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Enhanced antiretroviral therapy in rhesus macaques improves RT-SHIV viral decay kinetics. Antimicrob Agents Chemother 2014; 58:3927-33. [PMID: 24777106 DOI: 10.1128/aac.02522-14] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Using an established nonhuman primate model, rhesus macaques were infected intravenously with a chimeric simian immunodeficiency virus (SIV) consisting of SIVmac239 with the human immunodeficiency virus type 1 (HIV-1) reverse transcriptase from clone HXBc2 (RT-SHIV). The impacts of two enhanced (four- and five-drug) highly active antiretroviral therapies (HAART) on early viral decay and rebound were determined. The four-drug combination consisted of an integrase inhibitor, L-870-812 (L-812), together with a three-drug regimen comprising emtricitabine [(-)-FTC], tenofovir (TFV), and efavirenz (EFV). The five-drug combination consisted of one analog for each of the four DNA precursors {using TFV, (-)-FTC, (-)-β-D-(2R,4R)-1,3-dioxolane-2,6-diaminopurine (amdoxovir [DAPD]), and zidovudine (AZT)}, together with EFV. A cohort treated with a three-drug combination of (-)-FTC, TFV, and EFV served as treated controls. Daily administration of a three-, four-, or five-drug combination of antiretroviral agents was initiated at week 6 or 8 after inoculation and continued up to week 50, followed by a rebound period. Plasma samples were collected routinely, and drug levels were monitored using liquid chromatography-tandem mass spectrometry (LC-MS-MS). Viral loads were monitored with a standard TaqMan quantitative reverse transcriptase PCR (qRT-PCR) assay. Comprehensive analyses of replication dynamics were performed. RT-SHIV infection in rhesus macaques produced typical viral infection kinetics, with untreated controls establishing persistent viral loads of >10(4) copies of RNA/ml. RT-SHIV loads at the start of treatment (V0) were similar in all treated cohorts (P > 0.5). All antiretroviral drug levels were measureable in plasma. The four-drug and five-drug combination regimens (enhanced HAART) improved suppression of the viral load (within 1 week; P < 0.01) and had overall greater potency (P < 0.02) than the three-drug regimen (HAART). Moreover, rebound viremia occurred rapidly following cessation of any treatment. The enhanced HAART (four- or five-drug combination) showed significant improvement in viral suppression compared to the three-drug combination, but no combination was sufficient to eliminate viral reservoirs.
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Gorantla S, Gendelman HE, Poluektova LY. Can humanized mice reflect the complex pathobiology of HIV-associated neurocognitive disorders? J Neuroimmune Pharmacol 2012; 7:352-62. [PMID: 22222956 PMCID: PMC3782112 DOI: 10.1007/s11481-011-9335-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Accepted: 12/14/2011] [Indexed: 01/22/2023]
Abstract
There is a rebirth of humanized mouse models in reflecting human immunodeficiency virus (HIV) pathobiology. This has allowed new investigations of viral diversity, immunity and developmental therapeutics. In the past, HIV infection and disease were, in part, mirrored in immune deficient mice reconstituted with human hematopoietic stem cells. What remained from early studies reflected the ability to mirror central nervous system (CNS) disease. As the wide spread use of combination antiretroviral therapies has changed the severity, but not prevalence, of HIV-associated neurocognitive disorders (HAND), mimicking such virus-induced CNS morbidities in humanized animals is essential for HIV/AIDS research activities. To this end, we now review the evidence for how and under what circumstances humanized mice may be utilized for studies of HIV-1 neuropathogenesis.
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Affiliation(s)
- Santhi Gorantla
- Department of Pharmacology and Experimental Neuroscience and Center for Neurodegenerative Disorders, University of Nebraska Medical Center, Omaha, NE, USA
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Horiike M, Iwami S, Kodama M, Sato A, Watanabe Y, Yasui M, Ishida Y, Kobayashi T, Miura T, Igarashi T. Lymph nodes harbor viral reservoirs that cause rebound of plasma viremia in SIV-infected macaques upon cessation of combined antiretroviral therapy. Virology 2011; 423:107-18. [PMID: 22196013 DOI: 10.1016/j.virol.2011.11.024] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2011] [Revised: 11/06/2011] [Accepted: 11/29/2011] [Indexed: 12/16/2022]
Abstract
Attempts to find a cure for HIV infection are hindered by the presence of viral reservoirs that resist highly active antiretroviral therapy. To identify the properties of these reservoirs, four SIV239-infected Rhesus macaques were treated with combined antiretroviral therapy (cART) for 1 year. While plasma viral RNA (vRNA) was effectively suppressed, a systemic analysis revealed that vRNA was distributed in the following order: lymphatic tissues>lungs and intestine>other tissues. Histochemistry yielded no cells with viral signals. To increase the chance of detection, two additional SIV-infected animals were treated and analyzed on Day 10 after the cessation of cART. These animals exhibited similar vRNA distribution patterns to the former animals, and immunohistochemistry revealed Nef-positive T lymphocytes predominantly in the follicles of mesenteric lymph nodes (MLNs). These data suggest that lymphatic tissues, including MLNs, contain major cellular reservoirs that cause rebound of plasma viremia upon cessation of therapy.
