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

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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.

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

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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

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

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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.

Variable context Markov chains for HIV protease cleavage site prediction.

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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.

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

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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.

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

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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.

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

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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.

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

African Journals Online (AJOL)

... 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, ...

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

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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.

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

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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.

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

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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

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

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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.

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

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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.

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

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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.

HIV-1 protease inhibitory substances from Cassia garrettiana

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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.

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

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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.

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

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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.

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

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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.

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

DEFF Research Database (Denmark)

Ullum, H; Katzenstein, T; Aladdin, H

1999-01-01

The present study examines the influence of effective anti-retroviral treatment on immune function, evaluated by a broad array of immunological tests. We followed 12 individuals infected with human immunodeficiency virus (HIV) for 6 months after initiation of combination anti-retroviral treatment...... 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...

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

Czech Academy of Sciences Publication Activity Database

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

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.

Science.gov (United States)

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.

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

Science.gov (United States)

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.

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

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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

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

Science.gov (United States)

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.

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

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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.

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

International Nuclear Information System (INIS)

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

PRACTICE OF USING VIRAL PROTEASE INHIBITORS IN CHILDREN WITH HIV INFECTION

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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

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

Science.gov (United States)

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.

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

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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

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

Czech Academy of Sciences Publication Activity Database

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

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.

Science.gov (United States)

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.

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

Science.gov (United States)

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.

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

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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

Contemporary protease inhibitors and cardiovascular risk

DEFF Research Database (Denmark)

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...

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

Science.gov (United States)

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.

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

Science.gov (United States)

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.

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

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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.

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

Science.gov (United States)

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.

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

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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.

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

Czech Academy of Sciences Publication Activity Database

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

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

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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.

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

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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.

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

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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.

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

OpenAIRE

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...

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.

OpenAIRE

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...

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

Czech Academy of Sciences Publication Activity Database

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

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

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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.

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

Science.gov (United States)

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.

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

Science.gov (United States)

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.

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

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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.

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

Czech Academy of Sciences Publication Activity Database

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

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

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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.

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

International Nuclear Information System (INIS)

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

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

Czech Academy of Sciences Publication Activity Database

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

2012-01-01

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

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

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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

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

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Caramelli Bruno

2001-01-01

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

HIV Structural Database

Science.gov (United States)

SRD 102 HIV Structural Database (Web, free access)   The HIV Protease Structural Database is an archive of experimentally determined 3-D structures of Human Immunodeficiency Virus 1 (HIV-1), Human Immunodeficiency Virus 2 (HIV-2) and Simian Immunodeficiency Virus (SIV) Proteases and their complexes with inhibitors or products of substrate cleavage.

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

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

2017-11-01

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

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

OpenAIRE

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...

High level of APOBEC3F/3G editing in HIV-2 DNA vif and pol sequences from antiretroviral-naive patients.

Science.gov (United States)

Bertine, Mélanie; Charpentier, Charlotte; Visseaux, Benoit; Storto, Alexandre; Collin, Gilles; Larrouy, Lucile; Damond, Florence; Matheron, Sophie; Brun-Vézinet, Françoise; Descamps, Diane

2015-04-24

In HIV-1, hypermutation introduced by APOBEC3F/3G cytidine deaminase activity leads to defective viruses. In-vivo impact of APOBEC3F/3G editing on HIV-2 sequences remains unknown. The objective of this study was to assess the level of APOBEC3F/3G editing in HIV-2-infected antiretroviral-naive patients. Direct sequencing of vif and pol regions was performed on HIV-2 proviral DNA from antiretroviral-naive patients included in the French Agence Nationale de Recherches sur le SIDA et les hépatites virales CO5 HIV-2 cohort. Hypermutated sequences were identified using Hypermut2.0 program. HIV-1 proviral sequences from Genbank were also assessed. Among 82 antiretroviral-naive HIV-2-infected patients assessed, 15 (28.8%) and five (16.7%) displayed Vif proviral defective sequences in HIV-2 groups A and B, respectively. A lower proportion of defective sequences was observed in protease-reverse transcriptase region. A higher median number of G-to-A mutations was observed in HIV-2 group B than in group A, both in Vif and protease-reverse transcriptase regions (P = 0.02 and P = 0.006, respectively). Compared with HIV-1 Vif sequences, a higher number of Vif defective sequences was observed in HIV-2 group A (P = 0.00001) and group B sequences (P = 0.013). We showed for the first time a high level of APOBEC3F/3G editing in HIV-2 sequences from antiretroviral-naive patients. Our study reported a group effect with a significantly higher level of APOBEC3F/3G editing in HIV-2 group B than in group A sequences.

