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Cilento ME, Wen X, Reeve AB, Ukah OB, Snyder AA, Carrillo CM, Smith CP, Edwards K, Wahoski CC, Kitzler DR, Kodama EN, Mitsuya H, Parniak MA, Tedbury PR, Sarafianos SG. HIV-1 Resistance to Islatravir/Tenofovir Combination Therapy in Wild-Type or NRTI-Resistant Strains of Diverse HIV-1 Subtypes. Viruses 2023; 15:1990. [PMID: 37896768 PMCID: PMC10612037 DOI: 10.3390/v15101990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 09/15/2023] [Accepted: 09/18/2023] [Indexed: 10/29/2023] Open
Abstract
Tenofovir disoproxil fumarate (TDF) and islatravir (ISL, 4'-ethynyl-2-fluoro-2'-deoxyadensine, or MK-8591) are highly potent nucleoside reverse transcriptase inhibitors. Resistance to TDF and ISL is conferred by K65R and M184V, respectively. Furthermore, K65R and M184V increase sensitivity to ISL and TDF, respectively. Therefore, these two nucleoside analogs have opposing resistance profiles and could present a high genetic barrier to resistance. To explore resistance to TDF and ISL in combination, we performed passaging experiments with HIV-1 WT, K65R, or M184V in the presence of ISL and TDF. We identified K65R, M184V, and S68G/N mutations. The mutant most resistant to ISL was S68N/M184V, yet it remained susceptible to TDF. To further confirm our cellular findings, we implemented an endogenous reverse transcriptase assay to verify in vitro potency. To better understand the impact of these resistance mutations in the context of global infection, we determined potency of ISL and TDF against HIV subtypes A, B, C, D, and circulating recombinant forms (CRF) 01_AE and 02_AG with and without resistance mutations. In all isolates studied, we found K65R imparted hypersensitivity to ISL whereas M184V conferred resistance. We demonstrated that the S68G polymorphism can enhance fitness of drug-resistant mutants in some genetic backgrounds. Collectively, the data suggest that the opposing resistance profiles of ISL and TDF suggest that a combination of the two drugs could be a promising drug regimen for the treatment of patients infected with any HIV-1 subtype, including those who have failed 3TC/FTC-based therapies.
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Affiliation(s)
- Maria E. Cilento
- Center for ViroScience and Cure, Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Xin Wen
- Center for ViroScience and Cure, Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Aaron B. Reeve
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Obiaara B. Ukah
- CS Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA
| | - Alexa A. Snyder
- Center for ViroScience and Cure, Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Ciro M. Carrillo
- Center for ViroScience and Cure, Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Cole P. Smith
- Center for ViroScience and Cure, Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Kristin Edwards
- Center for ViroScience and Cure, Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Claudia C. Wahoski
- Center for ViroScience and Cure, Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Deborah R. Kitzler
- Center for ViroScience and Cure, Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Eiichi N. Kodama
- Division of Infectious Disease, International Institute of Disaster Science, Tohoku University, Sendai 980-8572, Japan
| | - Hiroaki Mitsuya
- Department of Refractory Viral Infections, National Center for Global Health & Medicine Research Institute, Tokyo 162-8655, Japan
- Experimental Retrovirology Section, HIV and AIDS Malignancy Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
- Department of Clinical Sciences, Kumamoto University Hospital, Kumamoto 860-8556, Japan
| | - Michael A. Parniak
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Philip R. Tedbury
- Center for ViroScience and Cure, Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Stefan G. Sarafianos
- Center for ViroScience and Cure, Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA
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Mainella V, Morrow M, Brooks K, Bushman L, Abdelmawla F, Nerguizian D, Choi YJ, Patton D, Cosgrove Sweeney Y, Patel SK, Anderson P, Rohan L. Intracellular Islatravir-Triphosphate in Dried Blood Spots and Peripheral Blood Mononuclear Cells from Pig-Tailed Macaques. AIDS Res Hum Retroviruses 2023. [PMID: 37382422 DOI: 10.1089/aid.2023.0059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/30/2023] Open
Abstract
The purpose of this study was to evaluate the relationship between intracellular islatravir-triphosphate (ISL-TP) in paired peripheral blood mononuclear cells (PBMCs) and dried blood spots (DBS). Three pig-tailed macaques (PMs) were dosed with a single intravaginal extended-release ISL-etonogestrel film for a period of 31 days. After extraction and quantification, repeated measures correlation (rrm) was assessed between log-transformed DBS and PBMC ISL-TP concentrations. Twenty-six paired PBMC/DBS samples were included. Peak ISL-TP concentrations in DBS ranged from 262 to 913 fmol/punches, PBMC Cmax ranged from 427 to 857 fmol/106 cells. Repeated measures correlation yielded an rrm value of 0.96 (95% confidence interval 0.92-0.98; p < .0001). Importantly, ISL-TP was quantifiable in DBS and its pharmacokinetics were similar to PBMC in PMs. Human studies should evaluate DBS applications in clinical pharmacokinetic studies to help define ISL's place in the antiretroviral drug armamentarium.
