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Sepúlveda-Crespo D, Sánchez-Rodríguez J, Serramía MJ, Gómez R, De La Mata FJ, Jiménez JL, Muñoz-Fernández MÁ. Triple combination of carbosilane dendrimers, tenofovir and maraviroc as potential microbicide to prevent HIV-1 sexual transmission. Nanomedicine (Lond) 2015; 10:899-914. [PMID: 25867856 DOI: 10.2217/nnm.14.79] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
AIM To research the synergistic activity by triple combinations of carbosilane dendrimers with tenofovir and maraviroc as topical microbicide. METHODS Cytotoxicity, anti-HIV-1 activity, vaginal irritation and histological analysis of triple combinations were determined. Analysis of combined effects and the median effective concentration were performed using CalcuSyn software. RESULTS Combinations showed a greater broad-spectrum anti-HIV-1 activity than the single-drug, and preserved this activity in acid environment or seminal fluid. The strongest combinations were G2-STE16/G2-S24P/tenofovir, G2-STE16/G2-S16/maraviroc and G2-STE16/tenofovir/maraviroc at 2:2:1, 10:10:1 10:5:1 ratios, respectively. They demonstrated strong synergistic activity profile due to the weighted average combination indices varied between 0.06 and 0.38. No irritation was detected in female BALB/c mice. CONCLUSION The three-drug combination increases their antiviral potency and act synergistically as potential microbicide.
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Affiliation(s)
- Daniel Sepúlveda-Crespo
- Laboratorio InmunoBiología Molecular, Hospital General Universitario Gregorio Marañón, Instituto de Investigación Sanitaria Gregorio Marañón, Spanish HIV-HGM Biobank, Networking Research Center on Bioengineering, Biomaterials & Nanomedicine (CIBER-BBN), Madrid, Spain
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Wang L, Koppolu S, Chappell C, Moncla BJ, Hillier SL, Mahal LK. Studying the effects of reproductive hormones and bacterial vaginosis on the glycome of lavage samples from the cervicovaginal cavity. PLoS One 2015; 10:e0127021. [PMID: 25993513 PMCID: PMC4439148 DOI: 10.1371/journal.pone.0127021] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Accepted: 04/10/2015] [Indexed: 01/15/2023] Open
Abstract
The cervicovaginal fluid (CVF) coating the vaginal epithelium is an important immunological mediator, providing a barrier to infection. Glycosylation of CVF proteins, such as mucins, IgG and S-IgA, plays a critical role in their immunological functions. Although multiple factors, such as hormones and microflora, may influence glycosylation of the CVF, few studies have examined their impact on this important immunological fluid. Herein we analyzed the glycosylation of cervicovaginal lavage (CVL) samples collected from 165 women under different hormonal conditions including: (1) no contraceptive, post-menopausal, (2) no contraceptive, days 1-14 of the menstrual cycle, (3) no contraceptive, days 15-28 of the menstrual cycle, (4) combined-oral contraceptive pills for at least 6 months, (5) depo-medroxyprogesterone acetate (Depo-Provera) injections for at least 6 months, (6) levonorgestrel IUD for at least 1 month. Glycomic profiling was obtained using our lectin microarray system, a rapid method to analyze carbohydrate composition. Although some small effects were observed due to hormone levels, the major influence on the glycome was the presence of an altered bacterial cohort due to bacterial vaginosis (BV). Compared to normal women, samples from women with BV contained lower levels of sialic acid and high-mannose glycans in their CVL. The change in high mannose levels was unexpected and may be related to the increased risk of HIV-infection observed in women with BV, as high mannose receptors are a viral entry pathway. Changes in the glycome were also observed with hormonal contraceptive use, in a contraceptive-dependent manner. Overall, microflora had a greater impact on the glycome than hormonal levels, and both of these effects should be more closely examined in future studies given the importance of glycans in the innate immune system.
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Affiliation(s)
- Linlin Wang
- Biomedical Chemistry Institute, Department of Chemistry, New York University, New York, NY, 10003, United States of America
| | - Sujeethraj Koppolu
- Biomedical Chemistry Institute, Department of Chemistry, New York University, New York, NY, 10003, United States of America
| | - Catherine Chappell
- Department of Obstetrics, Gynecology and Reproductive Sciences, Magee-Womens Hospital of the University of Pittsburgh Medical Center, Pittsburgh, PA, 15213, United States of America
| | - Bernard J. Moncla
- Department of Obstetrics, Gynecology and Reproductive Sciences, Magee-Womens Hospital of the University of Pittsburgh Medical Center, Pittsburgh, PA, 15213, United States of America
- Magee-Womens Research Institute, Pittsburgh, PA, 15213, United States of America
| | - Sharon L. Hillier
- Department of Obstetrics, Gynecology and Reproductive Sciences, Magee-Womens Hospital of the University of Pittsburgh Medical Center, Pittsburgh, PA, 15213, United States of America
- Magee-Womens Research Institute, Pittsburgh, PA, 15213, United States of America
| | - Lara K. Mahal
- Biomedical Chemistry Institute, Department of Chemistry, New York University, New York, NY, 10003, United States of America
- * E-mail:
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Acharya P, Lusvarghi S, Bewley CA, Kwong PD. HIV-1 gp120 as a therapeutic target: navigating a moving labyrinth. Expert Opin Ther Targets 2015; 19:765-83. [PMID: 25724219 DOI: 10.1517/14728222.2015.1010513] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
INTRODUCTION The HIV-1 gp120 envelope (Env) glycoprotein mediates attachment of virus to human target cells that display requisite receptors, CD4 and co-receptor, generally CCR5. Despite high-affinity interactions with host receptors and proof-of-principle by the drug maraviroc that interference with CCR5 provides therapeutic benefit, no licensed drug currently targets gp120. AREAS COVERED An overview of the role of gp120 in HIV-1 entry and of sites of potential gp120 vulnerability to therapeutic inhibition is presented. Viral defenses that protect these sites and turn gp120 into a moving labyrinth are discussed together with strategies for circumventing these defenses to allow therapeutic targeting of gp120 sites of vulnerability. EXPERT OPINION The gp120 envelope glycoprotein interacts with host proteins through multiple interfaces and has conserved structural features at these interaction sites. In spite of this, targeting gp120 for therapeutic purposes is challenging. Env mechanisms that have evolved to evade the humoral immune response also shield it from potential therapeutics. Nevertheless, substantial progress has been made in understanding HIV-1 gp120 structure and its interactions with host receptors, and in developing therapeutic leads that potently neutralize diverse HIV-1 strains. Synergies between advances in understanding, needs for therapeutics against novel viral targets and characteristics of breadth and potency for a number of gp120-targetting lead molecules bodes well for gp120 as a HIV-1 therapeutic target.
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Affiliation(s)
- Priyamvada Acharya
- National Institute of Allergy and Infectious Diseases/National Institutes of Health, Vaccine Research Center, Structural Biology Section , Room 4609B, 40 Convent Drive, Bethesda, MD 20892 , USA
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Fuqua JL, Wanga V, Palmer KE. Improving the large scale purification of the HIV microbicide, griffithsin. BMC Biotechnol 2015; 15:12. [PMID: 25887919 PMCID: PMC4349730 DOI: 10.1186/s12896-015-0120-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Accepted: 01/30/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Griffithsin is a broad spectrum antiviral lectin that inhibits viral entry and maturation processes through binding clusters of oligomannose glycans on viral envelope glycoproteins. An efficient, scaleable manufacturing process for griffithsin active pharmaceutical ingredient (API) is essential for particularly cost-sensitive products such as griffithsin -based topical microbicides for HIV-1 prevention in resource poor settings. Our previously published purification method used ceramic filtration followed by two chromatography steps, resulting in a protein recovery of 30%. Our objective was to develop a scalable purification method for griffithsin expressed in Nicotiana benthamiana plants that would increase yield, reduce production costs, and simplify manufacturing techniques. Considering the future need to transfer griffithsin manufacturing technology to resource poor areas, we chose to focus modifying the purification process, paying particular attention to introducing simple, low-cost, and scalable procedures such as use of temperature, pH, ion concentration, and filtration to enhance product recovery. RESULTS We achieved >99% pure griffithsin API by generating the initial green juice extract in pH 4 buffer, heating the extract to 55°C, incubating overnight with a bentonite MgCl2 mixture, and final purification with Capto™ multimodal chromatography. Griffithsin extracted with this protocol maintains activity comparable to griffithsin purified by the previously published method and we are able to recover a substantially higher yield: 88 ± 5% of griffithsin from the initial extract. The method was scaled to produce gram quantities of griffithsin with high yields, low endotoxin levels, and low purification costs maintained. CONCLUSIONS The methodology developed to purify griffithsin introduces and develops multiple tools for purification of recombinant proteins from plants at an industrial scale. These tools allow for robust cost-effective production and purification of griffithsin. The methodology can be readily scaled to the bench top or industry and process components can be used for purification of additional proteins based on biophysical characteristics.
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Affiliation(s)
- Joshua L Fuqua
- Owensboro Cancer Research Program, 1020 Breckenridge St., Suite 201, Owensboro, KY, 42303, USA.
- University of Louisville School of Medicine, James Graham Brown Cancer Center, 529 S Jackson Street, Louisville, KY, 40202, USA.
| | - Valentine Wanga
- Institute for Health Metrics and Evaluation, University of Washington, 2301 5th Ave, Suite 600, Seattle, WA, USA.
| | - Kenneth E Palmer
- Owensboro Cancer Research Program, 1020 Breckenridge St., Suite 201, Owensboro, KY, 42303, USA.
- University of Louisville School of Medicine, James Graham Brown Cancer Center, 529 S Jackson Street, Louisville, KY, 40202, USA.
