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  1. Small molecule HIV entry inhibitors: Part II. Attachment and fusion inhibitors: 2004-2010.

    Science.gov (United States)

    Singh, Inder Pal; Chauthe, Siddheshwar Kisan

    2011-03-01

    The first US FDA approved HIV entry inhibitor drug Enfuvirdine belongs to the fusion inhibitor category. Earlier efforts in this area were focused on peptides and monoclonal antibodies; recently, the focus has shifted towards the development of small molecule HIV attachment and fusion inhibitors. They can be used for prophylactic purposes and also hold potential for the development of HIV microbicides. In a previous paper ('Small molecule HIV entry inhibitors: Part I'), we reviewed patents and patent applications for small molecule chemokine receptor antagonists from major pharmaceutical companies. In this paper, the development of small molecule HIV attachment and fusion inhibitors is discussed in detail. It covers patents and patent applications for small molecule HIV attachment and fusion inhibitors published between 2004 and 2010 and related literature with a focus on recent developments based on lead generation and lead modification. To augment the potency of currently available antiretroviral drug combinations and to fight drug-resistant virus variants, more effective drugs which target additional steps in the viral replication cycle are urgently needed. HIV attachment and fusion processes are such targets. Inhibitors of these targets will provide additional options for the treatment of HIV drug-resistant strains. Small molecule HIV attachment inhibitors such as BMS-378806 and analogs from Bristol Myers Squibb, N-aryl piperidine derivatives from Propharmacon, and NBD-556 and NBD-557 from New York Blood Center may have potential as vaginal microbicidal agents and can be an economical alternative to monoclonal antibodies.

  2. Assessment of HIV-1 entry inhibitors by MLV/HIV-1 pseudotyped vectors

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    Thaler Sonja

    2005-09-01

    Full Text Available Abstract Background Murine leukemia virus (MLV vector particles can be pseudotyped with a truncated variant of the human immunodeficiency virus type 1 (HIV-1 envelope protein (Env and selectively target gene transfer to human cells expressing both CD4 and an appropriate co-receptor. Vector transduction mimics the HIV-1 entry process and is therefore a safe tool to study HIV-1 entry. Results Using FLY cells, which express the MLV gag and pol genes, we generated stable producer cell lines that express the HIV-1 envelope gene and a retroviral vector genome encoding the green fluorescent protein (GFP. The BH10 or 89.6 P HIV-1 Env was expressed from a bicistronic vector which allowed the rapid selection of stable cell lines. A codon-usage-optimized synthetic env gene permitted high, Rev-independent Env expression. Vectors generated by these producer cells displayed different sensitivity to entry inhibitors. Conclusion These data illustrate that MLV/HIV-1 vectors are a valuable screening system for entry inhibitors or neutralizing antisera generated by vaccines.

  3. Current Status of the Pharmacokinetics and Pharmacodynamics of HIV-1 Entry Inhibitors and HIV Therapy.

    Science.gov (United States)

    Xu, Fengyan; Acosta, Edward P; Liang, Liyu; He, Yingchun; Yang, Juan; Kerstner-Wood, Corenna; Zheng, Qingshang; Huang, Jihan; Wang, Kun

    2017-10-16

    Human Immunodeficiency Virus (HIV) entry inhibitors target the first step of the HIV life cycle and efficiently inhibit HIV from infecting the immune cells which is a key prerequisite for viral spread. Because of their unique mechanism of action on cell-cell transmission, they may provide a promising perspective for the treatment of AIDS. Maraviroc (MVC) and Enfuvirtide (ENF) have been approved by the FDA for the treatment of HIV-1 infection. Attachment inhibitors (BMS-663068 and TNX-355) and co-receptor inhibitors (PRO-140 and cenicriviroc (CVC)) have reached phase II or III clinical trials. These entry inhibitors show beneficial pharmacokinetics and substantial reductions of plasma HIV-1 RNA load in HIV infected patients. Most entry inhibitors are generally safe, without serious Adverse Event (AE) or AE leading to discontinuation. The pharmacokinetics of MVC, CVC and BMS-663068 was affected by CYP3A4 inhibitors or inducers. The FDA has proposed that the dosage of MVC (300 mg, BID, orally) be adjusted to half or two-fold for patients if it is combined with a major CYP3A4 inhibitor or inducer, respectively. Researchers suggested that the dosage of CVC (50-75 mg, QD, orally) may also need adjustment but the dosage of BMS-663068 (600 mg, BID, orally) does not. The standard, recommended ENF dosage is 90 mg BID, injected subcutaneously for adults, and 2 mg/kg BID, up to a maximum dose of 90 mg, injected subcutaneously for pediatric patients. TNX-355 (10-15 mg/kg, BID, intravenously) and PRO-140(5-10 mg/kg, BID, intravenously; 324 mg, biweekly, subcutaneously) are administered by intravenous infusion or subcutaneous injection. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  4. Soybean-derived Bowman-Birk inhibitor (BBI) blocks HIV entry into macrophages.

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    Ma, Tong-Cui; Le Guo; Zhou, Run-Hong; Wang, Xu; Liu, Jin-Biao; Li, Jie-Liang; Zhou, Yu; Hou, Wei; Ho, Wen-Zhe

    2018-01-01

    Bowman-Birk inhibitor (BBI) is a soybean-derived protease inhibitor that has anti-inflammation and anti-HIV effect. Here, we further investigated the anti-HIV action of BBI in macrophages, focusing on its effect on viral entry. We found that BBI could significantly block HIV entry into macrophages. Investigation of the mechanism(s) of the BBI action on HIV inhibition showed that BBI down-regulated the expression of CD4 receptor (as much as 80%) and induced the production of the CC chemokines (up to 60 folds at protein level) in macrophages. This inhibitory effect of BBI on HIV entry could be blocked by the neutralization antibodies to CC chemokines. These findings indicate that BBI may have therapeutic potential as a viral entry inhibitor for the prevention and treatment of HIV infection. Copyright © 2017. Published by Elsevier Inc.

  5. Approaches for Identification of HIV-1 Entry Inhibitors Targeting gp41 Pocket

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    Asim K. Debnath

    2013-01-01

    Full Text Available The hydrophobic pocket in the HIV-1 gp41 N-terminal heptad repeat (NHR domain plays an important role in viral fusion and entry into the host cell, and serves as an attractive target for development of HIV-1 fusion/entry inhibitors. The peptide anti-HIV drug targeting gp41 NHR, T-20 (generic name: enfuvirtide; brand name: Fuzeon, was approved by the U.S. FDA in 2003 as the first HIV fusion/entry inhibitor for treatment of HIV/AIDS patients who fail to respond to the current antiretroviral drugs. However, because T20 lacks the pocket-binding domain (PBD, it exhibits low anti-HIV-1 activity and short half-life. Therefore, several next-generation HIV fusion inhibitory peptides with PBD have been developed. They possess longer half-life and more potent antiviral activity against a broad spectrum of HIV-1 strains, including the T-20-resistant variants. Nonetheless, the clinical application of these peptides is still limited by the lack of oral availability and the high cost of production. Thus, development of small molecule compounds targeting the gp41 pocket with oral availability has been promoted. This review describes the main approaches for identification of HIV fusion/entry inhibitors targeting the gp41 pocket and summarizes the latest progress in developing these inhibitors as a new class of anti-HIV drugs.

  6. Topical application of entry inhibitors as "virustats" to prevent sexual transmission of HIV infection

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    Root Michael

    2008-12-01

    Full Text Available Abstract With the continuing march of the AIDS epidemic and little hope for an effective vaccine in the near future, work to develop a topical strategy to prevent HIV infection is increasingly important. This stated, the track record of large scale "microbicide" trials has been disappointing with nonspecific inhibitors either failing to protect women from infection or even increasing HIV acquisition. Newer strategies that target directly the elements needed for viral entry into cells have shown promise in non-human primate models of HIV transmission and as these agents have not yet been broadly introduced in regions of highest HIV prevalence, they are particularly attractive for prophylaxis. We review here the agents that can block HIV cellular entry and that show promise as topical strategies or "virustats" to prevent mucosal transmission of HIV infection

  7. Small-molecule HIV-1 entry inhibitors targeting gp120 and gp41: a patent review (2010-2015).

    Science.gov (United States)

    Li, Wen; Lu, Lu; Li, Weihua; Jiang, Shibo

    2017-06-01

    It is essential to discover and develop small-molecule HIV-1 entry inhibitors with suitable pharmaceutical properties. Areas covered: We review the development of small-molecule HIV-1 entry inhibitors as evidenced in patents, patent applications, and related research articles published between 2010 and 2015. Expert opinion: HIV-1 Env gp120 and gp41 are important targets for development of HIV-1 entry inhibitors. The Phe43 pocket in gp120 and the highly conserved hydrophobic pocket on gp41 NHR-trimer are important targets for identification of HIV-1 attachment and fusion inhibitors, respectively. Compounds that bind to Phe43 pocket can block viral gp120 binding to CD4 on T cells, thus inhibiting HIV-1 attachment. However, most compounds targeting Phe43 pocket identified so far are HIV-1 entry agonists with the ability to enhance infectivity of HIV-1 in CD4-negative cells. Therefore, it is essential to identify HIV-1 entry antagonist-based HIV-1 attachment/entry inhibitors. Compounds binding to the gp41 hydrophobic pocket may inhibit CHR binding to the gp41 NHR trimer, thus blocking six-helix bundle formation and gp41-mediated virus-cell fusion. However, most lead compounds targeting this pocket have low potency, possibly because the pocket is too big or too deep. Therefore, it is necessary to identify other pockets in gp41 for developing HIV-1 fusion/entry inhibitors.

  8. A high throughput Cre–lox activated viral membrane fusion assay identifies pharmacological inhibitors of HIV entry

    Energy Technology Data Exchange (ETDEWEB)

    Esposito, Anthony M. [Division of Infectious Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, Immunology Institute, New York, NY (United States); Cheung, Pamela [Integrated Screening Core, Icahn School of Medicine at Mount Sinai, New York, NY (United States); Swartz, Talia H.; Li, Hongru [Division of Infectious Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, Immunology Institute, New York, NY (United States); Tsibane, Tshidi [Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY (United States); Durham, Natasha D. [Division of Infectious Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, Immunology Institute, New York, NY (United States); Basler, Christopher F. [Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY (United States); Felsenfeld, Dan P. [Integrated Screening Core, Icahn School of Medicine at Mount Sinai, New York, NY (United States); Chen, Benjamin K., E-mail: benjamin.chen@mssm.edu [Division of Infectious Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, Immunology Institute, New York, NY (United States)

    2016-03-15

    Enveloped virus entry occurs when viral and cellular membranes fuse releasing particle contents into the target cell. Human immunodeficiency virus (HIV) entry occurs by cell-free virus or virus transferred between infected and uninfected cells through structures called virological synapses. We developed a high-throughput cell-based assay to identify small molecule inhibitors of cell-free or virological synapse-mediated entry. An HIV clone carrying Cre recombinase as a Gag-internal gene fusion releases active Cre into cells upon viral entry activating a recombinatorial gene switch changing dsRed to GFP-expression. A screen of a 1998 known-biological profile small molecule library identified pharmacological HIV entry inhibitors that block both cell-free and cell-to-cell infection. Many top hits were noted as HIV inhibitors in prior studies, but not previously recognized as entry antagonists. Modest therapeutic indices for simvastatin and nigericin were observed in confirmatory HIV infection assays. This robust assay is adaptable to study HIV and heterologous viral pseudotypes. - Highlights: • Cre recombinase viral fusion assay screens cell-free or cell–cell entry inhibitors. • This Gag-iCre based assay is specific for the entry step of HIV replication. • Screened a library of known pharmacologic compounds for HIV fusion antagonists. • Many top hits were previously noted as HIV inhibitors, but here are classified as entry antagonists. Many top hits were previously noted as HIV inhibitors, but not as entry antagonists. • The assay is compatible with pseudotyping with HIV and heterologous viruses.

  9. Development of aptamer based HIV-1 entry inhibitor prophylactic drugs

    CSIR Research Space (South Africa)

    London, G

    2013-08-01

    Full Text Available AIDS remains a major public health problem globally, especially in Southern Africa where over 6.4 million people are infected by the most prevalent HIV-1 subtype C. To help stop the spread of HIV-1 subtype C, we isolated 2ʹ-F-RNA aptamers against gp...

  10. Protein/peptide-based entry/fusion inhibitors as anti-HIV therapies: challenges and future direction.

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    Fumakia, Miral; Yang, Sidi; Gu, Jijin; Ho, Emmanuel A

    2016-01-01

    The failures of several first-generation and second-generation small molecule drug-based anti-HIV therapies in various stages of clinical trials are an indication that there is a need for a paradigm shift in the future designs of anti-HIV therapeutics. Over the past several decades, various anti-HIV drugs have been developed, among them, protein/peptide-based therapies. From the first peptide discovered (SJ2176) to the first peptide approved by the Food and Drug Administration (DP178/T20/enfuvirtide/Fuzeon®), anti-HIV proteins/peptides as fusion/entry inhibitors have been shown to provide potent effects and benefits. This review summarizes the past and current endeavors in this area, discusses the potential mechanisms of action for various anti-HIV proteins/peptides, compares the advantages and disadvantages between the different proteins/peptides, and finally, examines the future direction of the field, specifically, strategies that will enhance the therapeutic efficacy of fusion/entry inhibitor-based anti-HIV proteins/peptides. Although there are numerous reviews highlighting the general field of entry/fusion inhibitors, there is a lack of literature focused on protein/peptide-based entry/fusion inhibitors for HIV therapy, and as a result, this review is intended to fill this void by summarizing the past, current, and future development of these macromolecules. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  11. Punica granatum (Pomegranate juice provides an HIV-1 entry inhibitor and candidate topical microbicide

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    Li Yun-Yao

    2004-10-01

    Full Text Available Abstract Background For ≈ 24 years the AIDS pandemic has claimed ≈ 30 million lives, causing ≈ 14,000 new HIV-1 infections daily worldwide in 2003. About 80% of infections occur by heterosexual transmission. In the absence of vaccines, topical microbicides, expected to block virus transmission, offer hope for controlling the pandemic. Antiretroviral chemotherapeutics have decreased AIDS mortality in industrialized countries, but only minimally in developing countries. To prevent an analogous dichotomy, microbicides should be: acceptable; accessible; affordable; and accelerative in transition from development to marketing. Already marketed pharmaceutical excipients or foods, with established safety records and adequate anti-HIV-1 activity, may provide this option. Methods Fruit juices were screened for inhibitory activity against HIV-1 IIIB using CD4 and CXCR4 as cell receptors. The best juice was tested for inhibition of: (1 infection by HIV-1 BaL, utilizing CCR5 as the cellular coreceptor; and (2 binding of gp120 IIIB and gp120 BaL, respectively, to CXCR4 and CCR5. To remove most colored juice components, the adsorption of the effective ingredient(s to dispersible excipients and other foods was investigated. A selected complex was assayed for inhibition of infection by primary HIV-1 isolates. Results HIV-1 entry inhibitors from pomegranate juice adsorb onto corn starch. The resulting complex blocks virus binding to CD4 and CXCR4/CCR5 and inhibits infection by primary virus clades A to G and group O. Conclusion These results suggest the possibility of producing an anti-HIV-1 microbicide from inexpensive, widely available sources, whose safety has been established throughout centuries, provided that its quality is adequately standardized and monitored.

  12. Structure of the CCR5 Chemokine Receptor-HIV Entry Inhibitor Maraviroc Complex

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    Tan, Qiuxiang; Zhu, Ya; Li, Jian; Chen, Zhuxi; Han, Gye Won; Kufareva, Irina; Li, Tingting; Ma, Limin; Fenalti, Gustavo; Li, Jing; Zhang, Wenru; Xie, Xin; Yang, Huaiyu; Jiang, Hualiang; Cherezov, Vadim; Liu, Hong; Stevens, Raymond C.; Zhao, Qiang; Wu, Beili [Scripps; (Chinese Aca. Sci.); (UCSD)

    2013-10-21

    The CCR5 chemokine receptor acts as a co-receptor for HIV-1 viral entry. Here we report the 2.7 angstrom–resolution crystal structure of human CCR5 bound to the marketed HIV drug maraviroc. The structure reveals a ligand-binding site that is distinct from the proposed major recognition sites for chemokines and the viral glycoprotein gp120, providing insights into the mechanism of allosteric inhibition of chemokine signaling and viral entry. A comparison between CCR5 and CXCR4 crystal structures, along with models of co-receptor–gp120-V3 complexes, suggests that different charge distributions and steric hindrances caused by residue substitutions may be major determinants of HIV-1 co-receptor selectivity. These high-resolution insights into CCR5 can enable structure-based drug discovery for the treatment of HIV-1 infection.

  13. Enfuvirtide (T20)-Based Lipopeptide Is a Potent HIV-1 Cell Fusion Inhibitor: Implications for Viral Entry and Inhibition.

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    Ding, Xiaohui; Zhang, Xiujuan; Chong, Huihui; Zhu, Yuanmei; Wei, Huamian; Wu, Xiyuan; He, Jinsheng; Wang, Xinquan; He, Yuxian

    2017-09-15

    The peptide drug enfuvirtide (T20) is the only viral fusion inhibitor used in combination therapy for HIV-1 infection, but it has relatively low antiviral activity and easily induces drug resistance. Emerging studies demonstrate that lipopeptide-based fusion inhibitors, such as LP-11 and LP-19, which mainly target the gp41 pocket site, have greatly improved antiviral potency and in vivo stability. In this study, we focused on developing a T20-based lipopeptide inhibitor that lacks pocket-binding sequence and targets a different site. First, the C-terminal tryptophan-rich motif (TRM) of T20 was verified to be essential for its target binding and inhibition; then, a novel lipopeptide, termed LP-40, was created by replacing the TRM with a fatty acid group. LP-40 showed markedly enhanced binding affinity for the target site and dramatically increased inhibitory activity on HIV-1 membrane fusion, entry, and infection. Unlike LP-11 and LP-19, which required a flexible linker between the peptide sequence and the lipid moiety, addition of a linker to LP-40 sharply reduced its potency, implying different binding modes with the extended N-terminal helices of gp41. Also, interestingly, LP-40 showed more potent activity than LP-11 in inhibiting HIV-1 Env-mediated cell-cell fusion while it was less active than LP-11 in inhibiting pseudovirus entry, and the two inhibitors displayed synergistic antiviral effects. The crystal structure of LP-40 in complex with a target peptide revealed their key binding residues and motifs. Combined, our studies have not only provided a potent HIV-1 fusion inhibitor, but also revealed new insights into the mechanisms of viral inhibition. IMPORTANCE T20 is the only membrane fusion inhibitor available for treatment of viral infection; however, T20 requires high doses and has a low genetic barrier for resistance, and its inhibitory mechanism and structural basis remain unclear. Here, we report the design of LP-40, a T20-based lipopeptide inhibitor

  14. Closing two doors of viral entry: Intramolecular combination of a coreceptor- and fusion inhibitor of HIV-1

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    Cammack Nick

    2008-05-01

    Full Text Available Abstract We describe a novel strategy in which two inhibitors of HIV viral entry were incorporated into a single molecule. This bifunctional fusion inhibitor consists of an antibody blocking the binding of HIV to its co-receptor CCR5, and a covalently linked peptide which blocks envelope mediated virus-cell fusion. This novel bifunctional molecule is highly active on CCR5- and X4-tropic viruses in a single cycle assay and a reporter cell line with IC50 values of 0.03–0.05 nM. We demonstrated that both inhibitors contribute to the antiviral activity. In the natural host peripheral blood mononuclear cells (PBMC the inhibition of CXCR4-tropic viruses is dependant on the co-expression of CCR5 and CXCR4 receptors. This bifunctional inhibitor may offer potential for improved pharmacokinetic parameters for a fusion inhibitor in humans and the combination of two active antiviral agents in one molecule may provide better durability in controlling the emergence of resistant viruses.

  15. Non-aqueous silicone elastomer gels as a vaginal microbicide delivery system for the HIV-1 entry inhibitor maraviroc

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    Forbes, Claire J.; Lowry, Deborah; Geer, Leslie; Veazey, Ronald S.; Shattock, Robin J.; Klasse, Per Johan; Mitchnick, Mark; Goldman, Laurie; Doyle, Lara A.; Muldoon, Brendan C.O.; Woolfson, A. David; Moore, John P.; Malcolm, R. Karl

    2011-01-01

    Aqueous semi-solid polymeric gels, such as those based on hydroxyethylcellulose (HEC) and polyacrylic acid (e.g. Carbopol®), have a long history of use in vaginal drug delivery. However, despite their ubiquity, they often provide sub-optimal clinical performance, due to poor mucosal retention and limited solubility for poorly water-soluble actives. These issues are particularly pertinent for vaginal HIV microbicides, since many lead candidates are poorly water-soluble and where a major goal is the development of a coitally independent, once daily gel product. In this study, we report the use of a non-aqueous silicone elastomer gel for vaginal delivery of the HIV-1 entry inhibitor maraviroc. In vitro rheological, syringeability and retention studies demonstrated enhanced performance for silicone gels compared with a conventional aqueous HEC gel, while testing of the gels in the slug model confirmed a lack of mucosal irritancy. Pharmacokinetic studies following single dose vaginal administration of a maraviroc silicone gel in rhesus macaques showed higher and sustained MVC levels in vaginal fluid, vaginal tissue and plasma compared with a HEC gel containing the same maraviroc loading. The results demonstrate that non-aqueous silicone gels have potential as a formulation platform for coitally independent vaginal HIV microbicides. PMID:21864598

  16. Computer-aided design of novel HIV-1 entry inhibitors blocking the virus envelope gp120 V3 loop

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    Tuzikov A. V.

    2012-12-01

    Full Text Available Aim. The object of this study was to implement computer-aided design of the water-soluble analog of glycolipid β -galactosylceramide (β-GalCer, which presents a potential HIV-1 entry inhibitor, by the analysis of intermolecular interactions of β-GalCer with the central region of the virus envelope gp120 V3 loop followed by synthesis of this glycolipid derivative and testing for antiviral activity. Methods. To reach the object of view, computer modeling procedures, such as quantum chemical calculations, molecular docking, molecular dynamics and free energy simulations, were involved in the studies in conjunction with chemical synthesis and anti-HIV-1 assay methods. Results. As a result, the high probability of exhibiting of antiviral activity was predicted for the designed β-GalCer analog. The data of molecular modeling were confirmed by those of primary medical trials of the synthesized compound. Conclusions. In the light of the findings obtained, the designed analog of β-GalCer may be considered as the basic structure for simulation of its more potent structural forms and for posterior selection of drug candidates most promising for synthesis and anti-HIV-1 assays.

  17. Novel Approaches to Inhibit HIV Entry

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    Chukwuka A. Didigu

    2012-02-01

    Full Text Available Human Immunodeficiency Virus (HIV entry into target cells is a multi-step process involving binding of the viral glycoprotein, Env, to its receptor CD4 and a coreceptor—either CCR5 or CXCR4. Understanding the means by which HIV enters cells has led to the identification of genetic polymorphisms, such as the 32 base-pair deletion in the ccr5 gene (ccr5∆32 that confers resistance to infection in homozygous individuals, and has also resulted in the development of entry inhibitors—small molecule antagonists that block infection at the entry step. The recent demonstration of long-term control of HIV infection in a leukemic patient following a hematopoietic stem cell transplant using cells from a ccr5∆32 homozygous donor highlights the important role of the HIV entry in maintaining an established infection and has led to a number of attempts to treat HIV infection by genetically modifying the ccr5 gene. In this review, we describe the HIV entry process and provide an overview of the different classes of approved HIV entry inhibitors while highlighting novel genetic strategies aimed at blocking HIV infection at the level of entry.

  18. AMD3465, a monomacrocyclic CXCR4 antagonist and potent HIV entry inhibitor

    DEFF Research Database (Denmark)

    Hatse, Sigrid; Princen, Katrien; De Clercq, Erik

    2005-01-01

    The chemokine receptors CCR5 and CXCR4 function as coreceptors for human immunodeficiency virus (HIV) and are attractive targets for the development of anti-HIV drugs. The most potent CXCR4 antagonists described until today are the bicyclams. The prototype compound, AMD3100, exhibits potent...... and selective anti-HIV activity against CXCR4-using (X4) viruses and showed antiviral efficacy in X4 HIV-1-infected persons in a phase II clinical trial. However, AMD3100 lacks oral bioavailability due to its high overall positive charge. Initial structure-activity relationship studies with bicyclam analogues...... suggested that the bis-macrocyclic structure was a prerequisite for anti-HIV activity. Now, we report that the N-pyridinylmethylene cyclam AMD3465, which lacks the structural constraints mentioned above, fully conserves all the biological properties of AMD3100. Like AMD3100, AMD3465 blocked the cell surface...

  19. Integrated Computational Tools for Identification of CCR5 Antagonists as Potential HIV-1 Entry Inhibitors: Homology Modeling, Virtual Screening, Molecular Dynamics Simulations and 3D QSAR Analysis

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    Suri Moonsamy

    2014-04-01

    Full Text Available Using integrated in-silico computational techniques, including homology modeling, structure-based and pharmacophore-based virtual screening, molecular dynamic simulations, per-residue energy decomposition analysis and atom-based 3D-QSAR analysis, we proposed ten novel compounds as potential CCR5-dependent HIV-1 entry inhibitors. Via validated docking calculations, binding free energies revealed that novel leads demonstrated better binding affinities with CCR5 compared to maraviroc, an FDA-approved HIV-1 entry inhibitor and in clinical use. Per-residue interaction energy decomposition analysis on the averaged MD structure showed that hydrophobic active residues Trp86, Tyr89 and Tyr108 contributed the most to inhibitor binding. The validated 3D-QSAR model showed a high cross-validated rcv2 value of 0.84 using three principal components and non-cross-validated r2 value of 0.941. It was also revealed that almost all compounds in the test set and training set yielded a good predicted value. Information gained from this study could shed light on the activity of a new series of lead compounds as potential HIV entry inhibitors and serve as a powerful tool in the drug design and development machinery.

  20. HIV: cell binding and entry

    National Research Council Canada - National Science Library

    Wilen, Craig B; Tilton, John C; Doms, Robert W

    2012-01-01

    The first step of the human immunodeficiency virus (HIV) replication cycle-binding and entry into the host cell-plays a major role in determining viral tropism and the ability of HIV to degrade the human immune system...

  1. Gene Therapy Targeting HIV Entry

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    Chuka Didigu

    2014-03-01

    Full Text Available Despite the unquestionable success of antiretroviral therapy (ART in the treatment of HIV infection, the cost, need for daily adherence, and HIV-associated morbidities that persist despite ART all underscore the need to develop a cure for HIV. The cure achieved following an allogeneic hematopoietic stem cell transplant (HSCT using HIV-resistant cells, and more recently, the report of short-term but sustained, ART-free control of HIV replication following allogeneic HSCT, using HIV susceptible cells, have served to both reignite interest in HIV cure research, and suggest potential mechanisms for a cure. In this review, we highlight some of the obstacles facing HIV cure research today, and explore the roles of gene therapy targeting HIV entry, and allogeneic stem cell transplantation in the development of strategies to cure HIV infection.

  2. Energetics of dendrimer binding to HIV-1 gp120-CD4 complex and mechanismic aspects of its role as an entry-inhibitor

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    Saurabh, Suman; Sahoo, Anil Kumar; Maiti, Prabal K.

    2016-10-01

    Experiments and computational studies have established that de-protonated dendrimers (SPL7013 and PAMAM) act as entry-inhibitors of HIV. SPL7013 based Vivagel is currently under clinical development. The dendrimer binds to gp120 in the gp120-CD4 complex, destabilizes it by breaking key contacts between gp120 and CD4 and prevents viral entry into target cells. In this work, we provide molecular details and energetics of the formation of the SPL7013-gp120-CD4 ternary complex and decipher modes of action of the dendrimer in preventing viral entry. It is also known from experiments that the dendrimer binds weakly to gp120 that is not bound to CD4. It binds even more weakly to the CD4-binding region of gp120 and thus cannot directly block gp120-CD4 complexation. In this work, we examine the feasibility of dendrimer binding to the gp120-binding region of CD4 and directly blocking gp120-CD4 complex formation. We find that the process of the dendrimer binding to CD4 can compete with gp120-CD4 binding due to comparable free energy change for the two processes, thus creating a possibility for the dendrimer to directly block gp120-CD4 complexation by binding to the gp120-binding region of CD4.

  3. HIV protease inhibitor resistance

    NARCIS (Netherlands)

    Wensing, Annemarie M.J.; Fun, Axel; Nijhuis, Monique

    2017-01-01

    HIV protease is pivotal in the viral replication cycle and directs the formation of mature infectious virus particles. The development of highly specific HIV protease inhibitors (PIs), based on thorough understanding of the structure of HIV protease and its substrate, serves as a prime example of

  4. Molecular interaction of gp120 and B40 aptamer: A potential new HIV-1 entry inhibitor drug

    CSIR Research Space (South Africa)

    Baron, MK

    2008-11-01

    Full Text Available HIV-1 infection and its concomitant disease – Aids, remain major public health problems in southern Africa. While current antiretroviral drugs have prolonged the quality of life for many HIV-positive individuals, they do not eliminate the virus (2...

  5. A novel bivalent HIV-1 entry inhibitor reveals fundamental differences in CCR5 -μ- opioid receptor interactions in human astroglia and microglia

    Science.gov (United States)

    EL-HAGE, Nazira; DEVER, Seth M.; PODHAIZER, Elizabeth M.; ARNATT, Cristopher K.; ZHANG, Yan; HAUSER, Kurt F.

    2013-01-01

    Objective We explored whether the opiate, morphine, affects the actions of maraviroc, as well as a recently synthesized bivalent derivative of maraviroc linked to an opioid antagonist, naltrexone, on HIV-1 entry in primary human glia. Methods HIV-1 entry was monitored in glia transiently transfected with an LTR construct containing a luciferase reporter gene under control of a promoter for the HIV-1 transactivator protein Tat. The effect of maraviroc and the bivalent ligand ± morphine on CCR5 surface expression and cytokine release was also explored. Results Maraviroc inhibits HIV-1 entry into glial cells, while morphine negates the effects of maraviroc leading to a significant increase in viral entry. We also demonstrate that the maraviroc-containing bivalent ligand better inhibits R5-tropic viral entry in astrocytes than microglia compared to maraviroc when coadministered with morphine. Importantly, the inhibitory effects of the bivalent compound in astrocytes were not compromised by morphine. Exposure to maraviroc decreased the release of pro-inflammatory cytokines and restricted HIV-1-dependent increases in CCR5 expression in both astrocytes and microglia, while exposure to the bivalent had similar effect in astrocytes but not in microglia. CCR5-MOR stoichiometric ratio varied among the two cell types with CCR5 expressed at much higher levels than MOR in microglia, which could explain the effectiveness of the bivalent ligand in astrocytes compared to microglia. Conclusion A novel bivalent compound reveals fundamental differences in CCR5-MOR interactions and HIV-1 infectivity among glia, and has unique therapeutic potential in opiate abuse-HIV interactive comorbidity. PMID:23751259

  6. Stoichiometric parameters of HIV-1 entry.

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    Zarr, Melissa; Siliciano, Robert

    2015-01-01

    During HIV type 1 (HIV-1) entry, trimers of gp120 bind to CD4 and either the CCR5 or CXCR4 coreceptor on the target cell. The stoichiometric parameters associated with HIV-1 entry remain unclear. Important unanswered questions include: how many trimers must attach to CD4 molecules, how many must bind coreceptors, and how many functional gp120 subunits per trimer are required for entry? We performed single round infectivity assays with chimeric viruses and compared the experimental relative infectivity curves with curves generated by mathematical models. Our results indicate that HIV-1 entry requires only a small number of functional spikes (one or two), that Env trimers may function with fewer than three active subunits, and that there is no major difference in the stoichiometric requirements for CCR5 vs. CXCR4 mediated HIV-1 entry into host cells. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Dopamine Receptor Activation Increases HIV Entry into Primary Human Macrophages

    Science.gov (United States)

    Gaskill, Peter J.; Yano, Hideaki H.; Kalpana, Ganjam V.; Javitch, Jonathan A.; Berman, Joan W.

    2014-01-01

    Macrophages are the primary cell type infected with HIV in the central nervous system, and infection of these cells is a major component in the development of neuropathogenesis and HIV-associated neurocognitive disorders. Within the brains of drug abusers, macrophages are exposed to increased levels of dopamine, a neurotransmitter that mediates the addictive and reinforcing effects of drugs of abuse such as cocaine and methamphetamine. In this study we examined the effects of dopamine on HIV entry into primary human macrophages. Exposure to dopamine during infection increased the entry of R5 tropic HIV into macrophages, irrespective of the concentration of the viral inoculum. The entry pathway affected was CCR5 dependent, as antagonizing CCR5 with the small molecule inhibitor TAK779 completely blocked entry. The effect was dose-dependent and had a steep threshold, only occurring above 108 M dopamine. The dopamine-mediated increase in entry required dopamine receptor activation, as it was abrogated by the pan-dopamine receptor antagonist flupenthixol, and could be mediated through both subtypes of dopamine receptors. These findings indicate that the effects of dopamine on macrophages may have a significant impact on HIV pathogenesis. They also suggest that drug-induced increases in CNS dopamine may be a common mechanism by which drugs of abuse with distinct modes of action exacerbate neuroinflammation and contribute to HIV-associated neurocognitive disorders in infected drug abusers. PMID:25268786

  8. Protease inhibitors targeting coronavirus and filovirus entry.

    Science.gov (United States)

    Zhou, Yanchen; Vedantham, Punitha; Lu, Kai; Agudelo, Juliet; Carrion, Ricardo; Nunneley, Jerritt W; Barnard, Dale; Pöhlmann, Stefan; McKerrow, James H; Renslo, Adam R; Simmons, Graham

    2015-04-01

    In order to gain entry into cells, diverse viruses, including Ebola virus, SARS-coronavirus and the emerging MERS-coronavirus, depend on activation of their envelope glycoproteins by host cell proteases. The respective enzymes are thus excellent targets for antiviral intervention. In cell culture, activation of Ebola virus, as well as SARS- and MERS-coronavirus can be accomplished by the endosomal cysteine proteases, cathepsin L (CTSL) and cathepsin B (CTSB). In addition, SARS- and MERS-coronavirus can use serine proteases localized at the cell surface, for their activation. However, it is currently unclear which protease(s) facilitate viral spread in the infected host. We report here that the cysteine protease inhibitor K11777, ((2S)-N-[(1E,3S)-1-(benzenesulfonyl)-5-phenylpent-1-en-3-yl]-2-{[(E)-4-methylpiperazine-1-carbonyl]amino}-3-phenylpropanamide) and closely-related vinylsulfones act as broad-spectrum antivirals by targeting cathepsin-mediated cell entry. K11777 is already in advanced stages of development for a number of parasitic diseases, such as Chagas disease, and has proven to be safe and effective in a range of animal models. K11777 inhibition of SARS-CoV and Ebola virus entry was observed in the sub-nanomolar range. In order to assess whether cysteine or serine proteases promote viral spread in the host, we compared the antiviral activity of an optimized K11777-derivative with that of camostat, an inhibitor of TMPRSS2 and related serine proteases. Employing a pathogenic animal model of SARS-CoV infection, we demonstrated that viral spread and pathogenesis of SARS-CoV is driven by serine rather than cysteine proteases and can be effectively prevented by camostat. Camostat has been clinically used to treat chronic pancreatitis, and thus represents an exciting potential therapeutic for respiratory coronavirus infections. Our results indicate that camostat, or similar serine protease inhibitors, might be an effective option for treatment of SARS and

  9. CCR5 inhibitors in HIV-1 therapy.

    Science.gov (United States)

    Dorr, Patrick; Perros, Manos

    2008-11-01

    The human immunodeficiency virus 1 (HIV-1) is the causative pathogen of AIDS, the world's biggest infectious disease killer. About 33 million people are infected worldwide, with 2.1 million deaths a year as a direct consequence. The devastating nature of AIDS has prompted widespread research, which has led to an extensive array of therapies to suppress viral replication and enable recovery of the immune system to prolong and improve patient life substantially. However, the genetic plasticity and replication rate of HIV-1 are considerable, which has lead to rapid drug resistance. This, together with the need for reducing drug side effects and increasing regimen compliance, has led researchers to identify antiretroviral drugs with new modes of action. This review describes the discovery and clinical development of CCR5 antagonists and the recent approval of maraviroc as a breakthrough in anti-HIV-1 therapy. CCR5 inhibitors target a human cofactor to disable HIV-1 entry into the cells, and thereby provide a new hurdle for the virus to overcome. The status and expert opinion of CCR5 antagonists for the treatment of HIV-1 infection are detailed.

  10. Direct inactivation of human immunodeficiency virus type 1 by a novel small-molecule entry inhibitor, DCM205.

    Science.gov (United States)

    Duong, Yen T; Meadows, D Christopher; Srivastava, Indresh K; Gervay-Hague, Jacquelyn; North, Thomas W

    2007-05-01

    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.

  11. A novel small molecule inhibitor of hepatitis C virus entry.

    Directory of Open Access Journals (Sweden)

    Carl J Baldick

    Full Text Available Small molecule inhibitors of hepatitis C virus (HCV are being developed to complement or replace treatments with pegylated interferons and ribavirin, which have poor response rates and significant side effects. Resistance to these inhibitors emerges rapidly in the clinic, suggesting that successful therapy will involve combination therapy with multiple inhibitors of different targets. The entry process of HCV into hepatocytes represents another series of potential targets for therapeutic intervention, involving viral structural proteins that have not been extensively explored due to experimental limitations. To discover HCV entry inhibitors, we utilized HCV pseudoparticles (HCVpp incorporating E1-E2 envelope proteins from a genotype 1b clinical isolate. Screening of a small molecule library identified a potent HCV-specific triazine inhibitor, EI-1. A series of HCVpp with E1-E2 sequences from various HCV isolates was used to show activity against all genotype 1a and 1b HCVpp tested, with median EC50 values of 0.134 and 0.027 µM, respectively. Time-of-addition experiments demonstrated a block in HCVpp entry, downstream of initial attachment to the cell surface, and prior to or concomitant with bafilomycin inhibition of endosomal acidification. EI-1 was equally active against cell-culture adapted HCV (HCVcc, blocking both cell-free entry and cell-to-cell transmission of virus. HCVcc with high-level resistance to EI-1 was selected by sequential passage in the presence of inhibitor, and resistance was shown to be conferred by changes to residue 719 in the carboxy-terminal transmembrane anchor region of E2, implicating this envelope protein in EI-1 susceptibility. Combinations of EI-1 with interferon, or inhibitors of NS3 or NS5A, resulted in additive to synergistic activity. These results suggest that inhibitors of HCV entry could be added to replication inhibitors and interferons already in development.

  12. Biased small-molecule ligands for selective inhibition of HIV-1 cell entry via CCR5

    DEFF Research Database (Denmark)

    Berg, Christian; Spiess, Katja; von Lüttichau, Hans Rudolf

    2016-01-01

    Since the discovery of HIV's use of CCR5 as the primary coreceptor in fusion, the focus on developing small-molecule receptor antagonists for inhibition hereof has only resulted in one single drug, Maraviroc. We therefore investigated the possibility of using small-molecule CCR5 agonists as HIV-1......, the efficacy switch mutation (Leu203Phe) - converting small-molecule antagonists/inverse agonists to full agonists biased toward G-protein activation - uncovered that also small-molecule agonists can function as direct HIV-1 cell entry inhibitors. Importantly, no agonist-induced receptor internalization...

  13. Curcumin derivatives as HIV-1 protease inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Sui, Z.; Li, J.; Craik, C.S.; Ortiz de Montellano, P.R. [Univ. of California, San Francisco, CA (United States)

    1993-12-31

    Curcumin, a non-toxic natural compound from Curcuma longa, has been found to be an HIV-1 protease inhibitor. Some of its derivatives were synthesized and their inhibitory activity against the HIV-1 protease was tested. Curcumin analogues containing boron enhanced the inhibitory activity. At least of the the synthesized compounds irreversibly inhibits the HIV-1 protease.

  14. Kinetic factors control efficiencies of cell entry, efficacies of entry inhibitors, and mechanisms of adaptation of human immunodeficiency virus.

    Science.gov (United States)

    Platt, Emily J; Durnin, James P; Kabat, David

    2005-04-01

    Replication of human immunodeficiency virus type 1 (HIV-1) in diverse conditions limiting for viral entry into cells frequently leads to adaptive mutations in the V3 loop of the gp120 envelope glycoprotein. This has suggested that the V3 loop limits the efficiencies of HIV-1 infections, possibly by directly affecting gp120-coreceptor affinities. In contrast, V3 loop mutations that enable HIV-1(JR-CSF) to use the low-affinity mutant coreceptor CCR5(Y14N) are shown here to have negligible effects on the virus-coreceptor affinity but to dramatically accelerate the irreversible conformational conversion of the envelope gp41 subunits from a three-stranded coil into a six-helix bundle. This slow step is blocked irreversibly by the inhibitor T-20. To further evaluate the role of entry rates in controlling infection efficiencies and viral adaptations, we developed methods to quantitatively measure viral entry kinetics. The virions were adsorbed by spinoculation at 4 degrees C onto HeLa-CD4/CCR5 cell clones that either had limiting or saturating concentrations of CCR5. After warming to 37 degrees C, the completion of entry was monitored over time by the resistance of infections to the competitive CCR5 inhibitor TAK-779. Our results suggest that the efficiency of entry of cell-attached infectious HIV-1 is principally controlled by three kinetic processes. The first is a lag phase that is caused in part by the concentration-dependent reversible association of virus with CD4 and CCR5 to form an equilibrium assemblage of complexes. Second, this assembly step lowers but does not eliminate a large activation energy barrier for a rate-limiting, CCR5-dependent conformational change in gp41 that is sensitive to blockage by T-20. The rate of infection therefore depends on the fraction of infectious virions that are sufficiently saturated with CCR5 to undergo this conformational change and on the magnitude of the activation energy barrier. Although only a small fraction of fully

  15. An expanded model of HIV cell entry phenotype based on multi-parameter single-cell data

    Directory of Open Access Journals (Sweden)

    Bozek Katarzyna

    2012-07-01

    Full Text Available Abstract Background Entry of human immunodeficiency virus type 1 (HIV-1 into the host cell involves interactions between the viral envelope glycoproteins (Env and the cellular receptor CD4 as well as a coreceptor molecule (most importantly CCR5 or CXCR4. Viral preference for a specific coreceptor (tropism is in particular determined by the third variable loop (V3 of the Env glycoprotein gp120. The approval and use of a coreceptor antagonist for antiretroviral therapy make detailed understanding of tropism and its accurate prediction from patient derived virus isolates essential. The aim of the present study is the development of an extended description of the HIV entry phenotype reflecting its co-dependence on several key determinants as the basis for a more accurate prediction of HIV-1 entry phenotype from genotypic data. Results Here, we established a new protocol of quantitation and computational analysis of the dependence of HIV entry efficiency on receptor and coreceptor cell surface levels as well as viral V3 loop sequence and the presence of two prototypic coreceptor antagonists in varying concentrations. Based on data collected at the single-cell level, we constructed regression models of the HIV-1 entry phenotype integrating the measured determinants. We developed a multivariate phenotype descriptor, termed phenotype vector, which facilitates a more detailed characterization of HIV entry phenotypes than currently used binary tropism classifications. For some of the tested virus variants, the multivariant phenotype vector revealed substantial divergences from existing tropism predictions. We also developed methods for computational prediction of the entry phenotypes based on the V3 sequence and performed an extrapolating calculation of the effectiveness of this computational procedure. Conclusions Our study of the HIV cell entry phenotype and the novel multivariate representation developed here contributes to a more detailed

  16. Respiratory Syncytial Virus Entry Inhibitors Targeting the F Protein

    Directory of Open Access Journals (Sweden)

    Shibo Jiang

    2013-01-01

    Full Text Available Human respiratory syncytial virus (RSV is the main viral cause of respiratory tract infection in infants as well as some elderly and high-risk adults with chronic pulmonary disease and the severely immunocompromised. So far, no specific anti-RSV therapeutics or effective anti-RSV vaccines have been reported. Only one humanized monoclonal antibody, Palivizumab, has been approved for use in high-risk infants to prevent RSV infection. Ribavirin is the only drug licensed for therapy of RSV infection, but its clinical use is limited by its nonspecific anti-RSV activity, toxic effect, and relatively high cost. Therefore, development of novel effective anti-RSV therapeutics is urgently needed. The RSV envelope glycoprotein F plays an important role in RSV fusion with, and entry into, the host cell and, consequently, serves as an attractive target for developing RSV entry inhibitors. This article reviews advances made in studies of the structure and function of the F protein and the development of RSV entry inhibitors targeting it.

  17. A new class of synthetic peptide inhibitors blocks attachment and entry of human pathogenic viruses.

    Science.gov (United States)

    Krepstakies, Marcel; Lucifora, Julie; Nagel, Claus-Henning; Zeisel, Mirjam B; Holstermann, Barbara; Hohenberg, Heinrich; Kowalski, Ina; Gutsmann, Thomas; Baumert, Thomas F; Brandenburg, Klaus; Hauber, Joachim; Protzer, Ulrike

    2012-06-01

    Many enveloped viruses, including herpes viruses, hepatitis B virus (HBV), and hepatitis C virus (HCV), and human immunodeficiency virus (HIV), are among the most important human pathogens and are often responsible for coinfections involving ≥2 types of viruses. However, therapies that are effective against multiple virus classes are rare. Here we present a new class of synthetic anti-lipopolysaccharide peptides (SALPs) that bind to heparan sulfate moieties on the cell surface and inhibit infection with a variety of enveloped viruses. We demonstrate that SALPs inhibit entry of human immunodeficiency virus type 1 (HIV-1), herpes simplex virus (HSV) 1 and 2, HBV, and HCV to their respective host cells. Despite their high antiviral efficiency, SALPs were well tolerated, and neither toxicity nor measurable inhibitor-induced adverse effects were observed. Since these broad-spectrum antiviral peptides target a host cell rather than a viral component, they may also be useful for suppression of viruses that are resistant to antiviral drugs.

  18. Clinical use of CCR5 inhibitors in HIV and beyond

    Directory of Open Access Journals (Sweden)

    Gilliam Bruce

    2010-01-01

    Full Text Available Abstract Since the discovery of CCR5 as a coreceptor for HIV entry, there has been interest in blockade of the receptor for treatment and prevention of HIV infection. Although several CCR5 antagonists have been evaluated in clinical trials, only maraviroc has been approved for clinical use in the treatment of HIV-infected patients. The efficacy, safety and resistance profile of CCR5 antagonists with a focus on maraviroc are reviewed here along with their usage in special and emerging clinical situations. Despite being approved for use since 2007, the optimal use of maraviroc has yet to be well-defined in HIV and potentially in other diseases. Maraviroc and other CCR5 antagonists have the potential for use in a variety of other clinical situations such as the prevention of HIV transmission, intensification of HIV treatment and prevention of rejection in organ transplantation. The use of CCR5 antagonists may be potentiated by other agents such as rapamycin which downregulate CCR5 receptors thus decreasing CCR5 density. There may even be a role for their use in combination with other entry inhibitors. However, clinical use of CCR5 antagonists may have negative consequences in diseases such as West Nile and Tick-borne encephalitis virus infections. In summary, CCR5 antagonists have great therapeutic potential in the treatment and prevention of HIV as well as future use in novel situations such as organ transplantation. Their optimal use either alone or in combination with other agents will be defined by further investigation.

  19. Raltegravir: first in class HIV integrase inhibitor

    Directory of Open Access Journals (Sweden)

    Zelalem Temesgen

    2008-06-01

    Full Text Available Zelalem Temesgen1, Dawd S Siraj21Mayo Clinic, Rochester, MN, USA; 2East Carolina University Greenville, NC, USAAbstract: On October 16, 2007, the US Food and Drug Administration (FDA approved raltegravir for treatment of human immunodeficiency virus (HIV-1 infection in combination with other antiretroviral agents in treatment-experienced adult patients who have evidence of viral replication and HIV-1 strains resistant to multiple antiretroviral agents. Raltegravir is first in a novel class of antiretroviral drugs known as integrase inhibitors. It has demonstrated potent anti HIV activity in both antiretroviral treatment-naïve and experienced patients. The most common adverse events reported with raltegravir during phase 2 and 3 clinical trials were diarrhea, nausea, and headache. Laboratory abnormalities include mild elevations in liver transaminases and creatine phosphokinase.Keywords: raltegravir, HIV, antiretroviral agents, integrase inhibitors

  20. New influenza A Virus Entry Inhibitors Derived from the Viral Fusion Peptides.

    Directory of Open Access Journals (Sweden)

    Wenjiao Wu

    Full Text Available Influenza A viral (IAV fusion peptides are known for their important role in viral-cell fusion process and membrane destabilization potential which are compatible with those of antimicrobial peptides. Thus, by replacing the negatively or neutrally charged residues of FPs with positively charged lysines, we synthesized several potent antimicrobial peptides derived from the fusogenic peptides (FPs of hemagglutinin glycoproteins (HAs of IAV. The biological screening identified that in addition to the potent antibacterial activities, these positively charged fusion peptides (pFPs effectively inhibited the replication of influenza A viruses including oseltamivir-resistant strain. By employing pseudovirus-based entry inhibition assays including H5N1 influenza A virus (IAV, and VSV-G, the mechanism study indicated that the antiviral activity may be associated with the interactions between the HA2 subunit and pFP, of which, the nascent pFP exerted a strong effect to interrupt the conformational changes of HA2, thereby blocking the entry of viruses into host cells. In addition to providing new peptide "entry blockers", these data also demonstrate a useful strategy in designing potent antibacterial agents, as well as effective viral entry inhibitors. It would be meaningful in treatment of bacterial co-infection during influenza pandemic periods, as well as in our current war against those emerging pathogenic microorganisms such as IAV and HIV.

  1. Targeting CXCR4 in HIV Cell-Entry Inhibition

    DEFF Research Database (Denmark)

    Steen, Anne; Schwartz, T W; Rosenkilde, M M

    2010-01-01

    CXCR4 and CCR5 constitute the two major coreceptors for HIV-1 entry into host cells. In the course of an HIV-infection, a coreceptor switch takes place in approximately half of the patients - from R5 HIV-1 (CCR5 utilizing) strains to X4 HIV-1 (CXCR4 utilizing) strains. Treatment of HIV......-infected individuals with CXCR4 antagonists delays the onset of AIDS by preventing the CCR5 to CXCR4 coreceptor switch. In addition to the endogenous CXCR4 and CCR5 ligands, other chemokines, for example the human herpesvirus 8 encoded CC-chemokine, vCCL2, and modifications hereof, have proven efficient HIV-1 cell...... no oral bioavailability. The hunt for orally active small-molecule CXCR4 antagonists led to the development of monocyclam-based compounds, and recently to the non-cyclam antagonist AMD070, which is orally active and currently in Phase II clinical trial as anti-HIV treatment. Current review provides...

  2. Inhibition of HIV-1 entry by extracts derived from traditional Chinese medicinal herbal plants

    Directory of Open Access Journals (Sweden)

    Song Xinming

    2009-08-01

    HIV-1 interaction with target cells, i.e., the interaction between gp120 and CD4/CCR5 or gp120 and CD4/CXCR4 and point to the potential of developing these two extracts to be HIV-1 entry inhibitors.

  3. Safety aspects of HIV-protease inhibitors

    NARCIS (Netherlands)

    J.P. Dieleman (Jeanne)

    2002-01-01

    textabstractThe objectives of this thesis were to provide more insight into the risk and risk factors of adverse drug reactions associated with HIV-protease inhibitor treatment under non-experimental everyday circumstances. By recognition of risk factors, patients at risk can be identified

  4. Sargassum fusiforme fraction is a potent and specific inhibitor of HIV-1 fusion and reverse transcriptase

    Directory of Open Access Journals (Sweden)

    Thornber Carol

    2008-01-01

    Full Text Available Abstract Sargassum fusiforme (Harvey Setchell has been shown to be a highly effective inhibitor of HIV-1 infection. To identify its mechanism of action, we performed bioactivity-guided fractionation on Sargassum fusiforme mixture. Here, we report isolation of a bioactive fraction SP4-2 (S. fusiforme, which at 8 μg/ml inhibited HIV-1 infection by 86.9%, with IC50 value of 3.7 μg. That represents 230-fold enhancement of antiretroviral potency as compared to the whole extract. Inhibition was mediated against both CXCR4 (X4 and CCR5 (R5 tropic HIV-1. Specifically, 10 μg/ml SP4-2 blocked HIV-1 fusion and entry by 53%. This effect was reversed by interaction of SP4-2 with sCD4, suggesting that S. fusiforme inhibits HIV-1 infection by blocking CD4 receptor, which also explained observed inhibition of both X4 and R5-tropic HIV-1. SP4-2 also inhibited HIV-1 replication after virus entry, by directly inhibiting HIV-1 reverse transcriptase (RT in a dose dependent manner by up to 79%. We conclude that the SP4-2 fraction contains at least two distinct and biologically active molecules, one that inhibits HIV-1 fusion by interacting with CD4 receptor, and another that directly inhibits HIV-1 RT. We propose that S. fusiforme is a lead candidate for anti-HIV-1 drug development.

  5. The current status and challenges in the development of fusion inhibitors as therapeutics for HIV-1 infection.

    Science.gov (United States)

    Tan, Jian Jun; Ma, Xue Ting; Liu, Chang; Zhang, Xiao Yi; Wang, Cun Xin

    2013-01-01

    HIV-1 membrane fusion as a part of the process of viral entry in the target cells is facilitated by gp41 and gp120, which are encoded by Env gene of HIV-1. Based on the structure and the mechanism researches, new treatment options targeting HIV-1 entry process have been proposed. Enfuvirtide, which mimics amino acid sequences of viral envelope glycoprotein gp41, is the first HIV-1 fusion inhibitor approved by FDA. Although it fulfills vital functions by binding to gp41 and abolishing the membrane fusion reaction when used in combination, it could induce drug resistant virus variants. Currently, a number of design and modification schemes have been presented, a large number of prospective fusion peptides have emerged. For these fusion inhibitors, multiple mutations in gp41 have been associated with the loss of susceptibility to agents. This review reported the current developments and innovative designs of HIV-1 membrane fusion inhibitors.

  6. HIV-1 predisposed to acquiring resistance to maraviroc (MVC) and other CCR5 antagonists in vitro has an inherent, low-level ability to utilize MVC-bound CCR5 for entry

    National Research Council Canada - National Science Library

    Roche, Michael; Jakobsen, Martin R; Ellett, Anne; Salimiseyedabad, Hamid; Jubb, Becky; Westby, Mike; Lee, Benhur; Lewin, Sharon R; Churchill, Melissa J; Gorry, Paul R

    2011-01-01

    Maraviroc (MVC) and other CCR5 antagonists are HIV-1 entry inhibitors that bind to- and alter the conformation of CCR5, such that CCR5 is no longer recognized by the viral gp120 envelope (Env) glycoproteins...

  7. Expanded Tropism and Altered Activation of a Retroviral Glycoprotein Resistant to an Entry Inhibitor Peptide

    Science.gov (United States)

    Amberg, Sean M.; Netter, Robert C.; Simmons, Graham; Bates, Paul

    2006-01-01

    The envelope of class I viruses can be a target for potent viral inhibitors, such as the human immunodeficiency virus type 1 (HIV-1) inhibitor enfuvirtide, which are derived from the C-terminal heptad repeat (HR2) of the transmembrane (TM) subunit. Resistance to an HR2-based peptide inhibitor of a model retrovirus, subgroup A of the Avian Sarcoma and Leukosis Virus genus (ASLV-A), was studied by examining mutants derived by viral passage in the presence of inhibitor. Variants with reduced sensitivity to inhibitor were readily selected in vitro. Sensitivity determinants were identified for 13 different isolates, all of which mapped to the TM subunit. These determinants were identified in two regions: (i) the N-terminal heptad repeat (HR1) and (ii) the N-terminal segment of TM, between the subunit cleavage site and the fusion peptide. The latter class of mutants identified a region outside of the predicted HR2-binding site that can significantly alter sensitivity to inhibitor. A subset of the HR1 mutants displayed the unanticipated ability to infect nonavian cells. This expanded tropism was associated with increased efficiency of envelope triggering by soluble receptor at low temperatures, as measured by protease sensitivity of the surface subunit (SU) of envelope. In addition, expanded tropism was linked for the most readily triggered mutants with increased sensitivity to neutralization by SU-specific antiserum. These observations depict a class of HR2 peptide-selected mutations with a reduced activation threshold, thereby allowing the utilization of alternative receptors for viral entry. PMID:16352560

  8. FAITH - Fast Assembly Inhibitor Test for HIV

    Czech Academy of Sciences Publication Activity Database

    Hadravová, Romana; Rumlová, Michaela; Ruml, T.

    2015-01-01

    Roč. 486, Dec (2015), s. 78-87 ISSN 0042-6822 R&D Projects: GA ČR(CZ) GA14-15326S; GA MŠk LO1302; GA MŠk(CZ) LO1304 Institutional support: RVO:61388963 Keywords : retrovirus * HIV * assembly * assay * inhibitor Subject RIV: EE - Microbiology, Virology Impact factor: 3.200, year: 2015 http://www.sciencedirect.com/science/article/pii/S0042682215003864

  9. HIV protease-mediated activation of sterically capped proteasome inhibitors and substrates.

    Science.gov (United States)

    Buckley, Dennis L; Corson, Timothy W; Aberle, Nicholas; Crews, Craig M

    2011-02-02

    Strategies for selectively killing HIV-infected cells present an appealing alternative to traditional antiretroviral drugs. We show here the first example of an inactive “Trojan horse” molecule that releases a cytotoxic, small-molecule proteasome inhibitor upon cleavage by HIV-1 protease. As a proof-of-concept strategy, the protein avidin was used to block entry of the compound into the proteasome in the absence of HIV-1 protease. We demonstrate that this strategy is also feasible without requiring an exogenous protein; a polylysine dendrimer-containing molecule is unable to enter the proteasome until cleaved by HIV-1 protease. These results demonstrate that conditional proteasome inhibitors could prove useful in the development of new tools for chemical biology and future therapeutics.

  10. Advances in non-peptidomimetic HIV protease inhibitors.

    Science.gov (United States)

    Pang, X; Liu, Z; Zhai, G

    2014-06-01

    HIV protease plays a crucial role in the viral life cycle. It can cleave a series of heptamers in the viral Gag and GagPol precursor proteins to generate mature infectious virus particles. Successful inhibition of the protease will prevent this maturation step and hence block the spreading of HIV. However, the rapid emergence of drug resistance makes it urgent to develop new HIV protease inhibitors to combat the global disease. Besides, poor oral bioavailability, unacceptable side effects, high treatment cost and pill burden also trouble the application of HIV protease inhibitors. In such situations, non-peptidomimetic HIV protease inhibitors have drawn an increasing interest as a potential therapeutic option due to their small molecular weight, favorable bioavailability, high stability in vivo, low resistance and cost of production. In this review, we present the recent advances in non-peptidomimetic HIV protease inhibitors. Their design strategies, biological activities, resistance profiles, as well as clinical application will also be discussed.

  11. Novel inhibitors of the early steps of the HIV-1 life cycle.

    Science.gov (United States)

    Citterio, Paola; Rusconi, Stefano

    2007-01-01

    Considerable advances have been made on compounds that are active as inhibitors of HIV entry and fusion. The discovery of chemokines a few years ago focused the attention on coreceptor inhibitors in addition to fusion and attachment blockers. During the last 5 years, there has been an intense research activity from both private companies and academic institutions to find effective compounds that are capable of inhibiting the initial steps in the HIV life cycle. Some of the presented compounds demonstrated in vitro synergism, thus there is the rationale of their combined use in HIV-infected individuals. Many entry and fusion inhibitors of HIV are being investigated in controlled clinical trials and there are a number of them that are bioavailable as oral formulations. This is an essential feature for an extended use of these compounds with the purpose of ameliorating patients' adherence to medications; therefore, preventing the development of drug resistance. Among the many compounds that are being investigated, some are in the preclinical arena and others are more advanced in development stages. Overall, the main aim is to establish the action of these compounds on the immune system (e.g., the balance of the system after shutting off CCR5 or CXCR4 coreceptors) and the possible burden of unexplained side effects. This review focuses on the recent developments in this field with a particular attention on promising compounds in preclinical and clinical trials.

  12. Electron tomography of the contact between T cells and SIV/HIV-1: implications for viral entry.

    Directory of Open Access Journals (Sweden)

    Rachid Sougrat

    2007-05-01

    Full Text Available The envelope glycoproteins of primate lentiviruses, including human and simian immunodeficiency viruses (HIV and SIV, are heterodimers of a transmembrane glycoprotein (usually gp41, and a surface glycoprotein (gp120, which binds CD4 on target cells to initiate viral entry. We have used electron tomography to determine the three-dimensional architectures of purified SIV virions in isolation and in contact with CD4+ target cells. The trimeric viral envelope glycoprotein surface spikes are heterogeneous in appearance and typically approximately 120 A long and approximately 120 A wide at the distal end. Docking of SIV or HIV-1 on the T cell surface occurs via a neck-shaped contact region that is approximately 400 A wide and consistently consists of a closely spaced cluster of five to seven rod-shaped features, each approximately 100 A long and approximately 100 A wide. This distinctive structure is not observed when viruses are incubated with T lymphocytes in the presence of anti-CD4 antibodies, the CCR5 antagonist TAK779, or the peptide entry inhibitor SIVmac251 C34. For virions bound to cells, few trimers were observed away from this cluster at the virion-cell interface, even in cases where virus preparations showing as many as 70 envelope glycoprotein trimers per virus particle were used. This contact zone, which we term the "entry claw", provides a spatial context to understand the molecular mechanisms of viral entry. Determination of the molecular composition and structure of the entry claw may facilitate the identification of improved drugs for the inhibition of HIV-1 entry.

  13. Survival of the fittest: positive selection of CD4+ T cells expressing a membrane-bound fusion inhibitor following HIV-1 infection.

    Directory of Open Access Journals (Sweden)

    Janine Kimpel

    2010-08-01

    Full Text Available Although a variety of genetic strategies have been developed to inhibit HIV replication, few direct comparisons of the efficacy of these inhibitors have been carried out. Moreover, most studies have not examined whether genetic inhibitors are able to induce a survival advantage that results in an expansion of genetically-modified cells following HIV infection. We evaluated the efficacy of three leading genetic strategies to inhibit HIV replication: 1 an HIV-1 tat/rev-specific small hairpin (sh RNA; 2 an RNA antisense gene specific for the HIV-1 envelope; and 3 a viral entry inhibitor, maC46. In stably transduced cell lines selected such that >95% of cells expressed the genetic inhibitor, the RNA antisense envelope and viral entry inhibitor maC46 provided the strongest inhibition of HIV-1 replication. However, when mixed populations of transduced and untransduced cells were challenged with HIV-1, the maC46 fusion inhibitor resulted in highly efficient positive selection of transduced cells, an effect that was evident even in mixed populations containing as few as 1% maC46-expressing cells. The selective advantage of the maC46 fusion inhibitor was also observed in HIV-1-infected cultures of primary T lymphocytes as well as in HIV-1-infected humanized mice. These results demonstrate robust inhibition of HIV replication with the fusion inhibitor maC46 and the antisense Env inhibitor, and importantly, a survival advantage of cells expressing the maC46 fusion inhibitor both in vitro and in vivo. Evaluation of the ability of genetic inhibitors of HIV-1 replication to confer a survival advantage on genetically-modified cells provides unique information not provided by standard techniques that may be important in the in vivo efficacy of these genes.

  14. Development of potent and long-acting HIV-1 fusion inhibitors.

    Science.gov (United States)

    Chong, Huihui; Wu, Xiyuan; Su, Yang; He, Yuxian

    2016-05-15

    T20 (enfuvirtide) is the first approved HIV entry inhibitor and currently the only viral fusion inhibitor, but its low efficacy and genetic barrier to resistance significantly limit its application, calling for a next-generation drug. On the basis of the M-T hook structure, we recently developed a short-peptide named HP23, which mainly targets the deep pocket site of gp41 and possesses highly potent antiviral activity. To improve the pharmaceutical properties of a peptide-based inhibitor, we modified HP23 by different classes of lipids including fatty acid, cholesterol, and sphingolipids. To avoid the potential problem of oxidation, the methionine residue in the M-T hook sequence of HP23 was replaced with leucine. Peptides were synthesized and their anti-HIV activity and biophysical properties were determined. A group of lipopeptides were generated with greatly improved anti-HIV activity. Promisingly, a fatty acid-conjugated lipopeptide named LP-11 showed potent and broad inhibitory activity against diverse primary HIV-1 isolates and clinically drug-resistant mutants, and it had dramatically increased ex-vivo antiviral activity and extended half-life. Also, LP-11 displayed highly enhanced α-helicity and thermal stability, and it was physically stable under high temperature and humidity. LP-11 has high potentials for clinical development and it can serve as an ideal tool for exploring the mechanisms of HIV-1 fusion and inhibition.

  15. HIV-1 Non-Nucleoside Reverse Transcriptase Inhibitors

    DEFF Research Database (Denmark)

    Vanangamudi, Murugesan; Poongavanam, Vasanthanathan; Namasivayam, Vigneshwaran

    2017-01-01

    BACKGROUND: Design of inhibitors for HIV-1 reverse transcriptase inhibition (HIV-1 RT) is one of the successful chemotherapies for the treatment of HIV infection. Among the inhibitors available for HIV-1 RT, non-nucleoside reverse transcriptase inhibitors (NNRTIs) have shown to be very promising...... and clinically approved drugs. However, the efficiency of many of these drugs has been reduced by the drug-resistant variants of HIV-1 RT. The aim of the current review is to provide a summary of lead optimization strategies from the 3D-QSARs studies on NNRTI class from the past 21 years (1995 to 2016). METHODS......, formimidoester disulfides, thiocarbamate, thiazolidinone derivatives, etc. have been discussed in detail. In addition, we explore the position of the functional groups that drive the protein-ligand interaction. RESULTS: The structure-activity relationship (SAR) revealed from CoMFA and CoMSIA studies...

  16. FAITH – Fast Assembly Inhibitor Test for HIV

    Energy Technology Data Exchange (ETDEWEB)

    Hadravová, Romana [Institute of Organic Chemistry and Biochemistry IOCB Research Centre & Gilead Sciences, Academy of Sciences of the Czech Republic, Flemingovo nám. 2, 166 10 Prague (Czech Republic); Rumlová, Michaela, E-mail: michaela.rumlova@vscht.cz [Institute of Organic Chemistry and Biochemistry IOCB Research Centre & Gilead Sciences, Academy of Sciences of the Czech Republic, Flemingovo nám. 2, 166 10 Prague (Czech Republic); Department of Biotechnology, University of Chemistry and Technology, Prague, Technická 5, 166 28 Prague (Czech Republic); Ruml, Tomáš, E-mail: tomas.ruml@vscht.cz [Department of Biochemistry and Microbiology, University of Chemistry and Technology, Prague, Technická 3, 166 28 Prague (Czech Republic)

    2015-12-15

    Due to the high number of drug-resistant HIV-1 mutants generated by highly active antiretroviral therapy (HAART), there is continuing demand for new types of inhibitors. Both the assembly of the Gag polyprotein into immature and mature HIV-1 particles are attractive candidates for the blocking of the retroviral life cycle. Currently, no therapeutically-used assembly inhibitor is available. One possible explanation is the lack of a reliable and simple assembly inhibitor screening method. To identify compounds potentially inhibiting the formation of both types of HIV-1 particles, we developed a new fluorescent high-throughput screening assay. This assay is based on the quantification of the assembly efficiency in vitro in a 96-well plate format. The key components of the assay are HIV-1 Gag-derived proteins and a dual-labelled oligonucleotide, which emits fluorescence only when the assembly of retroviral particles is inhibited. The method was validated using three (CAI, BM2, PF74) reported assembly inhibitors. - Highlights: • Allows screening of assembly inhibitors of both mature and immature HIV-1 particles. • Based on Gag-derived proteins with CA in mature or immature conformation. • Simple and sensitive method suitable for high-throughput screening of inhibitors. • Unlike in other HIV assembly methods, works under physiological conditions. • No washing steps are necessary.

  17. HIV-1 integrase inhibitors as new components of antiviral therapy

    Energy Technology Data Exchange (ETDEWEB)

    Prikazchikova, T A; Aleksandrov, D A; Gottikh, M B [A. N. Belozersky Institute of Physico-Chemical Biology, M. V. Lomonosov Moscow State University, Moscow (Russian Federation); Sycheva, A M; Agapkina, Y Y [Department of Chemistry, M.V. Lomonosov Moscow State University, Moscow (Russian Federation)

    2008-05-31

    Structural and functional features of HIV-1 integrase are considered and the state of the art in the quest for effective inhibitors of this enzyme is reported. The major classes of integrase inhibitors with known mechanisms of action as well as their in vitro and in vivo inhibitory activities are presented.

  18. Activity and Safety of Synthetic Lectins Based on Benzoboroxole-Functionalized Polymers for Inhibition of HIV Entry

    Science.gov (United States)

    Mahalingam, Alamelu; Geonnotti, Anthony R.; Balzarini, Jan; Kiser, Patrick F.

    2011-01-01

    Lectins derived from plant and microbial sources constitute a vital class of entry inhibitors that target the oligomannose residues on the HIV envelope gp120. Despite their potency and specificity, success of lectin-based entry inhibitors may be impeded by issues in regards to economical production, formulation and potential mitogenicity. Therefore, there exists a gap in the HIV therapeutics pipeline that underscores the need for mass producible, synthetic, broad-spectrum, and biocomptabile inhibitors of HIV entry. Here, we present the development of a polymeric synthetic lectin, based on benzoboroxole (BzB), which exhibits weak affinity (~25 M−1) for non-reducing sugars, similar to those found on the HIV envelope. High molecular weight BzB-functionalized polymers demonstrated antiviral activity that increased with an increase in ligand density and molecular weight of the polymer construct; revealing that polyvalency improves activity. Polymers showed significant increase in activity from 25 to 75 mol% BzB functionalization with EC50 of 15 μM and 15 nM, respectively. A further increase in mole functionalization to 90% resulted in an increase of the EC50 (59 ± 5 nM), likely due to the elongated rigid structure of the polymer chain compelled by electrostatic repulsion between the boronic acid groups. An increase in molecular weight of the polymer at 50 mol% BzB functionalization showed a gradual but significant increase in antiviral activity, with the highest activity seen with the 382 kDa polymer (EC50 of 1.1 ± 0.5 nM in CEM cells and 11 ± 3 nM in TZM-bl cells). Supplementing the polymer backbone with 10 mol% sulfonic acid not only increased the aqueous solubility of the polymers by at least 50-fold, but also demonstrated a synergistic increase in anti-HIV activity (4.0 ± 1.5 nM in TZM-bl cells), possibly due to electrostatic interactions between the negatively charged polymer backbone and the positively charged V3-loop in the gp120. The benzoboroxole

  19. HIV-protease inhibitors for the treatment of cancer

    DEFF Research Database (Denmark)

    Maksimovic-Ivanic, Danijela; Fagone, Paolo; McCubrey, James

    2017-01-01

    The possible use of HIV protease inhibitors (HIV-PI) as new therapeutic option for the treatment of cancer primarily originated from their success in treating HIV-related Kaposi's sarcoma (KS). While these findings were initially attributed to immune reconstitution and better control of oncogenic...... weak anticancer potency and important side effects. This has propelled several groups to generate derivatives of HIV-PIs for anticancer use, through modifications such as attachment of different moieties, ligands and transporters, including saquinavir-loaded folic acid conjugated nanoparticles...

  20. Asymmetric deactivation of HIV-1 gp41 following fusion inhibitor binding.

    Directory of Open Access Journals (Sweden)

    Kristen M Kahle

    2009-11-01

    Full Text Available Both equilibrium and nonequilibrium factors influence the efficacy of pharmaceutical agents that target intermediate states of biochemical reactions. We explored the intermediate state inhibition of gp41, part of the HIV-1 envelope glycoprotein complex (Env that promotes viral entry through membrane fusion. This process involves a series of gp41 conformational changes coordinated by Env interactions with cellular CD4 and a chemokine receptor. In a kinetic window between CD4 binding and membrane fusion, the N- and C-terminal regions of the gp41 ectodomain become transiently susceptible to inhibitors that disrupt Env structural transitions. In this study, we sought to identify kinetic parameters that influence the antiviral potency of two such gp41 inhibitors, C37 and 5-Helix. Employing a series of C37 and 5-Helix variants, we investigated the physical properties of gp41 inhibition, including the ability of inhibitor-bound gp41 to recover its fusion activity once inhibitor was removed from solution. Our results indicated that antiviral activity critically depended upon irreversible deactivation of inhibitor-bound gp41. For C37, which targets the N-terminal region of the gp41 ectodomain, deactivation was a slow process that depended on chemokine receptor binding to Env. For 5-Helix, which targets the C-terminal region of the gp41 ectodomain, deactivation occurred rapidly following inhibitor binding and was independent of chemokine receptor levels. Due to this kinetic disparity, C37 inhibition was largely reversible, while 5-Helix inhibition was functionally irreversible. The fundamental difference in deactivation mechanism points to an unappreciated asymmetry in gp41 following inhibitor binding and impacts the development of improved fusion inhibitors and HIV-1 vaccines. The results also demonstrate how the activities of intermediate state inhibitors critically depend upon the final disposition of inhibitor-bound states.

  1. A Lipopeptide HIV-1/2 Fusion Inhibitor with Highly Potent In Vitro, Ex Vivo, and In Vivo Antiviral Activity.

    Science.gov (United States)

    Chong, Huihui; Xue, Jing; Xiong, Shengwen; Cong, Zhe; Ding, Xiaohui; Zhu, Yuanmei; Liu, Zixuan; Chen, Ting; Feng, Yifan; He, Lei; Guo, Yan; Wei, Qiang; Zhou, Yusen; Qin, Chuan; He, Yuxian

    2017-06-01

    Peptides derived from the C-terminal heptad repeat (CHR) region of the human immunodeficiency virus type 1 (HIV-1) fusogenic protein gp41 are potent viral entry inhibitors, and currently, enfuvirtide (T-20) is the only one approved for clinical use; however, emerging drug resistance largely limits its efficacy. In this study, we generated a novel lipopeptide inhibitor, named LP-19, by integrating multiple design strategies, including an N-terminal M-T hook structure, an HIV-2 sequence, intrahelical salt bridges, and a membrane-anchoring lipid tail. LP-19 showed stable binding affinity and highly potent, broad, and long-lasting antiviral activity. In in vitro studies, LP-19 efficiently inhibited HIV-1-, HIV-2-, and simian immunodeficiency virus (SIV)-mediated cell fusion, viral entry, and infection, and it was highly active against diverse subtypes of primary HIV-1 isolates and inhibitor-resistant mutants. Ex vivo studies demonstrated that LP-19 exhibited dramatically increased anti-HIV activity and an extended half-life in rhesus macaques. In short-term monotherapy, LP-19 reduced viral loads to undetectable levels in acutely and chronically simian-human immunodeficiency virus (SHIV)-infected monkeys. Therefore, this study offers an ideal HIV-1/2 fusion inhibitor for clinical development and emphasizes the importance of the viral fusion step as a drug target.IMPORTANCE The peptide drug T-20 is the only viral fusion inhibitor in the clinic, which is used for combination therapy of HIV-1 infection; however, it requires a high dosage and easily induces drug resistance, calling for a new drug with significantly improved pharmaceutical profiles. Here, we have developed a short-lipopeptide-based fusion inhibitor, termed LP-19, which mainly targets the conserved gp41 pocket site and shows highly potent inhibitory activity against HIV-1, HIV-2, and even SIV isolates. LP-19 exhibits dramatically increased antiviral activity and an extended half-life in rhesus macaques, and

  2. Development of peptide inhibitors of HIV transmission

    Directory of Open Access Journals (Sweden)

    Siyu Shi

    2016-12-01

    Full Text Available Treatment of HIV has long faced the challenge of high mutation rates leading to rapid development of resistance, with ongoing need to develop new methods to effectively fight the infection. Traditionally, early HIV medications were designed to inhibit RNA replication and protein production through small molecular drugs. Peptide based therapeutics are a versatile, promising field in HIV therapy, which continues to develop as we expand our understanding of key protein-protein interactions that occur in HIV replication and infection. This review begins with an introduction to HIV, followed by the biological basis of disease, current clinical management of the disease, therapeutics on the market, and finally potential avenues for improved drug development.

  3. HIV protease inhibitors in pregnancy : pharmacology and clinical use.

    Science.gov (United States)

    Andany, Nisha; Loutfy, Mona R

    2013-03-01

    The impact of antiretroviral therapy (ART) on the natural history of HIV-1 infection has resulted in dramatic reductions in disease-associated morbidity and mortality. Additionally, the epidemiology of HIV-1 infection worldwide is changing, as women now represent a substantial proportion of infected adults. As more highly effective and tolerable antiretroviral regimens become available, and as the prevention of mother-to-child transmission becomes an attainable goal in the management of HIV-infected individuals, more and more HIV-positive women are choosing to become pregnant and have children. Consequently, it is important to consider the efficacy and safety of antiretroviral agents in pregnancy. Protease inhibitors are a common class of medication used in the treatment of HIV-1 infection and are increasingly being used in pregnancy. However, several studies have raised concerns regarding pharmacokinetic alterations in pregnancy, particularly in the third trimester, which results in suboptimal drug concentrations and a theoretically higher risk of virologic failure and perinatal transmission. Drug level reductions have been observed with each individual protease inhibitor and dose adjustments in pregnancy are suggested for certain agents. Furthermore, studies have also raised concerns regarding the safety of protease inhibitors in pregnancy, particularly as they may increase the risk of pre-term birth and metabolic disturbances. Overall, protease inhibitors are safe and effective for the treatment of HIV-infected pregnant women. Specifically, ritonavir-boosted lopinavir- and atazanavir-based regimens are preferred in pregnancy, while ritonavir-boosted darunavir- and saquinavir-based therapies are reasonable alternatives. This paper reviews the use of protease inhibitors in pregnancy, focusing on pharmacokinetic and safety considerations, and outlines the recommendations for use of this class of medication in the HIV-1-infected pregnant woman.

  4. Monocyte chemotactic protein-2 activates CCR5 and blocks CD4/CCR5-mediated HIV-1 entry/replication.

    Science.gov (United States)

    Gong, W; Howard, O M; Turpin, J A; Grimm, M C; Ueda, H; Gray, P W; Raport, C J; Oppenheim, J J; Wang, J M

    1998-02-20

    Human immunodeficiency virus, type I (HIV-1) cell-type tropism is dictated by chemokine receptor usage: T-cell line tropic viruses use CXCR4, whereas monocyte tropic viruses primarily use CCR5 as fusion coreceptors. CC chemokines macrophage inflammatory protein (MIP)-1alpha, MIP-1beta, and RANTES (regulated on activation normal T cell expressed and secreted) inhibit CD4/CCR5-mediated HIV-1 cell fusion. MCP-2 is also a member of the CC chemokine subfamily and has the capacity to interact with at least two receptors including CCR-1 and CCR2B. In an effort to further characterize the binding properties of MCP-2 on leukocytes, we observed that MCP-2, but not MCP-1, effectively competed with MIP-1beta for binding to monocytes, suggesting that MCP-2 may interact with CCR5. As predicted, MCP-2 competitively inhibited MIP-1beta binding to HEK293 cells stably transfected with CCR5 (CCR5/293 cells). MCP-2 also bound to and induced chemotaxis of CCR5/293 cells with a potency comparable with that of MIP-1beta. Confocal microscopy indicates that MCP-2 caused remarkable and dose-dependent internalization of CCR5 in CCR5/293 cells. Furthermore, MCP-2 inhibited the entry/replication of HIV-1ADA in CCR5/293 cells coexpressing CD4. These results indicated that MCP-2 uses CCR5 as one of its functional receptors and is an additional potent natural inhibitor of HIV-1.

