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Sample records for hiv protease pr

  1. HIV-1 protease-substrate coevolution in nelfinavir resistance.

    Kolli, Madhavi; Ozen, Ayşegül; Kurt-Yilmaz, Nese; Schiffer, Celia A

    2014-07-01

    Resistance to various human immunodeficiency virus type 1 (HIV-1) protease inhibitors (PIs) challenges the effectiveness of therapies in treating HIV-1-infected individuals and AIDS patients. The virus accumulates mutations within the protease (PR) that render the PIs less potent. Occasionally, Gag sequences also coevolve with mutations at PR cleavage sites contributing to drug resistance. In this study, we investigated the structural basis of coevolution of the p1-p6 cleavage site with the nelfinavir (NFV) resistance D30N/N88D protease mutations by determining crystal structures of wild-type and NFV-resistant HIV-1 protease in complex with p1-p6 substrate peptide variants with L449F and/or S451N. Alterations of residue 30's interaction with the substrate are compensated by the coevolving L449F and S451N cleavage site mutations. This interdependency in the PR-p1-p6 interactions enhances intermolecular contacts and reinforces the overall fit of the substrate within the substrate envelope, likely enabling coevolution to sustain substrate recognition and cleavage in the presence of PR resistance mutations. Resistance to human immunodeficiency virus type 1 (HIV-1) protease inhibitors challenges the effectiveness of therapies in treating HIV-1-infected individuals and AIDS patients. Mutations in HIV-1 protease selected under the pressure of protease inhibitors render the inhibitors less potent. Occasionally, Gag sequences also mutate and coevolve with protease, contributing to maintenance of viral fitness and to drug resistance. In this study, we investigated the structural basis of coevolution at the Gag p1-p6 cleavage site with the nelfinavir (NFV) resistance D30N/N88D protease mutations. Our structural analysis reveals the interdependency of protease-substrate interactions and how coevolution may restore substrate recognition and cleavage in the presence of protease drug resistance mutations. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  2. Curcumin derivatives as HIV-1 protease inhibitors

    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.

  3. HIV-1 protease inhibitory substances from Cassia garrettiana

    Jindaporn Puripattanvong

    2007-01-01

    Full Text Available Cassia garrettiana Craib, a Thai medicinal plant locally known as Samae-sarn, was investigated for its active constituents against HIV-1 protease (HIV-1 PR. Bioassay-guided fractionation of the heart woodof this plant led to the isolation of a stilbene derivative (1, piceatannol and an anthraquinone derivative (2, chrysophanol. Piceatannol exhibited appreciable inhibitory effect against HIV-1 PR with an IC50 value of25.4 μg/ml, whereas that of chrysophanol was 73.5 μg/ml. In addition, other two stilbenoids together with three anthraquinone derivatives were also investigated for their anti-HIV-1 PR activities. The resultindicated that resveratrol possessed anti-HIV-1 PR activity with an IC50 value of 85.0 μg/ml, whereas other stilbenoid (oxyresveratrol and anthraquinone derivatives (emodin, aloe-emodin, rhein were inactive (IC50 > 100 μg/ml.

  4. Current and Novel Inhibitors of HIV Protease

    Pokorná, Jana; Machala, L.; Řezáčová, Pavlína; Konvalinka, Jan

    2009-01-01

    Roč. 1, č. 3 (2009), s. 1209-1239 ISSN 1999-4915 R&D Projects: GA MŠk 1M0508 Grant - others:GA AV ČR(CZ) IAAX00320901 Program:IA Institutional research plan: CEZ:AV0Z40550506 Keywords : HIV protease * protease inhibitor * HAART Subject RIV: CE - Biochemistry

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

    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. HIV-1 protease-induced apoptosis

    Rumlová, Michaela; Křížová, Ivana; Keprová, Alena; Hadravová, Romana; Doležal, Michal; Strohalmová, Karolína; Pichová, Iva; Hájek, Miroslav; Ruml, T.

    2014-01-01

    Roč. 11, May 20 (2014), 37/1-37/15 ISSN 1742-4690 R&D Projects: GA ČR GA204/09/1388 Institutional support: RVO:61388963 Keywords : HIV protease * BCA3 * AKIP-1 * apoptosis * mitochondria Subject RIV: EE - Microbiology, Virology Impact factor: 4.185, year: 2014 http://www.retrovirology.com/content/11/1/37

  7. Exploration of the effect of sequence variations located inside the binding pocket of HIV-1 and HIV-2 proteases.

    Triki, Dhoha; Billot, Telli; Visseaux, Benoit; Descamps, Diane; Flatters, Delphine; Camproux, Anne-Claude; Regad, Leslie

    2018-04-10

    HIV-2 protease (PR2) is naturally resistant to most FDA (Food and Drug Administration)-approved HIV-1 protease inhibitors (PIs), a major antiretroviral class. In this study, we compared the PR1 and PR2 binding pockets extracted from structures complexed with 12 ligands. The comparison of PR1 and PR2 pocket properties showed that bound PR2 pockets were more hydrophobic with more oxygen atoms and fewer nitrogen atoms than PR1 pockets. The structural comparison of PR1 and PR2 pockets highlighted structural changes induced by their sequence variations and that were consistent with these property changes. Specifically, substitutions at residues 31, 46, and 82 induced structural changes in their main-chain atoms that could affect PI binding in PR2. In addition, the modelling of PR1 mutant structures containing V32I and L76M substitutions revealed a cooperative mechanism leading to structural deformation of flap-residue 45 that could modify PR2 flexibility. Our results suggest that substitutions in the PR1 and PR2 pockets can modify PI binding and flap flexibility, which could underlie PR2 resistance against PIs. These results provide new insights concerning the structural changes induced by PR1 and PR2 pocket variation changes, improving the understanding of the atomic mechanism of PR2 resistance to PIs.

  8. Potential elucidation of a novel CTL epitope in HIV-1 protease by the protease inhibitor resistance mutation L90M.

    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.

  9. Potential elucidation of a novel CTL epitope in HIV-1 protease by the protease inhibitor resistance mutation L90M.

    Smidt, Werner

    2013-01-01

    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.

  10. Optimizing HIV-1 protease production in Escherichia coli as fusion protein

    Piubelli Luciano

    2011-06-01

    Full Text Available Abstract Background Human immunodeficiency virus (HIV is the etiological agent in AIDS and related diseases. The aspartyl protease encoded by the 5' portion of the pol gene is responsible for proteolytic processing of the gag-pol polyprotein precursor to yield the mature capsid protein and the reverse transcriptase and integrase enzymes. The HIV protease (HIV-1Pr is considered an attractive target for designing inhibitors which could be used to tackle AIDS and therefore it is still the object of a number of investigations. Results A recombinant human immunodeficiency virus type 1 protease (HIV-1Pr was overexpressed in Escherichia coli cells as a fusion protein with bacterial periplasmic protein dithiol oxidase (DsbA or glutathione S-transferase (GST, also containing a six-histidine tag sequence. Protein expression was optimized by designing a suitable HIV-1Pr cDNA (for E. coli expression and to avoid autoproteolysis and by screening six different E. coli strains and five growth media. The best expression yields were achieved in E. coli BL21-Codon Plus(DE3-RIL host and in TB or M9 medium to which 1% (w/v glucose was added to minimize basal expression. Among the different parameters assayed, the presence of a buffer system (based on phosphate salts and a growth temperature of 37°C after adding IPTG played the main role in enhancing protease expression (up to 10 mg of chimeric DsbA:HIV-1Pr/L fermentation broth. GST:HIVPr was in part (50% produced as soluble protein while the overexpressed DsbA:HIV-1Pr chimeric protein largely accumulated in inclusion bodies as unprocessed fusion protein. A simple refolding procedure was developed on HiTrap Chelating column that yielded a refolded DsbA:HIV-1Pr with a > 80% recovery. Finally, enterokinase digestion of resolubilized DsbA:HIV-1Pr gave more than 2 mg of HIV-1Pr per liter of fermentation broth with a purity ≤ 80%, while PreScission protease cleavage of soluble GST:HIVPr yielded ~ 0.15 mg of pure HIV-1

  11. Boosted protease inhibitors and the electrocardiographic measures of QT and PR durations

    Soliman, Elsayed Z; Lundgren, Jens D; Roediger, Mollie P

    2011-01-01

    There are contradictory reports regarding the effects of protease inhibitors on the ECG measures of QT and PR interval durations. The effect of interrupting use of protease inhibitors on QT and PR progression is also unknown.......There are contradictory reports regarding the effects of protease inhibitors on the ECG measures of QT and PR interval durations. The effect of interrupting use of protease inhibitors on QT and PR progression is also unknown....

  12. Impact of Stereochemistry on Ligand Binding: X-ray Crystallographic Analysis of an Epoxide-Based HIV Protease Inhibitor.

    Benedetti, Fabio; Berti, Federico; Campaner, Pietro; Fanfoni, Lidia; Demitri, Nicola; Olajuyigbe, Folasade M; De March, Matteo; Geremia, Silvano

    2014-09-11

    A new pseudopeptide epoxide inhibitor, designed for irreversible binding to HIV protease (HIV-PR), has been synthesized and characterized in solution and in the solid state. However, the crystal structure of the complex obtained by inhibitor-enzyme cocrystallization revealed that a minor isomer, with inverted configuration of the epoxide carbons, has been selected by HIV-PR during crystallization. The structural characterization of the well-ordered pseudopeptide, inserted in the catalytic channel with its epoxide group intact, provides deeper insights into inhibitor binding and HIV-PR stereoselectivity, which aids development of future epoxide-based HIV inhibitors.

  13. HIV protease drug resistance and its impact on inhibitor design.

    Ala, P J; Rodgers, J D; Chang, C H

    1999-07-01

    The primary cause of resistance to the currently available HIV protease inhibitors is the accumulation of multiple mutations in the viral protease. So far more than 20 substitutions have been observed in the active site, dimer interface, surface loops and flaps of the homodimer. While many mutations reduce the protease's affinity for inhibitors, others appear to enhance its catalytic efficiency. This high degree of genetic flexibility has made the protease an elusive drug target. The design of the next generation of HIV protease inhibitors will be discussed in light of the current structural information.

  14. Cold denaturation of the HIV-1 protease monomer

    Rösner, Heike Ilona; Caldarini, Martina; Prestel, Andreas

    2017-01-01

    The HIV-1-protease is a complex protein which in its active form adopts a homodimer dominated by -sheet structures. We have discovered a cold-denatured state of the monomeric subunit of HIV-1-protease which is populated above 0ºC and therefore directly accessible to various spectroscopic approac...

  15. Crystal structure of an FIV/HIV chimeric protease complexed with the broad-based inhibitor, TL-3

    Elder John H

    2007-01-01

    Full Text Available Abstract We have obtained the 1.7 Å crystal structure of FIV protease (PR in which 12 critical residues around the active site have been substituted with the structurally equivalent residues of HIV PR (12X FIV PR. The chimeric PR was crystallized in complex with the broad-based inhibitor TL-3, which inhibits wild type FIV and HIV PRs, as well as 12X FIV PR and several drug-resistant HIV mutants 1234. Biochemical analyses have demonstrated that TL-3 inhibits these PRs in the order HIV PR > 12X FIV PR > FIV PR, with Ki values of 1.5 nM, 10 nM, and 41 nM, respectively 234. Comparison of the crystal structures of the TL-3 complexes of 12X FIV and wild-typeFIV PR revealed theformation of additinal van der Waals interactions between the enzyme inhibitor in the mutant PR. The 12X FIV PR retained the hydrogen bonding interactions between residues in the flap regions and active site involving the enzyme and the TL-3 inhibitor in comparison to both FIV PR and HIV PR. However, the flap regions of the 12X FIV PR more closely resemble those of HIV PR, having gained several stabilizing intra-flap interactions not present in wild type FIV PR. These findings offer a structural explanation for the observed inhibitor/substrate binding properties of the chimeric PR.

  16. Sequence Quality Analysis Tool for HIV Type 1 Protease and Reverse Transcriptase

    DeLong, Allison K.; Wu, Mingham; Bennett, Diane; Parkin, Neil; Wu, Zhijin; Hogan, Joseph W.; Kantor, Rami

    2012-01-01

    Access to antiretroviral therapy is increasing globally and drug resistance evolution is anticipated. Currently, protease (PR) and reverse transcriptase (RT) sequence generation is increasing, including the use of in-house sequencing assays, and quality assessment prior to sequence analysis is essential. We created a computational HIV PR/RT Sequence Quality Analysis Tool (SQUAT) that runs in the R statistical environment. Sequence quality thresholds are calculated from a large dataset (46,802...

  17. Structure of HIV-1 protease determined by neutron crystallography

    Adachi, Motoyasu; Kuroki, Ryota

    2009-01-01

    HIV-1 protease is an aspartic protease, and plays an essential role in replication of HIV. To develop HIV-1 protease inhibitors through structure-based drug design, it is necessary to understand the catalytic mechanism and inhibitor recognition of HIV-1 protease. We have determined the crystal structure of HIV-1 protease in complex with KNI-272 to 1.9 A resolution by neutron crystallography in combination with 1.4 A resolution X-ray diffraction data. The results show that the carbonyl group of hydroxymethylcarbonyl (HMC) in KNI-272 forms a hydrogen bonding interaction with protonated Asp 25 and the hydrogen atom from the hydroxyl group of HMC forms a hydrogen bonding interaction with the deprotonated Asp125. This is the first neutron report for HIV-1/inhibitor complex and shows directly the locations of key hydrogen atoms in catalysis and in the binding of a transition-state analog. The results confirm key aspect of the presumed catalytic mechanism of HIV-1 protease and will aid in the further development of protease inhibitors. (author)

  18. Dynamics of Preferential Substrate Recognition in HIV-1 Protease: Redefining the Substrate Envelope

    Özen, Ayşegül; Haliloğlu, Türkan; Schiffer, Celia A.

    2011-01-01

    HIV-1 protease (PR) permits viral maturation by processing the Gag and Gag-Pro-Pol polyproteins. Though HIV-1 PR inhibitors (PIs) are used in combination antiviral therapy, the emergence of drug resistance has limited their efficacy. The rapid evolution of HIV-1 necessitates the consideration of drug resistance in novel drug-design strategies. Drug-resistant HIV-1 PR variants, while no longer efficiently inhibited, continue to efficiently hydrolyze the natural viral substrates. Though highly diverse in sequence, the HIV-1 PR substrates bind in a conserved three-dimensional shape we defined as the “substrate envelope”. We previously showed that resistance mutations arise where PIs protrude beyond the substrate envelope, as these regions are crucial for drug binding but not for substrate recognition. Here, we extend this model by considering the role of protein dynamics in the interaction of HIV-1 PR with its substrates. Seven molecular dynamics simulations of PR-substrate complexes were performed to estimate the conformational flexibility of substrates in their complexes. Interdependency of the substrate-protease interactions may compensate for the variations in cleavage-site sequences, and explain how a diverse set of sequences can be recognized as substrates by the same enzyme. This diversity may be essential for regulating sequential processing of substrates. We also define a dynamic substrate envelope as a more accurate representation of PR-substrate interactions. This dynamic substrate envelope, described by a probability distribution function, is a powerful tool for drug design efforts targeting ensembles of resistant HIV-1 PR variants with the aim of developing drugs that are less susceptible to resistance. PMID:21762811

  19. Synthetic, structural mimetics of the β-hairpin flap of HIV-1 protease inhibit enzyme function.

    Chauhan, Jay; Chen, Shen-En; Fenstermacher, Katherine J; Naser-Tavakolian, Aurash; Reingewertz, Tali; Salmo, Rosene; Lee, Christian; Williams, Emori; Raje, Mithun; Sundberg, Eric; DeStefano, Jeffrey J; Freire, Ernesto; Fletcher, Steven

    2015-11-01

    Small-molecule mimetics of the β-hairpin flap of HIV-1 protease (HIV-1 PR) were designed based on a 1,4-benzodiazepine scaffold as a strategy to interfere with the flap-flap protein-protein interaction, which functions as a gated mechanism to control access to the active site. Michaelis-Menten kinetics suggested our small-molecules are competitive inhibitors, which indicates the mode of inhibition is through binding the active site or sterically blocking access to the active site and preventing flap closure, as designed. More generally, a new bioactive scaffold for HIV-1PR inhibition has been discovered, with the most potent compound inhibiting the protease with a modest K(i) of 11 μM. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Teaching Foundational Topics and Scientific Skills in Biochemistry within the Conceptual Framework of HIV Protease

    Johnson, R. Jeremy

    2014-01-01

    HIV protease has served as a model protein for understanding protein structure, enzyme kinetics, structure-based drug design, and protein evolution. Inhibitors of HIV protease are also an essential part of effective HIV/AIDS treatment and have provided great societal benefits. The broad applications for HIV protease and its inhibitors make it a…

  1. molecular biology approach to the search for novel hiv proteases ...

    ... which could be tested in the animal models of HIV infection before subjection to clinical trials. Optimistically, the magic HIV therapeutics may be hidden in such insects and may require the application of molecular biology techniques to unravel. KEY WORDS: Antiretroviral drugs, malaria, proteases, restriction enzymes, ...

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

    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.

  3. Molecular Basis for Drug Resistance in HIV-1 Protease

    Celia A. Schiffer

    2010-11-01

    Full Text Available HIV-1 protease is one of the major antiviral targets in the treatment of patients infected with HIV-1. The nine FDA approved HIV-1 protease inhibitors were developed with extensive use of structure-based drug design, thus the atomic details of how the inhibitors bind are well characterized. From this structural understanding the molecular basis for drug resistance in HIV-1 protease can be elucidated. Selected mutations in response to therapy and diversity between clades in HIV-1 protease have altered the shape of the active site, potentially altered the dynamics and even altered the sequence of the cleavage sites in the Gag polyprotein. All of these interdependent changes act in synergy to confer drug resistance while simultaneously maintaining the fitness of the virus. New strategies, such as incorporation of the substrate envelope constraint to design robust inhibitors that incorporate details of HIV-1 protease’s function and decrease the probability of drug resistance, are necessary to continue to effectively target this key protein in HIV-1 life cycle.

  4. HIV-protease inhibitors for the treatment of cancer

    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...... and nitric oxide (NO) derivatives of HIV-PIs. In this article, we discuss the current preclinical and clinical evidences for the potential use of HIV-PIs, and of novel derivatives, such as saquinavir-NO in the treatment of cancer....

  5. Variable context Markov chains for HIV protease cleavage site prediction.

    Oğul, Hasan

    2009-06-01

    Deciphering the knowledge of HIV protease specificity and developing computational tools for detecting its cleavage sites in protein polypeptide chain are very desirable for designing efficient and specific chemical inhibitors to prevent acquired immunodeficiency syndrome. In this study, we developed a generative model based on a generalization of variable order Markov chains (VOMC) for peptide sequences and adapted the model for prediction of their cleavability by certain proteases. The new method, called variable context Markov chains (VCMC), attempts to identify the context equivalence based on the evolutionary similarities between individual amino acids. It was applied for HIV-1 protease cleavage site prediction problem and shown to outperform existing methods in terms of prediction accuracy on a common dataset. In general, the method is a promising tool for prediction of cleavage sites of all proteases and encouraged to be used for any kind of peptide classification problem as well.

  6. Drug-resistant molecular mechanism of CRF01_AE HIV-1 protease due to V82F mutation

    Liu, Xiaoqing; Xiu, Zhilong; Hao, Ce

    2009-05-01

    Human immunodeficiency virus type 1 protease (HIV-1 PR) is one of the major targets of anti-AIDS drug discovery. The circulating recombinant form 01 A/E (CRF01_AE, abbreviated AE) subtype is one of the most common HIV-1 subtypes, which is infecting more humans and is expanding rapidly throughout the world. It is, therefore, necessary to develop inhibitors against subtype AE HIV-1 PR. In this work, we have performed computer simulation of subtype AE HIV-1 PR with the drugs lopinavir (LPV) and nelfinavir (NFV), and examined the mechanism of resistance of the V82F mutation of this protease against LPV both structurally and energetically. The V82F mutation at the active site results in a conformational change of 79's loop region and displacement of LPV from its proper binding site, and these changes lead to rotation of the side-chains of residues D25 and I50'. Consequently, the conformation of the binding cavity is deformed asymmetrically and some interactions between PR and LPV are destroyed. Additionally, by comparing the interactive mechanisms of LPV and NFV with HIV-1 PR we discovered that the presence of a dodecahydroisoquinoline ring at the P1' subsite, a [2-(2,6-dimethylphenoxy)acetyl]amino group at the P2' subsite, and an N2 atom at the P2 subsite could improve the binding affinity of the drug with AE HIV-1 PR. These findings are helpful for promising drug design.

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

    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.

  8. Sequence quality analysis tool for HIV type 1 protease and reverse transcriptase.

    Delong, Allison K; Wu, Mingham; Bennett, Diane; Parkin, Neil; Wu, Zhijin; Hogan, Joseph W; Kantor, Rami

    2012-08-01

    Access to antiretroviral therapy is increasing globally and drug resistance evolution is anticipated. Currently, protease (PR) and reverse transcriptase (RT) sequence generation is increasing, including the use of in-house sequencing assays, and quality assessment prior to sequence analysis is essential. We created a computational HIV PR/RT Sequence Quality Analysis Tool (SQUAT) that runs in the R statistical environment. Sequence quality thresholds are calculated from a large dataset (46,802 PR and 44,432 RT sequences) from the published literature ( http://hivdb.Stanford.edu ). Nucleic acid sequences are read into SQUAT, identified, aligned, and translated. Nucleic acid sequences are flagged if with >five 1-2-base insertions; >one 3-base insertion; >one deletion; >six PR or >18 RT ambiguous bases; >three consecutive PR or >four RT nucleic acid mutations; >zero stop codons; >three PR or >six RT ambiguous amino acids; >three consecutive PR or >four RT amino acid mutations; >zero unique amino acids; or 15% genetic distance from another submitted sequence. Thresholds are user modifiable. SQUAT output includes a summary report with detailed comments for troubleshooting of flagged sequences, histograms of pairwise genetic distances, neighbor joining phylogenetic trees, and aligned nucleic and amino acid sequences. SQUAT is a stand-alone, free, web-independent tool to ensure use of high-quality HIV PR/RT sequences in interpretation and reporting of drug resistance, while increasing awareness and expertise and facilitating troubleshooting of potentially problematic sequences.

  9. Higher Desolvation Energy Reduces Molecular Recognition in Multi-Drug Resistant HIV-1 Protease

    Ladislau C. Kovari

    2012-05-01

    Full Text Available Designing HIV-1 protease inhibitors that overcome drug-resistance is still a challenging task. In this study, four clinical isolates of multi-drug resistant HIV-1 proteases that exhibit resistance to all the US FDA-approved HIV-1 protease inhibitors and also reduce the substrate recognition ability were examined. A multi-drug resistant HIV-1 protease isolate, MDR 769, was co-crystallized with the p2/NC substrate and the mutated CA/p2 substrate, CA/p2 P1’F. Both substrates display different levels of molecular recognition by the wild-type and multi-drug resistant HIV-1 protease. From the crystal structures, only limited differences can be identified between the wild-type and multi-drug resistant protease. Therefore, a wild-type HIV-1 protease and four multi-drug resistant HIV-1 proteases in complex with the two peptides were modeled based on the crystal structures and examined during a 10 ns-molecular dynamics simulation. The simulation results reveal that the multi-drug resistant HIV-1 proteases require higher desolvation energy to form complexes with the peptides. This result suggests that the desolvation of the HIV-1 protease active site is an important step of protease-ligand complex formation as well as drug resistance. Therefore, desolvation energy could be considered as a parameter in the evaluation of future HIV-1 protease inhibitor candidates.

  10. Molecular insights on analogs of HIV PR inhibitors toward HTLV-1 PR through QM/MM interactions and molecular dynamics studies: comparative structure analysis of wild and mutant HTLV-1 PR.

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

    2014-12-01

    Retroviruses HTLV-1 and HIV-1 are the primary causative agents of fatal adult T-cell leukemia and acquired immune deficiency syndrome (AIDS) disease. Both retroviruses are similar in characteristics mechanism, and it encodes for protease that mainly involved in the viral replication process. On the basis of the therapeutic success of HIV-1 PR inhibitors, the protease of HTLV-1 is mainly considered as a potential target for chemotherapy. At the same time, structural similarities in both enzymes that originate HIV PR inhibitors can also be an HTLV-1 PR inhibitor. But the expectations failed because of rejection of HIV PR inhibitors from the HTLV-1 PR binding pocket. In this present study, the reason for the HIV PR inhibitor rejection from the HTLV-1 binding site was identified through sequence analysis and molecular dynamics simulation method. Functional analysis of M37A mutation in HTLV PR clearly shows that the MET37 specificity and screening of potential inhibitors targeting MET37 is performed by using approved 90% similar HIV PR inhibitor compounds. From this approach, we report few compounds with a tendency to accept/donate electron specifically to an important site residue MET37 in HTLV-1 PR binding pocket. Copyright © 2014 John Wiley & Sons, Ltd.

  11. Structure of the Unbound Form of HIV-1 Subtype A Protease: Comparison with Unbound Forms of Proteases from other HIV Subtypes

    Robbins, Arthur H.; Coman, Roxana M.; Bracho-Sanchez, Edith; Fernandez, Marty A.; Gilliland, C.Taylor; Li, Mi; Agbandje-McKenna, Mavis; Wlodawer, Alexander; Dunn, Ben M.; McKenna, Robert (NCI); (Florida)

    2010-03-12

    The crystal structure of the unbound form of HIV-1 subtype A protease (PR) has been determined to 1.7 {angstrom} resolution and refined as a homodimer in the hexagonal space group P6{sub 1} to an R{sub cryst} of 20.5%. The structure is similar in overall shape and fold to the previously determined subtype B, C and F PRs. The major differences lie in the conformation of the flap region. The flaps in the crystal structures of the unbound subtype B and C PRs, which were crystallized in tetragonal space groups, are either semi-open or wide open. In the present structure of subtype A PR the flaps are found in the closed position, a conformation that would be more anticipated in the structure of HIV protease complexed with an inhibitor. The amino-acid differences between the subtypes and their respective crystal space groups are discussed in terms of the differences in the flap conformations.

  12. Metabolic complications associated with HIV protease inhibitor therapy.

    Nolan, David

    2003-01-01

    HIV protease inhibitors were introduced into clinical practice over 7 years ago as an important component of combination antiretroviral drug regimens which in many ways revolutionised the treatment of HIV infection. The significant improvements in prognosis that have resulted from the use of these regimens, combined with the need for lifelong treatment, have increasingly focused attention on the adverse effects of antiretroviral drugs and on the metabolic complications of HIV protease inhibitors in particular. In this review, the cluster of metabolic abnormalities characterised by triglyceride-rich dyslipidaemia and insulin resistance associated with HIV protease inhibitor therapy are considered, along with implications for cardiovascular risk in patients affected by these complications. Toxicity profiles of individual drugs within the HIV protease inhibitor class are examined, as there is an increased recognition of significant intra-class differences both in terms of absolute risk of metabolic complications as well as the particular metabolic phenotype associated with these drugs. Guidelines for clinical assessment and treatment are emphasised, along with pathophysiological mechanisms that may provide a rational basis for the treatment of metabolic complications. Finally, these drug-specific effects are considered within the context of HIV-specific effects on lipid metabolism as well as lifestyle factors that have contributed to a rapidly increasing incidence of similar metabolic syndromes in the general population. These data highlight the importance of individualising patient management in terms of choice of antiretroviral regimen, assessment of metabolic outcomes and use of therapeutic interventions, based on the assessment of baseline (pre-treatment) metabolic status as well as the presence of potentially modifiable cardiovascular risk factors.

  13. Interdependence of Inhibitor Recognition in HIV-1 Protease.

    Paulsen, Janet L; Leidner, Florian; Ragland, Debra A; Kurt Yilmaz, Nese; Schiffer, Celia A

    2017-05-09

    Molecular recognition is a highly interdependent process. Subsite couplings within the active site of proteases are most often revealed through conditional amino acid preferences in substrate recognition. However, the potential effect of these couplings on inhibition and thus inhibitor design is largely unexplored. The present study examines the interdependency of subsites in HIV-1 protease using a focused library of protease inhibitors, to aid in future inhibitor design. Previously a series of darunavir (DRV) analogs was designed to systematically probe the S1' and S2' subsites. Co-crystal structures of these analogs with HIV-1 protease provide the ideal opportunity to probe subsite interdependency. All-atom molecular dynamics simulations starting from these structures were performed and systematically analyzed in terms of atomic fluctuations, intermolecular interactions, and water structure. These analyses reveal that the S1' subsite highly influences other subsites: the extension of the hydrophobic P1' moiety results in 1) reduced van der Waals contacts in the P2' subsite, 2) more variability in the hydrogen bond frequencies with catalytic residues and the flap water, and 3) changes in the occupancy of conserved water sites both proximal and distal to the active site. In addition, one of the monomers in this homodimeric enzyme has atomic fluctuations more highly correlated with DRV than the other monomer. These relationships intricately link the HIV-1 protease subsites and are critical to understanding molecular recognition and inhibitor binding. More broadly, the interdependency of subsite recognition within an active site requires consideration in the selection of chemical moieties in drug design; this strategy is in contrast to what is traditionally done with independent optimization of chemical moieties of an inhibitor.

  14. Visualization of early events in acetic acid denaturation of HIV-1 protease: a molecular dynamics study.

    Aditi Narendra Borkar

    Full Text Available Protein denaturation plays a crucial role in cellular processes. In this study, denaturation of HIV-1 Protease (PR was investigated by all-atom MD simulations in explicit solvent. The PR dimer and monomer were simulated separately in 9 M acetic acid (9 M AcOH solution and water to study the denaturation process of PR in acetic acid environment. Direct visualization of the denaturation dynamics that is readily available from such simulations has been presented. Our simulations in 9 M AcOH reveal that the PR denaturation begins by separation of dimer into intact monomers and it is only after this separation that the monomer units start denaturing. The denaturation of the monomers is flagged off by the loss of crucial interactions between the α-helix at C-terminal and surrounding β-strands. This causes the structure to transit from the equilibrium dynamics to random non-equilibrating dynamics. Residence time calculations indicate that denaturation occurs via direct interaction of the acetic acid molecules with certain regions of the protein in 9 M AcOH. All these observations have helped to decipher a picture of the early events in acetic acid denaturation of PR and have illustrated that the α-helix and the β-sheet at the C-terminus of a native and functional PR dimer should maintain both the stability and the function of the enzyme and thus present newer targets for blocking PR function.

  15. Thermodynamic and structural analysis of HIV protease resistance to darunavir - analysis of heavily mutated patient- derived HIV-1 proteases

    Kožíšek, Milan; Lepšík, Martin; Grantz Šašková, Klára; Brynda, Jiří; Konvalinka, Jan; Řezáčová, Pavlína

    2014-01-01

    Roč. 281, č. 7 (2014), s. 1834-1847 ISSN 1742-464X R&D Projects: GA ČR GAP207/11/1798 Grant - others:OPPC(XE) CZ.2.16/3.1.00/24016 Institutional support: RVO:61388963 ; RVO:68378050 Keywords : enthropic contribution * HIV protease inhibitors * isothermal titration calorimetry * resistance mutation * X-ray crystallography Subject RIV: CE - Biochemistry Impact factor: 4.001, year: 2014

  16. Structural basis for drug and substrate specificity exhibited by FIV encoding a chimeric FIV/HIV protease

    Lin, Ying-Chuan; Perryman, Alexander L.; Olson, Arthur J.; Torbett, Bruce E.; Elder, John H.; Stout, C. David

    2011-01-01

    Crystal structures of the 6s-98S FIV protease chimera with darunavir and lopinavir bound have been determined at 1.7 and 1.8 Å resolution, respectively. A chimeric feline immunodeficiency virus (FIV) protease (PR) has been engineered that supports infectivity but confers sensitivity to the human immunodeficiency virus (HIV) PR inhibitors darunavir (DRV) and lopinavir (LPV). The 6s-98S PR has five replacements mimicking homologous residues in HIV PR and a sixth which mutated from Pro to Ser during selection. Crystal structures of the 6s-98S FIV PR chimera with DRV and LPV bound have been determined at 1.7 and 1.8 Å resolution, respectively. The structures reveal the role of a flexible 90s loop and residue 98 in supporting Gag processing and infectivity and the roles of residue 37 in the active site and residues 55, 57 and 59 in the flap in conferring the ability to specifically recognize HIV PR drugs. Specifically, Ile37Val preserves tertiary structure but prevents steric clashes with DRV and LPV. Asn55Met and Val59Ile induce a distinct kink in the flap and a new hydrogen bond to DRV. Ile98Pro→Ser and Pro100Asn increase 90s loop flexibility, Gln99Val contributes hydrophobic contacts to DRV and LPV, and Pro100Asn forms compensatory hydrogen bonds. The chimeric PR exhibits a comparable number of hydrogen bonds, electrostatic interactions and hydrophobic contacts with DRV and LPV as in the corresponding HIV PR complexes, consistent with IC 50 values in the nanomolar range

  17. Structural basis for drug and substrate specificity exhibited by FIV encoding a chimeric FIV/HIV protease

    Lin, Ying-Chuan; Perryman, Alexander L.; Olson, Arthur J.; Torbett, Bruce E.; Elder, John H.; Stout, C. David, E-mail: dave@scripps.edu [The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037 (United States)

    2011-06-01

    Crystal structures of the 6s-98S FIV protease chimera with darunavir and lopinavir bound have been determined at 1.7 and 1.8 Å resolution, respectively. A chimeric feline immunodeficiency virus (FIV) protease (PR) has been engineered that supports infectivity but confers sensitivity to the human immunodeficiency virus (HIV) PR inhibitors darunavir (DRV) and lopinavir (LPV). The 6s-98S PR has five replacements mimicking homologous residues in HIV PR and a sixth which mutated from Pro to Ser during selection. Crystal structures of the 6s-98S FIV PR chimera with DRV and LPV bound have been determined at 1.7 and 1.8 Å resolution, respectively. The structures reveal the role of a flexible 90s loop and residue 98 in supporting Gag processing and infectivity and the roles of residue 37 in the active site and residues 55, 57 and 59 in the flap in conferring the ability to specifically recognize HIV PR drugs. Specifically, Ile37Val preserves tertiary structure but prevents steric clashes with DRV and LPV. Asn55Met and Val59Ile induce a distinct kink in the flap and a new hydrogen bond to DRV. Ile98Pro→Ser and Pro100Asn increase 90s loop flexibility, Gln99Val contributes hydrophobic contacts to DRV and LPV, and Pro100Asn forms compensatory hydrogen bonds. The chimeric PR exhibits a comparable number of hydrogen bonds, electrostatic interactions and hydrophobic contacts with DRV and LPV as in the corresponding HIV PR complexes, consistent with IC{sub 50} values in the nanomolar range.

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

    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.

  19. A new class of HIV-1 protease inhibitor: the crystallographic structure, inhibition and chemical synthesis of an aminimide peptide isostere.

    Rutenber, E E; McPhee, F; Kaplan, A P; Gallion, S L; Hogan, J C; Craik, C S; Stroud, R M

    1996-09-01

    The essential role of HIV-1 protease (HIV-1 PR) in the viral life cycle makes it an attractive target for the development of substrate-based inhibitors that may find efficacy as anti-AIDS drugs. However, resistance has arisen to potent peptidomimetic drugs necessitating the further development of novel chemical backbones for diversity based chemistry focused on probing the active site for inhibitor interactions and binding modes that evade protease resistance. AQ148 is a potent inhibitor of HIV-1 PR and represents a new class of transition state analogues incorporating an aminimide peptide isostere. A 3-D crystallographic structure of AQ148, a tetrapeptide isostere, has been determined in complex with its target HIV-1 PR to a resolution of 2.5 A and used to evaluate the specific structural determinants of AQ148 potency and to correlate structure-activity relationships within the class of related compounds. AQ148 is a competitive inhibitor of HIV-1 PR with a Ki value of 137 nM. Twenty-nine derivatives have been synthesized and chemical modifications have been made at the P1, P2, P1', and P2' sites. The atomic resolution structure of AQ148 bound to HIV-1 PR reveals both an inhibitor binding mode that closely resembles that of other peptidomimetic inhibitors and specific protein/inhibitor interactions that correlate with structure-activity relationships. The structure provides the basis for the design, synthesis and evaluation of the next generation of hydroxyethyl aminimide inhibitors. The aminimide peptide isostere is a scaffold with favorable biological properties well suited to both the combinatorial methods of peptidomimesis and the rational design of potent and specific substrate-based analogues.

  20. Evolution of inhibitor-resistant natural mutant forms of HIV-1 protease probed by pre-steady state kinetic analysis.

    Zakharova, Maria Yu; Kuznetsova, Alexandra A; Kaliberda, Elena N; Dronina, Maria A; Kolesnikov, Alexander V; Kozyr, Arina V; Smirnov, Ivan V; Rumsh, Lev D; Fedorova, Olga S; Knorre, Dmitry G; Gabibov, Alexander G; Kuznetsov, Nikita A

    2017-11-01

    Pre-steady state kinetic analysis of mechanistic features of substrate binding and processing is crucial for insight into the evolution of inhibitor-resistant forms of HIV-1 protease. These data may provide a correct vector for rational drug design assuming possible intrinsic dynamic effects. These data should also give some clues to the molecular mechanism of protease action and resistance to inhibitors. Here we report pre-steady state kinetics of the interaction of wild type or mutant forms of HIV-1 protease with a FRET-labeled peptide. The three-stage "minimal" kinetic scheme with first and second reversible steps of substrate binding and with following irreversible peptide cleavage step adequately described experimental data. For the first time, a set of "elementary" kinetic parameters of wild type HIV-1 protease and its natural mutant inhibitor-resistant forms MDR-HM, ANAM-11 and prDRV4 were compared. Inhibitors of the first and second generation were used to estimate the inhibitory effects on HIV-1 protease activity. The resulting set of kinetic data supported that the mutant forms are kinetically unaffected by inhibitors of the first generation, proving their functional resistance to these compounds. The second generation inhibitor darunavir inhibited mutant forms MDR-HM and ANAM-11, but was ineffective against prDRV4. Our kinetic data revealed that these inhibitors induced different conformational changes in the enzyme and, thereby they have different mode of binding in the enzyme active site. These data confirmed hypothesis that the driving force of the inhibitor-resistance evolution is disruption of enzyme-inhibitor complex by changing of the contact network in the inhibitor binding site. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  1. Analysis of the HIV-2 protease's adaptation to various ligands: characterization of backbone asymmetry using a structural alphabet.

    Triki, Dhoha; Cano Contreras, Mario Enrique; Flatters, Delphine; Visseaux, Benoit; Descamps, Diane; Camproux, Anne-Claude; Regad, Leslie

    2018-01-15

    The HIV-2 protease (PR2) is a homodimer of 99 residues with asymmetric assembly and binding various ligands. We propose an exhaustive study of the local structural asymmetry between the two monomers of all available PR2 structures complexed with various inhibitors using a structural alphabet approach. On average, PR2 exhibits asymmetry in 31% of its positions-i.e., exhibiting different backbone local conformations in the two monomers. This asymmetry was observed all along its structure, particularly in the elbow and flap regions. We first differentiated structural asymmetry conserved in most PR2 structures from the one specific to some PR2. Then, we explored the origin of the detected asymmetry in PR2. We localized asymmetry that could be induced by PR2's flexibility, allowing transition from the semi-open to closed conformations and the asymmetry potentially induced by ligand binding. This latter could be important for the PR2's adaptation to diverse ligands. Our results highlighted some differences between asymmetry of PR2 bound to darunavir and amprenavir that could explain their differences of affinity. This knowledge is critical for a better description of PR2's recognition and adaptation to various ligands and for a better understanding of the resistance of PR2 to most PR2 inhibitors, a major antiretroviral class.

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

    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.

  3. Small protease sensitive oligomers of PrPSc in distinct human prions determine conversion rate of PrP(C.

    Chae Kim

    Full Text Available The mammalian prions replicate by converting cellular prion protein (PrP(C into pathogenic conformational isoform (PrP(Sc. Variations in prions, which cause different disease phenotypes, are referred to as strains. The mechanism of high-fidelity replication of prion strains in the absence of nucleic acid remains unsolved. We investigated the impact of different conformational characteristics of PrP(Sc on conversion of PrP(C in vitro using PrP(Sc seeds from the most frequent human prion disease worldwide, the Creutzfeldt-Jakob disease (sCJD. The conversion potency of a broad spectrum of distinct sCJD prions was governed by the level, conformation, and stability of small oligomers of the protease-sensitive (s PrP(Sc. The smallest most potent prions present in sCJD brains were composed only of∼20 monomers of PrP(Sc. The tight correlation between conversion potency of small oligomers of human sPrP(Sc observed in vitro and duration of the disease suggests that sPrP(Sc conformers are an important determinant of prion strain characteristics that control the progression rate of the disease.

  4. Noninvasive High-Throughput Single-Cell Analysis of HIV Protease Activity Using Ratiometric Flow Cytometry

    Rok Gaber

    2013-11-01

    Full Text Available To effectively fight against the human immunodeficiency virus infection/ acquired immunodeficiency syndrome (HIV/AIDS epidemic, ongoing development of novel HIV protease inhibitors is required. Inexpensive high-throughput screening assays are needed to quickly scan large sets of chemicals for potential inhibitors. We have developed a Förster resonance energy transfer (FRET-based, HIV protease-sensitive sensor using a combination of a fluorescent protein pair, namely mCerulean and mCitrine. Through extensive in vitro characterization, we show that the FRET-HIV sensor can be used in HIV protease screening assays. Furthermore, we have used the FRET-HIV sensor for intracellular quantitative detection of HIV protease activity in living cells, which more closely resembles an actual viral infection than an in vitro assay. We have developed a high-throughput method that employs a ratiometric flow cytometry for analyzing large populations of cells that express the FRET-HIV sensor. The method enables FRET measurement of single cells with high sensitivity and speed and should be used when subpopulation-specific intracellular activity of HIV protease needs to be estimated. In addition, we have used a confocal microscopy sensitized emission FRET technique to evaluate the usefulness of the FRET-HIV sensor for spatiotemporal detection of intracellular HIV protease activity.

  5. Noninvasive High-Throughput Single-Cell Analysis of HIV Protease Activity Using Ratiometric Flow Cytometry

    Gaber, Rok; Majerle, Andreja; Jerala, Roman; Benčina, Mojca

    2013-01-01

    To effectively fight against the human immunodeficiency virus infection/acquired immunodeficiency syndrome (HIV/AIDS) epidemic, ongoing development of novel HIV protease inhibitors is required. Inexpensive high-throughput screening assays are needed to quickly scan large sets of chemicals for potential inhibitors. We have developed a Förster resonance energy transfer (FRET)-based, HIV protease-sensitive sensor using a combination of a fluorescent protein pair, namely mCerulean and mCitrine. Through extensive in vitro characterization, we show that the FRET-HIV sensor can be used in HIV protease screening assays. Furthermore, we have used the FRET-HIV sensor for intracellular quantitative detection of HIV protease activity in living cells, which more closely resembles an actual viral infection than an in vitro assay. We have developed a high-throughput method that employs a ratiometric flow cytometry for analyzing large populations of cells that express the FRET-HIV sensor. The method enables FRET measurement of single cells with high sensitivity and speed and should be used when subpopulation-specific intracellular activity of HIV protease needs to be estimated. In addition, we have used a confocal microscopy sensitized emission FRET technique to evaluate the usefulness of the FRET-HIV sensor for spatiotemporal detection of intracellular HIV protease activity. PMID:24287545

  6. Conserved hydrogen bonds and water molecules in MDR HIV-1 protease substrate complexes

    Liu, Zhigang [Wayne State Univ., Detroit, MI (United States); Case Western Reserve Univ., Cleveland, OH (United States); Harbor Hospital Baltimore, MD (United States); Wang, Yong [Wayne State Univ., Detroit, MI (United States); Yedidi, Ravikiran S. [Wayne State Univ., Detroit, MI (United States); National Institutes of Health, Bethesda, MD (United States); Dewdney, Tamaria G. [Wayne State Univ., Detroit, MI (United States); Reiter, Samuel J. [Wayne State Univ., Detroit, MI (United States); Brunzelle, Joseph S. [Northwestern Univ. Feinberg School of Medicine, Chicago, IL (United States); Kovari, Iulia A. [Wayne State Univ., Detroit, MI (United States); Kovari, Ladislau C. [Wayne State Univ., Detroit, MI (United States)

    2012-12-19

    Success of highly active antiretroviral therapy (HAART) in anti-HIV therapy is severely compromised by the rapidly developing drug resistance. HIV-1 protease inhibitors, part of HAART, are losing their potency and efficacy in inhibiting the target. Multi-drug resistant (MDR) 769 HIV-1 protease (resistant mutations at residues 10, 36, 46, 54, 62, 63, 71, 82, 84, 90) was selected for the present study to understand the binding to its natural substrates. The nine crystal structures of MDR769 HIV-1 protease substrate hepta-peptide complexes were analyzed in order to reveal the conserved structural elements for the purpose of drug design against MDR HIV-1 protease. Our structural studies demonstrated that highly conserved hydrogen bonds between the protease and substrate peptides, together with the conserved crystallographic water molecules, played a crucial role in the substrate recognition, substrate stabilization and protease stabilization. Additionally, the absence of the key flap-ligand bridging water molecule might imply a different catalytic mechanism of MDR769 HIV-1 protease compared to that of wild type (WT) HIV-1 protease.

  7. A new method for the characterization of strain-specific conformational stability of protease-sensitive and protease-resistant PrPSc.

    Laura Pirisinu

    Full Text Available Although proteinacious in nature, prions exist as strains with specific self-perpetuating biological properties. Prion strains are thought to be associated with different conformers of PrP(Sc, a disease-associated isoform of the host-encoded cellular protein (PrP(C. Molecular strain typing approaches have been developed which rely on the characterization of protease-resistant PrP(Sc. However, PrP(Sc is composed not only of protease-resistant but also of protease-sensitive isoforms. The aim of this work was to develop a protocol for the molecular characterization of both, protease-resistant and protease-sensitive PrP(Sc aggregates. We first set up experimental conditions which allowed the most advantageous separation of PrP(C and PrP(Sc by means of differential centrifugation. The conformational solubility and stability assay (CSSA was then developed by measuring PrP(Sc solubility as a function of increased exposure to GdnHCl. Brain homogenates from voles infected with human and sheep prion isolates were analysed by CSSA and showed strain-specific conformational stabilities, with mean [GdnHCl](1/2 values ranging from 1.6 M for MM2 sCJD to 2.1 for scrapie and to 2.8 M for MM1/MV1 sCJD and E200K gCJD. Interestingly, the rank order of [GdnHCl](1/2 values observed in the human and sheep isolates used as inocula closely matched those found following transmission in voles, being MM1 sCJD the most resistant (3.3 M, followed by sheep scrapie (2.2 M and by MM2 sCJD (1.6 M. In order to test the ability of CSSA to characterise protease-sensitive PrP(Sc, we analysed sheep isolates of Nor98 and compared them to classical scrapie isolates. In Nor98, insoluble PrP(Sc aggregates were mainly protease-sensitive and showed a conformational stability much lower than in classical scrapie. Our results show that CSSA is able to reveal strain-specified PrP(Sc conformational stabilities of protease-resistant and protease-sensitive PrP(Sc and that it is a valuable tool

  8. Energetic basis for drug resistance of HIV-1 protease mutants against amprenavir

    Kar, Parimal; Knecht, Volker

    2012-02-01

    Amprenavir (APV) is a high affinity (0.15 nM) HIV-1 protease (PR) inhibitor. However, the affinities of the drug resistant protease variants V32I, I50V, I54V, I54M, I84V and L90M to amprenavir are decreased 3 to 30-fold compared to the wild-type. In this work, the popular molecular mechanics Poisson-Boltzmann surface area method has been used to investigate the effectiveness of amprenavir against the wild-type and these mutated protease variants. Our results reveal that the protonation state of Asp25/Asp25' strongly affects the dynamics, the overall affinity and the interactions of the inhibitor with individual residues. We emphasize that, in contrast to what is often assumed, the protonation state may not be inferred from the affinities but requires pKa calculations. At neutral pH, Asp25 and Asp25' are ionized or protonated, respectively, as suggested from pKa calculations. This protonation state was thus mainly considered in our study. Mutation induced changes in binding affinities are in agreement with the experimental findings. The decomposition of the binding free energy reveals the mechanisms underlying binding and drug resistance. Drug resistance arises from an increase in the energetic contribution from the van der Waals interactions between APV and PR (V32I, I50V, and I84V mutant) or a rise in the energetic contribution from the electrostatic interactions between the inhibitor and its target (I54M and I54V mutant). For the V32I mutant, also an increased free energy for the polar solvation contributes to the drug resistance. For the L90M mutant, a rise in the van der Waals energy for APV-PR interactions is compensated by a decrease in the polar solvation free energy such that the net binding affinity remains unchanged. Detailed understanding of the molecular forces governing binding and drug resistance might assist in the design of new inhibitors against HIV-1 PR variants that are resistant against current drugs.

  9. Effects of HIV-1 protease on cellular functions and their potential applications in antiretroviral therapy

    Yang Hailiu

    2012-09-01

    Full Text Available Abstract Human Immunodeficiency Virus Type 1 (HIV-1 protease inhibitors (PIs are the most potent class of drugs in antiretroviral therapies. However, viral drug resistance to PIs could emerge rapidly thus reducing the effectiveness of those drugs. Of note, all current FDA-approved PIs are competitive inhibitors, i.e., inhibitors that compete with substrates for the active enzymatic site. This common inhibitory approach increases the likelihood of developing drug resistant HIV-1 strains that are resistant to many or all current PIs. Hence, new PIs that move away from the current target of the active enzymatic site are needed. Specifically, allosteric inhibitors, inhibitors that prohibit PR enzymatic activities through non-competitive binding to PR, should be sought. Another common feature of current PIs is they were all developed based on the structure-based design. Drugs derived from a structure-based strategy may generate target specific and potent inhibitors. However, this type of drug design can only target one site at a time and drugs discovered by this method are often associated with strong side effects such as cellular toxicity, limiting its number of target choices, efficacy, and applicability. In contrast, a cell-based system may provide a useful alternative strategy that can overcome many of the inherited shortcomings associated with structure-based drug designs. For example, allosteric PIs can be sought using a cell-based system without considering the site or mechanism of inhibition. In addition, a cell-based system can eliminate those PIs that have strong cytotoxic effect. Most importantly, a simple, economical, and easy-to-maintained eukaryotic cellular system such as yeast will allow us to search for potential PIs in a large-scaled high throughput screening (HTS system, thus increasing the chances of success. Based on our many years of experience in using fission yeast as a model system to study HIV-1 Vpr, we propose the use of

  10. Lysine sulfonamides as novel HIV-protease inhibitors: Nepsilon-acyl aromatic alpha-amino acids.

    Stranix, Brent R; Lavallée, Jean-François; Sévigny, Guy; Yelle, Jocelyn; Perron, Valérie; LeBerre, Nicholas; Herbart, Dominik; Wu, Jinzi J

    2006-07-01

    A series of lysine sulfonamide analogues bearing Nepsilon-acyl aromatic amino acids were synthesized using an efficient synthetic route. Evaluation of these novel protease inhibitors revealed compounds with high potency against wild-type and multiple-protease inhibitor-resistant HIV viruses.

  11. An efficient procedure for the expression and purification of HIV-1 protease from inclusion bodies.

    Nguyen, Hong-Loan Thi; Nguyen, Thuy Thi; Vu, Quy Thi; Le, Hang Thi; Pham, Yen; Trinh, Phuong Le; Bui, Thuan Phuong; Phan, Tuan-Nghia

    2015-12-01

    Several studies have focused on HIV-1 protease for developing drugs for treating AIDS. Recombinant HIV-1 protease is used to screen new drugs from synthetic compounds or natural substances. However, large-scale expression and purification of this enzyme is difficult mainly because of its low expression and solubility. In this study, we constructed 9 recombinant plasmids containing a sequence encoding HIV-1 protease along with different fusion tags and examined the expression of the enzyme from these plasmids. Of the 9 plasmids, pET32a(+) plasmid containing the HIV-1 protease-encoding sequence along with sequences encoding an autocleavage site GTVSFNF at the N-terminus and TEV plus 6× His tag at the C-terminus showed the highest expression of the enzyme and was selected for further analysis. The recombinant protein was isolated from inclusion bodies by using 2 tandem Q- and Ni-Sepharose columns. SDS-PAGE of the obtained HIV-1 protease produced a single band of approximately 13 kDa. The enzyme was recovered efficiently (4 mg protein/L of cell culture) and had high specific activity of 1190 nmol min(-1) mg(-1) at an optimal pH of 4.7 and optimal temperature of 37 °C. This procedure for expressing and purifying HIV-1 protease is now being scaled up to produce the enzyme on a large scale for its application. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. PrEP Whores and HIV Prevention: The Queer Communication of HIV Pre-Exposure Prophylaxis (PrEP).

    Spieldenner, Andrew

    2016-12-01

    HIV pre-exposure prophylaxis (PrEP) has been introduced as another biomedical tool in HIV prevention. Whereas other such tools-including post-exposure prophylaxis (PEP) and interruption of perinatal transmission-have been embraced by those impacted by HIV, PrEP has been met with more conflict, especially within the gay community and HIV organizations. The "PrEP whore" has come to designate the social value and personal practices of those taking PrEP. This study examines the "PrEP whore" discourse by using queer theory and quare theory. Within these theoretical vantage points, the study explicates four discursive areas: slut shaming, dirty/clean binaries, mourning the loss of condoms, and reclaiming the inner whore. The study illuminates possible discursive strategies that lie outside of the domains of public health and within the individual and community.

  13. An insight to the molecular interactions of the FDA approved HIV PR drugs against L38L↑N↑L PR mutant

    Sanusi, Zainab K.; Govender, Thavendran; Maguire, Glenn E. M.; Maseko, Sibusiso B.; Lin, Johnson; Kruger, Hendrik G.; Honarparvar, Bahareh

    2018-03-01

    The aspartate protease of the human immune deficiency type-1 virus (HIV-1) has become a crucial antiviral target in which many useful antiretroviral inhibitors have been developed. However, it seems the emergence of new HIV-1 PR mutations enhances drug resistance, hence, the available FDA approved drugs show less activity towards the protease. A mutation and insertion designated L38L↑N↑L PR was recently reported from subtype of C-SA HIV-1. An integrated two-layered ONIOM (QM:MM) method was employed in this study to examine the binding affinities of the nine HIV PR inhibitors against this mutant. The computed binding free energies as well as experimental data revealed a reduced inhibitory activity towards the L38L↑N↑L PR in comparison with subtype C-SA HIV-1 PR. This observation suggests that the insertion and mutations significantly affect the binding affinities or characteristics of the HIV PIs and/or parent PR. The same trend for the computational binding free energies was observed for eight of the nine inhibitors with respect to the experimental binding free energies. The outcome of this study shows that ONIOM method can be used as a reliable computational approach to rationalize lead compounds against specific targets. The nature of the intermolecular interactions in terms of the host-guest hydrogen bond interactions is discussed using the atoms in molecules (AIM) analysis. Natural bond orbital analysis was also used to determine the extent of charge transfer between the QM region of the L38L↑N↑L PR enzyme and FDA approved drugs. AIM analysis showed that the interaction between the QM region of the L38L↑N↑L PR and FDA approved drugs are electrostatic dominant, the bond stability computed from the NBO analysis supports the results from the AIM application. Future studies will focus on the improvement of the computational model by considering explicit water molecules in the active pocket. We believe that this approach has the potential to provide

  14. Solid-state characterization of the HIV protease inhibitor

    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.

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

    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)] Monogram (11 patients)] and 1.5 (1.0-2.2) [single-cycle (4 patients)]. The 2 post-PI treatment samples showing GSK3532795 CFB >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.

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

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

    2017-01-01

    Background: 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). Methods: 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)] Monogram (11 patients)] and 1.5 (1.0–2.2) [single-cycle (4 patients)]. The 2 post-PI treatment samples showing GSK3532795 CFB >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. Conclusions: 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. PMID:28234686

  17. Protease inhibitor associated mutations compromise the efficacy of therapy in human immunodeficiency virus – 1 (HIV-1 infected pediatric patients: a cross-sectional study

    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

  18. Fifteen years of HIV Protease Inhibitors: raising the barrier to resistance.

    Wensing, Annemarie M J; van Maarseveen, Noortje M; Nijhuis, Monique

    2010-01-01

    HIV protease plays a crucial role in the viral life cycle and is essential for the generation of mature infectious virus particles. Detailed knowledge of the structure of HIV protease and its substrate has led to the design of specific HIV protease inhibitors. Unfortunately, resistance to all protease inhibitors (PIs) has been observed and the genetic basis of resistance has been well documented over the past 15 years. The arrival of the early PIs was a pivotal moment in the development of antiretroviral therapy. They made possible the dual class triple combination therapy that became known as HAART. However, the clinical utility of the first generation of PIs was limited by low bioavailability and high pill burdens, which ultimately reduced adherence and limited long-term viral inhibition. When therapy failure occurred multiple protease resistance mutations were observed, often resulting in broad class resistance. To combat PI-resistance development, second-generation approaches have been developed. The first advance was to increase the level of existing PIs in the plasma by boosting with ritonavir. The second was to develop novel PIs with high potency against the known PI-resistant HIV protease variants. Both approaches increased the number of protease mutations required for clinical resistance, thereby raising the genetic barrier. This review provides an overview of the history of protease inhibitor therapy, its current status and future perspectives. It forms part of a special issue of Antiviral Research marking the 25th anniversary of antiretroviral drug discovery and development, vol. 85, issue 1, 2010. Copyright 2009 Elsevier B.V. All rights reserved.

  19. Development and evaluation of a phenotypic assay monitoring resistance formation to protease inhibitors in HIV-1-infected patients.

    Gehringer, Heike; Von der Helm, Klaus; Seelmeir, Sigrid; Weissbrich, Benedikt; Eberle, Josef; Nitschko, Hans

    2003-05-01

    A novel phenotypic assay, based on recombinant expression of the HIV-1-protease was developed and evaluated; it monitors the formation of resistance to protease inhibitors. The HIV-1 protease-encoding region from the blood sample of patients was amplified, ligated into the expression vector pBD2, and recombinantly expressed in Escherichia coli TG1 cells. The resulting recombinant enzyme was purified by a newly developed one-step acid extraction protocol. The protease activity was determined in presence of five selected HIV protease inhibitors and the 50% inhibitory concentration (IC(50)) to the respective protease inhibitors determined. The degree of resistance was expressed in terms of x-fold increase in IC(50) compared to the IC(50) value of an HIV-1 wild type protease preparation. The established test system showed a reproducible recombinant expression of each individual patients' HIV-1 protease population. Samples of nine clinically well characterised HIV-1-infected patients with varying degrees of resistance were analysed. There was a good correlation between clinical parameters and the results obtained by this phenotypic assay. For the majority of patients a blind genotypic analysis of the patients' protease domain revealed a fair correlation to the results of the phenotypic assay. In a minority of patients our phenotypic results diverged from the genotypic ones. This novel phenotypic assay can be carried out within 8-10 days, and offers a significant advantage in time to the current employed phenotypic tests.

  20. Structure-Based Design of Novel HIV-1 Protease Inhibitors to Combat Drug Resistance

    Ghosh,A.; Sridhar, P.; Leshchenko, S.; Hussain, A.; Li, J.; Kovalevsky, A.; Walters, D.; Wedelind, J.; Grum-Tokars, V.; et al.

    2006-01-01

    Structure-based design and synthesis of novel HIV protease inhibitors are described. The inhibitors are designed specifically to interact with the backbone of HIV protease active site to combat drug resistance. Inhibitor 3 has exhibited exceedingly potent enzyme inhibitory and antiviral potency. Furthermore, this inhibitor maintains impressive potency against a wide spectrum of HIV including a variety of multi-PI-resistant clinical strains. The inhibitors incorporated a stereochemically defined 5-hexahydrocyclopenta[b]furanyl urethane as the P2-ligand into the (R)-(hydroxyethylamino)sulfonamide isostere. Optically active (3aS,5R,6aR)-5-hydroxy-hexahydrocyclopenta[b]furan was prepared by an enzymatic asymmetrization of meso-diacetate with acetyl cholinesterase, radical cyclization, and Lewis acid-catalyzed anomeric reduction as the key steps. A protein-ligand X-ray crystal structure of inhibitor 3-bound HIV-1 protease (1.35 Angstroms resolution) revealed extensive interactions in the HIV protease active site including strong hydrogen bonding interactions with the backbone. This design strategy may lead to novel inhibitors that can combat drug resistance.

  1. Immune pressure analysis of protease and reverse transcriptase ...

    /dn) were analyzed for 33 HIV-1 subtype C protease (PR) and reverse transcriptase (RT) nucleotide sequences each from antiretroviral naïve South African chronically infected individuals. The ds/dn ratios were calculated using the ...

  2. Fluctuating partially native-like topologies in the acid denatured ensemble of autolysis resistant HIV-1 protease.

    Rout, Manoj Kumar; Hosur, Ramakrishna V

    2009-02-01

    Folding, in-vivo, starts from a denatured state and thus the nature of the denatured state would play an important role in directing the folding of a protein. We report here NMR characterization of the acid-denatured state of a mutant of HIV-1 protease, designed to prevent autolysis (Q7K, L33I, L63I) and to prevent cysteine oxidation (C67A and C95A). Secondary chemical shifts, TALOS analysis of chemical shifts and (15)N relaxation data (R(1), R(2), NOE) coupled with AABUF and hydrophobicity calculations, suggest formation of hydrophobic clusters and possibility of some partially native-like topologies in the acid denatured state of the protease. The structural and dynamics characteristics of the acid denatured PR seem to be considerably different from those of the guanidine or urea denatured states of some variants of PR. These would have implications for the folding and auto-processing of the enzyme in-vivo.

  3. Potent inhibition of drug-resistant HIV protease variants by monoclonal antibodies

    Bartoňová, Vanda; Král, Vlastimil; Sieglová, Irena; Brynda, Jiří; Fábry, Milan; Hořejší, Magdalena; Kožíšek, Milan; Grantz Šašková, Klára; Konvalinka, Jan; Sedláček, Juraj; Řezáčová, Pavlína

    2008-01-01

    Roč. 78, č. 3 (2008), s. 275-277 ISSN 0166-3542 R&D Projects: GA MZd NR8571 Institutional research plan: CEZ:AV0Z50520514; CEZ:AV0Z40550506 Keywords : HIV protease * drug resistance * Inhibiting antibody Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.613, year: 2008

  4. Characteristic Ligand-Induced Crystal Forms of HIV-1 Protease Complexes: A Novel Discovery of X-Ray Crystallography

    Olajuyigbe, Folasade M.; Geremia, Silvano

    2009-10-01

    Mixtures of saquinavir (SQV) and ritonavir (RTV) were cocrystallized with HIV-1 protease (PR) in an attempt to compare their relative potencies using a crystallographic approach and factors responsible for the respective crystal forms obtained were examined. The mixture ratio of the SQV/RTV was in the range of 1:1 to 1:50 with increasing concentration of dimethyl sulphoxide (DMSO) used. Two crystal forms of PR complexes were obtained. At concentrations of 0.8 and 1.2 % DMSO using 1:1 and 1:15 ratios of SQV/RTV, the crystal form was monoclinic while increasing the concentration of DMSO to 3.2 and 5.0% using 1:15 and 1:50 ratios of SQV/RTV, the orthorhombic crystal form was obtained. The high resolution X-ray crystal structures of the PR/ inhibitor complexes reveal that crystal forms with respective space groups are dependent on the occupancy of either SQV or RTV in the active site of the PR. The occupancy of either of the PR inhibitors in the active site of PR has interestingly demonstrated unique cooperativity effects in crystallization of protein-ligand complexes. The crystal forms obtained were also related to the concentration of DMSO and ammonium sulphate in crystallization, and storage conditions of purified PR. Surprisingly, the relative occupancies of these inhibitors in the active site suggested a competition between the two inhibitors which were not inhibition constants related. Analysis of the structures in both crystal forms show no difference in DMSO content but at higher concentration of DMSO (3.2 - 5.0%) in the orthorhombic crystal forms, there were protein-sulphate interactions which were absent in the monoclinic forms with lower concentration (0.8 - 1.2%) of DMSO. This work has clearly demonstrated that there is cooperativity in crystallization and the conditions of crystallization influence specific intermolecular contacts in crystal packing (crystal form). (author)

  5. HIV-protease inhibitors for the treatment of cancer: Repositioning HIV protease inhibitors while developing more potent NO-hybridized derivatives?

    Maksimovic-Ivanic, Danijela; Fagone, Paolo; McCubrey, James; Bendtzen, Klaus; Mijatovic, Sanja; Nicoletti, Ferdinando

    2017-04-15

    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 viral infections, the number of reports on solid tumors, KS, lymphoma, fibrosarcoma, multiple myeloma and prostate cancer suggest other mechanisms for the anti-neoplastic activity of PIs. However, a major drawback for the possible adoption of HIV-PIs in the therapy of cancer relies on their relatively 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 and nitric oxide (NO) derivatives of HIV-PIs. In this article, we discuss the current preclinical and clinical evidences for the potential use of HIV-PIs, and of novel derivatives, such as saquinavir-NO in the treatment of cancer. © 2016 UICC.

  6. PRACTICE OF USING VIRAL PROTEASE INHIBITORS IN CHILDREN WITH HIV INFECTION

    V.B. Denisenko

    2010-01-01

    Full Text Available Selection of the most effective and safest high-active antiretroviral therapies is a critical issue faced by modern HIV medicine. Authors studied 28 children with HIV infection aged from 3 to 7 divided into two groups administered a combination of two HIV reverse transcriptase nucleoside inhibitors with viral protease nelfinavir inhibitors (n = 13 and lopinavir/ritonavir (n = 15. The subjects in both groups demonstrated a decreased frequency of HIV-associated symptoms and opportunistic infections, positive dynamics of immunological indicators, suppression of HIV replication. When lopinavir/ritonavir was administered, there was more even better dynamics in clinical, immunological and virologic parameters, which allows this medication to be recommended as a antiretroviral therapy for children. Key words: HIV infection, lopinavir/ritonavir, nelfinavir, children. (Pediatric Pharmacology. – 2010; 7(1:62-67

  7. Mining the protein data bank to differentiate error from structural variation in clustered static structures: an examination of HIV protease.

    Venkatakrishnan, Balasubramanian; Palii, Miorel-Lucian; Agbandje-McKenna, Mavis; McKenna, Robert

    2012-03-01

    The Protein Data Bank (PDB) contains over 71,000 structures. Extensively studied proteins have hundreds of submissions available, including mutations, different complexes, and space groups, allowing for application of data-mining algorithms to analyze an array of static structures and gain insight about a protein's structural variation and possibly its dynamics. This investigation is a case study of HIV protease (PR) using in-house algorithms for data mining and structure superposition through generalized formulæ that account for multiple conformations and fractional occupancies. Temperature factors (B-factors) are compared with spatial displacement from the mean structure over the entire study set and separately over bound and ligand-free structures, to assess the significance of structural deviation in a statistical context. Space group differences are also examined.

  8. Fotodegradovatelné inhibitory HIV proteasy

    Schimer, Jiří; Pávová, Marcela; Prouzová, Hana; Weber, Jan; Cígler, Petr; Majer, Pavel; Konvalinka, Jan

    2014-01-01

    Roč. 108, č. 5 (2014), s. 549 ISSN 0009-2770. [Mezioborové setkání mladých biologů, biochemiků a chemiků /14./. 13.05.2014-16.05.2014, Milovy] Institutional support: RVO:61388963 Keywords : HIV protease * HIV PR inhibitors * Caged HIV Pr * HIV maturation Subject RIV: CE - Biochemistry

  9. Sequence requirements of the HIV-1 protease flap region determined by saturation mutagenesis and kinetic analysis of flap mutants

    Shao, Wei; Everitt, Lorraine; Manchester, Marianne; Loeb, Daniel D.; Hutchison, Clyde A.; Swanstrom, Ronald

    1997-01-01

    The retroviral proteases (PRs) have a structural feature called the flap, which consists of a short antiparallel β-sheet with a turn. The flap extends over the substrate binding cleft and must be flexible to allow entry and exit of the polypeptide substrates and products. We analyzed the sequence requirements of the amino acids within the flap region (positions 46–56) of the HIV-1 PR. The phenotypes of 131 substitution mutants were determined using a bacterial expression system. Four of the mutant PRs with mutations in different regions of the flap were selected for kinetic analysis. Our phenotypic analysis, considered in the context of published structures of the HIV-1 PR with a bound substrate analogs, shows that: (i) Met-46 and Phe-53 participate in hydrophobic interactions on the solvent-exposed face of the flap; (ii) Ile-47, Ile-54, and Val-56 participate in hydrophobic interactions on the inner face of the flap; (iii) Ile-50 has hydrophobic interactions at the distance of both the δ and γ carbons; (iv) the three glycine residues in the β-turn of the flap are virtually intolerant of substitutions. Among these mutant PRs, we have identified changes in both kcat and Km. These results establish the nature of the side chain requirements at each position in the flap and document a role for the flap in both substrate binding and catalysis. PMID:9122179

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

    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.......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......%) developed major PI resistance mutations. Mutations in the p7/p1 and p1/p6 gag CS only developed in patients with major or minor mutations in PR. Drug concentrations were low or undetectable in 10 out of the 19 patients. In total PR resistance mutations and low drug levels could account for 12 (63...

  11. 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

    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.

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

    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.

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

    Folasade M. Olajuyigbe

    2016-10-01

    Full Text Available 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. 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

    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 0.025 nM and antiviral IC50 of 69 nM. An X-ray crystal structure of inhibitor 4b-HIV-1 protease complex was determined at 1.33 Å resolution. We have also determined X-ray structure of 3b-bound HIV-1 protease at 1.27 Å resolution. These structures revealed important molecular insight into the inhibitor–HIV-1 protease interactions in the active site.

