.00865-11] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2011] [Accepted: 08/27/2011] [Indexed: 12/21/2022] Open
Abstract
Recombinant strains of replication-competent rhesus monkey rhadinovirus (RRV) were constructed in which strong promoter/enhancer elements were used to drive expression of simian immunodeficiency virus (SIV) Env or Gag or a Rev-Tat-Nef fusion protein. Cultured rhesus monkey fibroblasts infected with each recombinant strain were shown to express the expected protein. Three RRV-negative and two RRV-positive rhesus monkeys were inoculated intravenously with a mixture of these three recombinant RRVs. Expression of SIV Gag was readily detected in lymph node biopsy specimens taken at 3 weeks postimmunization. Impressive anti-SIV cellular immune responses were elicited on the basis of major histocompatibility complex (MHC) tetramer staining and gamma interferon enzyme-linked immunospot (ELISPOT) assays. Responses were much greater in magnitude in the monkeys that were initially RRV negative but were still readily detected in the two monkeys that were naturally infected with RRV at the time of immunization. By 3 weeks postimmunization, responses measured by MHC tetramer staining in the two Mamu-A*01(+) RRV-negative monkeys reached 9.3% and 13.1% of all CD8(+) T cells in peripheral blood to the Gag CM9 epitope and 2.3% and 7.3% of all CD8(+) T cells in peripheral blood to the Tat SL8 epitope. Virus-specific CD8(+) T cell responses persisted at high levels up to the time of challenge at 18 weeks postimmunization, and responding cells maintained an effector memory phenotype. Despite the ability of the RRVenv recombinant to express high levels of Env in cultured cells, and despite the appearance of strong anti-RRV antibody responses in immunized monkeys, anti-Env antibody responses were below our ability to detect them. Immunized monkeys, together with three unimmunized controls, were challenged intravenously with 10 monkey infectious doses of SIVmac239. All five immunized monkeys and all three controls became infected with SIV, but peak viral loads were 1.2 to 3.0 log(10) units lower and chronic-phase viral loads were 1.0 to 3.0 log(10) units lower in immunized animals than the geometric mean of unimmunized controls. These differences were statistically significant. Anti-Env antibody responses following challenge indicated an anamnestic response in the vaccinated monkeys. These findings further demonstrate the potential of recombinant herpesviruses as preventive vaccines for AIDS. We hypothesize that this live, replication-competent, persistent herpesvirus vector could match, or come close to matching, live attenuated strains of SIV in the degree of protection if the difficulty with elicitation of anti-Env antibody responses can be overcome.
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MESH Headings
- Animals
- Antibodies, Viral/immunology
- Blotting, Western
- Enzyme-Linked Immunosorbent Assay
- Flow Cytometry
- Gammaherpesvirinae/genetics
- Gammaherpesvirinae/immunology
- Gene Products, env/administration & dosage
- Gene Products, env/genetics
- Gene Products, env/immunology
- Gene Products, gag/administration & dosage
- Gene Products, gag/genetics
- Gene Products, gag/immunology
- Gene Products, nef/genetics
- Gene Products, nef/immunology
- Genetic Vectors
- Herpesviridae Infections/genetics
- Herpesviridae Infections/metabolism
- Herpesviridae Infections/virology
- Humans
- Immunity, Cellular
- Immunoenzyme Techniques
- Kidney/cytology
- Kidney/metabolism
- Kidney/virology
- Macaca mulatta/genetics
- Macaca mulatta/immunology
- Macaca mulatta/virology
- Neutralization Tests
- Plasmids
- Recombination, Genetic
- SAIDS Vaccines/administration & dosage
- SAIDS Vaccines/genetics
- SAIDS Vaccines/immunology
- Simian Acquired Immunodeficiency Syndrome/immunology
- Simian Acquired Immunodeficiency Syndrome/prevention & control
- Simian Acquired Immunodeficiency Syndrome/virology
- Simian Immunodeficiency Virus/immunology
- Vaccination
- Viral Load
- Virus Replication
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Affiliation(s)
- John P. Bilello
- New England Primate Research Center, Harvard Medical School, Southborough, Massachusetts 01772-9102
| | - Julieta M. Manrique
- New England Primate Research Center, Harvard Medical School, Southborough, Massachusetts 01772-9102
| | - Young C. Shin