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

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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.

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

Science.gov (United States)

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.

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

Science.gov (United States)

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.

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

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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.

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

International Nuclear Information System (INIS)

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

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

NARCIS (Netherlands)

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

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

Science.gov (United States)

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.

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

Czech Academy of Sciences Publication Activity Database

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

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

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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.

Solid-state characterization of the HIV protease inhibitor

CERN Document Server

Kim, Y A

2002-01-01

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

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.

Science.gov (United States)

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.

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

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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

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

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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.

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

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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.

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

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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

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

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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.

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

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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

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

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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

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

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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.

High Levels of Transmitted HIV Drug Resistance in a Study in Papua New Guinea.

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Lavu, Evelyn; Kave, Ellan; Mosoro, Euodia; Markby, Jessica; Aleksic, Eman; Gare, Janet; Elsum, Imogen A; Nano, Gideon; Kaima, Petronia; Dala, Nick; Gurung, Anup; Bertagnolio, Silvia; Crowe, Suzanne M; Myatt, Mark; Hearps, Anna C; Jordan, Michael R

2017-01-01

Papua New Guinea is a Pacific Island nation of 7.3 million people with an estimated HIV prevalence of 0.8%. ART initiation and monitoring are guided by clinical staging and CD4 cell counts, when available. Little is known about levels of transmitted HIV drug resistance in recently infected individuals in Papua New Guinea. Surveillance of transmitted HIV drug resistance in a total of 123 individuals recently infected with HIV and aged less than 30 years was implemented in Port Moresby (n = 62) and Mount Hagen (n = 61) during the period May 2013-April 2014. HIV drug resistance testing was performed using dried blood spots. Transmitted HIV drug resistance was defined by the presence of one or more drug resistance mutations as defined by the World Health Organization surveillance drug resistance mutations list. The prevalence of non-nucleoside reverse transcriptase inhibitor transmitted HIV drug resistance was 16.1% (95% CI 8.8%-27.4%) and 8.2% (95% CI 3.2%-18.2%) in Port Moresby and Mount Hagen, respectively. The prevalence of nucleoside reverse transcriptase inhibitor transmitted HIV drug resistance was 3.2% (95% CI 0.2%-11.7%) and 3.3% (95% CI 0.2%-11.8%) in Port Moresby and Mount Hagen, respectively. No protease inhibitor transmitted HIV drug resistance was observed. The level of non-nucleoside reverse transcriptase inhibitor drug resistance in antiretroviral drug naïve individuals recently infected with HIV in Port Moresby is amongst the highest reported globally. This alarming level of transmitted HIV drug resistance in a young sexually active population threatens to limit the on-going effective use of NNRTIs as a component of first-line ART in Papua New Guinea. To support the choice of nationally recommended first-line antiretroviral therapy, representative surveillance of HIV drug resistance among antiretroviral therapy initiators in Papua New Guinea should be urgently implemented.

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

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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

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

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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.

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

DEFF Research Database (Denmark)

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 ...

Cardiovascular disease and use of contemporary protease inhibitors

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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...

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

Czech Academy of Sciences Publication Activity Database

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

Reduced sTWEAK and increased sCD163 levels in HIV-infected patients: modulation by antiretroviral treatment, HIV replication and HCV co-infection.

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Luis M Beltrán

Full Text Available Patients infected with the human immunodeficiency virus (HIV have an increased risk of cardiovascular disease due to increased inflammation and persistent immune activation. CD163 is a macrophage scavenger receptor that is involved in monocyte-macrophage activation in HIV-infected patients. CD163 interacts with TWEAK, a member of the TNF superfamily. Circulating levels of sTWEAK and sCD163 have been previously associated with cardiovascular disease, but no previous studies have fully analyzed their association with HIV.The aim of this study was to analyze circulating levels of sTWEAK and sCD163 as well as other known markers of inflammation (hsCRP, IL-6 and sTNFRII and endothelial dysfunction (sVCAM-1 and ADMA in 26 patients with HIV before and after 48 weeks of antiretroviral treatment (ART and 23 healthy subjects.Patients with HIV had reduced sTWEAK levels and increased sCD163, sVCAM-1, ADMA, hsCRP, IL-6 and sTNFRII plasma concentrations, as well as increased sCD163/sTWEAK ratio, compared with healthy subjects. Antiretroviral treatment significantly reduced the concentrations of sCD163, sVCAM-1, hsCRP and sTNFRII, although they remained elevated when compared with healthy subjects. Antiretroviral treatment had no effect on the concentrations of ADMA and sTWEAK, biomarkers associated with endothelial function. The use of protease inhibitors as part of antiretroviral therapy and the presence of HCV-HIV co-infection and/or active HIV replication attenuated the ART-mediated decrease in sCD163 plasma concentrations.HIV-infected patients showed a proatherogenic profile characterized by increased inflammatory, immune-activation and endothelial-dysfunction biomarkers that partially improved after ART. HCV-HIV co-infection and/or active HIV replication enhanced immune activation despite ART.

