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Wang C, Wang X, Wang H, Pu J, Li Q, Li J, Liu Y, Lu L, Jiang S. A "Two-Birds-One-Stone" Approach toward the Design of Bifunctional Human Immunodeficiency Virus Type 1 Entry Inhibitors Targeting the CCR5 Coreceptor and gp41 N-Terminal Heptad Repeat Region. J Med Chem 2021; 64:11460-11471. [PMID: 34261320 DOI: 10.1021/acs.jmedchem.1c00781] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Previous studies have reported the stepwise nature of human immunodeficiency virus type 1 (HIV-1) entry and the pivotal role of coreceptor CCR5 and the gp41 N-terminal heptad repeat (NHR) region in this event. With this in mind, we herein report a dual-targeted drug compound featuring bifunctional entry inhibitors, consisting of a piperidine-4-carboxamide-based CCR5 antagonist, TAK-220, and a gp41 NHR-targeting fusion-inhibitory peptide, C34. The resultant chimeras were constructed by linking both pharmacophores with a polyethylene glycol spacer. One chimera, CP12TAK, exhibited exceptionally potent antiviral activity, about 40- and 306-fold over that of its parent inhibitors, C34 and TAK-220, respectively. In addition to R5-tropic viruses, CP12TAK also strongly inhibited infection of X4-tropic HIV-1 strains. These data are promising for the further development of CP12TAK as a new anti-HIV-1 drug. Results show that this strategy could be extended to the design of therapies against infection of other enveloped viruses.
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Affiliation(s)
- Chao Wang
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, 27 Tai-Ping Road, Beijing 100850, China
| | - Xinling Wang
- Key Laboratory of Medical Molecular Virology (MOE/NHC/CAMS), School of Basic Medical Sciences and Shanghai Public Health Clinical Center, Shanghai Institute of Infectious Diseases and Biosecurity, Fudan University, 131 Dong An Road, Shanghai 200032, China
| | - Huan Wang
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, 27 Tai-Ping Road, Beijing 100850, China
| | - Jing Pu
- Key Laboratory of Medical Molecular Virology (MOE/NHC/CAMS), School of Basic Medical Sciences and Shanghai Public Health Clinical Center, Shanghai Institute of Infectious Diseases and Biosecurity, Fudan University, 131 Dong An Road, Shanghai 200032, China
| | - Qing Li
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, 27 Tai-Ping Road, Beijing 100850, China
| | - Jiahui Li
- Key Laboratory of Structure-based Drug Design & Discovery of Ministry of Education, School of Pharmaceutical Engineering, Shenyang Pharmaceutical University, Shenyang 110016, China
| | - Yang Liu
- Key Laboratory of Structure-based Drug Design & Discovery of Ministry of Education, School of Pharmaceutical Engineering, Shenyang Pharmaceutical University, Shenyang 110016, China
| | - Lu Lu
- Key Laboratory of Medical Molecular Virology (MOE/NHC/CAMS), School of Basic Medical Sciences and Shanghai Public Health Clinical Center, Shanghai Institute of Infectious Diseases and Biosecurity, Fudan University, 131 Dong An Road, Shanghai 200032, China
| | - Shibo Jiang
- Key Laboratory of Medical Molecular Virology (MOE/NHC/CAMS), School of Basic Medical Sciences and Shanghai Public Health Clinical Center, Shanghai Institute of Infectious Diseases and Biosecurity, Fudan University, 131 Dong An Road, Shanghai 200032, China
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2
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Twarog NR, Connelly M, Shelat AA. A critical evaluation of methods to interpret drug combinations. Sci Rep 2020; 10:5144. [PMID: 32198459 PMCID: PMC7083968 DOI: 10.1038/s41598-020-61923-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 03/05/2020] [Indexed: 11/09/2022] Open
Abstract
Combination therapy is increasingly central to modern medicine. Yet reliable analysis of combination studies remains an open challenge. Previous work suggests that common methods of combination analysis are too susceptible to noise to support robust scientific conclusions. In this paper, we use simulated and real-world combination datasets to demonstrate that traditional index methods are unstable and biased by pharmacological and experimental conditions, whereas response-surface approaches such as the BRAID method are more consistent and unbiased. Using a publicly-available data set, we show that BRAID more accurately captures variations in compound mechanism of action, and is therefore better able to discriminate between synergistic, antagonistic, and additive interactions. Finally, we applied BRAID analysis to identify a clear pattern of consistently enhanced AKT sensitivity in a subset of cancer cell lines, and a far richer array of PARP inhibitor combination therapies for BRCA1-deficient cancers than would be identified by traditional synergy analysis.
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Affiliation(s)
- Nathaniel R Twarog
- Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA
| | - Michele Connelly
- Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA
| | - Anang A Shelat
- Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA.
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3
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Figueira TN, Domingues MM, Illien F, Cadima-Couto I, Todorovski T, Andreu D, Sagan S, Castanho MARB, Walrant A, Veiga AS. Enfuvirtide-Protoporphyrin IX Dual-Loaded Liposomes: In Vitro Evidence of Synergy against HIV-1 Entry into Cells. ACS Infect Dis 2020; 6:224-236. [PMID: 31855415 DOI: 10.1021/acsinfecdis.9b00285] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
We have developed a nanocarrier consisting of large unilamellar vesicles (LUVs) for combined delivery of two human immunodeficiency virus type 1 (HIV-1) entry inhibitors, enfuvirtide (ENF) and protoporphyrin IX (PPIX). The intrinsic lipophilicity of ENF and PPIX, a fusion inhibitor and an attachment inhibitor, respectively, leads to their spontaneous incorporation into the lipid bilayer of the LUVs nanocarrier. Both entry inhibitors partition significantly toward LUVs composed of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) and a 9:1 mixture of POPC:1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)-2000] (DPPE-PEG2000), representative of conventional and immune-evasive drug delivery formulations, respectively. These colocalize in the core of lipid membranes. Dual-loaded nanocarriers are monodispersed and retain the size distribution, thermotropic behavior, and surface charge of the unloaded form. Combination of the two entry inhibitors in the nanocarrier resulted in improved synergy against HIV-1 entry compared to combination in free form, strongly when immune-evasive formulations are used. We propose that the improved action of the entry inhibitors when loaded into the nanocarriers results from their slow release at the site of viral entry. Overall, liposomes remain largely unexplored platforms for combination of viral entry inhibitors, with potential for improvement of current antiretroviral therapy drug safety and application. Our work calls for a reappraisal of the potential of entry inhibitor combinations and delivery for clinical use in antiretroviral therapy.
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Affiliation(s)
- Tiago N. Figueira
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisbon, Portugal
| | - Marco M. Domingues
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisbon, Portugal
| | - Françoise Illien
- Sorbonne Université, École Normale Supérieure, PSL University, CNRS, Laboratoire des Biomolécules, LBM, 75005 Paris, France
| | - Iris Cadima-Couto
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisbon, Portugal
| | - Toni Todorovski
- Department of Experimental and Health Science, Universitat Pompeu Fabra, Barcelona Biomedical Research Park, 08003 Barcelona, Spain
| | - David Andreu
- Department of Experimental and Health Science, Universitat Pompeu Fabra, Barcelona Biomedical Research Park, 08003 Barcelona, Spain
| | - Sandrine Sagan
- Sorbonne Université, École Normale Supérieure, PSL University, CNRS, Laboratoire des Biomolécules, LBM, 75005 Paris, France
| | - Miguel A. R. B. Castanho
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisbon, Portugal
| | - Astrid Walrant
- Sorbonne Université, École Normale Supérieure, PSL University, CNRS, Laboratoire des Biomolécules, LBM, 75005 Paris, France
| | - Ana Salomé Veiga
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisbon, Portugal
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Yuan C, Wang JY, Zhao HJ, Li Y, Li D, Ling H, Zhuang M. Mutations of Glu560 within HIV-1 Envelope Glycoprotein N-terminal heptad repeat region contribute to resistance to peptide inhibitors of virus entry. Retrovirology 2019; 16:36. [PMID: 31796053 PMCID: PMC6889725 DOI: 10.1186/s12977-019-0496-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 11/21/2019] [Indexed: 11/17/2022] Open
Abstract
Background Peptides corresponding to N- and C-terminal heptad repeat regions (HR1 and HR2, respectively) of gp41 can inhibit HIV-1 infection in a dominant negative manner by interfering with refolding of the viral HR1 and HR2 to form a six-helix bundle (6HB) that induces fusion between viral and host cell membranes. Previously, we found that HIV-1 acquired the mutations of Glu560 (E560) in HR1 of envelope (Env) to escape peptide inhibitors. The present study aimed to elucidate the critical role of position 560 in the virus entry and potential resistance mechanisms. Results The Glu560Lys/Asp/Gly (E560K/D/G) mutations in HR1 of gp41 that are selected under the pressure of N- and C-peptide inhibitors modified its molecular interactions with HR2 to change 6HB stability and peptide inhibitor binding. E560K mutation increased 6HB thermostability and resulted in resistance to N peptide inhibitors, but E560G or E560D as compensatory mutations destabilized the 6HB to reduce inhibitor binding and resulted in increased resistance to C peptide inhibitor, T20. Significantly, the neutralizing activities of all mutants to soluble CD4 and broadly neutralizing antibodies targeting membrane proximal external region, 2F5 and 4E10 were improved, indicating the mutations of E560 could regulate Env conformations through cross interactions with gp120 or gp41. The molecular modeling analysis of E560K/D/G mutants suggested that position 560 might interact with the residues within two potentially flexible topological layer 1 and layer 2 in the gp120 inner domain to apparently affect the CD4 utilization. The E560K/D/G mutations changed its interactions with Gln650 (Q650) in HR2 to contribute to the resistance of peptide inhibitors. Conclusions These findings identify the contributions of mutations of E560K/D/G in the highly conserved gp41 and highlight Env’s high degree of plasticity for virus entry and inhibitor design.
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Affiliation(s)
- Chen Yuan
- Department of Microbiology, Harbin Medical University, Harbin, Heilongjiang, China
| | - Jia-Ye Wang
- Department of Microbiology, Harbin Medical University, Harbin, Heilongjiang, China.,Heilongjiang Provincial Key Laboratory of Infection and Immunity, Harbin, China
| | - Hai-Jiao Zhao
- Department of Microbiology, Harbin Medical University, Harbin, Heilongjiang, China
| | - Yan Li
- Department of Microbiology, Harbin Medical University, Harbin, Heilongjiang, China.,Heilongjiang Provincial Key Laboratory of Infection and Immunity, Harbin, China.,Key Laboratory of Pathogen Biology, Harbin, China
| | - Di Li
- Department of Microbiology, Harbin Medical University, Harbin, Heilongjiang, China.,Heilongjiang Provincial Key Laboratory of Infection and Immunity, Harbin, China.,Key Laboratory of Pathogen Biology, Harbin, China
| | - Hong Ling
- Department of Microbiology, Harbin Medical University, Harbin, Heilongjiang, China. .,Heilongjiang Provincial Key Laboratory of Infection and Immunity, Harbin, China. .,Key Laboratory of Pathogen Biology, Harbin, China. .,Wu Lien-Teh Institute, Harbin Medical University, Harbin, China.
| | - Min Zhuang
- Department of Microbiology, Harbin Medical University, Harbin, Heilongjiang, China. .,Heilongjiang Provincial Key Laboratory of Infection and Immunity, Harbin, China. .,Key Laboratory of Pathogen Biology, Harbin, China. .,Wu Lien-Teh Institute, Harbin Medical University, Harbin, China.