  5. Antimalarial activity of HIV-1 protease inhibitor in chromone series.

    Science.gov (United States)

    Lerdsirisuk, Pradith; Maicheen, Chirattikan; Ungwitayatorn, Jiraporn

    2014-12-01

    Increasing parasite resistance to nearly all available antimalarial drugs becomes a serious problem to human health and necessitates the need to continue the search for new effective drugs. Recent studies have shown that clinically utilized HIV-1 protease (HIV-1 PR) inhibitors can inhibit the in vitro and in vivo growth of Plasmodium falciparum. In this study, a series of chromone derivatives possessing HIV-1 PR inhibitory activity has been tested for antimalarial activity against P. falciparum (K1 multi-drug resistant strain). Chromone 15, the potent HIV-1 PR inhibitor (IC50=0.65μM), was found to be the most potent antimalarial compound with IC50=0.95μM while primaquine and tafenoquine showed IC50=2.41 and 1.95μM, respectively. Molecular docking study of chromone compounds against plasmepsin II, an aspartic protease enzyme important in hemoglobin degradation, revealed that chromone 15 exhibited the higher binding affinity (binding energy=-13.24kcal/mol) than the known PM II inhibitors. Thus, HIV-1 PR inhibitor in chromone series has the potential to be a new class of antimalarial agent. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. Design of HIV Protease Inhibitors Based on Inorganic Polyhedral Metallacarboranes

    Energy Technology Data Exchange (ETDEWEB)

    Rezacova, Pavlina; Pokorna, Jana; Brynda, Ji; Kozisek, Milan; Cigler, Petr; Lesik, Martin; Fanfrlik, Jindrich; Rezac, Jan; Saskova, Klara Grantz; Sieglova, Irena; Plesek, Jaromir; Sicha, Vaclav; Gruner, Bohumir; Oberwinkler, Heike; Sedlacek, Juraj; Krausslich, Hans-Georg; Hobza, Pavel; Kral, Vladimir; Konvalinka, Jan; (Heidelberg); (ASCR-ICP); (ICT-Czech)

    2010-04-19

    HIV protease (HIV PR) is a primary target for anti-HIV drug design. We have previously identified and characterized substituted metallacarboranes as a new class of HIV protease inhibitors. In a structure-guided drug design effort, we connected the two cobalt bis(dicarbollide) clusters with a linker to substituted ammonium group and obtained a set of compounds based on a lead formula [H{sub 2}N-(8-(C{sub 2}H{sub 4}O){sub 2}-1,2-C{sub 2}B{sub 9}H{sub 10})(1',2'-C{sub 2}B{sub 9}H{sub 11})-3,3'-Co){sub 2}]Na. We explored inhibition properties of these compounds with various substitutions, determined the HIV PR:inhibitor crystal structure, and computationally explored the conformational space of the linker. Our results prove the capacity of linker-substituted dual-cage cobalt bis(dicarbollides) as lead compounds for design of more potent inhibitors of HIV PR.

  7. A compensatory mutation provides resistance to disparate HIV fusion inhibitor peptides and enhances membrane fusion.

    Directory of Open Access Journals (Sweden)

    Matthew P Wood

    Full Text Available Fusion inhibitors are a class of antiretroviral drugs used to prevent entry of HIV into host cells. Many of the fusion inhibitors being developed, including the drug enfuvirtide, are peptides designed to competitively inhibit the viral fusion protein gp41. With the emergence of drug resistance, there is an increased need for effective and unique alternatives within this class of antivirals. One such alternative is a class of cyclic, cationic, antimicrobial peptides known as θ-defensins, which are produced by many non-human primates and exhibit broad-spectrum antiviral and antibacterial activity. Currently, the θ-defensin analog RC-101 is being developed as a microbicide due to its specific antiviral activity, lack of toxicity to cells and tissues, and safety in animals. Understanding potential RC-101 resistance, and how resistance to other fusion inhibitors affects RC-101 susceptibility, is critical for future development. In previous studies, we identified a mutant, R5-tropic virus that had evolved partial resistance to RC-101 during in vitro selection. Here, we report that a secondary mutation in gp41 was found to restore replicative fitness, membrane fusion, and the rate of viral entry, which were compromised by an initial mutation providing partial RC-101 resistance. Interestingly, we show that RC-101 is effective against two enfuvirtide-resistant mutants, demonstrating the clinical importance of RC-101 as a unique fusion inhibitor. These findings both expand our understanding of HIV drug-resistance to diverse peptide fusion inhibitors and emphasize the significance of compensatory gp41 mutations.

  8. Continued challenge posed by HIV-related restrictions on entry, stay and residence.

    Science.gov (United States)

    Amon, Joe

    2008-12-01

    Restrictions on entry, stay, and residence for people living with HIV/AIDS violate international human rights law and cannot be justified by public health rationales. In this article, based upon his presentation in a concurrent session at the conference, Joe Amon argues that governments must immediately repeal these laws and policies.

  9. Aqueous Extracts of the Marine Brown Alga Lobophora variegata Inhibit HIV-1 Infection at the Level of Virus Entry into Cells

    KAUST Repository

    Kremb, Stephan

    2014-08-21

    In recent years, marine algae have emerged as a rich and promising source of molecules with potent activities against various human pathogens. The widely distributed brown alga Lobophora variegata that is often associated with tropical coral reefs exerts strong antibacterial and antiprotozoal effects, but so far has not been associated with specific anti-viral activities. This study investigated potential HIV-1 inhibitory activity of L. variegata collected from different geographical regions, using a cell-based full replication HIV-1 reporter assay. Aqueous L. variegata extracts showed strong inhibitory effects on several HIV-1 strains, including drug-resistant and primary HIV-1 isolates, and protected even primary cells (PBMC) from HIV-1-infection. Anti-viral potency was related to ecological factors and showed clear differences depending on light exposition or epiphyte growth. Assays addressing early events of the HIV-1 replication cycle indicated that L. variegata extracts inhibited entry of HIV-1 into cells at a pre-fusion step possibly by impeding mobility of virus particles. Further characterization of the aqueous extract demonstrated that even high doses had only moderate effects on viability of cultured and primary cells (PBMCs). Imaging-based techniques revealed extract effects on the plasma membrane and actin filaments as well as induction of apoptosis at concentrations exceeding EC50 of anti-HIV-1 activity by more than 400 fold. In summary, we show for the first time that L. variegata extracts inhibit HIV-1 entry, thereby suggesting this alga as promising source for the development of novel HIV-1 inhibitors.

  10. Aqueous extracts of the marine brown alga Lobophora variegata inhibit HIV-1 infection at the level of virus entry into cells.

    Directory of Open Access Journals (Sweden)

    Stephan Kremb

    Full Text Available In recent years, marine algae have emerged as a rich and promising source of molecules with potent activities against various human pathogens. The widely distributed brown alga Lobophora variegata that is often associated with tropical coral reefs exerts strong antibacterial and antiprotozoal effects, but so far has not been associated with specific anti-viral activities. This study investigated potential HIV-1 inhibitory activity of L. variegata collected from different geographical regions, using a cell-based full replication HIV-1 reporter assay. Aqueous L. variegata extracts showed strong inhibitory effects on several HIV-1 strains, including drug-resistant and primary HIV-1 isolates, and protected even primary cells (PBMC from HIV-1-infection. Anti-viral potency was related to ecological factors and showed clear differences depending on light exposition or epiphyte growth. Assays addressing early events of the HIV-1 replication cycle indicated that L. variegata extracts inhibited entry of HIV-1 into cells at a pre-fusion step possibly by impeding mobility of virus particles. Further characterization of the aqueous extract demonstrated that even high doses had only moderate effects on viability of cultured and primary cells (PBMCs. Imaging-based techniques revealed extract effects on the plasma membrane and actin filaments as well as induction of apoptosis at concentrations exceeding EC50 of anti-HIV-1 activity by more than 400 fold. In summary, we show for the first time that L. variegata extracts inhibit HIV-1 entry, thereby suggesting this alga as promising source for the development of novel HIV-1 inhibitors.

  11. Sensing of HIV-1 Entry Triggers a Type I Interferon Response in Human Primary Macrophages.

    Science.gov (United States)

    Decalf, Jérémie; Desdouits, Marion; Rodrigues, Vasco; Gobert, François-Xavier; Gentili, Matteo; Marques-Ladeira, Santy; Chamontin, Célia; Mougel, Marylène; Cunha de Alencar, Bruna; Benaroch, Philippe

    2017-08-01

    Along with CD4(+) T lymphocytes, macrophages are a major cellular source of HIV-1 replication and a potential viral reservoir. Following entry and reverse transcription in macrophages, cloaking of the viral cDNA by the HIV-1 capsid limits its cytosolic detection, enabling efficient replication. However, whether incoming HIV-1 particles are sensed by macrophages prior to reverse transcription remains unclear. Here, we show that HIV-1 triggers a broad expression of interferon (IFN)-stimulated genes (ISG) in monocyte-derived macrophages within a few hours after infection. This response does not require viral reverse transcription or the presence of HIV-1 RNA within particles, but viral fusion is essential. This response is elicited by viruses carrying different envelope proteins and thus different receptors to proceed for viral entry. Expression of ISG in response to viral entry requires TBK1 activity and type I IFNs signaling. Remarkably, the ISG response is transient but affects subsequent viral spread. Together, our results shed light on an early step of HIV-1 sensing by macrophages at the level of entry, which confers an early protection through type I IFN signaling and has potential implications in controlling the infection.IMPORTANCE HIV infection is restricted to T lymphocytes and macrophages. HIV-1-infected macrophages are found in many tissues of infected patients, even under antiretroviral therapy, and are considered a viral reservoir. How HIV-1 is detected and what type of responses are elicited upon sensing remain in great part elusive. The kinetics and localization of the production of cytokines such as interferons in response to HIV is of critical importance to understanding how the infection and the immune response are established. Our study provides evidence that macrophages can detect HIV-1 as soon as it enters the cell. Interestingly, this sensing is independent of the presence of viral nucleic acids within the particles but requires their fusion

  12. An anti-HIV microbicide engineered in commensal bacteria: secretion of HIV-1 fusion inhibitors by lactobacilli

    NARCIS (Netherlands)

    Pusch, O.; Kalyanaraman, R.; Tucker, L.D.; Wells, J.; Rmanratnam, B.; Boden, D.

    2006-01-01

    Objectives: To engineer Lactobacillus spp. to secrete HIV-1 fusion inhibitors with potent neutralizing activity against primary HIV-1 isolates. Methods: HIV-1 fusion inhibitors (FI-1, FI-2, and FI-3) were introduced into the previously developed shuttle vector pTSV2 and transformed in L. plantarum

  13. The phosphatidylinositol-3-phosphate 5-kinase inhibitor apilimod blocks filoviral entry and infection.

    Directory of Open Access Journals (Sweden)

    Elizabeth A Nelson

    2017-04-01

    Full Text Available Phosphatidylinositol-3-phosphate 5-kinase (PIKfyve is a lipid kinase involved in endosome maturation that emerged from a haploid genetic screen as being required for Ebola virus (EBOV infection. Here we analyzed the effects of apilimod, a PIKfyve inhibitor that was reported to be well tolerated in humans in phase 2 clinical trials, for its effects on entry and infection of EBOV and Marburg virus (MARV. We first found that apilimod blocks infections by EBOV and MARV in Huh 7, Vero E6 and primary human macrophage cells, with notable potency in the macrophages (IC50, 10 nM. We next observed that similar doses of apilimod block EBOV-glycoprotein-virus like particle (VLP entry and transcription-replication competent VLP infection, suggesting that the primary mode of action of apilimod is as an entry inhibitor, preventing release of the viral genome into the cytoplasm to initiate replication. After providing evidence that the anti-EBOV action of apilimod is via PIKfyve, we showed that it blocks trafficking of EBOV VLPs to endolysosomes containing Niemann-Pick C1 (NPC1, the intracellular receptor for EBOV. Concurrently apilimod caused VLPs to accumulate in early endosome antigen 1-positive endosomes. We did not detect any effects of apilimod on bulk endosome acidification, on the activity of cathepsins B and L, or on cholesterol export from endolysosomes. Hence by antagonizing PIKfyve, apilimod appears to block EBOV trafficking to its site of fusion and entry into the cytoplasm. Given the drug's observed anti-filoviral activity, relatively unexplored mechanism of entry inhibition, and reported tolerability in humans, we propose that apilimod be further explored as part of a therapeutic regimen to treat filoviral infections.

  14. Inhibition of herpes simplex virus type 1 entry by chloride channel inhibitors tamoxifen and NPPB

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Kai [Guangzhou Jinan Biomedicine Research and Development Center, National Engineering Research Center of Genetic Medicine, Jinan University, Guangzhou (China); College of Life Science and Technology, Jinan University, Guangzhou (China); Chen, Maoyun [Guangzhou Jinan Biomedicine Research and Development Center, National Engineering Research Center of Genetic Medicine, Jinan University, Guangzhou (China); College of pharmacy, Jinan University, Guangzhou (China); Xiang, Yangfei; Ma, Kaiqi [Guangzhou Jinan Biomedicine Research and Development Center, National Engineering Research Center of Genetic Medicine, Jinan University, Guangzhou (China); Jin, Fujun [Guangzhou Jinan Biomedicine Research and Development Center, National Engineering Research Center of Genetic Medicine, Jinan University, Guangzhou (China); College of pharmacy, Jinan University, Guangzhou (China); Wang, Xiao [School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006 (China); Wang, Xiaoyan; Wang, Shaoxiang [Guangzhou Jinan Biomedicine Research and Development Center, National Engineering Research Center of Genetic Medicine, Jinan University, Guangzhou (China); Wang, Yifei, E-mail: twang-yf@163.com [Guangzhou Jinan Biomedicine Research and Development Center, National Engineering Research Center of Genetic Medicine, Jinan University, Guangzhou (China)

    2014-04-18

    Highlights: • We analyze the anti-HSV potential of chloride channel inhibitors. • Tamoxifen and NPPB show anti-HSV-1 and anti-ACV-resistant HSV-1 activities. • HSV-1 infection induces intracellular chloride concentration increasing. • Tamoxifen and NPPB inhibit HSV-1 early infection. • Tamoxifen and NPPB prevent the fusion process of HSV-1. - Abstract: Herpes simplex virus type 1 (HSV-1) infection is very common worldwide and can cause significant health problems from periodic skin and corneal lesions to encephalitis. Appearance of drug-resistant viruses in clinical therapy has made exploring novel antiviral agents emergent. Here we show that chloride channel inhibitors, including tamoxifen and 5-nitro-2-(3-phenyl-propylamino) benzoic acid (NPPB), exhibited extensive antiviral activities toward HSV-1 and ACV-resistant HSV viruses. HSV-1 infection induced chloride ion influx while treatment with inhibitors reduced the increase of intracellular chloride ion concentration. Pretreatment or treatment of inhibitors at different time points during HSV-1 infection all suppressed viral RNA synthesis, protein expression and virus production. More detailed studies demonstrated that tamoxifen and NPPB acted as potent inhibitors of HSV-1 early entry step by preventing viral binding, penetration and nuclear translocation. Specifically the compounds appeared to affect viral fusion process by inhibiting virus binding to lipid rafts and interrupting calcium homeostasis. Taken together, the observation that tamoxifen and NPPB can block viral entry suggests a stronger potential for these compounds as well as other ion channel inhibitors in antiviral therapy against HSV-1, especially the compound tamoxifen is an immediately actionable drug that can be reused for treatment of HSV-1 infections.

  15. The Microtubule Inhibitor Podofilox Inhibits an Early Entry Step of Human Cytomegalovirus

    Directory of Open Access Journals (Sweden)

    Tobias Cohen

    2016-10-01

    Full Text Available Human cytomegalovirus is a ubiquitous β-herpesvirus that infects many different cell types through an initial binding to cell surface receptors followed by a fusion event at the cell membrane or endocytic vesicle. A recent high-throughput screen to identify compounds that block a step prior to viral gene expression identified podofilox as a potent and nontoxic inhibitor. Time-of-addition studies in combination with quantitative-PCR analysis demonstrated that podofilox limits an early step of virus entry at the cell surface. Podofilox was also able to drastically reduce infection by herpes simplex 1, an α-herpesvirus with a very similar entry process to CMV. Podofilox caused a reduced maximal plateau inhibition of infection by viruses with single step binding processes prior to fusion-like Newcastle disease virus, Sendai virus, and influenza A virus or viruses that enter via endocytosis like vesicular stomatitis virus and a clinical-like strain of CMV. These results indicate that microtubules appear to be participating in the post-binding step of virus entry including the pre- and post-penetration events. Modulation of the plasma membrane is required to promote virus entry for herpesviruses, and that podofilox, unlike colchicine or nocodazole, is able to preferentially target microtubule networks at the plasma membrane.

  16. Lipopeptides as dimerization inhibitors of HIV-1 protease

    OpenAIRE

    Schramm, H. J.; de Rosny, E.; Reboud-Ravaux, M.; Büttner, J.; Dick, A.; Schramm, W.

    1999-01-01

    In AIDS therapy, attempts have been made to inhibit the virus-encoded enzymes, e.g, HIV-1 protease, using active site-directed inhibitors. This approach is questionable, however, due to virus mutations and the high toxicity of the drugs, An alternative method to inhibit the dimeric HIV protease is the targeting of the interface region of the protease subunits in order to prevent subunit dimerization and enzyme activity, This approach should be less prone to inactivation by mutation, A list of...

  17. A post-entry role for CD63 in early HIV-1 replication.

    Science.gov (United States)

    Li, Guangyu; Dziuba, Natallia; Friedrich, Brian; Murray, James L; Ferguson, Monique R

    2011-04-10

    Macrophages and CD4(+) lymphocytes are the major reservoirs for HIV-1 infection. CD63 is a tetraspanin transmembrane protein, which has been shown to play an essential role during HIV-1 replication in macrophages. In this study, we further confirm the requirement of CD63 in early HIV-1 replication events in both macrophages and a CD4(+) cell line. Further analysis revealed that viral attachment and cell-cell fusion were unaffected by CD63 silencing. However, CD63-depleted macrophages showed a significant decrease in the initiation and completion of HIV-1 reverse transcription, affecting subsequent events of the HIV-1 life cycle. Integration of HIV-1 cDNA as well as the formation of 2-LTR circles was notably reduced. Reporter assays showed that CD63 down regulation reduced production of the early HIV protein Tat. In agreement, CD63 silencing also inhibited production of the late protein p24. These findings suggest that CD63 plays an early post-entry role prior to or at the reverse transcription step. Copyright © 2010 Elsevier Inc. All rights reserved.

  18. Identification of a human protein-derived HIV-1 fusion inhibitor targeting the gp41 fusion core structure.

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    Lijun Chao

    Full Text Available The HIV-1 envelope glycoprotein (Env gp41 plays a crucial role in the viral fusion process. The peptides derived from the C-terminal heptad repeat (CHR of gp41 are potent HIV fusion inhibitors. However, the activity of these anti-HIV-1 peptides in vivo may be attenuated by their induction of anti-gp41 antibodies. Thus, it is essential to identify antiviral peptides or proteins with low, or no, immunogenicity to humans. Here, we found that the C-terminal fragment (aa 462-521 of the human POB1 (the partner of RalBP1, designated C60, is an HIV-1 fusion inhibitor. It bound to N36, the peptide derived from the N-terminal heptad repeat (NHR of gp41, and to the six-helix bundle (6-HB formed by N36 and C34, a CHR-peptide, but it did not bind to C34. Unlike the CHR-peptides, C60 did not block gp41 6-HB formation. Rather, results suggest that C60 inhibits HIV-1 fusion by binding to the 6-HB, in particular, the residues in the gp41 NHR domain that are exposed on the surface of 6-HB. Since 6-HB plays a crucial role in the late stage of fusion between the viral envelope and endosomal membrane during the endocytic process of HIV-1, C60 may serve as a host restriction factor to suppress HIV-1 entry into CD4+ T lymphocytes. Taken together, it can be concluded from these results that C60 can be used as a lead for the development of anti-HIV-1 therapeutics or microbicides for the treatment and prevention of HIV-1 infection, as well as a molecular probe to study the fusogenic mechanism of HIV-1.

  19. Identification of HIV Inhibitors Guided by Free Energy Perturbation Calculations

    OpenAIRE

    Acevedo, Orlando; Ambrose, Zandrea; Patrick T. Flaherty; Aamer, Hadega; Jain, Prashi; Sambasivarao, Somisetti V.

    2012-01-01

    Free energy perturbation (FEP) theory coupled to molecular dynamics (MD) or Monte Carlo (MC) statistical mechanics offers a theoretically precise method for determining the free energy differences of related biological inhibitors. Traditionally requiring extensive computational resources and expertise, it is only recently that its impact is being felt in drug discovery. A review of computer-aided anti-HIV efforts employing FEP calculations is provided here that describes early and recent succ...

  20. Novel Acylguanidine-Based Inhibitor of HIV-1

    Science.gov (United States)

    Mwimanzi, Philip; Tietjen, Ian; Miller, Scott C.; Shahid, Aniqa; Cobarrubias, Kyle; Kinloch, Natalie N.; Baraki, Bemuluyigza; Richard, Jonathan; Finzi, Andrés; Fedida, David; Brumme, Zabrina L.

    2016-01-01

    ABSTRACT The emergence of transmissible HIV-1 strains with resistance to antiretroviral drugs highlights a continual need for new therapies. Here we describe a novel acylguanidine-containing compound, 1-(2-(azepan-1-yl)nicotinoyl)guanidine (or SM111), that inhibits in vitro replication of HIV-1, including strains resistant to licensed protease, reverse transcriptase, and integrase inhibitors, without major cellular toxicity. At inhibitory concentrations, intracellular p24Gag production was unaffected, but virion release (measured as extracellular p24Gag) was reduced and virion infectivity was substantially impaired, suggesting that SM111 acts at a late stage of viral replication. SM111-mediated inhibition of HIV-1 was partially overcome by a Vpu I17R mutation alone or a Vpu W22* truncation in combination with Env N136Y. These mutations enhanced virion infectivity and Env expression on the surface of infected cells in the absence and presence of SM111 but also impaired Vpu's ability to downregulate CD4 and BST2/tetherin. Taken together, our results support acylguanidines as a class of HIV-1 inhibitors with a distinct mechanism of action compared to that of licensed antiretrovirals. Further research on SM111 and similar compounds may help to elucidate knowledge gaps related to Vpu's role in promoting viral egress and infectivity. IMPORTANCE New inhibitors of HIV-1 replication may be useful as therapeutics to counteract drug resistance and as reagents to perform more detailed studies of viral pathogenesis. SM111 is a small molecule that blocks the replication of wild-type and drug-resistant HIV-1 strains by impairing viral release and substantially reducing virion infectivity, most likely through its ability to prevent Env expression at the infected cell surface. Partial resistance to SM111 is mediated by mutations in Vpu and/or Env, suggesting that the compound affects host/viral protein interactions that are important during viral egress. Further characterization of

  1. Role of TIM-4 in exosome-dependent entry of HIV-1 into human immune cells.

    Science.gov (United States)

    Sims, Brian; Farrow, Anitra L; Williams, Sparkle D; Bansal, Anju; Krendelchtchikov, Alexandre; Gu, Linlin; Matthews, Qiana L

    2017-01-01

    Exosomes, 30-200 nm nanostructures secreted from donor cells and internalized by recipient cells, can play an important role in the cellular entry of some viruses. These microvesicles are actively secreted into various body fluids, including blood, urine, saliva, cerebrospinal fluid, and breast milk. We successfully isolated exosomes from human breast milk and plasma. The size and concentration of purified exosomes were measured by nanoparticle tracking, while Western blotting confirmed the presence of the exosomal-associated proteins CD9 and CD63, clathrin, and T cell immunoglobulin and mucin proteins (TIMs). Through viral infection assays, we determined that HIV-1 utilizes an exosome-dependent mechanism for entry into human immune cells. The virus contains high amounts of phosphatidylserine (PtdSer) and may bind PtdSer receptors, such as TIMs. This mechanism is supported by our findings that exosomes from multiple sources increased HIV-1 entry into T cells and macrophages, and viral entry was potently blocked with anti-TIM-4 antibodies.

  2. Predictors of Delayed Entry into Medical Care of Children Diagnosed with HIV Infection: Data from an HIV Cohort Study in India

    Directory of Open Access Journals (Sweden)

    Gerardo Alvarez-Uria

    2013-01-01

    Full Text Available Data about the attrition before entry into care of children diagnosed with HIV in low- or middle-income countries are scarce. The aim of this study is to describe the attrition before engagement in HIV medical care in 523 children who were diagnosed with HIV from 2007 to 2012 in a cohort study in India. The cumulative incidence of children who entered into care was 87.2% at one year, but most children who did not enter into care within one year were lost to followup. The mortality before entry into care was low (1.3% at one year and concentrated during the first three months after HIV diagnosis. Factors associated with delayed entry into care were being diagnosed after mother’s HIV diagnosis, belonging to scheduled castes, age 90 minutes from the HIV centre. Children whose parents were alive and were living in a rented house were at a higher risk of delayed entry into care than those who were living in an owned house. The results of this study can be used to improve the linkage between HIV testing and HIV care of children diagnosed with HIV in India.

  3. Motivations for entry into sex work and HIV risk among mobile female sex workers in India.

    Science.gov (United States)

    Saggurti, Niranjan; Verma, Ravi K; Halli, Shiva S; Swain, Suvakanta N; Singh, Rajendra; Modugu, Hanimi Reddy; Ramarao, Saumya; Mahapatra, Bidhubhusan; Jain, Anrudh K

    2011-09-01

    This paper assesses the reasons for entry into sex work and its association with HIV risk behaviours among mobile female sex workers (FSWs) in India. Data were collected from a cross-sectional survey conducted in 22 districts across four high HIV prevalence states in India during 2007-2008. Analyses were limited to 5498 eligible mobile FSWs. The reasons given by FSWs for entering sex work and associations with socio-demographic characteristics were assessed. Reported reasons for entering sex work include poor or deprived economic conditions; negative social circumstances in life; own choice; force by an external person; and family tradition. The results from multivariate analyses indicate that those FSWs who entered sex work due to poor economic conditions or negative social circumstances in life or force demonstrated elevated levels of current inconsistent condom use as well as in the past in comparison with those FSWs who reported entering sex work by choice or family tradition. This finding indicates the need for a careful assessment of the pre-entry contexts among HIV prevention interventions since these factors may continue to hinder the effectiveness of efforts to reduce the spread of HIV/AIDS in India and elsewhere.

  4. Owl monkey CCR5 reveals synergism between CD4 and CCR5 in HIV-1 entry.

    Science.gov (United States)

    Nahabedian, John; Sharma, Amit; Kaczmarek, Maryska E; Wilkerson, Greg K; Sawyer, Sara L; Overbaugh, Julie

    2017-12-01

    Studying HIV-1 replication in the presence of functionally related proteins from different species has helped define host determinants of HIV-1 infection. Humans and owl monkeys, but not macaques, encode a CD4 receptor that permits entry of transmissible HIV-1 variants due to a single residue difference. However, little is known about whether divergent CCR5 receptor proteins act as determinants of host-range. Here we show that both owl monkey (Aotus vociferans) CD4 and CCR5 receptors are functional for the entry of transmitted HIV-1 when paired with human versions of the other receptor. By contrast, the owl monkey CD4/CCR5 pair is generally a suboptimal receptor combination, although there is virus-specific variation in infection with owl monkey receptors. Introduction of the human residues 15Y and 16T within a sulfation motif into owl monkey CCR5 resulted in a gain of function. These findings suggest there is cross-talk between CD4 and CCR5 involving the sulfation motif. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Contribution of intrinsic reactivity of the HIV-1 envelope glycoproteins to CD4-independent infection and global inhibitor sensitivity.

    Directory of Open Access Journals (Sweden)

    Hillel Haim

    2011-06-01

    inhibitor/antibody binding to the envelope glycoprotein trimer and by envelope glycoprotein reactivity to the inhibitor/antibody binding event. Quantitative differences in intrinsic reactivity contribute to HIV-1 strain variability in global susceptibility to neutralization and explain the long-observed relationship between increased inhibitor sensitivity and decreased entry requirements for target cell CD4.

  6. Contribution of Intrinsic Reactivity of the HIV-1 Envelope Glycoproteins to CD4-Independent Infection and Global Inhibitor Sensitivity

    Science.gov (United States)

    Haim, Hillel; Strack, Bettina; Kassa, Aemro; Madani, Navid; Wang, Liping; Courter, Joel R.; Princiotto, Amy; McGee, Kathleen; Pacheco, Beatriz; Seaman, Michael S.; Smith, Amos B.; Sodroski, Joseph

    2011-01-01

    inhibitor/antibody binding to the envelope glycoprotein trimer and by envelope glycoprotein reactivity to the inhibitor/antibody binding event. Quantitative differences in intrinsic reactivity contribute to HIV-1 strain variability in global susceptibility to neutralization and explain the long-observed relationship between increased inhibitor sensitivity and decreased entry requirements for target cell CD4. PMID:21731494

  7. Targeting spare CC chemokine receptor 5 (CCR5) as a principle to inhibit HIV-1 entry.

    Science.gov (United States)

    Jin, Jun; Colin, Philippe; Staropoli, Isabelle; Lima-Fernandes, Evelyne; Ferret, Cécile; Demir, Arzu; Rogée, Sophie; Hartley, Oliver; Randriamampita, Clotilde; Scott, Mark G H; Marullo, Stefano; Sauvonnet, Nathalie; Arenzana-Seisdedos, Fernando; Lagane, Bernard; Brelot, Anne

    2014-07-04

    CCR5 binds the chemokines CCL3, CCL4, and CCL5 and is the major coreceptor for HIV-1 entry into target cells. Chemokines are supposed to form a natural barrier against human immunodeficiency virus, type 1 (HIV-1) infection. However, we showed that their antiviral activity is limited by CCR5 adopting low-chemokine affinity conformations at the cell surface. Here, we investigated whether a pool of CCR5 that is not stabilized by chemokines could represent a target for inhibiting HIV infection. We exploited the characteristics of the chemokine analog PSC-RANTES (N-α-(n-nonanoyl)-des-Ser(1)-[l-thioprolyl(2), l-cyclohexylglycyl(3)]-RANTES(4-68)), which displays potent anti-HIV-1 activity. We show that native chemokines fail to prevent high-affinity binding of PSC-RANTES, analog-mediated calcium release (in desensitization assays), and analog-mediated CCR5 internalization. These results indicate that a pool of spare CCR5 may bind PSC-RANTES but not native chemokines. Improved recognition of CCR5 by PSC-RANTES may explain why the analog promotes higher amounts of β-arrestin 2·CCR5 complexes, thereby increasing CCR5 down-regulation and HIV-1 inhibition. Together, these results highlight that spare CCR5, which might permit HIV-1 to escape from chemokines, should be targeted for efficient viral blockade. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  8. The conserved residue Arg46 in the N-terminal heptad repeat domain of HIV-1 gp41 is critical for viral fusion and entry.

    Directory of Open Access Journals (Sweden)

    Xiaoyi Wang

    Full Text Available During the process of HIV-1 fusion with the target cell, the N-terminal heptad repeat (NHR of gp41 interacts with the C-terminal heptad repeat (CHR to form fusogenic six-helix bundle (6-HB core. We previously identified a crucial residue for 6-HB formation and virus entry--Lys63 (K63 in the C-terminal region of NHR (aa 54-70, which forms a hydrophobic cavity. It can form an important salt bridge with Asp121 (D121 in gp41 CHR. Here, we found another important conserved residue for virus fusion and entry, Arg46 (R46, in the N-terminal region of NHR (aa 35-53, which forms a hydrogen bond with a polar residue, Asn43 (N43, in NHR, as a part of the hydrogen-bond network. R46 can also form a salt bridge with a negatively charged residue, Glu137 (E137, in gp41 CHR. Substitution of R46 with the hydrophobic residue Ala (R46A or the negatively charged residue Glu (R46E resulted in disruption of the hydrogen bond network, breakage of the salt bridge and reduction of 6-HB's stability, leading to impairment of viral fusion and decreased inhibition of N36, an NHR peptide. Similarly, CHR peptide C34 with substitution of E137 for Ala (E137A or Arg (E137R also exhibited reduced inhibitory activity against HIV-1 infection and HIV-1-mediated cell-to-cell fusion. These results suggest that the positively charged residue R46 and its hydrogen bond network, together with the salt bridge between R46 and E137, are important for viral fusion and entry and may therefore serve as a target for designing novel HIV fusion/entry inhibitors.

  9. Autophagy induction by histone deacetylase inhibitors inhibits HIV type 1.

    Science.gov (United States)

    Campbell, Grant R; Bruckman, Rachel S; Chu, Yen-Lin; Spector, Stephen A

    2015-02-20

    Histone deacetylase inhibitors (HDACi) are being evaluated in a "shock-and-kill" therapeutic approach to reverse human immunodeficiency virus type-1 (HIV) latency from CD4(+) T cells. Using this approach, HDACi have induced HIV RNA synthesis in latently infected cells from some patients. The hope is that the increase in viral production will lead to killing of the infected cell either by the virus itself or by the patient's immune system, a "sterilizing cure." Although administered within the context of combination antiretroviral therapy, the infection of bystander cells remains a concern. In this study, we investigated the effect of HDACi (belinostat, givinostat, panobinostat, romidepsin, and vorinostat) on the productive infection of macrophages. We demonstrate that the HDACi tested do not alter the initial susceptibility of macrophages to HIV infection. However, we demonstrate that HDACi decrease HIV release from macrophages in a dose-dependent manner (belinostat the canonical autophagy pathway. This mechanism involves unc-51-like autophagy-activating kinase 1 (ULK1) and the inhibition of the mammalian target of rapamycin and requires the formation of autophagosomes and their maturation into autolysosomes in the absence of increased cell death. These data provide further evidence in support of a role for autophagy in the control of HIV infection and suggest that careful consideration of off-target effects will be essential if HDACi are to be a component of a multipronged approach to eliminate latently infected cells. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  10. V3-independent competitive resistance of a dual-X4 HIV-1 to the CXCR4 inhibitor AMD3100.

    Directory of Open Access Journals (Sweden)

    Yosuke Maeda

    Full Text Available A CXCR4 inhibitor-resistant HIV-1 was isolated from a dual-X4 HIV-1 in vitro. The resistant variant displayed competitive resistance to the CXCR4 inhibitor AMD3100, indicating that the resistant variant had a higher affinity for CXCR4 than that of the wild-type HIV-1. Amino acid sequence analyses revealed that the resistant variant harbored amino acid substitutions in the V2, C2, and C4 regions, but no remarkable changes in the V3 loop. Site-directed mutagenesis confirmed that the changes in the C2 and C4 regions were principally involved in the reduced sensitivity to AMD3100. Furthermore, the change in the C4 region was associated with increased sensitivity to soluble CD4, and profoundly enhanced the entry efficiency of the virus. Therefore, it is likely that the resistant variant acquired the higher affinity for CD4/CXCR4 by the changes in non-V3 regions. Taken together, a CXCR4 inhibitor-resistant HIV-1 can evolve using a non-V3 pathway.

  11. SJ-3366, a unique and highly potent nonnucleoside reverse transcriptase inhibitor of human immunodeficiency virus type 1 (HIV-1) that also inhibits HIV-2.

    Science.gov (United States)

    Buckheit, R W; Watson, K; Fliakas-Boltz, V; Russell, J; Loftus, T L; Osterling, M C; Turpin, J A; Pallansch, L A; White, E L; Lee, J W; Lee, S H; Oh, J W; Kwon, H S; Chung, S G; Cho, E H

    2001-02-01

    We have identified and characterized a potent new nonnucleoside reverse transcriptase (RT) inhibitor (NNRTI) of human immunodeficiency virus type 1 (HIV-1) that also is active against HIV-2 and which interferes with virus replication by two distinct mechanisms. 1-(3-Cyclopenten-1-yl)methyl-6-(3,5-dimethylbenzoyl)-5-ethyl-2,4-pyrimidinedione (SJ-3366) inhibits HIV-1 replication at concentrations of approximately 1 nM, with a therapeutic index of greater than 4 x 10(6). The efficacy and toxicity of SJ-3366 are consistent when evaluated with established or fresh human cells, and the compound is equipotent against all strains of HIV-1 evaluated, including syncytium-inducing, non-syncytium-inducing, monocyte/macrophage-tropic, and subtype virus strains. Distinct from other members of the pharmacologic class of NNRTIs, SJ-3366 inhibited laboratory and clinical strains of HIV-2 at a concentration of approximately 150 nM, yielding a therapeutic index of approximately 20,000. Like most NNRTIs, the compound was less active when challenged with HIV-1 strains possessing the Y181C, K103N, and Y188C amino acid changes in the RT and selected for a virus with a Y181C amino acid change in the RT after five tissue culture passages in the presence of the compound. In combination anti-HIV assays with nucleoside and nonnucleoside RT and protease inhibitors, additive interactions occurred with all compounds tested with the exception of dideoxyinosine, with which a synergistic interaction was found. Biochemically, SJ-3366 exhibited a K(i) value of 3.2 nM, with a mixed mechanism of inhibition against HIV-1 RT, but it did not inhibit HIV-2 RT. SJ-3366 also inhibited the entry of both HIV-1 and HIV-2 into target cells. On the basis of its therapeutic index and multiple mechanisms of anti-HIV action, SJ-3366 represents an exciting new compound for use in HIV-infected individuals.

  12. Fear of Foreigners: HIV-related restrictions on entry, stay, and residence.

    Science.gov (United States)

    Amon, Joseph J; Todrys, Katherine Wiltenburg

    2008-12-16

    Among the earliest and the most enduring responses to the HIV/AIDS epidemic has been the imposition by governments of entry, stay, and residence restrictions for non-nationals living with HIV and AIDS. Sixty-six of the 186 countries in the world for which data are available currently have some form of restriction in place. Although international human rights law allows for discrimination in the face of public health considerations, such discrimination must be the least intrusive measure required to effectively address the public health concern. HIV-related travel restrictions, by contrast, not only do not protect public health, but result in deleterious effects both at the societal level - negatively impacting HIV prevention and treatment efforts - and at the individual level, affecting, in particular, labor migrants, refugee candidates, students, and short-term travelers. Governments should repeal these laws and policies, and instead devote legislative attention and national resources to comprehensive HIV prevention, care, and treatment programmes serving citizens and non-citizens alike.

  13. Journey describing the discoveries of anti-HIV triterpene acid families targeting HIV-entry/fusion, protease functioning and maturation stages.

    Science.gov (United States)

    Patel, Rahul V; Park, Se Won

    2014-01-01

    HIV infection/AIDS, is a fatal disease multiplying rapidly in virtually every country. Extensive creations are in progress to arrest the replication of the HIV, following the destruction of either particular step involved in the progression of HIV infection. In such endeavors, mechanistically more diverse antiviral therapies were showcased using naturally occurring triterpene acid and their derivatives acting at various stages of HIV life cycle like entry or fusion, function of HIV protease enzyme and finally at maturation. The present article holds an extensive step-by-step summary of anti-HIV breakthroughs of triterpene acid analogues and their derivatives with synthetic and activity aspects, featuring fertile clues for novel anti-HIV drug design, which helps to develop unprecedented opportunities to discover the next-generation anti- HIV armamentarium.

  14. Progress in the Identification of Dengue Virus Entry/Fusion Inhibitors

    Directory of Open Access Journals (Sweden)

    Carolina De La Guardia

    2014-01-01

    Full Text Available Dengue fever, a reemerging disease, is putting nearly 2.5 billion people at risk worldwide. The number of infections and the geographic extension of dengue fever infection have increased in the past decade. The disease is caused by the dengue virus, a flavivirus that uses mosquitos Aedes sp. as vectors. The disease has several clinical manifestations, from the mild cold-like illness to the more serious hemorrhagic dengue fever and dengue shock syndrome. Currently, there is no approved drug for the treatment of dengue disease or an effective vaccine to fight the virus. Therefore, the search for antivirals against dengue virus is an active field of research. As new possible receptors and biological pathways of the virus biology are discovered, new strategies are being undertaken to identify possible antiviral molecules. Several groups of researchers have targeted the initial step in the infection as a potential approach to interfere with the virus. The viral entry process is mediated by viral proteins and cellular receptor molecules that end up in the endocytosis of the virion, the fusion of both membranes, and the release of viral RNA in the cytoplasm. This review provides an overview of the targets and progress that has been made in the quest for dengue virus entry inhibitors.

  15. HIV-1 uncoating: connection to nuclear entry and regulation by host proteins

    Energy Technology Data Exchange (ETDEWEB)

    Ambrose, Zandrea, E-mail: zaa4@pitt.edu [Division of Infectious Diseases, Department of Medicine, University of Pittsburgh, School of Medicine, Pittsburgh, PA 15261 (United States); Aiken, Christopher [Department of Pathology, Microbiology and Immunology, Vanderbilt University, School of Medicine, Nashville, TN 37232 (United States)

    2014-04-15

    The RNA genome of human immunodeficiency virus type 1 (HIV-1) is enclosed by a capsid shell that dissociates within the cell in a multistep process known as uncoating, which influences completion of reverse transcription of the viral genome. Double-stranded viral DNA is imported into the nucleus for integration into the host genome, a hallmark of retroviral infection. Reverse transcription, nuclear entry, and integration are coordinated by a capsid uncoating process that is regulated by cellular proteins. Although uncoating is not well understood, recent studies have revealed insights into the process, particularly with respect to nuclear import pathways and protection of the viral genome from DNA sensors. Understanding uncoating will be valuable toward developing novel antiretroviral therapies for HIV-infected individuals.

  16. Inhibition of HIV-1 entry by the tricyclic coumarin GUT-70 through the modification of membrane fluidity

    Energy Technology Data Exchange (ETDEWEB)

    Matsuda, Kouki; Hattori, Shinichiro; Kariya, Ryusho [Division of Hematopoiesis, Center for AIDS Research, Kumamoto University, 2-2-1 Honjo, Chuo-ku, Kumamoto 860-0811 (Japan); Komizu, Yuji [Division of Applied Life Science, Graduate School of Engineering, Sojo University, 4-22-1 Ikeda, Nishi-ku, Kumamoto 860-0082 (Japan); Kudo, Eriko; Goto, Hiroki; Taura, Manabu [Division of Hematopoiesis, Center for AIDS Research, Kumamoto University, 2-2-1 Honjo, Chuo-ku, Kumamoto 860-0811 (Japan); Ueoka, Ryuichi [Division of Applied Life Science, Graduate School of Engineering, Sojo University, 4-22-1 Ikeda, Nishi-ku, Kumamoto 860-0082 (Japan); Kimura, Shinya [Division of Hematology, Respiratory Medicine and Oncology, Department of Internal Medicine, Faculty of Medicine, Saga University, 5-1-1 Nabeshima, Saga 849-8501 (Japan); Okada, Seiji, E-mail: okadas@kumamoto-u.ac.jp [Division of Hematopoiesis, Center for AIDS Research, Kumamoto University, 2-2-1 Honjo, Chuo-ku, Kumamoto 860-0811 (Japan)

    2015-02-13

    Membrane fusion between host cells and HIV-1 is the initial step in HIV-1 infection, and plasma membrane fluidity strongly influences infectivity. In the present study, we demonstrated that GUT-70, a natural product derived from Calophyllum brasiliense, stabilized plasma membrane fluidity, inhibited HIV-1 entry, and down-regulated the expression of CD4, CCR5, and CXCR4. Since GUT-70 also had an inhibitory effect on viral replication through the inhibition of NF-κB, it is expected to be used as a dual functional and viral mutation resistant reagent. Thus, these unique properties of GUT-70 enable the development of novel therapeutic agents against HIV-1 infection.

  17. Discovery of MK-8718, an HIV Protease Inhibitor Containing a Novel Morpholine Aspartate Binding Group.

    Science.gov (United States)

    Bungard, Christopher J; Williams, Peter D; Ballard, Jeanine E; Bennett, David J; Beaulieu, Christian; Bahnck-Teets, Carolyn; Carroll, Steve S; Chang, Ronald K; Dubost, David C; Fay, John F; Diamond, Tracy L; Greshock, Thomas J; Hao, Li; Holloway, M Katharine; Felock, Peter J; Gesell, Jennifer J; Su, Hua-Poo; Manikowski, Jesse J; McKay, Daniel J; Miller, Mike; Min, Xu; Molinaro, Carmela; Moradei, Oscar M; Nantermet, Philippe G; Nadeau, Christian; Sanchez, Rosa I; Satyanarayana, Tummanapalli; Shipe, William D; Singh, Sanjay K; Truong, Vouy Linh; Vijayasaradhi, Sivalenka; Wiscount, Catherine M; Vacca, Joseph P; Crane, Sheldon N; McCauley, John A

    2016-07-14

    A novel HIV protease inhibitor was designed using a morpholine core as the aspartate binding group. Analysis of the crystal structure of the initial lead bound to HIV protease enabled optimization of enzyme potency and antiviral activity. This afforded a series of potent orally bioavailable inhibitors of which MK-8718 was identified as a compound with a favorable overall profile.

  18. Discovery of MK-8718, an HIV Protease Inhibitor Containing a Novel Morpholine Aspartate Binding Group

    Energy Technology Data Exchange (ETDEWEB)

    Bungard, Christopher J.; Williams, Peter D.; Ballard, Jeanine E.; Bennett, David J.; Beaulieu, Christian; Bahnck-Teets, Carolyn; Carroll, Steve S.; Chang, Ronald K.; Dubost, David C.; Fay, John F.; Diamond, Tracy L.; Greshock, Thomas J.; Hao, Li; Holloway, M. Katharine; Felock, Peter J.; Gesell, Jennifer J.; Su, Hua-Poo; Manikowski, Jesse J.; McKay, Daniel J.; Miller, Mike; Min, Xu; Molinaro, Carmela; Moradei, Oscar M.; Nantermet, Philippe G.; Nadeau, Christian; Sanchez, Rosa I.; Satyanarayana, Tummanapalli; Shipe, William D.; Singh, Sanjay K.; Truong, Vouy Linh; Vijayasaradhi, Sivalenka; Wiscount, Catherine M.; Vacca, Joseph P.; Crane, Sheldon N.; McCauley, John A. (Merck); (Albany MR)

    2016-07-14

    A novel HIV protease inhibitor was designed using a morpholine core as the aspartate binding group. Analysis of the crystal structure of the initial lead bound to HIV protease enabled optimization of enzyme potency and antiviral activity. This afforded a series of potent orally bioavailable inhibitors of which MK-8718 was identified as a compound with a favorable overall profile.

  19. HIV-2 integrase variation in integrase inhibitor-naïve adults in Senegal, West Africa.

    Directory of Open Access Journals (Sweden)

    Geoffrey S Gottlieb

    Full Text Available Antiretroviral therapy for HIV-2 infection is hampered by intrinsic resistance to many of the drugs used to treat HIV-1. Limited studies suggest that the integrase inhibitors (INIs raltegravir and elvitegravir have potent activity against HIV-2 in culture and in infected patients. There is a paucity of data on genotypic variation in HIV-2 integrase that might confer intrinsic or transmitted INI resistance.We PCR amplified and analyzed 122 HIV-2 integrase consensus sequences from 39 HIV-2-infected, INI-naive adults in Senegal, West Africa. We assessed genetic variation and canonical mutations known to confer INI-resistance in HIV-1.No amino acid-altering mutations were detected at sites known to be pivotal for INI resistance in HIV-1 (integrase positions 143, 148 and 155. Polymorphisms at several other HIV-1 INI resistance-associated sites were detected at positions 72, 95, 125, 154, 165, 201, 203, and 263 of the HIV-2 integrase protein.Emerging genotypic and phenotypic data suggest that HIV-2 is susceptible to the new class of HIV integrase inhibitors. We hypothesize that intrinsic HIV-2 integrase variation at "secondary" HIV-1 INI-resistance sites may affect the genetic barrier to HIV-2 INI resistance. Further studies will be needed to assess INI efficacy as part of combination antiretroviral therapy in HIV-2-infected patients.

  20. HIV-2 Integrase Variation in Integrase Inhibitor-Naïve Adults in Senegal, West Africa

    Science.gov (United States)

    Gottlieb, Geoffrey S.; Smith, Robert A.; Dia Badiane, Ndeye Mery; Ba, Selly; Hawes, Stephen E.; Toure, Macoumba; Starling, Alison K.; Traore, Fatou; Sall, Fatima; Cherne, Stephen L.; Stern, Joshua; Wong, Kim G.; Lu, Paul; Kim, Moon; Raugi, Dana N.; Lam, Airin; Mullins, James I.; Kiviat, Nancy B.

    2011-01-01

    Background Antiretroviral therapy for HIV-2 infection is hampered by intrinsic resistance to many of the drugs used to treat HIV-1. Limited studies suggest that the integrase inhibitors (INIs) raltegravir and elvitegravir have potent activity against HIV-2 in culture and in infected patients. There is a paucity of data on genotypic variation in HIV-2 integrase that might confer intrinsic or transmitted INI resistance. Methods We PCR amplified and analyzed 122 HIV-2 integrase consensus sequences from 39 HIV-2–infected, INI-naive adults in Senegal, West Africa. We assessed genetic variation and canonical mutations known to confer INI-resistance in HIV-1. Results No amino acid-altering mutations were detected at sites known to be pivotal for INI resistance in HIV-1 (integrase positions 143, 148 and 155). Polymorphisms at several other HIV-1 INI resistance-associated sites were detected at positions 72, 95, 125, 154, 165, 201, 203, and 263 of the HIV-2 integrase protein. Conclusion Emerging genotypic and phenotypic data suggest that HIV-2 is susceptible to the new class of HIV integrase inhibitors. We hypothesize that intrinsic HIV-2 integrase variation at “secondary” HIV-1 INI-resistance sites may affect the genetic barrier to HIV-2 INI resistance. Further studies will be needed to assess INI efficacy as part of combination antiretroviral therapy in HIV-2–infected patients. PMID:21765953

  1. Novel small-molecule inhibitors of hepatitis C virus entry block viral spread and promote viral clearance in cell culture.

    Directory of Open Access Journals (Sweden)

    Glen A Coburn

    Full Text Available Combinations of direct-acting anti-virals offer the potential to improve the efficacy, tolerability and duration of the current treatment regimen for hepatitis C virus (HCV infection. Viral entry represents a distinct therapeutic target that has been validated clinically for a number of pathogenic viruses. To discover novel inhibitors of HCV entry, we conducted a high throughput screen of a proprietary small-molecule compound library using HCV pseudoviral particle (HCVpp technology. We independently discovered and optimized a series of 1,3,5-triazine compounds that are potent, selective and non-cytotoxic inhibitors of HCV entry. Representative compounds fully suppress both cell-free virus and cell-to-cell spread of HCV in vitro. We demonstrate, for the first time, that long term treatment of an HCV cell culture with a potent entry inhibitor promotes sustained viral clearance in vitro. We have confirmed that a single amino acid variant, V719G, in the transmembrane domain of E2 is sufficient to confer resistance to multiple compounds from the triazine series. Resistance studies were extended by evaluating both the fusogenic properties and growth kinetics of drug-induced and natural amino acid variants in the HCVpp and HCV cell culture assays. Our results indicate that amino acid variations at position 719 incur a significant fitness penalty. Introduction of I719 into a genotype 1b envelope sequence did not affect HCV entry; however, the overall level of HCV replication was reduced compared to the parental genotype 1b/2a HCV strain. Consistent with these findings, I719 represents a significant fraction of the naturally occurring genotype 1b sequences. Importantly, I719, the most relevant natural polymorphism, did not significantly alter the susceptibility of HCV to the triazine compounds. The preclinical properties of these triazine compounds support further investigation of entry inhibitors as a potential novel therapy for HCV infection.

  2. Targeting the AKT pathway: Repositioning HIV protease inhibitors as radiosensitizers

    Directory of Open Access Journals (Sweden)

    Jayant S Goda

    2016-01-01

    Full Text Available Cellular resistance in tumour cells to different therapeutic approaches has been a limiting factor in the curative treatment of cancer. Resistance to therapeutic radiation is a common phenomenon which significantly reduces treatment options and impacts survival. One of the mechanisms of acquiring resistance to ionizing radiation is the overexpression or activation of various oncogenes like the EGFR (epidermal growth factor receptor, RAS (rat sarcoma oncogene or loss of PTEN (phosphatase and tensin homologue which in turn activates the phosphatidyl inositol 3-kinase/protein kinase B (PI3-K/AKT pathway responsible for radiation resistance in various tumours. Blocking the pathway enhances the radiation response both in vitro and in vivo. Due to the differential activation of this pathway (constitutively activated in tumour cells and not in the normal host cells, it is an excellent candidate target for molecular targeted therapy to enhance radiation sensitivity. In this regard, HIV protease inhibitors (HPIs known to interfere with PI3-K/AKT signaling in tumour cells, have been shown to sensitize various tumour cells to radiation both in vitro and in vivo. As a result, HPIs are now being investigated as possible radiosensitizers along with various chemotherapeutic drugs. This review describes the mechanisms by which PI3-K/AKT pathway causes radioresistance and the role of HIV protease inhibitors especially nelfinavir as a potential candidate drug to target the AKT pathway for overcoming radioresistance and its use in various clinical trials for different malignancies.

  3. Targeting the AKT pathway: Repositioning HIV protease inhibitors as radiosensitizers.

    Science.gov (United States)

    Goda, Jayant S; Pachpor, Tejaswini; Basu, Trinanjan; Chopra, Supriya; Gota, Vikram

    2016-02-01

    Cellular resistance in tumour cells to different therapeutic approaches has been a limiting factor in the curative treatment of cancer. Resistance to therapeutic radiation is a common phenomenon which significantly reduces treatment options and impacts survival. One of the mechanisms of acquiring resistance to ionizing radiation is the overexpression or activation of various oncogenes like the EGFR (epidermal growth factor receptor), RAS (rat sarcoma) oncogene or loss of PTEN (phosphatase and tensin homologue) which in turn activates the phosphatidyl inositol 3-kinase/protein kinase B (PI3-K)/AKT pathway responsible for radiation resistance in various tumours. Blocking the pathway enhances the radiation response both in vitro and in vivo. Due to the differential activation of this pathway (constitutively activated in tumour cells and not in the normal host cells), it is an excellent candidate target for molecular targeted therapy to enhance radiation sensitivity. In this regard, HIV protease inhibitors (HPIs) known to interfere with PI3-K/AKT signaling in tumour cells, have been shown to sensitize various tumour cells to radiation both in vitro and in vivo. As a result, HPIs are now being investigated as possible radiosensitizers along with various chemotherapeutic drugs. This review describes the mechanisms by which PI3-K/AKT pathway causes radioresistance and the role of HIV protease inhibitors especially nelfinavir as a potential candidate drug to target the AKT pathway for overcoming radioresistance and its use in various clinical trials for different malignancies.

  4. HIV-1 stimulates nuclear entry of amyloid beta via dynamin dependent EEA1 and TGF-β/Smad signaling

    Energy Technology Data Exchange (ETDEWEB)

    András, Ibolya E., E-mail: iandras@med.miami; Toborek, Michal, E-mail: mtoborek@med.miami.edu

    2014-04-15

    Clinical evidence indicates increased amyloid deposition in HIV-1-infected brains, which contributes to neurocognitive dysfunction in infected patients. Here we show that HIV-1 exposure stimulates amyloid beta (Aβ) nuclear entry in human brain endothelial cells (HBMEC), the main component of the blood–brain barrier (BBB). Treatment with HIV-1 and/or Aβ resulted in concurrent increase in early endosomal antigen-1 (EEA1), Smad, and phosphorylated Smad (pSmad) in nuclear fraction of HBMEC. A series of inhibition and silencing studies indicated that Smad and EEA1 closely interact by influencing their own nuclear entry; the effect that was attenuated by dynasore, a blocker of GTP-ase activity of dynamin. Importantly, inhibition of dynamin, EEA1, or TGF-β/Smad effectively attenuated HIV-1-induced Aβ accumulation in the nuclei of HBMEC. The present study indicates that nuclear uptake of Aβ involves the dynamin-dependent EEA1 and TGF-β/Smad signaling pathways. These results identify potential novel targets to protect against HIV-1-associated dysregulation of amyloid processes at the BBB level. - Highlights: • HIV-1 induces nuclear accumulation of amyloid beta (Aβ) in brain endothelial cells. • EEA-1 and TGF-Β/Smad act in concert to regulate nuclear entry of Aβ. • Dynamin appropriates the EEA-1 and TGF-Β/Smad signaling. • Dynamin serves as a master regulator of HIV-1-induced nuclear accumulation of Aβ.

  5. HIV-1 Entry in SupT1-R5, CEM-ss, and Primary CD4+ T Cells Occurs at the Plasma Membrane and Does Not Require Endocytosis

    Science.gov (United States)

    Herold, Nikolas; Anders-Ößwein, Maria; Glass, Bärbel; Eckhardt, Manon; Müller, Barbara

    2014-01-01

    ABSTRACT Cytoplasmic entry of HIV-1 requires binding of the viral glycoproteins to the cellular receptor and coreceptor, leading to fusion of viral and cellular membranes. Early studies suggested that productive HIV-1 infection occurs by direct fusion at the plasma membrane. Endocytotic uptake of HIV-1 was frequently observed but was considered to constitute an unspecific dead-end pathway. More recent evidence suggested that endocytosis contributes to productive HIV-1 entry and may even represent the predominant or exclusive route of infection. We have analyzed HIV-1 binding, endocytosis, cytoplasmic entry, and infection in T-cell lines and in primary CD4+ T cells. Efficient cell binding and endocytosis required viral glycoproteins and CD4, but not the coreceptor. The contribution of endocytosis to cytoplasmic entry and infection was assessed by two strategies: (i) expression of dominant negative dynamin-2 was measured and was found to efficiently block HIV-1 endocytosis but to not affect fusion or productive infection. (ii) Making use of the fact that HIV-1 fusion is blocked at temperatures below 23°C, cells were incubated with HIV-1 at 22°C for various times, and endocytosis was quantified by parallel analysis of transferrin and fluorescent HIV-1 uptake. Subsequently, entry at the plasma membrane was blocked by high concentrations of the peptidic fusion inhibitor T-20, which does not reach previously endocytosed particles. HIV-1 infection was scored after cells were shifted to 37°C in the presence of T-20. These experiments revealed that productive HIV-1 entry occurs predominantly at the plasma membrane in SupT1-R5, CEM-ss, and primary CD4+ T cells, with little, if any, contribution coming from endocytosed virions. IMPORTANCE HIV-1, like all enveloped viruses, reaches the cytoplasm by fusion of the viral and cellular membranes. Many viruses enter the cytoplasm by endosomal uptake and fusion from the endosome, while cell entry can also occur by direct fusion at

  6. Exotic Dance in Baltimore: From Entry to STI/HIV Risk.

    Science.gov (United States)

    Lilleston, Pamela S; Reuben, Jacqueline; Sherman, Susan G

    2015-01-01

    Research has documented health risks associated with sex work, but few U.S. studies have focused on the exotic dance industry. We undertook this study to describe the factors that influenced women's entry into exotic dance and explored the relation of these forces to their subsequent sexually transmitted infection (STI)/HIV risk trajectory. Qualitative interviews (N = 25) were conducted with female exotic dancers from June through August 2009. Data were analyzed through Atlas-ti using an inductive approach. Economic vulnerability was the primary force behind women's initiation into the profession. Drug use, physical abuse, and enjoyment of dancing were often concurrent with economic need and provided a further push toward exotic dance. Social networks facilitated entry by normalizing the profession and presenting it as a solution to financial hardship. Characteristics of exotic dance clubs, such as immediate hire and daily pay, attracted women in a state of financial vulnerability. Women's motivations for dancing, including economic vulnerability and drug use practices, shaped their STI/HIV risk once immersed in the club environment, with social networks often facilitating sexual risk behavior. Understanding the factors that drive women to exotic dance and influence risk behavior in the club may assist in the development of targeted harm reduction interventions for exotic dancers.

  7. The Productive Entry Pathway of HIV-1 in Macrophages Is Dependent on Endocytosis through Lipid Rafts Containing CD4

    Science.gov (United States)

    van Wilgenburg, Bonnie; Moore, Michael D.; James, William S.; Cowley, Sally A.

    2014-01-01

    Macrophages constitute an important reservoir of HIV-1 infection, yet HIV-1 entry into these cells is poorly understood due to the difficulty in genetically manipulating primary macrophages. We developed an effective genetic approach to manipulate the sub-cellular distribution of CD4 in macrophages, and investigated how this affects the HIV-1 entry pathway. Pluripotent Stem Cells (PSC) were transduced with lentiviral vectors designed to manipulate CD4 location and were then differentiated into genetically modified macrophages. HIV-1 infection of these cells was assessed by performing assays that measure critical steps of the HIV-1 lifecycle (fusion, reverse transcription, and expression from HIV-1 integrants). Expression of LCK (which tethers CD4 to the surface of T cells, but is not normally expressed in macrophages) in PSC-macrophages effectively tethered CD4 at the cell surface, reducing its normal endocytic recycling route, and increasing surface CD4 expression 3-fold. This led to a significant increase in HIV-1 fusion and reverse transcription, but productive HIV-1 infection efficiency (as determined by reporter expression from DNA integrants) was unaffected. This implies that surface-tethering of CD4 sequesters HIV-1 into a pathway that is unproductive in macrophages. Secondly, to investigate the importance of lipid rafts (as detergent resistant membranes - DRM) in HIV-1 infection, we generated genetically modified PSC-macrophages that express CD4 mutants known to be excluded from DRM. These macrophages were significantly less able to support HIV-1 fusion, reverse-transcription and integration than engineered controls. Overall, these results support a model in which productive infection by HIV-1 in macrophages occurs via a CD4-raft-dependent endocytic uptake pathway. PMID:24465876

  8. US refuses to issue entry visas to people with HIV / AIDS.

    Science.gov (United States)

    1991-07-01

    The US government, ignoring the almost unanimous recommendation of medical and public health experts throughout the world, continues to ban both immigration and travel by people with HIV. Following recommendations from the US Centers for Disease Control and Prevention, the US Department of Health and Human Services indicated its intention to reduce the list of dangerous and contagious diseases for excluding entry to the US to include only active tuberculosis. That decision would have removed HIV/AIDS from the list. However, due to the subsequent 35,000 letters and postcards, mostly generated by conservative religious broadcasters and mailing houses opposed to lifting the ban, AIDS remained on the list. Opposition to lifting the ban came from the US Justice Department, as well as in the form of a signed statement to that end from 67 Republican members of the US Congress. US AIDS activists have organized their own letter campaign to support the removal of HIV/AIDS from the list. The June 1990 Sixth International Conference on AIDS was disrupted because of the travel ban. More than 70 AIDS, medical, and governmental organizations, including the International Red Cross, the British Medical Association, and the European Parliament boycotted the conferences. Planning for the 8th International Conference on AIDS, scheduled to be held in Boston in May 1992, is already being disputed and may not be held.

  9. Timing of entry to care by newly diagnosed HIV cases before and after the 2010 New York State HIV testing law.

    Science.gov (United States)

    Gordon, Daniel E; Bian, Fuqin; Anderson, Bridget J; Smith, Lou C

    2015-01-01

    Prompt entry to care after HIV diagnosis benefits the infected individual and reduces the likelihood of further transmission of the virus. The New York State HIV Testing Law of 2010 requires diagnosing providers to refer persons newly diagnosed with HIV to follow-up medical care. This study used routinely collected HIV-related laboratory data from the New York State HIV surveillance system to assess whether the fraction of newly diagnosed cases entering care within 90 days of diagnosis increased after the implementation of the law. Laboratory data on 23,302 newly diagnosed cases showed that entry to care within 90 days rose steadily from 72.0% in 2007 to 85.4% in 2012. The rise was observed across all race/ethnic groups, ages, transmission risk groups, sexes, and regions of residence. Logistic regression analyses of entry to care pre-law and post-law, controlling for demographic characteristics, transmission risk, and geographic area, indicate that percentage of newly diagnosed cases entering care within 90 days grew more rapidly in the post-law period. This is consistent with a positive effect of the law on entry to care.

  10. Interleukin-27 is a potent inhibitor of cis HIV-1 replication in monocyte-derived dendritic cells via a type I interferon-independent pathway.

    Directory of Open Access Journals (Sweden)

    Qian Chen

    Full Text Available IL-27, a member of the IL-12 family of cytokines, plays an important and diverse role in the function of the immune system. Whilst generally recognized as an anti-inflammatory cytokine, in addition IL-27 has been found to have broad anti-viral effects. Recently, IL-27 has been shown to be a potent inhibitor of HIV-1 infection in CD4+ T cells and macrophages. The main objective of this study was to see whether IL-27 has a similar inhibitory effect on HIV-1 replication in dendritic cells (DCs. Monocytes were differentiated into immature DCs (iDCs and mature DCs (mDCs with standard techniques using a combination of GM-CSF, IL-4 and LPS. Following differentiation, iDCs were infected with HIV-1 and co-cultured in the presence or absence of IL-27. IL-27 treated DCs were shown to be highly potent inhibitors of cis HIV-1, particularly of CCR5 tropic strains. Of note, other IL-12 family members (IL-12, IL-23 and IL-35 had no effect on HIV-1 replication. Microarray studies of IL-27 treated DCs showed no up-regulation of Type I (IFN gene expression. Neutralization of the Type-I IFN receptor had no impact on the HIV inhibition. Lastly, IL-27 mediated inhibition was shown to act post-viral entry and prior to completion of reverse transcription. These results show for the first time that IL-27 is a potent inhibitor of cis HIV-1 infection in DCs by a Type I IFN independent mechanism. IL-27 has previously been reported to inhibit HIV-1 replication in CD4+ T cells and macrophages, thus taken together, this cytokine is a potent anti-HIV agent against all major cell types targeted by the HIV-1 virus and may have a therapeutic role in the future.

  11. Drug design: new inhibitors for HIV-1 protease based on Nelfinavir as lead.

    Science.gov (United States)

    Perez, M A S; Fernandes, P A; Ramos, M J

    2007-10-01

    Nelfinavir (Viracept) is a potent, non-peptidic inhibitor of HIV-1 Protease, which has been marketed for the treatment of HIV infected patients. However, HIV-1 develops drug-resistance which decreases the affinity of Nelfinavir for the binding pocket of Protease. We present here three new variants of Nelfinavir, which we have designed with computational tools, with greater affinity for HIV-1 Protease than Nelfinavir itself. Accordingly, we have introduced rational modifications in Nelfinavir, optimizing its affinity to the most conserved amino acids in Protease, in order to increase the efficiency of the three new inhibitors. Minimization and molecular dynamics simulations have been carried out on four complexes, HIV-1 Protease with Nelfinavir and subsequently with the new inhibitors, respectively, in order to analyze the behavior of the systems. Additionally, we have calculated the binding free energy differences Protease:inhibitor, which gave us a quantitative idea of the new molecules inhibitory efficiency in silico.

  12. HIV-1 Entry Cofactor: Functional cDNA Cloning of a Seven-Transmembrane, G Protein–Coupled Receptor

    OpenAIRE

    Feng, Yu; Broder, Christopher C.; Kennedy, Paul E.; Berger, Edward A.

    2011-01-01

    A cofactor for HIV-1 (human immunodeficiency virus-type 1) fusion and entry was identified with the use of a novel functional complementary DNA (cDNA) cloning strategy. This protein, designated “fusin,” is a putative G protein–coupled receptor with seven transmembrane segments. Recombinant fusin enabled CD4-expressing nonhuman cell types to support HIV-1 Env-mediated cell fusion and HIV-1 infection. Antibodies to fusin blocked cell fusion and infection with normal CD4-positive human target ce...

  13. Generation of VSV pseudotypes using recombinant ΔG-VSV for studies on virus entry, identification of entry inhibitors, and immune responses to vaccines.

    Science.gov (United States)

    Whitt, Michael A

    2010-11-01

    Vesicular stomatitis virus (VSV) is a prototypic enveloped animal virus that has been used extensively to study virus entry, replication and assembly due to its broad host range and robust replication properties in a wide variety of mammalian and insect cells. Studies on VSV assembly led to the creation of a recombinant VSV in which the glycoprotein (G) gene was deleted. This recombinant (rVSV-ΔG) has been used to produce VSV pseudotypes containing the envelope glycoproteins of heterologous viruses, including viruses that require high-level biocontainment; however, because the infectivity of rVSV-ΔG pseudotypes is restricted to a single round of replication the analysis can be performed using biosafety level 2 (BSL-2) containment. As such, rVSV-ΔG pseudotypes have facilitated the analysis of virus entry for numerous viral pathogens without the need for specialized containment facilities. The pseudotypes also provide a robust platform to screen libraries for entry inhibitors and to evaluate the neutralizing antibody responses following vaccination. This manuscript describes methods to produce and titer rVSV-ΔG pseudotypes. Procedures to generate rVSV-ΔG stocks and to quantify virus infectivity are also described. These protocols should allow any laboratory knowledgeable in general virological and cell culture techniques to produce successfully replication-restricted rVSV-ΔG pseudotypes for subsequent analysis. Copyright © 2010 Elsevier B.V. All rights reserved.

  14. Design of HIV Protease Inhibitors Targeting Protein Backbone: An Effective Strategy for Combating Drug Resistance

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Arun K.; Chapsal, Bruno D.; Weber, Irene T.; Mitsuya, Hiroaki (GSU); (Kumamoto Univ., Japan); (Purdue)

    2008-06-03

    The discovery of human immunodeficiency virus (HIV) protease inhibitors (PIs) and their utilization in highly active antiretroviral therapy (HAART) have been a major turning point in the management of HIV/acquired immune-deficiency syndrome (AIDS). However, despite the successes in disease management and the decrease of HIV/AIDS-related mortality, several drawbacks continue to hamper first-generation protease inhibitor therapies. The rapid emergence of drug resistance has become the most urgent concern because it renders current treatments ineffective and therefore compels the scientific community to continue efforts in the design of inhibitors that can efficiently combat drug resistance.

  15. "Right Here is the Gateway": Mobility, Sex Work Entry and HIV Risk Along the Mexico-U.S. Border.

    Science.gov (United States)

    Goldenberg, Sm; Silverman, Js; Engstrom, D; Bojorquez-Chapela, I; Strathdee, Sa

    2014-08-01

    Women comprise an increasing proportion of migrants. Many voluntarily migrate for sex work or practice survival sex, while others may be trafficked for sexual exploitation. To investigate how the context of mobility shapes sex work entry and HIV risk, we conducted in-depth interviews with formerly trafficked women currently engaged in sex work (n=31) in Tijuana, Mexico and their service providers (n=7) in Tijuana and San Diego, USA from 2010-2011. Women's experiences of coerced and deceptive migration, deportation as forced migration, voluntary mobility, and migration to a risk environment illustrate that circumstances driving and resulting from migration shape vulnerability to sex trafficking, voluntary sex work entry, and HIV risk. Findings suggest an urgent need for public health and immigration policies that provide integrated support for deported and/or recently arrived female migrants. Policies to prevent sex trafficking and assist trafficked females must also consider the varying levels of personal agency involved in migration and sex work entry.

  16. A cell-based high-throughput protocol to screen entry inhibitors of highly pathogenic viruses with Traditional Chinese Medicines.

    Science.gov (United States)

    Yang, Yong; Cheng, Han; Yan, Hui; Wang, Peng-Zhan; Rong, Rong; Zhang, Ying-Ying; Zhang, Cheng-Bo; Du, Rui-Kun; Rong, Li-Jun

    2017-05-01

    Emerging viruses such as Ebola virus (EBOV), Lassa virus (LASV), and avian influenza virus H5N1 (AIV) are global health concerns. Since there is very limited options (either vaccine or specific therapy) approved for humans against these viruses, there is an urgent need to develop prophylactic and therapeutic treatments. Previously we reported a high-throughput screening (HTS) protocol to identify entry inhibitors for three highly pathogenic viruses (EBOV, LASV, and AIV) using a human immunodeficiency virus-based pseudotyping platform which allows us to perform the screening in a BSL-2 facility. In this report, we have adopted this screening protocol to evaluate traditional Chinese Medicines (TCMs) in an effort to discover entry inhibitors against these viruses. Here we show that extracts of the following Chinese medicinal herbs exhibit potent anti-Ebola viral activities: Gardenia jasminoides Ellis, Citrus aurantium L., Viola yedoensis Makino, Prunella vulgaris L., Coix lacryma-jobi L. var. mayuen (Roman.) Stapf, Pinellia ternata (Thunb.) Breit., and Morus alba L. This study represents a proof-of-principle investigation supporting the suitability of this assay for rapid screening TCMs and identifying putative entry inhibitors for these viruses. J. Med. Virol. 89:908-916, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  17. Focus on Chirality of HIV-1 Non-Nucleoside Reverse Transcriptase Inhibitors

    Directory of Open Access Journals (Sweden)

    Valeria Famiglini

    2016-02-01

    Full Text Available Chiral HIV-1 non-nucleoside reverse transcriptase inhibitors (NNRTIs are of great interest since one enantiomer is often more potent than the corresponding counterpart against the HIV-1 wild type (WT and the HIV-1 drug resistant mutant strains. This review exemplifies the various studies made to investigate the effect of chirality on the antiretroviral activity of top HIV-1 NNRTI compounds, such as nevirapine (NVP, efavirenz (EFV, alkynyl- and alkenylquinazolinone DuPont compounds (DPC, diarylpyrimidine (DAPY, dihydroalkyloxybenzyloxopyrimidine (DABO, phenethylthiazolylthiourea (PETT, indolylarylsulfone (IAS, arylphosphoindole (API and trifluoromethylated indole (TFMI The chiral separation, the enantiosynthesis, along with the biological properties of these HIV-1 NNRTIs, are discussed.

  18. Triggering HIV polyprotein processing by light using rapid photodegradation of a tight-binding protease inhibitor.

    Science.gov (United States)

    Schimer, Jiří; Pávová, Marcela; Anders, Maria; Pachl, Petr; Šácha, Pavel; Cígler, Petr; Weber, Jan; Majer, Pavel; Řezáčová, Pavlína; Kräusslich, Hans-Georg; Müller, Barbara; Konvalinka, Jan

    2015-03-09

    HIV protease (PR) is required for proteolytic maturation in the late phase of HIV replication and represents a prime therapeutic target. The regulation and kinetics of viral polyprotein processing and maturation are currently not understood in detail. Here we design, synthesize, validate and apply a potent, photodegradable HIV PR inhibitor to achieve synchronized induction of proteolysis. The compound exhibits subnanomolar inhibition in vitro. Its photolabile moiety is released on light irradiation, reducing the inhibitory potential by 4 orders of magnitude. We determine the structure of the PR-inhibitor complex, analyze its photolytic products, and show that the enzymatic activity of inhibited PR can be fully restored on inhibitor photolysis. We also demonstrate that proteolysis of immature HIV particles produced in the presence of the inhibitor can be rapidly triggered by light enabling thus to analyze the timing, regulation and spatial requirements of viral processing in real time.

  19. Sketching the historical development of pyrimidones as the inhibitors of the HIV integrase

    Czech Academy of Sciences Publication Activity Database

    Patel, Rahul V.; Keum, Y.S.; Park, S.W.

    2015-01-01

    Roč. 97, JUN 5 (2015), s. 649-663 ISSN 0223-5234 Institutional support: RVO:61389030 Keywords : Pyrimidones * Anti- HIV * Integrase inhibitors Subject RIV: CE - Biochemistry Impact factor: 3.902, year: 2015

  20. The histone deacetylase inhibitor panobinostat lowers biomarkers of cardiovascular risk and inflammation in HIV patients

    NARCIS (Netherlands)

    Kjaer, A.S. Hogh Kolbaek; Brinkmann, C.R.; Dinarello, C.A.; Olesen, R.; Ostergaard, L.; Sogaard, O.S.; Tolstrup, M.; Rasmussen, T.A.

    2015-01-01

    OBJECTIVE: To investigate the effect of the histone deacetylase inhibitor panobinostat on HIV-associated inflammation. DESIGN: Sub-study of a single-arm, phase I/II clinical trial. METHODS: HIV-infected adults on suppressive antiretroviral therapy received oral panobinostat 20 mg three times per

  1. HIV Nonnucleoside Reverse Transcriptase Inhibitors and Trimethoprim-Sulfamethoxazole Inhibit Plasmodium Liver Stages

    OpenAIRE

    Hobbs, Charlotte V.; Voza, Tatiana; de la Vega, Patricia; Vanvliet, Jillian; Conteh, Solomon; Penzak, Scott R.; Michael P Fay; Anders, Nicole; Ilmet, Tiina; Li, Yonghua; Borkowsky, William; Krzych, Urszula; Duffy, Patrick E.; Sinnis, Photini

    2012-01-01

    Background. Although nonnucleoside reverse transcriptase inhibitors (NNRTIs) are usually part of first-line treatment regimens for human immunodeficiency virus (HIV), their activity on Plasmodium liver stages remains unexplored. Additionally, trimethoprim-sulfamethoxazole (TMP-SMX), used for opportunistic infection prophylaxis in HIV-exposed infants and HIV-infected patients, reduces clinical episodes of malaria; however, TMP-SMX effect on Plasmodium liver stages requires further study.

  2. Two inhibitors of store operated Ca2+ entry suppress excitation contraction coupling in frog skeletal muscle.

    Science.gov (United States)

    Olivera, J Fernando; Fernando Olivera, J; Pizarro, Gonzalo

    2010-08-01

    Two drugs, 2-APB and SKF-96365, commonly used to block Store Operated Ca(2+) Entry (SOCE) were found to have inhibitory effects at different levels of the Excitation Contraction Coupling (ECC) process in frog skeletal muscle fibers. Treatment with either drug suppressed Ca(2+) release from the Sarcoplasmic Reticulum, but this effect was not due to inhibition of SOCE as it occurred in Ca(2+)-free conditions. 2-APB applied extracellularly at 100 microM, the usual concentration to suppress SOCE, reversibly reduced the charge movement elicited by pulses in the range between -45 and -35 mV from 7.99 +/- 0.73 nC/microF (N = 17) before drug application to 6.27 +/- 0.68 nC/microF in the presence of 2-APB. This effect was mostly on the delayed Q(gamma) component. In fibers treated with the SERCA ATPase inhibitor CPA the Q(gamma) component disappeared, under this condition the application of 2-APB did not suppress the remaining charge movement. Thus the effect of 2-APB on charge movement currents seemed to be secondary to the suppression of Ca(2+) release, likely occurring directly on the release channels. No significant suppression of ECC was observed for concentration below 20 muM. 2-APB also inhibited the L-type Ca(2+) current (20 +/- 4%, N = 8). On the other hand SKF-96365 had a direct effect on the voltage sensor promoting its voltage dependent inactivation. Applied at 20 muM, a typical concentration used for inhibiting SOCE, to fibers held at -80 mV inhibited the charge moved in response to pulses ranging -45 to -30 mV from 7.95 +/- 2.59 nC/microF to 3.48 +/- 0.9 nC/microF (N = 12). A parallel reduction of Ca(2+) release was observed. Wash out was drastically increased by hyperpolarization of the holding potential to -100 mV. SKF-96365 also inhibited the L-type Ca(2+) current (41 +/- 8%, N = 4) and increased its rate of inactivation.

