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HIV-1 Reverse Transcriptase Promotes Tumor Growth and Metastasis Formation via ROS-Dependent Upregulation of Twist. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2019; 2019:6016278. [PMID: 31885806 PMCID: PMC6915010 DOI: 10.1155/2019/6016278] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 11/01/2019] [Accepted: 11/05/2019] [Indexed: 12/15/2022]
Abstract
HIV-induced immune suppression results in the high prevalence of HIV/AIDS-associated malignancies including Kaposi sarcoma, non-Hodgkin lymphoma, and cervical cancer. HIV-infected people are also at an increased risk of “non-AIDS-defining” malignancies not directly linked to immune suppression but associated with viral infections. Their incidence is increasing despite successful antiretroviral therapy. The mechanism behind this phenomenon remains unclear. Here, we obtained daughter clones of murine mammary gland adenocarcinoma 4T1luc2 cells expressing consensus reverse transcriptase of HIV-1 subtype A FSU_A strain (RT_A) with and without primary mutations of drug resistance. In in vitro tests, mutations of resistance to nucleoside inhibitors K65R/M184V reduced the polymerase, and to nonnucleoside inhibitors K103N/G190S, the RNase H activities of RT_A. Expression of these RT_A variants in 4T1luc2 cells led to increased production of the reactive oxygen species (ROS), lipid peroxidation, enhanced cell motility in the wound healing assay, and upregulation of expression of Vimentin and Twist. These properties, particularly, the expression of Twist, correlated with the levels of expression RT_A and/or the production of ROS. When implanted into syngeneic BALB/C mice, 4T1luc2 cells expressing nonmutated RT_A demonstrated enhanced rate of tumor growth and increased metastatic activity, dependent on the level of expression of RT_A and Twist. No enhancement was observed for the clones expressing mutated RT_A variants. Plausible mechanisms are discussed involving differential interactions of mutated and nonmutated RTs with its cellular partners involved in the regulation of ROS. This study establishes links between the expression of HIV-1 RT, production of ROS, induction of EMT, and enhanced propagation of RT-expressing tumor cells. Such scenario can be proposed as one of the mechanisms of HIV-induced/enhanced carcinogenesis not associated with immune suppression.
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Perales C, Moreno E, Domingo E. Clonality and intracellular polyploidy in virus evolution and pathogenesis. Proc Natl Acad Sci U S A 2015; 112:8887-92. [PMID: 26195777 PMCID: PMC4517279 DOI: 10.1073/pnas.1501715112] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In the present article we examine clonality in virus evolution. Most viruses retain an active recombination machinery as a potential means to initiate new levels of genetic exploration that go beyond those attainable solely by point mutations. However, despite abundant recombination that may be linked to molecular events essential for genome replication, herein we provide evidence that generation of recombinants with altered biological properties is not essential for the completion of the replication cycles of viruses, and that viral lineages (near-clades) can be defined. We distinguish mechanistically active but inconsequential recombination from evolutionarily relevant recombination, illustrated by episodes in the field and during experimental evolution. In the field, recombination has been at the origin of new viral pathogens, and has conferred fitness advantages to some viruses once the parental viruses have attained a sufficient degree of diversification by point mutations. In the laboratory, recombination mediated a salient genome segmentation of foot-and-mouth disease virus, an important animal pathogen whose genome in nature has always been characterized as unsegmented. We propose a model of continuous mutation and recombination, with punctuated, biologically relevant recombination events for the survival of viruses, both as disease agents and as promoters of cellular evolution. Thus, clonality is the standard evolutionary mode for viruses because recombination is largely inconsequential, since the decisive events for virus replication and survival are not dependent on the exchange of genetic material and formation of recombinant (mosaic) genomes.
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Affiliation(s)
- Celia Perales
- Centro de Biologia Molecular "Severo Ochoa" (CSIC-UAM), Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid, E-28049 Madrid, Spain; Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas, Barcelona, Spain; and Liver Unit, Internal Medicine, Laboratory of Malalties Hepàtiques, Vall d'Hebron Institut de Recerca-Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona, 08035 Barcelona, Spain
| | - Elena Moreno
- Centro de Biologia Molecular "Severo Ochoa" (CSIC-UAM), Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid, E-28049 Madrid, Spain
| | - Esteban Domingo
- Centro de Biologia Molecular "Severo Ochoa" (CSIC-UAM), Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid, E-28049 Madrid, Spain; Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas, Barcelona, Spain; and
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Subtype-specific analysis of the K65R substitution in HIV-1 that confers hypersusceptibility to a novel nucleotide-competing reverse transcriptase inhibitor. Antimicrob Agents Chemother 2015; 59:3189-96. [PMID: 25779585 DOI: 10.1128/aac.00315-15] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Accepted: 03/11/2015] [Indexed: 12/20/2022] Open
Abstract
Compound A is a novel nucleotide-competing HIV-1 reverse transcriptase (RT) inhibitor (NcRTI) that selects for a unique W153L substitution that confers hypersusceptibility to tenofovir, while the K65R substitution in RT confers resistance against tenofovir and enhances susceptibility to NcRTIs. Although the K65R substitution is more common in subtype C viruses, the impact of subtype variability on NcRTI susceptibility has not been studied. In the present study, we performed experiments with compound A by using purified recombinant RT enzymes and viruses of subtypes B and C and circulating recombinant form CRF_A/G. We confirmed the hypersusceptibility of K65R substitution-containing RTs to compound A for subtype C, CRF_A/G, and subtype B. Steady-state kinetic analysis showed that K65R RTs enhanced the susceptibility to compound A by increasing binding of the inhibitor to the nucleotide binding site of RT in a subtype-independent manner, without significantly discriminating against the natural nucleotide substrate. These data highlight the potential utility of NcRTIs, such as compound A, for treatment of infections with K65R substitution-containing viruses, regardless of HIV-1 subtype.