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

    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

  16. In vitro protease cleavage and computer simulations reveal the HIV-1 capsid maturation pathway

    Ning, Jiying; Erdemci-Tandogan, Gonca; Yufenyuy, Ernest L.; Wagner, Jef; Himes, Benjamin A.; Zhao, Gongpu; Aiken, Christopher; Zandi, Roya; Zhang, Peijun

    2016-12-01

    HIV-1 virions assemble as immature particles containing Gag polyproteins that are processed by the viral protease into individual components, resulting in the formation of mature infectious particles. There are two competing models for the process of forming the mature HIV-1 core: the disassembly and de novo reassembly model and the non-diffusional displacive model. To study the maturation pathway, we simulate HIV-1 maturation in vitro by digesting immature particles and assembled virus-like particles with recombinant HIV-1 protease and monitor the process with biochemical assays and cryoEM structural analysis in parallel. Processing of Gag in vitro is accurate and efficient and results in both soluble capsid protein and conical or tubular capsid assemblies, seemingly converted from immature Gag particles. Computer simulations further reveal probable assembly pathways of HIV-1 capsid formation. Combining the experimental data and computer simulations, our results suggest a sequential combination of both displacive and disassembly/reassembly processes for HIV-1 maturation.

  17. Ion specific effects of alkali cations on the catalytic activity of HIV-1 protease

    Pokorná, Jana; Heyda, J.; Konvalinka, Jan

    2013-01-01

    Roč. 160, č. 1 (2013), s. 359-370 ISSN 1359-6640 R&D Projects: GA ČR GBP208/12/G016; GA ČR GAP207/11/1798 Institutional support: RVO:61388963 Keywords : HIV -1 protease * ion-protein interaction * Hofmeister series * enzyme kinetics * molecular dynamics Subject RIV: CE - Biochemistry Impact factor: 4.194, year: 2013

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

    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

  19. Anomalous adsorptive properties of HIV protease: Indication of two-dimensional crystallization?

    Cígler, Petr; Král, V.; Kožíšek, Milan; Konvalinka, Jan; Mirsky, V.M.

    2008-01-01

    Roč. 64, č. 1 (2008), s. 145-149 ISSN 0927-7765 R&D Projects: GA MŠk 1M0508; GA MŠk LC512 Grant - others:RASP(XE) SP5A-CT-2006-044515 Institutional research plan: CEZ:AV0Z40550506 Keywords : HIV protease * protein adsorption * protein-resistant surfaces * self-assembled monolayer * surface plasmon resonance Subject RIV: CE - Biochemistry Impact factor: 2.593, year: 2008

  20. HIV-1 protease mutations and inhibitor modifications. Results from a series of X-ray structures

    Skálová, Tereza; Dohnálek, Jan; Dušková, Jarmila; Petroková, Hana; Hašek, Jindřich

    2006-01-01

    Roč. 13, č. 3 (2006), s. 142 ISSN 1211-5894. [Czech and Slovak Crystallographic Colloquium. 22.06.2006-24.06.2006, Grenoble] R&D Projects: GA AV ČR KJB4050312; GA AV ČR IAA4050811; GA MŠk 1K05008 Keywords : HIV-1 protease * X-ray diffraction Subject RIV: EB - Genetics ; Molecular Biology http://www. xray .cz/ms/default.htm

  1. Screening of HIV-1 Protease Using a Combination of an Ultra-High-Throughput Fluorescent-Based Assay and RapidFire Mass Spectrometry.

    Meng, Juncai; Lai, Ming-Tain; Munshi, Vandna; Grobler, Jay; McCauley, John; Zuck, Paul; Johnson, Eric N; Uebele, Victor N; Hermes, Jeffrey D; Adam, Gregory C

    2015-06-01

    HIV-1 protease (PR) represents one of the primary targets for developing antiviral agents for the treatment of HIV-infected patients. To identify novel PR inhibitors, a label-free, high-throughput mass spectrometry (HTMS) assay was developed using the RapidFire platform and applied as an orthogonal assay to confirm hits identified in a fluorescence resonance energy transfer (FRET)-based primary screen of > 1 million compounds. For substrate selection, a panel of peptide substrates derived from natural processing sites for PR was evaluated on the RapidFire platform. As a result, KVSLNFPIL, a new substrate measured to have a ~ 20- and 60-fold improvement in k cat/K m over the frequently used sequences SQNYPIVQ and SQNYPIV, respectively, was identified for the HTMS screen. About 17% of hits from the FRET-based primary screen were confirmed in the HTMS confirmatory assay including all 304 known PR inhibitors in the set, demonstrating that the HTMS assay is effective at triaging false-positives while capturing true hits. Hence, with a sampling rate of ~7 s per well, the RapidFire HTMS assay enables the high-throughput evaluation of peptide substrates and functions as an efficient tool for hits triage in the discovery of novel PR inhibitors. © 2015 Society for Laboratory Automation and Screening.

  2. Implications of HIV PrEP Trials Results

    Anton, Peter; Fletcher, Courtney V.; DeGruttola, Victor; McGowan, Ian; Becker, Stephen; Zwerski, Sheryl; Burns, David

    2011-01-01

    Abstract Six randomized clinical trials have been implemented to examine the efficacy of tenofovir disoproxil fumarate (TDF) and/or TDF/emtricitabine (TDF/FTC) as preexposure prophylaxis for HIV-1 infection (PrEP). Although largely complementary, the six trials have many similar features. As the earliest results become available, an urgent question may arise regarding whether changes should be made in the conduct of the other trials. To consider this in advance, a Consultation on the Implications of HIV Pre-Exposure Prophylaxis (PrEP) Trials Results sponsored by the Division of AIDS (DAIDS) of the National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), and the Bill and Melinda Gates Foundation (BMGF) was held on January 29, 2010, at the Natcher Conference Center, NIH, Bethesda, MD. Participants included basic scientists, clinical researchers (including investigators performing the current PrEP trials), and representatives from the U.S. Food and Drug Administration (FDA) and the agencies sponsoring the trials: the U.S. Centers for Disease Control and Prevention (CDC), the U.S. Agency for International Development (USAID), the BMGF, and the U.S. NIH. We report here a summary of the presentations and highlights of salient discussion topics from this workshop. PMID:20969483

  3. The thermodynamics of Pr55Gag-RNA interaction regulate the assembly of HIV.

    Hanumant S Tanwar

    2017-02-01

    Full Text Available The interactions that occur during HIV Pr55Gag oligomerization and genomic RNA packaging are essential elements that facilitate HIV assembly. However, mechanistic details of these interactions are not clearly defined. Here, we overcome previous limitations in producing large quantities of full-length recombinant Pr55Gag that is required for isothermal titration calorimetry (ITC studies, and we have revealed the thermodynamic properties of HIV assembly for the first time. Thermodynamic analysis showed that the binding between RNA and HIV Pr55Gag is an energetically favourable reaction (ΔG<0 that is further enhanced by the oligomerization of Pr55Gag. The change in enthalpy (ΔH widens sequentially from: (1 Pr55Gag-Psi RNA binding during HIV genome selection; to (2 Pr55Gag-Guanosine Uridine (GU-containing RNA binding in cytoplasm/plasma membrane; and then to (3 Pr55Gag-Adenosine(A-containing RNA binding in immature HIV. These data imply the stepwise increments of heat being released during HIV biogenesis may help to facilitate the process of viral assembly. By mimicking the interactions between A-containing RNA and oligomeric Pr55Gag in immature HIV, it was noted that a p6 domain truncated Pr50Gag Δp6 is less efficient than full-length Pr55Gag in this thermodynamic process. These data suggest a potential unknown role of p6 in Pr55Gag-Pr55Gag oligomerization and/or Pr55Gag-RNA interaction during HIV assembly. Our data provide direct evidence on how nucleic acid sequences and the oligomeric state of Pr55Gag regulate HIV assembly.

  4. Prediction of mutational tolerance in HIV-1 protease and reverse transcriptase using flexible backbone protein design.

    Elisabeth Humphris-Narayanan

    Full Text Available Predicting which mutations proteins tolerate while maintaining their structure and function has important applications for modeling fundamental properties of proteins and their evolution; it also drives progress in protein design. Here we develop a computational model to predict the tolerated sequence space of HIV-1 protease reachable by single mutations. We assess the model by comparison to the observed variability in more than 50,000 HIV-1 protease sequences, one of the most comprehensive datasets on tolerated sequence space. We then extend the model to a second protein, reverse transcriptase. The model integrates multiple structural and functional constraints acting on a protein and uses ensembles of protein conformations. We find the model correctly captures a considerable fraction of protease and reverse-transcriptase mutational tolerance and shows comparable accuracy using either experimentally determined or computationally generated structural ensembles. Predictions of tolerated sequence space afforded by the model provide insights into stability-function tradeoffs in the emergence of resistance mutations and into strengths and limitations of the computational model.

  5. Protease-sensitive conformers in broad spectrum of distinct PrPSc structures in sporadic Creutzfeldt-Jakob disease are indicator of progression rate.

    Chae Kim

    2011-09-01

    Full Text Available The origin, range, and structure of prions causing the most common human prion disease, sporadic Creutzfeldt-Jakob disease (sCJD, are largely unknown. To investigate the molecular mechanism responsible for the broad phenotypic variability of sCJD, we analyzed the conformational characteristics of protease-sensitive and protease-resistant fractions of the pathogenic prion protein (PrP(Sc using novel conformational methods derived from a conformation-dependent immunoassay (CDI. In 46 brains of patients homozygous for polymorphisms in the PRNP gene and exhibiting either Type 1 or Type 2 western blot pattern of the PrP(Sc, we identified an extensive array of PrP(Sc structures that differ in protease sensitivity, display of critical domains, and conformational stability. Surprisingly, in sCJD cases homozygous for methionine or valine at codon 129 of the PRNP gene, the concentration and stability of protease-sensitive conformers of PrP(Sc correlated with progression rate of the disease. These data indicate that sCJD brains exhibit a wide spectrum of PrP(Sc structural states, and accordingly argue for a broad spectrum of prion strains coding for different phenotypes. The link between disease duration, levels, and stability of protease-sensitive conformers of PrP(Sc suggests that these conformers play an important role in the pathogenesis of sCJD.

  6. Getting PrEPared for HIV Prevention Navigation: Young Black Gay Men Talk About HIV Prevention in the Biomedical Era.

    Mutchler, Matt G; McDavitt, Bryce; Ghani, Mansur A; Nogg, Kelsey; Winder, Terrell J A; Soto, Juliana K

    2015-09-01

    Biomedical HIV prevention strategies, such as pre-exposure prophylaxis (PrEP) and post-exposure prophylaxis (PEP), represent new opportunities to reduce critically high HIV infection rates among young black men who have sex with men (YBMSM). We report results of 24 dyadic qualitative interviews (N=48), conducted in Los Angeles, CA, exploring how YBMSM and their friends view PrEP and PEP. Interviews were analyzed using a grounded theory approach. Participants had widely divergent levels of knowledge about these prevention methods. Misconceptions and mistrust regarding PrEP were common, and concerns were expressed about PrEP-related stigma and the potential for gossip among peers who might assume a person on PrEP was HIV-positive. Yet participants also framed PrEP and PEP as valuable new options within an expanded "tool kit" of HIV prevention strategies that created possibilities for preventing new HIV infections, dating men with a different HIV status, and decreased anxiety about exposure to HIV. We organized themes around four main areas: (1) information and misinformation about biomedical HIV prevention; (2) expectations about PrEP, sexual behavior, and stigma; (3) gossip, disclosure, and "spreading the word" about PrEP and PEP; and (4) the roles of PrEP and PEP in an expanded HIV prevention tool kit. The findings suggest a need for guidance in navigating the increasingly complex array of HIV-prevention options available to YBMSM. Such "prevention navigation" could counter misconceptions and address barriers, such as stigma and mistrust, while helping YBMSM make informed selections from among expanded HIV prevention options.

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

    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...... 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...

  8. Purification and characterization of naturally occurring HIV-1 (South African subtype C) protease mutants from inclusion bodies.

    Maseko, Sibusiso B; Natarajan, Satheesh; Sharma, Vikas; Bhattacharyya, Neelakshi; Govender, Thavendran; Sayed, Yasien; Maguire, Glenn E M; Lin, Johnson; Kruger, Hendrik G

    2016-06-01

    Human immunodeficiency virus (HIV) infections in sub-Saharan Africa represent about 56% of global infections. Many studies have targeted HIV-1 protease for the development of drugs against AIDS. Recombinant HIV-1 protease is used to screen new drugs from synthetic compounds or natural substances. Along with the wild type (C-SA) we also over-expressed and characterized two mutant forms from patients that had shown resistance to protease inhibitors. Using recombinant DNA technology, we constructed three recombinant plasmids in pGEX-6P-1 and expressed them containing a sequence encoding wild type HIV protease and two mutants (I36T↑T contains 100 amino acids and L38L↑N↑L contains 101 amino acids). These recombinant proteins were isolated from inclusion bodies by using QFF anion exchange and GST trap columns. In SDS-PAGE, we obtained these HIV proteases as single bands of approximately 11.5, 11.6 and 11.7 kDa for the wild type, I36T↑Tand L38L↑N↑L mutants, respectively. The enzyme was recovered efficiently (0.25 mg protein/L of Escherichia coli culture) and had high specific activity of 2.02, 2.20 and 1.33 μmol min(-1) mg(-1) at an optimal pH of 5 and temperature of 37 °C for the wild type, I36T↑T and L38L↑N↑L, respectively. The method employed here provides an easy and rapid purification of the HIV-1(C-SA) protease from the inclusion bodies, with high yield and high specific activities. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Methamphetamine increases Prion Protein and induces dopamine-dependent expression of protease resistant PrPsc.

    Ferrucci, M; Ryskalin, L; Biagioni, F; Gambardella, S; Busceti, C L; Falleni, A; Lazzeri, G; Fornai, F

    2017-07-01

    The cellular prion protein (PrPc) is physiologically expressed within selective brain areas of mammals. Alterations in the secondary structure of this protein lead to scrapie-like prion protein (PrPsc), which precipitates in the cell. PrPsc has been detected in infectious, inherited or sporadic neurodegenerative disorders. Prion protein metabolism is dependent on autophagy and ubiquitin proteasome. Despite not being fully elucidated, the physiological role of prion protein relates to chaperones which rescue cells under stressful conditions.Methamphetamine (METH) is a widely abused drug which produces oxidative stress in various brain areas causing mitochondrial alterations and protein misfolding. These effects produce a compensatory increase of chaperones while clogging cell clearing pathways. In the present study, we explored whether METH administration modifies the amount of PrPc. Since high levels of PrPc when the clearing systems are clogged may lead to its misfolding into PrPsc, we further tested whether METH exposure triggers the appearance of PrPsc. We analysed the effects of METH and dopamine administration in PC12 and striatal cells by using SDS-PAGE Coomassie blue, immune- histochemistry and immune-gold electron microscopy. To analyze whether METH administration produces PrPsc aggregates we used antibodies directed against PrP following exposure to proteinase K or sarkosyl which digest folded PrPc but misfolded PrPsc. We fond that METH triggers PrPsc aggregates in DA-containing cells while METH is not effective in primary striatal neurons which do not produce DA. In the latter cells exogenous DA is needed to trigger PrPsc accumulation similarly to what happens in DA containing cells under the effects of METH. The present findings, while fostering novel molecular mechanisms involving prion proteins, indicate that, cell pathology similar to prion disorders can be mimicked via a DA-dependent mechanism by a drug of abuse.

  10. Virtual screening for HIV protease inhibitors: a comparison of AutoDock 4 and Vina.

    Max W Chang

    Full Text Available BACKGROUND: The AutoDock family of software has been widely used in protein-ligand docking research. This study compares AutoDock 4 and AutoDock Vina in the context of virtual screening by using these programs to select compounds active against HIV protease. METHODOLOGY/PRINCIPAL FINDINGS: Both programs were used to rank the members of two chemical libraries, each containing experimentally verified binders to HIV protease. In the case of the NCI Diversity Set II, both AutoDock 4 and Vina were able to select active compounds significantly better than random (AUC = 0.69 and 0.68, respectively; p<0.001. The binding energy predictions were highly correlated in this case, with r = 0.63 and iota = 0.82. For a set of larger, more flexible compounds from the Directory of Universal Decoys, the binding energy predictions were not correlated, and only Vina was able to rank compounds significantly better than random. CONCLUSIONS/SIGNIFICANCE: In ranking smaller molecules with few rotatable bonds, AutoDock 4 and Vina were equally capable, though both exhibited a size-related bias in scoring. However, as Vina executes more quickly and is able to more accurately rank larger molecules, researchers should look to it first when undertaking a virtual screen.

  11. Multiple routes and milestones in the folding of HIV-1 protease monomer.

    Massimiliano Bonomi

    Full Text Available Proteins fold on a time scale incompatible with a mechanism of random search in conformational space thus indicating that somehow they are guided to the native state through a funneled energetic landscape. At the same time the heterogeneous kinetics suggests the existence of several different folding routes. Here we propose a scenario for the folding mechanism of the monomer of HIV-1 protease in which multiple pathways and milestone events coexist. A variety of computational approaches supports this picture. These include very long all-atom molecular dynamics simulations in explicit solvent, an analysis of the network of clusters found in multiple high-temperature unfolding simulations and a complete characterization of free-energy surfaces carried out using a structure-based potential at atomistic resolution and a combination of metadynamics and parallel tempering. Our results confirm that the monomer in solution is stable toward unfolding and show that at least two unfolding pathways exist. In our scenario, the formation of a hydrophobic core is a milestone in the folding process which must occur along all the routes that lead this protein towards its native state. Furthermore, the ensemble of folding pathways proposed here substantiates a rational drug design strategy based on inhibiting the folding of HIV-1 protease.

  12. Gag mutations strongly contribute to HIV-1 resistance to protease inhibitors in highly drug-experienced patients besides compensating for fitness loss.

    Elisabeth Dam

    2009-03-01

    Full Text Available Human immunodeficiency virus type 1 (HIV-1 resistance to protease inhibitors (PI results from mutations in the viral protease (PR that reduce PI binding but also decrease viral replicative capacity (RC. Additional mutations compensating for the RC loss subsequently accumulate within PR and in Gag substrate cleavage sites. We examined the respective contribution of mutations in PR and Gag to PI resistance and RC and their interdependence using a panel of HIV-1 molecular clones carrying different sequences from six patients who had failed multiple lines of treatment. Mutations in Gag strongly and directly contributed to PI resistance besides compensating for fitness loss. This effect was essentially carried by the C-terminal region of Gag (containing NC-SP2-p6 with little or no contribution from MA, CA, and SP1. The effect of Gag on resistance depended on the presence of cleavage site mutations A431V or I437V in NC-SP2-p6 and correlated with processing of the NC/SP2 cleavage site. By contrast, reverting the A431V or I437V mutation in these highly evolved sequences had little effect on RC. Mutations in the NC-SP2-p6 region of Gag can be dually selected as compensatory and as direct PI resistance mutations, with cleavage at the NC-SP2 site behaving as a rate-limiting step in PI resistance. Further compensatory mutations render viral RC independent of the A431V or I437V mutations while their effect on resistance persists.

  13. Modulation of HIV-1 Gag NC/p1 cleavage efficiency affects protease inhibitor resistance and viral replicative capacity

    Maarseveen van, N. M.; Andersson, Dan; Lepšík, Martin; Fun, A.; Schipper, P. J.; Jong de, D.; Boucher, Ch. A. B.; Nijhuis, M.

    2012-01-01

    Roč. 9, č. 29 (2012), s. 1-7 ISSN 1742-4690 EU Projects: European Commission(XE) 37693 - HIV PI RESISTANCE Grant - others:Dutch AIDS Fund(XE) 2006028; (NWO) VIDI(XE) 91796349 Institutional research plan: CEZ:AV0Z40550506 Keywords : HIV-1 * protease * Gag * resistance * cleavage Subject RIV: CE - Biochemistry Impact factor: 5.657, year: 2012

  14. Processing sites in the human immunodeficiency virus type 1 (HIV-1 Gag-Pro-Pol precursor are cleaved by the viral protease at different rates

    Lindquist Jeffrey N

    2005-11-01

    Full Text Available Abstract We have examined the kinetics of processing of the HIV-1 Gag-Pro-Pol precursor in an in vitro assay with mature protease added in trans. The processing sites were cleaved at different rates to produce distinct intermediates. The initial cleavage occurred at the p2/NC site. Intermediate cleavages occurred at similar rates at the MA/CA and RT/IN sites, and to a lesser extent at sites upstream of RT. Late cleavages occurred at the sites flanking the protease (PR domain, suggesting sequestering of these sites. We observed paired intermediates indicative of half- cleavage of RT/RH site, suggesting that the RT domain in Gag-Pro-Pol was in a dimeric form under these assay conditions. These results clarify our understanding of the processing kinetics of the Gag-Pro-Pol precursor and suggest regulated cleavage. Our results further suggest that early dimerization of the PR and RT domains may serve as a regulatory element to influence the kinetics of processing within the Pol domain.

  15. Processing sites in the human immunodeficiency virus type 1 (HIV-1) Gag-Pro-Pol precursor are cleaved by the viral protease at different rates.

    Pettit, Steve C; Lindquist, Jeffrey N; Kaplan, Andrew H; Swanstrom, Ronald

    2005-11-01

    We have examined the kinetics of processing of the HIV-1 Gag-Pro-Pol precursor in an in vitro assay with mature protease added in trans. The processing sites were cleaved at different rates to produce distinct intermediates. The initial cleavage occurred at the p2/NC site. Intermediate cleavages occurred at similar rates at the MA/CA and RT/IN sites, and to a lesser extent at sites upstream of RT. Late cleavages occurred at the sites flanking the protease (PR) domain, suggesting sequestering of these sites. We observed paired intermediates indicative of half- cleavage of RT/RH site, suggesting that the RT domain in Gag-Pro-Pol was in a dimeric form under these assay conditions. These results clarify our understanding of the processing kinetics of the Gag-Pro-Pol precursor and suggest regulated cleavage. Our results further suggest that early dimerization of the PR and RT domains may serve as a regulatory element to influence the kinetics of processing within the Pol domain.

  16. Mutations in HIV-1 gag and pol Compensate for the Loss of Viral Fitness Caused by a Highly Mutated Protease

    Kožíšek, Milan; Henke, S.; Grantz Šašková, Klára; Jacobs, G. B.; Schuch, A.; Buchholz, B.; Müller, V.; Kräusslich, H. G.; Řezáčová, Pavlína; Konvalinka, Jan; Bodem, J.

    2012-01-01

    Roč. 56, č. 8 (2012), s. 4320-4330 ISSN 0066-4804 R&D Projects: GA ČR GAP207/11/1798 Institutional research plan: CEZ:AV0Z40550506 Keywords : HIV protease * resistance * inhibitor * viral fitness * AG subtype Subject RIV: EE - Microbiology, Virology Impact factor: 4.565, year: 2012

  17. Reversal of atherogenic lipoprotein profile in HIV-1 infected patients with lipodystrophy after replacing protease inhibitors by nevirapine

    Negredo, Eugenia; Ribalta, Josep; Paredes, Roger; Ferré, Raimón; Sirera, Guillem; Ruiz, Lidia; Salazar, Juliana; Reiss, Peter; Masana, Lluís; Clotet, Bonaventura

    2002-01-01

    Background: The widespread use of protease inhibitors (PI) has been associated with abnormalities in the lipid profile of HIV-1-infected patients. Treatment simplification approaches in which PI are replaced by nevirapine (NVP) have been shown to improve PI-related toxicity. Objective: To assess the

  18. The Role of Shed PrPc in the Neuropathogenesis of HIV Infection.

    Megra, Bezawit W; Eugenin, Eliseo A; Berman, Joan W

    2017-07-01

    HIV-1 enters the CNS soon after peripheral infection and causes chronic neuroinflammation and neuronal damage that leads to cognitive impairment in 40-70% of HIV-infected people. The nonpathogenic cellular isoform of the human prion protein (PrP c ) is an adhesion molecule constitutively expressed in the CNS. Previously, our laboratory showed that shed PrP c (sPrP c ) is increased in the cerebrospinal fluid of HIV-infected people with cognitive deficits as compared with infected people with no impairment. In this article, we demonstrate that CCL2 and TNF-α, inflammatory mediators that are elevated in the CNS of HIV-infected people, increase shedding of PrP c from human astrocytes by increasing the active form of the metalloprotease ADAM10. We show that the consequence of this shedding can be the production of inflammatory mediators, because treatment of astrocytes with rPrP c increased secretion of CCL2, CXCL-12, and IL-8. Supernatants from rPrP c -treated astrocytes containing factors produced in response to this treatment, but not rPrP c by itself, cause increased chemotaxis of both uninfected and HIV-infected human monocytes, suggesting a role for sPrP c in monocyte recruitment into the brain. Furthermore, we examined whether PrP c participates in glutamate uptake and found that rPrP c decreased uptake of this metabolite in astrocytes, which could lead to neurotoxicity and neuronal loss. Collectively, our data characterize mediators involved in PrP c shedding and the effect of this sPrP c on monocyte chemotaxis and glutamate uptake from astrocytes. We propose that shedding of PrP c could be a potential target for therapeutics to limit the cognitive impairment characteristic of neuroAIDS. Copyright © 2017 by The American Association of Immunologists, Inc.

  19. Multi-step inhibition explains HIV-1 protease inhibitor pharmacodynamics and resistance

    Rabi, S. Alireza; Laird, Gregory M.; Durand, Christine M.; Laskey, Sarah; Shan, Liang; Bailey, Justin R.; Chioma, Stanley; Moore, Richard D.; Siliciano, Robert F.

    2013-01-01

    HIV-1 protease inhibitors (PIs) are among the most effective antiretroviral drugs. They are characterized by highly cooperative dose-response curves that are not explained by current pharmacodynamic theory. An unresolved problem affecting the clinical use of PIs is that patients who fail PI-containing regimens often have virus that lacks protease mutations, in apparent violation of fundamental evolutionary theory. Here, we show that these unresolved issues can be explained through analysis of the effects of PIs on distinct steps in the viral life cycle. We found that PIs do not affect virion release from infected cells but block entry, reverse transcription, and post–reverse transcription steps. The overall dose-response curves could be reconstructed by combining the curves for each step using the Bliss independence principle, showing that independent inhibition of multiple distinct steps in the life cycle generates the highly cooperative dose-response curves that make these drugs uniquely effective. Approximately half of the inhibitory potential of PIs is manifest at the entry step, likely reflecting interactions between the uncleaved Gag and the cytoplasmic tail (CT) of the Env protein. Sequence changes in the CT alone, which are ignored in current clinical tests for PI resistance, conferred PI resistance, providing an explanation for PI failure without resistance. PMID:23979165

  20. Understanding the HIV-1 protease reactivity with DFT: what do we gain from recent functionals?

    Garrec, J; Sautet, P; Fleurat-Lessard, P

    2011-07-07

    The modeling of HIV-1 plays a crucial role in the understanding of its reactivity and its interactions with specific drugs. In this work, we propose a medium sized model to test the ability of a variety of quantum chemistry approaches to provide reasonable geometric parameters and energetics for this system. Although our model is large enough to include the main polarizing groups of the active site, it is small enough to be used within full quantum studies up to the second order Møller-Plesset (MP2) level with extrapolations to coupled cluster CCSD(T) level. These high level calculations are used as reference to assess the ability of electronic structure methods (semiempirical and DFT) to provide accurate geometries and energies for the HIV-1 protease reaction. All semiempirical methods fail to describe the geometry of the protease active site. Within DFT, pure generalized gradient approximation (GGA) functionals have difficulty in reproducing the reaction energy and underestimate the barrier. Hybrid and/or meta GGA approaches do not yield a consistent improvement. The best results are obtained with hybrid GGA B3LYP or X3LYP and with hybrid meta GGA functionals with a fraction of exact exchange around 30-40%, such as M06, B1B95, or BMK functionals. On the basis of these results, we propose an accurate and computationally efficient strategy, employing quantum chemistry methods. This is applied here to study the protonation state of the reaction intermediate and could be easily used in further QM/MM studies.

  1. The future of pre-exposure prophylaxis (PrEP) for human immunodeficiency virus (HIV) infection.

    Özdener, Ayşe Elif; Park, Tae Eun; Kalabalik, Julie; Gupta, Rachna

    2017-05-01

    People at high risk for HIV acquisition should be offered pre-exposure prophylaxis (PrEP). Tenofovir disoproxil fumarate (TDF)/emtricitabine (FTC) is currently the only medication recommended for pre-exposure prophylaxis (PrEP) by the Centers for Disease Control and Prevention (CDC) in people at high risk for HIV acquisition. This article will review medications currently under investigation and the future landscape of PrEP therapy. Areas covered: This article will review clinical trials that have investigated nontraditional regimens of TDF/FTC, antiretroviral agents from different drug classes such as integrase strand transfer inhibitors (INSTI), nucleoside reverse transcriptase inhibitors (NRTI), and non-nucleoside reverse transcriptase inhibitors (NNRTI) as potential PrEP therapies. Expert commentary: Currently, there are several investigational drugs in the pipeline for PrEP against HIV infection. Increased utilization of PrEP therapy depends on provider identification of people at high risk for HIV transmission. Advances in PrEP development will expand options and access for people and reduce the risk of HIV acquisition.

  2. Hydroxyethylamine derivatives as HIV-1 protease inhibitors: a predictive QSAR modelling study based on Monte Carlo optimization.

    Bhargava, S; Adhikari, N; Amin, S A; Das, K; Gayen, S; Jha, T

    2017-12-01

    Application of HIV-1 protease inhibitors (as an anti-HIV regimen) may serve as an attractive strategy for anti-HIV drug development. Several investigations suggest that there is a crucial need to develop a novel protease inhibitor with higher potency and reduced toxicity. Monte Carlo optimized QSAR study was performed on 200 hydroxyethylamine derivatives with antiprotease activity. Twenty-one QSAR models with good statistical qualities were developed from three different splits with various combinations of SMILES and GRAPH based descriptors. The best models from different splits were selected on the basis of statistically validated characteristics of the test set and have the following statistical parameters: r 2 = 0.806, Q 2 = 0.788 (split 1); r 2 = 0.842, Q 2 = 0.826 (split 2); r 2 = 0.774, Q 2 = 0.755 (split 3). The structural attributes obtained from the best models were analysed to understand the structural requirements of the selected series for HIV-1 protease inhibitory activity. On the basis of obtained structural attributes, 11 new compounds were designed, out of which five compounds were found to have better activity than the best active compound in the series.

  3. PrEP-dossier : Pre-Expositie Profylaxe voor hiv-negatieven in Nederland

    Urbanus AT; Blom C; Zantkuijl P; David S; P&B; I&V

    2017-01-01

    In October 2016, the Minister for Health, Welfare and Sport requested advice from the Health Council of the Netherlands on the use of medication to prevent HIV infection (pre-exposure prophylaxis, or PrEP) in people with an increased risk of HIV. The National Institute for Public Health and the

  4. The impact of pre-exposure prophylaxis (PrEP) on HIV epidemics in Africa and India: A simulation study

    D.C.J. Vissers (Debby); H.A.C.M. Voeten (Hélène); N.J.D. Nagelkerke (Nico); J.D.F. Habbema (Dik); S.J. de Vlas (Sake)

    2008-01-01

    textabstractBackground: Pre-exposure prophylaxis (PrEP) is a promising new HIV prevention method, especially for women. An urgent demand for implementation of PrEP is expected at the moment efficacy has been demonstrated in clinical trials. We explored the long-term impact of PrEP on HIV

  5. Expression of a serine protease gene prC is up-regulated by oxidative stress in the fungus Clonostachys rosea: implications for fungal survival.

    Cheng-Gang Zou

    Full Text Available BACKGROUND: Soil fungi face a variety of environmental stresses such as UV light, high temperature, and heavy metals. Adaptation of gene expression through transcriptional regulation is a key mechanism in fungal response to environmental stress. In Saccharomyces cerevisiae, the transcription factors Msn2/4 induce stress-mediated gene expression by binding to the stress response element. Previous studies have demonstrated that the expression of extracellular proteases is up-regulated in response to heat shock in fungi. However, the physiological significance of regulation of these extracellular proteases by heat shock remains unclear. The nematophagous fungus Clonostachys rosea can secret an extracellular serine protease PrC during the infection of nematodes. Since the promoter of prC has three copies of the stress response element, we investigated the effect of environmental stress on the expression of prC. METHODOLOGY/PRINCIPAL FINDINGS: Our results demonstrated that the expression of prC was up-regulated by oxidants (H(2O(2 or menadione and heat shock, most likely through the stress response element. After oxidant treatment or heat shock, the germination of conidia in the wild type strain was significantly higher than that in the prC mutant strain in the presence of nematode cuticle. Interestingly, the addition of nematode cuticle significantly attenuated the production of reactive oxygen species (ROS induced by oxidants and heat shock in the wild type strain, but not in prC mutant strain. Moreover, low molecule weight (<3 kD degradation products of nematode cuticle suppressed the inhibitory effect of conidial germination induced by oxidants and heat shock. CONCLUSIONS/SIGNIFICANCE: These results indicate that PrC plays a protective role in oxidative stress in C. rosea. PrC degrades the nematode cuticle to produce degradation products, which in turn offer a protective effect against oxidative stress by scavenging ROS. Our study reveals a novel

  6. Subtype-Specific Differences in Gag-Protease-Driven Replication Capacity Are Consistent with Intersubtype Differences in HIV-1 Disease Progression.

    Kiguoya, Marion W; Mann, Jaclyn K; Chopera, Denis; Gounder, Kamini; Lee, Guinevere Q; Hunt, Peter W; Martin, Jeffrey N; Ball, T Blake; Kimani, Joshua; Brumme, Zabrina L; Brockman, Mark A; Ndung'u, Thumbi

    2017-07-01

    There are marked differences in the spread and prevalence of HIV-1 subtypes worldwide, and differences in clinical progression have been reported. However, the biological reasons underlying these differences are unknown. Gag-protease is essential for HIV-1 replication, and Gag-protease-driven replication capacity has previously been correlated with disease progression. We show that Gag-protease replication capacity correlates significantly with that of whole isolates ( r = 0.51; P = 0.04), indicating that Gag-protease is a significant contributor to viral replication capacity. Furthermore, we investigated subtype-specific differences in Gag-protease-driven replication capacity using large well-characterized cohorts in Africa and the Americas. Patient-derived Gag-protease sequences were inserted into an HIV-1 NL4-3 backbone, and the replication capacities of the resulting recombinant viruses were measured in an HIV-1-inducible reporter T cell line by flow cytometry. Recombinant viruses expressing subtype C Gag-proteases exhibited substantially lower replication capacities than those expressing subtype B Gag-proteases ( P identified Gag residues 483 and 484, located within the Alix-binding motif involved in virus budding, as major contributors to subtype-specific replicative differences. In East African cohorts, we observed a hierarchy of Gag-protease-driven replication capacities, i.e., subtypes A/C differences in disease progression. We thus hypothesize that the lower Gag-protease-driven replication capacity of subtypes A and C slows disease progression in individuals infected with these subtypes, which in turn leads to greater opportunity for transmission and thus increased prevalence of these subtypes. IMPORTANCE HIV-1 subtypes are unevenly distributed globally, and there are reported differences in their rates of disease progression and epidemic spread. The biological determinants underlying these differences have not been fully elucidated. Here, we show that

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

    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 < 0.001) but was naturally present in half of untreated Ethiopian HIV-1C sequences. The insertion is predicted to restore 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.

  8. Activities of the human immunodeficiency virus type 1 (HIV-1) protease inhibitor nelfinavir mesylate in combination with reverse transcriptase and protease inhibitors against acute HIV-1 infection in vitro.

    Patick, A K; Boritzki, T J; Bloom, L A

    1997-01-01

    Nelfinavir mesylate (formerly AG1343) is a potent and selective, nonpeptidic inhibitor of human immunodeficiency virus type 1 (HIV-1) protease that was discovered by protein structure-based design methodologies. We evaluated the antiviral and cytotoxic effects of two-drug combinations of nelfinavir with the clinically approved antiretroviral therapeutics zidovudine (ZDV), lamivudine (3TC), dideoxycytidine (ddC; zalcitabine), stavudine (d4T), didanosine (ddI), indinavir, saquinavir, and ritona...

  9. Inhibition of cornifins and up-regulation of protease inhibitors in cervicovaginal lavage imparts resistance to heterosexual HIV transmission

    Sushama Rokade

    2017-12-01

    Full Text Available HIV-exposed seronegative individuals (HESNs are persons who remain seronegative despite repeated exposure to HIV, suggesting an in vivo resistance mechanism to HIV. Elucidation of endogenous factors responsible for this phenomenon may aid in the development of new classes of microbicides and therapeutics. The genital mucosal secretions of both men and women are known to contain a spectrum of antimicrobials and immune mediators that may contribute to resistance against HIV-1. Existence of HIV serodiscordant couples is a testimony to mucosal factors in the genital tract that prevent sexual transmission of the virus. We attempted to map such mucosal factors in female genital secretions of the serodiscordant couples in comparison with HIV infected and healthy participants using quantitative proteomics. The cervico vaginal lavage (CVL samples were collected from three groups of study participants (HIV infected, n=30; Un-infected Controls, n=10; Serodiscordant, n=24. Abundant proteins, albumin and globulins were removed from the pooled samples using multiple affinity removal spin cartridge (Agilent to enhance the sensitivity of iTRAQ proteomics analysis. Initial analysis identified a total of 135 proteins and associated 497 peptide matches. Serodiscordant females showed significantly down regulated levels of Cornifin A, B and C, Neutrophil gelatinase, myeloperoxidase and eosinophil peroxidase. Cornifins are cross-linked envelope protein of keratinocytes and are upregulated during inflammation. Downregulation of oxidative stress inducing enzymes and cornifins suggests immune-quiescence in serodiscordant females. CVL of these women showed significantly upregulated levels of Mucin 5B, S100A7, Alpha-2-macroglobulin, Cystatin A (protease inhibitor, Lacto-transferrin, SLPI (anti-leukoproteinase inhibitor and SERPIN G1 (protease inhibitor.  Significantly elevated levels of Cystatin B and Elafin in the CVL of serodiscordant females were confirmed by ELISA

  10. PrPC has nucleic acid chaperoning properties similar to the nucleocapsid protein of HIV-1.

    Derrington, Edmund; Gabus, Caroline; Leblanc, Pascal; Chnaidermann, Jonas; Grave, Linda; Dormont, Dominique; Swietnicki, Wieslaw; Morillas, Manuel; Marck, Daniel; Nandi, Pradip; Darlix, Jean-Luc

    2002-01-01

    The function of the cellular prion protein (PrPC) remains obscure. Studies suggest that PrPC functions in several processes including signal transduction and Cu2+ metabolism. PrPC has also been established to bind nucleic acids. Therefore we investigated the properties of PrPC as a putative nucleic acid chaperone. Surprisingly, PrPC possesses all the nucleic acid chaperoning properties previously specific to retroviral nucleocapsid proteins. PrPC appears to be a molecular mimic of NCP7, the nucleocapsid protein of HIV-1. Thus PrPC, like NCP7, chaperones the annealing of tRNA(Lys) to the HIV-1 primer binding site, the initial step of retrovirus replication. PrPC also chaperones the two DNA strand transfers required for production of a complete proviral DNA with LTRs. Concerning the functions of NCP7 during budding, PrPC also mimices NCP7 by dimerizing the HIV-1 genomic RNA. These data are unprecedented because, although many cellular proteins have been identified as nucleic acid chaperones, none have the properties of retroviral nucleocapsid proteins.

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

    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.

  12. GS-8374, a Prototype Phosphonate-Containing Inhibitor of HIV-1 Protease, Effectively Inhibits Protease Mutants with Amino Acid Insertions

    Grantz Šašková, Klára; Kožíšek, Milan; Stray, K.; Jong de, D.; Řezáčová, Pavlína; Brynda, Jiří; Maarseveen van, N. M.; Nijhuis, M.; Cihlář, T.; Konvalinka, Jan

    2014-01-01

    Roč. 88, č. 6 (2014), s. 3586-3590 ISSN 0022-538X R&D Projects: GA ČR GAP207/11/1798 Grant - others:OPPC(XE) CZ.2.16/3.1.00/24016 Institutional support: RVO:61388963 ; RVO:68378050 Keywords : virus type-1 protease * antiviral activity * drug resistance Subject RIV: EE - Microbiology, Virology Impact factor: 4.439, year: 2014

  13. The crystal structure of protease Sapp1p from Candida parapsilosis in complex with the HIV protease inhibitor ritonavir

    Dostál, Jiří; Brynda, Jiří; Hrušková-Heidingsfeldová, Olga; Pachl, Petr; Pichová, Iva; Řezáčová, Pavlína

    2012-01-01

    Roč. 27, č. 1 (2012), s. 160-165 ISSN 1475-6366 R&D Projects: GA MŠk(CZ) LC531; GA ČR GA310/09/1945; GA ČR GA203/09/0820 Institutional research plan: CEZ:AV0Z40550506; CEZ:AV0Z50520514 Keywords : secreted aspartic protease * virulence factor * X-ray structure * candidiasis Subject RIV: CE - Biochemistry Impact factor: 1.495, year: 2012

  14. Differential body composition effects of protease inhibitors recommended for initial treatment of HIV infection: A randomized clinical trial

    Martinez, Esteban; Gonzalez-Cordon, Ana; Ferrer, Elena; Domingo, Pere; Negredo, Eugenia; Gutierrez, Felix; Portilla, Joaquin; Curran, Adrià; Podzamczer, Daniel; Ribera, Esteban; Murillas, Javier; Bernardino, Jose I.; Santos, Ignacio; Carton, Jose A.; Peraire, Joaquim

    2015-01-01

    This article has been accepted for publication in Clinical Infectious Diseases ©2014 The Authors .Published by Oxford University Press on Clinical Infectious Disease 60.5. DOI: 10.1093/cid/ciu898 Background. It is unclear whether metabolic or body composition effects may differ between protease inhibitor-based regimens recommended for initial treatment of HIV infection. Methods. ATADAR is a phase IV, open-label, multicenter randomized clinical trial. Stable antiretroviral-naive HIV-in...

  15. ReFlexIn: a flexible receptor protein-ligand docking scheme evaluated on HIV-1 protease.

    Simon Leis

    Full Text Available For many targets of pharmaceutical importance conformational changes of the receptor protein are relevant during the ligand binding process. A new docking approach, ReFlexIn (Receptor Flexibility by Interpolation, that combines receptor flexibility with the computationally efficient potential grid representation of receptor molecules has been evaluated on the retroviral HIV-1 (Human Immunodeficiency Virus 1 protease system. An approximate inclusion of receptor flexibility is achieved by using interpolation between grid representations of individual receptor conformations. For the retroviral protease the method was tested on an ensemble of protease structures crystallized in the presence of different ligands and on a set of structures obtained from morphing between the unbound and a ligand-bound protease structure. Docking was performed on ligands known to bind to the protease and several non-binders. For the binders the ReFlexIn method yielded in almost all cases ligand placements in similar or closer agreement with experiment than docking to any of the ensemble members without degrading the discrimination with respect to non-binders. The improved docking performance compared to docking to rigid receptors allows for systematic virtual screening applications at very small additional computational cost.

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

    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.

  17. 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

    Yedidi, Ravikiran S.; Muhuhi, Joseck M.; Liu, Zhigang; Bencze, Krisztina Z.; Koupparis, Kyriacos; O’Connor, Carrie E.; Kovari, Iulia A.; Spaller, Mark R.; Kovari, Ladislau C.

    2013-01-01

    Highlights: •Inhibitors against MDR HIV-1 protease were designed, synthesized and evaluated. •Lead peptide (6a) showed potent inhibition (IC 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 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 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 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

  18. 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

    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.

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

    See, Alfred P; Zeng, Jing; Tran, Phuoc T; Lim, Michael

    2011-01-01

    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. 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. 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. In this study of recent radiotherapy in HIV-positive patients taking second generation PIs, no difference in toxicities was

  20. Clinical validation and applicability of different tipranavir/ritonavir genotypic scores in HIV-1 protease inhibitor-experienced patients.

    Saracino, Annalisa; Monno, Laura; Tartaglia, Alessandra; Tinelli, Carmine; Seminari, Elena; Maggiolo, Franco; Bonora, Stefano; Rusconi, Stefano; Micheli, Valeria; Lo Caputo, Sergio; Lazzaroni, Laura; Ferrara, Sergio; Ladisa, Nicoletta; Nasta, Paola; Parruti, Giustino; Bellagamba, Rita; Forbici, Federica; Angarano, Gioacchino

    2009-07-01

    Tipranavir, a non-peptidic protease inhibitor which shows in vitro efficacy against some HIV-1-resistant strains, can be used in salvage therapies for multi-experienced HIV patients due to its peculiar resistance profile including 21 mutations at 16 protease positions according to International AIDS Society (IAS). Other genotypic scores, however, which attribute a different weight to single amino-acid substitutions, have been recently proposed. To validate the clinical utility of four different genotypic scores for selecting tipranavir responders, the baseline resistance pattern of 176 HIV heavily experienced patients was correlated with virological success (HIV-RNA42.5% of patients. With univariate analysis, genotypic scores were all associated with outcome but showed a low accuracy with ROC analysis, with the weighted score (WS) by Scherer et al. demonstrating the best performance with an AUC of 68%. Only 52% of patients classified as susceptible (WSIAS mutations: L33F, I54AMV, Q58E, and non-IAS mutation: N37DES. On the contrary, the use of T20 in T20-naïve patients and the V82AFSI and F53LY non-IAS mutations were associated with virological success. The study suggests that even if the "weighted" scores are able to interpret correctly the antiretroviral resistance profile of multi-experienced patients, it is difficult to individuate a cut-off which can be easily applied to this population for discriminating responders.

  1. HIV-negative male couples' attitudes about pre-exposure prophylaxis (PrEP) and using PrEP with a sexual agreement.

    Mitchell, Jason W; Lee, Ji-Young; Woodyatt, Cory; Bauermeister, José; Sullivan, Patrick; Stephenson, Rob

    2016-08-01

    One efficacious strategy to help prevent HIV is oral pre-exposure prophylaxis (PrEP), a daily regimen of antiretroviral treatment taken by HIV-negative individuals. Two of the recommendations of Centers for Disease Control and Prevention (CDC) guidelines for PrEP pertain to being in a relationship (i.e., male couples). Despite the recognition of how primary partners in male couples' relationships shape HIV risk and CDC's PrEP guidelines, there is a paucity of data that examine HIV-negative male couples' attitudes toward PrEP use and using PrEP with a sexual agreement. A sexual agreement is an explicit agreement made between two individuals about what sex and other related behaviors may occur within and outside of their relationship. In this qualitative study, we examine HIV-negative male couples' attitudes toward PrEP use and whether they thought PrEP could be integrated into a sexual agreement. Data for this study are drawn from couple-level interviews conducted in 2014 with 29 HIV-negative male couples who had a sexual agreement and were from Atlanta or Detroit. Both passive (e.g., flyers) and active (e.g., targeted Facebook advertisements) recruitment methods were used; the sample was stratified by agreement type. Thematic analysis was applied to identify the following themes regarding HIV-negative male couples' attitudes toward PrEP use: (1) PrEP and condom use; (2) concerns about PrEP (e.g., effectiveness, side effects, and promoting sexually risky behavior); and (3) accessibility of PrEP. Some thought PrEP could be a part of couples' agreement because it could help reduce sexual anxiety and sexual risk, and would help keep the couple safe. Others described PrEP use with an agreement as something for "others". Some were also concerned that incorporating PrEP could usurp the need for a sexual agreement in a couples' relationship. These themes highlight the need to improve informational messaging and promotion efforts about PrEP among HIV-negative male couples

  2. "I Did Not Want to Give Birth to a Child Who has HIV": Experiences Using PrEP During Pregnancy Among HIV-Uninfected Kenyan Women in HIV-Serodiscordant Couples.

    Pintye, Jillian; Beima-Sofie, Kristin M; Kimemia, Grace; Ngure, Kenneth; Trinidad, Susan Brown; Heffron, Renee A; Baeten, Jared M; Odoyo, Josephine; Mugo, Nelly; Bukusi, Elizabeth A; Kelley, Maureen C; John-Stewart, Grace C

    2017-11-01

    The perceptions, motivations, and beliefs of HIV-uninfected women about pre-exposure prophylaxis (PrEP) use during pregnancy can influence its uptake and adherence. This study elicited the views of HIV-uninfected women with personal experience taking PrEP during pregnancy. Qualitative interviews were conducted with HIV-uninfected women who had personal experience taking PrEP while pregnant. Semistructured interviews were conducted with 21 HIV-uninfected Kenyan women in HIV-serodiscordant couples enrolled in an open-label PrEP demonstration project who became pregnant while using PrEP and continued PrEP through their pregnancy. Interviews were audio-recorded and transcribed into English. A qualitative descriptive analysis was performed, using a constant comparison approach to identify key themes related to PrEP use in pregnancy. Desire to remain HIV uninfected and have an HIV-free infant were strong motivators influencing continued use of PrEP during pregnancy. Supporting HIV-infected partners and childbearing within an HIV-serodiscordant relationship were also motivators. Women had challenges distinguishing normal pregnancy symptoms from PrEP side effects and were concerned that observed side effects could be signs of danger for the infant related to PrEP exposure. Health care providers were important conduits of knowledge about PrEP, and continuity of PrEP providers throughout pregnancy facilitated adherence. HIV-uninfected women in HIV-serodiscordant couples were motivated to use PrEP during pregnancy to remain HIV uninfected and to have an HIV-free child but had concerns about side effects. Health care providers will be important for PrEP messaging and adherence support in this unique population.

  3. Computational Studies of a Mechanism for Binding and Drug Resistance in the Wild Type and Four Mutations of HIV-1 Protease with a GRL-0519 Inhibitor

    Guodong Hu

    2016-05-01

    Full Text Available Drug resistance of mutations in HIV-1 protease (PR is the most severe challenge to the long-term efficacy of HIV-1 PR inhibitor in highly active antiretroviral therapy. To elucidate the molecular mechanism of drug resistance associated with mutations (D30N, I50V, I54M, and V82A and inhibitor (GRL-0519 complexes, we have performed five molecular dynamics (MD simulations and calculated the binding free energies using the molecular mechanics Poisson–Boltzmann surface area (MM-PBSA method. The ranking of calculated binding free energies is in accordance with the experimental data. The free energy spectra of each residue and inhibitor interaction for all complexes show a similar binding model. Analysis based on the MD trajectories and contribution of each residues show that groups R2 and R3 mainly contribute van der Waals energies, while groups R1 and R4 contribute electrostatic interaction by hydrogen bonds. The drug resistance of D30N can be attributed to the decline in binding affinity of residues 28 and 29. The size of Val50 is smaller than Ile50 causes the residue to move, especially in chain A. The stable hydrophobic core, including the side chain of Ile54 in the wild type (WT complex, became unstable in I54M because the side chain of Met54 is flexible with two alternative conformations. The binding affinity of Ala82 in V82A decreases relative to Val82 in WT. The present study could provide important guidance for the design of a potent new drug resisting the mutation inhibitors.

  4. Perceptions of pre-exposure prophylaxis (PrEP) among HIV-negative and HIV-positive men who have sex with men.

    Jaspal, Rusi; Daramilas, C.

    2016-01-01

    open access article Pre-exposure prophylaxis (PrEP) is a novel bio-medical HIV prevention op- tion for individuals at high risk of HIV exposure. This qualitative interview study ex- plores perceptions and understandings of PrEP among a sample of 20 HIV-negative and HIV-positive men who have sex with men (MSM) in the UK, where there is a debate about the feasibility of o ering PrEP on the NHS. Data were analysed using qualitative thematic analysis and social representations theory from soci...

  5. Prion seeding activities of mouse scrapie strains with divergent PrPSc protease sensitivities and amyloid plaque content using RT-QuIC and eQuIC.

    Sarah Vascellari

    Full Text Available Different transmissible spongiform encephalopathy (TSE-associated forms of prion protein (e.g. PrP(Sc can vary markedly in ultrastructure and biochemical characteristics, but each is propagated in the host. PrP(Sc propagation involves conversion from its normal isoform, PrP(C, by a seeded or templated polymerization mechanism. Such a mechanism is also the basis of the RT-QuIC and eQuIC prion assays which use recombinant PrP (rPrP(Sen as a substrate. These ultrasensitive detection assays have been developed for TSE prions of several host species and sample tissues, but not for murine models which are central to TSE pathogenesis research. Here we have adapted RT-QuIC and eQuIC to various murine prions and evaluated how seeding activity depends on glycophosphatidylinositol (GPI anchoring and the abundance of amyloid plaques and protease-resistant PrP(Sc (PrP(Res. Scrapie brain dilutions up to 10(-8 and 10(-13 were detected by RT-QuIC and eQuIC, respectively. Comparisons of scrapie-affected wild-type mice and transgenic mice expressing GPI anchorless PrP showed that, although similar concentrations of seeding activity accumulated in brain, the heavily amyloid-laden anchorless mouse tissue seeded more rapid reactions. Next we compared seeding activities in the brains of mice with similar infectivity titers, but widely divergent PrP(Res levels. For this purpose we compared the 263K and 139A scrapie strains in transgenic mice expressing P101L PrP(C. Although the brains of 263K-affected mice had little immunoblot-detectable PrP(Res, RT-QuIC indicated that seeding activity was comparable to that associated with a high-PrP(Res strain, 139A. Thus, in this comparison, RT-QuIC seeding activity correlated more closely with infectivity than with PrP(Res levels. We also found that eQuIC, which incorporates a PrP(Sc immunoprecipitation step, detected seeding activity in plasma from wild-type and anchorless PrP transgenic mice inoculated with 22L, 79A and/or RML

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

    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.

  7. Autoprocessing of human immunodeficiency virus type 1 protease miniprecursor fusions in mammalian cells

    Chen Chaoping

    2010-07-01

    Full Text Available Abstract Background HIV protease (PR is a virus-encoded aspartic protease that is essential for viral replication and infectivity. The fully active and mature dimeric protease is released from the Gag-Pol polyprotein as a result of precursor autoprocessing. Results We here describe a simple model system to directly examine HIV protease autoprocessing in transfected mammalian cells. A fusion precursor was engineered encoding GST fused to a well-characterized miniprecursor, consisting of the mature protease along with its upstream transframe region (TFR, and small peptide epitopes to facilitate detection of the precursor substrate and autoprocessing products. In HEK 293T cells, the resulting chimeric precursor undergoes effective autoprocessing, producing mature protease that is rapidly degraded likely via autoproteolysis. The known protease inhibitors Darunavir and Indinavir suppressed both precursor autoprocessing and autoproteolysis in a dose-dependent manner. Protease mutations that inhibit Gag processing as characterized using proviruses also reduced autoprocessing efficiency when they were introduced to the fusion precursor. Interestingly, autoprocessing of the fusion precursor requires neither the full proteolytic activity nor the majority of the N-terminal TFR region. Conclusions We suggest that the fusion precursors provide a useful system to study protease autoprocessing in mammalian cells, and may be further developed for screening of new drugs targeting HIV protease autoprocessing.

  8. Structural Studies of a Rationally Selected Multi-Drug Resistant HIV-1 Protease Reveal Synergistic Effect of Distal Mutations on Flap Dynamics

    Agniswamy, Johnson; Louis, John M.; Roche, Julien; Harrison, Robert W.; Weber, Irene T. (GSU); (NIH); (Iowa State)

    2016-12-16

    We report structural analysis of HIV protease variant PRS17 which was rationally selected by machine learning to represent wide classes of highly drug-resistant variants. Crystal structures were solved of PRS17 in the inhibitor-free form and in complex with antiviral inhibitor, darunavir. Despite its 17 mutations, PRS17 has only one mutation (V82S) in the inhibitor/substrate binding cavity, yet exhibits high resistance to all clinical inhibitors. PRS17 has none of the major mutations (I47V, I50V, I54ML, L76V and I84V) associated with darunavir resistance, but has 10,000-fold weaker binding affinity relative to the wild type PR. Comparable binding affinity of 8000-fold weaker than PR is seen for drug resistant mutant PR20, which bears 3 mutations associated with major resistance to darunavir (I47V, I54L and I84V). Inhibitor-free PRS17 shows an open flap conformation with a curled tip correlating with G48V flap mutation. NMR studies on inactive PRS17 D25N unambiguously confirm that the flaps adopt mainly an open conformation in solution very similar to that in the inhibitor-free crystal structure. In PRS17, the hinge loop cluster of mutations, E35D, M36I and S37D, contributes to the altered flap dynamics by a mechanism similar to that of PR20. An additional K20R mutation anchors an altered conformation of the hinge loop. Flap mutations M46L and G48V in PRS17/DRV complex alter the Phe53 conformation by steric hindrance between the side chains. Unlike the L10F mutation in PR20, L10I in PRS17 does not break the inter-subunit ion pair or diminish the dimer stability, consistent with a very low dimer dissociation constant comparable to that of wild type PR. Distal mutations A71V, L90M and I93L propagate alterations to the catalytic site of PRS17. PRS17 exhibits a molecular mechanism whereby mutations act synergistically to alter the flap dynamics resulting in significantly weaker binding yet maintaining active site contacts with darunavir.

  9. Prevalence, Mutation Patterns, and Effects on Protease Inhibitor Susceptibility of the L76V Mutation in HIV-1 Protease▿ †

    Young, Thomas P.; Parkin, Neil T.; Stawiski, Eric; Pilot-Matias, Tami; Trinh, Roger; Kempf, Dale J.; Norton, Michael

    2010-01-01

    Patterns of HIV-1 protease inhibitor (PI) resistance-associated mutations (RAMs) and effects on PI susceptibility associated with the L76V mutation were studied in a large database. Of 20,501 sequences with ≥1 PI RAM, 3.2% contained L76V; L76V was alone in 0.04%. Common partner mutations included M46I, I54V, V82A, I84V, and L90M. L76V was associated with a 2- to 6-fold decrease in susceptibility to lopinavir, darunavir, amprenavir, and indinavir and a 7- to 8-fold increase in susceptibility to atazanavir and saquinavir. PMID:20805393

  10. Fertility Intentions, Pregnancy, and Use of PrEP and ART for Safer Conception Among East African HIV Serodiscordant Couples.

    Heffron, Renee; Thomson, Kerry; Celum, Connie; Haberer, Jessica; Ngure, Kenneth; Mugo, Nelly; Bukusi, Elizabeth; Katabira, Elly; Odoyo, Josephine; Bulya, Nulu; Asiimwe, Stephen; Tindimwebwa, Edna; Baeten, Jared M

    2017-09-11

    African HIV serodiscordant couples often desire pregnancy, despite sexual HIV transmission risk during pregnancy attempts. Pre-exposure prophylaxis (PrEP) and antiretroviral therapy (ART) reduce HIV risk and can be leveraged for safer conception but how well these strategies are used for safer conception is not known. We conducted an open-label demonstration project of the integrated delivery of PrEP and ART among 1013 HIV serodiscordant couples from Kenya and Uganda followed quarterly for 2 years. We evaluated fertility intentions, pregnancy incidence, the use of PrEP and ART during peri-conception, and peri-conception HIV incidence. At enrollment, 80% of couples indicated a desire for more children. Pregnancy incidence rates were 18.5 and 18.7 per 100 person years among HIV-uninfected and HIV-infected women, and higher among women who recently reported fertility intention (adjusted odds ratio 3.43, 95% CI 2.38-4.93) in multivariable GEE models. During the 6 months preceding pregnancy, 82.9% of couples used PrEP or ART and there were no HIV seroconversions. In this cohort with high pregnancy rates, integrated PrEP and ART was readily used by HIV serodiscordant couples, including during peri-conception periods. Widespread scale-up of safer conception counseling and services is warranted to respond to strong desires for pregnancy among HIV-affected men and women.

  11. Contemporary protease inhibitors and cardiovascular risk

    Lundgren, Jens; Mocroft, Amanda; Ryom, Lene

    2018-01-01

    PURPOSE OF REVIEW: To review the evidence linking use of HIV protease inhibitors with excess risk of cardiovascular disease (CVD) in HIV+ populations. RECENT FINDINGS: For the two contemporary most frequently used protease inhibitors, darunavir and atazanavir [both pharmacologically boosted...

  12. Role of the pharmacist in pre-exposure chemoprophylaxis (PrEP therapy for HIV prevention

    Clauson KA

    2009-03-01

    Full Text Available With a global estimate of 2.5 million new infections of HIV occurring yearly, discovering novel methods to help stem the spread of the virus is critical. The use of antiretroviral chemoprophylaxis for preventing HIV after accidental or occupational exposure and in maternal to fetal transmission has become a widely accepted method to combat HIV. Based on this success, pre-exposure chemoprophylaxis (PrEP is being explored in at-risk patient populations such as injecting drug users, female sex workers and men who have sex with men. This off-label and unmonitored use has created a need for education and intervention by pharmacists and other healthcare professionals. Pharmacists should educate themselves on PrEP and be prepared to counsel patients about their means of obtaining it (e.g. borrowing or sharing medications and ordering from disreputable Internet pharmacies. They should also be proactive about medication therapy management in these patients due to clinically important drug interactions with PrEP medications. Only one trial exploring the safety and efficacy of tenofovir as PrEP has been completed thus far. However, five ongoing trials are in various stages and two additional studies are scheduled for the near future. Unfortunately, studies in this arena have met with many challenges that have threatened to derail progress. Ethical controversy surrounding post-trial care of participants who seroconvert during studies, as well as concerns over emerging viral resistance and logistical site problems, have already halted several PrEP trials. Information about these early trials has already filtered down to affected individuals who are experimenting with this unproven therapy as an “evening before pill”. The potential for PrEP is promising; however, more extensive trials are necessary to establish its safety and efficacy. Pharmacists are well-positioned to play a key role in helping patients make choices about PrEP, managing their therapy

  13. PrPST, a Soluble, Protease Resistant and Truncated PrP Form Features in the Pathogenesis of a Genetic Prion Disease

    Frid, Kati; Binyamin, Orli; Gabizon, Ruth

    2013-01-01

    While the conversion of PrPC into PrPSc in the transmissible form of prion disease requires a preexisting PrPSc seed, in genetic prion disease accumulation of disease related PrP could be associated with biochemical and metabolic modifications resulting from the designated PrP mutation. To investigate this possibility, we looked into the time related changes of PrP proteins in the brains of TgMHu2ME199K/wt mice, a line modeling for heterozygous genetic prion disease linked to the E200K PrP mutation. We found that while oligomeric entities of mutant E199KPrP exist at all ages, aggregates of wt PrP in the same brains presented only in advanced disease, indicating a late onset conversion process. We also show that most PK resistant PrP in TgMHu2ME199K mice is soluble and truncated (PrPST), a pathogenic form never before associated with prion disease. We next looked into brain samples from E200K patients and found that both PK resistant PrPs, PrPST as in TgMHu2ME199K mice, and “classical” PrPSc as in infectious prion diseases, coincide in the patient's post mortem brains. We hypothesize that aberrant metabolism of mutant PrPs may result in the formation of previously unknown forms of the prion protein and that these may be central for the fatal outcome of the genetic prion condition. PMID:23922744

  14. PrP(ST), a soluble, protease resistant and truncated PrP form features in the pathogenesis of a genetic prion disease.

    Friedman-Levi, Yael; Mizrahi, Michal; Frid, Kati; Binyamin, Orli; Gabizon, Ruth

    2013-01-01

    While the conversion of PrP(C) into PrP(Sc) in the transmissible form of prion disease requires a preexisting PrP(Sc) seed, in genetic prion disease accumulation of disease related PrP could be associated with biochemical and metabolic modifications resulting from the designated PrP mutation. To investigate this possibility, we looked into the time related changes of PrP proteins in the brains of TgMHu2ME199K/wt mice, a line modeling for heterozygous genetic prion disease linked to the E200K PrP mutation. We found that while oligomeric entities of mutant E199KPrP exist at all ages, aggregates of wt PrP in the same brains presented only in advanced disease, indicating a late onset conversion process. We also show that most PK resistant PrP in TgMHu2ME199K mice is soluble and truncated (PrP(ST)), a pathogenic form never before associated with prion disease. We next looked into brain samples from E200K patients and found that both PK resistant PrPs, PrP(ST) as in TgMHu2ME199K mice, and "classical" PrP(Sc) as in infectious prion diseases, coincide in the patient's post mortem brains. We hypothesize that aberrant metabolism of mutant PrPs may result in the formation of previously unknown forms of the prion protein and that these may be central for the fatal outcome of the genetic prion condition.

  15. PrP(ST, a soluble, protease resistant and truncated PrP form features in the pathogenesis of a genetic prion disease.

    Yael Friedman-Levi

    Full Text Available While the conversion of PrP(C into PrP(Sc in the transmissible form of prion disease requires a preexisting PrP(Sc seed, in genetic prion disease accumulation of disease related PrP could be associated with biochemical and metabolic modifications resulting from the designated PrP mutation. To investigate this possibility, we looked into the time related changes of PrP proteins in the brains of TgMHu2ME199K/wt mice, a line modeling for heterozygous genetic prion disease linked to the E200K PrP mutation. We found that while oligomeric entities of mutant E199KPrP exist at all ages, aggregates of wt PrP in the same brains presented only in advanced disease, indicating a late onset conversion process. We also show that most PK resistant PrP in TgMHu2ME199K mice is soluble and truncated (PrP(ST, a pathogenic form never before associated with prion disease. We next looked into brain samples from E200K patients and found that both PK resistant PrPs, PrP(ST as in TgMHu2ME199K mice, and "classical" PrP(Sc as in infectious prion diseases, coincide in the patient's post mortem brains. We hypothesize that aberrant metabolism of mutant PrPs may result in the formation of previously unknown forms of the prion protein and that these may be central for the fatal outcome of the genetic prion condition.

  16. A consistency-based feature selection method allied with linear SVMs for HIV-1 protease cleavage site prediction.

    Orkun Oztürk

    Full Text Available BACKGROUND: Predicting type-1 Human Immunodeficiency Virus (HIV-1 protease cleavage site in protein molecules and determining its specificity is an important task which has attracted considerable attention in the research community. Achievements in this area are expected to result in effective drug design (especially for HIV-1 protease inhibitors against this life-threatening virus. However, some drawbacks (like the shortage of the available training data and the high dimensionality of the feature space turn this task into a difficult classification problem. Thus, various machine learning techniques, and specifically several classification methods have been proposed in order to increase the accuracy of the classification model. In addition, for several classification problems, which are characterized by having few samples and many features, selecting the most relevant features is a major factor for increasing classification accuracy. RESULTS: We propose for HIV-1 data a consistency-based feature selection approach in conjunction with recursive feature elimination of support vector machines (SVMs. We used various classifiers for evaluating the results obtained from the feature selection process. We further demonstrated the effectiveness of our proposed method by comparing it with a state-of-the-art feature selection method applied on HIV-1 data, and we evaluated the reported results based on attributes which have been selected from different combinations. CONCLUSION: Applying feature selection on training data before realizing the classification task seems to be a reasonable data-mining process when working with types of data similar to HIV-1. On HIV-1 data, some feature selection or extraction operations in conjunction with different classifiers have been tested and noteworthy outcomes have been reported. These facts motivate for the work presented in this paper. SOFTWARE AVAILABILITY: The software is available at http

  17. HIV providers' likelihood to prescribe pre-exposure prophylaxis (PrEP) for HIV prevention differs by patient type: a short report.

    Adams, Leah M; Balderson, Benjamin H

    2016-09-01

    Pre-exposure prophylaxis (PrEP), the antiretroviral treatment regimen for HIV-negative people at high risk of acquiring HIV, has demonstrated efficacy across clinical trials in several patient populations. The Centers for Disease Control (CDC) have released detailed guidelines to aid providers in prescribing PrEP for their high-risk patients, including men who have sex with men (MSM), high-risk heterosexuals, and injection drug users (IDUs). Given that much attention in PrEP has focused on MSM patients, the present study used an online survey to assess factors involved in HIV care providers' (n = 363) decisions about prescribing PrEP, along with their willingness to prescribe PrEP to patients from various risk populations (e.g., MSM, heterosexuals, IDUs). The efficacy of PrEP was an important factor in providers' decisions about prescribing PrEP, as were considerations about patients' adherence to the regimen, regular follow-up for care, and medication costs. This survey's findings also suggest that providers' willingness to prescribe PrEP varies by patient group, with providers most willing to initiate the regimen with MSM who have an HIV-positive partner, and least willing to prescribe to high-risk heterosexuals or IDUs. In the context of the current CDC recommendations for PrEP that include MSM, heterosexuals, and IDUs, examining providers' rationales for and barriers against supporting this HIV prevention strategy across patient groups merits further attention.

  18. What Primary Care Providers Need to Know about Pre-Exposure Prophylaxis (PrEP) for HIV Prevention: Narrative Review

    Krakower, Douglas; Mayer, Kenneth H.

    2013-01-01

    As HIV prevalence climbs globally, including more than 50,000 new infections per year in the United States, we need effective HIV prevention strategies. The use of antiretrovirals for pre-exposure prophylaxis (known as “PrEP”) among high-risk HIV-uninfected persons is emerging as one such strategy. Randomized controlled trials have demonstrated that once daily oral PrEP decreased HIV incidence among at-risk MSM and African heterosexuals, including HIV serodiscordant couples. An additional randomized control trial of a pericoital topical application of antiretroviral microbicide gel reduced HIV incidence among at-risk heterosexual South African women. Two other studies in African women did not demonstrate the efficacy of oral or topical PrEP, raising concerns about adherence patterns and efficacy in this population. The FDA Antiretroviral Advisory Panel reviewed these studies and additional data in May 2012 and recommended the approval of oral tenofovir-emtricitabine for PrEP in high-risk populations. Patients may seek PrEP from their primary care providers and those on PrEP require monitoring. Thus, primary care providers should become familiar with PrEP. This review outlines the current state of knowledge about PrEP as it pertains to primary care including identification of individuals likely to benefit from PrEP, counseling to maximize adherence and minimize potential increases in risky behavior, and monitoring for potential drug toxicities, HIV acquisition, and antiretroviral drug resistance. Issues related to cost and insurance coverage are also discussed. Recent data suggest that PrEP, in conjunction with other prevention strategies, holds promise in helping to curtail the HIV epidemic. PMID:22821365

  19. Review of HIV Pre exposure prophylaxis (PrEP) and example of HIV PrEP Toolkit

    2017-08-28

    at Initiation of Sexual Activity Correct & Consistent Condom Use Prevention of mother-to- child transmission July 16, 2012: FDA approves...Okulicz JF, Medicine 2016 PrEP Utilization in a Managed Care System (Kaiser Permanente) 1200 ~ 1045 1000 . 800 600 . 400 200 0 835 657 0

  20. A Novel Aspartic Protease with HIV-1 Reverse Transcriptase Inhibitory Activity from Fresh Fruiting Bodies of the Wild Mushroom Xylaria hypoxylon

    Qing-Xiu Hu

    2012-01-01

    Full Text Available A novel aspartic protease with HIV-1 RT inhibitory activity was isolated and characterized from fruiting bodies of the wild mushroom Xylaria hypoxylon. The purification protocol comprised distilled water homogenization and extraction step, three ion exchange chromatographic steps (on DEAE-cellulose, Q-Sepharose, and CM-cellulose in succession, and final purification was by FPLC on Superdex 75. The protease was adsorbed on all the three ion exchangers. It was a monomeric protein with a molecular mass of 43 kDa as estimated by SDS-PAGE and FPLC. Its N-terminal amino acid sequence was HYTELLSQVV, which exhibited no sequence homology to other proteases reported. The activity of the protease was adversely affected by Pepstatin A, indicating that it is an aspartic protease. The protease activity was maximal or nearly so in the pH range 6–8 and in the temperature range 35–60°C. The purified enzyme exhibited HIV-1 RT inhibitory activity with an IC50 value of 8.3 μM, but was devoid of antifungal, ribonuclease, and hemagglutinating activities.