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

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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.

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

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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.

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

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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.

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

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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.

Mast cells limit extracellular levels of IL-13 via a serglycin proteoglycan-serine protease axis.

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Waern, Ida; Karlsson, Iulia; Thorpe, Michael; Schlenner, Susan M; Feyerabend, Thorsten B; Rodewald, Hans-Reimer; Åbrink, Magnus; Hellman, Lars; Pejler, Gunnar; Wernersson, Sara

2012-12-01

Mast cell (MC) granules contain large amounts of proteases of the chymase, tryptase and carboxypeptidase A (MC-CPA) type that are stored in complex with serglycin,a proteoglycan with heparin side chains. Hence, serglycinprotease complexes are released upon MC degranulation and may influence local inflammation. Here we explored the possibility that a serglycin-protease axis may regulate levels of IL-13, a cytokine involved in allergic asthma. Indeed, we found that wild-type MCs efficiently degraded exogenous or endogenously produced IL-13 upon degranulation,whereas serglycin −/− MCs completely lacked this ability.Moreover, MC-mediated IL-13 degradation was blocked both by a serine protease inhibitor and by a heparin antagonist,which suggests that IL-13 degradation is catalyzed by serglycin-dependent serine proteases and that optimal IL-13 degradation is dependent on both the serglycin and the protease component of the serglycin-protease complex.Moreover, IL-13 degradation was abrogated in MC-CPA −/−MC cultures, but was normal in cultures of MCs with an inactivating mutation of MC-CPA, which suggests that the IL-13-degrading serine proteases rely on MC-CPA protein.Together, our data implicate a serglycin-serine protease axis in the regulation of extracellular levels of IL-13. Reduction of IL-13 levels through this mechanism possibly can provide a protective function in the context of allergic inflammation.

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

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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.

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

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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.

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

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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.

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

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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.

Effects of eye rubbing on the levels of protease, protease activity and cytokines in tears: relevance in keratoconus.

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Balasubramanian, Sivaraman A; Pye, David C; Willcox, Mark D P

2013-03-01

Proteases, protease activity and inflammatory molecules in tears have been found to be relevant in the pathogenesis of keratoconus. We sought to determine the influence of eye rubbing on protease expression, protease activity and concentration of inflammatory molecules in tears. Basal tears were collected from normal volunteers before and after 60 seconds of experimental eye rubbing. The total amount of matrix metalloproteinase (MMP)-13 and inflammatory molecules interleukin (IL)-6 and tumour necrosis factor (TNF)-α in the tear samples were measured using specific enzyme-linked immunosorbent assays (ELISA). Tear collagenase activity was investigated using a specific activity assay. The concentrations of MMP-13 (51.9 ± 34.3 versus 63 ± 36.8 pg/ml, p = 0.006), IL-6 (1.24 ± 0.98 versus 2.02 ± 1.52 pg/ml, p = 0.004) and TNF-α (1.16 ± 0.74 versus 1.44 ± 0.66 pg/ml, p = 0.003) were significantly increased in normal subjects after eye rubbing. The experimental eye rub did not alter significantly the collagenase activity (5.02 ± 3 versus 7.50 ± 3.90 fluorescent intensity units, p = 0.14) of tears. Eye rubbing for 60 seconds increased the level of tear MMP-13, IL-6 and TNF-α in normal study subjects. This increase in protease, protease activity and inflammatory mediators in tears after eye rubbing may be exacerbated even further during persistent and forceful eye rubbing seen in people with keratoconus and this in turn may contribute to the progression of the disease. © 2013 The Authors. Clinical and Experimental Optometry © 2013 Optometrists Association Australia.

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

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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-1_NL4-3variants 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.

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

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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.

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

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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

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

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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.

Factors associated with collagen deposition in lymphoid tissue in long-term treated HIV-infected patients.

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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.

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

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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.