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Development of a stochastic model for the efficacy of NRTIs using known mechanisms of action. J Theor Biol 2010; 265:704-17. [PMID: 20510251 DOI: 10.1016/j.jtbi.2010.05.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2009] [Revised: 03/16/2010] [Accepted: 05/06/2010] [Indexed: 01/10/2023]
Abstract
We analyze the mechanisms by which nucleoside-analogue reverse transcriptase inhibitors, the most common class of drugs used in the treatment of HIV-1, exert their antiviral effects. We then seek to identify ways in which those known mechanisms can be employed to generate mathematical models for drug efficacy in terms of measurable physical values. We demonstrate that the probability a NRTI instead of a natural nucleotide is included can be expressed in terms of intracellular drug concentrations, natural nucleotide concentrations, and relevant rate constants derived from reverse transcriptase's mechanism of nucleotide addition. In order to determine the ultimate effect, the resistance of the NRTI to removal from the genome must be considered, which is achieved via stochastic modeling. We employ this model to determine the relationship between efficacy and drug concentration, as well as other drug characteristics like half life. We also investigate the effect of drug administration time on the overall efficacy. The model is employed for four different drugs and a sensitivity analysis on mutation and resistance is performed.
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5
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HIV Genetic Diversity and Drug Resistance. Viruses 2010; 2:503-531. [PMID: 21994646 PMCID: PMC3185604 DOI: 10.3390/v2020503] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2009] [Revised: 12/11/2009] [Accepted: 02/01/2010] [Indexed: 02/07/2023] Open
Abstract
Most of the current knowledge on antiretroviral (ARV) drug development and resistance is based on the study of subtype B of HIV-1, which only accounts for 10% of the worldwide HIV infections. Cumulative evidence has emerged that different HIV types, groups and subtypes harbor distinct biological properties, including the response and susceptibility to ARV. Recent laboratory and clinical data highlighting such disparities are summarized in this review. Variations in drug susceptibility, in the emergence and selection of specific drug resistance mutations, in viral replicative capacity and in the dynamics of resistance acquisition under ARV selective pressure are discussed. Clinical responses to ARV therapy and associated confounding factors are also analyzed in the context of infections by distinct HIV genetic variants.
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Xu HT, Martinez-Cajas JL, Ntemgwa ML, Coutsinos D, Frankel FA, Brenner BG, Wainberg MA. Effects of the K65R and K65R/M184V reverse transcriptase mutations in subtype C HIV on enzyme function and drug resistance. Retrovirology 2009; 6:14. [PMID: 19210791 PMCID: PMC2644664 DOI: 10.1186/1742-4690-6-14] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2008] [Accepted: 02/11/2009] [Indexed: 01/25/2023] Open
Abstract
Background We investigated the effects of mutations K65R and K65R plus M184V on enzymatic function and mechanisms of drug resistance in subtype C reverse transcriptase (RT). Methods Recombinant subtype C HIV-1 RTs containing K65R or K65R+M184V were purified from Escherichia coli. Enzyme activities and tenofovir (TFV) incorporation efficiency by wild-type (WT) and mutant RTs of both subtypes were determined in cell-free assays. Efficiency of (-) ssDNA synthesis and initiation by subtype C RTs was measured using gel-based assays with HIV-1 PBS RNA template and tRNA3Lys as primer. Single-cycle processivity was assayed under variable dNTP concentrations. Steady-state analysis was performed to measure the relative inhibitory capacity (ki/km) of TFV-disphosphate (TFV-DP). ATP-dependent excision and rescue of TFV-or ZDV-terminated DNA synthesis was monitored in time-course experiments. Results The efficiency of tRNA-primed (-)ssDNA synthesis by subtype C RTs was: WT > K65R > K65R+M184V RT. At low dNTP concentration, K65R RT exhibited lower activity in single-cycle processivity assays while the K65R+M184V mutant showed diminished processivity independent of dNTP concentration. ATP-mediated excision of TFV-or ZDV-terminated primer was decreased for K65R and for K65R+M184V RT compared to WT RT. K65R and K65R+M184V displayed 9.8-and 5-fold increases in IC50 for TFV-DP compared to WT RT. The Ki/Km of TFV was increased by 4.1-and 7.2-fold, respectively, for K65R and K65R+M184V compared to WT RT. Conclusion The diminished initiation efficiency of K65R-containing RTs at low dNTP concentrations have been confirmed for subtype C as well as subtype B. Despite decreased excision, this decreased binding/incorporation results in diminished susceptibility of K65R and K65R+M184 RT to TFV-DP.