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Martinez JP, Sasse F, Brönstrup M, Diez J, Meyerhans A. Antiviral drug discovery: broad-spectrum drugs from nature. Nat Prod Rep 2015; 32:29-48. [PMID: 25315648 DOI: 10.1039/c4np00085d] [Citation(s) in RCA: 128] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Covering: up to April 2014. The development of drugs with broad-spectrum antiviral activities is a long pursued goal in drug discovery. It has been shown that blocking co-opted host-factors abrogates the replication of many viruses, yet the development of such host-targeting drugs has been met with scepticism mainly due to toxicity issues and poor translation to in vivo models. With the advent of new and more powerful screening assays and prediction tools, the idea of a drug that can efficiently treat a wide range of viral infections by blocking specific host functions has re-bloomed. Here we critically review the state-of-the-art in broad-spectrum antiviral drug discovery. We discuss putative targets and treatment strategies, with particular focus on natural products as promising starting points for antiviral lead development.
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Affiliation(s)
- J P Martinez
- Infection Biology Group, Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona, Spain.
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Akkouh O, Ng TB, Singh SS, Yin C, Dan X, Chan YS, Pan W, Cheung RCF. Lectins with anti-HIV activity: a review. Molecules 2015; 20:648-68. [PMID: 25569520 PMCID: PMC6272367 DOI: 10.3390/molecules20010648] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 11/29/2014] [Indexed: 11/18/2022] Open
Abstract
Lectins including flowering plant lectins, algal lectins, cyanobacterial lectins, actinomycete lectin, worm lectins, and the nonpeptidic lectin mimics pradimicins and benanomicins, exhibit anti-HIV activity. The anti-HIV plant lectins include Artocarpus heterophyllus (jacalin) lectin, concanavalin A, Galanthus nivalis (snowdrop) agglutinin-related lectins, Musa acuminata (banana) lectin, Myrianthus holstii lectin, Narcissus pseudonarcissus lectin, and Urtica diocia agglutinin. The anti-HIV algal lectins comprise Boodlea coacta lectin, Griffithsin, Oscillatoria agardhii agglutinin. The anti-HIV cyanobacterial lectins are cyanovirin-N, scytovirin, Microcystis viridis lectin, and microvirin. Actinohivin is an anti-HIV actinomycete lectin. The anti-HIV worm lectins include Chaetopterus variopedatus polychaete marine worm lectin, Serpula vermicularis sea worm lectin, and C-type lectin Mermaid from nematode (Laxus oneistus). The anti-HIV nonpeptidic lectin mimics comprise pradimicins and benanomicins. Their anti-HIV mechanisms are discussed.
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Affiliation(s)
- Ouafae Akkouh
- Department of Biology and Medical Laboratory Research, Faculty of Technology, University of Applied Sciences Leiden, Zernikdreef 11, 2333 CK Leiden, The Netherlands.
| | - Tzi Bun Ng
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong, China.
| | - Senjam Sunil Singh
- Department of Biochemistry, Manipur University, Canchipur, Imphal 795003, India.
| | - Cuiming Yin
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong, China.
| | - Xiuli Dan
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong, China.
| | - Yau Sang Chan
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong, China.
| | - Wenliang Pan
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong, China.
| | - Randy Chi Fai Cheung
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong, China.
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Férir G, Gordts SC, Schols D. HIV-1 and its resistance to peptidic carbohydrate-binding agents (CBAs): an overview. Molecules 2014; 19:21085-112. [PMID: 25517345 PMCID: PMC6270665 DOI: 10.3390/molecules191221085] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Revised: 12/04/2014] [Accepted: 12/08/2014] [Indexed: 11/16/2022] Open
Abstract
The glycoproteins on the surfaces of enveloped viruses, such as HIV, can be considered as a unique target for antiviral therapy. Different carbohydrate-binding agents (CBAs) target specific glycans present on viral glycoproteins of enveloped viruses. It has been shown that long-term CBA pressure in vitro can result in mutant HIV-1 isolates with several N-linked glycan deletions on gp120. These studies demonstrated that mainly high-mannose type glycans are deleted. However, interestingly, N241, N262 and N356 on gp120 have never been found to be affected after prolonged CBA exposure. Here, we review the mutation and (cross)-resistance profiles of eleven specific generated CBA-resistant HIV-1 strains. We observed that the broad-neutralizing anti-carbohydrate binding mAb 2G12 became completely inactive against all the generated CBA-resistant HIV-1 clade B isolates. In addition, all of the CBAs discussed in this review, with the exception of NICTABA, interfered with the binding of 2G12 mAb to gp120 expressed on HIV-1-infected T cells. The cross-resistance profiles of mutant HIV-1 strains are varying from increased susceptibility to very high resistance levels, even among different classes of CBAs with dissimilar sugar specificities or binding moieties [e.g., α(1,3), α(1,2), α(1,6)]. Recent studies demonstrated promising results in non-topical formulations (e.g., intranasally or subcutaneously), highlighting their potential for prevention (microbicides) and antiviral therapy.
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Affiliation(s)
- Geoffrey Férir
- Laboratory of Virology and Chemotherapy, Rega Institute for Medical Research, University of Leuven, Minderbroedersstraat 10. Leuven B-3000, Belgium.
| | - Stephanie C Gordts
- Laboratory of Virology and Chemotherapy, Rega Institute for Medical Research, University of Leuven, Minderbroedersstraat 10. Leuven B-3000, Belgium.
| | - Dominique Schols
- Laboratory of Virology and Chemotherapy, Rega Institute for Medical Research, University of Leuven, Minderbroedersstraat 10. Leuven B-3000, Belgium.
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Sánchez-Rodríguez J, Vacas-Córdoba E, Gómez R, De La Mata FJ, Muñoz-Fernández MÁ. Nanotech-derived topical microbicides for HIV prevention: the road to clinical development. Antiviral Res 2014; 113:33-48. [PMID: 25446339 DOI: 10.1016/j.antiviral.2014.10.014] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Revised: 10/20/2014] [Accepted: 10/29/2014] [Indexed: 11/15/2022]
Abstract
More than three decades since its discovery, HIV infection remains one of the most aggressive epidemics worldwide, with more than 35 million people infected. In sub-Saharan Africa, heterosexual transmissions represent nearly 80% of new infections, with 50% of these occurring in women. In an effort to stop the dramatic spread of the HIV epidemic, new preventive treatments, such as microbicides, have been developed. Nanotechnology has revolutionized this field by designing and engineering novel highly effective nano-sized materials as microbicide candidates. This review illustrates the most recent advances in nanotech-derived HIV prevention strategies, as well as the main steps required to translate promising in vitro results into clinical trials.
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Affiliation(s)
- Javier Sánchez-Rodríguez
- Laboratorio InmunoBiología Molecular, Hospital General Universitario Gregorio Marañón, Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain; Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid, Spain
| | - Enrique Vacas-Córdoba
- Laboratorio InmunoBiología Molecular, Hospital General Universitario Gregorio Marañón, Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain; Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid, Spain
| | - Rafael Gómez
- Dendrimers for Biomedical Applications Group (BioInDen), University of Alcalá, Alcalá de Henares, Madrid, Spain; Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid, Spain
| | - F Javier De La Mata
- Dendrimers for Biomedical Applications Group (BioInDen), University of Alcalá, Alcalá de Henares, Madrid, Spain; Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid, Spain
| | - Ma Ángeles Muñoz-Fernández
- Laboratorio InmunoBiología Molecular, Hospital General Universitario Gregorio Marañón, Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain; Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid, Spain.
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Guo HJ, Liu YZ, Paskaleva EE, Arra M, Kennedy JS, Shekhtman A, Canki M. Use of Sargassum fusiforme Extract and its Bioactive Molecules to inhibit HIV Infection: Bridging Two Paradigms between Eastern and Western Medicine. CHINESE HERBAL MEDICINES 2014. [DOI: 10.1016/s1674-6384(14)60041-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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Férir G, Huskens D, Noppen S, Koharudin LMI, Gronenborn AM, Schols D. Broad anti-HIV activity of the Oscillatoria agardhii agglutinin homologue lectin family. J Antimicrob Chemother 2014; 69:2746-58. [PMID: 24970741 DOI: 10.1093/jac/dku220] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
OBJECTIVES Oscillatoria agardhii agglutinin homologue (OAAH) proteins belong to a recently discovered lectin family. The founding member OAA and a designed hybrid OAAH (OPA) recognize similar but unique carbohydrate structures of Man-9, compared with other antiviral carbohydrate-binding agents (CBAs). These two newly described CBAs were evaluated for their inactivating properties on HIV replication and transmission and for their potential as microbicides. METHODS Various cellular assays were used to determine antiviral activity against wild-type and certain CBA-resistant HIV-1 strains: (i) free HIV virion infection in human T lymphoma cell lines and PBMCs; (ii) syncytium formation assay using persistently HIV-infected T cells and non-infected CD4+ T cells; (iii) DC-SIGN-mediated viral capture; and (iv) transmission to uninfected CD4+ T cells. OAA and OPA were also evaluated for their mitogenic properties and potential synergistic effects using other CBAs. RESULTS OAA and OPA inhibit HIV replication, syncytium formation between HIV-1-infected and uninfected T cells, DC-SIGN-mediated HIV-1 capture and transmission to CD4+ target T cells, thereby rendering a variety of HIV-1 and HIV-2 clinical isolates non-infectious, independent of their coreceptor use. Both CBAs competitively inhibit the binding of the Manα(1-2)Man-specific 2G12 monoclonal antibody (mAb) as shown by flow cytometry and surface plasmon resonance analysis. The HIV-1 NL4.3(2G12res), NL4.3(MVNres) and IIIB(GRFTres) strains were equally inhibited as the wild-type HIV-1 strains by these CBAs. Combination studies indicate that OAA and OPA act synergistically with Hippeastrum hybrid agglutinin, 2G12 mAb and griffithsin (GRFT), with the exception of OPA/GRFT. CONCLUSIONS OAA and OPA are unique CBAs with broad-spectrum anti-HIV activity; however, further optimization will be necessary for microbicidal application.