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5
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Rashad AA, Song LR, Holmes AP, Acharya K, Zhang S, Wang ZL, Gary E, Xie X, Pirrone V, Kutzler MA, Long YQ, Chaiken I. Bifunctional Chimera That Coordinately Targets Human Immunodeficiency Virus 1 Envelope gp120 and the Host-Cell CCR5 Coreceptor at the Virus-Cell Interface. J Med Chem 2018; 61:5020-5033. [PMID: 29767965 DOI: 10.1021/acs.jmedchem.8b00477] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
To address the urgent need for new agents to reduce the global occurrence and spread of AIDS, we investigated the underlying hypothesis that antagonists of the HIV-1 envelope (Env) gp120 protein and the host-cell coreceptor (CoR) protein can be covalently joined into bifunctional synergistic combinations with improved antiviral capabilities. A synthetic protocol was established to covalently combine a CCR5 small-molecule antagonist and a gp120 peptide triazole antagonist to form the bifunctional chimera. Importantly, the chimeric inhibitor preserved the specific targeting properties of the two separate chimera components and, at the same time, exhibited low to subnanomolar potencies in inhibiting cell infection by different pseudoviruses, which were substantially greater than those of a noncovalent mixture of the individual components. The results demonstrate that targeting the virus-cell interface with a single molecule can result in improved potencies and also the introduction of new phenotypes to the chimeric inhibitor, such as the irreversible inactivation of HIV-1.
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Affiliation(s)
| | - Li-Rui Song
- CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica , Chinese Academy of Science , Shanghai 201203 , China.,College of Pharmaceutical Sciences , Soochow University Medical College , Suzhou 215123 , China.,University of Chinese Academy of Sciences , Number 19A Yuquan Road , Beijing 100049 , China
| | | | | | - Shiyu Zhang
- School of Biomedical Engineering, Science and Health Systems , Drexel University , Philadelphia , Pennsylvania 19104 , United States
| | - Zhi-Long Wang
- CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica , Chinese Academy of Science , Shanghai 201203 , China
| | | | - Xin Xie
- CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica , Chinese Academy of Science , Shanghai 201203 , China
| | | | | | - Ya-Qiu Long
- CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica , Chinese Academy of Science , Shanghai 201203 , China.,College of Pharmaceutical Sciences , Soochow University Medical College , Suzhou 215123 , China
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6
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Zhou KX, Xie LH, Peng X, Guo QM, Wu QY, Wang WH, Zhang GL, Wu JF, Zhang GJ, Du CW. CXCR4 antagonist AMD3100 enhances the response of MDA-MB-231 triple-negative breast cancer cells to ionizing radiation. Cancer Lett 2018; 418:196-203. [PMID: 29317253 DOI: 10.1016/j.canlet.2018.01.009] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 12/22/2017] [Accepted: 01/05/2018] [Indexed: 02/05/2023]
Abstract
Radiation therapy (RT) is one of the primary modalities for triple-negative breast cancer (TNBC) treatment. However, due to the pro-metastatic potential of radiation and the intrinsic radiation resistance of some tumors, many patients experience RT failure, which leads to cancer relapse and distant metastasis. This preclinical study evaluated the efficacy of the antagonist of the SDF-1 receptor CXCR4, AMD3100, as a radiosensitizer in TNBC models. The combined effect of ionizing radiation and AMD3100 was determined in vitro by surviving fraction, cell cycle distribution, Bax and Bcl-2 expression, and apoptosis assays in a TNBC cell line (MDA-MB-231). For in vivo studies, human xenograft athymic nude mice were used. Treatment of TNBC cells with AMD3100 significantly augmented cellular radiosensitivity. Radiosensitivity was enhanced specifically through increased Bax expression, reduced Bcl-2 expression, prolonged G2-M arrest, and increased apoptosis. Combined treatment with AMD3100 and irradiation also enhanced tumor growth delay, with an enhancement factor ranging from 1.5 to 1.8. These findings support the evaluation of antagonists of the SDF-1 receptor CXCR4, such as AMD3100, as potent radiosensitizers in TNBC.
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Affiliation(s)
- K X Zhou
- The Third Affiliated Hospital of ChongQing Medical University, No.1 Shuanghu Road, ChongQing, 410013, PR China
| | - L H Xie
- Department of Medical Oncology, Shantou Central Hospital, Affiliated Shantou Hospital of Sun Yat-sen University, No. 114 Waima Road, Shantou, 515031, PR China
| | - X Peng
- Department of Radiotherapy, Cancer Hospital of Shantou University Medical College, No.7 Raoping Road, Shantou, 515031, PR China
| | - Q M Guo
- Shantou University Medical College, No.22 Xinling Road, Shantou, 515041, PR China
| | - Q Y Wu
- Shantou University Medical College, No.22 Xinling Road, Shantou, 515041, PR China
| | - W H Wang
- Shantou University Medical College, No.22 Xinling Road, Shantou, 515041, PR China
| | - G L Zhang
- Shantou University Medical College, No.22 Xinling Road, Shantou, 515041, PR China
| | - J F Wu
- Shantou University Medical College, No.22 Xinling Road, Shantou, 515041, PR China
| | - G J Zhang
- Shantou University Medical College, No.22 Xinling Road, Shantou, 515041, PR China; Xiang'an Hospital, Xiamen University, 2000 East Xiang'an Road, Xiamen, 361000, PR China
| | - C W Du
- Shantou University Medical College, No.22 Xinling Road, Shantou, 515041, PR China; Breast Medical Oncology, National Cancer Center/Cancer Hospital & Shenzhen Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 113 Baohe Road, ShengZhen, 518116, China.
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7
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Ahn KW, Root MJ. Complex interplay of kinetic factors governs the synergistic properties of HIV-1 entry inhibitors. J Biol Chem 2017; 292:16498-16510. [PMID: 28696261 DOI: 10.1074/jbc.m117.791731] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Revised: 07/09/2017] [Indexed: 01/04/2023] Open
Abstract
The homotrimeric HIV-1 envelope glycoprotein (Env) undergoes receptor-triggered structural changes that mediate viral entry through membrane fusion. This process is inhibited by chemokine receptor antagonists (CoRAs) that block Env-receptor interactions and by fusion inhibitors (FIs) that disrupt Env conformational transitions. Synergy between CoRAs and FIs has been attributed to a CoRA-dependent decrease in the rate of viral membrane fusion that extends the lifetime of the intermediate state targeted by FIs. Here, we demonstrated that the magnitude of CoRA/FI synergy unexpectedly depends on FI-binding affinity and the stoichiometry of chemokine receptor binding to trimeric Env. For C-peptide FIs (clinically represented by enfuvirtide), synergy waned as binding strength decreased until inhibitor combinations behaved additively. Curiously, this affinity dependence on synergy was absent for 5-Helix-type FIs. We linked this complex behavior to the CoRA dependence of Env deactivation following FI binding. For both FI classes, reducing chemokine receptor levels on target cells or eliminating competent chemokine receptor-binding sites on Env trimers resulted in a loss of synergistic activity. These data imply that the stoichiometry required for CoRA/FI synergy exceeds that required for HIV-1 entry. Our analysis suggests two distinct roles for chemokine receptor binding, one to trigger formation of the FI-sensitive intermediate state and another to facilitate subsequent conformational transitions. Together, our results could explain the wide variety of previously reported activities for CoRA/FI combinations. These findings also have implications for the combined use of CoRAs and FIs in antiviral therapies and point to a multifaceted role for chemokine receptor binding in promoting HIV-1 entry.
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Affiliation(s)
- Koree W Ahn
- From the Department of Biochemistry and Molecular Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Michael J Root
- From the Department of Biochemistry and Molecular Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
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8
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Alexandre KB, Mufhandu HT, London GM, Chakauya E, Khati M. Progress and Perspectives on HIV-1 microbicide development. Virology 2016; 497:69-80. [PMID: 27429040 DOI: 10.1016/j.virol.2016.07.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2016] [Revised: 07/01/2016] [Accepted: 07/04/2016] [Indexed: 12/12/2022]
Abstract
The majority of HIV-1 infections occur via sexual intercourse. Women are the most affected by the epidemic, particularly in developing countries, due to their socio-economic dependence on men and the fact that they are often victims of gender based sexual violence. Despite significant efforts that resulted in the reduction of infection rates in some countries, there is still need for effective prevention methods against the virus. One of these methods for preventing sexual transmission in women is the use of microbicides. In this review we provide a summary of the progress made toward the discovery of affordable and effective HIV-1 microbicides and suggest future directions. We show that there is a wide range of compounds that have been proposed as potential microbicides. Although most of them have so far failed to show protection in humans, there are many promising ones currently in pre-clinical studies and in clinical trials.
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Affiliation(s)
- Kabamba B Alexandre
- Council for Scientific and Industrial Research, Pioneering Health Sciences Laboratory, Biosciences Unit, Pretoria, Gauteng, South Africa.
| | - Hazel T Mufhandu
- Council for Scientific and Industrial Research, Pioneering Health Sciences Laboratory, Biosciences Unit, Pretoria, Gauteng, South Africa
| | - Grace M London
- Department of Health Free State District Health Services and Health Programs, South Africa
| | - E Chakauya
- Council for Scientific and Industrial Research, Pioneering Health Sciences Laboratory, Biosciences Unit, Pretoria, Gauteng, South Africa
| | - M Khati
- Council for Scientific and Industrial Research, Pioneering Health Sciences Laboratory, Biosciences Unit, Pretoria, Gauteng, South Africa; University of Cape Town and Groote Schuur Hospital, Department of Medicine, Cape Town, South Africa
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9
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Twarog NR, Stewart E, Hammill CV, Shelat AA. BRAID: A Unifying Paradigm for the Analysis of Combined Drug Action. Sci Rep 2016; 6:25523. [PMID: 27160857 PMCID: PMC4861905 DOI: 10.1038/srep25523] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Accepted: 04/18/2016] [Indexed: 01/01/2023] Open
Abstract
With combination therapies becoming increasingly vital to understanding and combatting disease, a reliable method for analyzing combined dose response is essential. The importance of combination studies both in basic and translational research necessitates a method that can be applied to a wide range of experimental and analytical conditions. However, despite increasing demand, no such unified method has materialized. Here we introduce the Bivariate Response to Additive Interacting Doses (BRAID) model, a response surface model that combines the simplicity and intuitiveness needed for basic interaction classifications with the versatility and depth needed to analyze a combined response in the context of pharmacological and toxicological constraints. We evaluate the model in a series of simulated combination experiments, a public combination dataset, and several experiments on Ewing’s Sarcoma. The resulting interaction classifications are more consistent than those produced by traditional index methods, and show a strong relationship between compound mechanisms and nature of interaction. Furthermore, analysis of fitted response surfaces in the context of pharmacological constraints yields a more concrete prediction of combination efficacy that better agrees with in vivo evaluations.