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Affiliation(s)
- Mariko Horiike
- Laboratory of Primate Model, Experimental Research Center for Infectious Diseases, Institute for Virus Research, Kyoto University, Kyoto 606-8507, Japan
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Abstract
PURPOSE OF REVIEW This review will focus on recent developments in several nonhuman primate models of AIDS. These models are being used to address viral latency and persistence during antiretroviral therapy in studies that are not feasible in humans. RECENT FINDINGS Further characterization of the various macaque models of AIDS has demonstrated that several aspects of viral persistence during antiretroviral therapy model HIV-1 infection in humans, including viral decay kinetics. Widespread distribution of viral RNA and viral DNA has been detected in many tissue organs. In addition, the brain has been identified as a site of persistent viral DNA. SUMMARY The macaque models of AIDS are well suited for addressing viral persistence during antiretroviral therapy, including viral latency, residual replication, and tissue organ distribution.
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Nagai-Fukataki M, Ohashi T, Hashimoto I, Kimura T, Hakata Y, Shida H. Nuclear and cytoplasmic effects of human CRM1 on HIV-1 production in rat cells. Genes Cells 2011; 16:203-16. [PMID: 21251165 DOI: 10.1111/j.1365-2443.2010.01476.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The human immunodeficiency virus type 1 (HIV-1) regulatory protein, Rev, mediates the nuclear export of unspliced gag and singly spliced env mRNAs by bridging viral RNA and the export receptor, CRM1. Recently, rat CRM1 was found to be less efficient than human CRM1 in supporting Rev function in rats. In this study, to understand the role of CRM1 in HIV propagation, the mechanism underlying the function of human and rat CRM1 in HIV-1 replication was investigated in rat cells. The production of viral particles, represented by the p24 Gag protein, was greatly enhanced by hCRM1 expression in rat cells; however, this effect was not simply because of the enhanced export of gag mRNA. The translation initiation rate of gag mRNA was not increased, nor was the Gag protein stabilized in the presence of hCRM1. However, the processing of the p55 Gag precursor and the release of viral particles were facilitated. These results indicated that hCRM1 exports gag mRNA to the cytoplasm, not only more efficiently than rCRM1 but also correctly, leading to efficient processing of Gag proteins and particle formation.
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Affiliation(s)
- Mika Nagai-Fukataki
- Institute for Genetic Medicine, Hokkaido University, Kita-ku, Sapporo 060-0815, Japan
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Deere JD, Higgins J, Cannavo E, Villalobos A, Adamson L, Fromentin E, Schinazi RF, Luciw PA, North TW. Viral decay kinetics in the highly active antiretroviral therapy-treated rhesus macaque model of AIDS. PLoS One 2010; 5:e11640. [PMID: 20668516 PMCID: PMC2909142 DOI: 10.1371/journal.pone.0011640] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2010] [Accepted: 06/28/2010] [Indexed: 11/18/2022] Open
Abstract
To prevent progression to AIDS, persons infected with human immunodeficiency virus type 1 (HIV-1) must remain on highly active antiretroviral therapy (HAART) indefinitely since this modality does not eradicate the virus. The mechanisms involved in viral persistence during HAART are poorly understood, but an animal model of HAART could help elucidate these mechanisms and enable studies of HIV-1 eradication strategies. Due to the specificity of non-nucleoside reverse transcriptase (RT) inhibitors (NNRTIs) for HIV-1, we have used RT-SHIV, a chimeric virus of simian immunodeficiency virus with RT from HIV-1. This virus is susceptible to NNRTIs and causes an AIDS-like disease in rhesus macaques. In this study, two groups of HAART-treated, RT-SHIV-infected macaques were analyzed to determine viral decay kinetics. In the first group, viral loads were monitored with a standard TaqMan RT-PCR assay with a limit of detection of 50 viral RNA copies per mL. Upon initiation of HAART, viremia decayed in a bi-phasic manner with half-lives of 1.7 and 8.5 days, respectively. A third phase was observed with little further decay. In the second group, the macaques were followed longitudinally with a more sensitive assay utilizing ultracentrifugation to concentrate virus from plasma. Bi-phasic decay of viral RNA was also observed in these animals with half-lives of 1.8 and 5.8 days. Viral loads in these animals during a third phase ranged from 2-58 RNA copies/mL, with little decay over time. The viral decay kinetics observed in these macaques are similar to those reported for HIV-1 infected humans. These results demonstrate that low-level viremia persists in RT-SHIV-infected macaques despite a HAART regimen commonly used in humans.