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Affiliation(s)
- Geoffrey Férir
- Rega Institute for Medical Research, University of Leuven, Minderbroedersstraat 10, B-3000 Leuven, Belgium
| | - Dana Huskens
- Rega Institute for Medical Research, University of Leuven, Minderbroedersstraat 10, B-3000 Leuven, Belgium
| | - Sam Noppen
- Rega Institute for Medical Research, University of Leuven, Minderbroedersstraat 10, B-3000 Leuven, Belgium
| | - Leonardus M I Koharudin
- Department of Structural Biology, University of Pittsburgh School of Medicine, Biomedical Science Tower 3, 3501 Fifth Avenue, Pittsburgh, PA 15260, USA
| | - Angela M Gronenborn
- Department of Structural Biology, University of Pittsburgh School of Medicine, Biomedical Science Tower 3, 3501 Fifth Avenue, Pittsburgh, PA 15260, USA
| | - Dominique Schols
- Rega Institute for Medical Research, University of Leuven, Minderbroedersstraat 10, B-3000 Leuven, Belgium
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Microbicides: Molecular Strategies for Prevention of Sexually Transmitted Viral Disease. Antiviral Res 2014. [DOI: 10.1128/9781555815493.ch15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Romano J, Manning J, Hemmerling A, McGrory E, Young Holt B. Prioritizing multipurpose prevention technology development and investments using a target product profile. Antiviral Res 2013; 100 Suppl:S32-8. [DOI: 10.1016/j.antiviral.2013.09.016] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Accepted: 09/21/2013] [Indexed: 11/16/2022]
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Kenney J, Rodríguez A, Kizima L, Seidor S, Menon R, Jean-Pierre N, Pugach P, Levendosky K, Derby N, Gettie A, Blanchard J, Piatak M, Lifson JD, Paglini G, Zydowsky TM, Robbiani M, Fernández Romero JA. A modified zinc acetate gel, a potential nonantiretroviral microbicide, is safe and effective against simian-human immunodeficiency virus and herpes simplex virus 2 infection in vivo. Antimicrob Agents Chemother 2013; 57:4001-9. [PMID: 23752515 PMCID: PMC3719770 DOI: 10.1128/aac.00796-13] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Accepted: 06/06/2013] [Indexed: 11/20/2022] Open
Abstract
We previously showed that a prototype gel comprising zinc acetate (ZA) in carrageenan (CG) protected mice against vaginal and rectal herpes simplex virus 2 (HSV-2) challenge as well as macaques against vaginal simian-human immunodeficiency virus reverse transcriptase (SHIV-RT) challenge. In this work, we modified buffers and cosolvents to obtain a stable, nearly iso-osmolal formulation and evaluated its safety and efficacy against SHIV-RT and HSV-2. In vitro toxicity to lactobacilli and Candida albicans was determined. Macaques were given daily doses of ZA and CG (ZA/CG) or CG alone vaginally for 14 days and challenged with SHIV-RT 24 h later. Mice were challenged vaginally or rectally with HSV-2 immediately after a single gel treatment to measure efficacy or vaginally 12 h after daily gel treatment for 7 days to evaluate the gel's impact on susceptibility to HSV-2 infection. The modified ZA/CG neither affected the viability of lactobacilli or C. albicans nor enhanced vaginal HSV-2 infection after daily ZA/CG treatment. Vaginal SHIV-RT infection of macaques was reduced by 66% (P = 0.006) when macaques were challenged 24 h after the last dose of gel. We observed 60% to 80% uninfected mice after vaginal (P < 0.0001) and rectal (P = 0.008) high-dose HSV-2 challenge. The modified ZA/CG gel is safe and effective in animal models and represents a potential candidate to limit the transmission of HIV and HSV-2.
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Affiliation(s)
- Jessica Kenney
- Center for Biomedical Research, Population Council, New York, New York, USA
| | - Aixa Rodríguez
- Center for Biomedical Research, Population Council, New York, New York, USA
| | - Larisa Kizima
- Center for Biomedical Research, Population Council, New York, New York, USA
| | - Samantha Seidor
- Center for Biomedical Research, Population Council, New York, New York, USA
| | - Radhika Menon
- Center for Biomedical Research, Population Council, New York, New York, USA
| | | | - Pavel Pugach
- Center for Biomedical Research, Population Council, New York, New York, USA
| | - Keith Levendosky
- Center for Biomedical Research, Population Council, New York, New York, USA
| | - Nina Derby
- Center for Biomedical Research, Population Council, New York, New York, USA
| | - Agegnehu Gettie
- Aaron Diamond AIDS Research Center, Rockefeller University, New York, New York, USA
| | - James Blanchard
- Tulane National Primate Research Center, Tulane University, Covington, Louisiana, USA
| | - Michael Piatak
- AIDS and Cancer Virus Program, SAIC-Frederick, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland, USA
| | - Jeffrey D. Lifson
- AIDS and Cancer Virus Program, SAIC-Frederick, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland, USA
| | - Gabriela Paglini
- Instituto de Virología J.M.Vanella, Facultad de Ciencias Médicas-Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Thomas M. Zydowsky
- Center for Biomedical Research, Population Council, New York, New York, USA
| | - Melissa Robbiani
- Center for Biomedical Research, Population Council, New York, New York, USA
| | - José A. Fernández Romero
- Center for Biomedical Research, Population Council, New York, New York, USA
- Instituto de Virología J.M.Vanella, Facultad de Ciencias Médicas-Universidad Nacional de Córdoba, Córdoba, Argentina
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Abstract
Lectins are natural bioactive ubiquitous proteins or glycoproteins of non-immune response that bind reversibly to glycans of glycoproteins, glycolipids and polysaccharides possessing at least one non-catalytic domain causing agglutination. Some of them consist of several carbohydrate-binding domains which endow them with the properties of cell agglutination or precipitation of glycoconjugates. Lectins are rampant in nature from plants, animals and microorganisms. Among microorganisms, algae are the potent source of lectins with unique properties specifically from red algae. The demand of peculiar and neoteric biologically active substances has intensified the developments on isolation and biomedical applications of new algal lectins. Comprehensively, algal lectins are used in biomedical research for antiviral, antinociceptive, anti-inflammatory, anti-tumor activities, etc. and in pharmaceutics for the fabrication of cost-effective protein expression systems and nutraceutics. In this review, an attempt has been made to collate the information on various biomedical applications of algal lectins.
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Affiliation(s)
- Ram Sarup Singh
- Carbohydrate and Protein Biotechnology Laboratory, Department of Biotechnology, Punjabi University , Patiala, Punjab , India and
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Farr C, Nomellini JF, Ailon E, Shanina I, Sangsari S, Cavacini LA, Smit J, Horwitz MS. Development of an HIV-1 Microbicide Based on Caulobacter crescentus: Blocking Infection by High-Density Display of Virus Entry Inhibitors. PLoS One 2013; 8:e65965. [PMID: 23840383 PMCID: PMC3686833 DOI: 10.1371/journal.pone.0065965] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Accepted: 05/02/2013] [Indexed: 01/23/2023] Open
Abstract
The HIV/AIDS pandemic remains an enormous global health concern. Despite effective prevention options, 2.6 million new infections occur annually, with women in developing countries accounting for more than half of these infections. New prevention strategies that can be used by women are urgently needed. Topical microbicides specific for HIV-1 represent a promising prevention strategy. Conceptually, using harmless bacteria to display peptides or proteins capable of blocking entry provides an inexpensive approach to microbicide development. To avoid the potential pitfalls of engineering commensal bacteria, our strategy is to genetically display infection inhibitors on a non-native bacterium and rely on topical application of stabilized bacteria before potential virus exposure. Due to the high density cell-surface display capabilities and the inherent low toxicity of the bacterium, the S-layer mediated protein display capabilities of the non-pathogenic bacterium Caulobacter crescentus has been exploited for this approach. We have demonstrated that C. crescentus displaying MIP1α or CD4 interfered with the virus entry pathway and provided significant protection from HIV-1 pseudovirus representing clade B in a standard single cycle infection assay. Here we have expanded our C. crescentus based microbicide approach with additional and diverse classes of natural and synthetic inhibitors of the HIV-1 entry pathway. All display constructs provided variable but significant protection from HIV-1 infection; some with protection as high as 70%. Further, we describe protection from infection with additional viral clades. These findings indicate the significant potential for engineering C. crescentus to be an effective and readily adaptable HIV-1 microbicide platform.
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Affiliation(s)
- Christina Farr
- Department of Microbiology and Immunology, The University of British Columbia, Vancouver, British Columbia, Canada
| | - John F. Nomellini
- Department of Microbiology and Immunology, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Evan Ailon
- Department of Microbiology and Immunology, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Iryna Shanina
- Department of Microbiology and Immunology, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Sassan Sangsari
- Department of Microbiology and Immunology, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Lisa A. Cavacini
- Beth Israel Deaconess Medical Center, Boston, Massachusetts, United States of America
| | - John Smit
- Department of Microbiology and Immunology, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Marc S. Horwitz
- Department of Microbiology and Immunology, The University of British Columbia, Vancouver, British Columbia, Canada
- * E-mail:
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The griffithsin dimer is required for high-potency inhibition of HIV-1: evidence for manipulation of the structure of gp120 as part of the griffithsin dimer mechanism. Antimicrob Agents Chemother 2013; 57:3976-89. [PMID: 23752505 DOI: 10.1128/aac.00332-13] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Griffithsin (Grft) is a protein lectin derived from red algae that tightly binds the HIV envelope protein gp120 and effectively inhibits virus infection. This inhibition is due to the binding by Grft of high-mannose saccharides on the surface of gp120. Grft has been shown to be a tight dimer, but the role of the dimer in Grft's anti-HIV function has not been fully explored. To investigate the role of the Grft dimer in anti-HIV function, an obligate dimer of Grft was designed by expressing the protein with a peptide linker between the two subunits. This "Grft-linker-Grft" is a folded protein dimer, apparently nearly identical in structural properties to the wild-type protein. A "one-armed" obligate dimer was also designed (Grft-linker-Grft OneArm), with each of the three carbohydrate binding sites of one subunit mutated while the other subunit remained intact. While both constructed dimers retained the ability to bind gp120 and the viral surface, Grft-linker-Grft OneArm was 84- to 1,010-fold less able to inhibit HIV than wild-type Grft, while Grft-linker-Grft had near-wild-type antiviral potency. Furthermore, while the wild-type protein demonstrated the ability to alter the structure of gp120 by exposing the CD4 binding site, Grft-linker-Grft OneArm largely lost this ability. In experiments to investigate gp120 shedding, it was found that Grft has different effects on gp120 shedding for strains from subtype B and subtype C, and this might correlate with Grft function. Evidence is provided that the dimer form of Grft is critical to the function of this protein in HIV inhibition.