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Affiliation(s)
- Nathaniel R Twarog
- Departments of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis, Tennessee 38105, USA
| | - Elizabeth Stewart
- Developmental Neurobiology St. Jude Children's Research Hospital, Memphis, Tennessee 38105, USA
| | - Courtney Vowell Hammill
- Departments of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis, Tennessee 38105, USA
| | - Anang A Shelat
- Departments of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis, Tennessee 38105, USA
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10
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Engineering Cellular Resistance to HIV-1 Infection In Vivo Using a Dual Therapeutic Lentiviral Vector. MOLECULAR THERAPY-NUCLEIC ACIDS 2015; 4:e236. [DOI: 10.1038/mtna.2015.10] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Accepted: 02/25/2015] [Indexed: 11/08/2022]
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11
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Haqqani AA, Tilton JC. Entry inhibitors and their use in the treatment of HIV-1 infection. Antiviral Res 2013; 98:158-70. [PMID: 23541872 DOI: 10.1016/j.antiviral.2013.03.017] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2013] [Revised: 03/18/2013] [Accepted: 03/19/2013] [Indexed: 12/20/2022]
Abstract
Entry of HIV into target cells is a complex, multi-stage process involving sequential attachment and CD4 binding, coreceptor binding, and membrane fusion. HIV entry inhibitors are a complex group of drugs with multiple mechanisms of action depending on the stage of the viral entry process they target. Two entry inhibitors are currently approved for the treatment of HIV-infected patients. Maraviroc, a CCR5 antagonist, blocks interactions between the viral envelope proteins and the CCR5 coreceptor. Enfuvirtide, a fusion inhibitor, disrupts conformational changes in gp41 that drive membrane fusion. A wide array of additional agents are in various stages of development. This review covers the entry inhibitors and their use in the treatment of HIV-infected patients.
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Affiliation(s)
- Aiman A Haqqani
- Case Center for Proteomics and Bioinformatics, Case Western Reserve University, Cleveland, OH 44106, USA
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12
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Kang Y, Guo J, Chen Z. Closing the door to human immunodeficiency virus. Protein Cell 2013; 4:86-102. [PMID: 23479426 DOI: 10.1007/s13238-012-2111-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Accepted: 11/22/2012] [Indexed: 10/27/2022] Open
Abstract
The pandemic of human immunodeficiency virus type one (HIV-1), the major etiologic agent of acquired immunodeficiency disease (AIDS), has led to over 33 million people living with the virus, among which 18 million are women and children. Until now, there is neither an effective vaccine nor a therapeutic cure despite over 30 years of efforts. Although the Thai RV144 vaccine trial has demonstrated an efficacy of 31.2%, an effective vaccine will likely rely on a breakthrough discovery of immunogens to elicit broadly reactive neutralizing antibodies, which may take years to achieve. Therefore, there is an urgency of exploring other prophylactic strategies. Recently, antiretroviral treatment as prevention is an exciting area of progress in HIV-1 research. Although effective, the implementation of such strategy faces great financial, political and social challenges in heavily affected regions such as developing countries where drug resistant viruses have already been found with growing incidence. Activating latently infected cells for therapeutic cure is another area of challenge. Since it is greatly difficult to eradicate HIV-1 after the establishment of viral latency, it is necessary to investigate strategies that may close the door to HIV-1. Here, we review studies on non-vaccine strategies in targeting viral entry, which may have critical implications for HIV-1 prevention.
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Affiliation(s)
- Yuanxi Kang
- AIDS Institute and Department of Microbiology of Li Ka Shing Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Pokfulam, Hong Kong SAR, China
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13
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Approaches for identification of HIV-1 entry inhibitors targeting gp41 pocket. Viruses 2013; 5:127-49. [PMID: 23344560 PMCID: PMC3564113 DOI: 10.3390/v5010127] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Revised: 01/03/2013] [Accepted: 01/03/2013] [Indexed: 01/08/2023] Open
Abstract
The hydrophobic pocket in the HIV-1 gp41 N-terminal heptad repeat (NHR) domain plays an important role in viral fusion and entry into the host cell, and serves as an attractive target for development of HIV-1 fusion/entry inhibitors. The peptide anti-HIV drug targeting gp41 NHR, T-20 (generic name: enfuvirtide; brand name: Fuzeon), was approved by the U.S. FDA in 2003 as the first HIV fusion/entry inhibitor for treatment of HIV/AIDS patients who fail to respond to the current antiretroviral drugs. However, because T20 lacks the pocket-binding domain (PBD), it exhibits low anti-HIV-1 activity and short half-life. Therefore, several next-generation HIV fusion inhibitory peptides with PBD have been developed. They possess longer half-life and more potent antiviral activity against a broad spectrum of HIV-1 strains, including the T-20-resistant variants. Nonetheless, the clinical application of these peptides is still limited by the lack of oral availability and the high cost of production. Thus, development of small molecule compounds targeting the gp41 pocket with oral availability has been promoted. This review describes the main approaches for identification of HIV fusion/entry inhibitors targeting the gp41 pocket and summarizes the latest progress in developing these inhibitors as a new class of anti-HIV drugs.
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Heald-Sargent T, Gallagher T. Ready, set, fuse! The coronavirus spike protein and acquisition of fusion competence. Viruses 2012; 4:557-80. [PMID: 22590686 PMCID: PMC3347323 DOI: 10.3390/v4040557] [Citation(s) in RCA: 238] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Revised: 03/29/2012] [Accepted: 04/02/2012] [Indexed: 12/16/2022] Open
Abstract
Coronavirus-cell entry programs involve virus-cell membrane fusions mediated by viral spike (S) proteins. Coronavirus S proteins acquire membrane fusion competence by receptor interactions, proteolysis, and acidification in endosomes. This review describes our current understanding of the S proteins, their interactions with and their responses to these entry triggers. We focus on receptors and proteases in prompting entry and highlight the type II transmembrane serine proteases (TTSPs) known to activate several virus fusion proteins. These and other proteases are essential cofactors permitting coronavirus infection, conceivably being in proximity to cell-surface receptors and thus poised to split entering spike proteins into the fragments that refold to mediate membrane fusion. The review concludes by noting how understanding of coronavirus entry informs antiviral therapies.
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Affiliation(s)
| | - Tom Gallagher
- Department of Microbiology and Immunology, Loyola University Medical Center, 2160 South First Avenue, Maywood, IL 60153, USA;
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15
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UCLA1, a synthetic derivative of a gp120 RNA aptamer, inhibits entry of human immunodeficiency virus type 1 subtype C. J Virol 2012; 86:4989-99. [PMID: 22379083 DOI: 10.1128/jvi.06893-11] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Entry of human immunodeficiency virus type 1 (HIV-1) into cells is mediated by the virion surface envelope (Env) glycoproteins, making it a desirable target for antiretroviral entry inhibitors. We previously isolated a family of gp120 binding RNA aptamers and showed that they neutralized the infectivity of HIV-1. In this study, we assessed the activity of a shortened synthetic derivative of the B40 aptamer, called UCLA1, against a large panel of HIV-1 subtype C viruses. UCLA1 tightly bound to a consensus HIV-1 subtype C gp120 and neutralized isolates of the same subtype with 50% inhibitory concentrations (IC(50)s) in the nanomolar range. The aptamer had little toxicity in tests with cell lines and primary cells. Furthermore, it exhibited high therapeutic indices, suggesting that it may be effective at very low doses. Mapping of UCLA1 binding sites on gp120 revealed eight amino acid residues that modulated neutralization resistance. This included residues within the coreceptor binding site, at the base of the V3 loop, and in the bridging sheet within the conserved V1/V2 stem-loop of gp120. The aptamer was also shown to have synergistic effects with T20, a gp41 fusion inhibitor, and IgG1b12 (b12), an anti-CD4 binding site monoclonal antibody. These results suggest that UCLA1 may be suitable for development as a potent HIV-1 entry inhibitor.
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16
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Ketas TJ, Holuigue S, Matthews K, Moore JP, Klasse PJ. Env-glycoprotein heterogeneity as a source of apparent synergy and enhanced cooperativity in inhibition of HIV-1 infection by neutralizing antibodies and entry inhibitors. Virology 2011; 422:22-36. [PMID: 22018634 DOI: 10.1016/j.virol.2011.09.019] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2011] [Revised: 08/19/2011] [Accepted: 09/17/2011] [Indexed: 10/16/2022]
Abstract
We measured the inhibition of infectivity of HIV-1 isolates and derivative clones by combinations of neutralizing antibodies (NAbs) and other entry inhibitors in a single-cycle-replication assay. Synergy was analyzed both by the current linear and a new non-linear method. The new method reduced spurious indications of synergy and antagonism. Synergy between NAbs was overall weaker than between other entry inhibitors, and no stronger where one ligand is known to enhance the binding of another. However, synergy was stronger for a genetically heterogeneous HIV-1 R5 isolate than for its derivative clones. Enhanced cooperativity in inhibition by combinations, compared with individual inhibitors, correlated with increased synergy at higher levels of inhibition, while being less variable. Again, cooperativity enhancement was stronger for isolates than clones. We hypothesize that genetic, post-translational or conformational heterogeneity of the Env protein and of other targets for inhibitors can yield apparent synergy and increased cooperativity between inhibitors.
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Affiliation(s)
- Thomas J Ketas
- Department of Microbiology and Immunology, Weill Medical College of Cornell University, New York, NY 10065-4896, USA
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17
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Sedaghat AR, Wilke CO. Kinetics of the viral cycle influence pharmacodynamics of antiretroviral therapy. Biol Direct 2011; 6:42. [PMID: 21910865 PMCID: PMC3203257 DOI: 10.1186/1745-6150-6-42] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2011] [Accepted: 09/12/2011] [Indexed: 11/26/2022] Open
Abstract
Background More and more antiretroviral therapies are being developed for treatment of HIV infection. The in-vivo efficacy of these drugs is commonly predicted based on in-vitro measures of antiviral effect. One primary in-vitro measure is the IC50, the amount of drug required for 50% inhibition of viral replication. We have previously shown that HIV life-cycle kinetics impact clinically observed HIV viral dynamics. Here we present a mathematical model of how they affect the pharmacodynamics of antiretroviral drugs. Results We find that experimentally measured antiretroviral IC50s are determined by three factors: (i) intrinsic drug properties (e.g. drug-target binding), (ii) kinetics of the HIV life cycle, and (iii) kinetics of drug-inhibited infected cells. Our model predicts that the IC50 is a declining function of the duration of the drug-susceptible stage in the host cell. We combine our model with known viral life-cycle kinetics to derive a measure of intrinsic properties, reflecting drug action, for known antiretroviral drugs from previously measured IC50s. We show that this measure of intrinsic drug property correlates very well with in vitro-measured antiviral activity, whereas experimentally measured IC50 does not. Conclusions Our results have implications for understanding pharmacodynamics of and improving activity of antiretroviral drugs. Our findings predict that drug activity can be improved through co-administration of synergistic drugs that delay the viral life cycle but are not inhibitory by themselves. Moreover, our results may easily extend to treatment of other pathogens. This article was reviewed by Dr. Ruy Ribeiro, Dr. Ha Youn Lee, Dr. Alan Perelson and Dr. Christoph Adami.
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Affiliation(s)
- Ahmad R Sedaghat
- Department of Otolaryngology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA, USA.