- New England Primate Research Center, Harvard Medical School, Southborough, Massachusetts 01772-9102
| | - William Lauer
- New England Primate Research Center, Harvard Medical School, Southborough, Massachusetts 01772-9102
| | - Wenjun Li
- University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, Massachusetts 01655
| | - Jeffrey D. Lifson
- AIDS and Cancer Virus Program, SAIC Frederick Inc., National Cancer Institute, NCI Frederick, Frederick, Maryland 21702
| | - Keith G. Mansfield
- New England Primate Research Center, Harvard Medical School, Southborough, Massachusetts 01772-9102
| | - R. Paul Johnson
- New England Primate Research Center, Harvard Medical School, Southborough, Massachusetts 01772-9102
| | - Ronald C. Desrosiers
- New England Primate Research Center, Harvard Medical School, Southborough, Massachusetts 01772-9102
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60
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Potent intratype neutralizing activity distinguishes human immunodeficiency virus type 2 (HIV-2) from HIV-1. J Virol 2011; 86:961-71. [PMID: 22072782 DOI: 10.1128/jvi.06315-11] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
HIV-2 has a lower pathogenicity and transmission rate than HIV-1. Neutralizing antibodies could be contributing to these observations. Here we explored side by side the potency and breadth of intratype and intertype neutralizing activity (NAc) in plasma of 20 HIV-1-, 20 HIV-2-, and 11 dually HIV-1/2 (HIV-D)-seropositive individuals from Guinea-Bissau, West Africa. Panels of primary isolates, five HIV-1 and five HIV-2 isolates, were tested in a plaque reduction assay using U87.CD4-CCR5 cells as targets. Intratype NAc in HIV-2 plasma was found to be considerably more potent and also broader than intratype NAc in HIV-1 plasma. This indicates that HIV-2-infected individuals display potent type-specific neutralizing antibodies, whereas such strong type-specific antibodies are absent in HIV-1 infection. Furthermore, the potency of intratype NAc was positively associated with the viral load of HIV-1 but not HIV-2, suggesting that NAc in HIV-1 infection is more antigen stimulation dependent than in HIV-2 infection, where plasma viral loads typically are at least 10-fold lower than in HIV-1 infection. Intertype NAc of both HIV-1 and HIV-2 infections was, instead, of low potency. HIV-D subjects had NAc to HIV-2 with similar high potency as singly HIV-2-infected individuals, whereas neutralization of HIV-1 remained poor, indicating that the difference in NAc between HIV-1 and HIV-2 infections depends on the virus itself. We suggest that immunogenicity and/or antigenicity, meaning the neutralization phenotype, of HIV-2 is distinct from that of HIV-1 and that HIV-2 may display structures that favor triggering of potent neutralizing antibody responses.
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Ketas TJ, Holuigue S, Matthews K, Moore JP, Klasse PJ. Env-glycoprotein heterogeneity as a source of apparent synergy and enhanced cooperativity in inhibition of HIV-1 infection by neutralizing antibodies and entry inhibitors. Virology 2011; 422:22-36. [PMID: 22018634 DOI: 10.1016/j.virol.2011.09.019] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2011] [Revised: 08/19/2011] [Accepted: 09/17/2011] [Indexed: 10/16/2022]
Abstract
We measured the inhibition of infectivity of HIV-1 isolates and derivative clones by combinations of neutralizing antibodies (NAbs) and other entry inhibitors in a single-cycle-replication assay. Synergy was analyzed both by the current linear and a new non-linear method. The new method reduced spurious indications of synergy and antagonism. Synergy between NAbs was overall weaker than between other entry inhibitors, and no stronger where one ligand is known to enhance the binding of another. However, synergy was stronger for a genetically heterogeneous HIV-1 R5 isolate than for its derivative clones. Enhanced cooperativity in inhibition by combinations, compared with individual inhibitors, correlated with increased synergy at higher levels of inhibition, while being less variable. Again, cooperativity enhancement was stronger for isolates than clones. We hypothesize that genetic, post-translational or conformational heterogeneity of the Env protein and of other targets for inhibitors can yield apparent synergy and increased cooperativity between inhibitors.