  1. 'PrEP is not ready for our community, and our community is not ready for PrEP': pre-exposure prophylaxis for HIV for people who inject drugs and limits to the HIV prevention response.

    Guise, Andy; Albers, Eliot Ross; Strathdee, Steffanie A

    2017-04-01

    Pre-exposure prophylaxis for HIV, or 'PrEP', is the use of antiretroviral medicines by people who are HIV-negative to protect themselves against acquiring HIV. PrEP has shown efficacy for preventing HIV acquisition. Despite the potential, many concerns have been voiced by people who inject drugs (PWID) and their organizations. There is a need to engage with these views and ensure their integration in to policy and strategy. This paper presents PWID views on PrEP to foster the uptake of these opinions into scientific and policy debate around PrEP METHODS: Critical analysis of a report of a community consultation led by the International Network of People who Use Drugs (INPUD). The INPUD report highlights enthusiasm from PWID for PrEP, but also three main concerns: the feasibility and ethics of PrEP, its potential use as a substitute for other harm reduction strategies and how a focus on PrEP heralds a re-medicalization of HIV. Each concern relates to evidenced gaps in essential services or opposition to harm reduction and PWID human rights. People who use drugs have fundamental concerns about the potential impacts of pre-exposure prophylaxis for HIV which reflect a 'fault line' in HIV prevention: a predominance of biomedical approaches over community perspectives. Greater community engagement in HIV prevention strategy is needed, or we risk continuing to ignore the need for action on the underlying structural drivers and social context of the HIV epidemic. © 2016 Society for the Study of Addiction.

  2. Low fraction of the 222K PrP variant in the protease-resistant moiety of PrPres in heterozygous scrapie positive goats.

    Mazza, Maria; Guglielmetti, Chiara; Ingravalle, Francesco; Brusadore, Sonia; Langeveld, Jan P M; Ekateriniadou, Loukia V; Andréoletti, Olivier; Casalone, Cristina; Acutis, Pier Luigi

    2017-07-01

    The presence of lysine (K) at codon 222 has been associated with resistance to classical scrapie in goats, but few scrapie cases have been identified in 222Q/K animals. To investigate the contribution of the 222K variant to PrPres formation in natural and experimental Q/K scrapie cases, we applied an immunoblotting method based on the use of two different monoclonal antibodies, F99/97.6.1 and SAF84, chosen for their different affinities to 222K and 222Q PrP variants. Our finding that PrPres seems to be formed nearly totally by the 222Q variant provides evidence that the 222K PrP variant confers resistance to conversion to PrPres formation and reinforces the view that this mutation has a protective role against classical scrapie in goats.

  3. Long-term analysis of resistance development in HIV-1 positive patients treated with protease and reverse transcriptase inhibitors: Correlation of the genotype and disease progression

    Prejdová, Jana; Weber, Jan; Machala, L.; Reiniš, Milan; Linka, M.; Brůčková, M.; Vandasová, M.; Staňková, M.; Konvalinka, Jan

    2005-01-01

    Roč. 49, č. 1 (2005), 29-36 ISSN 0001-723X R&D Projects: GA MZd(CZ) NI6339 Grant - others:5th Framework(XE) QLK2-CT-2001-02360 Institutional research plan: CEZ:AV0Z4055905 Keywords : HIV * protease inhibitors * resistance development Subject RIV: CE - Biochemistry Impact factor: 0.696, year: 2005

  4. Low fraction of the 222K PrP variant in the protease-resistant moiety of PrPres in heterozygous scrapie positive goats

    Mazza, Maria; Guglielmetti, Chiara; Ingravalle, Francesco; Brusadore, Sonia; Langeveld, Jan P. M.; Ekateriniadou, Loukia V.; Andréoletti, Olivier; Casalone, Cristina; Acutis, Pier Luigi

    2017-01-01

    The presence of lysine (K) at codon 222 has been associated with resistance to classical scrapie in goats, but few scrapie cases have been identified in 222Q/K animals. To investigate the contribution of the 222K variant to PrPres formation in natural and experimental Q/K scrapie cases, we applied an immunoblotting method based on the use of two different monoclonal antibodies, F99/97.6.1 and SAF84, chosen for their different affinities to 222K and 222Q PrP variants. Our finding that PrPres s...

  5. Pairwise and higher-order correlations among drug-resistance mutations in HIV-1 subtype B protease

    Morozov Alexandre V

    2009-08-01

    Full Text Available Abstract Background The reaction of HIV protease to inhibitor therapy is characterized by the emergence of complex mutational patterns which confer drug resistance. The response of HIV protease to drugs often involves both primary mutations that directly inhibit the action of the drug, and a host of accessory resistance mutations that may occur far from the active site but may contribute to restoring the fitness or stability of the enzyme. Here we develop a probabilistic approach based on connected information that allows us to study residue, pair level and higher-order correlations within the same framework. Results We apply our methodology to a database of approximately 13,000 sequences which have been annotated by the treatment history of the patients from which the samples were obtained. We show that including pair interactions is essential for agreement with the mutational data, since neglect of these interactions results in order-of-magnitude errors in the probabilities of the simultaneous occurence of many mutations. The magnitude of these pair correlations changes dramatically between sequences obtained from patients that were or were not exposed to drugs. Higher-order effects make a contribution of as much as 10% for residues taken three at a time, but increase to more than twice that for 10 to 15-residue groups. The sequence data is insufficient to determine the higher-order effects for larger groups. We find that higher-order interactions have a significant effect on the predicted frequencies of sequences with large numbers of mutations. While relatively rare, such sequences are more prevalent after multi-drug therapy. The relative importance of these higher-order interactions increases with the number of drugs the patient had been exposed to. Conclusion Correlations are critical for the understanding of mutation patterns in HIV protease. Pair interactions have substantial qualitative effects, while higher-order interactions are

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

    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

  7. Resveratrol Co-Treatment Attenuates the Effects of HIV Protease Inhibitors on Rat Body Weight and Enhances Cardiac Mitochondrial Respiration.

    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.

  8. Impact of HIV-1 subtype and antiretroviral therapy on protease and reverse transcriptase genotype: results of a global collaboration.

    Rami Kantor

    2005-04-01

    Full Text Available The genetic differences among HIV-1 subtypes may be critical to clinical management and drug resistance surveillance as antiretroviral treatment is expanded to regions of the world where diverse non-subtype-B viruses predominate.To assess the impact of HIV-1 subtype and antiretroviral treatment on the distribution of mutations in protease and reverse transcriptase, a binomial response model using subtype and treatment as explanatory variables was used to analyze a large compiled dataset of non-subtype-B HIV-1 sequences. Non-subtype-B sequences from 3,686 persons with well characterized antiretroviral treatment histories were analyzed in comparison to subtype B sequences from 4,769 persons. The non-subtype-B sequences included 461 with subtype A, 1,185 with C, 331 with D, 245 with F, 293 with G, 513 with CRF01_AE, and 618 with CRF02_AG. Each of the 55 known subtype B drug-resistance mutations occurred in at least one non-B isolate, and 44 (80% of these mutations were significantly associated with antiretroviral treatment in at least one non-B subtype. Conversely, of 67 mutations found to be associated with antiretroviral therapy in at least one non-B subtype, 61 were also associated with antiretroviral therapy in subtype B isolates.Global surveillance and genotypic assessment of drug resistance should focus primarily on the known subtype B drug-resistance mutations.

  9. Activities of the human immunodeficiency virus type 1 (HIV-1) protease inhibitor nelfinavir mesylate in combination with reverse transcriptase and protease inhibitors against acute HIV-1 infection in vitro.

    Patick, A K; Boritzki, T J; Bloom, L A

    1997-10-01

    Nelfinavir mesylate (formerly AG1343) is a potent and selective, nonpeptidic inhibitor of human immunodeficiency virus type 1 (HIV-1) protease that was discovered by protein structure-based design methodologies. We evaluated the antiviral and cytotoxic effects of two-drug combinations of nelfinavir with the clinically approved antiretroviral therapeutics zidovudine (ZDV), lamivudine (3TC), dideoxycytidine (ddC; zalcitabine), stavudine (d4T), didanosine (ddI), indinavir, saquinavir, and ritonavir and a three-drug combination of nelfinavir with ZDV and 3TC against an acute HIV-1 strain RF infection of CEM-SS cells in vitro. Quantitative assessment of drug interaction was evaluated by a universal response surface approach (W. R. Greco, G. Bravo, and J. C. Parsons, Pharm. Rev. 47:331-385, 1995) and by the method of M. N. Prichard and C. Shipman (Antiviral Res. 14:181-206, 1990). Both analytical methods yielded similar results and showed that the two-drug combinations of nelfinavir with the reverse transcriptase inhibitors ZDV, 3TC, ddI, d4T, and ddC and the three-drug combination with ZDV and 3TC resulted in additive to statistically significant synergistic interactions. In a similar manner, the combination of nelfinavir with the three protease inhibitors resulted in additive (ritonavir and saquinavir) to slightly antagonistic (indinavir) interactions. In all combinations, minimal cellular cytotoxicity was observed with any drug alone and in combination. These results suggest that administration of combinations of the appropriate doses of nelfinavir with other currently approved antiretroviral therapeutic agents in vivo may result in enhanced antiviral activity with no associated increase in cellular cytotoxicity.

  10. The HIV-1 protease resistance mutation I50L is associated with resistance to atazanavir and susceptibility to other protease inhibitors in multiple mutational contexts.

    Sista, P; Wasikowski, B; Lecocq, P; Pattery, T; Bacheler, L

    2008-08-01

    The HIV-1 protease mutation I50 L causes atazanavir resistance but increases susceptibility to other PIs. Predicted phenotypic FC values were obtained from viral genotypes, using the virtual Phenotype-LM bioinformatics tool (powering vircoTYPE). To evaluate I50 L's effect on susceptibility to 8 PIs, in a large genotype database. I50 L containing routine clinical isolate samples in Virco's genotype database were paired with samples having like patterns (or profiles) of IAS-USA-defined primary PI mutations, but lacking I50 L. Using vircoTYPE (version 4.1), the median predicted FC for each mutational profile was determined. I50 L-associated shifts in FC were evaluated using drug-specific CCOs. We selected 307 and 37098 samples with and without I50 L. These corresponded to 31 mutation patterns of > or =3 samples each. I50 L caused resistance to atazanavir in all 31 mutation contexts, but was associated with higher susceptibility for other PIs. The largest I50 L-associated shifts in median predicted FC were: 1.2 to 42.4 (atazanavir), 10.2 to 3.2 (amprenavir), 3.3 to 0.5 (darunavir), 13 to 0.5 (indinavir), 34.9 to 1.3 (lopinavir), 22.3 to 1.3 (nelfinavir), 5.2 to 0.3 (saquinavir) and 29.9 to 5.2 (tipranavir). The PI mutation I50 L causes clinically relevant resistance and increased susceptibility to atazanavir and other PIs respectively.

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

    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

    2014-01-01

    A novel tetra-peptide insertion was identified in Gag-p6 ALIX-binding region which is appears in protease inhibitor (PI) failure Indian HIV-1C sequences (Odds Ratio 17.1, p<0.001) but naturally present in half of untreated Ethiopian sequences. The insertion will probably restore the ALIX mediated virus release pathway, which is lacking in HIV-1C. The clinical importance of such insertion need to be evaluated in HIV-1C dominating regions were PI-drugs are being scaled up as second line treatment options. PMID:25102091

  12. Evaluation of HIV protease inhibitor use and the risk of sudden death or nonhemorrhagic stroke

    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...

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

    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.

  14. Targeting cysteine residues of human immunodeficiency virus type 1 protease by reactive free radical species.

    Basu, A; Sehajpal, P K; Ogiste, J S; Lander, H M

    1999-01-01

    Nitric oxide (NO) is a naturally occurring free radical with many functions. The oxidized form of NO, the nitrosonium ion, reacts with the thiol group of cysteine residues resulting in their modification to S-nitrosothiols. The human immunodeficiency virus type 1 (HIV-1) protease (HIV-PR) has two cysteine residues that are conserved amongst different viral isolates found in patients with acquired immunodeficiency syndrome (AIDS). In an active dimer, these residues are located near the surface of the protease. We have found that treatment of HIV-PR with different NO congeners results in loss of its proteolytic activity and simultaneous formation of S-nitrosothiols. Sodium nitroprusside inhibited HIV-PR up to 70% and S-nitroso-N-acetylpenicillamine completely inhibited the protease within 5 min of treatment. The pattern of inhibition by NO donors is comparable to its inhibition by N-acetyl pepstatin. Using electrospray ionization-mass spectrometry, we identified the modification of HIV-PR by NO as that of S-nitrosation. Our findings point towards a possible role of NO in mediating resistance to HIV-1 infection.

  15. Gendered differences in the perceived risks and benefits of oral PrEP among HIV-serodiscordant couples in Kenya.

    Carroll, Jennifer J; Ngure, Kenneth; Heffron, Renee; Curran, Kathryn; Mugo, Nelly R; Baeten, Jared M

    2016-08-01

    Pre-exposure prophylaxis (PrEP) is effective for preventing HIV among HIV-serodiscordant heterosexual couples. Gender roles may influence perceived personal and social risks related to HIV-prevention behaviors and may affect use of PrEP. In this study, interviews and focus groups were conducted with 68 individuals from 34 mutually disclosed serodiscordant heterosexual partnerships in Thika, Kenya. Sociocultural factors that affect adherence to PrEP were explored using grounded analysis. Three factors were identified, which shape perceptions of PrEP: gendered power dynamics and control over decision-making in the household; conflicts between risk-reduction strategies and male sexual desire; culture-bound definitions of women's work. Adherence to PrEP in the Partners PrEP Study was high; however, participants articulated conflicting interests related to PrEP in connection with traditional gender roles. The successful delivery of PrEP will require understanding of key social factors, particularly related to gender and dyadic dynamics around HIV serostatus.

  16. Inhibitors of HIV-protease from computational design. A history of theory and synthesis still to be fully appreciated.

    Berti, Federico; Frecer, Vladimir; Miertus, Stanislav

    2014-01-01

    Despite the fact that HIV-Protease is an over 20 years old target, computational approaches to rational design of its inhibitors still have a great potential to stimulate the synthesis of new compounds and the discovery of new, potent derivatives, ever capable to overcome the problem of drug resistance. This review deals with successful examples of inhibitors identified by computational approaches, rather than by knowledge-based design. Such methodologies include the development of energy and scoring functions, docking protocols, statistical models, virtual combinatorial chemistry. Computations addressing drug resistance, and the development of related models as the substrate envelope hypothesis are also reviewed. In some cases, the identified structures required the development of synthetic approaches in order to obtain the desired target molecules; several examples are reported.

  17. Description of the L76V resistance protease mutation in HIV-1 B and "non-B" subtypes.

    Charlotte Charpentier

    Full Text Available OBJECTIVE: To describe the prevalence of the L76V protease inhibitors resistance-associated mutation (PI-RAM in relation with patients' characteristics and protease genotypic background in HIV-1 B- and "non-B"-infected patients. METHODS: Frequency of the L76V mutation between 1998 and 2010 was surveyed in the laboratory database of 3 clinical centers. Major PI-RAMs were identified according to the IAS-USA list. Fisher's and Wilcoxon tests were used to compare variables. RESULTS: Among the overall 29,643 sequences analyzed, the prevalence of L76V was 1.50%, while was 5.42% in PI-resistant viruses. Since 2008 the prevalence of L76V was higher in "non-B"-infected than in B-infected patients each year. Median time since diagnosis of HIV-1 infection and median time under antiretroviral-based regimen were both shorter in "non-B"- than in B-infected patients (8 vs 11 years, P<0.0001; and 7 vs 8 years, P = 0.004. In addition, "non-B"-infected patients had been pre-exposed to a lower number of PI (2 vs 3, P = 0.016. The L76V was also associated with a lower number of major PI-RAMs in "non-B" vs B samples (3 vs 4, P = 0.0001, and thus it was more frequent found as single major PI-RAM in "non-B" vs B subtype (10% vs 2%, P = 0.014. CONCLUSIONS: We showed an impact of viral subtype on the selection of the L76V major PI-RAM with a higher prevalence in "non-B" subtypes observed since 2008. In addition, in "non-B"-infected patients this mutation appeared more rapidly and was associated with less PI-RAM.

  18. Description of the L76V resistance protease mutation in HIV-1 B and "non-B" subtypes.

    Charpentier, Charlotte; Lambert-Niclot, Sidonie; Alteri, Claudia; Storto, Alexandre; Flandre, Philippe; Svicher, Valentina; Perno, Carlo-Federico; Brun-Vézinet, Françoise; Calvez, Vincent; Marcelin, Anne-Geneviève; Ceccherini-Silberstein, Francesca; Descamps, Diane

    2013-01-01

    To describe the prevalence of the L76V protease inhibitors resistance-associated mutation (PI-RAM) in relation with patients' characteristics and protease genotypic background in HIV-1 B- and "non-B"-infected patients. Frequency of the L76V mutation between 1998 and 2010 was surveyed in the laboratory database of 3 clinical centers. Major PI-RAMs were identified according to the IAS-USA list. Fisher's and Wilcoxon tests were used to compare variables. Among the overall 29,643 sequences analyzed, the prevalence of L76V was 1.50%, while was 5.42% in PI-resistant viruses. Since 2008 the prevalence of L76V was higher in "non-B"-infected than in B-infected patients each year. Median time since diagnosis of HIV-1 infection and median time under antiretroviral-based regimen were both shorter in "non-B"- than in B-infected patients (8 vs 11 years, P<0.0001; and 7 vs 8 years, P = 0.004). In addition, "non-B"-infected patients had been pre-exposed to a lower number of PI (2 vs 3, P = 0.016). The L76V was also associated with a lower number of major PI-RAMs in "non-B" vs B samples (3 vs 4, P = 0.0001), and thus it was more frequent found as single major PI-RAM in "non-B" vs B subtype (10% vs 2%, P = 0.014). We showed an impact of viral subtype on the selection of the L76V major PI-RAM with a higher prevalence in "non-B" subtypes observed since 2008. In addition, in "non-B"-infected patients this mutation appeared more rapidly and was associated with less PI-RAM.

  19. Secretory leukocyte protease inhibitor expression and high-risk HPV infection in anal lesions of HIV positive patients

    NUOVO, Gerard J.; GRINSZTEJN, Beatriz; FRIEDMAN, Ruth K.; VELOSO, Valdiléa G.; CUNHA, Cynthia B.; COUTINHO, José R.; VIANNA-ANDRADE, Cecilia; OLIVEIRA, Nathalia S.; WOODHAM, Andrew W.; DA SILVA, Diane M.; KAST, W. Martin

    2016-01-01

    Objective The aim of the current study was to evaluate secretory leukocyte protease inhibitor (SLPI) expression in anal biopsies from HIV-positive (HIV+) individuals, and compare that to anal intraepithelial neoplasia (AIN) diagnoses and human papillomavirus (HPV) status. Design This is a cross-sectional study of a cohort of 54 HIV+ (31 males and 23 females) from an AIDS clinic in Rio de Janeiro, Brazil. Methods The study material consisted of anorectal tissue biopsies obtained from HIV+ subjects, which were used to construct tissue microarray paraffin blocks for immunohistochemical analysis of SLPI expression. Biopsies were evaluated by an expert pathologist and classified as low-grade anal intraepithelial neoplasia (AIN1), high-grade anal intraepithelial neoplasia (AIN2/3), or normal squamous epithelium. Additionally, DNA from the biopsies was extracted and analyzed for the presence of low- or high-risk HPV DNA. Results Histologically normal squamous epithelium from the anorectal region showed strong positive SLPI staining in 17/20 (85%) samples. In comparison, 9/17 (53%) dysplastic squamous epithelial samples from AIN1 patients showed strong SLPI staining, and only 5/17 (29%) samples from AIN2-3 patients exhibited strong SPLI staining, which both were significantly fewer than those from normal tissue (p=0.005). Furthermore, there was a significantly higher proportion of samples in which oncogenic high-risk HPV genotypes were detected in low SLPI expressing tissues than that in tissues with high SLPI expression (p=0.040). Conclusion Taken together these results suggest that low SLPI expression is associated with high-risk HPV infections in the development of AIN. PMID:27149102

  20. Brief Report: Medication Sharing Is Rare Among African HIV-1 Serodiscordant Couples Enrolled in an Efficacy Trial of Oral Pre-exposure Prophylaxis (PrEP) for HIV-1 Prevention.

    Thomson, Kerry A; Haberer, Jessica E; Marzinke, Mark A; Mujugira, Andrew; Hendrix, Craig W; Celum, Connie; Ndase, Patrick; Ronald, Allan; Bangsberg, David R; Baeten, Jared M

    2017-06-01

    Sharing of pre-exposure prophylaxis (PrEP) medications is a concern for PrEP implementation. For HIV-1 serodiscordant couples, sharing may undermine the HIV-1 prevention benefit and also cause antiretroviral resistance if taken by HIV-1 infected partners. Within a PrEP efficacy trial among HIV-1 serodiscordant couples, we assessed the occurrence of PrEP sharing by self-report and plasma tenofovir concentrations in HIV-1 infected partners. PrEP sharing was self-reported at <0.01% of visits, and 0%-1.6% of randomly selected and 0% of purposively selected specimens from HIV-1 infected participants had detectable tenofovir concentrations (median: 66.5 ng/mL, range: 1.3-292 ng/mL). PrEP sharing within HIV-1 serodiscordant couples was extremely rare.

  1. The impact of nevirapine- versus protease inhibitor-based regimens on virological markers of HIV-1 persistence during seemingly suppressive ART.

    Kiselinova, Maja; Anna, Maria; Malatinkova, Eva; Vervish, Karen; Beloukas, Apostolos; Messiaen, Peter; Bonczkowski, Pawel; Trypsteen, Wim; Callens, Steven; Verhofstede, Chris; De Spiegelaere, Ward; Vandekerckhove, Linos

    2014-01-01

    The source and significance of residual plasma HIV-1 RNA detection during suppressive ART remain controversial. It has been proposed that nevirapine (NVP)-based regimens achieve a greater HIV-1 RNA suppression than regimens containing a protease inhibitor (PI). The aim of this study was to compare the effect of receiving NVP- vs PI-based ART on the virological markers of HIV persistence in peripheral blood. The study population comprised 161 HIV-1 infected patients receiving either NVP-based (n=81) or PI-based (n=80) ART and showing a HIV-1 RNA load stably suppressed ART, with median (IQR) levels of 5 (3-6) and 5 (3-8) copies/mL, respectively. HIV-1 RNA detection was associated with shorter duration of suppressive ART regardless of treatment arm (p=0.007), and lower CD4 nadir (p=0.015). HIV-1 DNA levels were median 282 (120-484) and 213 (87-494) copies/106 PBMCs in the two groups respectively, and were lowest (ART HIV-1 RNA load (p=0.0001). In this comprehensive characterization of patients on long-term suppressive ART, we did not observe evidence for a greater suppressive activity of NVP-based over PI-based therapy on plasma and intracellular markers of virus persistence. Overall excellent correlation was observed between the markers, allowing the identification of a subset of treated patients with low HIV-1 expression as an important cohort for future HIV cure studies.

  2. HIV-1 transcripts use IRES-initiation under conditions where Cap-dependent translation is restricted by poliovirus 2A protease.

    Raquel Amorim

    Full Text Available The 30 different species of mRNAs synthesized during the HIV-1 replication cycle are all capped and polyadenilated. Internal ribosome entry sites have been recognized in the 5' untranslated region of some mRNA species of HIV-1, which would contribute to an alternative mechanism of initiation of mRNA translation. However, the Cap-dependent translation is assumed to be the main mechanism driving the initiation of HIV-1 protein synthesis. In this work, we describe a cell system in which lower to higher levels of transient expression of the poliovirus 2A protease strongly inhibited cellular Cap-dependent translation with no toxic effect to the cells during a 72-hour time frame. In this system, the synthesis of HIV-1 proteins was inhibited in a temporal dose-dependent way. Higher levels of 2A protease expression severely inhibited HIV-1 protein synthesis during the first 24 hours of infection consequently inhibiting viral production and infectivity. Intermediate to lower levels of 2A Protease expression caused the inhibition of viral protein synthesis only during the first 48 hours of viral replication. After this period both protein synthesis and viral release were recovered to the control levels. However, the infectivity of viral progeny was still partially inhibited. These results indicate that two mechanisms of mRNA translation initiation contribute to the synthesis of HIV-1 proteins; during the first 24-48 hours of viral replication HIV-1 protein synthesis is strongly dependent on Cap-initiation, while at later time points IRES-driven translation initiation is sufficient to produce high amounts of viral particles.

  3. Glyceroneogenesis is inhibited through HIV protease inhibitor-induced inflammation in human subcutaneous but not visceral adipose tissue

    Leroyer, Stéphanie; Vatier, Camille; Kadiri, Sarah; Quette, Joëlle; Chapron, Charles; Capeau, Jacqueline; Antoine, Bénédicte

    2011-01-01

    Glyceroneogenesis, a metabolic pathway that participates during lipolysis in the recycling of free fatty acids to triglycerides into adipocytes, contributes to the lipid-buffering function of adipose tissue. We investigated whether glyceroneogenesis could be affected by human immunodeficiency virus (HIV) protease inhibitors (PIs) responsible or not for dyslipidemia in HIV-infected patients. We treated explants obtained from subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) depots from lean individuals. We observed that the dyslipidemic PIs nelfinavir, lopinavir and ritonavir, but not the lipid-neutral PI atazanavir, increased lipolysis and decreased glyceroneogenesis, leading to an increased release of fatty acids from SAT but not from VAT. At the same time, dyslipidemic PIs decreased the amount of perilipin and increased interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) secretion in SAT but not in VAT. Parthenolide, an inhibitor of the NFκB pathway, counteracted PI-induced increased inflammation and decreased glyceroneogenesis. IL-6 (100 ng) inhibited the activity of phosphoenolpyruvate carboxykinase, the key enzyme of glyceroneogenesis, in SAT but not in VAT. Our data show that dyslipidemic but not lipid-neutral PIs decreased glyceroneogenesis as a consequence of PI-induced increased inflammation in SAT that could have an affect on adipocytes and/or macrophages. These results add a new link between fat inflammation and increased fatty acids release and suggest a greater sensitivity of SAT than VAT to PI-induced inflammation. PMID:21068005

  4. Oral Pre-Exposure Prophylaxis (PrEP) for Prevention of HIV in Serodiscordant Heterosexual Couples in the United States: Opportunities and Challenges

    Myers, Julie E.; Kurth, Ann E.; Cohen, Stephanie E.; Mannheimer, Sharon B.; Simmons, Janie; Pouget, Enrique R.; Trabold, Nicole; Haberer, Jessica E.

    2014-01-01

    Abstract Oral HIV pre-exposure prophylaxis (PrEP) is a promising new biomedical prevention approach in which HIV-negative individuals are provided with daily oral antiretroviral medication for the primary prevention of HIV-1. Several clinical trials have demonstrated efficacy of oral PrEP for HIV prevention among groups at high risk for HIV, with adherence closely associated with level of risk reduction. In the United States (US), three groups have been prioritized for initial implementation of PrEP—injection drug users, men who have sex with men at substantial risk for HIV, and HIV-negative partners within serodiscordant heterosexual couples. Numerous demonstration projects involving PrEP implementation among MSM are underway, but relatively little research has been devoted to study PrEP implementation in HIV-serodiscordant heterosexual couples in the US. Such couples face a unique set of challenges to PrEP implementation at the individual, couple, and provider level with regard to PrEP uptake and maintenance, adherence, safety and toxicity, clinical monitoring, and sexual risk behavior. Oral PrEP also provides new opportunities for serodiscordant couples and healthcare providers for primary prevention and reproductive health. This article provides a review of the critical issues, challenges, and opportunities involved in the implementation of oral PrEP among HIV-serodiscordant heterosexual couples in the US. PMID:25045996

  5. Validation of Simultaneous Quantitative Method of HIV Protease Inhibitors Atazanavir, Darunavir and Ritonavir in Human Plasma by UPLC-MS/MS

    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.

  6. Distinguishing Binders from False Positives by Free Energy Calculations: Fragment Screening Against the Flap Site of HIV Protease

    2015-01-01

    Molecular docking is a powerful tool used in drug discovery and structural biology for predicting the structures of ligand–receptor complexes. However, the accuracy of docking calculations can be limited by factors such as the neglect of protein reorganization in the scoring function; as a result, ligand screening can produce a high rate of false positive hits. Although absolute binding free energy methods still have difficulty in accurately rank-ordering binders, we believe that they can be fruitfully employed to distinguish binders from nonbinders and reduce the false positive rate. Here we study a set of ligands that dock favorably to a newly discovered, potentially allosteric site on the flap of HIV-1 protease. Fragment binding to this site stabilizes a closed form of protease, which could be exploited for the design of allosteric inhibitors. Twenty-three top-ranked protein–ligand complexes from AutoDock were subject to the free energy screening using two methods, the recently developed binding energy analysis method (BEDAM) and the standard double decoupling method (DDM). Free energy calculations correctly identified most of the false positives (≥83%) and recovered all the confirmed binders. The results show a gap averaging ≥3.7 kcal/mol, separating the binders and the false positives. We present a formula that decomposes the binding free energy into contributions from the receptor conformational macrostates, which provides insights into the roles of different binding modes. Our binding free energy component analysis further suggests that improving the treatment for the desolvation penalty associated with the unfulfilled polar groups could reduce the rate of false positive hits in docking. The current study demonstrates that the combination of docking with free energy methods can be very useful for more accurate ligand screening against valuable drug targets. PMID:25189630

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

    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...

  8. Treatment Failure in HIV-Infected Children on Second-line Protease Inhibitor-Based Antiretroviral Therapy.

    Suaysod, Rapeepan; Ngo-Giang-Huong, Nicole; Salvadori, Nicolas; Cressey, Tim R; Kanjanavanit, Suparat; Techakunakorn, Pornchai; Krikajornkitti, Sawitree; Srirojana, Sakulrat; Laomanit, Laddawan; Chalermpantmetagul, Suwalai; Lallemant, Marc; Le Cœur, Sophie; McIntosh, Kenneth; Traisathit, Patrinee; Jourdain, Gonzague

    2015-07-01

    Human immunodeficiency virus (HIV)-infected children failing second-line antiretroviral therapy (ART) have no access to third-line antiretroviral drugs in many resource-limited settings. It is important to identify risk factors for second-line regimen failure. HIV-infected children initiating protease inhibitor (PI)-containing second-line ART within the Program for HIV Prevention and Treatment observational cohort study in Thailand between 2002 and 2010 were included. Treatment failure was defined as confirmed HIV type 1 RNA load >400 copies/mL after at least 6 months on second-line regimen or death. Adherence was assessed by drug plasma levels and patient self-report. Cox proportional hazards regression analyses were used to identify risk factors for failure. A total of 111 children started a PI-based second-line regimen, including 59 girls (53%). Median first-line ART duration was 1.9 years (interquartile range [IQR], 1.4-3.3 years), and median age at second-line initiation was 10.7 years (IQR, 6.3-13.4 years). Fifty-four children (49%) experienced virologic failure, and 2 (2%) died. The risk of treatment failure 24 months after second-line initiation was 41%. In multivariate analyses, failure was independently associated with exposure to first-line ART for >2 years (adjusted hazard ratio [aHR], 1.8; P = .03), age >13 years (aHR, 2.9; P < .001), body mass index-for-age z score < -2 standard deviations at second-line initiation (aHR, 2.8; P = .03), and undetectable drug levels within 6 months following second-line initiation (aHR, 4.5; P < .001). Children with longer exposure to first-line ART, entry to adolescence, underweight, and/or undetectable drug levels were at higher risk of failing second-line ART and thus should be closely monitored. © The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  9. Towards a fair consideration of PrEP as part of combination HIV prevention in Latin America.

    Ravasi, Giovanni; Grinsztejn, Beatriz; Baruch, Ricardo; Guanira, Juan Vicente; Luque, Ricardo; Cáceres, Carlos F; Ghidinelli, Massimo

    2016-01-01

    Despite progress in scaling up antiretroviral treatment, HIV prevention strategies have not been successful in significantly curbing HIV incidence in Latin America. HIV prevention interventions need to be expanded to target the most affected key populations with a combination approach, including new high impact technologies. Oral pre-exposure prophylaxis (PrEP) is recommended as additional prevention choice for individuals at higher risk of infection and could become a cost-effective prevention tool. We discuss the barriers and solutions for a fair consideration of PrEP as part of combination HIV prevention strategies in Latin America. Although demonstration projects are ongoing or being planned in a number of countries, to date no Latin American country has implemented a public PrEP programme. The knowledge of policymakers about PrEP implementation needs to be strengthened, and programmatic guidance and cost estimate tools need to be developed to support adequate planning. Despite high levels of awareness among health providers, especially if engaged in HIV or key population care, willingness to prescribe PrEP is still low due to the lack of national policies and guidelines. Key populations, especially men who have sex with men, transgender women and sex workers, have been engaged in demonstration projects, and qualitative research shows high awareness and willingness to use PrEP, especially if accessible in the public sector for free or at affordable price. Concerns of safety, adherence, effectiveness and risk compensation need to be addressed through targeted social communication strategies to improve PrEP knowledge and stimulate demand. Alliance among policymakers, civil society and representatives from key populations, healthcare providers and researchers will be critical for the design and successful implementation of PrEP demonstration projects of locally adapted delivery models. The use of mechanisms of joint negotiation and procurement of antiretrovirals

  10. Role of oral pre-exposure prophylaxis (PrEP) in current and future HIV prevention strategies.

    Burns, David N; Grossman, Cynthia; Turpin, Jim; Elharrar, Vanessa; Veronese, Fulvia

    2014-12-01

    Treatment as prevention is expected to have a major role in reducing HIV incidence, but other prevention interventions will also be required to bring the epidemic under control, particularly among key populations. One or more forms of pre-exposure prophylaxis (PrEP) will likely play a critical role. Oral PrEP with emtricitabine-tenofovir (Truvada®) is currently available in the US and some other countries, but uptake has been slow. We review the concerns that have contributed to this slow uptake and discuss current and future research in this critical area of HIV prevention research.

  11. Comparing the impact of increasing condom use or HIV pre-exposure prophylaxis (PrEP use among female sex workers

    Zindoga Mukandavire

    2016-03-01

    Full Text Available In many settings, interventions targeting female sex workers (FSWs could significantly reduce the overall transmission of HIV. To understand the role HIV pre-exposure prophylaxis (PrEP could play in controlling HIV transmission amongst FSWs, it is important to understand how its impact compares with scaling-up condom use—one of the proven HIV prevention strategies for FSWs. It is important to remember that condoms also have other benefits such as reducing the incidence of sexually transmitted infections and preventing pregnancy. A dynamic deterministic model of HIV transmission amongst FSWs, their clients and other male partners (termed ‘pimps’ was used to compare the protection provided by PrEP for HIV-negative FSWs with FSWs increasing their condom use with clients and/or pimps. For different HIV prevalence scenarios, levels of pimp interaction, and baseline condom use, we estimated the coverage of PrEP that gives the same reduction in endemic FSW HIV prevalence or HIV infections averted as different increases in condom use. To achieve the same impact on FSW HIV prevalence as increasing condom use by 1%, the coverage of PrEP has to increase by >2%. The relative impact of PrEP increases for scenarios where pimps contribute to HIV transmission, but not greatly, and decreases with higher baseline condom use. In terms of HIV infections averted over 10 years, the relative impact of PrEP compared to condoms was reduced, with a >3% increase in PrEP coverage achieving the same impact as a 1% increase in condom use. Condom promotion interventions should remain the mainstay HIV prevention strategy for FSWs, with PrEP only being implemented once condom interventions have been maximised or to fill prevention gaps where condoms cannot be used.

  12. Multi-spectroscopic and molecular docking studies on the interaction of darunavir, a HIV protease inhibitor with calf thymus DNA.

    Shi, Jie-Hua; Zhou, Kai-Li; Lou, Yan-Yue; Pan, Dong-Qi

    2018-03-15

    Molecular interaction of darunavir (DRV), a HIV protease inhibitor with calf thymus deoxyribonucleic acid (ct-DNA) was studied in physiological buffer (pH7.4) by multi-spectroscopic approaches hand in hand with viscosity measurements and molecular docking technique. The UV absorption and fluorescence results together revealed the formation of a DRV-ct-DNA complex having binding affinities of the order of 10 3 M -1 , which was more in keeping with the groove binding. The results that DRV bound to ct-DNA via groove binding mode was further evidenced by KI quenching studies, viscosity measurements, competitive binding investigations with EB and Rhodamine B and CD spectral analysis. The effect of ionic strength indicated the negligible involvement of electrostatic interaction between DRV and ct-DNA. The thermodynamic parameters regarding the binding interaction of DRV with ct-DNA in terms of enthalpy change (ΔH 0 ) and entropy change (ΔS 0 ) were -63.19kJ mol -1 and -141.92J mol -1 K -1 , indicating that hydrogen bonds and van der Waals forces played a predominant role in the binding process. Furthermore, molecular simulation studies suggested that DRV molecule was prone to bind in the A-T rich region of the minor groove of DNA. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Willingness to use pre-exposure prophylaxis (PrEP) for HIV prevention among men who have sex with men (MSM) in Malaysia: findings from a qualitative study

    Adam Bourne; Matteo Cassolato; Clayton Koh Thuan Wei; Bangyuan Wang; Joselyn Pang; Sin How Lim; Iskandar Azwa; Ilias Yee; Gitau Mburu

    2017-01-01

    Abstract Background: Men who have sex with men (MSM) continue to be disproportionately affected by HIV in Malaysia. Recent success has been observed within demonstration projects examining the efficacy of HIV pre-exposure prophylaxis (PrEP), an antiretroviral -based medication taken by HIV-negative men to prevent sero-conversion. In order for such promising findings to be translated in real-world settings, it is important to understand the acceptability of PrEP, including perceived barriers t...

  14. Phylogeny and resistance profiles of HIV-1 POL sequences from rectal biopsies and blood

    Katzenstein, Terese Lea; Petersen, A B; Storgaard, M

    2010-01-01

    The phylogeny and resistance profiles of human immunodeficiency virus type 1 (HIV-1) protease (PR) and reverse transcriptase (RT) sequences were compared among six patients with HIV-1 who had received numerous treatments. RNA and DNA fractions were obtained from concurrent blood and rectal biopsy...

  15. PrEP as a feature in the optimal landscape of combination HIV prevention in sub-Saharan Africa.

    McGillen, Jessica B; Anderson, Sarah-Jane; Hallett, Timothy B

    2016-01-01

    The new WHO guidelines recommend offering pre-exposure prophylaxis (PrEP) to people who are at substantial risk of HIV infection. However, where PrEP should be prioritised, and for which population groups, remains an open question. The HIV landscape in sub-Saharan Africa features limited prevention resources, multiple options for achieving cost saving, and epidemic heterogeneity. This paper examines what role PrEP should play in optimal prevention in this complex and dynamic landscape. We use a model that was previously developed to capture subnational HIV transmission in sub-Saharan Africa. With this model, we can consider how prevention funds could be distributed across and within countries throughout sub-Saharan Africa to enable optimal HIV prevention (that is, avert the greatest number of infections for the lowest cost). Here, we focus on PrEP to elucidate where, and to whom, it would optimally be offered in portfolios of interventions (alongside voluntary medical male circumcision, treatment as prevention, and behaviour change communication). Over a range of continental expenditure levels, we use our model to explore prevention patterns that incorporate PrEP, exclude PrEP, or implement PrEP according to a fixed incidence threshold. At low-to-moderate levels of total prevention expenditure, we find that the optimal intervention portfolios would include PrEP in only a few regions and primarily for female sex workers (FSW). Prioritisation of PrEP would expand with increasing total expenditure, such that the optimal prevention portfolios would offer PrEP in more subnational regions and increasingly for men who have sex with men (MSM) and the lower incidence general population. The marginal benefit of including PrEP among the available interventions increases with overall expenditure by up to 14% (relative to excluding PrEP). The minimum baseline incidence for the optimal offer of PrEP declines for all population groups as expenditure increases. We find that using

  16. Towards tricking a pathogen's protease into fighting infection: the 3D structure of a stable circularly permuted onconase variant cleavedby HIV-1 protease.

    Mariona Callís

    Full Text Available Onconase® is a highly cytotoxic amphibian homolog of Ribonuclease A. Here, we describe the construction of circularly permuted Onconase® variants by connecting the N- and C-termini of this enzyme with amino acid residues that are recognized and cleaved by the human immunodeficiency virus protease. Uncleaved circularly permuted Onconase® variants are unusually stable, non-cytotoxic and can internalize in human T-lymphocyte Jurkat cells. The structure, stability and dynamics of an intact and a cleaved circularly permuted Onconase® variant were determined by Nuclear Magnetic Resonance spectroscopy and provide valuable insight into the changes in catalytic efficiency caused by the cleavage. The understanding of the structural environment and the dynamics of the activation process represents a first step toward the development of more effective drugs for the treatment of diseases related to pathogens expressing a specific protease. By taking advantage of the protease's activity to initiate a cytotoxic cascade, this approach is thought to be less susceptible to known resistance mechanisms.

  17. Cost-effectiveness of Pre-Exposure Prophylaxis (PrEP) in preventing HIV-1 infections in rural Zambia: a modeling study

    Nichols, B.E.; Boucher, C.A.B.; van Dijk, J.H.; Thuma, P.E.; Nouwen, J.L.; Baltussen, R.; van de Wijgert, J.; Sloot, P.M.A.; van de Vijver, D.A.M.C.

    2013-01-01

    Background: Pre-exposure prophylaxis (PrEP) with tenofovir and emtricitabine effectively prevents new HIV infections. The optimal scenario for implementing PrEP where most infections are averted at the lowest cost is unknown. We determined the impact of different PrEP strategies on averting new

  18. Are Thai MSM willing to take PrEP for HIV prevention? An analysis of attitudes, preferences and acceptance.

    Ana Wheelock

    Full Text Available We aimed to understand the attitudes, preferences and acceptance of oral and parenteral PrEP among men who have sex with men (MSM in Thailand.Pre-exposure prophylaxis (PrEP, the use of antiretrovirals to prevent HIV acquisition, has shown promising results in recent trials. To assess the potential impact of this new HIV prevention method, in addition to efficacy data, we need to understand which psychosocial factors are likely to determine its uptake among members of potential user groups.Surveys of willingness to use PrEP products were administered to MSM. Spearman's rank tests were used to uncover associations between questionnaire items. Mann-Whitney tests were performed to ascertain differences between groups. Conjoint analysis was used to examine the attitudes and preferences of MSM towards PrEP attributes. Most participants were willing to consider taking PrEP (39.2% "yes, definitely" and 49.2% "yes, probably" and perceived PrEP as giving them new possibilities in their lives (38.5% "a lot of hope" and 55.8% "some hope", even after being instructed of potential side effects and costs. HIV testing was considered the most important attribute and a daily pill and longer lasting injection in the arm were the preferred routes of administration.Despite its multiple challenges, MSM in Thailand would be willing to take PrEP, even if they had to experience inconvenience and expense. If PrEP were to be implemented in Thailand, our findings show that its uptake could be considerable.

  19. Pre-exposure prophylaxis (PrEP against HIV: efficacy, safety and uncertainties

    Santiago Moreno Guillen

    2017-09-01

    Full Text Available Despite the global stabilization of the number of new HIV infections in recent years, there has been an increase in new infections among men who have sex with men. This fact indicates the lack of effectiveness of the measures and prevention campaigns established so far for this group. It is therefore necessary to implement alternative preventive measures for them. Pre-exposure pharmacological prophylaxis (PrEP is one of the best evaluated options and has had high protection rates in both clinical and real-life trials. The strategy has also shown an adequate profile in terms of safety, tolerance, adverse effects and cost-effectiveness in the studies carried out to assess this important topic.

  20. Complex and Conflicting Social Norms: Implications for Implementation of Future HIV Pre-Exposure Prophylaxis (PrEP Interventions in Vancouver, Canada.

    Rod Knight

    Full Text Available HIV Pre-Exposure Prophylaxis (PrEP has been found to be efficacious in preventing HIV acquisition among seronegative individuals in a variety of risk groups, including men who have sex with men and people who inject drugs. To date, however, it remains unclear how socio-cultural norms (e.g., attitudes towards HIV; social understandings regarding HIV risk practices may influence the scalability of future PrEP interventions. The objective of this study is to assess how socio-cultural norms may influence the implementation and scalability of future HIV PrEP interventions in Vancouver, Canada.We conducted 50 interviews with young men (ages 18-24 with a variety of HIV risk behavioural profiles (e.g., young men who inject drugs; MSM. Interviews focused on participants' experiences and perceptions with various HIV interventions and policies, including PrEP.While awareness of PrEP was generally low, perceptions about the potential personal and public health gains associated with PrEP were interconnected with expressions of complex and sometimes conflicting social norms. Some accounts characterized PrEP as a convenient form of reliable protection against HIV, likening it to the female birth control pill. Other accounts cast PrEP as a means to facilitate 'socially unacceptable' behaviour (e.g., promiscuity. Stigmatizing rhetoric was used to position PrEP as a tool that could promote some groups' proclivities to take 'risks'.Stigma regarding 'risky' behaviour and PrEP should not be underestimated as a serious implementation challenge. Pre-implementation strategies that concomitantly aim to improve knowledge about PrEP, while addressing associated social prejudices, may be key to effective implementation and scale-up.

  1. Raman chemical mapping reveals site of action of HIV protease inhibitors in HPV16 E6 expressing cervical carcinoma cells.

    Kim, Dong-Hyun; Jarvis, Roger M; Allwood, J William; Batman, Gavin; Moore, Rowan E; Marsden-Edwards, Emma; Hampson, Lynne; Hampson, Ian N; Goodacre, Royston

    2010-12-01

    It has been shown that the HIV protease inhibitors indinavir and lopinavir may have activity against the human papilloma virus (HPV) type 16 inhibiting HPV E6-mediated proteasomal degradation of p53 in cultured cervical carcinoma cells. However, their mode and site of action is unknown. HPV-negative C33A cervical carcinoma cells and the same cells stably transfected with E6 (C33AE6) were exposed to indinavir and lopinavir at concentrations of 1 mM and 30 μM, respectively. The intracellular distribution of metabolites and metabolic changes induced by these treatments were investigated by Raman microspectroscopic imaging combined with the analysis of cell fractionation products by liquid chromatography-mass spectrometry (LC-MS). A uniform cellular distribution of proteins was found in drug-treated cells irrespective of cell type. Indinavir was observed to co-localise with nucleic acid in the nucleus, but only in E6 expressing cells. Principal components analysis (PCA) score maps generated on the full Raman hypercube and the corresponding PCA loadings plots revealed that the majority of metabolic variations influenced by the drug exposure within the cells were associated with changes in nucleic acids. Analysis of cell fractionation products by LC-MS confirmed that the level of indinavir in nuclear extracts was approximately eight-fold greater than in the cytoplasm. These data demonstrate that indinavir undergoes enhanced nuclear accumulation in E6-expressing cells, which suggests that this is the most likely site of action for this compound against HPV.

  2. Preferences for Long-Acting Pre-exposure Prophylaxis (PrEP), Daily Oral PrEP, or Condoms for HIV Prevention Among U.S. Men Who Have Sex with Men.

    Greene, George J; Swann, Greg; Fought, Angela J; Carballo-Diéguez, Alex; Hope, Thomas J; Kiser, Patrick F; Mustanski, Brian; D'Aquila, Richard T

    2017-05-01

    HIV prevention method preferences were evaluated among 512 U.S. men who have sex with men (MSM; median age: 22 years). Approximately 90 % consistently preferred one option across pairwise comparisons of condoms, daily oral pre-exposure prophylaxis (PrEP), and long-acting PrEP delivered via either an injectable or one of two types of PrEP implants differing in visibility. Condoms were most frequently preferred (33.8 %), followed by non-visible implants (21.5 %), and oral PrEP (17.0 %); HIV risk was reported by more choosing implants. In a follow-up question comparing the four PrEP options only, daily oral pills and non-visible implants were most frequently preferred (35.5 and 34.3 %, respectively), followed by injections (25.2 %) and visible implants (4.3 %). An inductive, open-coding approach determined that convenience, duration of protection, and privacy were the most commonly cited reasons for a PrEP method choice, and associated with self-report of HIV risk. Tailoring PrEP product development to privacy and other concerns important to those at highest HIV risk may improve HIV prevention.

  3. HIV Protease Inhibitor Use During Pregnancy Is Associated With Decreased Progesterone Levels, Suggesting a Potential Mechanism Contributing to Fetal Growth Restriction

    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

    Background. 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. Methods. 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. Results. 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. Conclusions. Our data suggest that PI use in pregnancy may lead to lower progesterone levels that could contribute to adverse birth outcomes. PMID:25030058

  4. HIV protease inhibitor use during pregnancy is associated with decreased progesterone levels, suggesting a potential mechanism contributing to fetal growth restriction.

    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.

  5. Naturally occurring hepatitis C virus protease inhibitors resistance-associated mutations among chronic hepatitis C genotype 1b patients with or without HIV co-infection.

    Cao, Ying; Zhang, Yu; Bao, Yi; Zhang, Renwen; Zhang, Xiaxia; Xia, Wei; Wu, Hao; Xu, Xiaoyuan

    2016-05-01

    The aim of this study was to measure the frequency of natural mutations in hepatitis C virus (HCV) mono-infected and HIV/HCV co-infected protease inhibitor (PI)-naive patients. Population sequence of the non-structural (NS)3 protease gene was evaluated in 90 HCV mono-infected and 96 HIV/HCV co-infected PI treatment-naive patients. The natural prevalence of PI resistance mutations in both groups was compared. Complete HCV genotype 1b NS3 sequence information was obtained for 152 (81.72%) samples. Seven sequences (8.33%) of the 84 HCV mono-infected patients and 21 sequences (30.88%) of the 68 HIV/HCV co-infected patients showed amino acid substitutions associated with HCV PI resistance. There was a significant difference in the natural prevalence of PI resistance mutations between these two groups (P = 0.000). The mutations T54S, R117H and N174F were observed in 1.19%, 5.95% and 1.19% of HCV mono-infected patients. The mutations F43S, T54S, Q80K/R, R155K, A156G/V, D168A/E/G and V170A were found in 1.47%, 4.41%, 1.47%/1.47%, 2.94%, 23.53%/1.47%, 1.47%/1.47%/1.47% and 1.47% of HIV/HCV co-infected patients, respectively. In addition, the combination mutations in the NS3 region were detected only in HIV/HCV genotype 1b co-infected patients. Naturally occurring HCV PI resistance mutations existed in HCV mono-infected and HIV/HCV co-infected genotype 1b PI-naive patients. HIV co-infection was associated with a greater frequency of PI resistance mutations. The impact of HIV infection on baseline HCV PI resistance mutations and treatment outcome in chronic hepatitis C (CHC) patients should be further analyzed. © 2015 The Japan Society of Hepatology.

  6. The Effect of PrEP on HIV Incidence Among Men Who Have Sex With Men in the Context of Condom Use, Treatment as Prevention, and Seroadaptive Practices.

    LeVasseur, Michael T; Goldstein, Neal D; Tabb, Loni P; Olivieri-Mui, Brianne L; Welles, Seth L

    2018-01-01

    HIV preexposure prophylaxis (PrEP) is an effective tool in preventing HIV infection among high-risk men who have sex with men (MSM). It is unknown how effective PrEP is in the context of other implemented HIV prevention strategies, including condom use, seroadaption, and treatment as prevention (TasP). We evaluate the impact of increasing uptake of PrEP in conjunction with established prevention strategies on HIV incidence in a high-risk population of MSM through simulation. Agent-based simulation models representing the sexual behavior of high-risk, urban MSM in the United States over the period of 1 year were used to evaluate the effect of PrEP on HIV infection rates. Simulations included data for 10,000 MSM and compared increasing rates of PrEP uptake under 8 prevention paradigms: no additional strategies, TasP, condom use, seroadaptive behavior, and combinations thereof. We observed a mean of 103.2 infections per 10,000 MSM in the absence of any prevention method. PrEP uptake at 25% without any additional prevention strategies prevented 30.7% of infections. In the absence of PrEP, TasP, condom use, and seroadaptive behavior independently prevented 27.1%, 48.8%, and 37.7% of infections, respectively, and together prevented 72.2%. The addition of PrEP to the 3 aforementioned prevention methods, at 25% uptake, prevented an additional 5.0% of infections. To achieve a 25% reduction in HIV infections by 2020, HIV prevention efforts should focus on significantly scaling up access to PrEP in addition to HIV testing, access to antiretroviral therapy, and promoting condom use.

  7. Fluorometric assay for phenotypic differentiation of drug-resistant HIV mutants

    Zhu, Qinchang; Yu, Zhiqiang; Kabashima, Tsutomu; Yin, Sheng; Dragusha, Shpend; El-Mahdy, Ahmed F. M.; Ejupi, Valon; Shibata, Takayuki; Kai, Masaaki

    2015-01-01

    Convenient drug-resistance testing of viral mutants is indispensable to effective treatment of viral infection. We developed a novel fluorometric assay for phenotypic differentiation of drug-resistant mutants of human immunodeficiency virus-I protease (HIV-PR) which uses enzymatic and peptide-specific fluorescence (FL) reactions and high-performance liquid chromatography (HPLC) of three HIV-PR substrates. This assay protocol enables use of non-purified enzyme sources and multiple substrates f...

  8. Knowledge, Practices, and Barriers to HIV Pre-Exposure Prophylaxis (PrEP) Prescribing Among Washington State Medical Providers.

    Wood, Brian R; McMahan, Vanessa M; Naismith, Kelly; Stockton, Jonathan B; Delaney, Lori A; Stekler, Joanne D

    2018-01-04

    We aimed to assess HIV pre-exposure prophylaxis (PrEP) awareness and prescribing practices among Washington State medical providers from diverse professional disciplines and practice types. In May 2016, we administered an anonymous online survey to licensed medical practitioners who provide primary, longitudinal, walk-in, emergency, obstetric, gynecologic, sexually transmitted infection (STI), or family planning care. Of 735 eligible providers, 64.8% had heard of PrEP. Younger providers and providers with a Doctor of Medicine (MD) degree were more likely to be aware of PrEP compared to older providers (p=0.0001) and providers of other training backgrounds (Advanced Registered Nurse Practitioner [ARNP], Doctor of Osteopathic Medicine [DO], or Physician Assistant [PA]) (p=0.04). Among providers aware of PrEP, most frequent reported concerns about prescribing were adherence (46.0%) and costs (42.9%). Providers felt very (20.1%) or somewhat (33.8%) comfortable discussing PrEP overall, but very (26.8%) or somewhat (44.7%) uncomfortable discussing cost and insurance issues. The 124 PrEP prescribers reported a median of 2 (range 1-175, total 1,142) patients prescribed PrEP. Prior authorizations and insurance denials had prevented prescriptions for 28.7% and 12.1% of prescribers, respectively. Interventions to improve PrEP access should include education to inform medical providers about PrEP, with particular attention to provider types less likely to be aware. Continued efforts to eliminate cost and insurance barriers and educate providers regarding financial resources would help improve PrEP access.

  9. Natural Polymorphisms Conferring Resistance to HCV Protease and Polymerase Inhibitors in Treatment-Naïve HIV/HCV Co-Infected Patients in China.

    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.

  10. Insights into the mechanism of drug resistance: X-ray structure analysis of G48V/C95F tethered HIV-1 protease dimer/saquinavir complex

    Prashar, Vishal; Bihani, Subhash C.; Das, Amit; Rao, D.R.; Hosur, M.V.

    2010-01-01

    The mutation G48V in HIV-1 protease is a major resistance mutation against the drug saquinavir. Recently, G48V mutation is found to co-exist with the mutation C95F in AIDS patients treated with saquinavir. We report here the three-dimensional crystal structure of G48V/C95F tethered HIV-1 protease/saquinavir complex. The structure indicates following as the possible causes of drug resistance: (1) loss of direct van der Waals interactions between saquinavir and enzyme residues PHE-53 and PRO-1081, (2) loss of water-mediated hydrogen bonds between the carbonyl oxygen atoms in saquinavir and amide nitrogen atoms of flap residues 50 and 1050, (3) changes in inter-monomer interactions, which could affect the energetics of domain movements associated with inhibitor-binding, and (4) significant reduction in the stability of the mutant dimer. The present structure also provides a rationale for the clinical observation that the resistance mutations C95F/G48V/V82A occur as a cluster in AIDS patients.

  11. Enhanced Effector Function of CD8+ T Cells From Healthy Controls and HIV-Infected Patients Occurs Through Thrombin Activation of Protease-Activated Receptor 1

    Hurley, Amanda; Smith, Mindy; Karpova, Tatiana; Hasley, Rebecca B.; Belkina, Natalya; Shaw, Stephen; Balenga, Nariman; Druey, Kirk M.; Nickel, Erin; Packard, Beverly; Imamichi, Hiromi; Hu, Zonghui; Follmann, Dean; McNally, James; Higgins, Jeanette; Sneller, Michael; Lane, H. Clifford; Catalfamo, Marta

    2013-01-01

    Disruption of vascular integrity by trauma and other tissue insults leads to inflammation and activation of the coagulation cascade. The serine protease thrombin links these 2 processes. The proinflammatory function of thrombin is mediated by activation of protease-activated receptor 1 (PAR-1). We found that peripheral blood effector memory CD4+ and CD8+ T lymphocytes expressed PAR-1 and that expression was increased in CD8+ T cells from human immunodeficiency virus (HIV)–infected patients. Thrombin enhanced cytokine secretion in CD8+ T cells from healthy controls and HIV-infected patients. In addition, thrombin induced chemokinesis, but not chemotaxis, of CD8+ T cells, which led to structural changes, including cell polarization and formation of a structure rich in F-actin and phosphorylated ezrin-radexin-moesin proteins. These findings suggest that thrombin mediates cross-talk between the coagulation system and the adaptive immune system at sites of vascular injury through increased T-cell motility and production of proinflammatory cytokines. PMID:23204166

  12. Enhanced effector function of CD8(+) T cells from healthy controls and HIV-infected patients occurs through thrombin activation of protease-activated receptor 1.

    Hurley, Amanda; Smith, Mindy; Karpova, Tatiana; Hasley, Rebecca B; Belkina, Natalya; Shaw, Stephen; Balenga, Nariman; Druey, Kirk M; Nickel, Erin; Packard, Beverly; Imamichi, Hiromi; Hu, Zonghui; Follmann, Dean; McNally, James; Higgins, Jeanette; Sneller, Michael; Lane, H Clifford; Catalfamo, Marta

    2013-02-15

    Disruption of vascular integrity by trauma and other tissue insults leads to inflammation and activation of the coagulation cascade. The serine protease thrombin links these 2 processes. The proinflammatory function of thrombin is mediated by activation of protease-activated receptor 1 (PAR-1). We found that peripheral blood effector memory CD4(+) and CD8(+) T lymphocytes expressed PAR-1 and that expression was increased in CD8(+) T cells from human immunodeficiency virus (HIV)-infected patients. Thrombin enhanced cytokine secretion in CD8(+) T cells from healthy controls and HIV-infected patients. In addition, thrombin induced chemokinesis, but not chemotaxis, of CD8(+) T cells, which led to structural changes, including cell polarization and formation of a structure rich in F-actin and phosphorylated ezrin-radexin-moesin proteins. These findings suggest that thrombin mediates cross-talk between the coagulation system and the adaptive immune system at sites of vascular injury through increased T-cell motility and production of proinflammatory cytokines.

  13. Transitioning to HIV Pre-Exposure Prophylaxis (PrEP) from Non-Occupational Post-Exposure Prophylaxis (nPEP) in a Comprehensive HIV Prevention Clinic: A Prospective Cohort Study.

    Siemieniuk, Reed A C; Sivachandran, Nirojini; Murphy, Pauline; Sharp, Andrea; Walach, Christine; Placido, Tania; Bogoch, Isaac I

    2015-08-01

    The uptake of pre-exposure prophylaxis (PrEP) for HIV prevention remains low. We hypothesized that a high proportion of patients presenting for HIV non-occupational post-exposure prophylaxis (nPEP) would be candidates for PrEP based on current CDC guidelines. Outcomes from a comprehensive HIV Prevention Clinic are described. We evaluated all patients who attended the HIV Prevention Clinic for nPEP between January 1, 2013 and September 30, 2014. Each patient was evaluated for PrEP candidacy based on current CDC-guidelines and subjectively based on physician opinion. Patients were then evaluated for initiation of PrEP if they met guideline suggestions. Demographic, social, and behavioral factors were then analyzed with logistic regression for associations with PrEP candidacy and initiation. 99 individuals who attended the nPEP clinic were evaluated for PrEP. The average age was 32 years (range, 18-62), 83 (84%) were male, of whom 46 (55%) men who had have sex with men (MSM). 31 (31%) met CDC guidelines for PrEP initiation, which had very good agreement with physician recommendation (kappa=0.88, 0.78-0.98). Factors associated with PrEP candidacy included sexual exposure to HIV, prior nPEP use, and lack of drug insurance (p<0.05 for all comparisons). Combining nPEP and PrEP services in a dedicated clinic can lead to identification of PrEP candidates and may facilitate PrEP uptake. Strategies to ensure equitable access of PrEP should be explored such that those without drug coverage may also benefit from this effective HIV prevention modality.

  14. Virologic failure of protease inhibitor-based second-line antiretroviral therapy without resistance in a large HIV treatment program in South Africa.

    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. Sex, PrEP, and Stigma: Experiences with HIV Pre-exposure Prophylaxis Among New York City MSM Participating in the HPTN 067/ADAPT Study.

    Franks, Julie; Hirsch-Moverman, Yael; Loquere, Avelino S; Amico, K Rivet; Grant, Robert M; Dye, Bonnie J; Rivera, Yan; Gamboa, Robert; Mannheimer, Sharon B

    2018-04-01

    The HPTN 067/Alternative Dosing to Augment Pre-Exposure Prophylaxis Pill Taking (ADAPT) study evaluated daily and non-daily dosing schedules for oral pre-exposure prophylaxis (PrEP) to prevent HIV. A qualitative sub-study including focus groups and in-depth interviews was conducted among men who have sex with men participating in New York City to understand their experience with PrEP and study dosing schedules. The 37 sub-study participants were 68% black, 11% white, and 8% Asian; 27% were of Hispanic/Latino ethnicity. Mean age was 34 years. Themes resulting from qualitative analysis include: PrEP is a significant advance for HIV prevention; non-daily dosing of PrEP is congruent with HIV risk; and pervasive stigma connected to HIV and risk behavior is a barrier to PrEP adherence, especially for non-daily dosing schedules. The findings underscore how PrEP intersects with other HIV prevention practices and highlight the need to understand and address multidimensional stigma related to PrEP use.

  16. Risk perception and sex behaviour in pregnancy and breastfeeding in high HIV prevalence settings: Programmatic implications for PrEP delivery

    Farley, Elise; Towriss, Catriona; Gomba, Yolanda; Bekker, Linda-Gail; Gorbach, Pamina; Shoptaw, Steven; Coates, Thomas; Myer, Landon

    2018-01-01

    HIV acquisition during pregnancy and breastfeeding significantly contributes toward paediatric HIV infection; however, little is known about risk behaviours in HIV-uninfected pregnant and postpartum women. We conducted twenty-six in-depth-interviews between July and December 2016 using a semi-structured interview guide among HIV-uninfected pregnant and recently postpartum women at-risk of HIV acquisition (defined as reporting ≥1 of the following: partner’s serostatus unknown or HIV-infected, recent condomless sex in pregnancy, and/or alcohol use during pregnancy) who attended primary healthcare services. Our study contextualizes factors related to risky sexual behaviours during pregnancy and postpartum periods and assesses knowledge and hypothetical acceptability of pre-exposure prophylaxis (PrEP) in pregnancy. Translated and transcribed data were coded and analysed by three researchers using a thematic analysis approach. In interviews with HIV-uninfected pregnant/postpartum women at-risk of HIV acquisition, we identified common themes associated with sexual risk behaviours during pregnancy, including: lack of control over decisions in sex and condom use in pregnancy, low perceived risk (e.g. beliefs that their partner has the same HIV-negative serostatus), and socio-cultural beliefs around condom use during pregnancy (e.g. contact with sperm is essential for baby’s development). PrEP knowledge was low among HIV-uninfected pregnant and breastfeeding women, and potential acceptability was good, though primary concerns were around the potential impact on the infant. While mothers presented a clear desire to protect themselves from HIV acquisition once pregnant, they also reported lack of control, and socio-cultural beliefs, like sex is good for the baby, that increased their risk of seroconversion. Mothers had limited PrEP awareness but reported hypothetical willingness to use PrEP because of concerns over HIV acquisition and onward mother to child transmission

  17. 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

    Tiziana Latronico

    2016-03-01

    Full Text Available 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.

  18. In vitro protein digestibility of enzymatically pre-treated bean (Phaseolus vulgaris L. flour using commercial protease and Bacillus sp. protease Digestibilidade protéica in vitro de farinhas de feijão (Phaseolus vulgaris L. pré-tratadas com protease comercial e protease de Bacillus sp.

    Disney Ribeiro Dias

    2010-03-01

    Full Text Available The common bean (Phaseolus vulgaris L. is a staple food in the Brazilian diet and represents the major source of dietary protein and other micronutrients and minerals. Despite the considerable protein concentration in beans, the food is considered of low biological value when compared to animal proteins and other plant protein sources. To improve the availability of protein in beans, enzymatic treatments were performed in four cultivars (ON, OPNS, TAL and VC3. The approach was a completely randomized design with four replicates. We used a 4 × 3 factorial arrangement (four cultivars and three treatments: treatment 1-addition of commercial protease (Trypsin 250, Difco, treatment 2-addition of protease from Bacillus sp., and treatment 3:-control without enzyme addition. The enzyme: substrate ratio was 5% w/w (amount of enzyme per total protein in bean flour. The approach was a completely randomized design with four replicates. A 4 × 3 factorial arrangement (four cultivars and three treatments, the same as those mentioned above was used. The concentration of total protein (g.100 g-1 of dry matter in the samples ranged from 16.94 to 18.06%, while the concentration of total phenolics was between 0.78 and 1.12% (g Eq. tannic acid.100 g-1 dry matter. The in vitro protein digestibility of enzymatically untreated bean flour (control ranged from 47.30 to 56.17% based on the digestibility of casein. Concentrations of P, K, Ca, Mg, and Zn observed in the four cultivars tested were within the average values available in the literature. Treatment 2 with protease from Bacillus sp. induced decreases in the levels of Cu and Mn. The average Fe content increased in all bean flour samples when treated with proteases, reaching a maximum increase of 102% in the TAL flour treated with protease from Bacillus sp. The digestibility of all beans tested was significantly increased (p O feijão (Phaseolus vulgaris L. é um alimento básico na refeição do brasileiro

  19. Estimation of the Binding Free Energy of AC1NX476 to HIV-1 Protease Wild Type and Mutations Using Free Energy Perturbation Method.

    Ngo, Son Tung; Mai, Binh Khanh; Hiep, Dinh Minh; Li, Mai Suan

    2015-10-01

    The binding mechanism of AC1NX476 to HIV-1 protease wild type and mutations was studied by the docking and molecular dynamics simulations. The binding free energy was calculated using the double-annihilation binding free energy method. It is shown that the binding affinity of AC1NX476 to wild type is higher than not only ritonavir but also darunavir, making AC1NX476 become attractive candidate for HIV treatment. Our theoretical results are in excellent agreement with the experimental data as the correlation coefficient between calculated and experimentally measured binding free energies R = 0.993. Residues Asp25-A, Asp29-A, Asp30-A, Ile47-A, Gly48-A, and Val50-A from chain A, and Asp25-B from chain B play a crucial role in the ligand binding. The mutations were found to reduce the receptor-ligand interaction by widening the binding cavity, and the binding propensity is mainly driven by the van der Waals interaction. Our finding may be useful for designing potential drugs to combat with HIV. © 2015 John Wiley & Sons A/S.