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18
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Alexandre KB, Gray ES, Pantophlet R, Moore PL, McMahon JB, Chakauya E, O'Keefe BR, Chikwamba R, Morris L. Binding of the mannose-specific lectin, griffithsin, to HIV-1 gp120 exposes the CD4-binding site. J Virol 2011; 85:9039-50. [PMID: 21697467 PMCID: PMC3165825 DOI: 10.1128/jvi.02675-10] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2010] [Accepted: 06/13/2011] [Indexed: 01/08/2023] Open
Abstract
The glycans on HIV-1 gp120 play an important role in shielding neutralization-sensitive epitopes from antibody recognition. They also serve as targets for lectins that bind mannose-rich glycans. In this study, we investigated the interaction of the lectin griffithsin (GRFT) with HIV-1 gp120 and its effects on exposure of the CD4-binding site (CD4bs). We found that GRFT enhanced the binding of HIV-1 to plates coated with anti-CD4bs antibodies b12 and b6 or the CD4 receptor mimetic CD4-IgG2. The average enhancement of b12 or b6 binding was higher for subtype B viruses than for subtype C, while for CD4-IgG2, it was similar for both subtypes, although lower than observed with antibodies. This GRFT-mediated enhancement of HIV-1 binding to b12 was reflected in synergistic neutralization for 2 of the 4 viruses tested. The glycan at position 386, which shields the CD4bs, was involved in both GRFT-mediated enhancement of binding and neutralization synergism between GRFT and b12. Although GRFT enhanced CD4bs exposure, it simultaneously inhibited ligand binding to the coreceptor binding site, suggesting that GRFT-dependent enhancement and neutralization utilize independent mechanisms. This study shows for the first time that GRFT interaction with gp120 exposes the CD4bs through binding the glycan at position 386, which may have implications for how to access this conserved site.
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Affiliation(s)
| | - Elin S. Gray
- AIDS Virus Research Unit, National Institute for Communicable Diseases, Johannesburg, South Africa
| | - Ralph Pantophlet
- Faculty of Health Sciences
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, Canada
| | - Penny L. Moore
- AIDS Virus Research Unit, National Institute for Communicable Diseases, Johannesburg, South Africa
| | - James B. McMahon
- Molecular Targets Laboratory, Center for Cancer Research, NCI, Frederick, Maryland
| | - Ereck Chakauya
- Centre for Scientific and Industrial Research, Pretoria, South Africa
| | - Barry R. O'Keefe
- Molecular Targets Laboratory, Center for Cancer Research, NCI, Frederick, Maryland
| | - Rachel Chikwamba
- Centre for Scientific and Industrial Research, Pretoria, South Africa
| | - Lynn Morris
- AIDS Virus Research Unit, National Institute for Communicable Diseases, Johannesburg, South Africa
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19
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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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20
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Joly V, Jidar K, Tatay M, Yeni P. Enfuvirtide: from basic investigations to current clinical use. Expert Opin Pharmacother 2011; 11:2701-13. [PMID: 20977403 DOI: 10.1517/14656566.2010.522178] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
IMPORTANCE OF THE FIELD Drug resistance is a major challenge in the treatment of HIV infection. Enfuvirtide is the first entry inhibitor to have been approved for clinical use. AREAS COVERED IN THIS REVIEW Relevant information through searches of MEDLINE (1998 to June 2010) and meeting abstracts of major HIV/AIDS conferences (2003 - June 2010) using the search terms 'enfuvirtide', 'T-20' and 'fusion inhibitor'. WHAT THE READER WILL GAIN Enfuvirtide blocks HIV fusion to host cells. It works against the different HIV-1 variants but is not active against HIV-2. The recommended dosage of enfuvirtide is 90 mg b.i.d. subcutaneously. The two large Phase III pivotal clinical trials TORO 1 and 2 showed that enfuvirtide is an effective therapeutic option as rescue therapy in combination with other active antiretroviral drugs. Resistance to enfuvirtide is conferred by mutations in the HR1 region of gp41. Single and double mutations have been shown to result in high-level resistance to enfuvirtide. Postmarketing studies have been helpful to define more precisely the place of enfuvirtide in the sequence of antiretroviral therapy. TAKE HOME MESSAGE The emergence of new compounds and new classes of drugs, highly active against multiresistant virus but more convenient to administer than enfuvirtide, will probably prevent the extensive use of enfuvirtide. This drug remains attractive in some subgroups of patients because of its excellent systemic tolerance and the lack of interactions with the major cytochrome P450 isoenzymes.
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Affiliation(s)
- Véronique Joly
- Hôpital Bichat Claude Bernard, Maladies Infectieuses, 46 rue Henri Huchard, 75877 Paris Cedex 18, France.
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21
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Abstract
Enveloped viruses penetrate their cell targets following the merging of their membrane with that of the cell. This fusion process is catalyzed by one or several viral glycoproteins incorporated on the membrane of the virus. These envelope glycoproteins (EnvGP) evolved in order to combine two features. First, they acquired a domain to bind to a specific cellular protein, named "receptor." Second, they developed, with the help of cellular proteins, a function of finely controlled fusion to optimize the replication and preserve the integrity of the cell, specific to the genus of the virus. Following the activation of the EnvGP either by binding to their receptors and/or sometimes the acid pH of the endosomes, many changes of conformation permit ultimately the action of a specific hydrophobic domain, the fusion peptide, which destabilizes the cell membrane and leads to the opening of the lipidic membrane. The comprehension of these mechanisms is essential to develop medicines of the therapeutic class of entry inhibitor like enfuvirtide (Fuzeon) against human immunodeficiency virus (HIV). In this chapter, we will summarize the different envelope glycoprotein structures that viruses develop to achieve membrane fusion and the entry of the virus. We will describe the different entry pathways and cellular proteins that viruses have subverted to allow infection of the cell and the receptors that are used. Finally, we will illustrate more precisely the recent discoveries that have been made within the field of the entry process, with a focus on the use of pseudoparticles. These pseudoparticles are suitable for high-throughput screenings that help in the development of natural or artificial inhibitors as new therapeutics of the class of entry inhibitors.
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Affiliation(s)
- François-Loic Cosset
- Université de Lyon, UCB-Lyon1, IFR128, Lyon, France,INSERM, U758, Lyon, France,Ecole Normale Supérieure de Lyon, Lyon, France
| | - Dimitri Lavillette
- Université de Lyon, UCB-Lyon1, IFR128, Lyon, France,INSERM, U758, Lyon, France,Ecole Normale Supérieure de Lyon, Lyon, France
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22
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Pan C, Liu S, Jiang S. HIV-1 gp41 Fusion Intermediate: A Target for HIV Therapeutics. J Formos Med Assoc 2010; 109:94-105. [DOI: 10.1016/s0929-6646(10)60029-0] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2009] [Revised: 09/25/2009] [Accepted: 09/25/2009] [Indexed: 11/28/2022] Open
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23
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Combinations of the first and next generations of human immunodeficiency virus (HIV) fusion inhibitors exhibit a highly potent synergistic effect against enfuvirtide- sensitive and -resistant HIV type 1 strains. J Virol 2009; 83:7862-72. [PMID: 19493996 DOI: 10.1128/jvi.00168-09] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
T20 (generic name, enfuvirtide; brand name, Fuzeon) is a first-generation human immunodeficiency virus (HIV) fusion inhibitor approved for salvage therapy of HIV-infected patients refractory to current antiretroviral drugs. However, its clinical use is limited because of rapid emergence of T20-resistant viruses in T20-treated patients. Therefore, T1249 and T1144 are being developed as the second- and third-generation HIV fusion inhibitors, respectively, with improved efficacy and drug resistance profiles. Here, we found that combinations of T20 with T1249 and/or T1144 resulted in exceptionally potent synergism (combination index, <0.01) against HIV-1-mediated membrane fusion by 2 to 3 orders of magnitude in dose reduction. Highly potent synergistic antiviral efficacy was also achieved against infection by laboratory-adapted and primary HIV-1 strains, including T20-resistant variants. The mechanism underlying the synergistic effect could be attributed to the fact that T20, T1249, and T1144 all contain different functional domains and have different primary binding sites in gp41. As such, they may work cooperatively to inhibit gp41 six-helix bundle core formation, thereby suppressing virus-cell fusion. Therefore, these findings strongly imply that, rather than replacing T20, combining it with HIV fusion inhibitors of different generations might produce synergistic activity against both T20-sensitive and -resistant HIV-1 strains, suggesting a new therapeutic strategy for the treatment of HIV-1 infection/AIDS.
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24
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Du Q, Huang R, Wei Y, Wang C, Chou K. Peptide reagent design based on physical and chemical properties of amino acid residues. J Comput Chem 2007; 28:2043-50. [PMID: 17450553 PMCID: PMC7166493 DOI: 10.1002/jcc.20732] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2007] [Revised: 02/18/2007] [Accepted: 02/19/2007] [Indexed: 11/30/2022]
Abstract
It has tremendous values for both drug discovery and basic research to develop a solid bioinformatical tool for guiding peptide reagent design. Based on the physical and chemical properties of amino acids, a new strategy for peptide reagent design, the so-called AABPD (amino acid based-peptide design), is proposed. The peptide samples in a training dataset are described by a series of HMLP (heuristic molecular lipophilicity potential) parameters and other physicochemical properties of amino acid residues that form a three-dimensional data matrix where each component is defined by three indexes: the first index refers to the peptide samples, the second to the amino acid positions, and the third to the amino acid parameters. The binding free energy between a peptide ligand and its protein receptor is calculated by a linear free energy equation through the physicochemical parameters, resulting in a set of simultaneous linear equations between the bioactivity of the peptides and the physicochemical properties of amino acids. An iterative double least square technique is developed for the solution of the three-dimensional simultaneous linear equation set to determine the amino acid position coefficients of peptide sequence and the physicochemical parameter coefficients of amino acid residues alternately. The two sets of coefficients thus obtained are used for predicting the bioactivity of other query peptide reagents. Two calculation examples, the peptide substrate specificity of the SARS coronavirus 3C-like proteinase and the affinity prediction for epitope-peptides with Class I MHC molecules are studied by using the peptide reagent design strategy.
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Affiliation(s)
- Qi‐Shi Du
- Guangxi Key Laboratory of Subtropical Bioresource Conservation and Utilization, Guangxi University, Nanning, Guangxi, 530004, China
- Institute of Bioinformatics and Drug Discovery, Tianjin Normal University, Tianjin, 300074, China
- Gordon Life Science Institute, San Diego, California 92130, USA
| | - Ri‐Bo Huang
- Guangxi Key Laboratory of Subtropical Bioresource Conservation and Utilization, Guangxi University, Nanning, Guangxi, 530004, China
- Guangxi Academy of Sciences, 98 Daling Road, Nanning, Guangxi 530004, China
| | - Yu‐Tuo Wei
- Guangxi Key Laboratory of Subtropical Bioresource Conservation and Utilization, Guangxi University, Nanning, Guangxi, 530004, China
| | - Cheng‐Hua Wang
- Guangxi Key Laboratory of Subtropical Bioresource Conservation and Utilization, Guangxi University, Nanning, Guangxi, 530004, China
| | - Kuo‐Chen Chou
- Gordon Life Science Institute, San Diego, California 92130, USA
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25
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Citterio P, Rusconi S. Novel inhibitors of the early steps of the HIV-1 life cycle. Expert Opin Investig Drugs 2007; 16:11-23. [PMID: 17155850 DOI: 10.1517/13543784.16.1.11] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Considerable advances have been made on compounds that are active as inhibitors of HIV entry and fusion. The discovery of chemokines a few years ago focused the attention on coreceptor inhibitors in addition to fusion and attachment blockers. During the last 5 years, there has been an intense research activity from both private companies and academic institutions to find effective compounds that are capable of inhibiting the initial steps in the HIV life cycle. Some of the presented compounds demonstrated in vitro synergism, thus there is the rationale of their combined use in HIV-infected individuals. Many entry and fusion inhibitors of HIV are being investigated in controlled clinical trials and there are a number of them that are bioavailable as oral formulations. This is an essential feature for an extended use of these compounds with the purpose of ameliorating patients' adherence to medications; therefore, preventing the development of drug resistance. Among the many compounds that are being investigated, some are in the preclinical arena and others are more advanced in development stages. Overall, the main aim is to establish the action of these compounds on the immune system (e.g., the balance of the system after shutting off CCR5 or CXCR4 coreceptors) and the possible burden of unexplained side effects. This review focuses on the recent developments in this field with a particular attention on promising compounds in preclinical and clinical trials.