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Affiliation(s)
- Jesse D. Deere
- Center for Comparative Medicine, University of California Davis, Davis, California, United States of America
| | - Joanne Higgins
- Center for Comparative Medicine, University of California Davis, Davis, California, United States of America
| | - Elda Cannavo
- Center for Comparative Medicine, University of California Davis, Davis, California, United States of America
| | - Andradi Villalobos
- Center for Comparative Medicine, University of California Davis, Davis, California, United States of America
| | - Lourdes Adamson
- Center for Comparative Medicine, University of California Davis, Davis, California, United States of America
| | - Emilie Fromentin
- Center for AIDS Research, Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Veterans Affairs Medical Center, Decatur, Georgia, United States of America
| | - Raymond F. Schinazi
- Center for AIDS Research, Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Veterans Affairs Medical Center, Decatur, Georgia, United States of America
| | - Paul A. Luciw
- Center for Comparative Medicine, University of California Davis, Davis, California, United States of America
- Department of Pathology, School of Medicine, University of California Davis, Davis, California, United States of America
| | - Thomas W. North
- Center for Comparative Medicine, University of California Davis, Davis, California, United States of America
- Department of Veterinary Molecular Biosciences, University of California Davis, Davis, California, United States of America
- * E-mail:
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Van Rompay KKA. Evaluation of antiretrovirals in animal models of HIV infection. Antiviral Res 2009; 85:159-75. [PMID: 19622373 DOI: 10.1016/j.antiviral.2009.07.008] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2009] [Revised: 07/07/2009] [Accepted: 07/13/2009] [Indexed: 01/07/2023]
Abstract
Animal models of HIV infection have played an important role in the development of antiretroviral drugs. Although each animal model has its limitations and never completely mimics HIV infection of humans, a carefully designed study allows experimental approaches that are not feasible in humans, but that can help to better understand disease pathogenesis and to provide proof-of-concept of novel intervention strategies. While rodent and feline models are useful for initial screening, further testing is best done in non-human primate models, such as simian immunodeficiency virus (SIV) infection of macaques, because they share more similarities with HIV infection of humans. In the early years of the HIV pandemic, non-human primate models played a relatively minor role in the antiretroviral drug development process. Since then, a better understanding of the disease and the development of better drugs and assays to monitor antiviral efficacy have increased the usefulness of the animal models. In particular, non-human primate models have provided proof-of-concept for (i) the benefits of chemoprophylaxis and early treatment, (ii) the preclinical efficacy of novel drugs such as tenofovir, (iii) the virulence and clinical significance of drug-resistant viral mutants, and (iv) the role of antiviral immune responses during drug therapy. Ongoing comparison of results obtained in animal models with those observed in human studies will further validate and improve these animal models so they can continue to help advance our scientific knowledge and to guide clinical trials. This article forms part of a special issue of Antiviral Research marking the 25th anniversary of antiretroviral drug discovery and development, Vol 85, issue 1, 2010.
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Affiliation(s)
- Koen K A Van Rompay
- California National Primate Research Center, University of California, Davis, CA 95616, USA.
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Okada H, Zhang X, Ben Fofana I, Nagai M, Suzuki H, Ohashi T, Shida H. Synergistic effect of human CycT1 and CRM1 on HIV-1 propagation in rat T cells and macrophages. Retrovirology 2009; 6:43. [PMID: 19435492 PMCID: PMC2693497 DOI: 10.1186/1742-4690-6-43] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2008] [Accepted: 05/12/2009] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND In vivo studies of HIV-1 pathogenesis and testing of antiviral strategies have been hampered by the lack of an immunocompetent small animal model that is highly susceptible to HIV-1 infection. Although transgenic rats that express the HIV-1 receptor complex hCD4 and hCCR5 are susceptible to infection, HIV-1 replicates very poorly in these animals. To demonstrate the molecular basis for developing a better rat model for HIV-1 infection, we evaluated the effect of human CyclinT1 (hCycT1) and CRM1 (hCRM1) on Gag p24 production in rat T cells and macrophages using both established cell lines and primary cells prepared from hCycT1/hCRM1 transgenic rats. RESULTS Expression of hCycT1 augmented Gag production 20-50 fold in rat T cells, but had little effect in macrophages. Expression of hCRM1 enhanced Gag production 10-15 fold in macrophages, but only marginally in T cells. Expression of both factors synergistically enhanced p24 production to levels approximately 10-40% of those detected in human cells. R5 viruses produced in rat T cells and macrophages were fully infectious. CONCLUSION The expression of both hCycT1 and hCRM1 appears to be fundamental to developing a rat model that supports robust propagation of HIV-1.