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Affiliation(s)
- Vincent Mainella
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado-Anschutz Medical Campus, Aurora, Colorado, USA
| | - Mary Morrow
- Department of Biostatistics and Bioinformatics, Colorado School of Public Health, Aurora, Colorado, USA
| | - Kristina Brooks
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado-Anschutz Medical Campus, Aurora, Colorado, USA
| | - Lane Bushman
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado-Anschutz Medical Campus, Aurora, Colorado, USA
| | - Farah Abdelmawla
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado-Anschutz Medical Campus, Aurora, Colorado, USA
| | - David Nerguizian
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado-Anschutz Medical Campus, Aurora, Colorado, USA
| | - Ye Ji Choi
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado-Anschutz Medical Campus, Aurora, Colorado, USA
| | - Dorothy Patton
- Department of Obstetrics and Gynecology, University of Washington, Seattle, Washington, USA
| | | | - Sravan Kumar Patel
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Magee-Women's Research Institute, Pittsburgh, Pennsylvania, USA
| | - Peter Anderson
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado-Anschutz Medical Campus, Aurora, Colorado, USA
| | - Lisa Rohan
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Magee-Women's Research Institute, Pittsburgh, Pennsylvania, USA
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Kovarova M, Wessel SE, Johnson CE, Anderson SV, Cottrell ML, Sykes C, Cohen MS, Garcia JV. EFdA efficiently suppresses HIV replication in the male genital tract and prevents penile HIV acquisition. mBio 2023; 14:e0222422. [PMID: 37306625 PMCID: PMC10470584 DOI: 10.1128/mbio.02224-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Accepted: 04/12/2023] [Indexed: 06/13/2023] Open
Abstract
Sexually transmitted HIV infections in heterosexual men are acquired through the penis. Low adherence to condom usage and the fact that 40% of circumcised men are not protected indicate the need for additional prevention strategies. Here, we describe a new approach to evaluate the prevention of penile HIV transmission. We demonstrated that the entire male genital tract (MGT) of bone marrow/liver/thymus (BLT) humanized mice is repopulated with human T and myeloid cells. The majority of the human T cells in the MGT express CD4 and CCR5. Direct penile exposure to HIV leads to systemic infection including all tissues of the MGT. HIV replication throughout the MGT was reduced 100-1,000-fold by treatment with 4'-ethynyl-2-fluoro-2'-deoxyadenosine (EFdA), resulting in the restoration of CD4+ T cell levels. Importantly, systemic preexposure prophylaxis with EFdA effectively protects from penile HIV acquisition. IMPORTANCE Over 84.2 million people have been infected by the human immunodeficiency virus type 1 (HIV-1) during the past 40 years, most through sexual transmission. Men comprise approximately half of the HIV-infected population worldwide. Sexually transmitted HIV infections in exclusively heterosexual men are acquired through the penis. However, direct evaluation of HIV infection throughout the human male genital tract (MGT) is not possible. Here, we developed a new in vivo model that permits, for the first time, the detail analysis of HIV infection. Using BLT humanized mice, we showed that productive HIV infection occurs throughout the entire MGT and induces a dramatic reduction in human CD4 T cells compromising immune responses in this organ. Antiretroviral treatment with novel drug EFdA suppresses HIV replication in all tissues of the MGT, restores normal levels of CD4 T cells and is highly efficient at preventing penile transmission.