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Hoorelbeke B, Xue J, LiWang PJ, Balzarini J. Role of the carbohydrate-binding sites of griffithsin in the prevention of DC-SIGN-mediated capture and transmission of HIV-1. PLoS One 2013; 8:e64132. [PMID: 23741304 PMCID: PMC3669349 DOI: 10.1371/journal.pone.0064132] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Accepted: 04/10/2013] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The glycan-targeting C-type DC-SIGN lectin receptor is implicated in the transmission of the human immunodeficiency virus (HIV) by binding the virus and transferring the captured HIV-1 to CD4(+) T lymphocytes. Carbohydrate binding agents (CBAs) have been reported to block HIV-1 infection. We have now investigated the potent mannose-specific anti-HIV CBA griffithsin (GRFT) on its ability to inhibit the capture of HIV-1 to DC-SIGN, its DC-SIGN-directed transmission to CD4(+) T-lymphocytes and the role of the three carbohydrate-binding sites (CBS) of GRFT in these processes. FINDINGS GRFT inhibited HIV-1(IIIB) infection of CEM and HIV-1(NL4.3) infection of C8166 CD4(+) T-lymphocytes at an EC50 of 0.059 and 0.444 nM, respectively. The single mutant CBS variants of GRFT (in which a key Asp in one of the CBS was mutated to Ala) were about ∼20 to 60-fold less potent to prevent HIV-1 infection and ∼20 to 90-fold less potent to inhibit syncytia formation in co-cultures of persistently HIV-1 infected HuT-78 and uninfected C8166 CD4(+) T-lymphocytes. GRFT prevents DC-SIGN-mediated virus capture and HIV-1 transmission to CD4(+) T-lymphocytes at an EC50 of 1.5 nM and 0.012 nM, respectively. Surface plasmon resonance (SPR) studies revealed that wild-type GRFT efficiently blocked the binding between DC-SIGN and immobilized gp120, whereas the point mutant CBS variants of GRFT were ∼10- to 15-fold less efficient. SPR-analysis also demonstrated that wild-type GRFT and its single mutant CBS variants have the capacity to expel bound gp120 from the gp120-DC-SIGN complex in a dose dependent manner, a property that was not observed for HHA, another mannose-specific potent anti-HIV-1 CBA. CONCLUSION GRFT is inhibitory against HIV gp120 binding to DC-SIGN, efficiently prevents DC-SIGN-mediated transfer of HIV-1 to CD4(+) T-lymphocytes and is able to expel gp120 from the gp120-DC-SIGN complex. Functionally intact CBS of GRFT are important for the optimal action of GRFT.
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Affiliation(s)
- Bart Hoorelbeke
- Rega Institute for Medical Research, KU Leuven, Leuven, Belgium
| | - Jie Xue
- School of Natural Sciences, University of California Merced, Merced, California, United States of America
| | - Patricia J. LiWang
- School of Natural Sciences, University of California Merced, Merced, California, United States of America
| | - Jan Balzarini
- Rega Institute for Medical Research, KU Leuven, Leuven, Belgium
- * E-mail:
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Férir G, Petrova MI, Andrei G, Huskens D, Hoorelbeke B, Snoeck R, Vanderleyden J, Balzarini J, Bartoschek S, Brönstrup M, Süssmuth RD, Schols D. The lantibiotic peptide labyrinthopeptin A1 demonstrates broad anti-HIV and anti-HSV activity with potential for microbicidal applications. PLoS One 2013; 8:e64010. [PMID: 23724015 PMCID: PMC3665789 DOI: 10.1371/journal.pone.0064010] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Accepted: 04/08/2013] [Indexed: 01/24/2023] Open
Abstract
Lantibiotics are peptides, produced by bacteria, that contain the noncanonical amino acid lanthionine and many of them exhibit antibacterial activities. The labyrinthopeptin A1 (LabyA1) is a prototype peptide of a novel class of carbacyclic lantibiotics. Here, we extensively evaluated its broad-spectrum activity against HIV and HSV in vitro, studied its mechanism of action and evaluated potential microbicidal applications. LabyA1 exhibited a consistent and broad anti-HIV activity (EC50s: 0.70–3.3 µM) and anti-HSV activity (EC50s: 0.29–2.8 µM) in cell cultures. LabyA1 also inhibited viral cell-cell transmission between persistently HIV-infected T cells and uninfected CD4+ T cells (EC50∶2.5 µM) and inhibited the transmission of HIV captured by DC-SIGN+-cells to uninfected CD4+ T cells (EC50∶4.1 µM). Time-of-drug addition studies revealed that LabyA1 acts as an entry inhibitor against HIV and HSV. Cellular and virus binding studies combined with SPR/FLIPR technology showed that LabyA1 interacted with the HIV envelope protein gp120, but not with the HIV cellular receptors. LabyA1 also demonstrated additive to synergistic effects in its anti-HIV-1 and anti-HSV-2 activity with anti(retro)viral drugs in dual combinations such as tenofovir, acyclovir, saquinavir, raltegravir and enfuvirtide. LabyA1 can be considered as a novel lead peptide as it had profound antiviral activity against HIV and HSV. Pre-treatment of PBMCs with LabyA1 neither increased the expression of the activation markers CD69 and CD25, nor enhanced HIV replication, nor significantly induced various inflammatory cytokines/chemokines. LabyA1 also did not affect the growth of vaginal Lactobacilli populations. Based on the lack of toxicity on the vaginal Lactobacillus strains and its synergistic/additive profile in combination with clinically approved anti(retro)virals, it deserves further attention as a potential microbicide candidate in the prevention of sexual transmitted diseases.
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Affiliation(s)
- Geoffrey Férir
- Rega Institute for Medical Research, University of Leuven, Leuven, Belgium
| | - Mariya I. Petrova
- Centre of Microbial and Plant Genetics, University of Leuven, Leuven, Belgium
- Department of Bioscience Engineering, Antwerp University, Antwerp, Belgium
| | - Graciela Andrei
- Rega Institute for Medical Research, University of Leuven, Leuven, Belgium
| | - Dana Huskens
- Rega Institute for Medical Research, University of Leuven, Leuven, Belgium
| | - Bart Hoorelbeke
- Rega Institute for Medical Research, University of Leuven, Leuven, Belgium
| | - Robert Snoeck
- Rega Institute for Medical Research, University of Leuven, Leuven, Belgium
| | - Jos Vanderleyden
- Centre of Microbial and Plant Genetics, University of Leuven, Leuven, Belgium
| | - Jan Balzarini
- Rega Institute for Medical Research, University of Leuven, Leuven, Belgium
| | | | | | - Roderich D. Süssmuth
- Technische Universität Berlin, Fakultät II – Institut für Chemie; Berlin, Germany
| | - Dominique Schols
- Rega Institute for Medical Research, University of Leuven, Leuven, Belgium
- * E-mail:
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69
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Zhou Y, Simmons G. Development of novel entry inhibitors targeting emerging viruses. Expert Rev Anti Infect Ther 2013. [PMID: 23199399 DOI: 10.1586/eri.12.104] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Emerging viral diseases pose a unique risk to public health, and thus there is a need to develop therapies. A current focus of funding agencies, and hence research, is the development of broad-spectrum antivirals, and in particular, those targeting common cellular pathways. The scope of this article is to review screening strategies and recent advances in this area, with a particular emphasis on antivirals targeting the step of viral entry for emerging lipid-enveloped viruses such as Ebola virus and SARS-coronavirus.
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Affiliation(s)
- Yanchen Zhou
- Blood Systems Research Institute and Department of Laboratory Medicine, University of California, San Francisco, 270 Masonic Avenue, San Francisco, CA 94118, USA
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70
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Abstract
Griffithsin, which binds N-linked glycans on gp120 to prevent HIV entry, has the most potent HIV-1 inhibitory activity described for any antiviral lectin and is being developed for topical preexposure prophylaxis. The current studies were designed to further assess its potential by exploring its activity against herpes simplex virus 2 (HSV-2), a cofactor for HIV acquisition, in vitro and in a murine model. Safety was evaluated by examining its impact on epithelial barrier integrity in polarized cultures and testing whether repeated intravaginal dosing potentiates the susceptibility of mice to genital herpes. Griffithsin displayed modest inhibitory activity against HSV-2 if present during viral entry but completely blocked plaque formation if present postentry, reduced plaque size, and prevented cell-to-cell spread. These in vitro findings translated to significant protection against genital herpes in mice treated with 0.1% griffithsin gel. Griffithsin, but not placebo gel, prevented viral spread (visualized with a luciferase-expressing virus), significantly reduced disease scores, and resulted in greater survival (P < 0.05, log rank test). Protection persisted when HSV-2 was introduced in seminal plasma. Although griffithsin triggered a small decline in transepithelial electrical resistance in polarized cultures, this did not translate to any significant increase in the ability of HIV to migrate from the apical to the basolateral chamber nor to an increase in susceptibility to HSV-2 in mice treated with griffithsin gel for 7 days. These findings demonstrate that griffithsin inhibits HSV-2 by a unique mechanism of blocking cell-to-cell spread and support its further development for HIV and HSV-2 prevention.