  20. Investigation of the binding free energies of FDA approved drugs against subtype B and C-SA HIV PR: ONIOM approach.

    Sanusi, Z K; Govender, T; Maguire, G E M; Maseko, S B; Lin, J; Kruger, H G; Honarparvar, B

    2017-09-01

    Human immune virus subtype C is the most widely spread HIV subtype in Sub-Sahara Africa and South Africa. A profound structural insight on finding potential lead compounds is therefore necessary for drug discovery. The focus of this study is to rationalize the nine Food and Drugs Administration (FDA) HIV antiviral drugs complexed to subtype B and C-SA PR using ONIOM approach. To achieve this, an integrated two-layered ONIOM model was used to optimize the geometrics of the FDA approved HIV-1 PR inhibitors for subtype B. In our hybrid ONIOM model, the HIV-1 PR inhibitors as well as the ASP 25/25' catalytic active residues were treated at high level quantum mechanics (QM) theory using B3LYP/6-31G(d), and the remaining HIV PR residues were considered using the AMBER force field. The experimental binding energies of the PR inhibitors were compared to the ONIOM calculated results. The theoretical binding free energies (?G bind ) for subtype B follow a similar trend to the experimental results, with one exemption. The computational model was less suitable for C-SA PR. Analysis of the results provided valuable information about the shortcomings of this approach. Future studies will focus on the improvement of the computational model by considering explicit water molecules in the active pocket. We believe that this approach has the potential to provide much improved binding energies for complex enzyme drug interactions. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Intimacy motivations and pre-exposure prophylaxis (PrEP) adoption intentions among HIV-negative men who have sex with men (MSM) in romantic relationships.

    Gamarel, Kristi E; Golub, Sarit A

    2015-04-01

    In the USA, men who have sex with men (MSM) in primary partnerships are at elevated risk for human immunodeficiency virus (HIV) infection. Pre-exposure prophylaxis (PrEP), a new biomedical prevention strategy, has potential to reduce HIV transmission. This study examined predictors of PrEP adoption intentions among HIV-negative MSM in primary partnerships. The sample included HIV-negative MSM (n = 164) who participated in an ongoing cross-sectional study with an in-person interview examining PrEP adoption intentions. Higher HIV risk perception, intimacy motivations for condomless sex, recent condomless anal sex with outside partners, education, and age were each independently associated with PrEP adoption intentions. In a multivariate model, only age, education, and intimacy motivations for condomless sex were significantly associated with PrEP adoption intentions. Intimacy motivations may play a central role in PrEP adoption for MSM couples. Incorporating relationship dynamics into biomedical strategies is a promising avenue for research and intervention.

  2. Knowledge, Attitudes, and Experiences of HIV Pre-Exposure Prophylaxis (PrEP) Trial Participants in Botswana.

    Toledo, Lauren; McLellan-Lemal, Eleanor; Henderson, Faith L; Kebaabetswe, Poloko M

    2015-03-01

    Recent clinical trials have shown that a daily dose of oral TDF/FTC pre-exposure prophylaxis (PrEP) is effective in reducing human immunodeficiency (HIV) risk. Understanding trial participants' perspectives about retention and PrEP adherence is critical to inform future PrEP trials and the scale-up and implementation of PrEP programs. We analyzed 53 in-depth interviews conducted in April 2010 with participants in the TDF2 study, a Phase 3, randomized, double-blind, placebo-controlled clinical trial of daily oral TDF/FTC with heterosexual men and women in Francistown and Gaborone, Botswana. We examined participants' knowledge, attitudes, and experiences of the trial, identified facilitators and barriers to enrollment and retention, and compared participant responses by study site, sex, and study drug adherence. Our findings point to several factors to consider for participant retention and adherence in PrEP trials and programs, including conducting pre-enrollment education and myth reduction counseling, providing accurate estimates of participant obligations and side effect symptoms, ensuring participant understanding of the effects of non-adherence, gauging personal commitment and interest in study outcomes, and developing a strong external social support network for participants.

  3. Awareness of pre-exposure prophylaxis (PrEP) among women who inject drugs in NYC: the importance of networks and syringe exchange programs for HIV prevention.

    Walters, Suzan M; Reilly, Kathleen H; Neaigus, Alan; Braunstein, Sarah

    2017-06-29

    Women who inject drugs (WWID) are at heightened risk for HIV due to biological, behavioral, and structural factors. Pre-exposure prophylaxis (PrEP) could aid in HIV prevention for WWID. However, little is known about WWID awareness of PrEP, which is a necessary step that must occur before PrEP uptake. We report factors associated with greater awareness among WWID to identify efficient means of awareness dissemination. Data from the 2015 National HIV Behavioral Surveillance (NHBS) system cycle on injection drug use collected in New York City (NYC) were used. Bivariable analyses, using chi-squared statistics, were conducted to examine correlates of awareness of PrEP with socio-demographic, behavioral, and health care variables. Multivariable logistic regression was used to estimate adjusted associations and determine differences in awareness of PrEP. The analysis consisted of 118 WWID. Awareness of PrEP was relatively low (31%), and risk factors were high. In the last 12 months, almost two thirds (65%) reported condomless sex, approximately one third (31%) reported transactional sex, and one third (32%) reported sharing injection equipment. In multivariable logistic regression, increased PrEP awareness was associated with reported transactional sex (AOR 3.32, 95% CI 1.22-9.00) and having a conversation about HIV prevention at a syringe exchange program (SEP) (AOR 7.61, 95% CI 2.65-21.84). We did not find race, education, household income, age, binge drinking, or sexual identity to be significantly associated with PrEP awareness. Large proportions of WWID were unaware of PrEP. These findings suggest that social networks (specifically sex work and SEP networks) are an efficient means for disseminating messaging about prevention materials such as PrEP. We recommend that SEP access increase, SEP processes be adopted in other health care settings, and WWID networks be utilized to increase PrEP awareness.

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

    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: ...

  5. Protease-sensitive synthetic prions.

    David W Colby

    2010-01-01

    Full Text Available Prions arise when the cellular prion protein (PrP(C undergoes a self-propagating conformational change; the resulting infectious conformer is designated PrP(Sc. Frequently, PrP(Sc is protease-resistant but protease-sensitive (s prions have been isolated in humans and other animals. We report here that protease-sensitive, synthetic prions were generated in vitro during polymerization of recombinant (rec PrP into amyloid fibers. In 22 independent experiments, recPrP amyloid preparations, but not recPrP monomers or oligomers, transmitted disease to transgenic mice (n = 164, denoted Tg9949 mice, that overexpress N-terminally truncated PrP. Tg9949 control mice (n = 174 did not spontaneously generate prions although they were prone to late-onset spontaneous neurological dysfunction. When synthetic prion isolates from infected Tg9949 mice were serially transmitted in the same line of mice, they exhibited sPrP(Sc and caused neurodegeneration. Interestingly, these protease-sensitive prions did not shorten the life span of Tg9949 mice despite causing extensive neurodegeneration. We inoculated three synthetic prion isolates into Tg4053 mice that overexpress full-length PrP; Tg4053 mice are not prone to developing spontaneous neurological dysfunction. The synthetic prion isolates caused disease in 600-750 days in Tg4053 mice, which exhibited sPrP(Sc. These novel synthetic prions demonstrate that conformational changes in wild-type PrP can produce mouse prions composed exclusively of sPrP(Sc.

  6. Catalytic water co-existing with a product peptide in the active site of HIV-1 protease revealed by X-ray structure analysis.

    Vishal Prashar

    Full Text Available BACKGROUND: It is known that HIV-1 protease is an important target for design of antiviral compounds in the treatment of Acquired Immuno Deficiency Syndrome (AIDS. In this context, understanding the catalytic mechanism of the enzyme is of crucial importance as transition state structure directs inhibitor design. Most mechanistic proposals invoke nucleophilic attack on the scissile peptide bond by a water molecule. But such a water molecule coexisting with any ligand in the active site has not been found so far in the crystal structures. PRINCIPAL FINDINGS: We report here the first observation of the coexistence in the active site, of a water molecule WAT1, along with the carboxyl terminal product (Q product peptide. The product peptide has been generated in situ through cleavage of the full-length substrate. The N-terminal product (P product has diffused out and is replaced by a set of water molecules while the Q product is still held in the active site through hydrogen bonds. The position of WAT1, which hydrogen bonds to both the catalytic aspartates, is different from when there is no substrate bound in the active site. We propose WAT1 to be the position from where catalytic water attacks the scissile peptide bond. Comparison of structures of HIV-1 protease complexed with the same oligopeptide substrate, but at pH 2.0 and at pH 7.0 shows interesting changes in the conformation and hydrogen bonding interactions from the catalytic aspartates. CONCLUSIONS/SIGNIFICANCE: The structure is suggestive of the repositioning, during substrate binding, of the catalytic water for activation and subsequent nucleophilic attack. The structure could be a snap shot of the enzyme active site primed for the next round of catalysis. This structure further suggests that to achieve the goal of designing inhibitors mimicking the transition-state, the hydrogen-bonding pattern between WAT1 and the enzyme should be replicated.

  7. Catalytic water co-existing with a product peptide in the active site of HIV-1 protease revealed by X-ray structure analysis.

    Prashar, Vishal; Bihani, Subhash; Das, Amit; Ferrer, Jean-Luc; Hosur, Madhusoodan

    2009-11-17

    It is known that HIV-1 protease is an important target for design of antiviral compounds in the treatment of Acquired Immuno Deficiency Syndrome (AIDS). In this context, understanding the catalytic mechanism of the enzyme is of crucial importance as transition state structure directs inhibitor design. Most mechanistic proposals invoke nucleophilic attack on the scissile peptide bond by a water molecule. But such a water molecule coexisting with any ligand in the active site has not been found so far in the crystal structures. We report here the first observation of the coexistence in the active site, of a water molecule WAT1, along with the carboxyl terminal product (Q product) peptide. The product peptide has been generated in situ through cleavage of the full-length substrate. The N-terminal product (P product) has diffused out and is replaced by a set of water molecules while the Q product is still held in the active site through hydrogen bonds. The position of WAT1, which hydrogen bonds to both the catalytic aspartates, is different from when there is no substrate bound in the active site. We propose WAT1 to be the position from where catalytic water attacks the scissile peptide bond. Comparison of structures of HIV-1 protease complexed with the same oligopeptide substrate, but at pH 2.0 and at pH 7.0 shows interesting changes in the conformation and hydrogen bonding interactions from the catalytic aspartates. The structure is suggestive of the repositioning, during substrate binding, of the catalytic water for activation and subsequent nucleophilic attack. The structure could be a snap shot of the enzyme active site primed for the next round of catalysis. This structure further suggests that to achieve the goal of designing inhibitors mimicking the transition-state, the hydrogen-bonding pattern between WAT1 and the enzyme should be replicated.

  8. Knowledge of Pre-exposure Prophylaxis (PrEP) for HIV Prevention Among Men Who Have Sex with Men in Denver, Colorado

    Al-Tayyib, Alia A.; Thrun, Mark W.; Haukoos, Jason S.; Walls, N. Eugene

    2014-01-01

    As part of the National HIV Behavioral Surveillance System among men who have sex with men (MSM) in Denver, Colorado, we assessed knowledge of pre-exposure prophylaxis (PrEP); willingness to use PrEP; and potential changes in risk behaviors among HIV-negative participants reporting sexual activity with a male partner in the preceding 12 months. We examined knowledge of PrEP before (2008) and after (2011) results of the iPrEx trial were available. Of the 425 participants in the 2008 sample, 91 (21 %) were aware of PrEP compared to 131 (28 %) of the 461 participants in the 2011 sample (adjusted prevalence ratio: 1.43, 95 % confidence interval: 1.18, 1.72). Despite the increase in 2011, few MSM in Denver were aware of PrEP. Educating high-risk MSM about the potential utility of PrEP as an adjunct to other effective prevention methods is needed when considering the addition of PrEP to the HIV prevention arsenal. PMID:23824227

  9. Sexual Behavior, Risk Compensation, and HIV Prevention Strategies Among Participants in the San Francisco PrEP Demonstration Project: A Qualitative Analysis of Counseling Notes.

    Carlo Hojilla, J; Koester, Kimberly A; Cohen, Stephanie E; Buchbinder, Susan; Ladzekpo, Deawodi; Matheson, Tim; Liu, Albert Y

    2016-07-01

    Pre-exposure prophylaxis (PrEP) is a viable HIV prevention strategy but risk compensation could undermine potential benefits. There are limited data that examine this phenomenon outside of clinical trials. We conducted a qualitative analysis of counseling notes from the San Francisco site of the US PrEP demonstration project to assess how men who have sex with men used PrEP as a prevention strategy and its impact on their sexual practices. Four major themes emerged from our analysis of 130 distinct notes associated with 26 participants. Prevention strategy decision-making was dynamic, often influenced by the context and perceived risk of a sexual encounter. Counselors noted that participants used PrEP in conjunction with other health promotion strategies like condoms, asking about HIV status of their sex partners, and seroadaptation. With few exceptions, existing risk reduction strategies were not abandoned upon initiation of PrEP. Risk-taking behavior was 'seasonal' and fluctuations were influenced by various personal, psychosocial, and health-related factors. PrEP also helped relieve anxiety regarding sex and HIV, particularly among serodiscordant partners. Understanding sexual decision-making and how PrEP is incorporated into existing prevention strategies can help inform future PrEP implementation efforts.

  10. Increased levels of inflammatory cytokines in the female reproductive tract are associated with altered expression of proteases, mucosal barrier proteins, and an influx of HIV-susceptible target cells.

    Arnold, Kelly B; Burgener, Adam; Birse, Kenzie; Romas, Laura; Dunphy, Laura J; Shahabi, Kamnoosh; Abou, Max; Westmacott, Garrett R; McCorrister, Stuart; Kwatampora, Jessie; Nyanga, Billy; Kimani, Joshua; Masson, Lindi; Liebenberg, Lenine J; Abdool Karim, Salim S; Passmore, Jo-Ann S; Lauffenburger, Douglas A; Kaul, Rupert; McKinnon, Lyle R

    2016-01-01

    Elevated inflammatory cytokines (EMCs) at mucosal surfaces have been associated with HIV susceptibility, but the underlying mechanisms remain unclear. We characterized the soluble mucosal proteome associated with elevated cytokine expression in the female reproductive tract. A scoring system was devised based on the elevation (upper quartile) of at least three of seven inflammatory cytokines in cervicovaginal lavage. Using this score, HIV-uninfected Kenyan women were classified as either having EMC (n=28) or not (n=68). Of 455 proteins quantified in proteomic analyses, 53 were associated with EMC (5% false discovery rate threshold). EMCs were associated with proteases, cell motility, and actin cytoskeletal pathways, whereas protease inhibitor, epidermal cell differentiation, and cornified envelope pathways were decreased. Multivariate analysis identified an optimal signature of 16 proteins that distinguished the EMC group with 88% accuracy. Three proteins in this signature were neutrophil-associated proteases that correlated with many cytokines, especially GM-CSF (granulocyte-macrophage colony-stimulating factor), IL-1β (interleukin-1β), MIP-3α (macrophage inflammatory protein-3α), IL-17, and IL-8. Gene set enrichment analyses implicated activated immune cells; we verified experimentally that EMC women had an increased frequency of endocervical CD4(+) T cells. These data reveal strong linkages between mucosal cytokines, barrier function, proteases, and immune cell movement, and propose these as potential mechanisms that increase risk of HIV acquisition.

  11. Prevalence and factors associated with darunavir resistance mutations in multi-experienced HIV-1-infected patients failing other protease inhibitors in a referral teaching center in Brazil

    Jose E Vidal

    Full Text Available Information about resistance profile of darunavir (DRV is scarce in Brazil. Our objectives were to estimate the prevalence of DRV resistance mutations in patients failing protease inhibitors (PI and to identify factors associated with having more DRV resistance mutations. All HIV-infected patients failing PI-based regimens with genotyping performed between 2007 and 2008 in a referral teaching center in São Paulo, Brazil, were included. DRV-specific resistance mutations listed by December 2008 IAS-USA panel update were considered. Two Poisson regression models were constructed to assess factors related to the presence of more DRV resistance mutations. A total of 171 HIV-infected patients with available genotyping were included. The number of patients with lopinavir, saquinavir, and amprenavir used in previous regimen were 130 (76%, 83 (49%, and 35 (20%, respectively. The prevalence of major DRV resistance mutations was 50V: 5%; 54M: 1%; 76V: 4%; 84V: 15%. For minor mutations, the rates were 11I: 3%; 32I: 7%; 33F: 23%; 47V: 6%; 54L: 6%; 74P: 3%; 89V: 6%. Only 11 (6% of the genotypes had > 3 DRV resistance mutations. In the clinical model, time of HIV infection of > 10 years and use of amprenavir were independently associated with having more DRV resistance mutations. In the genotyping-based model, only total number of PI resistance mutations was associated with our outcome. In conclusion, the prevalence of DRV mutations was low. Time of HIV infection, use of amprenavir and total number of PI resistance mutations were associated with having more DRV mutations.

  12. Values and Preferences on the Use of Oral Pre-exposure Prophylaxis (PrEP) for HIV Prevention Among Multiple Populations: A Systematic Review of the Literature.

    Koechlin, Florence M; Fonner, Virginia A; Dalglish, Sarah L; O'Reilly, Kevin R; Baggaley, Rachel; Grant, Robert M; Rodolph, Michelle; Hodges-Mameletzis, Ioannis; Kennedy, Caitlin E

    2017-05-01

    Daily oral pre-exposure prophylaxis (PrEP) is the use of antiretroviral drugs by HIV-negative people to prevent HIV infection. WHO released new guidelines in 2015 recommending PrEP for all populations at substantial risk of HIV infection. To prepare these guidelines, we conducted a systematic review of values and preferences among populations that might benefit from PrEP, women, heterosexual men, young women and adolescent girls, female sex workers, serodiscordant couples, transgender people and people who inject drugs, and among healthcare providers who may prescribe PrEP. A comprehensive search strategy reviewed three electronic databases of articles and HIV-related conference abstracts (January 1990-April 2015). Data abstraction used standardised forms to categorise by population groups and relevant themes. Of 3068 citations screened, 76 peer-reviewed articles and 28 conference abstracts were included. Geographic coverage was global. Most studies (N = 78) evaluated hypothetical use of PrEP, while 26 studies included individuals who actually took PrEP or placebo. Awareness of PrEP was low, but once participants were presented with information about PrEP, the majority said they would consider using it. Concerns about safety, side effects, cost and effectiveness were the most frequently cited barriers to use. There was little indication of risk compensation. Healthcare providers would consider prescribing PrEP, but need more information before doing so. Findings from a rapidly expanding evidence base suggest that the majority of populations most likely to benefit from PrEP feel positively towards it. These same populations would benefit from overcoming current implementation challenges with the shortest possible delay.

  13. HIV Structural Database

    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.

  14. The bile acid sensor FXR protects against dyslipidemia and aortic plaques development induced by the HIV protease inhibitor ritonavir in mice.

    Andrea Mencarelli

    Full Text Available BACKGROUND: Although human immunodeficiency virus (HIV-related morbidity and mortality rates in patients treated with a combination of high active antiretroviral therapy (HAART have declined, significant metabolic/vascular adverse effects associated with the long term use of HIV protease inhibitors (PIs have emerged as a significant side effect. Here we illustrate that targeting the bile acid sensor farnesoid X receptor (FXR protects against dyslipidemia and vascular injury induced HIV-PIs in rodents. METHODOLOGY/PRINCIPAL FINDINGS: Administration of the HIV PI ritonavir to wild type mice increased plasma triacylglycerols and cholesterol levels and this effect was exacerbated by dosing ritonavir to mice harbouring a disrupted FXR. Dyslipidemia induced by ritonavir associated with a shift in the liver expression of signature genes, Sterol Regulatory Element-Binding Protein (SREBP-1 and fatty acid synthase. Treating wild type mice with the FXR agonist (chenodeoxycholic acid, CDCA protected against development of dyslipidemia induced by ritonavir. Administration of ritonavir to ApoE(-/- mice, a strain that develop spontaneously atherosclerosis, increased the extent of aortic plaques without worsening the dyslipidemia. Treating these mice with CDCA reduced the extent of aortic plaques by 70% without changing plasma lipoproteins or the liver expression of signature genes. A beneficial effect on aortic plaques was also obtained by treating ApoE(-/- mice with gemfibrozil, a PPARα agonist. FXR activation counter-regulated induction of expression/activity of CD36 caused by HIV-PIs in circulating monocytes and aortic plaques. In macrophages cell lines, CDCA attenuated CD36 induction and uptake of acetylated LDL caused by ritonavir. Natural and synthetic FXR ligands reduced the nuclear translocation of SREBP1c caused by ritonavir. CONCLUSIONS/SIGNIFICANCE: Activation of the bile acid sensor FXR protects against dyslipidemia and atherosclerotic caused by

  15. Safety, adherence and acceptability of intermittent tenofovir/emtricitabine as HIV pre-exposure prophylaxis (PrEP among HIV-uninfected Ugandan volunteers living in HIV-serodiscordant relationships: a randomized, clinical trial.

    Freddie M Kibengo

    Full Text Available BACKGROUND: Efficacy of oral pre-exposure prophylaxis (PrEP in prevention of HIV acquisition has been evaluated using a daily regimen. However, adherence to long term daily medication is rarely perfect. Intermittent regimen may be a feasible alternative. Preclinical studies have demonstrated effectiveness of intermittent PrEP in SHIV prevention among animals. However, little is known about intermittent PrEP regimens. DESIGN: Seventy two HIV-uninfected volunteers in HIV serodiscordant couple relationships in Uganda were randomly assigned to receive daily oral Tenofovir/Emtricitabine (TDF/FTC-Truvada or placebo, or intermittent (Monday, Friday and within 2 hours after sex, not to exceed one dose per day oral TDF/FTC or placebo in a 2:1:2:1 ratio. Volunteers and study staff were blinded to drug assignment, but not to regimen assignment. METHODS: Volunteers were followed for 4 months after randomization, with monthly clinical and laboratory safety assessments and comprehensive HIV risk reduction services. Adherence was monitored using medication event monitoring system (MEMS and self-report. Sexual activity data were collected via daily short text message (SMS and self-report. HIV-specific immune responses were assessed by IFN-γ ELISPOT. RESULTS: Both daily and intermittent oral TDF/FTC regimens were well tolerated. Median MEMS adherence rates were 98% (IQR: 93-100 for daily PrEP regimen, 91% (IQR: 73-97 for fixed intermittent dosing and 45% (IQR: 20-63 for post-coital dosing. SMS response rate was 74%, but increased to 80% after excluding server outages; results may have been affected by the novelty of this measure. The majority of volunteers expressed willingness with no particular preference for either regimen. CONCLUSIONS: Both daily and intermittent oral PrEP dosing regimens were safe. Adherence was high for daily and fixed intermittent dosing; post-coital dosing was associated with poor adherence. Fixed intermittent PrEP regimens may be

  16. Multi-spectroscopic and molecular modeling approaches to elucidate the binding interaction between bovine serum albumin and darunavir, a HIV protease inhibitor

    Shi, Jie-Hua; Zhou, Kai-Li; Lou, Yan-Yue; Pan, Dong-Qi

    2018-01-01

    Darunavir (DRV), a second-generation HIV protease inhibitor, is widely used across the world as an important component of HIV therapy. The interaction of DRV with bovine serum albumin (BSA), a major carrier protein, has been studied under simulated physiological conditions (pH 7.4) by multi-spectroscopic techniques in combination with molecular modeling. Fluorescence data revealed that the intrinsic fluorescence of BSA was quenched by DRV in terms of a static quenching procedure due to the formation of the DRV-BSA complex. The results indicated the presence of single weak affinity binding site ( 103 M- 1, 310 K) on protein. The thermodynamic parameters, namely enthalpy change (ΔH0), entropy change (ΔS0) and Gibbs free energy change (ΔG0) were calculated, which signified that the binding reaction was spontaneous, the main binding forces were hydrogen bonding and van der Waals forces. Importantly, competitive binding experiments with three site probes, phenylbutazone (in sub-domain IIA, site I), ibuprofen (in sub-domain IIIA, site II) and artemether (in the interface between sub-domain IIA and IIB, site II'), suggested that DRV was preferentially bound to the hydrophobic cavity in site II' of BSA, and this finding was validated by the docking results. Additionally, synchronous fluorescence, three-dimensional fluorescence and Resonance Rayleigh Scattering (RRS) spectroscopy gave qualitative information on the conformational changes of BSA upon adding DRV, while quantitative data were obtained with Fourier transform infrared spectroscopy (FT-IR).

  17. Plasma selenium concentrations are sufficient and associated with protease inhibitor use in treated HIV-infected adults

    Background: Selenium (Se) is an essential constituent of selenoproteins which play significant roles in antioxidant defense and inflammatory cascades. Selenium deficiency is associated with disease states characterized by inflammation including cardiovascular disease (CVD). While HIV infection has b...

  18. HIV na gestação: pré-natal, parto e puerpério = HIV in pregnancy: prenatal, labor and puerperium

    Lima, Suzane da Silva de

    2017-01-01

    Full Text Available Objetivo: O presente estudo tem como propósitos identificar os fatores que influenciam a adesão da gestante ao acompanhamento pré-natal e destacar os principais cuidados com a gestante soropositiva durante o pré-natal, parto e puerpério. Materiais e Métodos: Trata-se de uma revisão integrativa da literatura, com análise baseada em níveis de evidências. Os dados foram obtidos através da busca em bases de dados virtuais em saúde. Resultados: Treze estudos compuseram a amostra, sendo que o maior índice foi de evidências moderadas, seis (46,1% estudos. Os principais cuidados à gestante soropositiva durante o pré-natal, parto e puerpério foram: uso da terapia antirretroviral, evidenciado em sete (53,8% estudos, seguido do teste Anti-HIV e da preocupação em orientar as puérperas a não amamentar destacados em seis (46,1% estudos. Conclusão: Torna-se necessária a implantação de uma assistência de qualidade às gestantes soropositivas, evidenciando a necessidade de estratégias de educação permanente para sensibilizar, mobilizar e capacitar profissionais envolvidos no cuidado, visando, assim, à prevenção da transmissão vertical do HIV para o recém-nascido e à melhora na qualidade de vida da gestante

  19. A combination of luxR1 and luxR2 genes activates Pr-promoters of psychrophilic Aliivibrio logei lux-operon independently of chaperonin GroEL/ES and protease Lon at high concentrations of autoinducer.

    Konopleva, Maria N; Khrulnova, Svetlana A; Baranova, Ancha; Ekimov, Leonid V; Bazhenov, Sergey V; Goryanin, Ignatiy I; Manukhov, Ilya V

    2016-05-13

    Lux-operon of psychrophilic bacteria Aliivibrio logei contains two copies of luxR and is regulated by Type I quorum sensing (QS). Activation of lux-operon of psychrophilic bacteria A. logei by LuxR1 requires about 100 times higher concentrations of autoinducer (AI) than the activation by LuxR2. On the other hand, LuxR1 does not require GroEL/ES chaperonin for its folding and cannot be degraded by protease Lon, while LuxR2 sensitive to Lon and requires GroEL/ES. Here we show that at 10(-5) - 10(-4)М concentrations of AI a combination of luxR1 and luxR2 products is capable of activating the Pr-promoters of A. logei lux-operon in Escherichia coli independently of GroEL/ES and protease Lon. The presence of LuxR1 assists LuxR2 in gro(-) cells when AI was added at high concentration, while at low concentration of AI in a cell LuxR1 decreases the LuxR2 activity. These observations may be explained by the formation of LuxR1/LuxR2 heterodimers that act in complex with AI independently from GroEL/ES and protease Lon. This study expands current understanding of QS regulation in A. logei as it implies cooperative regulation of lux-operon by LuxR1 and LuxR2 proteins. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Willingness to use pre-exposure prophylaxis (PrEP) for HIV prevention among men who have sex with men (MSM) in Malaysia: findings from a qualitative study.

    Bourne, Adam; Cassolato, Matteo; Thuan Wei, Clayton Koh; Wang, Bangyuan; Pang, Joselyn; Lim, Sin How; Azwa, Iskandar; Yee, Ilias; Mburu, Gitau

    2017-08-02

    Men who have sex with men (MSM) continue to be disproportionately affected by HIV in Malaysia. Recent success has been observed within demonstration projects examining the efficacy of HIV pre-exposure prophylaxis (PrEP), an antiretroviral -based medication taken by HIV-negative men to prevent sero-conversion. In order for such promising findings to be translated in real-world settings, it is important to understand the acceptability of PrEP, including perceived barriers to access or uptake. As part of a larger mixed-methods study exploring acceptability and willingness to use PrEP among MSM in Malaysia, 19 men took part in audio-recorded focus group discussions hosted by a community-based HIV organization and facilitated by a trained researcher. Discussions focussed on awareness and potential information management, general perceptions of PrEP and potential motivations or barriers to the use of PrEP, including those at the personal, social, health system or structural level. Data were transcribed verbatim and underwent a detailed thematic analysis. Rather than perceiving PrEP as a replacement for condoms in terms of having safer sex, many participants viewed it as an additional layer protection, serving as a crucial barrier to infection on occasions where condom use was intended, but did not occur. It was also perceived as more valuable to "at-risk" men, such as those in HIV sero-discordant relationships or those with a higher number of sexual partners. Elements of discussion tended to suggest that some men taking PrEP may be subject to stigma from others, on the assumption they may be promiscuous or engage in high-risk sexual behaviours. This qualitative study indicates that, broadly speaking, PrEP may be acceptable to MSM in Malaysia. However, in order for its potential to be realized, and uptake achieved, educative interventions are required to inform the target population as to the efficacy and potential, positive impact of PrEP. Given concerns for how those

  1. Hepatitis A outbreak in HIV-infected MSM and in PrEP-using MSM despite a high level of immunity, Lyon, France, January to June 2017.

    Charre, Caroline; Ramière, Christophe; Roque-Afonso, Anne-Marie; Chidiac, Christian; Zoulim, Fabien; Godinot, Matthieu; Koffi, Joseph; Scholtès, Caroline; Livrozet, Jean-Michel; Hav Lyon Study Group; Cotte, Laurent

    2017-11-01

    Since 2016, an increase in the number of hepatitis A cases affecting mainly men who have sex with men (MSM) has been reported in low endemic countries in Europe. We calculated the attack rate in Lyon, France, in populations considered at high-risk: HIV-infected MSM and HIV-negative MSM receiving HIV pre-exposure prophylaxis (PrEP). In these populations, high level of immunity did not prevent the outbreak, indicating that vaccination should be reinforced, particularly in younger individuals.

  2. Acceptability of HIV Pre-Exposure Prophylaxis (PrEP) and Implementation Challenges Among Men Who Have Sex with Men in India: A Qualitative Investigation.

    Chakrapani, Venkatesan; Newman, Peter A; Shunmugam, Murali; Mengle, Shruta; Varghese, Jarvis; Nelson, Ruban; Bharat, Shalini

    2015-10-01

    This qualitative study explored the acceptability of HIV pre-exposure prophylaxis (PrEP) among MSM in India, and identified facilitators and barriers to future PrEP uptake. In 2014, we conducted 10 focus groups (n=61) among a purposive sample of diverse MSM recruited through community-based organizations in Chennai and Mumbai, and 10 key informant interviews with community leaders and health care providers. Participants' mean age was 26.1 years (SD 4.8); 62% completed secondary education, and 42% engaged in sex work. No focus group participants had heard of PrEP, but once explained, most reported they would likely use it. PrEP was alternately perceived as a 'back-up plan', a condom substitute, or a burden with concurrent condom use. Facilitators were potential for covert use, sex without condoms, and anxiety-less sex. Potential barriers emerged around stigma associated with PrEP use, fear of disclosures to one's family, wife, or male steady partner, and being labeled as HIV-positive or promiscuous by peers. Preferences emerged for intermittent rather than daily PrEP use, injectable PrEP, and free or subsidized access through community organizations or government hospitals. Key informants expressed additional concerns about risk compensation, non-adherence, and impact on ART availability for treatment. Demonstration projects are needed in India to support PrEP implementation tailored for at-risk MSM. Educational interventions for MSM should address concerns about PrEP effectiveness, side effects, and mitigate risk compensation. Community engagement may facilitate broad acceptability and challenge stigma around PrEP use. Importantly, provision of free or subsidized PrEP is necessary to making implementation feasible among low socioeconomic status MSM in India.

  3. Estudo da reatividade vascular em portadores de HIV com e sem uso de inibidor de protease Estudio de la reactividad vascular en portadores de VIH con y sin uso de inhibidor de proteasa Study of vascular reactivity in HIV patients whether or not receiving protease inhibitor

    Hamilton Nenrod Pereira Teixeira

    2009-10-01

    Full Text Available FUNDAMENTO: Considerando o alto número de pacientes infectados por HIV em uso de antirretrovirais, evoluindo com alteração da função endotelial e aterotrombose, levando ao alto custo médico social, é importante identificar mecanismos fisiopatológicos envolvidos com a função endotelial em portadores de HIV, para que, precocemente, possamos intervir e evitar a progressão da doença. OBJETIVO: Avaliar a função endotelial pela vasodilatação endotélio dependente e independente em pacientes HIV positivo e em grupo controle. MÉTODOS: O estudo avaliou 27 pacientes HIV positivo e 16 do grupo controle. A avaliação da função endotelial foi realizada por meio da vasodilatação da artéria braquial endotélio dependente (hiperemia reativa e independente (nitroglicerina SL. RESULTADOS: Pacientes HIV positivo em uso de inibidor de protease (IP apresentaram vasodilatação endotélio independente significativamente menor que os subgrupos HIV negativo (p = 0,020 e HIV positivo sem uso de IP (p = 0,034. A variação do diâmetro da artéria braquial durante hiperemia reativa não apresentou significância estatística em qualquer subgrupo. A análise de regressão linear múltipla mostrou que apenas o IP estava associado ao delta relativo da reatividade braquial pelo vasodilatador, nos pacientes HIV positivo, aos 60 e 90 segundos. CONCLUSÃO: Os pacientes HIV positivo em uso de IP apresentam disfunção endotélio independente quando comparados a pacientes HIV positivo que não fazem uso de IP e a um grupo controle.FUNDAMENTO: Considerando el alto número de pacientes infectados por VIH en uso de antirretrovirales, evolucionando con la alteración de la función endotelial y aterotrombosis, llevando al alto coste médico social, es importante identificar mecanismos fisiopatológicos implicados en la función endotelial en portadores de VIH, para que, precozmente, podamos intervenir y evitar la progresión de la enfermedad. OBJETIVO: Evaluar

  4. Supermarket Proteases.

    Hagar, William G.; Bullerwell, Lornie D.

    2003-01-01

    Presents a laboratory activity on enzymes. Uses common items found in the supermarket that contain protease enzymes, such as contact lens cleaner and meat tenderizer. Demonstrates the digestion of gelatin proteins as part of enzymatic reactions. (Author/SOE)

  5. Earthworm Protease

    Rong Pan

    2010-01-01

    Full Text Available The alimentary tract of earthworm secretes a group of proteases with a relative wide substrate specificity. In 1983, six isozymes were isolated from earthworm with fibrinolytic activities and called fibriniolytic enzymes. So far, more isozymes have been found from different earthworm species such as Lumbricus rubellus and Eisenia fetida. For convenience, the proteases are named on the basis of the earthworm species and the protein function, for instance, Eisenia fetida protease (EfP. The proteases have the abilities not only to hydrolyze fibrin and other protein, but also activate proenzymes such as plasminogen and prothrombin. In the light of recent studies, eight of the EfPs contain oligosaccharides chains which are thought to support the enzyme structure. Interestingly, EfP-II has a broader substrate specificity presenting alkaline trypsin, chymotrypsin and elastase activities, but EfP-III-1 has a stricter specificity. The protein crystal structures show the characteristics in their specificities. Earthworm proteases have been applied in several areas such as clinical treatment of clotting diseases, anti-tumor study, environmental protection and nutritional production. The current clinical utilizations and some potential new applications of the earthworm protease will be discussed in this paper.

  6. Earthworm Protease

    Pan, R.; Zhang, Z.; He, R.

    2010-01-01

    The alimentary tract of earthworm secretes a group of proteases with a relative wide substrate specificity. In 1983, six isozymes were isolated from earthworm with fibrinolytic activities and called fibrinolytic enzymes. So far, more isozymes have been found from different earthworm species such as Lumbricus rubellus and Eisenia fetida. For convenience, the proteases are named on the basis of the earthworm species and the protein function, for instance, Eisenia fetida protease (EfP). The proteases have the abilities not only to hydrolyze fibrin and other protein, but also activate pro enzymes such as plasminogen and prothrombin. In the light of recent studies, eight of the EfPs contain oligosaccharides chains which are thought to support the enzyme structure. Interestingly, EfP-II has a broader substrate specificity presenting alkaline trypsin, chymotrypsin and elastase activities, but EfP-III-1 has a stricter specificity. The protein crystal structures show the characteristics in their specificities. Earthworm proteases have been applied in several areas such as clinical treatment of clotting diseases, anti-tumor study, environmental protection and nutritional production. The current clinical utilizations and some potential new applications of the earthworm protease will be discussed in this paper.

  7. Using data from a behavioural survey of men who have sex with men (MSM) to estimate the number likely to present for HIV pre-exposure prophylaxis (PrEP) in Ireland, 2017.

    Nic Lochlainn, Laura; O'Donnell, Kate; Hurley, Caroline; Lyons, Fiona; Igoe, Derval

    2017-11-01

    In Ireland, men who have sex with men (MSM) have increased HIV risk. Pre-exposure prophylaxis (PrEP), combined with safe sex practices, can reduce HIV acquisition. We estimated MSM numbers likely to present for PrEP by applying French PrEP criteria to Irish MSM behavioural survey data. We adjusted for survey bias, calculated proportions accessing testing services and those likely to take PrEP. We estimated 1-3% of MSM in Ireland were likely to present for PrEP.

  8. Multi-spectroscopic and molecular modeling approaches to elucidate the binding interaction between bovine serum albumin and darunavir, a HIV protease inhibitor.

    Shi, Jie-Hua; Zhou, Kai-Li; Lou, Yan-Yue; Pan, Dong-Qi

    2018-01-05

    Darunavir (DRV), a second-generation HIV protease inhibitor, is widely used across the world as an important component of HIV therapy. The interaction of DRV with bovine serum albumin (BSA), a major carrier protein, has been studied under simulated physiological conditions (pH7.4) by multi-spectroscopic techniques in combination with molecular modeling. Fluorescence data revealed that the intrinsic fluorescence of BSA was quenched by DRV in terms of a static quenching procedure due to the formation of the DRV-BSA complex. The results indicated the presence of single weak affinity binding site (~10 3 M -1 , 310K) on protein. The thermodynamic parameters, namely enthalpy change (ΔH 0 ), entropy change (ΔS 0 ) and Gibbs free energy change (ΔG 0 ) were calculated, which signified that the binding reaction was spontaneous, the main binding forces were hydrogen bonding and van der Waals forces. Importantly, competitive binding experiments with three site probes, phenylbutazone (in sub-domain IIA, site I), ibuprofen (in sub-domain IIIA, site II) and artemether (in the interface between sub-domain IIA and IIB, site II'), suggested that DRV was preferentially bound to the hydrophobic cavity in site II' of BSA, and this finding was validated by the docking results. Additionally, synchronous fluorescence, three-dimensional fluorescence and Resonance Rayleigh Scattering (RRS) spectroscopy gave qualitative information on the conformational changes of BSA upon adding DRV, while quantitative data were obtained with Fourier transform infrared spectroscopy (FT-IR). Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Does Pre-exposure prophylaxis (PrEP) for HIV prevention in men who have sex with men (MSM) change risk behavior? A systematic review.

    Freeborn, Kellie; Portillo, Carmen J

    2017-08-03

    Pre-exposure prophylaxis (PrEP) for HIV has been available since 2012. Even so, PrEP has not been widely accepted among healthcare providers and MSM some of whom are convinced that PrEP decreases condom use, and increases sexually transmitted infections (STIs). A systematic review of the state of the evidence regarding the association of PrEP with condom use, STI incidence and change in sexual risk behaviors in MSM. A structured search of databases resulted in 142 potential citations, but only ten publications met inclusion criteria and underwent data abstraction and critical appraisal. An adapted Cochrane Collaboration domain based assessment tool was used to critically appraise the methodological components of each quantitative study, and the Mixed Methods Appraisal Tool (MMAT) was used to critically appraise qualitative and mixed-methods studies. Condom use in MSM utilizing PrEP is influenced by multiple factors. Studies indicate rates of STIs in treatment and placebo groups were high. PrEP did not significantly change STI rates between baseline and follow-up. Reporting of sexual risk improved when questionnaires were completed in private by clients. Our review found that PrEP may provide an opportunity for MSM to access sexual health care, testing, treatment and counselling services. We did not find any conclusive evidence that PrEP users increase sexual risk behaviors. The perception among healthcare providers that PrEP leads to increased sexual risk behaviors has yet to be confirmed. In order to provide effective sexual health services, clinicians need to be knowledgeable about PrEP as an HIV prevention tool. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  10. Framing HIV Pre-Exposure Prophylaxis (PrEP) for the General Public: How Inclusive Messaging May Prevent Prejudice from Diminishing Public Support.

    Calabrese, Sarah K; Underhill, Kristen; Earnshaw, Valerie A; Hansen, Nathan B; Kershaw, Trace S; Magnus, Manya; Krakower, Douglas S; Mayer, Kenneth H; Betancourt, Joseph R; Dovidio, John F

    2016-07-01

    Strategic framing of public messages about HIV pre-exposure prophylaxis (PrEP) may influence public support for policies and programs affecting access. This survey study examined how public attitudes toward PrEP differed based on the social group PrEP was described as benefiting ("beneficiary") and the moderating effect of prejudice. Members of the general public (n = 154) recruited online were randomly assigned to three beneficiary conditions: general population, gay men, or Black gay men. All participants received identical PrEP background information before completing measures of PrEP attitudes (specifying beneficiary), racism, and heterosexism. Despite anticipating greater PrEP adherence among gay men and Black gay men and perceiving PrEP as especially beneficial to the latter, participants expressed lower support for policies/programs making PrEP affordable for these groups vs. the general population. This disparity in support was stronger among participants reporting greater prejudice. Inclusive framing of PrEP in public discourse may prevent prejudice from undermining implementation efforts.

  11. Fluorometric assay for phenotypic differentiation of drug-resistant HIV mutants

    Zhu, Qinchang; Yu, Zhiqiang; Kabashima, Tsutomu; Yin, Sheng; Dragusha, Shpend; El-Mahdy, Ahmed F. M.; Ejupi, Valon; Shibata, Takayuki; Kai, Masaaki

    2015-01-01

    Convenient drug-resistance testing of viral mutants is indispensable to effective treatment of viral infection. We developed a novel fluorometric assay for phenotypic differentiation of drug-resistant mutants of human immunodeficiency virus-I protease (HIV-PR) which uses enzymatic and peptide-specific fluorescence (FL) reactions and high-performance liquid chromatography (HPLC) of three HIV-PR substrates. This assay protocol enables use of non-purified enzyme sources and multiple substrates for the enzymatic reaction. In this study, susceptibility of HIV mutations to drugs was evaluated by selective formation of three FL products after the enzymatic HIV-PR reaction. This proof-of-concept study indicates that the present HPLC-FL method could be an alternative to current phenotypic assays for the evaluation of HIV drug resistance. PMID:25988960

  12. The prion protein has RNA binding and chaperoning properties characteristic of nucleocapsid protein NCP7 of HIV-1.

    Gabus, C; Derrington, E; Leblanc, P; Chnaiderman, J; Dormont, D; Swietnicki, W; Morillas, M; Surewicz, W K; Marc, D; Nandi, P; Darlix, J L

    2001-06-01

    Transmissible spongiform encephalopathies are fatal neurodegenerative diseases associated with the accumulation of a protease-resistant form of the prion protein (PrP). Although PrP is conserved in vertebrates, its function remains to be identified. In vitro PrP binds large nucleic acids causing the formation of nucleoprotein complexes resembling human immunodeficiency virus type 1 (HIV-1) nucleocapsid-RNA complexes and in vivo MuLV replication accelerates the scrapie infectious process, suggesting possible interactions between retroviruses and PrP. Retroviruses, including HIV-1 encode a major nucleic acid binding protein (NC protein) found within the virus where 2000 NC protein molecules coat the dimeric genome. NC is required in virus assembly and infection to chaperone RNA dimerization and packaging and in proviral DNA synthesis by reverse transcriptase (RT). In HIV-1, 5'-leader RNA/NC interactions appear to control these viral processes. This prompted us to compare and contrast the interactions of human and ovine PrP and HIV-1 NCp7 with HIV-1 5'-leader RNA. Results show that PrP has properties characteristic of NCp7 with respect to viral RNA dimerization and proviral DNA synthesis by RT. The NC-like properties of huPrP map to the N-terminal region of huPrP. Interestingly, PrP localizes in the membrane and cytoplasm of PrP-expressing cells. These findings suggest that PrP is a multifunctional protein possibly participating in nucleic acid metabolism.

  13. QSAR models for prediction study of HIV protease inhibitors using support vector machines, neural networks and multiple linear regression

    Rachid Darnag

    2017-02-01

    Full Text Available Support vector machines (SVM represent one of the most promising Machine Learning (ML tools that can be applied to develop a predictive quantitative structure–activity relationship (QSAR models using molecular descriptors. Multiple linear regression (MLR and artificial neural networks (ANNs were also utilized to construct quantitative linear and non linear models to compare with the results obtained by SVM. The prediction results are in good agreement with the experimental value of HIV activity; also, the results reveal the superiority of the SVM over MLR and ANN model. The contribution of each descriptor to the structure–activity relationships was evaluated.

  14. A qualitative study of provider thoughts on implementing pre-exposure prophylaxis (PrEP in clinical settings to prevent HIV infection.

    Emily A Arnold

    Full Text Available A recent clinical trial demonstrated that a daily dose tenofovir disoproxil fumarate and emtricitabrine (TDF-FTC can reduce HIV acquisition among men who have sex with men (MSM and transgender (TG women by 44%, and up to 90% if taken daily. We explored how medical and service providers understand research results and plan to develop clinical protocols to prescribe, support and monitor adherence for patients on PrEP in the United States.Using referrals from our community collaborators and snowball sampling, we recruited 22 healthcare providers in San Francisco, Oakland, and Los Angeles for in-depth interviews from May-December 2011. The providers included primary care physicians seeing high numbers of MSM and TG women, HIV specialists, community health clinic providers, and public health officials. We analyzed interviews thematically to produce recommendations for setting policy around implementing PrEP. Interview topics included: assessing clinician impressions of PrEP and CDC guidance, considerations of cost, office capacity, dosing schedules, and following patients over time.Little or no demand for PrEP from patients was reported at the time of the interviews. Providers did not agree on the most appropriate patients for PrEP and believed that current models of care, which do not involve routine frequent office visits, were not well suited for prescribing PrEP. Providers detailed the need to build capacity and were concerned about monitoring side effects and adherence. PrEP was seen as potentially having impact on the epidemic but providers also noted that community education campaigns needed to be tailored to effectively reach specific vulnerable populations.While PrEP may be a novel and clinically compelling prevention intervention for MSM and TG women, it raises a number of important implementation challenges that would need to be addressed. Nonetheless, most providers expressed optimism that they eventually could prescribe and monitor Pr

  15. A qualitative study of provider thoughts on implementing pre-exposure prophylaxis (PrEP) in clinical settings to prevent HIV infection.

    Arnold, Emily A; Hazelton, Patrick; Lane, Tim; Christopoulos, Katerina A; Galindo, Gabriel R; Steward, Wayne T; Morin, Stephen F

    2012-01-01

    A recent clinical trial demonstrated that a daily dose tenofovir disoproxil fumarate and emtricitabrine (TDF-FTC) can reduce HIV acquisition among men who have sex with men (MSM) and transgender (TG) women by 44%, and up to 90% if taken daily. We explored how medical and service providers understand research results and plan to develop clinical protocols to prescribe, support and monitor adherence for patients on PrEP in the United States. Using referrals from our community collaborators and snowball sampling, we recruited 22 healthcare providers in San Francisco, Oakland, and Los Angeles for in-depth interviews from May-December 2011. The providers included primary care physicians seeing high numbers of MSM and TG women, HIV specialists, community health clinic providers, and public health officials. We analyzed interviews thematically to produce recommendations for setting policy around implementing PrEP. Interview topics included: assessing clinician impressions of PrEP and CDC guidance, considerations of cost, office capacity, dosing schedules, and following patients over time. Little or no demand for PrEP from patients was reported at the time of the interviews. Providers did not agree on the most appropriate patients for PrEP and believed that current models of care, which do not involve routine frequent office visits, were not well suited for prescribing PrEP. Providers detailed the need to build capacity and were concerned about monitoring side effects and adherence. PrEP was seen as potentially having impact on the epidemic but providers also noted that community education campaigns needed to be tailored to effectively reach specific vulnerable populations. While PrEP may be a novel and clinically compelling prevention intervention for MSM and TG women, it raises a number of important implementation challenges that would need to be addressed. Nonetheless, most providers expressed optimism that they eventually could prescribe and monitor PrEP in their

  16. Expanded HIV pre-exposure prophylaxis (PrEP) implementation in communities in New South Wales, Australia (EPIC-NSW): design of an open label, single arm implementation trial.

    Zablotska, Iryna B; Selvey, Christine; Guy, Rebecca; Price, Karen; Holden, Jo; Schmidt, Heather-Marie; McNulty, Anna; Smith, David; Jin, Fengyi; Amin, Janaki; Cooper, David A; Grulich, Andrew E

    2018-02-02

    The New South Wales (NSW) HIV Strategy 2016-2020 aims for the virtual elimination of HIV transmission in NSW, Australia, by 2020. Despite high and increasing levels of HIV testing and treatment since 2012, the annual number of HIV diagnoses in NSW has remained generally unchanged. Pre-exposure prophylaxis (PrEP) is highly effective in preventing HIV infection among gay and bisexual men (GBM) when taken appropriately. However, there have been no population-level studies that evaluate the impact of rapid PrEP scale-up in high-risk GBM. Expanded PrEP Implementation in Communities in NSW (EPIC-NSW) is a population-level evaluation of the rapid, targeted roll-out of PrEP to high-risk individuals. EPIC-NSW, is an open-label, single-arm, multi-centre prospective observational study of PrEP implementation and impact. Over 20 public and private clinics across urban and regional areas in NSW have participated in the rapid roll-out of PrEP, supported by strong community mobilization and PrEP promotion. The study began on 1 March 2016, aiming to enroll at least 3700 HIV negative people at high risk of HIV. This estimate took into consideration criteria for PrEP prescription in people at high risk for acquiring HIV as defined in the NSW PrEP guidelines. Study participants receive once daily co-formulated tenofovir disoproxil fumarate and emtricitabine (TDF/FTC) and are followed for up to 24 months. Follow-up includes: testing for HIV at 1 month, HIV and other sexually transmissible infections three-monthly, HCV annually and monitoring of renal function six-monthly. Optional online behavioural surveys are conducted quarterly. The co-primary endpoints are (i) HIV diagnoses and incidence in the cohort and (ii) HIV diagnoses in NSW. EPIC-NSW is a population-based PrEP implementation trial which targets the entire estimated population of GBM at high risk for HIV infection in NSW. It will provide a unique opportunity to evaluate the population impact of PrEP on a concentrated HIV

  17. Processing Proteases

    Ødum, Anders Sebastian Rosenkrans

    -terminal of the scissile bond, leaving C-terminal fusions to have non-native C-termini after processing. A solution yielding native C-termini would allow novel expression and purification systems for therapeutic proteins and peptides.The peptidyl-Lys metallopeptidase (LysN) of the fungus Armillaria mellea (Am) is one...... of few known proteases to have substrate specificity for the C-terminal side of the scissile bond. LysN exhibits specificity for lysine, and has primarily been used to complement trypsin in to proteomic studies. A working hypothesis during this study was the potential of LysN as a processing protease...

  18. Boosted protease inhibitor monotherapy versus boosted protease inhibitor plus lamivudine dual therapy as second-line maintenance treatment for HIV-1-infected patients in sub-Saharan Africa (ANRS12 286/MOBIDIP): a multicentre, randomised, parallel, open-label, superiority trial.

    Ciaffi, Laura; Koulla-Shiro, Sinata; Sawadogo, Adrien Bruno; Ndour, Cheik Tidiane; Eymard-Duvernay, Sabrina; Mbouyap, Pretty Rosereine; Ayangma, Liliane; Zoungrana, Jacques; Gueye, Ndeye Fatou Ngom; Diallo, Mohamadou; Izard, Suzanne; Bado, Guillaume; Kane, Coumba Toure; Aghokeng, Avelin Fobang; Peeters, Martine; Girard, Pierre Marie; Le Moing, Vincent; Reynes, Jacques; Delaporte, Eric

    2017-09-01

    Despite satisfactory efficacy of WHO-recommended second-line antiretroviral treatment for patients with HIV in low-income countries, the need for simplified, low-cost, and less-toxic maintenance strategies remains high. We compared boosted protease inhibitor monotherapy with dual therapy with boosted protease inhibitor plus lamivudine in patients on second-line antiretrovial therapy (ART). We did a multicentre, randomised, parallel, open-label, superiority, trial in the HIV services of five hospitals in sub-Saharan Africa (Yaoundé, Cameroon; Dakar, Senegal; and Bobo Dioulasso, Burkina Faso). We recruited patients from the long-term, post-trial cohort of the ANRS 12169/2LADY study that compared the efficacy of three second-line combinations based on boosted protease inhibitors. Participants for our study were HIV-1 infected with multiple mutations including M184V, at first-line failure, aged 18 years and older, on boosted protease inhibitor plus two nucleoside reverse transcriptase inhibitors (NRTI) for at least 48 weeks with at least 48 weeks follow-up in the 2LADY trial, with two viral load measurements of less than 200 copies per mL in the previous 6 months, CD4 counts of more than 100 cells per μL, adherence of at least 90%, and no change to ART in the past 3 months. We randomly assigned participants (1:1) to receive either monotherapy with their boosted protease inhibitor (once-daily darunavir 800 mg [two 400 mg tablets] boosted with ritonavir 100 mg [one tablet] or coformulation of lopinavir 200 mg with ritonavir 50 mg [two tablets taken twice per day]) or to boosted protease inhibitor plus once-daily lamivudine 300 mg (one 300 mg tablet or two 150 mg tablets). Computer-generated randomisation was stratified by study site and viral load at screening (treatment allocation was not masked from clinicians or patients]. Patients had follow-up visits at weeks 4 and 12, and every 3 months until 96 weeks; if viral load exceeded 500 copies per mL at any visit, NRTI

  19. A Multi-US City Assessment of Awareness and Uptake of Pre-exposure Prophylaxis (PrEP) for HIV Prevention Among Black Men and Transgender Women Who Have Sex with Men.

    Eaton, Lisa A; Matthews, Derrick D; Driffin, Daniel D; Bukowski, Leigh; Wilson, Patrick A; Stall, Ron D

    2017-07-01

    The HIV epidemic among Black men and transgender women who have sex with men (BMTW) demands an urgent public health response. HIV point prevalence among this population ranges from 25 to 43%-a rate far exceeding any other group. Pre-exposure prophylaxis (PrEP) for HIV prevention is a very promising prevention tool; however, its full potential to slow the epidemic has yet to be realized. For the current study, random time-location sampling at Black Gay Pride Events was used to collect data from N = 1274 BMTW, from five US cities, reporting HIV-negative/unknown status. In-field HIV testing was also provided to participants. Participants were assessed on awareness and use of PrEP, health care factors, HIV testing history, psychosocial variables, and sex behaviors. About one third of participants were aware of PrEP (39%), and a small percentage of participants were users of PrEP (4.6%). In multivariable analyses, being in a relationship, testing for HIV in the past 6 months, and others being aware of one's sexuality were positively associated with PrEP awareness. Higher levels of internalized homophobia and greater numbers of female sex partners were positively associated with PrEP use, while education and condom use were negatively associated. Based on study findings, messaging and uptake of PrEP needs greater expansion and requires novel approaches for scale-up. Improving linkage to HIV testing services is likely critical for engaging BMTW with PrEP. The potential for PrEP to slow the HIV epidemic is high; however, we must strengthen efforts to ensure universal availability and uptake.

  20. The Impact of Human Papilloma Viruses, Matrix Metallo-Proteinases and HIV Protease Inhibitors on the Onset and Progression of Uterine Cervix Epithelial Tumors: A Review of Preclinical and Clinical Studies

    Giovanni Barillari

    2018-05-01

    Full Text Available Infection of uterine cervix epithelial cells by the Human Papilloma Viruses (HPV is associated with the development of dysplastic/hyperplastic lesions, termed cervical intraepithelial neoplasia (CIN. CIN lesions may regress, persist or progress to invasive cervical carcinoma (CC, a leading cause of death worldwide. CIN is particularly frequent and aggressive in women infected by both HPV and the Human Immunodeficiency Virus (HIV, as compared to the general female population. In these individuals, however, therapeutic regimens employing HIV protease inhibitors (HIV-PI have reduced CIN incidence and/or clinical progression, shedding light on the mechanism(s of its development. This article reviews published work concerning: (i the role of HPV proteins (including HPV-E5, E6 and E7 and of matrix-metalloproteinases (MMPs in CIN evolution into invasive CC; and (ii the effect of HIV-PI on events leading to CIN progression such as basement membrane and extracellular matrix invasion by HPV-positive CIN cells and the formation of new blood vessels. Results from the reviewed literature indicate that CIN clinical progression can be monitored by evaluating the expression of MMPs and HPV proteins and they suggest the use of HIV-PI or their derivatives for the block of CIN evolution into CC in both HIV-infected and uninfected women.

  1. An insight to the molecular interactions of the FDA approved HIV PR drugs against L38L↑N↑L PR mutant.

    Sanusi, Zainab K; Govender, Thavendran; Maguire, Glenn E M; Maseko, Sibusiso B; Lin, Johnson; Kruger, Hendrik G; Honarparvar, Bahareh

    2018-03-01

    The aspartate protease of the human immune deficiency type-1 virus (HIV-1) has become a crucial antiviral target in which many useful antiretroviral inhibitors have been developed. However, it seems the emergence of new HIV-1 PR mutations enhances drug resistance, hence, the available FDA approved drugs show less activity towards the protease. A mutation and insertion designated L38L↑N↑L PR was recently reported from subtype of C-SA HIV-1. An integrated two-layered ONIOM (QM:MM) method was employed in this study to examine the binding affinities of the nine HIV PR inhibitors against this mutant. The computed binding free energies as well as experimental data revealed a reduced inhibitory activity towards the L38L↑N↑L PR in comparison with subtype C-SA HIV-1 PR. This observation suggests that the insertion and mutations significantly affect the binding affinities or characteristics of the HIV PIs and/or parent PR. The same trend for the computational binding free energies was observed for eight of the nine inhibitors with respect to the experimental binding free energies. The outcome of this study shows that ONIOM method can be used as a reliable computational approach to rationalize lead compounds against specific targets. The nature of the intermolecular interactions in terms of the host-guest hydrogen bond interactions is discussed using the atoms in molecules (AIM) analysis. Natural bond orbital analysis was also used to determine the extent of charge transfer between the QM region of the L38L↑N↑L PR enzyme and FDA approved drugs. AIM analysis showed that the interaction between the QM region of the L38L↑N↑L PR and FDA approved drugs are electrostatic dominant, the bond stability computed from the NBO analysis supports the results from the AIM application. Future studies will focus on the improvement of the computational model by considering explicit water molecules in the active pocket. We believe that this approach has the potential to

  2. The dimer interfaces of protease and extra-protease domains influence the activation of protease and the specificity of GagPol cleavage.

    Pettit, Steven C; Gulnik, Sergei; Everitt, Lori; Kaplan, Andrew H

    2003-01-01

    Activation of the human immunodeficiency virus type 1 (HIV-1) protease is an essential step in viral replication. As is the case for all retroviral proteases, enzyme activation requires the formation of protease homodimers. However, little is known about the mechanisms by which retroviral proteases become active within their precursors. Using an in vitro expression system, we have examined the determinants of activation efficiency and the order of cleavage site processing for the protease of HIV-1 within the full-length GagPol precursor. Following activation, initial cleavage occurs between the viral p2 and nucleocapsid proteins. This is followed by cleavage of a novel site located in the transframe domain. Mutational analysis of the dimer interface of the protease produced differential effects on activation and specificity. A subset of mutations produced enhanced cleavage at the amino terminus of the protease, suggesting that, in the wild-type precursor, cleavages that liberate the protease are a relatively late event. Replacement of the proline residue at position 1 of the protease dimer interface resulted in altered cleavage of distal sites and suggests that this residue functions as a cis-directed specificity determinant. In summary, our studies indicate that interactions within the protease dimer interface help determine the order of precursor cleavage and contribute to the formation of extended-protease intermediates. Assembly domains within GagPol outside the protease domain also influence enzyme activation.

  3. An exploratory survey of money boys and HIV transmission risk in Jilin Province, PR China

    Lee Zixuan

    2010-06-01

    Full Text Available Abstract This report represents the first exploratory study of Chinese men who provide commercial sex services to other men ("money boys" in Jilin Province, People's Republic of China, through a convenience sample drawn from Changchun and Jilin City. A total of 86 active money boy participants (Changchun, n = 49; Jilin City, n = 37 were surveyed concerning background and demographics, basic HIV transmission knowledge, and sexual practices. The survey indicated that while Jilin Province money boy behavior matches other studies concerning propensity to high risk behavior and significant bridging potential, the Jilin money boys, unlike previous studies, exhibited a high level of basic HIV/AIDS transmission knowledge. In spite of this level of knowledge, none of the participants reported always using a condom in their sexual activities. They also exhibited a high level of awareness of voluntary counseling and testing available in the province, yet relatively few had availed themselves of these services. These preliminary findings will be used as a baseline and springboard for continuing study in the Jilin Province money boy community. Even now, however, it is becoming clear that the dynamics of male commercial sex work may vary greatly depending upon local influences, and will necessitate that future interventions are highly tailored to area-specific circumstances.

  4. Cascade detection for the extraction of localized sequence features; specificity results for HIV-1 protease and structure-function results for the Schellman loop.

    Newell, Nicholas E

    2011-12-15

    The extraction of the set of features most relevant to function from classified biological sequence sets is still a challenging problem. A central issue is the determination of expected counts for higher order features so that artifact features may be screened. Cascade detection (CD), a new algorithm for the extraction of localized features from sequence sets, is introduced. CD is a natural extension of the proportional modeling techniques used in contingency table analysis into the domain of feature detection. The algorithm is successfully tested on synthetic data and then applied to feature detection problems from two different domains to demonstrate its broad utility. An analysis of HIV-1 protease specificity reveals patterns of strong first-order features that group hydrophobic residues by side chain geometry and exhibit substantial symmetry about the cleavage site. Higher order results suggest that favorable cooperativity is weak by comparison and broadly distributed, but indicate possible synergies between negative charge and hydrophobicity in the substrate. Structure-function results for the Schellman loop, a helix-capping motif in proteins, contain strong first-order features and also show statistically significant cooperativities that provide new insights into the design of the motif. These include a new 'hydrophobic staple' and multiple amphipathic and electrostatic pair features. CD should prove useful not only for sequence analysis, but also for the detection of multifactor synergies in cross-classified data from clinical studies or other sources. Windows XP/7 application and data files available at: https://sites.google.com/site/cascadedetect/home. nacnewell@comcast.net Supplementary information is available at Bioinformatics online.

  5. No impact of HIV-1 protease minority resistant variants on the virological response to a first-line PI-based regimen containing darunavir or atazanavir.

    Perrier, Marine; Visseaux, Benoit; Landman, Roland; Joly, Véronique; Todesco, Eve; Yazdanpanah, Yazdan; Calvez, Vincent; Marcelin, Anne-Geneviève; Descamps, Diane; Charpentier, Charlotte

    2018-01-01

    To evaluate, in a clinical cohort of HIV-1-infected patients, the prevalence of PI minority resistant variants (MRV) at ART baseline and their impact on the virological response to a first-line PI-based regimen. In an observational single-centre cohort, we assessed all ART-naive patients initiating a first-line regimen including two NRTI and one boosted PI, darunavir/ritonavir or atazanavir/ritonavir, between January 2012 and March 2015. Ultra-deep sequencing of the pol gene was performed using Illumina® technology. Protease mutations were identified using the WHO transmitted drug resistance list and major PI resistance mutations (IAS-USA drug resistance mutations list). Ninety-four and 16 patients initiating a darunavir/ritonavir-based regimen and an atazanavir/ritonavir-based regimen, respectively, were assessed. Twenty-eight percent of the patients were HIV-1 subtype B, 39% CRF02_AG and 33% other non-B subtypes. Thirteen patients (13.8%) in the darunavir group and three patients (18.8%) in the atazanavir group experienced a virological failure (VF). Overall, 13 (11.8%) subjects had PI MRV at baseline in the median proportion of 1.3% (IQR = 1.1-1.7). The most prevalent PI MRV were G73C (n = 5) and M46I (n = 3). The proportion of patients harbouring baseline PI MRV was similar between those with virological success (10.6%) and those experiencing VF (18.8%) (P = 0.40). No difference was observed in the rate of PI MRV by viral subtype (P = 0.51) or by PI drug (P = 0.40). This study showed a prevalence of 11.8% of PI MRV among 110 ART-naive subjects, without significant impact on the virological response to a first-line PI-based regimen containing darunavir or atazanavir. © The Author 2017. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  6. Gestação e HIV: Preditores da Adesão ao Tratamento no Contexto do Pré-natal

    Evelise Rigoni Faria

    Full Text Available Este estudo avaliou adesão ao tratamento em gestantes vivendo com HIV. Foram entrevistadas 89 gestantes com HIV, no último trimestre gestacional, que forneceram informações sobre dados sociodemográficos, apoio social, pré-natal e tratamento, além de exames laboratoriais. Constatou-se que 51,7% das gestantes aderiam à medicação. Essas gestantes eram mais escolarizadas, começaram o pré-natal antes, realizaram mais consultas e referiram maior apoio emocional. No modelo de regressão logística, o número de consultas realizadas e a presença de maior apoio emocional foram preditores da adesão. Adesão em gestantes vivendo com HIV ainda é um desafio, mesmo quando há acesso e disponibilidade de tratamento. Início precoce do pré-natal e fortalecimento da rede de apoio social são cruciais para a promoção da adesão em gestantes.

  7. Aconselhamento em HIV/AIDS: pressupostos teóricos para uma prática clínica fundamentada

    Clarisse Sampaio Pequeno

    2013-06-01

    Full Text Available Com o avanço da AIDS no Brasil, o Ministério da Saúde sentiu a necessidade de sensibilizar e treinar profissionais de saúde para trabalhar com questões provocadas pela infecção ou pela doença. Neste sentido, surgiu a implantação de centros de orientação e apoio sorológico (CTA, que passaram a ser a principal referência em aconselhamento. O aconselhamento em HIV/AIDS é um dispositivo utilizado por profissionais de saúde buscando trabalhar informação, orientação, avaliação de risco e apoio na realização da sorologia anti-HIV. Entretanto, faz-se necessário que esta estratégia tenha fundamentos teórico-filosóficos que sirvam para embasar a prática clínica do aconselhador. Logo, este artigo objetivou apresentar os principais pressupostos de algumas teorias do aconselhamento psicológico e sua relação com a prática do aconselhamento em HIV/AIDS. Acredita-se que estas reflexões poderão contribuir para fundamentar teoricamente os profissionais que realizam aconselhamento em HIV/AIDS, configurando-o realmente em um dispositivo para promoção da saúde.

  8. Positive selection pressure introduces secondary mutations at Gag cleavage sites in human immunodeficiency virus type 1 harboring major protease resistance mutations

    Banke, S.; Lillemark, M.R.; Gerstoft, J.

    2009-01-01

    Human immunodeficiency virus type 1 (HIV-1) protease inhibitors (PIs) specifically target the HIV-1 protease enzyme. Mutations in the enzyme can result in PI resistance (termed PI mutations); however, mutations in the HIV-1 gag region, the substrate for the protease enzyme, might also lead to PI ...

  9. Could the FDA-approved anti-HIV PR inhibitors be promising anticancer agents? An answer from enhanced docking approach and molecular dynamics analyses

    Arodola OA

    2015-11-01

    Full Text Available Olayide A Arodola, Mahmoud ES SolimanMolecular Modelling and Drug Design Lab, School of Health Sciences, Westville Campus, University of KwaZulu-Natal, Durban, South AfricaAbstract: Based on experimental data, the anticancer activity of nelfinavir (NFV, a US Food and Drug Administration (FDA-approved HIV-1 protease inhibitor (PI, was reported. Nevertheless, the mechanism of action of NFV is yet to be verified. It was hypothesized that the anticancer activity of NFV is due to its inhibitory effect on heat shock protein 90 (Hsp90, a promising target for anticancer therapy. Such findings prompted us to investigate the potential anticancer activity of all other FDA-approved HIV-1 PIs against human Hsp90. To accomplish this, “loop docking” – an enhanced in-house developed molecular docking approach – followed by molecular dynamic simulations and postdynamic analyses were performed to elaborate on the binding mechanism and relative binding affinities of nine FDA-approved HIV-1 PIs against human Hsp90. Due to the lack of the X-ray crystal structure of human Hsp90, homology modeling was performed to create its 3D structure for subsequent simulations. Results showed that NFV has better binding affinity (ΔG =−9.2 kcal/mol when compared with other PIs: this is in a reasonable accordance with the experimental data (IC50 3.1 µM. Indinavir, saquinavir, and ritonavir have close binding affinity to NFV (ΔG =−9.0, −8.6, and −8.5 kcal/mol, respectively. Per-residue interaction energy decomposition analysis showed that hydrophobic interaction (most importantly with Val534 and Met602 played the most predominant role in drug binding. To further validate the docking outcome, 5 ns molecular dynamic simulations were performed in order to assess the stability of the docked complexes. To our knowledge, this is the first account of detailed computational investigations aimed to investigate the potential anticancer activity and the binding

  10. Fatores psicossociais e a infecção por HIV em mulheres, Maringá, PR Psychosocial aspects of HIV infection among women in Brazil

    Rozilda Neves Alves

    2002-08-01

    Full Text Available OBJETIVO: Analisar a percepção do risco de infecção em mulheres infectadas pelo HIV, antes de elas receberem o resultado positivo para essa patologia. MÉTODOS: Estudo exploratório com entrevistas em profundidade em amostra de conveniência constituída de 26 mulheres que freqüentavam o ambulatório de um centro regional de saúde em Maringá, PR. A entrevista foi semidirigida com um roteiro de perguntas fechadas e abertas sobre características sociodemográficos, conhecimento sobre prevenção primária e secundária, percepção de risco antes do teste positivo para HIV, impacto do resultado em suas vidas -- inclusive a sexual -- depois de saberem ser portadoras do vírus. Os resultados foram analisados pela metodologia de análise de conteúdo. RESULTADOS: Apesar de ter consciência de que essa doença pode atingir qualquer um, nenhuma das 26 mulheres estudadas acreditava estar infectada pelo HIV/Aids. Os mecanismos psicológicos, "negação", "evitação", "onipotência do pensamento" e "projeção" foram os que puderam ser identificados como aqueles que as mulheres mais utilizaram para lidar com as dificuldades e as ansiedades decorrentes da percepção de risco e das normas e relações de gêneros hegemônicas presentes na cultura brasileira. Verificou-se que, se o uso desses mecanismos alivia a angústia, por outro lado aumenta a vulnerabilidade das mulheres. Elas se sentem incapazes de atuar, e muitas mantêm relações sexuais desprotegidas com os parceiros, expondo-se à gravidez indesejada e à reinfecção. CONCLUSÕES: Os programas de prevenção do HIV devem considerar também aspectos psicológicos, socioeconômicos e culturais que interferem na vulnerabilidade das mulheres, antes e depois da infecção. Para haver maior alcance de suas ações, os programas devem ir além da distribuição massiva de informações e usar abordagens psicoeducativas em pequenos grupos que estimulem a conscientização das mulheres para al

  11. Redistribuição da gordura corporal induzida pelos inibidores de protease em pacientes com Aids Redistribution of body fat induced by HIV protease inhibitors in patients with AIDS

    Cristina Mansur

    2006-10-01

    Full Text Available Apresentam-se quatro pacientes com infecção pelo vírus da imunodeficiência humana em tratamento com inibidores de proteases há oito meses e três semanas em média. Ressaltam-se o acúmulo de gordura na região dorsocervical e fáscies de lua cheia, semelhante à que ocorre na síndrome de Cushing.Four patients with Human Immunodeficiency Virus Infection in treatment with protease inhibitors for an average of 8 months and 3 weeks are reported. Fat accumulation in the cervical-dorsal region (buffalo hump and moon face, similar to that of Cushing's Syndrome, are highlighted.