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Affiliation(s)
- Hong-Tao Xu
- McGill University AIDS Centre, Lady Davis Institute, Jewish General Hospital, Montreal, Quebec H3T1E2, Canada.
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HIV-1 reverse transcriptase inhibitor resistance mutations and fitness: a view from the clinic and ex vivo. Virus Res 2008; 134:104-23. [PMID: 18289713 DOI: 10.1016/j.virusres.2007.12.021] [Citation(s) in RCA: 112] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2007] [Revised: 12/27/2007] [Accepted: 12/28/2007] [Indexed: 01/04/2023]
Abstract
Genetic diversity plays a key role in human immunodeficiency virus (HIV) adaptation, providing a mechanism to escape host immune responses and develop resistance to antiretroviral drugs. This process is driven by the high-mutation rate during DNA synthesis by reverse transcriptase (RT), by the large viral populations, by rapid viral turnover, and by the high-recombination rate. Drugs targeting HIV RT are included in all regimens of highly active antiretroviral therapy (HAART), which helps to reduce the morbidity and mortality of HIV-infected patients. However, the emergence of resistant viruses is a significant obstacle to effective long-term management of HIV infection and AIDS. The increasing complexity of antiretroviral regimens has favored selection of HIV variants harboring multiple drug resistance mutations. Evolution of drug resistance is characterized by severe fitness losses when the drug is not present, which can be partially overcome by compensatory mutations or other adaptive changes that restore replication capacity. Here, we review the impact of mutations conferring resistance to nucleoside and nonnucleoside RT inhibitors on in vitro and in vivo fitness, their involvement in pathogenesis, persistence upon withdrawal of treatment, and transmission. We describe the techniques used to estimate viral fitness, the molecular mechanisms that help to improve the viral fitness of drug-resistant variants, and the clinical implications of viral fitness data, by exploring the potential relationship between plasma viral load, drug resistance, and disease progression.
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Delaugerre C, Flandre P, Marcelin A, Descamps D, Tamalet C, Cottalorda J, Schneider V, Yerly S, LeGoff J, Morand-Joubert L, Chaix M, Costagliola D, Calvez V. National survey of the prevalence and conditions of selection of HIV-1 reverse transcriptase K70E mutation. J Med Virol 2008; 80:762-5. [DOI: 10.1002/jmv.21158] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Domingo E, Escarmís C, Menéndez-Arias L, Perales C, Herrera M, Novella IS, Holland JJ. Viral Quasispecies: Dynamics, Interactions, and Pathogenesis *. ORIGIN AND EVOLUTION OF VIRUSES 2008. [PMCID: PMC7149507 DOI: 10.1016/b978-0-12-374153-0.00004-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Quasispecies theory is providing a solid, evolving conceptual framework for insights into virus population dynamics, adaptive potential, and response to lethal mutagenesis. The complexity of mutant spectra can influence disease progression and viral pathogenesis, as demonstrated using virus variants selected for increased replicative fidelity. Complementation and interference exerted among components of a viral quasispecies can either reinforce or limit the replicative capacity and disease potential of the ensemble. In particular, a progressive enrichment of a replicating mutant spectrum with interfering mutant genomes prompted by enhanced mutagenesis may be a key event in the sharp transition of virus populations into error catastrophe that leads to virus extinction. Fitness variations are influenced by the passage regimes to which viral populations are subjected, notably average fitness decreases upon repeated bottleneck events and fitness gains upon competitive optimization of large viral populations. Evolving viral quasispecies respond to selective constraints by replication of subpopulations of variant genomes that display higher fitness than the parental population in the presence of the selective constraint. This has been profusely documented with fitness effects of mutations associated with resistance of pathogenic viruses to antiviral agents. In particular, selection of HIV-1 mutants resistant to one or multiple antiretroviral inhibitors, and the compensatory effect of mutations in the same genome, offers a compendium of the molecular intricacies that a virus can exploit for its survival. This chapter reviews the basic principles of quasispecies dynamics as they can serve to explain the behavior of viruses.
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Quiñones-Mateu ME, Moore-Dudley DM, Jegede O, Weber J, J Arts E. Viral drug resistance and fitness. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2008; 56:257-96. [PMID: 18086415 DOI: 10.1016/s1054-3589(07)56009-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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11
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Bradshaw D, Malik S, Booth C, Van Houtte M, Pattery T, Waters A, Ainsworth J, Geretti AM. Novel drug resistance pattern associated with the mutations K70G and M184V in human immunodeficiency virus type 1 reverse transcriptase. Antimicrob Agents Chemother 2007; 51:4489-91. [PMID: 17876005 PMCID: PMC2167988 DOI: 10.1128/aac.00687-07] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We describe an unusual pathway of human immunodeficiency virus type 1 reverse transcriptase resistance during therapy with tenofovir-emtricitabine, characterized initially by the mutations K70E and M184V and later by K70G and M184V, with the two mutations coexisting on the same viral genome. Phenotypic resistance to lamivudine, emtricitabine, abacavir, didanosine, and tenofovir was observed, whereas susceptibility to zidovudine and stavudine was preserved.