  3. Solid-state characterization of the HIV protease inhibitor

    CERN Document Server

    Kim, Y A

    2002-01-01

    The LB71350, (3S, 4R)-Epoxy-(5S)-[[N-(1-methylethoxy) carbonyl]-3-(methylsulfonyl)-L-valinyl]amin= o]-N-[2-methyl-(1R)-[(phenyl)carbonyl]propyl-6-phenylhexanamide, is a novel HIV protease inhibitor. Its equilibrium solubility at room temperature was less than 40 mu g/mL. It was speculated that the low aqueous solubility might be due to the high crystalline lattice energy resulting from intermolecular hydrogen bonds. The present study was carried out to learn the solid-state characteristics of LB71350 using analytical methods such as NMR, FT-IR and XRD. sup 1 sup 3 C Solid-state NMR, solution NMR, and FT-IR spectra of the various solid forms of LB71350 were used to identify the conformation and structure of the solid forms. The chemical shifts of sup 1 sup 3 C solid-state NMR spectra suggest that the crystalline form might have 3 intermolecular hydrogen bondings between monomers.

  4. Four Amino Acid Changes in HIV-2 Protease Confer Class-Wide Sensitivity to Protease Inhibitors

    Science.gov (United States)

    Smith, Robert A.; Gottlieb, Geoffrey S.

    2015-01-01

    ABSTRACT Protease is essential for retroviral replication, and protease inhibitors (PI) are important for treating HIV infection. HIV-2 exhibits intrinsic resistance to most FDA-approved HIV-1 PI, retaining clinically useful susceptibility only to lopinavir, darunavir, and saquinavir. The mechanisms for this resistance are unclear; although HIV-1 and HIV-2 proteases share just 38 to 49% sequence identity, all critical structural features of proteases are conserved. Structural studies have implicated four amino acids in the ligand-binding pocket (positions 32, 47, 76, and 82). We constructed HIV-2ROD9 molecular clones encoding the corresponding wild-type HIV-1 amino acids (I32V, V47I, M76L, and I82V) either individually or together (clone PRΔ4) and compared the phenotypic sensitivities (50% effective concentration [EC50]) of mutant and wild-type viruses to nine FDA-approved PI. Single amino acid replacements I32V, V47I, and M76L increased the susceptibility of HIV-2 to multiple PI, but no single change conferred class-wide sensitivity. In contrast, clone PRΔ4 showed PI susceptibility equivalent to or greater than that of HIV-1 for all PI. We also compared crystallographic structures of wild-type HIV-1 and HIV-2 proteases complexed with amprenavir and darunavir to models of the PRΔ4 enzyme. These models suggest that the amprenavir sensitivity of PRΔ4 is attributable to stabilizing enzyme-inhibitor interactions in the P2 and P2′ pockets of the protease dimer. Together, our results show that the combination of four amino acid changes in HIV-2 protease confer a pattern of PI susceptibility comparable to that of HIV-1, providing a structural rationale for intrinsic HIV-2 PI resistance and resolving long-standing questions regarding the determinants of differential PI susceptibility in HIV-1 and HIV-2. IMPORTANCE Proteases are essential for retroviral replication, and HIV-1 and HIV-2 proteases share a great deal of structural similarity. However, only three of nine

  5. A modular system to evaluate the efficacy of protease inhibitors against HIV-2.

    Science.gov (United States)

    Mahdi, Mohamed; Matúz, Krisztina; Tóth, Ferenc; Tőzsér, József

    2014-01-01

    The human immunodeficiency virus (HIV) protease is a homodimeric aspartyl protease that is crucial for the viral life-cycle, cleaving proviral polyproteins, hence creating mature protein components that are required for the formation of an infectious virus. With diagnostic measures and clinically used protease inhibitors focusing on HIV-1, due to its higher virulence and prevalence, studies of the efficacy of those inhibitors on HIV-2 protease remain widely lacking. Utilizing a wild-type HIV-2 vector backbone and cloning techniques we have developed a cassette system where the efficacy of clinically used protease inhibitors can be studied for various serotypes of HIV-2 protease both in enzymatic and cell culture assays. In our experiments, optimization of the expression protocol led to a relatively stable enzyme, for cell culture assays, the efficiency of transfection and transduction capability of the modified vector was tested and was not found to differ from that of the wild-type, moreover, a 2nd generation protease inhibitor was used to demonstrate the usefulness of the system. The combination of assays performed with our cassette system is expected to provide an accurate measure of the efficacy of currently used; as well as experimental protease inhibitors on HIV-2.

  6. Molecular modeling studies and comparative analysis on structurally similar HTLV and HIV protease using HIV-PR inhibitors.

    Science.gov (United States)

    Selvaraj, Chandrabose; Singh, Poonam; Singh, Sanjeev Kumar

    2014-10-01

    Retroviruses are most perilous viral family, which cause much damage to the Homo sapiens. HTLV-1 mechanism found to more similar with HIV-1 and both retroviruses are causative agents of severe and fatal diseases including adult T-cell leukemia (ATL) and the acquired immune deficiency syndrome (AIDS). Both viruses code for a protease (PR) that is essential for replication and therefore represents a key target for drugs interfering with viral infection. In this work, the comparative study of HIV-1 and HTLV-1 PR enzymes through sequence and structural analysis is reported along with approved drugs of HIV-PR. Conformation of each HIV PR drugs have been examined with different parameters of interactions and energy scorings parameters. MD simulations with respect to timescale event of 20 ns favors that, few HIV-PR inhibitors can be more active inside the HTLV-1 PR binding pocket. Overall results suggest that, some of HIV inhibitors like Tipranavir, Indinavir, Darunavir and Amprenavir are having good energy levels with HTLV-1. Due to absence of interactions with MET37, here we report that derivatives of these compounds can be much better inhibitors for targeting HTLV-1 proteolytic activity.

  7. O-GalNAcylation of RANTES Improves Its Properties as a Human Immunodeficiency Virus Type 1 Entry Inhibitor.

    Science.gov (United States)

    Guan, Xiaoyang; Chaffey, Patrick K; Chen, Huan; Feng, Wei; Wei, Xiuli; Yang, Liu-Meng; Ruan, Yuan; Wang, Xinfeng; Li, Yaohao; Barosh, Kimberly B; Tran, Amy H; Zhu, Jaimie; Liang, Wei; Zheng, Yong-Tang; Wang, Xu; Tan, Zhongping

    2018-01-09

    Many human proteins have the potential to be developed as therapeutic agents. However, side effects caused by direct administration of natural proteins have significantly slowed expansion of protein therapeutics into the clinic. Post-translational modifications (PTMs) can improve protein properties, but because of significant knowledge gaps, we are considerably limited in our ability to apply PTMs to generate better protein therapeutics. Here, we seek to fill the gaps by studying the PTMs of a small representative chemotactic cytokine, RANTES. RANTES can inhibit HIV-1 infection by competing with it for binding to receptor CCR5 and stimulating CCR5 endocytosis. Unfortunately, RANTES can induce strong signaling, leading to severe inflammatory side effects. We apply a chemical biology approach to explore the potential of post-translationally modified RANTES as safe inhibitors of HIV-1 infection. We synthesized and systematically tested a library of RANTES isoforms for their ability to inhibit inflammatory signaling and prevent HIV-1 infection of primary human cells. Through this research, we revealed that most of the glycosylated variants have decreased inflammation-associated properties and identified one particular glyco variant, a truncated RANTES containing a Galβ1-3GalNAc disaccharide α-linked to Ser4, which stands out as having the best overall properties: relatively high HIV-1 inhibition potency but also weak inflammatory properties. Moreover, our results provided a structural basis for the observed changes in the properties of RANTES. Taken together, this work highlights the potential importance of glycosylation as an alternative strategy for developing CCR5 inhibitors to treat HIV-1 infection and, more generally, for reducing or eliminating unwanted properties of therapeutic proteins.

  8. Inhibitors of alphavirus entry and replication identified with a stable Chikungunya replicon cell line and virus-based assays.

    Directory of Open Access Journals (Sweden)

    Leena Pohjala

    Full Text Available Chikungunya virus (CHIKV, an alphavirus, has recently caused epidemic outbreaks and is therefore considered a re-emerging pathogen for which no effective treatment is available. In this study, a CHIKV replicon containing the virus replicase proteins together with puromycin acetyltransferase, EGFP and Renilla luciferase marker genes was constructed. The replicon was transfected into BHK cells to yield a stable cell line. A non-cytopathic phenotype was achieved by a Pro718 to Gly substitution and a five amino acid insertion within non-structural protein 2 (nsP2, obtained through selection for stable growth. Characterization of the replicon cell line by Northern blotting analysis revealed reduced levels of viral RNA synthesis. The CHIKV replicon cell line was validated for antiviral screening in 96-well format and used for a focused screen of 356 compounds (natural compounds and clinically approved drugs. The 5,7-dihydroxyflavones apigenin, chrysin, naringenin and silybin were found to suppress activities of EGFP and Rluc marker genes expressed by the CHIKV replicon. In a concomitant screen against Semliki Forest virus (SFV, their anti-alphaviral activity was confirmed and several additional inhibitors of SFV with IC₅₀ values between 0.4 and 24 µM were identified. Chlorpromazine and five other compounds with a 10H-phenothiazinyl structure were shown to inhibit SFV entry using a novel entry assay based on a temperature-sensitive SFV mutant. These compounds also reduced SFV and Sindbis virus-induced cytopathic effect and inhibited SFV virion production in virus yield experiments. Finally, antiviral effects of selected compounds were confirmed using infectious CHIKV. In summary, the presented approach for discovering alphaviral inhibitors enabled us to identify potential lead structures for the development of alphavirus entry and replication phase inhibitors as well as demonstrated the usefulness of CHIKV replicon and SFV as biosafe surrogate

  9. Continuum in HIV care from entry to ART initiation in rural KwaZulu-Natal, South Africa.

    Science.gov (United States)

    Plazy, Mélanie; Dray-Spira, Rosemary; Orne-Gliemann, Joanna; Dabis, François; Newell, Marie-Louise

    2014-06-01

    To quantify time from entry in HIV care until Antiretroviral therapy (ART) initiation and identify factors associated with ART initiation in rural KwaZulu-Natal, South Africa. Adults ≥16 years entering the decentralised Hlabisa ART programme between 2007 and 2011 were followed until June 2013. Median survival times to ART initiation from date of programme entry and from date of ART eligibility were estimated with Kaplan-Meier methods. Associated factors were evaluated in Cox regressions, censoring for deaths. Of 37 749 adults (71.6% female), 17 638 (46.7%) initiated ART. Nearly half (46.9%) met the CD4 criteria for treatment eligibility at programme entry. Among the 20 039 individuals not yet ART-eligible at entry, only 62.5% were retained in care with at least one further CD4 measurement, of whom 6688 subsequently became ART-eligible. Overall, 65.5% of the 24 398 ART-eligible individuals initiated ART over the study period. ART initiation was more likely in women (P < 0.001), in individuals ≥ 25 years old (P < 0.001) and in patients with low CD4 count (P < 0.001). Patients who became eligible during follow up were significantly more likely to initiate ART than those eligible at programme entry (72.6% vs. 62.9%, Adjusted Hazard Ratio = 1.46; 95% Confidence Interval [1.41-1.51]), adjusting for sex, age, year and CD4 count at eligibility. In this rural programme, continuation of care remains challenging, especially in men and younger adults. ART initiation is more likely in those engaged prior eligibility than in those entering HIV care only late in their HIV disease. © 2014 John Wiley & Sons Ltd.

  10. Preclinical safety and efficacy of an anti–HIV-1 lentiviral vector containing a short hairpin RNA to CCR5 and the C46 fusion inhibitor

    Directory of Open Access Journals (Sweden)

    Orit Wolstein

    2014-01-01

    Full Text Available Gene transfer has therapeutic potential for treating HIV-1 infection by generating cells that are resistant to the virus. We have engineered a novel self-inactivating lentiviral vector, LVsh5/C46, using two viral-entry inhibitors to block early steps of HIV-1 cycle. The LVsh5/C46 vector encodes a short hairpin RNA (shRNA for downregulation of CCR5, in combination with the HIV-1 fusion inhibitor, C46. We demonstrate here the effective delivery of LVsh5/C46 to human T cell lines, peripheral blood mononuclear cells, primary CD4+ T lymphocytes, and CD34+ hematopoietic stem/progenitor cells (HSPC. CCR5-targeted shRNA (sh5 and C46 peptide were stably expressed in the target cells and were able to effectively protect gene-modified cells against infection with CCR5- and CXCR4-tropic strains of HIV-1. LVsh5/C46 treatment was nontoxic as assessed by cell growth and viability, was noninflammatory, and had no adverse effect on HSPC differentiation. LVsh5/C46 could be produced at a scale sufficient for clinical development and resulted in active viral particles with very low mutagenic potential and the absence of replication-competent lentivirus. Based on these in vitro results, plus additional in vivo safety and efficacy data, LVsh5/C46 is now being tested in a phase 1/2 clinical trial for the treatment of HIV-1 disease.

  11. Inhibition Profiling of Retroviral Protease Inhibitors Using an HIV-2 Modular System.

    Science.gov (United States)

    Mahdi, Mohamed; Szojka, Zsófia; Mótyán, János András; Tőzsér, József

    2015-11-27

    Retroviral protease inhibitors (PIs) are fundamental pillars in the treatment of HIV infection and acquired immunodeficiency syndrome (AIDS). Currently used PIs are designed against HIV-1, and their effect on HIV-2 is understudied. Using a modular HIV-2 protease cassette system, inhibition profiling assays were carried out for protease inhibitors both in enzymatic and cell culture assays. Moreover, the treatment-associated resistance mutations (I54M, L90M) were introduced into the modular system, and comparative inhibition assays were performed to determine their effect on the susceptibility of the protease. Our results indicate that darunavir, saquinavir, indinavir and lopinavir were very effective HIV-2 protease inhibitors, while tipranavir, nelfinavir and amprenavir showed a decreased efficacy. I54M, L90M double mutation resulted in a significant reduction in the susceptibility to most of the inhibitors with the exception of tipranavir. To our knowledge, this modular system constitutes a novel approach in the field of HIV-2 protease characterization and susceptibility testing.

  12. Robust Vaginal Colonization of Macaques with a Novel Vaginally Disintegrating Tablet Containing a Live Biotherapeutic Product to Prevent HIV Infection in Women: e0122730

    National Research Council Canada - National Science Library

    Laurel A Lagenaur; Iwona Swedek; Peter P Lee; Thomas P Parks

    2015-01-01

      MucoCept is a biotherapeutic for prevention of HIV-1 infection in women and contains a human, vaginal Lactobacillus jensenii that has been genetically enhanced to express the HIV-1 entry inhibitor...

  13. Design, Synthesis and Structure-activity Studies of Rhodanine Derivatives as HIV-1 Integrase Inhibitors

    Directory of Open Access Journals (Sweden)

    Kavya Ramkumar

    2010-06-01

    Full Text Available Raltegravir was the first HIV-1 integrase inhibitor that gained FDA approval for use in the treatment of HIV-1 infection. Because of the emergence of IN inhibitor-resistant viral strains, there is a need to identify innovative second-generation IN inhibitors. Previously, we identified 2-thioxo-4-thiazolidinone (rhodanine-containing compounds as IN inhibitors. Herein, we report the design, synthesis and docking studies of a series of novel rhodanine derivatives as IN inhibitors. All these compounds were further tested against human apurinic/apyrimidinic endonuclease 1 (APE1 to determine their selectivity. Two compounds showed significant cytotoxicity in a panel of human cancer cell lines. Taken together, our results show that rhodanines are a promising class of compounds for developing drugs with antiviral and anticancer properties.

  14. Plasma Selenium Concentrations Are Sufficient and Associated with Protease Inhibitor Use in Treated HIV-Infected Adults.

    Science.gov (United States)

    Hileman, Corrilynn O; Dirajlal-Fargo, Sahera; Lam, Suet Kam; Kumar, Jessica; Lacher, Craig; Combs, Gerald F; McComsey, Grace A

    2015-10-01

    Selenium is an essential constituent of selenoproteins, which play a substantial role in antioxidant defense and inflammatory cascades. Selenium deficiency is associated with disease states characterized by inflammation, including cardiovascular disease (CVD). Although HIV infection has been associated with low selenium, the role of selenium status in HIV-related CVD is unclear. We sought to assess associations between plasma selenium and markers of inflammation, immune activation, and subclinical vascular disease in HIV-infected adults on contemporary antiretroviral therapy (ART) and to determine if statin therapy modifies selenium status. In the Stopping Atherosclerosis and Treating Unhealthy bone with RosuvastatiN trial, HIV-infected adults on stable ART were randomly assigned 1:1 to rosuvastatin or placebo. Plasma selenium concentrations were determined at entry, week 24, and week 48. Spearman correlation and linear regression analyses were used to assess relations between baseline selenium, HIV-related factors and markers of inflammation, immune activation, and subclinical vascular disease. Changes in selenium over 24 and 48 wk were compared between groups. One hundred forty-seven HIV-infected adults were included. All participants were on ART. Median current CD4+ count was 613, and 76% had HIV-1 RNA ≤48 copies/mL (range: selenium concentration was 122 μg/L (range: 62-200). At baseline, higher selenium was associated with protease inhibitor (PI) use, lower body mass index, and a higher proportion of activated CD8+ T cells (CD8+CD38+human leukocyte antigen-DR+), but not markers of inflammation or subclinical vascular disease. Over 48 wk, selenium concentrations increased in the statin group (P selenium concentrations were within the normal range for the background population and were not associated with subclinical vascular disease in HIV-infected adults on contemporary ART. The association between current PI use and higher selenium may have implications for

  15. Plasma Selenium Concentrations Are Sufficient and Associated with Protease Inhibitor Use in Treated HIV-Infected Adults123

    Science.gov (United States)

    Hileman, Corrilynn O; Dirajlal-Fargo, Sahera; Lam, Suet Kam; Kumar, Jessica; Lacher, Craig; Combs, Gerald F; McComsey, Grace A

    2015-01-01

    Background: Selenium is an essential constituent of selenoproteins, which play a substantial role in antioxidant defense and inflammatory cascades. Selenium deficiency is associated with disease states characterized by inflammation, including cardiovascular disease (CVD). Although HIV infection has been associated with low selenium, the role of selenium status in HIV-related CVD is unclear. Objectives: We sought to assess associations between plasma selenium and markers of inflammation, immune activation, and subclinical vascular disease in HIV-infected adults on contemporary antiretroviral therapy (ART) and to determine if statin therapy modifies selenium status. Methods: In the Stopping Atherosclerosis and Treating Unhealthy bone with RosuvastatiN trial, HIV-infected adults on stable ART were randomly assigned 1:1 to rosuvastatin or placebo. Plasma selenium concentrations were determined at entry, week 24, and week 48. Spearman correlation and linear regression analyses were used to assess relations between baseline selenium, HIV-related factors and markers of inflammation, immune activation, and subclinical vascular disease. Changes in selenium over 24 and 48 wk were compared between groups. Results: One hundred forty-seven HIV-infected adults were included. All participants were on ART. Median current CD4+ count was 613, and 76% had HIV-1 RNA ≤48 copies/mL (range: selenium concentration was 122 μg/L (range: 62–200). At baseline, higher selenium was associated with protease inhibitor (PI) use, lower body mass index, and a higher proportion of activated CD8+ T cells (CD8+CD38+human leukocyte antigen-DR+), but not markers of inflammation or subclinical vascular disease. Over 48 wk, selenium concentrations increased in the statin group (P selenium concentrations were within the normal range for the background population and were not associated with subclinical vascular disease in HIV-infected adults on contemporary ART. The association between current PI use

  16. Immunological changes in human immunodeficiency virus (HIV)-infected individuals during HIV-specific protease inhibitor treatment

    DEFF Research Database (Denmark)

    Ullum, H; Katzenstein, T; Aladdin, H

    1999-01-01

    Vaccinia virus was increased after 3-6 months, whereas the specific HIV-directed CTL activity and the concentration and lytic activity of natural killer (NK) cells were unchanged during follow-up. These results demonstrate that the initiation of a treatment including an HIV protease inhibitor is followed......The present study examines the influence of effective anti-retroviral treatment on immune function, evaluated by a broad array of immunological tests. We followed 12 individuals infected with human immunodeficiency virus (HIV) for 6 months after initiation of combination anti-retroviral treatment...... including a protease inhibitor. Unstimulated and pokeweed mitogen (PWM)-, interleukin (IL)-2- and phytohaemagglutinin (PHA)-stimulated lymphocyte proliferative responses increased during follow-up reaching average levels from 1.3-fold (PHA) to 3.7-fold (PWM) above baseline values. The total CD4+ lymphocyte...

  17. RT-SHIV, an infectious CCR5-tropic chimeric virus suitable for evaluating HIV reverse transcriptase inhibitors in macaque models

    Directory of Open Access Journals (Sweden)

    Emau Peter

    2009-11-01

    Full Text Available Abstract Background Non-nucleoside reverse transcriptase inhibitors (NNRTIs are an important category of drugs for both chemotherapy and prevention of human immunodeficiency virus type 1 (HIV-1 infection. However, current non-human primate (NHP models utilizing simian immunodeficiency virus (SIV or commonly used chimeric SHIV (SIV expressing HIV-1 envelope are inadequate due to the insensitivity to NNRTIs. To develop a NHP model for evaluation of NNRTI compounds, we characterized a RT-SHIV virus that was assembled by replacing the SIVmac239 reverse transcriptase (RT with that of HIV-1HXB2. Since RT-SHIV exhibited in vitro characteristics of high infectivity, CCR5-usage, and sensitivity to HIV-1 specific NNRTIs, this virus was thought to be suitable for mucosal transmission and then was used to carry out a vaginal transmission study in pigtail macaques (Macaca nemestrina. Results RT-SHIV exhibited in vitro characteristics of an infectious CCR5-tropic chimeric virus. This virus was not only highly sensitive to HIV-1 RT specific NNRTIs; its replication was also inhibited by a variety of NRTIs and protease inhibitors. For in vivo vaginal transmission studies, macaques were either pretreated with a single dose of DMPA (depot medroxyprogesterone acetate or left untreated before intravaginal inoculation with 500 or 1,000 TCID50 of RT-SHIV. All macaques became systemically infected by 2 or 3 weeks post-inoculation exhibiting persistent high viremia, marked CD4+T cell depletion, and antiviral antibody response. DMPA-pretreated macaques showed a higher mean plasma viral load after the acute infection stage, highly variable antiviral antibody response, and a higher incidence of AIDS-like disease as compared with macaques without DMPA pretreatment. Conclusion This chimeric RT-SHIV has exhibited productive replication in both macaque and human PBMCs, predominantly CCR5-coreceptor usage for viral entry, and sensitivity to NNRTIs as well as other anti-HIV

  18. Multi-level factors affecting entry into and engagement in the HIV continuum of care in Iringa, Tanzania.

    Science.gov (United States)

    Layer, Erica H; Kennedy, Caitlin E; Beckham, Sarah W; Mbwambo, Jessie K; Likindikoki, Samuel; Davis, Wendy W; Kerrigan, Deanna L; Brahmbhatt, Heena

    2014-01-01

    Progression through the HIV continuum of care, from HIV testing to lifelong retention in antiretroviral therapy (ART) care and treatment programs, is critical to the success of HIV treatment and prevention efforts. However, significant losses occur at each stage of the continuum and little is known about contextual factors contributing to disengagement at these stages. This study sought to explore multi-level barriers and facilitators influencing entry into and engagement in the continuum of care in Iringa, Tanzania. We used a mixed-methods study design including facility-based assessments and interviews with providers and clients of HIV testing and treatment services; interviews, focus group discussions and observations with community-based providers and clients of HIV care and support services; and longitudinal interviews with men and women living with HIV to understand their trajectories in care. Data were analyzed using narrative analysis to identify key themes across levels and stages in the continuum of care. Participants identified multiple compounding barriers to progression through the continuum of care at the individual, facility, community and structural levels. Key barriers included the reluctance to engage in HIV services while healthy, rigid clinic policies, disrespectful treatment from service providers, stock-outs of supplies, stigma and discrimination, alternate healing systems, distance to health facilities and poverty. Social support from family, friends or support groups, home-based care providers, income generating opportunities and community mobilization activities facilitated engagement throughout the HIV continuum. Findings highlight the complex, multi-dimensional dynamics that individuals experience throughout the continuum of care and underscore the importance of a holistic and multi-level perspective to understand this process. Addressing barriers at each level is important to promoting increased engagement throughout the continuum.

  19. Potent Inhibitor of Drug-Resistant HIV-1 Strains Identified from the Medicinal Plant Justicia gendarussa.

    Science.gov (United States)

    Zhang, Hong-Jie; Rumschlag-Booms, Emily; Guan, Yi-Fu; Wang, Dong-Ying; Liu, Kang-Lun; Li, Wan-Fei; Nguyen, Van H; Cuong, Nguyen M; Soejarto, Djaja D; Fong, Harry H S; Rong, Lijun

    2017-06-23

    Justicia gendarussa, a medicinal plant collected in Vietnam, was identified as a potent anti-HIV-1 active lead from the evaluation of over 4500 plant extracts. Bioassay-guided separation of the extracts of the stems and roots of this plant led to the isolation of an anti-HIV arylnaphthalene lignan (ANL) glycoside, patentiflorin A (1). Evaluation of the compound against both the M- and T-tropic HIV-1 isolates showed it to possess a significantly higher inhibition effect than the clinically used anti-HIV drug AZT. Patentiflorin A and two congeners were synthesized, de novo, as an efficient strategy for resupply as well as for further structural modification of the anti-HIV ANL glycosides in the search for drug leads. Subsequently, it was determined that the presence of a quinovopyranosyloxy group in the structure is likely essential to retain the high degree of anti-HIV activity of this type of compounds. Patentiflorin A was further investigated against the HIV-1 gene expression of the R/U5 and U5/gag transcripts, and the data showed that the compound acts as a potential inhibitor of HIV-1 reverse transcription. Importantly, the compound displayed potent inhibitory activity against drug-resistant HIV-1 isolates of both the nucleotide analogue (AZT) and non-nucleotide analogue (nevaripine). Thus, the ANL glycosides have the potential to be developed as novel anti-HIV drugs.

  20. Outcome of protease inhibitor substitution with nevirapine in HIV-1 infected children

    Directory of Open Access Journals (Sweden)

    Gomez M Luisa

    2008-10-01

    Full Text Available Abstract Background Protease inhibitors (PIs have been associated with metabolic complications. There is a trend to switch to simpler therapy to improve these disturbances. We report a case-series describing the effects in metabolic abnormalities in seven HIV-infected children, previously treated with protease inhibitor (PI after switching to nevirapine. Methods Seven children with stable PI-containing regimen and a long lasting HIV-1 RNA Results Seven HIV-infected children were enrolled. Median age: 130 months (99,177. Median baseline CD4%: 32%. All had HIV-1 RNA Conclusion PI substitution with nevirapine improved lipid profile in our patients, although this strategy did not show significant changes in body fat or lipodystrophy.

  1. Selective inhibition of HIV-1 replication by the CDK9 inhibitor FIT-039.

    Science.gov (United States)

    Okamoto, Mika; Hidaka, Akemi; Toyama, Masaaki; Hosoya, Takamitsu; Yamamoto, Makoto; Hagiwara, Masatoshi; Baba, Masanori

    2015-11-01

    FIT-039 has recently been identified as a novel cyclin-dependent kinase 9 inhibitor with potent antiviral activity against a broad spectrum of DNA viruses, such as herpes simplex virus type 1 (HSV-1) and human cytomegaloviruses. In this study, FIT-039 was examined for its inhibitory effect on human immunodeficiency virus type 1 (HIV-1) replication in chronically infected cells. Its 50% effective concentration was 1.4-2.1μM, irrespective of the cells used for antiviral assays, while its 50% cytotoxic concentration was >20μM, indicating that FIT-039 is a selective inhibitor of HIV-1 replication. FIT-039 also inhibited HIV-1 RNA expression in a dose-dependent fashion. Since previous studies demonstrated that FIT-039 exhibited antiviral efficacy without noticeable adverse effects in HSV-1-infected mice, the compound should be further investigated for its clinical potential against HIV-1 infection. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Immunological changes in human immunodeficiency virus (HIV)-infected individuals during HIV-specific protease inhibitor treatment

    DEFF Research Database (Denmark)

    Ullum, H; Katzenstein, T; Aladdin, H

    1999-01-01

    The present study examines the influence of effective anti-retroviral treatment on immune function, evaluated by a broad array of immunological tests. We followed 12 individuals infected with human immunodeficiency virus (HIV) for 6 months after initiation of combination anti-retroviral treatment...... Vaccinia virus was increased after 3-6 months, whereas the specific HIV-directed CTL activity and the concentration and lytic activity of natural killer (NK) cells were unchanged during follow-up. These results demonstrate that the initiation of a treatment including an HIV protease inhibitor is followed...... count increased mainly due to increases in numbers of CD4+ CD28+ and CD4+ CD45RO+ cells, whereas increases in numbers of CD4+ CD45RA+ cells contributed little to the increase in CD4+ cell count. The total cytotoxic T-cell (CTL) killing of autologous B cells infected with HIV-encoding recombinant...

  3. A New Class of Multimerization Selective Inhibitors of HIV-1 Integrase

    Science.gov (United States)

    Sharma, Amit; Slaughter, Alison; Jena, Nivedita; Feng, Lei; Kessl, Jacques J.; Fadel, Hind J.; Malani, Nirav; Male, Frances; Wu, Li; Poeschla, Eric; Bushman, Frederic D.; Fuchs, James R.; Kvaratskhelia, Mamuka

    2014-01-01

    The quinoline-based allosteric HIV-1 integrase (IN) inhibitors (ALLINIs) are promising candidates for clinically useful antiviral agents. Studies using these compounds have highlighted the role of IN in both early and late stages of virus replication. However, dissecting the exact mechanism of action of the quinoline-based ALLINIs has been complicated by the multifunctional nature of these inhibitors because they both inhibit IN binding with its cofactor LEDGF/p75 and promote aberrant IN multimerization with similar potencies in vitro. Here we report design of small molecules that allowed us to probe the role of HIV-1 IN multimerization independently from IN-LEDGF/p75 interactions in infected cells. We altered the rigid quinoline moiety in ALLINIs and designed pyridine-based molecules with a rotatable single bond to allow these compounds to bridge between interacting IN subunits optimally and promote oligomerization. The most potent pyridine-based inhibitor, KF116, potently (EC50 of 0.024 µM) blocked HIV-1 replication by inducing aberrant IN multimerization in virus particles, whereas it was not effective when added to target cells. Furthermore, KF116 inhibited the HIV-1 IN variant with the A128T substitution, which confers resistance to the majority of quinoline-based ALLINIs. A genome-wide HIV-1 integration site analysis demonstrated that addition of KF116 to target or producer cells did not affect LEDGF/p75-dependent HIV-1 integration in host chromosomes, indicating that this compound is not detectably inhibiting IN-LEDGF/p75 binding. These findings delineate the significance of correctly ordered IN structure for HIV-1 particle morphogenesis and demonstrate feasibility of exploiting IN multimerization as a therapeutic target. Furthermore, pyridine-based compounds present a novel class of multimerization selective IN inhibitors as investigational probes for HIV-1 molecular biology. PMID:24874515

  4. The Root Extract of the Medicinal Plant Pelargonium sidoides Is a Potent HIV-1 Attachment Inhibitor

    Science.gov (United States)

    Helfer, Markus; Koppensteiner, Herwig; Schneider, Martha; Rebensburg, Stephanie; Forcisi, Sara; Müller, Constanze; Schmitt-Kopplin, Philippe; Schindler, Michael; Brack-Werner, Ruth

    2014-01-01

    Global HIV-1 treatment would benefit greatly from safe herbal medicines with scientifically validated novel anti-HIV-1 activities. The root extract from the medicinal plant Pelargonium sidoides (PS) is licensed in Germany as the herbal medicine EPs®7630, with numerous clinical trials supporting its safety in humans. Here we provide evidence from multiple cell culture experiments that PS extract displays potent anti-HIV-1 activity. We show that PS extract protects peripheral blood mononuclear cells and macrophages from infection with various X4 and R5 tropic HIV-1 strains, including clinical isolates. Functional studies revealed that the extract from PS has a novel mode-of-action. It interferes directly with viral infectivity and blocks the attachment of HIV-1 particles to target cells, protecting them from virus entry. Analysis of the chemical footprint of anti-HIV activity indicates that HIV-1 inhibition is mediated by multiple polyphenolic compounds with low cytotoxicity and can be separated from other extract components with higher cytotoxicity. Based on our data and its excellent safety profile, we propose that PS extract represents a lead candidate for the development of a scientifically validated herbal medicine for anti-HIV-1 therapy with a mode-of-action different from and complementary to current single-molecule drugs. PMID:24489923

  5. ["Buffalo neck": an unintended secondary effect of treatment with anti-HIV protease inhibitors].

    Science.gov (United States)

    Milpied-Homsi, B; Krempf, M; Gueglio, B; Raffi, F; Stalder, J F

    1999-03-01

    Lipodystrophy and other fat distribution disorders have been reported in patients receiving protease inhibitor therapy for HIV infection. A 50-year-old HIV-positive patient was given protease inhibitor therapy (indinavir) for 6 months when he developed a lipomatous formation in the retrocervical area. Abdominal fat also increased in volume and the subcutaneous fat on the lower limbs decreased. We describe the main clinical features of these fat distribution disorders and discuss the pathogenic hypothesis of an interaction between antiprotease activity and hepatic lipoprotein receptor binding.

  6. Design and synthesis of hybrids of diarylpyrimidines and diketo acids as HIV-1 inhibitors.

    Science.gov (United States)

    Xue, Ping; Lu, Huan-Huan; Zhu, Yuan-Yuan; Ju, Xiu-Lian; Pannecouque, Christophe; Zheng, Xiao-Jiao; Liu, Gen-Yan; Zhang, Xiu-Lan; Gu, Shuang-Xi

    2017-04-15

    Based on the strategy of molecular hybridization, diketo acid fragment as a classical phamacophore of integrase inhibitors was introduced to reverse transcriptase inhibitors diarylpyrimidines to design a series of diarylpyrimidine-diketo acid hybrids (DAPY-DKAs). The target molecules 10b and 11b showed inhibitory activities against WT HIV-1 with EC50 values of 0.18μM and 0.14μM, respectively. And the results of molecular docking demonstrated the potential binding mode and revealed that the DKA moiety and its ester could both be tolerated in the nonnucleoside binding site (NNBS) of HIV-1 RT. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Residues in the gp41 Ectodomain Regulate HIV-1 Envelope Glycoprotein Conformational Transitions Induced by gp120-Directed Inhibitors.

    Science.gov (United States)

    Pacheco, Beatriz; Alsahafi, Nirmin; Debbeche, Olfa; Prévost, Jérémie; Ding, Shilei; Chapleau, Jean-Philippe; Herschhorn, Alon; Madani, Navid; Princiotto, Amy; Melillo, Bruno; Gu, Christopher; Zeng, Xin; Mao, Youdong; Smith, Amos B; Sodroski, Joseph; Finzi, Andrés

    2017-03-01

    Interactions between the gp120 and gp41 subunits of the human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein (Env) trimer maintain the metastable unliganded form of the viral spike. Binding of gp120 to the receptor, CD4, changes the Env conformation to promote gp120 interaction with the second receptor, CCR5 or CXCR4. CD4 binding also induces the transformation of Env into the prehairpin intermediate, in which the gp41 heptad repeat 1 (HR1) coiled coil is assembled at the trimer axis. In nature, HIV-1 Envs must balance the requirements to maintain the noncovalent association of gp120 with gp41 and to evade the host antibody response with the need to respond to CD4 binding. Here we show that the gp41 HR1 region contributes to gp120 association with the unliganded Env trimer. Changes in particular amino acid residues in the gp41 HR1 region decreased the efficiency with which Env moved from the unliganded state. Thus, these gp41 changes decreased the sensitivity of HIV-1 to cold inactivation and ligands that require Env conformational changes to bind efficiently. Conversely, these gp41 changes increased HIV-1 sensitivity to small-molecule entry inhibitors that block Env conformational changes induced by CD4. Changes in particular gp41 HR1 amino acid residues can apparently affect the relative stability of the unliganded state and CD4-induced conformations. Thus, the gp41 HR1 region contributes to the association with gp120 and regulates Env transitions from the unliganded state to downstream conformations.IMPORTANCE The development of an efficient vaccine able to prevent HIV infection is a worldwide priority. Knowledge of the envelope glycoprotein structure and the conformational changes that occur after receptor engagement will help researchers to develop an immunogen able to elicit antibodies that block HIV-1 transmission. Here we identify residues in the HIV-1 transmembrane envelope glycoprotein that stabilize the unliganded state by modulating the

  8. Delayed entry into HIV care after diagnosis in two specialized care and treatment centres in Cameroon: the influence of CD4 count and WHO staging

    Directory of Open Access Journals (Sweden)

    Noah F. Takah

    2016-07-01

    Full Text Available Abstract Background Delayed entry into HIV care has complicated the challenges faced in sub-Saharan Africa due to the high HIV burden. A clear knowledge of the factors affecting delayed entry will be essential in directing interventions towards reducing delayed entry into HIV care. There exist very limited data on delayed entry in Cameroon despite its relevance; hence this study was conducted to determine the rate of delayed entry and its associated factors in HIV programmes in Cameroon. Methods Data used for this study was routine data obtained from the files of HIV patients who were diagnosed between January 1, 2015 and June 30, 2015 at Limbe and Buea regional hospital HIV centers in the South West region of Cameroon. Data analysis was done using SPSS version 20. Results Of the 223 patients included in the study, nearly one-quarter of patients (22.4 % delayed to enter HIV care within 3 months. Those who delayed to enter care were less likely to present at first diagnosis (using HIV rapid test with symptoms such as fever > 1 month (5 % versus 30 %, p = 0.01 and weight loss > 10 % (13 % versus 48 %, p < 0.001. Alcohol consumption, WHO stage and CD4 count levels were also associated with delayed entry in bivariate analysis. In multivariate analysis only CD4 count greater than 500cells/μl and WHO stages I and II were independently associated with delayed entry into HIV care within 3 months. Conclusion In the South West region of Cameroon, approximately 1 out of 4 patients delay to enter HIV care. This high proportion of patients who delay to enter care correlates to the findings recorded by other studies in sub Saharan Africa. Interventions tackling delayed entry into HIV care might need to be favorably directed towards patients that have high CD4 counts and are at very early WHO clinical stages.

  9. HIV-1 variants with a single-point mutation in the gp41 pocket region exhibiting different susceptibility to HIV fusion inhibitors with pocket- or membrane-binding domain.

    Science.gov (United States)

    Lu, Lu; Tong, Pei; Yu, Xiaowen; Pan, Chungen; Zou, Peng; Chen, Ying-Hua; Jiang, Shibo

    2012-12-01

    Enfuvirtide (T20), the first FDA-approved peptide HIV fusion/entry inhibitor derived from the HIV-1 gp41 C-terminal heptad-repeat (CHR) domain, is believed to share a target with C34, another well-characterized CHR-peptide, by interacting with the gp41 N-terminal heptad-repeat (NHR) to form six-helix bundle core. However, our previous studies showed that T20 mainly interacts with the N-terminal region of the NHR (N-NHR) and lipid membranes, while C34 mainly binds to the NHR C-terminal pocket region. But so far, no one has shown that C34 can induce drug-resistance mutation in the gp41 pocket region. In this study, we constructed pseudoviruses in which the Ala at the position of 67 in the gp41 pocket region was substituted with Asp, Gly or Ser, respectively, and found that these mutations rendered the viruses highly resistant to C34, but sensitive to T20. The NHR-peptide N36 with mutations of A67 exhibited reduced anti-HIV-1 activity and decreased α-helicity. The stability of six-helix bundle formed by C34 and N36 with A67 mutations was significantly lower than that formed by C34 and N36 with wild-type sequence. The combination of C34 and T20 resulted in potent synergistic anti-HIV-1 effect against the viruses with mutations in either N- or C-terminal region in NHR. These results suggest that C34 with a pocket-binding domain and T20 containing the N-NHR- and membrane-binding domains inhibit HIV-1 fusion by interacting with different target sites and the combinatorial use of C34 and T20 is expected to be effective against HIV-1 variants resistant to HIV fusion inhibitors. Copyright © 2012 Elsevier B.V. All rights reserved.

  10. Triggering HIV polyprotein processing by light using rapid photodegradation of a tight-binding protease inhibitor

    Czech Academy of Sciences Publication Activity Database

    Schimer, Jiří; Pávová, Marcela; Anders, M.; Pachl, Petr; Šácha, Pavel; Cígler, Petr; Weber, Jan; Majer, Pavel; Řezáčová, Pavlína; Kräusslich, H. G.; Müller, B.; Konvalinka, Jan

    2015-01-01

    Roč. 6, Mar (2015), 6461/1-6461/8 ISSN 2041-1723 R&D Projects: GA ČR GBP208/12/G016; GA MŠk LO1302 Grant - others:GA MŠk(CZ) ED1.1.00/02.0109 Program:ED Institutional support: RVO:61388963 Keywords : HIV maturation * HIV PR photodegradable inhibitor * HIV PR caging Subject RIV: CE - Biochemistry Impact factor: 11.329, year: 2015 http://www.nature.com/ncomms/2015/150309/ncomms7461/pdf/ncomms7461.pdf

  11. Plasma plasminogen activator inhibitor-1 predicts myocardial infarction in HIV-1-infected individuals

    DEFF Research Database (Denmark)

    Knudsen, Andreas; Katzenstein, Terese L; Benfield, Thomas

    2014-01-01

    of seven biomarkers with first-time myocardial infarction (MI) in an HIV-1-infected population. DESIGN: A matched case-control study of 54 cases and 54 controls. METHODS: We compared 54 HIV-1-infected patients with verified first-time MI and 54 HIV-1-infected controls matched for age, duration...... of antiretroviral therapy, sex, smoking and no known cardiovascular disease. Levels of high-sensitivity C-reactive protein, soluble endothelial selectin, soluble vascular cell adhesion molecule, soluble intercellular adhesion molecule, matrix metalloprotease 9, myeloperoxidase, and plasminogen activator inhibitor 1...... levels of PAI-1 were associated with risk of first-time MI in HIV-1-infected individuals independently of cardiovascular risk factors, HIV parameters and antiretroviral therapy. Therefore PAI-1 may be used for risk stratification and prediction of CHD, but further studies are needed....

  12. HIV protease inhibitor exposure predicts cerebral small vessel disease

    OpenAIRE

    Soontornniyomkij, V; Umlauf, A; Chung, SA; Cochran, ML; Soontornniyomkij, B; Gouaux, B; Toperoff, W; Moore, DJ; Masliah, E; Ellis, RJ; Grant, I.; Achim, CL

    2014-01-01

    © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins. Objective: HIV-associated neurocognitive disorders (HANDs) remain prevalent in patients who receive HAART and may be associated with cumulative exposure to antiretroviral medications and other factors. We proposed that chronic toxic effects of antiretroviral drugs could contribute to cerebral small vessel disease (CSVD), which might be one of the key underpinnings of HAND. Design: Clinicopathological cross-sectional study of HIV-...

  13. Developing HIV-1 Protease Inhibitors through Stereospecific Reactions in Protein Crystals.

    Science.gov (United States)

    Olajuyigbe, Folasade M; Demitri, Nicola; De Zorzi, Rita; Geremia, Silvano

    2016-10-31

    Protease inhibitors are key components in the chemotherapy of HIV infection. However, the appearance of viral mutants routinely compromises their clinical efficacy, creating a constant need for new and more potent inhibitors. Recently, a new class of epoxide-based inhibitors of HIV-1 protease was investigated and the configuration of the epoxide carbons was demonstrated to play a crucial role in determining the binding affinity. Here we report the comparison between three crystal structures at near-atomic resolution of HIV-1 protease in complex with the epoxide-based inhibitor, revealing an in-situ epoxide ring opening triggered by a pH change in the mother solution of the crystal. Increased pH in the crystal allows a stereospecific nucleophile attack of an ammonia molecule onto an epoxide carbon, with formation of a new inhibitor containing amino-alcohol functions. The described experiments open a pathway for the development of new stereospecific protease inhibitors from a reactive lead compound.

  14. Cryo-electron microscopy and single molecule fluorescent microscopy detect CD4 receptor induced HIV size expansion prior to cell entry.

    Science.gov (United States)

    Pham, Son; Tabarin, Thibault; Garvey, Megan; Pade, Corinna; Rossy, Jérémie; Monaghan, Paul; Hyatt, Alex; Böcking, Till; Leis, Andrew; Gaus, Katharina; Mak, Johnson

    2015-12-01

    Viruses are often thought to have static structure, and they only remodel after the viruses have entered target cells. Here, we detected a size expansion of virus particles prior to viral entry using cryo-electron microscopy (cryo-EM) and single molecule fluorescence imaging. HIV expanded both under cell-free conditions with soluble receptor CD4 (sCD4) targeting the CD4 binding site on the HIV-1 envelope protein (Env) and when HIV binds to receptor on cellular membrane. We have shown that the HIV Env is needed to facilitate receptor induced virus size expansions, showing that the 'lynchpin' for size expansion is highly specific. We demonstrate that the size expansion required maturation of HIV and an internal capsid core with wild type stability, suggesting that different HIV compartments are linked and are involved in remodelling. Our work reveals a previously unknown event in HIV entry, and we propose that this pre-entry priming process enables HIV particles to facilitate the subsequent steps in infection. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. Cryo-electron microscopy and single molecule fluorescent microscopy detect CD4 receptor induced HIV size expansion prior to cell entry

    Energy Technology Data Exchange (ETDEWEB)

    Pham, Son [Deakin University, Victoria 3216 (Australia); CSIRO Australian Animal Health Laboratory, Victoria 3220 (Australia); Tabarin, Thibault [ARC Centre of Excellence in Advanced Molecular Imaging, University of New South Wales, New South Wales 3220 (Australia); Garvey, Megan; Pade, Corinna [Deakin University, Victoria 3216 (Australia); CSIRO Australian Animal Health Laboratory, Victoria 3220 (Australia); Rossy, Jérémie [ARC Centre of Excellence in Advanced Molecular Imaging, University of New South Wales, New South Wales 3220 (Australia); Monaghan, Paul; Hyatt, Alex [CSIRO Australian Animal Health Laboratory, Victoria 3220 (Australia); Böcking, Till [ARC Centre of Excellence in Advanced Molecular Imaging, University of New South Wales, New South Wales 3220 (Australia); Leis, Andrew [CSIRO Australian Animal Health Laboratory, Victoria 3220 (Australia); Gaus, Katharina, E-mail: k.gaus@unsw.edu.au [ARC Centre of Excellence in Advanced Molecular Imaging, University of New South Wales, New South Wales 3220 (Australia); Mak, Johnson, E-mail: j.mak@deakin.edu.au [Deakin University, Victoria 3216 (Australia); CSIRO Australian Animal Health Laboratory, Victoria 3220 (Australia)

    2015-12-15

    Viruses are often thought to have static structure, and they only remodel after the viruses have entered target cells. Here, we detected a size expansion of virus particles prior to viral entry using cryo-electron microscopy (cryo-EM) and single molecule fluorescence imaging. HIV expanded both under cell-free conditions with soluble receptor CD4 (sCD4) targeting the CD4 binding site on the HIV-1 envelope protein (Env) and when HIV binds to receptor on cellular membrane. We have shown that the HIV Env is needed to facilitate receptor induced virus size expansions, showing that the ‘lynchpin’ for size expansion is highly specific. We demonstrate that the size expansion required maturation of HIV and an internal capsid core with wild type stability, suggesting that different HIV compartments are linked and are involved in remodelling. Our work reveals a previously unknown event in HIV entry, and we propose that this pre-entry priming process enables HIV particles to facilitate the subsequent steps in infection. - Highlights: • Cell free viruses are able to receive external trigger that leads to apparent size expansion. • Virus envelope and CD4 receptor engagement is the lynchpin of virus size expansion. • Internal capsid organisation can influence receptor mediated virus size expansion. • Pre-existing virus-associated lipid membrane in cell free virus can accommodate the receptor mediated virus size expansion.

  16. Conventional HPLC Method Used for Simultaneous Determination of the Seven HIV Protease Inhibitors and Nonnucleoside Reverse Transcription Inhibitor Efavirenz in Human Plasma

    National Research Council Canada - National Science Library

    Takahashi, Masaaki; Yoshida, Masao; Oki, Tsuyoshi; Okumura, Naoya; Suzuki, Tatsuo; Kaneda, Tsuguhiro

    2005-01-01

    We developed a simple HPLC method for the simultaneous quantitative determination of seven HIV protease inhibitors: amprenavir (APV), atazanavir (ATV), indinavir (IDV), lopinavir (LPV), nelfinavir (NFV), ritonavir (RTV), saquinavir (SQV...

  17. Protease inhibitors effectively block cell-to-cell spread of HIV-1 between T cells.

    Science.gov (United States)

    Titanji, Boghuma Kabisen; Aasa-Chapman, Marlen; Pillay, Deenan; Jolly, Clare

    2013-12-24

    The Human Immunodeficiency Virus type-1 (HIV-1) spreads by cell-free diffusion and by direct cell-to-cell transfer, the latter being a significantly more efficient mode of transmission. Recently it has been suggested that cell-to-cell spread may permit ongoing virus replication in the presence of antiretroviral therapy (ART) based on studies performed using Reverse Transcriptase Inhibitors (RTIs). Protease Inhibitors (PIs) constitute an important component of ART; however whether this class of inhibitors can suppress cell-to-cell transfer of HIV-1 is unexplored. Here we have evaluated the inhibitory effect of PIs during cell-to-cell spread of HIV-1 between T lymphocytes. Using quantitative assays in cell line and primary cell systems that directly measure the early steps of HIV-1 infection we find that the PIs Lopinavir and Darunavir are equally potent against both cell-free and cell-to-cell spread of HIV-1. We further show that a protease resistant mutant maintains its resistant phenotype during cell-to-cell spread and is transmitted more efficiently than wild-type virus in the presence of drug. By contrast we find that T cell-T cell spread of HIV-1 is 4-20 fold more resistant to inhibition by the RTIs Nevirapine, Zidovudine and Tenofovir. Notably, varying the ratio of infected and uninfected cells in co-culture impacted on the degree of inhibition, indicating that the relative efficacy of ART is dependent on the multiplicity of infection. We conclude that if the variable effects of antiviral drugs on cell-to-cell virus dissemination of HIV-1 do indeed impact on viral replication and maintenance of viral reservoirs this is likely to be influenced by the antiviral drug class, since PIs appear particularly effective against both modes of HIV-1 spread.

  18. Bis-Tetrahydrofuran: a Privileged Ligand for Darunavir and a New Generation of HIV Protease Inhibitors That Combat Drug Resistance

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Arun K.; Sridhar, Perali Ramu; Kumaragurubaran, Nagaswamy; Koh, Yasuhiro; Weber, Irene T.; Mitsuya, Hiroaki (Kumamoto Univ, Japan); (GSU); (NIH); (Purdue)

    2008-06-06

    Two inhibitors that incorporate bis-THF as an effective high-affinity P{sub 2} ligand for the HIV-1 protease substrate binding site maintain impressive potency against mutant strains resistant to currently approved protease inhibitors. Crystallographic structures of protein-ligand complexes help to explain the superior antiviral property of these inhibitors and their potency against a wide spectrum of HIV-1 strains.

  19. HIV aspartyl peptidase inhibitors interfere with cellular proliferation, ultrastructure and macrophage infection of Leishmania amazonensis.

    Directory of Open Access Journals (Sweden)

    Lívia O Santos

    Full Text Available BACKGROUND: Leishmania is the etiologic agent of leishmanisais, a protozoan disease whose pathogenic events are not well understood. Current therapy is suboptimal due to toxicity of the available therapeutic agents and the emergence of drug resistance. Compounding these problems is the increase in the number of cases of Leishmania-HIV coinfection, due to the overlap between the AIDS epidemic and leishmaniasis. METHODOLOGY/PRINCIPAL FINDINGS: In the present report, we have investigated the effect of HIV aspartyl peptidase inhibitors (PIs on the Leishmania amazonensis proliferation, ultrastructure, interaction with macrophage cells and expression of classical peptidases which are directly involved in the Leishmania pathogenesis. All the HIV PIs impaired parasite growth in a dose-dependent fashion, especially nelfinavir and lopinavir. HIV PIs treatment caused profound changes in the leishmania ultrastructure as shown by transmission electron microscopy, including cytoplasm shrinking, increase in the number of lipid inclusions and some cells presenting the nucleus closely wrapped by endoplasmic reticulum resembling an autophagic process, as well as chromatin condensation which is suggestive of apoptotic death. The hydrolysis of HIV peptidase substrate by L. amazonensis extract was inhibited by pepstatin and HIV PIs, suggesting that an aspartyl peptidase may be the intracellular target of the inhibitors. The treatment with HIV PIs of either the promastigote forms preceding the interaction with macrophage cells or the amastigote forms inside macrophages drastically reduced the association indexes. Despite all these beneficial effects, the HIV PIs induced an increase in the expression of cysteine peptidase b (cpb and the metallopeptidase gp63, two well-known virulence factors expressed by Leishmania spp. CONCLUSIONS/SIGNIFICANCE: In the face of leishmaniasis/HIV overlap, it is critical to further comprehend the sophisticated interplays among Leishmania

  20. N-hydroxy-substituted 2-aryl acetamide analogs: A novel class of HIV-1 integrase inhibitors.

    Science.gov (United States)

    Debnath, Utsab; Kumar, Prachi; Agarwal, Aakanksha; Kesharwani, Ajay; Gupta, Satish K; Katti, Seturam B

    2017-10-01

    An in silico method has been used to discover N-hydroxy-substituted 2-aryl acetamide analogs as a new class of HIV-1 integrase inhibitors. Based on the molecular requirements of the binding pocket of catalytic active site, two molecules (compounds 2 and 4b) were designed as fragments. These were further synthesized and biologically evaluated. In vitro potency along with docking studies highlighted compound 4b as an active fragment which was further used to synthesize new leads as HIV-1 integrase inhibitors. Finally, six promising compounds (compounds 5b, 5c, 5e, 6-2c, 6-3b, and 6-5b) were identified by integrase inhibition assay (>50% inhibition). Based on in vitro anti-HIV-1 activity in a reporter gene-based cell assay system, compounds 5d, 6s, and 6k were found as novel HIV-1 integrase inhibitors due to its better selectivity index. Additionally, docking study revealed the importance of H-bond as well as hydrophobic interactions with Asn155, Lys156, and Lys159 which were required for their anti-HIV-1 activity. © 2017 John Wiley & Sons A/S.

  1. Pulsed EPR characterization of HIV-1 protease conformational sampling and inhibitor-induced population shifts.

    Science.gov (United States)

    Liu, Zhanglong; Casey, Thomas M; Blackburn, Mandy E; Huang, Xi; Pham, Linh; de Vera, Ian Mitchelle S; Carter, Jeffrey D; Kear-Scott, Jamie L; Veloro, Angelo M; Galiano, Luis; Fanucci, Gail E

    2016-02-17

    The conformational landscape of HIV-1 protease (PR) can be experimentally characterized by pulsed-EPR double electron-electron resonance (DEER). For this characterization, nitroxide spin labels are attached to an engineered cysteine residue in the flap region of HIV-1 PR. DEER distance measurements from spin-labels contained within each flap of the homodimer provide a detailed description of the conformational sampling of apo-enzyme as well as induced conformational shifts as a function of inhibitor binding. The distance distribution profiles are further interpreted in terms of a conformational ensemble scheme that consists of four unique states termed "curled/tucked", "closed", "semi-open" and "wide-open" conformations. Reported here are the DEER results for a drug-resistant variant clinical isolate sequence, V6, in the presence of FDA approved protease inhibitors (PIs) as well as a non-hydrolyzable substrate mimic, CaP2. Results are interpreted in the context of the current understanding of the relationship between conformational sampling, drug resistance, and kinetic efficiency of HIV-1PR as derived from previous DEER and kinetic data for a series of HIV-1PR constructs that contain drug-pressure selected mutations or natural polymorphisms. Specifically, these collective results support the notion that inhibitor-induced closure of the flaps correlates with inhibitor efficiency and drug resistance. This body of work also suggests DEER as a tool for studying conformational sampling in flexible enzymes as it relates to function.

  2. Placental transfer of the HIV integrase inhibitor dolutegravir in an ex vivo human cotyledon perfusion model

    NARCIS (Netherlands)

    Schalkwijk, S.J.; Greupink, R.; Colbers, A.P.; Wouterse, A.C.; Verweij, V.G.M.; Drongelen, J. van; Teulen, M.J.A.; Oetelaar, D. van den; Burger, D.M.; Russel, F.G.

    2016-01-01

    OBJECTIVES: Data on fetal exposure to antiretroviral agents during pregnancy are important to estimate their potential for prevention of mother-to-child transmission (PMTCT) and possible toxicity. For the recently developed HIV integrase inhibitor dolutegravir, clinical data on fetal disposition are

  3. Structures of HIV Protease Guide Inhibitor Design to Overcome Drug Resistance

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Irene T.; Kovalevsky, Andrey Y.; Harrison, Robert W. (GSU)

    2008-06-03

    The HIV/AIDS infection continues to be a major epidemic worldwide despite the initial promise of antiviral drugs. Current therapy includes a combination of drugs that inhibit two of the virally-encoded enzymes, the reverse transcriptase and the protease. The first generation of HIV protease inhibitors that have been in clinical use for treatment of AIDS since 1995 was developed with the aid of structural analysis of protease-inhibitor complexes. These drugs were successful in improving the life span of HIV-infected people. Subsequently, the rapid emergence of drug resistance has necessitated the design of new inhibitors that target mutant proteases. This second generation of antiviral protease inhibitors has been developed with the aid of data from medicinal chemistry, kinetics, and X-ray crystallographic analysis. Traditional computational methods such as molecular mechanics and dynamics can be supplemented with intelligent data mining approaches. One approach, based on similarities to the protease interactions with substrates, is to incorporate additional interactions with main chain atoms that cannot easily be eliminated by mutations. Our structural and inhibition data for darunavir have helped to understand its antiviral activity and effectiveness on drug resistant HIV and demonstrate the success of this approach.

  4. Lack of a clinically significant drug-drug interaction in healthy volunteers between the hepatitis C virus protease inhibitor boceprevir and the HIV integrase inhibitor raltegravir

    NARCIS (Netherlands)

    Kanter, C.T. de; Blonk, M.I.; Colbers, A.P.; Schouwenberg, B.J.J.W.; Burger, D.M.

    2013-01-01

    BACKGROUND: Patients coinfected with human immunodeficiency virus (HIV) and hepatitis C virus (HCV) are likely to use both HIV and HCV treatment. Drug-drug interactions have been demonstrated between boceprevir, an HCV protease inhibitor, and frequently prescribed antiretroviral drugs, such as

  5. Protonation state and free energy calculation of HIV-1 protease-inhibitor complex based on electrostatic polarisation effect

    Science.gov (United States)

    Yang, Maoyou; Jiang, Xiaonan; Jiang, Ning

    2014-06-01

    The protonation states of catalytic Asp25/25‧ residues remarkably affect the binding mechanism of the HIV-1 protease-inhibitor complex. Here we report a molecular dynamics simulation study, which includes electrostatic polarisation effect, to investigate the influence of Asp25/25‧ protonation states upon the binding free energy of the HIV-1 protease and a C2-symmetric inhibitor. Good agreements are obtained on inhibitor structure, hydrogen bond network, and binding free energy between our theoretical calculations and the experimental data. The calculations show that the Asp25 residue is deprotonated, and the Asp25‧ residue is protonated. Our results reveal that the Asp25/25‧ residues can have different protonation states when binding to different inhibitors although the protease and the inhibitors have the same symmetry. This study offers some insights into understanding the protonation state of HIV-1 protease-inhibitor complex, which could be helpful in designing new inhibitor molecules.

  6. HIV-related restrictions on entry, residence and stay in the WHO European Region: a survey

    DEFF Research Database (Denmark)

    Lazarus, Jeff; Curth, Nadja; Weait, Matthew

    2010-01-01

    Back in 1987, the World Health Organization (WHO) concluded that the screening of international travellers was an ineffective way to prevent the spread of HIV. However, some countries still restrict the entrance and/or residency of foreigners with an HIV infection. HIV-related travel restrictions...... have serious implications for individual and public health, and violate internationally recognized human rights. In this study, we reviewed the current situation regarding HIV-related travel restrictions in the 53 countries of the WHO European Region....

  7. HIV-1 efficient entry in inner foreskin is mediated by elevated CCL5/RANTES that recruits T cells and fuels conjugate formation with Langerhans cells.

    Directory of Open Access Journals (Sweden)

    Zhicheng Zhou

    2011-06-01

    Full Text Available Male circumcision reduces acquisition of HIV-1 by 60%. Hence, the foreskin is an HIV-1 entry portal during sexual transmission. We recently reported that efficient HIV-1 transmission occurs following 1 h of polarized exposure of the inner, but not outer, foreskin to HIV-1-infected cells, but not to cell-free virus. At this early time point, Langerhans cells (LCs and T-cells within the inner foreskin epidermis are the first cells targeted by the virus. To gain in-depth insight into the molecular mechanisms governing inner foreskin HIV-1 entry, foreskin explants were inoculated with HIV-1-infeceted cells for 4 h. The chemokine/cytokine milieu secreted by the foreskin tissue, and resulting modifications in density and spatial distribution of T-cells and LCs, were then investigated. Our studies show that in the inner foreskin, inoculation with HIV-1-infected cells induces increased CCL5/RANTES (1.63-fold and decreased CCL20/MIP-3-alpha (0.62-fold secretion. Elevated CCL5/RANTES mediates recruitment of T-cells from the dermis into the epidermis, which is blocked by a neutralizing CCL5/RANTES Ab. In parallel, HIV-1-infected cells mediate a bi-phasic modification in the spatial distribution of epidermal LCs: attraction to the apical surface at 1 h, followed by migration back towards the basement membrane later on at 4 h, in correlation with reduced CCL20/MIP-3-alpha at this time point. T-cell recruitment fuels the continuous formation of LC-T-cell conjugates, permitting the transfer of HIV-1 captured by LCs. Together, these results reveal that HIV-1 induces a dynamic process of immune cells relocation in the inner foreskin that is associated with specific chemokines secretion, which favors efficient HIV-1 entry at this site.

  8. HIV-1 Efficient Entry in Inner Foreskin Is Mediated by Elevated CCL5/RANTES that Recruits T Cells and Fuels Conjugate Formation with Langerhans Cells

    Science.gov (United States)

    Zhou, Zhicheng; Barry de Longchamps, Nicolas; Schmitt, Alain; Zerbib, Marc; Vacher-Lavenu, Marie-Cécile; Bomsel, Morgane; Ganor, Yonatan

    2011-01-01

    Male circumcision reduces acquisition of HIV-1 by 60%. Hence, the foreskin is an HIV-1 entry portal during sexual transmission. We recently reported that efficient HIV-1 transmission occurs following 1 h of polarized exposure of the inner, but not outer, foreskin to HIV-1-infected cells, but not to cell-free virus. At this early time point, Langerhans cells (LCs) and T-cells within the inner foreskin epidermis are the first cells targeted by the virus. To gain in-depth insight into the molecular mechanisms governing inner foreskin HIV-1 entry, foreskin explants were inoculated with HIV-1-infeceted cells for 4 h. The chemokine/cytokine milieu secreted by the foreskin tissue, and resulting modifications in density and spatial distribution of T-cells and LCs, were then investigated. Our studies show that in the inner foreskin, inoculation with HIV-1-infected cells induces increased CCL5/RANTES (1.63-fold) and decreased CCL20/MIP-3-alpha (0.62-fold) secretion. Elevated CCL5/RANTES mediates recruitment of T-cells from the dermis into the epidermis, which is blocked by a neutralizing CCL5/RANTES Ab. In parallel, HIV-1-infected cells mediate a bi-phasic modification in the spatial distribution of epidermal LCs: attraction to the apical surface at 1 h, followed by migration back towards the basement membrane later on at 4 h, in correlation with reduced CCL20/MIP-3-alpha at this time point. T-cell recruitment fuels the continuous formation of LC-T-cell conjugates, permitting the transfer of HIV-1 captured by LCs. Together, these results reveal that HIV-1 induces a dynamic process of immune cells relocation in the inner foreskin that is associated with specific chemokines secretion, which favors efficient HIV-1 entry at this site. PMID:21738469

  9. Design of Annulated Pyrazoles As Inhibitors of HIV-1 Reverse Transcriptase

    Energy Technology Data Exchange (ETDEWEB)

    Sweeney, Z.K.; Harris, S.F.; Arora, N.; Javanbakht, H.; Li, Y.; Fretland, J.; Davidson, J.P.; Billedeau, J.R.; Gleason, S.; Hirschfeld, D.; Kennedy-Smith, J.J.; Mirzadegan, T.; Roetz, R.; Smith, M.; Sperry, S.; Suh, J.M.; Wu, J.; Tsing, S.; Villasenor, A.G.; Paul, A.; Su, G.

    2009-05-26

    Non-nucleoside reverse transcriptase inhibitors (NNRTIs) are recommended components of preferred combination antiretroviral therapies used for the treatment of HIV. These regimens are extremely effective in suppressing virus replication. Structure-based optimization of diaryl ether inhibitors led to the discovery of a new series of pyrazolo[3,4-c]pyridazine NNRTIs that bind the reverse transcriptase enzyme of human immunodeficiency virus-1 (HIV-RT) in an expanded volume relative to most other inhibitors in this class. The binding mode maintains the {beta}13 and {beta}14 strands bearing Pro236 in a position similar to that in the unliganded reverse transcriptase structure, and the distribution of interactions creates the opportunity for substantial resilience to single point mutations. Several pyrazolopyridazine NNRTIs were found to be highly effective against wild-type and NNRTI-resistant viral strains in cell culture.

  10. Computational Design of Hypothetical New Peptides Based on a Cyclotide Scaffold as HIV gp120 Inhibitor.

    Directory of Open Access Journals (Sweden)

    Apiwat Sangphukieo

    Full Text Available Cyclotides are a family of triple disulfide cyclic peptides with exceptional resistance to thermal/chemical denaturation and enzymatic degradation. Several cyclotides have been shown to possess anti-HIV activity, including kalata B1 (KB1. However, the use of cyclotides as anti-HIV therapies remains limited due to the high toxicity in normal cells. Therefore, grafting anti-HIV epitopes onto a cyclotide might be a promising approach for reducing toxicity and simultaneously improving anti-HIV activity. Viral envelope glycoprotein gp120 is required for entry of HIV into CD4+ T cells. However, due to a high degree of variability and physical shielding, the design of drugs targeting gp120 remains challenging. We created a computational protocol in which molecular modeling techniques were combined with a genetic algorithm (GA to automate the design of new cyclotides with improved binding to HIV gp120. We found that the group of modified cyclotides has better binding scores (23.1% compared to the KB1. By using molecular dynamic (MD simulation as a post filter for the final candidates, we identified two novel cyclotides, GA763 and GA190, which exhibited better interaction energies (36.6% and 22.8%, respectively when binding to gp120 compared to KB1. This computational design represents an alternative tool for modifying peptides, including cyclotides and other stable peptides, as therapeutic agents before the synthesis process.

  11. Neoechinulin B and its analogues as potential entry inhibitors of influenza viruses, targeting viral hemagglutinin.

    Science.gov (United States)

    Chen, Xueqing; Si, Longlong; Liu, Dong; Proksch, Peter; Zhang, Lihe; Zhou, Demin; Lin, Wenhan

    2015-03-26

    A class of prenylated indole diketopiperazine alkaloids including 15 new compounds namely rubrumlines A-O obtained from marine-derived fungus Eurotium rubrum, were tested against influenza A/WSN/33 virus. Neoechinulin B (18) exerted potent inhibition against H1N1 virus infected in MDCK cells, and is able to inhibit a panel of influenza virus strains including amantadine- and oseltamivir-resistant clinical isolates. Mechanism of action studies indicated that neoechinulin B binds to influenza envelope hemagglutinin, disrupting its interaction with the sialic acid receptor and the attachment of viruses to host cells. In addition, neoechinulin B was still efficient in inhibiting influenza A/WSN/33 virus propagation even after a fifth passage. The high potency and broad-spectrum activities against influenza viruses with less drug resistance make neoechinulin B as a new lead for the development of potential inhibitor of influenza viruses. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  12. Synthesis of a Vpr-Binding Derivative for Use as a Novel HIV-1 Inhibitor

    Science.gov (United States)

    Hagiwara, Kyoji; Ishii, Hideki; Murakami, Tomoyuki; Takeshima, Shin-nosuke; Chutiwitoonchai, Nopporn; Kodama, Eiichi N.; Kawaji, Kumi; Kondoh, Yasumitsu; Honda, Kaori; Osada, Hiroyuki; Tsunetsugu-Yokota, Yasuko; Suzuki, Masaaki; Aida, Yoko

    2015-01-01

    The emergence of multidrug-resistant viruses compromises the efficacy of anti-human immunodeficiency virus type 1 (HIV-1) therapy and limits treatment options. Therefore, new targets that can be used to develop novel antiviral agents need to be identified. We previously identified a potential parent compound, hematoxylin, which suppresses the nuclear import of HIV-1 via the Vpr-importin α interaction and inhibits HIV-1 replication in a Vpr-dependent manner by blocking nuclear import of the pre-integration complex. However, it was unstable. Here, we synthesized a stable derivative of hematoxylin that bound specifically and stably to Vpr and inhibited HIV-1 replication in macrophages. Furthermore, like hematoxylin, the derivative inhibited nuclear import of Vpr in an in vitro nuclear import assay, but had no effect on Vpr-induced G2/M phase cell cycle arrest or caspase activity. Interestingly, this derivative bound strongly to amino acid residues 54–74 within the C-terminal α-helical domain (αH3) of Vpr. These residues are highly conserved among different HIV strains, indicating that this region is a potential target for drug-resistant HIV-1 infection. Thus, we succeeded in developing a stable hematoxylin derivative that bound directly to Vpr, suggesting that specific inhibitors of the interaction between cells and viral accessory proteins may provide a new strategy for the treatment of HIV-1 infection. PMID:26701275

  13. Potent influenza A virus entry inhibitors targeting a conserved region of hemagglutinin.

    Science.gov (United States)

    Lin, Dongguo; Luo, Yinzhu; Yang, Guang; Li, Fangfang; Xie, Xiangkun; Chen, Daiwei; He, Lifang; Wang, Jingyu; Ye, Chunfeng; Lu, Shengsheng; Lv, Lin; Liu, Shuwen; He, Jian

    2017-11-15

    Influenza A viruses (IAVs) induce acute respiratory disease and cause significant morbidity and mortality throughout the world. With the emergence of drug-resistant viral strains, new and effective anti-IAV drugs with different modes of action are urgently needed. In this study, by conjugating cholesterol to the N-terminus of the short peptide KKWK, a lipopeptide named S-KKWK was created. The anti-IAV test indicated that S-KKWK and its derivatives displayed potent antiviral activities against a broad variety of influenza A viral strains including oseltamivir-resistant strains and clinically relevant isolates with IC 50 values ranging from 0.7 to 3.0µM. An extensive mechanistic study showed that these peptides functioned as viral "entry blockers" by inhibiting the conformational rearrangements of HA2 subunit, thereby interrupting the fusion of virus-host cell membranes. Significantly, a computer-aided docking simulation and protein sequence alignment identified conserved residues in the stem region of HA2 as the possible binding site of S-KKWK, which may be employed as a potential drug target for designing anti-IAVs with a broad-spectrum of activity. By targeting this region, a potent anti-IAV agent was subsequently created. In addition, the anti-IAV activity of S-KKWK was assessed by experiments with influenza A virus-infected mice, in which S-KKWK reduced the mortality of infected animals and extended survival time significantly. Overall, in addition to providing a strategy for designing broad-spectrum anti-IAV agents, these results indicate that S-KKWK and its derivatives are prospective candidates for potent antivirals. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Drug Resistance in Non-B Subtype HIV-1: Impact of HIV-1 Reverse Transcriptase Inhibitors

    Directory of Open Access Journals (Sweden)

    Kamalendra Singh

    2014-09-01

    Full Text Available Human immunodeficiency virus (HIV causes approximately 2.5 million new infections every year, and nearly 1.6 million patients succumb to HIV each year. Several factors, including cross-species transmission and error-prone replication have resulted in extraordinary genetic diversity of HIV groups. One of these groups, known as group M (main contains nine subtypes (A-D, F-H and J-K and causes ~95% of all HIV infections. Most reported data on susceptibility and resistance to anti-HIV therapies are from subtype B HIV infections, which are prevalent in developed countries but account for only ~12% of all global HIV infections, whereas non-B subtype HIV infections that account for ~88% of all HIV infections are prevalent primarily in low and middle-income countries. Although the treatments for subtype B infections are generally effective against non-B subtype infections, there are differences in response to therapies. Here, we review how polymorphisms, transmission efficiency of drug-resistant strains, and differences in genetic barrier for drug resistance can differentially alter the response to reverse transcriptase-targeting therapies in various subtypes.

  15. Analysis of endoplasmic reticulum stress in placentas of HIV-infected women treated with protease inhibitors.

    Science.gov (United States)

    Brüning, Ansgar; Kimmich, Tanja; Brem, German J; Buchholtz, Marie L; Mylonas, Ioannis; Kost, Bernd; Weizsäcker, Katharina; Gingelmaier, Andrea

    2014-12-01

    Combined antiretroviral therapy has proven efficacy in decreasing vertical HIV transmission. However, endoplasmic reticulum stress is a known side effect of HIV protease inhibitors. We investigated endoplasmic reticulum stress in placentas of HIV-infected and uninfected mothers by PCR-based splicing analysis of the specific endoplasmic reticulum stress marker XBP1 in post-delivery placental samples of uninfected mothers and in HIV-infected mothers taking antiretroviral therapy. No elevated XBP1 splicing could be detected in placentas of uninfected mothers and most of the mothers receiving combined anti-retroviral therapy. However, markedly elevated XBP1 splicing was found in the placentas of three individuals on combined antiviral therapy, all receiving lopinavir or atazanavir. In vitro experiments confirmed induction of endoplasmic reticulum stress by lopinavir and atazanavir in trophoblast-derived cell lines. Since endoplasmic reticulum stress occurred in selective patients only, individual differences in susceptibility of HIV-infected mothers to protease inhibitor induced endoplasmic reticulum stress can be postulated. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. Design of novel HIV-1 protease inhibitors incorporating isophthalamide-derived P2-P3 ligands: Synthesis, biological evaluation and X-ray structural studies of inhibitor-HIV-1 protease complex.

    Science.gov (United States)

    Ghosh, Arun K; Brindisi, Margherita; Nyalapatla, Prasanth R; Takayama, Jun; Ella-Menye, Jean-Rene; Yashchuk, Sofiya; Agniswamy, Johnson; Wang, Yuan-Fang; Aoki, Manabu; Amano, Masayuki; Weber, Irene T; Mitsuya, Hiroaki

    2017-10-01

    Based upon molecular insights from the X-ray structures of inhibitor-bound HIV-1 protease complexes, we have designed a series of isophthalamide-derived inhibitors incorporating substituted pyrrolidines, piperidines and thiazolidines as P2-P3 ligands for specific interactions in the S2-S3 extended site. Compound 4b has shown an enzyme Ki of 0.025nM and antiviral IC50 of 69nM. An X-ray crystal structure of inhibitor 4b-HIV-1 protease complex was determined at 1.33Å resolution. We have also determined X-ray structure of 3b-bound HIV-1 protease at 1.27Å resolution. These structures revealed important molecular insight into the inhibitor-HIV-1 protease interactions in the active site. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Rapid screening for entry inhibitors of highly pathogenic viruses under low-level biocontainment.

    Directory of Open Access Journals (Sweden)

    Aparna Talekar

    Full Text Available Emerging viruses including Nipah, Hendra, Lujo, and Junin viruses have enormous potential to spread rapidly. Nipah virus, after emerging as a zoonosis, has also evolved the capacity for human-to-human transmission. Most of the diseases caused by these pathogens are untreatable and require high biocontainment conditions. Universal methods for rapidly identifying and screening candidate antivirals are urgently needed. We have developed a modular antiviral platform strategy that relies on simple bioinformatic and genetic information about each pathogen. Central to this platform is the use of envelope glycoprotein cDNAs to establish multi-cycle replication systems under BSL2 conditions for viral pathogens that normally require BSL3 and BSL4 facilities. We generated monoclonal antibodies against Nipah G by cDNA immunization in rats, and we showed that these antibodies neutralize both Nipah and Hendra live viruses. We then used these effective Henipavirus inhibitors to validate our screening strategy. Our proposed strategy should contribute to the response capability for emerging infectious diseases, providing a way to initiate antiviral development immediately upon identifying novel viruses.

  18. Rapid Screening for Entry Inhibitors of Highly Pathogenic Viruses under Low-Level Biocontainment

    Science.gov (United States)

    Talekar, Aparna; Pessi, Antonello; Glickman, Fraser; Sengupta, Uttara; Briese, Thomas; Whitt, Michael A.; Mathieu, Cyrille; Horvat, Branka; Moscona, Anne; Porotto, Matteo

    2012-01-01

    Emerging viruses including Nipah, Hendra, Lujo, and Junin viruses have enormous potential to spread rapidly. Nipah virus, after emerging as a zoonosis, has also evolved the capacity for human-to-human transmission. Most of the diseases caused by these pathogens are untreatable and require high biocontainment conditions. Universal methods for rapidly identifying and screening candidate antivirals are urgently needed. We have developed a modular antiviral platform strategy that relies on simple bioinformatic and genetic information about each pathogen. Central to this platform is the use of envelope glycoprotein cDNAs to establish multi-cycle replication systems under BSL2 conditions for viral pathogens that normally require BSL3 and BSL4 facilities. We generated monoclonal antibodies against Nipah G by cDNA immunization in rats, and we showed that these antibodies neutralize both Nipah and Hendra live viruses. We then used these effective Henipavirus inhibitors to validate our screening strategy. Our proposed strategy should contribute to the response capability for emerging infectious diseases, providing a way to initiate antiviral development immediately upon identifying novel viruses. PMID:22396728

  19. Suramin is a potent inhibitor of Chikungunya and Ebola virus cell entry.

    Science.gov (United States)

    Henß, Lisa; Beck, Simon; Weidner, Tatjana; Biedenkopf, Nadine; Sliva, Katja; Weber, Christopher; Becker, Stephan; Schnierle, Barbara S

    2016-08-31

    Chikungunya virus (CHIKV) is a mosquito-transmitted alphavirus that causes high fever, rash, and recurrent arthritis in humans. It has efficiently adapted to Aedes albopictus, which also inhabits temperate regions and currently causes large outbreaks in the Caribbean and Latin America. Ebola virus (EBOV) is a member of the filovirus family. It causes the Ebola virus disease (EDV), formerly known as Ebola hemorrhagic fever in humans and has a mortality rate of up to 70 %. The last outbreak in Western Africa was the largest in history and has caused approximately 25,000 cases and 10,000 deaths. For both viral infections no specific treatment or licensed vaccine is currently available. The bis-hexasulfonated naphthylurea, suramin, is used as a treatment for trypanosome-caused African river blindness. As a competitive inhibitor of heparin, suramin has been described to have anti-viral activity. We tested the activity of suramin during CHIKV or Ebola virus infection, using CHIKV and Ebola envelope glycoprotein pseudotyped lentiviral vectors and wild-type CHIKV and Ebola virus. Suramin efficiently inhibited CHIKV and Ebola envelope-mediated gene transfer while vesicular stomatitis virus G protein pseudotyped vectors were only marginally affected. In addition, suramin was able to inhibit wild-type CHIKV and Ebola virus replication in vitro. Inhibition occurred at early time points during CHIKV infection. Suramin, also known as Germanin or Bayer-205, is a market-authorized drug, however shows significant side effects, which probably prevents its use as a CHIKV drug, but due to the high lethality of Ebola virus infections, suramin might be valuable against Ebola infections.