  12. Low body weight and type of protease inhibitor predict discontinuation and treatment-limiting adverse drug reactions among HIV-infected patients starting a protease inhibitor regimen: consistent results from a randomized trial and an observational cohort

    Kirk, O; Gerstoft, J; Pedersen, C

    2001-01-01

    OBJECTIVES: To assess predictors for discontinuation and treatment-limiting adverse drug reactions (TLADR) among patients starting their first protease inhibitor (PI). METHODS: Data on patients starting a PI regimen (indinavir, ritonavir, ritonavir/saquinavir and saquinavir hard gel) in a randomi......OBJECTIVES: To assess predictors for discontinuation and treatment-limiting adverse drug reactions (TLADR) among patients starting their first protease inhibitor (PI). METHODS: Data on patients starting a PI regimen (indinavir, ritonavir, ritonavir/saquinavir and saquinavir hard gel....... Low body weight and initiation of ritonavir relative to other PIs were associated with an increased risk of TLADRs. Very consistent results were found in a randomized trial and an observational cohort....

  13. The Safety of Tenofovir-Emtricitabine for HIV Pre-Exposure Prophylaxis (PrEP) in Individuals With Active Hepatitis B.

    Solomon, Marc M; Schechter, Mauro; Liu, Albert Y; McMahan, Vanessa M; Guanira, Juan V; Hance, Robert J; Chariyalertsak, Suwat; Mayer, Kenneth H; Grant, Robert M

    2016-03-01

    Pre-exposure prophylaxis (PrEP) with daily oral emtricitabine and tenofovir disoproxil fumarate (FTC/TDF) prevents HIV infection. The safety and feasibility of HIV PrEP in the setting of hepatitis B virus (HBV) infection were evaluated. The Iniciativa Profilaxis Pre-Exposición study randomized 2499 HIV-negative men and transgender women who have sex with men to once-daily oral FTC/TDF versus placebo. Hepatitis serologies and transaminases were obtained at screening and at the time PrEP was discontinued. HBV DNA was assessed by polymerase chain reaction, and drug resistance was assessed by population sequencing. Vaccination was offered to individuals susceptible to HBV infection. Of the 2499 participants, 12 (0.5%; including 6 randomized to FTC/TDF) had chronic HBV infection. After stopping FTC/TDF, 5 of the 6 participants in the active arm had liver function tests performed at follow-up. Liver function tests remained within normal limits at post-stop visits except for a grade 1 elevation in 1 participant at post-stop week 12 (alanine aminotransferase = 90, aspartate aminotransferase = 61). There was no evidence of hepatic flares. Polymerase chain reaction of stored samples showed that 2 participants in the active arm had evidence of acute HBV infection at enrollment. Both had evidence of grade 4 transaminase elevations with subsequent resolution. Overall, there was no evidence of TDF or FTC resistance among tested genotypes. Of 1633 eligible for vaccination, 1587 (97.2%) received at least 1 vaccine; 1383 (84.7%) completed the series. PrEP can be safely provided to individuals with HBV infection if there is no evidence of cirrhosis or substantial transaminase elevation. HBV vaccination rates at screening were low globally, despite recommendations for its use, yet uptake and efficacy were high when offered.

  14. The Safety of Tenofovir–Emtricitabine for HIV Pre-Exposure Prophylaxis (PrEP) in Individuals With Active Hepatitis B

    Schechter, Mauro; Liu, Albert Y.; McManhan, Vanessa M.; Guanira, Juan V.; Hance, Robert J.; Chariyalertsak, Suwat; Mayer, Kenneth H.; Grant, Robert M.

    2016-01-01

    Background: Pre-exposure prophylaxis (PrEP) with daily oral emtricitabine and tenofovir disoproxil fumarate (FTC/TDF) prevents HIV infection. The safety and feasibility of HIV PrEP in the setting of hepatitis B virus (HBV) infection were evaluated. Methods: The Iniciativa Profilaxis Pre-Exposición study randomized 2499 HIV-negative men and transgender women who have sex with men to once-daily oral FTC/TDF versus placebo. Hepatitis serologies and transaminases were obtained at screening and at the time PrEP was discontinued. HBV DNA was assessed by polymerase chain reaction, and drug resistance was assessed by population sequencing. Vaccination was offered to individuals susceptible to HBV infection. Results: Of the 2499 participants, 12 (0.5%; including 6 randomized to FTC/TDF) had chronic HBV infection. After stopping FTC/TDF, 5 of the 6 participants in the active arm had liver function tests performed at follow-up. Liver function tests remained within normal limits at post-stop visits except for a grade 1 elevation in 1 participant at post-stop week 12 (alanine aminotransferase = 90, aspartate aminotransferase = 61). There was no evidence of hepatic flares. Polymerase chain reaction of stored samples showed that 2 participants in the active arm had evidence of acute HBV infection at enrollment. Both had evidence of grade 4 transaminase elevations with subsequent resolution. Overall, there was no evidence of TDF or FTC resistance among tested genotypes. Of 1633 eligible for vaccination, 1587 (97.2%) received at least 1 vaccine; 1383 (84.7%) completed the series. Conclusions: PrEP can be safely provided to individuals with HBV infection if there is no evidence of cirrhosis or substantial transaminase elevation. HBV vaccination rates at screening were low globally, despite recommendations for its use, yet uptake and efficacy were high when offered. PMID:26413853

  15. Low Prolactin and High 20-α-Hydroxysteroid Dehydrogenase Levels Contribute to Lower Progesterone Levels in HIV-Infected Pregnant Women Exposed to Protease Inhibitor-Based Combination Antiretroviral Therapy.

    Papp, Eszter; Balogun, Kayode; Banko, Nicole; Mohammadi, Hakimeh; Loutfy, Mona; Yudin, Mark H; Shah, Rajiv; MacGillivray, Jay; Murphy, Kellie E; Walmsley, Sharon L; Silverman, Michael; Serghides, Lena

    2016-05-15

    It has been reported that pregnant women receiving protease inhibitor (PI)-based combination antiretroviral therapy (cART) have lower levels of progesterone, which put them at risk of adverse birth outcomes, such as low birth weight. We sought to understand the mechanisms involved in this decline in progesterone level. We assessed plasma levels of progesterone, prolactin, and lipids and placental expression of genes involved in progesterone metabolism in 42 human immunodeficiency virus (HIV)-infected and 31 HIV-uninfected pregnant women. In vitro studies and a mouse pregnancy model were used to delineate the effect of HIV from that of PI-based cART on progesterone metabolism. HIV-infected pregnant women receiving PI-based cART showed a reduction in plasma progesterone levels (P= .026) and an elevation in placental expression of the progesterone inactivating enzyme 20-α-hydroxysteroid dehydrogenase (20α-HSD; median, 2.5 arbitrary units [AU]; interquartile range [IQR], 1.00-4.10 AU), compared with controls (median, 0.89 AU; IQR, 0.66-1.26 AU;P= .002). Prolactin, a key regulator of 20α-HSD, was lower (P= .012) in HIV-infected pregnant women. We observed similar data in pregnant mice exposed to PI-based cART. In vitro inhibition of 20α-HSD activity in trophoblast cells reversed PI-based cART-induced decreases in progesterone levels. Our data suggest that the decrease in progesterone levels observed in HIV-infected pregnant women exposed to PI-based cART is caused, at least in part, by an increase in placental expression of 20α-HSD, which may be due to lower prolactin levels observed in these women. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

  16. Virological responses to lamivudine or emtricitabine when combined with tenofovir and a protease inhibitor in treatment-naïve HIV-1-infected patients in the Dutch AIDS Therapy Evaluation in the Netherlands (ATHENA) cohort.

    Rokx, C; Gras, L; van de Vijver, Damc; Verbon, A; Rijnders, Bja

    2016-09-01

    Lamivudine (3TC) and emtricitabine (FTC) are considered interchangeable in recommended tenofovir disoproxil-fumarate (TDF)-containing combination antiretroviral therapies (cARTs). This statement of equivalence has not been systematically studied. We compared the treatment responses to 3TC and FTC combined with TDF in boosted protease inhibitor (PI)-based cART for HIV-1-infected patients. An observational study in the AIDS Therapy Evaluation in the Netherlands (ATHENA) cohort was carried out between 2002 and 2013. Virological failure rates, time to HIV RNA suppression treatment failure were analysed using multivariable logistic regression and Cox proportional hazard models. Sensitivity analyses included propensity score-adjusted models. A total of 1582 ART-naïve HIV-1-infected patients initiated 3TC or FTC with TDF and ritonavir-boosted darunavir (29.6%), atazanavir (41.5%), lopinavir (27.1%) or another PI (1.8%). Week 48 virological failure rates on 3TC and FTC were comparable (8.9% and 5.6%, respectively; P = 0.208). The multivariable adjusted odds ratio of virological failure when using 3TC instead of FTC with TDF in PI-based cART was 0.75 [95% confidence interval (CI) 0.32-1.79; P = 0.51]. Propensity score-adjusted models showed comparable results. The adjusted hazard ratio (HR) for treatment failure of 3TC compared with FTC was 1.15 (95% CI 0.58-2.27) within 240 weeks after cART initiation. The time to two consecutive HIV RNA measurements treatment failure after suppression treatment-naïve HIV-1-infected patients starting either 3TC/TDF or FTC/TDF and a ritonavir-boosted PI. © 2016 British HIV Association.

  17. Frequency of human immunodeficiency virus type-2 in hiv infected patients in Maputo City, Mozambique

    Bhatt Nilesh

    2011-08-01

    Full Text Available Abstract The HIV/AIDS pandemic is primarily caused by HIV-1. Another virus type, HIV-2, is found mainly in West African countries. We hypothesized that population migration and mobility in Africa may have facilitated the introduction and spreading of HIV-2 in Mozambique. The presence of HIV-2 has important implications for diagnosis and choice of treatment of HIV infection. Hence, the aim of this study was to estimate the prevalence of HIV-2 infection and its genotype in Maputo, Mozambique. HIV-infected individuals (N = 1,200 were consecutively enrolled and screened for IgG antibodies against HIV-1 gp41 and HIV-2 gp36 using peptide-based enzyme immunoassays (pepEIA. Specimens showing reactivity on the HIV-2 pepEIA were further tested using the INNO-LIA immunoblot assay and HIV-2 PCR targeting RT and PR genes. Subtype analysis of HIV-2 was based on the protease gene. After screening with HIV-2 pepEIA 1,168 were non-reactive and 32 were reactive to HIV-2 gp36 peptide. Of this total, 30 specimens were simultaneously reactive to gp41 and gp36 pepEIA while two samples reacted solely to gp36 peptide. Only three specimens containing antibodies against gp36 and gp105 on the INNO-LIA immunoblot assay were found to be positive by PCR to HIV-2 subtype A. The proportion of HIV-2 in Maputo City was 0.25% (90%CI 0.01-0.49. The HIV epidemic in Southern Mozambique is driven by HIV-1, with HIV-2 also circulating at a marginal rate. Surveillance program need to improve HIV-2 diagnosis and consider periodical survey aiming to monitor HIV-2 prevalence in the country.

  18. Safety and adherence to intermittent pre-exposure prophylaxis (PrEP for HIV-1 in African men who have sex with men and female sex workers.

    Gaudensia Mutua

    Full Text Available Little is known about safety of and adherence to intermittent HIV PrEP regimens, which may be more feasible than daily dosing in some settings. We present safety and adherence data from the first trial of an intermittent PrEP regimen among Kenyan men who have sex with men (MSM and female sex workers (FSW.MSM and FSW were randomized to daily oral FTC/TDF or placebo, or intermittent (Monday, Friday and within 2 hours after sex, not to exceed one dose per day oral FTC/TDF or placebo in a 2:1:2:1 ratio; volunteers were followed monthly for 4 months. Adherence was assessed with the medication event monitoring system (MEMS. Sexual activity data were collected via daily text message (SMS queries and timeline followback interviews with a one-month recall period. Sixty-seven men and 5 women were randomized into the study. Safety was similar among all groups. Median MEMS adherence rates were 83% [IQR: 63-92] for daily dosing and 55% [IQR:28-78] for fixed intermittent dosing (p = 0.003, while adherence to any post-coital doses was 26% [IQR:14-50]. SMS response rates were low, which may have impaired measurement of post-coital dosing adherence. Acceptability of PrEP was high, regardless of dosing regimen.Adherence to intermittent dosing regimens, fixed doses, and in particular coitally-dependent doses, may be more difficult than adherence to daily dosing. However, intermittent dosing may still be appropriate for PrEP if intracellular drug levels, which correlate with prevention of HIV acquisition, can be attained with less than daily dosing and if barriers to adherence can be addressed. Additional drug level data, qualitative data on adherence barriers, and better methods to measure sexual activity are necessary to determine whether adherence to post-coital PrEP could be comparable to more standard regimens.ClinicalTrials.gov NCT00971230.

  19. Safety and adherence to intermittent pre-exposure prophylaxis (PrEP) for HIV-1 in African men who have sex with men and female sex workers.

    Mutua, Gaudensia; Sanders, Eduard; Mugo, Peter; Anzala, Omu; Haberer, Jessica E; Bangsberg, David; Barin, Burc; Rooney, James F; Mark, David; Chetty, Paramesh; Fast, Patricia; Priddy, Frances H

    2012-01-01

    Little is known about safety of and adherence to intermittent HIV PrEP regimens, which may be more feasible than daily dosing in some settings. We present safety and adherence data from the first trial of an intermittent PrEP regimen among Kenyan men who have sex with men (MSM) and female sex workers (FSW). MSM and FSW were randomized to daily oral FTC/TDF or placebo, or intermittent (Monday, Friday and within 2 hours after sex, not to exceed one dose per day) oral FTC/TDF or placebo in a 2:1:2:1 ratio; volunteers were followed monthly for 4 months. Adherence was assessed with the medication event monitoring system (MEMS). Sexual activity data were collected via daily text message (SMS) queries and timeline followback interviews with a one-month recall period. Sixty-seven men and 5 women were randomized into the study. Safety was similar among all groups. Median MEMS adherence rates were 83% [IQR: 63-92] for daily dosing and 55% [IQR:28-78] for fixed intermittent dosing (p = 0.003), while adherence to any post-coital doses was 26% [IQR:14-50]. SMS response rates were low, which may have impaired measurement of post-coital dosing adherence. Acceptability of PrEP was high, regardless of dosing regimen. Adherence to intermittent dosing regimens, fixed doses, and in particular coitally-dependent doses, may be more difficult than adherence to daily dosing. However, intermittent dosing may still be appropriate for PrEP if intracellular drug levels, which correlate with prevention of HIV acquisition, can be attained with less than daily dosing and if barriers to adherence can be addressed. Additional drug level data, qualitative data on adherence barriers, and better methods to measure sexual activity are necessary to determine whether adherence to post-coital PrEP could be comparable to more standard regimens. ClinicalTrials.gov NCT00971230.

  20. Safety and immunogenicity of a live recombinant canarypox virus expressing HIV type 1 gp120 MN MN tm/gag/protease LAI (ALVAC-HIV, vCP205) followed by a p24E-V3 MN synthetic peptide (CLTB-36) administered in healthy volunteers at low risk for HIV infection. AGIS Group and L'Agence Nationale de Recherches sur Le Sida.

    Salmon-Céron, D; Excler, J L; Finkielsztejn, L; Autran, B; Gluckman, J C; Sicard, D; Matthews, T J; Meignier, B; Valentin, C; El Habib, R; Blondeau, C; Raux, M; Moog, C; Tartaglia, J; Chong, P; Klein, M; Milcamps, B; Heshmati, F; Plotkin, S

    1999-05-01

    A live recombinant canarypox vector expressing HIV-1 gpl20 MN tm/gag/protease LAI (ALVAC-HIV, vCP205) alone or boosted by a p24E-V3 MN synthetic peptide (CLTB-36) was tested in healthy volunteers at low risk for HIV infection for their safety and immunogenicity. Both antigens were well tolerated. ALVAC-HIV (vCP205) induced low levels of neutralizing antibodies against HIV-1 MN in 33% of the volunteers. None of them had detectable neutralizing antibodies against a nonsyncytium-inducing HIV-1 clade B primary isolate (Bx08). After the fourth injection of vCP205, CTL activity was detected in 33% of the volunteers and was directed against Env, Gag, and Pol. This activity was mediated by both CD4+ and CD8+ lymphocytes. On the other hand, the CLTB-36 peptide was poorly immunogenic and induced no neutralizing antibodies or CTLs. Although the ALVAC-HIV (vCP205) and CLTB-36 prime-boost regimen was not optimal, further studies with ALVAC-HIV (vCP205) are warranted because of its clear induction of a cellular immune response and utility as a priming agent for other subunit antigens such as envelope glycoproteins, pseudoparticles, or new peptides.

  1. Specific in vitro cleavage of Mason-Pfizer monkey virus capsid protein: evidence for a potential role of retroviral protease in early stages of infection

    Rumlova, Michaela; Ruml, Tomas; Pohl, Jan; Pichova, Iva

    2003-01-01

    Processing of Gag polyproteins by viral protease (PR) leads to reorganization of immature retroviral particles and formation of a ribonucleoprotein core. In some retroviruses, such as HIV and RSV, cleavage of a spacer peptide separating capsid and nucleocapsid proteins is essential for the core formation. We show here that no similar spacer peptide is present in the capsid-nucleocapsid (CA-NC) region of Mason-Pfizer monkey virus (M-PMV) and that the CA protein is cleaved in vitro by the PR within the major homology region (MHR) and the NC protein in several sites at the N-terminus. The CA cleavage product was also identified shortly after penetration of M-PMV into COS cells, suggesting that the protease-catalyzed cleavage is involved in core disintegration

  2. Molecular epidemiological analysis of env and pol sequences in newly diagnosed HIV type 1-infected, untreated patients in Hungary.

    Mezei, Mária; Ay, Eva; Koroknai, Anita; Tóth, Renáta; Balázs, Andrea; Bakos, Agnes; Gyori, Zoltán; Bánáti, Ferenc; Marschalkó, Márta; Kárpáti, Sarolta; Minárovits, János

    2011-11-01

    The aim of our study was to monitor the diversity of HIV-1 strains circulating in Hungary and investigate the prevalence of resistance-associated mutations to reverse transcriptase (RT) and protease (PR) inhibitors in newly diagnosed, drug-naive patients. A total of 30 HIV-1-infected patients without prior antiretroviral treatment diagnosed during the period 2008-2010 were included into this study. Viral subtypes and the presence of RT, PR resistance-associated mutations were established by sequencing. Classification of HIV-1 strains showed that 29 (96.6%) patients were infected with subtype B viruses and one patient (3.3%) with subtype A virus. The prevalence of HIV-1 strains with transmitted drug resistance mutations in newly diagnosed individuals was 16.6% (5/30). This study showed that HIV-1 subtype B is still highly predominant in Hungary and documented a relatively high transmission rate of drug resistance in our country.

  3. A Robust PCR Protocol for HIV Drug Resistance Testing on Low-Level Viremia Samples

    Shivani Gupta

    2017-01-01

    Full Text Available The prevalence of drug resistance (DR mutations in people with HIV-1 infection, particularly those with low-level viremia (LLV, supports the need to improve the sensitivity of amplification methods for HIV DR genotyping in order to optimize antiretroviral regimen and facilitate HIV-1 DR surveillance and relevant research. Here we report on a fully validated PCR-based protocol that achieves consistent amplification of the protease (PR and reverse transcriptase (RT regions of HIV-1 pol gene across many HIV-1 subtypes from LLV plasma samples. HIV-spiked plasma samples from the External Quality Assurance Program Oversight Laboratory (EQAPOL, covering various HIV-1 subtypes, as well as clinical specimens were used to optimize and validate the protocol. Our results demonstrate that this protocol has a broad HIV-1 subtype coverage and viral load span with high sensitivity and reproducibility. Moreover, the protocol is robust even when plasma sample volumes are limited, the HIV viral load is unknown, and/or the HIV subtype is undetermined. Thus, the protocol is applicable for the initial amplification of the HIV-1 PR and RT genes required for subsequent genotypic DR assays.

  4. A Modified P1 Moiety Enhances in vitro Antiviral Activity against Various Multi-Drug-Resistant HIV-1 Variants and in vitro CNS Penetration Properties of a Novel Nonpeptidic Protease Inhibitor, GRL-10413

    Amano, Masayuki; Salcedo-Gómez, Pedro Miguel; Zhao, Rui; Yedidi, Ravikiran S.; Das, Debananda; Bulut, Haydar; Delino, Nicole S.; Sheri, Venkata Reddy; Ghosh, Arun K.; Mitsuya, Hiroaki (Kumamoto); (NIH); (Purdue)

    2016-09-12

    We here report that GRL-10413, a novel non-peptidic HIV-1 protease inhibitor (PI) containing a modified P1 moiety and a sulfonamide isostere, is highly active against laboratory HIV-1 strains and primary clinical isolates (EC50: 0.00035 - 0.0018 μM) with minimal cytotoxicity (CC50: 35.7 μM). GRL-10413 blocked the infectivity and replication of HIV-1NL4-3variants selected by up to 5 μM concentrations of atazanavir, lopinavir, or amprenavir (EC50: 0.0021 - 0.0023 μM). GRL-10413 also maintained its strong antiviral activity against multi-drug-resistant clinical HIV-1 variants isolated from patients, who no longer responded to various antiviral regimens after long-term antiretroviral therapy. The development of resistance against GRL-10413 was significantly delayed compared to that of APV. In addition, GRL-10413 showed a favorable central nervous system (CNS) penetration property as assessed with anin vitroblood brain barrier (BBB) reconstruction system. Analysis of the crystal structure of HIV-1 protease in complex with GRL-10413 demonstrated that the modified P1 moiety of GRL-10413 has a greater hydrophobic surface area and makes greater van der Waals contacts with active-site amino acids of protease than in the case of darunavir. Moreover, the chlorine substituent in the P1 moiety interacts with protease in two distinct configurations. The present data demonstrate that GRL-10413 has desirable features for treating patients infected with wild-type and/or multi-drug-resistant HIV-1 variants with favorable CNS-penetration capability and that the newly modified P1-moiety may confer desirable features in designing novel anti-HIV-1 PIs.

  5. Barriers to uptake and use of pre-exposure prophylaxis (PrEP) among communities most affected by HIV in the UK: findings from a qualitative study in Scotland.

    Young, Ingrid; Flowers, Paul; McDaid, Lisa M

    2014-11-20

    To explore the acceptability of pre-exposure prophylaxis (PrEP) among gay, bisexual and men who have sex with men (MSM) and migrant African communities in Scotland, UK. Consecutive mixed qualitative methods consisting of focus groups (FGs) and in-depth interviews (IDIs) explored PrEP acceptability. Data were digitally recorded, transcribed and analysed thematically to identify anticipated and emerging themes. Participants were recruited through community sexual health and outreach support services, and from non-sexual health settings across Scotland. Inclusion criteria included identification as either MSM and/or from migrant African communities; 18 years and older; living in Scotland at the time of participation. 7 FGs were conducted (n=33): 5 with MSM (n=22) and 2 mixed-sex groups with African participants (n=11, women=8), aged 18-75 years. 34 IDIs were conducted with MSM (n=20) and African participants (n=14, women=10), aged 19-60 years. The sample included participants who were HIV-positive and HIV-negative or untested (HIV-positive FG participants, n=22; HIV-positive IDI participants, n=17). Understandings of PrEP effectiveness and concerns about maintaining regular adherence were identified as barriers to potential PrEP uptake and use. Low perception of HIV risk due to existing risk management strategies meant few participants saw themselves as PrEP candidates. Participants identified risk of other sexually transmitted infections and pregnancy as a concern which PrEP did not address for either themselves or their sexual partners. PrEP emerged as a contentious issue because of the potentially negative implications it had for HIV prevention. Many participants viewed PrEP as problematic because they perceived that others would stop using condoms if PrEP was to become available. PrEP implementation needs to identify appropriate communication methods in the context of diverse HIV literacy; address risk-reduction concerns and; demonstrate how PrEP can be part of a

  6. A realização do teste anti-hiv no pré-natal: os significados para a gestante

    Silva, Roberta Maria de Oliveira; Araújo, Carla Luzia França; Paz, Fatima Maria Trigo da

    2008-01-01

    O estudo teve por objetivo conhecer e analisar o significado da realização do teste anti-HIV no pré-natal para as gestantes. Trata-se de uma pesquisa com abordagem qualitativa e foi realizada em um Hospital Escola e em uma Maternidade do município do Rio de Janeiro. Como recurso técnico-metodológico utilizou-se o discurso do sujeito coletivo (DSC). Após a análise dos discursos verificamos que para as gestantes a realização do teste significa a possibilidade de prevenir a transmissão vertical ...

  7. Pre-exposure prophylaxis (PrEP) in HIV-uninfected individuals with high-risk behaviour

    Nadery, S.; Geerlings, S. E.

    2013-01-01

    The global incidence of human immunodeficiency virus (HIV) infection has decreased by 15% over the past years, but is still too high. Despite current programs to reduce the incidence of HIV infection, further approaches are needed to limit this epidemic. Oral antiretroviral pre-exposure prophylaxis

  8. PrEP (Pre-Exposure Prophylaxis) 101

    ... than 70%. Your risk of getting HIV from sex can be even lower if you combine PrEP with condoms and other prevention methods. Download PrEP 101 Consumer Info Sheet Vital Signs Fact Sheet on Daily Pill Can Prevent HIV (PrEP) Expand All Collapse All Video Introductions to PrEP What is PrEP? A Brief ...

  9. The intention to use HIV-pre-exposure prophylaxis (PrEP) among men who have sex with men in Switzerland: testing an extended explanatory model drawing on the unified theory of acceptance and use of technology (UTAUT).

    Nideröst, Sibylle; Gredig, Daniel; Hassler, Benedikt; Uggowitzer, Franziska; Weber, Patrick

    2018-01-01

    The aim of this study was to determine the intention to use pre-exposure prophylaxis (PrEP) when available and to identify predictors of the intention to use PrEP among men who have sex with men (MSM) living in Switzerland. The theoretical model drew on the Unified Theory of Acceptance and Use of Technology and considered additional variables related specifically to PrEP, HIV protection and the resources of MSM. For data collection, we used an anonymous, standardized self-administered online questionnaire. In 2015, we gathered a convenience sample of 556 HIV-negative MSM living in Switzerland. We analyzed the data using descriptive and bivariate statistics and used structural equation modeling to test the hypothesized model. Predictors of respondents' moderate intention to use PrEP were performance expectancy, effort expectancy, perceived social influence, concerns about using PrEP, attitudes toward condom use, negative experiences of condom use and age. These variables were predicted by HIV protection-related aspects and resources. The findings provide insights into the complex dynamic underlying the intention to use PrEP.

  10. High pre-exposure prophylaxis uptake and early adherence among men who have sex with men and transgender women at risk for HIV Infection: the PrEP Brasil demonstration project.

    Hoagland, Brenda; Moreira, Ronaldo I; De Boni, Raquel B; Kallas, Esper G; Madruga, José Valdez; Vasconcelos, Ricardo; Goulart, Silvia; Torres, Thiago S; Marins, Luana M S; Anderson, Peter L; Luz, Paula M; Costa Leite, Iuri da; Liu, Albert Y; Veloso, Valdilea G; Grinsztejn, Beatriz

    2017-04-06

    The efficacy of pre-exposure prophylaxis (PrEP) in preventing sexual acquisition of human immunodeficiency virus (HIV) is well established. Little is known about the feasibility of PrEP implementation in middle-income settings with concentrated epidemics among men who have sex with men (MSM) and transgender women (TGW). PrEP Brasil is a prospective, multicentre, open-label demonstration project assessing PrEP delivery in the context of the Brazilian Public Health System. HIV-uninfected MSM and TGW in 3 referral centres in Rio de Janeiro and São Paulo were evaluated for eligibility and offered 48 weeks of daily emtricitabine/tenofovir for PrEP. Concentrations of tenofovir diphosphate in dried blood spot samples (DBS) at week 4 after enrolment (early adherence) were measured. Predictors of drug levels were assessed using ordinal logistic regression models considering the DBS drug level as a 3 level variable (<350 fmol/punch, ≥350-699 fmol/punch and ≥700 fmol/punch). 1,270 individuals were assessed for participation; n = 738 were potentially eligible and n = 450 were offered PrEP (PrEP uptake was 60.9%). Eligible but not enrolled individuals were younger, had lower HIV risk perception and had lower PrEP awareness. At week 4, 424 participants (of the 450 enrolled) had DBS TFV-DP concentrations, 94.1% in the protective range (≥350 fmol/punch, consistent with ≥2 pills per week), and 78% were in the highly protective range (≥700 fmol/punch, ≥4 pills per week). Participants with ≥12 years of schooling had 1.9 times the odds (95%CI 1.10-3.29) of a higher versus lower drug level than participants with <12 years of schooling. Condomless receptive anal intercourse in the prior 3 months was also associated with higher drug levels (adjusted OR = 1.78; 95% CI 1.08-2.94). The high uptake and early adherence indicate that PrEP for high-risk MSM and TGW can be successfully delivered in the context of the Brazilian Public Health System. Interventions to

  11. Lower genetic variability of HIV-1 and antiretroviral drug resistance in pregnant women from the state of Pará, Brazil.

    Machado, Luiz Fernando Almeida; Costa, Iran Barros; Folha, Maria Nazaré; da Luz, Anderson Levy Bessa; Vallinoto, Antonio Carlos Rosário; Ishak, Ricardo; Ishak, Marluisa Oliveira Guimarães

    2017-04-12

    The present study aimed to describe the genetic diversity of HIV-1, as well as the resistance profile of the viruses identified in HIV-1 infected pregnant women under antiretroviral therapy in the state of Pará, Northern Brazil. Blood samples were collected from 45 HIV-1 infected pregnant to determine the virus subtypes according to the HIV-1 protease (PR) gene and part of the HIV-1 reverse transcriptase (RT) gene by sequencing the nucleotides of these regions. Drug resistance mutations and susceptibility to antiretroviral drugs were analyzed by the Stanford HIV Drug Resistance Database. Out of 45 samples, only 34 could be amplified for PR and 30 for RT. Regarding the PR gene, subtypes B (97.1%) and C (2.9%) were identified; for the RT gene, subtypes B (90.0%), F (6.7%), and C (3.3%) were detected. Resistance to protease inhibitors (PI) was identified in 5.8% of the pregnant, and mutations conferring resistance to nucleoside reverse transcriptase inhibitors were found in 3.3%, while mutations conferring resistance to non-nucleoside reverse transcriptase inhibitors were found in 3.3%. These results showed a low frequency of strains resistant to antiretroviral drugs, the prevalence of subtypes B and F, and the persistent low transmission of subtype C in pregnant of the state of Pará, Brazil.

  12. Views of policymakers, healthcare workers and NGOs on HIV pre-exposure prophylaxis (PrEP): a multinational qualitative study

    Wheelock, Ana; Eisingerich, Andreas B.; Gomez, Gabriela B.; Gray, Emily; Dybul, Mark R.; Piot, Peter

    2012-01-01

    To examine policymakers and providers' views on pre-exposure prophylaxis (PrEP) and their willingness to support its introduction, to inform policy and practice in this emerging field. Semistructured qualitative interview study. Peru, Ukraine, India, Kenya, Uganda, Botswana and South Africa. 35

  13. Formação, práticas e trajetórias de aconselhadores de centros de testagem anti-HIV do Rio de Janeiro, Brasil

    Claudia Mora

    2015-12-01

    Full Text Available Perante a importância do aconselhamento na testagem anti-HIV, analisamos as diretrizes institucionais, as competências privilegiadas no treinamento profissional e os saberes/práticas de aconselhadores. Trata-se de estudo qualitativo centrado na análise documental, observação e entrevista com aconselhadores de Centros de Testagem e Aconselhamento (CTA do estado do Rio de Janeiro. A análise foi orientada pela teoria de Pierre Bourdieu. Foi evidenciado que o habitus profissional dos aconselhadores resulta da articulação dos treinamentos, da graduação e de experiências e interesses pessoais. A operacionalização de competências, como a escuta ativa, é limitada pela rotina dos serviços e escassez de espaços de reflexão. Para incrementar a prática do aconselhamento, é importante desenvolver competências no treinamento, manter a educação continuada e fazer adequações na rotina do serviço. Tais ajustes podem fortalecer a passagem das diretrizes à ação e o aprimoramento da organização e gestão dos CTA.

  14. Distinguishing hypothetical willingness from behavioral intentions to initiate HIV pre-exposure prophylaxis (PrEP): Findings from a large cohort of gay and bisexual men in the U.S.

    Rendina, H Jonathon; Whitfield, Thomas H F; Grov, Christian; Starks, Tyrel J; Parsons, Jeffrey T

    2017-01-01

    Much of the data on the acceptability of HIV Pre-Exposure Prophylaxis (PrEP) is based on willingness to take PrEP (i.e., hypothetical receptivity) rather than actual intentions (i.e., planned behavioral action) to do so. We sought to examine differences between hypothetical willingness and behavioral intentions to begin PrEP in a national sample of gay and bisexual men (GBM) across the U.S. We utilized data collected in 2015 to examine differences between those Unwilling (42.6% n = 375), Willing but not intending (41.4%, n = 365), and willing and Intending to take PrEP (15.9%, n = 140) in a multivariable, multinomial logistic regression. Men with less education had higher odds of Intending to take PrEP. Compared to men unsure about PrEP's efficacy, those who believed PrEP was at least 90% efficacious had higher odds of Intending to take PrEP. Those who saw themselves as appropriate candidates for PrEP had higher odds of Intending to take PrEP while those who saw themselves as inappropriate candidates for PrEP had lower odds of Intending to take PrEP in comparison to men unsure if they were appropriate candidates. Increased motivation for condom non-use because of perceived sexual pressure by partners was associated with higher odds of Intending to take PrEP. The groups did not differ by risk behavior nor recent STI diagnosis. Overall, the distinction between willingness and intentions to take PrEP was meaningful and may help explain disparities between PrEP acceptability and uptake. While much of the literature has focused on hypothetical willingness to take PrEP, these results highlight the importance of simultaneously assessing willingness and intentions when examining correspondence with uptake and developing interventions to increase PrEP uptake. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Short communication: Phenotypic protease inhibitor resistance and cross-resistance in the clinic from 2006 to 2008 and mutational prevalences in HIV from patients with discordant tipranavir and darunavir susceptibility phenotypes.

    Bethell, Richard; Scherer, Joseph; Witvrouw, Myriam; Paquet, Agnes; Coakley, Eoin; Hall, David

    2012-09-01

    To test tipranavir (TPV) or darunavir (DRV) as treatment options for patients with phenotypic resistance to protease inhibitors (PIs), including lopinavir, saquinavir, atazanavir, and fosamprenavir, the PhenoSense GT database was analyzed for susceptibility to DRV or TPV among PI-resistant isolates. The Monogram Biosciences HIV database (South San Francisco, CA) containing 7775 clinical isolates (2006-2008) not susceptible to at least one first-generation PI was analyzed. Phenotypic responses [resistant (R), partially susceptible (PS), or susceptible (S)] were defined by upper and lower clinical cut-offs to each PI. Genotypes were screened for amino acid substitutions associated with TPV-R/DRV-S and TPV-S/DRV-R phenotypes. In all, 4.9% (378) of isolates were resistant to all six PIs and 31.0% (2407) were resistant to none. Among isolates resistant to all four first-generation PIs, DRV resistance increased from 21.2% to 41.9% from 2006 to 2008, respectively, and resistance to TPV remained steady (53.9 to 57.3%, respectively). Higher prevalence substitutions in DRV-S/TPV-R isolates versus DRV-R/TPV-S isolates, respectively, were 82L/T (44.4% vs. 0%) and 83D (5.8% vs. 0%). Higher prevalence substitutions in DRV-R/TPV-S virus were 50V (0.0% vs. 28.9%), 54L (1.0% vs. 36.1%), and 76V (0.4% vs. 15.5%). Mutations to help predict discordant susceptibility to DRV and TPV in isolates with reduced susceptibility to other PIs were identified. DRV resistance mutations associated with improved virologic response to TPV were more prevalent in DRV-R/TPV-S isolates. TPV resistance mutations were more prevalent in TPV-R and DRV-S isolates. These results confirm the impact of genotype on phenotype, illustrating how HIV genotype and phenotype data assist regimen optimization.

  16. Perspectives on HIV Pre- and Post-Exposure Prophylaxes (PrEP and PEP) Among Female and Male Sex Workers in Mombasa, Kenya: Implications for Integrating Biomedical Prevention into Sexual Health Services.

    Restar, Arjee J; Tocco, Jack Ume; Mantell, Joanne E; Lafort, Yves; Gichangi, Peter; Masvawure, Tsitsi B; Chabeda, Sophie Vusha; Sandfort, Theo G M

    2017-04-01

    Pre- and post-exposure prophylaxes (PrEP and PEP) can reduce the risk of HIV acquisition, yet often are inaccessible to and underutilized by most-vulnerable populations, including sex workers in sub-Saharan Africa. Based on in-depth interviews with 21 female and 23 male HIV-negative sex workers in Mombasa, Kenya, we found that awareness and knowledge of PrEP and PEP were low, although willingness to use both was high. Participants felt PrEP would be empowering and give added protection against infection, although some expressed concerns about side effects. Despite PEP's availability, few knew about it and even fewer had used it, but most who had would use it again. Sex workers valued confidentiality, privacy, trustworthiness, and convenient location in health services and wanted thorough HIV/STI assessments. These findings suggest the importance of situating PrEP and PEP within sex worker-friendly health services and conducting outreach to promote these biomedical prevention methods for Kenyan sex workers.

  17. The Use of Online Posts to Identify Barriers to and Facilitators of HIV Pre-exposure Prophylaxis (PrEP) Among Men Who Have Sex with Men: A Comparison to a Systematic Review of the Peer-Reviewed Literature.

    Hannaford, Alisse; Lipshie-Williams, Madeleine; Starrels, Joanna L; Arnsten, Julia H; Rizzuto, Jessica; Cohen, Phillip; Jacobs, Damon; Patel, Viraj V

    2018-04-01

    Pre-exposure prophylaxis (PrEP) remains an under-utilized HIV prevention tool among men who have sex with men (MSM). To more comprehensively elucidate barriers and facilitators to PrEP use among US MSM, we conducted a systematic review of peer-reviewed published articles and content analysis of online posts about PrEP. We searched peer-reviewed databases (Medline, Web of Science, Google Scholar) using MESH headings and keywords about PrEP and/or HIV prevention from 2005 to 2015. We included original studies among MSM in the US that reported on barriers, facilitators, or other factors related to PrEP use. We also searched online posts and associated comments (news articles, opinion pieces, blogs and other social media posts) in diverse venues (Facebook, Slate Outward, Huffington Post Gay Voices, Queerty, and My PrEP Experience blog) to identify posts about PrEP. We used content analysis to identify themes and compare potential differences between the peer-reviewed literature and online posts. We identified 25 peer-reviewed articles and 28 online posts meeting inclusion criteria. We identified 48 unique barriers and 46 facilitators to using PrEP. These 94 themes fit into six overarching categories: (1) access (n = 14), (2) attitudes/beliefs (n = 24), (3) attributes of PrEP (n = 13), (4) behaviors (n = 11), (5) sociodemographic characteristics (n = 8), and (6) social network (n = 6). In all categories, analysis of online posts resulted in identification of a greater number of unique themes. Thirty-eight themes were identified in the online posts that were not identified in the peer-reviewed literature. We identified barriers and facilitators to PrEP in online posts that were not identified in a systematic review of the peer-reviewed literature. By incorporating data both from a systematic review of peer-reviewed articles and from online posts, we have identified salient and novel information about barriers to and facilitators of PrEP use. Traditional

  18. Patients with discordant responses to antiretroviral therapy have impaired killing of HIV-infected T cells.

    Sekar Natesampillai

    2010-11-01

    Full Text Available In medicine, understanding the pathophysiologic basis of exceptional circumstances has led to an enhanced understanding of biology. We have studied the circumstance of HIV-infected patients in whom antiretroviral therapy results in immunologic benefit, despite virologic failure. In such patients, two protease mutations, I54V and V82A, occur more frequently. Expressing HIV protease containing these mutations resulted in less cell death, caspase activation, and nuclear fragmentation than wild type (WT HIV protease or HIV protease containing other mutations. The impaired induction of cell death was also associated with impaired cleavage of procaspase 8, a requisite event for HIV protease mediated cell death. Primary CD4 T cells expressing I54V or V82A protease underwent less cell death than with WT or other mutant proteases. Human T cells infected with HIV containing these mutations underwent less cell death and less Casp8p41 production than WT or HIV containing other protease mutations, despite similar degrees of viral replication. The reductions in cell death occurred both within infected cells, as well as in uninfected bystander cells. These data indicate that single point mutations within HIV protease which are selected in vivo can significantly impact the ability of HIV to kill CD4 T cells, while not impacting viral replication. Therefore, HIV protease regulates both HIV replication as well as HIV induced T cell depletion, the hallmark of HIV pathogenesis.

  19. Conhecimento, atitude e prática do uso de preservativos por presidiárias: prevenção das DST/HIV no cenário prisional

    Nicolau, Ana Izabel Oliveira; Ribeiro, Samila Gomes; Lessa, Paula Renata Amorim; Monte, Alana Santos; Bernardo, Elizian Braga Rodrigues; Pinheiro, Ana Karina Bezerra

    2012-01-01

    Objetivou-se avaliar o conhecimento, a atitude e a prática de presidiárias quanto ao uso do preservativo masculino e feminino como medida preventiva às DST/HIV. Pesquisa quantitativa e avaliativa do tipo Conhecimento, Atitude e Prática (CAP), envolvendo 155 presidiárias. A coleta de dados realizou-se de janeiro a março de 2010 na penitenciária feminina do estado do Ceará. Embora tivessem ouvido falar e/ou soubessem as finalidades do uso, apenas 35 mulheres (22,6%) tinham conhecimento adequado...

  20. Bacterial proteases and virulence

    Frees, Dorte; Brøndsted, Lone; Ingmer, Hanne

    2013-01-01

    signalling to short-circuit host cell processes. Common to both intra- and extracellular proteases is the tight control of their proteolytic activities. In general, substrate recognition by the intracellular proteases is highly selective which is, in part, attributed to the chaperone activity associated...... tolerance to adverse conditions such as those experienced in the host. In the membrane, HtrA performs similar functions whereas the extracellular proteases, in close contact with host components, pave the way for spreading infections by degrading host matrix components or interfering with host cell...... with the proteases either encoded within the same polypeptide or on separate subunits. In contrast, substrate recognition by extracellular proteases is less selective and therefore these enzymes are generally expressed as zymogens to prevent premature proteolytic activity that would be detrimental to the cell...

  1. Saber e prática contraceptiva e prevenção de DST/HIV/AIDS em universitários da área da saúde Conocimiento y práctica contraceptiva y prevención de las DST/SIDA entre estudiantes de la universidad Knowledge, contraceptive practice and HIV/AIDS prevention among university students

    Maria da Trindade Ferreira Leite

    2007-08-01

    Full Text Available Trata-se de uma pesquisa qualitativa, cujo objeto de estudo consiste na análise da prática dos universitários acerca da contracepção e controle das DSTS/HIV/AIDS. E teve como objetivo identificar o método contraceptivo de preferência no universo dos universitários, bem como descobrir os aspectos que pesam na hora dessa escolha e se há relação na escolha desse método contraceptivo com a prevenção das doenças. Os resultados alertam para a necessidade de mudanças na atitude dos futuros profissionais de saúde, seja na maneira atual de ensino, seja no modo de oferecer suporte para que estes realmente entendam a importância e necessidade das práticas sexuais seguras, associadas ao uso de métodos contraceptivos.Investigación descriptiva cualitativo sobre el conocimento de los estudiantes de infermage e medicina de la universidad y de cuidado referentes la opción anticonceptiva y al control de DST/SIDA. Identificando la opción anticonceptiva del método entre éstos que gradúan, y la evidencia si ellos métodos del associate a la prevención del DST's/SIDA o no. Los datos fueron recogidos por entrevistas semi structuralized en cassette de cinta. Los datos producidos foran reorganizados y analizados basado en referencial teórico. Los resultados alertan para cambio de las actitudes de los estudiantes, de la educación de modo que realmente entiendan la importancia y la necesidad de práctico sexual seguro, y a los métodos anticonceptivos asociados a enfermedades sexuales, control de HIV/SIDA y prevención del embarazo.Descriptive research of qualitative approach, with the study object about college medicine and nursing students concerning the contraceptive choice and DST/SIDA control. Identifying the contraceptive method choice between these graduating, and to evidence if they associate the methods to the prevention of the DST's/SIDA or not. The data were collected by semi-structured interviews in ribbon cassette. The produced

  2. Molecular characterization of hepatitis C virus for determination of subtypes and detection of resistance mutations to protease inhibitors in a group of intravenous drug users co-infected with HIV.

    Silva, Tânia; Cortes Martins, Helena; Coutinho, Rodrigo; Leitão, Emília; Silva, Rui; Pádua, Elizabeth

    2015-09-01

    Modifications in therapeutic regimens for the treatment of hepatitis C virus (HCV) have been observed since the approval of viral protease inhibitors (PI), and the selection of natural drug-resistant variants has been also reported. Thus, it becomes crucial to be aware of consequences of new therapeutic approaches and make available tools for monitoring the infection. The study aimed to apply an "in-house" method for amplification and sequencing of the NS3 region which is the target of PI, and allowing simultaneously the classification of viral subtypes and identification of resistance mutations. Forty-seven samples collected from HIV injecting drug users and drug naive for HCV protease inhibitors were tested for anti-HCV antibodies, 93.6% of them had a positive result and in 70.5% was determined HCV active infection. High frequency of subtype 1a (46.2%), followed by an equal proportion of subtypes 3a, 4a, and 4d (15.4%) was obtained. Two potential recombinants, RF1_2k/1b (3.8%) and 2q/2k (3.8%) were identified. Substitutions V36L/P, T54A, I72L/N/T/V, Q80K/G, S122R/T, D168Q, and I170L/V were observed in 65.4% of the samples. The T54A and Q80K mutations, and the combination V36L + T54A were also identified. Polymorphisms were observed exclusively associated with specific genotypes, particularly, I72L and D168Q with genotype 3, and S122T with genotype 4. The V36L substitution was identified in 92.8% of sequences of non-genotype 1 denoting that this amino acid substitution is a natural polymorphism associated with non-genotype 1 strains. Although no major PI resistance mutations were detected, a more extensive study is needed to evaluate the impact of mutations identified in efficacy of PI treatment. © 2015 Wiley Periodicals, Inc.

  3. Facilitators and barriers to medication adherence in an HIV prevention study among men who have sex with men in the iPrEx study in Chiang Mai, Thailand.

    Tangmunkongvorakul, Arunrat; Chariyalertsak, Suwat; Amico, K Rivet; Saokhieo, Pongpun; Wannalak, Vorawan; Sangangamsakun, Thirayut; Goicochea, Pedro; Grant, Robert

    2013-08-01

    In 2008, the Pre-exposure Prophylaxis Initiative (iPrEx) study expanded to include men who have sex with men (MSM) in Chiang Mai, Thailand. In full, 114 participants from Chiang Mai joined this international double-blinded trial of daily FTC-TDF (Truvada®) or placebo as a pre-exposure prophylaxis (PrEP) HIV prevention strategy. To better understand the characteristics of iPrEx participants specifically from this underserved population in Thailand, and gain insights into their experiences of trying to take a daily tablet as part of this blinded PrEP trial, we conducted a qualitative study. In 2010, 32 MSM iPrEx participants provided in-depth interviews and an additional 14 joined focus group discussions. Results of the qualitative analyzes suggested that participants held generally positive attitudes toward the iPrEx study and study medication and related this to high rates of adherence to the daily regimen. Participants also reflected on the provision of quality health care as part of participation in the trial, as well as support from clinical research staff, family and friends as helpful in supporting high rates of study medication adherence. Discourse concerning challenges to adherence included medication taking behavior, which was contextualized by lifestyle, living arrangement, social life, social stigma in terms of being mistakenly identified as HIV positive or unintentional disclosure of sexual identity to family and friends, and relationship conflicts with partners. The results provide broader perspectives of participant experiences of the study medication and daily adherence in the larger contexts of the MSM community, close relationships, and the study climate, and can be leveraged in constructing PrEP adherence support approaches within these communities.

  4. As necessidades comunicacionais das práticas educativas na prevenção da transmissão materno-fetal do HIV Communication needs of education practices in preventing maternal-fetal HIV transmission

    Katia Virginia de O Feliciano

    2003-12-01

    Full Text Available OBJETIVOS: elucidar a fecundidade da prática educativa centrada na prevenção da transmissão materno-fetal da AIDS para promover a comunicação usuárias-serviços. MÉTODOS: Estudo exploratório, parte de uma pesquisa sobre atenção pré-natal, realizado em 19 centros de saúde, duas maternidades e seis unidades de saúde da família da Secretaria de Saúde da cidade do Recife, de maio a julho de 1998. O processo de trabalho foi observado, equipes técnicas entrevistadas e um questionário foi aplicado às 355 mulheres em atendimento; dessas, 81 foram submetidas à sondagem. RESULTADOS: nenhum serviço faz aconselhamento, mesmo quando informam sobre o teste anti-HIV (48,1%. O trabalho educativo está focalizado no fornecimento de informações durante a consulta, pois, as atividades coletivas, nas unidades que realizam-nas (48,1%, não ocorrem em todos os horários do pré-natal. A prática educativa baseada na racionalidade estratégica subestima a importância da aproximação às decisões valorativas das mulheres, das quais somente 11,1% utilizam camisinha de modo sistemático. CONCLUSÕES: a pequena oferta de atividades educativas no pré-natal e o "monólogo tecnocrático" que predomina nas relações entre usuárias e serviços de saúde têm repercussões negativas na vulnerabilidade da população feminina e de seus filhos.OBJECTIVES: to determine the efficiency of educational methods in preventing maternal-fetal AIDS transmission through communication among users and health services providers. METHODS: exploratory study, part of the survey on pre-natal care, accomplished in 19 clinics, two maternity hospitals and six family health units performed by the Health Secretariat of the city of Recife, from May to July, 1998. Procedures were observed, technical teams were interviewed and questionnaires applied to 355 women being seen, of these, 81 participated of the survey. RESULTS: healthcare providers do not perform counseling, even

  5. Reverse transcriptase and protease inhibitor resistant mutations in art treatment naïve and treated HIV-1 infected children in India A Short Review

    Dinesh Bure,

    2016-08-01

    Full Text Available Introduction of first line and second line antiretroviral therapy has dramatically improved the quality of life and survival of the HIV-1 infected individuals. Extension of this therapy in children has similar effect. However the emergence of drug selected resistance has hampered the response to the therapy. A database of prevalence of drug resistance mutations in the Indian children both ART naïve and treated will help in deciding the appropriate regimen for the individual patient as well as formulating the policies regarding the composition of drugs included in the fixed dose combinations and its periodic review by analysis of the information that is made available from time to time. This will enable us to utilize our limited resources in most prudent way.

  6. Randomized trial of time-limited interruptions of protease inhibitor-based antiretroviral therapy (ART vs. continuous therapy for HIV-1 infection.

    Cynthia Firnhaber

    Full Text Available The clinical outcomes of short interruptions of PI-based ART regimens remains undefined.A 2-arm non-inferiority trial was conducted on 53 HIV-1 infected South African participants with viral load 450 cells/µl on stavudine (or zidovudine, lamivudine and lopinavir/ritonavir. Subjects were randomized to a sequential 2, 4 and 8-week ART interruptions or b continuous ART (cART. Primary analysis was based on the proportion of CD4 count >350 cells(c/ml over 72 weeks. Adherence, HIV-1 drug resistance, and CD4 count rise over time were analyzed as secondary endpoints.The proportions of CD4 counts >350 cells/µl were 82.12% for the intermittent arm and 93.73 for the cART arm; the difference of 11.95% was above the defined 10% threshold for non-inferiority (upper limit of 97.5% CI, 24.1%; 2-sided CI: -0.16, 23.1. No clinically significant differences in opportunistic infections, adverse events, adherence or viral resistance were noted; after randomization, long-term CD4 rise was observed only in the cART arm.We are unable to conclude that short PI-based ART interruptions are non-inferior to cART in retention of immune reconstitution; however, short interruptions did not lead to a greater rate of resistance mutations or adverse events than cART suggesting that this regimen may be more forgiving than NNRTIs if interruptions in therapy occur.ClinicalTrials.gov NCT00100646.

  7. Aconselhamento em DST/Aids às gestantes que realizaram o teste anti-HIV na admissão para o parto: os sentidos de uma prática

    Patrícia de Lima Fonseca

    Full Text Available Foram analisadas as práticas e os sentidos do aconselhamento para gestantes submetidas ao teste anti-HIV na admissão para o parto, e para profissionais de saúde que atuam na assistência à maternidade em Salvador, Brasil. Foi realizado um estudo qualitativo em uma maternidade, com observação participante e entrevistas semiestruturadas com 13 puérperas sem diagnóstico prévio para o HIV e sete profissionais de saúde. Observou-se que o exame anti-HIV é realizado de forma compulsória, sem considerar a autonomia da gestante, e que o aconselhamento se limita a informar o diagnóstico e dar orientações no pós-teste somente àquelas cujos resultados foram positivos. Os sentidos que permeiam o exame, assim como o entendimento da experiência e os significados construídos pelas puérperas, sobretudo quando se descobrem positivas para o HIV, não são abordados pelos profissionais, que não se sentem capacitados para acolherem a subjetividade das pacientes.

  8. Aconselhamento em DST/Aids às gestantes que realizaram o teste anti-HIV na admissão para o parto: os sentidos de uma prática

    Patrícia de Lima Fonseca

    2012-06-01

    Full Text Available Foram analisadas as práticas e os sentidos do aconselhamento para gestantes submetidas ao teste anti-HIV na admissão para o parto, e para profissionais de saúde que atuam na assistência à maternidade em Salvador, Brasil. Foi realizado um estudo qualitativo em uma maternidade, com observação participante e entrevistas semiestruturadas com 13 puérperas sem diagnóstico prévio para o HIV e sete profissionais de saúde. Observou-se que o exame anti-HIV é realizado de forma compulsória, sem considerar a autonomia da gestante, e que o aconselhamento se limita a informar o diagnóstico e dar orientações no pós-teste somente àquelas cujos resultados foram positivos. Os sentidos que permeiam o exame, assim como o entendimento da experiência e os significados construídos pelas puérperas, sobretudo quando se descobrem positivas para o HIV, não são abordados pelos profissionais, que não se sentem capacitados para acolherem a subjetividade das pacientes.

  9. Cardiovascular disease and use of contemporary protease inhibitors

    Ryom, Lene; Lundgren, Jens D; El-Sadr, Wafaa

    2018-01-01

    BACKGROUND: Although earlier protease inhibitors have been associated with increased risk of cardiovascular disease, whether this increased risk also applies to more contemporary protease inhibitors is unknown. We aimed to assess whether cumulative use of ritonavir-boosted atazanavir and ritonavir......-boosted darunavir were associated with increased incidence of cardiovascular disease in people living with HIV. METHODS: The prospective Data Collection on Adverse Events of Anti-HIV Drugs (D:A:D) study consists of people living with HIV-1 from 11 cohorts in Australia, Europe, and the USA. Participants were...... monitored from Jan 1, 2009, until the earliest of a cardiovascular event, 6 months after the last visit, or until Feb 1, 2016. The outcome of interest was the incidence of cardiovascular disease in adults (aged ≥16 years) living with HIV who were being treated with contemporary treatments. We defined...

  10. Práticas e sentidos do barebacking entre homens que vivem com HIV e fazem sexo com homens

    Luís Augusto Vasconcelos da Silva

    2010-08-01

    Full Text Available Este artigo é decorrente de uma etnografia online sobre o barebacking (sexo anal desprotegido de forma intencional no cenário brasileiro, entre os anos de 2004 e 2007. Mais especificamente, busca discutir a prática e sentidos do barebacking entre homens soropositivos que fazem sexo com homens, considerando as implicações e conflitos vividos por eles a partir do momento em que se descobrem soropositivos após o engajamento no sexo bareback. Para tal, utilizamos relatos produzidos em entrevistas abertas no MSN messenger, após a criação de uma página no orkut e participação em suas comunidades sobre o barebacking. Apresentamos histórias de três homens, de diferentes regiões do país, que praticavam o barebacking e passaram pelo processo da soroconversão. Nessas breves histórias, destacamos algumas tensões ou ambiguidades diante dos prazeres e das proibições ligados ao sexo sem camisinha, incluindo a culpa pelo engajamento no sexo desprotegido e o sentimento de liberdade produzido pelo mesmo.

  11. High acceptability of HIV pre-exposure prophylaxis but challenges in adherence and use: qualitative insights from a phase I trial of intermittent and daily PrEP in at-risk populations in Kenya.

    Van der Elst, Elisabeth Maria; Mbogua, Judie; Operario, Don; Mutua, Gaudensia; Kuo, Caroline; Mugo, Peter; Kanungi, Jennifer; Singh, Sagri; Haberer, Jessica; Priddy, Frances; Sanders, Eduard Joachim

    2013-07-01

    This paper used qualitative methods to explore experiences of men who have sex with men and female sex workers in Nairobi and Mtwapa, Kenya, who used oral pre-exposure prophylaxis (PrEP) for HIV prevention as part of a four-month trial of safety, acceptability and adherence. Fifty-one of 72 volunteers who took part in a randomized, placebo-controlled, blinded trial that compared daily and intermittent dosage of PrEP underwent qualitative assessments after completing the trial. Analyses identified three themes: (i) acceptability of PrEP was high, i.e. side effects were experienced early in the study but diminished over time, however characteristics of pills could improve comfort and use; (ii) social impacts such as stigma, rumors, and relationship difficulties due to being perceived as HIV positive were prevalent; (iii) adherence was challenged by complexities of daily life, in particular post-coital dosing adherence suffered from alcohol use around time of sex, mobile populations, and transactional sex work. These themes resonated across dosing regimens and gender, and while most participants favored the intermittent dosing schedule, those in the intermittent group noted particular challenges in adhering to the post-coital dose. Culturally appropriate and consistent counseling addressing these issues may be critical for PrEP effectiveness.

  12. PrEP Chicago: A randomized controlled peer change agent intervention to promote the adoption of pre-exposure prophylaxis for HIV prevention among young Black men who have sex with men.

    Young, Lindsay E; Schumm, Phil; Alon, Leigh; Bouris, Alida; Ferreira, Matthew; Hill, Brandon; Khanna, Aditya S; Valente, Thomas W; Schneider, John A

    2018-02-01

    Advances in biomedical prevention strategies such as pre-exposure prophylaxis (PrEP) represent a new opportunity for reducing HIV incidence among young Black men who have sex with men, for whom the number of new HIV infections continues to rise. However, studies have documented low rates of PrEP uptake in this community. Research suggests that the peer networks of young Black men who have sex with men play important roles in their sexual health decisions. PrEP Chicago is a randomized controlled trial network intervention designed to increase PrEP uptake among young Black men who have sex with men living in Chicago. The aims of this study are twofold. Aim 1 is to estimate the effectiveness of a peer change agent intervention for (1) increasing the number of referrals made to a PrEP information line, (2) increasing the rate of PrEP adoption among non-participant peers, and (3) increasing PrEP knowledge, attitudes, and intentions among participants. Aim 2 is to determine the individual and network variables that explain peer change agent effectiveness. PrEP Chicago is a social network intervention that utilizes the influence of peer change agents to link young Black men who have sex with men in Chicago to PrEP. Young Black men who have sex with men were recruited using respondent-driven sampling. Once screened for eligibility, participants were randomly assigned to either one of two treatment sequences: (1) intervention treatment in Year 1 followed by a minimal contact attention control in Year 2 or (2) the minimal contact attention control in Year 1 followed by treatment in Year 2. The treatment consists of a PrEP/peer change agent training workshop followed by booster calls for 12 months. The attention control consists of a sex diary activity designed to help participants assess sexual risk. Psychosocial, sexual health, and network data are collected from all participants at baseline and at 12- and 24-month follow-ups. In total, 423 participants aged 18-35 have

  13. Randomised study to assess the efficacy and safety of once-daily etravirine-based regimen as a switching strategy in HIV-infected patients receiving a protease inhibitor-containing regimen. Etraswitch study.

    Patricia Echeverría

    Full Text Available Etravirine (ETR was approved for patients with virological failure and antiretroviral resistance mutations. It has also shown antiviral efficacy in antiretroviral-naïve patients. However, data on the switching from protease inhibitors (PI to ETR are lacking.HIV-1-infected patients with suppressed viral load (VL during a PI-containing regimen (>12 months and no previous virological failure were randomized to switch from the PI to ETR (400 mg/day, dissolved in water (ETR group, n = 22 or to continue with the same regimen (control group, n = 21. Percentage of patients with VL ≤ 50 copies/mL were assessed at week 48, as well as changes in CD4 T-cell counts and metabolic profile.We included 43 patients [72.9% male, 46.3 (42.2; 50.6 years]. Two patients receiving ETR (grade-1 diarrhea and voluntary discontinuation and another in the control group (simplification discontinued therapy early. No patients presented virological failure (two consecutive VL>50 copies/mL; treatment was successful in 95.2% of the control group and 90.9% of the ETR group (intention-to-treat analysis, missing = failure (p = 0.58. CD4+ T-cell counts did not significantly vary [+49 cells/µL in the ETR group (p = 0.25 and -4 cells/µL in the control group (p = 0.71]. The ETR group showed significant reductions in cholesterol (p<0.001, triglycerides (p = <0.001, and glycemia (p = 0.03 and higher satisfaction (0-10 scale (p = 0.04. Trough plasma concentrations of ETR were similar to observed in studies using ETR twice daily.Switch from a PI-based regimen to a once-daily combination based on ETR maintained undetectable VL during 48 weeks in virologically suppressed HIV-infected patients while lipid profile and patient satisfaction improved significantly.ClinicalTrials.gov NCT01034917.

  14. Gestantes HIV positivas e sua não-adesão à profilaxia no pré-natal=HIV positive pregnant women who do not follow the prenatal prophylaxis=Mujeres embarazadas con HIV positivo y su non adhesión a la profilaxia en el prenatal

    Cechim, Petrolina Libana; Perdomini, Fernanda Rosa Indriunas; Quaresma, Lisiane Moitin

    2007-01-01

    Este é um estudo exploratório descritivo com abordagem qualitativa. Investigamos a não-adesão de gestantes portadoras do vírus HIV/AIDS ao tratamento preconizado pelo Ministério da Saúde no período pré-natal. Os sujeitos desta pesquisa foram sete mulheres soropositivos, que, durante a gestação, não aderiram ao tratamento profilático recomendado. Os dados foram coletados por uma entrevista semiestruturada. Para a análise dos dados, elaboramos categorias com base nas falas destes sujeitos. Com ...

  15. A Closer Look at Racism and Heterosexism in Medical Students' Clinical Decision-Making Related to HIV Pre-Exposure Prophylaxis (PrEP): Implications for PrEP Education.

    Calabrese, Sarah K; Earnshaw, Valerie A; Krakower, Douglas S; Underhill, Kristen; Vincent, Wilson; Magnus, Manya; Hansen, Nathan B; Kershaw, Trace S; Mayer, Kenneth H; Betancourt, Joseph R; Dovidio, John F

    2018-04-01

    Social biases among healthcare providers could limit PrEP access. In this survey study of 115 US medical students, we examined associations between biases (racism and heterosexism) and PrEP clinical decision-making and explored prior PrEP education as a potential buffer. After viewing a vignette about a PrEP-seeking MSM patient, participants reported anticipated patient behavior (condomless sex, extra-relational sex, and adherence), intention to prescribe PrEP to the patient, biases, and background characteristics. Minimal evidence for racism affecting clinical decision-making emerged. In unadjusted analyses, heterosexism indirectly affected prescribing intention via all anticipated behaviors, tested as parallel mediators. Participants expressing greater heterosexism more strongly anticipated increased risk behavior and adherence problems, which were associated with lower prescribing intention. The indirect effect via condomless sex remained significant adjusting for background characteristics. Prior PrEP education did not buffer any indirect effects. Heterosexism may compromise PrEP provision to MSM and should be addressed in PrEP-related medical education.

  16. Novinky v léčbě HIV infekce

    Krečmerová, Marcela

    2012-01-01

    Roč. 8, č. 1 (2012), s. 18-21 ISSN 1801-2434 Institutional support: RVO:61388963 Keywords : HIV * AIDS * cART * HAART * tenofovir * reverse transcriptase * HIV protease * mikrobicides Subject RIV: CC - Organic Chemistry

  17. Phylogeny and resistance profiles of HIV-1 POL sequences from rectal biopsies and blood

    Katzenstein, T L; Petersen, A B; Storgaard, M

    2010-01-01

    The phylogeny and resistance profiles of human immunodeficiency virus type 1 (HIV-1) protease (PR) and reverse transcriptase (RT) sequences were compared among six patients with HIV-1 who had received numerous treatments. RNA and DNA fractions were obtained from concurrent blood and rectal biopsy...... samples. Phylogenetic trees and resistance profiles showed that the rectal mucosa and the peripheral blood mononuclear cells (PBMCs) harbored different HIV-1 strains. The resistance-associated mutations found in each strain corresponded to the treatment history of the patients. The resistance mutations...... acquired during earlier treatment regimens were detected in the sequences obtained from the rectal samples and in the PBMCs in several of the patients. Also, differences in the resistance profiles were observed between anatomical sites and between RNA and DNA fractions. Thus, a single sample probably...

  18. Sex inequalities in HIV-related practices in the Brazilian population aged 15 to 64 years old, 2008 Desigualdades por sexo nas práticas relacionadas à infecção pelo HIV na população brasileira de 15 a 64 anos, 2008

    Ana Roberta Pati Pascom

    2011-01-01

    Full Text Available The objective of this study is to analyze gender differences in HIV-related practices in the Brazilian population. A national survey was carried out in 2008 with a sample size of 8,000 individuals aged 15-64 years old. The sampling was stratified by macro geographical region and urban/rural areas. Logistic regression models were used to investigate the main predictors of consistent condom use. The results showed that women have less sexy, start sexual life later than men, have fewer casual sexual partners, but use condom less frequently than men. On the other hand, the coverage of HIV testing is significantly greater among women. Significant differences by gender were seen in all HIV-related risky practices. The greater vulnerability was always associated with women, with exception of HIV testing. The low proportion of condom use in infidelity situations was a problem for box sexes and deserves special consideration when developing prevention strategies.O objetivo do trabalho foi analisar as diferenças por sexo nas práticas relacionadas à infecção pelo HIV na população brasileira. Inquérito de âmbito nacional foi realizado em 2008, com amostra de 8 mil indivíduos de 15-64 anos. A amostragem foi estratificada por macrorregião geográfica e situação urbano/rural. Utilizou-se modelo de regressão logística para investigar os principais fatores associados às práticas de sexo protegido. Os resultados indicaram que as mulheres têm menor taxa de atividade sexual, iniciam a vida sexual mais tardiamente, têm menos parceiros casuais do que os homens, mas usam menos o preservativo. Por outro lado, a cobertura de teste de HIV é significativamente maior entre as mulheres quando comparadas aos homens. Foram evidenciadas grandes diferenças por sexo nas práticas relacionadas à infecção pelo HIV, sempre com maior vulnerabilidade associada às mulheres, exceto no que diz respeito ao teste de HIV. O baixo uso de preservativo nas situa

  19. Nucleic Acid Aptamers Against Proteases

    Dupont, D M; Andersen, L M; Bøtkjær, Kenneth Alrø

    2011-01-01

    , directed against blood coagulation factors, are in clinical trials as anticoagulant drugs. Several of the studies on protease-binding aptamers have been pioneering and trend-setting in the field. The work with protease-binding aptamers also demonstrates many interesting examples of non-standard selection......Proteases are potential or realized therapeutic targets in a wide variety of pathological conditions. Moreover, proteases are classical subjects for studies of enzymatic and regulatory mechanisms. We here review the literature on nucleic acid aptamers selected with proteases as targets. Designing...... small molecule protease inhibitors of sufficient specificity has proved a daunting task. Aptamers seem to represent a promising alternative. In our review, we concentrate on biochemical mechanisms of aptamer selection, proteinaptamer recognition, protease inhibition, and advantages of aptamers...