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Affiliation(s)
- Paola Citterio
- Università degli Studi, Dipartimento di Scienze Cliniche Luigi Sacco, Sezione di Malattie Infettive e Immunopatologia, Ospedale Luigi Sacco, 20157 Milan, Italy
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26
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Murga JD, Franti M, Pevear DC, Maddon PJ, Olson WC. Potent antiviral synergy between monoclonal antibody and small-molecule CCR5 inhibitors of human immunodeficiency virus type 1. Antimicrob Agents Chemother 2006; 50:3289-96. [PMID: 17005807 PMCID: PMC1610098 DOI: 10.1128/aac.00699-06] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The chemokine receptor CCR5 provides a portal of entry for human immunodeficiency virus type 1 (HIV-1) into susceptible CD4(+) cells. Both monoclonal antibody (MAb) and small-molecule CCR5 inhibitors have entered human clinical testing, but little is known regarding their potential interactions. We evaluated the interactions between CCR5 MAbs, small-molecule CCR5 antagonists, and inhibitors of HIV-1 gp120, gp41, and reverse transcriptase in vitro. Inhibition data were analyzed for cooperative effects using the combination index (CI) method and stringent statistical criteria. Potent, statistically significant antiviral synergy was observed between the CCR5 MAb PRO 140 and the small-molecule CCR5 antagonists maraviroc (UK-427,857), vicriviroc (SCH-D), and TAK-779. High-level synergy was observed consistently across various assay systems, HIV-1 envelopes, CCR5 target cells, and inhibition levels. CI values ranged from 0.18 to 0.64 and translated into in vitro dose reductions of up to 14-fold. Competition binding studies revealed nonreciprocal patterns of CCR5 binding by MAb and small-molecule CCR5 inhibitors, suggesting that synergy occurs at the level of receptor binding. In addition, both PRO 140 and maraviroc synergized with the chemokine RANTES, a natural ligand for CCR5; however, additive effects were observed for both small-molecule CCR5 antagonists and PRO 140 in combination with other classes of HIV-1 inhibitors. The findings provide a rationale for clinical exploration of MAb and small-molecule CCR5 inhibitors in novel dual-CCR5 regimens for HIV-1 therapy.
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Affiliation(s)
- Jose D Murga
- Progenics Pharmaceuticals, Inc, Tarrytown, NY 10591, USA
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27
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Zhang XQ, Sorensen M, Fung M, Schooley RT. Synergistic in vitro antiretroviral activity of a humanized monoclonal anti-CD4 antibody (TNX-355) and enfuvirtide (T-20). Antimicrob Agents Chemother 2006; 50:2231-3. [PMID: 16723592 PMCID: PMC1479151 DOI: 10.1128/aac.00761-05] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Recently, antiretroviral agents directed at several steps involved in viral entry have been shown to reduce viral replication in vitro and in vivo. We have demonstrated a high level of in vitro synergistic antiretroviral activity for two entry inhibitors that are directed at sequential steps in the entry process.
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28
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Chan E, Heilek-Snyder G, Cammack N, Sankuratri S, Ji C. Development of a Moloney murine leukemia virus-based pseudotype anti-HIV assay suitable for accurate and rapid evaluation of HIV entry inhibitors. ACTA ACUST UNITED AC 2006; 11:652-63. [PMID: 16844967 DOI: 10.1177/1087057106288881] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
There has been increasing interest in the identification of novel HIV entry inhibitors. For the discovery of these entry inhibitors, robust surrogate anti-HIV assays are highly desired. The authors report a novel anti-HIV assay system using Moloney murine leukemia viruses (MMLVs) pseudotyped with cytoplasmic tail-truncated HIV envelope protein gp140. These pseudotyped MMLV-HIVgp140 viral particles carry luciferase transcripts; therefore, robust luciferase signal can be detected in cells infected by these pseudotypes. Polycationic agent polybrene and spinoculation markedly enhanced the infection efficiency of these pseudotypes. It was demonstrated that the tropism of these pseudotypes is dependent on the pseudotyped HIV envelope proteins. MMLV viruses pseudotyped with gp140 from an R5 HIV virus specifically infect CCR5-expressing cells, and viruses pseudotyped with gp140 from an X4 HIV virus specifically infect CXCR4-expressing cells. Furthermore, CCR5 antagonists inhibited only MMLV-gp140(R5) infections, and CXCR4 antagonists inhibited only MMLV-gp140(X4) infections. A variety of known HIV entry inhibitors were tested in both R5- and X4-dependent pseudotype antiviral assays, and the IC50 values generated were consistent with published results. The pseudotype antiviral assay was also used in the characterization of hundreds of novel CCR5 antagonists. The IC50 values determined in this assay were compared with those determined in HIV antiviral and cell-cell fusion (CCF) assays, and good correlation was found between pseudotype antiviral assay and HIV antiviral assay (R2 = 0.9) or CCF assay (R2 = 0.8).
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Affiliation(s)
- Eva Chan
- Viral Diseases, Roche Palo Alto, Palo Alto, California 94304, USA
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29
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Debnath AK. Progress in identifying peptides and small-molecule inhibitors targeted to gp41 of HIV-1. Expert Opin Investig Drugs 2006; 15:465-78. [PMID: 16634685 DOI: 10.1517/13543784.15.5.465] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
During the last decade, a great number of activities have been geared in identifying newer targets for inhibiting HIV infection as well as understanding the targets for already identified anti-HIV-1 agents. The success in converting a proof-of-concept peptide T-20 (previously named DP-178), from the C-terminal heptad repeat (CHR) region of the envelope glycoprotein gp41 of HIV-1, to a drug named enfuvirtide was one of the phenomenal successes in HIV-1 drug discovery research that has been made in recent years. There were many reports of modifying peptides from the N-terminal heptad repeat and CHR regions with the objective of improving their activity. A few laboratories also reported the identification of small-molecule inhibitors that apparently bind to the hydrophobic cavity identified in the gp41 core structure and prevent the CHR peptide binding to the N-terminal heptad repeat peptide, thereby prevent the formation of the typical six-helix bundle, which has been thought to be necessary for the fusion between HIV and cell membranes.
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Affiliation(s)
- Asim K Debnath
- Laboratory of Molecular Modeling & Drug Design, Lindsley F. Kimball Research Institute of The New York Blood Centre, 310 East 67th Street, New York, NY 10021, USA.
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30
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Melikyan GB, Egelhofer M, von Laer D. Membrane-anchored inhibitory peptides capture human immunodeficiency virus type 1 gp41 conformations that engage the target membrane prior to fusion. J Virol 2006; 80:3249-58. [PMID: 16537592 PMCID: PMC1440409 DOI: 10.1128/jvi.80.7.3249-3258.2006] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Soluble peptides derived from the C-terminal heptad repeat domain of human immunodeficiency virus type 1 (HIV-1) gp41 are potent inhibitors of HIV-1 entry and gp41-induced fusion. Target membrane-anchored variants of these peptides have been shown to retain inhibitory activity. Both soluble and membrane-anchored C peptides (MACs) are thought to block fusion by binding to the N-terminal coiled coil domain of gp41 and preventing formation of the final six-helix bundle structure. However, interactions of target MACs with gp41 must be restricted to a subset of trimers that have their hydrophobic fusion peptides inserted into the target membrane. This unique feature of MACs was used to identify the intermediate step of fusion at which gp41 engaged the target membrane. Fusion between HIV envelope-expressing effector cells and target cells was measured by fluorescence microscopy. Expression of MACs in target cells led to less than twofold reduction in the extent of fusion. However, when reaction was first arrested by adding lysolipids that disfavored membrane merger, and the lipids were subsequently removed by washing, control cells supported fusion, whereas those that expressed MACs did not. The drastically improved potency of MACs implies that, at lipid-arrested stage, gp41 bridges the viral and target cell membranes and therefore more optimally binds the membrane-anchored peptides. Experimental demonstration of this intermediate shows that, similar to fusion induced by many other viral glycoproteins, engaging the target membrane by HIV-1 gp41 permits coupling between six-helix bundle formation and membrane merger.
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Affiliation(s)
- Gregory B Melikyan
- Department of Molecular Biophysics and Physiology, Rush University Medical Center, Chicago, Illinois 60612, USA.
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31
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Ji C, Zhang J, Cammack N, Sankuratri S. Development of a novel dual CCR5-dependent and CXCR4-dependent cell-cell fusion assay system with inducible gp160 expression. ACTA ACUST UNITED AC 2005; 11:65-74. [PMID: 16314403 DOI: 10.1177/1087057105282959] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
In the current study, a novel coreceptor-specific cell-cell fusion (CCF) assay system is reported. The system possesses the following features: dual CCR5-dependent and CXCR4-dependent CCF assays, all stable cell lines, inducible expression of gp160 to minimize cytotoxicity, robust luciferase reporter, and 384-well format. These assays have been validated using various known HIV entry inhibitors targeting various stages of the HIV entry/fusion process, including fusion inhibitors, gp120 inhibitors, CCR5 antagonists, CCR5 antibodies, and CXCR4 antagonists. IC50 data generated from this assay system were well correlated to that from the antiviral assays. The effects of DMSO on this assay system were assessed, and a 2- to 3-fold increase in luciferase activity was observed in the presence of 0.05% to 2% DMSO. Although cell-cell fusion efficiency was enhanced, no changes in drug response kinetics for entry inhibitors were found in the presence of 0.1% or 0.5% DMSO. This assay system has been successfully used for the identification and characterization of thousands of CCR5 inhibitors.
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Affiliation(s)
- Changhua Ji
- Roche Palo Alto, 3411 Hillview Avenue, Palo Alto, CA 94304, USA.