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71
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Férir G, Huskens D, Palmer KE, Boudreaux DM, Swanson MD, Markovitz DM, Balzarini J, Schols D. Combinations of griffithsin with other carbohydrate-binding agents demonstrate superior activity against HIV Type 1, HIV Type 2, and selected carbohydrate-binding agent-resistant HIV Type 1 strains. AIDS Res Hum Retroviruses 2012; 28:1513-23. [PMID: 22607556 DOI: 10.1089/aid.2012.0026] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Carbohydrate-binding agents (CBAs) are potential HIV microbicidal agents with a high genetic barrier to resistance. We wanted to evaluate whether two mannose-specific CBAs, recognizing multiple and often distinct glycan structures on the HIV envelope gp120, can interact synergistically against HIV-1, HIV-2, and HIV-1 strains that were selected for resistance against particular CBAs [i.e., 2G12 mAb and microvirin (MVN)]. Paired CBA/CBA combinations mainly showed synergistic activity against both wild-type HIV-1 and HIV-2 but also 2G12 mAb- and MVN-resistant HIV-1 strains as based on the median effect principle with combination indices (CIs) ranging between 0.29 and 0.97. Upon combination, an increase in antiviral potency of griffithsin (GRFT) up to ∼12-fold (against HIV-1), ∼8-fold (against HIV-2), and ∼6-fold (against CBA-resistant HIV-1) was observed. In contrast, HHA/GNA combinations showed additive activity against wild-type HIV-1 and HIV-2 strains, but remarkable synergy with HHA and GNA was observed against 2G12 mAb- and MVN-resistant HIV-1 strains (CI, 0.64 and 0.49, respectively). Overall, combinations of GRFT and other CBAs showed synergistic activity against HIV-1, HIV-2, and even against certain CBA-resistant HIV-1 strains. The CBAs tested appear to have distinct binding patterns on the gp120 envelope and therefore do not necessarily compete with each other's glycan binding sites on gp120. As a result, there might be no steric hindrance between two different CBAs in their competition for glycan binding (except for the HHA/GNA combination). These data are encouraging for the use of paired CBA combinations in topical microbicide applications (e.g., creams, gels, or intravaginal rings) to prevent HIV transmission.
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Affiliation(s)
- Geoffrey Férir
- Rega Institute for Medical Research, University of Leuven, Leuven, Belgium
| | - Dana Huskens
- Rega Institute for Medical Research, University of Leuven, Leuven, Belgium
| | - Kenneth E. Palmer
- Department of Pharmacology and Toxicology and Owensboro Cancer Research Program, James Graham Brown Cancer Center, University of Louisville, School of Medicine, Louisville, Kentucky
| | - Daniel M. Boudreaux
- Department of Internal Medicine, Division of Infectious Diseases, University of Michigan, Medical Center, Ann Arbor, Michigan
| | - Michael D. Swanson
- Department of Internal Medicine, Division of Infectious Diseases, University of Michigan, Medical Center, Ann Arbor, Michigan
| | - David M. Markovitz
- Department of Internal Medicine, Division of Infectious Diseases, University of Michigan, Medical Center, Ann Arbor, Michigan
| | - Jan Balzarini
- Rega Institute for Medical Research, University of Leuven, Leuven, Belgium
| | - Dominique Schols
- Rega Institute for Medical Research, University of Leuven, Leuven, Belgium
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72
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Lotter-Stark HCT, Rybicki EP, Chikwamba RK. Plant made anti-HIV microbicides--a field of opportunity. Biotechnol Adv 2012; 30:1614-26. [PMID: 22750509 PMCID: PMC7132877 DOI: 10.1016/j.biotechadv.2012.06.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2011] [Revised: 06/10/2012] [Accepted: 06/20/2012] [Indexed: 12/15/2022]
Abstract
HIV remains a significant global burden and without an effective vaccine, it is crucial to develop microbicides to halt the initial transmission of the virus. Several microbicides have been researched with various levels of success. Amongst these, the broadly neutralising antibodies and peptide lectins are promising in that they can immediately act on the virus and have proven efficacious in in vitro and in vivo protection studies. For the purpose of development and access by the relevant population groups, it is crucial that these microbicides be produced at low cost. For the promising protein and peptide candidate molecules, it appears that current production systems are overburdened and expensive to establish and maintain. With recent developments in vector systems for protein expression coupled with downstream protein purification technologies, plants are rapidly gaining credibility as alternative production systems. Here we evaluate the advances made in host and vector system development for plant expression as well as the progress made in expressing HIV neutralising antibodies and peptide lectins using plant-based platforms.
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73
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Griffithsin inhibits Japanese encephalitis virus infection in vitro and in vivo. Arch Virol 2012; 158:349-58. [PMID: 23053519 PMCID: PMC7087312 DOI: 10.1007/s00705-012-1489-2] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2012] [Accepted: 08/16/2012] [Indexed: 11/23/2022]
Abstract
Griffithsin (GRFT) is a broad-spectrum antiviral protein that is effective against several glycosylated viruses. Here, we have evaluated the in vitro and in vivo antiviral activities of GRFT against Japanese encephalitis virus (JEV) infection. In vitro experiments showed that treatment of JEV with GRFT before inoculation of BHK-21 cells inhibited infection in a dose-dependent manner, with 99 % inhibition at 100 μg/ml and a 50 % inhibitory concentration (IC50) of 265 ng/ml (20 nM). Binding assays suggested that binding of GRFT to JEV virions inhibited JEV infection. In vivo experiment showed that GRFT (5 mg/kg) administered intraperitoneally before virus infection could completely prevent mortality in mice challenged intraperitoneally with a lethal dose of JEV. Our study also suggested that GRFT prevents JEV infection at the entry phase by targeting the virus. Collectively, our data demonstrate that GRFT is an antiviral agent with potential application in the development of therapeutics against JEV or other flavivirus infections.
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Xue J, Gao Y, Hoorelbeke B, Kagiampakis I, Zhao B, Demeler B, Balzarini J, Liwang PJ. The role of individual carbohydrate-binding sites in the function of the potent anti-HIV lectin griffithsin. Mol Pharm 2012; 9:2613-25. [PMID: 22827601 DOI: 10.1021/mp300194b] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Griffithsin (GRFT) is a lectin that has been shown to inhibit HIV infection by binding to high mannose glycan structures on the surface of gp120, and it is among the most potent HIV entry inhibitors reported so far. However, important biochemical details on the antiviral mechanism of GRFT action remain unexplored. In order to understand the role of the three individual carbohydrate-binding sites (CBS) in GRFT, mutations were made at each site (D30A, D70A, and D112A), and the resulting mutants were investigated. NMR studies revealed that each GRFT variant was folded but showed significant peak movement on the carbohydrate-binding face of the protein. The wild-type and each point mutant protein appeared as tight dimers with a K(d) below 4.2 μM. Mutation of any individual CBS on GRFT reduced binding of the protein to mannose, and ELISA assays revealed a partial loss of ability of each GRFT point mutant to bind gp120, with a near-complete loss of binding by the triple mutant D30A/D70A/D112A GRFT. A more quantitative surface plasmon resonance (SPR) examination showed a rather small loss of binding to gp120 for the individual GRFT point mutants (K(D): 123 to 245 pM range versus 73 pM for wild-type GRFT), but dramatic loss of the triple mutant to bind gp120 derived from R5 and X4 strains (K(D) > 12 nM). In contrast to the 2- to 3-fold loss of binding to gp120, the single CBS point mutants of GRFT were significantly less able to inhibit viral infection, exhibiting a 26- to 1900-fold loss of potency, while the triple mutant was at least 875-fold less effective against HIV-1 infection. The disparity between HIV-1 gp120 binding ability and HIV inhibitory potency for these GRFT variants indicates that gp120 binding and virus neutralization do not necessarily correlate, and suggests a mechanism that is not based on simple gp120 binding.
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Affiliation(s)
- Jie Xue
- University of California Merced, 5200 North Lake Road, Merced, California 95343, United States
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75
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VANPOUILLE C, ARAKELYAN A, MARGOLIS L. Microbicides: still a long road to success. Trends Microbiol 2012; 20:369-75. [PMID: 22705107 PMCID: PMC3756685 DOI: 10.1016/j.tim.2012.05.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Revised: 05/14/2012] [Accepted: 05/21/2012] [Indexed: 10/28/2022]
Abstract
The development of efficient microbicides, the topically applied compounds that protect uninfected individuals from acquiring HIV-1, is a promising strategy to contain HIV-1 epidemics. Such microbicides should of course possess anti-HIV-1 activity, but they should also act against other genital pathogens, which facilitate HIV-1 transmission. The new trend in microbicide strategy is to use drugs currently used in HIV-1 therapy. The success of this strategy is mixed so far and is impaired by our limited knowledge of the basic mechanisms of HIV-1 transmission as well as by the inadequacy of the systems in which microbicides are tested in preclinical studies.