  20. HIV-1 incorporates and proteolytically processes human NDR1 and NDR2 serine-threonine kinases

    Devroe, Eric; Silver, Pamela A.; Engelman, Alan

    2005-01-01

    Mammalian genomes encode two related serine-threonine kinases, nuclear Dbf2 related (NDR)1 and NDR2, which are homologous to the Saccharomyces cerevisiae Dbf2 kinase. Recently, a yeast genetic screen implicated the Dbf2 kinase in Ty1 retrotransposition. Since several virion-incorporated kinases regulate the infectivity of human immunodeficiency virus type 1 (HIV-1), we speculated that the human NDR1 and NDR2 kinases might play a role in the HIV-1 life cycle. Here we show that the NDR1 and NDR2 kinases were incorporated into HIV-1 particles. Furthermore, NDR1 and NDR2 were cleaved by the HIV-1 protease (PR), both within virions and within producer cells. Truncation at the PR cleavage site altered NDR2 subcellular localization and inhibited NDR1 and NDR2 enzymatic activity. These studies identify two new virion-associated host cell enzymes and suggest a novel mechanism by which HIV-1 alters the intracellular environment of human cells

  1. HIV-1 subtypes and mutations associated to antiretroviral drug resistance in human isolates from Central Brazil Subtipos e mutações associadas à resistência aos anti-retrovirais em isolados de HIV-1 do Distrito Federal

    Daniela Marreco Cerqueira

    2004-09-01

    Full Text Available The detection of polymorphisms associated to HIV-1 drug-resistance and genetic subtypes is important for the control and treatment of HIV-1 disease. Drug pressure selects resistant variants that carry mutations in the viral reverse transcriptase (RT and protease (PR genes. For a contribution to the public health authorities in planning the availability of therapeutic treatment, we therefore described the genetic variability, the prevalence of mutations associated to drug resistance and the antiretroviral resistance profile in HIV-1 isolates from infected individuals in Central Brazil. Nineteen HIV-1 RNA samples from a Public Health Laboratory of the Federal District were reversely transcribed and cDNAs were amplified by nested PCR. One fragment of 297 bp coding the entire protease gene, and another of 647 bp, corresponding to the partial RT gene (codons 19-234, were obtained. Automated sequencing and BLAST analysis revealed the presence of 17 B and 2 F1 HIV-1 subtypes. The amino acid sequences were analyzed for the presence of resistance-associated mutations. A total of 6 PR mutations, 2 major and 4 accessory, and 8 RT mutations related to drug resistance were found. Our data suggest a high prevalence of HIV-1 B subtype in the studied population of Federal District as well as the presence of genetically-resistant strains in individuals failing treatment.A detecção de polimorfismos do HIV-1 que estejam associados à resistência às drogas anti-retrovirais e aos subtipos genéticos é importante para o controle e tratamento da infecção pelo HIV-1. A pressão exercida pela terapia anti-retroviral seleciona variantes resistentes com mutações nos genes virais da transcriptase reversa (RT e da protease (PR. Assim, visando contribuir com as autoridades de saúde pública na perspectiva de planejar a disponibilidade de um tratamento terapêutico, nós descrevemos a variabilidade genética e a prevalência de mutações associadas à resist

  2. Protease-resistant prions selectively decrease Shadoo protein.

    Joel C Watts

    2011-11-01

    Full Text Available The central event in prion diseases is the conformational conversion of the cellular prion protein (PrP(C into PrP(Sc, a partially protease-resistant and infectious conformer. However, the mechanism by which PrP(Sc causes neuronal dysfunction remains poorly understood. Levels of Shadoo (Sho, a protein that resembles the flexibly disordered N-terminal domain of PrP(C, were found to be reduced in the brains of mice infected with the RML strain of prions [1], implying that Sho levels may reflect the presence of PrP(Sc in the brain. To test this hypothesis, we examined levels of Sho during prion infection using a variety of experimental systems. Sho protein levels were decreased in the brains of mice, hamsters, voles, and sheep infected with different natural and experimental prion strains. Furthermore, Sho levels were decreased in the brains of prion-infected, transgenic mice overexpressing Sho and in infected neuroblastoma cells. Time-course experiments revealed that Sho levels were inversely proportional to levels of protease-resistant PrP(Sc. Membrane anchoring and the N-terminal domain of PrP both influenced the inverse relationship between Sho and PrP(Sc. Although increased Sho levels had no discernible effect on prion replication in mice, we conclude that Sho is the first non-PrP marker specific for prion disease. Additional studies using this paradigm may provide insight into the cellular pathways and systems subverted by PrP(Sc during prion disease.

  3. Multifunctional Mitochondrial AAA Proteases.

    Glynn, Steven E

    2017-01-01

    Mitochondria perform numerous functions necessary for the survival of eukaryotic cells. These activities are coordinated by a diverse complement of proteins encoded in both the nuclear and mitochondrial genomes that must be properly organized and maintained. Misregulation of mitochondrial proteostasis impairs organellar function and can result in the development of severe human diseases. ATP-driven AAA+ proteins play crucial roles in preserving mitochondrial activity by removing and remodeling protein molecules in accordance with the needs of the cell. Two mitochondrial AAA proteases, i-AAA and m-AAA, are anchored to either face of the mitochondrial inner membrane, where they engage and process an array of substrates to impact protein biogenesis, quality control, and the regulation of key metabolic pathways. The functionality of these proteases is extended through multiple substrate-dependent modes of action, including complete degradation, partial processing, or dislocation from the membrane without proteolysis. This review discusses recent advances made toward elucidating the mechanisms of substrate recognition, handling, and degradation that allow these versatile proteases to control diverse activities in this multifunctional organelle.

  4. Conhecimento, atitude e prática do uso de preservativos por presidiárias: prevenção das DST/HIV no cenário prisional

    Ana Izabel Oliveira Nicolau

    2012-06-01

    Full Text Available Objetivou-se avaliar o conhecimento, a atitude e a prática de presidiárias quanto ao uso do preservativo masculino e feminino como medida preventiva às DST/HIV. Pesquisa quantitativa e avaliativa do tipo Conhecimento, Atitude e Prática (CAP, envolvendo 155 presidiárias. A coleta de dados realizou-se de janeiro a março de 2010 na penitenciária feminina do estado do Ceará. Embora tivessem ouvido falar e/ou soubessem as finalidades do uso, apenas 35 mulheres (22,6% tinham conhecimento adequado sobre o preservativo masculino e 11 (7,1% a respeito do feminino. As atitudes foram menos favoráveis quanto ao uso no sexo oral. A prática adequada apresentou pouca representatividade, em especial, do feminino. A homo/bissexualidade, as questões de gênero, a falta de conhecimento e o difícil acesso aos preservativos representaram obstáculos a serem considerados na promoção da saúde sexual do grupo estudado.

  5. Morphogenesis of the infectious HIV-1 virion

    Jun-Ichi eSakuragi

    2011-12-01

    Full Text Available The virion of HIV-1 is spherical and viral glycoprotein spikes (gp120, gp41 protrude from its envelope. The characteristic cone-shaped core exists within the virion, caging the ribonucleoprotein (RNP complex, which is comprised of viral RNA, nucleocapsid (NC and viral enzymes. The HIV-1 virion is budded and released from the infected cell as an immature donut-shaped particle. During or immediately after release, viral protease (PR is activated and subsequently processes the viral structural protein Gag. Through this maturation process, virions acquire infectivity, but its mechanism and transition of morphology largely remain unclear. Recent technological advances in experimental devices and techniques have made it possible to closely dissect the viral production site on the cell, the exterior – or even the interior – of an individual virion, and many new aspects on virion morphology and maturation. In this manuscript, I review the morphogenesis of HIV-1 virions. I focus on several studies, including some of our recent findings, which examined virion formation and/or maturation processes. The story of novel compound, which inhibits virion maturation, and the importance of maturation research are also discussed.

  6. High HIV-1 Diversity and Prevalence of Transmitted Drug Resistance Among Antiretroviral-Naive HIV-Infected Pregnant Women from Rio de Janeiro, Brazil.

    Delatorre, Edson; Silva-de-Jesus, Carlos; Couto-Fernandez, José Carlos; Pilotto, Jose H; Morgado, Mariza G

    2017-01-01

    Antiretroviral (ARV) resistance mutations in human immunodeficiency virus type 1 (HIV-1) infection may reduce the efficacy of prophylactic therapy to prevent mother-to-child transmission (PMTCT) and future treatment options. This study evaluated the diversity and the prevalence of transmitted drug resistance (TDR) in protease (PR) and reverse transcriptase (RT) regions of HIV-1 pol gene among 87 ARV-naive HIV-1-infected pregnant women from Rio de Janeiro, Brazil, between 2012 and 2015. The viral diversity comprised HIV-1 subtypes B (67.8%), F1 (17.2%), and C (4.6%); the circulating recombinant forms 12_BF (2.3%), 28/29_BF, 39_BF, 02_AG (1.1% each) and unique recombinants forms (4.5%). The overall prevalence of any TDR was 17.2%, of which 5.7% for nucleoside RT inhibitors, 5.7% for non-nucleoside RT inhibitors, and 8% for PR inhibitors. The TDR prevalence found in this population may affect the virological outcome of the standard PMTCT ARV-regimens, reinforcing the importance of continuous monitoring.

  7. Construction of dengue virus protease expression plasmid and in vitro protease assay for screening antiviral inhibitors.

    Lai, Huiguo; Teramoto, Tadahisa; Padmanabhan, Radhakrishnan

    2014-01-01

    Dengue virus serotypes 1-4 (DENV1-4) are mosquito-borne human pathogens of global significance causing ~390 million cases annually worldwide. The virus infections cause in general a self-limiting disease, known as dengue fever, but occasionally also more severe forms, especially during secondary infections, dengue hemorrhagic fever and dengue shock syndrome causing ~25,000 deaths annually. The DENV genome contains a single-strand positive sense RNA, approximately 11 kb in length. The 5'-end has a type I cap structure. The 3'-end has no poly(A) tail. The viral RNA has a single long open reading frame that is translated by the host translational machinery to yield a polyprotein precursor. Processing of the polyprotein precursor occurs co-translationally by cellular proteases and posttranslationally by the viral serine protease in the endoplasmic reticulum (ER) to yield three structural proteins (capsid (C), precursor membrane (prM), and envelope (E) and seven nonstructural (NS) proteins (NS1, NS2A, NS2B, NS3, NS4A, NS4B, and NS5). The active viral protease consists of both NS2B, an integral membrane protein in the ER, and the N-terminal part of NS3 (180 amino acid residues) that contains the trypsin-like serine protease domain having a catalytic triad of H51, D75, and S135. The C-terminal part of NS3, ~170-618 amino acid residues, encodes an NTPase/RNA helicase and 5'-RNA triphosphatase activities; the latter enzyme is required for the first step in 5'-capping. The cleavage sites of the polyprotein by the viral protease consist of two basic amino acid residues such as KR, RR, or QR, followed by short chain amino acid residues, G, S, or T. Since the cleavage of the polyprotein by the viral protease is absolutely required for assembly of the viral replicase, blockage of NS2B/NS3pro activity provides an effective means for designing dengue virus (DENV) small-molecule therapeutics. Here we describe the screening of small-molecule inhibitors against DENV2 protease.

  8. The action of neutrophil serine proteases on elastin and its precursor

    Heinz, Andrea; Jung, Michael C; Jahreis, Günther

    2012-01-01

    This study aimed to investigate the degradation of the natural substrates tropoelastin and elastin by the neutrophil-derived serine proteases human leukocyte elastase (HLE), proteinase 3 (PR3) and cathepsin G (CG). Focus was placed on determining their cleavage site specificities using mass...... spectrometric techniques. Moreover, the release of bioactive peptides from elastin by the three proteases was studied. Tropoelastin was comprehensively degraded by all three proteases, whereas less cleavage occurred in mature cross-linked elastin. An analysis of the cleavage site specificities of the three...... proteases in tropoelastin and elastin revealed that HLE and PR3 similarly tolerate hydrophobic and/or aliphatic amino acids such as Ala, Gly and Val at P(1), which are also preferred by CG. In addition, CG prefers the bulky hydrophobic amino acid Leu and accepts the bulky aromatic amino acids Phe and Tyr...

  9. Identification of a large, fast-expanding HIV-1 subtype B transmission cluster among MSM in Valencia, Spain.

    Patiño-Galindo, Juan Ángel; Torres-Puente, Manoli; Bracho, María Alma; Alastrué, Ignacio; Juan, Amparo; Navarro, David; Galindo, María José; Gimeno, Concepción; Ortega, Enrique; González-Candelas, Fernando

    2017-01-01

    We describe and characterize an exceptionally large HIV-1 subtype B transmission cluster occurring in the Comunidad Valenciana (CV, Spain). A total of 1806 HIV-1 protease-reverse transcriptase (PR/RT) sequences from different patients were obtained in the CV between 2004 and 2014. After subtyping and generating a phylogenetic tree with additional HIV-1 subtype B sequences, a very large transmission cluster which included almost exclusively sequences from the CV was detected (n = 143 patients). This cluster was then validated and characterized with further maximum-likelihood phylogenetic analyses and Bayesian coalescent reconstructions. With these analyses, the CV cluster was delimited to 113 patients, predominately men who have sex with men (MSM). Although it was significantly located in the city of Valencia (n = 105), phylogenetic analyses suggested this cluster derives from a larger HIV lineage affecting other Spanish localities (n = 194). Coalescent analyses estimated its expansion in Valencia to have started between 1998 and 2004. From 2004 to 2009, members of this cluster represented only 1.46% of the HIV-1 subtype B samples studied in Valencia (n = 5/143), whereas from 2010 onwards its prevalence raised to 12.64% (n = 100/791). In conclusion, we have detected a very large transmission cluster in the CV where it has experienced a very fast growth in the recent years in the city of Valencia, thus contributing significantly to the HIV epidemic in this locality. Its transmission efficiency evidences shortcomings in HIV control measures in Spain and particularly in Valencia.

  10. Gestantes HIV positivas e sua não-adesão à profilaxia no pré-natal Mujeres embarazadas con HIV positivo y su non adhesión a la profilaxia en el prenatal HIV positive pregnant women who do not follow the prenatal prophylaxis

    Petrolina Libana Cechim

    2007-10-01

    Full Text Available Este é um estudo exploratório descritivo com abordagem qualitativa. Investigamos a não-adesão de gestantes portadoras do vírus HIV/AIDS ao tratamento preconizado pelo Ministério da Saúde no período pré-natal. Os sujeitos desta pesquisa foram sete mulheres soropositivos, que, durante a gestação, não aderiram ao tratamento profilático recomendado. Os dados foram coletados por uma entrevista semi-estruturada. Para a análise dos dados, elaboramos categorias com base nas falas destes sujeitos. Com os resultados, observamos que existe a vulnerabilidade da mulher em realizar a negociação do sexo seguro com o seu parceiro e que associado às baixas condições socio-econômicas, desemprego e falta de afeto, faz com que as mulheres se tornem vítimas do HIV/AIDS.Este es un estudio exploratorio descriptivo con abordaje cualitativo. Se buscó investigar a la no adhesión de las gestantes portadoras del vírus HIV/SIDA al tratamiento preconizado por el Ministério de la Salud en el periodo prenatal. Los sujetos de esta encuesta fueron siete mujeres seropositivas, que durante la gestación, no se adhirieron al tratamiento profiláctico recomendado por el Ministerio de la Salud. Los datos fueron colectados por las autoras del estudio, a través de una entrevista semiestructurada. Para el análisis de los datos, elaboramos categorías desde lo que expresaron estos sujetos. Con los resultados observamos que existe la vulnerabilidad de la mujer en realizar negociación del sexo seguro con su compañero y que asociado a las bajas condiciones socioeconómicas, desempleo y falta de afecto, hace con que las mujeres se conviertan en víctimas del HIV/SIDA.This is an exploratory study based on a qualitative approach. The objective was to investigate why HIV positive pregnant women do not follow the treatment which is recommended by the Health Ministry during the prenatal period. The individuals participating of this investigation were seven HIV

  11. A recombinant fusion protein-based, fluorescent protease assay for high throughput-compatible substrate screening.

    Bozóki, Beáta; Gazda, Lívia; Tóth, Ferenc; Miczi, Márió; Mótyán, János András; Tőzsér, József

    2018-01-01

    In connection with the intensive investigation of proteases, several methods have been developed for analysis of the substrate specificity. Due to the great number of proteases and the expected target molecules to be analyzed, time- and cost-efficient high-throughput screening (HTS) methods are preferred. Here we describe the development and application of a separation-based HTS-compatible fluorescent protease assay, which is based on the use of recombinant fusion proteins as substrates of proteases. The protein substrates used in this assay consists of N-terminal (hexahistidine and maltose binding protein) fusion tags, cleavage sequences of the tobacco etch virus (TEV) and HIV-1 proteases, and a C-terminal fluorescent protein (mApple or mTurquoise2). The assay is based on the fluorimetric detection of the fluorescent proteins, which are released from the magnetic bead-attached substrates by the proteolytic cleavage. The protease assay has been applied for activity measurements of TEV and HIV-1 proteases to test the suitability of the system for enzyme kinetic measurements, inhibition studies, and determination of pH optimum. We also found that denatured fluorescent proteins can be renatured after SDS-PAGE of denaturing conditions, but showed differences in their renaturation abilities. After in-gel renaturation both substrates and cleavage products can be identified by in-gel UV detection. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. A qualitative study of provider thoughts on implementing pre-exposure prophylaxis (PrEP) in clinical settings to prevent HIV infection

    Morin, Stephen; Arnold, EA; Hazelton, P; Lane, T; Christopoulos, KA; Galindo, GR; Steward, WT; Morin, SF

    2012-01-01

    Background: A recent clinical trial demonstrated that a daily dose tenofovir disoproxil fumarate and emtricitabrine (TDF-FTC) can reduce HIV acquisition among men who have sex with men (MSM) and transgender (TG) women by 44%, and up to 90% if taken daily.

  13. Safety, pharmacokinetics, and antiviral activity of A77003, a C2 symmetry-based human immunodeficiency virus protease inhibitor

    Reedijk, M.; Boucher, C. A.; van Bommel, T.; Ho, D. D.; Tzeng, T. B.; Sereni, D.; Veyssier, P.; Jurriaans, S.; Granneman, R.; Hsu, A.

    1995-01-01

    A77003, an inhibitor of the human immunodeficiency virus type 1 (HIV-1) protease, was administered to asymptomatic HIV-1-infected patients in a phase I trial. The drug was given by continuous intravenous infusion at dosages of 0.035, 0.07, 0.14, and 0.28 mg/kg of body weight per h. The drug was

  14. Protease resistance of infectious prions is suppressed by removal of a single atom in the cellular prion protein.

    Leske, Henning; Hornemann, Simone; Herrmann, Uli Simon; Zhu, Caihong; Dametto, Paolo; Li, Bei; Laferriere, Florent; Polymenidou, Magdalini; Pelczar, Pawel; Reimann, Regina Rose; Schwarz, Petra; Rushing, Elisabeth Jane; Wüthrich, Kurt; Aguzzi, Adriano

    2017-01-01

    Resistance to proteolytic digestion has long been considered a defining trait of prions in tissues of organisms suffering from transmissible spongiform encephalopathies. Detection of proteinase K-resistant prion protein (PrPSc) still represents the diagnostic gold standard for prion diseases in humans, sheep and cattle. However, it has become increasingly apparent that the accumulation of PrPSc does not always accompany prion infections: high titers of prion infectivity can be reached also in the absence of protease resistant PrPSc. Here, we describe a structural basis for the phenomenon of protease-sensitive prion infectivity. We studied the effect on proteinase K (PK) resistance of the amino acid substitution Y169F, which removes a single oxygen atom from the β2-α2 loop of the cellular prion protein (PrPC). When infected with RML or the 263K strain of prions, transgenic mice lacking wild-type (wt) PrPC but expressing MoPrP169F generated prion infectivity at levels comparable to wt mice. The newly generated MoPrP169F prions were biologically indistinguishable from those recovered from prion-infected wt mice, and elicited similar pathologies in vivo. Surprisingly, MoPrP169F prions showed greatly reduced PK resistance and density gradient analyses showed a significant reduction in high-density aggregates. Passage of MoPrP169F prions into mice expressing wt MoPrP led to full recovery of protease resistance, indicating that no strain shift had taken place. We conclude that a subtle structural variation in the β2-α2 loop of PrPC affects the sensitivity of PrPSc to protease but does not impact prion replication and infectivity. With these findings a specific structural feature of PrPC can be linked to a physicochemical property of the corresponding PrPSc.

  15. A realização do teste anti-hiv no pré-natal: os significados para a gestante El establecimiento de la lucha contra la prueba del vih en pre-navidad: significados para el embarazo The establishment of anti-hiv test in pre-natal: meanings for pregnancy

    Roberta Maria de Oliveira Silva

    2008-12-01

    Full Text Available O estudo teve por objetivo conhecer e analisar o significado da realização do teste anti-HIV no pré-natal para as gestantes. Trata-se de uma pesquisa com abordagem qualitativa e foi realizada em um Hospital Escola e em uma Maternidade do município do Rio de Janeiro. Como recurso técnico-metodológico utilizou-se o discurso do sujeito coletivo (DSC. Após a análise dos discursos verificamos que para as gestantes a realização do teste significa a possibilidade de prevenir a transmissão vertical do HIV e como parte da assistência pré-natal. O pré-natal foi considerado pelas gestantes uma excelente oportunidade para a realização do teste anti HIV, para o conhecimento da condição sorológica e início precoce do tratamento. Conclui-se que o teste, para a maioria das gestantes, representa a possibilidade de proteger o filho do HIV, além de fazer parte da construção do papel materno a partir de um cuidado concreto com a saúde do bebê.El estudio que tenía para que el objetivo sepa y analice el significado de la realización del anti-VIH de la prueba en el prenatal para las mujeres embarazadas. Uno está sobre una investigación con acercamiento cualitativo y fue ejecutado en una escuela del hospital y una maternidad de la ciudad de Rio de Janeiro. Como recurso técnico-metodológico el discurso del ciudadano colectivo fue utilizado (DSC. Después de que el análisis de los discursos, nosotros verificamos que para las mujeres embarazadas la realización de la prueba significa la posibilidad para prevenir la transmisión vertical del VIH y como parte de la ayuda prenatal. El prenatal era considerado por las mujeres embarazadas una ocasión excelente para la realización del anti VIH de la prueba, para el conocimiento de la condición sorological y del principio precoz del tratamiento. Se concluye que la prueba, para la mayoría de las mujeres embarazadas, representa la posibilidad para proteger al hijo del VIH, más allá de ser

  16. Insecticide resistance and intracellular proteases.

    Wilkins, Richard M

    2017-12-01

    Pesticide resistance is an example of evolution in action with mechanisms of resistance arising from mutations or increased expression of intrinsic genes. Intracellular proteases have a key role in maintaining healthy cells and in responding to stressors such as pesticides. Insecticide-resistant insects have constitutively elevated intracellular protease activity compared to corresponding susceptible strains. This increase was shown for some cases originally through biochemical enzyme studies and subsequently putatively by transcriptomics and proteomics methods. Upregulation and expression of proteases have been characterised in resistant strains of some insect species, including mosquitoes. This increase in proteolysis results in more degradation products (amino acids) of intracellular proteins. These may be utilised in the resistant strain to better protect the cell from stress. There are changes in insect intracellular proteases shortly after insecticide exposure, suggesting a role in stress response. The use of protease and proteasome inhibitors or peptide mimetics as synergists with improved application techniques and through protease gene knockdown using RNA interference (possibly expressed in crop plants) may be potential pest management strategies, in situations where elevated intracellular proteases are relevant. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  17. Scrapie susceptibility-linked polymorphisms modulate the in vitro conversion of sheep prion protein to protease-resistant forms

    Bossers, A.; Belt, P.B.G.M.; Raymond, G.J.; Caughey, B.; Vries, de R.; Smits, M.

    1997-01-01

    Prion diseases are natural transmissible neurodegenerative disorders in humans and animals. They are characterized by the accumulation of a protease-resistant scrapie-associated prion protein (PrPSc) of the host-encoded cellular prion protein (PrPC) mainly in the central nervous system.

  18. Prática educativa com jovens usuários de crack visando a prevenção do HIV/AIDS

    Agnes Caroline Souza Pinto

    2016-01-01

    Full Text Available RESUMO Objetivo: Relatar a intervenção educativa com jovens usuários de crack visando à prevenção do HIV/AIDS através da metodologia de Círculo de Cultura. Métodos: Pesquisa de natureza qualitativa, realizada em 2012 com 10 jovens usuários de crack atendidos em uma comunidade terapêutica de Fortaleza-CE. A coleta de informações incluiu: observação participante com diário de campo; registro fotográfico e filmagem; e, como produção do grupo, teatro de fantoches. Resultados: O Círculo de Cultura permitiu aos jovens desvelar as suas principais vulnerabilidades ao HIV/AIDS, como o compartilhamento de canudos e cachimbos no uso da cocaína/crack e a perda da consciência como influenciadora na diversidade de parceiros e no não uso do preservativo nas relações sexuais. Conclusão: A intervenção educativa criou possibilidades para a inserção do(a enfermeiro(a no cenário da comunidade terapêutica, a fim de fortalecer articulações em rede para o trabalho de prevenção ao HIV/AIDS entre usuários de crack.

  19. Co-evolution of insect proteases and plant protease inhibitors.

    Jongsma, Maarten A; Beekwilder, Jules

    2011-08-01

    Plants are at the basis of the food chain, but there is no such thing as a "free lunch" for herbivores. To promote reproductive success, plants evolved multi-layered defensive tactics to avoid or discourage herbivory. To the detriment of plants, herbivores, in turn, evolved intricate strategies to find, eat, and successfully digest essential plant parts to raise their own offspring. In this battle the digestive tract is the arena determining final victory or defeat as measured by growth or starvation of the herbivore. Earlier, specific molecular opponents were identified as proteases and inhibitors: digestive proteases of herbivores evolved structural motifs to occlude plant protease inhibitors, or alternatively, the insects evolved proteases capable of specifically degrading the host plant inhibitors. In response plant inhibitors evolved hyper-variable and novel protein folds to remain active against potential herbivores. At the level of protease regulation in herbivorous insects, it was shown that inhibition-insensitive digestive proteases are up-regulated when sensitive proteases are inhibited. The way this regulation operates in mammals is known as negative feedback by gut-luminal factors, so-called 'monitor peptides' that are sensitive to the concentration of active enzymes. We propose that regulation of gut enzymes by endogenous luminal factors has been an open invitation to plants to "hijack" this regulation by evolving receptor antagonists, although yet these plant factors have not been identified. In future research the question of the co-evolution of insect proteases and plant inhibitors should, therefore, be better approached from a systems level keeping in mind that evolution is fundamentally opportunistic and that the plant's fitness is primarily improved by lowering the availability of essential amino acids to an herbivore by any available mechanism.

  20. Specific in vitro cleavage of Mason-Pfizer monkey virus capsid protein: evidence for a potential role of retroviral protease in early stages of infection

    Rumlová, Michaela; Ruml, T.; Pohl, J.; Pichová, Iva

    2003-01-01

    Roč. 310, - (2003), s. 310-318 ISSN 0042-6822 R&D Projects: GA ČR GA203/00/1241; GA AV ČR IAB4055202 Institutional research plan: CEZ:AV0Z4055905 Keywords : M-PMV protease * HIV-1 capsid protein * HIV-1 protease Subject RIV: CE - Biochemistry Impact factor: 3.391, year: 2003

  1. The molecular epidemiology of HIV-1 in the Comunidad Valenciana (Spain): analysis of transmission clusters.

    Patiño-Galindo, Juan Ángel; Torres-Puente, Manoli; Bracho, María Alma; Alastrué, Ignacio; Juan, Amparo; Navarro, David; Galindo, María José; Ocete, Dolores; Ortega, Enrique; Gimeno, Concepción; Belda, Josefina; Domínguez, Victoria; Moreno, Rosario; González-Candelas, Fernando

    2017-09-14

    HIV infections are still a very serious concern for public heath worldwide. We have applied molecular evolution methods to study the HIV-1 epidemics in the Comunidad Valenciana (CV, Spain) from a public health surveillance perspective. For this, we analysed 1804 HIV-1 sequences comprising protease and reverse transcriptase (PR/RT) coding regions, sampled between 2004 and 2014. These sequences were subtyped and subjected to phylogenetic analyses in order to detect transmission clusters. In addition, univariate and multinomial comparisons were performed to detect epidemiological differences between HIV-1 subtypes, and risk groups. The HIV epidemic in the CV is dominated by subtype B infections among local men who have sex with men (MSM). 270 transmission clusters were identified (>57% of the dataset), 12 of which included ≥10 patients; 11 of subtype B (9 affecting MSMs) and one (n = 21) of CRF14, affecting predominately intravenous drug users (IDUs). Dated phylogenies revealed these large clusters to have originated from the mid-80s to the early 00 s. Subtype B is more likely to form transmission clusters than non-B variants and MSMs to cluster than other risk groups. Multinomial analyses revealed an association between non-B variants, which are not established in the local population yet, and different foreign groups.

  2. Boceprevir: a protease inhibitor for the treatment of hepatitis C.

    Chang, Mei H; Gordon, Lori A; Fung, Horatio B

    2012-10-01

    Boceprevir is a protease inhibitor indicated for the treatment of chronic hepatitis C virus (HCV) genotype 1 infection in combination with peginterferon and ribavirin for treatment-naive patients and those who previously failed to improve with interferon and ribavirin treatment. This article provides an overview of the mechanism of action, pharmacologic and pharmacokinetic properties, clinical efficacy, and tolerability of boceprevir. Relevant information was identified through a search of PubMed (1990-July 2012), EMBASE (1990-July 2012), International Pharmaceutical Abstracts (1970-July 2012), and Google Scholar using the key words boceprevir, SCH 503034, non-structural protein 3 (NS3) serine protease inhibitor, and direct-acting antiviral agent (DAA). Additional information was obtained from the US Food and Drug Administration's Web site, review of the reference lists of identified articles, and posters and abstracts from scientific meetings. Clinical efficacy of boceprevir was assessed in 2 Phase III trials, Serine Protease Inhibitor Therapy-2 (SPRINT-2) for treatment-naive patients and Retreatment with HCV Serine Protease Inhibitor Boceprevir and PegIntron/Rebetol 2 (RESPOND-2) for treatment-experienced patients. In SPRINT-2, patients were randomized to receive peginterferon + ribavirin (PR) or peginterferon + ribavirin + boceprevir (PRB); duration of boceprevir therapy varied from 24, 32, to 44 weeks on the basis of HCV RNA results. The primary endpoint was achievement of sustained virologic response (SVR; lower limit of detection, 9.3 IU/mL). The addition of boceprevir was shown to be superior, with overall SVR rates ranging from 63% to 66% compared with 38% with PR (P < 0.001). Results of SVR in SPRINT-2 were also reorganized to monitor SVRs in black and non-black patients. Treatment-experienced patients were assessed in RESPOND-2; however, null responders were excluded. Patients were again randomized to PR or PRB; duration of boceprevir therapy varied from

  3. Inhibitors of Deubiquitinating Enzymes Block HIV-1 Replication and Augment the Presentation of Gag-Derived MHC-I Epitopes.

    Setz, Christian; Friedrich, Melanie; Rauch, Pia; Fraedrich, Kirsten; Matthaei, Alina; Traxdorf, Maximilian; Schubert, Ulrich

    2017-08-12

    In recent years it has been well established that two major constituent parts of the ubiquitin proteasome system (UPS)-the proteasome holoenzymes and a number of ubiquitin ligases-play a crucial role, not only in virus replication but also in the regulation of the immunogenicity of human immunodeficiency virus type 1 (HIV-1). However, the role in HIV-1 replication of the third major component, the deubiquitinating enzymes (DUBs), has remained largely unknown. In this study, we show that the DUB-inhibitors (DIs) P22077 and PR-619, specific for the DUBs USP7 and USP47, impair Gag processing and thereby reduce the infectivity of released virions without affecting viral protease activity. Furthermore, the replication capacity of X4- and R5-tropic HIV-1 NL4-3 in human lymphatic tissue is decreased upon treatment with these inhibitors without affecting cell viability. Most strikingly, combinatory treatment with DIs and proteasome inhibitors synergistically blocks virus replication at concentrations where mono-treatment was ineffective, indicating that DIs can boost the therapeutic effect of proteasome inhibitors. In addition, P22077 and PR-619 increase the polyubiquitination of Gag and thus its entry into the UPS and the major histocompatibility complex (MHC)-I pathway. In summary, our data point towards a model in which specific inhibitors of DUBs not only interfere with virus spread but also increase the immune recognition of HIV-1 expressing cells.

  4. Degradation of the disease-associated prion protein by a serine protease from lichens

    Johnson, C.J.; Bennett, J.P.; Biro, S.M.; Duque-Velasquez, J.C.; Rodriguez, C.M.; Bessen, R.A.; Rocke, T.E.; Bartz, Jason C.

    2011-01-01

    The disease-associated prion protein (PrP(TSE)), the probable etiological agent of the transmissible spongiform encephalopathies (TSEs), is resistant to degradation and can persist in the environment. Lichens, mutualistic symbioses containing fungi, algae, bacteria and occasionally cyanobacteria, are ubiquitous in the environment and have evolved unique biological activities allowing their survival in challenging ecological niches. We investigated PrP(TSE) inactivation by lichens and found acetone extracts of three lichen species (Parmelia sulcata, Cladonia rangiferina and Lobaria pulmonaria) have the ability to degrade prion protein (PrP) from TSE-infected hamsters, mice and deer. Immunoblots measuring PrP levels and protein misfolding cyclic amplification indicated at least two logs of reductions in PrP(TSE). Degradative activity was not found in closely related lichen species or in algae or a cyanobacterium that inhabit lichens. Degradation was blocked by Pefabloc SC, a serine protease inhibitor, but not inhibitors of other proteases or enzymes. Additionally, we found that PrP levels in PrP(TSE)-enriched preps or infected brain homogenates are also reduced following exposure to freshly-collected P. sulcata or an aqueous extract of the lichen. Our findings indicate that these lichen extracts efficiently degrade PrP(TSE) and suggest that some lichens could have potential to inactivate TSE infectivity on the landscape or be a source for agents to degrade prions. Further work to clone and characterize the protease, assess its effect on TSE infectivity and determine which organism or organisms present in lichens produce or influence the protease activity is warranted.

  5. Home-based pre-exposure prophylaxis (PrEP services for gay and bisexual men: An opportunity to address barriers to PrEP uptake and persistence.

    Steven A John

    Full Text Available Gay, bisexual, and other men who have sex with men (GBM are disproportionately affected by the HIV epidemic. Despite the promise of pre-exposure prophylaxis (PrEP in reducing HIV transmission risk, barriers for uptake and persistence exist. We sought to identify whether GBM in a nationwide cohort who have not yet initiated PrEP (n = 906 would prefer to get PrEP-related care from a primary care provider (PCP compared to a specialist clinic or provider. We then sought to identify their level of interest and factors associated with preference for using home-based PrEP services (i.e., HB-PrEP, defined to participants as conducting HIV/STI self-testing from home with PrEP prescription mailing after an initial in-person clinic visit. We examined the associations of demographics, sexual HIV transmission risk, concern about frequent medical checkups associated with PrEP, health care access, and PrEP intentions with preferences for healthcare provider type and HB-PrEP. Concern about frequent medical checkups were associated with preferring a PCP for PrEP-related care, but men who perceived a barrier to bringing up the topic of PrEP with a doctor preferred a specialist clinic or provider more than a PCP. HB-PrEP was more appealing for younger men and those engaged in sexual HIV transmission risk, suggesting HB-PrEP could help reach GBM most vulnerable to HIV and in need of PrEP. HB-PrEP expansion has potential to increase PrEP uptake and persistence among GBM, particularly for men with barriers to clinic-based care and higher intentions to initiate PrEP. Clinical guidelines regarding HB-PrEP are needed to expand its use.

  6. Lack of integrase inhibitors associated resistance mutations among HIV-1C isolates.

    Mulu, Andargachew; Maier, Melanie; Liebert, Uwe Gerd

    2015-12-01

    Although biochemical analysis of HIV-1 integrase enzyme suggested the use of integrase inhibitors (INIs) against HIV-1C, different viral subtypes may favor different mutational pathways potentially leading to varying levels of drug resistance. Thus, the aim of this study was to search for the occurrence and natural evolution of integrase polymorphisms and/or resistance mutations in HIV-1C Ethiopian clinical isolates prior to the introduction of INIs. Plasma samples from chronically infected drug naïve patients (N = 45), of whom the PR and RT sequence was determined previously, were used to generate population based sequences of HIV-1 integrase. HIV-1 subtype was determined using the REGA HIV-1 subtyping tool. Resistance mutations were interpreted according to the Stanford HIV drug resistance database ( http://hivdb.stanford.edu ) and the updated International Antiviral Society (IAS)-USA mutation lists. Moreover, rates of polymorphisms in the current isolates were compared with South African and global HIV-1C isolates. All subjects were infected with HIV-1C concordant to the protease (PR) and reverse transcriptase (RT) regions. Neither major resistance-associated IN mutations (T66I/A/K, E92Q/G, T97A, Y143HCR, S147G, Q148H/R/K, and N155H) nor silent mutations known to change the genetic barrier were observed. Moreover, the DDE-catalytic motif (D64G/D116G/E152 K) and signature HHCC zinc-binding motifs at codon 12, 16, 40 and 43 were found to be highly conserved. However, compared to other South African subtype C isolates, the rate of polymorphism was variable at various positions. Although the sample size is small, the findings suggest that this drug class could be effective in Ethiopia and other southern African countries where HIV-1C is predominantly circulating. The data will contribute to define the importance of integrase polymorphism and to improve resistance interpretation algorithms in HIV-1C isolates.

  7. Commentary: the value of PrEP for people who inject drugs

    Rosalind L Coleman; Susie McLean

    2016-01-01

    Introduction: The offer of pre-exposure prophylaxis (PrEP) is recommended as an additional option for HIV prevention for people at substantial risk of HIV infection as part of combination HIV prevention approaches. Implementing this depends on integrating PrEP in public health programmes that address risky practices with evidence-based interventions, and that operate in an enabling legal and policy environment for the delivery of health services to those at higher risk of HIV infection. What ...

  8. The association between HIV, antiretroviral therapy, and gestational diabetes mellitus

    Soepnel, Larske M; Norris, Shane A; Schrier, Verena J M M; Browne, Joyce L; Rijken, Marcus J; Gray, Glenda; Klipstein-Grobusch, Kerstin

    2017-01-01

    OBJECTIVES: The widespread, chronic use of antiretroviral therapy raises questions concerning the metabolic consequences of HIV infection and treatment. Antiretroviral therapy, and specifically protease inhibitors, has been associated with hyperglycemia. As pregnant women are vulnerable to

  9. Cytomegalovirus protease targeted prodrug development.

    Sabit, Hairat; Dahan, Arik; Sun, Jing; Provoda, Chester J; Lee, Kyung-Dall; Hilfinger, John H; Amidon, Gordon L

    2013-04-01

    Human cytomegalovirus (HCMV) is a prevalent virus that infects up to 90% of the population. The goal of this research is to determine if small molecular prodrug substrates can be developed for a specific HCMV encoded protease and thus achieve site-specific activation. HCMV encodes a 256 amino acid serine protease that is responsible for capsid assembly, an essential process for herpes virus production. The esterase activity of the more stable HCMV A143T/A144T protease mutant was evaluated with model p-nitrophenol (ONp) esters, Boc-Xaa-ONp (Ala, Leu, Ile, Val, Gln, Phe at the Xaa position). We demonstrate that the A143T/A144T mutant has esterase activity toward specific small ester compounds, e.g., Boc-L-Ala-ONp. Mono amino acid and dipeptide prodrugs of ganciclovir (GCV) were also synthesized and evaluated for hydrolysis by the A143T/A144T protease mutant in solution. Hydrolysis of these prodrugs was also evaluated in Caco-2 cell homogenates, human liver microsomes (HLMs), and rat and human plasma. For the selectivity potential of the prodrugs, the hydrolysis ratio was evaluated as a percentage of prodrug hydrolyzed by the HCMV protease over the percentages of prodrug hydrolyses by Caco-2 cell homogenates, HLMs, and human/rat plasma. A dipeptide prodrug of ganciclovir, Ac-l-Gln-l-Ala-GCV, emerged as a potential selective prodrug candidate. The results of this research demonstrate that targeting prodrugs for activation by a specific protease encoded by the infectious HCMV pathogen may be achievable.

  10. Pre-exposure prophylaxis for HIV-negative persons with partners living with HIV: uptake, use, and effectiveness in an open-label demonstration project in East Africa.

    Heffron, Renee; Ngure, Kenneth; Odoyo, Josephine; Bulya, Nulu; Tindimwebwa, Edna; Hong, Ting; Kidoguchi, Lara; Donnell, Deborah; Mugo, Nelly R; Bukusi, Elizabeth A; Katabira, Elly; Asiimwe, Stephen; Morton, Jennifer; Morrison, Susan; Haugen, Harald; Mujugira, Andrew; Haberer, Jessica E; Ware, Norma C; Wyatt, Monique A; Marzinke, Mark A; Frenkel, Lisa M; Celum, Connie; Baeten, Jared M

    2017-11-06

    Introduction : Pre-exposure prophylaxis (PrEP) can provide high protection against HIV infection and is a recommended intervention for HIV-negative persons with substantial HIV risk, such as individuals with a partner living with HIV.  Demonstration projects of PrEP have been conducted in diverse settings worldwide to illustrate practical examples of how PrEP can be delivered.  Methods : We evaluated delivery of PrEP for HIV-negative partners within heterosexual HIV serodiscordant couples in an open-label demonstration project in East Africa.  The delivery model integrated PrEP into HIV treatment services, prioritizing PrEP for HIV-negative partners within serodiscordant couples prior to and during the first 6 months after the partner living with HIV initiated antiretroviral therapy (ART).  We measured adherence to PrEP through medication event monitoring system (MEMS) bottle caps and quantification of tenofovir in plasma among a random sample of participants. We estimated HIV infections prevented using a counterfactual cohort simulated from the placebo arm of a previous PrEP clinical trial. Results : We enrolled 1,010 HIV serodiscordant couples that were naïve to ART and PrEP.  Ninety-seven percent (97%) of HIV-negative partners initiated PrEP, and when PrEP was dispensed, objective measures suggest high adherence: 71% of HIV-negative participants took ≥80% of expected doses, as recorded via MEMS, and 81% of plasma samples had tenofovir detected.  A total of 4 incident HIV infections were observed (incidence rate=0.24 per 100 person-years), a 95% reduction (95% CI 86-98%, pproject for African HIV-negative individuals whose partners were known to be living with HIV.  Delivery of PrEP to HIV-negative partners within HIV serodiscordant couples was feasible and should be prioritized for wide-scale implementation.

  11. Experimental Models of Inherited PrP Prion Diseases.

    Watts, Joel C; Prusiner, Stanley B

    2017-11-01

    The inherited prion protein (PrP) prion disorders, which include familial Creutzfeldt-Jakob disease, Gerstmann-Sträussler-Scheinker disease, and fatal familial insomnia, constitute ∼10%-15% of all PrP prion disease cases in humans. Attempts to generate animal models of these disorders using transgenic mice expressing mutant PrP have produced variable results. Although many lines of mice develop spontaneous signs of neurological illness with accompanying prion disease-specific neuropathological changes, others do not. Furthermore, demonstrating the presence of protease-resistant PrP species and prion infectivity-two of the hallmarks of the PrP prion disorders-in the brains of spontaneously sick mice has proven particularly challenging. Here, we review the progress that has been made toward developing accurate mouse models of the inherited PrP prion disorders. Copyright © 2017 Cold Spring Harbor Laboratory Press; all rights reserved.

  12. Efficacy and safety of switching from boosted protease inhibitors plus emtricitabine and tenofovir disoproxil fumarate regimens to single-tablet darunavir, cobicistat, emtricitabine, and tenofovir alafenamide at 48 weeks in adults with virologically suppressed HIV-1 (EMERALD): a phase 3, randomised, non-inferiority trial.

    Orkin, Chloe; Molina, Jean-Michel; Negredo, Eugenia; Arribas, José R; Gathe, Joseph; Eron, Joseph J; Van Landuyt, Erika; Lathouwers, Erkki; Hufkens, Veerle; Petrovic, Romana; Vanveggel, Simon; Opsomer, Magda

    2018-01-01

    Simplified regimens with reduced pill burden and fewer side-effects are desirable for people living with HIV. We investigated the efficacy and safety of switching to a single-tablet regimen of darunavir, cobicistat, emtricitabine, and tenofovir alafenamide versus continuing a regimen of boosted protease inhibitor, emtricitabine, and tenofovir disoproxil fumarate. EMERALD was a phase-3, randomised, active-controlled, open-label, international, multicentre trial, done at 106 sites across nine countries in North America and Europe. HIV-1-infected adults were eligible to participate if they were treatment-experienced and virologically suppressed (viral load <50 copies per mL for ≥2 months; one viral load of 50-200 copies per mL was allowed within 12 months before screening), and patients with a history of virological failure on non-darunavir regimens were allowed. Randomisation was by computer-generated interactive web-response system and stratified by boosted protease inhibitor use at baseline. Patients were randomly assigned (2:1) to switch to the open-label study regimen or continue the control regimen. The study regimen consisted of a fixed-dose tablet containing darunavir 800 mg, cobicistat 150 mg, emtricitabine 200 mg, and tenofovir alafenamide 10 mg, which was taken once per day for 48 weeks. The primary outcome was the proportion of participants with virological rebound (confirmed viral load ≥50 copies per mL or premature discontinuations, with last viral load ≥50 copies per mL) cumulative through week 48; we tested non-inferiority (4% margin) of the study regimen versus the control regimen in the intention-to-treat population. This study is registered with ClinicalTrials.gov, number NCT02269917. The study began on April 1, 2015, and the cutoff date for the week 48 primary analysis was Feb 24, 2017. Of 1141 patients (763 in the study group and 378 in the control group), 664 (58%) had previously received five or more antiretrovirals, including screening

  13. A genomic survey of proteases in Aspergilli

    Budak, Sebnem Ozturkoglu; Zhou, M.; Brouwer, Carlo; Wiebenga, A.; Benoit, Isabelle; Di Falco, Marcos; Tsang, Adrian; de Vries, Ronald P; van den Brink, J.

    2014-01-01

    BACKGROUND: Proteases can hydrolyze peptides in aqueous environments. This property has made proteases the most important industrial enzymes by taking up about 60% of the total enzyme market. Microorganisms are the main sources for industrial protease production due to their high yield and a wide

  14. tolerant alkaline protease from Bacillus coagulans PSB

    oyaide

    2013-05-22

    May 22, 2013 ... suggest the suitability of the enzyme for applications in peptide synthesis, detergent formulation and ... The cell free supernatant was recovered as crude enzyme preparation and used for further studies. Assay of protease activity. Protease activity was ... Effect of pH on growth and protease production.

  15. Factor VII-activating protease

    Ramanathan, Ramshanker; Gram, Jørgen B; Sand, Niels Peter R

    2017-01-01

    : Factor VII-activating protease (FSAP) may regulate development of cardiovascular disease (CVD). We evaluated sex differences in FSAP measures and examined the association between FSAP and coronary artery calcification (CAC) in a middle-aged population. Participants were randomly selected citizens...

  16. Carbohydrase and protease supplementation increased ...

    A trial was conducted to evaluate whether the addition of commercial enzyme preparations containing carbohydrases and a protease would increase the available metabolizable energy (ME) of maize-soya-based broiler diets. Seven thousand five hundred and sixty (7560) day-old Ross 788 chicks were randomly allocated ...

  17. Saúde sexual e reprodutiva com enfoque na transmissão do HIV: práticas de puérperas atendidas em maternidades filantrópicas do município de São Paulo Sexual and reproductive health focused on the HIV transmission: the postpartum women' practices in maternities of São Paulo city

    Neide de Souza Praça

    2003-03-01

    Full Text Available OBJETIVOS: caracterizar puérperas internadas em duas maternidades filantrópicas no município de São Paulo, quanto às características sócio-demográficas, comportamento para promoção da saúde sexual e reprodutiva, e informações e práticas relacionadas à AIDS. MÉTODOS: estudo descritivo, exploratório, com 384 puérperas entrevistadas durante a internação. Utilizou-se estatística descritiva. RESULTADOS: 85% da amostra iniciaram o relacionamento sexual na adolescência; 48% eram analfabetas ou possuíam o primeiro grau incompleto; 60% tinham renda familiar inferior a cinco salários mínimos; 71% eram católicas e 78% viviam em união consensual. Quando grávidas, 65% iniciaram consulta pré-natal no primeiro trimestre; 84% submeteram-se ao teste anti-HIV; 70% acreditavam na fidelidade do parceiro, 56% nunca usaram preservativo e 61% não modificaram seu comportamento em função da epidemia de AIDS. CONCLUSÕES: O risco de exposição ao HIV mostrou-se presente pelo reduzido número de mulheres que adotavam medidas de sexo mais seguro, desconhecimento do comportamento do parceiro fora do lar, início precoce do relacionamento sexual, pouca abrangência da cobertura do Papanicolaou, presença de DST e uso de drogas. Fatores culturais influenciam esta situação, bem como atitudes na prevenção e no controle da própria saúde.OBJECTIVES: to classify puerperas admitted in two charity maternities in the municipality of São Paulo according to social and demographic data, sexual and reproductive health behavior, information and practices related to AIDS. METHODS: descriptive, exploratory study with 384 puerperas interviewed during hospital stay. Descriptive statistics was used. RESULTS: 85% of the women initiated sexual intercourse during adolescence; 48% were illiterate or had dropped out of elementary school; 60% were from families with incomes below five minimum wages; 71% were catholic and 78% lived with their partners out of

  18. HIV type-1 genotypic resistance profiles in vertically infected patients from Argentina reveal an association between K103N+L100I and L74V mutations.

    Aulicino, Paula C; Rocco, Carlos A; Mecikovsky, Debora; Bologna, Rosa; Mangano, Andrea; Sen, Luisa

    2010-01-01

    Patterns and pathways of HIV type-1 (HIV-1) antiretroviral (ARV) drug resistance-associated mutations in clinical isolates are conditioned by ARV history and factors such as viral subtype and fitness. Our aim was to analyse the frequency and association of ARV drug resistance mutations in a group of long-term vertically infected patients from Argentina. Plasma samples from 71 patients (38 children and 33 adolescents) were collected for genotypic HIV-1 ARV resistance testing during the period between February 2006 and October 2008. Statistically significant pairwise associations between ARV resistance mutations in pol, as well as associations between mutations and drug exposure, were identified using Fisher's exact tests with Bonferroni and false discovery rate corrections. Phylogenetic analyses were performed for subtype assignment. In protease (PR), resistance-associated mutations M46I/L, I54M/L/V/A/S and V82A/F/T/S/M/I were associated with each other and with minor mutations at codons 10, 24 and 71. Mutations V82A/F/T/S/M/I were primarily selected by the administration of ritonavir (RTV) in an historical ARV regimen. In reverse transcriptase, thymidine analogue mutation (TAM)1 profile was more common than TAM2. The non-nucleoside K103N+L100I mutations were observed at high frequency (15.5%) and were significantly associated with the nucleoside mutation L74V in BF recombinants. Associations of mutations at PR sites reflect the frequent use of RTV at an early time in this group of patients and convergent resistance mechanisms driven by the high exposure to protease inhibitors, as well as local HIV-1 diversity. The results provide clinical evidence of a molecular interaction between K103N+L100I and L74V mutations at the reverse transcriptase gene in vivo, limiting the future use of second-generation non-nucleoside reverse transcriptase inhibitors such as etravirine.

  19. Antibody proteases: induction of catalytic response.

    Gabibov, A G; Friboulet, A; Thomas, D; Demin, A V; Ponomarenko, N A; Vorobiev, I I; Pillet, D; Paon, M; Alexandrova, E S; Telegin, G B; Reshetnyak, A V; Grigorieva, O V; Gnuchev, N V; Malishkin, K A; Genkin, D D

    2002-10-01

    Most of the data accumulated throughout the years on investigation of catalytic antibodies indicate that their production increases on the background of autoimmune abnormalities. The different approaches to induction of catalytic response toward recombinant gp120 HIV-1 surface protein in mice with various autoimmune pathologies are described. The peptidylphosphonate conjugate containing structural part of gp120 molecule is used for reactive immunization of NZB/NZW F1, MRL, and SJL mice. The specific modification of heavy and light chains of mouse autoantibodies with Val-Ala-Glu-Glu-Glu-Val-PO(OPh)2 reactive peptide was demonstrated. Increased proteolytic activity of polyclonal antibodies in SJL mice encouraged us to investigate the production of antigen-specific catalytic antibodies on the background of induced experimental autoimmune encephalomyelitis (EAE). The immunization of autoimmune-prone mice with the engineered fusions containing the fragments of gp120 and encephalitogenic epitope of myelin basic protein (MBP(89-104)) was made. The proteolytic activity of polyclonal antibodies isolated from the sera of autoimmune mice immunized by the described antigen was shown. Specific immune response of SJL mice to these antigens was characterized. Polyclonal antibodies purified from sera of the immunized animals revealed proteolytic activity. The antiidiotypic approach to raise the specific proteolytic antibody as an "internal image" of protease is described. The "second order" monoclonal antibodies toward subtilisin Carlsberg revealed pronounced proteolytic activity.

  20. Effects of FlAsH/Tetracysteine (TC) tag on PrP proteolysis and PrPres formation by TC-scanning

    Taguchi, Yuzuru; Hohsfield, Lindsay A.; Hollister, Jason R.

    2014-01-01

    The FlAsH/tetracysteine (FlAsH/TC) tag is a powerful tool for fluorescent labeling of proteins. However, even small tags such as FlAsH/TC could alter the behavior of the tagged proteins, especially if the insertion occurs at internal sites. Defining the influence of FlAsH/TC on nearby protein-protein interactions might aid in selecting appropriate positions for internal TC insertions and allow the exploitation of serial FlAsH/TC insertions (TC-scanning) as a probe to characterize sites of protein-protein interaction. To explore this application in the context of substrate-protease interactions, we analyzed the effect of FlAsH/TC insertions on proteolysis of cellular prion protein (PrPsen) in in vitro reactions and generation of the C1 metabolic fragment of PrPsen in live neuroblastoma cells. The influence of FlAsH/TC insertion was evaluated by TC-scanning across the cleavage sites of each protease. The results showed that FlAsH/TC inhibited protease cleavage only within limited ranges of the cleavage sites that varied from about 1 to 6 residues-wide depending on the protease, providing an estimate of the PrP residues interacting with each protease. TC-scanning was also used to probe a different type of protein-protein interaction, the conformational conversion of FlAsH-PrPsen to the prion disease-associated isoform, PrPres. PrP constructs with FlAsH/TC insertions at residues 90–96 but not 97–101 were converted to FlAsH-PrPres, identifying a boundary separating loosely versus compactly folded regions of PrPres. Our observations demonstrate that TC-scanning with the FlAsH/TC tag can be a versatile method for probing protein-protein interactions and folding processes. PMID:23943295

  1. Cysteine Protease Zymography: Brief Review.

    Wilkesman, Jeff

    2017-01-01

    Cysteine proteases play multiple roles in basically all aspects of physiology and development. In plants, they are involved in growth and development and in accumulation and mobilization of storage proteins. Furthermore, they are engaged in signalling pathways and in the response to biotic and abiotic stresses. In animals and also in humans, they are responsible for senescence and apoptosis, prohormone processing, and ECM remodelling. When analyzed by zymography, the enzyme must be renaturated after SDS-PAGE. SDS must be washed out and substituted by Triton X-100. Gels are then further incubated under ideal conditions for activity detection. Cysteine proteases require an acidic pH (5.0-6.0) and a reducing agent, usually DTT. When screening biological samples, there is generally no previous clue on what peptidase class will be present, neither optimal proteolysis conditions are known. Hence, it is necessary to assess several parameters, such as incubation time, pH, temperature, influence of ions or reducing agents, and finally evaluate the inhibition profile. For detection of cysteine peptidase activity, the use of specific inhibitors, such as E-64, can be used to prevent the development of cysteine peptidase activity bands and positively confirm its presence. Here four different protocols to assess cysteine protease activity from different sources are presented.

  2. Mutation V111I in HIV-2 reverse transcriptase increases the fitness of the nucleoside analogue-resistant K65R and Q151M viruses

    I. Deuzing (Ilona); C. Charpentier (Charlotte); D.J. Wright (David Justin); S. Matheron (Sophie); J. Paton (Jack); D. Frentz (Dineke); D.A.M.C. van de Vijver (David); P.V. Coveney (Peter); D. Descamps (Diane); C.A.B. Boucher (Charles); N. Beerens (Nancy)

    2015-01-01

    textabstractInfection with HIV-2 can ultimately lead to AIDS, although disease progression is much slower than with HIV-1. HIV-2 patients are mostly treated with a combination of nucleoside reverse transcriptase (RT) inhibitors (NRTIs) and protease inhibitors designed for HIV-1. Many studies have

  3. Identification of a large, fast-expanding HIV-1 subtype B transmission cluster among MSM in Valencia, Spain.

    Juan Ángel Patiño-Galindo

    Full Text Available We describe and characterize an exceptionally large HIV-1 subtype B transmission cluster occurring in the Comunidad Valenciana (CV, Spain. A total of 1806 HIV-1 protease-reverse transcriptase (PR/RT sequences from different patients were obtained in the CV between 2004 and 2014. After subtyping and generating a phylogenetic tree with additional HIV-1 subtype B sequences, a very large transmission cluster which included almost exclusively sequences from the CV was detected (n = 143 patients. This cluster was then validated and characterized with further maximum-likelihood phylogenetic analyses and Bayesian coalescent reconstructions. With these analyses, the CV cluster was delimited to 113 patients, predominately men who have sex with men (MSM. Although it was significantly located in the city of Valencia (n = 105, phylogenetic analyses suggested this cluster derives from a larger HIV lineage affecting other Spanish localities (n = 194. Coalescent analyses estimated its expansion in Valencia to have started between 1998 and 2004. From 2004 to 2009, members of this cluster represented only 1.46% of the HIV-1 subtype B samples studied in Valencia (n = 5/143, whereas from 2010 onwards its prevalence raised to 12.64% (n = 100/791. In conclusion, we have detected a very large transmission cluster in the CV where it has experienced a very fast growth in the recent years in the city of Valencia, thus contributing significantly to the HIV epidemic in this locality. Its transmission efficiency evidences shortcomings in HIV control measures in Spain and particularly in Valencia.

  4. Advances in protease engineering for laundry detergents.

    Vojcic, Ljubica; Pitzler, Christian; Körfer, Georgette; Jakob, Felix; Ronny Martinez; Maurer, Karl-Heinz; Schwaneberg, Ulrich

    2015-12-25

    Proteases are essential ingredients in modern laundry detergents. Over the past 30 years, subtilisin proteases employed in the laundry detergent industry have been engineered by directed evolution and rational design to tailor their properties towards industrial demands. This comprehensive review discusses recent success stories in subtilisin protease engineering. Advances in protease engineering for laundry detergents comprise simultaneous improvement of thermal resistance and activity at low temperatures, a rational strategy to modulate pH profiles, and a general hypothesis for how to increase promiscuous activity towards the production of peroxycarboxylic acids as mild bleaching agents. The three protease engineering campaigns presented provide in-depth analysis of protease properties and have identified principles that can be applied to improve or generate enzyme variants for industrial applications beyond laundry detergents. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Proteolytic crosstalk in multi-protease networks

    Ogle, Curtis T.; Mather, William H.

    2016-04-01

    Processive proteases, such as ClpXP in E. coli, are conserved enzyme assemblies that can recognize and rapidly degrade proteins. These proteases are used for a number of purposes, including degrading mistranslated proteins and controlling cellular stress response. However, proteolytic machinery within the cell is limited in capacity and can lead to a bottleneck in protein degradation, whereby many proteins compete (‘queue’) for proteolytic resources. Previous work has demonstrated that such queueing can lead to pronounced statistical relationships between different protein counts when proteins compete for a single common protease. However, real cells contain many different proteases, e.g. ClpXP, ClpAP, and Lon in E. coli, and it is not clear how competition between proteins for multiple classes of protease would influence the dynamics of cellular networks. In the present work, we theoretically demonstrate that a multi-protease proteolytic bottleneck can substantially couple the dynamics for both simple and complex (oscillatory) networks, even between substrates with substantially different affinities for protease. For these networks, queueing often leads to strong positive correlations between protein counts, and these correlations are strongest near the queueing theoretic point of balance. Furthermore, we find that the qualitative behavior of these networks depends on the relative size of the absolute affinity of substrate to protease compared to the cross affinity of substrate to protease, leading in certain regimes to priority queue statistics.

  6. Ninety-nine is not enough: molecular characterization of inhibitor-resistant human immunodeficiency virus type 1 protease mutants with insertions in the flap region

    Kožíšek, Milan; Grantz Šašková, Klára; Řezáčová, Pavlína; Brynda, Jiří; Maarseveen van, N. M.; De Jongh, D.; Boucher, Ch. A. B.; Kagan, R. M.; Nijhuis, M.; Konvalinka, Jan

    2008-01-01

    Roč. 82, č. 12 (2008), s. 5869-5878 ISSN 0022-538X R&D Projects: GA MŠk 1M0508; GA MZd NR8571 Institutional research plan: CEZ:AV0Z40550506; CEZ:AV0Z50520514 Keywords : HIV protease inhibitors * aspartic proteases * viral resistance * insertions Subject RIV: CE - Biochemistry Impact factor: 5.308, year: 2008

  7. Cell-based fluorescence assay for human immunodeficiency virus type 1 protease activity

    Lindsten, K.; Kondrová, Taťána; Konvalinka, Jan; Masucci, M. G.; Dantuma, N. P.

    2001-01-01

    Roč. 45, č. 9 (2001), s. 2616-2622 ISSN 0066-4804 R&D Projects: GA ČR GA303/98/1559 Grant - others:HHMI(US) 75195-540801; ECTM(XE) ERBFMRXCT960026 Institutional research plan: CEZ:AV0Z4055905 Keywords : HIV-1 * protease activity Subject RIV: CE - Biochemistry Impact factor: 4.562, year: 2001

  8. Evolução das práticas de cuidado dos trabalhadores da saúde às pessoas com HIV/AIDS, em um hospital referência em doenças infectocontagiosas de Santa Catarina

    Villarinho, Mariana Vieira

    2012-01-01

    Tese (doutorado) - Universidade Federal de Santa Catarina, Centro de Ciências da Saúde, Programa de Pós-Graduação em Enfermagem, Florianópolis, 2012 Pesquisa sócio-histórica, com abordagem qualitativa, que tem por objetivo geral compreender a partir das memórias dos trabalhadores da saúde, de um Hospital Referência em doenças infecto contagiosas, suas estratégias de biossegurança, práticas de cuidado, comportamentos diante às pessoas com HIV/aids, no período de 1986 à 2006. Utilizamos como...

  9. The effect of fluconazole on ritonavir and saquinavir pharmacokinetics in HIV-1-infected individuals

    Koks, C. H.; Crommentuyn, K. M.; Hoetelmans, R. M.; Burger, D. M.; Koopmans, P. P.; Mathôt, R. A.; Mulder, J. W.; Meenhorst, P. L.; Beijnen, J. H.

    2001-01-01

    To study the effect of fluconazole on the steady-state pharmacokinetics of the protease inhibitors ritonavir and saquinavir in HIV-1-infected patients. Five subjects treated with saquinavir and three with ritonavir received the protease inhibitor alone (saquinavir 1200 mg three times daily,

  10. Fragment-Based Protein-Protein Interaction Antagonists of a Viral Dimeric Protease.

    Gable, Jonathan E; Lee, Gregory M; Acker, Timothy M; Hulce, Kaitlin R; Gonzalez, Eric R; Schweigler, Patrick; Melkko, Samu; Farady, Christopher J; Craik, Charles S

    2016-04-19

    Fragment-based drug discovery has shown promise as an approach for challenging targets such as protein-protein interfaces. We developed and applied an activity-based fragment screen against dimeric Kaposi's sarcoma-associated herpesvirus protease (KSHV Pr) using an optimized fluorogenic substrate. Dose-response determination was performed as a confirmation screen, and NMR spectroscopy was used to map fragment inhibitor binding to KSHV Pr. Kinetic assays demonstrated that several initial hits also inhibit human cytomegalovirus protease (HCMV Pr). Binding of these hits to HCMV Pr was also confirmed by NMR spectroscopy. Despite the use of a target-agnostic fragment library, more than 80 % of confirmed hits disrupted dimerization and bound to a previously reported pocket at the dimer interface of KSHV Pr, not to the active site. One class of fragments, an aminothiazole scaffold, was further explored using commercially available analogues. These compounds demonstrated greater than 100-fold improvement of inhibition. This study illustrates the power of fragment-based screening for these challenging enzymatic targets and provides an example of the potential druggability of pockets at protein-protein interfaces. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Optimization of alkaline protease production from Pseudomonas ...

    PRECIOUS

    2009-12-15

    Dec 15, 2009 ... protease production was 37°C at pH 9, with 2% inoculum in the medium for 24 h. .... Positive. Catalase test. Positive ... The enzyme activity gradually decreases from ... Effect of temperature on protease production by Pseudomonas fluorescens. 0 .... between RNA polymerase and upstream promotes DNA.

  12. Purification and characterization of protease enzyme from ...

    user

    2013-03-20

    Mar 20, 2013 ... Full Length Research Paper. Purification and ... ting into small peptides and free amino acids, which can ... Isolated strain was cultured in synthetic medium- casein (SMC; ... Protease activity was assayed by sigma's non-specific protease ... following buffers: 0.05 M citrate-phosphate buffer (pH 5 to 6), Tris-.

  13. Kager's fat pad inflammation associated with HIV infection and AIDS: MRI findings

    Godoy-Santos, Alexandre Leme; Fernandes, Tulio Diniz; Camanho, Gilberto Luis [University of Sao Paulo, Department of Orthopedic Surgery, Sao Paulo, SP (Brazil); Bordalo-Rodrigues, Marcelo; Rosemberg, Laercio [University of Sao Paulo, Department of Radiology, Sao Paulo (Brazil); Lei Munhoz Lima, Ana Lucia [University of Sao Paulo, Department of Infectious Disease, Sao Paulo (Brazil); Maffulli, Nicola [Mile End Hospital, Centre for Sports and Exercise Medicine Barts and The London School of Medicine and Dentistry, London (United Kingdom)

    2014-09-15

    To describe magnetic resonance imaging (MRI) features of Kager's fat pad inflammation in HIV-positive patients with lipodystrophy due to protease inhibitor treatment and posterior ankle pain. A case-control, cross-sectional study; group 1 included 14 HIV-positive patients using protease inhibitors, presenting lipodystrophy syndrome and having posterior ankle pain; group 2 (CGHIV-) included 112 HIV-negative patients without lipodystrophy syndrome who were being evaluated for posterior ankle pain; group 3 (CGHIV + 1) included 23 HIV-positive patients not using a protease inhibitor, without lipodystrophy syndrome and with posterior ankle pain; group 4 (CGHIV + 2) comprised 18 HIV-positive patients who were being treated with a protease inhibitor and had lipodystrophy syndrome but did not have posterior ankle pain. Images were evaluated for the presence of edema by two radiologists who were blinded to clinical features. Fisher's exact test was used to evaluate differences among the groups. Interobserver variation was tested using Cohen's kappa (κ) statistic. The presence of edema within Kager's fat pad was strongly associated with symptoms in HIV-positive patients who had lipodystrophy (p ≤ 0.0001). Concordance between observers was excellent (κ > 0.9). MRI findings of Kager's fat pad inflammation related to HIV/AIDS is a source of symptoms in HIV patients with posterior ankle pain using protease inhibitors and having lipodystrophy syndrome. (orig.)

  14. Kager's fat pad inflammation associated with HIV infection and AIDS: MRI findings

    Godoy-Santos, Alexandre Leme; Fernandes, Tulio Diniz; Camanho, Gilberto Luis; Bordalo-Rodrigues, Marcelo; Rosemberg, Laercio; Lei Munhoz Lima, Ana Lucia; Maffulli, Nicola

    2014-01-01

    To describe magnetic resonance imaging (MRI) features of Kager's fat pad inflammation in HIV-positive patients with lipodystrophy due to protease inhibitor treatment and posterior ankle pain. A case-control, cross-sectional study; group 1 included 14 HIV-positive patients using protease inhibitors, presenting lipodystrophy syndrome and having posterior ankle pain; group 2 (CGHIV-) included 112 HIV-negative patients without lipodystrophy syndrome who were being evaluated for posterior ankle pain; group 3 (CGHIV + 1) included 23 HIV-positive patients not using a protease inhibitor, without lipodystrophy syndrome and with posterior ankle pain; group 4 (CGHIV + 2) comprised 18 HIV-positive patients who were being treated with a protease inhibitor and had lipodystrophy syndrome but did not have posterior ankle pain. Images were evaluated for the presence of edema by two radiologists who were blinded to clinical features. Fisher's exact test was used to evaluate differences among the groups. Interobserver variation was tested using Cohen's kappa (κ) statistic. The presence of edema within Kager's fat pad was strongly associated with symptoms in HIV-positive patients who had lipodystrophy (p ≤ 0.0001). Concordance between observers was excellent (κ > 0.9). MRI findings of Kager's fat pad inflammation related to HIV/AIDS is a source of symptoms in HIV patients with posterior ankle pain using protease inhibitors and having lipodystrophy syndrome. (orig.)

  15. HIV pre-exposure prophylaxis trials: socio-economic and ethical ...

    The advent of HIV pre-exposure prophylaxis (PrEP) as a HIV-prevention strategy has received optimistic support among HIV researchers. However, discourse on PrEP trials has tended to be dominated by the disputes arising between some activist groups and researchers about the research methodologies. Instead, this ...

  16. Early Delivery of Misfolded PrP from ER to Lysosomes by Autophagy

    Cortes, Constanza J.; Qin, Kefeng; Norstrom, Eric M.; Green, William N.; Bindokas, Vytautas P.; Mastrianni, James A.