Nutritional assessment and lipid profile in HIV-infected children and adolescents treated with highly active antiretroviral therapy

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Marina Hjertquist Tremeschin

2011-06-01

Full Text Available INTRODUCTION: HIV-infected children and adolescents treated with highly active antiretroviral therapy (HAART regimens that include a protease inhibitor (PI can show significant improvements in clinical outcomes, nutritional status and quality of life. The study aimed to report nutritional and metabolic alterations for pediatric patients continuously exposed to HAART and for healthy controls for up to 1 year. METHODS: Clinical, anthropometric, lipid profile and food intake data were collected prospectively over approximately 12-months for each patient. RESULTS: Fifty-one individuals were studied, of these, 16 were healthy. After 12 months follow-up, HIV-positive individuals remained below the healthy control group parameters. No change was observed concerning food intake. Triglyceride serum levels were higher in patients using protease inhibitor at the onset of the study [PI groups: 114 (43 - 336, and 136 (63 - 271 versus control group: 54.5 (20 - 162; p = 0.003], but after twelve months follow-up, only the group using protease inhibitor for up to two months presented higher values [140 (73 - 273 versus 67.5 (33 - 117; p = 0.004]. HDL-cholesterol was lower in HIV-positive individuals [HIV-positive groups: 36 (27 - 58 and 36 (23 - 43; control 49.5 (34 - 69; p = 0.004]. CONCLUSIONS: HIV-infected children and adolescents treated with highly active antiretroviral therapy showed compromised nutritional parameters compared to a paired healthy control group. Individuals using protease inhibitor presented worse triglyceride serum levels compared to their healthy counterparts.

Immune pressure analysis of protease and reverse transcriptase ...

African Journals Online (AJOL)

/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 ...

Aspartic Protease Zymography Case Study: Detection of Fungal Acid Proteases by Zymography.

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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.

Kager's fat pad inflammation associated with HIV infection and AIDS: MRI findings

International Nuclear Information System (INIS)

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.)

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

Science.gov (United States)

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.

High-level expression of alkaline protease using recombinant ...

African Journals Online (AJOL)

AJL

2012-02-16

Feb 16, 2012 ... compared with that of wild-type B. licheniformis CICIM B5102. Key word: Alkaline protease, Bacillus amyloliquefaciens, Bacillus licheniformis. INTRODUCTION. Proteases are one of the most important industrial enzyme groups, accounting for approximately 60% of the total enzyme sales (Beg et al., 2003).

Cervical Shedding of HIV-1 RNA Among Women With Low Levels of Viremia While Receiving Highly Active Antiretroviral Therapy

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Neely, Michael N.; Benning, Lorie; Xu, Jiaao; Strickler, Howard D.; Greenblatt, Ruth M.; Minkoff, Howard; Young, Mary; Bremer, James; Levine, Alexandra M.; Kovacs, Andrea

2011-01-01

Background Among women with low o r undetectable quantities of HIV-1 RNA in plasma, factors associated with genital HIV-1 RNA shedding, including choice of treatment regimen, are poorly characterized. Methods We measured HIV-1 RNA in cervical swab specimens obtained from participants in the Women’s Interagency HIV Study who had concurrent plasma viral RNA levels <500 copies/mL, and we assessed factors associated with genital HIV shedding. The study was powered to determine the relative effects of antiretroviral protease inhibitors (PIs) versus nonnucleoside reverse transcriptase inhibitors (NNRTIs) on viral RNA shedding. Results Overall, 44 (15%) of 290 women had detectable HIV-1 RNA in cervical specimens. In the final multivariate model, shedding was independently associated with NNRTI (vs. PI) use (odds ratio [OR], 95% confidence interval [CI]: 2.24, 1.13 to 4.45) and illicit drug use (OR, 95% CI: 2.41, 0.96 to 5.69). Conclusions This is the largest study to define risks for genital HIV-1 RNA shedding in women with low/undetectable plasma virus. Shedding in this population was common, and NNRTI-based highly active antiretroviral therapy (HAART) (vs. PI-based HAART) was associated with genital HIV shedding. Further study is required to determine the impact of these findings on transmission of HIV from mother to child or to sexual partners. PMID:17106279

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

Czech Academy of Sciences Publication Activity Database

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

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

International Nuclear Information System (INIS)

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.

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

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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.

Fotodegradovatelné inhibitory HIV proteasy

Czech Academy of Sciences Publication Activity Database

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

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.