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32
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Tremblay CL, Giguel F, Chou TC, Dong H, Takashima K, Hirsch MS. TAK-652, a Novel CCR5 Inhibitor, has Favourable Drug Interactions with other Antiretrovirals in Vitro. Antivir Ther 2005. [DOI: 10.1177/135965350501000801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Cécile L Tremblay
- Massachusetts General Hospital, Infectious Diseases Unit, Harvard Medical School, Cambridge, MA, USA
- Centre Hospitalier de l'Université de Montréal, Montréal, Canada
| | - Françoise Giguel
- Massachusetts General Hospital, Infectious Diseases Unit, Harvard Medical School, Cambridge, MA, USA
| | - Ting-Chao Chou
- Memorial Sloan-Kettering Cancer Center, New York, NY, USA
| | | | | | - Martin S Hirsch
- Massachusetts General Hospital, Infectious Diseases Unit, Harvard Medical School, Cambridge, MA, USA
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33
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Cilliers T, Willey S, Sullivan WM, Patience T, Pugach P, Coetzer M, Papathanasopoulos M, Moore JP, Trkola A, Clapham P, Morris L. Use of alternate coreceptors on primary cells by two HIV-1 isolates. Virology 2005; 339:136-44. [PMID: 15992849 DOI: 10.1016/j.virol.2005.05.027] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2005] [Revised: 03/30/2005] [Accepted: 05/25/2005] [Indexed: 10/25/2022]
Abstract
Two HIV-1 isolates (CM4 and CM9) able to use alternate HIV-1 coreceptors on transfected cell lines were tested for their sensitivity to inhibitors of HIV-1 entry on primary cells. CM4 was able to use CCR5 and Bob/GPR15 efficiently in transfected cells. The R5 isolate grew in Delta32/Delta32 CCR5 PBMC in the absence or presence of AMD3100, a CXCR4-specific inhibitor, indicating that it uses a receptor other than CCR5 or CXCR4 on primary cells. It was insensitive to the CCR5 entry inhibitors RANTES and PRO140, but was partially inhibited by vMIP-1, a chemokine that binds CCR3, CCR8, GPR15 and CXCR6. The coreceptor used by this isolate on primary cells is currently unknown. CM9 used CCR5, CXCR4, Bob/GPR15, CXCR6, CCR3, and CCR8 on transfected cells and was able to replicate in the absence or presence of AMD3100 in Delta32/Delta32 CCR5 PBMC. It was insensitive to eotaxin, vMIP-1 and I309 when tested individually, but was inhibited completely when vMIP-1 or I309 was combined with AMD3100. Both I309 and vMIP-1 bind CCR8, strongly suggesting that this isolate can use CCR8 on primary cells. Collectively, these data suggest that some HIV-1 isolates can use alternate coreceptors on primary cells, which may have implications for strategies that aim to block viral entry.
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Affiliation(s)
- Tonie Cilliers
- AIDS Virus Research Unit, National Institute for Communicable Diseases, Private Bag X4, Sandringham 2131, Johannesburg, South Africa
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34
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Vasilevskaya IA, O'Dwyer PJ. 17-Allylamino-17-demethoxygeldanamycin overcomes TRAIL resistance in colon cancer cell lines. Biochem Pharmacol 2005; 70:580-9. [PMID: 15993848 DOI: 10.1016/j.bcp.2005.05.018] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2005] [Revised: 05/12/2005] [Accepted: 05/16/2005] [Indexed: 12/01/2022]
Abstract
Tumor necrosis factor related apoptosis-inducing ligand (TRAIL) is a promising candidate for treatment of cancer, but displays variable cytotoxicity in cell lines. The mechanisms of sensitivity and resistance have not been fully elucidated; both AKT and NF-kappaB pathways may modulate cytotoxic responses. We have shown that the Hsp90 inhibitor 17-AAG enhances the cytotoxicity of oxaliplatin in colon cancer cell lines through inhibition of NF-kappaB. We analyzed the effects of TRAIL and 17-AAG in combination in a series of nine colon cancer cell lines and characterized activation of the pathways to apoptosis. IC(50) values for a 72 h exposure to TRAIL ranged from 30 to 4000 ng/ml. Cytotoxicity assays demonstrated additivity or synergism of the TRAIL/17-AAG combination in all cell lines, with combination indices at IC(50) ranging from 0.53 to 1. The sensitizing effect of 17-AAG was greater in the TRAIL-resistant cell lines. In TRAIL-resistant cell lines, the combination of 17-AAG and TRAIL resulted in activation of both extrinsic and intrinsic apoptotic pathways, though with quantitative differences between HT29 and RKO cells: differential effects of 17-AAG on AKT and NF-kappaB characterized these cell lines. In both cell lines, the combination also led to down-regulation of X-linked inhibitor of apoptosis protein (XIAP) and enhanced activation of caspase-3. We conclude that either AKT or NF-kappaB may promote resistance to TRAIL in colon cancer cells, and that the ability of 17-AAG to target multiple putative determinants of TRAIL sensitivity warrants their further investigation in combination.
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Affiliation(s)
- Irina A Vasilevskaya
- University of Pennsylvania Cancer Center, 1020 BRB II/III, 421 Curie Blvd., Philadelphia, PA 19104, USA.
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35
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Tremblay CL, Giguel F, Guan Y, Chou TC, Takashima K, Hirsch MS. TAK-220, a novel small-molecule CCR5 antagonist, has favorable anti-human immunodeficiency virus interactions with other antiretrovirals in vitro. Antimicrob Agents Chemother 2005; 49:3483-5. [PMID: 16048964 PMCID: PMC1196290 DOI: 10.1128/aac.49.8.3483-3485.2005] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
TAK-220 is a CCR5 antagonist, part of the new class of anti-human immunodeficiency virus type 1 (anti-HIV-1) entry inhibitors. We evaluated the anti-HIV-1 interactions between TAK-220 and various antiretrovirals in vitro. Synergy was observed with all drugs at the 90 and 95% inhibitory concentrations. The favorable drug interactions observed suggest that further clinical evaluation is warranted.
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Affiliation(s)
- Cécile L Tremblay
- Massachusetts General Hospital, 65 Landsdowne St., Room 419, Cambridge, MA 02139, USA.
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36
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Adkison KK, Shachoy-Clark A, Fang L, Lou Y, O'Mara K, Berrey MM, Piscitelli SC. Pharmacokinetics and short-term safety of 873140, a novel CCR5 antagonist, in healthy adult subjects. Antimicrob Agents Chemother 2005; 49:2802-6. [PMID: 15980352 PMCID: PMC1168695 DOI: 10.1128/aac.49.7.2802-2806.2005] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
873140 is a novel CCR5 antagonist with potent in vitro anti-human immunodeficiency virus (HIV) activity. This study was a double-blind, randomized, placebo-controlled, single- and repeat-dose escalation investigation of the safety, pharmacokinetics, and food effect of 873140 in 70 adult subjects. During single-dose escalation, three cohorts (each composed of 10 subjects, with 8 subjects receiving the active drug and 2 subjects receiving the placebo [8 active and 2 placebo]) received doses of 50, 200, 400, 800, and 1,200 mg after an overnight fast, or 400 mg plus a standard high-fat breakfast in an alternating panel design. During repeat-dose escalation, four cohorts (each with 8 active and 2 placebo) received doses of 200, 400, 600, or 800 mg every 12 h (BID) for 8 days. Laboratory safety tests, vital signs, and electrocardiograms (ECGs) were performed at regular intervals, and blood samples were obtained for pharmacokinetics. Single and repeat doses of 50 mg to 800 mg were well tolerated, with no serious adverse events and no grade 3 or 4 adverse events. The mild-to-moderate side effects were primarily gastrointestinal and included abdominal cramping, nausea, and diarrhea. No specific trends in laboratory parameters or clinically significant ECG changes were noted. Plasma 873140 concentrations increased rapidly; the median time to maximum concentration of drug in serum was 1.75 to 5 h. The median area under the plasma concentration-time profile (AUC) and the maximum concentration of drug in serum (C(max)) ranged from 127 ng.h/ml and 24 ng/ml at 200 mg BID to 329 ng.h/ml and 100 ng/ml at 800 mg BID, respectively. Food consumption increased the AUC and C(max) by a mean of 1.7- and 2.2-fold, respectively. The pharmacokinetic and safety profile supports the continued investigation of 873140 with HIV-infected subjects.
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Affiliation(s)
- Kimberly K Adkison
- GlaxoSmithKline, 5 Moore Drive, Research Triangle Park, North Carolina 27709, USA
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37
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Abstract
Current HIV entry inhibitors target the binding of the viral envelope glycoprotein gp120 to cellular CD4 and co-receptors, or block a late stage of the fusogenic activation of adjacent gp41. New targets are suggested by the role of cell surface protein disulfide isomerase (PDI), which attaches to the primary receptor CD4 close to the gp120-binding site. This could enable PDI to reduce gp120 disulfide bonds, which triggers the major conformational changes in gp120 and gp41 required for virus entry. Inhibiting cell surface PDI prevents HIV-1 entry. The new potential targets outlined are PDI activity as well as the sites of PDI-CD4 and PDI-gp120 interaction.
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Affiliation(s)
- Hugues J-P Ryser
- Departments of Pathology and Pharmacology, Boston University School of Medicine, Boston, MA 02118, USA.
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38
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Reeves JD, Lee FH, Miamidian JL, Jabara CB, Juntilla MM, Doms RW. Enfuvirtide resistance mutations: impact on human immunodeficiency virus envelope function, entry inhibitor sensitivity, and virus neutralization. J Virol 2005; 79:4991-9. [PMID: 15795284 PMCID: PMC1069568 DOI: 10.1128/jvi.79.8.4991-4999.2005] [Citation(s) in RCA: 125] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Enfuvirtide (ENF/T-20/Fuzeon), the first human immunodeficiency virus (HIV) entry inhibitor to be licensed, targets a structural intermediate of the entry process. ENF binds the HR1 domain in gp41 after Env has bound CD4, preventing conformational changes needed for membrane fusion. Mutations in HR1 that confer ENF resistance can arise following ENF therapy. ENF resistance mutations were introduced into an R5- and X4-tropic Env to examine their impact on fusion, infection, and sensitivity to different classes of entry inhibitors and neutralizing antibodies. HR1 mutations could reduce infection and fusion efficiency and also delay fusion kinetics, likely accounting for their negative impact on viral fitness. HR1 mutations had minimal effect on virus sensitivity to other classes of entry inhibitors, including those targeting CD4 binding (BMS-806 and a CD4-specific monoclonal antibody [MAb]), coreceptor binding (CXCR4 inhibitor AMD3100 and CCR5 inhibitor TAK-779), or fusion (T-1249), indicating that ENF-resistant viruses can remain sensitive to other entry inhibitors in vivo. Some HR1 mutations conferred increased sensitivity to a subset of neutralizing MAbs that likely target fusion intermediates or with epitopes preferentially exposed following receptor interactions (17b, 48D, 2F5, 4E10, and IgGb12), as well as sera from some HIV-positive individuals. Mechanistically, enhanced neutralization correlated with reduced fusion kinetics, indicating that, in addition to steric constraints, kinetics may also limit virus neutralization by some antibodies. Therefore, escape from ENF comes at a cost to viral fitness and may confer enhanced sensitivity to humoral immunity due to prolonged exposure of epitopes that are not readily accessible in the native Env trimer. Resistance to other entry inhibitors was not observed.
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Affiliation(s)
- Jacqueline D Reeves
- Department of Microbiology, University of Pennsylvania, 225 Johnson Pavilion, 3610 Hamilton Walk, Philadelphia, PA 19104, USA.