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Affiliation(s)
- Hiroyuki Okada
- Institute for Genetic Medicine, Hokkaido University, Kita-ku, Sapporo 060-0815, Japan
| | - Xianfeng Zhang
- Institute for Genetic Medicine, Hokkaido University, Kita-ku, Sapporo 060-0815, Japan
| | - Ismael Ben Fofana
- Institute for Genetic Medicine, Hokkaido University, Kita-ku, Sapporo 060-0815, Japan
- Microbiology Division, New England Primate Research Center, Harvard Medical School, One Pine Hill Drive, Southborough, Maryland 01772, USA
| | - Mika Nagai
- Institute for Genetic Medicine, Hokkaido University, Kita-ku, Sapporo 060-0815, Japan
| | - Hajime Suzuki
- Institute for Genetic Medicine, Hokkaido University, Kita-ku, Sapporo 060-0815, Japan
| | - Takashi Ohashi
- Institute for Genetic Medicine, Hokkaido University, Kita-ku, Sapporo 060-0815, Japan
| | - Hisatoshi Shida
- Institute for Genetic Medicine, Hokkaido University, Kita-ku, Sapporo 060-0815, Japan
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9
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Abstract
The mechanisms underlying the lack of disease progression in natural simian immunodeficiency virus (SIV) hosts are still poorly understood. To test the hypothesis that SIV-infected African green monkeys (AGMs) avoid AIDS due to virus replication occurring in long-lived infected cells, we infected six animals with SIVagm and treated them with potent antiretroviral therapy [ART; 9-R-(2-phosphonomethoxypropyl) adenine (tenofovir) and beta-2,3-dideoxy-3-thia-5-fluorocytidine (emtricitabine)]. All AGMs showed a rapid decay of plasma viremia that became undetectable 36 h after ART initiation. A significant decrease of viral load was observed in peripheral blood mononuclear cells and intestine. Mathematical modeling of viremia decay post-ART indicates a half-life of productively infected cells ranging from 4 to 9.5 h, i.e., faster than previously reported for human immunodeficiency virus and SIV. ART induced a slight but significant increase in peripheral CD4(+) T-cell counts but no significant changes in CD4(+) T-cell levels in lymph nodes and intestine. Similarly, ART did not significantly change the levels of cell proliferation, activation, and apoptosis, already low in AGMs chronically infected with SIVagm. Collectively, these results indicate that, in SIVagm-infected AGMs, the bulk of virus replication is sustained by short-lived cells; therefore, differences in disease outcome between SIVmac infection of macaques and SIVagm infection of AGMs are unlikely due to intrinsic differences in the in vivo cytopathicities between the two viruses.
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Duong YT, Meadows DC, Srivastava IK, Gervay-Hague J, North TW. Direct inactivation of human immunodeficiency virus type 1 by a novel small-molecule entry inhibitor, DCM205. Antimicrob Agents Chemother 2007; 51:1780-6. [PMID: 17307982 PMCID: PMC1855571 DOI: 10.1128/aac.01001-06] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
With more than 40 million people living with human immunodeficiency virus (HIV), there is an urgent need to develop drugs that can be used in the form of a topical microbicide to prevent infection through sexual transmission. DCM205 is a recently discovered small-molecule inhibitor of HIV type 1 (HIV-1) that is able to directly inactivate HIV-1 in the absence of a cellular target. DCM205 is active against CXCR4-, CCR5-, and dual-tropic laboratory-adapted and primary strains of HIV-1. DCM205 binds to the HIV-1 envelope glycoprotein, and competition studies map the DCM205 binding at or near the V3 loop of gp120. Binding to this site interferes with the soluble CD4 interaction. With its ability to disable the virus particle, DCM205 represents a promising new class of HIV entry inhibitor that can be used as a strategy in the prevention of HIV-1/AIDS.