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Affiliation(s)
- D Bradshaw
- Department of Virology, Royal Free Hospital, Pond Street, London NW3 2QG, United Kingdom
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Van Rompay KKA, Johnson JA, Blackwood EJ, Singh RP, Lipscomb J, Matthews TB, Marthas ML, Pedersen NC, Bischofberger N, Heneine W, North TW. Sequential emergence and clinical implications of viral mutants with K70E and K65R mutation in reverse transcriptase during prolonged tenofovir monotherapy in rhesus macaques with chronic RT-SHIV infection. Retrovirology 2007; 4:25. [PMID: 17417971 PMCID: PMC1852805 DOI: 10.1186/1742-4690-4-25] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2007] [Accepted: 04/06/2007] [Indexed: 01/29/2023] Open
Abstract
BACKGROUND We reported previously on the emergence and clinical implications of simian immunodeficiency virus (SIVmac251) mutants with a K65R mutation in reverse transcriptase (RT), and the role of CD8+ cell-mediated immune responses in suppressing viremia during tenofovir therapy. Because of significant sequence differences between SIV and HIV-1 RT that affect drug susceptibilities and mutational patterns, it is unclear to what extent findings with SIV can be extrapolated to HIV-1 RT. Accordingly, to model HIV-1 RT responses, 12 macaques were inoculated with RT-SHIV, a chimeric SIV containing HIV-1 RT, and started on prolonged tenofovir therapy 5 months later. RESULTS The early virologic response to tenofovir correlated with baseline viral RNA levels and expression of the MHC class I allele Mamu-A*01. For all animals, sensitive real-time PCR assays detected the transient emergence of K70E RT mutants within 4 weeks of therapy, which were then replaced by K65R mutants within 12 weeks of therapy. For most animals, the occurrence of these mutations preceded a partial rebound of plasma viremia to levels that remained on average 10-fold below baseline values. One animal eventually suppressed K65R viremia to undetectable levels for more than 4 years; sequential experiments using CD8+ cell depletion and tenofovir interruption demonstrated that both CD8+ cells and continued tenofovir therapy were required for sustained suppression of viremia. CONCLUSION This is the first evidence that tenofovir therapy can select directly for K70E viral mutants in vivo. The observations on the clinical implications of the K65R RT-SHIV mutants were consistent with those of SIVmac251, and suggest that for persons infected with K65R HIV-1 both immune-mediated and drug-dependent antiviral activities play a role in controlling viremia. These findings suggest also that even in the presence of K65R virus, continuation of tenofovir treatment as part of HAART may be beneficial, particularly when assisted by antiviral immune responses.
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Affiliation(s)
- Koen KA Van Rompay
- California National Primate Research Center, University of California, Davis, USA
| | - Jeffrey A Johnson
- Division of HIV/AIDS Prevention, National Center for HIV, STD and Tuberculosis Prevention, Centers for Disease Control and Prevention, Atlanta, USA
| | - Emily J Blackwood
- California National Primate Research Center, University of California, Davis, USA
| | - Raman P Singh
- California National Primate Research Center, University of California, Davis, USA
| | - Jonathan Lipscomb
- Division of HIV/AIDS Prevention, National Center for HIV, STD and Tuberculosis Prevention, Centers for Disease Control and Prevention, Atlanta, USA
| | | | - Marta L Marthas
- California National Primate Research Center, University of California, Davis, USA
| | - Niels C Pedersen
- Department of Medicine and Epidemiology, School of Veterinary Medicine; University of California, Davis, USA
| | | | - Walid Heneine
- Division of HIV/AIDS Prevention, National Center for HIV, STD and Tuberculosis Prevention, Centers for Disease Control and Prevention, Atlanta, USA
| | - Thomas W North
- Center for Comparative Medicine, University of California, Davis, USA
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, USA
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Delaney WE, Ray AS, Yang H, Qi X, Xiong S, Zhu Y, Miller MD. Intracellular metabolism and in vitro activity of tenofovir against hepatitis B virus. Antimicrob Agents Chemother 2006; 50:2471-7. [PMID: 16801428 PMCID: PMC1489769 DOI: 10.1128/aac.00138-06] [Citation(s) in RCA: 186] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Tenofovir is an acyclic nucleotide analog with activity against human immunodeficiency virus (HIV) and hepatitis B virus (HBV). Tenofovir disoproxil fumarate (tenofovir DF), a bis-alkoxyester prodrug of tenofovir, is approved for the treatment of HIV and is currently being developed to treat chronic hepatitis B. In this report, we further characterize the in vitro activity of tenofovir against HBV as well as its metabolism in hepatic cells. We show that tenofovir is efficiently phosphorylated to tenofovir diphosphate (TFV-DP) in both HepG2 cells and primary human hepatocytes. TFV-DP has a long intracellular half-life (95 h) and is a potent and competitive inhibitor of HBV polymerase (Ki = 0.18 microM). Tenofovir has a 50% effective concentration of 1.1 microM against HBV in cell-based assays, and potency is improved > 50-fold by the addition of bis-isoproxil progroups. Tenofovir has previously demonstrated full activity against lamivudine-resistant HBV in vitro and clinically. Here we show that the major adefovir resistance mutation, rtN236T, confers three- to fourfold-reduced susceptibility to tenofovir in cell culture; the clinical significance of this susceptibility shift has not yet been determined. The rtA194T HBV polymerase mutation recently identified in tenofovir DF-treated HIV/HBV-coinfected patients did not confer in vitro resistance to tenofovir as a single mutation or in a lamivudine-resistant viral background. Overall, the antiviral and metabolic profile of tenofovir supports its development for the treatment of chronic hepatitis B.