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Affiliation(s)
- Martina Kovarova
- International Center for the Advancement of Translational Science, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Division of Infectious Diseases, Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Center for AIDS Research, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Sarah E. Wessel
- International Center for the Advancement of Translational Science, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Division of Infectious Diseases, Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Center for AIDS Research, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Claire E. Johnson
- International Center for the Advancement of Translational Science, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Division of Infectious Diseases, Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Center for AIDS Research, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Shelby V. Anderson
- International Center for the Advancement of Translational Science, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Division of Infectious Diseases, Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Center for AIDS Research, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | | | - Craig Sykes
- UNC Eshelman School of Pharmacy, Chapel Hill, North Carolina, USA
| | - Myron S. Cohen
- Institute for Global Health and Infectious Diseases, University of North Carolina, Chapel Hill, North Carolina, USA
| | - J. Victor Garcia
- International Center for the Advancement of Translational Science, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Division of Infectious Diseases, Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Center for AIDS Research, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
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Cilento ME, Ong YT, Tedbury PR, Sarafianos SG. Drug Interactions in Lenacapavir-Based Long-Acting Antiviral Combinations. Viruses 2022; 14:1202. [PMID: 35746673 PMCID: PMC9229705 DOI: 10.3390/v14061202] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 05/25/2022] [Accepted: 05/27/2022] [Indexed: 02/04/2023] Open
Abstract
Long-acting (LA) anti-HIV regimens show promise for increasing dosing intervals and consequently, improving the patients' quality of life. The first FDA-approved LA therapy is Cabenuva, which comprises rilpivirine (a non-nucleoside reverse transcriptase inhibitor) and cabotegravir (integrase strand transfer inhibitor). Novel promising LA anti-HIV agents such as lenacapavir (a capsid-targeting antiviral) and islatravir (EFdA, a nucleoside reverse transcriptase translocation inhibitor) need to be explored as combination therapies. Therefore, we sought to determine whether combination of lenacapavir with islatravir, rilpivirine, or cabotegravir displayed synergy, additivity, or antagonism. We performed dose-response matrices of these drug combinations in an HIV-1 reporter cell line and subsequently analyzed the data with SynergyFinder Plus, which employs four major drug interaction models: highest single agent, Bliss independence, Loewe additivity, and zero interaction potency. Most of these models predict additive inhibition by the studied drug combinations This work highlights the importance of effective drug combinations in LA-regimens.
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Affiliation(s)
| | | | | | - Stefan G. Sarafianos
- Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Children’s Healthcare of Atlanta, Atlanta, GA 30307, USA; (M.E.C.); (Y.T.O.); (P.R.T.)
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Beloor J, Kudalkar SN, Buzzelli G, Yang F, Mandl HK, Rajashekar JK, Spasov KA, Jorgensen WL, Saltzman WM, Anderson KS, Kumar P. Long-acting and extended-release implant and nanoformulations with a synergistic antiretroviral two-drug combination controls HIV-1 infection in a humanized mouse model. Bioeng Transl Med 2022; 7:e10237. [PMID: 35079625 PMCID: PMC8780078 DOI: 10.1002/btm2.10237] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 05/23/2021] [Accepted: 06/04/2021] [Indexed: 11/21/2022] Open
Abstract
The HIV pandemic has affected over 38 million people worldwide with close to 26 million currently accessing antiretroviral therapy (ART). A major challenge in the long-term treatment of HIV-1 infection is nonadherence to ART. Long-acting antiretroviral (LA-ARV) formulations, that reduce dosing frequency to less than once a day, are an urgent need that could tackle the adherence issue. Here, we have developed two LA-ART interventions, one an injectable nanoformulation, and the other, a removable implant, for the delivery of a synergistic two-drug ARV combination comprising a pre-clinical nonnucleoside reverse transcriptase inhibitor (NNRTI), Compound I, and the nucleoside reverse transcriptase inhibitor (NRTI), 4'-ethynyl-2-fluoro-2'-deoxyadenosine. The nanoformulation is poly(lactide-co-glycolide)-based and the implant is a copolymer of ω-pentadecalactone and p-dioxanone, poly(PDL-co-DO), a novel class of biocompatible, biodegradable materials. Both the interventions, packaged independently with each ARV, released sustained levels of the drugs, maintaining plasma therapeutic indices for over a month, and suppressed viremia in HIV-1-infected humanized mice for up to 42 days with maintenance of CD4+ T cells. These data suggest promise in the use of these new drugs as LA-ART formulations in subdermal implant and injectable mode.