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Affiliation(s)
- Christophe VANPOUILLE
- Eunice Kennedy-Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Anush ARAKELYAN
- Eunice Kennedy-Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Leonid MARGOLIS
- Eunice Kennedy-Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
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76
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Algal lectins as potential HIV microbicide candidates. Mar Drugs 2012; 10:1476-1497. [PMID: 22851920 PMCID: PMC3407925 DOI: 10.3390/md10071476] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Revised: 06/22/2012] [Accepted: 06/29/2012] [Indexed: 11/23/2022] Open
Abstract
The development and use of topical microbicides potentially offers an additional strategy to reduce the spread of the Human Immunodeficiency Virus (HIV). Carbohydrate-binding agents (CBAs) that show specificity for high mannose carbohydrates on the surface of the heavily glycosylated envelope of HIV are endowed with potent anti-HIV activity. In fact, a number of algal lectins such as cyanovirin-N, microvirin, microcystis viridis lectin, scytovirin, Oscillatoria agardhii agglutinin and griffithsin are considered as potential microbicide candidates to prevent the sexual transmission of HIV through topical applications. They not only inhibit infection of cells by cell-free virus but they can also efficiently prevent virus transmission from virus-infected cells to uninfected CD4+ target T-lymphocytes and DC-SIGN-directed capture of HIV-1 and transmission to CD4+ T lymphocytes. This review focuses on the structural properties and carbohydrate specificity of these algal lectins, their antiviral activity against HIV and several other enveloped viruses, their safety profile and viral resistance patterns.
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77
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Eade CR, Wood MP, Cole AM. Mechanisms and modifications of naturally occurring host defense peptides for anti-HIV microbicide development. Curr HIV Res 2012; 10:61-72. [PMID: 22264047 DOI: 10.2174/157016212799304580] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Revised: 09/30/2011] [Accepted: 10/27/2011] [Indexed: 11/22/2022]
Abstract
Despite advances in the treatment of HIV infection, heterosexual transmission of HIV remains high, and vaccines to prevent HIV acquisition have been unfruitful. Vaginal microbicides, on the other hand, have demonstrated considerable potential for HIV prevention, and a variety of compounds have been screened for their activity and safety as anti-HIV microbicides. Among these are the naturally occurring host defense peptides, small peptides from diverse lineages with intrinsic antiviral activity. Naturally occurring host defense peptides with anti-HIV activity are promising candidates for vaginal microbicide development. Their structural variance and accompanying mechanistic diversity provide a wide range of inhibitors whose antiviral activity can be exerted at nearly every stage of the HIV lifecycle. Additionally, peptide modification has been explored as a method for improving the anti-HIV activity of host defense peptides. Structure- and sequence-based alterations have achieved varying success in improving the potency and specificity of anti-HIV peptides. Overall, peptides have been discovered or engineered to inhibit HIV with therapeutic indices of > 1000, encouraging their advancement toward clinical trials. Here we review the naturally occurring anti-HIV host defense peptides, demonstrating their breadth of mechanistic diversity, and exploring approaches to enhance and optimize their activity in order to expedite their development as safe and effective anti-HIV vaginal microbicides.
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Affiliation(s)
- Colleen R Eade
- Department of Molecular Biology and Microbiology, Burnett School of Biomedical Sciences, University of Central Florida College of Medicine, Orlando, FL 32816, USA.
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78
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Zhao B, Mankowski MK, Snyder BA, Ptak RG, Liwang PJ. Highly potent chimeric inhibitors targeting two steps of HIV cell entry. J Biol Chem 2011; 286:28370-81. [PMID: 21659523 PMCID: PMC3151080 DOI: 10.1074/jbc.m111.234799] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2011] [Revised: 06/03/2011] [Indexed: 11/06/2022] Open
Abstract
Blocking HIV-1 cell entry has long been a major goal of anti-HIV drug development. Here, we report a successful design of two highly potent chimeric HIV entry inhibitors composed of one CCR5-targeting RANTES (regulated on activation normal T cell expressed and secreted) variant (5P12-RANTES or 5P14-RANTES (Gaertner, H., Cerini, F., Escola, J. M., Kuenzi, G., Melotti, A., Offord, R., Rossitto-Borlat, I., Nedellec, R., Salkowitz, J., Gorochov, G., Mosier, D., and Hartley, O. (2008) Proc. Natl. Acad. Sci. U.S.A. 105, 17706-17711)) linked to a gp41 fusion inhibitor, C37. Chimeric inhibitors 5P12-linker-C37 and 5P14-linker-C37 showed extremely high antiviral potency in single cycle and replication-competent viral assays against R5-tropic viruses, with IC(50) values as low as 0.004 nm. This inhibition was somewhat strain-dependent and was up to 100-fold better than the RANTES variant alone or in combination with unlinked C37. The chimeric inhibitors also fully retained the antiviral activity of C37 against X4-tropic viruses, and this inhibition can be further enhanced significantly if the target cell co-expresses CCR5 receptor. On human peripheral blood mononuclear cells, the inhibitors showed very strong inhibition against R5-tropic Ba-L strain and X4-tropic IIIB strain, with IC(50) values as low as 0.015 and 0.44 nm, which are 45- and 16-fold better than the parent inhibitors, respectively. A clear delivery mechanism requiring a covalent linkage between the two segments of the chimera was observed and characterized. Furthermore, the two chimeric inhibitors are fully recombinant and are easily produced at low cost. These attributes make them excellent candidates for anti-HIV microbicides. The results of this study also suggest a potent approach for optimizing existing HIV entry inhibitors or designing new inhibitors.
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Affiliation(s)
- Bo Zhao
- University of California, Merced, California 95343, USA
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Kouokam JC, Huskens D, Schols D, Johannemann A, Riedell SK, Walter W, Walker JM, Matoba N, O'Keefe BR, Palmer KE. Investigation of griffithsin's interactions with human cells confirms its outstanding safety and efficacy profile as a microbicide candidate. PLoS One 2011; 6:e22635. [PMID: 21829638 PMCID: PMC3149051 DOI: 10.1371/journal.pone.0022635] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2011] [Accepted: 06/27/2011] [Indexed: 11/18/2022] Open
Abstract
Many natural product-derived lectins such as the red algal lectin griffithsin (GRFT) have potent in vitro activity against viruses that display dense clusters of oligomannose N-linked glycans (NLG) on their surface envelope glycoproteins. However, since oligomannose NLG are also found on some host proteins it is possible that treatment with antiviral lectins may trigger undesirable side effects. For other antiviral lectins such as concanavalin A, banana lectin and cyanovirin-N (CV-N), interactions between the lectin and as yet undescribed cellular moieties have been reported to induce undesirable side effects including secretion of inflammatory cytokines and activation of host T-cells. We show that GRFT, unlike CV-N, binds the surface of human epithelial and peripheral blood mononuclear cells (PBMC) through an exclusively oligosaccharide-dependent interaction. In contrast to several other antiviral lectins however, GRFT treatment induces only minimal changes in secretion of inflammatory cytokines and chemokines by epithelial cells or human PBMC, has no measureable effect on cell viability and does not significantly upregulate markers of T-cell activation. In addition, GRFT appears to retain antiviral activity once bound to the surface of PBMC. Finally, RNA microarray studies show that, while CV-N and ConA regulate expression of a multitude of cellular genes, GRFT treatment effects only minimal alterations in the gene expression profile of a human ectocervical cell line. These studies indicate that GRFT has an outstanding safety profile with little evidence of induced toxicity, T-cell activation or deleterious immunological consequence, unique attributes for a natural product-derived lectin.
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Affiliation(s)
- Joseph Calvin Kouokam
- Owensboro Cancer Research Program, James Graham Brown Cancer Center and Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, Kentucky, United States of America
| | - Dana Huskens
- Rega Institute for Medical Research, K.U. Leuven, Leuven, Belgium
| | - Dominique Schols
- Rega Institute for Medical Research, K.U. Leuven, Leuven, Belgium
| | - Andrew Johannemann
- Owensboro Cancer Research Program, James Graham Brown Cancer Center and Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, Kentucky, United States of America
| | - Shonna K. Riedell
- Owensboro Cancer Research Program, James Graham Brown Cancer Center and Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, Kentucky, United States of America
| | - Wendye Walter
- Owensboro Cancer Research Program, James Graham Brown Cancer Center and Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, Kentucky, United States of America
| | - Janice M. Walker
- Owensboro Cancer Research Program, James Graham Brown Cancer Center and Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, Kentucky, United States of America
| | - Nobuyuki Matoba
- Owensboro Cancer Research Program, James Graham Brown Cancer Center and Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, Kentucky, United States of America
| | - Barry R. O'Keefe
- Molecular Targets Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland, United States of America
| | - Kenneth E. Palmer
- Owensboro Cancer Research Program, James Graham Brown Cancer Center and Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, Kentucky, United States of America
- * E-mail:
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80
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Sassi AB, Bunge KE, Hood BL, Conrads TP, Cole AM, Gupta P, Rohan LC. Preformulation and stability in biological fluids of the retrocyclin RC-101, a potential anti-HIV topical microbicide. AIDS Res Ther 2011; 8:27. [PMID: 21801426 PMCID: PMC3199744 DOI: 10.1186/1742-6405-8-27] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2011] [Accepted: 07/29/2011] [Indexed: 11/30/2022] Open
Abstract
Background RC-101, a cationic peptide retrocyclin analog, has in vitro activity against HIV-1. Peptide drugs are commonly prone to conformational changes, oxidation and hydrolysis when exposed to excipients in a formulation or biological fluids in the body, this can affect product efficacy. We aimed to investigate RC-101 stability under several conditions including the presence of human vaginal fluids (HVF), enabling the efficient design of a safe and effective microbicide product. Stability studies (temperature, pH, and oxidation) were performed by HPLC, Circular Dichroism, and Mass Spectrometry (LC-MS/MS). Additionally, the effect of HVF on formulated RC-101 was evaluated with fluids collected from healthy volunteers, or from subjects with bacterial vaginosis (BV). RC-101 was monitored by LC-MS/MS for up to 72 h. Results RC-101 was stable at pH 3, 4, and 7, at 25 and 37°C. High concentrations of hydrogen peroxide resulted in less than 10% RC-101 reduction over 24 h. RC-101 was detected 48 h after incubation with normal HVF; however, not following incubation with HVF from BV subjects. Conclusions Our results emphasize the importance of preformulation evaluations and highlight the impact of HVF on microbicide product stability and efficacy. RC-101 was stable in normal HVF for at least 48 h, indicating that it is a promising candidate for microbicide product development. However, RC-101 stability appears compromised in individuals with BV, requiring more advanced formulation strategies for stabilization in this environment.