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Affiliation(s)
- William E Delaney
- Gilead Sciences Inc., 333 Lakeside Drive, Foster City, CA 94404, USA.
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White KL, Margot NA, Ly JK, Chen JM, Ray AS, Pavelko M, Wang R, McDermott M, Swaminathan S, Miller MD. A combination of decreased NRTI incorporation and decreased excision determines the resistance profile of HIV-1 K65R RT. AIDS 2005; 19:1751-60. [PMID: 16227782 DOI: 10.1097/01.aids.0000189851.21441.f1] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To determine the mechanisms of resistance of K65R mutant reverse transcriptase (RT) to the currently approved nucleoside and nucleotide RT inhibitors (NRTI). METHODS Susceptibilities of K65R mutant HIV-1 to NRTI were determined in cell culture. The Ki/Km values were measured to determine the relative binding or incorporation of the NRTI, and ATP-mediated excision of incorporated NRTI was measured to determine NRTI stability as chain terminators. RESULTS K65R HIV-1 had decreased susceptibility to most NRTI, but increased susceptibility to zidovudine (ZDV). Ki/Km values were increased 2- to 13-fold for K65R compared to wild-type RT for all NRTI, indicating decreased binding or incorporation. However, K65R also showed decreased excision of all NRTI compared to wild-type, indicating greater stability once incorporated. At physiological nucleotide concentrations, excision of ZDV, carbovir (the active metabolite of abacavir; ABC), stavudine (d4T), and tenofovir was further decreased, while excision of didanosine (ddI), zalcitabine (ddC), lamivudine (3TC), and emtricitabine (FTC) was unchanged. The decreased binding or incorporation of ZDV by K65R appeared counteracted by decreased excision resulting in overall increased susceptibility to ZDV in cell culture. For ABC, tenofovir, and d4T, despite having decreased excision, decreased binding or incorporation resulted in reduced susceptibilities to K65R. For ddI, ddC, 3TC, and FTC, decreased binding or incorporation by K65R appeared responsible for the decreased susceptibilities in cell culture. CONCLUSIONS NRTI resistance in cells can consist of both altered binding or incorporation and altered excision of the NRTI. For K65R, the combination of these opposing mechanisms results in decreased susceptibility to most NRTI but increased susceptibility to ZDV.
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Chu CK, Yadav V, Chong YH, Schinazi RF. Anti-HIV Activity of (−)-(2R,4R)-1- (2-Hydroxymethyl-1,3-dioxolan-4-yl)- thymine against Drug-Resistant HIV-1 Mutants and Studies of Its Molecular Mechanism. J Med Chem 2005; 48:3949-52. [PMID: 15943470 DOI: 10.1021/jm050060l] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
(-)-(2R,4R)-1-(2-Hydroxymethyl-1,3-dioxolan-4-yl)thymine (DOT) is the first thymidine kinase-activated nucleoside that is significantly active against all of the clinically significant NRTI-resistant HIV-1 mutants, including AZT (D67N/K70R/T215Y/K219Q), Tenofovir (K65R), and Lamivudine (M184V). To understand the molecular mechanism of drug resistance and the antiviral activity of DOT against drug-resistant RTs, molecular modeling studies of DOT-TP complexed with the wild-type (WT) and mutated RT were conducted. The key reason for this interesting antiviral activity profile is the presence of a dioxolane ring.
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Affiliation(s)
- Chung K Chu
- College of Pharmacy, The University of Georgia, Athens, 30602, USA.
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Delaugerre C, Roudiere L, Peytavin G, Rouzioux C, Viard JP, Chaix ML. Selection of a rare resistance profile in an HIV-1-infected patient exhibiting a failure to an antiretroviral regimen including tenofovir DF. J Clin Virol 2005; 32:241-4. [PMID: 15722030 DOI: 10.1016/j.jcv.2004.05.020] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2004] [Accepted: 05/10/2004] [Indexed: 10/26/2022]
Abstract
The human immunodeficiency virus type 1 (HIV-1) resistance profile, K65R, K70E and M184V, on reverse transcriptase gene was associated with the virologic rebound consecutively to the switch of lopinavir/r to tenofovir DF in a stable regimen with nucleoside backbone of abacavir, lamivudine and didanosine. The high selective pressure on the same resistance pathway was probably associated with the loss of antiviral potency, even in well-controlled patient.
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Affiliation(s)
- Constance Delaugerre
- Department of Virology, Necker-Enfants Malades Hospital, 149 rue de Sèvres, 75015 Paris, France.