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Affiliation(s)
- Jagadish Beloor
- Department of Internal Medicine, Section of Infectious DiseasesYale University School of MedicineNew HavenConnecticutUSA
| | - Shalley N. Kudalkar
- Department of PharmacologyYale University School of MedicineNew HavenConnecticutUSA
- Department of Molecular Biophysics and BiochemistryYale University School of MedicineNew HavenConnecticutUSA
| | - Gina Buzzelli
- Department of Biomedical EngineeringYale UniversityNew HavenConnecticutUSA
| | - Fan Yang
- Department of Biomedical EngineeringYale UniversityNew HavenConnecticutUSA
| | - Hanna K. Mandl
- Department of Biomedical EngineeringYale UniversityNew HavenConnecticutUSA
| | - Jyothi K. Rajashekar
- Department of Internal Medicine, Section of Infectious DiseasesYale University School of MedicineNew HavenConnecticutUSA
| | - Krasimir A. Spasov
- Department of PharmacologyYale University School of MedicineNew HavenConnecticutUSA
- Department of Molecular Biophysics and BiochemistryYale University School of MedicineNew HavenConnecticutUSA
| | | | - W. Mark Saltzman
- Department of Biomedical EngineeringYale UniversityNew HavenConnecticutUSA
| | - Karen S. Anderson
- Department of PharmacologyYale University School of MedicineNew HavenConnecticutUSA
- Department of Molecular Biophysics and BiochemistryYale University School of MedicineNew HavenConnecticutUSA
| | - Priti Kumar
- Department of Internal Medicine, Section of Infectious DiseasesYale University School of MedicineNew HavenConnecticutUSA
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Sun L, Chavez-Eng C, Fillgrove KL, Lu B, Xie I, Rudd DJ, Breidinger S, Anderson M, Yeh S, Zhang R, Woolf EJ. Toward highly sensitive and reproducible LC-MS/MS analysis of MK-8591 phosphorylated anabolites in human peripheral blood mononuclear cells. Bioanalysis 2019; 11:233-50. [PMID: 30767560 DOI: 10.4155/bio-2018-0101] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Aim: MK-8591 (EFdA), a novel anti-HIV nucleoside analog, is converted to mono-, di- and tri-phosphates (MK-8591-MP, MK-8591-DP and MK-8591-TP) intracellularly, among which MK-8591-TP is the active pharmacological form. An ultrasensitive LC-MS/MS assay was required to measure MK-8591-DP and MK-8591-TP levels in human peripheral blood mononuclear cells (PBMCs). Sensitivity and reproducibility were major bottlenecks in these analyses. Materials and methods: Human PBMCs were isolated from blood and lysed with 70/30 methanol/RPMI-1640. An LC-MS/MS method was developed to simultaneously quantify MK-8591-DP and MK-8581-TP in PBMC lysates. Results: Low flow LC and dimethyl sulfoxide mediated signal enhancement enabled an extreme sensitivity with limit of quantitation at 0.1 ng/ml. Assay accuracy was 92.5-106% and precision was 0.7-12.1% for a linear curve range of 0.1-40 ng/ml. Matrix variability and interference liability were comprehensively evaluated. Conclusion: Our study findings and steps taken in addressing clinical sample issues help understand and overcome the challenges facing intracellular nucleotide analog analysis.