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Affiliation(s)
- Thomas J Ketas
- Department of Microbiology and Immunology, Weill Medical College of Cornell University, New York, NY 10065-4896, USA
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62
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Lara HH, Ixtepan-Turrent L, Garza Treviño EN, Singh DK. Use of silver nanoparticles increased inhibition of cell-associated HIV-1 infection by neutralizing antibodies developed against HIV-1 envelope proteins. J Nanobiotechnology 2011; 9:38. [PMID: 21923937 PMCID: PMC3180349 DOI: 10.1186/1477-3155-9-38] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2011] [Accepted: 09/18/2011] [Indexed: 12/22/2022] Open
Abstract
Background HIV/AIDS pandemic is a worldwide public health issue. There is a need for new approaches to develop new antiviral compounds or other therapeutic strategies to limit viral transmission. The envelope glycoproteins gp120 and gp41 of HIV are the main targets for both silver nanoparticles (AgNPs) and neutralizing antibodies. There is an urgency to optimize the efficiency of the neutralizing antibodies (NABs). In this study, we demonstrated that there is an additive effect between the four NABs and AgNPs when combined against cell-associated HIV-1 infection in vitro Results Four NABs (Monoclonal antibody to HIV-1 gp41 126-7, HIV-1 gp120 Antiserum PB1 Sub 2, HIV-1 gp120 Antiserum PB1, HIV-1 gp120 Monoclonal Antibody F425 B4e8) with or without AgNPs of 30-50 nm in size were tested against cell free and cell-associated HIVIIIB virus. All NABs inhibited HIV-1 cell free infection at a dose response manner, but with AgNPs an antiviral additive effect was not achieved Although there was no inhibition of infection with cell-associated virus by the NABs itself, AgNPs alone were able to inhibit cell associated virus infection and more importantly, when mixed together with NABs they inhibited the HIV-1 cell associated infection in an additive manner. Discussion The most attractive strategies to deal with the HIV problem are the development of a prophylactic vaccine and the development of effective topical vaginal microbicide. For two decades a potent vaccine that inhibits transmission of infection of HIV has been searched. There are vaccines that elicit NABs but none of them has the efficacy to stop transmission of HIV-1 infection. We propose that with the addition of AgNPs, NABs will have an additive effect and become more potent to inhibit cell-associated HIV-1 transmission/infection. Conclusions The addition of AgNPs to NABs has significantly increased the neutralizing potency of NABs in prevention of cell-associated HIV-1 transmission/infection. Further exploration is required to standardize potentiation of NABs by AgNPs. It is also required to evaluate in vivo toxicity of AgNPs before AgNPs could be incorporated in any antiviral vaginal creams.
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Affiliation(s)
- Humberto H Lara
- Department of Life Sciences, Winston-Salem State University, Winston Salem, NC 27110, USA
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63
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Trimeric HIV-1 glycoprotein gp140 immunogens and native HIV-1 envelope glycoproteins display the same closed and open quaternary molecular architectures. Proc Natl Acad Sci U S A 2011; 108:11440-5. [PMID: 21709254 DOI: 10.1073/pnas.1101414108] [Citation(s) in RCA: 136] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The initial step in HIV-1 infection occurs with the binding of cell surface CD4 to trimeric HIV-1 envelope glycoproteins (Env), a heterodimer of a transmembrane glycoprotein (gp41) and a surface glycoprotein (gp120). The design of soluble versions of trimeric Env that display structural and functional properties similar to those observed on intact viruses is highly desirable from the viewpoint of designing immunogens that could be effective as vaccines against HIV/AIDS. Using cryoelectron tomography combined with subvolume averaging, we have analyzed the structure of SOSIP gp140 trimers, which are cleaved, solubilized versions of the ectodomain of trimeric HIV-1 Env. We show that unliganded gp140 trimers adopt a quaternary arrangement similar to that displayed by native unliganded trimers on the surface of intact HIV-1 virions. When complexed with soluble CD4, Fab 17b, which binds to gp120 at its chemokine coreceptor binding site, or both soluble CD4 and 17b Fab, gp140 trimers display an open conformation in which there is an outward rotation and displacement of each gp120 protomer. We demonstrate that the molecular arrangements of gp120 trimers in the closed and open conformations of the soluble trimer are the same as those observed for the closed and open states, respectively, of trimeric gp120 on intact HIV-1 BaL virions, establishing that soluble gp140 trimers can be designed to mimic the quaternary structural transitions displayed by native trimeric Env.
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