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White KL, Chen JM, Margot NA, Wrin T, Petropoulos CJ, Naeger LK, Swaminathan S, Miller MD. Molecular mechanisms of tenofovir resistance conferred by human immunodeficiency virus type 1 reverse transcriptase containing a diserine insertion after residue 69 and multiple thymidine analog-associated mutations. Antimicrob Agents Chemother 2004; 48:992-1003. [PMID: 14982794 PMCID: PMC353090 DOI: 10.1128/aac.48.3.992-1003.2004] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Two amino acids inserted between residues 69 and 70 of human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) are rare mutations that may develop in viruses containing multiple thymidine analog (zidovudine [AZT], stavudine)-associated mutations and that confer high-level resistance to all currently approved chain-terminating nucleoside and nucleotide RT inhibitors (NRTIs). The two known mechanisms of resistance to NRTIs are decreased incorporation and increased excision. The mechanism used by RT insertion mutants has not been described for tenofovir (TFV), a recently approved agent in this class. A patient-derived HIV-1 strain (strain FS-SSS) that contained an insertion mutation in a background of additional resistance mutations M41L, L74V, L210W, and T215Y was obtained. A second virus (strain FS) was derived from FS-SSS. In strain FS the insertion and T69S were reverted but the other resistance mutations were retained. The FS virus showed strong resistance to AZT but low-level changes in susceptibilities to other NRTIs and TFV. The FS-SSS virus showed reduced susceptibilities to all NRTIs including TFV. Steady-state kinetics demonstrated that the relative binding or incorporation of TFV was slightly decreased for FS-SSS RT compared to those for wild-type RT. However, significant ATP-mediated excision of TFV was detected for both mutant RT enzymes and followed the order FS-SSS RT > FS RT > wild-type RT. The presence of physiological concentrations of the +1 nucleotide inhibited TFV excision by the wild-type RT and slightly inhibited excision by the FS RT, whereas the level of excision by the FS-SSS RT remained high. Computer modeling suggests that the increased mobility of the beta3-beta4 loop may contribute to the high-level and broad NRTI resistance caused by the T69 insertion mutation.
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White KL, Margot NA, Wrin T, Petropoulos CJ, Miller MD, Naeger LK. Molecular mechanisms of resistance to human immunodeficiency virus type 1 with reverse transcriptase mutations K65R and K65R+M184V and their effects on enzyme function and viral replication capacity. Antimicrob Agents Chemother 2002; 46:3437-46. [PMID: 12384348 PMCID: PMC128721 DOI: 10.1128/aac.46.11.3437-3446.2002] [Citation(s) in RCA: 155] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) resistance mutations K65R and M184V result in changes in susceptibility to several nucleoside and nucleotide RT inhibitors. K65R-containing viruses showed decreases in susceptibility to tenofovir, didanosine (ddI), abacavir, and (-)-beta-D-dioxolane guanosine (DXG; the active metabolite of amdoxovir) but appeared to be fully susceptible to zidovudine and stavudine in vitro. Viruses containing the K65R and M184V mutations showed further decreases in susceptibility to ddI and abacavir but increased susceptibility to tenofovir compared to the susceptibilities of viruses with the K65R mutation. Enzymatic and viral replication analyses were undertaken to elucidate the mechanisms of altered drug susceptibilities and potential fitness defects for the K65R and K65R+M184V mutants. The relative inhibitory capacities (K(i)/K(m)) of the active metabolites of tenofovir, ddI, and DXG were increased for the RT containing the K65R mutation compared to that for the wild-type RT, but the relative inhibitory capacity of abacavir was only minimally increased. For the mutant viruses with the K65R and M184V mutations, the increase in tenofovir susceptibility compared to that of the mutants with K65R correlated with a decrease in the tenofovir inhibitory capacity that was mediated primarily by an increased K(m) of dATP. The decrease in susceptibility to ddI by mutants with the K65R and M184V mutations correlated with an increase in the inhibitory capacity mediated by an increased K(i). ATP-mediated removal of carbovir as well as small increases in the inhibitory capacity of carbovir appear to contribute to the resistance of mutants with the K65R mutation and the mutants with the K65R and M184V mutations to abacavir. Finally, both the HIV-1 K65R mutant and, more notably, the HIV-1 K65R+M184V double mutant showed reduced replication capacities and reduced RT processivities in vitro, consistent with a potential fitness defect in vivo and the low prevalence of the K65R mutation among isolates from antiretroviral agent-experienced patients.