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Wu VH, Smith RA, Masoum S, Raugi DN, Ba S, Seydi M, Grobler JA, Gottlieb GS; University of Washington–Dakar HIV-2 Study Group. MK-8591 (4'-Ethynyl-2-Fluoro-2'-Deoxyadenosine) Exhibits Potent Activity against HIV-2 Isolates and Drug-Resistant HIV-2 Mutants in Culture. Antimicrob Agents Chemother 2017; 61:e00744-17. [PMID: 28559249 DOI: 10.1128/AAC.00744-17] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 05/19/2017] [Indexed: 11/20/2022] Open
Abstract
There is a pressing need to identify more effective antiretroviral drugs for HIV-2 treatment. Here, we show that the investigational compound MK-8591 (4'-ethynyl-2-fluoro-2'-deoxyadenosine [EFdA]) is highly active against group A and B isolates of HIV-2; 50% effective concentrations [EC50] for HIV-2 were, on average, 4.8-fold lower than those observed for HIV-1. MK-8591 also retains potent activity against multinucleoside-resistant HIV-2 mutants (EC50 ≤ 11 nM). These data suggest that MK-8591 may have antiviral activity in HIV-2-infected individuals.
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Salie ZL, Kirby KA, Michailidis E, Marchand B, Singh K, Rohan LC, Kodama EN, Mitsuya H, Parniak MA, Sarafianos SG. Structural basis of HIV inhibition by translocation-defective RT inhibitor 4'-ethynyl-2-fluoro-2'-deoxyadenosine ( EFdA). Proc Natl Acad Sci U S A 2016; 113:9274-9. [PMID: 27489345 DOI: 10.1073/pnas.1605223113] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
4'-Ethynyl-2-fluoro-2'-deoxyadenosine (EFdA) is the most potent nucleoside analog inhibitor of HIV reverse transcriptase (RT). It retains a 3'-OH yet acts as a chain-terminating agent by diminishing translocation from the pretranslocation nucleotide-binding site (N site) to the posttranslocation primer-binding site (P site). Also, facile misincorporation of EFdA-monophosphate (MP) results in difficult-to-extend mismatched primers. To understand the high potency and unusual inhibition mechanism of EFdA, we solved RT crystal structures (resolutions from 2.4 to 2.9 Å) that include inhibition intermediates (i) before inhibitor incorporation (catalytic complex, RT/DNA/EFdA-triphosphate), (ii) after incorporation of EFdA-MP followed by dT-MP (RT/DNAEFdA-MP(P)• dT-MP(N) ), or (iii) after incorporation of two EFdA-MPs (RT/DNAEFdA-MP(P)• EFdA-MP(N) ); (iv) the latter was also solved with EFdA-MP mismatched at the N site (RT/DNAEFdA-MP(P)• EFdA-MP(*N) ). We report that the inhibition mechanism and potency of EFdA stem from interactions of its 4'-ethynyl at a previously unexploited conserved hydrophobic pocket in the polymerase active site. The high resolution of the catalytic complex structure revealed a network of ordered water molecules at the polymerase active site that stabilize enzyme interactions with nucleotide and DNA substrates. Finally, decreased translocation results from favorable interactions of primer-terminating EFdA-MP at the pretranslocation site and unfavorable posttranslocation interactions that lead to observed localized primer distortions.
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Michailidis E, Huber AD, Ryan EM, Ong YT, Leslie MD, Matzek KB, Singh K, Marchand B, Hagedorn AN, Kirby KA, Rohan LC, Kodama EN, Mitsuya H, Parniak MA, Sarafianos SG. 4'-Ethynyl-2-fluoro-2'-deoxyadenosine ( EFdA) inhibits HIV-1 reverse transcriptase with multiple mechanisms. J Biol Chem 2014; 289:24533-48. [PMID: 24970894 DOI: 10.1074/jbc.m114.562694] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
4'-Ethynyl-2-fluoro-2'-deoxyadenosine (EFdA) is a nucleoside analog that, unlike approved anti-human immunodeficiency virus type 1 (HIV-1) nucleoside reverse transcriptase inhibitors, has a 3'-OH and exhibits remarkable potency against wild-type and drug-resistant HIVs. EFdA triphosphate (EFdA-TP) is unique among nucleoside reverse transcriptase inhibitors because it inhibits HIV-1 reverse transcriptase (RT) with multiple mechanisms. (a) EFdA-TP can block RT as a translocation-defective RT inhibitor that dramatically slows DNA synthesis, acting as a de facto immediate chain terminator. Although non-translocated EFdA-MP-terminated primers can be unblocked, they can be efficiently converted back to the EFdA-MP-terminated form. (b) EFdA-TP can function as a delayed chain terminator, allowing incorporation of an additional dNTP before blocking DNA synthesis. In such cases, EFdA-MP-terminated primers are protected from excision. (c) EFdA-MP can be efficiently misincorporated by RT, leading to mismatched primers that are extremely hard to extend and are also protected from excision. The context of template sequence defines the relative contribution of each mechanism and affects the affinity of EFdA-MP for potential incorporation sites, explaining in part the lack of antagonism between EFdA and tenofovir. Changes in the type of nucleotide before EFdA-MP incorporation can alter its mechanism of inhibition from delayed chain terminator to immediate chain terminator. The versatility of EFdA in inhibiting HIV replication by multiple mechanisms may explain why resistance to EFdA is more difficult to emerge.