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81
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Férir G, Palmer KE, Schols D. Synergistic activity profile of griffithsin in combination with tenofovir, maraviroc and enfuvirtide against HIV-1 clade C. Virology 2011; 417:253-8. [PMID: 21802104 DOI: 10.1016/j.virol.2011.07.004] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2011] [Revised: 06/06/2011] [Accepted: 07/07/2011] [Indexed: 12/19/2022]
Abstract
Griffithsin (GRFT) is possibly the most potent anti-HIV peptide found in natural sources. Due to its potent and broad-spectrum antiviral activity and unique safety profile it has great potential as topical microbicide component. Here, we evaluated various combinations of GRFT against HIV-1 clade B and clade C isolates in primary peripheral blood mononuclear cells (PBMCs) and in CD4(+) MT-4 cells. In all combinations tested, GRFT showed synergistic activity profile with tenofovir, maraviroc and enfuvirtide based on the median effect principle with combination indices (CI) varying between 0.34 and 0.79 at the calculated EC(95) level. Furthermore, the different glycosylation patterns on the viral envelope of clade B and clade C gp120 had no observable effect on the synergistic interactions. Overall, we can conclude that the evaluated two-drug combination increases their antiviral potency and supports further clinical investigations in pre-exposure prophylaxis for GRFT combinations in the context of HIV-1 clade C infection.
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Affiliation(s)
- Geoffrey Férir
- Rega Institute for Medical Research, Katholieke Universiteit Leuven, Leuven, Belgium.
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82
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Huang X, Jin W, Griffin GE, Shattock RJ, Hu Q. Removal of two high-mannose N-linked glycans on gp120 renders human immunodeficiency virus 1 largely resistant to the carbohydrate-binding agent griffithsin. J Gen Virol 2011; 92:2367-2373. [PMID: 21715597 DOI: 10.1099/vir.0.033092-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
High-mannose N-linked glycans recognized by carbohydrate-binding agents (CBAs) are potential targets for topical microbicides. To better understand the mechanisms by which CBAs inhibit human immunodeficiency virus (HIV)-1 infection at the molecular level, we systematically analysed the contribution of site-specific glycans to the anti-HIV activity of CBAs by site-directed mutagenesis. Our results demonstrate that a single deglycosylation at N295 or N448 in a range of primary and T-cell-line-adapted HIV-1 isolates resulted in marked resistance to griffithsin (GRFT) but maintained the sensitivity to cyanovirin (CV-N), Galanthus nivalis agglutinin (GNA) and a range of neutralizing antibodies. Unlike CV-N and GNA, the interaction between GRFT and gp120 appeared to be dependent on the specific trimeric 'sugar tower' including N295 and N448. This was further strengthened by the results of GRFT-Env binding experiments. Our study identifies GRFT-specific gp120 glycans and may provide information for the design of novel CBA antiviral strategies.
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Affiliation(s)
- Xin Huang
- Graduate School, Chinese Academy of Sciences, Beijing 100049, PR China.,State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PR China
| | - Wei Jin
- Graduate School, Chinese Academy of Sciences, Beijing 100049, PR China.,State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PR China
| | - George E Griffin
- Center for Infection and Immunity, St George's University of London, London SW17 0RE, UK
| | - Robin J Shattock
- Center for Infection and Immunity, St George's University of London, London SW17 0RE, UK
| | - Qinxue Hu
- Center for Infection and Immunity, St George's University of London, London SW17 0RE, UK.,State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PR China
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83
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Affiliation(s)
- Barry R O’Keefe
- Molecular Targets Laboratory, Center for Cancer Research, National Cancer Institute, Building 562, Room 201, NCI-Frederick, Frederick, MD 21702-1201, USA
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84
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Ariën KK, Jespers V, Vanham G. HIV sexual transmission and microbicides. Rev Med Virol 2011; 21:110-33. [PMID: 21412935 DOI: 10.1002/rmv.684] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2010] [Revised: 01/25/2011] [Accepted: 01/26/2011] [Indexed: 12/12/2022]
Abstract
Pathogens often rely on the contacts between hosts for transmission. Most viruses have adapted their transmission mechanisms to defined behaviours of their host(s) and have learned to exploit these for their own propagation. Some viruses, such as HIV, the human papillomavirus (HPV), HSV-2 and HCV, cause sexually transmitted infections (STIs). Understanding the transmission of particular viral variants and comprehending the early adaptation and evolution is fundamental to eventually inhibiting sexual transmission of HIV. Here, we review the current understanding of the mechanisms of sexual transmission and the biology of the transmitted HIV. Next, we present a timely overview of candidate microbicides, including past, ongoing and future clinical trials of HIV topical microbicides.
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Affiliation(s)
- Kevin K Ariën
- Virology Unit, Department of Microbiology, Institute of Tropical Medicine, Antwerpen, Belgium.
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85
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Micewicz ED, Cole AL, Jung CL, Luong H, Phillips ML, Pratikhya P, Sharma S, Waring AJ, Cole AM, Ruchala P. Grifonin-1: a small HIV-1 entry inhibitor derived from the algal lectin, Griffithsin. PLoS One 2010; 5:e14360. [PMID: 21179548 PMCID: PMC3002932 DOI: 10.1371/journal.pone.0014360] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2010] [Accepted: 11/22/2010] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND Griffithsin, a 121-residue protein isolated from a red algal Griffithsia sp., binds high mannose N-linked glycans of virus surface glycoproteins with extremely high affinity, a property that allows it to prevent the entry of primary isolates and laboratory strains of T- and M-tropic HIV-1. We used the sequence of a portion of griffithsin's sequence as a design template to create smaller peptides with antiviral and carbohydrate-binding properties. METHODOLOGY/RESULTS The new peptides derived from a trio of homologous β-sheet repeats that comprise the motifs responsible for its biological activity. Our most active antiviral peptide, grifonin-1 (GRFN-1), had an EC50 of 190.8±11.0 nM in in vitro TZM-bl assays and an EC(50) of 546.6±66.1 nM in p24gag antigen release assays. GRFN-1 showed considerable structural plasticity, assuming different conformations in solvents that differed in polarity and hydrophobicity. Higher concentrations of GRFN-1 formed oligomers, based on intermolecular β-sheet interactions. Like its parent protein, GRFN-1 bound viral glycoproteins gp41 and gp120 via the N-linked glycans on their surface. CONCLUSION Its substantial antiviral activity and low toxicity in vitro suggest that GRFN-1 and/or its derivatives may have therapeutic potential as topical and/or systemic agents directed against HIV-1.
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Affiliation(s)
- Ewa D. Micewicz
- Department of Medicine, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, California, United States of America
- Department of Radiation Oncology, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, California, United States of America
| | - Amy L. Cole
- Department of Molecular Biology and Microbiology, Burnett School of Biomedical Sciences, University of Central Florida College of Medicine, Orlando, Florida, United States of America
| | - Chun-Ling Jung
- Department of Medicine, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, California, United States of America
| | - Hai Luong
- Department of Medicine, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, California, United States of America
| | - Martin L. Phillips
- Department of Chemistry and Biochemistry, University of California at Los Angeles, Los Angeles, California, United States of America
| | - Pratikhya Pratikhya
- Department of Medicine, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, California, United States of America
| | - Shantanu Sharma
- Materials and Process Simulation Center, California Institute of Technology, Pasadena, California, United States of America
| | - Alan J. Waring
- Department of Medicine, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, California, United States of America
| | - Alexander M. Cole
- Department of Molecular Biology and Microbiology, Burnett School of Biomedical Sciences, University of Central Florida College of Medicine, Orlando, Florida, United States of America
| | - Piotr Ruchala
- Department of Medicine, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, California, United States of America
- * E-mail:
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86
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Potent strategy to inhibit HIV-1 by binding both gp120 and gp41. Antimicrob Agents Chemother 2010; 55:264-75. [PMID: 20956603 DOI: 10.1128/aac.00376-10] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The development of an anti-HIV microbicide is critical in the fight against the spread of HIV. It is shown here that the covalent linking of compounds that bind gp120 with compounds that bind gp41 can inhibit HIV entry even more potently than individual inhibitors or noncovalent combinations. The most striking example involves griffithsin, a potent HIV inhibitor that binds to the surface of HIV gp120. While griffithsin inhibits HIV Env-mediated fusion in a CCR5-tropic cell-cell fusion assay with a 50% inhibitory concentration (IC(50)) of 1.31 ± 0.87 nM and the gp41-binding peptide C37 shows an IC(50) of 18.2 ± 7.6 nM, the covalently linked combination of griffithsin with C37 (Griff37) has an IC(50) of 0.15 ± 0.05 nM, exhibiting a potency 8.7-fold greater than that of griffithsin alone. Similarly, in CXCR4-tropic cell-cell fusion assays, Griff37 is 5.2-fold more potent than griffithsin alone. In viral assays, both griffithsin and Griff37 inhibit HIV replication at midpicomolar levels, but the linked compound Griff37 is severalfold more potent than griffithsin alone against both CCR5- and CXCR4-tropic virus strains. Another example of this strategy is the covalently linked combination of peptide C37 with a variant of the gp120-binding peptide CD4M33 (L. Martin et al., Nat. Biotechnol. 21:71-76, 2003). Also, nuclear magnetic resonance (NMR) spectra for several of these compounds are shown, including, to our knowledge, the first published NMR spectrum for griffithsin.