  20. Changes in antiviral susceptibility to entry inhibitors and endocytic uptake of dengue-2 virus serially passaged in Vero or C6/36 cells.

    Science.gov (United States)

    Acosta, Eliana G; Piccini, Luana E; Talarico, Laura B; Castilla, Viviana; Damonte, Elsa B

    2014-05-12

    The aim of the present study was to analyze the influence of virus origin, mammalian or mosquito cell-derived, on antiviral susceptibility of DENV-2 to entry inhibitors and the association of this effect with any alteration in the mode of entry into the cell. To this end, ten serial passages of DENV-2 were performed in mosquito C6/36 cells or monkey Vero cells and the antiviral susceptibility of each virus passage to sulfated polysaccharides (SPs), like heparin and carrageenans, was evaluated by a virus plaque reduction assay. After serial passaging in Vero cells, DENV-2 became increasingly resistant to SP inhibition whereas the antiviral susceptibility was not altered in virus propagated in C6/36 cells. The change in antiviral susceptibility was associated to a differential mode of entry into the host cell. The route of endocytic entry for productive Vero cell infection was altered from a non-classical clathrin independent pathway for C6/36-grown virus to a clathrin-mediated endocytosis when the virus was serially propagated in Vero cells. Our results show the impact of the cellular system used for successive propagation of DENV on the initial interaction between the host cell and the virion in the next round of infection and the relevant consequences it might have during the in vitro evaluation of entry inhibitors. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Decoding the anti-Trypanosoma cruzi action of HIV peptidase inhibitors using epimastigotes as a model.

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    Leandro S Sangenito

    Full Text Available BACKGROUND: Aspartic peptidase inhibitors have shown antimicrobial action against distinct microorganisms. Due to an increase in the occurrence of Chagas' disease/AIDS co-infection, we decided to explore the effects of HIV aspartic peptidase inhibitors (HIV-PIs on Trypanosoma cruzi, the etiologic agent of Chagas' disease. METHODOLOGY AND PRINCIPAL FINDINGS: HIV-PIs presented an anti-proliferative action on epimastigotes of T. cruzi clone Dm28c, with IC50 values ranging from 0.6 to 14 µM. The most effective inhibitors, ritonavir, lopinavir and nelfinavir, also had an anti-proliferative effect against different phylogenetic T. cruzi strains. The HIV-PIs induced some morphological alterations in clone Dm28c epimastigotes, as reduced cell size and swollen of the cellular body. Transmission electron microscopy revealed that the flagellar membrane, mitochondrion and reservosomes are the main targets of HIV-PIs in T. cruzi epimastigotes. Curiously, an increase in the epimastigote-into-trypomastigote differentiation process of clone Dm28c was observed, with many of these parasites presenting morphological alterations including the detachment of flagellum from the cell body. The pre-treatment with the most effective HIV-PIs drastically reduced the interaction process between epimastigotes and the invertebrate vector Rhodnius prolixus. It was also noted that HIV-PIs induced an increase in the expression of gp63-like and calpain-related molecules, and decreased the cruzipain expression in epimastigotes as judged by flow cytometry and immunoblotting assays. The hydrolysis of a cathepsin D fluorogenic substrate was inhibited by all HIV-PIs in a dose-dependent manner, showing that the aspartic peptidase could be a possible target to these drugs. Additionally, we verified that ritonavir, lopinavir and nelfinavir reduced drastically the viability of clone Dm28c trypomastigotes, causing many morphological damages. CONCLUSIONS AND SIGNIFICANCE: The results

  2. The evaluation of catechins that contain a galloyl moiety as potential HIV-1 integrase inhibitors.

    Science.gov (United States)

    Jiang, Fan; Chen, Wei; Yi, Kejia; Wu, Zhiqiang; Si, Yiling; Han, Weidong; Zhao, Yali

    2010-12-01

    Four catechins with the galloyl moiety, including catechin gallate (CG), epigallocatechin gallate (EGCG), gallocatechin gallate (GCG), and epicatechin gallate (ECG), were found to inhibit HIV-1 integrase effectively as determined by our ELISA method. In our docking study, it is proposed that when the HIV-1 integrase does not combine with virus DNA, the four catechins may bind to Tyr143 and Gln148, thus altering the flexibility of the loop (Gly140-Gly149), which could lead to an inhibition of HIV-1 integrase activity. In addition, after combining HIV-1 integrase with virus DNA, the four catechins may bind between the integrase and virus DNA, consequently, disrupt this interaction. Thus, the four catechins may reduce the activity of HIV-1 integrase by disrupting its interaction with virus DNA. The four catechins have a highly cooperative inhibitory effect (IC₅₀=0.1 μmol/L). Our study suggests that catechins with the galloyl moiety could be a novel and effective class of HIV-1 integrase inhibitors. Copyright © 2010 Elsevier Inc. All rights reserved.

  3. HIV nonnucleoside reverse transcriptase inhibitors and trimethoprim-sulfamethoxazole inhibit plasmodium liver stages.

    Science.gov (United States)

    Hobbs, Charlotte V; Voza, Tatiana; De La Vega, Patricia; Vanvliet, Jillian; Conteh, Solomon; Penzak, Scott R; Fay, Michael P; Anders, Nicole; Ilmet, Tiina; Li, Yonghua; Borkowsky, William; Krzych, Urszula; Duffy, Patrick E; Sinnis, Photini

    2012-12-01

    Although nonnucleoside reverse transcriptase inhibitors (NNRTIs) are usually part of first-line treatment regimens for human immunodeficiency virus (HIV), their activity on Plasmodium liver stages remains unexplored. Additionally, trimethoprim-sulfamethoxazole (TMP-SMX), used for opportunistic infection prophylaxis in HIV-exposed infants and HIV-infected patients, reduces clinical episodes of malaria; however, TMP-SMX effect on Plasmodium liver stages requires further study. We characterized NNRTI and TMP-SMX effects on Plasmodium liver stages in vivo using Plasmodium yoelii. On the basis of these results, we conducted in vitro studies assessing TMP-SMX effects on the rodent parasites P. yoelii and Plasmodium berghei and on the human malaria parasite Plasmodium falciparum. Our data showed NNRTI treatment modestly reduced P. yoelii liver stage parasite burden and minimally extended prepatent period. TMP-SMX administration significantly reduced liver stage parasite burden, preventing development of patent parasitemia in vivo. TMP-SMX inhibited development of rodent and P. falciparum liver stage parasites in vitro. NNRTIs modestly affect liver stage Plasmodium parasites, whereas TMP-SMX prevents patent parasitemia. Because drugs that inhibit liver stages target parasites when they are present in lower numbers, these results may have implications for eradication efforts. Understanding HIV drug effects on Plasmodium liver stages will aid in optimizing treatment regimens for HIV-exposed and HIV-infected infected patients in malaria-endemic areas.

  4. Structural basis for HTLV-1 protease inhibition by the HIV-1 protease inhibitor indinavir.

    Science.gov (United States)

    Kuhnert, Maren; Steuber, Holger; Diederich, Wibke E

    2014-07-24

    HTLV-1 protease (HTLV-1 PR) is an aspartic protease which represents a promising drug target for the discovery of novel anti-HTLV-1 drugs. The X-ray structure of HTLV-1 PR in complex with the well-known and approved HIV-1 PR inhibitor Indinavir was determined at 2.40 Å resolution. In this contribution, we describe the first crystal structure in complex with a nonpeptidic inhibitor that accounts for rationalizing the rather moderate affinity of Indinavir against HTLV-1 PR and provides the basis for further structure-guided optimization strategies.

  5. Are blockers of gp120/CD4 interaction effective inhibitors of HIV-1 immunopathogenesis?

    Science.gov (United States)

    Herbeuval, Jean-Philippe; Shearer, Gene M

    2006-01-01

    The immunopathogenic mechanisms that result in the depletion of CD4+ T-cells after HIV-1 infection remain controversial. We consider here mechanisms that have been suggested, and propose a data-supported model in which CD4+ T-cells undergo apoptosis that is signaled by the binding of viral gp120 to cellular CD4. Blood leucocytes from HIV-1-uninfected donors, including CD4+ and CD8+ T-cells, monocytes, myeloid and plasmacytoid dendritic cells (pDC) were cultured with either infectious or noninfectious HIV-1. The cultures were tested for expression of interferon-alpha, TRAIL, DR5 and apoptosis. Inhibitors of IFNalpha, TRAIL, DR5 and gp120/CD4 binding were added to the cultures. Ex vivo studies were performed using peripheral blood mononuclear cells (PBMC) from HIV-1-infected patients to test the validity of our in vitro findings. Both infectious and noninfectious HIV-1 induced pDC to produce IFNalpha, which induced expression of TRAIL by CD4+ but not CD8+ T-cells. CD4+ T-cells expressed the TRAIL death receptor 5 (DR5), upon HIV-1 binding to CD4. Antibodies against TRAIL and DR5 partly inhibited apoptosis. However, soluble CD4 (sCD4-IgG) efficiently blocked IFNalpha production, TRAIL and DR5 expression and apoptosis of T helper cells. Studies of HIV-1-infected patients' PBMC indicated increased plasma TRAIL production and CD4+ T-cell DR5 expression, which correlated directly with viral load and inversely with CD4 count. Noninfectious interactions between HIV-1 and CD4 are major contributors to CD4+ T-cell death via IFNalpha-induced TRAIL expression and HIV-1-induced DR5 expression on CD4+ T-cells. Since noninfectious as well as infectious HIV-1 induces the death cascade resulting in selective apoptosis of CD4+ T-cells, these HIV-1/CD4-dependent binding events would not necessarily be reflected in HIV-1 RNA and DNA expression by the CD4+ target T-cells. Because each step of this model leading to apoptosis requires the binding of gp120 to CD4, we suggest that molecules

  6. Contribution of HIV minority variants to drug resistance in an integrase strand transfer inhibitor-based therapy

    Czech Academy of Sciences Publication Activity Database

    Weber, Jan; Gibson, R. M.; Meyer, A. M.; Winner, D.; Robertson, D. L.; Miller, M. D.; Quinones-Mateu, M. E.

    2013-01-01

    Roč. 18, Suppl. 1 (2013), A66-A66 ISSN 1359-6535. [International Workshop on HIV & Hepatitis Virus Drug Resistance Curative Strategies. 04.06.2013-08.06.2013, Toronto] Institutional support: RVO:61388963 Keywords : HIV minority variants * integrase inhibitor * replicative fitness Subject RIV: CE - Biochemistry

  7. A three step continuous flow synthesis of the biaryl unit of the HIV protease inhibitor Atazanavir.

    Science.gov (United States)

    Dalla-Vechia, Luciana; Reichart, Benedikt; Glasnov, Toma; Miranda, Leandro S M; Kappe, C Oliver; de Souza, Rodrigo O M A

    2013-10-21

    The development of multistep continuous flow reactions for the synthesis of important intermediates for the pharmaceutical industry is still a significant challenge. In the present contribution the biaryl-hydrazine unit of Atazanavir, an important HIV protease inhibitor, was prepared in a three-step continuous flow sequence in 74% overall yield. The synthesis involved Pd-catalyzed Suzuki–Miyaura cross-coupling, followed by hydrazone formation and a subsequent hydrogenation step, and additionally incorporates a liquid–liquid extraction step.

  8. Structure-Aided Design of Novel Inhibitors of HIV Protease Based on a Benzodiazepine Scaffold

    Czech Academy of Sciences Publication Activity Database

    Schimer, Jiří; Cígler, Petr; Veselý, J.; Grantz Šašková, Klára; Lepšík, Martin; Brynda, Jiří; Řezáčová, Pavlína; Kožíšek, Milan; Císařová, I.; Oberwinkler, H.; Kraeusslich, H. G.; Konvalinka, Jan

    2012-01-01

    Roč. 55, č. 22 (2012), s. 10130-10135 ISSN 0022-2623 R&D Projects: GA ČR GBP208/12/G016; GA ČR GAP207/11/1798 Institutional research plan: CEZ:AV0Z40550506; CEZ:AV0Z50520514 Keywords : HIV protease inhibitor * rational drug design * 1,4-benzodiazepines Subject RIV: CE - Biochemistry Impact factor: 5.614, year: 2012

  9. Fluorogenic Assay for Inhibitors of HIV-1 Protease with Sub-picomolar Affinity

    Science.gov (United States)

    Windsor, Ian W.; Raines, Ronald T.

    2015-08-01

    A fluorogenic substrate for HIV-1 protease was designed and used as the basis for a hypersensitive assay. The substrate exhibits a kcat of 7.4 s-1, KM of 15 μM, and an increase in fluorescence intensity of 104-fold upon cleavage, thus providing sensitivity that is unmatched in a continuous assay of HIV-1 protease. These properties enabled the enzyme concentration in an activity assay to be reduced to 25 pM, which is close to the Kd value of the protease dimer. By fitting inhibition data to Morrison’s equation, Ki values of amprenavir, darunavir, and tipranavir were determined to be 135, 10, and 82 pM, respectively. This assay, which is capable of measuring Ki values as low as 0.25 pM, is well-suited for characterizing the next generation of HIV-1 protease inhibitors.

  10. JAK-STAT Signaling Pathways and Inhibitors Affect Reversion of Envelope-Mutated HIV-1.

    Science.gov (United States)

    Quan, Yudong; Xu, Hongtao; Han, Yingshan; Mesplède, Thibault; Wainberg, Mark A

    2017-05-01

    HIV can spread by both cell-free and cell-to-cell transmission. Here, we show that many of the amino acid changes in Env that are close to the CD4 binding pocket can affect HIV replication. We generated a number of mutant viruses that were unable to infect T cells as cell-free viruses but were nevertheless able to infect certain T cell lines as cell-associated viruses, which was followed by reversion to the wild type. However, the activation of JAK-STAT signaling pathways caused the inhibition of such cell-to-cell infection as well as the reversion of multiple HIV Env mutants that displayed differences in their abilities to bind to the CD4 receptor. Specifically, two T cell activators, interleukin-2 (IL-2) and phorbol 12-myristate 13-acetate (PMA), both capable of activation of JAK-STAT pathways, were able to inhibit cell-to-cell viral transmission. In contrast, but consistent with the above result, a number of JAK-STAT and mTOR inhibitors actually promoted HIV-1 transmission and reversion. Hence, JAK-STAT signaling pathways may differentially affect the replication of a variety of HIV Env mutants in ways that differ from the role that these pathways play in the replication of wild-type viruses.IMPORTANCE Specific alterations in HIV Env close to the CD4 binding site can differentially change the ability of HIV to mediate infection for cell-free and cell-associated viruses. However, such differences are dependent to some extent on the types of target cells used. JAK-STAT signaling pathways are able to play major roles in these processes. This work sheds new light on factors that can govern HIV infection of target cells. Copyright © 2017 American Society for Microbiology.

  11. 2D-QSAR study of fullerene nanostructure derivatives as potent HIV-1 protease inhibitors

    Science.gov (United States)

    Barzegar, Abolfazl; Jafari Mousavi, Somaye; Hamidi, Hossein; Sadeghi, Mehdi

    2017-09-01

    The protease of human immunodeficiency virus1 (HIV-PR) is an essential enzyme for antiviral treatments. Carbon nanostructures of fullerene derivatives, have nanoscale dimension with a diameter comparable to the diameter of the active site of HIV-PR which would in turn inhibit HIV. In this research, two dimensional quantitative structure-activity relationships (2D-QSAR) of fullerene derivatives against HIV-PR activity were employed as a powerful tool for elucidation the relationships between structure and experimental observations. QSAR study of 49 fullerene derivatives was performed by employing stepwise-MLR, GAPLS-MLR, and PCA-MLR models for variable (descriptor) selection and model construction. QSAR models were obtained with higher ability to predict the activity of the fullerene derivatives against HIV-PR by a correlation coefficient (R2training) of 0.942, 0.89, and 0.87 as well as R2test values of 0.791, 0.67and 0.674 for stepwise-MLR, GAPLS-MLR, and PCA -MLR models, respectively. Leave-one-out cross-validated correlation coefficient (R2CV) and Y-randomization methods confirmed the models robustness. The descriptors indicated that the HIV-PR inhibition depends on the van der Waals volumes, polarizability, bond order between two atoms and electronegativities of fullerenes derivatives. 2D-QSAR simulation without needing receptor's active site geometry, resulted in useful descriptors mainly denoting ;C60 backbone-functional groups; and ;C60 functional groups; properties. Both properties in fullerene refer to the ligand fitness and improvement van der Waals interactions with HIV-PR active site. Therefore, the QSAR models can be used in the search for novel HIV-PR inhibitors based on fullerene derivatives.

  12. The Second-Generation Maturation Inhibitor GSK3532795 Maintains Potent Activity Toward HIV Protease Inhibitor-Resistant Clinical Isolates.

    Science.gov (United States)

    Ray, Neelanjana; Li, Tianbo; Lin, Zeyu; Protack, Tricia; van Ham, Petronella Maria; Hwang, Carey; Krystal, Mark; Nijhuis, Monique; Lataillade, Max; Dicker, Ira

    2017-05-01

    Protease inhibitor (PI)-resistant HIV-1 isolates with primary substitutions in protease (PR) and secondary substitutions in Gag could potentially exhibit cross-resistance to maturation inhibitors. We evaluated the second-generation maturation inhibitor, GSK3532795, for activity toward clinical isolates with genotypic and phenotypic characteristics associated with PI resistance (longitudinal). Longitudinal clinical isolates from 15 PI-treated patients and 7 highly PI-resistant (nonlongitudinal) viruses containing major and minor PI resistance-associated mutations were evaluated for GSK3532795 sensitivity. Phenotypic sensitivity was determined using the PhenoSense Gag/PR assay (Monogram Biosciences) or in-house single- and multiple-cycle assays. Changes from baseline [CFB; ratio of post- to pre-treatment FC-IC50 (fold-change in IC50 versus wild-type virus)] 3 (Monogram) were retested using single- and multiple-cycle assays. Neither sample had meaningful sensitivity changes in the multiple-cycle assay. Gag changes were not associated with an increased GSK3532795 CFB. GSK3532795 maintained antiviral activity against PI-resistant isolates with emergent PR and/or Gag mutations. This finding supports continued development of GSK3532795 in treatment-experienced patients with or without previous PI therapy.

  13. QSAR and docking studies of coumarin derivatives as potent HIV-1 integrase inhibitors

    Directory of Open Access Journals (Sweden)

    V.K. Srivastav

    2017-02-01

    Full Text Available Human immunodeficiency virus integrase (HIV-1IN is an emerging and potential drug target for anti-HIV therapy. It is an enzyme essential for 3′ processing and integration step in the life cycle of HIV. In the present study a series of coumarin derivatives (containing 26 compounds as HIV-1IN inhibitors was subjected to quantitative structure–activity relationship (QSAR analysis. For building the regression models two different variable selection approaches namely, genetic function approximation (GFA and sequential multiple linear regression (SQ-MLR were used and compared to predict the HIV-1IN inhibition activity. Based on prediction, the best validation model for 3′ processing inhibition activity with squared correlation coefficient (r2 = 0.8965, cross validated correlation coefficient (Q2 = 0.8307 and external prediction ability pred_r2 = 0.5400 showed that Henry’s law Constant (HLC, Partition Coefficient (PC and Dipole moment-Z component (D3 were the positive contributors, whereas for integration inhibition activity, parameters r2 = 0.8904, Q2 = 0.8174 and pred_r2 = 0.7159 showed HLC, Logarithm of Partition Coefficient (LogP and Dipole moment-Y component (D2 contributed positively to the activity. The binding mode pattern of the compounds to the binding site of integrase enzyme was confirmed by docking studies. The results of the present study may be useful for designing more potent HIV-1IN inhibitors.

  14. Insight into the structural similarity between HIV protease and secreted aspartic protease-2 and binding mode analysis of HIV-Candida albicans inhibitors.

    Science.gov (United States)

    Calugi, Chiara; Guarna, Antonio; Trabocchi, Andrea

    2013-10-01

    The analysis of the structural similarity between Candida albicans Sap2 and HIV-1 aspartic proteases by molecular modeling gave insight into the common requirements for inhibition of both targets. Structure superimposition of Sap2 and HIV-1 protease confirmed the similarity between their active sites and flap regions. HIV-1 protease inhibitors herein investigated can fit the active site of Sap2, adopting very similar ligand-backbone conformations. In particular, key anchoring sites consisting of Gly85 in Sap2 and Ile50 in HIV-1 protease, both belonging to their corresponding flap regions, were found as elements of a similar binding-mode interaction. The knowledge of the molecular basis for binding to both Sap2 and HIV-1 proteases may ultimately lead to the development of single inhibitor acting on both targets.

  15. Binding kinetics of aptamers to gp120 derived from HIV-1 subtype C

    CSIR Research Space (South Africa)

    Millroy, L

    2011-02-01

    Full Text Available aptamers with specific and strong affinity to the HIV-1 envelope glycoprotein gp120 and act as novel HIV-1 entry inhibitor drugs or as targeted drug delivery systems to HIV-1 infected cells. Prior to any downstream applications, novel gp120 aptamers need...

  16. Novel functions of plant cyclin-dependent kinase inhibitors, ICK1/KRP1, can act non-cell-autonomously and inhibit entry into mitosis

    DEFF Research Database (Denmark)

    Weinl, Christina; Marquardt, Sebastian; Kuijt, Suzanne J H

    2005-01-01

    numbers of cells consistent with a function of CKIs in blocking the G1-S cell cycle transition. Here, we demonstrate that at least one inhibitor from Arabidopsis, ICK1/KRP1, can also block entry into mitosis but allows S-phase progression causing endoreplication. Our data suggest that plant CKIs act...... independently from ICK1/KRP1-induced endoreplication. Strikingly, we found that endoreplicated cells were able to reenter mitosis, emphasizing the high degree of flexibility of plant cells during development. Moreover, we show that in contrast with animal CDK inhibitors, ICK1/KRP1 can move between cells...

  17. Discovery of a small-molecule HIV-1 integrase inhibitor-binding site | Center for Cancer Research

    Science.gov (United States)

    The lowest energy-binding conformation of an inhibitor bound to the dimeric interface of HIV-1 integrase core domain. The yellow region represents a unique allosteric binding site identified by affinity labeling and mass spectrometry and validated through mutagenesis. This site can provide a potential platform for the rational design of inhibitors selective for disruption of integrase multimerization.

  18. The Tat Inhibitor Didehydro-Cortistatin A Prevents HIV-1 Reactivation from Latency.

    Science.gov (United States)

    Mousseau, Guillaume; Kessing, Cari F; Fromentin, Rémi; Trautmann, Lydie; Chomont, Nicolas; Valente, Susana T

    2015-07-07

    Antiretroviral therapy (ART) inhibits HIV-1 replication, but the virus persists in latently infected resting memory CD4(+) T cells susceptible to viral reactivation. The virus-encoded early gene product Tat activates transcription of the viral genome and promotes exponential viral production. Here we show that the Tat inhibitor didehydro-cortistatin A (dCA), unlike other antiretrovirals, reduces residual levels of viral transcription in several models of HIV latency, breaks the Tat-mediated transcriptional feedback loop, and establishes a nearly permanent state of latency, which greatly diminishes the capacity for virus reactivation. Importantly, treatment with dCA induces inactivation of viral transcription even after its removal, suggesting that the HIV promoter is epigenetically repressed. Critically, dCA inhibits viral reactivation upon CD3/CD28 or prostratin stimulation of latently infected CD4(+) T cells from HIV-infected subjects receiving suppressive ART. Our results suggest that inclusion of a Tat inhibitor in current ART regimens may contribute to a functional HIV-1 cure by reducing low-level viremia and preventing viral reactivation from latent reservoirs. Antiretroviral therapy (ART) reduces HIV-1 replication to very low levels, but the virus persists in latently infected memory CD4(+) T cells, representing a long-lasting source of resurgent virus upon ART interruption. Based on the mode of action of didehydro-cortistatin A (dCA), a Tat-dependent transcription inhibitor, our work highlights an alternative approach to current HIV-1 eradication strategies to decrease the latent reservoir. In our model, dCA blocks the Tat feedback loop initiated after low-level basal reactivation, blocking transcriptional elongation and hence viral production from latently infected cells. Therefore, dCA combined with ART would be aimed at delaying or halting ongoing viral replication, reactivation, and replenishment of the latent viral reservoir. Thus, the latent pool of

  19. HIV-1 Protease with 20 Mutations Exhibits Extreme Resistance to Clinical Inhibitors through Coordinated Structural Rearrangements

    Energy Technology Data Exchange (ETDEWEB)

    Agniswamy, Johnson; Shen, Chen-Hsiang; Aniana, Annie; Sayer, Jane M.; Louis, John M.; Weber, Irene T. (GSU); (NIH)

    2012-06-28

    The escape mutant of HIV-1 protease (PR) containing 20 mutations (PR20) undergoes efficient polyprotein processing even in the presence of clinical protease inhibitors (PIs). PR20 shows >3 orders of magnitude decreased affinity for PIs darunavir (DRV) and saquinavir (SQV) relative to PR. Crystal structures of PR20 crystallized with yttrium, substrate analogue p2-NC, DRV, and SQV reveal three distinct conformations of the flexible flaps and diminished interactions with inhibitors through the combination of multiple mutations. PR20 with yttrium at the active site exhibits widely separated flaps lacking the usual intersubunit contacts seen in other inhibitor-free dimers. Mutations of residues 35-37 in the hinge loop eliminate interactions and perturb the flap conformation. Crystals of PR20/p2-NC contain one uninhibited dimer with one very open flap and one closed flap and a second inhibitor-bound dimer in the closed form showing six fewer hydrogen bonds with the substrate analogue relative to wild-type PR. PR20 complexes with PIs exhibit expanded S2/S2' pockets and fewer PI interactions arising from coordinated effects of mutations throughout the structure, in agreement with the strikingly reduced affinity. In particular, insertion of the large aromatic side chains of L10F and L33F alters intersubunit interactions and widens the PI binding site through a network of hydrophobic contacts. The two very open conformations of PR20 as well as the expanded binding site of the inhibitor-bound closed form suggest possible approaches for modifying inhibitors to target extreme drug-resistant HIV.

  20. Pyrazolo[1,5-a]pyrimidine-based macrocycles as novel HIV-1 inhibitors: a patent evaluation of WO2015123182.

    Science.gov (United States)

    Sun, Lin; Gao, Ping; Zhan, Peng; Liu, Xinyong

    2016-09-01

    The emergence of drug resistance in Combination Antiretroviral Therapy (cART) confirms a continuing need to investigate novel HIV-1 inhibitors with unexplored mechanisms of action. Recently, a series of pyrazolopyrimidine-based macrocyclic compounds were reported as inhibitors of HIV-1 replication disclosed in the patent WO2015123182. Most of the disclosed compounds possessed in vitro antiviral potency in single-digit nanomolar range, which were determined by MT-2 cell assay. Then, the structural diversity, pharmacophore similarity of HIV-1 IN-LEDGF/p75 inhibitors, and implications for drug design were analyzed. In the end of this article, a glimpse of some macrocycles as potent antiviral agents (drug candidates) was provided. Some strategies and technologies enabling macrocycle design were also described. We expect that further development of these macrocyclic compounds will offer new anti-HIV-1 drug candidates.

  1. Generation of VSV Pseudotypes Using Recombinant ΔG-VSV for Studies on Virus Entry, Identification of Entry Inhibitors, and Immune Responses to Vaccines

    OpenAIRE

    Whitt, Michael A.

    2010-01-01

    Vesicular stomatitis virus (VSV) is a prototypic enveloped animal virus that has been used extensively to study virus entry, replication and assembly due to its broad host range and robust replication properties in a wide variety of mammalian and insect cells. Studies on VSV assembly led to the creation of a recombinant VSV in which the glycoprotein (G) gene was deleted. This recombinant (rVSV-ΔG) has been used to produce VSV pseudotypes containing the envelope glycoproteins of heterologous v...

  2. Relation between flexibility and positively selected HIV-1 protease mutants against inhibitors.

    Science.gov (United States)

    Braz, Antônio S K; Tufanetto, Patrícia; Perahia, David; Scott, Luis P B

    2012-12-01

    The antiretroviral chemotherapy helps to reduce the mortality of HIVs infected patients. However, RNA dependant virus replication has a high mutation rate. Human immunodeficiency virus Type 1 protease plays an essential role in viral replication cycle. This protein is an important target for therapy with viral protein inhibitors. There are few works using normal mode analysis to investigate this problem from the structural changes viewpoint. The investigation of protein flexibility may be important for the study of processes associated with conformational changes and state transitions. The normal mode analysis allowed us to investigate structural changes in the protease (such as flexibility) in a straightforward way and try to associate these changes with the increase of fitness for each positively selected HIV-1 mutant protease of patients treated with several protease inhibitors (saquinavir, indinavir, ritonavir, nelfinavir, lopinavir, fosamprenavir, atazanavir, darunavir, and tripanavir) in combination or separately. These positively selected mutations introduce significant flexibility in important regions such as the active site cavity and flaps. These mutations were also able to cause changes in accessible solvent area. This study showed that the majority of HIV-1 protease mutants can be grouped into two main classes of protein flexibility behavior. We presented a new approach to study structural changes caused by positively selected mutations in a pathogen protein, for instance the HIV-1 protease and their relationship with their resistance mechanism against known inhibitors. The method can be applied to any pharmaceutically relevant pathogen proteins and could be very useful to understand the effects of positively selected mutations in the context of structural changes. Copyright © 2012 Wiley Periodicals, Inc.

  3. Design and synthesis of highly potent HIV-1 protease inhibitors with novel isosorbide-derived P2 ligands.

    Science.gov (United States)

    Qiu, Xin; Zhao, Guo-Dong; Tang, Long-Qiang; Liu, Zhao-Peng

    2014-06-01

    The design, synthesis, and biological evaluation of a series of six HIV-1 protease inhibitors incorporating isosorbide moiety as novel P2 ligands are described. All the compounds are very potent HIV-1 protease inhibitors with IC50 values in the nanomolar or picomolar ranges (0.05-0.43 nM). Molecular docking studies revealed the formation of an extensive hydrogen-bonding network between the inhibitor and the active site. Particularly, the isosorbide-derived P2 ligand is involved in strong hydrogen bonding interactions with the backbone atoms. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Reduction of the HIV protease inhibitor-induced ER stress and inflammatory response by raltegravir in macrophages.

    Directory of Open Access Journals (Sweden)

    Xiaoxuan Zhang

    Full Text Available HIV protease inhibitor (PI, the core component of highly active antiretroviral treatment (HAART for HIV infection, has been implicated in HAART-associated cardiovascular complications. Our previous studies have demonstrated that activation of endoplasmic reticulum (ER stress is linked to HIV PI-induced inflammation and foam cell formation in macrophages. Raltegravir is a first-in-its-class HIV integrase inhibitor, the newest class of anti-HIV agents. We have recently reported that raltegravir has less hepatic toxicity and could prevent HIV PI-induced dysregulation of hepatic lipid metabolism by inhibiting ER stress. However, little information is available as to whether raltegravir would also prevent HIV PI-induced inflammatory response and foam cell formation in macrophages.In this study, we examined the effect of raltegravir on ER stress activation and lipid accumulation in cultured mouse macrophages (J774A.1, primary mouse macrophages, and human THP-1-derived macrophages, and further determined whether the combination of raltegravir with existing HIV PIs would potentially exacerbate or prevent the previously observed activation of inflammatory response and foam cell formation. The results indicated that raltegravir did not induce ER stress and inflammatory response in macrophages. Even more interestingly, HIV PI-induced ER stress, oxidative stress, inflammatory response and foam cell formation were significantly reduced by raltegravir. High performance liquid chromatography (HPLC analysis further demonstrated that raltegravir did not affect the uptake of HIV PIs in macrophages.Raltegravir could prevent HIV PI-induced inflammatory response and foam cell formation by inhibiting ER stress. These results suggest that incorporation of this HIV integrase inhibitor may reduce the cardiovascular complications associated with current HAART.

  5. Reduction of the HIV protease inhibitor-induced ER stress and inflammatory response by raltegravir in macrophages.

    Science.gov (United States)

    Zhang, Xiaoxuan; Cao, Risheng; Liu, Runping; Zhao, Renping; Huang, Yi; Gurley, Emily C; Hylemon, Phillip B; Pandak, William M; Wang, Guangji; Zhang, Luyong; Li, Xiaokun; Zhou, Huiping

    2014-01-01

    HIV protease inhibitor (PI), the core component of highly active antiretroviral treatment (HAART) for HIV infection, has been implicated in HAART-associated cardiovascular complications. Our previous studies have demonstrated that activation of endoplasmic reticulum (ER) stress is linked to HIV PI-induced inflammation and foam cell formation in macrophages. Raltegravir is a first-in-its-class HIV integrase inhibitor, the newest class of anti-HIV agents. We have recently reported that raltegravir has less hepatic toxicity and could prevent HIV PI-induced dysregulation of hepatic lipid metabolism by inhibiting ER stress. However, little information is available as to whether raltegravir would also prevent HIV PI-induced inflammatory response and foam cell formation in macrophages. In this study, we examined the effect of raltegravir on ER stress activation and lipid accumulation in cultured mouse macrophages (J774A.1), primary mouse macrophages, and human THP-1-derived macrophages, and further determined whether the combination of raltegravir with existing HIV PIs would potentially exacerbate or prevent the previously observed activation of inflammatory response and foam cell formation. The results indicated that raltegravir did not induce ER stress and inflammatory response in macrophages. Even more interestingly, HIV PI-induced ER stress, oxidative stress, inflammatory response and foam cell formation were significantly reduced by raltegravir. High performance liquid chromatography (HPLC) analysis further demonstrated that raltegravir did not affect the uptake of HIV PIs in macrophages. Raltegravir could prevent HIV PI-induced inflammatory response and foam cell formation by inhibiting ER stress. These results suggest that incorporation of this HIV integrase inhibitor may reduce the cardiovascular complications associated with current HAART.

  6. Integrase inhibitors in late pregnancy and rapid HIV viral load reduction.

    Science.gov (United States)

    Rahangdale, Lisa; Cates, Jordan; Potter, JoNell; Badell, Martina L; Seidman, Dominika; Miller, Emilly S; Coleman, Jenell S; Lazenby, Gweneth B; Levison, Judy; Short, William R; Yawetz, Sigal; Ciaranello, Andrea; Livingston, Elizabeth; Duthely, Lunthita; Rimawi, Bassam H; Anderson, Jean R; Stringer, Elizabeth M

    2016-03-01

    Minimizing time to HIV viral suppression is critical in pregnancy. Integrase strand transfer inhibitors (INSTIs), like raltegravir, are known to rapidly suppress plasma HIV RNA in nonpregnant adults. There are limited data in pregnant women. We describe time to clinically relevant reduction in HIV RNA in pregnant women using INSTI-containing and non-INSTI-containing antiretroviral therapy (ART) options. We conducted a retrospective cohort study of pregnant HIV-infected women in the United States from 2009 through 2015. We included women who initiated ART, intensified their regimen, or switched to a new regimen due to detectable viremia (HIV RNA >40 copies/mL) at ≥20 weeks gestation. Among women with a baseline HIV RNA permitting 1-log reduction, we estimated time to 1-log RNA reduction using the Kaplan-Meier estimator comparing women starting/adding an INSTI in their regimen vs other ART. To compare groups with similar follow-up time, we also conducted a subgroup analysis limited to women with ≤14 days between baseline and follow-up RNA data. This study describes 101 HIV-infected pregnant women from 11 US clinics. In all, 75% (76/101) of women were not taking ART at baseline; 24 were taking non-INSTI containing ART, and 1 received zidovudine monotherapy. In all, 39% (39/101) of women started an INSTI-containing regimen or added an INSTI to their ART regimen. Among 90 women with a baseline HIV RNA permitting 1-log reduction, the median time to 1-log RNA reduction was 8 days (interquartile range [IQR], 7-14) in the INSTI group vs 35 days (IQR, 20-53) in the non-INSTI ART group (P pregnancy. Inclusion of an INSTI may play a role in optimal reduction of HIV RNA for HIV-infected pregnant women presenting late to care or failing initial therapy. Larger studies are urgently needed to assess the safety and effectiveness of this approach. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Structure of HIV-1 Reverse Transcriptase with the Inhibitor -thujaplicinol Bound at the RNase H Active Site

    Energy Technology Data Exchange (ETDEWEB)

    Himmel, D.; Maegley, K; Pauly, T; Bauman, J; Das, K; Dharia, C; Clark, Jr., A; Ryan, K; Hickey, M; et al.

    2009-01-01

    Novel inhibitors are needed to counteract the rapid emergence of drug-resistant HIV variants. HIV-1 reverse transcriptase (RT) has both DNA polymerase and RNase H (RNH) enzymatic activities, but approved drugs that inhibit RT target the polymerase. Inhibitors that act against new targets, such as RNH, should be effective against all of the current drug-resistant variants. Here, we present 2.80 {angstrom} and 2.04 {angstrom} resolution crystal structures of an RNH inhibitor, {beta}-thujaplicinol, bound at the RNH active site of both HIV-1 RT and an isolated RNH domain. {beta}-thujaplicinol chelates two divalent metal ions at the RNH active site. We provide biochemical evidence that {beta}-thujaplicinol is a slow-binding RNH inhibitor with noncompetitive kinetics and suggest that it forms a tropylium ion that interacts favorably with RT and the RNA:DNA substrate.

  8. Inhibitors

    Science.gov (United States)

    ... and exercise, immune tolerance therapy, and needs of older adults with hemophilia and an inhibitor. For more information, visit https://www.hemophilia.org/Events-Educational-Programs/Inhibitor-Education/Inhibitor-Education-Summits The NHF’s Inhibitor Education Summits ...

  9. Application of an R-group search technique into molecular design of HIV-1 integrase inhibitors

    Directory of Open Access Journals (Sweden)

    Tong Jian-Bo

    2016-01-01

    Full Text Available In this paper, a three-dimensional quantitative structure-activity relationship (3D-QSAR study for 62 HIV-1 integrase(IN inhibitors was established using Topomer CoMFA. The multiple correlation coefficient of fitting, cross validation and external validation were 0.942, 0.670 and 0.748, respectively. The results indicated that the Topomer CoMFA model obtained has both favorable estimation stability and good prediction capability. Topomer Search was used to search R group from ZINC database. As the result, a series of R groups with relatively high activity contribution was obtained. By filtering with the most potent molecule in the set, 1 Ra group and 21 Rb groups were selected. We employed the 1 Ra groups and 21 Rb groups to alternately substitute the Ra and Rb of sample 42. Finally, we designed 21 new compounds and further predicted their activities using the Topomer CoMFA model and there were 10 new compounds with higher activity than that of the template molecule. The results suggested the Topomer Search technology could be effectively used to screen and design new HIV-1 IN inhibitors and has good predictive capability to guide the design of new HIV/AIDS drugs.

  10. In silico design, synthesis, and screening of novel deoxyhypusine synthase inhibitors targeting HIV-1 replication.

    Science.gov (United States)

    Schroeder, Marcus; Kolodzik, Adrian; Pfaff, Katharina; Priyadarshini, Poornima; Krepstakies, Marcel; Hauber, Joachim; Rarey, Matthias; Meier, Chris

    2014-05-01

    The human enzyme deoxyhypusine synthase (DHS) is an important host cell factor that participates in the post-translational hypusine modification of eukaryotic initiation factor 5A (eIF-5A). Hypusine-modified eIF-5A plays a role in a number of diseases, including HIV infection/AIDS. Thus, DHS represents a novel and attractive drug target. So far, four crystal structures are available, and various substances have been tested for inhibition of human DHS. Among these inhibitors, N-1-guanyl-1,7-diaminoheptane (GC7) has been co-crystallized in the active site of DHS. However, despite its potency, GC7 is not selective enough to be used in drug applications. Therefore, new compounds that target DHS are needed. Herein we report the in silico design, chemical synthesis, and biological evaluation of new DHS inhibitors. One of these inhibitors showed dose-dependent inhibition of DHS in vitro, as well as suppression of HIV replication in cell cultures. Furthermore, the compound exhibited no cytotoxic effects at active concentrations. Thus, this designed compound demonstrated proof of principle and represents a promising starting point for the development of new drug candidates to specifically interfere with DHS activity. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. UCLA1, a synthetic derivative of a gp120 RNA aptamer, inhibits entry of human immunodeficiency virus type 1 subtype C

    CSIR Research Space (South Africa)

    Mufhandu, Hazel T

    2012-05-01

    Full Text Available Entry of human immunodeficiency virus type 1 (HIV-1) into cells is mediated by the virion surface envelope (Env) glycoproteins, making it a desirable target for antiretroviral entry inhibitors. We previously isolated a family of gp120 binding RNA...

  12. Structure-based design of potent HIV-1 protease inhibitors with modified P1-biphenyl ligands: synthesis, biological evaluation, and enzyme-inhibitor X-ray structural studies.

    Science.gov (United States)

    Ghosh, Arun K; Yu, Xufen; Osswald, Heather L; Agniswamy, Johnson; Wang, Yuan-Fang; Amano, Masayuki; Weber, Irene T; Mitsuya, Hiroaki

    2015-07-09

    We report the design, synthesis, X-ray structural studies, and biological evaluation of a novel series of HIV-1 protease inhibitors. We designed a variety of functionalized biphenyl derivatives to make enhanced van der Waals interactions in the S1 subsite of HIV-1 protease. These biphenyl derivatives were conveniently synthesized using a Suzuki-Miyaura cross-coupling reaction as the key step. We examined the potential of these functionalized biphenyl-derived P1 ligands in combination with 3-(S)-tetrahydrofuranyl urethane and bis-tetrahydrofuranyl urethane as the P2 ligands. Inhibitor 21e, with a 2-methoxy-1,1'-biphenyl derivative as P1 ligand and bis-THF as the P2 ligand, displayed the most potent enzyme inhibitory and antiviral activity. This inhibitor also exhibited potent activity against a panel of multidrug-resistant HIV-1 variants. A high resolution X-ray crystal structure of related Boc-derivative 17a-bound HIV-1 protease provided important molecular insight into the ligand-binding site interactions of the biphenyl core in the S1 subsite of HIV-1 protease.

  13. Structure of a Dihydroxycoumarin Active-Site Inhibitor in Complex with the RNase H Domain of HIV-1 Reverse Transcriptase and Structure-Activity Analysis of Inhibitor Analogs

    Science.gov (United States)

    Himmel, Daniel M.; Myshakina, Nataliya S.; Ilina, Tatiana; Van Ry, Alexander; Ho, William C.; Parniak, Michael A.; Arnold, Eddy

    2014-01-01

    HIV encodes four essential enzymes: protease, integrase, reverse transcriptase (RT) associated DNA polymerase, and RT-associated ribonuclease H (RNase H). Current clinically approved anti-AIDS drugs target all HIV enzymatic activities except RNase H, which has proven to be a very difficult target for HIV drug discovery. Our high-throughput screening activities identified the dihydroxycoumarin compound F3284-8495 as a specific inhibitor of RT RNase H, with low micromolar potency in vitro. Optimization of inhibitory potency can be facilitated by structural information about inhibitor-target binding. Here, we report the crystal structure of F3284-8495 bound to the active site of an isolated RNase H domain of HIV-1 RT at a resolution limit of 1.71 Å. From predictions based on this structure, compounds were obtained that showed improved inhibitory activity. Computational analysis suggested structural alterations that could provide additional interactions with RT and thus improve inhibitory potency. These studies established proof-of-concept that F3284-8495 could be used as a favorable chemical scaffold for development of HIV RNase H inhibitors. PMID:24840303

  14. Strengthening Health Systems Using HIV Services as an entry point in Plateau State, Nigeria

    Directory of Open Access Journals (Sweden)

    Olubunmi O. Chirdan

    2010-12-01

    Full Text Available AIM: The AIDS Prevention Initiative in Nigeria, Jos University Teaching Hospital’s Community Directed Intervention (CDI approach to prevention and control of the spread of HIV/AIDS, in Plateau state, Nigeria commenced in July, 2008. Management of Tuberculosis and Sexually Transmitted Infections were also included in the package. METHODS: The project utilized the ‘hub and spoke’ principle with the Jos University Teaching Hospital as the hub. Provision of health services commenced in December, 2008 after a period of community sensitization, advocacy and mobilization as well as training and re-training of various cadres of health staff and volunteer community members. RESULTS: To date (July, 2009, thirty PHCs have been renovated and furnished; more than 300 healthcare workers trained, about 115 communities reached and about 8000 patients managed. Other outcomes of the project include equipping of the PHCs, strengthening of the PHC and referral systems, and improved community involvement in programme implementation. CONCLUSION: The project methodology utilized showed that it is possible to achieve additional long term benefits from programmes primarily aimed at controlling HIV/AIDS. It is recommended that other programmes adapt this methodology for the control of diseases, so as to achieve similar impact and strengthen existing health care systems. [TAF Prev Med Bull 2010; 9(6.000: 563-568

  15. Inhibitor Ranking Through QM based Chelation Calculations for Virtual Screening of HIV-1 RNase H inhibition

    DEFF Research Database (Denmark)

    Poongavanam, Vasanthanathan; Svendsen, Casper Steinmann; Kongsted, Jacob

    2014-01-01

    Quantum mechanical (QM) calculations have been used to predict the binding affinity of a set of ligands towards HIV-1 RT associated RNase H (RNH). The QM based chelation calculations show improved binding affinity prediction for the inhibitors compared to using an empirical scoring function...... of the methods based on the use of a training set of molecules, QM based chelation calculations were used as filter in virtual screening of compounds in the ZINC database. By this, we find, compared to regular docking, QM based chelation calculations to significantly reduce the large number of false positives...

  16. Characterization of the virus-cell interactions by HIV-1 subtype C variants from an antiretroviral therapy-naïve subject with baseline resistance to the CCR5 inhibitor maraviroc

    DEFF Research Database (Denmark)

    Jakobsen, Martin Roelsgaard

    resistance to MVC that persisted (as a subset of the viral quasispecies) for approximately 12 months in an antiretroviral therapy-naïve subject infected with HIV-1 subtype C (C-HIV). From a large, longitudinal study of C-HIV Envs (n=323) cloned from 21 subjects experiencing progressive C-HIV infection (see...... in vivo, can use the MVCbound form of CCR5 for HIV-1 entry via adaptive alterations in gp120. Partial baseline resistance to another CCR5 inhibitor through this mechanism, AD101, has been noted recently in one subject (1). Here, we identified and characterized envelope (Env) clones with baseline...... related abstract by Jakobsen et al., “Preferential CCR5-usage by R5X4 subtype C HIV-1 imparts sensitivity to maraviroc and tempers disease progression”), nine subjects persistently harboured CCR5-using (R5) Envs to late stages of infection. Virus inhibition assays in NP2-CD4/CCR5 cells using Env...

  17. “Right Here is the Gateway”: Mobility, Sex Work Entry and HIV Risk Along the Mexico-U.S. Border

    OpenAIRE

    Goldenberg, SM; Silverman, JS; Engstrom, D; Bojorquez-Chapela, I; Strathdee, SA

    2013-01-01

    Women comprise an increasing proportion of migrants. Many voluntarily migrate for sex work or practice survival sex, while others may be trafficked for sexual exploitation. To investigate how the context of mobility shapes sex work entry and HIV risk, we conducted in-depth interviews with formerly trafficked women currently engaged in sex work (n=31) in Tijuana, Mexico and their service providers (n=7) in Tijuana and San Diego, USA from 2010–2011. Women’s experiences of coerced and deceptive ...

  18. The association between adolescent entry into the trucking industry and risk of HIV among long-distance truck drivers in India.

    Science.gov (United States)

    Mishra, Ram Manohar; Dube, Madhulika; Saggurti, Niranjan; Pandey, Arvind; Mahapatra, Bidhubhusan; Ramesh, Sowmya

    2012-01-01

    This study examines the relationship between entry into the trucking industry during adolescence and both sexually transmitted infections (STIs) and infection by the human immunodeficiency virus (HIV) among long-distance truck drivers in India. Data were sourced from a cross-sectional survey (sample size: 2066) undertaken in 2007 among long-distance truck drivers. The survey spread across major transshipment locations covering the bulk of India's transport volume along four routes. Participants were interviewed about sexual behaviors and were tested for HIV and STIs. The present authors constructed two synthetic cohorts based on the participants' duration of employment in the trucking industry: (1) low (duration ≤ 6 years) and (2) high experience (duration ≥ 7 years). Based on age at entry into the trucking industry, participants were termed as either adolescent (age at entry 4.0%, respectively; adjusted OR: 1.9; 95% CI: 1.2-3.1) and syphilis (5.7% versus 3.5%, respectively; adjusted OR: 1.8; 95% CI: 1.1-3.1). These results suggest the need for focused behavioral change programs in HIV prevention interventions for adolescent truckers in India and elsewhere.

  19. Synthesis and biological evaluation of novel HIV-1 protease inhibitors using tertiary amine as P2-ligands.

    Science.gov (United States)

    Yang, Zhi-Heng; Bai, Xiao-Guang; Zhou, Lei; Wang, Ju-Xian; Liu, Hong-Tao; Wang, Yu-Cheng

    2015-05-01

    A series of tertiary amine derivatives exhibiting potent HIV-1 protease inhibiting properties were identified. These novel inhibitors were designed based on the structure of Darunavir with modification on the P2 and P2' position. This effort led to discovery of 35e and 38e, which exhibited excellent HIV-1 protease inhibition with IC50 values of 15 nM and 64 nM, respectively. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. The HIV-1 integrase-LEDGF allosteric inhibitor MUT-A: resistance profile, impairment of virus maturation and infectivity but without influence on RNA packaging or virus immunoreactivity

    NARCIS (Netherlands)

    Amadori, Céline; Ubeles van der Velden, Yme; Bonnard, Damien; Orlov, Igor; van Bel, Nikki; Le Rouzic, Erwann; Miralles, Laia; Brias, Julie; Chevreuil, Francis; Spehner, Daniele; Chasset, Sophie; Ledoussal, Benoit; Mayr, Luzia; Moreau, François; García, Felipe; Gatell, José; Zamborlini, Alessia; Emiliani, Stéphane; Ruff, Marc; Klaholz, Bruno P.; Moog, Christiane; Berkhout, Ben; Plana, Montserrat; Benarous, Richard

    2017-01-01

    HIV-1 Integrase (IN) interacts with the cellular co-factor LEDGF/p75 and tethers the HIV preintegration complex to the host genome enabling integration. Recently a new class of IN inhibitors was described, the IN-LEDGF allosteric inhibitors (INLAIs). Designed to interfere with the IN-LEDGF

  1. Inhibition of P-glycoprotein by HIV protease inhibitors increases intracellular accumulation of berberine in murine and human macrophages.

    Directory of Open Access Journals (Sweden)

    Weibin Zha

    Full Text Available HIV protease inhibitor (PI-induced inflammatory response in macrophages is a major risk factor for cardiovascular diseases. We have previously reported that berberine (BBR, a traditional herbal medicine, prevents HIV PI-induced inflammatory response through inhibiting endoplasmic reticulum (ER stress in macrophages. We also found that HIV PIs significantly increased the intracellular concentrations of BBR in macrophages. However, the underlying mechanisms of HIV PI-induced BBR accumulation are unknown. This study examined the role of P-glycoprotein (P-gp in HIV PI-mediated accumulation of BBR in macrophages.Cultured mouse RAW264.7 macrophages, human THP-1-derived macrophages, Wild type MDCK (MDCK/WT and human P-gp transfected (MDCK/P-gp cells were used in this study. The intracellular concentration of BBR was determined by HPLC. The activity of P-gp was assessed by measuring digoxin and rhodamine 123 (Rh123 efflux. The interaction between P-gp and BBR or HIV PIs was predicated by Glide docking using Schrodinger program. The results indicate that P-gp contributed to the efflux of BBR in macrophages. HIV PIs significantly increased BBR concentrations in macrophages; however, BBR did not alter cellular HIV PI concentrations. Although HIV PIs did not affect P-gp expression, P-gp transport activities were significantly inhibited in HIV PI-treated macrophages. Furthermore, the molecular docking study suggests that both HIV PIs and BBR fit the binding pocket of P-gp, and HIV PIs may compete with BBR to bind P-gp.HIV PIs increase the concentration of BBR by modulating the transport activity of P-gp in macrophages. Understanding the cellular mechanisms of potential drug-drug interactions is critical prior to applying successful combinational therapy in the clinic.

  2. A Mos1 transposase in vivo assay to screen new HIV-1 integrase inhibitors.

    Science.gov (United States)

    Cancian, Mariana; Loreto, Elgion L S

    2018-01-19

    The integrase and transposase enzymes of retrovirus and transposons, respectively, share the catalytic DDE domain. In vitro assays showed that inhibitors of HIV-1 integrase generally inhibit the mariner Mos1 transposase. Using a Drosophila strain in which the mobilisation of the mariner element can be quantified by mosaic eyes, we showed that flies maintained in medium containing 210 µM to 4 mM of raltegravir, or 1 or 2 mM of dolutegravir, which are HIV-1 integrase inhibitor used in AIDS treatment, have 23-33% less somatic mobilisation in mosaic eyes when treated with raltegravir and 28-32% when treated with dolutegravir. The gene expression of the mariner transposase gene, estimated by qPCR, is similar among treated and control flies. The results suggest that in vivo assays using Drosophila can be used as a primary screening of inhibitory drugs for transposase and retroviral integrase. The advantages of this assay are that it is easy, quick, cheap and is an in vivo test, meaning that the tested substance has to have been taken in by cells and has arrived at the target site, which is not the case when in vitro assays are applied.

  3. CD4 Counts at Entry to HIV Care in Mexico for Patients under the "Universal Antiretroviral Treatment Program for the Uninsured Population," 2007-2014.

    Directory of Open Access Journals (Sweden)

    Alfonso C Hernández-Romieu

    Full Text Available In Mexico, public health services have provided universal access to antiretroviral therapy (ART since 2004. For individuals receiving HIV care in public healthcare facilities, the data are limited regarding CD4 T-lymphocyte counts (CD4e at the time of entry into care. Relevant population-based estimates of CD4e are needed to inform strategies to maximize the impact of Mexico's national ART program, and may be applicable to other countries implementing universal HIV treatment programs. For this study, we retrospectively analyzed the CD4e of persons living with HIV and receiving care at state public health facilities from 2007 to 2014, comparing CD4e by demographic characteristics and the marginalization index of the state where treatment was provided, and assessing trends in CD4e over time. Our sample included 66,947 individuals who entered into HIV care between 2007 and 2014, of whom 79% were male. During the study period, the male-to-female ratio increased from 3.0 to 4.3, reflecting the country's HIV epidemic; the median age at entry decreased from 34 years to 32 years. Overall, 48.6% of individuals entered care with a CD4≤200 cells/μl, ranging from 42.2% in states with a very low marginalization index to 52.8% in states with a high marginalization index, and from 38.9% among individuals aged 18-29 to 56.5% among those older than 50. The adjusted geometric mean (95% confidence interval CD4e increased among males from 135 (131,142 cells/μl in 2007 to 148 (143,155 cells/μl in 2014 (p-value<0.0001; no change was observed among women, with a geometric mean of 178 (171,186 and 171 (165,183 in 2007 and 2014, respectively. There have been important gains in access to HIV care and treatment; however, late entry into care remains an important barrier in achieving optimal outcomes of ART in Mexico. The geographic, socioeconomic, and demographic differences observed reflect important inequities in timely access to HIV prevention, care, and treatment

  4. Identification of a 3-aminoimidazo[1,2-a]pyridine inhibitor of HIV-1 reverse transcriptase

    Directory of Open Access Journals (Sweden)

    Elleder Daniel

    2012-12-01

    Full Text Available Abstract Background Despite the effectiveness of highly active antiretroviral therapy (HAART, there remains an urgent need to develop new human immunodeficiency virus type 1 (HIV-1 inhibitors with better pharmacokinetic properties that are well tolerated, and that block common drug resistant virus strains. Methods Here we screened an in-house small molecule library for novel inhibitors of HIV-1 replication. Results An active compound containing a 3-aminoimidazo[1,2-a]pyridine scaffold was identified and quantitatively characterized as a non-nucleoside reverse transcriptase inhibitor (NNRTI. Conclusions The potency of this compound coupled with its inexpensive chemical synthesis and tractability for downstream SAR analysis make this inhibitor a suitable lead candidate for further development as an antiviral drug.

  5. Global Conformational Dynamics of HIV-1 Reverse Transcriptase Bound to Non-Nucleoside Inhibitors

    Directory of Open Access Journals (Sweden)

    Peter V. Coveney

    2012-07-01

    Full Text Available HIV-1 Reverse Transcriptase (RT is a multifunctional enzyme responsible for the transcription of the RNA genome of the HIV virus into DNA suitable for incorporation within the DNA of human host cells. Its crucial role in the viral life cycle has made it one of the major targets for antiretroviral drug therapy. The Non-Nucleoside RT Inhibitor (NNRTI class of drugs binds allosterically to the enzyme, affecting many aspects of its activity. We use both coarse grained network models and atomistic molecular dynamics to explore the changes in protein dynamics induced by NNRTI binding. We identify changes in the flexibility and conformation of residue Glu396 in the RNaseH primer grip which could provide an explanation for the acceleration in RNaseH cleavage rate observed experimentally in NNRTI bound HIV-1 RT. We further suggest a plausible path for conformational and dynamic changes to be communicated from the vicinity of the NNRTI binding pocket to the RNaseH at the other end of the enzyme.

  6. The HIV protease inhibitor nelfinavir inhibits Kaposi's sarcoma-associated herpesvirus replication in vitro.

    Science.gov (United States)

    Gantt, Soren; Carlsson, Jacquelyn; Ikoma, Minako; Gachelet, Eliora; Gray, Matthew; Geballe, Adam P; Corey, Lawrence; Casper, Corey; Lagunoff, Michael; Vieira, Jeffrey

    2011-06-01

    Kaposi's sarcoma (KS) is the most common HIV-associated cancer worldwide and is associated with high levels of morbidity and mortality in some regions. Antiretroviral (ARV) combination regimens have had mixed results for KS progression and resolution. Anecdotal case reports suggest that protease inhibitors (PIs) may have effects against KS that are independent of their effect on HIV infection. As such, we evaluated whether PIs or other ARVs directly inhibit replication of Kaposi's sarcoma-associated herpesvirus (KSHV), the gammaherpesvirus that causes KS. Among a broad panel of ARVs tested, only the PI nelfinavir consistently displayed potent inhibitory activity against KSHV in vitro as demonstrated by an efficient quantitative assay for infectious KSHV using a recombinant virus, rKSHV.294, which expresses the secreted alkaline phosphatase. This inhibitory activity of nelfinavir against KSHV replication was confirmed using virus derived from a second primary effusion lymphoma cell line. Nelfinavir was similarly found to inhibit in vitro replication of an alphaherpesvirus (herpes simplex virus) and a betaherpesvirus (human cytomegalovirus). No activity was observed with nelfinavir against vaccinia virus or adenovirus. Nelfinavir may provide unique benefits for the prevention or treatment of HIV-associated KS and potentially other human herpesviruses by direct inhibition of replication.

  7. Dendritic cell immunoreceptor is a new target for anti-AIDS drug development: identification of DCIR/HIV-1 inhibitors.

    Directory of Open Access Journals (Sweden)

    Alexandra A Lambert

    Full Text Available The HIV-1 pandemic continues to expand while no effective vaccine or cure is yet available. Existing therapies have managed to limit mortality and control viral proliferation, but are associated with side effects, do not cure the disease and are subject to development of resistance. Finding new therapeutic targets and drugs is therefore crucial. We have previously shown that the dendritic cell immunoreceptor (DCIR, a C-type lectin receptor expressed on dendritic cells (DCs, acts as an attachment factor for HIV-1 to DCs and contributes to HIV-1 transmission to CD4(+ T lymphocytes (CD4TL. Directly involved in HIV-1 infection, DCIR is expressed in apoptotic or infected CD4TL and promotes trans-infection to bystander cells. Here we report the 3D modelling of the extracellular domain of DCIR. Based on this structure, two surface accessible pockets containing the carbohydrate recognition domain and the EPS binding motif, respectively, were targeted for screening of chemicals that will disrupt normal interaction with HIV-1 particle. Preliminary screening using Raji-CD4-DCIR cells allowed identification of two inhibitors that decreased HIV-1 attachment and propagation. The impact of these inhibitors on infection of DCs and CD4TL was evaluated as well. The results of this study thus identify novel molecules capable of blocking HIV-1 transmission by DCs and CD4TL.

  8. Novel tetra-peptide insertion in Gag-p6 ALIX-binding motif in HIV-1 subtype C associated with protease inhibitor failure in Indian patients.

    Science.gov (United States)

    Neogi, Ujjwal; Rao, Shwetha D; Bontell, Irene; Verheyen, Jens; Rao, Vasudev R; Gore, Sagar C; Soni, Neelesh; Shet, Anita; Schülter, Eugen; Ekstrand, Maria L; Wondwossen, Amogne; Kaiser, Rolf; Madhusudhan, Mallur S; Prasad, Vinayaka R; Sonnerborg, Anders

    2014-09-24

    A novel tetra-peptide insertion was identified in Gag-p6 ALIX-binding region, which appeared in protease inhibitor failure Indian HIV-1C sequences (odds ratio=17.1, P ALIX-mediated virus release pathway, which is lacking in HIV-1C. The clinical importance of the insertion needs to be evaluated in HIV-1C dominating regions wherein the use of protease inhibitor drugs are being scaled up.

  9. Evaluation of 4-thiazolidinone derivatives as potential reverse transcriptase inhibitors against HIV-1 drug resistant strains.

    Science.gov (United States)

    Suryawanshi, Rahul; Jadhav, Sushama; Makwana, Nandini; Desai, Dipen; Chaturbhuj, Devidas; Sonawani, Archana; Idicula-Thomas, Susan; Murugesan, Vanangamudi; Katti, Seturam B; Tripathy, Srikanth; Paranjape, Ramesh; Kulkarni, Smita

    2017-04-01

    Rapid emergence of drug resistance is crucial in management of HIV infection limiting implementation of efficacious drugs in the ART regimen. Designing new molecules against HIV drug resistant strains is utmost essential. Based on the anti-HIV-1 activity, we selected four 4-thiazolidinone derivatives (S009-1908, S009-1909, S009-1911, S009-1912) and studied their interaction with reverse transcriptase (RT) from a panel of 10 clinical isolates (8 nevirapine resistant and two susceptible) using in silico methods, and inhibition pattern using in vitro cell based assays. On the basis of binding affinity observed in in silico analysis, 2-(2-chloro-6-nitrophenyl)-3-(4, 6-dimethylpyridin-2-yl) thiazolidin-4-one (S009-1912) was identified as the lead molecule followed by S009-1908, S009-1909 and S009-1911. The in vitro activity against the same panel was assessed using TZM-bl assay (IC50: 0.4-11.44µg/ml, TI: 4-126) and subsequently in PBMC assay against a nevirapine resistant clinical isolate (IC50: 0.8-6.65µg/ml, TI: 8.31-11.43) and standard strain from NIH ARRRP (IC50: 0.95-3.6µg/ml, TI: 9-26). The study shows analogue with pyrimidin-2-yl amino substitution at N-3 position of thiazolidin-4-one ring (S009-1908, S009-1909, S009-1911) exhibited enhanced activity as compared to pyridin-2-yl substituted derivatives (S009-1912), suggesting the use 4-thiazolidinones for developing potent inhibitors against HIV-1 drug resistant strains. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Protease-Mediated Maturation of HIV: Inhibitors of Protease and the Maturation Process

    Directory of Open Access Journals (Sweden)

    Catherine S. Adamson

    2012-01-01

    Full Text Available Protease-mediated maturation of HIV-1 virus particles is essential for virus infectivity. Maturation occurs concomitant with immature virus particle release and is mediated by the viral protease (PR, which sequentially cleaves the Gag and Gag-Pol polyproteins into mature protein domains. Maturation triggers a second assembly event that generates a condensed conical capsid core. The capsid core organizes the viral RNA genome and viral proteins to facilitate viral replication in the next round of infection. The fundamental role of proteolytic maturation in the generation of mature infectious particles has made it an attractive target for therapeutic intervention. Development of small molecules that target the PR active site has been highly successful and nine protease inhibitors (PIs have been approved for clinical use. This paper provides an overview of their development and clinical use together with a discussion of problems associated with drug resistance. The second-half of the paper discusses a novel class of antiretroviral drug termed maturation inhibitors, which target cleavage sites in Gag not PR itself. The paper focuses on bevirimat (BVM the first-in-class maturation inhibitor: its mechanism of action and the implications of naturally occurring polymorphisms that confer reduced susceptibility to BVM in phase II clinical trials.

  11. Screening for antiviral inhibitors of the HIV integrase-LEDGF/p75 interaction using the AlphaScreen luminescent proximity assay.

    Science.gov (United States)

    Hou, Yan; McGuinness, Debra E; Prongay, Andrew J; Feld, Boris; Ingravallo, Paul; Ogert, Robert A; Lunn, Charles A; Howe, John A

    2008-06-01

    Small-molecule inhibitors of HIV integrase (HIV IN) have emerged as a promising new class of antivirals for the treatment of HIV/AIDS. The compounds currently approved or in clinical development specifically target HIV DNA integration and were identified using strand-transfer assays targeting the HIV IN/viral DNA complex. The authors have developed a second biochemical assay for identification of HIV integrase inhibitors, targeting the interaction between HIV IN and the cellular cofactor LEDGF/p75. They developed a luminescent proximity assay (AlphaScreen) designed to measure the association of the 80-amino-acid integrase binding domain of LEDGF/p75 with the 163-amino-acid catalytic core domain of HIV IN. This assay proved to be quite robust (with a Z' factor of 0.84 in screening libraries arrayed as orthogonal mixtures) and successfully identified several compounds specific for this protein-protein interaction.

  12. HIV-1 Reverse Transcriptase Still Remains a New Drug Target: Structure, Function, Classical Inhibitors, and New Inhibitors with Innovative Mechanisms of Actions

    Directory of Open Access Journals (Sweden)

    Francesca Esposito

    2012-01-01

    Full Text Available During the retrotranscription process, characteristic of all retroviruses, the viral ssRNA genome is converted into integration-competent dsDNA. This process is accomplished by the virus-coded reverse transcriptase (RT protein, which is a primary target in the current treatments for HIV-1 infection. In particular, in the approved therapeutic regimens two classes of drugs target RT, namely, nucleoside RT inhibitors (NRTIs and nonnucleoside RT inhibitors (NNRTIs. Both classes inhibit the RT-associated polymerase activity: the NRTIs compete with the natural dNTP substrate and act as chain terminators, while the NNRTIs bind to an allosteric pocket and inhibit polymerization noncompetitively. In addition to these two classes, other RT inhibitors (RTIs that target RT by distinct mechanisms have been identified and are currently under development. These include translocation-defective RTIs, delayed chain terminators RTIs, lethal mutagenesis RTIs, dinucleotide tetraphosphates, nucleotide-competing RTIs, pyrophosphate analogs, RT-associated RNase H function inhibitors, and dual activities inhibitors. This paper describes the HIV-1 RT function and molecular structure, illustrates the currently approved RTIs, and focuses on the mechanisms of action of the newer classes of RTIs.

  13. Molecular modeling study on the allosteric inhibition mechanism of HIV-1 integrase by LEDGF/p75 binding site inhibitors.

    Directory of Open Access Journals (Sweden)

    Weiwei Xue

    Full Text Available HIV-1 integrase (IN is essential for the integration of viral DNA into the host genome and an attractive therapeutic target for developing antiretroviral inhibitors. LEDGINs are a class of allosteric inhibitors targeting LEDGF/p75 binding site of HIV-1 IN. Yet, the detailed binding mode and allosteric inhibition mechanism of LEDGINs to HIV-1 IN is only partially understood, which hinders the structure-based design of more potent anti-HIV agents. A molecular modeling study combining molecular docking, molecular dynamics simulation, and binding free energy calculation were performed to investigate the interaction details of HIV-1 IN catalytic core domain (CCD with two recently discovered LEDGINs BI-1001 and CX14442, as well as the LEDGF/p75 protein. Simulation results demonstrated the hydrophobic domain of BI-1001 and CX14442 engages one subunit of HIV-1 IN CCD dimer through hydrophobic interactions, and the hydrophilic group forms hydrogen bonds with HIV-1 IN CCD residues from other subunit. CX14442 has a larger tert-butyl group than the methyl of BI-1001, and forms better interactions with the highly hydrophobic binding pocket of HIV-1 IN CCD dimer interface, which can explain the stronger affinity of CX14442 than BI-1001. Analysis of the binding mode of LEDGF/p75 with HIV-1 IN CCD reveals that the LEDGF/p75 integrase binding domain residues Ile365, Asp366, Phe406 and Val408 have significant contributions to the binding of the LEDGF/p75 to HIV1-IN. Remarkably, we found that binding of BI-1001 and CX14442 to HIV-1 IN CCD induced the structural rearrangements of the 140 s loop and oration displacements of the side chains of the three conserved catalytic residues Asp64, Asp116, and Glu152 located at the active site. These results we obtained will be valuable not only for understanding the allosteric inhibition mechanism of LEDGINs but also for the rational design of allosteric inhibitors of HIV-1 IN targeting LEDGF/p75 binding site.

  14. Determination of the absolute binding free energies of HIV-1 protease inhibitors using non-equilibrium molecular dynamics simulations

    Science.gov (United States)

    Ngo, Son Tung; Nguyen, Minh Tung; Nguyen, Minh Tho

    2017-05-01

    The absolute binding free energy of an inhibitor to HIV-1 Protease (PR) was determined throughout evaluation of the non-bonded interaction energy difference between the two bound and unbound states of the inhibitor and surrounding molecules by the fast pulling of ligand (FPL) process using non-equilibrium molecular dynamics (NEMD) simulations. The calculated free energy difference terms help clarifying the nature of the binding. Theoretical binding affinities are in good correlation with experimental data, with R = 0.89. The paradigm used is able to rank two inhibitors having the maximum difference of ∼1.5 kcal/mol in absolute binding free energies.

  15. Compounds acting against HIV: Imidazo[1,2-a]pyridines as non-nucleoside reverse transcriptase inhibitors (NNRTIs)

    CSIR Research Space (South Africa)

    Bode, M

    2010-09-01

    Full Text Available A compound possessing anti-HIV activity similar to that of FDA-approved nevirapine was developed. It acts as a non-nucleoside reverse transcriptase inhibitor, the compound shows good cell permeability, and a quantitative structure activity...

  16. “Right Here is the Gateway”: Mobility, Sex Work Entry and HIV Risk Along the Mexico-U.S. Border

    Science.gov (United States)

    Goldenberg, SM; Silverman, JS; Engstrom, D; Bojorquez-Chapela, I; Strathdee, SA

    2013-01-01

    Women comprise an increasing proportion of migrants. Many voluntarily migrate for sex work or practice survival sex, while others may be trafficked for sexual exploitation. To investigate how the context of mobility shapes sex work entry and HIV risk, we conducted in-depth interviews with formerly trafficked women currently engaged in sex work (n=31) in Tijuana, Mexico and their service providers (n=7) in Tijuana and San Diego, USA from 2010–2011. Women’s experiences of coerced and deceptive migration, deportation as forced migration, voluntary mobility, and migration to a risk environment illustrate that circumstances driving and resulting from migration shape vulnerability to sex trafficking, voluntary sex work entry, and HIV risk. Findings suggest an urgent need for public health and immigration policies that provide integrated support for deported and/or recently arrived female migrants. Policies to prevent sex trafficking and assist trafficked females must also consider the varying levels of personal agency involved in migration and sex work entry. PMID:25346548

  17. HIV protease inhibitors disrupt lipid metabolism by activating endoplasmic reticulum stress and inhibiting autophagy activity in adipocytes.

    Directory of Open Access Journals (Sweden)

    Beth S Zha

    Full Text Available HIV protease inhibitors (PI are core components of Highly Active Antiretroviral Therapy (HAART, the most effective treatment for HIV infection currently available. However, HIV PIs have now been linked to lipodystrophy and dyslipidemia, which are major risk factors for cardiovascular disease and metabolic syndrome. Our previous studies have shown that HIV PIs activate endoplasmic reticulum (ER stress and disrupt lipid metabolism in hepatocytes and macrophages. Yet, little is known on how HIV PIs disrupt lipid metabolism in adipocytes, a major cell type involved in the pathogenesis of metabolic syndrome.Cultured and primary mouse adipocytes and human adipocytes were used to examine the effect of frequently used HIV PIs in the clinic, lopinavir/ritonavir, on adipocyte differentiation and further identify the underlying molecular mechanism of HIV PI-induced dysregulation of lipid metabolism in adipocytes. The results indicated that lopinavir alone or in combination with ritonavir, significantly activated the ER stress response, inhibited cell differentiation, and induced cell apoptosis in adipocytes. In addition, HIV PI-induced ER stress was closely linked to inhibition of autophagy activity. We also identified through the use of primary adipocytes of CHOP(-/- mice that CHOP, the major transcriptional factor of the ER stress signaling pathway, is involved in lopinavir/ritonavir-induced inhibition of cell differentiation in adipocytes. In addition, lopinavir/ritonavir-induced ER stress appears to be associated with inhibition of autophagy activity in adipocytes.Activation of ER stress and impairment of autophagy activity are involved in HIV PI-induced dysregulation of lipid metabolism in adipocytes. The key components of ER stress and autophagy signaling pathways are potential therapeutic targets for HIV PI-induced metabolic side effects in HIV patients.

  18. Using water and sanitation as an entry point to fight poverty and respond to HIV/AIDS: The case of Isulabasha Small Medium Enterprise

    Science.gov (United States)

    Manase, G.; Nkuna, Z.; Ngorima, E.

    South Africa is faced by a number of challenges that include low water and sanitation coverage in rural and peri-urban areas, high unemployment and increasing inequality between the rich and the poor as indicated by a Gini coefficient of 0.77; the second highest inequality in the world after Brazil. The situation is compounded by high HIV prevalence with South Africa having the largest HIV infection in the world. This case study demonstrates how water and sanitation is used as an entry point to address these major challenges and to empower communities. The project has two main components: the Small Medium Enterprise (SME) that trades in water and sanitation facilities and a community garden that ensures food security and nutrition for people living with HIV/AIDS. Income generated through these activities is ploughed back into the community through construction of sanitation facilities, maintenance of water pipes and paying school fees for orphans. In addition to creating employment, the project has also empowered the community to mobilise and address other challenges such as gender, child abuse and crime. The case study identifies weaknesses with projects designed solely to provide domestic drinking water and sanitation and calls for an integrated approach that uses water and sanitation as an entry point to unlock opportunities and empower the targeted communities.

  19. Design and Development of Highly Potent HIV-1 Protease Inhibitors with a Crown-Like Oxotricyclic Core as the P2-Ligand To Combat Multidrug-Resistant HIV Variants.

    Science.gov (United States)

    Ghosh, Arun K; Rao, Kalapala Venkateswara; Nyalapatla, Prasanth R; Osswald, Heather L; Martyr, Cuthbert D; Aoki, Manabu; Hayashi, Hironori; Agniswamy, Johnson; Wang, Yuan-Fang; Bulut, Haydar; Das, Debananda; Weber, Irene T; Mitsuya, Hiroaki

    2017-05-25

    Design, synthesis, and evaluation of a new class of exceptionally potent HIV-1 protease inhibitors are reported. Inhibitor 5 displayed superior antiviral activity and drug-resistance profiles. In fact, this inhibitor showed several orders of magnitude improved antiviral activity over the FDA approved drug darunavir. This inhibitor incorporates an unprecedented 6-5-5 ring-fused crown-like tetrahydropyranofuran as the P2 ligand and an aminobenzothiazole as the P2' ligand with the (R)-hydroxyethylsulfonamide isostere. The crown-like P2 ligand for this inhibitor has been synthesized efficiently in an optically active form using a chiral Diels-Alder catalyst providing a key intermediate in high enantiomeric purity. Two high resolution X-ray structures of inhibitor-bound HIV-1 protease revealed extensive interactions with the backbone atoms of HIV-1 protease and provided molecular insight into the binding properties of these new inhibitors.

  20. Immune activation and HIV-specific T cell responses are modulated by a cyclooxygenase-2 inhibitor in untreated HIV-infected individuals: An exploratory clinical trial.

    Directory of Open Access Journals (Sweden)

    Christian Prebensen

    Full Text Available Pathologically elevated immune activation and inflammation contribute to HIV disease progression and immunodeficiency, potentially mediated by elevated levels of prostaglandin E2, which suppress HIV-specific T cell responses. We have previously shown that a high dose of the cyclooxygenase-2 inhibitor celecoxib can reduce HIV-associated immune activation and improve IgG responses to T cell-dependent vaccines. In this follow-up study, we included 56 HIV-infected adults, 28 antiretroviral therapy (ART-naïve and 28 on ART with undetectable plasma viremia but CD4 counts below 500 cells/μL. Patients in each of the two study groups were randomized to receive 90 mg qd of the cyclooxygenase-2 inhibitor etoricoxib for six months, two weeks or to a control arm, respectively. T cell activation status, HIV Gag-specific T cell responses and plasma inflammatory markers, tryptophan metabolism and thrombin generation were analyzed at baseline and after four months. In addition, patients received tetanus toxoid, conjugated pneumococcal and seasonal influenza vaccines, to which IgG responses were determined after four weeks. In ART-naïve patients, etoricoxib reduced the density of the activation marker CD38 in multiple CD8+ T cell subsets, improved Gag-specific T cell responses, and reduced in vitro plasma thrombin generation, while no effects were seen on plasma markers of inflammation or tryptophan metabolism. No significant immunological effects of etoricoxib were observed in ART-treated patients. Patients receiving long-term etoricoxib treatment had poorer tetanus toxoid and conjugated pneumococcal vaccine responses than those receiving short-course etoricoxib. Cyclooxygenase-2 inhibitors may attenuate harmful immune activation in HIV-infected patients without access to ART.

  1. Characterization of HIV-1 from patients with virological failure to a boosted protease inhibitor regimen

    DEFF Research Database (Denmark)

    Lillemark, Marie Rathcke; Gerstoft, Jan; Obel, Niels

    2011-01-01

    The use of highly active antiretroviral treatment (HAART) regimens with unboosted protease inhibitors (PIs) has resulted in a high level of virological failure primarily due to the development of resistant virus. Current boosted PI regimens combine successfully low-dose ritonavir (r) with a second...... PI. The aim of the study was to estimate the proportion of patients, in a population based setting, who develop virological failure on a PI/r regimen. Through The Danish HIV Cohort Study 1,007 patients who received PI/r based treatment between 1995 and 2008 were identified. Twenty-three (2.......3%) experienced virological failure, of whom 19 (83%) started PI/r treatment before 2001. Patients from Copenhagen (n=19) were selected to study the development of protease (PR) and gag cleavage site (CS) mutations during PI/r treatment and PI plasma levels at the time of virological failure. Three patients (16...

  2. Peptide fibrils as monomer storage of the covalent HIV-1 integrase inhibitor.

    Science.gov (United States)

    Chandra, Koushik; Das, Priyadip; Metanis, Norman; Friedler, Assaf; Reches, Meital

    2017-02-01

    We have recently reported the covalent inhibition of HIV-1 integrase by an N-terminal succinimide-modified lens epithelium-derived growth factor (361-370) peptide. We also showed that this peptide is proteolytically stable. Here, we show that this inhibitor is stored as fibrils that serve as a stock for the inhibitory monomers. The fibrils increase the local concentration of the peptide at the target protein. When the monomers bind integrase, the equilibrium between the fibrils and their monomers shifts towards the formation of peptide monomers. The combination of fibril formation and subsequent proteolytic stability of the peptide may bring to new strategy for developing therapeutic agents. Copyright © 2017 European Peptide Society and John Wiley & Sons, Ltd. Copyright © 2017 European Peptide Society and John Wiley & Sons, Ltd.