    2013-01-01

    Prion diseases are linked to the accumulation of a misfolded isoform (PrPSc) of prion protein (PrP). Evidence suggests that lysosomes are degradation endpoints and sites of the accumulation of PrPSc. We questioned whether lysosomes participate in the early quality control of newly generated misfolded PrP. We found PrP carrying the disease-associated T182A mutation (Mut-PrP) was delivered to lysosomes in a Golgi-independent manner. Time-lapse live cell imaging revealed early formation and uptake of GFP-tagged Mut-PrP aggregates into LysoTracker labeled vesicles. Compared with Wt-PrP, Mut-PrP expression was associated with an elevation in several markers of the autophagy-lysosomal pathway, and it extensively colocalized with the autophagosome-specific marker, LC3B. In autophagy deficient (ATG5−/−) mouse embryonic fibroblasts, or in normal cells treated with the autophagy-inhibitor 3-MA, Mut-PrP colocalization with lysosomes was reduced to a similar extent. Additionally, 3-MA selectively impaired the degradation of insoluble Mut-PrP, resulting in an increase in protease-resistant PrP, whereas the induction of autophagy by rapamycin reduced it. These findings suggest that autophagy might function as a quality control mechanism to limit the accumulation of misfolded PrP that normally leads to the generation of PrPSc. PMID:24454378

  17. Interaction between HIV Awareness, Knowledge, Safe Sex Practice and HIV Incidence: Evidence from Botswana

    Ranjan Ray; Kompal Sinha

    2011-01-01

    This paper makes methodological and empirical contributions to the study of HIV awareness, knowledge, incidence and safe sex practice in the context of Botswana, one of the most HIV prone countries in the world. While the focus is on Botswana, the paper presents comparable evidence from India to put the Botswana results in perspective. The results point to the strong role played by affluence and education in increasing HIV knowledge, promoting safe sex and reducing HIV incidence. The study pr...

  18. Biomedical Approaches to HIV Prevention in Women.

    Heumann, Christine L

    2018-04-17

    Effective HIV prevention techniques for women are of critical importance, as nearly half of all HIV infections globally are in women. This article reviews the recent literature on biomedical approaches to HIV prevention in women. In trials in which women were adherent to oral pre-exposure prophylaxis (PrEP), PrEP was equally efficacious in men and women. However, in studies of oral PrEP exclusively in women, adherence was low, and it was not efficacious. In trials of topical PrEP, including vaginal tenofovir gel and the monthly dapivirine ring, efficacy was also dependent upon adherence. Treatment as prevention (TasP) is a very effective HIV prevention strategy, though limited in that it is not controlled by the HIV-uninfected partner. Adherence is an important factor in the efficacy of biomedical interventions for HIV prevention in women; continued research is needed to identify the most efficacious and acceptable agents for women. Oral PrEP is currently recommended for the following groups of HIV-negative women: heterosexual women in ongoing sexual relationships with a partner infected with or at substantial risk of HIV infection and women who inject drugs and share injection or drug preparation equipment.

  19. HIV-1 transmitted drug resistance and genetic diversity among patients from Piauí State, Northeast Brazil.

    Moura, Maria Edileuza Soares; da Guarda Reis, Mônica Nogueira; Lima, Yanna Andressa Ramos; Eulálio, Kelsen Dantas; Cardoso, Ludimila Paula Vaz; Stefani, Mariane Martins Araújo

    2015-05-01

    HIV-1 transmitted-drug-resistance and genetic diversity are dynamic and may differ in distinct locations/risk groups. In Brazil, increased AIDS incidence and related mortality have been detected in the Northeast region, differently from the epicenter in the Southeast. This cross-sectional study describes transmitted-dru- resistance and HIV-1 subtypes in protease/PR and reverse transcriptase/RT regions among antiretroviral naïve patients from Piauí State, Northeast Brazil. Among 96 patients recruited 89 (92.7%) had HIV-1 PR/RT regions sequenced: 44 females and 45 males, 22 self-declared as men who have sex with men. Transmitted-drug-resistance was investigated by CPR tool (Stanford HIV-1 Drug Resistance/SDRM). HIV-1 subtypes were assigned by REGA and phylogenetic inference. Overall, transmitted-drug-resistance rate was 11.2% (10/89; CI 95%: 5.8-19.1%); 22.7% among men who have sex with men (5/22; CI 95%: 8.8-43.4%), 10% in heterosexual men (2/20; CI 95%: 1.7-29.3%) and 6.8% in women (3/44; CI 95%: 1.8-17.4%). Singleton mutations to protease-inhibitor/PI, nucleoside-reverse-transcriptase-inhibitor/NRTI or non-nucleoside-reverse-transcriptase-inhibitor/NNRTI predominated (8/10): PI mutations (M46L, V82F, L90M); NRTI mutations (M41L, D67N) and NNRTI mutations (K103N/S). Dual class resistance mutations to NRTI and NNRTI were observed: T215L (NRTI), Y188L (NNRTI) and T215N (NRTI), F227L (NNRTI). Subtype B prevailed (86.6%; 77/89), followed by subtype F1 (1.1%, 1/89) and subtype C (1.1%, 1/89). B/F1 and B/C intersubtype recombinants represented 11.2% (10/89). In Piauí State extensive testing of incidence and transmitted-drug-resistance in all populations with risk behaviors may help control AIDS epidemic locally. © 2015 Wiley Periodicals, Inc.

  20. Management of HIV During Pregnancy

    Chamma JP; Monteleone VF; V dos Reis L; Bonafe SM; Panão M

    2016-01-01

    According to UNAIDS, in 2015, one hundred and fifty thousand children were infected by HIV worldwide, therefore the use of antiretroviral therapy (ARV) during pregnancy is an important development for the reduction of maternal-fetal transmission. The treatment of a pregnant woman is done by combining two different ARV classes. The combination of two nucleoside reverse transcriptase inhibitors (NRTIs) with one non-nucleoside reverse transcriptase inhibitor (NNRTI) or protease inhibitor (PI) is...

  1. Regulation of cuticle-degrading subtilisin proteases from the entomopathogenic fungi, Lecanicillium spp: implications for host specificity.

    Bye, Natasha J; Charnley, A Keith

    2008-01-01

    The ability to produce cuticle-degrading proteases to facilitate host penetration does not distinguish per se entomopathogenic fungi from saprophytes. However, adapted pathogens may produce host-protein specific enzymes in response to cues. This possibility prompted an investigation of the regulation of isoforms of the subtilisin Pr1-like proteases from five aphid-pathogenic isolates of Lecanicillium spp. Significant differences were found in substrate specificity and regulation of Pr1-like proteases between isoforms of the same isolate and between different isolates. For example, the pI 8.6 isoform from KV71 was considerably more active against aphid than locust cuticle and was induced specifically by N-acetylglucosamine (NAG). Isoform pI 9.1 from the same isolate was only produced on insect cuticle while most other isoforms were more prominent on chitin containing substrates but not induced by NAG. The ability to regulate isoforms independently may allow production at critical points in host penetration. Appearance of proteases (not subtilisins) with pI 4.2 and 4.4 only on aphid cuticle was a possible link with host specificity of KV71. The absence of C or N metabolite repression in subtilisins from KV42 is unusual for pathogen proteases and may help to account for differences in virulence strategy between aphid-pathogenic isolates of Lecanicillium longisporum (unpublished data).

  2. Variably Protease-Sensitive Prionopathy: A New Sporadic Disease of the Prion Protein

    Zou, Wen-Quan; Puoti, Gianfranco; Xiao, Xiangzhu; Yuan, Jue; Qing, Liuting; Cali, Ignazio; Shimoji, Miyuki; Langeveld, Jan P. M.; Castellani, Rudy; Notari, Silvio; Crain, Barbara; Schmidt, Robert E.; Geschwind, Michael; DeArmond, Stephen J.; Cairns, Nigel J.; Dickson, Dennis; Honig, Lawrence; Torres, Juan Maria; Mastrianni, James; Capellari, Sabina; Giaccone, Giorgio; Belay, Ermias D.; Schonberger, Lawrence B.; Cohen, Mark; Perry, George; Kong, Qingzhong; Parchi, Piero; Tagliavini, Fabrizio; Gambetti, Pierluigi

    2011-01-01

    Objective The objective of the study is to report 2 new genotypic forms of protease-sensitive prionopathy (PSPr), a novel prion disease described in 2008, in 11 subjects all homozygous for valine at codon 129 of the prion protein (PrP) gene (129VV). The 2 new PSPr forms affect individuals who are either homozygous for methionine (129MM) or heterozygous for methionine/valine (129MV). Methods Fifteen affected subjects with 129MM, 129MV, and 129VV underwent comparative evaluation at the National Prion Disease Pathology Surveillance Center for clinical, histopathologic, immunohistochemical, genotypical, and PrP characteristics. Results Disease duration (between 22 and 45 months) was significantly different in the 129VV and 129MV subjects. Most other phenotypic features along with the PrP electrophoretic profile were similar but distinguishable in the 3 129 genotypes. A major difference laid in the sensitivity to protease digestion of the disease-associated PrP, which was high in 129VV but much lower, or altogether lacking, in 129MV and 129MM. This difference prompted the substitution of the original designation with “variably protease-sensitive prionopathy” (VPSPr). None of the subjects had mutations in the PrP gene coding region. Interpretation Because all 3 129 genotypes are involved, and are associated with distinguishable phenotypes, VPSPr becomes the second sporadic prion protein disease with this feature after Creutzfeldt-Jakob disease, originally reported in 1920. However, the characteristics of the abnormal prion protein suggest that VPSPr is different from typical prion diseases, and perhaps more akin to subtypes of Gerstmann-Sträussler-Scheinker disease. PMID:20695009

  3. Optimization of a multi-gene HIV-1 recombinant subtype CRF02AG DNA vaccine for expression of multiple immunogenic forms

    Ellenberger, Dennis; Li Bin; Smith, James; Yi Hong; Folks, Thomas; Robinson, Harriet; Butera, Salvatore

    2004-01-01

    We developed an AIDS vaccine for Western and West-Central Africa based on a DNA plasmid vector expressing HIV-1 recombinant subtype CRF02 A G gag, pol, and env genes. To optimize the production of noninfectious HIV-like particles (VLPs) and potentially improve the effectiveness of the vaccine, we generated four potential vaccine constructs: the parental (IC2) and three modifications (IC25, IC48, and IC90) containing mutations within the HIV protease. While the parental construct IC2 expressed aggregates of Gag proteins, the IC25 construct resulted in the production of immature VLPs (the core comprises unprocessed Pr 55Gag ). The remaining two constructs (IC48 and IC90) produced mature VLPs (the core comprises processed capsid p24) in addition to immature VLPs and aggregates of Gag proteins. VLPs incorporated significant levels of mature gp120 envelope glycoprotein. Importantly, the mature VLPs were fusion competent and entered coreceptor-specific target cells. The production of multiple antigenic forms, including fusion-competent VLPs, by candidate DNA vaccine constructs may provide immunologic advantages for induction of protective cellular and humoral responses against HIV-1 proteins

  4. An Efficient Microarray-Based Genotyping Platform for the Identification of Drug-Resistance Mutations in Majority and Minority Subpopulations of HIV-1 Quasispecies.

    Martín, Verónica; Perales, Celia; Fernández-Algar, María; Dos Santos, Helena G; Garrido, Patricia; Pernas, María; Parro, Víctor; Moreno, Miguel; García-Pérez, Javier; Alcamí, José; Torán, José Luis; Abia, David; Domingo, Esteban; Briones, Carlos

    2016-01-01

    The response of human immunodeficiency virus type 1 (HIV-1) quasispecies to antiretroviral therapy is influenced by the ensemble of mutants that composes the evolving population. Low-abundance subpopulations within HIV-1 quasispecies may determine the viral response to the administered drug combinations. However, routine sequencing assays available to clinical laboratories do not recognize HIV-1 minority variants representing less than 25% of the population. Although several alternative and more sensitive genotyping techniques have been developed, including next-generation sequencing (NGS) methods, they are usually very time consuming, expensive and require highly trained personnel, thus becoming unrealistic approaches in daily clinical practice. Here we describe the development and testing of a HIV-1 genotyping DNA microarray that detects and quantifies, in majority and minority viral subpopulations, relevant mutations and amino acid insertions in 42 codons of the pol gene associated with drug- and multidrug-resistance to protease (PR) and reverse transcriptase (RT) inhibitors. A customized bioinformatics protocol has been implemented to analyze the microarray hybridization data by including a new normalization procedure and a stepwise filtering algorithm, which resulted in the highly accurate (96.33%) detection of positive/negative signals. This microarray has been tested with 57 subtype B HIV-1 clinical samples extracted from multi-treated patients, showing an overall identification of 95.53% and 89.24% of the queried PR and RT codons, respectively, and enough sensitivity to detect minority subpopulations representing as low as 5-10% of the total quasispecies. The developed genotyping platform represents an efficient diagnostic and prognostic tool useful to personalize antiviral treatments in clinical practice.

  5. Safety of oral tenofovir disoproxil fumarate-based HIV pre-exposure prophylaxis use in lactating HIV-uninfected women.

    Mugwanya, Kenneth K; John-Stewart, Grace; Baeten, Jared

    2017-07-01

    In settings where HIV is prevalent in heterosexual populations, pregnancy and postpartum breastfeeding periods can be associated with substantial HIV acquisition risk. Pre-exposure prophylaxis (PrEP) with daily oral tenofovir disoproxil fumarate (TDF)/emtricitabine is an attractive HIV prevention option for women who are lactating but data are limited on its safety during the lactation period. Areas covered: We provide a concise synthesis and summary of current evidence on the safety of TDF-based PrEP during breastfeeding. We conducted a review, searching Pubmed database and major PrEP conferences for primary studies with TDF-based PrEP exposure during postpartum breastfeeding. Expert opinion: TDF-based oral PrEP is an effective female-controlled HIV prevention option. There is evidence supporting the safety of TDF use for infant outcomes during breastfeeding in antiretroviral treatment regimens for HIV and hepatitis B virus, and more limited, but consistently safe, data from use of TDF as PrEP. The potential for risk is arguably outweighed for at-risk individuals by HIV prevention benefits, including indirect protection to the infant as a result of preventing HIV in the breastfeeding mother. As PrEP delivery is scaled up in heterosexual populations in high HIV prevalence settings and for at-risk persons in other settings, implementation science studies can provide a framework to increase the accrual of safety, acceptability, and use data related to PrEP during lactation.

  6. Assessment of phylogenetic sensitivity for reconstructing HIV-1 epidemiological relationships.

    Beloukas, Apostolos; Magiorkinis, Emmanouil; Magiorkinis, Gkikas; Zavitsanou, Asimina; Karamitros, Timokratis; Hatzakis, Angelos; Paraskevis, Dimitrios

    2012-06-01

    Phylogenetic analysis has been extensively used as a tool for the reconstruction of epidemiological relations for research or for forensic purposes. It was our objective to assess the sensitivity of different phylogenetic methods and various phylogenetic programs to reconstruct epidemiological links among HIV-1 infected patients that is the probability to reveal a true transmission relationship. Multiple datasets (90) were prepared consisting of HIV-1 sequences in protease (PR) and partial reverse transcriptase (RT) sampled from patients with documented epidemiological relationship (target population), and from unrelated individuals (control population) belonging to the same HIV-1 subtype as the target population. Each dataset varied regarding the number, the geographic origin and the transmission risk groups of the sequences among the control population. Phylogenetic trees were inferred by neighbor-joining (NJ), maximum likelihood heuristics (hML) and Bayesian methods. All clusters of sequences belonging to the target population were correctly reconstructed by NJ and Bayesian methods receiving high bootstrap and posterior probability (PP) support, respectively. On the other hand, TreePuzzle failed to reconstruct or provide significant support for several clusters; high puzzling step support was associated with the inclusion of control sequences from the same geographic area as the target population. In contrary, all clusters were correctly reconstructed by hML as implemented in PhyML 3.0 receiving high bootstrap support. We report that under the conditions of our study, hML using PhyML, NJ and Bayesian methods were the most sensitive for the reconstruction of epidemiological links mostly from sexually infected individuals. Copyright © 2012 Elsevier B.V. All rights reserved.

  7. Neutrophil Protease Cleavage of Von Willebrand Factor in Glomeruli – An Anti-thrombotic Mechanism in the Kidney

    Ramesh Tati

    2017-02-01

    Full Text Available Adequate cleavage of von Willebrand factor (VWF prevents formation of thrombi. ADAMTS13 is the main VWF-cleaving protease and its deficiency results in development of thrombotic microangiopathy. Besides ADAMTS13 other proteases may also possess VWF-cleaving activity, but their physiological importance in preventing thrombus formation is unknown. This study investigated if, and which, proteases could cleave VWF in the glomerulus. The content of the glomerular basement membrane (GBM was studied as a reflection of processes occurring in the subendothelial glomerular space. VWF was incubated with human GBMs and VWF cleavage was assessed by multimer structure analysis, immunoblotting and mass spectrometry. VWF was cleaved into the smallest multimers by the GBM, which contained ADAMTS13 as well as neutrophil proteases, elastase, proteinase 3 (PR3, cathepsin-G and matrix-metalloproteinase 9. The most potent components of the GBM capable of VWF cleavage were in the serine protease or metalloprotease category, but not ADAMTS13. Neutralization of neutrophil serine proteases inhibited GBM-mediated VWF-cleaving activity, demonstrating a marked contribution of elastase and/or PR3. VWF-platelet strings formed on the surface of primary glomerular endothelial cells, in a perfusion system, were cleaved by both elastase and the GBM, a process blocked by elastase inhibitor. Ultramorphological studies of the human kidney demonstrated neutrophils releasing elastase into the GBM. Neutrophil proteases may contribute to VWF cleavage within the subendothelium, adjacent to the GBM, and thus regulate thrombus size. This anti-thrombotic mechanism would protect the normal kidney during inflammation and could also explain why most patients with ADAMTS13 deficiency do not develop severe kidney failure.

  8. High-resolution structure of a retroviral protease folded as a monomer

    Gilski, Miroslaw; Kazmierczyk, Maciej; Krzywda, Szymon; Zábranská, Helena; Cooper, Seth; Popović, Zoran; Khatib, Firas; DiMaio, Frank; Thompson, James; Baker, David; Pichová, Iva; Jaskolski, Mariusz

    2011-01-01

    The crystal structure of Mason–Pfizer monkey virus protease folded as a monomer has been solved by molecular replacement using a model generated by players of the online game Foldit. The structure shows at high resolution the details of a retroviral protease folded as a monomer which can guide rational design of protease dimerization inhibitors as retroviral drugs. Mason–Pfizer monkey virus (M-PMV), a D-type retrovirus assembling in the cytoplasm, causes simian acquired immunodeficiency syndrome (SAIDS) in rhesus monkeys. Its pepsin-like aspartic protease (retropepsin) is an integral part of the expressed retroviral polyproteins. As in all retroviral life cycles, release and dimerization of the protease (PR) is strictly required for polyprotein processing and virion maturation. Biophysical and NMR studies have indicated that in the absence of substrates or inhibitors M-PMV PR should fold into a stable monomer, but the crystal structure of this protein could not be solved by molecular replacement despite countless attempts. Ultimately, a solution was obtained in mr-rosetta using a model constructed by players of the online protein-folding game Foldit. The structure indeed shows a monomeric protein, with the N- and C-termini completely disordered. On the other hand, the flap loop, which normally gates access to the active site of homodimeric retropepsins, is clearly traceable in the electron density. The flap has an unusual curled shape and a different orientation from both the open and closed states known from dimeric retropepsins. The overall fold of the protein follows the retropepsin canon, but the C α deviations are large and the active-site ‘DTG’ loop (here NTG) deviates up to 2.7 Å from the standard conformation. This structure of a monomeric retropepsin determined at high resolution (1.6 Å) provides important extra information for the design of dimerization inhibitors that might be developed as drugs for the treatment of retroviral infections

  9. A biotechnology perspective of fungal proteases

    Paula Monteiro de Souza

    2015-06-01

    Full Text Available Proteases hydrolyze the peptide bonds of proteins into peptides and amino acids, being found in all living organisms, and are essential for cell growth and differentiation. Proteolytic enzymes have potential application in a wide number of industrial processes such as food, laundry detergent and pharmaceutical. Proteases from microbial sources have dominated applications in industrial sectors. Fungal proteases are used for hydrolyzing protein and other components of soy beans and wheat in soy sauce production. Proteases can be produced in large quantities in a short time by established methods of fermentation. The parameters such as variation in C/N ratio, presence of some sugars, besides several other physical factors are important in the development of fermentation process. Proteases of fungal origin can be produced cost effectively, have an advantage faster production, the ease with which the enzymes can be modified and mycelium can be easily removed by filtration. The production of proteases has been carried out using submerged fermentation, but conditions in solid state fermentation lead to several potential advantages for the production of fungal enzymes. This review focuses on the production of fungal proteases, their distribution, structural-functional aspects, physical and chemical parameters, and the use of these enzymes in industrial applications.

  10. Natural inhibitors of tumor-associated proteases

    Magdolen, U.; Krol, J.; Sato, S.; Schmitt, M.; Magdolen, V.; Krueger, A.; Mueller, M.M.; Sperl, S.

    2002-01-01

    The turnover and remodelling of extracellular matrix (ECM) is an essential part of many normal biological processes including development, morphogenesis, and wound healing. ECM turnover also occurs in severe pathological situations like artherosclerosis, fibrosis, tumor invasion and metastasis. The major proteases involved in this turnover are serine proteases (especially the urokinase-type plasminogen activator/plasmin system), matrix metalloproteases (a family of about 20 zinc-dependent endopeptidases including collagenases, gelatinases, stromelysins, and membrane-type metalloproteases), and cysteine proteases. In vivo, the activity of these proteases is tightly regulated in the extracellular space by zymogen activation and/or controlled inhibition. In the present review, we give an overview on the structure and biochemical properties of important tumor-associated protease inhibitors such as plasminogen activator inhibitor type 1 and type 2 (PAI-1, PAI-2), tissue inhibitors of metalloproteinases (TIMP-1, -2, -3, and -4), and the cysteine protease inhibitor cystatin C. Interestingly, some of these inhibitors of tumor-associated proteases display multiple functions which rather promote than inhibit tumor progression, when the presence of inhibitors in the tumor tissue is not balanced. (author)

  11. Extracellular proteases of Trichoderma species. A review.

    Kredics, L; Antal, Zsuzsanna; Szekeres, A; Hatvani, L; Manczinger, L; Vágvölgyi, Cs; Nagy, Erzsébet

    2005-01-01

    Cellulolytic, xylanolytic, chitinolytic and beta-1,3-glucanolytic enzyme systems of species belonging to the filamentous fungal genus Trichoderma have been investigated in details and are well characterised. The ability of Trichoderma strains to produce extracellular proteases has also been known for a long time, however, the proteolytic enzyme system is relatively unknown in this genus. Fortunately, in the recent years more and more attention is focused on the research in this field. The role of Trichoderma proteases in the biological control of plant pathogenic fungi and nematodes has been demonstrated, and it is also suspected that they may be important for the competitive saprophytic ability of green mould isolates and may represent potential virulence factors of Trichoderma strains as emerging fungal pathogens of clinical importance. The aim of this review is to summarize the information available about the extracellular proteases of Trichoderma. Numerous studies are available about the extracellular proteolytic enzyme profiles of Trichoderma strains and about the effect of abiotic environmental factors on protease activities. A number of protease enzymes have been purified to homogeneity and some protease encoding genes have been cloned and characterized. These results will be reviewed and the role of Trichoderma proteases in biological control as well as their advantages and disadvantages in biotechnology will be discussed.

  12. Gut proteases target Yersinia invasin in vivo

    Freund Sandra

    2011-04-01

    Full Text Available Abstract Background Yersinia enterocolitica is a common cause of food borne gastrointestinal disease. After oral uptake, yersiniae invade Peyer's patches of the distal ileum. This is accomplished by the binding of the Yersinia invasin to β1 integrins on the apical surface of M cells which overlie follicle associated lymphoid tissue. The gut represents a barrier that severely limits yersiniae from reaching deeper tissues such as Peyer's patches. We wondered if gut protease attack on invasion factors could contribute to the low number of yersiniae invading Peyer's patches. Findings Here we show that invasin is rapidly degraded in vivo by gut proteases in the mouse infection model. In vivo proteolytic degradation is due to proteolysis by several gut proteases such as trypsin, α-chymotrypsin, pancreatic elastase, and pepsin. Protease treated yersiniae are shown to be less invasive in a cell culture model. YadA, another surface adhesin is cleaved by similar concentrations of gut proteases but Myf was not cleaved, showing that not all surface proteins are equally susceptible to degradation by gut proteases. Conclusions We demonstrate that gut proteases target important Yersinia virulence factors such as invasin and YadA in vivo. Since invasin is completely degraded within 2-3 h after reaching the small intestine of mice, it is no longer available to mediate invasion of Peyer's patches.

  13. El VIH/sida en el lugar de trabajo: Recomendaciones prácticas de la OIT HIV/AIDS in the workplace: Practical recommendations from the International Labor Organization

    2002-03-01

    Full Text Available There are now some 36 million people in the world infected with HIV/AIDS. It is estimated that more than 23 million of them are economically active, including 642 000 persons in Latin America and the Caribbean. In the workplace, HIV/ AIDS reduces incomes, imposes added costs on companies, and undermines fundamental labor laws due to the discrimination and rejection that infected individuals suffer. In response, the International Labor Organization (ILO has produced a document entitled An ILO code of practice on HIV/AIDS and the world of work, which is summarized in this piece. The ILO document aims to help those in the workplace to cope with the HIV/AIDS epidemic through a set of guidelines related to: (a preventing infection, (b managing and reducing the impact that HIV/AIDS has on the workplace, (c delivering care and support for infected workers and, in general, to all the people affected by this epidemic, and (d eliminating discrimination against persons who are infected or are suspected of being infected. The ILO Code is intended to help in preparing and adopting specific measures in the workplace, thus promoting dialogue and other forms of cooperation among the government, employers, workers and their representatives, workplace health and safety officers, HIV/AIDS specialists, and other interested parties. The intention is also for the Code recommendations to be implemented and integrated with national laws, policies, and programs; company or business agreements; and workplace policies and action plans. This ILO Code is an important step in the struggle against HIV/AIDS. Aimed at governments, employers, and workers throughout the world, the Code recommendations constitute a useful tool in addressing the problem of HIV/AIDS in the workplace, in a just manner. As a "motor" of society, work cannot remain separated from issues of such great social impact.

  14. Young Transgender Women's Attitudes Toward HIV Pre-exposure Prophylaxis.

    Wood, Sarah M; Lee, Susan; Barg, Frances K; Castillo, Marne; Dowshen, Nadia

    2017-05-01

    Our primary aim was to explore themes regarding attitudes toward HIV pre-exposure prophylaxis (PrEP) among young transgender women (YTW), in order to develop a theoretical model of PrEP uptake in this population disproportionally affected by HIV. Qualitative study nested within a mixed-method study characterizing barriers and facilitators to health services for YTW. Participants completed an in-depth interview exploring awareness of and attitudes toward PrEP. Key themes were identified using a grounded theory approach. Participants (n = 25) had a mean age of 21.2 years (standard deviation 2.2, range 17-24) and were predominately multiracial (36%) and of HIV-negative or unknown status (68%). Most participants (64%) reported prior knowledge of PrEP, and 28% reported current use or intent to use PrEP. Three major content themes that emerged were variability of PrEP awareness, barriers and facilitators to PrEP uptake, and emotional benefits of PrEP. Among participants without prior PrEP knowledge, participants reported frustration that PrEP information has not been widely disseminated to YTW, particularly by health care providers. Attitudes toward PrEP were overwhelmingly positive; however, concerns were raised regarding barriers including cost, stigma, and adherence challenges. Both HIV-positive and negative participants discussed emotional and relationship benefits of PrEP, which were felt to extend beyond HIV prevention alone. A high proportion of YTW in this study had prior knowledge of PrEP, and attitudes toward PrEP were positive among participants. Our findings suggest several domains to be further explored in PrEP implementation research, including methods of facilitating PrEP dissemination and emotional motivation for PrEP uptake. Copyright © 2016 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

  15. Protease and protease inhibitory activity in pregnant and postpartum involuting uterus

    Milwidsky, A.; Beller, U.; Palti, Z.; Mayer, M.

    1982-01-01

    The presence of two distinct proteolytic activities in the rat uterus was confirmed with 14 C-labeled globin used as a sensitive protein substrate and following release of label into the trichloroacetic acid-soluble supernatant fraction. Protease I is a cytoplasmic acid protease while protease II is associated with the pellet fraction, can be extracted by 0.6 M sodium chloride, and is active at pH 7.0. Protease I activity is low during pregnancy and markedly increases at term achieving maximal activity at day 3 post partum with a subsequent decline to preterm activity values. Lactation did not affect the uterine protease I activity. Protease II activity is not significantly different during pregnancy, at term, and post partum. The presence of an inhibitor of protease I was suggested by a decrease in enzyme activity with an increased cytosolic protein concentration. The inhibitor also lessened bovine trypsin activity but had no effect on protease II. Although its inhibitory potency on trypsin fluctuated during the various uterine physiologic stages, these changes appeared to be statistically insignificant. Human uterine samples were also found to contain the two protease activities with similar changes in protease I post partum. It is suggested that, both in the rat and in man, uterine involution post partum is associated with a marked increase in activity of acid cytosolic protease, while a particulate neutral protease and a soluble inhibitor of trypsin, which are also present in uterine cells, do not appear to play a significant role in the dissolution of uterine tissues after parturition

  16. PrEP implementation in the Asia-Pacific region: opportunities, implementation and barriers

    Zablotska, Iryna; Grulich, Andrew E; Phanuphak, Nittaya; Anand, Tarandeep; Janyam, Surang; Poonkasetwattana, Midnight; Baggaley, Rachel; van Griensven, Frits; Lo, Ying-Ru

    2016-01-01

    Introduction HIV epidemics in the Asia-Pacific region are concentrated among men who have sex with men (MSM) and other key populations. Pre-exposure prophylaxis (PrEP) is an effective HIV prevention intervention and could be a potential game changer in the region. We discuss the progress towards PrEP implementation in the Asia-Pacific region, including opportunities and barriers. Discussion Awareness about PrEP in the Asia-Pacific is still low and so are its levels of use. A high proportion of MSM who are aware of PrEP are willing to use it. Key PrEP implementation barriers include poor knowledge about PrEP, limited access to PrEP, weak or non-existent HIV prevention programmes for MSM and other key populations, high cost of PrEP, stigma and discrimination against key populations and restrictive laws in some countries. Only several clinical trials, demonstration projects and a few larger-scale implementation studies have been implemented so far in Thailand and Australia. However, novel approaches to PrEP implementation have emerged: researcher-, facility- and community-led models of care, with PrEP services for fee and for free. The WHO consolidated guidelines on HIV testing, treatment and prevention call for an expanded access to PrEP worldwide and have provided guidance on PrEP implementation in the region. Some countries like Australia have released national PrEP guidelines. There are growing community leadership and consultation processes to initiate PrEP implementation in Asia and the Pacific. Conclusions Countries of the Asia-Pacific region will benefit from adding PrEP to their HIV prevention packages, but for many this is a critical step that requires resourcing. Having an impact on the HIV epidemic requires investment. The next years should see the region transitioning from limited PrEP implementation projects to growing access to PrEP and expansion of HIV prevention programmes. PMID:27760688

  17. Diagnosis, antiretroviral therapy, and emergence of resistance to antiretroviral agents in HIV-2 infection: a review

    Maia Hightower

    Full Text Available Human immunodeficiency virus type 1 (HIV-1 and type 2 (HIV-2 are the causative agents of AIDS. HIV-2 is prevalent at moderate to high rates in West African countries, such as Senegal, Guinea, Gambia, and Cape Verde. Diagnosis of HIV-2 is made with a positive HIV-1/HIV-2 ELISA or simple/rapid assay, followed by one or two confirmatory tests specific for HIV-2. Following CD4+ T cell counts, HIV-2 viral burden and clinical signs and symptoms of immunodeficiency are beneficial in monitoring HIV-2 disease progression. Although non-nucleoside reverse transcriptase inhibitors are ineffective in treating HIV-2, nucleoside reverse transcriptase inhibitors and protease inhibitors can be effective in dual and triple antiretroviral regimens. Their use can decrease HIV-2 viral load, increase CD4+ T cell counts and improve AIDS-related symptoms. HIV-2 resistance to various nucleoside reverse transcriptase inhibitors and protease inhibitors, including zidovudine, lamivudine, ritonavir and indinavir, has been identified in some HIV-2 infected patients on antiretroviral therapy. The knowledge of HIV-2 peculiarities, when compared to HIV-1, is crucial to helping diagnose and guide the clinician in the choice of the initial antiretroviral regimen and for monitoring therapy success.

  18. Aspartic Protease Zymography Case Study: Detection of Fungal Acid Proteases by Zymography.

    Kernaghan, Gavin; Mayerhofer, Michael

    2017-01-01

    This chapter describes a method for the production and characterization of fungal acid proteases. Protease production is induced by growth on BSA media over a pH gradient and protein levels are monitored over time with the Bradford assay. Once protein is depleted, the media is purified and proteases are characterized by gelatin zymography using acrylamide and buffers at near-neutral pH. Maintaining pH levels below those found in traditional zymographic systems avoids the potential loss of activity that may occur in aspartic proteases under alkaline conditions.

  19. Activation of ADAM 12 protease by copper

    Loechel, F; Wewer, Ulla M.

    2001-01-01

    Conversion of latent proteases to the active form occurs by various mechanisms characteristic for different protease families. Here we report that the disintegrin metalloprotease ADAM 12-S is activated by Cu(II). Copper activation is distinct from the cysteine switch component of latency: elimina......Conversion of latent proteases to the active form occurs by various mechanisms characteristic for different protease families. Here we report that the disintegrin metalloprotease ADAM 12-S is activated by Cu(II). Copper activation is distinct from the cysteine switch component of latency......: elimination of the ADAM 12 cysteine switch by a point mutation in the propeptide had no effect on copper activation, whereas mutation of an unpaired cysteine residue in the catalytic domain resulted in a mutant form of ADAM 12-S that was insensitive to copper. This suggests a multi-step activation mechanism...... for ADAM 12 involving both furin cleavage and copper binding....

  20. Optimization of medium composition for thermostable protease ...

    SERVER

    2008-04-17

    Apr 17, 2008 ... Optimization of the fermentation medium for maximization of thermostable neutral protease production by Bacillus sp. ..... Each contour curve represented an infinite number of combinations of two ..... Production in sea-water of.

  1. Partial Purification and Characterization of Extracellular Protease ...

    USER

    Keywords: Protease, lactic acid bacteria, Pediococcus acidilactici, enzyme ... confers organoleptic improvements in fermented foods ... was characterized by studying the effect of substrate ... addition of solid ammonium sulphate up to 80%.

  2. CDC Vital Signs-Daily Pill Can Prevent HIV

    This podcast is based on the November 24, 2015 CDC Vital Signs report. Preexposure prophylaxis, or PrEP, is a daily medicine that can be used to prevent getting HIV. PrEP is for people who don’t have HIV but who are at very high risk for getting it from sex or injection drug use. Unfortunately, many people who can benefit from PrEP aren’t taking it.

  3. Combining biomedical preventions for HIV: Vaccines with pre-exposure prophylaxis, microbicides or other HIV preventions.

    McNicholl, Janet M

    2016-12-01

    Biomedical preventions for HIV, such as vaccines, microbicides or pre-exposure prophylaxis (PrEP) with antiretroviral drugs, can each only partially prevent HIV-1 infection in most human trials. Oral PrEP is now FDA approved for HIV-prevention in high risk groups, but partial adherence reduces efficacy. If combined as biomedical preventions (CBP) an HIV vaccine could provide protection when PrEP adherence is low and PrEP could prevent vaccine breakthroughs. Other types of PrEP or microbicides may also be partially protective. When licensed, first generation HIV vaccines are likely to be partially effective. Individuals at risk for HIV may receive an HIV vaccine combined with other biomedical preventions, in series or in parallel, in clinical trials or as part of standard of care, with the goal of maximally increasing HIV prevention. In human studies, it is challenging to determine which preventions are best combined, how they interact and how effective they are. Animal models can determine CBP efficacy, whether additive or synergistic, the efficacy of different products and combinations, dose, timing and mechanisms. CBP studies in macaques have shown that partially or minimally effective candidate HIV vaccines combined with partially effective oral PrEP, vaginal PrEP or microbicide generally provided greater protection than either prevention alone against SIV or SHIV challenges. Since human CBP trials will be complex, animal models can guide their design, sample size, endpoints, correlates and surrogates of protection. This review focuses on animal studies and human models of CBP and discusses implications for HIV prevention.

  4. Purification and characterization of protease enzyme from ...

    The enzyme was active in pH range 5 to11 and temperature of 30 to 80°C. The optimum pH and the temperature for protease activity were recorded to be pH 8 and 50°C, respectively. The enzyme was stable up to 40°C and pH 9. The protease activity was inhibited by Zn2+, Ni2+ and Sn2+ and increased by Ca2+, Mg2+ ...

  5. PrEP implementation research in Africa: what is new?

    Cowan, Frances M; Delany-Moretlwe, Sinead; Sanders, Eduard J; Mugo, Nelly R; Guedou, Fernand A; Alary, Michel; Behanzin, Luc; Mugurungi, Owen; Bekker, Linda-Gail

    2016-01-01

    Of the two million new HIV infections in adults in 2014, 70% occurred in sub-Saharan Africa. Several African countries have already approved guidelines for pre-exposure prophylaxis (PrEP) for individuals at substantial risk of HIV as part of combination HIV prevention but key questions remain about how to identify and deliver PrEP to those at greatest need. Throughout the continent, individuals in sero-discordant relationships, and members of key populations (sex workers, men who have sex with men (MSM), transgender women and injection drug users) are likely to benefit from the availability of PrEP. In addition, adolescent girls and young women (AGYW) are at substantial risk in some parts of the continent. It has been estimated that at least three million individuals in Africa are likely to be eligible for PrEP according to WHO's criteria. Tens of demonstration projects are planned or underway across the continent among a range of countries, populations and delivery settings. In each of the target populations, there are overarching issues related to (i) creating demand for PrEP, (ii) addressing supply-side issues and (iii) providing appropriate and tailored adherence support. Critical for creating demand for PrEP is the normalization of HIV prevention. Community-level interventions which engage opinion leaders as well as empowerment interventions for those at highest risk will be key. Critical to supply of PrEP is that services are accessible for all, including for stigmatized populations. Establishing accessible integrated services provides the opportunity to address other public health priorities including the unmet need for HIV testing, contraception and sexually transmitted infections treatment. National policies need to include minimum standards for training and quality assurance for PrEP implementation and to address supply chain issues. Adherence support needs to recognize that social and structural factors are likely to have an important influence

  6. Kosmotropic anions promote conversion of recombinant prion protein into a PrPSc-like misfolded form.

    Rodrigo Diaz-Espinoza

    Full Text Available Prions are self-propagating proteins involved in transmissible spongiform encephalopaties in mammals. An aberrant conformation with amyloid-like features of a cell surface protein, termed prion protein (PrP, is thought to be the essential component of the infectious particle, though accessory co-factor molecules such as lipids and nucleotides may be involved. The cellular co-factors and environmental conditions implicated in PrP misfolding are not completely understood. To address this issue, several studies have been done inducing misfolding of recombinant PrP (recPrP into classical amyloid structures using partially denaturing conditions. In this work, we report that misfolding of recPrP into PrP(Sc-like aggregates can be induced by simply incubating the protein in the presence of kosmotropic salts at concentrations that are known to retain or increase the stability of the protein. We used a simple experimental reaction (protein, buffer and salts submitted to agitation/incubation cycles at physiological temperature and pH. The formation of protease resistant-recPrP was time and salt-concentration dependent and required the presence of kosmotropic anions such as F(- or SO(4(-2. The molecular weights of the protease resistant recPrP fragments are reminiscent of those found in degradation assays of bona fide PrP(Sc. The aggregates also exhibited PrP(Sc-like ultrastructural features including rod-shape morphology under electron microscope, high beta-sheet content and thioflavin-T positive signal. The formation of recPrP aggregates with PrP(Sc biochemical features under conditions closer to physiological in the absence of organic co-factor molecules provides a simple setup that may prove helpful to understand the molecular mechanism of PrP misfolding.

  7. Plasminogen stimulates propagation of protease-resistant prion protein in vitro.

    Mays, Charles E; Ryou, Chongsuk

    2010-12-01

    To clarify the role of plasminogen as a cofactor for prion propagation, we conducted functional assays using a cell-free prion protein (PrP) conversion assay termed protein misfolding cyclic amplification (PMCA) and prion-infected cell lines. Here, we report that plasminogen stimulates propagation of the protease-resistant scrapie PrP (PrP(Sc)). Compared to control PMCA conducted without plasminogen, addition of plasminogen in PMCA using wild-type brain material significantly increased PrP conversion, with an EC(50) = ∼56 nM. PrP conversion in PMCA was substantially less efficient with plasminogen-deficient brain material than with wild-type material. The activity stimulating PrP conversion was specific for plasminogen and conserved in its kringle domains. Such activity was abrogated by modification of plasminogen structure and interference of PrP-plasminogen interaction. Kinetic analysis of PrP(Sc) generation demonstrated that the presence of plasminogen in PMCA enhanced the PrP(Sc) production rate to ∼0.97 U/μl/h and reduced turnover time to ∼1 h compared to those (∼0.4 U/μl/h and ∼2.5 h) obtained without supplementation. Furthermore, as observed in PMCA, plasminogen and kringles promoted PrP(Sc) propagation in ScN2a and Elk 21(+) cells. Our results demonstrate that plasminogen functions in stimulating conversion processes and represents the first cellular protein cofactor that enhances the hypothetical mechanism of prion propagation.

  8. Pre-Exposure Prophylaxis (PrEP) Use and Condomless Anal Sex: Evidence of Risk Compensation in a Cohort of Young Men Who Have Sex with Men.

    Newcomb, Michael E; Moran, Kevin; Feinstein, Brian A; Forscher, Emily; Mustanski, Brian

    2018-04-01

    Young men who have sex with men (YMSM) are disproportionately impacted by HIV. Pre-exposure prophylaxis (PrEP) is highly effective at preventing HIV acquisition. It remains unclear if PrEP use increases rates of condomless sex (ie, risk compensation), which may increase risk of infection if PrEP adherence is not optimal. This study aimed to examine whether PrEP use and PrEP adherence were associated with change in sexual risk behaviors in a large longitudinal cohort of YMSM reporting on multiple sexual partnerships over time. Data were obtained from the first 3 visits of an ongoing cohort study of YMSM in Chicago (analytic N = 953; 14.1% HIV-positive at baseline). Participants reported up to 4 sexual partnerships at each visit, including sexual behavior, PrEP use, and PrEP adherence within partnerships. YMSM reported higher rates of receptive condomless anal sex (CAS) in partnerships during which they were on PrEP compared with those when they were not on PrEP. This association was consistent across both HIV-negative and HIV-positive participants reporting on partnerships with both perceived HIV-negative/unknown and HIV-positive partners. The rate of receptive CAS was higher in PrEP nonadherent partnerships compared with non-PrEP partnerships. The rate of receptive CAS was also higher in PrEP nonadherent than adherent partnerships, but this was not statistically significant. These analyses provide compelling data suggesting that YMSM are engaging in risk compensation when on PrEP. If rates of receptive CAS are highest among YMSM who are PrEP nonadherent, PrEP as a prevention strategy could fail to curb HIV incidence among YMSM.

  9. Cuticle-degrading proteases and toxins as virulence markers of Beauveria bassiana (Balsamo) Vuillemin.

    Cito, Annarita; Barzanti, Gian Paolo; Strangi, Agostino; Francardi, Valeria; Zanfini, Assunta; Dreassi, Elena

    2016-09-01

    Beauveria bassiana is one of the most known entomopathogenic fungal species and its entomopathogenic mechanism involves several bioactive metabolites, mainly cuticle-degrading enzymes and toxic molecules, which are predicted to play a key role as virulence factors. In this study six Beauveria bassiana strains (B 13/I03, B 13/I11, B 13/I49, B 13/I57, B 13/I63, and B 13/I64) were assayed against Tenebrio molitor larvae. Enzymatic activity of total proteases and specifically Pr 1 and Pr 2, as well as the production of toxic compounds were investigated in each fungal strain. Toxins were detected both in vitro-in medium filtrates and mycelia-and in vivo-in Tenebrio molitor larvae infected by the fungal strains tested. B 13/I11 and B 13/I63 strains showed the most significant entomopathogenic activity against Tenebrio molitor larvae (cumulative mortality rate 100 and 97%, respectively; average survival time 5.85 and 6.74 days, respectively). A widely variable and fungal strain-dependent enzymatic activity of total proteases, Pr 1 and Pr 2 was found. Beauvericin, beauvericin A and bassianolide resulted the most prevalent toxins detected in the substrates analyzed. It has been found that an increase of beauvericin content in vivo resulted significantly correlated to a decrease of Tenebrio molitor larvae average survival time in entomopathogenic bioassay (inverse correlation). The involvement of beauvericin in B. bassiana entomopathogenic process is confirmed; in vitro analysis of cuticle degrading proteases activity and toxins production in relation to the methods adopted resulted insufficient for a rapid screening to determine the virulence of B. bassiana strains against Tenebrio molitor larvae. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. HIV Prevention After Discontinuing Pre-Exposure Prophylaxis: Conclusions From a Case Study

    Kai J. Jonas

    2018-05-01

    Full Text Available Pre-exposure prophylaxis (PrEP with tenofovir disoproxil fumarate in combination with emtricitabine (FTC is a highly effective form of HIV prevention. Endeavors of health-care providers and activists in many countries over the world are directed at making access to PrEP possible, or increasing PrEP use among men-who-have-sex-with-men (MSM. We argue while this effort is necessary, we also need to consider modes of HIV prevention after a period of PrEP use. PrEP uptake is not a one-way street, meaning that individuals may discontinue PrEP use, either voluntarily and involuntarily. Voluntary discontinued PrEP use in conjunction with decreased or no HIV risk exposure is unproblematic, but involuntary discontinuations with continuous high level of HIV risk exposure calls for tailored post-PrEP use HIV prevention. We present a case study of an MSM individual who discontinued PrEP for medical reasons (renal function and seroconverted soon afterward, to illustrate the need for tailored HIV prevention post-PrEP. Furthermore, we provide additional contexts of PrEP discontinuation leading to populations that are in need for post-PrEP types of HIV prevention. Subsequently, we present suggestions for modes of post-PrEP HIV prevention based on knowledge–communication–choice model. Community organization and health-care providers should consider and prepare their HIV prevention consulting protocols for such types of clients and add post-PrEP HIV prevention measures to their consulting offer.

  11. Carbohydrate protease conjugates: Stabilized proteases for peptide synthesis

    Wartchow, C.A.; Wang, Peng; Bednarski, M.D.; Callstrom, M.R. [Ohio State Univ., Columbus, OH (United States)]|[Lawrence Berkeley Lab., CA (United States)

    1995-12-31

    The synthesis of oligopeptides using stable carbohydrate protease conjugates (CPCs) was examined in acetonitrile solvent systems. CPC[{alpha}-chymotrypsin] was used for the preparation of peptides containing histidine, phenylalanine, tryptophan in the P{sub 1} position in 60-93% yield. The CPC[{alpha}-chymotrypsin]-catalyzed synthesis of octamer Z-Gly-Gly-Phe-Gly-Gly-Phe-Gly-Gly-OEt from Z-Gly-Gly-Phe-Gly-Gly-Phe-OMe was achieved in 71% yield demonstrating that synthesis peptides containing both hydrophylic and hydrophobic amino acids. The P{sub 2} specificity of papain for aromatic residues was utilized for the 2 + 3 coupling of Z-Tyr-Gly-OMe to H{sub 2}N-Gly-Phe-Leu-OH to generate the leucine enkephalin derivative in 79% yield. Although papain is nonspecific for the hydrolysis of N-benzyloxycarbonyl amino acid methyl esters in aqueous solution, the rates of synthesis for these derivitives with nucleophile leucine tert-butyl ester differed by nearly 2 orders of magnitude. CPC[thermolysin] was used to prepare the aspartame precursor Z-Asp-Phe-OMe in 90% yield. The increased stability of CPCs prepared from periodate-modified poly(2-methacryl- amido-2-deoxy-D-glucose), poly(2-methacrylamido-2-deoxy-D-galactose), and poly(5-methacryl-amido-5-deoxy-D-ribose), carbohydrate materials designed to increase the aldehyde concentration in aqueous solution, suggests that the stability of CPCs is directly related to the aldehyde concentration of the carbohydrate material. Periodate oxidation of poly(2-methacrylamido-2-deoxy-D-glucose) followed by covalent attachment to {alpha}-chymotrypsin gave a CPC with catalytic activity in potassium phosphate buffer at 90{degrees}C for 2 h. 1 fig., 1 tab., 40 refs.

  12. Preliminary evidence of HIV seroconversion among HIV-negative men who have sex with men taking non-prescribed antiretroviral medication for HIV prevention in Miami, Florida, USA.

    Buttram, Mance E; Kurtz, Steven P

    2017-04-01

    Background Limited information suggests that men who have sex with men (MSM) are informally obtaining antiretroviral medication (ARVs) and using them for HIV pre-exposure prophylaxis (PrEP). Data are drawn from an on-going study examining the use of non-prescribed ARVs for PrEP. To date, 24 qualitative interviews have been conducted with HIV-negative, substance-using MSM living in Miami, Florida, USA. Data are presented from two participants who reported HIV seroconversion while using non-prescribed ARVs for PrEP. Preliminary data indicate that some young MSM: (i) lack awareness of and accurate information about the efficacious use of PrEP; (ii) obtain non-prescribed ARVs from HIV-positive sex partners and use these medications for PrEP in a way that does not provide adequate protection against HIV infection or cohere with established guidelines; and (iii) engage in multiple HIV transmission risk behaviours, including condomless anal sex and injection drug use. The informal, non-prescribed and non-medically supervised use of ARVs for HIV prevention has the potential to undermine the protective benefits of PrEP and leave men unprotected against HIV transmission and at risk for ARV resistance.

  13. Escherichia coli contains a soluble ATP-dependent protease (Ti) distinct from protease La

    Hwang, B.J.; Park, W.J.; Chung, C.H.; Goldberg, A.L.

    1987-08-01

    The energy requirement for protein breakdown in Escherichia coli has generally been attributed to the ATP-dependence of protease La, the lon gene product. The authors have partially purified another ATP-dependent protease from lon/sup -/ cells that lack protease La (as shown by immunoblotting). This enzyme hydrolyzes (/sup 3/H)methyl-casein to acid-soluble products in the presence of ATP and Mg/sup 2 +/. ATP hydrolysis appears necessary for proteolytic activity. Since this enzyme is inhibited by diisopropyl fluorophosphate, it appears to be a serine protease, but it also contains essential thiol residues. They propose to name this enzyme protease Ti. It differs from protease La in nucleotide specificity, inhibitor sensitivity, and subunit composition. On gel filtration, protease Ti has an apparent molecular weight of 370,000. It can be fractionated by phosphocellulose chromatography or by DEAE chromatography into two components with apparent molecular weights of 260,000 and 140,000. When separated, they do not show preteolytic activity. One of these components, by itself, has ATPase activity and is labile in the absence of ATP. The other contains the diisopropyl fluorophosphate-sensitive proteolytic site. These results and the similar findings of Katayama-Fujimura et al. indicate that E. coli contains two ATP-hydrolyzing proteases, which differ in many biochemical features and probably in their physiological roles.

  14. Escherichia coli contains a soluble ATP-dependent protease (Ti) distinct from protease La

    Hwang, B.J.; Park, W.J.; Chung, C.H.; Goldberg, A.L.

    1987-01-01

    The energy requirement for protein breakdown in Escherichia coli has generally been attributed to the ATP-dependence of protease La, the lon gene product. The authors have partially purified another ATP-dependent protease from lon - cells that lack protease La (as shown by immunoblotting). This enzyme hydrolyzes [ 3 H]methyl-casein to acid-soluble products in the presence of ATP and Mg 2+ . ATP hydrolysis appears necessary for proteolytic activity. Since this enzyme is inhibited by diisopropyl fluorophosphate, it appears to be a serine protease, but it also contains essential thiol residues. They propose to name this enzyme protease Ti. It differs from protease La in nucleotide specificity, inhibitor sensitivity, and subunit composition. On gel filtration, protease Ti has an apparent molecular weight of 370,000. It can be fractionated by phosphocellulose chromatography or by DEAE chromatography into two components with apparent molecular weights of 260,000 and 140,000. When separated, they do not show preteolytic activity. One of these components, by itself, has ATPase activity and is labile in the absence of ATP. The other contains the diisopropyl fluorophosphate-sensitive proteolytic site. These results and the similar findings of Katayama-Fujimura et al. indicate that E. coli contains two ATP-hydrolyzing proteases, which differ in many biochemical features and probably in their physiological roles

  15. Three monoclonal antibodies against the serpin protease nexin-1 prevent protease translocation

    Kousted, Tina Mostrup; Skjoedt, K; Petersen, S V

    2013-01-01

    abolish the protease inhibitory activity of PN-1. In the presence of the antibodies, PN-1 does not form a complex with its target proteases, but is recovered in a reactive centre cleaved form. Using site-directed mutagenesis, we mapped the three overlapping epitopes to an area spanning the gap between...

  16. Pre-exposure prophylaxis of HIV

    Naswa, Smriti; Marfatia, Y. S.

    2011-01-01

    Pre-exposure prophylaxis (PrEP) is an experimental approach to HIV prevention and consists of antiretroviral drugs to be taken before potential HIV exposure in order to reduce the risk of HIV infection and continued during periods of risk. An effective PrEP could provide an additional safety net to sexually active persons at risk, when combined with other prevention strategies. Women represent nearly 60% of adults infected with HIV and PrEP can be a female-controlled prevention method for women who are unable to negotiate condom use. Two antiretroviral nucleoside analog HIV-1 reverse transcriptase inhibitor drugs are currently under trial as PrEP drugs, namely tenofovirdisoproxilfumarate (TDF) alone and TDF in combination with emricitabine (FTC), to be taken as daily single dose oral drugs. There are 11 ongoing trials of ARV-based prevention in different at risk populations across the world. The iPrex trial showed that daily use of oral TDF/FTC by MSM resulted in 44% reduction in the incidence of HIV. This led to publication of interim guidance by CDC to use of PrEP by health providers for MSM. Few other trials are Bangkok Tenofovir Study, Partners PrEP Study, FEM-PrEP study, and VOICE (MTN-003) study. Future trials are being formulated for intermittent PrEP (iPrEP) where drugs are taken before and after sex, “stand-in dose” iPrEP, vaginal or rectal PrEP, etc. There are various issues/concerns with PrEP such as ADRs and resistance to TDF/FTC, adherence to drugs, acceptability, sexual disinhibition, use of PrEP as first line of defense for HIV without other prevention strategies, and cost. The PrEP has a potential to address unmet need in public health if delivered as a part of comprehensive toolkit of prevention services, including risk-reduction, correct and consistent use of condoms, and diagnosis and treatment of sexually transmitted infections. PMID:21799568

  17. Purification and characterisation of a protease (tamarillin) from tamarillo fruit

    Li, Zhao

    2018-02-16

    A protease from tamarillo fruit (Cyphomandra betacea Cav.) was purified by ammonium sulphate precipitation and diethylaminoethyl-Sepharose chromatography. Protease activity was determined on selected peak fractions using a casein substrate. Sodium dodecyl sulphate polyacrylamide gel electrophoresis analysis showed that the peak with the highest protease activity consisted of one protein of molecular mass ca. 70 kDa. The protease showed optimal activity at pH 11 and 60°C. It was sensitive to phenylmethylsulphonyl fluoride while ethylenediaminetetraacetic acid and p-chloromercuribenzoic acid had little effect on its activity, indicating that this enzyme was a serine protease. Hg2+ strongly inhibited enzyme activity, possibly due to formation of mercaptide bonds with the thiol groups of the protease, suggesting that some cysteine residues may be located close to the active site. De novo sequencing strongly indicated that the protease was a subtilisin-like alkaline serine protease. The protease from tamarillo has been named \\'tamarillin\\'.

  18. Purification and characterisation of a protease (tamarillin) from tamarillo fruit

    Li, Zhao; Scott, Ken; Hemar, Yacine; Zhang, Huoming; Otter, Don

    2018-01-01

    A protease from tamarillo fruit (Cyphomandra betacea Cav.) was purified by ammonium sulphate precipitation and diethylaminoethyl-Sepharose chromatography. Protease activity was determined on selected peak fractions using a casein substrate. Sodium dodecyl sulphate polyacrylamide gel electrophoresis analysis showed that the peak with the highest protease activity consisted of one protein of molecular mass ca. 70 kDa. The protease showed optimal activity at pH 11 and 60°C. It was sensitive to phenylmethylsulphonyl fluoride while ethylenediaminetetraacetic acid and p-chloromercuribenzoic acid had little effect on its activity, indicating that this enzyme was a serine protease. Hg2+ strongly inhibited enzyme activity, possibly due to formation of mercaptide bonds with the thiol groups of the protease, suggesting that some cysteine residues may be located close to the active site. De novo sequencing strongly indicated that the protease was a subtilisin-like alkaline serine protease. The protease from tamarillo has been named 'tamarillin'.

  19. Impaired glucose metabolism in HIV-infected pregnant women: a retrospective analysis.

    Moore, Rebecca

    2015-05-20

    Metabolic complications including diabetes mellitus have been increasingly recognised in HIV-infected individuals since the introduction of antiretroviral therapy, particularly protease inhibitors (PIs). Pregnancy is also a risk factor for impaired glucose metabolism, and previous studies have given conflicting results regarding the contribution of PIs to impaired glucose tolerance (IGT) and gestational diabetes mellitus (GDM) in pregnant HIV-infected women.

  20. CD4 T cells remain the major source of HIV-1 during end stage disease.

    M.E. van der Ende (Marchina); M. Schutten (Martin); B. Raschdorff; G. Grosschupff; P. Racz; A.D.M.E. Osterhaus (Albert); K. Tenner-Racz

    1999-01-01

    textabstractOBJECTIVE: To assess the source of HIV-1 production in lymphoid tissue biopsies from HIV-infected patients, with no prior anti-retroviral protease inhibitor treatment, with a CD4 cell count > 150 x 10(6)/l (group I) or < 50 x 10(6)/l (group II), co-infected with Mycobacterium

  1. Changes in indinavir exposure over time : a case study in six HIV-1-infected children

    Fraaij, PLA; Bergshoeff, AS; van Rossum, AMC; Hartwig, NG; Burger, DM; de Groot, R

    2003-01-01

    Objective: To study changes in indinavir exposure over time in HIV-1-infected children. Materials and methods: Protease inhibitor (PI)-naive HIV-1-infected children were treated with indinavir, zidovudine and lamivudine. Steady-state plasma pharmacokinetic (PK) sampling was carried out as standard

  2. Sexual risk behaviors and acceptability of HIV pre-exposure prophylaxis among HIV-negative gay and bisexual men in serodiscordant relationships: a mixed methods study.

    Brooks, Ronald A; Landovitz, Raphael J; Kaplan, Rachel L; Lieber, Eli; Lee, Sung-Jae; Barkley, Thomas W

    2012-02-01

    The objective of this mixed methods study was to examine current sexual risk behaviors, acceptability and potential adoption of pre-exposure prophylaxis (PrEP) for HIV prevention, and sexual behavior intentions with PrEP adoption among HIV-negative gay and bisexual men (GBM) in HIV serodiscordant relationships. A multiracial/ethnic sample of 25 HIV-negative GBM in serodiscordant relationships completed a qualitative interview and a brief interviewer-administered survey. A modified grounded theory approach was used to identify key themes relating to acceptability and future adoption of PrEP. Participants reported engaging in sexual risk behaviors that place them at risk for HIV infection. Participants also reported a high level of acceptability for PrEP and willingness to adopt PrEP for HIV prevention. Qualitative themes explaining future PrEP adoption included: (1) the opportunity to engage in sex using a noncondom HIV prevention method, (2) protection from HIV infection, and (3) less anxiety when engaging in sex with an HIV-positive partner. Associated with the future adoption of PrEP, a majority (64%) of participants indicated the likelihood for an increase in sexual risk behaviors and a majority (60%) of participants also indicated the likelihood for a decrease or abandonment of condom use, both of which are in contrast to the findings from the large iPrEx study. These findings suggest that the use of PrEP by HIV-negative GBM in serodiscordant relationships carries with it the potential for risk compensation. The findings suggest that PrEP only be offered as part of a comprehensive HIV prevention strategy that includes ongoing risk reduction counseling in the delivery of PrEP to help moderate risk compensation.

  3. Human Immunodeficiency Virus Type 1 Protease and the Emergence of Drug Resistance

    Poulsen, Nina Rødtness

    in multi-drug-resistant PRs. Computational analysis of a vast number of inhibitor-resistant HIV-1 PR variants can broaden the knowledge of how and why the mutations arise, which would be a great advantage in the design on resistance-evading inhibitors. Here we present a diverse system to select...... in the virus life cycle has made it a major target for drug development and active site competitive inhibitors have been successful in the battle against HIV. Unfortunately, the massive drug pressure along with high-level replication and lack of proofreading by the viral reverse transcriptase have resulted...... for catalytically active HIV-1 PR in the presence of inhibitor. The system is based on the protein AraC, which regulates transcription of the araA, araB and araD genes necessary for arabinose catabolism in Escherichia coli, and its effectiveness was demonstrated by the isolation of both known and unknown inhibitor-resistant...

  4. Effectiveness of Ritonavir-Boosted Protease Inhibitor Monotherapy in Clinical Practice Even with Previous Virological Failures to Protease Inhibitor-Based Regimens.

    Luis F López-Cortés

    Full Text Available Significant controversy still exists about ritonavir-boosted protease inhibitor monotherapy (mtPI/rtv as a simplification strategy that is used up to now to treat patients that have not experienced previous virological failure (VF while on protease inhibitor (PI -based regimens. We have evaluated the effectiveness of two mtPI/rtv regimens in an actual clinical practice setting, including patients that had experienced previous VF with PI-based regimens.This retrospective study analyzed 1060 HIV-infected patients with undetectable viremia that were switched to lopinavir/ritonavir or darunavir/ritonavir monotherapy. In cases in which the patient had previously experienced VF while on a PI-based regimen, the lack of major HIV protease resistance mutations to lopinavir or darunavir, respectively, was mandatory. The primary endpoint of this study was the percentage of participants with virological suppression after 96 weeks according to intention-to-treat analysis (non-complete/missing = failure.A total of 1060 patients were analyzed, including 205 with previous VF while on PI-based regimens, 90 of whom were on complex therapies due to extensive resistance. The rates of treatment effectiveness (intention-to-treat analysis and virological efficacy (on-treatment analysis at week 96 were 79.3% (CI95, 76.8-81.8 and 91.5% (CI95, 89.6-93.4, respectively. No relationships were found between VF and earlier VF while on PI-based regimens, the presence of major or minor protease resistance mutations, the previous time on viral suppression, CD4+ T-cell nadir, and HCV-coinfection. Genotypic resistance tests were available in 49 out of the 74 patients with VFs and only four patients presented new major protease resistance mutations.Switching to mtPI/rtv achieves sustained virological control in most patients, even in those with previous VF on PI-based regimens as long as no major resistance mutations are present for the administered drug.

  5. Daily Pill Can Prevent HIV PSA (:60)

    This 60 second public service announcement (PSA) is based on the November 24, 2015 CDC Vital Signs report. Preexposure prophylaxis, or PrEP, is a daily medicine that can be used to prevent getting HIV. PrEP is for people who don’t have HIV but who are at very high risk for getting it from sex or injection drug use. Unfortunately, many people who can benefit from PrEP aren’t taking it.

  6. Explaining the Efficacy of Pre-exposure Prophylaxis (PrEP) for HIV Prevention: A Qualitative Study of Message Framing and Messaging Preferences Among US Men Who have Sex with Men.

    Underhill, Kristen; Morrow, Kathleen M; Colleran, Christopher; Calabrese, Sarah K; Operario, Don; Salovey, Peter; Mayer, Kenneth H

    2016-07-01

    We investigated message comprehension and message framing preferences for communicating about PrEP efficacy with US MSM. We conducted eight focus groups (n = 38) and n = 56 individual interviews with MSM in Providence, RI. Facilitators probed comprehension, credibility, and acceptability of efficacy messages, including percentages, non-numerical paraphrases, efficacy ranges versus point estimates, and success- versus failure-framed messages. Our findings indicated a range of comprehension and operational understandings of efficacy messages. Participants tended to prefer percentage-based and success-framed messages, although preferences varied for communicating about efficacy using a single percentage versus a range. Participants reported uncertainty about how to interpret numerical estimates, and many questioned whether trial results would predict personal effectiveness. These results suggest that providers and researchers implementing PrEP may face challenges in communicating with users about efficacy. Efforts to educate MSM about PrEP should incorporate percentage-based information, and message framing decisions may influence message credibility and overall PrEP acceptability.

  7. RC1339/APRc from Rickettsia conorii is a novel aspartic protease with properties of retropepsin-like enzymes.

    Rui Cruz

    2014-08-01

    Full Text Available Members of the species Rickettsia are obligate intracellular, gram-negative, arthropod-borne pathogens of humans and other mammals. The life-threatening character of diseases caused by many Rickettsia species and the lack of reliable protective vaccine against rickettsioses strengthens the importance of identifying new protein factors for the potential development of innovative therapeutic tools. Herein, we report the identification and characterization of a novel membrane-embedded retropepsin-like homologue, highly conserved in 55 Rickettsia genomes. Using R. conorii gene homologue RC1339 as our working model, we demonstrate that, despite the low overall sequence similarity to retropepsins, the gene product of rc1339 APRc (for Aspartic Protease from Rickettsia conorii is an active enzyme with features highly reminiscent of this family of aspartic proteases, such as autolytic activity impaired by mutation of the catalytic aspartate, accumulation in the dimeric form, optimal activity at pH 6, and inhibition by specific HIV-1 protease inhibitors. Moreover, specificity preferences determined by a high-throughput profiling approach confirmed common preferences between this novel rickettsial enzyme and other aspartic proteases, both retropepsins and pepsin-like. This is the first report on a retropepsin-like protease in gram-negative intracellular bacteria such as Rickettsia, contributing to the analysis of the evolutionary relationships between the two types of aspartic proteases. Additionally, we have also shown that APRc is transcribed and translated in R. conorii and R. rickettsii and is integrated into the outer membrane of both species. Finally, we demonstrated that APRc is sufficient to catalyze the in vitro processing of two conserved high molecular weight autotransporter adhesin/invasion proteins, Sca5/OmpB and Sca0/OmpA, thereby suggesting the participation of this enzyme in a relevant proteolytic pathway in rickettsial life-cycle. As a

  8. HIV Testing

    ... Abroad Treatment Basic Statistics Get Tested Find an HIV testing site near you. Enter ZIP code or city Follow HIV/AIDS CDC HIV CDC HIV/AIDS See RSS | ... All Collapse All Should I get tested for HIV? CDC recommends that everyone between the ages of ...

  9. Respiratory Failure Associated with the Lipodystrophy Syndrome in an HIV-Positive Patient with Compromised Lung Function

    Natasha Press

    2001-01-01

    Full Text Available Protease inhibitors, used as treatment in human immunodeficiency virus (HIV infection, are associated with a syndrome of peripheral lipodystrophy, central adiposity, hyperlipidemia and insulin resistance. An HIV-positive patient with chronic obstructive pulmonary disease is presented who developed the lipodystrophy syndrome that is associated with the use of protease inhibitors. It is postulated that the lipodystrophy syndrome further compromised his lung function, leading to respiratory failure. Patients who have pulmonary disease and are taking protease inhibitors require monitoring of clinical status and pulmonary function tests.

  10. Nurturing the Continuum of HIV Testing, Treatment and Prevention Matrix Cascade in Reducing HIV Transmission.

    Yah, Clarence S

    2017-11-01

    Despite the shift in antiretroviral therapy (ARVs) eligibility cascade from CD4 ≤ 200 to CD4 ≤ 350 to CD4 ≤ 500 mm 3 , HIV related morbidity and mortality continue to escalate annually, as do HIV infections. The new paradigm of treatment for all HIV positives individual irrespective of CD4 count may significantly reduce HIV and related illnesses. The author assumes that all HIV infected partners should be eligible for HIV treatment and care, irrespective of CD4 count. A second assumption is that high risk HIV negative partners have free access to continuum of HIV pre-exposure prophylaxis (PrEP), post exposure prophylaxis (PEP) and other prevention packages. A literature review search was used to extract evidence-based ARVs-HIV treatment and prevention interventions among HIV positives and high risk partners respectively. Only articles published in English and indexed in journal nuclei were used for the study. The information was used to nurture understanding of HIV treatment and prevention approaches as well as HIV incidence multiplier effect among HIV serodiscordant partners. The imputed HIV incident reference was assumed at 1.2 per 100 person-years (2). This was based on the imputation that retention in care, adherence and other predetermined factors are functions of an effective health care delivery system. The model showed a reduced HIV transmission from 1.2 per 100 person-years to 1.032 per 100 person-years in 6 months. The average threshold period of HIV suppressed partners on ARVs to an undetectable level. The combined multiplier protective-effect probability of transmitting HIV from HIV positive partners on ARVs-suppressed viremic load to HIV negative partners on PrEP/PEP-prevention was detected at 86. The model showed a significant reduction in HIV incidence. Placing serodiscordant sexual partners in HIV treatment and prevention plays a significant role in reducing and controlling HIV infection. Therefore, the policy of enrolling all HIV positives

  11. Serine protease inhibitors of parasitic helminths.

    Molehin, Adebayo J; Gobert, Geoffrey N; McManus, Donald P

    2012-05-01

    Serine protease inhibitors (serpins) are a superfamily of structurally conserved proteins that inhibit serine proteases and play key physiological roles in numerous biological systems such as blood coagulation, complement activation and inflammation. A number of serpins have now been identified in parasitic helminths with putative involvement in immune regulation and in parasite survival through interference with the host immune response. This review describes the serpins and smapins (small serine protease inhibitors) that have been identified in Ascaris spp., Brugia malayi, Ancylostoma caninum Onchocerca volvulus, Haemonchus contortus, Trichinella spiralis, Trichostrongylus vitrinus, Anisakis simplex, Trichuris suis, Schistosoma spp., Clonorchis sinensis, Paragonimus westermani and Echinococcus spp. and discusses their possible biological functions, including roles in host-parasite interplay and their evolutionary relationships.