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Affiliation(s)
- Yen T Duong
- Center for Comparative Medicine, University of California, Davis, Davis, CA 95616, USA
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Goffinet C, Allespach I, Keppler OT. HIV-susceptible transgenic rats allow rapid preclinical testing of antiviral compounds targeting virus entry or reverse transcription. Proc Natl Acad Sci U S A 2007; 104:1015-20. [PMID: 17209012 PMCID: PMC1783356 DOI: 10.1073/pnas.0607414104] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The current testing of anti-HIV drugs is hampered by the lack of a small animal that is readily available and easy to handle; can be infected systemically with HIV type 1 (HIV-1); harbors the major HIV-1 target cells in a physiological frequency, organ distribution, and activation state; and is established as a pharmacological model. Here, we explored the potential of outbred Sprague-Dawley rats that transgenically express the HIV-1 receptor complex on CD4 T cells and macrophages as a model for the preclinical evaluation of inhibitors targeting virus entry or reverse transcription. The concentrations of the peptidic fusion inhibitor enfuvirtide or the nonnucleoside reverse transcriptase inhibitor efavirenz required to inhibit HIV-1 infection of cultured primary CD4 T cells and macrophages from human CD4 and CCR5-transgenic rats differed by no more than 3-fold from those required for human reference cultures. Prophylactic treatment of double-transgenic rats with a weight-adapted pediatric dosing regimen for either enfuvirtide (s.c., twice-daily) or efavirenz (oral, once-daily) achieved a 92.5% or 98.8% reduction, respectively, of the HIV-1 cDNA load in the spleen 4 days after i.v. HIV-1 challenge. Notably, a once-daily dosing regimen for enfuvirtide resulted in a approximately 5-fold weaker inhibition of infection, unmasking the unfavorable pharmacokinetic characteristics of the synthetic peptide in the context of an efficacy trial. This work provides proof of principle that HIV-susceptible transgenic rats can allow a rapid and predictive preclinical evaluation of the inhibitory potency and of the pharmacokinetic properties of antiviral compounds targeting early steps in the HIV replication cycle.
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Affiliation(s)
- Christine Goffinet
- Department of Virology, University of Heidelberg, 69120 Heidelberg, Germany
| | - Ina Allespach
- Department of Virology, University of Heidelberg, 69120 Heidelberg, Germany
| | - Oliver T. Keppler
- Department of Virology, University of Heidelberg, 69120 Heidelberg, Germany
- *To whom correspondence should be addressed. E-mail:
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Meadows DC, Sanchez T, Neamati N, North TW, Gervay-Hague J. Ring substituent effects on biological activity of vinyl sulfones as inhibitors of HIV-1. Bioorg Med Chem 2006; 15:1127-37. [PMID: 17074494 PMCID: PMC1994090 DOI: 10.1016/j.bmc.2006.10.017] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2006] [Revised: 10/04/2006] [Accepted: 10/11/2006] [Indexed: 01/08/2023]
Abstract
In a previous study, we prepared a small library of chicoric acid analogs that possessed both potent anti-integrase and antiviral activity. It was also shown that active compounds fell into one of two groups: those that inhibited an early stage in viral replication and those that inhibited at a later stage. In this study, a series of vinyl geminal disulfone-containing compounds possessing a range of ring substituents has been synthesized to probe the impact of structure on inhibitory mechanisms. Four active compounds were identified using HIV drug susceptibility assays. Three of the inhibitors possessing either no substituents or electron-withdrawing substituents on the aromatic rings led to high levels of cytotoxicity and antiviral activity. Intrigued by the potential implications of electronic effects on activity, we probed whether the active compounds could be nonspecifically reacting via 1,4-addition. To investigate this hypothesis, the compounds were incubated with glutathione and upon LC/MS analysis, molecular ion peaks corresponding to both mono and double addition adducts were identified. Second, we synthesized analogs lacking the ability to participate in 1,4-addition and tested them for antiviral activity and cytotoxicity, and found the compounds inactive for both activities. Taken together, the studies reported herein suggest that compounds lacking electron-donating substituents on the aromatic ring are promiscuous acceptors of biological nucleophiles, whereas compounds possessing electron-donating substituents seem to resist addition or at least be more selective and significantly less toxic.
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Affiliation(s)
- D. Christopher Meadows
- Department of Chemistry, University of California, Davis, One Shields Ave., Davis, CA 95616, USA
- Center for Comparative Medicine and Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, Davis, CA 95616, USA
| | - Tino Sanchez
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Southern California, 1985 Zonal Ave., Los Angeles, CA 90089, USA
| | - Nouri Neamati
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Southern California, 1985 Zonal Ave., Los Angeles, CA 90089, USA
| | - Thomas W. North
- Center for Comparative Medicine and Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, Davis, CA 95616, USA
| | - Jacquelyn Gervay-Hague
- Department of Chemistry, University of California, Davis, One Shields Ave., Davis, CA 95616, USA
- * Corresponding author. Tel.: +530 754 9577; fax: +530 752 8995; e-mail:
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Meadows DC, Mathews TB, North TW, Hadd MJ, Kuo CL, Neamati N, Gervay-Hague J. Synthesis and biological evaluation of geminal disulfones as HIV-1 integrase inhibitors. J Med Chem 2005; 48:4526-34. [PMID: 15999991 DOI: 10.1021/jm049171v] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Integration of HIV-1 viral DNA into the host genome is carried out by HIV-integrase (IN) and is a critical step in viral replication. Although several classes of compounds have been reported to inhibit IN in enzymatic assays, inhibition is not always correlated with antiviral activity. Moreover, potent antiviral IN inhibitors such as the chicoric acids do not act upon the intended enzymatic target but behave as entry inhibitors instead. The charged nature of the chicoric acids contributes to poor cellular uptake, and these compounds are further plagued by rapid ester hydrolysis in vivo. To address these critical deficiencies, we designed neutral, nonhydrolyzable analogues of the chicoric acids. Herein, we report the synthesis, enzyme inhibition studies, and cellular antiviral data for a series of geminal disulfones. Of the 10 compounds evaluated, 8 showed moderate to high inhibition of IN in purified enzyme assays. The purified enzyme data correlated with antiviral assays for all but two compounds, suggesting alternative modes of inhibition. Time-of-addition studies were performed on these analogues, and the results indicate that they inhibit an early stage in the replication process, perhaps entry. In contrast, the most potent member of the correlative group shows behavior consistent with IN being the cellular target.