  3. Physiological Mg(2+) Conditions Significantly Alter the Inhibition of HIV-1 and HIV-2 Reverse Transcriptases by Nucleoside and Non-Nucleoside Inhibitors in Vitro.

    Science.gov (United States)

    Achuthan, Vasudevan; Singh, Kamlendra; DeStefano, Jeffrey J

    2017-01-10

    Reverse transcriptases (RTs) are typically assayed in vitro with 5-10 mM Mg(2+), whereas the free Mg(2+) concentration in cells is much lower. Artificially high Mg(2+) concentrations used in vitro can misrepresent different properties of human immunodeficiency virus (HIV) RT, including fidelity, catalysis, pausing, and RNase H activity. Here, we analyzed nucleoside (NRTIs) and non-nucleoside RT inhibitors (NNRTIs) in primer extension assays at different concentrations of free Mg(2+). At low concentrations of Mg(2+), NRTIs and dideoxynucleotides (AZTTP, ddCTP, ddGTP, and 3TCTP) inhibited HIV-1 and HIV-2 RT synthesis less efficiently than they did with large amounts of Mg(2+), whereas inhibition by the "translocation-defective RT inhibitor" EFdA (4'-ethynyl-2-fluoro-2'-deoxyadenosine) was unaffected by Mg(2+) concentrations. Steady-state kinetic analyses revealed that the reduced level of inhibition at low Mg(2+) concentrations resulted from a 3-9-fold (depending on the particular nucleotide and inhibitor) less efficient incorporation (based on kcat/Km) of these NRTIs under this condition compared to incorporation of natural dNTPs. In contrast, EFdATP was incorporated with an efficiency similar to that of its analogue dATP at low Mg(2+) concentrations. Unlike NRTIs, NNRTIs (nevirapine, efavirenz, and rilviripine), were approximately 4-fold (based on IC50 values) more effective at low than at high Mg(2+) concentrations. Drug-resistant HIV-1 RT mutants also displayed the Mg(2+)-dependent difference in susceptibility to NRTIs and NNRTIs. In summary, analyzing the efficiency of inhibitors under more physiologically relevant low-Mg(2+) conditions yielded results dramatically different from those from measurements using commonly employed high-Mg(2+) in vitro conditions. These results also emphasize differences in Mg(2+) sensitivity between the translocation inhibitor EFdATP and other NRTIs.

  4. Structure-based design, synthesis, X-ray studies, and biological evaluation of novel HIV-1 protease inhibitors containing isophthalamide-derived P2-ligands.

    Science.gov (United States)

    Ghosh, Arun K; Takayama, Jun; Kassekert, Luke A; Ella-Menye, Jean-Rene; Yashchuk, Sofiya; Agniswamy, Johnson; Wang, Yuan-Fang; Aoki, Manabu; Amano, Masayuki; Weber, Irene T; Mitsuya, Hiroaki

    2015-11-01

    We describe the design, synthesis and biological evaluation of a series of novel HIV-1 protease inhibitors bearing isophthalamide derivatives as the P2-P3 ligands. We have investigated a range of acyclic and heterocyclic amides as the extended P2-P3 ligands. These inhibitors displayed good to excellent HIV-1 protease inhibitory activity. Also, a number of inhibitors showed very good antiviral activity in MT cells. Compound 5n has shown an enzyme Ki of 0.17 nM and antiviral IC50 of 14 nM. An X-ray crystal structure of inhibitor 5o-bound to HIV-1 protease was determined at 1.11Å resolution. This structure revealed important molecular insight into the inhibitor-HIV-1 protease interactions in the active site. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Effects of Angiotensin Converting Enzyme Inhibitors on Liver Fibrosis in HIV and Hepatitis C Coinfection

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    Lindsey J. Reese

    2012-01-01

    Full Text Available Background. Liver fibrosis is accelerated in HIV and hepatitis C coinfection, mediated by profibrotic effects of angiotensin. The objective of this study was to determine if angiotensin converting enzyme inhibitors (ACE-Is attenuate liver fibrosis in coinfection. Methods. A retrospective review of 156 coinfected subjects was conducted to analyze the association between exposure to ACE-Is and liver fibrosis. Noninvasive indices of liver fibrosis (APRI, FIB-4, Forns indices were compared between subjects who had taken ACE-Is and controls who had not taken them. Linear regression was used to evaluate ACE-I use as an independent predictor of fibrosis. Results. Subjects taking ACE-Is for three years were no different than controls on the APRI and the FIB-4 but had significantly higher scores than controls on the Forns index, indicating more advanced fibrosis. The use of ACE-Is for three years remained independently associated with an elevated Forns score when adjusted for age, race, and HIV viral load (P<0.001. There were significant associations between all of the indices and significant fibrosis, as determined clinically and radiologically. Conclusions. There was not a protective association between angiotensin inhibition and liver fibrosis in coinfection. These noninvasive indices may be useful for ruling out significant fibrosis in coinfection.

  6. Linker-Region Modified Derivatives of the Deoxyhypusine Synthase Inhibitor CNI-1493 Suppress HIV-1 Replication.

    Science.gov (United States)

    Schröder, Marcus; Kolodzik, Adrian; Windshügel, Björn; Krepstakies, Marcel; Priyadarshini, Poornima; Hartjen, Philip; van Lunzen, Jan; Rarey, Matthias; Hauber, Joachim; Meier, Chris

    2016-02-01

    The inhibition of cellular factors that are involved in viral replication may be an important alternative to the commonly used strategy of targeting viral enzymes. The guanylhydrazone CNI-1493, a potent inhibitor of the deoxyhypusine synthase (DHS), prevents the activation of the cellular factor eIF-5A and thereby suppresses HIV replication and a number of other diseases. Here, we report on the design, synthesis and biological evaluation of a series of CNI-1493 analogues. The sebacoyl linker in CNI-1493 was replaced by different alkyl or aryl dicarboxylic acids. Most of the tested derivatives suppress HIV-1 replication efficiently in a dose-dependent manner without showing toxic side effects. The unexpected antiviral activity of the rigid derivatives point to a second binding mode as previously assumed for CNI-1493. Moreover, the chemical stability of CNI-1493 was analysed, showing a successive hydrolysis of the imino bonds. By molecular dynamics simulations, the behaviour of the parent CNI-1493 in solution and its interactions with DHS were investigated. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Design strategies in the prodrugs of HIV-1 protease inhibitors to improve the pharmaceutical properties.

    Science.gov (United States)

    Subbaiah, Murugaiah A M; Meanwell, Nicholas A; Kadow, John F

    2017-10-20

    Combination antiretroviral therapy (cART) is currently the most effective treatment for HIV-1 infection. HIV-1 protease inhibitors (PIs) are an important component of some regimens of cART. However, PIs are known for sub-optimal ADME properties, resulting in poor oral bioavailability. This often necessitates high drug doses, combination with pharmacokinetic enhancers and/or special formulations in order to effectively deliver PIs, which may lead to a high pill burden and reduced patient compliance. As a remedy, improving the ADME properties of existing drugs via prodrug and other approaches has been pursued in addition to the development of next generation PIs with improved pharmacokinetic, resistance and side effect profiles. Phosphate prodrugs have been explored to address the solubility-limiting absorption and high excipient load. Prodrug design to target carrier-mediated drug delivery has also been explored. Amino acid prodrugs have been shown to improve permeability by engaging active transport mechanisms, reduce efflux and mitigate first pass metabolism while acyl migration prodrugs have been shown to improve solubility. Prodrug design efforts have led to the identification of one marketed agent, fosamprenavir, and clinical studies with two other prodrugs. Several of the reported approaches lack detailed in vivo characterization and hence the potential preclinical or clinical benefits of these approaches are yet to be fully determined. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  8. Impact of resistance mutations on inhibitor binding to HIV-1 integrase

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    Chen, Qi [Shanghai Jiao Tong Univ., Shanghai (China); Buolamwini, John K. [Univ. of Tennessee Health Science Center, Memphis, TN (United States); Smith, Jeremy C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States); Li, Aixiu [Logistics College of Chinese People' s Armed Police Force, Tianjin (China); Xu, Qin [Shanghai Jiao Tong Univ., Shanghai (China); Cheng, Xiaolin [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States); Wei, Dongqing [Shanghai Jiao Tong Univ., Shanghai (China)

    2013-11-08

    Here, HIV-1 integrase (IN) is essential for HIV-1 replication, catalyzing two key reaction steps termed 3' processing and strand transfer. Therefore, IN has become an important target for antiviral drug discovery. However, mutants have emerged, such as E92Q/N155H and G140S/Q148H, which confer resistance to raltegravir (RAL), the first IN strand transfer inhibitor (INSTI) approved by the FDA, and to the recently approved elvitegravir (EVG). To gain insights into the molecular mechanisms of ligand binding and drug resistance, we performed molecular dynamics (MD) simulations of homology models of the HIV-1 IN and four relevant mutants complexed with viral DNA and RAL. The results show that the structure and dynamics of the 140s loop, comprising residues 140 to 149, are strongly influenced by the IN mutations. In the simulation of the G140S/Q148H double mutant, we observe spontaneous dissociation of RAL from the active site, followed by an intrahelical swing-back of the 3' -OH group of nucleotide A17, consistent with the experimental observation that the G140S/Q148H mutant exhibits the highest resistance to RAL compared to other IN mutants. An important hydrogen bond between residues 145 and 148 is present in the wild-type IN but not in the G140S/Q148H mutant, accounting for the structural and dynamical differences of the 140s' loop and ultimately impairing RAL binding in the double mutant. End-point free energy calculations that broadly capture the experimentally known RAL binding profiles elucidate the contributions of the 140s' loop to RAL binding free energies and suggest possible approaches to overcoming drug resistance.

  9. Histone deacetylase inhibitors impair the elimination of HIV-infected cells by cytotoxic T-lymphocytes.

    Directory of Open Access Journals (Sweden)

    Richard Brad Jones

    2014-08-01

    Full Text Available Resting memory CD4+ T-cells harboring latent HIV proviruses represent a critical barrier to viral eradication. Histone deacetylase inhibitors (HDACis, such as suberanilohydroxamic acid (SAHA, romidepsin, and panobinostat have been shown to induce HIV expression in these resting cells. Recently, it has been demonstrated that the low levels of viral gene expression induced by a candidate HDACi may be insufficient to cause the death of infected cells by viral cytopathic effects, necessitating their elimination by immune effectors, such as cytotoxic T-lymphocytes (CTL. Here, we study the impact of three HDACis in clinical development on T-cell effector functions. We report two modes of HDACi-induced functional impairment: i the rapid suppression of cytokine production from viable T-cells induced by all three HDACis ii the selective death of activated T-cells occurring at later time-points following transient exposures to romidepsin or, to a lesser extent, panobinostat. As a net result of these factors, HDACis impaired CTL-mediated IFN-γ production, as well as the elimination of HIV-infected or peptide-pulsed target cells, both in liquid culture and in collagen matrices. Romidepsin exerted greater inhibition of antiviral function than SAHA or panobinostat over the dose ranges tested. These data suggest that treatment with HDACis to mobilize the latent reservoir could have unintended negative impacts on the effector functions of CTL. This could influence the effectiveness of HDACi-based eradication strategies, by impairing elimination of infected cells, and is a critical consideration for trials where therapeutic interruptions are being contemplated, given the importance of CTL in containing rebound viremia.

  10. Acute toxicity of second generation HIV protease-inhibitors in combination with radiotherapy: a retrospective case series

    Directory of Open Access Journals (Sweden)

    Tran Phuoc T

    2011-03-01

    Full Text Available Abstract Background There is little data on the safety of combining radiation therapy and human immunodeficiency virus (HIV protease inhibitors to treat cancers in HIV-positive patients. We describe acute toxicities observed in a series of HIV-positive patients receiving modern radiation treatments, and compare patients receiving HIV protease inhibitors (PI with patients not receiving HIV PIs. Methods By reviewing the clinical records beginning January 1, 2009 from the radiation oncology department, we identified 29 HIV-positive patients who received radiation therapy to 34 body sites. Baseline information, treatment regimen, and toxicities were documented by review of medical records: patient age, histology and source of the primary tumor, HIV medication regimen, pre-radiation CD4 count, systemic chemotherapy, radiation therapy dose and fractionation, irradiated body region, toxicities, and duration of follow-up. Patients were grouped according to whether they received concurrent HIV PIs and compared using Pearson's chi-square test. Results At baseline, the patients in the two groups were similar with the exception of HIV medication regimens, CD4 count and presence of AIDS-defining malignancy. Patients taking concurrent PIs were more likely to be taking other HIV medications (p = 0.001 and have CD4 count >500 (p = 0.006. Patients taking PIs were borderline less likely to have an AIDS-defining malignancy (p = 0.06. After radiation treatment, 100 acute toxicities were observed and were equally common in both groups (64 [median 3 per patient, IQR 1-7] with PIs; 36 [median 3 per patient, IQR 2-3] without PIs. The observed toxicities were also equally severe in the two groups (Grades I, II, III respectively: 30, 30, 4 with PIs; 23, 13, 0 without PIs: p = 0.38. There were two cases that were stopped early, one in each group; these were not attributable to toxicity. Conclusions In this study of recent radiotherapy in HIV-positive patients taking

  11. CD4 Counts at Entry to HIV Care in Mexico for Patients under the "Universal Antiretroviral Treatment Program for the Uninsured Population," 2007-2014.

    Science.gov (United States)

    Hernández-Romieu, Alfonso C; del Rio, Carlos; Hernández-Ávila, Juan Eugenio; Lopez-Gatell, Hugo; Izazola-Licea, José Antonio; Uribe Zúñiga, Patricia; Hernández-Ávila, Mauricio

    2016-01-01

    In Mexico, public health services have provided universal access to antiretroviral therapy (ART) since 2004. For individuals receiving HIV care in public healthcare facilities, the data are limited regarding CD4 T-lymphocyte counts (CD4e) at the time of entry into care. Relevant population-based estimates of CD4e are needed to inform strategies to maximize the impact of Mexico's national ART program, and may be applicable to other countries implementing universal HIV treatment programs. For this study, we retrospectively analyzed the CD4e of persons living with HIV and receiving care at state public health facilities from 2007 to 2014, comparing CD4e by demographic characteristics and the marginalization index of the state where treatment was provided, and assessing trends in CD4e over time. Our sample included 66,947 individuals who entered into HIV care between 2007 and 2014, of whom 79% were male. During the study period, the male-to-female ratio increased from 3.0 to 4.3, reflecting the country's HIV epidemic; the median age at entry decreased from 34 years to 32 years. Overall, 48.6% of individuals entered care with a CD4≤200 cells/μl, ranging from 42.2% in states with a very low marginalization index to 52.8% in states with a high marginalization index, and from 38.9% among individuals aged 18-29 to 56.5% among those older than 50. The adjusted geometric mean (95% confidence interval) CD4e increased among males from 135 (131,142) cells/μl in 2007 to 148 (143,155) cells/μl in 2014 (p-valueentry into care remains an important barrier in achieving optimal outcomes of ART in Mexico. The geographic, socioeconomic, and demographic differences observed reflect important inequities in timely access to HIV prevention, care, and treatment services, and highlight the need to develop contextual and culturally appropriate prevention and HIV testing strategies and linkage programs.

  12. Reduced maximal inhibition in phenotypic susceptibility assays indicates that viral strains resistant to the CCR5 antagonist maraviroc utilize inhibitor-bound receptor for entry.

    Science.gov (United States)

    Westby, Mike; Smith-Burchnell, Caroline; Mori, Julie; Lewis, Marilyn; Mosley, Michael; Stockdale, Mark; Dorr, Patrick; Ciaramella, Giuseppe; Perros, Manos

    2007-03-01

    Maraviroc is a CCR5 antagonist in clinical development as one of a new class of antiretrovirals targeting human immunodeficiency virus type 1 (HIV-1) coreceptor binding. We investigated the mechanism of HIV resistance to maraviroc by using in vitro sequential passage and site-directed mutagenesis. Serial passage through increasing maraviroc concentrations failed to select maraviroc-resistant variants from some laboratory-adapted and clinical isolates of HIV-1. However, high-level resistance to maraviroc was selected from three of six primary isolates passaged in peripheral blood lymphocytes (PBL). The SF162 strain acquired resistance to maraviroc in both treated and control cultures; all resistant variants were able to use CXCR4 as a coreceptor. In contrast, maraviroc-resistant virus derived from isolates CC1/85 and RU570 remained CCR5 tropic, as evidenced by susceptibility to the CCR5 antagonist SCH-C, resistance to the CXCR4 antagonist AMD3100, and an inability to replicate in CCR5 Delta32/Delta32 PBL. Strain-specific mutations were identified in the V3 loop of maraviroc-resistant CC1/85 and RU570. The envelope-encoding region of maraviroc-resistant CC1/85 was inserted into an NL4-3 background. This recombinant virus was completely resistant to maraviroc but retained susceptibility to aplaviroc. Reverse mutation of gp120 residues 316 and 323 in the V3 loop (numbering from HXB2) to their original sequence restored wild-type susceptibility to maraviroc, while reversion of either mutation resulted in a partially sensitive virus with reduced maximal inhibition (plateau). The plateaus are consistent with the virus having acquired the ability to utilize maraviroc-bound receptor for entry. This hypothesis was further corroborated by the observation that a high concentration of maraviroc blocks the activity of aplaviroc against maraviroc-resistant virus.

  13. Liver Fibrosis in HCV Monoinfected and HIV/HCV Coinfected Patients: Dysregulation of Matrix Metalloproteinases (MMPs) and Their Tissue Inhibitors TIMPs and Effect of HCV Protease Inhibitors.

    Science.gov (United States)

    Latronico, Tiziana; Mascia, Claudia; Pati, Ilaria; Zuccala, Paola; Mengoni, Fabio; Marocco, Raffaella; Tieghi, Tiziana; Belvisi, Valeria; Lichtner, Miriam; Vullo, Vincenzo; Mastroianni, Claudio Maria; Liuzzi, Grazia Maria

    2016-03-26

    An imbalance between matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) may contribute to liver fibrosis in patients with hepatitis C (HCV) infection. We measured the circulating levels of different MMPs and TIMPs in HCV monoinfected and HIV/HCV coinfected patients and evaluated the potential for anti-HCV therapy to modulate MMP and TIMP levels in HCV subjects. We analyzed 83 plasma samples from 16 HCV monoinfected patients undergoing dual or triple anti-HCV therapy, 15 HIV/HCV coinfected patients with undetectable HIV load, and 10 healthy donors (HD). Levels of MMP-1, MMP-2, MMP-3, MMP-8, MMP-9, MMP-10, TIMP-1, and TIMP-2 were measured by a SearchLight Multiplex Immunoassay Kit. MMP-2 and MMP-9 were the highest expressed MMPs among all the analyzed samples and their levels significantly increased in HCV monoinfected and HIV/HCV coinfected subjects compared to HD. TIMP-1 levels were significantly higher in HCV and HIV/HCV subjects compared to HD and were correlated with liver stiffness. These findings raise the possibility of using circulating TIMP-1 as a non-invasive marker of liver fibrosis in HCV infection. A longitudinal study demonstrated that MMP-9 levels significantly decreased (40% reduction from baseline) in patients receiving dual as well as triple direct-acting antivirals (DAA) anti-HCV therapy, which had no effect on MMP-2, TIMP-1, and TIMP-2. As the dysregulation of MMP-2 and MMP-9 may reflect inflammatory processes in the liver, the decrease of MMP-9 following HCV protease inhibitor treatment suggests a positive effect on the reduction of liver inflammation.

  14. HIV-1 protease substrate-groove: Role in substrate recognition and inhibitor resistance.

    Science.gov (United States)

    Laco, Gary S

    2015-11-01

    A key target in the treatment of HIV-1/AIDS has been the viral protease. Here we first studied in silico the evolution of protease resistance. Primary active site resistance mutations were found to weaken interactions between protease and both inhibitor and substrate P4-P4' residues. We next studied the effects of secondary resistance mutations, often distant from the active site, on protease binding to inhibitors and substrates. Those secondary mutations contributed to the rise of multi-drug resistance while also enhancing viral replicative capacity. Here many secondary resistance mutations were found in the HIV-1 protease substrate-grooves, one on each face of the symmetrical protease dimer. The protease active site binds substrate P4-P4' residues, while the substrate-groove allows the protease to bind residues P12-P5/P5'-P12', for a total of twenty-four residues. The substrate-groove secondary resistance mutations were found to compensate for the loss of interactions between the inhibitor resistant protease active site and substrate P4-P4' residues, due to primary resistance mutations, by increasing interactions with substrate P12-P5/P5'-P12' residues. In vitro experiments demonstrated that a multi-drug resistant protease with substrate-groove resistance mutations was slower than wild-type protease in cleaving a peptide substrate, which did not allow for substrate-groove interactions, while it had similar activity as wild-type protease when using a Gag polyprotein in which cleavage-site P12-P5/P5'-P12' residues could be bound by the protease substrate-grooves. When the Gag MA/CA cleavage site P12-P5/P5'-P12' residues were mutated the multi-drug resistant protease cleaved the mutant Gag significantly slower, indicating the importance of the protease S-grooves in binding to substrate. Copyright © 2015 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  15. Validation of an algorithm to identify antiretroviral-naïve status at time of entry into a large, observational cohort of HIV-infected patients.

    Science.gov (United States)

    Gandhi, Neel R; Tate, Janet P; Rodriguez-Barradas, Maria C; Rimland, David; Goetz, Matthew Bidwell; Gibert, Cynthia; Brown, Sheldon T; Mattocks, Kristin; Justice, Amy C

    2013-09-01

    Large, observational HIV cohorts play an important role in answering questions which are difficult to study in randomized trials; however, they often lack detailed information regarding previous antiretroviral treatment (ART). Knowledge of ART treatment history is important when ascertaining the long-term impact of medications, co-morbidities, or adverse reactions on HIV outcomes. We performed a retrospective study to validate a prediction algorithm for identifying ART-naïve patients using the Veterans Aging Cohort Study's Virtual Cohort-an observational cohort of 40 594 HIV-infected veterans nationwide. Medical records for 3070 HIV-infected patients were reviewed to determine history of combination ART treatment. An algorithm using Virtual Cohort laboratory data was used to predict ART treatment status and compared to medical record review. Among 3070 patients' medical records reviewed, 1223 were eligible for analysis. Of these, 990 (81%) were ART naïve at cohort entry based on medical record review. The prediction algorithm's sensitivity was 86%, specificity 47%, positive predictive value (PPV) 87%, and negative predictive value 45%, using a viral load threshold of limit analyses to ART-naïve patients when studying the contribution of ART to outcomes and adverse events. Copyright © 2013 John Wiley & Sons, Ltd.

  16. HIV-1 Reverse Transcriptase Structure with RNase H Inhibitor dihydroxy benzoyl naphthyl Hydrazone Bound at a Novel Site

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    Himmel,D.; Sarafianos, S.; Dharmasena, S.; Hossain, M.; McCoy-Simandle, K.; Ilina, T.; Clark, A.; Knight, J.; Julias, J.; et al.

    2007-01-01

    The rapid emergence of drug-resistant variants of human immunodeficiency virus, type 1 (HIV-1), has limited the efficacy of anti-acquired immune deficiency syndrome (AIDS) treatments, and new lead compounds that target novel binding sites are needed. We have determined the 3.15 {angstrom} resolution crystal structure of HIV-1 reverse transcriptase (RT) complexed with dihydroxy benzoyl naphthyl hydrazone (DHBNH), an HIV-1 RT RNase H (RNH) inhibitor (RNHI). DHBNH is effective against a variety of drug-resistant HIV-1 RT mutants. While DHBNH has little effect on most aspects of RT-catalyzed DNA synthesis, at relatively high concentrations it does inhibit the initiation of RNA-primed DNA synthesis. Although primarily an RNHI, DHBNH binds >50 {angstrom} away from the RNH active site, at a novel site near both the polymerase active site and the non-nucleoside RT inhibitor (NNRTI) binding pocket. When DHBNH binds, both Tyr181 and Tyr188 remain in the conformations seen in unliganded HIV-1 RT. DHBNH interacts with conserved residues (Asp186, Trp229) and has substantial interactions with the backbones of several less well-conserved residues. On the basis of this structure, we designed substituted DHBNH derivatives that interact with the NNRTI-binding pocket. These compounds inhibit both the polymerase and RNH activities of RT.

  17. In vitro and ex vivo evaluations on transdermal delivery of the HIV inhibitor IQP-0410.

    Directory of Open Access Journals (Sweden)

    Anthony S Ham

    Full Text Available The aim of this study was to investigate the physicochemical and in vitro/ex vivo characteristics of the pyrmidinedione IQP-0410 formulated into transdermal films. IQP-0410 is a potent therapeutic anti-HIV nonnucleoside reverse transcriptase inhibitor that would be subjected to extensive first pass metabolism, through conventional oral administration. Therefore, IQP-0410 was formulated into ethyl cellulose/HPMC-based transdermal films via solvent casting. In mano evaluations were performed to evaluate gross physical characteristics. In vitro release studies were performed in both Franz cells and USP-4 dissolution vessels. Ex vivo release and permeability assays were performed on human epidermal tissue models, and the permeated IQP-0410 was collected for in vitro HIV-1 efficacy assays in CEM-SS cells and PBMCs. Film formulation D3 resulted in pliable, strong transdermal films that were loaded with 2% (w/w IQP-0410. Composed of 60% (w/w ethyl cellulose and 20% (w/w HPMC, the films contained < 1.2% (w/w of water and were hygroscopic resulting in significant swelling under humid conditions. The water permeable nature of the film resulted in complete in vitro dissolution and drug release in 26 hours. When applied to ex vivo epidermal tissues, the films were non-toxic to the tissue and also were non-toxic to HIV target cells used in the in vitro efficacy assays. Over a 3 day application, the films delivered IQP-0410 through the skin tissue at a zero-order rate of 0.94 ± 0.06 µg/cm(2/hr with 134 ± 14.7 µM collected in the basal media. The delivered IQP-0410 resulted in in vitro EC50 values against HIV-1 of 2.56 ± 0.40 nM (CEM-SS and 0.58 ± 0.03 nM (PBMC. The film formulation demonstrated no significant deviation from target values when packaged in foil pouches under standard and accelerated environmental conditions. It was concluded that the transdermal film formulation was a potentially viable method of administering IQP-0410 that warrants

  18. Proteochemometric modeling of the susceptibility of mutated variants of the HIV-1 virus to reverse transcriptase inhibitors.

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    Muhammad Junaid

    Full Text Available BACKGROUND: Reverse transcriptase is a major drug target in highly active antiretroviral therapy (HAART against HIV, which typically comprises two nucleoside/nucleotide analog reverse transcriptase (RT inhibitors (NRTIs in combination with a non-nucleoside RT inhibitor or a protease inhibitor. Unfortunately, HIV is capable of escaping the therapy by mutating into drug-resistant variants. Computational models that correlate HIV drug susceptibilities to the virus genotype and to drug molecular properties might facilitate selection of improved combination treatment regimens. METHODOLOGY/PRINCIPAL FINDINGS: We applied our earlier developed proteochemometric modeling technology to analyze HIV mutant susceptibility to the eight clinically approved NRTIs. The data set used covered 728 virus variants genotyped for 240 sequence residues of the DNA polymerase domain of the RT; 165 of these residues contained mutations; totally the data-set covered susceptibility data for 4,495 inhibitor-RT combinations. Inhibitors and RT sequences were represented numerically by 3D-structural and physicochemical property descriptors, respectively. The two sets of descriptors and their derived cross-terms were correlated to the susceptibility data by partial least-squares projections to latent structures. The model identified more than ten frequently occurring mutations, each conferring more than two-fold loss of susceptibility for one or several NRTIs. The most deleterious mutations were K65R, Q151M, M184V/I, and T215Y/F, each of them decreasing susceptibility to most of the NRTIs. The predictive ability of the model was estimated by cross-validation and by external predictions for new HIV variants; both procedures showed very high correlation between the predicted and actual susceptibility values (Q2=0.89 and Q2ext=0.86. The model is available at www.hivdrc.org as a free web service for the prediction of the susceptibility to any of the clinically used NRTIs for any HIV

  19. Efficacy of etravirine combined with darunavir or other ritonavir-boosted protease inhibitors in HIV-1-infected patients

    DEFF Research Database (Denmark)

    Vingerhoets, J; Calvez, V; Flandre, P

    2015-01-01

    data. METHODS: Two international (EuroSIDA; EUResist Network) and five national (France, Italy, Spain, Switzerland and UK) cohorts provided data (collected in 2007-2012). Stratum-adjusted (for confounding factors) Mantel-Haenszel differences in virological responses (viral load HIV-1 RNA copies......OBJECTIVES: This observational study in antiretroviral treatment-experienced, HIV-1-infected adults explored the efficacy of etravirine plus darunavir/ritonavir (DRV group; n = 999) vs. etravirine plus an alternative boosted protease inhibitor (other PI group; n = 116) using pooled European cohort...

  20. Discovery of 2-Pyridinone Aminals: A Prodrug Strategy to Advance a Second Generation of HIV-1 Integrase Strand Transfer Inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Raheem, Izzat T.; Walji, Abbas M.; Klein, Daniel; Sanders, John M.; Powell, David A.; Abeywickrema, Pravien; Barbe, Guillaume; Bennet, Amrith; Clas, Sophie−Dorothee; Dubost, David; Embrey, Mark; Grobler, Jay; Hafey, Michael J.; Hartingh, Timothy J.; Hazuda, Daria J.; Miller, Michael D.; Moore, Keith P.; Pajkovic, Natasa; Patel, Sangita; Rada, Vanessa; Rearden, Paul; Schreier, John D.; Sisko, John; Steele, Thomas G.; Truchon, Jean-François; Wai, John; Xu, Min; Coleman, Paul J.

    2015-10-22

    The search for new molecular constructs that resemble the critical two-metal binding pharmacophore required for HIV integrase strand transfer inhibition represents a vibrant area of research within drug discovery. Here we present the discovery of a new class of HIV integrase strand transfer inhibitors based on the 2-pyridinone core of MK-0536. These efforts led to the identification of two lead compounds with excellent antiviral activity and preclinical pharmacokinetic profiles to support a once-daily human dose prediction. Dose escalating PK studies in dog revealed significant issues with limited oral absorption and required an innovative prodrug strategy to enhance the high-dose plasma exposures of the parent molecules.

  1. Design, synthesis and biological evaluation of novel L-ascorbic acid-conjugated pentacyclic triterpene derivatives as potential influenza virus entry inhibitors.

    Science.gov (United States)

    Wang, Han; Xu, Renyang; Shi, Yongying; Si, Longlong; Jiao, Pingxuan; Fan, Zibo; Han, Xu; Wu, Xingyu; Zhou, Xiaoshu; Yu, Fei; Zhang, Yongmin; Zhang, Liangren; Zhang, Lihe; Zhou, Demin; Xiao, Sulong

    2016-03-03

    Since the influenza viruses can rapidly evolve, it is urgently required to develop novel anti-influenza agents possessing a novel mechanism of action. In our previous study, two pentacyclic triterpene derivatives (Q8 and Y3) have been found to have anti-influenza virus entry activities. Keeping the potential synergy of biological activity of pentacyclic triterpenes and l-ascorbic acid in mind, we synthesized a series of novel l-ascorbic acid-conjugated pentacyclic triterpene derivatives (18-26, 29-31, 35-40 and 42-43). Moreover, we evaluated these novel compounds for their anti-influenza activities against A/WSN/33 virus in MDCK cells. Among all evaluated compounds, the 2,3-O,O-dibenzyl-6-deoxy-l-ascorbic acid-betulinic acid conjugate (30) showed the most significant anti-influenza activity with an EC50 of 8.7 μM, and no cytotoxic effects on MDCK cells were observed. Time-of-addition assay indicated that compound 30 acted at an early stage of the influenza life cycle. Further analyses revealed that influenza virus-induced hemagglutination of chicken red blood cells was inhibited by treatment of compound 30, and the interaction between the influenza hemagglutinin (HA) and compound 30 was determined by surface plasmon resonance (SPR) with a dissociation constant of KD = 3.76 μM. Finally, silico docking studies indicated that compound 30 and its derivative 31 were able to occupy the binding pocket of HA for sialic acid receptor. Collectively, these results suggested that l-ascorbic acid-conjugated pentacyclic triterpenes were promising anti-influenza entry inhibitors, and HA protein associated with viral entry was a promising drug target. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  2. The tyrosine kinase Hck is an inhibitor of HIV-1 replication counteracted by the viral vif protein.

    Science.gov (United States)

    Hassaïne, G; Courcoul, M; Bessou, G; Barthalay, Y; Picard, C; Olive, D; Collette, Y; Vigne, R; Decroly, E

    2001-05-18

    The virus infectivity factor (Vif) protein facilitates the replication of human immunodeficiency virus type 1 (HIV-1) in primary lymphocytes and macrophages. Its action is strongly dependent on the cellular environment, and it has been proposed that the Vif protein counteracts cellular activities that would otherwise limit HIV-1 replication. Using a glutathione S-transferase pull-down assay, we identified that Vif binds specifically to the Src homology 3 domain of Hck, a tyrosine kinase from the Src family. The interaction between Vif and the full-length Hck was further assessed by co-precipitation assays in vitro and in human cells. The Vif protein repressed the kinase activity of Hck and was not itself a substrate for Hck phosphorylation. Within one single replication cycle of HIV-1, Hck was able to inhibit the production and the infectivity of vif-deleted virus but not that of wild-type virus. Accordingly, HIV-1 vif- replication was delayed in Jurkat T cell clones stably expressing Hck. Our data demonstrate that Hck controls negatively HIV-1 replication and that this inhibition is suppressed by the expression of Vif. Hck, which is present in monocyte-macrophage cells, represents the first identified cellular inhibitor of HIV-1 replication overcome by Vif.

  3. 3D-QSAR and molecular modeling of HIV-1 integrase inhibitors

    Science.gov (United States)

    Makhija, Mahindra T.; Kulkarni, Vithal M.

    2002-03-01

    Three-dimensional quantitative structure-activity relationship (3D QSAR) methods were applied on a series of inhibitors of HIV-1 integrase with respect to their inhibition of 3'-processing and 3'-end joining steps in vitro.The training set consisted of 27 compounds belonging to the class of thiazolothiazepines. The predictive ability of each model was evaluated using test set I consisting of four thiazolothiazepines and test set II comprised of seven compounds belonging to an entirely different structural class of coumarins. Maximum Common Substructure (MCS) based method was used to align the molecules and this was compared with other known methods of alignment. Two methods of 3D QSAR: comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) were analyzed in terms of their predictive abilities. CoMSIA produced significantly better results for all correlations. The results indicate a strong correlation between the inhibitory activity of these compounds and the steric and electrostatic fields around them. CoMSIA models with considerable internal as well as external predictive ability were obtained. A poor correlation obtained with hydrophobic field indicates that the binding of thiazolothiazepines to HIV-1 integrase is mainly enthalpic in nature. Further the most active compound of the series was docked into the active site using the crystal structure of integrase. The binding site was formed by the amino acid residues 64-67, 116, 148, 151-152, 155-156, and 159. The comparison of coefficient contour maps with the steric and electrostatic properties of the receptor shows high level of compatibility.

  4. Pravastatin in HIV-infected patients treated with protease inhibitors: a placebo-controlled randomized study.

    Science.gov (United States)

    Bonnet, Fabrice; Aurillac-Lavignolle, Valerie; Breilh, Dominique; Thiébaut, Rodolphe; Peuchant, Evelyne; Bernard, Noëlle; Lacoste, Denis; Dabis, François; Beylot, Jacques; Chêne, Geneviève; Morlat, Philippe

    2007-01-01

    The objectives of the study were to assess the effects of pravastatin on plasma HIV RNA, lipid parameters, and protease inhibitor (PI) concentrations in patients treated with PI-containing regimens and with total cholesterol (TC) > or = 5.5 mmol/L. A clinical trial including patients randomized to receive pravastatin or matching placebo for 12 weeks was implemented. Twelve patients were included in the pravastatin group and 9 in the placebo group. At week 12 (W12), no patient had experienced virological failure. Between week 0 (W0) and W12, the median differences for TC were -1.4 mmol/L in the pravastatin group and +0.2 mmol/L in the placebo group (p = .005); for LDL, they were -1.0 mmol/L and +0.3 (p = .007), respectively. A significant decrease of the PI concentration (12 hours after administration) ratio W12 - W0/W0 was noticed in the pravastatin group (-0.2 [interquartile range, -0.3 to -0.1] as compared with the placebo group (0.1 [IQR, 0.0 to 0.3]) (p = .03). When the study was restricted to patients treated with lopinavir/ritonavir, a decrease from 3.8 microg/mL at baseline to 2.9 mug/mL at W12 was noticed in the pravastatin arm (p = .04) but not in the control arm (p = 1.00). No clinical adverse event reached a severity of grade 3. We observed in this study that the use of pravastatin in PI-treated patients was not associated with major change in the plasma HIV RNA on 12 weeks of follow-up. However, we found a trend of decrease of the trough PI concentration at W12, suggesting a possible drug-drug interaction of pravastatin on PI metabolism.

  5. Immunovirological response to triple nucleotide reverse-transcriptase inhibitors and ritonavir-boosted protease inhibitors in treatment-naive HIV-2-infected patients : The ACHIEV2E Collaboration Study Group

    NARCIS (Netherlands)

    Benard, Antoine; van Sighem, Ard; Taieb, Audrey; Valadas, Emilia; Ruelle, Jean; Soriano, Vicente; Calmy, Alexandra; Balotta, Claudia; Damond, Florence; Brun-Vezinet, Françoise; Chene, Geneviève; Matheron, Sophie; Schölvinck, Elisabeth H.

    2011-01-01

    BACKGROUND: Triple nucleoside reverse-transcriptase inhibitors (NRTIs) are recommended by the World Health Organization as first-line regimen in treatment-naïve HIV-2-infected patients. However, ritonavir-boosted protease inhibitor (PI/r)-containing regimens are frequently prescribed. In the absence

  6. Ultra-fast analysis of plasma and intracellular levels of HIV protease inhibitors in children: A clinical application of MALDI mass spectrometry

    NARCIS (Netherlands)

    J.J.A. van Kampen (Jeroen); M.L. Reedijk (Mariska); P.C. Burgers (Peter); L.J.M. Dekker (Lennard); N.G. Hartwig (Nico); I.E. van der Ende (Ineke); R. de Groot (Ronald); A.D.M.E. Osterhaus (Albert); D.M. Burger (David); T.M. Luider (Theo); R.A. Gruters (Rob)

    2010-01-01

    textabstractHIV protease inhibitors must penetrate into cells to exert their action. Differences in the intracellular pharmacokinetics of these drugs may explain why some patients fail on therapy or suffer from drug toxicity. Yet, there is no information available on the intracellular levels of HIV

  7. Ultra-fast analysis of plasma and intracellular levels of HIV protease inhibitors in children: a clinical application of MALDI mass spectrometry.

    NARCIS (Netherlands)

    Kampen, J.J. van; Reedijk, M.L.; Burgers, P.C.; Dekker, L.J.; Hartwig, N.G.; Ende, I.E. van der; Groot, R. de; Osterhaus, A.D.; Burger, D.M.; Luider, T.M.; Gruters, R.A.

    2010-01-01

    HIV protease inhibitors must penetrate into cells to exert their action. Differences in the intracellular pharmacokinetics of these drugs may explain why some patients fail on therapy or suffer from drug toxicity. Yet, there is no information available on the intracellular levels of HIV protease

  8. Multi-nucleoside reverse transcriptase inhibitor resistant HIV type-1 in a patient from Sierra Leone failing stavudine, lamivudine and nevirapine

    NARCIS (Netherlands)

    Hamers, Raph L.; Wensing, Annemarie M. J.; Back, Nicole K. T.; Arcilla, Maria S.; Frissen, Jos P. H.

    2011-01-01

    We report a 33-year-old HIV type-1 (HIV-1)-infected male from Sierra Leone who harboured extensive drug resistance mutations to all nucleoside reverse transcriptase inhibitors (NRTIs) and non-NRTIs, including the multi-NRTI-resistance Q151M complex, K65R, M184I and Y181I, after using standard

  9. Efficiency of a second-generation HIV-1 protease inhibitor studied by molecular dynamics and absolute binding free energy calculations

    Czech Academy of Sciences Publication Activity Database

    Lepšík, Martin; Kříž, Z.; Havlas, Zdeněk

    2004-01-01

    Roč. 57, - (2004), s. 279-293 ISSN 0887-3585 R&D Projects: GA MŠk LN00A032; GA MŠk LN00A016; GA ČR GA203/00/0828 Institutional research plan: CEZ:AV0Z4055905 Keywords : HIV * inhibitor * resistance Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.429, year: 2004

  10. Diastereoselective synthesis and molecular docking studies of novel fused tetrahydropyridine derivatives as new inhibitors of HIV protease

    Science.gov (United States)

    Mohammadi, Ali A.; Taheri, Salman; Amouzegar, Ali; Ahdenov, Reza; Halvagar, Mohammad Reza; Sadr, Ahmad Shahir

    2017-07-01

    An efficient one-pot, catalyst-free, and four-components procedure for the synthesis of novel 10b-hydroxy-4-nitro-5-phenyl-2,3,5,5a-tetrahydro-1H-imidazo[1,2-a]indeno[2,1-e]pyridin-6(10bH)-one derivatives from corresponding diamine, nitro ketene dithioacetal, aldehydes and 1,3-indandione in ethanol has been achieved upon a Knoevenagel condensation-Michael addition-tautomerism-cyclisation sequence. All the newly synthesized compounds were screened for molecular docking studies. Molecular docking studies were carried out using the crystal structure of HIV protease enzyme. Some of the compounds obtain minimum binding energy and good affinity toward the active pocket of HIV protease enzyme in compare with Saquinavir as a standard HIV protease inhibitor.

  11. Nonnucleoside Reverse-transcriptase Inhibitor- vs Ritonavir-boosted Protease Inhibitor-based Regimens for Initial Treatment of HIV Infection

    DEFF Research Database (Denmark)

    Borges, Álvaro H; Lundh, Andreas; Tendal, Britta

    2016-01-01

    BACKGROUND: Previous studies suggest that nonnucleoside reverse-transcriptase inhibitors (NNRTIs) cause faster virologic suppression, while ritonavir-boosted protease inhibitors (PI/r) recover more CD4 cells. However, individual trials have not been powered to compare clinical outcomes. METHODS: ...

  12. Yeast cells as a tool for analysis of HIV-1 protease susceptibility to protease inhibitors, a comparative study.

    Science.gov (United States)

    Ravaux, Isabelle; Perrin-East, Christelle; Attias, Coralie; Cottalorda, Jacqueline; Durant, Jacques; Dellamonica, Pierre; Gluschankof, Pablo; Stein, Andreas; Tamalet, Catherine

    2014-01-01

    HIV develops drug resistance at a high rate under drug selection pressure. Resistance tests are recommended to help physicians optimize antiretroviral drug therapies. For this purpose, genotypic and phenotypic tests have been developed. In order to propose a new phenotypic test that will be less laborious, expensive, and time consuming than the standard ones, a new procedure to measure HIV-1 protease susceptibility to protease inhibitor (PIs) in Saccharomyces cerevisiae yeast cells was developed. This procedure is based on HIV-1 protease expression in yeast. While the viral protein induces yeast cell death, its inhibition by PIs in the culture medium allows the cell to grow in a dose-dependent manner. In a comparative study of standard genotypic analysis vs. yeast cell-based phenotypic tests, performed on HIV-1 protease coding DNA in 17 different plasma samples from infected individuals, a clear match was found between the results obtained using the two technologies. This suggests that the yeast-based procedure is at least as accurate as standard genotypic test in defining susceptibility to protease inhibitors. This encouraging result should be the basis for large-scale validation of the new phenotypic resistance test. Copyright © 2013 Elsevier B.V. All rights reserved.

  13. Constructing Interconsistent, Reasonable, and Predictive Models for Both the Kinetic and Thermodynamic Properties of HIV-1 Protease Inhibitors.

    Science.gov (United States)

    Qu, Sujun; Huang, Shuheng; Pan, Xianchao; Yang, Li; Mei, Hu

    2016-10-24

    Accumulated evidence suggests that the in vivo biological potency of a ligand is more strongly correlated with the binding/unbinding kinetics than the equilibrium thermodynamics of the protein-ligand interaction (PLI). However, the existing experimental and computational techniques are largely insufficient and limited in large-scale measurements or accurate predictions of the kinetic properties of PLI. In this work, elaborate efforts have been made to develop interconsistent, reasonable, and predictive models of the association rate constant (kon), dissociation rate constant (koff), and equilibrium dissociation constant (KD) of a series of HIV protease inhibitors with different structural skeletons. The results showed that nine Volsurf descriptors derived from water (OH2) and hydrophobic (DRY) probes are key molecular determinants for the kinetic and thermodynamic properties of HIV-1 protease inhibitors. To the best of our knowledge, this is the first time that interconsistent and reasonable models with strong prediction power have been established for both the kinetic and thermodynamic properties of HIV protease inhibitors.

  14. Design, Synthesis, and Biological and Structural Evaluations of Novel HIV-1 Protease Inhibitors To Combat Drug Resistance

    Energy Technology Data Exchange (ETDEWEB)

    Parai, Maloy Kumar; Huggins, David J.; Cao, Hong; Nalam, Madhavi N.L.; Ali, Akbar; Schiffer, Celia A.; Tidor, Bruce; Rana, Tariq M. (MIT); (UMASS, MED); (Sanford-Burnham)

    2012-09-11

    A series of new HIV-1 protease inhibitors (PIs) were designed using a general strategy that combines computational structure-based design with substrate-envelope constraints. The PIs incorporate various alcohol-derived P2 carbamates with acyclic and cyclic heteroatomic functionalities into the (R)-hydroxyethylamine isostere. Most of the new PIs show potent binding affinities against wild-type HIV-1 protease and three multidrug resistant (MDR) variants. In particular, inhibitors containing the 2,2-dichloroacetamide, pyrrolidinone, imidazolidinone, and oxazolidinone moieties at P2 are the most potent with Ki values in the picomolar range. Several new PIs exhibit nanomolar antiviral potencies against patient-derived wild-type viruses from HIV-1 clades A, B, and C and two MDR variants. Crystal structure analyses of four potent inhibitors revealed that carbonyl groups of the new P2 moieties promote extensive hydrogen bond interactions with the invariant Asp29 residue of the protease. These structure-activity relationship findings can be utilized to design new PIs with enhanced enzyme inhibitory and antiviral potencies.

  15. An isocratic liquid chromatography method for determining HIV non-nucleoside reverse transcriptase inhibitor and protease inhibitor concentrations in human plasma.

    Science.gov (United States)

    Weller, Dennis R; Brundage, Richard C; Balfour, Henry H; Vezina, Heather E

    2007-04-01

    An efficient, isocratic high performance liquid chromatography (HPLC) method for determining human immunodeficiency virus (HIV) non-nucleoside reverse transcriptase inhibitors (NNRTIs) and protease inhibitors (PIs) in plasma is advantageous for laboratories participating in clinical trials and therapeutic drug monitoring (TDM) programs, or conducting small animal research. The combination of isocratic reversed phase chromatography using an S-3, 3.0 mm x 150 mm column along with low plasma volume (200 microl), rapid liquid-liquid extraction, and detection at a single wavelength (212 nm) over a short run time makes this method valuable. Within and between assay variability ranges from 0.8 to 3.5% and 1.2-6.2%, respectively. Accuracy ranges from 91.0 to 112.8% for four quality controls (50, 100, 1000, and 10,000 ng/ml) for all drugs measured (efavirenz, nevirapine, amprenavir, atazanavir, indinavir, lopinavir, nelfinavir, ritonavir, and saquinavir).

  16. Selective histonedeacetylase inhibitor M344 intervenes in HIV-1 latency through increasing histone acetylation and activation of NF-kappaB.

    Directory of Open Access Journals (Sweden)

    Hao Ying

    Full Text Available BACKGROUND: Histone deacetylase (HDAC inhibitors present an exciting new approach to activate HIV production from latently infected cells to potentially enhance elimination of these cells and achieve a cure. M344, a novel HDAC inhibitor, shows robust activity in a variety of cancer cells and relatively low toxicity compared to trichostatin A (TSA. However, little is known about the effects and action mechanism of M344 in inducing HIV expression in latently infected cells. METHODOLOGY/PRINCIPAL FINDINGS: Using the Jurkat T cell model of HIV latency, we demonstrate that M344 effectively reactivates HIV-1 gene expression in latently infected cells. Moreover, M344-mediated activation of the latent HIV LTR can be strongly inhibited by a NF-κB inhibitor aspirin. We further show that M344 acts by increasing the acetylation of histone H3 and histone H4 at the nucleosome 1 (nuc-1 site of the HIV-1 long terminal repeat (LTR and by inducing NF-κB p65 nuclear translocation and direct RelA DNA binding at the nuc-1 region of the HIV-1 LTR. We also found that M344 synergized with prostratin to activate the HIV-1 LTR promoter in latently infected cells. CONCLUSIONS/SIGNIFICANCE: These results suggest the potential of M344 in anti-latency therapies and an important role for histone modifications and NF-κB transcription factors in regulating HIV-1 LTR gene expression.

  17. Potential use of rapamycin in HIV infection

    DEFF Research Database (Denmark)

    Donia, Marco; McCubrey, James A; Bendtzen, Klaus

    2010-01-01

    The strong need for the development of alternative anti-HIV agents is primarily due to the emergence of strain-resistant viruses, the need for sustained adherence to complex treatment regimens and the toxicity of currently used antiviral drugs. This review analyzes proof of concept studies...... indicating that the immunomodulatory drug rapamycin (RAPA) possesses anti-HIV properties both in vitro and in vivo that qualifies it as a potential new anti-HIV drug. It represents a literature review of published studies that evaluated the in vitro and in vivo activity of RAPA in HIV. RAPA represses HIV-1...... replication in vitro through different mechanisms including, but not limited, to down regulation of CCR5. In addition RAPA synergistically enhances the anti-HIV activity of entry inhibitors such as vicriviroc, aplaviroc and enfuvirtide in vitro. RAPA also inhibits HIV-1 infection in human peripheral blood...

  18. Naringin prevents HIV-1 protease inhibitors-induced metabolic complications in vivo.

    Directory of Open Access Journals (Sweden)

    Sanelisiwe Nzuza

    Full Text Available Insulin resistance, glucose intolerance and overt diabetes are known metabolic complications associated with chronic use of HIV-Protease Inhibitors. Naringin is a grapefruit-derived flavonoid with anti-diabetic, anti-dyslipidemia, anti-inflammatory and anti-oxidant activities.The study investigated the protective effects of naringin on glucose intolerance and impaired insulin secretion and signaling in vivo.Male Wistar rats were divided into six groups (n = 6 and were daily orally treated with distilled water {3.0 ml/kg body weight (BW}, atazanavir (133 mg/kg BW, saquinavir (333 mg/kg BW with or without naringin (50 mg/kg BW, respectively for 56 days. Body weights and water consumption were recorded daily. Glucose tolerance tests were carried out on day 55 of the treatment and thereafter, the rats were sacrificed by halothane overdose.Atazanavir (ATV- or saquinavir (SQV-treated rats exhibited significant weight loss, polydipsia, elevated Fasting blood glucose (FBG, reduced Fasting Plasma Insulin (FPI and expression of phosphorylated, Insulin Receptor Substrate-1 (IRS-1 and Akt proteins, hepatic and pancreatic glucokinase levels, and also increasing pancreatic caspase-3 and -9 as well as UCP2 protein expressions compared to controls, respectively. These effects were completely reversed by naringin treatment.Naringin prevents PI-induced glucose intolerance and impairment of insulin signaling and as nutritional supplement it could therefore alleviate metabolic complications associated with antiretroviral therapy.

  19. Dideoxynucleoside HIV reverse transcriptase inhibitors and drug-related hepatotoxicity: a case report

    Directory of Open Access Journals (Sweden)

    Lapadula Giuseppe

    2007-05-01

    Full Text Available Abstract This report regards the case of a 43 year-old HIV-positive woman who developed an episode of serious transaminase elevation during stavudine-including antiretroviral therapy. Diagnostic assessment ruled out hepatitis virus co-infection, alcohol abuse besides other possible causes of liver damage. No signs of lactic acidosis were present. Liver biopsy showed portal inflammatory infiltrate, spotty necrosis, vacuoles of macro- and micro-vesicular steatosis, acidophil and foamy hepatocytes degeneration with organelles clumping, poorly formed Mallory bodies and neutrophil granulocytes attraction (satellitosis. A dramatic improvement in liver function tests occurred when stavudine was discontinued and a new antiretroviral regimen with different nucleoside reverse transcriptase inhibitors was used. The importance of considering hepatotoxicity as an adverse event of HAART including stavudine, even in absence of other signs of mitochondrial toxicity should therefore be underlined. Liver biopsy may provide further important information regarding patients with severe transaminase elevation, for a better understanding of the etiology of liver damage.

  20. Boceprevir in combination with HIV protease inhibitors in patients with advanced fibrosis-altered drug-drug interactions?

    Directory of Open Access Journals (Sweden)

    C Schwarze-Zander

    2012-11-01

    Full Text Available In HIV/HCV co-infected patients improved treatment outcomes have been reported for the HCV protease inhibitors (PIs boceprevir (BOC and telaprevir (TVR, reaching SVR rates of up to 70% in pilot trials. Due to complex drug-drug-interactions triple therapy is substantially limited in HIV/HCV-coinfected individuals. Co-administration of BOC with the commonly available HIV PIs has been reported not only to decrease the level of BOC but also to lead to relevant decreases in the respective HIV PI. Here, we report on two patients who received BOC-containing HCV triple therapy in combination with a HIV PI. Patient 1 was on darunavir 800 mg/ritonavir 100 mg once-daily mono-therapy. Using FibroScan a liver stiffness of 34 kPa suggested liver cirrhosis prior to start of HCV triple therapy. At week 5 of HCV triple therapy darunavir trough concentration was measured in the reference range with 3777 ng/ml (reference trough concentration 2400–4600 ng/ml. HCV-RNA became negative at week 10 and HIV-RNA was below detection limit (<40 copies/ml at all times. Patient 2 was on a simplified FTC qd and fos-amprenavir 700 mg/ritonavir 100 mg bid regimen. Liver disease had also progressed to liver cirrhosis, confirmed in FibroScan, with a liver stiffness of 32 kPa. At week 8 of HCV triple therapy fos-amprenavir trough level was measured in the normal reference range with 1699 ng/ml (reference trough concentration 750–2500 ng/ml. At week 11 HCV-RNA was <12 IU/ml and HIV viral load was below detection limit of <40 copies/ml at all times. Our clinical data suggest that in patients with advanced liver disease possibly drug levels of HIV PIs which are coadministered with BOC may be within the normal range. In order to better understand the true amount of drug interactions between BOC and commonly used HIV PIs in HIV/HCV-coinfected patients with more advanced liver fibrosis, urgently more PK studies are required to make HCV triple therapy accessible for a wider number of

  1. Solid-Phase Synthesis of the Lipopeptide Myr-HBVpreS/2-78, a Hepatitis B Virus Entry Inhibitor

    Directory of Open Access Journals (Sweden)

    Walter Mier

    2010-07-01

    Full Text Available Chronic HBV infection is the leading cause of liver cirrhosis and hepatocellular carcinoma (HCC. Synthetic peptides derived from the N-terminus of the large HBV envelope protein (L-protein have been shown to efficiently block HBV entry. Myr-HBVpreS/2-78, the parent compound of these drugs, inhibits human HBV infection in vitro and in vivo. An efficient synthesis is required, as these peptides constitute a novel class of anti HBV drugs. Consequently, the solid phase synthesis of the N-terminal 77 amino acids of the viral L-protein was studied in detail. The peptide was N-terminally myristoylated to resemble the natural, postranslationally modified protein. The synthesis was monitored using the Fmoc cleavage pattern of the solid phase synthesis on a standard peptide synthesizer and by LC-MS analyses of the arising side products. “Difficult sequences” in the positions 42-47 of the peptide sequence complicate the efficient synthesis of the 77-mer peptide HBVpreS/2-78. Attempts were undertaken to optimize the synthesis by heating, double coupling or the use of pseudoproline dipeptides. HPLC-MS analyses showed that the efficiency of the synthesis could be increased best by temperature elevation. This resulted in a higher purity of the crude product after solid phase synthesis. It was possible to minimize the occurrence of side products due to the positive effects related to higher reaction temperature. In conclusion, the peptide is accessible by stepwise SPPS without the necessity of segment coupling.

  2. The allosteric HIV-1 integrase inhibitor BI-D affects virion maturation but does not influence packaging of a functional RNA genome

    NARCIS (Netherlands)

    van Bel, Nikki; van der Velden, Yme; Bonnard, Damien; Le Rouzic, Erwann; Das, Atze T.; Benarous, Richard; Berkhout, Ben

    2014-01-01

    The viral integrase (IN) is an essential protein for HIV-1 replication. IN inserts the viral dsDNA into the host chromosome, thereby aided by the cellular co-factor LEDGF/p75. Recently a new class of integrase inhibitors was described: allosteric IN inhibitors (ALLINIs). Although designed to

  3. An assay to monitor HIV-1 protease activity for the identification of novel inhibitors in T-cells.

    Directory of Open Access Journals (Sweden)

    Brett J Hilton

    Full Text Available The emergence of resistant HIV strains, together with the severe side-effects of existing drugs and lack of development of effective anti-HIV vaccines highlight the need for novel antivirals, as well as innovative methods to facilitate their discovery. Here, we have developed an assay in T-cells to monitor the proteolytic activity of the HIV-1 protease (PR. The assay is based on the inducible expression of HIV-1 PR fused within the Gal4 DNA-binding and transactivation domains. The fusion protein binds to the Gal4 responsive element and activates the downstream reporter, enhanced green fluorescent protein (eGFP gene only in the presence of an effective PR Inhibitor (PI. Thus, in this assay, eGFP acts as a biosensor of PR activity, making it ideal for flow cytometry based screening. Furthermore, the assay was developed using retroviral technology in T-cells, thus providing an ideal environment for the screening of potential novel PIs in a cell-type that represents the natural milieu of HIV infection. Clones with the highest sensitivity, and robust, reliable and reproducible reporter activity, were selected. The assay is easily adaptable to other PR variants, a multiplex platform, as well as to high-throughput plate reader based assays and will greatly facilitate the search for novel peptide and chemical compound based PIs in T-cells.

  4. Proteochemometric modeling of the bioactivity spectra of HIV-1 protease inhibitors by introducing protein-ligand interaction fingerprint.

    Directory of Open Access Journals (Sweden)

    Qi Huang

    Full Text Available HIV-1 protease is one of the main therapeutic targets in HIV. However, a major problem in treatment of HIV is the rapid emergence of drug-resistant strains. It should be particularly helpful to clinical therapy of AIDS if one method can be used to predict antivirus capability of compounds for different variants. In our study, proteochemometric (PCM models were created to study the bioactivity spectra of 92 chemical compounds with 47 unique HIV-1 protease variants. In contrast to other PCM models, which used Multiplication of Ligands and Proteins Descriptors (MLPD as cross-term, one new cross-term, i.e. Protein-Ligand Interaction Fingerprint (PLIF was introduced in our modeling. With different combinations of ligand descriptors, protein descriptors and cross-terms, nine PCM models were obtained, and six of them achieved good predictive abilities (Q(2(test>0.7. These results showed that the performance of PCM models could be improved when ligand and protein descriptors were complemented by the newly introduced cross-term PLIF. Compared with the conventional cross-term MLPD, the newly introduced PLIF had a better predictive ability. Furthermore, our best model (GD & P & PLIF: Q(2(test = 0.8271 could select out those inhibitors which have a broad antiviral activity. As a conclusion, our study indicates that proteochemometric modeling with PLIF as cross-term is a potential useful way to solve the HIV-1 drug-resistant problem.

  5. Histone deacetylase inhibitors for purging HIV-1 from the latent reservoir.

    NARCIS (Netherlands)

    Matalon, S.; Rasmussen, T.A.; Dinarello, C.A.

    2011-01-01

    A reservoir of latently infected memory CD4(+) T cells is believed to be the source of HIV-1 reemergence after discontinuation of antiretroviral therapy. HIV-1 eradication may depend on depletion of this reservoir. Integrated HIV-1 is inaccessible for expression, in part because of histone

  6. Insights into the broad cellular effects of nelfinavir and the HIV protease inhibitors supporting their role in cancer treatment and prevention.

    Science.gov (United States)

    Gantt, Soren; Casper, Corey; Ambinder, Richard F

    2013-09-01

    The development of HIV protease inhibitors more than two decades ago heralded a new era in HIV care, changing the infection from universally fatal to chronic but controllable. With the widespread use of protease inhibitors, there was a reduction in the incidence and mortality of HIV-associated malignancies. Studies later found these drugs to have promising direct antitumor effects. Protease inhibitors have a wide range of effects on several cellular pathways that are important for tumorigenesis and independent of inhibition of the HIV protease, including reducing angiogenesis and cell invasion, inhibition of the Akt pathway, induction of autophagy, and promotion of apoptosis. Among protease inhibitors, nelfinavir appears to have the most potent and broad antineoplastic activities, and also affects replication of the oncogenic herpesviruses Kaposi sarcoma-associated herpesvirus and Epstein-Barr virus. Nelfinavir is being studied for the prevention and treatment of a wide range of malignancies in persons with and without HIV infection. Nelfinavir and other protease inhibitors are well tolerated, oral drugs that have promising antitumor properties, and may prove to play an important role in the prevention and treatment of several cancers. Additional insights into protease inhibitors' mechanisms of action may lead to the development of novel cancer chemotherapy agents.

  7. α1Proteinase inhibitor regulates CD4+ lymphocyte levels and is rate limiting in HIV-1 disease.

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    Cynthia L Bristow

    Full Text Available BACKGROUND: The regulation of adult stem cell migration through human hematopoietic tissue involves the chemokine CXCL12 (SDF-1 and its receptor CXCR4 (CD184. In addition, human leukocyte elastase (HLE plays a key role. When HLE is located on the cell surface (HLE(CS, it acts not as a proteinase, but as a receptor for α(1proteinase inhibitor (α(1PI, α(1antitrypsin, SerpinA1. Binding of α(1PI to HLE(CS forms a motogenic complex. We previously demonstrated that α(1PI deficiency attends HIV-1 disease and that α(1PI augmentation produces increased numbers of immunocompetent circulating CD4(+ lymphocytes. Herein we investigated the mechanism underlying the α(1PI deficiency that attends HIV-1 infection. METHODS AND FINDINGS: Active α(1PI in HIV-1 subjects (median 17 µM, n = 35 was significantly below normal (median 36 µM, p220 CD4 cells/µl, CD4(+ lymphocytes were correlated solely with active α(1PI (r(2 = 0.93, p<0.0001, n = 26. The monoclonal anti-HIV-1 gp120 antibody 3F5 present in HIV-1 patient blood is shown to bind and inactivate human α(1PI. Chimpanzee α(1PI differs from human α(1PI by a single amino acid within the 3F5-binding epitope. Unlike human α(1PI, chimpanzee α(1PI did not bind 3F5 or become depleted following HIV-1 challenge, consistent with the normal CD4(+ lymphocyte levels and benign syndrome of HIV-1 infected chimpanzees. The presence of IgG-α(1PI immune complexes correlated with decreased CD4(+ lymphocytes in HIV-1 subjects. CONCLUSIONS: This report identifies an autoimmune component of HIV-1 disease that can be overcome therapeutically. Importantly, results identify an achievable vaccine modification with the novel objective to protect against AIDS as opposed to the current objective to protect against HIV-1 infection.

  8. Design, synthesis, X-ray studies, and biological evaluation of novel macrocyclic HIV-1 protease inhibitors involving the P1'-P2' ligands.

    Science.gov (United States)

    Ghosh, Arun K; Sean Fyvie, W; Brindisi, Margherita; Steffey, Melinda; Agniswamy, Johnson; Wang, Yuan-Fang; Aoki, Manabu; Amano, Masayuki; Weber, Irene T; Mitsuya, Hiroaki

    2017-11-01

    Design, synthesis, and evaluation of a new class of HIV-1 protease inhibitors containing diverse flexible macrocyclic P1'-P2' tethers are reported. Inhibitor 5a with a pyrrolidinone-derived macrocycle exhibited favorable enzyme inhibitory and antiviral activity (Ki=13.2nM, IC50=22nM). Further incorporation of heteroatoms in the macrocyclic skeleton provided macrocyclic inhibitors 5m and 5o. These compounds showed excellent HIV-1 protease inhibitory (Ki=62pM and 14pM, respectively) and antiviral activity (IC50=5.3nM and 2.0nM, respectively). Inhibitor 5o also remained highly potent against a DRV-resistant HIV-1 variant. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Design, synthesis, X-ray studies, and biological evaluation of novel macrocyclic HIV-1 protease inhibitors involving the P1'-P2' ligands

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    Ghosh, Arun K.; Sean Fyvie, W.; Brindisi, Margherita; Steffey, Melinda; Agniswamy, Johnson; Wang, Yuan-Fang; Aoki, Manabu; Amano, Masayuki; Weber, Irene T.; Mitsuya, Hiroaki

    2017-11-01

    Design, synthesis, and evaluation of a new class of HIV-1 protease inhibitors containing diverse flexible macrocyclic P1'-P2' tethers are reported. Inhibitor 5a with a pyrrolidinone-derived macrocycle exhibited favorable enzyme inhibitory and antiviral activity (Ki = 13.2 nM, IC50 = 22 nM). Further incorporation of heteroatoms in the macrocyclic skeleton provided macrocyclic inhibitors 5m and 5o. These compounds showed excellent HIV-1 protease inhibitory (Ki = 62 pM and 14 pM, respectively) and antiviral activity (IC50 = 5.3 nM and 2.0 nM, respectively). Inhibitor 5o also remained highly potent against a DRV-resistant HIV-1 variant.

  10. The HSP90 inhibitor NVP-AUY922 radiosensitizes by abrogation of homologous recombination resulting in mitotic entry with unresolved DNA damage.

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    Shane Zaidi

    Full Text Available Heat shock protein 90 (HSP90 is a molecular chaperone responsible for the conformational maintenance of a number of client proteins that play key roles in cell cycle arrest, DNA damage repair and apoptosis following radiation. HSP90 inhibitors exhibit antitumor activity by modulating the stabilisation and activation of HSP90 client proteins. We sought to evaluate NVP-AUY922, the most potent HSP90 inhibitor yet reported, in preclinical radiosensitization studies.NVP-AUY922 potently radiosensitized cells in vitro at low nanomolar concentrations with a concurrent depletion of radioresistance-linked client proteins. Radiosensitization by NVP-AUY922 was verified for the first time in vivo in a human head and neck squamous cell carcinoma xenograft model in athymic mice, as measured by delayed tumor growth and increased surrogate end-point survival (p = <0.0001. NVP-AUY922 was shown to ubiquitously inhibit resolution of dsDNA damage repair correlating to delayed Rad51 foci formation in all cell lines tested. Additionally, NVP-AUY922 induced a stalled mitotic phenotype, in a cell line-dependent manner, in HeLa and HN5 cell lines irrespective of radiation exposure. Cell cycle analysis indicated that NVP-AUY922 induced aberrant mitotic entry in all cell lines tested in the presence of radiation-induced DNA damage due to ubiquitous CHK1 depletion, but resultant downstream cell cycle effects were cell line dependent.These results identify NVP-AUY922 as the most potent HSP90-mediated radiosensitizer yet reported in vitro, and for the first time validate it in a clinically relevant in vivo model. Mechanistic analysis at clinically achievable concentrations demonstrated that radiosensitization is mediated by the combinatorial inhibition of cell growth and survival pathways, ubiquitous delay in Rad51-mediated homologous recombination and CHK1-mediated G(2/M arrest, but that the contribution of cell cycle perturbation to radiosensitization may be cell line

  11. Nelfinavir, an HIV-1 protease inhibitor, induces oxidative stress-mediated, caspase-independent apoptosis in Leishmania amastigotes.

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    Pranav Kumar

    2010-03-01

    Full Text Available Visceral leishmaniasis has now emerged as an important opportunistic disease in patients coinfected with human immunodeficiency virus type-1 (HIV-1. Although the effectiveness of HIV-1 protease inhibitors, such as nelfinavir, in antiretroviral therapies is well documented, little is known of the impact of these drugs on Leishmania in coinfected individuals.Here, we show that nelfinavir generates oxidative stress in the parasite, leading to altered physiological parameters such as an increase in the sub-G1 DNA content, nuclear DNA fragmentation and loss of mitochondrial potential, which are all characteristics of apoptosis. Pretreatment of axenic amastigotes with the caspase inhibitor z-VAD-fmk did not inhibit the increase in sub-G1 DNA content in nelfinavir-treated parasites, suggesting therefore that this antiviral agent does not kill Leishmania amastigotes in a caspase-dependent manner. Furthermore, we observed that the mitochondrial resident protein endonuclease G is involved. We also demonstrate that parasites overexpressing GSH1 (the rate limiting enzyme of glutathione biosynthesis were more resistant to nelfinavir when compared to untransfected controls.These data suggest that nelfinavir induces oxidative stress in Leishmania amastigotes, culminating in caspase-independent apoptosis, in which DNA is degraded by endonuclease G. This study provides a rationale for future, long-term design of new therapeutic strategies to test nelfinavir as a potential antileishmanial agent as well as for possible future use in Leishmania/HIV-1 coinfections.

  12. Hyperlipidemia related to the use of HIV-protease inhibitors: natural history and results of treatment with fenofibrate

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    Caramelli Bruno

    2001-01-01

    Full Text Available Hyperlipidemia has been frequently recorded as a side effect of treating HIV patients with protease inhibitors (PI. This study was initiated to analyze the modifications on blood lipids in HIV-patients receiving PI and the safety and efficacy of the treatment with fenofibrate. Total (TC and HDL-cholesterol, triglycerides (TG, and CD4+ T-cell counts were measured in 30 HAART-naive patients (Group I before and after PI introduction. In a second phase of the study, the effects of fenofibrate on lipids, CPK, CD4+, and viral load were determined in 13 patients (Group II with elevated TC or TG. In Group I, 60% of the patients showed TC or TG elevations. Average increments of 31% and 146% in TC and TG respectively (p<0.0006 and p<0.0001 were observed. In Group II, fenofibrate treatment was associated with decrements of 6.6% (TC and 45.7% (TG (p=0.07 and 0.0002 and no modifications on CPK, CD4+, and viral load. In conclusion, hyperlipidemia is common during the treatment of HIV with protease inhibitors, and fenofibrate appears to be an effective and safe choice for its treatment.

  13. Structural and electronic properties of new fullerene derivatives and their possible application as HIV-1 protease inhibitors.

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    Ibrahim, Medhat; Saleh, Noha A; Hameed, Ali Jameel; Elshemey, Wael M; Elsayed, Anwar A

    2010-02-01

    Density functional theory (DFT) calculations have been carried out at the hybrid Becke 3-Lee-Yang-Parr; B3LYP/3-21G** level of theory to study two series of hydroxy-chalca-acetic acid-(4-pyrrolidin-1-yl-phenyl) ester [C(60)-C(2)H(4)N-(4-XCOCH(2)OH)C(6)H(4)] and hydroxy-chalcoacetic acid-[2-(2-hydroxy-acetylchalcanyl)-4-pyrrolidin-1-yl-phenyl] ester[C(60)-C(2)H(4)N-(3,4-XCOCH(2)OH)C(6)H(4)]. The X atom is O, S or Se for the two series. The vibrational spectra, physical, chemical, thermodynamics and Quantitative Structure Activity Relationship (QSAR) properties of the studied molecules are calculated and discussed. We have evaluated these molecules as HIV-1 protease inhibitors based on the hydrogenation interaction between the hydroxymethylcarbonyl (HMC) groups and the two aspartic acid of the HIV-1 protease active site. Results show that some of the investigated fullerene-based derivatives can be considered promising as HIV-1 protease inhibitors. Copyright (c) 2009 Elsevier B.V. All rights reserved.

  14. Structural and electronic properties of new fullerene derivatives and their possible application as HIV-1 protease inhibitors

    Science.gov (United States)

    Ibrahim, Medhat; Saleh, Noha A.; Hameed, Ali Jameel; Elshemey, Wael M.; Elsayed, Anwar A.

    2010-02-01

    Density functional theory (DFT) calculations have been carried out at the hybrid Becke 3-Lee-Yang-Parr; B3LYP/3-21G** level of theory to study two series of hydroxy-chalca-acetic acid-(4-pyrrolidin-1-yl-phenyl) ester [C 60-C 2H 4N-(4-XCOCH 2OH)C 6H 4] and hydroxy-chalcoacetic acid-[2-(2-hydroxy-acetylchalcanyl)-4-pyrrolidin-1-yl-phenyl] ester[C 60-C 2H 4N-(3,4-XCOCH 2OH)C 6H 4]. The X atom is O, S or Se for the two series. The vibrational spectra, physical, chemical, thermodynamics and Quantitative Structure Activity Relationship (QSAR) properties of the studied molecules are calculated and discussed. We have evaluated these molecules as HIV-1 protease inhibitors based on the hydrogenation interaction between the hydroxymethylcarbonyl (HMC) groups and the two aspartic acid of the HIV-1 protease active site. Results show that some of the investigated fullerene-based derivatives can be considered promising as HIV-1 protease inhibitors.

  15. Docking of anti-HIV-1 oxoquinoline-acylhydrazone derivatives as potential HSV-1 DNA polymerase inhibitors

    Science.gov (United States)

    Yoneda, Julliane Diniz; Albuquerque, Magaly Girão; Leal, Kátia Zaccur; Santos, Fernanda da Costa; Batalha, Pedro Netto; Brozeguini, Leonardo; Seidl, Peter R.; de Alencastro, Ricardo Bicca; Cunha, Anna Cláudia; de Souza, Maria Cecília B. V.; Ferreira, Vitor F.; Giongo, Viveca A.; Cirne-Santos, Cláudio; Paixão, Izabel C. P.

    2014-09-01

    Although there are many antiviral drugs available for the treatment of herpes simplex virus (HSV) infections, still the synthesis of new anti-HSV candidates is an important strategy to be pursued, due to the emergency of resistant HSV strains mainly in human immunodeficiency virus (HIV) co-infected patients. Some 1,4-dihydro-4-oxoquinolines, such as PNU-183792 (1), show a broad spectrum antiviral activity against human herpes viruses, inhibiting the viral DNA polymerase (POL) without affecting the human POLs. Thus, on an ongoing antiviral research project, our group has synthesized ribonucleosides containing the 1,4-dihydro-4-oxoquinoline (quinolone) heterocyclic moiety, such as the 6-Cl derivative (2), which is a dual antiviral agent (HSV-1 and HIV-1). Molecular dynamics simulations of the complexes of 1 and 2 with the HSV-1 POL suggest that structural modifications of 2 should increase its experimental anti-HSV-1 activity, since its ribosyl and carboxyl groups are highly hydrophilic to interact with a hydrophobic pocket of this enzyme. Therefore, in this work, comparative molecular docking simulations of 1 and three new synthesized oxoquinoline-acylhydrazone HIV-1 inhibitors (3-5), which do not contain those hydrophilic groups, were carried out, in order to access these modifications in the proposition of new potential anti-HSV-1 agents, but maintaining the anti-HIV-1 activity. Among the docked compounds, the oxoquinoline-acylhydrazone 3 is the best candidate for an anti-HSV-1 agent, and, in addition, it showed anti-HIV-1 activity (EC50 = 3.4 ± 0.3 μM). Compounds 2 and 3 were used as templates in the design of four new oxoquinoline-acylhydrazones (6-9) as potential anti-HSV-1 agents to increase the antiviral activity of 2. Among the docked compounds, oxoquinoline-acylhydrazone 7 was selected as the best candidate for further development of dual anti-HIV/HSV activity.

  16. Structural Insights into the Mechanisms of Action of Short-Peptide HIV-1 Fusion Inhibitors Targeting the Gp41 Pocket

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    Xiujuan Zhang

    2018-02-01

    Full Text Available The deep hydrophobic pocket of HIV-1 gp41 has been considered a drug target, but short-peptides targeting this site usually lack potent antiviral activity. By applying the M-T hook structure, we previously generated highly potent short-peptide fusion inhibitors that specifically targeted the pocket site, such as MT-SC22EK, HP23L, and LP-11. Here, the crystal structures of HP23L and LP-11 bound to the target mimic peptide N36 demonstrated the critical intrahelical and interhelical interactions, especially verifying that the hook-like conformation was finely adopted while the methionine residue was replaced by the oxidation-less prone residue leucine, and that addition of an extra glutamic acid significantly enhanced the binding and inhibitory activities. The structure of HP23L bound to N36 with two mutations (E49K and L57R revealed the critical residues and motifs mediating drug resistance and provided new insights into the mechanism of action of inhibitors. Therefore, the present data help our understanding for the structure-activity relationship (SAR of HIV-1 fusion inhibitors and facilitate the development of novel antiviral drugs.

  17. Protease inhibitor monotherapy for long-term management of HIV infection: a randomised, controlled, open-label, non-inferiority trial.

    Science.gov (United States)

    Paton, Nicholas I; Stöhr, Wolfgang; Arenas-Pinto, Alejandro; Fisher, Martin; Williams, Ian; Johnson, Margaret; Orkin, Chloe; Chen, Fabian; Lee, Vincent; Winston, Alan; Gompels, Mark; Fox, Julie; Scott, Karen; Dunn, David T

    2015-10-01

    Standard-of-care antiretroviral therapy (ART) uses a combination of drugs deemed essential to minimise treatment failure and drug resistance. Protease inhibitors are potent, with a high genetic barrier to resistance, and have potential use as monotherapy after viral load suppression is achieved with combination treatment. We aimed to assess clinical risks and benefits of protease inhibitor monotherapy in long-term clinical use: in particular, the effect on drug resistance and future treatment options. In this pragmatic, parallel-group, randomised, controlled, open-label, non-inferiority trial, we enrolled adults (≥18 years of age) positive for HIV attending 43 public sector treatment centres in the UK who had suppressed viral load (protease inhibitor monotherapy (PI-mono); we recommended ritonavir (100 mg)-boosted darunavir (800 mg) once daily or ritonavir (100 mg)-boosted lopinavir (400 mg) twice daily, with prompt return to combination treatment if viral load rebounded. All treatments were oral. Randomisation was with permuted blocks of varying size and stratified by centre and baseline ART; we used a computer-generated, sequentially numbered randomisation list. The primary outcome was loss of future drug options, defined as new intermediate-level or high-level resistance to one or more drugs to which the patient's virus was deemed sensitive at trial entry (assessed at 3 years; non-inferiority margin of 10%). We estimated probability of rebound and resistance with Kaplan-Meier analysis. Analyses were by intention to treat. This trial is registered with the International Standard Randomised Controlled Trial Number registry, number ISRCTN04857074. Between Nov 4, 2008, and July 28, 2010, we randomly allocated 587 participants to OT (291) or PI-mono (296). At 3 years, one or more future drug options had been lost in two participants (Kaplan-Meier estimate 0·7%) in the OT group and six (2·1%) in the PI-mono group: difference 1·4% (-0·4 to 3·4); non

  18. The HIV protease inhibitor, nelfinavir, as a novel therapeutic approach for the treatment of refractory pediatric leukemia

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    Meier-Stephenson V

    2017-05-01

    Full Text Available Vanessa Meier-Stephenson,1,2 Justin Riemer,1,2 Aru Narendran1–3 1Department of Oncology, Cumming School of Medicine, University of Calgary, 2Department of Pediatrics, Alberta Children’s Hospital, 3Pediatric Oncology Experimental Therapeutics Investigators Consortium (POETIC Laboratory, Calgary, AB, Canada Purpose: Refractory pediatric leukemia remains one of the leading causes of death in children. Intensification of current chemotherapy regimens to improve the outcome in these children is often limited by the effects of drug resistance and cumulative toxicity. Hence, the search for newer agents and novel therapeutic approaches are urgently needed to formulate the next-generation early-phase clinical trials for these patients.Materials and methods: A comprehensive library of antimicrobials, including eight HIV protease inhibitors (nelfinavir [NFV], saquinavir, indinavir, ritonavir, amprenavir, atazanavir, lopinavir, and darunavir, was tested against a panel of pediatric leukemia cells by in vitro growth inhibition studies. Detailed target modulation studies were carried out by Western blot analyses. In addition, drug synergy experiments with conventional and novel antitumor agents were completed to identify effective treatment regimens for future clinical trials.Results: Several of the HIV protease inhibitors showed cytotoxicity at physiologically relevant concentrations (half-maximal inhibitory concentration values ranging from 1–24 µM. In particular, NFV was found to exhibit the most potent antileukemic properties across all cell lines tested. Mechanistic studies show that NFV leads to the induction of autophagy and apoptosis possibly through the induction of endoplasmic reticulum stress. Furthermore, interference with cell signaling pathways, including Akt and mTOR, was also noted. Finally, drug combination studies have identified agents with potential for synergy with NFV in its antileukemic activity. These include JQ1 (BET inhibitor

  19. Percentage of adherence correlates with the risk of protease inhibitor (PI) treatment failure in HIV-infected patients.