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Affiliation(s)
- Kirsten L White
- Gilead Sciences, Foster City, California 94404. ViroLogic, Inc., South San Francisco, California 94080, USA
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19
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Clavel F, Race E, Mammano F. HIV drug resistance and viral fitness. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2001; 49:41-66. [PMID: 11013760 DOI: 10.1016/s1054-3589(00)49023-x] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Affiliation(s)
- F Clavel
- Laboratoire de Recherche Antivirale IMEA/INSERM Hôpital Bichat-Claude Bernard, Paris, France
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20
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Naeger LK, Margot NA, Miller MD. Increased Drug Susceptibility of HIV-1 Reverse Transcriptase Mutants Containing M184V and Zidovudine-Associated Mutations: Analysis of Enzyme Processivity, Chain-Terminator Removal and Viral Replication. Antivir Ther 2001. [DOI: 10.1177/135965350100600205] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The presence of the HIV reverse transcriptase (RT) resistance mutation, M184V, induced by lamivudine and abacavir treatment results in increased tenofovir, adefovir and zidovudine susceptibility for HIV-1 with zidovudine-associated RT mutations in vitro. Treatment with oral prodrugs of tenofovir and adefovir has resulted in substantial HIV-1 RNA reductions in antiretroviral-experienced patient populations who have lamivudine-and zidovudine-resistant HIV-1. An enzymatic analysis was undertaken to elucidate the mechanisms of altered drug susceptibilities of HIV-1 containing zidovudine-associated mutations in the presence or absence of M184V. The inhibition constants (Ki) for the active metabolites of tenofovir, adefovir and zidovudine did not vary significantly between recombinant mutant and wild-type RT enzymes. Although increased removal of chain-terminating inhibitors by pyrophosphorolysis and ATP-dependent unblocking correlated with reduced susceptibility of viruses with zidovudine-associated mutations, a reduction in the removal of chain-terminators was not observed, which would explain the increased drug susceptibility of mutants containing M184V plus zidovudine-associated mutations. However, analyses of single-cycle processivity of the mutant RT enzymes on heteropolymeric RNA templates showed that all M184V-containing mutant RT enzymes were less processive than wild-type RT, most notably for mutants expressing both zidovudine-associated mutations and M184V. Similarly, the in vitro replication capacity of a mutant virus expressing a zidovudine-associated mutation and M184V was significantly reduced compared with wild-type virus. The observed decrease in enzymatic processivity of the M184V-expressing RT enzymes might result in decreased viral replication, which then might contribute to the increased drug susceptibility of HIV-1 expressing these RT mutations.
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21
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Delaney WE, Locarnini S, Shaw T. Resistance of hepatitis B virus to antiviral drugs: current aspects and directions for future investigation. Antivir Chem Chemother 2001; 12:1-35. [PMID: 11437320 DOI: 10.1177/095632020101200101] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Despite the existence of vaccines, chronic hepatitis B virus (HBV) infection remains a major health problem worldwide. Interferon therapy successfully controls infection in only a small percentage of chronically infected individuals. The recent approval of the nucleoside analogue lamivudine for the treatment of chronic HBV infection has ushered in a new era of antiviral therapy. While lamivudine is highly effective at controlling viral infection short-term, prolonged therapy has been associated with an increasing incidence of viral resistance. Thus, it appears that lamivudine alone will not be sufficient to control chronic viral infection in the majority of individuals. In addition to lamivudine, several new nucleoside and nucleotide analogues that show promising antihepadnaviral activity are in various stages of development. Lamivudine resistance has been found to confer cross-resistance to some of these compounds and it is likely that resistance to newer antivirals may also develop during prolonged use. Drug resistance therefore poses a major threat to nucleoside analogue-based therapies for chronic HBV infection. Fortunately, combination chemotherapy (antiviral therapy with two or more agents) can minimize the chance that resistance will develop and can be expected to achieve sustained reductions in viral load, provided that suitable combinations of agents are chosen. Here we review the basis of drug resistance in HBV, with emphasis on aspects that are likely to affect drug choice in future.
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MESH Headings
- 2-Aminopurine/analogs & derivatives
- 2-Aminopurine/pharmacology
- 2-Aminopurine/therapeutic use
- Adenine/analogs & derivatives
- Adenine/pharmacology
- Adenine/therapeutic use
- Amino Acid Sequence
- Animals
- Anti-HIV Agents/pharmacology
- Antimetabolites/pharmacology
- Antimetabolites/therapeutic use
- Antiviral Agents/chemistry
- Antiviral Agents/pharmacokinetics
- Antiviral Agents/pharmacology
- Antiviral Agents/therapeutic use
- Biological Availability
- Cell Line
- Clinical Trials as Topic
- DNA Replication/drug effects
- DNA, Viral/biosynthesis
- DNA, Viral/genetics
- DNA-Directed DNA Polymerase/chemistry
- Drug Design
- Drug Evaluation, Preclinical
- Drug Resistance, Multiple/genetics
- Drug Resistance, Viral/genetics
- Drug Therapy, Combination
- Enzyme Inhibitors/pharmacology
- Famciclovir
- Gene Products, pol/antagonists & inhibitors
- Gene Products, pol/chemistry
- Gene Products, pol/genetics
- Gene Products, pol/physiology
- HIV/drug effects
- Hepatitis B/drug therapy
- Hepatitis B virus/drug effects
- Hepatitis B virus/genetics
- Hepatitis B virus/physiology
- Hepatitis Viruses/drug effects
- Hepatitis Viruses/genetics
- Hepatitis, Animal/drug therapy
- Hepatitis, Animal/virology
- Humans
- Lamivudine/pharmacology
- Lamivudine/therapeutic use
- Models, Animal
- Molecular Sequence Data
- Molecular Structure
- Nucleosides/pharmacology
- Nucleosides/therapeutic use
- Organophosphonates
- Sequence Alignment
- Sequence Homology, Amino Acid
- Species Specificity
- Virus Replication/drug effects
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Affiliation(s)
- W E Delaney
- Victorian Infectious Diseases Reference Laboratory, North Melbourne, Australia.