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Joshi PJ, North TW, Prasad VR. Aptamers directed to HIV-1 reverse transcriptase display greater efficacy over small hairpin RNAs targeted to viral RNA in blocking HIV-1 replication. Mol Ther 2005; 11:677-86. [PMID: 15851006 DOI: 10.1016/j.ymthe.2005.01.013] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2004] [Accepted: 01/14/2005] [Indexed: 10/25/2022] Open
Abstract
RNA molecules can be powerful inhibitors of HIV-1 replication. To determine the relative efficacy of siRNAs and RNA aptamers, a direct comparison of three anti-HIV reverse transcriptase aptamers and three shRNAs targeted to HIV-1(R3b) was made. U6 promoter-driven anti-HIV genes were delivered into CEMx174 cells via a retroviral vector, and transduced cells were sorted out via green fluorescent protein function and challenged with HIV. The results show that, at low virus input, shRNAs can block HIV as efficiently as aptamers. When expressed in target cells, both classes of inhibitors blocked early events of reverse transcription, suggesting they are both able to access intracellular reverse transcription complexes. However, at higher multiplicities of infection (m.o.i. of 50), while the aptamers could efficiently inhibit HIV replication, shRNAs did not. RNase protection assays indicated similar steady-state levels or nucleocytoplasmic distribution showing that the differential efficacy was not a reflection of intracellular concentration. The higher potency of anti-RT aptamers could be due to their ability to inhibit two successive rounds of reverse transcription owing to their unique ability to be encapsidated into virion particles. Furthermore, anti-RT aptamers expressed in T cells afforded protection against high-dose infection by chimeric RT-SHIV viruses.
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Affiliation(s)
- Pheroze J Joshi
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, GB401, Bronx, NY 10461, USA
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15
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North TW, Van Rompay KKA, Higgins J, Matthews TB, Wadford DA, Pedersen NC, Schinazi RF. Suppression of virus load by highly active antiretroviral therapy in rhesus macaques infected with a recombinant simian immunodeficiency virus containing reverse transcriptase from human immunodeficiency virus type 1. J Virol 2005; 79:7349-54. [PMID: 15919889 PMCID: PMC1143671 DOI: 10.1128/jvi.79.12.7349-7354.2005] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We have modeled highly active antiretroviral therapy (HAART) for AIDS in rhesus macaques infected with a chimera (RT-SHIV) of simian immunodeficiency virus containing reverse transcriptase from human immunodeficiency virus type-1 (HIV-1). Seven RT-SHIV-infected macaques were treated with a combination of efavirenz (200 mg orally once daily), lamivudine (8 mg/kg subcutaneously once daily), and tenofovir (30 mg/kg subcutaneously once daily). Plasma viral RNA levels in all animals were reduced by more than 1,000-fold after 4 weeks and, in six of the seven animals, were reduced to undetectable levels after 10 weeks. Virus loads increased slightly between 12 and 16 weeks of treatment, associated with problems with the administration of efavirenz. After a change in the method of efavirenz administration, virus loads declined again and remained undetectable in the majority of animals for the duration of therapy. Treatment was stopped for three animals after 36 weeks of therapy, and virus loads increased rapidly. Posttreatment RT-SHIV isolates had no mutations associated with resistance to any of the three drugs. Efavirenz treatment was stopped, but lamivudine and tenofovir treatment for two other macaques was continued. The virus load in one of these two animals rebounded; virus from this animal was initially free of drug-resistance mutations but acquired the K65R mutation in reverse transcriptase at 11 weeks after efavirenz treatment was withdrawn. These results mimic HAART of HIV-1-infected humans. The RT-SHIV/rhesus macaque model should be useful for studies of tissue reservoirs and sites of residual replication that are not possible or practical with humans.