    Science.gov (United States)

    Casado, J L; Sabido, R; Perez-Elías, M J; Antela, A; Oliva, J; Dronda, F; Mejía, B; Fortún, J

    1999-01-01

    To determine the effect of adherence on the rate of protease inhibitor (PI) treatment failure among human immunodeficiency virus (HIV)-infected patients. A prospective study of a cohort of 282 patients who initiated PI therapy from March 1996 to December 1997. Adherence was quantified as the percentage of prescribed doses reportedly taken and treatment failure was defined as HIV RNA levels above 200 copies/ml after 1 year on therapy. Overall, 190 patients (67%) missed prescribed doses. However, mean percentage of doses taken was 91% (range, 21-100%). Demographic, virological and immunological characteristics could not predict adherence outcomes. The causes of non-adherence included intolerance or side effects (35%), complexity of treatment (23%), or recurrence in active drug abuse (17%), whereas abandonment owing to HIV-related disease was uncommon (6%). A degree of adherence above 90% correlated significantly with viral suppression [relative risk (RR) 1.69; 95% confidence interval (CI) 1.1-2.56; PHIV viral load (RR, 2.03; P=0.0001), prior antiretroviral therapy (RR, 2.5; P=0.01), and use of saquinavir-hard gel capsules (saquinavir-HGC) (RR, 1.77; P=0.03) were strongly associated with treatment failure. The percentage of adherence and initial HIV viral load are the most important determinants of virological response to PI therapy and non-adherence is related to treatment-related factors in the majority of cases.

  20. Amplification of the Gp41 gene for detection of mutations conferring resistance to HIV-1 fusion inhibitors on genotypic assay

    Science.gov (United States)

    Tanumihardja, J.; Bela, B.

    2017-08-01

    Fusion inhibitors have potential for future use in HIV control programs in Indonesia, so the capacity to test resistance to such drugs needs to be developed. Resistance-detection with a genotypic assay began with amplification of the target gene, gp41. Based on the sequence of the two most common HIV subtypes in Indonesia, AE and B, a primer pair was designed. Plasma samples containing both subtypes were extracted to obtain HIV RNA. Using PCR, the primer pair was used to produce the amplification product, the identity of which was checked based on length under electrophoresis. Eleven plasma samples were included in this study. One-step PCR using the primer pair was able to amplify gp41 from 54.5% of the samples, and an unspecific amplification product was seen in 1.1% of the samples. Amplification failed in 36.4% of the samples, which may be due to an inappropriate primer sequence. It was also found that the optimal annealing temperature for producing the single expected band was 57.2 °C. With one-step PCR, the designed primer pair amplified the HIV-1 gp41 gene from subtypes AE and B. However, further research should be done to determine the conditions that will increase the sensitivity and specificity of the amplification process.

  1. Lack of effects of statins on high-density lipoprotein subfractions in HIV-1-infected patients receiving protease inhibitors.

    Science.gov (United States)

    Bittar, Randa; Aslangul, Élisabeth; Giral, Philippe; Assoumou, Lambert; Valantin, Marc-Antoine; Kalmykova, Olga; Federspiel, Marie-Christine; Cherfils, Corinne; Costagliola, Dominique; Bonnefont-Rousselot, Dominique

    2017-02-01

    We evaluated the effect of 45 days of rosuvastatin or pravastatin treatment on the distribution of HDL subfractions in HIV-1-infected individuals receiving boosted protease inhibitors (PIs) with cardiovascular risk. The distribution of HDL subclasses by gradient gel electrophoresis was blindly assessed in 74 HIV-1-infected individuals receiving boosted PIs at baseline and at day 45 of statin treatment, and compared with the distribution obtained in 63 healthy normolipidemic individuals taken as controls. No significant modification appeared in HDL distribution between the two arms of statins for the HIV-1-infected individuals. Nevertheless, when compared to controls, HDL subfractions showed a significantly lower HDL2b proportion and significantly higher proportions of HDL2a and HDL3b (PHIV-1-infected individuals under PIs. Nevertheless, when compared to healthy normolipidemic subjects, HDL distribution is clearly different, with a distribution in HIV-infected individuals under PIs associated with an increased cardiovascular risk. Copyright © 2016 Académie des sciences. Published by Elsevier Masson SAS. All rights reserved.

  2. Synthesis of P1'-functionalized macrocyclic transition-state mimicking HIV-1 protease inhibitors encompassing a tertiary alcohol.

    Science.gov (United States)

    De Rosa, Maria; Unge, Johan; Motwani, Hitesh V; Rosenquist, Åsa; Vrang, Lotta; Wallberg, Hans; Larhed, Mats

    2014-08-14

    Seven novel tertiary alcohol containing linear HIV-1 protease inhibitors (PIs), decorated at the para position of the benzyl group in the P1' side with (hetero)aromatic moieties, were synthesized and biologically evaluated. To study the inhibition and antiviral activity effect of P1-P3 macrocyclization, 14- and 15-membered macrocyclic PIs were prepared by ring-closing metathesis of the corresponding linear PIs. The macrocycles were more active than the linear precursors and compound 10f, with a 2-thiazolyl group in the P1' position, was the most potent PI of this new series (Ki 2.2 nM, EC50 0.2 μM). Co-crystallized complexes of both linear and macrocyclic PIs with the HIV-1 protease enzyme were prepared and analyzed.

  3. Structural and Preclinical Studies of Computationally Designed Non-Nucleoside Reverse Transcriptase Inhibitors for Treating HIV infection

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    Kudalkar, Shalley N.; Beloor, Jagadish; Chan, Albert H.; Lee, Won-Gil; Jorgensen, William L.; Kumar, Priti; Anderson, Karen S.

    2017-02-06

    The clinical benefits of HIV-1 non-nucleoside reverse transcriptase (RT) inhibitors (NNRTIs) are hindered by their unsatisfactory pharmacokinetic (PK) properties along with the rapid development of drug-resistant variants. However, the clinical efficacy of these inhibitors can be improved by developing compounds with enhanced pharmacological profiles and heightened antiviral activity. We used computational and structure-guided design to develop two next-generation NNRTI drug candidates, compounds I and II, which are members of a class of catechol diethers. We evaluated the preclinical potential of these compounds in BALB/c mice because of their high solubility (510 µg/ml for compound I and 82.9 µg/ml for compound II), low cytotoxicity, and enhanced antiviral activity against wild-type (WT) HIV-1 RT and resistant variants. Additionally, crystal structures of compounds I and II with WT RT suggested an optimal binding to the NNRTI binding pocket favoring the high anti-viral potency. A single intraperitoneal dose of compounds I and II exhibited a prolonged serum residence time of 48 hours and concentration maximum (Cmax) of 4000- to 15,000-fold higher than their therapeutic/effective concentrations. These Cmax values were 4- to 15-fold lower than their cytotoxic concentrations observed in MT-2 cells. Compound II showed an enhanced area under the curve (0–last) and decreased plasma clearance over compound I and efavirenz, the standard of care NNRTI. Hence, the overall (PK) profile of compound II was excellent compared with that of compound I and efavirenz. Furthermore, both compounds were very well tolerated in BALB/c mice without any detectable acute toxicity. Taken together, these data suggest that compounds I and II possess improved anti-HIV-1 potency, remarkable in vivo safety, and prolonged in vivo circulation time, suggesting strong potential for further development as new NNRTIs for the potential treatment of HIV infection.

  4. Determination of the new HIV-protease inhibitor atazanavir by liquid chromatography after solid-phase extraction.

    Science.gov (United States)

    Colombo, S; Guignard, N; Marzolini, C; Telenti, A; Biollaz, J; Decosterd, L A

    2004-10-15

    An HPLC method previously described for the simultaneous assay of amprenavir, ritonavir, indinavir, saquinavir, nelfinavir and efavirenz is proposed here for the simultaneous analysis of the new HIV protease inhibitor atazanavir (ATV) in human plasma, by off-line solid-phase extraction (SPE) followed by HPLC coupled with UV-diode array detection. After viral inactivation by heat (60 degrees C for 60 min), plasma (600 microl) with clozapine (internal standard) is diluted 1 + 1 with phosphate buffer pH 7 and subjected to a SPE on a C18 cartridge. Matrix components are eliminated with 2 x 500 microl of a solution of 0.1% H(3)PO(4) neutralised with NaOH to pH 7. ATV is eluted with 3 x 500 microl MeOH. The resulting eluate is evaporated under nitrogen at room temperature and is reconstituted in 100 microl MeOH/H(2)O 50/50. A 40 microl volume is injected onto a Nucleosil 100-5 microm C18 AB column. ATV is analysed by UV detection at 201 nm using a gradient elution program with solvents constituted of MeCN and phosphate buffer adjusted to pH 5.14. The mobile phase also contains 0.02% sodium heptanesulfonate, enabling an excellent separation of ATV from the other HIV protease inhibitors (PIs) amprenavir, indinavir, saquinavir, ritonavir, lopinavir, nelfinavir and the non-nucleoside reverse transcriptase inhibitors (NNRTIs) efavirenz and nevirapine. The calibration curves are linear up to 10 microg/ml, with a lower limit of quantification of 0.2 microg/ml. The mean absolute recovery of ATV is 96.4 +/- 3.2%. The method is precise with mean inter-day CVs within 1.1-6.1%, and accurate (range of inter-day deviations +0.3 to +2.3%). The method has been validated and is currently applied to the monitoring of ATV in HIV patients.

  5. Changes in lipids over twelve months after initiating protease inhibitor therapy among persons treated for HIV/AIDS

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    Hogg Robert S

    2005-02-01

    Full Text Available Abstract Background Protease inhibitors are known to alter the lipid profiles in subjects treated for HIV/AIDS. However, the magnitude of this effect on plasma lipoproteins and lipids has not been adequately quantified. Objective To estimate the changes in plasma lipoproteins and triglycerides occurring within 12 months of initiating PI-based antiretroviral therapy among HIV/AIDS afflicted subjects. Methods We included all antiretroviral naïve HIV-infected persons treated at St-Paul's Hospital, British Columbia, Canada, who initiated therapy with protease inhibitor antiretroviral (ARV drugs between August 1996 and January 2002 and who had at least one plasma lipid measurement. Longitudinal associations between medication use and plasma lipids were estimated using mixed effects models that accounted for repeated measures on the same subjects and were adjusted for age, sex, time dependent CD4+ T-cell count, and time dependent cumulative use of non-nucleoside reverse transcriptase inhibitors and adherence. The cumulative number of prescriptions filled for PIs was considered time dependent. We estimated the changes in the 12 months following any initiation of a PI based regimen. Results A total of 679 eligible subjects were dispensed nucleoside analogues and PI at the initiation of therapy. Over a median 47 months of follow-up (interquartile range (IQR: 29–62, subjects had a median of 3 (IQR: 1–6 blood lipid measurements. Twelve months after treatment initiation of PI use, there was an estimated 20% (95% confidence interval: 17% – 24% increase in total cholesterol and 22% (12% – 33% increase in triglycerides. Conclusions Twelve months after treatment initiation with PIs, statistically significant increases in total cholesterol and triglycerides levels were observed in HIV-infected patients under conditions of standard treatment. Our results contribute to the growing body of evidence implicating PIs in the development of blood lipid

  6. V3 loop truncations in HIV-1 envelope impart resistance to coreceptor inhibitors and enhanced sensitivity to neutralizing antibodies.

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    Meg M Laakso

    2007-08-01

    Full Text Available The V1/V2 region and the V3 loop of the human immunodeficiency virus type I (HIV-1 envelope (Env protein are targets for neutralizing antibodies and also play an important functional role, with the V3 loop largely determining whether a virus uses CCR5 (R5, CXCR4 (X4, or either coreceptor (R5X4 to infect cells. While the sequence of V3 is variable, its length is highly conserved. Structural studies indicate that V3 length may be important for interactions with the extracellular loops of the coreceptor. Consistent with this view, genetic truncation of the V3 loop is typically associated with loss of Env function. We removed approximately one-half of the V3 loop from three different HIV-1 strains, and found that only the Env protein from the R5X4 strain R3A retained some fusion activity. Loss of V1/V2 (DeltaV1/V2 was well tolerated by this virus. Passaging of virus with the truncated V3 loop resulted in the derivation of a virus strain that replicated with wild-type kinetics. This virus, termed TA1, retained the V3 loop truncation and acquired several adaptive changes in gp120 and gp41. TA1 could use CCR5 but not CXCR4 to infect cells, and was extremely sensitive to neutralization by HIV-1 positive human sera, and by antibodies to the CD4 binding site and to CD4-induced epitopes in the bridging sheet region of gp120. In addition, TA1 was completely resistant to CCR5 inhibitors, and was more dependent upon the N-terminal domain of CCR5, a region of the receptor that is thought to contact the bridging sheet of gp120 and the base of the V3 loop, and whose conformation may not be greatly affected by CCR5 inhibitors. These studies suggest that the V3 loop protects HIV from neutralization by antibodies prevalent in infected humans, that CCR5 inhibitors likely act by disrupting interactions between the V3 loop and the coreceptor, and that altered use of CCR5 by HIV-1 associated with increased sensitivity to changes in the N-terminal domain can be linked

  7. Epigenetic silencing of human immunodeficiency virus (HIV) transcription by formation of restrictive chromatin structures at the viral long terminal repeat drives the progressive entry of HIV into latency.

    Science.gov (United States)

    Pearson, Richard; Kim, Young Kyeung; Hokello, Joseph; Lassen, Kara; Friedman, Julia; Tyagi, Mudit; Karn, Jonathan

    2008-12-01

    The molecular mechanisms utilized by human immunodeficiency virus (HIV) to enter latency are poorly understood. Following the infection of Jurkat T cells with lentiviral vectors that express Tat in cis, gene expression is progressively silenced. Silencing is greatly enhanced when the lentiviral vectors carry an attenuated Tat gene with the H13L mutation. Individual clones of lentivirus-infected cells showed a wide range of shutdown rates, with the majority showing a 50% silencing frequency between 30 to 80 days. The silenced clones characteristically contained a small fraction (0 to 15%) of activated cells that continued to express d2EGFP. When d2EGFP(+) and d2EGFP(-) cell populations were isolated from the shutdown clones, they quickly reverted to the original distribution of inactive and active cells, suggesting that the d2EGFP(+) cells arise from stochastic fluctuations in gene expression. The detailed analysis of transcription initiation and elongation using chromatin immunoprecipitation (ChIP) assays confirms that Tat levels are restricted in the latently infected cells but gradually rise during proviral reactivation. ChIP assays using clones of latently infected cells demonstrate that the latent proviruses carry high levels of deacetylated histones and trimethylated histones. In contrast, the cellular genes IkappaB alpha and GAPDH had high levels of acetylated histones and no trimethylated histones. The levels of trimethylated histone H3 and HP1-alpha associated with HIV proviruses fell rapidly after tumor necrosis factor alpha activation. The progressive shutdown of HIV transcription following infection suggests that epigenetic mechanisms targeting chromatin structures selectively restrict HIV transcription initiation. This decreases Tat production below the levels that are required to sustain HIV gene expression.

  8. Imidazo[1,2-a]pyridin-3-amines as potential HIV-1 non-nucleoside reverse transcriptase inhibitors

    CSIR Research Space (South Africa)

    Bode, ML

    2011-06-01

    Full Text Available in this study. HN N N NH CN CN TMC-278 Figure 5. PAMPA permeabilities and AlogP values for HIV RT inhibitors. Compounds were incubated in PAMPA plates for 5 h at 37 ?C at a starting concentration of 100 ?M in the donor wells. Atenolol, pindolol... INOVA instrument. Samples were referenced against chloroform at 77.00 ppm for 13C and against tetramethylsilane at 0.00 ppm for 1H. Spin multiplicities are given as s (singlet), br s (broad singlet), d (doublet), dd (doublet of doublets), t (triplet...

  9. Protein kinase C-delta regulates HIV-1 replication at an early post-entry step in macrophages

    Directory of Open Access Journals (Sweden)

    Contreras Xavier

    2012-05-01

    Full Text Available Abstract Background Macrophages, which are CD4 and CCR5 positive, can sustain HIV-1 replication for long periods of time. Thus, these cells play critical roles in the transmission, dissemination and persistence of viral infection. Of note, current antiviral therapies do not target macrophages efficiently. Previously, it was demonstrated that interactions between CCR5 and gp120 stimulate PKC. However, the PKC isozymes involved were not identified. Results In this study, we identified PKC-delta as a major cellular cofactor for HIV-1 replication in macrophages. Indeed, PKC-delta was stimulated following the interaction between the virus and its target cell. Moreover, inhibition of PKC-delta blocked the replication of R5-tropic viruses in primary human macrophages. However, this inhibition did not have significant effects on receptor and co-receptor expression or fusion. Additionally, it did not affect the formation of the early reverse transcription product containing R/U5 sequences, but did inhibit the synthesis of subsequent cDNAs. Importantly, the inhibition of PKC-delta altered the redistribution of actin, a cellular cofactor whose requirement for the completion of reverse transcription was previously established. It also prevented the association of the reverse transcription complex with the cytoskeleton. Conclusion This work highlights the importance of PKC-delta during early steps of the replicative cycle of HIV-1 in human macrophages.

  10. Curling of flap tips in HIV-1 protease as a mechanism for substrate entry and tolerance of drug resistance.

    Science.gov (United States)

    Scott, W R; Schiffer, C A

    2000-12-15

    The human immunodeficiency virus type 1 (HIV-1) protease is an essential viral protein that is a major drug target in the fight against Acquired Immune Deficiency Syndrome (AIDS). Access to the active site of this homodimeric enzyme is gained when two large flaps, one from each monomer, open. The flap movements are therefore central to the function of the enzyme, yet determining how these flaps move at an atomic level has not been experimentally possible. In the present study, we observe the flaps of HIV-1 protease completely opening during a 10 ns solvated molecular dynamics simulation starting from the unliganded crystal structure. This movement is on the time scale observed by Nuclear Magnetic Resonance (NMR) relaxation data. The highly flexible tips of the flaps, with the sequence Gly-Gly-Ile-Gly-Gly, are seen curling back into the protein and thereby burying many hydrophobic residues. This curled-in conformational change has never been previously described. Previous models of this movement, with the flaps as rigid levers, are not consistent with the experimental data. The residues that participate in this hydrophobic cluster as a result of the conformational change are highly sensitive to mutation and often contribute to drug resistance when they do change. However, several of these residues are not part of the active site cavity, and their essential role in causing drug resistance could possibly be rationalized if this conformational change actually occurs. Trapping HIV-1 protease in this inactive conformation would provide a unique opportunity for future drug design.

  11. Synthesis and biological evaluation in vitro and in mammalian cells of new heteroaryl carboxyamides as HIV-protease inhibitors.

    Science.gov (United States)

    Funicello, M; Chiummiento, L; Tramutola, F; Armentano, M F; Bisaccia, F; Miglionico, R; Milella, L; Benedetti, F; Berti, F; Lupattelli, P

    2017-09-01

    New heteroaryl HIV-protease inhibitors bearing a carboxyamide spacer were synthesized in few steps and high yield, from commercially available homochiral epoxides. Different substitution patterns were introduced onto a given isopropanoyl-sulfonamide core modifying the type of heteroarene and the central core, with the presence of either H or benzyl group. Their in vitro inhibition activity against recombinant protease showed a general beneficial effect of carboxyamide moiety, the IC50 values ranging between 1 and 15nM. In particular benzofuryl derivatives showed IC50 values among the best for such structurally simple inhibitors. Docking analysis allowed to identify the favorable situation of such benzofuryl derivatives in terms of number of interactions in the active site, supporting the experimental results on activity. The inhibition activity of such molecules has been also evaluated in HEK293 cells expressing the protease fused to green fluorescent protein, by western blotting analysis, fluorescence microscopy and cytofluorimetry. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Neither the HIV protease inhibitor lopinavir-ritonavir nor the antimicrobial trimethoprim-sulfamethoxazole prevent malaria relapse in plasmodium cynomolgi-infected non-human primates.

    Science.gov (United States)

    Hobbs, Charlotte V; Dixit, Saurabh; Penzak, Scott R; Sahu, Tejram; Orr-Gonzalez, Sachy; Lambert, Lynn; Zeleski, Katie; Chen, Jingyang; Neal, Jillian; Borkowsky, William; Wu, Yimin; Duffy, Patrick E

    2014-01-01

    Plasmodium vivax malaria causes significant morbidity and mortality worldwide, and only one drug is in clinical use that can kill the hypnozoites that cause P. vivax relapses. HIV and P. vivax malaria geographically overlap in many areas of the world, including South America and Asia. Despite the increasing body of knowledge regarding HIV protease inhibitors (HIV PIs) on P. falciparum malaria, there are no data regarding the effects of these treatments on P. vivax's hypnozoite form and clinical relapses of malaria. We have previously shown that the HIV protease inhibitor lopinavir-ritonavir (LPV-RTV) and the antibiotic trimethoprim sulfamethoxazole (TMP-SMX) inhibit Plasmodium actively dividing liver stages in rodent malarias and in vitro in P. falciparum, but effect against Plasmodium dormant hypnozoite forms remains untested. Separately, although other antifolates have been tested against hypnozoites, the antibiotic trimethoprim sulfamethoxazole, commonly used in HIV infection and exposure management, has not been evaluated for hypnozoite-killing activity. Since Plasmodium cynomolgi is an established animal model for the study of liver stages of malaria as a surrogate for P. vivax infection, we investigated the antimalarial activity of these drugs on Plasmodium cynomolgi relapsing malaria in rhesus macaques. Herein, we demonstrate that neither TMP-SMX nor LPV-RTV kills hypnozoite parasite liver stage forms at the doses tested. Because HIV and malaria geographically overlap, and more patients are being managed for HIV infection and exposure, understanding HIV drug impact on malaria infection is important.

  13. Novel 3′-Processing Integrase Activity Assay by Real-Time PCR for Screening and Identification of HIV-1 Integrase Inhibitors

    Directory of Open Access Journals (Sweden)

    Supachai Sakkhachornphop

    2015-01-01

    Full Text Available The 3′-end processing (3′P of each viral long terminal repeat (LTR during human immunodeficiency virus type-1 (HIV-1 integration is a vital step in the HIV life cycle. Blocking the 3′P using 3′P inhibitor has recently become an attractive strategy for HIV-1 therapeutic intervention. Recently, we have developed a novel real-time PCR based assay for the detection of 3′P activity in vitro. The methodology usually involves biotinylated HIV-1 LTR, HIV-1 integrase (IN, and specific primers and probe. In this novel assay, we designed the HIV-1 LTR substrate based on a sequence with a homology to HIV-1 LTR labeled at its 3′ end with biotin on the sense strand. Two nucleotides at the 3′ end were subsequently removed by IN activity. Only two nucleotides labeled biotin were captured on an avidin-coated tube; therefore, inhibiting the binding of primers and probe results in late signals in the real-time PCR. This novel assay has successfully detected both the 3′P activity of HIV-1 IN and the anti-IN activity by Raltegravir and sodium azide agent. This real-time PCR assay has been shown to be effective and inexpensive for a high-throughput screening of novel IN inhibitors.

  14. Neither the HIV protease inhibitor lopinavir-ritonavir nor the antimicrobial trimethoprim-sulfamethoxazole prevent malaria relapse in plasmodium cynomolgi-infected non-human primates.

    Directory of Open Access Journals (Sweden)

    Charlotte V Hobbs

    Full Text Available Plasmodium vivax malaria causes significant morbidity and mortality worldwide, and only one drug is in clinical use that can kill the hypnozoites that cause P. vivax relapses. HIV and P. vivax malaria geographically overlap in many areas of the world, including South America and Asia. Despite the increasing body of knowledge regarding HIV protease inhibitors (HIV PIs on P. falciparum malaria, there are no data regarding the effects of these treatments on P. vivax's hypnozoite form and clinical relapses of malaria. We have previously shown that the HIV protease inhibitor lopinavir-ritonavir (LPV-RTV and the antibiotic trimethoprim sulfamethoxazole (TMP-SMX inhibit Plasmodium actively dividing liver stages in rodent malarias and in vitro in P. falciparum, but effect against Plasmodium dormant hypnozoite forms remains untested. Separately, although other antifolates have been tested against hypnozoites, the antibiotic trimethoprim sulfamethoxazole, commonly used in HIV infection and exposure management, has not been evaluated for hypnozoite-killing activity. Since Plasmodium cynomolgi is an established animal model for the study of liver stages of malaria as a surrogate for P. vivax infection, we investigated the antimalarial activity of these drugs on Plasmodium cynomolgi relapsing malaria in rhesus macaques. Herein, we demonstrate that neither TMP-SMX nor LPV-RTV kills hypnozoite parasite liver stage forms at the doses tested. Because HIV and malaria geographically overlap, and more patients are being managed for HIV infection and exposure, understanding HIV drug impact on malaria infection is important.

  15. Quantification of 8 HIV-protease inhibitors and 2 nonnucleoside reverse transcriptase inhibitors by ultra-performance liquid chromatography with diode array detection.

    Science.gov (United States)

    Elens, Laure; Veriter, Sophie; Di Fazio, Vincent; Vanbinst, Roger; Boesmans, Daniel; Wallemacq, Pierre; Haufroid, Vincent

    2009-01-01

    Most HPLC-UV methods for therapeutic drug monitoring of anti-HIV drugs have long run times, which reduce their applicability for high-throughput analysis. We developed an ultra-performance liquid chromatography (UPLC)-diode array detection method for the simultaneous quantification of the HIV-protease inhibitors (PIs) amprenavir, atazanavir, indinavir, lopinavir, nelfinavir, ritonavir, saquinavir, and tipranavir (TPV), and the nonnucleoside reverse transcriptase inhibitors (NNRTIs) efavirenz and nevirapine. Solid-phase extraction of 1 mL plasma was performed with Waters HLB cartridges. After 3 wash steps, we eluted the drugs with methanol, evaporated the alcohol, and reconstituted the residue with 50 microL methanol. We injected a 4-microL volume into the UPLC system (Waters ACQUITY UPLC BEH C8 column maintained at 60 degrees C) and used a linear gradient of 50 mmol/L ammonium acetate and 50 mmol/L formic acid in water versus acetonitrile to achieve chromatographic separation of the drugs and internal standard (A-86093). Three wavelengths (215, 240, and 260 nm) were monitored. All drugs were eluted within 15 min. Calibration curves with concentrations of 0.025-10 mg/L (1.875-75 mg/L for TPV) showed coefficients of determination (r(2)) between 0.993 and 0.999. The lower limits of quantification were well below the trough concentrations reported in the literature. Inter- and intraassay CVs and the deviations between the nominal and measured concentrations were <15%. The method was validated by successful participation in an international interlaboratory QC program. This method allows fast and simultaneous quantification of all commercially available PIs and NNRTIs for therapeutic drug monitoring.

  16. Mutz-3-derived Langerhans cells are a model to study HIV-1 transmission and potential inhibitors

    NARCIS (Netherlands)

    M.A.W.P. de Jong (Marein); L. de Witte (Lot); S.J.A.M. Santegoets (Saskia); D. Fluitsma (Donna); M.E. Taylor (Maureen); T.D. de Gruijl (Tanja); T.B.H. Geijtenbeek (Teunis)

    2010-01-01

    textabstractSexual transmission is the primary route of HIV-1 infection, and DC subsets are thought to be involved in viral dissemination to T cells. In the genital mucosa, two main subsets of DCs are present: epithelial LCs capture and degrade HIV-1 through C-type lectin Langerin, whereas

  17. HIV Aspartic Peptidase Inhibitors Modulate Surface Molecules and Enzyme Activities Involved with Physiopathological Events in Fonsecaea pedrosoi

    Directory of Open Access Journals (Sweden)

    Vanila F. Palmeira

    2017-05-01

    Full Text Available Fonsecaea pedrosoi is the main etiological agent of chromoblastomycosis, a recalcitrant disease that is extremely difficult to treat. Therefore, new chemotherapeutics to combat this fungal infection are urgently needed. Although aspartic peptidase inhibitors (PIs currently used in the treatment of human immunodeficiency virus (HIV have shown anti-F. pedrosoi activity their exact mechanisms of action have not been elucidated. In the present study, we have investigated the effects of four HIV-PIs on crucial virulence attributes expressed by F. pedrosoi conidial cells, including surface molecules and secreted enzymes, both of which are directly involved in the disease development. In all the experiments, conidia were treated with indinavir, nelfinavir, ritonavir and saquinavir (100 μM for 24 h, and then fungal cells were used to evaluate the effects of HIV-PIs on different virulence attributes expressed by F. pedrosoi. In comparison to untreated controls, exposure of F. pedrosoi cells to HIV-PIs caused (i reduction on the conidial granularity; (ii irreversible surface ultrastructural alterations, such as shedding of electron dense and amorphous material from the cell wall, undulations/invaginations of the plasma membrane with and withdrawal of this membrane from the cell wall; (iii a decrease in both mannose-rich glycoconjugates and melanin molecules and an increase in glucosylceramides on the conidial surface; (iv inhibition of ergosterol and lanosterol production; (v reduction in the secretion of aspartic peptidase, esterase and phospholipase; (vi significant reduction in the viability of non-pigmented conidia compared to pigmented ones. In summary, HIV-PIs are efficient drugs with an ability to block crucial biological processes of F. pedrosoi and can be seriously considered as potential compounds for the development of new chromoblastomycosis chemotherapeutics.

  18. Design, Synthesis, Biological Evaluation, and X-ray Studies of HIV-1 Protease Inhibitors with Modified P2' Ligands of Darunavir.

    Science.gov (United States)

    Ghosh, Arun K; Fyvie, W Sean; Brindisi, Margherita; Steffey, Melinda; Agniswamy, Johnson; Wang, Yuan-Fang; Aoki, Manabu; Amano, Masayuki; Weber, Irene T; Mitsuya, Hiroaki

    2017-12-07

    The structure-based design, synthesis, and biological evaluation of a series of nonpeptidic HIV-1 protease inhibitors with rationally designed P2' ligands are described. The inhibitors are designed to enhance backbone binding interactions, particularly at the S2' subsite. Synthesis of inhibitors was carried out efficiently. The stereochemistry of alcohol functionalities of the P2' ligands was set by asymmetric reduction of the corresponding ketone using (R,R)- or (S,S)-Noyori catalysts. A number of inhibitors displayed very potent enzyme inhibitory and antiviral activity. Inhibitors 3g and 3h showed enzyme Ki values of 27.9 and 49.7 pm and antiviral activity of 6.2 and 3.9 nm, respectively. These inhibitors also remained quite potent against darunavir-resistant HIV-1 variants. An X-ray structure of inhibitor 3g in complex with HIV-1 protease revealed key interactions in the S2' subsite. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Variability in non-nucleoside reverse transcriptase and protease inhibitors concentrations among HIV-infected adults in routine clinical practice

    Science.gov (United States)

    Moltó, José; Blanco, Asunción; Miranda, Cristina; Miranda, José; Puig, Jordi; Valle, Marta; DelaVarga, Meritxell; Fumaz, Carmina R; Barbanoj, Manuel José; Clotet, Bonaventura

    2007-01-01

    Aims The objective of this study was to assess interindividual variability in plasma trough concentrations of non-nucleoside reverse transcriptase inhibitors (NNRTI) and protease inhibitors (PI) among HIV-infected adults in an outpatient routine clinical practice setting. Methods The study included 117 patients who attended our clinic for routine outpatient blood tests and who were receiving antiretroviral therapy which included NNRTI or PI. Patients were not informed that drug concentrations were going to be assessed until blood sampling. The time of the last antiretroviral treatment intake and blood sampling were recorded. Drug concentrations were considered optimal if they were above the proposed minimum effective concentration. In addition, efavirenz, nevirapine and atazanavir concentrations were considered potentially toxic if they were higher than 4.0 mg l−1, 6.0 mg l−1, and 0.85 mg l−1, respectively. Results Overall, interindividual variability in NNRTI and PI plasma concentrations was approximately 50%, and only 68.4% of the patients had drug concentrations within the proposed therapeutic range. Inappropriate adherence only explained 35% of subtherapeutic drug concentrations. Conclusion Interindividual variability in trough concentrations of NNRTI and PI among HIV-infected adults is large in routine clinical practice, with drug concentrations being outside the therapeutic window in a significant proportion of patients. Therapeutic drug monitoring may be useful to guide antiretroviral therapy in clinical practice. PMID:17223856

  20. Variability in non-nucleoside reverse transcriptase and protease inhibitor concentrations among HIV-infected adults in routine clinical practice.

    Science.gov (United States)

    Moltó, José; Blanco, Asunción; Miranda, Cristina; Miranda, José; Puig, Jordi; Valle, Marta; DelaVarga, Meritxell; Fumaz, Carmina R; Barbanoj, Manuel José; Clotet, Bonaventura

    2006-11-01

    The objective of this study was to assess interindividual variability in trough concentrations of plasma of non-nucleoside reverse transcriptase inhibitors (NNRTI) and protease inhibitors (PI) among HIV-infected adults in a routine outpatient setting. One hundred and seventeen patients who attended our clinic for routine blood tests, and who were receiving antiretroviral therapy which included NNRTI or PI were studied. Patients were not informed that drug concentrations were going to be measured until blood sampling. The times of the last antiretroviral dose and of blood sampling were recorded. Drug concentrations were considered optimal if they were above the proposed minimum effective value. In addition, efavirenz, nevirapine and atazanavir concentrations were considered potentially toxic if they were > 4.0 mg l(-1), > 6.0 mg l(-1) and > 0.85 mg l(-1), respectively. Overall, interindividual variability of NNRTI and PI concentrations in plasma was approximately 50%, and only 68.4% of the patients had drug concentrations within the proposed therapeutic range. Poor adherence explained only 35% of subtherapeutic drug concentrations. Interindividual variability in trough concentrations of NNRTI and PI among HIV-infected adults is large in routine clinical practice, with drug concentrations being outside the therapeutic window in a significant proportion of patients. These findings provide further evidence that therapeutic drug monitoring may be useful to guide antiretroviral therapy in clinical practice.

  1. Variability in non-nucleoside reverse transcriptase and protease inhibitors concentrations among HIV-infected adults in routine clinical practice.

    Science.gov (United States)

    Moltó, José; Blanco, Asunción; Miranda, Cristina; Miranda, José; Puig, Jordi; Valle, Marta; Delavarga, Meritxell; Fumaz, Carmina R; Barbanoj, Manuel José; Clotet, Bonaventura

    2007-06-01

    The objective of this study was to assess interindividual variability in plasma trough concentrations of non-nucleoside reverse transcriptase inhibitors (NNRTI) and protease inhibitors (PI) among HIV-infected adults in an outpatient routine clinical practice setting. The study included 117 patients who attended our clinic for routine outpatient blood tests and who were receiving antiretroviral therapy which included NNRTI or PI. Patients were not informed that drug concentrations were going to be assessed until blood sampling. The time of the last antiretroviral treatment intake and blood sampling were recorded. Drug concentrations were considered optimal if they were above the proposed minimum effective concentration. In addition, efavirenz, nevirapine and atazanavir concentrations were considered potentially toxic if they were higher than 4.0 mg l(-1), 6.0 mg l(-1), and 0.85 mg l(-1), respectively. Overall, interindividual variability in NNRTI and PI plasma concentrations was approximately 50%, and only 68.4% of the patients had drug concentrations within the proposed therapeutic range. Inappropriate adherence only explained 35% of subtherapeutic drug concentrations. Interindividual variability in trough concentrations of NNRTI and PI among HIV-infected adults is large in routine clinical practice, with drug concentrations being outside the therapeutic window in a significant proportion of patients. Therapeutic drug monitoring may be useful to guide antiretroviral therapy in clinical practice.

  2. Discovery of novel DAPY-IAS hybrid derivatives as potential HIV-1 inhibitors using molecular hybridization based on crystallographic overlays.

    Science.gov (United States)

    Huang, Boshi; Wang, Xueshun; Liu, Xinhao; Chen, Zihui; Li, Wanzhuo; Sun, Songkai; Liu, Huiqing; Daelemans, Dirk; De Clercq, Erik; Pannecouque, Christophe; Zhan, Peng; Liu, Xinyong

    2017-08-15

    Crystallographic overlap studies and pharmacophoric analysis indicated that diarylpyrimidine (DAPY)-based HIV-1 NNRTIs showed a similar binding mode and pharmacophoric features as indolylarylsulfones (IASs), another class of potent NNRTIs. Thus, a novel series of DAPY-IAS hybrid derivatives were identified as newer NNRTIs using structure-based molecular hybridization. Some target compounds exhibited moderate activities against HIV-1 IIIB strain, among which the two most potent inhibitors possessed EC50 values of 1.48μM and 1.61μM, respectively. They were much potent than the reference drug ddI (EC50=76.0μM) and comparable to 3TC (EC50=2.54μM). Compound 7a also exhibited the favorable selectivity index (SI=80). Preliminary structure-activity relationships (SARs), structure-cytotoxicity relationships, molecular modeling studies, and in silico calculation of physicochemical properties of these new inhibitors were also discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. In search of a treatment for HIV--current therapies and the role of non-nucleoside reverse transcriptase inhibitors (NNRTIs).

    Science.gov (United States)

    Reynolds, Chevonne; de Koning, Charles B; Pelly, Stephen C; van Otterlo, Willem A L; Bode, Moira L

    2012-07-07

    The human immunodeficiency virus (HIV) causes AIDS (acquired immune deficiency syndrome), a disease in which the immune system progressively deteriorates, making sufferers vulnerable to all manner of opportunistic infections. Currently, world-wide there are estimated to be 34 million people living with HIV, with the vast majority of these living in sub-Saharan Africa. Therefore, an important research focus is development of new drugs that can be used in the treatment of HIV/AIDS. This review gives an overview of the disease and addresses the drugs currently used for treatment, with specific emphasis on new developments within the class of allosteric non-nucleoside reverse transcriptase inhibitors (NNRTIs).

  4. Fluorine Substituted 1,2,4-Triazinones as Potential Anti-HIV-1 and CDK2 Inhibitors

    Directory of Open Access Journals (Sweden)

    Mohammed S. I. Makki

    2014-01-01

    Full Text Available Fluorine substituted 1,2,4-triazinones have been synthesized via alkylation, amination, and/or oxidation of 6-(2-amino-5-fluorophenyl-3-thioxo-3,4-dihydro-1,2,4-triazin-5(2H-one 1 and 4-fluoro-N-(4-fluoro-2-(5-oxo-3-thioxo-2,3,4,5-tetrahydro-1,2,4-triazin-6-ylphenylbenzamide 5 as possible anti-HIV-1 and CDK2 inhibitors. Alkylation on positions 2 and 4 in 1,2,4-triazinone gave compounds 6–8. Further modification was performed by selective alkylation and amination on position 3 to form compounds 9–15. However oxidation of 5 yielded compounds 16–18. Structures of the target compounds have been established by spectral analysis data. Five compounds (5, 11, 14, 16, and 17 have shown very good anti-HIV activity in MT-4 cells. Similarly, five compounds (1, 3, and 14–16 have exhibited very significant CDK2 inhibition activity. Compounds 14 and 16 were found to have dual anti-HIV and anticancer activities.

  5. Genetic Changes in HIV-1 Gag-Protease Associated with Protease Inhibitor-Based Therapy Failure in Pediatric Patients.

    Science.gov (United States)

    Giandhari, Jennifer; Basson, Adriaan E; Coovadia, Ashraf; Kuhn, Louise; Abrams, Elaine J; Strehlau, Renate; Morris, Lynn; Hunt, Gillian M

    2015-08-01

    Studies have shown a low frequency of HIV-1 protease drug resistance mutations in patients failing protease inhibitor (PI)-based therapy. Recent studies have identified mutations in Gag as an alternate pathway for PI drug resistance in subtype B viruses. We therefore genotyped the Gag and protease genes from 20 HIV-1 subtype C-infected pediatric patients failing a PI-based regimen. Major protease resistance mutations (M46I, I54V, and V82A) were identified in eight (40%) patients, as well as Gag cleavage site (CS) mutations (at codons 373, 374, 378, 428, 431, 449, 451, and 453) in nine (45%) patients. Four of these Gag CS mutations occurred in the absence of major protease mutations at PI failure. In addition, amino acid changes were noted at Gag non-CS with some predicted to be under HLA/KIR immune-mediated pressure and/or drug selection pressure. Changes in Gag during PI failure therefore warrant further investigation of the Gag gene and its role in PI failure in HIV-1 subtype C infection.

  6. Resveratrol Co-Treatment Attenuates the Effects of HIV Protease Inhibitors on Rat Body Weight and Enhances Cardiac Mitochondrial Respiration.

    Directory of Open Access Journals (Sweden)

    Burger Symington

    Full Text Available Since the early 1990s human immunodeficiency virus (HIV/acquired immunodeficiency syndrome (AIDS emerged as a global health pandemic, with sub-Saharan Africa the hardest hit. While the successful roll-out of antiretroviral (ARV therapy provided significant relief to HIV-positive individuals, such treatment can also elicit damaging side-effects. Here especially HIV protease inhibitors (PIs are implicated in the onset of cardio-metabolic complications such as type-2 diabetes and coronary heart disease. As there is a paucity of data regarding suitable co-treatments within this context, this preclinical study investigated whether resveratrol (RSV, aspirin (ASP or vitamin C (VitC co-treatment is able to blunt side-effects in a rat model of chronic PI exposure (Lopinavir/Ritonavir treatment for 4 months. Body weights and weight gain, blood metabolite levels (total cholesterol, HDL, LDL, triglycerides, echocardiography and cardiac mitochondrial respiration were assessed in PI-treated rats ± various co-treatments. Our data reveal that PI treatment significantly lowered body weight and cardiac respiratory function while no significant changes were found for heart function and blood metabolite levels. Moreover, all co-treatments ameliorated the PI-induced decrease in body weight after 4 months of PI treatment, while RSV co-treatment enhanced cardiac mitochondrial respiratory capacity in PI-treated rats. This pilot study therefore provides novel hypotheses regarding RSV co-treatment that should be further assessed in greater detail.

  7. Viral Entry into Cells

    Science.gov (United States)

    D'Orsogna, Maria R.

    2010-09-01

    Successful viral infection of a healthy cell requires complex host-pathogen interactions. In this talk we focus on the dynamics specific to the HIV virus entering a eucaryotic cell. We model viral entry as a stochastic engagement of receptors and coreceptors on the cell surface. We also consider the transport of virus material to the cell nucleus by coupling microtubular motion to the concurrent biochemical transformations that render the viral material competent for nuclear entry. We discuss both mathematical and biological consequences of our model, such as the formulation of an effective integrodifferential boundary condition embodying a memory kernel and optimal timing in maximizing viral probabilities.

  8. Protease Inhibitor Resistance Is Uncommon in HIV-1 Subtype C Infected Patients on Failing Second-Line Lopinavir/r-Containing Antiretroviral Therapy in South Africa

    Directory of Open Access Journals (Sweden)

    Carole L. Wallis

    2011-01-01

    Full Text Available Limited data exist on HIV-1 drug resistance patterns in South Africa following second-line protease-inhibitor containing regimen failure. This study examined drug resistance patterns emerging in 75 HIV-1 infected adults experiencing virologic failure on a second-line regimen containing 2 NRTI and lopinavir/ritonavir. Ninety six percent of patients (n=72 were infected with HIV-1 subtype C, two patients were infected with HIV-1 subtype D and one with HIV-1 subtype A1. Thirty nine percent (n=29 of patients had no resistance mutations in protease or reverse transcriptase suggesting that medication non-adherence was a major factor contributing to failure. Major lopinavir resistance mutations were infrequent (5 of 75; 7%, indicating that drug resistance is not the main barrier to future viral suppression.

  9. Decoding distinct membrane interactions of HIV-1 fusion inhibitors using a combined atomic force and fluorescence microscopy approach.

    Science.gov (United States)

    Franquelim, Henri G; Gaspar, Diana; Veiga, A Salomé; Santos, Nuno C; Castanho, Miguel A R B

    2013-08-01

    Enfuvirtide and T-1249 are two potent HIV-1 fusion inhibitor peptides. Recent studies indicate that lipids play an important role in the mode of action of those bioactive molecules. Using a combined tandem atomic force microscopy (AFM)-epifluorescence microscopy approach, we studied the interaction of both enfuvirtide and T-1249 with supported lipid bilayers. Fluid (ld)-gel (so) and ld-liquid ordered (lo) phase-separated membrane systems were tested. Results, especially for T-1249, show significant lipid membrane activity at a 15μM peptide concentration. T-1249, in opposition to enfuvirtide, induces an increase in membrane surface roughness, decrease in membrane fluidity, bilayer thinning at ld domains and disruption of the so domain borders. In terms of structural properties, both enfuvirtide and T-1249 possess distinct functional hydrophobic and amphipathic domains of HIV gp41. While enfuvirtide only yields the tryptophan-rich domain (TRD), T-1249 possesses both TRD and pocket-binding domain (PBD). TRD increases the hydrophobicity of the peptide while PBD enhances the amphipathic characteristics. As such, the enhanced membrane activity of T-1249 may be explained by a synergism between its amphipathic N-terminal segment and its hydrophophic C-terminal. Our findings provide valuable insights on the molecular-level mode of action of HIV-1 fusion inhibitors, unraveling the correlation between their structural properties and membrane interactions as a factor influencing their antiviral activity. Ultimately, this work validates the applicability of a combined AFM and fluorescence approach to evaluate the mechanic and structural properties of supported lipid bilayers upon interaction with membrane-active peptides. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. Variability in non-nucleoside reverse transcriptase and protease inhibitor concentrations among HIV-infected adults in routine clinical practice

    Science.gov (United States)

    Moltó, José; Blanco, Asunción; Miranda, Cristina; Miranda, José; Puig, Jordi; Valle, Marta; DelaVarga, Meritxell; Fumaz, Carmina R; Barbanoj, Manuel José; Clotet, Bonaventura

    2006-01-01

    What is already known about this subject The concentration of protease and non-nucleoside reverse transcriptase inhibtors in plasma has been related to both efficacy and toxicity. Most antiretroviral concentration data come from selected populations of patients undergoing therapeutic drug monitoring programmes, which may overestimate interindividual variability. What this study adds Our study has demonstrated the large interindividual variability in antiretroviral drug concentrations in an unselected population of patients during routine clinical practice. These results may provide interesting information to clinicians for the management of antiretroviral therapy in HIV-infected patients. Aims The objective of this study was to assess interindividual variability in trough concentrations of plasma of non-nucleoside reverse transcriptase inhibitors (NNRTI) and protease inhibitors (PI) among HIV-infected adults in a routine outpatient setting. Methods One hundred and seventeen patients who attended our clinic for routine blood tests, and who were receiving antiretroviral therapy which included NNRTI or PI were studied. Patients were not informed that drug concentrations were going to be measured until blood sampling. The times of the last antiretroviral dose and of blood sampling were recorded. Drug concentrations were considered optimal if they were above the proposed minimum effective value. In addition, efavirenz, nevirapine and atazanavir concentrations were considered potentially toxic if they were >4.0 mg l−1, >6.0 mg l−1 and >0.85 mg l−1, respectively. Results Overall, interindividual variability of NNRTI and PI concentrations in plasma was approximately 50%, and only 68.4% of the patients had drug concentrations within the proposed therapeutic range. Poor adherence explained only 35% of subtherapeutic drug concentrations. Conclusion Interindividual variability in trough concentrations of NNRTI and PI among HIV-infected adults is large in routine clinical

  11. A novel cell-based high-throughput screen for inhibitors of HIV-1 gene expression and budding identifies the cardiac glycosides.

    Science.gov (United States)

    Laird, Gregory M; Eisele, Evelyn E; Rabi, S Alireza; Nikolaeva, Daria; Siliciano, Robert F

    2014-04-01

    Highly active antiretroviral therapy (HAART) is the mainstay of treatment for HIV-1 infection. While current HAART regimens have been extremely effective, issues of associated toxicity, cost and resistance remain and there is a need for novel antiretroviral compounds to complement the existing therapy. We sought to develop a novel high-throughput method for identifying compounds that block later steps in the life cycle not targeted by current therapy. We designed a high-throughput screen to identify inhibitors of post-integration steps in the HIV-1 life cycle. The screening method was applied to a library of compounds that included numerous FDA-approved small molecules. Among the small molecules that inhibited late stages in HIV-1 replication were members of the cardiac glycoside family. We demonstrate that cardiac glycosides potently inhibit HIV-1 gene expression, thereby reducing the production of infectious HIV-1. We demonstrate that this inhibition is dependent upon the human Na(+)/K(+)-ATPase, but independent of cardiac glycoside-induced increases in intracellular Ca(2+). We have validated a novel high-throughput screen to identify small molecule inhibitors of HIV-1 gene expression, virion assembly and budding. Using this screen, we have demonstrated that a number of FDA-approved compounds developed for other purposes potently inhibit HIV-1 replication, including the cardiac glycosides. Our work indicates that the entire cardiac glycoside family of drugs shows potential for antiretroviral drug development.

  12. The QSAR and docking calculations of fullerene derivatives as HIV-1 protease inhibitors

    Science.gov (United States)

    Saleh, Noha A.

    2015-02-01

    The inhibition of HIV-1 protease is considered as one of the most important targets for drug design and the deactivation of HIV-1. In the present work, the fullerene surface (C60) is modified by adding oxygen atoms as well as hydroxymethylcarbonyl (HMC) groups to form 6 investigated fullerene derivative compounds. These compounds have one, two, three, four or five O atoms + HMC groups at different positions on phenyl ring. The effect of the repeating of these groups on the ability of suggested compounds to inhibit the HIV protease is studied by calculating both Quantitative Structure Activity Relationship (QSAR) properties and docking simulation. Based on the QSAR descriptors, the solubility and the hydrophilicity of studied fullerene derivatives increased with increasing the number of oxygen atoms + HMC groups in the compound. While docking calculations indicate that, the compound with two oxygen atoms + HMC groups could interact and binds with HIV-1 protease active site. This is could be attributed to the active site residues of HIV-1 protease are hydrophobic except the two aspartic acids. So that, the increase in the hydrophilicity and polarity of the compound is preventing and/or decreasing the hydrophobic interaction between the compound and HIV-1 protease active site.

  13. The inophyllums, novel inhibitors of HIV-1 reverse transcriptase isolated from the Malaysian tree, Calophyllum inophyllum Linn.

    Science.gov (United States)

    Patil, A D; Freyer, A J; Eggleston, D S; Haltiwanger, R C; Bean, M F; Taylor, P B; Caranfa, M J; Breen, A L; Bartus, H R; Johnson, R K

    1993-12-24

    As part of a search for novel inhibitors of HIV-1 reverse transcriptase, the acetone extract of the giant African snail, Achatina fulica, was shown to be active. Fractionation of the extract yielded inophyllums A, B, C, and E and calophyllolide (1a, 2a, 3a, 3b, and 6), previously isolated from Calophyllum inophyllum Linn., a known source of nutrition for A. fulica. From a methanol/methylene chloride extract of C. inophyllum, the same natural products in considerably greater yield were isolated in addition to a novel enantiomer of soulattrolide (4), inophyllum P (2b), and two other novel compounds, inophyllums G-1 (7) and G-2 (8). The absolute stereochemistry of inophyllum A (1a) was determined to be 10(R), 11(S), 12(S) from a single-crystal X-ray analysis of its 4-bromobenzoate derivative, and the relative stereochemistries of the other inophyllums isolated from C. inophyllum were established by a comparison of their 1H NMR NOE values and coupling constants to those of inophyllum A (1a). Inophyllums B and P (2a and 2b) inhibited HIV reverse transcriptase with IC50 values of 38 and 130 nM, respectively, and both were active against HIV-1 in cell culture (IC50 of 1.4 and 1.6 microM). Closely related inophyllums A, C, D, and E, including calophyllic acids, were significantly less active or totally inactive, indicating certain structural requirements in the chromanol ring. Altogether, 11 compounds of the inophyllum class were isolated from C. inophyllum and are described together with the SAR of these novel anti-HIV compounds.

  14. Protease inhibitor associated mutations compromise the efficacy of therapy in human immunodeficiency virus – 1 (HIV-1 infected pediatric patients: a cross-sectional study

    Directory of Open Access Journals (Sweden)

    Petrova Anna

    2007-07-01

    Full Text Available Abstract Background Although the introduction of combined therapy with reverse transcriptase and protease inhibitors has resulted in considerable decrease in HIV related mortality; it has also induced the development of multiple drug-resistant HIV-1 variants. The few studies on HIV-1 mutagenesis in HIV infected children have not evaluated the impact of HIV-1 mutations on the clinical, virological and immunological presentation of HIV disease that is fundamental to optimizing the treatment regimens for these patients. Results A cross sectional study was conducted to evaluate the impact of treatment regimens and resistance mutation patterns on the clinical, virological, and immunological presentation of HIV disease in 41 children (25 male and 16 female at the Robert Wood Johnson Pediatric AIDS Program in New Brunswick, New Jersey. The study participants were symptomatic and had preceding treatment history with combined ARV regimens including protease inhibitors (PIs, nucleoside reverse transcriptase inhibitors (NRTIs and non-nucleoside reverse transcriptase inhibitors (NNRTIs. Fifteen (36.6% children were treated with NRTI+NNRTI+ PI, 6 (14.6% with NRTI+NNRTIs, 13 (31.7% with NRTI+PIs, and the remaining 7 (17.1% received NRTIs only. Combined ARV regimens did not significantly influence the incidence of NRTI and NNRTI associated mutations. The duration of ARV therapy and the child's age had no significant impact on the ARV related mutations. The clinico-immunological presentation of the HIV disease was not associated with ARV treatment regimens or number of resistance mutations. However, primary mutations in the protease (PR gene increased the likelihood of plasma viral load (PVL ≥ 10,000 copies/mL irrespective of the child's age, duration of ARV therapy, presence of NRTI and NNRTI mutation. Viremia ≥ 10,000 copies/mL was recorded in almost all the children with primary mutations in the PR region (n = 12/13, 92.3% as compared with only 50.0% (n

  15. A trypsin inhibitor from rambutan seeds with antitumor, anti-HIV-1 reverse transcriptase, and nitric oxide-inducing properties.

    Science.gov (United States)

    Fang, Evandro Fei; Ng, Tzi Bun

    2015-04-01

    Nephelium lappaceum L., commonly known as "rambutan," is a typical tropical tree and is well known for its juicy and sweet fruit which has an exotic flavor. Chemical studies on rambutan have led to the identification of various components such as monoterpene lactones and volatile compounds. Here, a 22.5-kDa trypsin inhibitor (N . lappaceum trypsin inhibitor (NLTI)) was isolated from fresh rambutan seeds using liquid chromatographical techniques. NLTI reduced the proteolytic activities of both trypsin and α-chymotrypsin. Dithiothreitol reduced the trypsin inhibitory activity of NLTI at a concentration of 1 mM, indicating that an intact disulfide bond is essential to the activity. NLTI inhibited HIV-1 reverse transcriptase with an IC50 of 0.73 μM. In addition, NLTI manifested a time- and dose-dependent inhibitory effect on growth in many tumor cells. NLTI is one of the few trypsin inhibitors with nitric oxide-inducing activity and may find application in tumor therapy.

  16. Improving fold resistance prediction of HIV-1 against protease and reverse transcriptase inhibitors using artificial neural networks.

    Science.gov (United States)

    Sheik Amamuddy, Olivier; Bishop, Nigel T; Tastan Bishop, Özlem

    2017-08-15

    Drug resistance in HIV treatment is still a worldwide problem. Predicting resistance to antiretrovirals (ARVs) before starting any treatment is important. Prediction accuracy is essential, as low-accuracy predictions increase the risk of prescribing sub-optimal drug regimens leading to patients developing resistance sooner. Artificial Neural Networks (ANNs) are a powerful tool that would be able to assist in drug resistance prediction. In this study, we constrained the dataset to subtype B, sacrificing generalizability for a higher predictive performance, and demonstrated that the predictive quality of the ANN regression models have definite improvement for most ARVs. Trained regression ANNs were optimized for eight protease inhibitors, six nucleoside reverse transcriptase (RT) inhibitors and four non-nucleoside RT inhibitors by experimenting combinations of rare variant filtering (none versus 1 residue occurrence) and ANN topologies (1-3 hidden layers with 2, 4, 6, 8 and 10 nodes per layer). Single hidden layers (5-20 nodes) were used for training where overfitting was detected. 5-fold cross-validation produced mean R2 values over 0.95 and standard deviations lower than 0.04 for all but two antiretrovirals. Overall, higher accuracies and lower variances (compared to results published in 2016) were obtained by experimenting with various preprocessing methods, while focusing on the most prevalent subtype in the raw dataset (subtype B).We thus highlight the need to develop and make available subtype-specific datasets for developing higher accuracy in drug-resistance prediction methods.

  17. Substituted Bis-THF Protease Inhibitors with Improved Potency against Highly Resistant Mature HIV-1 Protease PR20.

    Science.gov (United States)

    Agniswamy, Johnson; Louis, John M; Shen, Chen-Hsiang; Yashchuk, Sofiya; Ghosh, Arun K; Weber, Irene T

    2015-06-25

    An extremely drug resistant mutant of HIV-1 protease (PR) bearing 20 mutations (PR20) has been studied with two potent antiviral investigational inhibitors. GRL-5010A and GRL-4410A were designed to introduce hydrogen bond interactions with the flexible flaps of the PR by incorporating gem-difluorines and alkoxy, respectively, at the C4 position of the bis-THF of darunavir. PR20 provides an excellent model for high level resistance, since clinical inhibitors are >1000-fold less active on PR20 than on wild-type enzyme. GRL-5010A and GRL-4410A show inhibition constants of 4.3 ± 7.0 and 1.7 ± 1.8 nM, respectively, for PR20, compared to the binding affinity of 41 ± 1 nM measured for darunavir. Crystal structures of PR20 in complexes with the two inhibitors confirmed the new hydrogen bond interactions with Gly 48 in the flap of the enzyme. The two new compounds are more effective than darunavir in inhibiting mature PR20 and show promise for further development of antiviral agents targeting highly resistant PR mutants.

  18. Clinical use of HIV integrase inhibitors: a systematic review and meta-analysis.

    Directory of Open Access Journals (Sweden)

    Peter Messiaen

    Full Text Available BACKGROUND: Optimal regimen choice of antiretroviral therapy is essential to achieve long-term clinical success. Integrase inhibitors have swiftly been adopted as part of current antiretroviral regimens. The purpose of this study was to review the evidence for integrase inhibitor use in clinical settings. METHODS: MEDLINE and Web-of-Science were screened from April 2006 until November 2012, as were hand-searched scientific meeting proceedings. Multiple reviewers independently screened 1323 citations in duplicate to identify randomized controlled trials, nonrandomized controlled trials and cohort studies on integrase inhibitor use in clinical practice. Independent, duplicate data extraction and quality assessment were conducted. RESULTS: 48 unique studies were included on the use of integrase inhibitors in antiretroviral therapy-naive patients and treatment-experienced patients with either virological failure or switching to integrase inhibitors while virologically suppressed. On the selected studies with comparable outcome measures and indication (n = 16, a meta-analysis was performed based on modified intention-to-treat (mITT, on-treatment (OT and as-treated (AT virological outcome data. In therapy-naive patients, favorable odds ratios (OR for integrase inhibitor-based regimens were observed, (mITT OR 0.71, 95% CI 0.59-0.86. However, integrase inhibitors combined with protease inhibitors only did not result in a significant better virological outcome. Evidence further supported integrase inhibitor use following virological failure (mITT OR 0.27; 95% CI 0.11-0.66, but switching to integrase inhibitors from a high genetic barrier drug during successful treatment was not supported (mITT OR 1.43; 95% CI 0.89-2.31. Integrase inhibitor-based regimens result in similar immunological responses compared to other regimens. A low genetic barrier to drug-resistance development was observed for raltegravir and elvitegravir, but not for dolutegravir

  19. Reported Church Attendance at the Time of Entry into HIV Care is Associated with Viral Load Suppression at 12 Months.

    Science.gov (United States)

    Van Wagoner, Nicholas; Elopre, Latesha; Westfall, Andrew O; Mugavero, Michael J; Turan, Janet; Hook, Edward W

    2016-08-01

    The Southeast has high rates of church attendance and HIV infection rates. We evaluated the relationship between church attendance and HIV viremia in a Southeastern US, HIV-infected cohort. Viremia (viral load ≥200 copies/ml) was analyzed 12 months after initiation of care. Univariate and multivariable logistic regression models were fit for variables potentially related to viremia. Of 382 patients, 74 % were virally suppressed at 12 months. Protective variables included church attendance (AOR 0.5; 95 % CI 0.2, 0.9), being on antiretroviral therapy (AOR 0.01; 95 % CI 0.004, 0.04), CD4(+) T lymphocyte count 200-350 cells/mm(3) at care entry (AOR 0.3; 95 % 0.1, 0.9), and education (AOR 0.5; 95 % CI 0.2, 0.9). Variables predicting viremia included black race (AOR 3.2; 95 % CI 1.4, 7.4) and selective disclosure of HIV status (AOR 2.7; 95 % CI 1.2, 5.6). Church attendance may provide needed support for patients entering HIV care for the first time. El Sur Este de los Estados Unidos tiene tasas altas de visitas a iglesias y de infección por VIH. Evaluamos la relación entre visitas a iglesias y viremia por VIH en una cohorte de pacientes infectados con VIH en el Sur Este de los EEUU. La viremia (carga viral ≥ 200 copias/ml) fue analizada a los 12 meses de iniciar el cuidado médico. Los modelos de regresión logística univariado y multivariado fueron ajustados para variables potencialmente relacionadas a viremia. De 382 pacientes, 75 % tuvieron supresión virológica a los 12 meses. Variables que ofrecieron protección fueron visitas a iglesias (AOR 0.5; IC95 % 0.2-0.9), recibir terapia antiretroviral (AOR 0.01; IC95 % 0.004,0.04), recuento de linfocitos T CD4 + 200-350 al iniciar cuidado médico (AOR 0.3; IC95 % 0.1,09), y educación (AOR 0.5; IC95 % 0.2,0.9). Las variables que predijeron viremia incluyeron raza negra (AOR 3.2; IC95 % 1.4,7.4) y la comunicación selectiva del diagnóstico de VIH a otras personas (AOR 2.7; 95 % IC 1

  20. HIV protease inhibitor use during pregnancy is associated with decreased progesterone levels, suggesting a potential mechanism contributing to fetal growth restriction.

    Science.gov (United States)

    Papp, Eszter; Mohammadi, Hakimeh; Loutfy, Mona R; Yudin, Mark H; Murphy, Kellie E; Walmsley, Sharon L; Shah, Rajiv; MacGillivray, Jay; Silverman, Michael; Serghides, Lena

    2015-01-01

    Protease inhibitor (PI)-based combination antiretroviral therapy (cART) is administered during pregnancy to prevent perinatal human immunodeficiency virus (HIV) transmission. However, PI use has been associated with adverse birth outcomes, including preterm delivery and small-for-gestational-age (SGA) births. The mechanisms underlying these outcomes are unknown. We hypothesized that PIs contribute to these adverse events by altering progesterone levels. PI effects on trophoblast progesterone production were assessed in vitro. A mouse pregnancy model was used to assess the impact of PI-based cART on pregnancy outcomes and progesterone levels in vivo. Progesterone levels were assessed in plasma specimens from 27 HIV-infected and 17 HIV-uninfected pregnant women. PIs (ritonavir, lopinavir, and atazanavir) but not nucleoside reverse transcriptase inhibitors (NRTIs) or nonnucleoside reverse transcriptase inhibitors reduced trophoblast progesterone production in vitro. In pregnant mice, PI-based cART but not dual-NRTI therapy was associated with significantly lower progesterone levels that directly correlated with fetal weight. Progesterone supplementation resulted in a significant improvement in fetal weight. We observed lower progesterone levels and smaller infants in HIV-infected women receiving PI-based cART, compared with the control group. In HIV-infected women, progesterone levels correlated significantly with birth weight percentile. Our data suggest that PI use in pregnancy may lead to lower progesterone levels that could contribute to adverse birth outcomes. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America.

  1. Comparative molecular field analysis (CoMFA), topomer CoMFA, and hologram QSAR studies on a series of novel HIV-1 protease inhibitors.

    Science.gov (United States)

    Heidari, Afsane; Fatemi, Mohammad H

    2017-06-01

    Comparative molecular field analysis (CoMFA), topomer CoMFA, and hologram QSAR as three efficient methods of QSAR have been performed on 40 newly synthesized inhibitors against HIV-1 protease. Molecular alignment was performed by aid of crystallographic structure of template inhibitor (indirect alignment) and also by the molecular mechanic (MM)-minimized structure. Both alignment methods produced satisfactory statistics for training set, but indirect alignment had more predictive power. Generated counter maps, especially by topomer CoMFA, give comprehensive information about structural features affecting the inhibitory activities of studied chemicals. Based on the obtained information, some new inhibitors were suggested. © 2016 John Wiley & Sons A/S.

  2. Enhancement of Probe Signal for Screening of HIV-1 Protease Inhibitors in Living Cells

    Directory of Open Access Journals (Sweden)

    Huantong Yao

    2012-12-01

    Full Text Available The global human immunodeficiency virus infection/acquired immuno-deficiency syndrome (HIV/AIDS epidemic is one of the biggest threats to human life. Mutation of the virus and toxicity of the existing drugs necessitate the development of new drugs for effective AIDS treatment. Previously, we developed a molecular probe that utilizes the Förster resonance energy transfer (FRET principle to visualize HIV-1 protease inhibition within living cells for drug screening. We explored using AcGFP1 (a fluorescent mutant of the wild-type green fluorescent protein as a donor and mCherry (a mutant of red fluorescent protein as an acceptor for FRET microscopy imaging measurement of HIV-1 protease activity within living cells and demonstrated that the molecular probe is suitable for the High-Content Screening (HCS of anti-HIV drugs through an automated FRET microscopy imaging measurement. In this study, we genetically engineered a probe with a tandem acceptor protein structure to enhance the probe’s signal. Both in vitro and in vivo studies revealed that the novel structure of the molecular probe exhibits a significant enhancement of FRET signals, reaching a probe FRET efficiency of 34%, as measured by fluorescence lifetime imaging microscopy (FLIM measurement. The probe developed herein would enable high-content screening of new anti-HIV agents.

  3. Interpatient variability in the pharmacokinetics of the HIV non-nucleoside reverse transcriptase inhibitor efavirenz: the effect of gender, race, and CYP2B6 polymorphism

    NARCIS (Netherlands)

    Burger, D.M.; Heiden, I. van der; Porte, C.J.L. la; Ende, M. van der; Groeneveld, P.; Richter, C.; Koopmans, P.; Kroon, F.; Sprenger, H.; Lindemans, J.; Schenk, P.; Schaik, R. van

    2006-01-01

    AIMS: To characterize the demographic and pharmacogenetic factors that influence interpatient variability in the plasma concentrations of the HIV non-nucleoside reverse transcriptase inhibitor efavirenz. METHODS: Data from all samples analyzed for efavirenz in our TDM service in 2002 and 2003 were

  4. Interpatient variability in the pharmacokinetics of the HIV non-nucleoside reverse transcriptase inhibitor efavirenz : the effect of gender, race, and CYP2B6 polymorphism

    NARCIS (Netherlands)

    Burger, D; van der Heiden, [No Value; la Porte, C; van der Ende, Marchina E.; Groeneveld, P; Richter, C; Koopmans, P; Sprenger, H; Lindemans, J; Schenk, P; van Schaik, R

    Aims To characterize the demographic and pharmacogenetic factors that influence interpatient variability in the plasma concentrations of the HIV non-nucleoside reverse transcriptase inhibitor efavirenz. Methods Data from all samples analyzed for efavirenz in our TDM service in 2002 and 2003 were

  5. Novel (2,6-difluorophenyl)(2-(phenylamino)pyrimidin-4-yl) methanones with restricted conformation as potent non-nucleoside reverse transcriptase inhibitors against HIV-1

    Czech Academy of Sciences Publication Activity Database

    Šimon, Petr; Baszczyňski, Ondřej; Šaman, David; Stepan, G.; Hu, E.; Lansdon, E. B.; Jansa, P.; Janeba, Zlatko

    2016-01-01

    Roč. 122, Oct 21 (2016), s. 185-195 ISSN 0223-5234 Institutional support: RVO:61388963 Keywords : diarylpyrimidine (DAPY) * etravirine * human immunodeficiency virus ( HIV ) * non-nucleoside reverse transcriptase inhibitors * NNRTIs * rilpivirine Subject RIV: CC - Organic Chemistry Impact factor: 4.519, year: 2016

  6. Dolutegravir Plus Two Nucleoside Reverse Transcriptase Inhibitors versus Efavirenz Plus Two Nucleoside Reverse Transcriptase Inhibitors As Initial Antiretroviral Therapy for People with HIV: A Systematic Review.

    Directory of Open Access Journals (Sweden)

    George W Rutherford

    Full Text Available Dolutegravir (DTG is a once-daily unboosted second-generation integrase-inhibitor that along with two nucleoside reverse transcriptase inhibitors is one of several regimens recommended by the United States, United Kingdom and European Union for first-line antiretroviral treatment of people with HIV infection. Our objective was to review the evidence for the efficacy and safety of DTG-based first-line regimens compared to efavirenz (EFV-based regimens.We conducted a systematic review. We comprehensively searched a range of databases as well as conference abstracts and a trials registry. We used Cochrane methods in screening and data collection and assessed each study's risk of bias with the Cochrane tool. We meta-analyzed data using a fixed-effects model. We used GRADE to assess evidence quality.From 492 search results, we identified two randomized controlled trials, reported in five peer-reviewed articles and one conference abstract. One trial tested two DTG-based regimens (DTG + abacavir (ABC + lamivudine (3TC or DTG + tenofovir + emtricitabine against an EFV-based regimen (EFV+ ABC+3TC. The other trial tested DTG+ABC+3TC against EFV+ABC+3TC. In meta-analysis, DTG-containing regimens were superior to EFV-containing regimens at 48 weeks and at 96 weeks (RR = 1.10, 95% CI 1.04-1.16; and RR = 1.12, 95% CI 1.04-1.21, respectively. In one trial, the DTG-containing regimen was superior at 144 weeks (RR = 1.13, 95% CI 1.02-1.24. DTG-containing regimens were superior in reducing treatment discontinuation compared to those containing EFV at 96 weeks and at 144 weeks (RR = 0.27, 95% CI 0.15-0.50; and RR = 0.28, 95% CI 0.16-0.48, respectively. Risk of serious adverse events was similar in each regimen at 96 weeks (RR = 1.15, 95% CI 0.80-1.63 and 144 weeks (RR = 0.93, 95% CI 0.68-1.29. Risk of bias was moderate overall, as was GRADE evidence quality.DTG-based regimens should be considered in future World Health Organization guidelines for initial HIV

  7. Factors Associated with the Development of Drug Resistance Mutations in HIV-1 Infected Children Failing Protease Inhibitor-Based Antiretroviral Therapy in South Africa.

    Directory of Open Access Journals (Sweden)

    Theresa M Rossouw

    Full Text Available Limited data are available from the developing world on antiretroviral drug resistance in HIV-1 infected children failing protease inhibitor-based antiretroviral therapy, especially in the context of a high tuberculosis burden. We describe the proportion of children with drug resistance mutations after failed protease inhibitor-based antiretroviral therapy as well as associated factors.Data from children initiated on protease inhibitor-based antiretroviral therapy with subsequent virological failure referred for genotypic drug resistance testing between 2008 and 2012 were retrospectively analysed. Frequencies of drug resistance mutations were determined and associations with these mutations identified through logistic regression analysis.The study included 65 young children (median age 16.8 months [IQR 7.8; 23.3] with mostly advanced clinical disease (88.5% WHO stage 3 or 4 disease, severe malnutrition (median weight-for-age Z-score -2.4 [IQR -3.7;-1.5]; median height-for-age Z-score -3.1 [IQR -4.3;-2.4], high baseline HIV viral load (median 6.04 log10, IQR 5.34;6.47 and frequent tuberculosis co-infection (66% at antiretroviral therapy initiation. Major protease inhibitor mutations were found in 49% of children and associated with low weight-for-age and height-for-age (p = 0.039; p = 0.05; longer duration of protease inhibitor regimens and virological failure (p = 0.001; p = 0.005; unsuppressed HIV viral load at 12 months of antiretroviral therapy (p = 0.001; tuberculosis treatment at antiretroviral therapy initiation (p = 0.048 and use of ritonavir as single protease inhibitor (p = 0.038. On multivariate analysis, cumulative months on protease inhibitor regimens and use of ritonavir as single protease inhibitor remained significant (p = 0.008; p = 0.033.Major protease inhibitor resistance mutations were common in this study of HIV-1-infected children, with the timing of tuberculosis treatment and subsequent protease inhibitor dosing strategy

  8. High-performance liquid chromatography assay for the quantification of HIV protease inhibitors and non-nucleoside reverse transcriptase inhibitors in human plasma.

    Science.gov (United States)

    Rezk, Naser L; Tidwell, Richard R; Kashuba, Angela D M

    2004-06-15

    An accurate, sensitive, and specific reverse-phase high-performance liquid chromatography (HPLC) assay for the simultaneous quantitative determination of HIV-protease inhibitors (PIs) (indinavir, IDV; amprenavir, APV; saquinavir, SQV; nelfinavir, NFV; ritonavir, RTV; and lopinavir, LPV) and non-nucleoside reverse transcriptase inhibitors (NNRTIs) (nevirapine, NVP; delavirdine, DLV; and efavirenz, EFV) in human blood plasma is described. The method provides excellent resolution and peak shape for nine analytes through a linear gradient (36-86%) of 25% phosphate buffer (pH 4.5), 60% acetonitrile, 15% methanol, and 0.75 ml TFA, with a gradient mobile phase flow rate (0.9-1.1 ml) over 30 min run time. The optimized solid phase extraction (SPE) extraction method using (1.0 ml, 100mg BOND ELUT-C18 Varian) column provides a clean base line and high extraction efficiency using a 550 microl plasma sample. The method was validated over the range of 10-10,000 ng/ml for NVP, IDV, and SQV; 10-5000 ng/ml for EFV; 25-10000 ng/ml for APV; and 25-5000 ng/ml for DLV, NFV, RTV, and LPV. This method is accurate (average accuracies of three different concentrations ranged from 91 to 112%), and precise (within- and between-day precision measures ranged from 0.2 to 5.7% and 0.1 to 5.4%, respectively). This method is suitable for use in clinical pharmacokinetic studies as well as in therapeutic drug monitoring (TDM).

  9. HIV-1 protease inhibitors do not interfere with provirus transcription and host cell apoptosis induced by combined treatment TNF-alpha + TSA.

    Science.gov (United States)

    Vandergeeten, Claire; Quivy, Vincent; Moutschen, Michel; Van Lint, Carine; Piette, Jacques; Legrand-Poels, Sylvie

    2007-06-01

    HIV-1 latency represents a major hurdle to the complete eradication of the virus from patients under highly active anti-retroviral therapy (HAART) regimens. One solution to this problem would be to eliminate the latently infected cellular reservoirs by forcing gene expression in presence of HAART to prevent spreading of the infection by the newly synthesized viruses. Many studies have reported that a combination of a histone deacetylase inhibitor (HDACi) (i.e. TSA, NaBut, Valproic acid, ...) with a pro-inflammatory cytokine (i.e. TNFalpha, IL-1, ...) reactivates in a synergistic manner HIV-1 transcription in latently infected cells. The aim of the present study was to determine whether HIV-1 protease inhibitors (PIs) used in HAART (such as Saquinavir, Indinavir, Nelfinavir, Lopinavir, Ritonavir and Amprenavir) could interfere with the potential purge of the cellular reservoirs induced by a combined treatment involving TSA and TNFalpha. We showed, in two HIV-1 latently infected cell lines (ACH-2 and U1) that all PIs efficiently inhibited release of mature viral particles but did neither affect cell apoptosis nor NF-kappaB induction and HIV-1 transcription activation following combined treatment with TNFalpha+TSA. This study is encouraging in the fight against HIV-1 and shows that PIs should be compatible with an inductive adjuvent therapy for latent reservoir reduction/elimination in association with efficient HAART regimens.

  10. A Novel Bromodomain Inhibitor Reverses HIV-1 Latency through Specific Binding with BRD4 to Promote Tat and P-TEFb Association

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    Huachao Huang

    2017-06-01

    Full Text Available While combinatory antiretroviral therapy (cART can effectively reduce HIV-1 viremia, it cannot eliminate HIV-1 infection. In the presence of cART, viral reservoirs remain latent, impeding the cure of HIV-1/AIDS. Recently, latency-reversing agents (LRAs have been developed with the intent of purging latent HIV-1, providing an intriguing strategy for the eradication of the residual viral reservoirs. Our earlier studies show that the first-generation, methyl-triazolo bromodomain, and extra-terminal domain inhibitor (BETi, JQ1, facilitates the reversal of HIV-1 latency. BETis have emerged as a new class of compounds that are promising for this HIV-1 “shock and kill” eradication approach. However, when used as a single drug, JQ1 only modestly reverses HIV-1 latency, which complicates studying the underlining mechanisms. Meanwhile, it has been widely discussed that the induction of latent proviruses is stochastic (Ho et al., 2013. Thus, new BETis are currently under active development with focus on improving potency, ease of synthesis and structural diversity. Using fluorous-tagged multicomponent reactions, we developed a novel second-generation, 3,5-dimethylisoxazole BETi based on an imidazo[1,2-a] pyrazine scaffold, UMB-32. Furthermore, we screened 37 UMB-32 derivatives and identified that one, UMB-136, reactivates HIV-1 in multiple cell models of HIV-1 latency with better efficiency than either JQ1 or UMB-32. UMB-136 enhances HIV-1 transcription and increases viral production through the release of P-TEFb. Importantly, UMB-136 enhances the latency-reversing effects of PKC agonists (prostratin, bryostatin-1 in CD8-depleted PBMCs containing latent viral reservoirs. Our results illustrate that structurally improved BETis, such as UMB-136, may be useful as promising LRAs for HIV-1 eradication.