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Affiliation(s)
- Eleftherios Michailidis
- From the Christopher Bond Life Sciences Center and Department of Molecular Microbiology and Immunology, University of Missouri School of Medicine, Columbia, Missouri 65211
| | - Andrew D Huber
- From the Christopher Bond Life Sciences Center and Departments of Veterinary Pathobiology and
| | - Emily M Ryan
- From the Christopher Bond Life Sciences Center and Department of Molecular Microbiology and Immunology, University of Missouri School of Medicine, Columbia, Missouri 65211
| | - Yee T Ong
- From the Christopher Bond Life Sciences Center and Department of Molecular Microbiology and Immunology, University of Missouri School of Medicine, Columbia, Missouri 65211
| | - Maxwell D Leslie
- From the Christopher Bond Life Sciences Center and Department of Molecular Microbiology and Immunology, University of Missouri School of Medicine, Columbia, Missouri 65211
| | - Kayla B Matzek
- From the Christopher Bond Life Sciences Center and Department of Molecular Microbiology and Immunology, University of Missouri School of Medicine, Columbia, Missouri 65211
| | - Kamalendra Singh
- From the Christopher Bond Life Sciences Center and Department of Molecular Microbiology and Immunology, University of Missouri School of Medicine, Columbia, Missouri 65211
| | - Bruno Marchand
- From the Christopher Bond Life Sciences Center and Department of Molecular Microbiology and Immunology, University of Missouri School of Medicine, Columbia, Missouri 65211
| | - Ariel N Hagedorn
- From the Christopher Bond Life Sciences Center and Department of Molecular Microbiology and Immunology, University of Missouri School of Medicine, Columbia, Missouri 65211
| | - Karen A Kirby
- From the Christopher Bond Life Sciences Center and Department of Molecular Microbiology and Immunology, University of Missouri School of Medicine, Columbia, Missouri 65211
| | - Lisa C Rohan
- Magee-Womens Research Institute and Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, Pennsylvania 15213
| | - Eiichi N Kodama
- Division of Emerging Infectious Diseases, Tohoku University, Sendai 980-8575, Japan
| | - Hiroaki Mitsuya
- Department of Internal Medicine, Kumamoto University, Kumamoto 860-8556, Japan, Experimental Retrovirology Section, HIV/AIDS Malignancy Branch, National Institutes of Health, Bethesda, Maryland 20892, and
| | - Michael A Parniak
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15219
| | - Stefan G Sarafianos
- From the Christopher Bond Life Sciences Center and Department of Molecular Microbiology and Immunology, University of Missouri School of Medicine, Columbia, Missouri 65211, Biochemistry, University of Missouri, Columbia, Missouri 65211,
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10
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Zhang W, Parniak MA, Sarafianos SG, Empey PE, Rohan LC. In vitro transport characteristics of EFdA, a novel nucleoside reverse transcriptase inhibitor using Caco-2 and MDCKII cell monolayers. Eur J Pharmacol 2014; 732:86-95. [PMID: 24690257 DOI: 10.1016/j.ejphar.2014.03.022] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Revised: 03/12/2014] [Accepted: 03/20/2014] [Indexed: 12/14/2022]
Abstract
4'-Ethynyl-2-fluoro-2'-deoxyadenosine (EFdA) is a novel nucleoside reverse transcriptase inhibitor with a unique mechanism of action and highly potent activity against both wild-type and clinically relevant drug resistant HIV-1 variants. Furthermore, in vivo efficacy and safety evaluations have shown EFdA to be a promising therapeutic candidate for use in the treatment of HIV infection. However, little is known about the pharmacokinetic and biopharmaceutical properties of EFdA. In this study, we evaluated cellular EFdA transport using Caco-2 and Madin-Darby Canine Kidney II (MDCKII) in