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39
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Vasilevskaya IA, Rakitina TV, O'Dwyer PJ. Quantitative effects on c-Jun N-terminal protein kinase signaling determine synergistic interaction of cisplatin and 17-allylamino-17-demethoxygeldanamycin in colon cancer cell lines. Mol Pharmacol 2004; 65:235-43. [PMID: 14722256 DOI: 10.1124/mol.65.1.235] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We investigated the effects of cisplatin and the hsp90 inhibitor 17-allylamino-17-demethoxygeldanamycin (17-AAG) in combination in a panel of human colon adenocarcinoma cell lines that differ in their p53 and mismatch repair status. Analysis of cytotoxicity after combined treatment revealed additive effects of cisplatin and 17-AAG in the HCT 116, DLD1, and SW480 cell lines and antagonism in HT-29 cells. Clonogenic assays demonstrated antagonism in HT-29, an additive effect in SW480, and synergism in HCT 116 and DLD1 cell lines. Analysis of signaling pathways revealed that cisplatin-induced activation of c-Jun N-terminal kinase (JNK) was fully blocked by 17-AAG in HT-29 and SW480 cells, whereas in HCT 116 and DLD1 cells it was inhibited only partially. The activation of caspases was also more pronounced in DLD1 and HCT 116 cell lines. These data suggested that a minimal level of apoptotic signaling through JNK was required for synergism with this combination. To test this hypothesis, we used the specific JNK inhibitor SP600125; when JNK was inhibited pharmacologically in HCT 116 and DLD1 cells, they demonstrated increased survival in clonogenic assays. Alternatively, sustained activation of JNK pathway led to an increase of the cytotoxicity of the cisplatin/17-AAG combination in HT-29 cells. Taken together, these data suggest that the synergistic interaction of this combination in colon cancer cell lines depends on the effect exerted by 17-AAG on cisplatin-induced signaling through JNK and associated pathways leading to cell death. An implication of that finding is that quantitative effects of signaling inhibitors may be critical for their ability to reverse cisplatin resistance.
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40
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Gazitt Y. Homing and mobilization of hematopoietic stem cells and hematopoietic cancer cells are mirror image processes, utilizing similar signaling pathways and occurring concurrently: circulating cancer cells constitute an ideal target for concurrent treatment with chemotherapy and antilineage-specific antibodies. Leukemia 2004; 18:1-10. [PMID: 14574330 DOI: 10.1038/sj.leu.2403173] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Adhesion molecules and stromal cell-derived factor-1 (SDF-1)/CXCR4 signaling play key role in homing and mobilization of hematopoietic progenitor (HPC) and hematopoietic cancer clonogenic cells (HCC). High expression of VLA-4 is required for homing of HPC and HCC, whereas downregulation of these molecules is required for successful mobilization of HPC and HCC. Upregulation and activation of the SDF-1/CXCR4 signaling is required for homing of HPC and HCC, whereas disruption of the SDF-1 signaling is required for mobilization of HPC and HCC. Hence, mobilizations of HPC and HCC occur concurrently. It is proposed that drug resistance evolves as a result of repeated cycles of chemotherapy. Following each cycle of chemotherapy, HCC lose adhesion molecules and SDF-1 signaling. Surviving cells, released from tumor sites, circulate until re-expression of adhesion molecules and CXCR4 occurs, then homing to stroma of distal tissues occurs. Cytokines secreted by cells in the new microenvironment induce proliferation and drug resistance of HCC. This process is amplified in each cycle of chemotherapy resulting in disease progression. A novel model for treatment is proposed in which circulating HCC are the target for clinical intervention, and concurrent treatment with chemotherapy and antilineage-specific antibodies will result in abrogation of the 'vicious cycle' of conventional anticancer therapy.
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Affiliation(s)
- Y Gazitt
- University of Texas Health Science Center, San Antonio, TX 78284, USA
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41
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Vermeire K, Schols D. Specific CD4 down-modulating compounds with potent anti-HIV activity. J Leukoc Biol 2003; 74:667-75. [PMID: 12960237 DOI: 10.1189/jlb.0403177] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Despite the availability of the current clinically approved anti-HIV drugs, new classes of effective antiviral agents are still urgently needed to combat AIDS. A promising approach for drug development and vaccine design involves targeting research on HIV-1 entry, a multistep process that comprises viral attachment, coreceptor interactions, and fusion. Determination of the viral entry process in detail has enabled the design of specific agents that can inhibit each step in the HIV entry process. Therapeutic agents that interfere with the binding of the HIV envelope glycoprotein gp120 to the CD4 receptor (e.g., PRO 542, PRO 2000, and CV-N) or the coreceptors CCR5 and CXCR4 (e.g., SCH-C and AMD3100) are briefly outlined in this review. The anti-HIV activity of cyclotriazadisulfonamides, a novel class of compounds with a unique mode of action by down-modulating the CD4 receptor in lymphocytic and monocytic cells, is especially highlighted. On the basis of the successful results of T-20, the first approved entry inhibitor, the development of effective antiretrovirals that block HIV entry will certainly be further encouraged.
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Affiliation(s)
- Kurt Vermeire
- Rega Institute for Medical Research, Katholieke Universiteit Leuven, Leuven, Belgium
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42
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Tremblay CL, Poulin DL, Hicks JL, Selliah S, Chamberland A, Giguel F, Kollmann CS, Chou TC, Dong H, Hirsch MS. Favorable interactions between enfuvirtide and 1-beta-D-2,6-diaminopurine dioxolane in vitro. Antimicrob Agents Chemother 2003; 47:3644-6. [PMID: 14576137 PMCID: PMC253786 DOI: 10.1128/aac.47.11.3644-3646.2003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2003] [Revised: 06/30/2003] [Accepted: 08/04/2003] [Indexed: 11/20/2022] Open
Abstract
We evaluated the in vitro anti-human immunodeficiency virus type 1 (HIV-1) interactions between 1-beta-D-2,6-diaminopurine dioxolane (DAPD) and enfuvirtide (T-20) against clinical isolates sensitive and resistant to reverse transcriptase and protease inhibitors. Interactions between T-20 and DAPD were synergistic to nearly additive, with combination index values ranging from 0.53 to 1.06 at 95% inhibitory concentrations. These studies suggest that a combination of T-20 and DAPD might be useful in the treatment of antiretroviral drug-experienced patients.
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Affiliation(s)
- Cécile L Tremblay
- Massachusetts General Hospital, Infectious Diseases Unit, Harvard Medical School, Boston, Massachusetts, USA.
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43
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Misumi S, Endo M, Mukai R, Tachibana K, Umeda M, Honda T, Takamune N, Shoji S. A novel cyclic peptide immunization strategy for preventing HIV-1/AIDS infection and progression. J Biol Chem 2003; 278:32335-43. [PMID: 12771150 DOI: 10.1074/jbc.m301209200] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
A novel synthetic peptide immunogen targeting the human immunodeficiency virus type-1 (HIV-1) coreceptor CXCR4 was evaluated for its capacity to induce CXCR4-specific antibodies with anti-HIV-1 activity in BALB/c mice and cynomolgus monkeys. A cyclic closed-chain dodecapeptide mimicking the conformation-specific domain of CXCR4 (cDDX4) was prepared in which Gly-Asp, as the dipeptide forming a spacer arm, links the amino and carboxyl termini of the decapeptidyl linear chain (linear DDX4, Asn176 to Ile185) derived from the undecapeptidyl arch (UPA; Asn176 to Cys186) of extracellular loop 2 (ECL-2) in CXCR4. Immunization of BALB/c mice with cDDX4 conjugated with a multiple-antigen peptide (cDDX4-MAP) induced conformational epitope-specific antibodies, and monoclonal antibody IA2-F9 reacted with cDDX4, but not with linear DDX4, as determined by real-time biomolecular interaction analysis using surface plasmon resonance. The antibody also reacted with cells expressing CXCR4 but not with cells expressing the other HIV coreceptor, CCR5. Furthermore, the antibody inhibited the replication of HIV-1 X4 virus (using CXCR4), as shown by an infection assay using both MAGIC-5 cells and MT4 cells, but not that of HIV-1 R5 virus (using CCR5). The antibody weakly interfered with chemotaxis induced by stromal cell-derived factor-1 alpha in THP-1 cells or moderately inhibited the chemotaxis of Molt4#8 cells under the same conditions. In addition, immunization of cynomolgus monkeys also induced cDDX4-specific antibodies with anti-HIV activity. Taken together, these results indicate that cDDX4 conjugated with a multi-antigen peptide induces the conformational epitope-specific antibodies to the undecapeptidyl arch of CXCR4 may be a novel candidate immunogen for preventing disease progression in HIV-1-infected individuals.
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MESH Headings
- AIDS Vaccines/administration & dosage
- AIDS Vaccines/chemistry
- AIDS Vaccines/immunology
- Amino Acid Sequence
- Animals
- Chemotaxis, Leukocyte
- Disease Progression
- Female
- HIV Infections/immunology
- HIV Infections/physiopathology
- HIV Infections/prevention & control
- HIV-1/physiology
- Macaca fascicularis
- Mice
- Mice, Inbred BALB C
- Molecular Sequence Data
- Neutralization Tests
- Peptides, Cyclic/administration & dosage
- Peptides, Cyclic/chemistry
- Peptides, Cyclic/immunology
- Receptors, CCR5/chemistry
- Receptors, CCR5/physiology
- Receptors, CXCR4/chemistry
- Receptors, CXCR4/physiology
- Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
- Virus Replication
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Affiliation(s)
- Shogo Misumi
- Department of Biochemistry, Faculty of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-Honmachi, Kumamoto, 862-0973, Japan
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44
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Affiliation(s)
- Roy M Gulick
- Cornell Clinical Trial Unit, Weill Medical College of Cornell University, New York, New York 10024, USA.
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45
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Lalezari JP, DeJesus E, Northfelt DW, Richmond G, Wolfe P, Haubrich R, Henry D, Powderly W, Becker S, Thompson M, Valentine F, Wright D, Carlson M, Riddler S, Haas FF, DeMasi R, Sista PR, Salgo M, Delehanty J. A Controlled Phase Ii Trial Assessing Three Doses of Enfuvirtide (T-20) in Combination with Abacavir, Amprenavir, Ritonavir and Efavirenz in Non-Nucleoside Reverse Transcriptase Inhibitor-Naive HIV-Infected Adults. Antivir Ther 2003. [DOI: 10.1177/135965350300800403] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Enfuvirtide is a novel antiretroviral that blocks HIV-1 cell fusion and viral entry. This Phase II, controlled, open-label, randomized, multicentre dose-ranging trial explored the safety, antiviral activity and pharmacoki-netics of enfuvirtide, administered by subcutaneous (SC) injection, in 71 HIV-1-infected, protease inhibitor-experienced, non-nucleoside reverse transcriptase inhibitor (NNRTI)-naive adults for 48 weeks. Study participants were randomized to receive enfuvirtide at a deliverable dose of 45, 67.5 or 90 mg twice daily; the 45 mg twice daily dose required 2 injections/day, while the higher doses required 4 injections/day. A background oral antiretroviral (ARV) regimen of abacavir (300 mg twice daily), amprenavir (1200 mg twice daily), ritonavir (200 mg twice daily) and efavirenz (600 mg once daily) was provided with enfuvirtide. A control group received the background ARV regimen alone. All potential participants underwent an HIV genotype at screen to ensure a homogenous population and to exclude patients with evidence of genotypic resistance to NNRTIs. Overall, the tolerability of the combination of abacavir, amprenavir, ritonavir, efavirenz and enfuvirtide was generally comparable to control through 48 weeks. No enfuvirtide dose-dependent adverse events (AEs) were observed across treatment groups. Injection site reactions (ISRs) occurred at least once in 68.5% of the enfuvirtide-treated population, and most ISRs were mild to moderate in severity, with no apparent dose relationship. Excluding ISRs, the most common treatment-emergent AEs were nausea, diarrhoea, dizziness and fatigue; with no clinically significant differences in the incidence of AEs observed between the control and enfuvirtide groups. Each treatment group benefited from ARV therapy, with a trend of increasing antiviral and immunological activity associated with increasing enfuvirtide dose. At 48 weeks, the median HIV-1 RNA change from baseline for the ITT population was –2.24 log10 copies/ml for the combined enfuvirtide groups compared with –1.87 log10 copies/ml for the control group. In addition, 54.9% of patients in the enfuvirtide group achieved HIV-1 RNA ≤400 copies/ml versus 36.8% of patients in the control group. These results indicate that enfuvirtide has a favourable safety profile and is a promising new antiviral agent for HIV-infected patients who have been on previously failing ARV regimens.