Science.gov (United States)

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

Antiretroviral treatment for HIV infection/AIDS and the risk of developing hyperglycemia and hyperlipidemia Tratamento antiretroviral para a infecção pelo HIV/AIDS e o risco de desenvolver hiperglicemia e dislipidemia

Directory of Open Access Journals (Sweden)

Paulo Sérgio Ramos de Araújo

2007-04-01

Full Text Available A cross-sectional study with internal comparison groups was conducted to describe sociodemographic characteristics, as well as verify the association between the type of antiretroviral treatment used and hyperglycemia and hyperlipidemia, with special attention to the use of HIV protease inhibitors. The data was obtained through an interview questionnaire, as well as blood and urine samples that were collected for the laboratory exams. A total of 418 patients were interviewed. 46 of these, however, met the exclusion criteria. The sample was therefore composed by 372 HIV positive patients, attended at the laboratory of the Correia Picanço State Hospital for the collection of blood, to estimate the HIV viral load and/or TCD4 cell counts from August to November 2000. The association between the variables was tested using the chi-square test and the p-value. A multiple logistic regression analysis was carried out to adjust for potential confounding factors. A greater frequency of patients with high glucose levels was observed among those making use of antiretroviral therapy without protease inhibitors, but the number of patients limited the comparisons. An association was verified between the total serum cholesterol level and the use of HIV protease inhibitors (p = 0.047 even after controlling for age. An association was also observed between the triglyceride levels and the use of HIV protease inhibitors, which remained after adjustment for age, sex and creatinine levels (p Um estudo epidemiológico transversal, com caráter analítico, foi realizado para descrever características sócio-demográficas bem como verificar a associação entre o tipo de tratamento antiretroviral empregado e hiperglicemia e hiperlipidemia, com especial atenção aos pacientes em uso de inibidores da protease do HIV. As informações foram obtidas a partir de um questionário e da coleta de sangue e urina para a execução dos exames laboratoriais. Foram entrevistados

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.

Science.gov (United States)

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.

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

Directory of Open Access Journals (Sweden)

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

Co-evolution of insect proteases and plant protease inhibitors.

Science.gov (United States)

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.

Viral dynamics in primary HIV-1 infection. Karolinska Institutet Primary HIV Infection Study Group.

Science.gov (United States)

Lindbäck, S; Karlsson, A C; Mittler, J; Blaxhult, A; Carlsson, M; Briheim, G; Sönnerborg, A; Gaines, H

2000-10-20

To study the natural course of viremia during primary HIV infection (PHI). Eight patients were followed from a median of 5 days from the onset of PHI illness. Plasma HIV-1 RNA levels were measured frequently and the results were fitted to mathematical models. HIV-1 RNA levels were also monitored in nine patients given two reverse transcriptase inhibitors and a protease inhibitor after a median of 7 days from the onset of PHI illness. HIV-1 RNA appeared in the blood during the week preceding onset of PHI illness and increased rapidly during the first viremic phase, reaching a peak at a mean of 7 days after onset of illness. This was followed by a phase of rapidly decreasing levels of HIV-1 RNA to an average of 21 days after onset. Viral density continued to decline thereafter but at a 5- to 50-fold lower rate; a steady-state level was reached at a median of 2 months after onset of PHI. Peak viral density levels correlated significantly with levels measured between days 50 and 600. Initiation of antiretroviral treatment during PHI resulted in rapidly declining levels to below 50 copies/mL. This study demonstrates the kinetic phases of viremia during PHI and indicates two new contributions to the natural history of HIV-1 infection: PHI peak levels correlate with steady-state levels and HIV-1 RNA declines biphasically; an initial rapid decay is usually followed by a slow decay, which is similar to the initial changes seen with antiviral treatment.

Kager's fat pad inflammation associated with HIV infection and AIDS: MRI findings

Energy Technology Data Exchange (ETDEWEB)

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.)

Detection of drug-induced dyslipidaemia in HIV-positive patients ...

African Journals Online (AJOL)

Purpose: To determine whether protease inhibitors (PIs) cause hypercholesterolaemia and hypertriglyceridaemia, and to assess the influence of sex and age on serum total cholesterol (TC) and triglycerides (TG), and the level of adherence to therapeutic laboratory monitoring guidelines in HIV positive patients in the ...

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

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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.

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

Science.gov (United States)

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.