vitro cell models. Studies using Caco-2 cell monolayers showed that EFdA efflux ratios were >2.0, suggesting that active drug transport mechanisms may play a role in EFdA flux. ABCB1 transporter (PGP1) inhibition was assessed using the acetomethoxy derivate of calcein (calcein-AM) as a fluorescent probe in both wild-type MDCKII and PGP1 overexpressing MDCKII cells. Nonetheless, our data showed that EFdA is not a substrate of PGP1. Additionally, comparative bidirectional flux of EFdA and Lucifer yellow (LY, a well-known paracellular marker) was studied over a range of EFdA concentrations. In MDCKII monolayers, EFdA had an apparent permeability coefficient (Papp) (a-b) of <1×10(-6)cm/s. The Papp values significantly increased in the presence of the paracellular permeability enhancer, indicating that EFdA primarily permeates via the paracellular route.
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Affiliation(s)
- Wei Zhang
- Magee-Womens Research Institute, University of Pittsburgh, Pittsburgh, PA 15213, USA; Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Michael A Parniak
- Department of Microbiology and Molecular Genetics, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15219, USA
| | - Stefan G Sarafianos
- Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri, Columbia, MO 65211, USA
| | - Philip E Empey
- Department of Pharmacy and Therapeutics, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Lisa C Rohan
- Magee-Womens Research Institute, University of Pittsburgh, Pittsburgh, PA 15213, USA; Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA 15213, USA.
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Muftuoglu Y, Sohl CD, Mislak AC, Mitsuya H, Sarafianos SG, Anderson KS. Probing the molecular mechanism of action of the HIV-1 reverse transcriptase inhibitor 4'-ethynyl-2-fluoro-2'-deoxyadenosine ( EFdA) using pre-steady-state kinetics. Antiviral Res 2014; 106:1-4. [PMID: 24632447 DOI: 10.1016/j.antiviral.2014.03.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Revised: 03/02/2014] [Accepted: 03/03/2014] [Indexed: 12/13/2022]
Abstract
The novel antiretroviral 4'-ethynyl-2-fluoro-2'-deoxyadenosine (EFdA) is a potent nucleoside HIV-1 reverse transcriptase (RT) inhibitor (NRTI). Unlike other FDA-approved NRTIs, EFdA contains a 3'-hydroxyl. Pre-steady-state kinetics showed RT preferred incorporating EFdA-TP over native dATP. Moreover, RT slowly inserted nucleotides past an EFdA-terminated primer, resulting in delayed chain termination with unaffected fidelity. This is distinct from KP1212, another 3'-hydroxyl-containing RT inhibitor considered to promote viral lethal mutagenesis. New mechanistic features of RT inhibition by EFdA are revealed.
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Affiliation(s)
- Yagmur Muftuoglu
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT 06520, United States
| | - Christal D Sohl
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT 06520, United States
| | - Andrea C Mislak
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT 06520, United States
| | - Hiroaki Mitsuya
- Department of Infectious Diseases, Kumamoto University Graduate School of Medical Sciences, Kumamoto 860-8556, Japan; Department of Hematology, Kumamoto University Graduate School of Medical Sciences, Kumamoto 860-8556, Japan; Experimental Retrovirology Section, HIV and AIDS Malignancy Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, United States
| | - Stefan G Sarafianos
- CS Bond Life Sciences Center and Department of Molecular Microbiology and Immunology, University of Missouri, School of Medicine, Columbia, MO 65211, United States; Department of Biochemistry, University of Missouri, School of Medicine, Columbia, MO 65211, United States
| | - Karen S Anderson
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT 06520, United States.