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Affiliation(s)
- Thomas W North
- Center for Comparative Medicine, University of California, Davis, CA 95616, USA.
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Hofman MJ, Higgins J, Matthews TB, Pedersen NC, Tan C, Schinazi RF, North TW. Efavirenz therapy in rhesus macaques infected with a chimera of simian immunodeficiency virus containing reverse transcriptase from human immunodeficiency virus type 1. Antimicrob Agents Chemother 2004; 48:3483-90. [PMID: 15328115 PMCID: PMC514752 DOI: 10.1128/aac.48.9.3483-3490.2004] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The specificity of nonnucleoside reverse transcriptase (RT) inhibitors (NNRTIs) for the RT of human immunodeficiency virus type 1 (HIV-1) has prevented the use of simian immunodeficiency virus (SIV) in the study of NNRTIs and NNRTI-based highly active antiretroviral therapy. However, a SIV-HIV-1 chimera (RT-SHIV), in which the RT from SIVmac239 was replaced with the RT-encoding region from HIV-1, is susceptible to NNRTIs and is infectious to rhesus macaques. We have evaluated the antiviral activity of efavirenz against RT-SHIV and the emergence of efavirenz-resistant mutants in vitro and in vivo. RT-SHIV was susceptible to efavirenz with a mean effective concentration of 5.9 +/- 4.5 nM, and RT-SHIV variants selected with efavirenz in cell culture displayed 600-fold-reduced susceptibility. The efavirenz-resistant mutants of RT-SHIV had mutations in RT similar to those of HIV-1 variants that were selected under similar conditions. Efavirenz monotherapy of RT-SHIV-infected macaques produced a 1.82-log-unit decrease in plasma viral-RNA levels after 1 week. The virus load rebounded within 3 weeks in one treated animal and more slowly in a second animal. Virus isolated from these two animals contained the K103N and Y188C or Y188L mutations. The RT-SHIV-rhesus macaque model may prove useful for studies of antiretroviral drug combinations that include efavirenz.
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Affiliation(s)
- Michael J Hofman
- Center for Comparative Medicine, University of California, Davis, CA 95616, USA
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Witvrouw M, Pannecouque C, Switzer WM, Folks TM, Clercq ED, Heneine W. Susceptibility of HIV-2, Siv and Shiv to Various Anti-HIV-1 Compounds: Implications for Treatment and Postexposure Prophylaxis. Antivir Ther 2004. [DOI: 10.1177/135965350400900115] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Limited information is available on the activity of anti-retroviral drugs against human immunodeficiency virus type 2 (HIV-2) and simian immunodeficiency virus (SIV) strains to guide their use in treatment or prophylaxis. We evaluated the antiviral activity of 16 approved drugs and one experimental drug, AMD3100, against two wild-type HIV-2 (ROD and EHO) isolates, two strains of SIV (mac251 and B670), and two strains of simian–human immunodeficiency virus (SHIV) that contain the reverse transcriptase (RTSHIV) or envelope glycoprotein (SHIV89.6) of human immunodeficiency virus type 1 (HIV-1) in a SIV(mac239) background. Drug susceptibility was measured conventionally by the MT-4/MTT assay, and results were analysed as fold changes in 50% effective concentration (EC50) relative to the EC50 for HIV-1(IIIB). The nucleoside reverse transcriptase inhibitors (NRTIs) zidovudine, lamivudine, stavudine, didanosine, zalcitabine and abacavir as well as the nucleotide reverse transcriptase inhibitor tenofovir retained full activity against all six viruses except for SIV and SHIV89.6 that showed low-level resistance to didanosine. The protease inhibitors (PIs) ritonavir, indinavir, saquinavir and nelfinavir were found to be active against some HIV-2 or SIV strains. However, a significant reduction in susceptibility was seen with indinavir against SHIV89.6 (3.3-fold), and with amprenavir against HIV-2(ROD) (8.8-fold). All viruses except for RTSHIV showed a >200-fold decrease in susceptibility for the non-nucleoside reverse transcriptase inhibitors (NNRTIs) nevirapine, delavirdine and efavirenz, indicating high-level resistance. AMD3100, a CXCR4 antagonist, was active against HIV-2 and SHIV89.6, a finding consistent with the use of the CXCR4 co-receptor by these isolates, but was inactive against SIV strains. In contrast, enfuvirtide (T-20) was active against SHIV89.6 but had reduced inhibitory activity against both HIV-2 and SIV strains predicting little therapeutic value against these viruses. These findings support the use of NRTIs, tenofovir, but not NNRTIs, for treating HIV-2-infected persons or for prophylaxis against HIV-2 and SIV. The clinical significance of the low-level resistance of HIV-2 and SIV to some PIs is unclear. Co-receptor antagonists such as AMD3100 show promising anti-HIV-2 therapeutic modalities. Both AMD3100 and enfuvirtide could be used for prophylaxis against SHIV89.6.