  11. Synthesis of Novel Uracil Non-Nucleoside Derivatives as Potential Reverse Transcriptase Inhibitors of HIV-1

    DEFF Research Database (Denmark)

    El-Brollosy, Nasser R.; Al-Deeb, Omar. A.; El-Emam, Ali A.

    2009-01-01

    with cyclopropylmethyloxymethyl 9a-d, 2-phenylethyloxymethyl 9e-h, and 3-phenylprop-1-yloxymethyl 9i-l were prepared on treatment of the corresponding uracils with the appropriate acetals 8a-c. Some of the tested compounds showed good activity against HIV-1 wild type. Among them, 1-cyclopropylmethyloxymethyl-5-ethyl-6......-(3,5-dimethylbenzyl)uracil 9c and 5-ethyl-6-(3,5-dimethylbenzyl)-1-(2-phenylethyloxymethyl)uracil 9g showed inhibitory potency equally to emivirine against HIV-1 wild type. Furthermore, compounds 9c and 9g showed marginal better activity against NNRTI resistant mutants than emivirine....

  12. Conversion of the HIV protease inhibitor nelfinavir to a bioactive metabolite by human liver CYP2C19.

    Science.gov (United States)

    Hirani, Vandana N; Raucy, Judy L; Lasker, Jerome M

    2004-12-01

    Antiretroviral therapy for human immunodeficiency virus (HIV) infection includes treatment with both reverse transcriptase inhibitors and protease inhibitors, which markedly suppress viral replication and circulating HIV RNA levels. Cytochrome P450 (P450) enzymes in human liver, chiefly CYP3A4, play a pivotal role in protease inhibitor biotransformation, converting these agents to largely inactive metabolites. However, the protease inhibitor nelfinavir (Viracept) is metabolized mainly to nelfinavir hydroxy-t-butylamide (M8), which exhibits potent antiviral activity, and to other minor products (termed M1 and M3) that are inactive. Since indirect evidence suggests that CYP2C19 underlies M8 formation, we examined the role of this inducible, polymorphic P450 enzyme in nelfinavir t-butylamide hydroxylation by human liver. Rates of microsomal M8 formation were 50.6 +/- 28.3 pmol of product formed/min/nmol P450 (n = 5 subjects), whereas kinetic analysis of the reaction revealed a KM of 21.6 microM and a Vmax of 24.6 pmol/min/nmol P450. In reconstituted systems, CYP2C19 catalyzed nelfinavir t-butylamide hydroxylation at a turnover rate of 2.2 min(-1), whereas CYP2C9, CYP2C8, and CYP3A4 were inactive toward nelfinavir. Polyclonal anti-CYP2C9 (cross-reactive with CYP2C19) and monoclonal anti-CYP2C19 completely inhibited microsomal M8 production, whereas monoclonal CYP2C9 and polyclonal CYP3A4 antibodies were without effect. Similarly, the CYP2C19 substrate omeprazole strongly inhibited (75%) hepatic nelfinavir t-butylamide hydroxylation at a concentration of only 12.5 microM. Our study shows that CYP2C19 underlies formation in human liver of M8, a bioactive nelfinavir metabolite. The inducibility of CYP2C19 by agents (e.g., rifampicin) often taken concurrently with nelfinavir, together with this P450's known polymorphic nature, may thus be important determinants of nelfinavir's antiviral potency.

  13. Design of gem-difluoro-bis-tetrahydrofuran as P2 ligand for HIV-1 protease inhibitors to improve brain penetration: synthesis, X-ray studies, and biological evaluation.

    Science.gov (United States)

    Ghosh, Arun K; Yashchuk, Sofiya; Mizuno, Akira; Chakraborty, Nilanjana; Agniswamy, Johnson; Wang, Yuan-Fang; Aoki, Manabu; Gomez, Pedro Miguel Salcedo; Amano, Masayuki; Weber, Irene T; Mitsuya, Hiroaki

    2015-01-01

    The structure-based design, synthesis, biological evaluation, and X-ray structural studies of fluorine-containing HIV-1 protease inhibitors are described. The synthesis of both enantiomers of the gem-difluoro-bis-THF ligands was carried out in a stereoselective manner using a Reformatskii-Claisen reaction as the key step. Optically active ligands were converted into protease inhibitors. Two of these inhibitors, (3R,3aS,6aS)-4,4-difluorohexahydrofuro[2,3-b]furan-3-yl(2S,3R)-3-hydroxy-4-((N-isobutyl-4-methoxyphenyl)sulfonamido)-1-phenylbutan-2-yl) carbamate (3) and (3R,3aS,6aS)-4,4-difluorohexahydrofuro[2,3-b]furan-3-yl(2S,3R)-3-hydroxy-4-((N-isobutyl-4-aminophenyl)sulfonamido)phenylbutan-2-yl) carbamate (4), exhibited HIV-1 protease inhibitory Ki values in the picomolar range. Both 3 and 4 showed very potent antiviral activity, with respective EC50 values of 0.8 and 3.1 nM against the laboratory strain HIV-1LAI . The two inhibitors exhibited better lipophilicity profiles than darunavir, and also showed much improved blood-brain barrier permeability in an in vitro model. A high-resolution X-ray structure of inhibitor 4 in complex with HIV-1 protease was determined, revealing that the fluorinated ligand makes extensive interactions with the S2 subsite of HIV-1 protease, including hydrogen bonding interactions with the protease backbone atoms. Moreover, both fluorine atoms on the bis-THF ligand formed strong interactions with the flap Gly 48 carbonyl oxygen atom. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. GRL-09510, a Unique P2-Crown-Tetrahydrofuranylurethane -Containing HIV-1 Protease Inhibitor, Maintains Its Favorable Antiviral Activity against Highly-Drug-Resistant HIV-1 Variants in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Amano, Masayuki; Miguel Salcedo-Gómez, Pedro; Yedidi, Ravikiran S.; Delino, Nicole S.; Nakata, Hirotomo; Venkateswara Rao, Kalapala; Ghosh, Arun K.; Mitsuya, Hiroaki

    2017-09-25

    We report that GRL-09510, a novel HIV-1 protease inhibitor (PI) containing a newly-generated P2-crown-tetrahydrofuranylurethane (Crwn-THF), a P2'-methoxybenzene, and a sulfonamide isostere, is highly active against laboratory and primary clinical HIV-1 isolates (EC50: 0.0014–0.0028 μM) with minimal cytotoxicity (CC50: 39.0 μM). Similarly, GRL-09510 efficiently blocked the replication of HIV-1NL4-3 variants, which were capable of propagating at high-concentrations of atazanavir, lopinavir, and amprenavir (APV). GRL-09510 was also potent against multi-drug-resistant clinical HIV-1 variants and HIV-2ROD. Under the selection condition, where HIV-1NL4-3 rapidly acquired significant resistance to APV, an integrase inhibitor raltegravir, and a GRL-09510 congener (GRL-09610), no variants highly resistant against GRL-09510 emerged over long-term in vitro passage of the virus. Crystallographic analysis demonstrated that the Crwn-THF moiety of GRL-09510 forms strong hydrogen-bond-interactions with HIV-1 protease (PR) active-site amino acids and is bulkier with a larger contact surface, making greater van der Waals contacts with PR than the bis-THF moiety of darunavir. The present data demonstrate that GRL-09510 has favorable features for treating patients infected with wild-type and/or multi-drug-resistant HIV-1 variants, that the newly generated P2-Crwn-THF moiety confers highly desirable anti-HIV-1 potency. The use of the novel Crwn-THF moiety sheds lights in the design of novel PIs.

  15. BST2/Tetherin enhances entry of human cytomegalovirus.

    Directory of Open Access Journals (Sweden)

    Kasinath Viswanathan

    2011-11-01

    Full Text Available Interferon-induced BST2/Tetherin prevents budding of vpu-deficient HIV-1 by tethering mature viral particles to the plasma membrane. BST2 also inhibits release of other enveloped viruses including Ebola virus and Kaposi's sarcoma associated herpesvirus (KSHV, indicating that BST2 is a broadly acting antiviral host protein. Unexpectedly however, recovery of human cytomegalovirus (HCMV from supernatants of BST2-expressing human fibroblasts was increased rather than decreased. Furthermore, BST2 seemed to enhance viral entry into cells since more virion proteins were released into BST2-expressing cells and subsequent viral gene expression was elevated. A significant increase in viral entry was also observed upon induction of endogenous BST2 during differentiation of the pro-monocytic cell line THP-1. Moreover, treatment of primary human monocytes with siRNA to BST2 reduced HCMV infection, suggesting that BST2 facilitates entry of HCMV into cells expressing high levels of BST2 either constitutively or in response to exogenous stimuli. Since BST2 is present in HCMV particles we propose that HCMV entry is enhanced via a reverse-tethering mechanism with BST2 in the viral envelope interacting with BST2 in the target cell membrane. Our data suggest that HCMV not only counteracts the well-established function of BST2 as inhibitor of viral egress but also employs this anti-viral protein to gain entry into BST2-expressing hematopoietic cells, a process that might play a role in hematogenous dissemination of HCMV.

  16. Measuring enzymatic HIV-1 susceptibility to two reverse transcriptase inhibitors as a rapid and simple approach to HIV-1 drug-resistance testing.

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    Dieter Hoffmann

    Full Text Available Simple and cost-effective approaches for HIV drug-resistance testing are highly desirable for managing increasingly expanding HIV-1 infected populations who initiate antiretroviral therapy (ART, particularly in resource-limited settings. Non-nucleoside reverse trancriptase inhibitor (NNRTI-based regimens with an NRTI backbone containing lamivudine (3TC or emtricitabine (FTC are preferred first ART regimens. Failure with these drug combinations typically involves the selection of NNRTI- and/or 3TC/FTC-resistant viruses. Therefore, the availability of simple assays to measure both types of drug resistance is critical. We have developed a high throughput screening test for assessing enzymatic resistance of the HIV-1 RT in plasma to 3TC/FTC and NNRTIs. The test uses the sensitive "Amp-RT" assay with a newly-developed real-time PCR format to screen biochemically for drug resistance in single reactions containing either 3TC-triphosphate (3TC-TP or nevirapine (NVP. Assay cut-offs were defined based on testing a large panel of subtype B and non-subtype B clinical samples with known genotypic profiles. Enzymatic 3TC resistance correlated well with the presence of M184I/V, and reduced NVP susceptibility was strongly associated with the presence of K103N, Y181C/I, Y188L, and G190A/Q. The sensitivity and specificity for detecting resistance were 97.0% and 96.0% in samples with M184V, and 97.4% and 96.2% for samples with NNRTI mutations, respectively. We further demonstrate the utility of an HIV capture method in plasma by using magnetic beads coated with CD44 antibody that eliminates the need for ultracentifugation. Thus our results support the use of this simple approach for distinguishing WT from NNRTI- or 3TC/FTC-resistant viruses in clinical samples. This enzymatic testing is subtype-independent and can assist in the clinical management of diverse populations particularly in resource-limited settings.

  17. Alterations in the Notch4 pathway in cerebral endothelial cells by the HIV aspartyl protease inhibitor, nelfinavir

    Directory of Open Access Journals (Sweden)

    Chao Ying

    2008-02-01

    Full Text Available Abstract Background Aspartyl protease inhibitors (PIs used to treat HIV belong to an important group of drugs that influence significantly endothelial cell functioning and angiogenic capacity, although specific mechanisms are poorly understood. Recently, PIs, particularly Nelfinavir, were reported to disrupt Notch signaling in the HIV-related endothelial cell neoplasm, Kaposi's sarcoma. Given the importance of maintaining proper cerebral endothelial cell signaling at the blood brain barrier during HIV infection, we considered potential signaling pathways such as Notch, that may be vulnerable to dysregulation during exposure to PI-based anti-retroviral regimens. Notch processing by γ-secretase results in cleavage of the notch intracellular domain that travels to the nucleus to regulate expression of genes such as vascular endothelial cell growth factor and NFκB that are critical in endothelial cell functioning. Since, the effects of HIV PIs on γ-secretase substrate pathways in cerebral endothelial cell signaling have not been addressed, we sought to determine the effects of HIV PIs on Notch and amyloid precursor protein. Results Exposure to reported physiological levels of Saquinavir, Indinavir, Nelfinavir and Ritonavir, significantly increased reactive oxygen species in cerebral endothelial cells, but had no effect on cell survival. Likewise, PIs decreased Notch 4-protein expression, but had no effect on Notch 1 or amyloid precursor protein expression. On the other hand, only Nelfinavir increased significantly Notch 4 processing, Notch4 intracellular domain nuclear localization and the expression of notch intracellular domain targets NFκB and matrix metalloproteinase 2. Pre-treatment with the antioxidant Vitamin E prevented PI-induced reactive oxygen species generation and partially prevented Nelfinavir-induced changes in both Notch 4 processing, and cellular localization patterns. Moreover, in support of increased expression of pro

  18. Molecular electrostatic potentials as input for the alignment of HIV-1 integrase inhibitors in 3D QSAR

    Science.gov (United States)

    Makhija, Mahindra T.; Kulkarni, Vithal M.

    2001-11-01

    Comparative molecular similarity indices analysis (CoMSIA), a three-dimensional quantitative structure activity relationship (3D QSAR) paradigm, was used to examine the correlations between the calculated physicochemical properties and the in vitro activities (3'-processing and 3'-strand transfer inhibition) of a series of human immunodeficiency virus type 1 (HIV-1) integrase inhibitors. The training set consisted of 34 molecules from five structurally diverse classes: salicylpyrazolinones, dioxepinones, coumarins, quinones, and benzoic hydrazides. The data set was aligned using extrema of molecular electrostatic potentials (MEPs). The predictive ability of the resultant model was evaluated using a test set comprised of 7 molecules belonging to a different structural class of thiazepinediones. A CoMSIA model using an MEP-based alignment showed considerable internal as well external predictive ability ( r 2 cv=0.821, r 2 pred.=0.608 for 3'-processing; and r 2 cv=0.759, r 2 pred.=0.660 for 3'-strand transfer).

  19. The Novel Cyclophilin Inhibitor CPI-431-32 Concurrently Blocks HCV and HIV-1 Infections via a Similar Mechanism of Action.

    Directory of Open Access Journals (Sweden)

    Philippe A Gallay

    Full Text Available HCV-related liver disease is the main cause of morbidity and mortality of HCV/HIV-1 co-infected patients. Despite the recent advent of anti-HCV direct acting antivirals (DAAs, the treatment of HCV/HIV-1 co-infected patients remains a challenge, as these patients are refractory to most therapies and develop liver fibrosis, cirrhosis and liver cancer more often than HCV mono-infected patients. Until the present study, there was no suitable in vitro assay to test the inhibitory activity of drugs on HCV/HIV-1 co-infection. Here we developed a novel in vitro "co-infection" model where HCV and HIV-1 concurrently replicate in their respective main host target cells--human hepatocytes and CD4+ T-lymphocytes. Using this co-culture model, we demonstrate that cyclophilin inhibitors (CypI, including a novel cyclosporin A (CsA analog, CPI-431-32, simultaneously inhibits replication of both HCV and HIV-1 when added pre- and post-infection. In contrast, the HIV-1 protease inhibitor nelfinavir or the HCV NS5A inhibitor daclatasvir only blocks the replication of a single virus in the "co-infection" system. CPI-431-32 efficiently inhibits HCV and HIV-1 variants, which are normally resistant to DAAs. CPI-431-32 is slightly, but consistently more efficacious than the most advanced clinically tested CypI--alisporivir (ALV--at interrupting an established HCV/HIV-1 co-infection. The superior antiviral efficacy of CPI-431-32 over ALV correlates with its higher potency inhibition of cyclophilin A (CypA isomerase activity and at preventing HCV NS5A-CypA and HIV-1 capsid-CypA interactions known to be vital for replication of the respective viruses. Moreover, we obtained evidence that CPI-431-32 prevents the cloaking of both the HIV-1 and HCV genomes from cellular sensors. Based on these results, CPI-431-32 has the potential, as a single agent or in combination with DAAs, to inhibit both HCV and HIV-1 infections.

  20. 3D-QSAR and molecular docking studies on HIV protease inhibitors

    Science.gov (United States)

    Tong, Jianbo; Wu, Yingji; Bai, Min; Zhan, Pei

    2017-02-01

    In order to well understand the chemical-biological interactions governing their activities toward HIV protease activity, QSAR models of 34 cyclic-urea derivatives with inhibitory HIV were developed. The quantitative structure activity relationship (QSAR) model was built by using comparative molecular similarity indices analysis (CoMSIA) technique. And the best CoMSIA model has rcv2, rncv2 values of 0.586 and 0.931 for cross-validated and non-cross-validated. The predictive ability of CoMSIA model was further validated by a test set of 7 compounds, giving rpred2 value of 0.973. Docking studies were used to find the actual conformations of chemicals in active site of HIV protease, as well as the binding mode pattern to the binding site in protease enzyme. The information provided by 3D-QSAR model and molecular docking may lead to a better understanding of the structural requirements of 34 cyclic-urea derivatives and help to design potential anti-HIV protease molecules.

  1. Sequence-Based Predictive Models of Resistance to HIV-1 Integrase Inhibitors: An n-Grams Approach to Phenotype Assessment.

    Science.gov (United States)

    Masso, Majid

    2015-01-01

    Amino acid substitutions in HIV-1 proteins critical to the viral replication cycle have the potential to undermine successful inhibition of those targets, with some mutations leading to either reduced susceptibility to certain medications or complete drug resistance. Phenotypic tests are best suited to quantify the effects of complex mutational patterns on drug resistance; however, the relatively high cost and long turnaround time associated with phenotyping has increased the demand for in silico drug-specific models capable of accurately predicting phenotype directly from the target protein sequences. The focus of this study is on the HIV-1 integrase (IN) enzyme, which mediates integration of reversibly transcribed viral DNA into the host cell genome, and the development of predictive statistical learning models of resistance to the IN inhibitors Raltegravir (RAL) and Elvitegravir (EVG). Models were trained using datasets of IN protein sequence variants each having a known phenotype, quantified as the fold change in susceptibility to the respective inhibitor, and obtained using an experimental assay. A sequence-based approach employing n-grams relative frequencies was implemented to uniquely characterize each IN variant as a feature vector of input attributes. Models for classifying IN variants as susceptible or resistant reach cross-validation balanced accuracy rates of 89% with RAL and 85% with EVG. Additionally, regression models achieve Pearson's correlation coefficients, between experimental and predicted log-transformed phenotypic fold change values, as high as r = 0.80 with RAL and r = 0.76 with EVG. Our results suggest that as additional training data are made publicly available, the models may hold promise as supplementary tools for making treatment decisions.

  2. Inhibition of the ribonuclease H activity of HIV-1 reverse transcriptase by GSK5750 correlates with slow enzyme-inhibitor dissociation.

    Science.gov (United States)

    Beilhartz, Greg L; Ngure, Marianne; Johns, Brian A; DeAnda, Felix; Gerondelis, Peter; Götte, Matthias

    2014-06-06

    Compounds that efficiently inhibit the ribonuclease (RNase) H activity of the human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) have yet to be developed. Here, we demonstrate that GSK5750, a 1-hydroxy-pyridopyrimidinone analog, binds to the enzyme with an equilibrium dissociation constant (K(d)) of ~400 nM. Inhibition of HIV-1 RNase H is specific, as DNA synthesis is not affected. Moreover, GSK5750 does not inhibit the activity of Escherichia coli RNase H. Order-of-addition experiments show that GSK5750 binds to the free enzyme in an Mg(2+)-dependent fashion. However, as reported for other active site inhibitors, binding of GSK5750 to a preformed enzyme-substrate complex is severely compromised. The bound nucleic acid prevents access to the RNase H active site, which represents a possible biochemical hurdle in the development of potent RNase H inhibitors. Previous studies suggested that formation of a complex with the prototypic RNase H inhibitor β-thujaplicinol is slow, and, once formed, it dissociates rapidly. This unfavorable kinetic behavior can limit the potency of RNase H active site inhibitors. Although the association kinetics of GSK5750 remains slow, our data show that this compound forms a long lasting complex with HIV-1 RT. We conclude that slow dissociation of the inhibitor and HIV-1 RT improves RNase H active site inhibitors and may circumvent the obstacle posed by the inability of these compounds to bind to a preformed enzyme-substrate complex. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  3. Computational Analysis of Molecular Interaction Networks Underlying Change of HIV-1 Resistance to Selected Reverse Transcriptase Inhibitors.

    Science.gov (United States)

    Kierczak, Marcin; Dramiński, Michał; Koronacki, Jacek; Komorowski, Jan

    2010-12-12

    Despite more than two decades of research, HIV resistance to drugs remains a serious obstacle in developing efficient AIDS treatments. Several computational methods have been developed to predict resistance level from the sequence of viral proteins such as reverse transcriptase (RT) or protease. These methods, while powerful and accurate, give very little insight into the molecular interactions that underly acquisition of drug resistance/hypersusceptibility. Here, we attempt at filling this gap by using our Monte Carlo feature selection and interdependency discovery method (MCFS-ID) to elucidate molecular interaction networks that characterize viral strains with altered drug resistance levels. We analyzed a number of HIV-1 RT sequences annotated with drug resistance level using the MCFS-ID method. This let us expound interdependency networks that characterize change of drug resistance to six selected RT inhibitors: Abacavir, Lamivudine, Stavudine, Zidovudine, Tenofovir and Nevirapine. The networks consider interdependencies at the level of physicochemical properties of mutating amino acids, eg,: polarity. We mapped each network on the 3D structure of RT in attempt to understand the molecular meaning of interacting pairs. The discovered interactions describe several known drug resistance mechanisms and, importantly, some previously unidentified ones. Our approach can be easily applied to a whole range of problems from the domain of protein engineering. A portable Java implementation of our MCFS-ID method is freely available for academic users and can be obtained at: http://www.ipipan.eu/staff/m.draminski/software.htm.

  4. Bringing research into a first semester organic chemistry laboratory with the multistep synthesis of carbohydrate-based HIV inhibitor mimics.

    Science.gov (United States)

    Pontrello, Jason K

    2015-01-01

    Benefits of incorporating research experiences into laboratory courses have been well documented, yet examples of research projects designed for the first semester introductory organic chemistry lab course are extremely rare. To address this deficiency, a Carbohydrate-Based human immunodeficiency virus (HIV) Inhibitor project consisting of a synthetic scheme of four reactions was developed for and implemented in the first semester organic lab. Students carried out the synthetic reactions during the last 6 of 10 total labs in the course, generating carbohydrate-based dimeric target molecules modeled after published dimers with application in HIV therapy. The project was designed to provide a research experience through use of literature procedures for reactions performed, exploration of variation in linker length in the target structure, and synthesis of compounds not previously reported in the scientific literature. Project assessment revealed strong student support, indicating enhanced engagement and interest in the course as a direct result of the use of scientific literature and the applications of the synthesized carbohydrate-based molecules. Regardless of discussed challenges in designing a research project for the first semester lab course, the finding from data analysis that a project implemented in the first semester lab had significantly greater student impact than a second semester project should provide motivation for development of additional research projects for a first semester organic course. © 2015 The International Union of Biochemistry and Molecular Biology.

  5. Docking and 3-D QSAR studies on the binding of tetrahydropyrimid-2-one HIV-1 protease inhibitors

    Science.gov (United States)

    Rao, Shashidhar N.; Balaji, Govardhan A.; Balaji, Vitukudi N.

    2013-06-01

    We present molecular docking and 3-D QSAR studies on a series of tetrahydropyrimid-2-one HIV-1 protease inhibitors whose binding affinities to the enzyme span nearly 6 orders of magnitude. The docking investigations have been carried out with Surflex (GEOM, GEOMX) and Glide (SP and XP) methodologies available through Tripos and Schrodinger suite of tools in the context of Sybyl-X and Maestro interfaces, respectively. The alignments for 3-D QSAR studies were obtained by using the automated Surflex-SIM methodology in Sybyl-X and the analyses were performed using the CoMFA and CoMSIA methods. Additionally, the top-ranked poses obtained from various docking protocols were also employed to generate CoMFA and CoMSIA models to evaluate the qualitative consistency of the docked models with experimental data. Our studies demonstrate that while there are a number of common features in the docked models obtained from Surflex-dock and Glide methodologies, the former sets of models are generally better correlated with deduced experimental binding modes based on the X-ray structures of known HIV-1 protease complexes with cyclic ureas. The urea moiety common to all the ligands are much more tightly aligned in Surflex docked structures than in the models obtained from Glide SP and XP dockings. The 3-D QSAR models are qualitatively and quantitatively similar to those previously reported, suggesting the utility of automatically generated alignments from Surflex-SIM methodology.

  6. Beneficial Effects of HIV Peptidase Inhibitors on Fonsecaea pedrosoi: Promising Compounds to Arrest Key Fungal Biological Processes and Virulence

    Science.gov (United States)

    Palmeira, Vanila F.; Kneipp, Lucimar F.; Rozental, Sonia; Alviano, Celuta S.; Santos, André L. S.

    2008-01-01

    Background Fonsecaea pedrosoi is the principal etiologic agent of chromoblastomycosis, a fungal disease whose pathogenic events are poorly understood. Current therapy for chromoblastomycosis is suboptimal due to toxicity of the available therapeutic agents and the emergence of drug resistance. Compounding these problems is the fact that endemic countries and regions are economically poor. Purpose and Principal Findings In the present work, we have investigated the effect of human immunodeficiency virus (HIV) peptidase inhibitors (PIs) on the F. pedrosoi conidial secreted peptidase, growth, ultrastructure and interaction with different mammalian cells. All the PIs impaired the acidic conidial-derived peptidase activity in a dose-dependent fashion, in which nelfinavir produced the best inhibitory effect. F. pedrosoi growth was also significantly reduced upon exposure to PIs, especially nelfinavir and saquinavir. PIs treatment caused profound changes in the conidial ultrastructure as shown by transmission electron microscopy, including invaginations in the cytoplasmic membrane, disorder and detachment of the cell wall, enlargement of fungi cytoplasmic vacuoles, and abnormal cell division. The synergistic action on growth ability between nelfinavir and amphotericin B, when both were used at sub-inhibitory concentrations, was also observed. PIs reduced the adhesion and endocytic indexes during the interaction between conidia and epithelial cells (CHO), fibroblasts or macrophages, in a cell type-dependent manner. Moreover, PIs interfered with the conidia into mycelia transformation when in contact with CHO and with the susceptibility killing by macrophage cells. Conclusions/Significance Overall, by providing the first evidence that HIV PIs directly affects F. pedrosoi development and virulence, these data add new insights on the wide-spectrum efficacy of HIV PIs, further arguing for the potential chemotherapeutic targets for aspartyl-type peptidase produced by this human

  7. C-5-Modified Tetrahydropyrano-Tetrahydofuran-Derived Protease Inhibitors (PIs) Exert Potent Inhibition of the Replication of HIV-1 Variants Highly Resistant to Various PIs, including Darunavir

    Science.gov (United States)

    Aoki, Manabu; Hayashi, Hironori; Yedidi, Ravikiran S.; Martyr, Cuthbert D.; Takamatsu, Yuki; Aoki-Ogata, Hiromi; Nakamura, Teruya; Nakata, Hirotomo; Das, Debananda; Yamagata, Yuriko; Ghosh, Arun K.

    2015-01-01

    ABSTRACT We identified three nonpeptidic HIV-1 protease inhibitors (PIs), GRL-015, -085, and -097, containing tetrahydropyrano-tetrahydrofuran (Tp-THF) with a C-5 hydroxyl. The three compounds were potent against a wild-type laboratory HIV-1 strain (HIV-1WT), with 50% effective concentrations (EC50s) of 3.0 to 49 nM, and exhibited minimal cytotoxicity, with 50% cytotoxic concentrations (CC50) for GRL-015, -085, and -097 of 80, >100, and >100 μM, respectively. All the three compounds potently inhibited the replication of highly PI-resistant HIV-1 variants selected with each of the currently available PIs and recombinant clinical HIV-1 isolates obtained from patients harboring multidrug-resistant HIV-1 variants (HIVMDR). Importantly, darunavir (DRV) was >1,000 times less active against a highly DRV-resistant HIV-1 variant (HIV-1DRVRP51); the three compounds remained active against HIV-1DRVRP51 with only a 6.8- to 68-fold reduction. Moreover, the emergence of HIV-1 variants resistant to the three compounds was considerably delayed compared to the case of DRV. In particular, HIV-1 variants resistant to GRL-085 and -097 did not emerge even when two different highly DRV-resistant HIV-1 variants were used as a starting population. In the structural analyses, Tp-THF of GRL-015, -085, and -097 showed strong hydrogen bond interactions with the backbone atoms of active-site amino acid residues (Asp29 and Asp30) of HIV-1 protease. A strong hydrogen bonding formation between the hydroxyl moiety of Tp-THF and a carbonyl oxygen atom of Gly48 was newly identified. The present findings indicate that the three compounds warrant further study as possible therapeutic agents for treating individuals harboring wild-type HIV and/or HIVMDR. IMPORTANCE Darunavir (DRV) inhibits the replication of most existing multidrug-resistant HIV-1 strains and has a high genetic barrier. However, the emergence of highly DRV-resistant HIV-1 strains (HIVDRVR) has recently been observed in vivo and in

  8. The HIV-1 integrase-LEDGF allosteric inhibitor MUT-A: resistance profile, impairment of virus maturation and infectivity but without influence on RNA packaging or virus immunoreactivity.

    Science.gov (United States)

    Amadori, Céline; van der Velden, Yme Ubeles; Bonnard, Damien; Orlov, Igor; van Bel, Nikki; Le Rouzic, Erwann; Miralles, Laia; Brias, Julie; Chevreuil, Francis; Spehner, Daniele; Chasset, Sophie; Ledoussal, Benoit; Mayr, Luzia; Moreau, François; García, Felipe; Gatell, José; Zamborlini, Alessia; Emiliani, Stéphane; Ruff, Marc; Klaholz, Bruno P; Moog, Christiane; Berkhout, Ben; Plana, Montserrat; Benarous, Richard

    2017-11-09

    HIV-1 Integrase (IN) interacts with the cellular co-factor LEDGF/p75 and tethers the HIV preintegration complex to the host genome enabling integration. Recently a new class of IN inhibitors was described, the IN-LEDGF allosteric inhibitors (INLAIs). Designed to interfere with the IN-LEDGF interaction during integration, the major impact of these inhibitors was surprisingly found on virus maturation, causing a reverse transcription defect in target cells. Here we describe the MUT-A compound as a genuine INLAI with an original chemical structure based on a new type of scaffold, a thiophene ring. MUT-A has all characteristics of INLAI compounds such as inhibition of IN-LEDGF/p75 interaction, IN multimerization, dual antiretroviral (ARV) activities, normal packaging of genomic viral RNA and complete Gag protein maturation. MUT-A has more potent ARV activity compared to other INLAIs previously reported, but similar profile of resistance mutations and absence of ARV activity on SIV. HIV-1 virions produced in the presence of MUT-A were non-infectious with the formation of eccentric condensates outside of the core. In studying the immunoreactivity of these non-infectious virions, we found that inactivated HIV-1 particles were captured by anti-HIV-specific neutralizing and non-neutralizing antibodies (b12, 2G12, PGT121, 4D4, 10-1074, 10E8, VRC01) with efficiencies comparable to non-treated virus. Autologous CD4+ T lymphocyte proliferation and cytokine induction by monocyte-derived dendritic cells (MDDC) pulsed either with MUT-A-inactivated HIV or non-treated HIV were also comparable. Although strongly defective in infectivity, HIV-1 virions produced in the presence of the MUT-A INLAI have a normal protein and genomic RNA content as well as B and T cell immunoreactivities comparable to non-treated HIV-1. These inactivated viruses might form an attractive new approach in vaccine research in an attempt to study if this new type of immunogen could elicit an immune response

  9. Binding of novel fullerene inhibitors to HIV-1 protease: insight through molecular dynamics and molecular mechanics Poisson-Boltzmann surface area calculations

    Science.gov (United States)

    Tzoupis, Haralambos; Leonis, Georgios; Durdagi, Serdar; Mouchlis, Varnavas; Mavromoustakos, Thomas; Papadopoulos, Manthos G.

    2011-10-01

    The objectives of this study include the design of a series of novel fullerene-based inhibitors for HIV-1 protease (HIV-1 PR), by employing two strategies that can also be applied to the design of inhibitors for any other target. Additionally, the interactions which contribute to the observed exceptionally high binding free energies were analyzed. In particular, we investigated: (1) hydrogen bonding (H-bond) interactions between specific fullerene derivatives and the protease, (2) the regions of HIV-1 PR that play a significant role in binding, (3) protease changes upon binding and (4) various contributions to the binding free energy, in order to identify the most significant of them. This study has been performed by employing a docking technique, two 3D-QSAR models, molecular dynamics (MD) simulations and the molecular mechanics Poisson-Boltzmann surface area (MM-PBSA) method. Our computed binding free energies are in satisfactory agreement with the experimental results. The suitability of specific fullerene derivatives as drug candidates was further enhanced, after ADMET (absorption, distribution, metabolism, excretion and toxicity) properties have been estimated to be promising. The outcomes of this study revealed important protein-ligand interaction patterns that may lead towards the development of novel, potent HIV-1 PR inhibitors.

  10. A Novel Tricyclic Ligand-Containing Nonpeptidic HIV-1 Protease Inhibitor, GRL-0739, Effectively Inhibits the Replication of Multidrug-Resistant HIV-1 Variants and Has a Desirable Central Nervous System Penetration Property In Vitro

    Science.gov (United States)

    Amano, Masayuki; Tojo, Yasushi; Salcedo-Gómez, Pedro Miguel; Parham, Garth L.; Nyalapatla, Prasanth R.; Das, Debananda; Ghosh, Arun K.

    2015-01-01

    We report here that GRL-0739, a novel nonpeptidic HIV-1 protease inhibitor containing a tricycle (cyclohexyl-bis-tetrahydrofuranylurethane [THF]) and a sulfonamide isostere, is highly active against laboratory HIV-1 strains and primary clinical isolates (50% effective concentration [EC50], 0.0019 to 0.0036 μM), with minimal cytotoxicity (50% cytotoxic concentration [CC50], 21.0 μM). GRL-0739 blocked the infectivity and replication of HIV-1NL4-3 variants selected by concentrations of up to 5 μM ritonavir or atazanavir (EC50, 0.035 to 0.058 μM). GRL-0739 was also highly active against multidrug-resistant clinical HIV-1 variants isolated from patients who no longer responded to existing antiviral regimens after long-term antiretroviral therapy, as well as against the HIV-2ROD variant. The development of resistance against GRL-0739 was substantially delayed compared to that of amprenavir (APV). The effects of the nonspecific binding of human serum proteins on the anti-HIV-1 activity of GRL-0739 were insignificant. In addition, GRL-0739 showed a desirable central nervous system (CNS) penetration property, as assessed using a novel in vitro blood-brain barrier model. Molecular modeling demonstrated that the tricyclic ring and methoxybenzene of GRL-0739 have a larger surface and make greater van der Waals contacts with protease than in the case of darunavir. The present data demonstrate that GRL-0739 has desirable features as a compound with good CNS-penetrating capability for treating patients infected with wild-type and/or multidrug-resistant HIV-1 variants and that the newly generated cyclohexyl-bis-THF moiety with methoxybenzene confers highly desirable anti-HIV-1 potency in the design of novel protease inhibitors with greater CNS penetration profiles. PMID:25691652

  11. Kinetic studies of HIV-1 and HIV-2 envelope glycoprotein-mediated fusion

    Directory of Open Access Journals (Sweden)

    Doms Robert W

    2006-12-01

    Full Text Available Abstract Background HIV envelope glycoprotein (Env-mediated fusion is driven by the concerted coalescence of the HIV gp41 N-helical and C-helical regions, which results in the formation of 6 helix bundles. Kinetics of HIV Env-mediated fusion is an important determinant of sensitivity to entry inhibitors and antibodies. However, the parameters that govern the HIV Env fusion cascade have yet to be fully elucidated. We address this issue by comparing the kinetics HIV-1IIIB Env with those mediated by HIV-2 from two strains with different affinities for CD4 and CXCR4. Results HIV-1 and HIV-2 Env-mediated cell fusion occurred with half times of about 60 and 30 min, respectively. Binding experiments of soluble HIV gp120 proteins to CD4 and co-receptor did not correlate with the differences in kinetics of fusion mediated by the three different HIV Envs. However, escape from inhibition by reagents that block gp120-CD4 binding, CD4-induced CXCR4 binding and 6-helix bundle formation, respectively, indicated large difference between HIV-1 and HIV-2 envelope glycoproteins in their CD4-induced rates of engagement with CXCR4. Conclusion The HIV-2 Env proteins studied here exhibited a significantly reduced window of time between the engagement of gp120 with CD4 and exposure of the CXCR4 binding site on gp120 as compared with HIV-1IIIB Env. The efficiency with which HIV-2 Env undergoes this CD4-induced conformational change is the major cause of the relatively rapid rate of HIV-2 Env mediated-fusion.

  12. Significantly improved HIV inhibitor efficacy prediction employing proteochemometric models generated from antivirogram data.

    Science.gov (United States)

    van Westen, Gerard J P; Hendriks, Alwin; Wegner, Jörg K; Ijzerman, Adriaan P; van Vlijmen, Herman W T; Bender, Andreas

    2013-01-01

    Infection with HIV cannot currently be cured; however it can be controlled by combination treatment with multiple anti-retroviral drugs. Given different viral genotypes for virtually each individual patient, the question now arises which drug combination to use to achieve effective treatment. With the availability of viral genotypic data and clinical phenotypic data, it has become possible to create computational models able to predict an optimal treatment regimen for an individual patient. Current models are based only on sequence data derived from viral genotyping; chemical similarity of drugs is not considered. To explore the added value of chemical similarity inclusion we applied proteochemometric models, combining chemical and protein target properties in a single bioactivity model. Our dataset was a large scale clinical database of genotypic and phenotypic information (in total ca. 300,000 drug-mutant bioactivity data points, 4 (NNRTI), 8 (NRTI) or 9 (PI) drugs, and 10,700 (NNRTI) 10,500 (NRTI) or 27,000 (PI) mutants). Our models achieved a prediction error below 0.5 Log Fold Change. Moreover, when directly compared with previously published sequence data, derived models PCM performed better in resistance classification and prediction of Log Fold Change (0.76 log units versus 0.91). Furthermore, we were able to successfully confirm both known and identify previously unpublished, resistance-conferring mutations of HIV Reverse Transcriptase (e.g. K102Y, T216M) and HIV Protease (e.g. Q18N, N88G) from our dataset. Finally, we applied our models prospectively to the public HIV resistance database from Stanford University obtaining a correct resistance prediction rate of 84% on the full set (compared to 80% in previous work on a high quality subset). We conclude that proteochemometric models are able to accurately predict the phenotypic resistance based on genotypic data even for novel mutants and mixtures. Furthermore, we add an applicability domain to the

  13. Thermodynamic characterization of the peptide assembly inhibitor binding to HIV-1 capsid protein

    Czech Academy of Sciences Publication Activity Database

    Kožíšek, Milan; Durčák, Jindřich; Konvalinka, Jan

    2013-01-01

    Roč. 10, Suppl. 1 (2013), S37-S37 ISSN 1742-4690. [Frontiers of Retrovirology: Complex retorviruses, retroelements and their hosts. 16.09.2013-18.09.2013, Cambridge] R&D Projects: GA ČR GA13-19561S Institutional support: RVO:61388963 Keywords : HIV -1 capsid protein * CAI Subject RIV: EE - Microbiology, Virology http://www.retrovirology.com/content/10/S1/P108

  14. Use of nucleoside reverse transcriptase inhibitors and risk of myocardial infarction in HIV-infected patients

    NARCIS (Netherlands)

    Lundgren, Jens D.; Neuhaus, Jacqueline; Babiker, Abdel; Cooper, David; Duprez, Daniel; El-Sadr, Wafaa; Emery, Sean; Gordin, Fred; Kowalska, Justyna; Phillips, Andrew; Prineas, Ronald J.; Reiss, Peter; Sabin, Caroline; Tracy, Russell; Weber, Rainer; Grund, Birgit; Neaton, James D.

    2008-01-01

    BACKGROUND: Two nucleos(t)ide reverse transcriptase inhibitors (NRTIs)--abacavir and didanosine--may each be associated with excess risk of myocardial infarction. The reproducibility of this finding in an independent dataset was explored and plausible biological mechanisms were sought. METHODS:

  15. Evaluation of HIV protease inhibitor use and the risk of sudden death or nonhemorrhagic stroke

    DEFF Research Database (Denmark)

    Worm, S W; Kamara, D A; Reiss, P

    2012-01-01

    Concerns have arisen about possible effects of protease inhibitors (PIs) on cardiac conductivity. We found no significant association between current or recent PI exposure and sudden death or nonhemorrhagic stroke (adjusted rate ratio, 1.22; 95% confidence interval, .95-1.57), whereas cumulative...

  16. High-performance liquid chromatography of HIV protease inhibitors in human biological matrices

    NARCIS (Netherlands)

    Aarnoutse, Rob E.; verweij-van wissen, CP; Underberg, W.J M; Kleinnijenhuis, Johanneke; Hekster, Yechiel A; Burger, D. M.

    2001-01-01

    Methods for HPLC analysis of protease inhibitors (PIs) in human biological matrices were reviewed. Assays have been developed for analysis of single PIs or for simultaneous measurement of multiple PIs in plasma-serum, saliva, cerebrospinal fluid and semen. Liquid-liquid extraction was most often

  17. High-performance liquid chromatography of HIV protease inhibitors in human biological matrices.

    NARCIS (Netherlands)

    Aarnoutse, R.E.; Verwey-van Wissen, C.P.W.G.M.; Underberg, W.J.M.; Kleinnijenhuis, J.; Hekster, Y.A.; Burger, D.M.

    2001-01-01

    Methods for HPLC analysis of protease inhibitors (PIs) in human biological matrices were reviewed. Assays have been developed for analysis of single PIs or for simultaneous measurement of multiple PIs in plasma-serum, saliva, cerebrospinal fluid and semen. Liquid-liquid extraction was most often

  18. Evaluation of HIV Protease Inhibitor Use and the Risk of Sudden Death or Nonhemorrhagic Stroke

    NARCIS (Netherlands)

    Worm, S. W.; Kamara, D. A.; Reiss, P.; Fontas, E.; de Wit, S.; El-Sadr, W.; d'Arminio Monforte, A.; Law, M.; Phillips, A.; Ryom, L.; Dabis, F.; Weber, R.; Sabin, C.; Lundgren, J. D.

    2012-01-01

    Concerns have arisen about possible effects of protease inhibitors (PIs) on cardiac conductivity. We found no significant association between current or recent PI exposure and sudden death or nonhemorrhagic stroke (adjusted rate ratio, 1.22; 95% confidence interval, .95-1.57), whereas cumulative

  19. The case for addressing primary resistance mutations to non-nucleoside reverse transcriptase inhibitors to treat children born from mothers living with HIV in sub-Saharan Africa

    OpenAIRE

    Khady Kébé; Laurent Bélec; Halimatou Diop Ndiaye; Sokhna Bousso Gueye; Abou Abdallah Malick Diouara; Safiétou Ngom; Ndéye Rama Diagne Gueye; Ngagne Mbaye; Haby Signaté Sy; Souleymane Mboup; Coumba Touré Kane

    2014-01-01

    The prevalence of human immunodeficiency virus (HIV) drug resistance mutations (DRMs) was estimated in 25 untreated infants who were living with HIV-1, younger than 13 months and living in Senegal. Antiretroviral DRMs were detected in 8 of 25 (32%) children. Non-nucleoside reverse transcriptase inhibitor (NNRTI) DRMs were present in all (100%) children whose viruses harboured DRMs: K103N in 43%; Y181C, K101E and V106M each in 29%; and Y188L in 14%. The D67N thymidine-analogue mutation was obs...

  20. Exploration of the structural requirements of HIV-protease inhibitors using pharmacophore, virtual screening and molecular docking approaches for lead identification.

    Science.gov (United States)

    Islam, Md Ataul; Pillay, Tahir S

    2015-03-01

    Pharmacoinformatics approaches are widely used in the field of drug discovery as it saves time, investment and animal sacrifice. In the present study, pharmacore-based virtual screening was adopted to identify potential HIV-protease ligands as anti-HIV agents. Pharmacophore is the 3D orientation and spatial arrangement of functional groups that are critical for binding at the active site cavity. Virtual screening retrieves potential hit molecules from databases based on imposed criteria. A set of 30 compounds were selected with inhibition constant as training set from 129 compounds of dataset set and subsequently the pharmacophore model was developed. The selected best model consists of hydrogen bond acceptor and donor, hydrophobic and aromatic ring, features critical for HIV-protease inhibitors. The model exhibits high correlation (R=0.933), less rmsd (1.014), high cross validated correlation coefficient (Q(2)=0.872) among the ten models examined and validated by Fischer's randomization test at 95% confidence level. The acceptable parameters of test set prediction, such as R(pred)(2)=0.768 and r(m(test))(2)=0.711 suggested that external predictivity of the model was significant. The pharmacophore model was used to perform a virtual screening employing the NCI database. Initial hits were sorted using a number of parameters and finally seven compounds were proposed as potential HIV-protease molecules. One potential HIV-protease ligand is reportedly confirmed as an active agent for anti-HIV screening, validating the current approach. It can be postulated that the pharmacophore model facilitates the selection of novel scaffold of HIV-protease inhibitors and can also allow the design of new chemical entities. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. HIV-1 Fusion Is Blocked through Binding of GB Virus C E2D Peptides to the HIV-1 gp41 Disulfide Loop

    Science.gov (United States)

    Eissmann, Kristin; Mueller, Sebastian; Sticht, Heinrich; Jung, Susan; Zou, Peng; Jiang, Shibo; Gross, Andrea; Eichler, Jutta; Fleckenstein, Bernhard; Reil, Heide

    2013-01-01

    A strategy for antiviral drug discovery is the elucidation and imitation of viral interference mechanisms. HIV-1 patients benefit from a coinfection with GB Virus C (GBV-C), since HIV-positive individuals with long-term GBV-C viraemia show better survival rates than HIV-1 patients without persisting GBV-C. A direct influence of GBV-C on HIV-1 replication has been shown in coinfection experiments. GBV-C is a human non-pathogenic member of the flaviviridae family that can replicate in T and B cells. Therefore, GBV-C shares partly the same ecological niche with HIV-1. In earlier work we have demonstrated that recombinant glycoprotein E2 of GBV-C and peptides derived from the E2 N-terminus interfere with HIV entry. In this study we investigated the underlying mechanism. Performing a virus-cell fusion assay and temperature-arrested HIV-infection kinetics, we provide evidence that the HIV-inhibitory E2 peptides interfere with late HIV-1 entry steps after the engagement of gp120 with CD4 receptor and coreceptor. Binding and competition experiments revealed that the N-terminal E2 peptides bind to the disulfide loop region of HIV-1 transmembrane protein gp41. In conjunction with computational analyses, we identified sequence similarities between the N-termini of GBV-C E2 and the HIV-1 glycoprotein gp120. This similarity appears to enable the GBV-C E2 N-terminus to interact with the HIV-1 gp41 disulfide loop, a crucial domain involved in the gp120-gp41 interface. Furthermore, the results of the present study provide initial proof of concept that peptides targeted to the gp41 disulfide loop are able to inhibit HIV fusion and should inspire the development of this new class of HIV-1 entry inhibitors. PMID:23349893

  2. HIV-1 fusion is blocked through binding of GB Virus C E2-derived peptides to the HIV-1 gp41 disulfide loop [corrected].

    Directory of Open Access Journals (Sweden)

    Kristin Eissmann

    Full Text Available A strategy for antiviral drug discovery is the elucidation and imitation of viral interference mechanisms. HIV-1 patients benefit from a coinfection with GB Virus C (GBV-C, since HIV-positive individuals with long-term GBV-C viraemia show better survival rates than HIV-1 patients without persisting GBV-C. A direct influence of GBV-C on HIV-1 replication has been shown in coinfection experiments. GBV-C is a human non-pathogenic member of the flaviviridae family that can replicate in T and B cells. Therefore, GBV-C shares partly the same ecological niche with HIV-1. In earlier work we have demonstrated that recombinant glycoprotein E2 of GBV-C and peptides derived from the E2 N-terminus interfere with HIV entry. In this study we investigated the underlying mechanism. Performing a virus-cell fusion assay and temperature-arrested HIV-infection kinetics, we provide evidence that the HIV-inhibitory E2 peptides interfere with late HIV-1 entry steps after the engagement of gp120 with CD4 receptor and coreceptor. Binding and competition experiments revealed that the N-terminal E2 peptides bind to the disulfide loop region of HIV-1 transmembrane protein gp41. In conjunction with computational analyses, we identified sequence similarities between the N-termini of GBV-C E2 and the HIV-1 glycoprotein gp120. This similarity appears to enable the GBV-C E2 N-terminus to interact with the HIV-1 gp41 disulfide loop, a crucial domain involved in the gp120-gp41 interface. Furthermore, the results of the present study provide initial proof of concept that peptides targeted to the gp41 disulfide loop are able to inhibit HIV fusion and should inspire the development of this new class of HIV-1 entry inhibitors.

  3. Antiretroviral therapy outcomes in HIV-infected children after adjusting protease inhibitor dosing during tuberculosis treatment.

    Directory of Open Access Journals (Sweden)

    Cordula Frohoff

    2011-02-01

    Full Text Available Modification of ritonavir-boosted lopinavir (LPV/r-based antiretroviral therapy is required for HIV-infected children co-treated for tuberculosis (TB. We aimed to determine virologic and toxicity outcomes among TB/HIV co-treated children with the following modifications to their antiretroviral therapy (ART: (1 super-boosted LPV/r, (2 double-dose LPV/r or (3 ritonavir.A medical record review was conducted at two clinical sites in Johannesburg, South Africa. The records of children 6-24 months of age initiating LPV/r-based therapy were reviewed. Children co-treated for TB were categorized based on the modifications made to their ART regimen and were compared to children of the same age at each site not treated for TB. Included are 526 children, 294 (56% co-treated for TB. All co-treated children had more severe HIV disease, including lower CD4 percents and worse growth indicators, than comparisons. Children in the super-boosted group (n = 156 were as likely to be virally suppressed (<400 copies/ml at 6 months as comparisons (69.2% vs. 74.8%, p = 0.36. Children in the double-dose (n = 47 and ritonavir groups (n = 91 were significantly less likely to be virally suppressed at 6 months (53.1% and 49.3% than comparisons (74.8% and 82.1%; p = 0.02 and p<0.0001, respectively. At 12 months only children in the ritonavir group still had lower rates of virological suppression relative to comparisons (63.9% vs 83.3% p<0.05. Grade 1 or greater ALT elevations were more common in the super-boosted (75% than double-dose (54.6% or ritonavir (33.9% groups (p = 0.09 and p<0.0001 but grade 3/4 elevations were observed in 3 (13.6% of the super-boosted, 7 (15.9% of the double-dose and 5 (8.9% of the ritonavir group (p = 0.81 and p = 0.29.Good short-term virologic outcomes were achieved in children co-treated for TB and HIV who received super-boosted LPV/r. Treatment limiting toxicity was rare. Strategies for increased dosing of LPV

  4. Synthesis, in vitro evaluation, and docking studies of novel chromone derivatives as HIV-1 protease inhibitor

    Science.gov (United States)

    Ungwitayatorn, Jiraporn; Wiwat, Chanpen; Samee, Weerasak; Nunthanavanit, Patcharawee; Phosrithong, Narumol

    2011-08-01

    Novel chromone derivatives with a benzopyran-4-one scaffold have been prepared by the one-pot cyclization reaction. The in vitro inhibitory activity of these new compounds towards HIV-1 protease have been evaluated using stop time HPLC method as the preliminary screening. The most potent compound, 7,8-dihydroxy-2-(3'-trifluoromethyl phenyl)-3-(3″-trifluoromethylbenzoyl)chromone ( 32), showed IC 50 = 0.34 μM. The molecular docking study supported results from experimental activity testing and also provided structure-activity relationship of this series.

  5. HPLC-MS method for the simultaneous quantification of the new HIV protease inhibitor darunavir, and 11 other antiretroviral agents in plasma of HIV-infected patients.

    Science.gov (United States)

    D'Avolio, Antonio; Siccardi, Marco; Sciandra, Mauro; Baietto, Lorena; Lorena, Baietto; Bonora, Stefano; Trentini, Laura; Di Perri, Giovanni

    2007-11-15

    A new method using high performance liquid chromatography coupled with electrospray mass spectrometry (HPLC-MS) was developed and validated, for the quantification of plasma concentration of the new protease inhibitors darunavir (DRV) and other 11 antiretroviral agents (ritonavir, amprenavir, atazanavir, lopinavir, saquinavir, indinavir, nelfinavir and its metabolite M-8, nevirapine, efavirenz and tipranavir). A simple protein precipitation extraction procedure was applied on 50 microl of plasma aliquots and chromatographic separation of drugs and Internal Standard (quinoxaline) was achieved with a gradient (acetonitrile and water with formic acid 0.05%) on an C-18 reverse phase analytical column with 25 min of analytical run. Calibration curves were optimised according to expected ranges of drug concentrations in patients, and correlation coefficient (r2) was higher than 0.998 for all analytes. Mean intra- and inter-day precision (relative standard deviation %) for all compounds were 8.4 and 8.3%, respectively, and mean accuracy (% of deviation from nominal level) was 3.9%. Extraction recovery ranged within 93 and 105% for all drugs analysed. This novel HPLC-MS methodology allows a specific, sensitive and reliable determination of DRV and 11 other antiretrovirals. In our hand, it was used to measure DRV and ritonavir plasma concentration in HIV-positive patients, and it is now successfully applied for routine therapeutic drug monitoring and pharmacokinetics studies.

  6. Parameterization of AZT-A widely used nucleoside inhibitor of HIV-1 reverse transcriptase

    Science.gov (United States)

    Carvalho, Alexandra T. P.; Fernandes, Pedro A.; Ramos, Maria J.

    Seven nucleoside reverse transcriptase (RT) inhibitors are currently used in the clinical treatment of acquired immunodeficiency syndrome (AIDS). These substrate analogues block DNA synthesis by the viral enzyme RT. However, the emergence of resistant variants of RT allied to their long-term toxicity requires the design of new and better RT inhibitors, with long-term in vivo efficacy. In this work we used density functional theory (DFT) calculations to develop a set of molecular mechanics (MM) parameters committed to the AMBER force field for one of the most used in the clinic nucleoside reverse transcriptase inhibitors (NRTIs): zidovudine (AZT). These parameters were tested by comparing the optimized geometries of AZT at both the DFT and MM levels of theory. The ability of the new parameters to reproduce the torsional energy of the azide group was also verified by scanning the surface in MM with the new parameters and comparing the results with the same potential energy surface (PES) at the DFT level. Finally, the parameters were validated through classical MD simulations of AZT in aqueous environment.

  7. Design of inhibitors of the HIV-1 integrase core domain using virtual screening.

    Science.gov (United States)

    Regon, Preetom; Gogoi, Dhrubajyoti; Rai, Ashok Kumar; Bordoloi, Manabjyoti; Bezbaruah, Rajib Lochan

    2014-01-01

    Acquired immunodeficiency syndrome (AIDS) is a disease of the human immune system caused by the human immunodeficiency virus (HIV). The integrase (IN) enzyme of HIV interacts with several cellular and viral proteins during the integration process. Thus, it represents an appropriate target for antiretroviral drugs (ARVs). We performed virtual screening of database compounds and designed analogues using Elvitegravir (EVG) as a standard compound. The 378 screened compounds were retrieved from ZINC, ChemSpider, PubChem, and ChemBank Chemical Databases based on chemical similarity and literature searches related to the structure of EVG. The Physiochemical properties, Bioactivity, Toxicity and Absorption, Distribution, Metabolism and Excretion of Molecules (ADME) of these compounds were predicted and docking Experiments were conducted using Molegro Virtual Docker software. The docking and ADME suggested very significant results in regard to EVG. The MolDock and Rerank scores were used to analyze the results. The compounds ZINC26507991 (-84.22), Analogue 9 (-68.49), ZINC20731658 (-66.79), ZINC00210363 (-43.44) showed better binding orientation with IN receptor model with respect to EVG (182.52). The ZINC26507991 has showed significant ADME result.

  8. Impact of Protease Inhibitor-Based Anti-Retroviral Therapy on Outcomes for HIV+ Kidney Transplant Recipients.

    Science.gov (United States)

    Sawinski, D; Shelton, B A; Mehta, S; Reed, R D; MacLennan, P A; Gustafson, S; Segev, D L; Locke, J E

    2017-07-11

    Excellent outcomes have been demonstrated among select HIV-positive kidney transplant (KT) recipients with well-controlled infection, but to date, no national study has explored outcomes among HIV+ KT recipients by antiretroviral therapy (ART) regimen. Intercontinental Marketing Services (IMS) pharmacy fills (1/1/01-10/1/12) were linked with Scientific Registry of Transplant Recipients (SRTR) data. A total of 332 recipients with pre- and posttransplantation fills were characterized by ART at the time of transplantation as protease inhibitor (PI) or non-PI-based ART (88 PI vs. 244 non-PI). Cox proportional hazards models were adjusted for recipient and donor characteristics. Comparing recipients by ART regimen, there were no significant differences in age, race, or HCV status. Recipients on PI-based regimens were significantly more likely to have an Estimated Post Transplant Survival (EPTS) score of >20% (70.9% vs. 56.3%, p = 0.02) than those on non-PI regimens. On adjusted analyses, PI-based regimens were associated with a 1.8-fold increased risk of allograft loss (adjusted hazard ratio [aHR] 1.84, 95% confidence interval [CI] 1.22-2.77, p = 0.003), with the greatest risk observed in the first posttransplantation year (aHR 4.48, 95% CI 1.75-11.48, p = 0.002), and a 1.9-fold increased risk of death as compared to non-PI regimens (aHR 1.91, 95% CI 1.02-3.59, p = 0.05). These results suggest that whenever possible, recipients should be converted to a non-PI regimen prior to kidney transplantation. © 2017 The American Society of Transplantation and the American Society of Transplant Surgeons.

  9. Premature delivery in HIV-infected women starting protease inhibitor therapy during pregnancy: role of the ritonavir boost?

    Science.gov (United States)

    Sibiude, Jeanne; Warszawski, Josiane; Tubiana, Roland; Dollfus, Catherine; Faye, Albert; Rouzioux, Christine; Teglas, Jean-Paul; Ekoukou, Dieudonné; Blanche, Stéphane; Mandelbrot, Laurent

    2012-05-01

    The association between combination antiretroviral (cARV) therapy use by human immunodeficiency virus (HIV)-infected women during pregnancy and risk of prematurity is still controversial. We explored this question, focusing on the initiation of ritonavir-boosted protease inhibitors (PIs) during pregnancy, which is now standard care. Trends in prematurity (pregnancies in the Agence Nationale de Recherche sur le SIDA (ANRS) French Perinatal Cohort from 1990 through 2009 (n = 13 271). In-depth analysis was conducted in a more detailed substudy of the cohort, among women starting PI-based ARV therapy during pregnancy (n = 1253). Multivariable analysis adjusted for immunovirological status and known risk factors for prematurity. Prematurity increased from 9.2% during 1990-1993 (no therapy) and 9.6% during 1994-1996 (mostly zidovudine monotherapy) to 12.4% during 1997-1999 (dual-nucleoside analog therapy) and 14.3% during 2005-2009 (routine cARV therapy; P pregnancy (14.4% vs 9.1% [P = .05]; adjusted hazard ratio, 2.03 [95% CI, 1.06-3.89; P = .03] in multivariate analysis). The difference concerned mainly induced preterm delivery for maternal or fetal indications (5.6% vs 1.6%; P = .02), The prematurity rate among HIV-infected pregnant women was twice that in the general population in France; this was not entirely explained by sociodemographic characteristics. Prematurity was independently associated with cARV therapy and, particularly, with the initiation of ritonavir-boosted PI therapy during pregnancy.

  10. Pharmacokinetic and metabolic effects of American ginseng (Panax quinquefolius in healthy volunteers receiving the HIV protease inhibitor indinavir

    Directory of Open Access Journals (Sweden)

    Flexner Charles W

    2008-08-01

    Full Text Available Abstract Background Complementary and alternative medicine (CAM use is prevalent among HIV-infected patients to reduce the toxicity of antiretroviral therapy. Ginseng has been used for treatment of hyperglycemia and insulin resistance, a common side effect of some HIV-1 protease inhibitors (PI. However, it is unknown whether American ginseng (AG can reverse insulin resistance induced by the PI indinavir (IDV, and whether these two agents interact pharmacologically. We evaluated potential pharmacokinetic interactions between IDV and AG, and assessed whether AG improves IDV-induced insulin resistance. Methods After baseline assessment of insulin sensitivity using the insulin clamp technique, healthy volunteers received IDV 800 mg q8 h for 3 days and then IDV and AG 1g q8h for 14 days. IDV pharmacokinetics and insulin sensitivity were assessed before and after AG co-administration. Results There was no difference in the area-under the plasma-concentration-time curve after the co-administration of AG, compared to IDV alone (n = 13. Although insulin-stimulated glucose disposal per unit of insulin (M/I decreased by an average of 14.8 ± 5.9% after 3 days of IDV (from 0.113 ± 0.012 to 0.096 ± 0.014 mg/kgFFM/min per μU/ml of insulin, p = 0.03, n = 11, M/I remained unchanged after co-administration of IDV and AG. Conclusion IDV decreases insulin sensitivity, which is unaltered by AG co-administration. AG does not significantly affect IDV pharmacokinetics.

  11. Discovery of a novel and potent class of anti-HIV-1 maturation inhibitors with improved virology profile against gag polymorphisms.

    Science.gov (United States)

    Tang, Jun; Jones, Stacey A; Jeffrey, Jerry L; Miranda, Sonia R; Galardi, Cristin M; Irlbeck, David M; Brown, Kevin W; McDanal, Charlene B; Johns, Brian A

    2017-06-15

    A new class of betulin-derived α-keto amides was identified as HIV-1 maturation inhibitors. Through lead optimization, GSK8999 was identified with IC50 values of 17nM, 23nM, 25nM, and 8nM for wild type, Q369H, V370A, and T371A respectively. When tested in a panel of 62 HIV-1 isolates covering a diversity of CA-SP1 genotypes including A, AE, B, C, and G using a PBMC based assay, GSK8999 was potent against 57 of 62 isolates demonstrating an improvement over the first generation maturation inhibitor BVM. The data disclosed here also demonstrated that the new α-keto amide GSK8999 has a mechanism of action consistent with inhibition of the proteolytic cleavage of CA-SP1. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. A bivalent recombinant protein inactivates HIV-1 by targeting the gp41 prehairpin fusion intermediate induced by CD4 D1D2 domains

    Directory of Open Access Journals (Sweden)

    Lu Lu

    2012-12-01

    Full Text Available Abstract Background Most currently approved anti-HIV drugs (e.g., reverse transcriptase inhibitors, protease inhibitors and fusion/entry inhibitors must act inside or on surface of the target cell to inhibit HIV infection, but none can directly inactivate virions away from cells. Although soluble CD4 (sCD4 can inactivate laboratory-adapted HIV-1 strains, it fails to reduce the viral loads in clinical trials because of its low potency against primary isolates and tendency to enhance HIV-1 infection at low concentration. Thus, it is essential to design a better HIV inactivator with improved potency for developing new anti-HIV therapeutics that can actively attack the virus in the circulation before it attaches to and enter into the target cell. Results We engineered a bivalent HIV-1 inactivator, designated 2DLT, by linking the D1D2 domain of CD4 to T1144, the next generation HIV fusion inhibitor, with a 35-mer linker. The D1D2 domain in this soluble 2DLT protein could bind to the CD4-binding site and induce the formation of the gp41 prehairpin fusion-intermediate (PFI, but showed no sCD4-mediated enhancement of HIV-1 infection. The T1144 domain in 2DLT then bound to the exposed PFI, resulting in rapid inactivation of HIV-1 virions in the absence of the target cell. Beside, 2DLT could also inhibit fusion of the virus with the target cell if the virion escapes the first attack of 2DLT. Conclusion This bivalent molecule can serve as a dual barrier against HIV infection by first inactivating HIV-1 virions away from cells and then blocking HIV-1 entry on the target cell surface, indicating its potential for development as a new class of anti-HIV drug.

  13. Ribonuclease H/DNA Polymerase HIV-1 Reverse Transcriptase Dual Inhibitor: Mechanistic Studies on the Allosteric Mode of Action of Isatin-Based Compound RMNC6.

    Directory of Open Access Journals (Sweden)

    Angela Corona

    Full Text Available The DNA polymerase and ribonuclease H (RNase H activities of human immunodeficiency virus type 1 (HIV-1 are needed for the replication of the viral genome and are validated drug targets. However, there are no approved drugs inhibiting RNase H and the efficiency of DNA polymerase inhibitors can be diminished by the presence of drug resistance mutations. In this context, drugs inhibiting both activities could represent a significant advance towards better anti-HIV therapies. We report on the mechanisms of allosteric inhibition of a newly synthesized isatin-based compound designated as RMNC6 that showed IC50 values of 1.4 and 9.8 μM on HIV-1 RT-associated RNase H and polymerase activities, respectively. Blind docking studies predict that RMNC6 could bind two different pockets in the RT: one in the DNA polymerase domain (partially overlapping the non-nucleoside RT inhibitor [NNRTI] binding pocket, and a second one close to the RNase H active site. Enzymatic studies showed that RMNC6 interferes with efavirenz (an approved NNRTI in its binding to the RT polymerase domain, although NNRTI resistance-associated mutations such as K103N, Y181C and Y188L had a minor impact on RT susceptibility to RMNC6. In addition, despite being naturally resistant to NNRTIs, the polymerase activity of HIV-1 group O RT was efficiently inhibited by RMNC6. The compound was also an inhibitor of the RNase H activity of wild-type HIV-1 group O RT, although we observed a 6.5-fold increase in the IC50 in comparison with the prototypic HIV-1 group M subtype B enzyme. Mutagenesis studies showed that RT RNase H domain residues Asn474 and Tyr501, and in a lesser extent Ala502 and Ala508, are critical for RMNC6 inhibition of the endonuclease activity of the RT, without affecting its DNA polymerization activity. Our results show that RMNC6 acts as a dual inhibitor with allosteric sites in the DNA polymerase and the RNase H domains of HIV-1 RT.

  14. Ribonuclease H/DNA Polymerase HIV-1 Reverse Transcriptase Dual Inhibitor: Mechanistic Studies on the Allosteric Mode of Action of Isatin-Based Compound RMNC6.

    Science.gov (United States)

    Corona, Angela; Meleddu, Rita; Esposito, Francesca; Distinto, Simona; Bianco, Giulia; Masaoka, Takashi; Maccioni, Elias; Menéndez-Arias, Luis; Alcaro, Stefano; Le Grice, Stuart F J; Tramontano, Enzo

    2016-01-01

    The DNA polymerase and ribonuclease H (RNase H) activities of human immunodeficiency virus type 1 (HIV-1) are needed for the replication of the viral genome and are validated drug targets. However, there are no approved drugs inhibiting RNase H and the efficiency of DNA polymerase inhibitors can be diminished by the presence of drug resistance mutations. In this context, drugs inhibiting both activities could represent a significant advance towards better anti-HIV therapies. We report on the mechanisms of allosteric inhibition of a newly synthesized isatin-based compound designated as RMNC6 that showed IC50 values of 1.4 and 9.8 μM on HIV-1 RT-associated RNase H and polymerase activities, respectively. Blind docking studies predict that RMNC6 could bind two different pockets in the RT: one in the DNA polymerase domain (partially overlapping the non-nucleoside RT inhibitor [NNRTI] binding pocket), and a second one close to the RNase H active site. Enzymatic studies showed that RMNC6 interferes with efavirenz (an approved NNRTI) in its binding to the RT polymerase domain, although NNRTI resistance-associated mutations such as K103N, Y181C and Y188L had a minor impact on RT susceptibility to RMNC6. In addition, despite being naturally resistant to NNRTIs, the polymerase activity of HIV-1 group O RT was efficiently inhibited by RMNC6. The compound was also an inhibitor of the RNase H activity of wild-type HIV-1 group O RT, although we observed a 6.5-fold increase in the IC50 in comparison with the prototypic HIV-1 group M subtype B enzyme. Mutagenesis studies showed that RT RNase H domain residues Asn474 and Tyr501, and in a lesser extent Ala502 and Ala508, are critical for RMNC6 inhibition of the endonuclease activity of the RT, without affecting its DNA polymerization activity. Our results show that RMNC6 acts as a dual inhibitor with allosteric sites in the DNA polymerase and the RNase H domains of HIV-1 RT.

  15. Potential use of rapamycin in HIV infection

    DEFF Research Database (Denmark)

    Donia, Marco; McCubrey, James A; Bendtzen, Klaus

    2010-01-01

    replication in vitro through different mechanisms including, but not limited, to down regulation of CCR5. In addition RAPA synergistically enhances the anti-HIV activity of entry inhibitors such as vicriviroc, aplaviroc and enfuvirtide in vitro. RAPA also inhibits HIV-1 infection in human peripheral blood......, the evidence presented in this review suggests that RAPA may be a useful drug that should be evaluated for the prevention and treatment of HIV-1 infection.......The strong need for the development of alternative anti-HIV agents is primarily due to the emergence of strain-resistant viruses, the need for sustained adherence to complex treatment regimens and the toxicity of currently used antiviral drugs. This review analyzes proof of concept studies...

  16. Inhibition of HIV-1 by Non-Nucleoside Reverse Transcriptase Inhibitors via an Induced Fit Mechanism - Importance of Slow Dissociation and Relaxation Rates for Antiviral Efficacy

    OpenAIRE

    Elinder, Malin; Selhorst, Philippe; Vanham, Guido; Öberg, Bo; Vrang, Lotta; Danielson, U. Helena

    2010-01-01

    Abstract The importance of slow dissociation of non-nucleoside reverse transcriptase inhibitors (NNRTI) for antiviral effect has been investigated. The interaction kinetic characteristics of a series of NNRTIs and wild type and drug resistant variants of HIV-1 RT (EC 2.7.7.49) were analyzed by SPR biosensor technology. The antiviral effect was determined in MT-4 and peripheral blood mononuclear cells. Due to extremely slow dissociation rates and a complex interaction mechanism, rat...

  17. Synthesis and activity of N-acyl azacyclic urea HIV-1 protease inhibitors with high potency against multiple drug resistant viral strains.

    Science.gov (United States)

    Zhao, Chen; Sham, Hing L; Sun, Minghua; Stoll, Vincent S; Stewart, Kent D; Lin, Shuqun; Mo, Hongmei; Vasavanonda, Sudthida; Saldivar, Ayda; Park, Chang; McDonald, Edith J; Marsh, Kennan C; Klein, Larry L; Kempf, Dale J; Norbeck, Daniel W

    2005-12-15

    As part of our efforts to identify potent HIV-1 protease inhibitors that are active against resistant viral strains, structural modification of the azacyclic urea (I) was undertaken by incorporating acyl groups as P(1)' ligands. The extensive SAR study has yielded a series of N-acyl azacyclic ureas (II), which are highly potent against both wild-type and multiple PI-resistant viral strains.

  18. Synthesis, biological evaluation and molecular modeling of 2-Hydroxyisoquinoline-1,3-dione analogues as inhibitors of HIV reverse transcriptase associated ribonuclease H and polymerase.

    Science.gov (United States)

    Tang, Jing; Vernekar, Sanjeev Kumar V; Chen, Yue-Lei; Miller, Lena; Huber, Andrew D; Myshakina, Nataliya; Sarafianos, Stefan G; Parniak, Michael A; Wang, Zhengqiang

    2017-06-16

    Human immunodeficiency virus (HIV) reverse transcriptase (RT) associated ribonuclease H (RNase H) remains the only virally encoded enzymatic function not clinically validated as an antiviral target. 2-Hydroxyisoquinoline-1,3-dione (HID) is known to confer active site directed inhibition of divalent metal-dependent enzymatic functions, such as HIV RNase H, integrase (IN) and hepatitis C virus (HCV) NS5B polymerase. We report herein the synthesis and biochemical evaluation of a few C-5, C-6 or C-7 substituted HID subtypes as HIV RNase H inhibitors. Our data indicate that while some of these subtypes inhibited both the RNase H and polymerase (pol) functions of RT, potent and selective RNase H inhibition was achieved with subtypes 8-9 as exemplified with compounds 8c and 9c. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  19. Selective killing of human immunodeficiency virus infected cells by non-nucleoside reverse transcriptase inhibitor-induced activation of HIV protease

    Directory of Open Access Journals (Sweden)

    Smeulders Liesbeth

    2010-10-01

    Full Text Available Abstract Background Current antiretroviral therapy against human immunodeficiency virus (HIV-1 reduces viral load and thereby prevents viral spread, but it cannot eradicate proviral genomes from infected cells. Cells in immunological sanctuaries as well as cells producing low levels of virus apparently contribute to a reservoir that maintains HIV persistence in the presence of highly active antiretroviral therapy. Thus, accelerated elimination of virus producing cells may represent a complementary strategy to control HIV infection. Here we sought to exploit HIV protease (PR related cytotoxicity in order to develop a strategy for drug induced killing of HIV producing cells. PR processes the viral Gag and Gag-Pol polyproteins during virus maturation, but is also implicated in killing of virus producing cells through off-target cleavage of host proteins. It has been observed previously that micromolar concentrations of certain non-nucleoside reverse transcriptase inhibitors (NNRTIs can stimulate intracellular PR activity, presumably by enhancing Gag-Pol dimerization. Results Using a newly developed cell-based assay we compared the degree of PR activation displayed by various NNRTIs. We identified inhibitors showing higher potency with respect to PR activation than previously described for NNRTIs, with the most potent compounds resulting in ~2-fold increase of the Gag processing signal at 250 nM. The degree of enhancement of intracellular Gag processing correlated with the compound's ability to enhance RT dimerization in a mammalian two-hybrid assay. Compounds were analyzed for their potential to mediate specific killing of chronically infected MT-4 cells. Levels of cytotoxicity on HIV infected cells determined for the different NNRTIs corresponded to the relative degree of drug induced intracellular PR activation, with CC50 values ranging from ~0.3 μM to above the tested concentration range (10 μM. Specific cytotoxicity was reverted by addition

  20. PLGA-PEG Nanoparticles Coated with Anti-CD45RO and Loaded with HDAC Plus Protease Inhibitors Activate Latent HIV and Inhibit Viral Spread

    Science.gov (United States)

    Tang, Xiaolong; Liang, Yong; Liu, Xinkuang; Zhou, Shuping; Liu, Liang; Zhang, Fujina; Xie, Chunmei; Cai, Shuyu; Wei, Jia; Zhu, Yongqiang; Hou, Wei

    2015-10-01

    Activating HIV-1 proviruses in latent reservoirs combined with inhibiting viral spread might be an effective anti-HIV therapeutic strategy. Active specific delivery of therapeutic drugs into cells harboring latent HIV, without the use of viral vectors, is a critical challenge to this objective. In this study, nanoparticles of poly(lactic-co-glycolic acid)-polyethylene glycol diblock copolymers conjugated with anti-CD45RO antibody and loaded with the histone deacetylase inhibitor suberoylanilide hydroxamic acid (SAHA) and/or protease inhibitor nelfinavir (Nel) were tested for activity against latent virus in vitro. Nanoparticles loaded with SAHA, Nel, and SAHA + Nel were characterized in terms of size, surface morphology, zeta potential, entrapment efficiency, drug release, and toxicity to ACH-2 cells. We show that SAHA- and SAHA + Nel-loaded nanoparticles can target latently infected CD4+ T-cells and stimulate virus production. Moreover, nanoparticles loaded with SAHA + NEL were capable of both activating latent virus and inhibiting viral spread. Taken together, these data demonstrate the potential of this novel reagent for targeting and eliminating latent HIV reservoirs.

  1. Chelation Motifs Affecting Metal-dependent Viral Enzymes: N'-acylhydrazone Ligands as Dual Target Inhibitors of HIV-1 Integrase and Reverse Transcriptase Ribonuclease H Domain.

    Science.gov (United States)

    Carcelli, Mauro; Rogolino, Dominga; Gatti, Anna; Pala, Nicolino; Corona, Angela; Caredda, Alessia; Tramontano, Enzo; Pannecouque, Christophe; Naesens, Lieve; Esposito, Francesca

    2017-01-01

    Human immunodeficiency virus type 1 (HIV-1) infection, still represent a serious global health emergency. The chronic toxicity derived from the current anti-retroviral therapy limits the prolonged use of several antiretroviral agents, continuously requiring the discovery of new antiviral agents with innovative strategies of action. In particular, the development of single molecules targeting two proteins (dual inhibitors) is one of the current main goals in drug discovery. In this contest, metal-chelating molecules have been extensively explored as potential inhibitors of viral metal-dependent enzymes, resulting in some important classes of antiviral agents. Inhibition of HIV Integrase (IN) is, in this sense, paradigmatic. HIV-1 IN and Reverse Transcriptase-associated Ribonuclease H (RNase H) active sites show structural homologies, with the presence of two Mg(II) cofactors, hence it seems possible to inhibit both enzymes by means of chelating ligands with analogous structural features. Here we present a series of N'-acylhydrazone ligands with groups able to chelate the Mg(II) hard Lewis acid ions in the active sites of both the enzymes, resulting in dual inhibitors with micromolar and even nanomolar activities. The most interesting identified N'-acylhydrazone analog, compound 18, shows dual RNase H-IN inhibition and it is also able to inhibit viral replication in cell-based antiviral assays in the low micromolar range. Computational modeling studies were also conducted to explore the binding attitudes of some model ligands within the active site of both the enzymes.

  2. Raltegravir, tenofovir, and emtricitabine in an HIV-Infected patient with HCV chronic hepatitis, NNRTI intolerance and protease inhibitors-induced severe liver Toxicity

    Directory of Open Access Journals (Sweden)

    Ortu F

    2010-02-01

    Full Text Available Abstract Background in HIV-infected patients with HCV-related chronic hepatitis, liver impairment and drug toxicity may substantially reduce the number of possible therapeutic options. Case Description we here describe the case of an HCV-HIV coinfected woman who had repeated severe episodes of drug-related liver toxicity with indinavir, saquinavir, fosamprenavir, and darunavir, with minimal further therapeutic options left in this class. Previous treatment-limiting side effects with efavirenz and nevirapine also precluded use of non-nucleoside reverse transcriptase inhibitors. Introduction of an integrase-inhibitor regimen based on raltegravir, tenofovir, and emtricitabine allowed a prompt achievement of undetectable viral load and a substantial rise of CD4 count to high levels, with no subsequent episodes of hepatic toxicity, and no other side effects. Conclusions given the relatively common prevalence of HCV-related chronic hepatitis among people with HIV, raltegravir might represent an important alternative option for a substantial number of patients who cannot be treated with protease inhibitors or NNRTI because of drug-related hepatic toxicity.

  3. Exploring the drug resistance of V32I and M46L mutant HIV-1 protease to inhibitor TMC114: flap dynamics and binding mechanism.