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Zhang W, Parniak MA, Sarafianos SG, Cost MR, Rohan LC. Development of a vaginal delivery film containing EFdA, a novel anti-HIV nucleoside reverse transcriptase inhibitor. Int J Pharm 2013; 461:203-13. [PMID: 24333452 DOI: 10.1016/j.ijpharm.2013.11.056] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Revised: 11/14/2013] [Accepted: 11/30/2013] [Indexed: 11/25/2022]
Abstract
The aim of this work was to develop a fast-dissolving film formulation containing EFdA for potential use as a topical vaginal microbicide for prevention of HIV sexual transmission. Solid state compatibility approaches were used to screen commonly used polymers for formulation development. Factorial design and desirability function were used to investigate the effect of two variables, the ratio of the polymers and the concentration of selected plasticizer on four mechanical responses including tensile strength, elongation at break, toughness and elastic modulus for optimization of the film formulation. Assessments of EFdA-loaded films included physicochemical characteristics, in vitro cytotoxicity, epithelia integrity, ex vivo permeability and bioactivity test. The optimal placebo film was composed of PVA, HPMC E5 and propylene glycol (7:3:3, w/w), and its mechanical characteristics were comparable to those of VCF(®) film (a commercial vaginal film product). Permeability studies using human ectocervical explants showed that there was no significant difference in cumulative permeated amount of EFdA between EFdA film and free EFdA. The results of in vitro cytotoxicity and bioactivity testing showed that 50% cytotoxic concentration (CC50) was several orders of magnitude higher than 50% effective concentration (EC50) of EFdA. Furthermore, epithelial integrity study showed that EFdA-loaded film had a much lower toxicity to HEC-1A cell monolayers as compared to VCF(®). Therefore, EFdA-loaded vaginal film may be considered as a promising vaginal microbicide for HIV prevention.
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Affiliation(s)
- Wei Zhang
- Magee Womens Research Institute, University of Pittsburgh, Pittsburgh, PA 15213, USA; Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Michael A Parniak
- Department of Microbiology and Molecular Genetics, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15219, USA
| | - Stefan G Sarafianos
- Department of Molecular Microbiology & Immunology, School of Medicine, University of Missouri, Columbia, MO 65211, USA
| | - Marilyn R Cost
- Magee Womens Research Institute, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Lisa C Rohan
- Magee Womens Research Institute, University of Pittsburgh, Pittsburgh, PA 15213, USA; Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA 15213, USA.
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Zhang W, Parniak MA, Mitsuya H, Sarafianos SG, Graebing PW, Rohan LC. Preformulation studies of EFdA, a novel nucleoside reverse transcriptase inhibitor for HIV prevention. Drug Dev Ind Pharm 2013; 40:1101-11. [PMID: 23841536 DOI: 10.3109/03639045.2013.809535] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
4'-Ethynyl-2-fluoro-2'-deoxyadenosine (EFdA) is a novel nucleoside analog of great interest because of its superior activity against wild-type and multidrug-resistant HIV-1 strains, and favorable safety profiles in vitro and in vivo. The aim of this work was to provide preformulation information of EFdA important for delivery system development. A simple, accurate and specific reverse-phase high performance liquid chromatographic (RP-HPLC) method with UV detection was developed for quantification of EFdA. In addition, physicochemical characterizations including pH solubility profile, octanol/water partition coefficient (Log Po/w), DSC analysis, field emission scanning electron microscopy, and stability studies under various conditions were conducted. EFdA existed in planar or flake shape, with a melting point of ∼130 °C, and had a pH dependent solubility. The log Po/w value of EFdA was -1.19. The compound was stable upon exposure to pH levels from 3 to 9 and showed good stability at elevated temperature (65 °C). In vitro cytotoxicity assessments were performed in two different epithelial cell lines. In cell-based studies, the EFdA selectivity index (50% cytotoxic concentration [CC50] values/50% effective concentration [EC50]) was found to be greater than 1 × 10(3). Permeability studies using cell- and tissue-based models showed that EFdA had an apparent permeability coefficient (Papp) <1 × 10(-6)cm/s and that the paracelluar pathway was the dominant transport route for EFdA. Overall, EFdA possesses favorable characteristics for further formulation development.
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Affiliation(s)
- Wei Zhang
- Magee Womens Research Institute, University of Pittsburgh , Pittsburgh, PA , USA
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