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Affiliation(s)
- Myriam Witvrouw
- Rega Institute for Medical Research, Katholieke Universiteit Leuven, Leuven, Belgium
| | | | - William M Switzer
- HIV and Retrovirology Branch, Division of AIDS, STD, and TB Laboratory Research, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Ga., USA
| | - Thomas M Folks
- HIV and Retrovirology Branch, Division of AIDS, STD, and TB Laboratory Research, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Ga., USA
| | - Erik De Clercq
- Rega Institute for Medical Research, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Walid Heneine
- HIV and Retrovirology Branch, Division of AIDS, STD, and TB Laboratory Research, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Ga., USA
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Abstract
Patients infected with HIV-1 of subtype other than B (‘non-subtype B’) or with HIV-2 are being treated with antiretroviral drugs in increasing numbers. In addition, healthcare providers and laboratory workers working with clinical specimens or animals infected with HIV, SIV or SHIV are at risk of being exposed to the virus and might require post-exposure prophylactic treatment. Thus, it is important to understand the inherent antiviral susceptibility of non-subtype B HIV-1, HIV-2 and SIV to currently available antiretroviral drugs, which have been developed with subtype B HIV-1-infected patients as the primary target population. In addition, knowledge about the consequences of treatment failure in non-subtype B HIV-1- and HIV-2-infected patients, with respect to the development of drug resistance, is crucial for designing optimal treatment strategies. This review summarizes the current state of knowledge in these areas. Non-subtype B group M HIV-1 appears to be susceptible to available agents, but follows several unique pathways to resistance to some drugs that have important clinical implications. Group O HIV-1 is naturally resistant to the non-nucleoside reverse transcriptase inhibitors (NNRTIs). HIV-2 and SIVsm are also naturally resistant to the NNRTIs as well as the protease inhibitor amprenavir. More research into the clinical responses to existing drugs and interpretation of genotypic information is needed, as well as development of diagnostic assays specific for non-subtype B HIV-1 and HIV-2.
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Affiliation(s)
| | - Jonathan M Schapiro
- National Hemophilia Center, Sheba Medical Center, Tel Aviv, Israel, and Stanford University, Calif., USA
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Kinman L, Brodie SJ, Tsai CC, Bui T, Larsen K, Schmidt A, Anderson D, Morton WR, Hu SL, Ho RJY. Lipid–Drug Association Enhanced HIV-1 Protease Inhibitor Indinavir Localization in Lymphoid Tissues and Viral Load Reduction: A Proof of Concept Study in HIV-2287-Infected Macaques. J Acquir Immune Defic Syndr 2003; 34:387-97. [PMID: 14615656 DOI: 10.1097/00126334-200312010-00005] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Analysis of indinavir levels in HIV-positive patients indicated that drug concentrations in lymph node mononuclear cells (LNMCs) were about 25-35% of mononuclear cells in blood. To enhance lymphatic delivery of anti-HIV drugs, a novel drug delivery strategy was designed consisting of lipid-associated indinavir (50-80 nm in diameter) complexes in suspension for subcutaneous (SC) injection. Due to the pH-dependent lipophilicity of indinavir, practically all the drug molecules are incorporated into lipid phase when formulated at pH 7.4 and 5:1 lipid-to-drug (m/m) ratio. At pH 5.5, about 20% of drugs were found in lipid-drug complexes. Effects of lipid association on the time course of plasma indinavir concentrations were determined in macaques (Macaca nemestrina) administered with either soluble or lipid-associated formulation of indinavir (10 mg/kg, SC). Results yielded about a 10-fold reduction in peak plasma concentration and a 6-fold enhancement in terminal half-life (t1/2beta = 12 vs. 2 hours). In addition, indinavir concentrations in both peripheral and visceral lymph nodes were 250-2270% higher than plasma (compared with <35% with soluble lipid-free drug administration in humans). Administration of lipid-associated indinavir (20 mg/kg daily) to HIV-2287-infected macaques (at 30-33 weeks after infection) resulted in significantly reduced viral RNA load and increased CD4 T cell number concentrations. Collectively, these data indicate that lipid association greatly enhances delivery of the anti-HIV drug indinavir to lymph nodes at levels that cannot be achieved with soluble drug, provides significant virus load reduction, and could potentially reverse CD4 T cell depletion due to HIV infection.
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Affiliation(s)
- Loren Kinman
- Department of Pharmaceutics, University of Washington, Seattle, WA, USA
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