    Science.gov (United States)

    Meher, Biswa Ranjan; Wang, Yixuan

    2015-03-01

    Inhibitors of HIV-1 protease (HIV-1-pr) generally only bind to the active site of the protease. However, for some mutants such as V32I and M46L the TMC114 can bind not only to the active cavity but also to the groove of the flexible flaps. Although the second binding site suggests the higher efficiency of the drug against HIV-1-pr, the drug resistance in HIV-1-pr due to mutations cannot be ignored, which prompts us to investigate the molecular mechanisms of drug resistance and behavior of double bound TMC114 (2T) to HIV-1-pr. The conformational dynamics of HIV-1-pr and the binding of TMC114 to the WT, V32I and M46L mutants were investigated with all-atom molecular dynamic (MD) simulation. The 20 ns MD simulation shows many fascinating effects of the inhibitor binding to the WT and mutant proteases. MM-PBSA calculations explain the binding free energies unfavorable for the M46L and V32I mutants as compared to the WT. For the single binding (1T) the less binding affinity can be attributed to the entropic loss for both V32I-1T and M46L-1T. Although the second binding of TMC114 with flap does increase binding energy for the mutants (V32I-2T and M46L-2T), the considerable entropy loss results in the lower binding Gibbs free energies. Thus, binding of TMC114 in the flap region does not help much in the total gain in binding affinity of the system, which was verified from this study and thereby validating experiments. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. Protease inhibitors as preferred initial regimen for antiretroviral-naive HIV patients.

    Science.gov (United States)

    Tejerina, Francisco; Bernaldo de Quirós, Juan Carlos López

    2011-01-01

    At present, the majority of patients who have initiated their first antiretroviral therapy have received a combination comprising a nonnucleoside and two nucleoside analogues. The use of nonnucleosides as first-line therapy has been favored for their more convenient dosing, with less pill numbers, and the possibility of co-formulation with nucleoside analogues. Although protease inhibitors are also considered to be a preferred standard, they have been less frequently used as first regimen of choice because of their adverse effects in the short to medium term. The introduction of darunavir and atazanavir as new protease inhibitors boosted with ritonavir has resulted in a significant change in this area. These drugs show a lower incidence of adverse effects, allow once-a-day administration, and have a high barrier to resistance that prevents the selection of resistance mutations in case of virologic failure. On this basis, it is likely that over the next few years these drugs will become a standard of care, gaining acceptance and being used more frequently as preferred first-line regimen.

  5. Structure of the HIV-1 reverse transcriptase Q151M mutant: insights into the inhibitor resistance of HIV-1 reverse transcriptase and the structure of the nucleotide-binding pocket of Hepatitis B virus polymerase

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Akiyoshi; Tamura, Noriko; Yasutake, Yoshiaki, E-mail: y-yasutake@aist.go.jp [National Institute of Advanced Industrial Science and Technology (AIST), 2-17-2-1 Tsukisamu-Higashi, Toyohira, Sapporo, Hokkaido 062-8517 (Japan)

    2015-10-23

    The structure of the HIV-1 reverse transcriptase Q151M mutant was determined at a resolution of 2.6 Å in space group P321. Hepatitis B virus polymerase (HBV Pol) is an important target for anti-HBV drug development; however, its low solubility and stability in vitro has hindered detailed structural studies. Certain nucleotide reverse transcriptase (RT) inhibitors (NRTIs) such as tenofovir and lamivudine can inhibit both HBV Pol and Human immunodeficiency virus 1 (HIV-1) RT, leading to speculation on structural and mechanistic analogies between the deoxynucleotide triphosphate (dNTP)-binding sites of these enzymes. The Q151M mutation in HIV-1 RT, located at the dNTP-binding site, confers resistance to various NRTIs, while maintaining sensitivity to tenofovir and lamivudine. The residue corresponding to Gln151 is strictly conserved as a methionine in HBV Pol. Therefore, the structure of the dNTP-binding pocket of the HIV-1 RT Q151M mutant may reflect that of HBV Pol. Here, the crystal structure of HIV-1 RT Q151M, determined at 2.6 Å resolution, in a new crystal form with space group P321 is presented. Although the structure of HIV-1 RT Q151M superimposes well onto that of HIV-1 RT in a closed conformation, a slight movement of the β-strands (β2–β3) that partially create the dNTP-binding pocket was observed. This movement might be caused by the introduction of the bulky thioether group of Met151. The structure also highlighted the possibility that the hydrogen-bonding network among amino acids and NRTIs is rearranged by the Q151M mutation, leading to a difference in the affinity of NRTIs for HIV-1 RT and HBV Pol.

  6. HIV

    African Journals Online (AJOL)

    Introduction. The·human immunodeficiency virus (HIV) can be transmiHed from one person to onother through the use of non-sterile nee- dles, syringes, and other skin-piercing and invasive instruments. Proper .sterilization of all such instruments is therefore important to prevent its transmission. HIV is very sensitive to ...

  7. hiv

    African Journals Online (AJOL)

    2016-03-31

    Mar 31, 2016 ... Indexed By: African Journal Online (AJOL); Texila American University; Genamics; Scholarsteer; EIJASR; CAS-American Chemical. Society; and IRMS Informatics India (J-Gate). ABSTRACT. This study evaluated the effect of HIV infection on CD4 T-lymphocyte depletion in people living with HIV/AIDS.

  8. Design, synthesis and evaluation of a potent substrate analog inhibitor identified by scanning Ala/Phe mutagenesis, mimicking substrate co-evolution, against multidrug-resistant HIV-1 protease

    Energy Technology Data Exchange (ETDEWEB)

    Yedidi, Ravikiran S. [Department of Biochemistry and Molecular Biology, School of Medicine, Wayne State University, Detroit, MI 48201 (United States); Muhuhi, Joseck M. [Department of Chemistry, Wayne State University, Detroit, MI 48202 (United States); Liu, Zhigang [Department of Biochemistry and Molecular Biology, School of Medicine, Wayne State University, Detroit, MI 48201 (United States); Bencze, Krisztina Z. [Department of Chemistry, Fort Hays State University, Hays, KS 67601 (United States); Koupparis, Kyriacos [Department of Biochemistry and Molecular Biology, School of Medicine, Wayne State University, Detroit, MI 48201 (United States); Department of Chemistry, Wayne State University, Detroit, MI 48202 (United States); O’Connor, Carrie E.; Kovari, Iulia A. [Department of Biochemistry and Molecular Biology, School of Medicine, Wayne State University, Detroit, MI 48201 (United States); Spaller, Mark R. [Department of Chemistry, Wayne State University, Detroit, MI 48202 (United States); Kovari, Ladislau C., E-mail: kovari@med.wayne.edu [Department of Biochemistry and Molecular Biology, School of Medicine, Wayne State University, Detroit, MI 48201 (United States)

    2013-09-06

    Highlights: •Inhibitors against MDR HIV-1 protease were designed, synthesized and evaluated. •Lead peptide (6a) showed potent inhibition (IC{sub 50}: 4.4 nM) of MDR HIV-1 protease. •(6a) Showed favorable binding isotherms against NL4-3 and MDR proteases. •(6a) Induced perturbations in the {sup 15}N-HSQC spectrum of MDR HIV-1 protease. •Molecular modeling suggested that (6a) may induce total flap closure inMDR protease. -- Abstract: Multidrug-resistant (MDR) clinical isolate-769, human immunodeficiency virus type-1 (HIV-1) protease (PDB ID: (1TW7)), was shown to exhibit wide-open flaps and an expanded active site cavity, causing loss of contacts with protease inhibitors. In the current study, the expanded active site cavity of MDR769 HIV-1 protease was screened with a series of peptide-inhibitors that were designed to mimic the natural substrate cleavage site, capsid/p2. Scanning Ala/Phe chemical mutagenesis approach was incorporated into the design of the peptide series to mimic the substrate co-evolution. Among the peptides synthesized and evaluated, a lead peptide (6a) with potent activity (IC{sub 50}: 4.4 nM) was identified against the MDR769 HIV-1 protease. Isothermal titration calorimetry data showed favorable binding profile for 6aagainst both wild type and MDR769 HIV-1 protease variants. Nuclear magnetic resonance spectrum of {sup 15}N-labeled MDR769 HIV-1 protease in complex with 6a showed some major perturbations in chemical shift, supporting the peptide induced conformational changes in protease. Modeling analysis revealed multiple contacts between 6a and MDR769 HIV-1 protease. The lead peptide-inhibitor, 6a, with high potency and good binding profile can be used as the basis for developing potent small molecule inhibitors against MDR variants of HIV.

  9. Simultaneous quantitation of HIV-protease inhibitors ritonavir, lopinavir and indinavir in human plasma by UPLC-ESI-MS-MS.

    Science.gov (United States)

    Das Mishra, Tulsi; Kurani, Hemal; Singhal, Puran; Shrivastav, Pranav S

    2012-08-01

    A selective, sensitive and high-throughput ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS-MS) method has been developed and validated for the quantification of HIV-protease inhibitors ritonavir (RTV), lopinavir (LPV) and indinavir (IDV) in human plasma. Sample clean-up involved protein precipitation of both drugs and fluconazole used as internal standard from 100 µL human plasma. All the analytes were chromatographically separated on a Waters Acquity UPLC BEH C18 (2.1 × 50 mm, 1.7 µm particle size) analytical column using 0.1% formic acid and methanol (40:60, v/v) as the mobile phase. The parent → product ion transitions for ritonavir (m/z 721.40→ 296.10), lopinavir (m/z 629.40→ 447.40) and indinavir (m/z 614.4→ 421.0) IS (m/z 307.10 → 220.10) were monitored on a triple quadrupole mass spectrometer, operating in the multiple reaction monitoring and positive ion mode. The method was validated over the concentration range of 30-15,000 ng/mL for LPV and IDV and 3-1500 ng/mL for RTV. The method was successfully applied to a pilot bioequivalence study in 36 healthy human subjects after oral administration of lopinavir 200 mg and ritonavir 50 mg tablet formulation under fasting conditions.

  10. Naringin Reverses Hepatocyte Apoptosis and Oxidative Stress Associated with HIV-1 Nucleotide Reverse Transcriptase Inhibitors-Induced Metabolic Complications

    Directory of Open Access Journals (Sweden)

    Oluwafeyisetan O. Adebiyi

    2015-12-01

    Full Text Available Nucleoside Reverse Transcriptase Inhibitors (NRTIs have not only improved therapeutic outcomes in the treatment of HIV infection but have also led to an increase in associated metabolic complications of NRTIs. Naringin’s effects in mitigating NRTI-induced complications were investigated in this study. Wistar rats, randomly allotted into seven groups (n = 7 were orally treated daily for 56 days with 100 mg/kg zidovudine (AZT (groups I, II III, 50 mg/kg stavudine (d4T (groups IV, V, VI and 3 mL/kg of distilled water (group VII. Additionally, rats in groups II and V were similarly treated with 50 mg/kg naringin, while groups III and VI were treated with 45 mg/kg vitamin E. AZT or d4T treatment significantly reduced body weight and plasma high density lipoprotein concentrations but increased liver weights, plasma triglycerides and total cholesterol compared to controls, respectively. Furthermore, AZT or d4T treatment significantly increased oxidative stress, adiposity index and expression of Bax protein, but reduced Bcl-2 protein expression compared to controls, respectively. However, either naringin or vitamin E significantly mitigated AZT- or d4T-induced weight loss, dyslipidemia, oxidative stress and hepatocyte apoptosis compared to AZT- or d4T-only treated rats. Our results suggest that naringin reverses metabolic complications associated with NRTIs by ameliorating oxidative stress and apoptosis. This implies that naringin supplements could mitigate lipodystrophy and dyslipidemia associated with NRTI therapy.

  11. Free energy calculation of single molecular interaction using Jarzynski's identity method: the case of HIV-1 protease inhibitor system

    Science.gov (United States)

    Li, De-Chang; Ji, Bao-Hua

    2012-06-01

    Jarzynski' identity (JI) method was suggested a promising tool for reconstructing free energy landscape of biomolecular interactions in numerical simulations and experiments. However, JI method has not yet been well tested in complex systems such as ligand-receptor molecular pairs. In this paper, we applied a huge number of steered molecular dynamics (SMD) simulations to dissociate the protease of human immunodeficiency type I virus (HIV-1 protease) and its inhibitors. We showed that because of intrinsic complexity of the ligand-receptor system, the energy barrier predicted by JI method at high pulling rates is much higher than experimental results. However, with a slower pulling rate and fewer switch times of simulations, the predictions of JI method can approach to the experiments. These results suggested that the JI method is more appropriate for reconstructing free energy landscape using the data taken from experiments, since the pulling rates used in experiments are often much slower than those in SMD simulations. Furthermore, we showed that a higher loading stiffness can produce higher precision of calculation of energy landscape because it yields a lower mean value and narrower bandwidth of work distribution in SMD simulations.

  12. Validation of Simultaneous Quantitative Method of HIV Protease Inhibitors Atazanavir, Darunavir and Ritonavir in Human Plasma by UPLC-MS/MS

    Directory of Open Access Journals (Sweden)

    Tulsidas Mishra

    2014-01-01

    Full Text Available Objectives. HIV protease inhibitors are used in the treatment of patients suffering from AIDS and they act at the final stage of viral replication by interfering with the HIV protease enzyme. The paper describes a selective, sensitive, and robust method for simultaneous determination of three protease inhibitors atazanavir, darunavir and ritonavir in human plasma by ultra performance liquid chromatography-tandem mass spectrometry. Materials and Methods. The sample pretreatment consisted of solid phase extraction of analytes and their deuterated analogs as internal standards from 50 μL human plasma. Chromatographic separation of analytes was performed on Waters Acquity UPLC C18 (50 × 2.1 mm, 1.7 μm column under gradient conditions using 10 mM ammonium formate, pH 4.0, and acetonitrile as the mobile phase. Results. The method was established over a concentration range of 5.0–6000 ng/mL for atazanavir, 5.0–5000 ng/mL for darunavir and 1.0–500 ng/mL for ritonavir. Accuracy, precision, matrix effect, recovery, and stability of the analytes were evaluated as per US FDA guidelines. Conclusions. The efficiency of sample preparation, short analysis time, and high selectivity permit simultaneous estimation of these inhibitors. The validated method can be useful in determining plasma concentration of these protease inhibitors for therapeutic drug monitoring and in high throughput clinical studies.

  13. 1-Hydroxypyrido[2,3-d]pyrimidin-2(1H)-ones as novel selective HIV integrase inhibitors obtained via privileged substructure-based compound libraries.

    Science.gov (United States)

    Gao, Ping; Zhang, Lingzi; Sun, Lin; Huang, Tianguang; Tan, Jing; Zhang, Jian; Zhou, Zhongxia; Zhao, Tong; Menéndez-Arias, Luis; Pannecouque, Christophe; Clercq, Erik De; Zhan, Peng; Liu, Xinyong

    2017-10-15

    A small library containing 3-hydroxyquinazoline-2,4(1H,3H)-dione and 1-hydroxypyrido[2,3-d]pyrimidin-2(1H)-one scaffolds was obtained via the copper(I)-catalyzed azidealkyne cycloaddition (CuAAC) reaction and evaluated for their anti-HIV activity in MT-4 cells. Among the synthesized compounds, several 1-hydroxypyrido[2,3-d]pyrimidin-2(1H)-one derivatives showed remarkable anti-HIV potency with EC 50 values ranging from 0.92 to 26.85µM. The most active one, IIA-2, also showed remarkable and selective potency against HIV type 1 integrase (IN). To the best of our knowledge, this is the first report showing that 1-hydroxypyrido[2,3-d]pyrimidin-2(1H)-ones are selective HIV IN inhibitors. Preliminary structure-activity relationship (SAR) studies suggested that the divalent metal ion chelators and the nature and position of substituents around the core are important for antiviral potency. Molecular modeling has been used to predict the binding site of the pyrido[2,3-d]pyrimidin-2(1H)-one core in HIV type 1 IN and suggestions are made for improvement of its inhibitory activity. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Lack of association between plasma levels of non-nucleoside reverse transcriptase inhibitors & virological outcomes during rifampicin co-administration in HIV-infected TB patients.

    Science.gov (United States)

    Ramachandran, Geetha; Kumar, A K Hemanth; Ponnuraja, C; Ramesh, K; Rajesh, Lakshmi; Chandrasekharan, C; Swaminathan, Soumya

    2013-12-01

    Among patients with HIV-associated tuberculosis (TB), reduced plasma non-nucleoside reverse transcriptase inhibitors (NNRTI) concentrations during rifampicin (RMP) co-administration could lead to HIV treatment failure. This study was undertaken to examine the association between plasma nevirapine (NVP) and efavirenz (EFV) concentrations and virological outcomes in patients infected with HIV-1 and TB. This was a nested study undertaken in a clinical trial of patients with HIV-1 and TB, randomized to two different once-daily antiretroviral treatment (ART) regimens along with anti-TB treatment (ATT). Trough concentrations of plasma NVP and EFV were estimated at months 1 (during ATT and ART) and 6 months (ART only) by HPLC. Plasma HIV-1 RNA level >400 copies/ml or death within 6 months of ART were considered as unfavourable outcomes. Genotyping of CYP2B6 516G>T polymorphism was performed. Twenty nine per cent of patients in NVP arm had an unfavourable outcome at 6 months compared to 9 per cent in EFV arm (PLogistic regression analysis showed CYP2B6 516G>T polymorphism significantly associated with virologic outcome in patients receiving EFV-based regimen. Trough plasma concentrations of NVP and EFV did not show any association with response to ART in patients on ATT and once-daily ART. CYP2B6 516G>T polymorphism was associated with virologic outcome among patients on EFV.

  15. Design and synthesis of potent HIV-1 protease inhibitors with (S)-tetrahydrofuran-tertiary amine-acetamide as P2-ligand: Structure-activity studies and biological evaluation.

    Science.gov (United States)

    Bai, Xiaoguang; Yang, Zhiheng; Zhu, Mei; Dong, Biao; Zhou, Lei; Zhang, Guoning; Wang, Juxian; Wang, Yucheng

    2017-09-08

    The design, synthesis, and SAR study of a new series of HIV-1 protease inhibitors incorporating stereochemically defined tetrahydrofuran-tertiary amine-acetamide P2-ligand are described. Various substituent effects on the tertiary amine P2-ligand and phenylsulfonamide P2'-ligand were investigated to maximize the ligand-binding site interactions in the protease active site. Most of inhibitors displayed low nanomolar to subnanomolar inhibitory potency. Inhibitor 20e containing N-(S-tetrahydrofuran)-N-(2-methoxyethyl)acetamide as P2-ligand along with 4-methoxylphenylsulfonamide as P2'-ligand displayed the most potent enzyme inhibitory activity (IC50 = 0.35 nM) and remarkably low cytotoxicity (CC50 = 305 μM). Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  16. Nuclear quantum effects in a HIV/cancer inhibitor: The case of ellipticine

    Science.gov (United States)

    Sappati, Subrahmanyam; Hassanali, Ali; Gebauer, Ralph; Ghosh, Prasenjit

    2016-11-01

    Ellipticine is a natural product that is currently being actively investigated for its inhibitory cancer and HIV properties. Here we use path-integral molecular dynamics coupled with excited state calculations to characterize the role of nuclear quantum effects on the structural and electronic properties of ellipticine in water, a common biological solvent. Quantum effects collectively enhance the fluctuations of both light and heavy nuclei of the covalent and hydrogen bonds in ellipticine. In particular, for the ellipticine-water system, where the proton donor and acceptor have different proton affinities, we find that nuclear quantum effects (NQEs) strengthen both the strong and the weak H bonds. This is in contrast to what is observed for the cases where the proton affinity of the donors and acceptors is same. These structural fluctuations cause a significant red-shift in the absorption spectra and an increase in the broadening, bringing it into closer agreement with the experiments. Our work shows that nuclear quantum effects alter both qualitatively and quantitatively the optical properties of this biologically relevant system and highlights the importance of the inclusion of these effects in the microscopic understanding of their optical properties. We propose that isotopic substitution will produce a blue shift and a reduction in the broadening of the absorption peak.

  17. Neoflavonoids as Inhibitors of HIV-1 Replication by Targeting the Tat and NF-κB Pathways

    Directory of Open Access Journals (Sweden)

    Dionisio A. Olmedo

    2017-02-01

    Full Text Available Twenty-eight neoflavonoids have been prepared and evaluated in vitro against HIV-1. Antiviral activity was assessed on MT-2 cells infected with viral clones carrying the luciferase reporter gene. Inhibition of HIV transcription and Tat function were tested on cells stably transfected with the HIV-LTR and Tat protein. Seven 4-phenylchromen-2-one derivatives showed HIV transcriptional inhibitory activity but only the phenylchrome-2-one 10 inhibited NF-κB and displayed anti-Tat activity simultaneously. Compounds 10, 14, and 25, inhibited HIV replication in both targets at concentrations <25 μM. The assays of these synthetic 4-phenylchromen-2-ones may aid in the investigation of some aspects of the anti-HIV activity of such compounds and could serve as a scaffold for designing better anti-HIV compounds, which may lead to a potential anti-HIV therapeutic drug.

  18. Natural Polymorphisms Conferring Resistance to HCV Protease and Polymerase Inhibitors in Treatment-Naïve HIV/HCV Co-Infected Patients in China.

    Directory of Open Access Journals (Sweden)

    Kali Zhou

    Full Text Available The advent of direct-acting agents (DAAs has improved treatment of HCV in HIV co-infection, but may be limited by primary drug resistance. This study reports the prevalence of natural polymorphisms conferring resistance to NS3/4A protease inhibitors and NS5B polymerase inhibitors in treatment-naïve HIV/HCV co-infected individuals in China.Population based NS3/4A sequencing was completed for 778 treatment-naïve HIV/HCV co-infected patients from twelve provinces. NS3 sequences were amplified by nested PCR using in-house primers for genotypes 1-6. NS5B sequencing was completed for genotyping in 350 sequences. Resistance-associated variants (RAVs were identified in positions associated with HCV resistance.Overall, 72.8% (566/778 of all HCV sequences had at least one RAV associated with HCV NS3/4A protease inhibitor resistance. Variants were found in 3.6% (7/193 of genotype 1, 100% (23/23 of genotype 2, 100% (237/237 of genotype 3 and 92% (299/325 of genotype 6 sequences. The Q80K variant was present in 98.4% of genotype 6a sequences. High-level RAVs were rare, occurring in only 0.8% of patients. 93% (64/69 patients with genotype 1b also carried the C316N variant associated with NS5B low-level resistance.The low frequency of high-level RAVs associated with primary HCV DAA resistance among all genotypes in HIV/HCV co-infected patients is encouraging. Further phenotypic studies and clinical research are needed.

  19. HIV-1 subtype influences susceptibility and response to monotherapy with the protease inhibitor lopinavir/ritonavir.

    Science.gov (United States)

    Sutherland, K A; Ghosn, J; Gregson, J; Mbisa, J L; Chaix, M L; Cohen Codar, I; Delfraissy, J F; Delaugerre, C; Gupta, R K

    2015-01-01

    PI susceptibility results from a complex interplay between protease and Gag proteins, with Gag showing wide variation across HIV-1 subtypes. We explored the impact of pre-treatment susceptibility on the outcome of lopinavir/ritonavir monotherapy. Treatment-naive individuals who experienced lopinavir/ritonavir monotherapy failure from the MONARK study were matched (by subtype, viral load and baseline CD4 count) with those who achieved virological response ('successes'). Successes were defined by viral load protease was amplified from patient samples for in vitro phenotypic susceptibility testing, with susceptibility expressed as fold change (FC) relative to a subtype B reference strain. Baseline lopinavir susceptibility was lower in viral failures compared with viral successes, but the differences were not statistically significant (median lopinavir susceptibility: 4.4 versus 8.5, respectively, P = 0.17). Among CRF02_AG/G patients, there was a significant difference in lopinavir susceptibility between the two groups (7.1 versus 10.4, P = 0.047), while in subtype B the difference was not significant (2.7 versus 3.4, P = 0.13). Subtype CRF02_AG/G viruses had a median lopinavir FC of 8.7 compared with 3.1 for subtype B (P = 0.001). We report an association between reduced PI susceptibility (using full-length Gag-protease sequences) at baseline and subsequent virological failure on lopinavir/ritonavir monotherapy in antiretroviral-naive patients harbouring subtype CRF02_AG/G viruses. We speculate that this may be important in the context of suboptimal adherence in determining viral failure. © The Author 2014. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy.

  20. Hologram quantitative structure-activity relationship and comparative molecular field analysis studies within a series of tricyclic phthalimide HIV-1 integrase inhibitors.

    Science.gov (United States)

    Magalhães, Uiaran de Oliveira; Souza, Alessandra Mendonça Teles de; Albuquerque, Magaly Girão; Brito, Monique Araújo de; Bello, Murilo Lamim; Cabral, Lucio Mendes; Rodrigues, Carlos Rangel

    2013-01-01

    Acquired immunodeficiency syndrome is a public health problem worldwide caused by the Human immunodeficiency virus (HIV). Treatment with antiretroviral drugs is the best option for viral suppression, reducing morbidity and mortality. However, viral resistance in HIV-1 therapy has been reported. HIV-1 integrase (IN) is an essential enzyme for effective viral replication and an attractive target for the development of new inhibitors. In the study reported here, two- and three-dimensional quantitative structure-activity relationship (2D/3D-QSAR) studies, applying hologram quantitative structure-activity relationship (HQSAR) and comparative molecular field analysis (CoMFA) methods, respectively, were performed on a series of tricyclic phthalimide HIV-1 IN inhibitors. The best HQSAR model (q (2) = 0.802, r (2) = 0.972) was obtained using atoms, bonds, and connectivity as the fragment distinction, a fragment size of 2-5 atoms, hologram length of 61 bins, and six components. The best CoMFA model (q (2) = 0.748, r (2) = 0.974) was obtained with alignment of all atoms of the tricyclic phthalimide moiety (alignment II). The HQSAR contribution map identified that the carbonyl-hydroxy-aromatic nitrogen motif made a positive contribution to the activity of the compounds. Furthermore, CoMFA contour maps suggested that bulky groups in meta and para positions in the phenyl ring would increase the biological activity of this class. The conclusions of this work may lead to a better understanding of HIV-1 IN inhibition and contribute to the design of new and more potent derivatives.

  1. Structural Basis for the Inhibition of RNase H Activity of HIV-1 Reverse Transcriptase by RNase H Active Site-Directed Inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Su, Hua-Poo; Yan, Youwei; Prasad, G. Sridhar; Smith, Robert F.; Daniels, Christopher L.; Abeywickrema, Pravien D.; Reid, John C.; Loughran, H. Marie; Kornienko, Maria; Sharma, Sujata; Grobler, Jay A.; Xu, Bei; Sardana, Vinod; Allison, Timothy J.; Williams, Peter D.; Darke, Paul L.; Hazuda, Daria J.; Munshi, Sanjeev (Merck)

    2010-09-02

    HIV/AIDS continues to be a menace to public health. Several drugs currently on the market have successfully improved the ability to manage the viral burden in infected patients. However, new drugs are needed to combat the rapid emergence of mutated forms of the virus that are resistant to existing therapies. Currently, approved drugs target three of the four major enzyme activities encoded by the virus that are critical to the HIV life cycle. Although a number of inhibitors of HIV RNase H activity have been reported, few inhibit by directly engaging the RNase H active site. Here, we describe structures of naphthyridinone-containing inhibitors bound to the RNase H active site. This class of compounds binds to the active site via two metal ions that are coordinated by catalytic site residues, D443, E478, D498, and D549. The directionality of the naphthyridinone pharmacophore is restricted by the ordering of D549 and H539 in the RNase H domain. In addition, one of the naphthyridinone-based compounds was found to bind at a second site close to the polymerase active site and non-nucleoside/nucleotide inhibitor sites in a metal-independent manner. Further characterization, using fluorescence-based thermal denaturation and a crystal structure of the isolated RNase H domain reveals that this compound can also bind the RNase H site and retains the metal-dependent binding mode of this class of molecules. These structures provide a means for structurally guided design of novel RNase H inhibitors.

  2. Conventional HPLC Method Used for Simultaneous Determination of the Seven HIV Protease Inhibitors and Nonnucleoside Reverse Transcription Inhibitor Efavirenz in Human Plasma

    National Research Council Canada - National Science Library

    Masaaki TAKAHASHIa; b; Masao YOSHIDAa; Tsuyoshi OKIa; Naoya OKUMURAa; Tatsuo SUZUKIa; Tsuguhiro KANEDAb

    2005-01-01

    We developed a simple HPLC method for the simultaneous quantitative determination of seven HIV protease inhibitors:amprenavir (APV), atazanavir (ATV), indinavir (IDV), lopinavir (LPV), nelfinavir (NFV), ritonavir (RTV), saquinavir (SQV...

  3. Impact of NRTI backbone on renal, bone and cardiovascular markers in HIV-infected individuals receiving a boosted protease inhibitor

    Directory of Open Access Journals (Sweden)

    Tristan Barber

    2014-11-01

    Full Text Available Introduction: We have previously shown in the SSAT 044 study that unconjugated hyperbilirubinaemia in subjects receiving a boosted protease inhibitor (PI/r has limited impact on renal, cardiovascular (CV and bone biomarkers, as well as on neurocognitive performance, relative to those receiving PI/r with a normal bilirubin. We present here a secondary analysis comparing markers in those receiving abacavir- vs tenofovir- based antiretroviral therapy (ART. Materials and Methods: This cross-sectional study included 101 HIV-1 infected individuals stable (HIV RNA6 months on antiretroviral regimens including tenofovir (TDF/emtricitabine or abacavir/lamivudine plus a ritonavir boosted PI. Results: Forty-three subjects had normal bilirubin (NBR levels and 35 had high bilirubin (>2.5 times upper limit; the remaining 23 patients had intermediate bilirubin levels or violated the protocol. The mean age of participants was 48 years; 93% were male and 84% Caucasian; 22 received ABC-based therapy and 78 TDF. No differences were seen in cardiovascular markers: Framingham (10-year risk % median, IQR: ABC 8.1, 5.6–15.3; TDF 9.5, 4.8–13.4 (p=ns; pulse wave velocity and carotid intimal thickness also showed no significant differences. No differences were seen in bone parameters: Calcaneal Stiffness Index (median score, IQR: ABC −0.5, −0.8 to 0.8; TDF −0.5, 1.4–0.4 (p=ns; 10 year FRAX score (% median, IQR: ABC 5.0, 2.4–6.2; TDF 3.6, 2.5–5.8 (p=ns. There were differences in renal parameters as shown in Table 1. We show statistically significant differences in urine protein/creatinine ratio (uPCR (10 vs 7; p=0.004 and urine albumin/creatinine ratio (uACR (15 vs 8; p=0.002, with both being higher in the TDF group. Conclusions: Tenofovir use is associated with excess loss of proteins including those typically resorbed in the renal tubule. Abacavir use was not associated with an increase in biomarkers of CV risk or vascular dysfunction.

  4. Effect of hyperbilirubinaemia on neurocognitive, renal, bone and cardiovascular markers in HIV infection treated with boosted protease inhibitors

    Directory of Open Access Journals (Sweden)

    Tristan J Barber

    2014-11-01

    Full Text Available Introduction: Use of some protease inhibitors (PI is associated with unconjugated hyperbilirubinaemia (HBR, due to inhibition of UGT1A1. As observed in Gilbert's syndrome, HBR may have antioxidant and anti-inflammatory effects. Inflammation may be relevant to neurocognitive (NC impairment, cardiovascular, renal and bone co-morbidities in HIV infection. This study aimed to analyse correlations between antiretroviral associated HBR and NC impairment as well as renal, bone and cardiovascular parameters. Material and Methods: This cross-sectional study included 101 HIV-1-infected individuals stable (>6 months on antiretroviral regimens including tenofovir/emtricitabine or abacavir/lamivudine plus a ritonavir-boosted PI. Patients with >grade 2 HBR were compared to patients with normal bilirubin on NC data collected using CogState. An overall composite score was calculated for each subject. Two-tail P-values were calculated using the Mann-Whitney U test. We measured the following parameters in all participants: Bone – Calcaneal Stiffness Index (CSI, blood bone markers, calculated FRAX score; CV – vascular endothelial function markers (iCAM, vCAM, lipid fractions and sub fractions (Total, HDL and LDL cholesterol, triglycerides, ApoB, Carotid Intimal Thickness (CIT, Pulse Wave Velocity (PWV, glucose and insulin for calculation of HOMA-IR, IL-6, d-dimer, uric acid, and hsCRP; Renal – urea and electrolytes (U&E, urinary protein/creatinine ratio (uPCR, urinary retinal binding protein (RBP/creatinine ratio. Results: Forty-three participants had normal bilirubin (NBR levels and 35 had high bilirubin (HBR; >2.5 times upper limit; the remaining 23 patients had intermediate bilirubin levels or violated the protocol. The mean age of participants was 48 years; 93% were male and 84% Caucasian. Mostly no significant differences were seen in any of the markers when comparing the NBR and HBR groups. Two component tests of the CogState were seen to be different

  5. HIV signaling through CD4 and CCR5 activates Rho family GTPases that are required for optimal infection of primary CD4+ T cells.

    Science.gov (United States)

    Lucera, Mark B; Fleissner, Zach; Tabler, Caroline O; Schlatzer, Daniela M; Troyer, Zach; Tilton, John C

    2017-01-24

    HIV-1 hijacks host cell machinery to ensure successful replication, including cytoskeletal components for intracellular trafficking, nucleoproteins for pre-integration complex import, and the ESCRT pathway for assembly and budding. It is widely appreciated that cellular post-translational modifications (PTMs) regulate protein activity within cells; however, little is known about how PTMs influence HIV replication. Previously, we reported that blocking deacetylation of tubulin using histone deacetylase inhibitors promoted the kinetics and efficiency of early post-entry viral events. To uncover additional PTMs that modulate entry and early post-entry stages in HIV infection, we employed a flow cytometric approach to assess a panel of small molecule inhibitors on viral fusion and LTR promoter-driven gene expression. While viral fusion was not significantly affected, early post-entry viral events were modulated by drugs targeting multiple processes including histone deacetylation, methylation, and bromodomain inhibition. Most notably, we observed that inhibitors of the Rho GTPase family of cytoskeletal regulators-including RhoA, Cdc42, and Rho-associated kinase signaling pathways-significantly reduced viral infection. Using phosphoproteomics and a biochemical GTPase activation assay, we found that virion-induced signaling via CD4 and CCR5 activated Rho family GTPases including Rac1 and Cdc42 and led to widespread modification of GTPase signaling-associated factors. Together, these data demonstrate that HIV signaling activates members of the Rho GTPase family of cytoskeletal regulators that are required for optimal HIV infection of primary CD4+ T cells.

  6. Inhibition of HIV-1 replication by P-TEFb inhibitors DRB, seliciclib and flavopiridol correlates with release of free P-TEFb from the large, inactive form of the complex

    Directory of Open Access Journals (Sweden)

    Nguyen Van Trung

    2007-07-01

    Full Text Available Abstract Background The positive transcription elongation factor, P-TEFb, comprised of cyclin dependent kinase 9 (Cdk9 and cyclin T1, T2 or K regulates the productive elongation phase of RNA polymerase II (Pol II dependent transcription of cellular and integrated viral genes. P-TEFb containing cyclin T1 is recruited to the HIV long terminal repeat (LTR by binding to HIV Tat which in turn binds to the nascent HIV transcript. Within the cell, P-TEFb exists as a kinase-active, free form and a larger, kinase-inactive form that is believed to serve as a reservoir for the smaller form. Results We developed a method to rapidly quantitate the relative amounts of the two forms based on differential nuclear extraction. Using this technique, we found that titration of the P-TEFb inhibitors flavopiridol, DRB and seliciclib onto HeLa cells that support HIV replication led to a dose dependent loss of the large form of P-TEFb. Importantly, the reduction in the large form correlated with a reduction in HIV-1 replication such that when 50% of the large form was gone, HIV-1 replication was reduced by 50%. Some of the compounds were able to effectively block HIV replication without having a significant impact on cell viability. The most effective P-TEFb inhibitor flavopiridol was evaluated against HIV-1 in the physiologically relevant cell types, peripheral blood lymphocytes (PBLs and monocyte derived macrophages (MDMs. Flavopiridol was found to have a smaller therapeutic index (LD50/IC50 in long term HIV-1 infectivity studies in primary cells due to greater cytotoxicity and reduced efficacy at blocking HIV-1 replication. Conclusion Initial short term studies with P-TEFb inhibitors demonstrated a dose dependent loss of the large form of P-TEFb within the cell and a concomitant reduction in HIV-1 infectivity without significant cytotoxicity. These findings suggested that inhibitors of P-TEFb may serve as effective anti-HIV-1 therapies. However, longer term HIV-1

  7. Multicenter study of skin rashes and hepatotoxicity in antiretroviral-na?ve HIV-positive patients receiving non-nucleoside reverse-transcriptase inhibitor plus nucleoside reverse-transcriptase inhibitors in Taiwan

    OpenAIRE

    Wu, Pei-Ying; Cheng, Chien-Yu; Liu, Chun-Eng; Lee, Yi-Chien; Yang, Chia-Jui; Tsai, Mao-Song; Cheng, Shu-Hsing; Lin, Shih-Ping; Lin, De-Yu; Wang, Ning-Chi; Lee, Yi-Chieh; Sun, Hsin-Yun; Tang, Hung-Jen; Hung, Chien-Ching

    2017-01-01

    Objectives Two nucleos(t)ide reverse-transcriptase inhibitors (NRTIs) plus 1 non-NRTI (nNRTI) remain the preferred or alternative combination antiretroviral therapy (cART) for antiretroviral-naive HIV-positive patients in Taiwan. The three most commonly used nNRTIs are nevirapine (NVP), efavirenz (EFV) and rilpivirine (RPV). This study aimed to determine the incidences of hepatotoxicity and skin rashes within 4 weeks of initiation of cART containing 1 nNRTI plus 2 NRTIs. Methods Between June,...

  8. Deep sequencing of protease inhibitor resistant HIV patient isolates reveals patterns of correlated mutations in Gag and protease.

    Science.gov (United States)

    Flynn, William F; Chang, Max W; Tan, Zhiqiang; Oliveira, Glenn; Yuan, Jinyun; Okulicz, Jason F; Torbett, Bruce E; Levy, Ronald M

    2015-04-01

    While the role of drug resistance mutations in HIV protease has been studied comprehensively, mutations in its substrate, Gag, have not been extensively cataloged. Using deep sequencing, we analyzed a unique collection of longitudinal viral samples from 93 patients who have been treated with therapies containing protease inhibitors (PIs). Due to the high sequence coverage within each sample, the frequencies of mutations at individual positions were calculated with high precision. We used this information to characterize the variability in the Gag polyprotein and its effects on PI-therapy outcomes. To examine covariation of mutations between two different sites using deep sequencing data, we developed an approach to estimate the tight bounds on the two-site bivariate probabilities in each viral sample, and the mutual information between pairs of positions based on all the bounds. Utilizing the new methodology we found that mutations in the matrix and p6 proteins contribute to continued therapy failure and have a major role in the network of strongly correlated mutations in the Gag polyprotein, as well as between Gag and protease. Although covariation is not direct evidence of structural propensities, we found the strongest correlations between residues on capsid and matrix of the same Gag protein were often due to structural proximity. This suggests that some of the strongest inter-protein Gag correlations are the result of structural proximity. Moreover, the strong covariation between residues in matrix and capsid at the N-terminus with p1 and p6 at the C-terminus is consistent with residue-residue contacts between these proteins at some point in the viral life cycle.

  9. Resistance of Human Immunodeficiency Virus Type 1 to a Third-Generation Fusion Inhibitor Requires Multiple Mutations in gp41 and Is Accompanied by a Dramatic Loss of gp41 Function

    NARCIS (Netherlands)

    Eggink, Dirk; Bontjer, Ilja; Langedijk, Johannes P. M.; Berkhout, Ben; Sanders, Rogier W.

    2011-01-01

    HIV-1 entry into target cells requires the fusion of viral and cellular membranes. This process is an attractive target for therapeutic intervention, and a first-generation fusion inhibitor, T20 (Enfuvirtide; Fuzeon), was approved for clinical use in 2003. Second-generation (T1249) and

  10. Homology modeling and molecular interaction field studies of α-glucosidases as a guide to structure-based design of novel proposed anti-HIV inhibitors

    Science.gov (United States)

    da Silva, C. H. Tomich, P.; Carvalho, Ivone; Taft, C. A.

    2005-02-01

    For AIDS therapy, there are currently a number of compounds available for multiple targets already approved by the FDA and in clinic, e.g. protease inhibitors, reverse transcriptase inhibitors (NRTI, NNRTI), fusion inhibitors, CCR4, CCR5 among others. Some pharmaceuticals act against the virus before the entrance of HIV into the host cells. One of these targets is the glucosidase protein. This novel fusion target has been recently explored because the synthesis of viral glycoproteins depends on the activity of enzymes, such as glucosidase and transferase, for the elaboration of the polysaccharides. In this work we have built an homology model of Saccharomyces cerevisiae glucosidase and superimposed all relevant glucosidase-like enzymes in complex with carbohydrates, and calculated as well molecular interaction fields in our S. cerevisiae active site model. Our results suggest that there are two saccharide binding sites which are the most important for the binding of inhibitors with this family of enzymes which supports the possibility of inhibitors containing only two sugar units. Based on these results, we have proposed a novel pseudo-dissacharide which is a potential pharmaceutical for AIDS treatment.

  11. Complex Patterns of Protease Inhibitor Resistance among Antiretroviral Treatment-Experienced HIV-2 Patients from Senegal: Implications for Second-Line Therapy

    Science.gov (United States)

    Smith, Robert A.; Ba, Selly; Toure, Macoumba; Traore, Fatou; Sall, Fatima; Pan, Charlotte; Blankenship, Lindsey; Montano, Alexandra; Olson, Julia; Dia Badiane, Ndeye Mery; Mullins, James I.; Kiviat, Nancy B.; Hawes, Stephen E.; Sow, Papa Salif; Gottlieb, Geoffrey S.

    2013-01-01

    Protease inhibitor (PI)-based antiretroviral therapy (ART) can effectively suppress HIV-2 plasma load and increase CD4 counts; however, not all PIs are equally active against HIV-2, and few data exist to support second-line therapy decisions. To identify therapeutic options for HIV-2 patients failing ART, we evaluated the frequency of PI resistance-associated amino acid changes in HIV-2 sequences from a cohort of 43 Senegalese individuals receiving unboosted indinavir (n = 18 subjects)-, lopinavir/ritonavir (n = 4)-, or indinavir and then lopinavir/ritonavir (n = 21)-containing ART. Common protease substitutions included V10I, V47A, I54M, V71I, I82F, I84V, L90M, and L99F, and most patients harbored viruses containing multiple changes. Based on genotypic data, we constructed a panel of 15 site-directed mutants of HIV-2ROD9 containing single- or multiple-treatment-associated amino acid changes in the protease-encoding region of pol. We then quantified the susceptibilities of the mutants to the HIV-2 “active” PIs saquinavir, lopinavir, and darunavir using a single-cycle assay. Relative to wild-type HIV-2, the V47A mutant was resistant to lopinavir (6.3-fold increase in the mean 50% effective concentration [EC50]), the I54M variant was resistant to darunavir and lopinavir (6.2- and 2.7-fold increases, respectively), and the L90M mutant was resistant to saquinavir (3.6-fold increase). In addition, the triple mutant that included I54M plus I84V plus L90M was resistant to all three PIs (31-, 10-, and 3.8-fold increases in the mean EC50 for darunavir, saquinavir, and lopinavir, respectively). Taken together, our data demonstrate that PI-treated HIV-2 patients frequently harbor viruses that exhibit complex patterns of PI cross-resistance. These findings suggest that sequential PI-based regimens for HIV-2 treatment may be ineffective. PMID:23571535

  12. LMP-420, a small-molecule inhibitor of TNF-alpha, reduces replication of HIV-1 and Mycobacterium tuberculosis in human cells

    Directory of Open Access Journals (Sweden)

    Tangsinmankong Nutthapong

    2006-03-01

    Full Text Available Abstract Background Co-infections of human immunodeficiency virus (HIV and Mycobacterium tuberculosis (M. Tb are steadily increasing and represent a major health crisis in many developing countries. Both pathogens individually stimulate tumor necrosis factor-alpha (TNF release from infected cells and TNF, in turn, enhances the replication of each. A recent report on a Phase I clinical trial suggested that etanercept (soluble TNF receptor might be beneficial in treating HIV/M. Tb co-infected patients. We sought to determine if a small molecule inhibitor of TNF synthesis and activity could block replication of either organism and thus be a potential adjunct to existing drugs targeting these agents. Results LMP-420, a novel anti-inflammatory agent that inhibits TNF, was tested for HIV-1 inhibition both alone and in combination with AZT (3' -azido-3-deoxythymidine. LMP-420 alone was tested against M. Tb. HIV-1 infected human peripheral blood mononuclear cells (PBMC or M. Tb-infected human alveolar macrophages (AM were treated with a single dose of LMP-420 and viral or bacterial replication determined after 7 or 5 days respectively. Viral replication was determined from supernatant p24 levels measured by ELISA. M. Tb replication was determined by bacterial culture of macrophage lysates. LMP-420 alone inhibited HIV replication over 7 days with an IC50 of ~300 nM. Combination of LMP-420 with AZT doubled the level of HIV inhibition observed with AZT alone. LMP-420 alone inhibited the replication of virulent M. Tb by >80%, more than that observed with anti-TNF antibody alone. Conclusion Inhibition of TNF with inexpensive, small-molecule, orally-active drugs may represent a useful strategy for enhancing the activity of currently-available antiviral and anti-M. Tb agents, particularly in those areas where co-infections with these pathogens act to synergistically enhance each other.

  13. HIV-1 strains belonging to large phylogenetic clusters show accelerated escape from integrase inhibitors in cell culture compared with viral isolates from singleton/small clusters.

    Science.gov (United States)

    Brenner, Bluma G; Ibanescu, Ruxandra-Ilinca; Oliveira, Maureen; Roger, Michel; Hardy, Isabelle; Routy, Jean-Pierre; Kyeyune, Fred; Quiñones-Mateu, Miguel E; Wainberg, Mark A

    2017-08-01

    Viral phylogenetics revealed two patterns of HIV-1 spread among MSM in Quebec. While most HIV-1 strains ( n  =   2011) were associated with singleton/small clusters (cluster size 1-4), 30 viral lineages formed large networks (cluster size 20-140), contributing to 42% of diagnoses between 2011 and 2015. Herein, tissue culture selections ascertained if large cluster lineages possessed higher replicative fitness than singleton/small cluster isolates, allowing for viral escape from integrase inhibitors. Primary HIV-1 isolates from large 20+ cluster ( n  =   11) or singleton/small cluster ( n  =   6) networks were passaged in vitro in escalating concentrations of dolutegravir, elvitegravir and lamivudine for 24-36 weeks. Sanger and deep sequencing assessed genotypic changes under selective drug pressure. Large cluster HIV-1 isolates selected for resistance to dolutegravir, elvitegravir and lamivudine faster than HIV-1 strains forming small clusters. With dolutegravir, large cluster HIV-1 variants acquired solitary R263K ( n  =   7), S153Y ( n  =   1) or H51Y ( n  =   1) mutations as the dominant quasi-species within 8-12 weeks as compared with small cluster lineages where R263K ( n  =   1/6), S153Y (1/6) or WT species (4/6) were observed after 24 weeks. Interestingly, dolutegravir-associated mutations compromised viral replicative fitness, precluding escalations in concentrations beyond 5-10 nM. With elvitegravir, large cluster variants more rapidly acquired first mutations (T66I, A92G, N155H or S147G) by week 8 followed by sequential accumulation of multiple mutations leading to viral escape (>10 μM) by week 24. Further studies are needed to understand virological features of large cluster viruses that may favour their transmissibility, replicative competence and potential to escape selective antiretroviral drug pressure.

  14. Virologic failure of protease inhibitor-based second-line antiretroviral therapy without resistance in a large HIV treatment program in South Africa.

    Directory of Open Access Journals (Sweden)

    Julie H Levison

    Full Text Available We investigated the prevalence of wild-type virus (no major drug resistance and drug resistance mutations at second-line antiretroviral treatment (ART failure in a large HIV treatment program in South Africa.HIV-infected patients ≥ 15 years of age who had failed protease inhibitor (PI-based second-line ART (2 consecutive HIV RNA tests >1000 copies/ml on lopinavir/ritonavir, didanosine, and zidovudine were identified retrospectively. Patients with virologic failure were continued on second-line ART. Genotypic testing for drug resistance was performed on frozen plasma samples obtained closest to and after the date of laboratory confirmed second-line ART failure. Of 322 HIV-infected patients on second-line ART, 43 were adults with confirmed virologic failure, and 33 had available plasma for viral sequencing. HIV-1 RNA subtype C predominated (n = 32, 97%. Mean duration on ART (SD prior to initiation of second-line ART was 23 (17 months, and time from second-line ART initiation to failure was 10 (9 months. Plasma samples were obtained 7(9 months from confirmed failure. At second-line failure, 22 patients (67% had wild-type virus. There was no major resistance to PIs found. Eleven of 33 patients had a second plasma sample taken 8 (5.5 months after the first. Median HIV-1 RNA and the genotypic resistance profile were unchanged.Most patients who failed second-line ART had wild-type virus. We did not observe evolution of resistance despite continuation of PI-based ART after failure. Interventions that successfully improve adherence could allow patients to continue to benefit from second-line ART therapy even after initial failure.

  15. Design, synthesis and biological evaluations of N-Hydroxy thienopyrimidine-2,4-diones as inhibitors of HIV reverse transcriptase-associated RNase H.

    Science.gov (United States)

    Kankanala, Jayakanth; Kirby, Karen A; Huber, Andrew D; Casey, Mary C; Wilson, Daniel J; Sarafianos, Stefan G; Wang, Zhengqiang

    2017-12-01

    Human immunodeficiency virus (HIV) reverse transcriptase (RT) associated ribonuclease H (RNase H) is the only HIV enzymatic function not targeted by current antiviral drugs. Although various chemotypes have been reported to inhibit HIV RNase H, few have shown significant antiviral activities. We report herein the design, synthesis and biological evaluation of a novel N-hydroxy thienopyrimidine-2,3-dione chemotype (11) which potently and selectively inhibited RNase H with considerable potency against HIV-1 in cell culture. Current structure-activity-relationship (SAR) identified analogue 11d as a nanomolar inhibitor of RNase H (IC 50  = 0.04 μM) with decent antiviral potency (EC 50  = 7.4 μM) and no cytotoxicity (CC 50  > 100 μM). In extended biochemical assays compound 11d did not inhibit RT polymerase (pol) while inhibiting integrase strand transfer (INST) with 53 fold lower potency (IC 50  = 2.1 μM) than RNase H inhibition. Crystallographic and molecular modeling studies confirmed the RNase H active site binding mode. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  16. A Biochemical/Biophysical Assay Dyad for HTS-Compatible Triaging of Inhibitors of the HIV-1 Nef/Hck SH3 Interaction

    KAUST Repository

    Breuer, Sebastian

    2013-07-26

    The current treatment regimens for HIV include over 20 anti-retrovirals. However, adverse drug effects and the emergence of drug resistance necessitates the continued improvement of the existing drug classes as well as the development of novel drugs that target as yet therapeutically unexploited viral and cellular pathways. Here we demonstrate a strategy for the discovery of protein-protein interaction inhibitors of the viral pathogenicity factor HIV-1 Nef and its interaction with the host factor SH3. A combination of a time-resolved fluorescence resonance energy resonance energy transfer-based assay and a label-free resonant waveguide grating-based assay was optimized for high-throughput screening formats.

  17. GRL-0519, a Novel Oxatricyclic Ligand-Containing Nonpeptidic HIV-1 Protease Inhibitor (PI), Potently Suppresses Replication of a Wide Spectrum of Multi-PI-Resistant HIV-1 Variants In Vitro

    Science.gov (United States)

    Amano, Masayuki; Tojo, Yasushi; Salcedo-Gómez, Pedro Miguel; Campbell, Joseph Richard; Das, Debananda; Aoki, Manabu; Xu, Chun-Xiao; Rao, Kalapala Venkateswara; Ghosh, Arun K.

    2013-01-01

    We report that GRL-0519, a novel nonpeptidic human immunodeficiency virus type 1 (HIV-1) protease inhibitor (PI) containing tris-tetrahydrofuranylurethane (tris-THF) and a sulfonamide isostere, is highly potent against laboratory HIV-1 strains and primary clinical isolates (50% effective concentration [EC50], 0.0005 to 0.0007 μM) with minimal cytotoxicity (50% cytotoxic concentration [CC50], 44.6 μM). GRL-0519 blocked the infectivity and replication of HIV-1NL4-3 variants selected by up to a 5 μM concentration of ritonavir, lopinavir, or atazanavir (EC50, 0.0028 to 0.0033 μM). GRL-0519 was also potent against multi-PI-resistant clinical HIV-1 variants isolated from patients who no longer responded to existing antiviral regimens after long-term antiretroviral therapy, highly darunavir (DRV)-resistant variants, and HIV-2ROD. The development of resistance against GRL-0519 was substantially delayed compared to other PIs, including amprenavir (APV) and DRV. The effects of nonspecific binding of human serum proteins on GRL-0519's antiviral activity were insignificant. Our analysis of the crystal structures of GRL-0519 (3OK9) and DRV (2IEN) with protease suggested that the tris-THF moiety, compared to the bis-THF moiety present in DRV, has greater water-mediated polar interactions with key active-site residues of protease and that the tris-THF moiety and paramethoxy group effectively fill the S2 and S2′ binding pockets, respectively, of the protease. The present data demonstrate that GRL-0519 has highly favorable features as a potential therapeutic agent for treating patients infected with wild-type and/or multi-PI-resistant variants and that the tris-THF moiety is critical for strong binding of GRL-0519 to the HIV protease substrate binding site and appears to be responsible for its favorable antiretroviral characteristics. PMID:23403426

  18. Development of a Novel Screening Strategy Designed to Discover a New Class of HIV Drugs.

    Science.gov (United States)

    Cheng, Nancy; Lee, Sook-Kyung; Donover, P Scott; Reichman, Mel; Schiffer, Celia A; Hull-Ryde, Emily A; Swanstrom, Ronald; Janzen, William P

    2014-06-01

    Current antiretroviral treatments target multiple pathways important for human immunodeficiency virus (HIV) multiplication, including viral entry, synthesis and integration of the DNA provirus, and the processing of viral polyprotein precursors. However, HIV is becoming increasingly resistant to these "combination therapies." Recent findings show that inhibition of HIV Gag protein cleavage into its two structural proteins, matrix (MA) and capsid (CA), has a devastating effect on viral production, revealing a potential new target class for HIV treatment. Unlike the widely used HIV protease inhibitors, this new class of inhibitor would target the substrate, not the protease enzyme itself. This approach offers a distinct advantage in that inhibitors of MA/CA would only need to affect a subset of the Gag molecules to disable viral replication. To discover MA/CA-specific inhibitors, we constructed a modified MA/CA fusion peptide (MA/CAΔ) that contains the HIV protease (PR) cleavage site as well as a tetracysteine motif for fluorescent labeling. The HIV PR cleavage of MA/CAΔ can then be monitored via fluorescence polarization (FP). We have adapted this FP assay for high-throughput screening and validated it according to industry standards using a 384-well plate format. We have currently tested 24,000 compounds in this assay and here detail the screening methodology and the results of this screening campaign. © 2013 Society for Laboratory Automation and Screening.

  19. Evaluation of Routine HIV Opt-Out Screening and Continuum of Care Services Following Entry into Eight Prison Reception Centers--California, 2012.

    Science.gov (United States)

    Lucas, Kimberley D; Eckert, Valorie; Behrends, Czarina N; Wheeler, Charlotte; MacGowan, Robin J; Mohle-Boetani, Janet C

    2016-02-26

    Early diagnosis of human immunodeficiency virus (HIV) infection and initiation of antiretroviral treatment (ART) improves health outcomes and prevents HIV transmission. Before 2010, HIV testing was available to inmates in the California state prison system upon request. In 2010, the California Correctional Health Care Services (CCHCS) integrated HIV opt-out screening into the health assessment for inmates entering California state prisons. Under this system, a medical care provider informs the inmate that an HIV test is routinely done, along with screening for sexually transmitted, communicable, and vaccine-preventable diseases, unless the inmate specifically declines the test. During 2012-2013, CCHCS, the California Department of Public Health, and CDC evaluated HIV screening, rates of new diagnoses, linkage to and retention in care, ART response, and post-release linkage to care among California prison inmates. All prison inmates are processed through one of eight specialized reception center facilities, where they undergo a comprehensive evaluation of their medical needs, mental health, and custody requirements for placement in one of 35 state prisons. Among 17,436 inmates who entered a reception center during April-September 2012, 77% were screened for HIV infection; 135 (1%) tested positive, including 10 (0.1%) with newly diagnosed infections. Among the 135 HIV-positive patient-inmates, 134 (99%) were linked to care within 90 days of diagnosis, including 122 (91%) who initiated ART. Among 83 who initiated ART and remained incarcerated through July 2013, 81 (98%) continued ART; 71 (88%) achieved viral suppression (HIV RNA copies/mL). Thirty-nine patient-inmates were released on ART; 12 of 14 who were linked to care within 30 days of release were virally suppressed at that time. Only one of nine persons with a viral load test conducted between 91 days and 1 year post-release had viral suppression. Although high rates of viral suppression were achieved in prison

  20. Molecular dynamics and MM/GBSA-integrated protocol probing the correlation between biological activities and binding free energies of HIV-1 TAR RNA inhibitors.

    Science.gov (United States)

    Peddi, Saikiran Reddy; Sivan, Sree Kanth; Manga, Vijjulatha

    2018-02-01

    The interaction of HIV-1 transactivator protein Tat with its cognate transactivation response (TAR) RNA has emerged as a promising target for developing antiviral compounds and treating HIV infection, since it is a crucial step for efficient transcription and replication. In the present study, molecular dynamics (MD) simulations and MM/GBSA calculations have been performed on a series of neamine derivatives in order to estimate appropriate MD simulation time for acceptable correlation between ΔG bind and experimental pIC 50 values. Initially, all inhibitors were docked into the active site of HIV-1 TAR RNA. Later to explore various conformations and examine the docking results, MD simulations were carried out. Finally, binding free energies were calculated using MM/GBSA method and were correlated with experimental pIC 50 values at different time scales (0-1 to 0-10 ns). From this study, it is clear that in case of neamine derivatives as simulation time increased the correlation between binding free energy and experimental pIC 50 values increased correspondingly. Therefore, the binding energies which can be interpreted at longer simulation times can be used to predict the bioactivity of new neamine derivatives. Moreover, in this work, we have identified some plausible critical nucleotide interactions with neamine derivatives that are responsible for potent inhibitory activity. Furthermore, we also provide some insights into a new class of oxadiazole-based back bone cyclic peptides designed by incorporating the structural features of neamine derivatives. On the whole, this approach can provide a valuable guidance for designing new potent inhibitors and modify the existing compounds targeting HIV-1 TAR RNA.

  1. Coarse-grained molecular dynamics of ligands binding into protein: The case of HIV-1 protease inhibitors

    Science.gov (United States)

    Li, Dechang; Liu, Ming S.; Ji, Baohua; Hwang, Kehchih; Huang, Yonggang

    2009-06-01

    Binding dynamics and pathways of ligands or inhibitors to target proteins are challenging both experimental and theoretical biologists. A dynamics understanding of inhibitors interacting with protein is essential for the design of novel potent drugs. In this work we applied a coarse-grained molecular dynamics method for simulating inhibitors entering the binding cavity of human immunodeficiency virus type 1 protease (PR). It shows that the coarse-grained dynamics, consistent with the experimental results, can capture the essential molecular dynamics of various inhibitors binding into PR. The primary driving force for the binding processes is the nonbond interaction between inhibitors and PR. The size and topology of inhibitors and the interacting strength between inhibitors and PR have great influence on the binding mode and processes. The interaction strength between the PR and various inhibitors is also analyzed by atomistic molecular mechanics and Poisson-Boltzmann solvation area method.

  2. HIV-1整合酶链转移反应抑制剂的荧光筛选方法%A Fluorescent Screening Assay for HIV-1 Integrase Inhibitors Targeting Strand Transfer

    Institute of Scientific and Technical Information of China (English)

    刘斌; 刘昕; 李杉; 何红秋; 张小轶; 谭建军; 陈慰祖; 王存新

    2013-01-01

    HIV-1 integrase is an ideal target for anti-HIV-1 drug discovery. The aim of the present study was to develop a highly effective and more convenient screening assay for HIV-1 integrase inhibitors targeting strand transfer. First, the recombinant expression vector pNL-IN, which contains the HIV-1 integrase gene, was transformed into E. coli BL21 ( DE3 ) competent cells for prokaryotic expression. The recombinant integrase protein was purified by affinity chromatography. It was validated that the recombinant integrase protein was pure and active for screening assay development. Then, the biotin-labeled donor DNA and the FITC-labeled target DNA were synthesized and applied in the assay, and streptavidin-coated magnetic beads were used to capture the product DNA in the reaction system. Finally, the fluorescence signal was detected by a fluorescence microplate reader for the calculation of sample activity. Two reported integrase inhibitors, S-1360 and MK-0518 , were tested to validate the screening assay, and the results are in accordance with previous studies, which indicated that the screening assay could be used for the screening of integrase inhibitor targeting strand transfer. The screening assay for HIV-1 integrase inhibitors developed in the present study is more convenient, time-saving and cost-effective than previous screening assays.%整合酶被认为是抗HIV-1药物研究的理想靶点之一.为了建立便捷高效的整合酶链转移反应抑制剂筛选方法,首先将HIV-1整合酶原核表达载体pNL-IN转化入大肠杆菌感受态细胞BL21(DE3)进行原核表达,并用镍琼脂糖凝胶进行亲和纯化,获得了纯度和活性均较高的整合酶重组蛋白;然后设计了生物素标记的供体DNA和FITC标记的靶DNA,用链霉亲和素磁珠捕获反应体系中的DNA产物;最后用荧光分析仪检测DNA产物的荧光信号,并计算待测样品的抑制率.用已知整合酶抑制剂S-1360和MK-0518对筛选方法进行了验

  3. Raltegravir cerebrospinal fluid concentrations in HIV-1 infection.

    Science.gov (United States)

    Yilmaz, Aylin; Gisslén, Magnus; Spudich, Serena; Lee, Evelyn; Jayewardene, Anura; Aweeka, Francesca; Price, Richard W

    2009-09-01

    Raltegravir is an HIV-1 integrase inhibitor currently used in treatment-experienced HIV-1-infected patients resistant to other drug classes. In order to assess its central nervous system penetration, we measured raltegravir concentrations in cerebrospinal fluid (CSF) and plasma in subjects receiving antiretroviral treatment regimens containing this drug. Raltegravir concentrations were determined by liquid chromatography tandem mass spectrometry in 25 paired CSF and plasma samples from 16 HIV-1-infected individuals. The lower limit of quantitation was 2.0 ng/ml for CSF and 10 ng/ml for plasma. Twenty-four of the 25 CSF samples had detectable raltegravir concentrations with a median raltegravir concentration of 18.4 ng/ml (range, <2.0-126.0). The median plasma raltegravir concentration was 448 ng/ml (range, 37-5180). CSF raltegravir concentrations correlated with CSF:plasma albumin ratios and CSF albumin concentrations. Approximately 50% of the CSF specimens exceeded the IC(95) levels reported to inhibit HIV-1 strains without resistance to integrase inhibitors. In addition to contributing to control of systemic HIV-1 infection, raltegravir achieves local inhibitory concentrations in CSF in most, but not all, patients. Blood-brain and blood-CSF barriers likely restrict drug entry, while enhanced permeability of these barriers enhances drug entry.

  4. Raltegravir cerebrospinal fluid concentrations in HIV-1 infection.

    Directory of Open Access Journals (Sweden)

    Aylin Yilmaz

    Full Text Available INTRODUCTION: Raltegravir is an HIV-1 integrase inhibitor currently used in treatment-experienced HIV-1-infected patients resistant to other drug classes. In order to assess its central nervous system penetration, we measured raltegravir concentrations in cerebrospinal fluid (CSF and plasma in subjects receiving antiretroviral treatment regimens containing this drug. METHODS: Raltegravir concentrations were determined by liquid chromatography tandem mass spectrometry in 25 paired CSF and plasma samples from 16 HIV-1-infected individuals. The lower limit of quantitation was 2.0 ng/ml for CSF and 10 ng/ml for plasma. RESULTS: Twenty-four of the 25 CSF samples had detectable raltegravir concentrations with a median raltegravir concentration of 18.4 ng/ml (range, <2.0-126.0. The median plasma raltegravir concentration was 448 ng/ml (range, 37-5180. CSF raltegravir concentrations correlated with CSF:plasma albumin ratios and CSF albumin concentrations. CONCLUSIONS: Approximately 50% of the CSF specimens exceeded the IC(95 levels reported to inhibit HIV-1 strains without resistance to integrase inhibitors. In addition to contributing to control of systemic HIV-1 infection, raltegravir achieves local inhibitory concentrations in CSF in most, but not all, patients. Blood-brain and blood-CSF barriers likely restrict drug entry, while enhanced permeability of these barriers enhances drug entry.

  5. Role of protease inhibitor 9 in survival and replication of Mycobacterium tuberculosis in mononuclear phagocytes from HIV-1-infected patients

    NARCIS (Netherlands)

    Toossi, Zahra; Wu, Mianda; Liu, Shigou; Hirsch, Christina S.; Walrath, Jessica; van Ham, Marieke; Silver, Richard F.

    2014-01-01

    Predisposition to opportunistic infections by Mycobacterium tuberculosis (MTB) is a concomitant of HIV-1 infection and occurrence of tuberculosis is independent of circulating CD4(+) T-cell count in HIV-1-infected patients. Infection of mononuclear phagocytes from healthy individuals by virulent MTB

  6. HIV Structural Database

    Science.gov (United States)

    SRD 102 HIV Structural Database (Web, free access)   The HIV Protease Structural Database is an archive of experimentally determined 3-D structures of Human Immunodeficiency Virus 1 (HIV-1), Human Immunodeficiency Virus 2 (HIV-2) and Simian Immunodeficiency Virus (SIV) Proteases and their complexes with inhibitors or products of substrate cleavage.

  7. Mutations at the CXCR4 interaction sites for AMD3100 influence anti-CXCR4 antibody binding and HIV-1 entry

    DEFF Research Database (Denmark)

    Hatse, Sigrid; Princen, Katrien; Vermeire, Kurt

    2003-01-01

    The interaction of the CXCR4 antagonist AMD3100 with its target is greatly influenced by specific aspartate residues in the receptor protein, including Asp(171) and Asp(262). We have now found that aspartate-to-asparagine substitutions at these positions differentially affect the binding of four...... different anti-CXCR4 monoclonal antibodies as well as the infectivity of diverse human immunodeficiency virus type 1 (HIV-1) strains and clinical isolates. Mutation of Asp(262) strongly decreased the coreceptor efficiency of CXCR4 for wild-type but not for AMD3100-resistant HIV-1 NL4.3. Thus, resistance...... of HIV-1 NL4.3 to AMD3100 is associated with a decreased dependence of the viral gp120 on Asp(262) of CXCR4, pointing to a different mode of interaction of wild-type versus AMD3100-resistant virus with CXCR4....

  8. Design, implementation, and evaluation at entry of a prospective cohort study of homosexual and bisexual HIV-1-negative men in Belo Horizonte, Brazil: Project Horizonte.

    Science.gov (United States)

    Carneiro, M; de Figueiredo Antunes, C M; Greco, M; Oliveira, E; Andrade, J; Lignani, L; Greco, D B

    2000-10-01

    Project Horizonte, an open cohort of homosexual and bisexual HIV-1-negative men, is a component of the Minas Gerais AIDS Vaccine Program of the Federal University of Minas Gerais, Belo Horizonte, Brazil. Its objectives included the evaluation of seroincidence of HIV, to ascertain the role of counseling on behavior modification and to assess their willingness to participate in future HIV vaccine trials. Various means of recruitment were used, including pamphlets, notices in community newspapers, radio, and television, at anonymous testing centers, and by word of mouth. From October 1994 to May 1999, 470 volunteers were enrolled. Their mean age was 26 years and over 70% of them had high school or college education. During the follow-up, they were seen every 6 months, when they received counseling and condoms, and when HIV testing was done. Eighteen seroconversions were observed, and the incidence rates estimates were 1.75 per 100 and 1.99 per 100 person-years, for 36 and 48 months of follow-up, respectively. During the entire period, 139 volunteers were lost to follow-up. Among them, 59 (42.4%) never returned after the initial visit and 51 (36.7) came only once after their initial visit. No losses were observed for those observed during follow-up for more than 3 years. At enrollment, 50% of participants said they would participate in a vaccine trial, and 30% said they might participate. The results obtained up to this moment confirm the feasibility of following this type of cohort for an extended period, estimating HIV incidence rate, and evaluating counseling for safe sexual practices in preparation for clinical trials with candidate HIV vaccines in Brazil.

  9. Multicenter study of skin rashes and hepatotoxicity in antiretroviral-naïve HIV-positive patients receiving non-nucleoside reverse-transcriptase inhibitor plus nucleoside reverse-transcriptase inhibitors in Taiwan.

    Directory of Open Access Journals (Sweden)

    Pei-Ying Wu

    Full Text Available Two nucleos(tide reverse-transcriptase inhibitors (NRTIs plus 1 non-NRTI (nNRTI remain the preferred or alternative combination antiretroviral therapy (cART for antiretroviral-naive HIV-positive patients in Taiwan. The three most commonly used nNRTIs are nevirapine (NVP, efavirenz (EFV and rilpivirine (RPV. This study aimed to determine the incidences of hepatotoxicity and skin rashes within 4 weeks of initiation of cART containing 1 nNRTI plus 2 NRTIs.Between June, 2012 and November, 2015, all antiretroviral-naive HIV-positive adult patients initiating nNRTI-containing cART at 8 designated hospitals for HIV care were included in this retrospective observational study. According to the national HIV treatment guidelines, patients were assessed at baseline, 2 and 4 weeks of cART initiation, and subsequently every 8 to 12 weeks. Plasma HIV RNA load, CD4 cell count and aminotransferases were determined. The toxicity grading scale of the Division of AIDS (DAIDS 2014 was used for reporting clinical and laboratory adverse events.During the 3.5-year study period, 2,341 patients initiated nNRTI-containing cART: NVP in 629 patients, EFV 1,363 patients, and RPV 349 patients. Rash of any grade occurred in 14.1% (n = 331 of the patients. In multiple logistic regression analysis, baseline CD4 cell counts (per 100-cell/μl increase, adjusted odds ratio [AOR], 1.125; 95% confidence interval [95% CI], 1.031-1.228 and use of NVP (AOR, 2.443; 95% CI, 1.816-3.286 (compared with efavirenz were independently associated with the development of skin rashes. Among the 1,455 patients (62.2% with aminotransferase data both at baseline and week 4, 72 (4.9% developed grade 2 or greater hepatotoxicity. In multiple logistic regression analysis, presence of antibody for hepatitis C virus (HCV (AOR, 2.865; 95% CI, 1.439-5.704 or hepatitis B surface antigen (AOR, 2.397; 95% CI, 1.150-4.997, and development of skin rashes (AOR, 2.811; 95% CI, 1.051-7.521 were independently

  10. Multicenter study of skin rashes and hepatotoxicity in antiretroviral-naïve HIV-positive patients receiving non-nucleoside reverse-transcriptase inhibitor plus nucleoside reverse-transcriptase inhibitors in Taiwan.

    Science.gov (United States)

    Wu, Pei-Ying; Cheng, Chien-Yu; Liu, Chun-Eng; Lee, Yi-Chien; Yang, Chia-Jui; Tsai, Mao-Song; Cheng, Shu-Hsing; Lin, Shih-Ping; Lin, De-Yu; Wang, Ning-Chi; Lee, Yi-Chieh; Sun, Hsin-Yun; Tang, Hung-Jen; Hung, Chien-Ching

    2017-01-01

    Two nucleos(t)ide reverse-transcriptase inhibitors (NRTIs) plus 1 non-NRTI (nNRTI) remain the preferred or alternative combination antiretroviral therapy (cART) for antiretroviral-naive HIV-positive patients in Taiwan. The three most commonly used nNRTIs are nevirapine (NVP), efavirenz (EFV) and rilpivirine (RPV). This study aimed to determine the incidences of hepatotoxicity and skin rashes within 4 weeks of initiation of cART containing 1 nNRTI plus 2 NRTIs. Between June, 2012 and November, 2015, all antiretroviral-naive HIV-positive adult patients initiating nNRTI-containing cART at 8 designated hospitals for HIV care were included in this retrospective observational study. According to the national HIV treatment guidelines, patients were assessed at baseline, 2 and 4 weeks of cART initiation, and subsequently every 8 to 12 weeks. Plasma HIV RNA load, CD4 cell count and aminotransferases were determined. The toxicity grading scale of the Division of AIDS (DAIDS) 2014 was used for reporting clinical and laboratory adverse events. During the 3.5-year study period, 2,341 patients initiated nNRTI-containing cART: NVP in 629 patients, EFV 1,363 patients, and RPV 349 patients. Rash of any grade occurred in 14.1% (n = 331) of the patients. In multiple logistic regression analysis, baseline CD4 cell counts (per 100-cell/μl increase, adjusted odds ratio [AOR], 1.125; 95% confidence interval [95% CI], 1.031-1.228) and use of NVP (AOR, 2.443; 95% CI, 1.816-3.286) (compared with efavirenz) were independently associated with the development of skin rashes. Among the 1,455 patients (62.2%) with aminotransferase data both at baseline and week 4, 72 (4.9%) developed grade 2 or greater hepatotoxicity. In multiple logistic regression analysis, presence of antibody for hepatitis C virus (HCV) (AOR, 2.865; 95% CI, 1.439-5.704) or hepatitis B surface antigen (AOR, 2.397; 95% CI, 1.150-4.997), and development of skin rashes (AOR, 2.811; 95% CI, 1.051-7.521) were independently

  11. Drogas anti-VIH: passado, presente e perspectivas futuras Drugs anti-HIV: past, present and future perspectives

    Directory of Open Access Journals (Sweden)

    Marcus Vinícius Nora de Souza

    2003-05-01

    Full Text Available Currently available anti-HIV drugs can be classified into three categories: nucleoside analogue reverse transcriptase inhibitors (NRTIs, non-nucleoside reverse transcriptase inhibitors (NNRTIs and protease inhibitors (PIs. In addition to the reverse transcriptase (RT and protease reaction, various other events in the HIV replicative cycle can be considered as potential targets for chemotherapeutic intervention: (1 viral adsorption, through binding to the viral envelope glycoprotein gp120; (2 viral entry, through blockage of the viral coreceptors CXCR4 and CCR5; (3 virus-cell fusion, through binding to the viral envelope glycoprotein gp 41; (4 viral assembly and disassembly through NCp7 zinc finger-targeted agents; (5 proviral DNA integration, through integrase inhibitors and (6 viral mRNA transcription, through inhibitors of the transcription (transactivation process. Also, various new NRTIs, NNRTIs and PIs have been developed, possessing different improved characteristics.

  12. Exploring the molecular mechanism of cross-resistance to HIV-1 integrase strand transfer inhibitors by molecular dynamics simulation and residue interaction network analysis.

    Science.gov (United States)

    Xue, Weiwei; Jin, Xiaojie; Ning, Lulu; Wang, Meixia; Liu, Huanxiang; Yao, Xiaojun

    2013-01-28

    The rapid emergence of cross-resistance to the integrase strand transfer inhibitors (INSTIs) has become a serious problem in the therapy of human immunodeficiency virus type 1 (HIV-1) infection. Understanding the detailed molecular mechanism of INSTIs cross-resistance is therefore critical for the development of new effective therapy against cross-resistance. On the basis of the homology modeling constructed structure of tetrameric HIV-1 intasome, the detailed molecular mechanism of the cross-resistance mutation E138K/Q148K to three important INSTIs (Raltegravir (RAL, FDA approved in 2007), Elvitegravir (EVG, FDA approved in 2012), and Dolutegravir (DTG, phase III clinical trials)) was investigated by using molecular dynamics (MD) simulation and residue interaction network (RIN) analysis. The results from conformation analysis and binding free energy calculation can provide some useful information about the detailed binding mode and cross-resistance mechanism for the three INSTIs to HIV-1 intasome. Binding free energy decomposition analysis revealed that Pro145 residue in the 140s 1oop (Gly140 to Gly149) of the HIV-1 intasome had strong hydrophobic interactions with INSTIs and played an important role in the binding of INSTIs to HIV-1 intasome active site. A systematic comparison and analysis of the RIN proves that the communications between the residues in the resistance mutant is increased when compared with that of the wild-type HIV-1 intasome. Further analysis indicates that residue Pro145 may play an important role and is relevant to the structure rearrangement in HIV-1 intasome active site. In addition, the chelating ability of the oxygen atoms in INSTIs (e.g., RAL and EVG) to Mg(2+) in the active site of the mutated intasome was reduced due to this conformational change and is also responsible for the cross-resistance mechanism. Notably, the cross-resistance mechanism we proposed could give some important information for the future rational design of novel

  13. Potential elucidation of a novel CTL epitope in HIV-1 protease by the protease inhibitor resistance mutation L90M.

    Directory of Open Access Journals (Sweden)

    Werner Smidt

    Full Text Available The combination of host immune responses and use of antiretrovirals facilitate partial control of human immunodeficiency virus type 1 (HIV-1 infection and result in delayed progression to Acquired Immunodeficiency Syndrome (AIDS. Both treatment and host immunity impose selection pressures on the highly mutable HIV-1 genome resulting in antiretroviral resistance and immune escape. Researchers have shown that antiretroviral resistance mutations can shape cytotoxic T-lymphocyte immunity by altering the epitope repertoire of HIV infected cells. Here it was discovered that an important antiretroviral resistance mutation, L90M in HIV protease, occurs at lower frequencies in hosts that harbor the B*15, B*48 or A*32 human leukocyte antigen subtypes. A likely reason is the elucidation of novel epitopes by L90M. NetMHCPan predictions reveal increased affinity of the peptide spanning the HIV protease region, PR 89-97 and PR 90-99 to HLA-B*15/B*48 and HLA-A*32 respectively due to the L90M substitution. The higher affinity could increase the chance of the epitope being presented and recognized by Cytotoxic T-lymphocytes and perhaps provide additional immunological pressures in the presence of antiretroviral attenuating mutations. This evidence supports the notion that knowledge of HLA allotypes in HIV infected individuals could augment antiretroviral treatment by the elucidation of epitopes due to antiretroviral resistance mutations in HIV protease.

  14. Pharmacophore modelling and atom-based 3D-QSAR studies on N-methyl pyrimidones as HIV-1 integrase inhibitors.

    Science.gov (United States)

    Reddy, Karnati Konda; Singh, Sanjeev Kumar; Dessalew, Nigus; Tripathi, Sunil Kumar; Selvaraj, Chandrabose

    2012-06-01

    Pharmacophore modelling and atom-based 3D-QSAR studies were carried out for a series of compounds belonging to N-methyl pyrimidones as HIV-1 integrase inhibitors. Based on the ligand-based pharmacophore model, we got 5-point pharmacophore model AADDR, with two hydrogen bond acceptors (A), two hydrogen bond donors (D) and one aromatic ring (R). The generated pharmacophore-based alignment was used to derive a predictive atom-based 3D-QSAR model for the training set (r(2) = 0.92, SD = 0.16, F = 84.8, N = 40) and for test set (Q(2) = 0.71, RMSE = 0.06, Pearson R = 0.90, N = 10). From these results, AADDR pharmacophore feature was selected as best common pharmacophore hypothesis, and atom-based 3D-QSAR results also support the outcome by means of favourable and unfavourable regions of hydrophobic and electron-withdrawing groups for the most potent compound 30. These results can be useful for further design of new and potent HIV-1 IN inhibitors.