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22
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Wainberg MA, Miller MD, Quan Y, Salomon H, Mulato AS, Lamy PD, Margot NA, Anton KE, Cherrington JM. In vitro selection and characterization of HIV-1 with reduced susceptibility to PMPA. Antivir Ther 2000; 4:87-94. [PMID: 10682153 DOI: 10.1177/135965359900400205] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
9-(2-phosphonomethoxypropyl)adenine (PMPA) has demonstrated remarkable anti-simian immunodeficiency virus (SIV) activity in macaque models of SIV infection and transmission prevention. Recently, PMPA and its oral prodrug, bis-POC PMPA, have also shown potent anti-human immunodeficiency virus type 1 (HIV-1) activity in Phase I clinical studies. In vitro experiments were performed to address the resistance properties of PMPA. After eight passages in increasing concentrations of PMPA, HIV-1IIIB was able to grow in the presence of 2 microM PMPA, fivefold above the IC50 of PMPA for wild-type parental virus. Sequence analysis of the reverse transcriptase (RT) genes from four of 15 RT clones demonstrated the presence of a K65R substitution in RT and recombinant HIV expressing the K65R RT mutation showed a threefold to fourfold increase in IC50 value for PMPA as compared to wild-type. Additional experiments demonstrated that viruses expressing other nucleoside-associated RT resistance mutations all showed wild-type or < threefold reduced susceptibility to PMPA in vitro. Interestingly, lamivudine-resistant viruses expressing the M184V RT mutation showed wild-type to slightly increased susceptibility to PMPA in vitro and addition of the M184V mutation to HIV with the K65R mutation resulted in reversion to wild-type susceptibility for PMPA. In agreement with the cell culture findings, Escherichia coli-expressed K65R RT showed fivefold reduced susceptibility to PMPA diphosphate, the active moiety of PMPA. Furthermore, in combination experiments, PMPA with hydroxyurea showed synergistic inhibition of HIV replication in vitro. The potent antiretroviral activity and favourable resistance profile of PMPA and bis-POC PMPA are being further investigated in ongoing clinical trials.
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Affiliation(s)
- M A Wainberg
- McGill University AIDS Center, Jewish General Hospital, Montreal, Quebec, Canada
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Sparidans RW, Veldkamp A, Hoetelmans RM, Beijnen JH. Improved and simplified liquid chromatographic assay for adefovir, a novel antiviral drug, in human plasma using derivatization with chloroacetaldehyde. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 1999; 736:115-21. [PMID: 10676990 DOI: 10.1016/s0378-4347(99)00447-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
A rapid and simplified chromatographic assay is reported for the quantification of adefovir (PMEA) utilizing derivatization with chloroacetaldehyde. Adefovir is isolated from plasma using protein precipitation with trichloroacetic acid; next, the fluorescent 1,N6-etheno derivative is directly formed at 98 degrees C in the buffered extract with chloroacetaldehyde. This derivative is analyzed using isocratic ion-pair liquid chromatography and fluorescence detection at 254 nm for excitation and 425 nm for emission. In the evaluated concentration range (10-1000 ng/ml) precisions < or = 5% and accuracies between 95 and 117% were found, using a 0.2-ml volume of plasma. The lower limit of quantification is 10 ng/ml with a intra-assay precision of 16%. The currently reported bioanalytical method is 20-25-fold more sensitive than previously published assays.
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Affiliation(s)
- R W Sparidans
- Utrecht University, Faculty of Pharmacy, Department of Pharmaceutical Analysis, The Netherlands.
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Palmer S, Shafer RW, Merigan TC. Hydroxyurea enhances the activities of didanosine, 9-[2-(phosphonylmethoxy)ethyl]adenine, and 9-[2-(phosphonylmethoxy)propyl]adenine against drug-susceptible and drug-resistant human immunodeficiency virus isolates. Antimicrob Agents Chemother 1999; 43:2046-50. [PMID: 10428934 PMCID: PMC89412 DOI: 10.1128/aac.43.8.2046] [Citation(s) in RCA: 27] [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
We assessed the effects of hydroxyurea (HU) at a concentration of 50 microM on the in vitro activities of 2',3'-dideoxyinosine (ddI), 9-[2-(phosphonylmethoxy)ethyl]adenine (PMEA), and 9-[2-(phosphonylmethoxy)propyl]adenine (PMPA) against a wild-type human immunodeficiency virus (HIV) type 1 (HIV-1) laboratory isolate and a panel of five well-characterized drug-resistant HIV isolates. Fifty micromolar HU significantly increased the activities of ddI, PMEA, and PMPA against both the wild-type and the drug-resistant HIV-1 isolates. In fixed combinations, both ddI and PMEA were synergistic with HU against wild-type and drug-resistant viruses.
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Affiliation(s)
- S Palmer
- Center for AIDS Research at Stanford, Stanford University Medical Center, Stanford, California 94305-5107, USA.
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