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87
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François KO, Balzarini J. Potential of carbohydrate-binding agents as therapeutics against enveloped viruses. Med Res Rev 2010; 32:349-87. [PMID: 20577974 PMCID: PMC7168447 DOI: 10.1002/med.20216] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Twenty‐seven years after the discovery of HIV as the cause of AIDS more than 25 drugs directed against four different viral targets (i.e. reverse transcriptase, protease, integrase, envelope gp41) and one cellular target (i.e. CCR5 co‐receptor) are available for treatment. However, the search for an efficient vaccine is still ongoing. One of the main problems is the presence of a continuously evolving dense carbohydrate shield, consisting of N‐linked glycans that surrounds the virion and protects it against efficient recognition and persistent neutralization by the immune system. However, several lectins from the innate immune system specifically bind to these glycans in an attempt to process the virus antigens to provoke an immune response. Across a wide variety of different species in nature lectins can be found that can interact with the glycosylated envelope of HIV‐1 and can block the infection of susceptible cells by the virus. In this review, we will give an overview of the lectins from non‐mammalian origin that are endowed with antiviral properties and discuss the complex interactions between lectins of the innate immune system and HIV‐1. Also, attention will be given to different carbohydrate‐related modalities that can be exploited for antiviral chemotherapy. © 2010 Wiley Periodicals, Inc. Med Res Rev
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Affiliation(s)
- K O François
- Rega Institute for Medical Research, K. U. Leuven, B-3000 Leuven, Belgium
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88
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Abstract
PURPOSE OF REVIEW To highlight promising areas of research and preview future generations of microbicides, this review will focus on reports that described new cellular or viral targets, drug substances, or strategies that are specifically intended for topical microbicides. Those reports that dealt with the design, discovery, and synthesis of anti-HIV agents for use in oral or parenteral formulations, while important for the microbicide field, are beyond the scope of this review. RECENT FINDINGS Drug substances intended for topical microbicides are becoming increasingly target specific and, structurally, more complex. New production methods might reduce the cost of microbicides that contain these complex molecules. Genetically engineered probiotic vaginal bacteria express an even wider range of antiviral compounds, perhaps resulting in uninterrupted, coitally independent protection. Combination microbicides that contain two or more drug substances frequently act synergistically. The discovery of new cellular targets such as syndecan-3 might lead to more effective microbicides. SUMMARY Future generations of microbicides will likely contain one or more complex or highly specific drug substances, resulting in safer and more effective products. Since compliance issues continue to confound HIV and herpes simplex virus trials, efforts to bring practical, coitally independent microbicides to developing countries will become a top priority.
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Jiang Y, Tian B, Saifuddin M, Agy MB, Emau P, Cairns JS, Tsai CC. RT-SHIV, an infectious CCR5-tropic chimeric virus suitable for evaluating HIV reverse transcriptase inhibitors in macaque models. AIDS Res Ther 2009; 6:23. [PMID: 19891783 PMCID: PMC2780452 DOI: 10.1186/1742-6405-6-23] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2009] [Accepted: 11/05/2009] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Non-nucleoside reverse transcriptase inhibitors (NNRTIs) are an important category of drugs for both chemotherapy and prevention of human immunodeficiency virus type 1 (HIV-1) infection. However, current non-human primate (NHP) models utilizing simian immunodeficiency virus (SIV) or commonly used chimeric SHIV (SIV expressing HIV-1 envelope) are inadequate due to the insensitivity to NNRTIs. To develop a NHP model for evaluation of NNRTI compounds, we characterized a RT-SHIV virus that was assembled by replacing the SIV mac239 reverse transcriptase (RT) with that of HIV-1HXB2. Since RT-SHIV exhibited in vitro characteristics of high infectivity, CCR5-usage, and sensitivity to HIV-1 specific NNRTIs, this virus was thought to be suitable for mucosal transmission and then was used to carry out a vaginal transmission study in pigtail macaques (Macaca nemestrina). RESULTS RT-SHIV exhibited in vitro characteristics of an infectious CCR5-tropic chimeric virus. This virus was not only highly sensitive to HIV-1 RT specific NNRTIs; its replication was also inhibited by a variety of NRTIs and protease inhibitors. For in vivo vaginal transmission studies, macaques were either pretreated with a single dose of DMPA (depot medroxyprogesterone acetate) or left untreated before intravaginal inoculation with 500 or 1,000 TCID50 of RT-SHIV. All macaques became systemically infected by 2 or 3 weeks post-inoculation exhibiting persistent high viremia, marked CD4+T cell depletion, and antiviral antibody response. DMPA-pretreated macaques showed a higher mean plasma viral load after the acute infection stage, highly variable antiviral antibody response, and a higher incidence of AIDS-like disease as compared with macaques without DMPA pretreatment. CONCLUSION This chimeric RT-SHIV has exhibited productive replication in both macaque and human PBMCs, predominantly CCR5-coreceptor usage for viral entry, and sensitivity to NNRTIs as well as other anti-HIV compounds. This study demonstrates rapid systemic infection in macaques following intravaginal exposure to RT-SHIV. This RT-SHIV/macaque model could be useful for evaluation of NNRTI-based therapies, microbicides, or other preventive strategies.
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90
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O'Keefe BR, Vojdani F, Buffa V, Shattock RJ, Montefiori DC, Bakke J, Mirsalis J, d'Andrea AL, Hume SD, Bratcher B, Saucedo CJ, McMahon JB, Pogue GP, Palmer KE. Scaleable manufacture of HIV-1 entry inhibitor griffithsin and validation of its safety and efficacy as a topical microbicide component. Proc Natl Acad Sci U S A 2009; 106:6099-104. [PMID: 19332801 PMCID: PMC2662964 DOI: 10.1073/pnas.0901506106] [Citation(s) in RCA: 188] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2008] [Indexed: 11/18/2022] Open
Abstract
To prevent sexually transmitted HIV, the most desirable active ingredients of microbicides are antiretrovirals (ARVs) that directly target viral entry and avert infection at mucosal surfaces. However, most promising ARV entry inhibitors are biologicals, which are costly to manufacture and deliver to resource-poor areas where effective microbicides are urgently needed. Here, we report a manufacturing breakthrough for griffithsin (GRFT), one of the most potent HIV entry inhibitors. This red algal protein was produced in multigram quantities after extraction from Nicotiana benthamiana plants transduced with a tobacco mosaic virus vector expressing GRFT. Plant-produced GRFT (GRFT-P) was shown as active against HIV at picomolar concentrations, directly virucidal via binding to HIV envelope glycoproteins, and capable of blocking cell-to-cell HIV transmission. GRFT-P has broad-spectrum activity against HIV clades A, B, and C, with utility as a microbicide component for HIV prevention in established epidemics in sub-Saharan Africa, South Asia, China, and the industrialized West. Cognizant of the imperative that microbicides not induce epithelial damage or inflammatory responses, we also show that GRFT-P is nonirritating and noninflammatory in human cervical explants and in vivo in the rabbit vaginal irritation model. Moreover, GRFT-P is potently active in preventing infection of cervical explants by HIV-1 and has no mitogenic activity on cultured human lymphocytes.
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Affiliation(s)
- Barry R. O'Keefe
- Molecular Targets Development Program, National Cancer Institute at Frederick, Frederick, MD 21702
| | | | - Viviana Buffa
- Saint George's Hospital Medical School, University of London, London SW17 0RE, United Kingdom
| | - Robin J. Shattock
- Saint George's Hospital Medical School, University of London, London SW17 0RE, United Kingdom
| | | | | | | | | | | | | | - Carrie J. Saucedo
- Molecular Targets Development Program, National Cancer Institute at Frederick, Frederick, MD 21702
- SAIC-Frederick, Frederick, MD 21702; and
| | - James B. McMahon
- Molecular Targets Development Program, National Cancer Institute at Frederick, Frederick, MD 21702
| | | | - Kenneth E. Palmer
- Intrucept Biomedicine, Owensboro, KY 42301
- Department of Pharmacology and Toxicology and James Graham Brown Cancer Center, University of Louisville School of Medicine, Louisville, KY 40292
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91
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Second-generation HIV microbicides: continued development of griffithsin. Proc Natl Acad Sci U S A 2009; 106:6029-30. [PMID: 19357305 DOI: 10.1073/pnas.0902239106] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Lederman MM, Jump R, Pilch-Cooper HA, Root M, Sieg SF. Topical application of entry inhibitors as "virustats" to prevent sexual transmission of HIV infection. Retrovirology 2008; 5:116. [PMID: 19094217 PMCID: PMC2637900 DOI: 10.1186/1742-4690-5-116] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2008] [Accepted: 12/18/2008] [Indexed: 11/10/2022] Open
Abstract
With the continuing march of the AIDS epidemic and little hope for an effective vaccine in the near future, work to develop a topical strategy to prevent HIV infection is increasingly important. This stated, the track record of large scale "microbicide" trials has been disappointing with nonspecific inhibitors either failing to protect women from infection or even increasing HIV acquisition. Newer strategies that target directly the elements needed for viral entry into cells have shown promise in non-human primate models of HIV transmission and as these agents have not yet been broadly introduced in regions of highest HIV prevalence, they are particularly attractive for prophylaxis. We review here the agents that can block HIV cellular entry and that show promise as topical strategies or "virustats" to prevent mucosal transmission of HIV infection.
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Affiliation(s)
- Michael M Lederman
- Department of Medicine, Case Western Reserve University, 1100 Euclid Ave, Cleveland, OH 44118, USA
| | - Robin Jump
- Department of Medicine, Case Western Reserve University, 1100 Euclid Ave, Cleveland, OH 44118, USA
| | - Heather A Pilch-Cooper
- Department of Medicine, Case Western Reserve University, 1100 Euclid Ave, Cleveland, OH 44118, USA
| | - Michael Root
- Kimmel Cancer Center, Thomas Jefferson University, 233 South 10th Street, Philadelphia PA, 19107, USA
| | - Scott F Sieg
- Department of Medicine, Case Western Reserve University, 1100 Euclid Ave, Cleveland, OH 44118, USA
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