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Affiliation(s)
- Jacob P Lalezari
- Quest Clinical Research and Mount Zion Hospital/UCSF, San Francisco, Calif., USA
| | - Edwin DeJesus
- IDC Research Initiative, Altamonte Springs, Fla., USA
| | | | | | - Peter Wolfe
- Pacific Oaks Research, Beverly Hills, Calif., USA
| | | | - David Henry
- Pennsylvania Oncology Hematology Associates, Philadelphia, Pa., USA
| | - William Powderly
- Washington University School of Medicine, AIDS Clinical Trials Unit, St Louis, Mo., USA
| | - Stephen Becker
- Pacific Horizons Medical Group, San Francisco, Calif., USA
| | | | - Fred Valentine
- NYU Medical Center, AIDS Clinical Trial Unit, New York, NY, USA
| | - David Wright
- Central Texas Clinical Research, LLC, Austin, Tex., USA
| | | | - Sharon Riddler
- University of Pittsburgh Medical Center, Pittsburgh, Pa., USA
| | - Frances F Haas
- Associates in Medical and Mental Health, P.C., Tulsa, Okla., USA
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Lalezari JP, Eron JJ, Carlson M, Cohen C, DeJesus E, Arduino RC, Gallant JE, Volberding P, Murphy RL, Valentine F, Nelson EL, Sista PR, Dusek A, Kilby JM. A phase II clinical study of the long-term safety and antiviral activity of enfuvirtide-based antiretroviral therapy. AIDS 2003; 17:691-8. [PMID: 12646792 DOI: 10.1097/00002030-200303280-00007] [Citation(s) in RCA: 115] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
OBJECTIVES The primary objective was to determine the long-term safety of the subcutaneous self-administration of enfuvirtide. Secondary objectives included the determination of enfuvirtide pharmacokinetics and antiviral activity and the immunological response to the enfuvirtide-containing regimen. METHODS A multicenter 48-week uncontrolled open-label rollover study was conducted on 71 HIV-infected adults recruited from previous enfuvirtide clinical trials. Patients with extensive previous use of protease and reverse transcriptase inhibitors received a twice-daily dose of 50 mg enfuvirtide subcutaneously (45 mg deliverable) combined with two or more antiretroviral drugs selected for each individual, guided by resistance testing and previous treatment history. RESULTS The mean baseline plasma HIV-RNA level was 4.81 log(10) copies/ml and the mean CD4 cell count was 134.8 cells/microl. The majority (86.9%) of treatment-emergent adverse events were grade 2 or less in severity. Injection site reactions were common, but no patients discontinued treatment. A mean HIV-RNA change of -1.33 log(10) was achieved within 14 days of treatment initiation. At week 48, approximately one-third of all patients in the intent-to-treat population maintained significant suppression of plasma HIV RNA, with either less than 400 copies/ml or more than a 1.0 log(10) decline from baseline. The mean gain in absolute CD4 cell counts at 48 weeks was 84.9 cells/microl. Trough plasma concentrations of enfuvirtide were consistently higher than target concentrations. CONCLUSION Self-administration of enfuvirtide is not associated with unexpected toxicities for up to one year, and combined with oral antiretroviral drugs was associated with a significant decrease in HIV RNA and an increase in CD4 cell counts.
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Abstract
Defining the mechanisms of HIV-1 entry has enabled the rational design of strategies aimed at interfering with the process. This article delineates what is currently understood about HIV-1 entry, as a window through which to understand what will likely be the next major group of antiretroviral therapeutics. These exciting new approaches offer the promise of adding viral entry to reverse transcription and protein processing as steps to block in the viral life cycle. Several principles learned with other antiretroviral drugs are sure to be valid for entry antagonists, whereas other considerations may be unique to this group of agents. There is no agent to which HIV-1 has not been able to acquire resistance and this is likely to remain the case. Multiple rounds of viral replication are required to generate the genetic diversity that forms the basis of resistance. Combination therapy in which replication is maximally suppressed will remain a cornerstone of treatment with entry inhibitors, as with other agents. Furthermore, the coreceptor specificity of some entry and fusion inhibitors argues that combinations will likely be needed to broaden the effective range of susceptible viral variants. Finally, the targeting of multiple steps within the entry process has the potential for synergy. The fusion inhibitor T20 and CXCR4 antagonist AMD3100 are synergistic in vitro at blocking infection of PBMC with clinical isolates [115] and T20 combined with the CD4 inhibitor PRO 542 have synergistic in vitro effects, with more than 10-fold greater inhibition of R5, X4, and R5X4 strains than either agent alone [116]. Entry antagonists raise other, unique issues. As discussed previously, the theoretic concern exists that blocking CCR5 could enhance the emergence of CXCR4-using variants and possibly accelerate disease. So far, in vitro selection for variants resistant to the CCR5 antagonist SCH-C in PBMC (which express both CCR5 and CXCR4) has resulted in mutants that were resistant to the blocker but still used CCR5. Alternatively, because many HIV-1 strains have the capacity to use several other chemokine or orphan receptors for entry, blocking both CCR5 and CXCR could lead to a variant that uses one of these other molecules in place of the principal coreceptors, although data in vitro so far suggest that this is unlikely [13,14]. This new class of antiviral drugs offers great promise but also novel concerns, and careful analysis of viruses that arise with their use in vivo is essential.
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Affiliation(s)
- Linda D Starr-Spires
- Pulmonary, Allergy and Critical Care Division, University of Pennsylvania School of Medicine, 522 Johnson Pavilion, 36th and Hamilton Walk, Philadelphia, PA 19104-6060, USA
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Abstract
Despite the considerable successes of highly active antiretroviral therapy, new classes of therapeutic agents are still urgently needed. Unfortunately, the emergence of antiviral resistance and drug toxicity remain challenging obstacles to successful treatment in many HIV-1-infected individuals. HIV-1 entry is a multi-step process that is an attractive target for the development of new classes of therapeutic agents. Considerable progress has been made in the understanding of HIV-1 cell entry, enabling the design of specific agents that can inhibit each step of cellular entry. A number of promising agents have commenced clinical trials, including the attachment inhibitor PRO 542, co-receptor inhibitor AMD3100 and fusion inhibitor T-20. A greater number of HIV-1 entry inhibitors are in preclinical development. This review outlines the mechanisms involved in HIV-1 entry and the sites of action of specific HIV-1 inhibitors.
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Affiliation(s)
- Louise A Cooley
- Victorian Infectious Diseases Reference Laboratory, The Royal Melbourne Hospital, Parkville, Vic, Australia
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Barretina J, Blanco J, Armand-Ugón M, Gutiérrez A, Clotet B, Esté JA. Anti-HIV-1 Activity of Enfuvirtide (T-20) by Inhibition of Bystander Cell Death. Antivir Ther 2003. [DOI: 10.1177/135965350300800210] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Infection by human immunodeficiency virus type 1 (HIV-1) has been associated with increased cell death of both infected and bystander cells. The envelope glycoprotein complex appears to play an active role in HIV-induced death of bystander cells. We quantified cell-to-cell fusion, single cell death and membrane lipid mixing in cocultures of effector, HIV-1 envelope-expressing cells with peripheral blood mononuclear cells or purified CD4 T lymphocytes from HIV-negative donors, in the presence or the absence of the fusion inhibitor enfuvirtide (T-20, pentafuside, Fuzeon™). T-20, which blocks gp41-dependent virus-cell fusion, showed a complete and dose-dependent inhibition of syncytium formation in cocultures of envelope-expressing cells with uninfected cells. Similarly, T-20 totally abrogated death of single bystander CD4 T cells with an IC50 of 0.04 μg/ml. Membrane lipid mixing, as a measure of interaction between envelope-expressing cells and CD4 cells, was also dose-dependently inhibited by T-20. Moreover, effector cells chronically infected with a T-20-resistant virus recovered the ability to induce bystander cell death in the presence of the drug, supporting the role of gp41 in single cell death. In conclusion, T-20 is able to protect CD4 T cells from envelope presentation with a dual effect: inhibition of virus replication and blockade of HIV-1 envelope-induced cell death of bystander CD4 T cells. Protection of cells prior to infection from HIV envelope-dependent bystander effect could lead to a better immune restoration of HIV-1-infected patients that are treated with T-20.
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Affiliation(s)
- Jordi Barretina
- Retrovirology Laboratory irsiCaixa, Hospital Universitari Germans Trias i Pujol, Universitat Autònoma de Barcelona, 08916 Badalona, Spain
| | - Julià Blanco
- Retrovirology Laboratory irsiCaixa, Hospital Universitari Germans Trias i Pujol, Universitat Autònoma de Barcelona, 08916 Badalona, Spain
| | - Mercedes Armand-Ugón
- Retrovirology Laboratory irsiCaixa, Hospital Universitari Germans Trias i Pujol, Universitat Autònoma de Barcelona, 08916 Badalona, Spain
| | - Arantxa Gutiérrez
- Retrovirology Laboratory irsiCaixa, Hospital Universitari Germans Trias i Pujol, Universitat Autònoma de Barcelona, 08916 Badalona, Spain
| | - Bonaventura Clotet
- Retrovirology Laboratory irsiCaixa, Hospital Universitari Germans Trias i Pujol, Universitat Autònoma de Barcelona, 08916 Badalona, Spain
| | - José A Esté
- Retrovirology Laboratory irsiCaixa, Hospital Universitari Germans Trias i Pujol, Universitat Autònoma de Barcelona, 08916 Badalona, Spain
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Sachpatzidis A, Benton BK, Manfredi JP, Wang H, Hamilton A, Dohlman HG, Lolis E. Identification of allosteric peptide agonists of CXCR4. J Biol Chem 2003; 278:896-907. [PMID: 12417595 DOI: 10.1074/jbc.m204667200] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The chemokine receptor CXCR4 is a co-receptor for T-tropic strains of HIV-1. A number of small molecule antagonists of CXCR4 are in development but all are likely to lead to adverse effects due to the physiological function of CXCR4. To prevent these complications, allosteric agonists may be therapeutically useful as adjuvant therapy in combination with small molecule antagonists. A synthetic cDNA library coding for 160,000 different SDF-based peptides was screened for CXCR4 agonist activity in a yeast strain expressing a functional receptor. Peptides that activated CXCR4 in an autocrine manner induced colony formation. Two peptides, designated RSVM and ASLW, were identified as novel agonists that are insensitive to the CXCR4 antagonist AMD3100. In chemotaxis assays using the acute lymphoblastic leukemia cell line CCRF-CEM, RSVM behaves as a partial agonist and ASLW as a superagonist. The superagonist activity of ASLW may be related to its inability to induce receptor internalization. In CCRF-CEM cells, the two peptides are also not inhibited by another CXCR4 antagonist, T140, or the neutralizing monoclonal antibodies 12G5 and 44717.111. These results suggest that alternative agonist-binding sites are present on CXCR4 that could be screened to develop molecules for therapeutic use.
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Affiliation(s)
- Aristidis Sachpatzidis
- Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut 06520, USA
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