  12. Tunable protease-activatable virus nanonodes.

    Judd, Justin; Ho, Michelle L; Tiwari, Abhinav; Gomez, Eric J; Dempsey, Christopher; Van Vliet, Kim; Igoshin, Oleg A; Silberg, Jonathan J; Agbandje-McKenna, Mavis; Suh, Junghae

    2014-05-27

    We explored the unique signal integration properties of the self-assembling 60-mer protein capsid of adeno-associated virus (AAV), a clinically proven human gene therapy vector, by engineering proteolytic regulation of virus-receptor interactions such that processing of the capsid by proteases is required for infection. We find the transfer function of our engineered protease-activatable viruses (PAVs), relating the degree of proteolysis (input) to PAV activity (output), is highly nonlinear, likely due to increased polyvalency. By exploiting this dynamic polyvalency, in combination with the self-assembly properties of the virus capsid, we show that mosaic PAVs can be constructed that operate under a digital AND gate regime, where two different protease inputs are required for virus activation. These results show viruses can be engineered as signal-integrating nanoscale nodes whose functional properties are regulated by multiple proteolytic signals with easily tunable and predictable response surfaces, a promising development toward advanced control of gene delivery.

  13. The Acceptability of Pre-Exposure Prophylaxis: Beliefs of Health-Care Professionals Working in Sexually Transmitted Infections Clinics and HIV Treatment Centers.

    Bil, Janneke P; Hoornenborg, Elske; Prins, Maria; Hogewoning, Arjan; Dias Goncalves Lima, Fernando; de Vries, Henry J C; Davidovich, Udi

    2018-01-01

    Pre-exposure prophylaxis (PrEP) is highly effective for preventing HIV infections, but is not yet implemented in the Netherlands. As the attitudes of health-care professionals toward PrEP can influence future PrEP implementation, we studied PrEP knowledge and beliefs and their association with PrEP

  14. The Acceptability of Pre-Exposure Prophylaxis: Beliefs of Health-Care Professionals Working in Sexually Transmitted Infections Clinics and HIV Treatment Centers

    Bil, Janneke P.; Hoornenborg, Elske; Prins, Maria; Hogewoning, Arjan; Dias Goncalves Lima, Fernando; de Vries, Henry J. C.; Davidovich, Udi

    2018-01-01

    Pre-exposure prophylaxis (PrEP) is highly effective for preventing HIV infections, but is not yet implemented in the Netherlands. As the attitudes of health-care professionals toward PrEP can influence future PrEP implementation, we studied PrEP knowledge and beliefs and their association with PrEP

  15. Lessons learned from the experiences of informal PrEP users in France: results from the ANRS-PrEPage study.

    Rivierez, I; Quatremere, G; Spire, B; Ghosn, J; Rojas Castro, D

    2018-05-30

    Before January 2016, Pre-Exposure Prophylaxis (PrEP), a new biomedical HIV-prevention tool, was only available in France via ANRS-Ipergay clinical study but informal use was reported outside this setting. PrEPage qualitative study reports profiles and experiences of participants who used PrEP outside of a biomedical trial before this prevention method was authorized. Between March 2015 and February 2016, a cross-section of twenty-four informal PrEP users, mostly MSM, was recruited to complete in-depth semi-structured interviews. While ANRS-Ipergay was still ongoing (2012-2016), participants described their initiation to PrEP, the way they used it and the difficulties they faced to acquire antiretroviral drugs in an environment where PrEP was still not widely known and often criticized . Through the testimonies, different user profiles and motivation toward informal PrEP use emerged: (a) participants who have increasing difficulties using condoms, (b) "opportunists" who tried PrEP without the intention of using it regularly and (c) participants with a risk aversion who sought additional protection against HIV. Participants chose to use PrEP and/or their usual prevention strategies depending on available supplies, type of partners and individual attitudes toward risk. The feeling of living a safer sex life helped participants to outweigh the fear of possible toxicity and drug resistance. Participants' needs and expectations about PrEP implementation in France were also presented.

  16. PrEP in Europe - expectations, opportunities and barriers.

    McCormack, Sheena Mary; Noseda, Veronica; Molina, Jean-Michel

    2016-01-01

    In contrast to the global trend showing a decline in new HIV infections, the number reported in the World Health Organization (WHO) region of Europe is increasing. Health systems are disparate, but even countries with free access to screening and treatment observe continuing high rates of new infections in key populations, notably men who have sex with men (MSM). Pre-exposure prophylaxis (PrEP) is only available in France. This commentary describes the European epidemics and healthcare settings where PrEP could be delivered, how need might be estimated for MSM and the residual barriers to access. Health systems and government commitment to HIV prevention and care, both financial and political, differ considerably between the countries that make up Europe. A common feature is that funds for prevention are a small fraction of funds for care. Although care is generally good, access is limited in the middle-income countries of Eastern Europe and central Asia, and only 19% of people living with HIV received antiretroviral therapy in 2014. It is challenging to motivate governments or civil society to implement PrEP in the context of this unmet treatment need, which is driven by limited national health budgets and diminishing assistance from foreign aid. The high-income countries of Western Europe have hesitated to embrace PrEP for different reasons, initially due to key gaps in the evidence. Now that PrEP has been shown to be highly effective in European MSM in two randomized controlled trials, it is clear that the major barrier is the cost of the drug which is still on patent, although inadequate health systems and diminishing investment in civil society are also key challenges to overcome. The momentum to implement PrEP in European countries is increasing and provides a welcome opportunity to expand and improve clinical services and civil society support focused on HIV and related infections including other sexually transmitted and blood-borne infections.

  17. Demographic differences in PrEP–related stereotypes: Implications for implementation

    Golub, Sarit. A.; Gamarel, Kristi E.; Surace, Anthony

    2015-01-01

    Qualitative interviews about pre-exposure prophylaxis (PrEP) stereotypes were conducted with a subsample of 160 MSM who participated in a PrEP messaging study. Negative stereotypes about PrEP users were identified by 80% of participants. Two types of stereotypes were most common: PrEP users are HIV-infected (and lying about it), and PrEP users are promiscuous and resistant to condom use. Participants’ identification of these stereotype categories differed significantly by demographic factors (i.e. race/ethnicity, education). Expanding access to PrEP requires recognizing potential differences in the experience or anticipation of PrEP-related stereotypes that might impact willingness to discuss PrEP with providers, friends, or partners. PMID:26143247

  18. Production of alkaline proteases by alkalophilic Bacillus subtilis ...

    Tuoyo Aghomotsegin

    2016-11-23

    Nov 23, 2016 ... Key words: Production, alkaline protease, Bacillus subtilis, animal wastes, enzyme activity. ... Generally, alkaline proteases are produced using submerged fermentation .... biopolymer concentrations were reported to have an influence ... adding nitrogenous compounds stimulate microorganism growth and ...

  19. Optimization of alkaline protease production and its fibrinolytic ...

    Optimization of alkaline protease production and its fibrinolytic activity from the ... nitrogen sources and sodium chloride concentration for protease production by the ... exploited to assist in protein degradation in various industrial processes.

  20. Purification and characterization of protease from Bacillus cereus ...

    Among them, SU12 isolate was selected due to its high enzyme production ... growth and protease production which includes different carbon and nitrogen sources, ... organism for the industrial production of the extracellular protease enzyme.

  1. Mosaic serine proteases in the mammalian central nervous system.

    Mitsui, Shinichi; Watanabe, Yoshihisa; Yamaguchi, Tatsuyuki; Yamaguchi, Nozomi

    2008-01-01

    We review the structure and function of three kinds of mosaic serine proteases expressed in the mammalian central nervous system (CNS). Mosaic serine proteases have several domains in the proenzyme fragment, which modulate proteolytic function, and a protease domain at the C-terminus. Spinesin/TMPRSS5 is a transmembrane serine protease whose presynaptic distribution on motor neurons in the spinal cord suggests that it is significant for neuronal plasticity. Cell type-specific alternative splicing gives this protease diverse functions by modulating its intracellular localization. Motopsin/PRSS12 is a mosaic protease, and loss of its function causes mental retardation. Recent reports indicate the significance of this protease for cognitive function. We mention the fibrinolytic protease, tissue plasminogen activator (tPA), which has physiological and pathological functions in the CNS.

  2. Cysteine proteases as potential antigens in antiparasitic DNA vaccines

    Jørgensen, Louise von Gersdorff; Buchmann, Kurt

    2011-01-01

    En litteraturgennemgang af muligheder for at bruge cystein proteaser som antigener i antiparasitære vacciner.......En litteraturgennemgang af muligheder for at bruge cystein proteaser som antigener i antiparasitære vacciner....

  3. CDC Vital Signs-Daily Pill Can Prevent HIV

    2015-11-24

    This podcast is based on the November 24, 2015 CDC Vital Signs report. Preexposure prophylaxis, or PrEP, is a daily medicine that can be used to prevent getting HIV. PrEP is for people who don’t have HIV but who are at very high risk for getting it from sex or injection drug use. Unfortunately, many people who can benefit from PrEP aren’t taking it.  Created: 11/24/2015 by National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention (NCHHSTP).   Date Released: 11/24/2015.

  4. Pengaruh PH dan Suhu terhadap Aktivitas Protease Penicillium SP.

    Yusriah, Yusriah; Kuswytasari, Nengah Dwianita

    2013-01-01

    Tujuan penelitian ini adalah untuk mengetahui pengaruh pH dan suhu terhadap aktivitas protease pada Penicillium sp.3 T3f2. Selanjutnya, isolat Penicillium sp. di kultur dalam media produksi protease untuk menghasilkan protease. Suhu yang digunakan adalah 300 – 500C sedangkan pH-nya 4 – 8. Aktivitas protease ditentukan dan diukur dengan spektrofotometer pada panjang gelombang 275 nm, dengan kasein sebagai substrat. Berdasarkan uji ANOVA yang dilanjutkan dengan uji Duncan dengan taraf kepercaya...

  5. Stakeholder Engagement in HIV Cure Research: Lessons Learned from Other HIV Interventions and the Way Forward.

    Lo, Ying-Ru; Chu, Carissa; Ananworanich, Jintanat; Excler, Jean-Louis; Tucker, Joseph D

    2015-07-01

    Clinical and basic science advances have raised considerable hope for achieving an HIV cure by accelerating research. This research is dominated primarily by issues about the nature and design of current and future clinical trials. Stakeholder engagement for HIV cure remains in its early stages. Our analysis examines timing and mechanisms of historical stakeholder engagement in other HIV research areas for HIV-uninfected individuals [vaccine development and pre-exposure prophylaxis (PrEP)], and HIV-infected individuals (treatment as prevention, prevention of mother-to-child transmission, and treatment of acute HIV infection) and articulate a plan for HIV cure stakeholder engagement. The experience from HIV vaccine development shows that early engagement of stakeholders helped manage expectations, mitigating the failure of several vaccine trials, while paving the way for subsequent trials. The relatively late engagement of HIV stakeholders in PrEP research may partly explain some of the implementation challenges. The treatment-related stakeholder engagement was strong and community-led from the onset and helped translation from research to implementation. We outline five steps to initiate and sustain stakeholder engagement in HIV cure research and conclude that stakeholder engagement represents a key investment in which stakeholders mutually agree to share knowledge, benefits, and risk of failure. Effective stakeholder engagement prevents misconceptions. As HIV cure research advances from early trials involving subjects with generally favorable prognosis to studies involving greater risk and uncertainty, success may depend on early and deliberate engagement of stakeholders.

  6. HIV Prevention: Opportunities and Challenges.

    Marrazzo, Jeanne M

    Preexposure prophylaxis (PrEP) with tenofovir disoproxil fumarate (TDF)-based regimens has been shown to be effective in preventing acquisition of HIV infection, with protective efficacy being dependent on adherence to treatment. Data from the PROUD (Preexposure Option for Reducing HIV in the UK) and IPERGAY (Action to Prevent Risk Exposure By and For Gay Men) studies, the later of which employed event-driven PrEP, showed a high rate of protective efficacy of PrEP with TDF and emtricitabine among men who have sex with men. Data from the ASPIRE (A Study to Prevent Infection With a Ring for Extended Use) study of a dapivirine vaginal ring showed a moderate rate of protective efficacy among women older than 21 years. Ongoing investigations are examining long-acting PrEP modalities and combination PrEP and contraception products. This article summarizes a presentation by Jeanne M. Marrazzo, MD, MPH, at the IAS-USA continuing education program, Improving the Management of HIV Disease, held in Washington, DC, in April 2016.

  7. High throughput in vivo protease inhibitor selection platform

    2017-01-01

    The invention relates to a recombinant microbial cell comprising a selection platform for screening for a protease inhibitor, wherein the platform comprises transgenes encoding a protease having selective peptide bond cleavage activity at a recognition site amino acid sequence; and transgenes...... platform for screening for a protease inhibitor....

  8. PrEP adopted by the brazilian national health system: What is the size of the demand?

    Luz, Paula M; Benzaken, Adele; Alencar, Tatianna M de; Pimenta, Cristina; Veloso, Valdilea G; Grinsztejn, Beatriz

    2018-05-01

    Brazil's response to the HIV epidemic now includes free access to preexposure prophylaxis (PrEP) to populations at substantial risk for HIV infection including men who have sex with men (MSM). We used nationally representative demographic, epidemiologic, and surveillance data to offer estimates for the number of MSM at substantial risk for HIV infection who might be eligible and willing to use PrEP in Brazil. Starting from the age/sex-stratified population, we calculated the number of men aged 15 to 64 years, in 5-year age groups, and the proportion of those who report sex with other men during their lifetime. We focused on 11 cities (representing all regions) that are responsible for a significant fraction of the HIV burden of the country and used city-specific HIV prevalence estimates to infer the fraction of MSM who are HIV-negative. We then derived the proportion of HIV-negative MSM under substantial risk for HIV infection defined as having unprotected receptive anal intercourse in the 6 months before study participation. Finally, PrEP uptake among the eligible was inferred from the PrEP Brazil study. Our results show that PrEP demand in these 11 cities is of 66,120 men aged 15 to 64 years. When we consider the lower and upper bounds for the available parameters, we find that PrEP demand in these 11 cities might vary from 33,378 to 97,962 men. If PrEP is restricted to those aged 15 to 49 years, demand drops by 20%. PrEP demand varies considerably by city, mostly because of the differences in population size and city-specific HIV prevalence. We have shed light on the probable size of PrEP demand in Brazil certain that the incorporation of PrEP as part of Brazil's combination prevention for populations at substantial risk for HIV infection is a necessary challenge. PrEP will not only prevent HIV infections, it will also expand testing among the most vulnerable with the added benefit of offering combination prevention for the uninfected and immediate treatment for

  9. Dataset of cocoa aspartic protease cleavage sites

    Katharina Janek

    2016-09-01

    Full Text Available The data provide information in support of the research article, “The cleavage specificity of the aspartic protease of cocoa beans involved in the generation of the cocoa-specific aroma precursors” (Janek et al., 2016 [1]. Three different protein substrates were partially digested with the aspartic protease isolated from cocoa beans and commercial pepsin, respectively. The obtained peptide fragments were analyzed by matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/TOF-MS/MS and identified using the MASCOT server. The N- and C-terminal ends of the peptide fragments were used to identify the corresponding in-vitro cleavage sites by comparison with the amino acid sequences of the substrate proteins. The same procedure was applied to identify the cleavage sites used by the cocoa aspartic protease during cocoa fermentation starting from the published amino acid sequences of oligopeptides isolated from fermented cocoa beans. Keywords: Aspartic protease, Cleavage sites, Cocoa, In-vitro proteolysis, Mass spectrometry, Peptides

  10. Lipase and protease extraction from activated sludge

    Gessesse, Amare; Dueholm, Thomas; Petersen, Steffen B.

    2003-01-01

    of gentle and efficient enzyme extraction methods from environmental samples is very important. In this study we present a method for the extraction of lipases and proteases from activated sludge using the non-ionic detergent Triton X-100, EDTA, and cation exchange resin (CER), alone or in combination...

  11. Bacterial proteases: targets for diagnostics and therapy

    Kaman, W.E.; Hays, J.P.; Endtz, H.P.; Bikker, F.J.

    2014-01-01

    Proteases are essential for the proliferation and growth of bacteria, and are also known to contribute to bacterial virulence. This makes them interesting candidates as diagnostic and therapeutic targets for infectious diseases. In this review, the authors discuss the most recent developments and

  12. Novel peptide-based protease inhibitors

    Roodbeen, Renée

    of novel peptide-based protease inhibitors, efforts were made towards improved methods for peptide synthesis. The coupling of Fmoc-amino acids onto N-methylated peptidyl resins was investigated. These couplings can be low yielding and the effect of the use of microwave heating combined with the coupling...

  13. Lipodystrophy syndrome among HIV infected children on highly ...

    Background: It is estimated that about 2.5 million people are living with HIV infection in India. Although antiretroviral drugs have been able to reduce the mortality, these drugs have serious side effects one of which is lipodystrophy syndrome. Most of the drugs used in HAART viz, protease inhibitors, stavudine and nevirapine ...

  14. New subtypes and genetic recombination in HIV type 1-infecting patients with highly active antiretroviral therapy in Peru (2008-2010).

    Yabar, Carlos Augusto; Acuña, Maribel; Gazzo, Cecilia; Salinas, Gabriela; Cárdenas, Fanny; Valverde, Ada; Romero, Soledad

    2012-12-01

    HIV-1 subtype B is the most frequent strain in Peru. However, there is no available data about the genetic diversity of HIV-infected patients receiving highly active antiretroviral therapy (HAART) here. A group of 267 patients in the Peruvian National Treatment Program with virologic failure were tested for genotypic evidence of HIV drug resistance at the Instituto Nacional de Salud (INS) of Peru between March 2008 and December 2010. Viral RNA was extracted from plasma and the segments of the protease (PR) and reverse transcriptase (RT) genes were amplified by reverse transcriptase polymerase chain reaction (RT-PCR), purified, and fully sequenced. Consensus sequences were submitted to the HIVdb Genotypic Resistance Interpretation Algorithm Database from Stanford University, and then aligned using Clustal X v.2.0 to generate a phylogenetic tree using the maximum likelihood method. Intrasubtype and intersubtype recombination analyses were performed using the SCUEAL program (Subtype Classification by Evolutionary ALgo-rithms). A total of 245 samples (91%) were successfully genotyped. The analysis obtained from the HIVdb program showed 81.5% resistance cases (n=198). The phylogenetic analysis revealed that subtype B was predominant in the population (98.8%), except for new cases of A, C, and H subtypes (n=4). Of these cases, only subtype C was imported. Likewise, recombination analysis revealed nine intersubtype and 20 intrasubtype recombinant cases. This is the first report of the presence of HIV-1 subtypes C and H in Peru. The introduction of new subtypes and circulating recombinants forms can make it difficult to distinguish resistance profiles in patients and consequently affect future treatment strategies against HIV in this country.

  15. A novel protease activity assay using a protease-responsive chaperone protein

    Sao, Kentaro; Murata, Masaharu; Fujisaki, Yuri; Umezaki, Kaori; Mori, Takeshi; Niidome, Takuro; Katayama, Yoshiki; Hashizume, Makoto

    2009-01-01

    Protease activity assays are important for elucidating protease function and for developing new therapeutic agents. In this study, a novel turbidimetric method for determining the protease activity using a protease-responsive chaperone protein is described. For this purpose, a recombinant small heat-shock protein (sHSP) with an introduced Factor Xa protease recognition site was synthesized in bacteria. This recombinant mutant, FXa-HSP, exhibited chaperone-like activity at high temperatures in cell lysates. However, the chaperone-like activity of FXa-HSP decreased dramatically following treatment with Factor Xa. Protein precipitation was subsequently observed in the cell lysates. The reaction was Factor Xa concentration-dependent and was quantitatively suppressed by a specific inhibitor for Factor Xa. Protein aggregation was detected by a simple method based on turbidimetry. The results clearly demonstrate that this assay is an effective, easy-to-use method for determining protease activities without the requirement of labeling procedures and the use of radioisotopes.

  16. A novel protease activity assay using a protease-responsive chaperone protein

    Sao, Kentaro [Graduate School of Systems Life Sciences, Kyushu University, 744 Motooka Nishi-ku, Fukuoka 819-0395 (Japan); Murata, Masaharu, E-mail: m-murata@dem.med.kyushu-u.ac.jp [Department of Advanced Medical Initiatives, Faculty of Medical Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku Fukuoka 812-8582 (Japan); Fujisaki, Yuri; Umezaki, Kaori [Department of Advanced Medical Initiatives, Faculty of Medical Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku Fukuoka 812-8582 (Japan); Mori, Takeshi; Niidome, Takuro; Katayama, Yoshiki [Graduate School of Systems Life Sciences, Kyushu University, 744 Motooka Nishi-ku, Fukuoka 819-0395 (Japan); Department of Applied Chemistry, Faculty of Engineering, Kyushu University, Nishi-ku Fukuoka 819-0395 (Japan); Center for Future Chemistry, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395 (Japan); Hashizume, Makoto [Department of Advanced Medical Initiatives, Faculty of Medical Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku Fukuoka 812-8582 (Japan)

    2009-06-05

    Protease activity assays are important for elucidating protease function and for developing new therapeutic agents. In this study, a novel turbidimetric method for determining the protease activity using a protease-responsive chaperone protein is described. For this purpose, a recombinant small heat-shock protein (sHSP) with an introduced Factor Xa protease recognition site was synthesized in bacteria. This recombinant mutant, FXa-HSP, exhibited chaperone-like activity at high temperatures in cell lysates. However, the chaperone-like activity of FXa-HSP decreased dramatically following treatment with Factor Xa. Protein precipitation was subsequently observed in the cell lysates. The reaction was Factor Xa concentration-dependent and was quantitatively suppressed by a specific inhibitor for Factor Xa. Protein aggregation was detected by a simple method based on turbidimetry. The results clearly demonstrate that this assay is an effective, easy-to-use method for determining protease activities without the requirement of labeling procedures and the use of radioisotopes.

  17. Proteases and protease inhibitors of urinary extracellular vesicles in diabetic nephropathy.

    Musante, Luca; Tataruch, Dorota; Gu, Dongfeng; Liu, Xinyu; Forsblom, Carol; Groop, Per-Henrik; Holthofer, Harry

    2015-01-01

    Diabetic nephropathy (DN) is one of the major complications of diabetes mellitus (DM), leads to chronic kidney disease (CKD), and, ultimately, is the main cause for end-stage kidney disease (ESKD). Beyond urinary albumin, no reliable biomarkers are available for accurate early diagnostics. Urinary extracellular vesicles (UEVs) have recently emerged as an interesting source of diagnostic and prognostic disease biomarkers. Here we used a protease and respective protease inhibitor array to profile urines of type 1 diabetes patients at different stages of kidney involvement. Urine samples were divided into groups based on the level of albuminuria and UEVs isolated by hydrostatic dialysis and screened for relative changes of 34 different proteases and 32 protease inhibitors, respectively. Interestingly, myeloblastin and its natural inhibitor elafin showed an increase in the normo- and microalbuminuric groups. Similarly, a characteristic pattern was observed in the array of protease inhibitors, with a marked increase of cystatin B, natural inhibitor of cathepsins L, H, and B as well as of neutrophil gelatinase-associated Lipocalin (NGAL) in the normoalbuminuric group. This study shows for the first time the distinctive alterations in comprehensive protease profiles of UEVs in diabetic nephropathy and uncovers intriguing mechanistic, prognostic, and diagnostic features of kidney damage in diabetes.

  18. Proteases and Protease Inhibitors of Urinary Extracellular Vesicles in Diabetic Nephropathy

    Luca Musante

    2015-01-01

    Full Text Available Diabetic nephropathy (DN is one of the major complications of diabetes mellitus (DM, leads to chronic kidney disease (CKD, and, ultimately, is the main cause for end-stage kidney disease (ESKD. Beyond urinary albumin, no reliable biomarkers are available for accurate early diagnostics. Urinary extracellular vesicles (UEVs have recently emerged as an interesting source of diagnostic and prognostic disease biomarkers. Here we used a protease and respective protease inhibitor array to profile urines of type 1 diabetes patients at different stages of kidney involvement. Urine samples were divided into groups based on the level of albuminuria and UEVs isolated by hydrostatic dialysis and screened for relative changes of 34 different proteases and 32 protease inhibitors, respectively. Interestingly, myeloblastin and its natural inhibitor elafin showed an increase in the normo- and microalbuminuric groups. Similarly, a characteristic pattern was observed in the array of protease inhibitors, with a marked increase of cystatin B, natural inhibitor of cathepsins L, H, and B as well as of neutrophil gelatinase-associated Lipocalin (NGAL in the normoalbuminuric group. This study shows for the first time the distinctive alterations in comprehensive protease profiles of UEVs in diabetic nephropathy and uncovers intriguing mechanistic, prognostic, and diagnostic features of kidney damage in diabetes.

  19. Counseling Framework for HIV-Serodiscordant Couples on the Integrated Use of Antiretroviral Therapy and Pre-exposure Prophylaxis for HIV Prevention.

    Morton, Jennifer F; Celum, Connie; Njoroge, John; Nakyanzi, Agnes; Wakhungu, Imeldah; Tindimwebwa, Edna; Ongachi, Snaidah; Sedah, Eric; Okwero, Emmanuel; Ngure, Kenneth; Odoyo, Josephine; Bulya, Nulu; Haberer, Jessica E; Baeten, Jared M; Heffron, Renee

    2017-01-01

    For HIV-serodiscordant couples, integrated delivery of antiretroviral therapy (ART) for HIV-positive partners and time-limited pre-exposure prophylaxis (PrEP) for negative partners virtually eliminates HIV transmission. Standardized messaging, sensitive to the barriers and motivators to HIV treatment and prevention, is needed for widespread scale-up of this approach. Within the Partners Demonstration Project, a prospective interventional project among 1013 serodiscordant couples in Kenya and Uganda, we offered ART to eligible HIV-positive partners and PrEP to HIV-negative partners before ART initiation and through the HIV-positive partner's first 6 months of ART use. We conducted individual and group discussions with counseling staff to elicit the health communication framework and key messages about ART and PrEP that were delivered to couples. Counseling sessions for serodiscordant couples about PrEP and ART included discussions of HIV serodiscordance, PrEP and ART initiation and integrated use, and PrEP discontinuation. ART messages emphasized daily, lifelong use for treatment and prevention, adherence, viral suppression, resistance, side effects, and safety of ART during pregnancy. PrEP messages emphasized daily dosing, time-limited PrEP use until the HIV-positive partner sustained 6 months of high adherence to ART, adherence, safety during conception, side effects, and other risks for HIV. Counseling messages for HIV-serodiscordant couples are integral to the delivery of time-limited PrEP as a "bridge" to ART-driven viral suppression. Their incorporation into programmatic scale-up will maximize intervention impact on the global epidemic.

  20. Detection of PrP(Sc) in peripheral tissues of clinically affected cattle after oral challenge with bovine spongiform encephalopathy

    Bovine spongiform encephalopathy (BSE) is a fatal neurodegenerative prion disease that affects cattle and can be transmitted to human beings as new variant Creutzfeldt-Jakob disease (vCJD). A protease-resistant, disease-associated isoform of the prion protein (PrP**Sc) accumulates in the central ner...

  1. Evaluating the impact of prioritization of antiretroviral pre-exposure prophylaxis (PrEP) in New York City

    Kessler, Jason; Myers, Julie E.; Nucifora, Kimberly A.; Mensah, Nana; Toohey, Christopher; Khademi, Amin; Cutler, Blayne; Braithwaite, R. Scott

    2015-01-01

    Objective To compare the value and effectiveness of different prioritization strategies of pre-exposure prophylaxis (PrEP) in New York City (NYC). Design Mathematical modeling utilized as clinical trial is not feasible. Methods Using a model accounting for both sexual and parenteral transmission of HIV we compare different prioritization strategies (PPS) for PrEP to two scenarios—no PrEP and PrEP for all susceptible at-risk individuals. The PPS included PrEP for all MSM, only high-risk MSM, high-risk heterosexuals, and injection drug users, and all combinations of these four strategies. Outcomes included HIV infections averted, and incremental cost effectiveness (per-infection averted) ratios. Initial assumptions regarding PrEP included a 44% reduction in HIV transmission, 50% uptake in the prioritized population and an annual cost per person of $9,762. Sensitivity analyses on key parameters were conducted. Results Prioritization to all MSM results in a 19% reduction in new HIV infections. Compared to PrEP for all persons at-risk this PPS retains 79% of the preventative effect at 15% of the total cost. PrEP prioritized to only high-risk MSM results in a reduction in new HIV infections of 15%. This PPS retains 60% of the preventative effect at 6% of the total cost. There are diminishing returns when PrEP utilization is expanded beyond this group. Conclusions PrEP implementation is relatively cost-inefficient under our initial assumptions. Our results suggest that PrEP should first be promoted among MSM who are at particularly high-risk of HIV acquisition. Further expansion beyond this group may be cost-effective, but is unlikely to be cost-saving. PMID:25493594

  2. Knowledge, attitudes, and beliefs about HIV pre-exposure prophylaxis among US Air Force Health Care Providers

    Hakre, Shilpa; Blaylock, Jason M; Dawson, Peter; Beckett, Charmagne; Garges, Eric C; Michael, Nelson L; Danaher, Patrick J; Scott, Paul T; Okulicz, Jason F

    2016-01-01

    Abstract Providers are central to effective implementation of HIV pre-exposure prophylaxis (PrEP). Primary care providers (PCP) and infectious disease physicians (ID) in the US Air Force (USAF) participated in a cross-sectional survey regarding knowledge, attitudes, and beliefs toward HIV PrEP. Characteristics associated with PrEP knowledge were assessed in univariate and multivariate analyses. Among 403 (40% of 1015 providers) participants, 9% (PCP 383, ID 20) ever prescribed PrEP. In univar...

  3. HIV transmitted drug resistance in adult and pediatric populations in Panama Farmacorresistencia transmitida del VIH en poblaciones adultas y pediátricas en Panamá

    Juan Castillo; Griselda Arteaga; Yaxelis Mendoza; Alexander A. Martínez; Rigoberto Samaniego; Dora Estripeaut; Kathleen R. Page; Rebecca E. Smith; Nestor Sosa; Juan M. Pascale

    2011-01-01

    OBJECTIVE: To investigate the prevalence of transmitted drug-resistant HIV among adults in Panama by using a modified World Health Organization Threshold Survey (WHO-TS) and to investigate rates of initial resistance among HIV-positive infants in Panama. METHODS: At the Gorgas Memorial Institute, 47 HIV-positive adults were genotyped for mutations associated with transmitted drug resistance (TDR) in the reverse transcriptase and protease genes of HIV-1, according to WHO-TS guidelines, modifie...

  4. CROI 2016: Hot Spots in HIV Infection and Advances in HIV Prevention.

    Buchbinder, Susan P; Liu, Albert Y

    2016-01-01

    The 2016 Conference on Retroviruses and Opportunistic Infections (CROI) highlighted hot spots in HIV infection. Men who have sex with men (MSM), transgender populations, people who inject drugs, fisherfolk, migrants, adolescents, and older adults are heavily impacted in a number of regions. Stigma contributes to risk behaviors and HIV acquisition across populations. HIV testing is a crucial first step in the HIV care continuum, and several large community-based surveys are underway in Africa to increase HIV testing, linkage to care, and uptake of antiretroviral treatment. Advances in preexposure prophylaxis (PrEP) featured prominently at CROI 2016. Two large efficacy trials of a vaginal ring containing the investigational drug dapivirine demonstrated efficacy and safety in preventing HIV infections in women in Africa. Data on the safety of long-acting injectable PrEP and several investigational PrEP drugs and formulations were also presented. Knowledge and use of PrEP among MSM in the United States appears to be increasing, and high uptake was seen among black MSM when provided as part of a culturally tailored support program. The use of broadly neutralizing antibodies for HIV prevention is a novel and promising approach to be evaluated in efficacy trials.

  5. Microbial alkaline proteases: Optimization of production parameters and their properties

    Kanupriya Miglani Sharma

    2017-06-01

    Full Text Available Proteases are hydrolytic enzymes capable of degrading proteins into small peptides and amino acids. They account for nearly 60% of the total industrial enzyme market. Proteases are extensively exploited commercially, in food, pharmaceutical, leather and detergent industry. Given their potential use, there has been renewed interest in the discovery of proteases with novel properties and a constant thrust to optimize the enzyme production. This review summarizes a fraction of the enormous reports available on various aspects of alkaline proteases. Diverse sources for isolation of alkaline protease producing microorganisms are reported. The various nutritional and environmental parameters affecting the production of alkaline proteases in submerged and solid state fermentation are described. The enzymatic and physicochemical properties of alkaline proteases from several microorganisms are discussed which can help to identify enzymes with high activity and stability over extreme pH and temperature, so that they can be developed for industrial applications.

  6. Pathophysiological significance and therapeutic applications of snake venom protease inhibitors.

    Thakur, Rupamoni; Mukherjee, Ashis K

    2017-06-01

    Protease inhibitors are important constituents of snake venom and play important roles in the pathophysiology of snakebite. Recently, research on snake venom protease inhibitors has provided valuable information to decipher the molecular details of various biological processes and offer insight for the development of some therapeutically important molecules from snake venom. The process of blood coagulation and fibrinolysis, in addition to affecting platelet function, are well known as the major targets of several snake venom protease inhibitors. This review summarizes the structure-functional aspects of snake venom protease inhibitors that have been described to date. Because diverse biological functions have been demonstrated by protease inhibitors, a comparative overview of their pharmacological and pathophysiological properties is also highlighted. In addition, since most snake venom protease inhibitors are non-toxic on their own, this review evaluates the different roles of individual protease inhibitors that could lead to the identification of drug candidates and diagnostic molecules. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. United States family planning providers' knowledge of and attitudes towards preexposure prophylaxis for HIV prevention: a national survey.

    Seidman, Dominika; Carlson, Kimberly; Weber, Shannon; Witt, Jacki; Kelly, Patricia J

    2016-05-01

    The Centers for Disease Control and Prevention defines HIV prevention as a core family planning service. The HIV community identified family planning visits as key encounters for women to access preexposure prophylaxis (PrEP) for HIV prevention. No studies explore US family planning providers' knowledge of and attitudes towards PrEP. We conducted a national survey of clinicians to understand barriers and facilitators to PrEP implementation in family planning. Family planning providers recruited via website postings, national meetings, and email completed an anonymous survey in 2015. Descriptive statistics were performed. Among 604 respondents, 495 were eligible for analysis and 342 were potential PrEP prescribers (physicians, nurse practitioners, midwives or physicians assistants). Among potential prescribers, 38% correctly defined PrEP [95% confidence interval (CI): 32.5-42.8], 37% correctly stated the efficacy of PrEP (95% CI: 32.0-42.4), and 36% chose the correct HIV test after a recent exposure (95% CI: 30.6-40.8). Characteristics of those who answered knowledge questions correctly included age less than 35 years, practicing in the Northeast or West, routinely offering HIV testing, providing rectal sexually transmitted infection screening or having seen any PrEP guidelines. Even among providers in the Northeast and West, the proportion of respondents answering questions correctly was less than 50%. Thirty-six percent of respondents had seen any PrEP guidelines. Providers identified lack of training as the main barrier to PrEP implementation; 87% wanted PrEP education. To offer comprehensive HIV prevention services, family planning providers urgently need training on PrEP and HIV testing. US family planning providers have limited knowledge about HIV PrEP and HIV testing, and report lack of provider training as the main barrier to PrEP provision. Provider education is needed to ensure that family planning clients access comprehensive HIV prevention methods

  8. Family planning providers' role in offering PrEP to women.

    Seidman, Dominika; Weber, Shannon; Carlson, Kimberly; Witt, Jacki

    2018-03-09

    Pre-exposure prophylaxis (PrEP) provides a radically different HIV prevention option for women. Not only is PrEP the first discrete, woman-controlled method that is taken in advance of exposure, but it is both safe and highly effective, offering over 90% protection if taken daily. While multiple modalities of PrEP are in development ranging from vaginal rings to injectables and implants, only PrEP with oral tenofovir/emtricitabine is currently FDA-approved. Family planning clinics provide key access points for many women to learn about and obtain PrEP. By incorporating PrEP services into family planning care, family planning providers have the opportunity to meet women's expectations, ensure women are aware of and offered comprehensive HIV prevention options, and reverse emerging disparities in PrEP access. Despite real and perceived barriers to integrating PrEP into family planning care, providing PrEP services, ranging from education to onsite provision, is not only possible but an important component of providing high-quality sexual and reproductive healthcare to women. Lessons learned from early adopters will help guide those in family planning settings initiating or enhancing PrEP services. Copyright © 2018. Published by Elsevier Inc.

  9. Assessing HIV Stigma on Prevention Strategies for Black Men Who Have Sex with Men in the United States.

    Sang, Jordan M; Matthews, Derrick D; Meanley, Steven P; Eaton, Lisa A; Stall, Ron D

    2018-06-02

    The deleterious effects of HIV stigma on HIV+ Black MSM care continuum outcomes have been well-documented. How HIV stigma shapes HIV prevention for HIV- persons in this community is poorly understood. We sought to test the relationship of HIV stigma with HIV- Black MSM on HIV testing, pre-exposure prophylaxis (PrEP) awareness, and PrEP use. We recruited 772 participants at Black Pride events across five US cities in 2016. Multivariable logistic regression models assessed the association of external HIV stigma on prevention outcomes adjusting for sociodemographic variables. Stigma was positively associated with PrEP awareness (AOR = 1.34; 95% CI = 1.09, 1.66; p value = 0.005), and not associated with PrEP use or HIV testing in our sample. These findings highlight the complex nature of HIV stigma among BMSM and include results for PrEP, which can affect uptake other prevention methods. We support anti-HIV stigma efforts and advise further exploration on HIV stigma among BMSM and prevention outcomes.

  10. Evaluation of HIV-Leishmania co-infection in patients from the northwestern Paraná State, Brazil = Avaliação da co-infecção HIV-Leishmania em pacientes da região noroeste do Estado do Paraná, Brasil

    Élide Aparecida Oliveira

    2011-01-01

    pelo HIV também apresentavam o DNA de Leishmania (Viannia, detectável no sangue por PCR. A sorologia, pesquisa direta de Leishmania, cultura e PCR de lesões de pele foram negativas. A positividade da PCR não estava associada à contagem de linfócitos T CD4+, doença oportunista, tratamento, uso de inibidores de protease, tatuagem, uso de drogas injetáveis, ambiente da residência ou história prévia de LTA. Os resultados mostraram que indivíduos portadores do vírus HIV que residem em área endêmica podem apresentar o DNA de Leishmania sem manifestar sintomas de LTA. Estes resultados podem ser atribuídos a ação dos medicamentos anti retrovirais que controlam a replicação viral mantendo a integridade do sistema imunológico ou a uma possível atividade anti-Leishmania destas drogas.

  11. PR-PR: cross-platform laboratory automation system.

    Linshiz, Gregory; Stawski, Nina; Goyal, Garima; Bi, Changhao; Poust, Sean; Sharma, Monica; Mutalik, Vivek; Keasling, Jay D; Hillson, Nathan J

    2014-08-15

    To enable protocol standardization, sharing, and efficient implementation across laboratory automation platforms, we have further developed the PR-PR open-source high-level biology-friendly robot programming language as a cross-platform laboratory automation system. Beyond liquid-handling robotics, PR-PR now supports microfluidic and microscopy platforms, as well as protocol translation into human languages, such as English. While the same set of basic PR-PR commands and features are available for each supported platform, the underlying optimization and translation modules vary from platform to platform. Here, we describe these further developments to PR-PR, and demonstrate the experimental implementation and validation of PR-PR protocols for combinatorial modified Golden Gate DNA assembly across liquid-handling robotic, microfluidic, and manual platforms. To further test PR-PR cross-platform performance, we then implement and assess PR-PR protocols for Kunkel DNA mutagenesis and hierarchical Gibson DNA assembly for microfluidic and manual platforms.

  12. HIV Pre-Exposure Prophylaxis Stigma as a Multidimensional Barrier to Uptake Among Women Who Attend Planned Parenthood.

    Calabrese, Sarah K; Dovidio, John F; Tekeste, Mehrit; Taggart, Tamara; Galvao, Rachel W; Safon, Cara B; Willie, Tiara C; Caldwell, Abigail; Kaplan, Clair; Kershaw, Trace S

    2018-05-22

    PrEP uptake has lagged among US women. PrEP stigma is a recognized barrier to uptake among MSM but remains largely unexplored among women. This study examined the pervasiveness of PrEP stigma among US women and its implications for uptake. Setting/Methods: In a 2017 online survey of Planned Parenthood patients drawn from the three cities with the highest numbers of new HIV infections in Connecticut, 597 heterosexually-active, HIV-negative, PrEP-inexperienced women reported background characteristics, two dimensions of anticipated PrEP stigma (PrEP-user stereotypes and PrEP disapproval by others), and three indicators of potential PrEP uptake (interest in learning more about PrEP, intention to use PrEP, and comfort discussing PrEP with a provider). Participants commonly perceived PrEP-user stereotypes, with many believing that others would regard them as promiscuous (37%), HIV-positive (32%), bad (14%), or gay (11%) if they used PrEP. Thirty percent would feel ashamed to disclose PrEP use. Many participants expected disapproval by family (36%), sex partners (34%), and friends (25%). In adjusted analyses, perception of PrEP-user stereotypes was uniquely associated with lower comfort discussing PrEP with a provider. Expected PrEP disapproval by others was uniquely associated with less PrEP interest, less intention to use PrEP, and less comfort discussing PrEP with a provider. Exploratory moderation analyses suggested intention to use PrEP was greatest when participants anticipated low levels of both PrEP-user stereotypes and PrEP disapproval by others. Findings highlight the need for positive messaging targeting potential PrEP users and their social networks to increase PrEP acceptance and uptake.

  13. A cyclic peptidic serine protease inhibitor

    Zhao, Baoyu; Xu, Peng; Jiang, Longguang

    2014-01-01

    Peptides are attracting increasing interest as protease inhibitors. Here, we demonstrate a new inhibitory mechanism and a new type of exosite interactions for a phage-displayed peptide library-derived competitive inhibitor, mupain-1 (CPAYSRYLDC), of the serine protease murine urokinase...... pocket, its carbonyl group aligning improperly relative to Ser195 and the oxyanion hole, explaining why the peptide is an inhibitor rather than a substrate. Substitution of the P1 Arg with novel unnatural Arg analogues with aliphatic or aromatic ring structures led to an increased affinity, depending......, in spite of a less favorable binding entropy and loss of a polar interaction. We conclude that increased flexibility of the peptide allows more favorable exosite interactions, which, in combination with the use of novel Arg analogues as P1 residues, can be used to manipulate the affinity and specificity...

  14. Daily Pill Can Prevent HIV PSA (:60)

    2015-11-24

    This 60 second public service announcement (PSA) is based on the November 24, 2015 CDC Vital Signs report. Preexposure prophylaxis, or PrEP, is a daily medicine that can be used to prevent getting HIV. PrEP is for people who don’t have HIV but who are at very high risk for getting it from sex or injection drug use. Unfortunately, many people who can benefit from PrEP aren’t taking it.  Created: 11/24/2015 by National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention (NCHHSTP).   Date Released: 11/24/2015.

  15. Luminometric method for screening retroviral protease inhibitors

    Horáková, D.; Rumlová, Michaela; Pichová, Iva; Ruml, Tomáš

    2005-01-01

    Roč. 345, č. 1 (2005), s. 96-101 ISSN 0003-2697 R&D Projects: GA AV ČR(CZ) IAA4055304; GA MŠk(CZ) 1M0508; GA MŠk(CZ) 1M0520 Institutional research plan: CEZ:AV0Z40550506 Keywords : retroviral protease * inhibitors * luminescent assay Subject RIV: CE - Biochemistry Impact factor: 2.670, year: 2005

  16. Dysregulation of protease and protease inhibitors in a mouse model of human pelvic organ prolapse.

    Madhusudhan Budatha

    Full Text Available Mice deficient for the fibulin-5 gene (Fbln5(-/- develop pelvic organ prolapse (POP due to compromised elastic fibers and upregulation of matrix metalloprotease (MMP-9. Here, we used casein zymography, inhibitor profiling, affinity pull-down, and mass spectrometry to discover additional protease upregulated in the vaginal wall of Fbln5(-/- mice, herein named V1 (25 kDa. V1 was a serine protease with trypsin-like activity similar to protease, serine (PRSS 3, a major extrapancreatic trypsinogen, was optimum at pH 8.0, and predominantly detected in estrogenized vaginal epithelium of Fbln5(-/- mice. PRSS3 was (a localized in epithelial secretions, (b detected in media of vaginal organ culture from both Fbln5(-/- and wild type mice, and (c cleaved fibulin-5 in vitro. Expression of two serine protease inhibitors [Serpina1a (α1-antitrypsin and Elafin] was dysregulated in Fbln5(-/- epithelium. Finally, we confirmed that PRSS3 was expressed in human vaginal epithelium and that SERPINA1 and Elafin were downregulated in vaginal tissues from women with POP. These data collectively suggest that the balance between proteases and their inhibitors contributes to support of the pelvic organs in humans and mice.

  17. HIV-1 proteins dysregulate motivational processes and dopamine circuitry.

    Bertrand, Sarah J; Mactutus, Charles F; Harrod, Steven B; Moran, Landhing M; Booze, Rosemarie M

    2018-05-18

    Motivational alterations, such as apathy, in HIV-1+ individuals are associated with decreased performance on tasks involving frontal-subcortical circuitry. We used the HIV-1 transgenic (Tg) rat to assess effect of long-term HIV-1 protein exposure on motivated behavior using sucrose (1-30%, w/v) and cocaine (0.01-1.0 mg/kg/infusion) maintained responding with fixed-ratio (FR) and progressive-ratio (PR) schedules of reinforcement. For sucrose-reinforced responding, HIV-1 Tg rats displayed no change in EC 50 relative to controls, suggesting no change in sucrose reinforcement but had a downward shifted concentration-response curves, suggesting a decrease in response vigor. Cocaine-maintained responding was attenuated in HIV-1 Tg rats (FR1 0.33 mg/kg/infusion and PR 1.0 mg/kg/infusion). Dose-response tests (PR) revealed that HIV-1 Tg animals responded significantly less than F344 control rats and failed to earn significantly more infusions of cocaine as the unit dose increased. When choosing between cocaine and sucrose, control rats initially chose sucrose but with time shifted to a cocaine preference. In contrast, HIV-1 disrupted choice behaviors. DAT function was altered in the striatum of HIV-1 Tg rats; however, prior cocaine self-administration produced a unique effect on dopamine homeostasis in the HIV-1 Tg striatum. These findings of altered goal directed behaviors may determine neurobiological mechanisms of apathy in HIV-1+ patients.

  18. Oral preexposure prophylaxis to prevent HIV infection: clinical and public health implications.

    Baker, Jonathan; OʼHara, Kevin Michael

    2014-12-01

    This article reviews the use of combination emtricitabine (FTC)/tenofovir as preexposure prophylaxis (PrEP) for HIV-negative patients at high risk of acquiring HIV, including heterosexual men and women, men who have sex with men, and IV drug users. When used with classic prevention strategies such as condoms, PrEP has been found effective in reducing the risk of HIV transmission.

  19. Role of Proteases in Chronic Obstructive Pulmonary Disease

    Kailash C. Pandey

    2017-08-01

    Full Text Available Chronic obstructive pulmonary disease (COPD is generally associated with progressive destruction of airways and lung parenchyma. Various factors play an important role in the development and progression of COPD, like imbalance of proteases, environmental and genetic factors and oxidative stress. This review is specifically focused on the role of proteases and their imbalance in COPD. There are three classes (serine, mettalo, and cysteine of proteases involved in COPD. In serine proteases, neutrophil elastase, cathepsin G, and proteinase-3 are involved in destruction of alveolar tissue. Matrix-mettaloproteinase-9, 12, 13, plays an influential role in severity of COPD. Among cysteine proteases, caspase-3, caspases-8 and caspase-9 play an important role in controlling apoptosis. These proteases activities can be regulated by inhibitors like α-1-antitrypsin, neutrophil elastase inhibitor, and leukocyte protease inhibitor. Studies suggest that neutrophil elastase may be a therapeutic target for COPD, and specific inhibitor against this enzyme has potential role to control the disease. Current study suggests that Dipeptidyl Peptidase IV is a potential marker for COPD. Since the expression of proteases and its inhibitors play an important role in COPD pathogenesis, therefore, it is worth investigating the role of proteases and their regulation. Understanding the biochemical basis of COPD pathogenesis using advanced tools in protease biochemistry and aiming toward translational research from bench-to-bedside will have great impact to deal with this health problem.

  20. PARTIAL PURIFICATION AND CHARACTERIZATION OF ALKALOPHILIC PROTEASE FROM PSEUDOMONAS AERUGINOSA

    R. Satheeskumar

    2013-10-01

    Full Text Available Partial purification and characterization of alkalophilic protease production from Pseudomonas aeruginosa was isolated from the gut of marine and coastal waters shrimp Penaeus monodon. The protease production was assayed in submerged fermentation to produce maximum protease activity (423 ± 0.09 U/ml. The enzyme was precipitated with ammonium sulphate and partially purified by ion exchange chromatography through DEAE Sephadex A-50 column. In 10th fraction showed maximum protease activity (734 ± 0.18 U/ml with increase in purification fold. The molecular weight of protease from Pseudomonas aeruginosa was recorded as 60 kDa. The stability of protease was tested at various pH and temperature; it showed maximum protease activity at pH-9 and temperature 50ºC. Among the various surfactants tested for enzyme stability, maximum activity was retained in poly ethylene glycol. The compatibility of protease enzyme with various commercial detergents; the enzyme retained maximum protease activity in tide. The results are indicated that all these properties make the bacterial proteases are most suitable for wide industrial applications.

  1. Understanding serine proteases implications on Leishmania spp lifecycle.

    Alves, Carlos Roberto; Souza, Raquel Santos de; Charret, Karen Dos Santos; Côrtes, Luzia Monteiro de Castro; Sá-Silva, Matheus Pereira de; Barral-Veloso, Laura; Oliveira, Luiz Filipe Gonçalves; da Silva, Franklin Souza

    2018-01-01

    Serine proteases have significant functions over a broad range of relevant biological processes to the Leishmania spp lifecycle. Data gathered here present an update on the Leishmania spp serine proteases and the status of these enzymes as part of the parasite degradome. The serine protease genes (n = 26 to 28) in Leishmania spp, which encode proteins with a wide range of molecular masses (35 kDa-115 kDa), are described along with their degrees of chromosomal and allelic synteny. Amid 17 putative Leishmania spp serine proteases, only ∼18% were experimentally demonstrated, as: signal peptidases that remove the signal peptide from secretory pre-proteins, maturases of other proteins and with metacaspase-like activity. These enzymes include those of clans SB, SC and SF. Classical inhibitors of serine proteases are used as tools for the characterization and investigation of Leishmania spp. Endogenous serine protease inhibitors, which are ecotin-like, can act modulating host actions. However, crude or synthetic based-natural serine protease inhibitors, such as potato tuber extract, Stichodactyla helianthus protease inhibitor I, fukugetin and epoxy-α-lapachone act on parasitic serine proteases and are promising leishmanicidal agents. The functional interrelationship between serine proteases and other Leishmania spp proteins demonstrate essential functions of these enzymes in parasite physiology and therefore their value as targets for leishmaniasis treatment. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Women and HIV

    ... Consumer Information by Audience For Women Women and HIV: Get the Facts on HIV Testing, Prevention, and Treatment Share Tweet Linkedin Pin ... How can you lower your chance of HIV? HIV Quick Facts What is HIV? HIV is the ...

  3. Corruption of innate immunity by bacterial proteases.

    Potempa, Jan; Pike, Robert N

    2009-01-01

    The innate immune system of the human body has developed numerous mechanisms to control endogenous and exogenous bacteria and thus prevent infections by these microorganisms. These mechanisms range from physical barriers such as the skin or mucosal epithelium to a sophisticated array of molecules and cells that function to suppress or prevent bacterial infection. Many bacteria express a variety of proteases, ranging from non-specific and powerful enzymes that degrade many proteins involved in innate immunity to proteases that are extremely precise and specific in their mode of action. Here we have assembled a comprehensive picture of how bacterial proteases affect the host's innate immune system to gain advantage and cause infection. This picture is far from being complete since the numbers of mechanisms utilized are as astonishing as they are diverse, ranging from degradation of molecules vital to innate immune mechanisms to subversion of the mechanisms to allow the bacterium to hide from the system or take advantage of it. It is vital that such mechanisms are elucidated to allow strategies to be developed to aid the innate immune system in controlling bacterial infections.

  4. The microbiome and HIV prevention strategies in women.

    Abdool Karim, Salim S; Passmore, Jo-Ann S; Baxter, Cheryl

    2018-01-01

    HIV prevention approaches that women can use and control are a priority. Results from topical and oral preexposure prophylaxis (PrEP) HIV prevention trials have produced inconsistent results in women. One of the main behavioural factors impacting effectiveness of PrEP has been suboptimal adherence. In this review, we examine biological factors that modulate topical PrEP efficacy, with particular focus on the vaginal microbiome. Genital inflammation is an independent risk factor for HIV acquisition in women. Using 16S rRNA sequencing of the vaginal microbiota, anaerobic bacteria linked with bacterial vaginosis have been shown to be associated with both genital inflammation and HIV risk. Using proteomics, it was recently discovered that a dysbiotic vaginal microbiome, comprising less than 50% Lactobacillus spp., directly influenced topical PrEP efficacy. Gardnerella vaginalis, the dominant vaginal species in dysbiotic women, was able to directly degrade tenofovir, but not dapivirine, an antiretroviral also being developed for topical PrEP. The link between bacterial vaginosis-associated organisms with HIV risk and altered tenofovir gel effectiveness underscores the importance of good vaginal health and good adherence for women to benefit maximally from topical PrEP. Altering the vaginal microbiome is one of the new directions being pursued for HIV prevention.

  5. Long acting systemic HIV pre-exposure prophylaxis: an examination of the field.

    Lykins, William R; Luecke, Ellen; Johengen, Daniel; van der Straten, Ariane; Desai, Tejal A

    2017-12-01

    Oral pre-exposure prophylaxis for the prevention of HIV-1 transmission (HIV PrEP) has been widely successful as demonstrated by a number of clinical trials. However, studies have also demonstrated the need for patients to tightly adhere to oral dosing regimens in order to maintain protective plasma and tissue concentrations. This is especially true for women, who experience less forgiveness from dose skipping than men in clinical trials of HIV PrEP. There is increasing interest in long-acting (LA), user-independent forms of HIV PrEP that could overcome this adherence challenge. These technologies have taken multiple forms including LA injectables and implantables. Phase III efficacy trials are ongoing for a LA injectable candidate for HIV PrEP. This review will focus on the design considerations for both LA injectable and implantable platforms for HIV PrEP. Additionally, we have summarized the existing LA technologies currently in clinical and pre-clinical studies for HIV PrEP as well as other technologies that have been applied to HIV PrEP and contraceptives. Our discussion will focus on the potential application of these technologies in low resource areas, and their use in global women's health.

  6. Human endogenous retrovirus K Gag coassembles with HIV-1 Gag and reduces the release efficiency and infectivity of HIV-1.

    Monde, Kazuaki; Contreras-Galindo, Rafael; Kaplan, Mark H; Markovitz, David M; Ono, Akira

    2012-10-01

    Human endogenous retroviruses (HERVs), which are remnants of ancestral retroviruses integrated into the human genome, are defective in viral replication. Because activation of HERV-K and coexpression of this virus with HIV-1 have been observed during HIV-1 infection, it is conceivable that HERV-K could affect HIV-1 replication, either by competition or by cooperation, in cells expressing both viruses. In this study, we found that the release efficiency of HIV-1 Gag was 3-fold reduced upon overexpression of HERV-K(CON) Gag. In addition, we observed that in cells expressing Gag proteins of both viruses, HERV-K(CON) Gag colocalized with HIV-1 Gag at the plasma membrane. Furthermore, HERV-K(CON) Gag was found to coassemble with HIV-1 Gag, as demonstrated by (i) processing of HERV-K(CON) Gag by HIV-1 protease in virions, (ii) coimmunoprecipitation of virion-associated HERV-K(CON) Gag with HIV-1 Gag, and (iii) rescue of a late-domain-defective HERV-K(CON) Gag by wild-type (WT) HIV-1 Gag. Myristylation-deficient HERV-K(CON) Gag localized to nuclei, suggesting cryptic nuclear trafficking of HERV-K Gag. Notably, unlike WT HERV-K(CON) Gag, HIV-1 Gag failed to rescue myristylation-deficient HERV-K(CON) Gag to the plasma membrane. Efficient colocalization and coassembly of HIV-1 Gag and HERV-K Gag also required nucleocapsid (NC). These results provide evidence that HIV-1 Gag heteromultimerizes with HERV-K Gag at the plasma membrane, presumably through NC-RNA interaction. Intriguingly, HERV-K Gag overexpression reduced not only HIV-1 release efficiency but also HIV-1 infectivity in a myristylation- and NC-dependent manner. Altogether, these results indicate that Gag proteins of endogenous retroviruses can coassemble with HIV-1 Gag and modulate the late phase of HIV-1 replication.

  7. HIV-1 infection and pregnancy in young women in Brazil: socioeconomic and drug resistance profiles in a cross-sectional study.

    Lima, Yanna Andressa Ramos; Reis, Mônica Nogueira Guarda; Cardoso, Ludimila Paula Vaz; Stefani, Mariane Martins Araújo

    2016-07-05

    To describe socioeconomic and antiretroviral (ARV) drug resistance profiles among young pregnant women infected with HIV-1. A public health antenatal programme responsible for screening ∼90 000 pregnant women per year for nine different infectious diseases in Central Western Brazil. 96 young pregnant women (15-24 years) infected with HIV-1. Standard interviews and blood samples were taken at the time of recruitment, at the first medical appointment after confirmation of diagnosis of HIV-1 infection, and before ARV prophylaxis initiation. Clinical and laboratory data were retrieved from medical files. HIV-1 pol gene sequences (entire protease/PR, partial reverse transcriptase/RT) were obtained from plasma RNA. ARV resistance mutations (CPR/Stanford HIV-1; International AIDS Society-USA databases) were identified. The median age was 21 years; most reported pregnancies. Possible heterosexual transmission by an HIV-1 infected partner (17%) and commercial sex work (2%) were reported. The median of CD4 cell count was 526 cells/mm(3); the median viral load was: 10 056 copies/mL in ARV-naïve (48/96) patients and 5881 copies/mL in ARV-exposed (48/96) patients. Two probable seroconversion cases during pregnancy were identified in adolescents. One mother-to-child transmission case (1.0%) was observed. Transmitted drug resistance among ARV-naïve patients was 9.3% (CI 95% 3.3% to 19.6%); secondary drug resistance among ARV-exposed patients was 12.5% (CI 95% 4.7% to 25.6%). Despite high access to antenatal care, the low socioeconomic-educational profiles seen in these young HIV-1-infected women highlight the necessity of improved public health educational and preventive strategies regarding HIV infection and early unplanned pregnancy. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  8. Defining success with HIV pre-exposure prophylaxis: A prevention-effective adherence paradigm

    Haberer, Jessica E.; Bangsberg, David R.; Baeten, Jared M.; Curran, Kathryn; Koechlin, Florence; Amico, K. Rivet; Anderson, Peter; Mugo, Nelly; Venter, Francois; Goicochea, Pedro; Caceres, Carlos; O’Reilly, Kevin

    2015-01-01

    Clinical trial data have shown that oral pre-exposure prophylaxis (PrEP) is efficacious when taken as prescribed; however, PrEP adherence is complex and must be understood within the context of variable risk for HIV infection and use of other HIV prevention methods. Different levels of adherence may be needed in different populations to achieve HIV prevention, and the optimal methods for achieving the necessary adherence for both individual and public health benefits are unknown. Guidance for PrEP use must consider these questions to determine the success of PrEP-based HIV prevention programs. In this article, we propose a new paradigm for understanding and measuring PrEP adherence, termed prevention-effective adherence, which incorporates dynamic HIV acquisition risk behaviors and the use of HIV alternative prevention strategies. We discuss the need for daily PrEP use only during periods of risk for HIV exposure, describe key issues for measuring and understanding relevant behaviors, review lessons from another health prevention field (i.e., family planning), and provide guidance for prevention-effective PrEP use. Moreover, we challenge emerging calls for sustained, near perfect PrEP adherence regardless of risk exposure and offer a more practical and public health-focused vision for this prevention intervention. PMID:26103095

  9. PrP mRNA and protein expression in brain and PrP(c) in CSF in Creutzfeldt-Jakob disease MM1 and VV2.

    Llorens, Franc; Ansoleaga, Belén; Garcia-Esparcia, Paula; Zafar, Saima; Grau-Rivera, Oriol; López-González, Irene; Blanco, Rosi; Carmona, Margarita; Yagüe, Jordi; Nos, Carlos; Del Río, José Antonio; Gelpí, Ellen; Zerr, Inga; Ferrer, Isidre

    2013-01-01

    Creutzfeldt-Jakob disease (CJD) is a heterogenic neurodegenerative disorder associated with abnormal post-translational processing of cellular prion protein (PrP(c)). CJD displays distinctive clinical and pathological features which correlate with the genotype at the codon 129 (methionine or valine: M or V respectively) in the prion protein gene and with size of the protease-resistant core of the abnormal prion protein PrP(sc) (type 1: 20/21 kDa and type 2: 19 kDa). MM1 and VV2 are the most common sporadic CJD (sCJD) subtypes. PrP mRNA expression levels in the frontal cortex and cerebellum are reduced in sCJD in a form subtype-dependent. Total PrP protein levels and PrP(sc) levels in the frontal cortex and cerebellum accumulate differentially in sCJD MM1 and sCJD VV2 with no relation between PrP(sc) deposition and spongiform degeneration and neuron loss, but with microgliosis, and IL6 and TNF-α response. In the CSF, reduced PrP(c), the only form present in this compartment, occurs in sCJD MM1 and VV2. PrP mRNA expression is also reduced in the frontal cortex in advanced stages of Alzheimer disease, Lewy body disease, progressive supranuclear palsy, and frontotemporal lobe degeneration, but PrP(c) levels in brain varies from one disease to another. Reduced PrP(c) levels in CSF correlate with PrP mRNA expression in brain, which in turn reflects severity of degeneration in sCJD.

  10. Awareness of and willingness to use oral pre-exposure prophylaxis for HIV prevention among HIV-serodiscordant heterosexual couples: a cross-sectional survey in Xinjiang, China.

    Peierdun Mijiti

    Full Text Available OBJECTIVES: We aimed to investigate the awareness of and willingness to use oral pre-exposure prophylaxis (PrEP for HIV prevention among HIV-negative partners in HIV-serodiscordant heterosexual couples in Xinjiang, China and determine factors that predict willingness to use oral PrEP. METHODS: Between November 2009 and December 2010, a cross-sectional survey was carried out among 351 HIV-negative partners in HIV-serodiscordant heterosexual couples from three cities in Xinjiang, China. Participants completed a self-administered questionnaire to assess their awareness of and willingness to use oral PrEP. Additionally, blood samples were collected to test for HIV infection. Univariate and multivariate logistic regression analyses were performed to identify predictors of willingness to use oral PrEP. RESULTS: Only 10 participants (2.8% reported having heard of PrEP, and only two reported ever using PrEP. However, 297 (84.6% reported that they were willing to use oral PrEP if it was proven to be both safe and effective. Results of multivariate analysis revealed the following independent predictors of willingness to use oral PrEP: monthly household income (adjusted odds ratio = 2.78, <1000 RMB vs. ≥ 1000 RMB, 95% confidence interval: 1.36-5.69, perceived likelihood of contracting HIV from HIV-positive partner (adjusted odds ratio = 2.63, likely vs. unlikely, 95% confidence interval: 1.12-6.19, and worrying about being discriminated against by others due to oral PrEP use (adjusted odds ratio = 9.43, No vs. Yes, 95% confidence interval: 3.78-23.50. CONCLUSIONS: Our results showed HIV-negative partners in HIV-serodiscordant heterosexual couples in China had low awareness of oral PrEP but high willingness to use oral PrEP for HIV prevention. Cost of oral PrEP should be taken into consideration in future PrEP prevention strategy. In addition, efforts should be made to reduce stigma attached to oral PrEP use, which may increase its acceptability among

  11. Prevention Strategies Against HIV Transmission: A Proactive Approach.

    Carrion, Antonio J; Miles, Jovan D; Mosley, Juan F; Smith, Lillian L; Prather, April S; Gurley, Marcus M; Phan, Linh D; Everton, Emily C

    2018-02-01

    Human immunodeficiency virus (HIV) has now transformed into a manageable chronic condition. Highly active antiretroviral therapy (HAART) has proven efficacious at controlling the disease progression. Based on compelling evidence, the Department of Health and Human Services (DHHS) and the Infectious Disease Society of America (IDSA) developed guidelines for the management of persons infected with HIV. However, there are approximately 50 000 new cases of HIV in the United States each year. In this article, we review proactive methods to reduce the transmission of HIV, which include reinforcing patient education, gel-coated condoms that destroy HIV, HIV vaccinations, and adequately utilizing pre-exposure prophylaxis (PrEP), and post-exposure prophylaxis (PEP). Further development and consistent utilization of innovative prevention tools can significantly reduce the incidence of HIV infections regardless of HIV status.

  12. Neutron Scattering from fcc Pr and Pr3Tl

    Birgeneau, R. J.; Als-Nielsen, Jens Aage; Bucher, E.

    1972-01-01

    Elastic-neutron-scattering measurements on the singlet-ground-state ferromagnets fcc Pr and Pr3 Tl are reported. Both exhibit magnetic phase transitions, possibly to a simple ferromagnetic state at 20 and 11.6 °K, respectively. The transitions appear to be of second order although that in fcc Pr...

  13. Molecular Characterization and Functional Analysis of PR-1-Like Proteins Identified from the Wheat Head Blight Fungus Fusarium graminearum.

    Lu, Shunwen; Edwards, Michael C

    2018-04-01

    The group 1 pathogenesis-related (PR-1) proteins originally identified from plants and their homologs are also found in other eukaryotic kingdoms. Studies on nonplant PR-1-like (PR-1L) proteins have been pursued widely in humans and animals but rarely in filamentous ascomycetes. Here, we report the characterization of four PR-1L proteins identified from the ascomycete fungus Fusarium graminearum, the primary cause of Fusarium head blight of wheat and barley (designated FgPR-1L). Molecular cloning revealed that the four FgPR-1L proteins are all encoded by small open reading frames (612 to 909 bp) that are often interrupted by introns, in contrast to plant PR-1 genes that lack introns. Sequence analysis indicated that all FgPR-1L proteins contain the PR-1-specific three-dimensional structure, and one of them features a C-terminal transmembrane (TM) domain that has not been reported for any stand-alone PR-1 proteins. Transcriptional analysis revealed that the four FgPR-1L genes are expressed in axenic cultures and in planta with different spatial or temporal expression patterns. Phylogenetic analysis indicated that fungal PR-1L proteins fall into three major groups, one of which harbors FgPR-1L-2-related TM-containing proteins from both phytopathogenic and human-pathogenic ascomycetes. Low-temperature sodium dodecyl sulfate polyacrylamide gel electrophoresis and proteolytic assays indicated that the recombinant FgPR-1L-4 protein exists as a monomer and is resistant to subtilisin of the serine protease family. Functional analysis confirmed that deletion of the FgPR-1L-4 gene from the fungal genome results in significantly reduced virulence on susceptible wheat. This study provides the first example that the F. graminearum-wheat interaction involves a pathogen-derived PR-1L protein that affects fungal virulence on the host.

  14. Factors associated with collagen deposition in lymphoid tissue in long-term treated HIV-infected patients.

    Diaz, Alba; Alós, Llúcia; León, Agathe; Mozos, Anna; Caballero, Miguel; Martinez, Antonio; Plana, Montserrat; Gallart, Teresa; Gil, Cristina; Leal, Manuel; Gatell, Jose M; García, Felipe

    2010-08-24

    The factors associated with fibrosis in lymphoid tissue in long-term treated HIV-infected patients and their correlation with immune reconstitution were assessed. Tonsillar biopsies were performed in seven antiretroviral-naive patients and 29 successfully treated patients (median time on treatment, 61 months). Twenty patients received protease inhibitors-sparing regimens and nine protease inhibitor-containing regimens. Five tonsillar resections of HIV-negative individuals were used as controls. Lymphoid tissue architecture, collagen deposition (fibrosis) and the mean interfollicular CD4(+) cell count per mum were assessed. Naive and long-term treated HIV-infected patients had a higher proportion of fibrosis than did HIV-uninfected persons (P lymphoid tissue (P = 0.03) and smaller increase in peripheral CD4(+) T cells (r = -0.40, P = 0.05). The factors independently associated with fibrosis in lymphoid tissue were age (P lymphoid tissue viral load when compared with patients with undetectable lymphoid tissue viral load (median 5 vs. 12%, respectively, P = 0.017) and patients receiving a protease inhibitor-sparing vs. a protease inhibitor-containing regimen (median 8 vs. 2.5%, respectively, P = 0.04). Fibrosis in lymphoid tissue was associated with a poor reconstitution of CD4(+) T cells and long-term antiretroviral therapy did not reverse this abnormality. HIV infection, older age, a detectable level of lymphoid tissue viral load in treated patients and protease inhibitor-sparing regimens seem to favour fibrosis in lymphoid tissue.

  15. Pre-Exposure Prophylaxis for HIV Prevention : Safety Concerns

    Tetteh, Raymond A; Yankey, Barbara A; Nartey, Edmund T; Lartey, Margaret; Leufkens, Hubert G M; Dodoo, Alexander N O