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

Science.gov (United States)

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

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

Science.gov (United States)

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

2015-01-01

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

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

Science.gov (United States)

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

2017-05-01

Protease inhibitor (PI)-resistant HIV-1 isolates with primary substitutions in protease (PR) and secondary substitutions in Gag could potentially exhibit cross-resistance to maturation inhibitors. We evaluated the second-generation maturation inhibitor, GSK3532795, for activity toward clinical isolates with genotypic and phenotypic characteristics associated with PI resistance (longitudinal). Longitudinal clinical isolates from 15 PI-treated patients and 7 highly PI-resistant (nonlongitudinal) viruses containing major and minor PI resistance-associated mutations were evaluated for GSK3532795 sensitivity. Phenotypic sensitivity was determined using the PhenoSense Gag/PR assay (Monogram Biosciences) or in-house single- and multiple-cycle assays. Changes from baseline [CFB; ratio of post- to pre-treatment FC-IC50 (fold-change in IC50 versus wild-type virus)] 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.

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

Czech Academy of Sciences Publication Activity Database

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

Effectiveness of Ritonavir-Boosted Protease Inhibitor Monotherapy in Clinical Practice Even with Previous Virological Failures to Protease Inhibitor-Based Regimens.

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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.

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

DEFF Research Database (Denmark)

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

2011-01-01

The use of highly active antiretroviral treatment (HAART) regimens with unboosted protease inhibitors (PIs) has resulted in a high level of virological failure primarily due to the development of resistant virus. Current boosted PI regimens combine successfully low-dose ritonavir (r) with a second.......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...

Macro-level implicit HIV prejudice and the health of community residents with HIV.

Science.gov (United States)

Miller, Carol T; Varni, Susan E; Solomon, Sondra E; DeSarno, Michael J; Bunn, Janice Y

2016-08-01

This study examined how community levels of implicit HIV prejudice are associated with the psychological and physical well-being of people with HIV living in those same communities. It also examined whether community motivation to control prejudice and/or explicit HIV prejudice moderates the relationship of implicit prejudice and well-being. Participants were 206 people with HIV living in 42 different communities in New England who completed measures that assessed psychological distress, thriving, and physical well-being. Telephone surveys of 347 residents of these same communities (selected via random digit dialing) were used to assess community explicit HIV prejudice and motivation to control HIV prejudice. These community residents then completed an online measure of implicit prejudice toward people with HIV, the Implicit Association Test (IAT; Greenwald, McGhee, & Schwartz, 1998). Multilevel analyses showed that higher community implicit HIV prejudice was associated with greater psychological distress among residents with HIV living in that community. The physical well-being of participants with HIV was negatively related to community implicit HIV prejudice in communities in which residents were unmotivated to control HIV prejudice or had high levels of explicit HIV prejudice. These findings indicate that implicit prejudice of residents of real-world communities may create an environment that may impair the well-being of stigmatized people. Implicit prejudice can therefore be considered an element of macro-level or structural stigma. The discussion considered the possible role of implicit HIV prejudice on a community's social capital as a pathway by which it compromises the well-being of residents with HIV. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

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

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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.

Nutritional assessment and lipid profile in HIV-infected children and adolescents treated with highly active antiretroviral therapy Avaliação nutricional e do perfil lipídico em crianças e adolescentes infectadas pelo HIV tratadas com terapia antirretroviral de alta potência

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Marina Hjertquist Tremeschin

2011-06-01

Full Text Available INTRODUCTION: HIV-infected children and adolescents treated with highly active antiretroviral therapy (HAART regimens that include a protease inhibitor (PI can show significant improvements in clinical outcomes, nutritional status and quality of life. The study aimed to report nutritional and metabolic alterations for pediatric patients continuously exposed to HAART and for healthy controls for up to 1 year. METHODS: Clinical, anthropometric, lipid profile and food intake data were collected prospectively over approximately 12-months for each patient. RESULTS: Fifty-one individuals were studied, of these, 16 were healthy. After 12 months follow-up, HIV-positive individuals remained below the healthy control group parameters. No change was observed concerning food intake. Triglyceride serum levels were higher in patients using protease inhibitor at the onset of the study [PI groups: 114 (43 - 336, and 136 (63 - 271 versus control group: 54.5 (20 - 162; p = 0.003], but after twelve months follow-up, only the group using protease inhibitor for up to two months presented higher values [140 (73 - 273 versus 67.5 (33 - 117; p = 0.004]. HDL-cholesterol was lower in HIV-positive individuals [HIV-positive groups: 36 (27 - 58 and 36 (23 - 43; control 49.5 (34 - 69; p = 0.004]. CONCLUSIONS: HIV-infected children and adolescents treated with highly active antiretroviral therapy showed compromised nutritional parameters compared to a paired healthy control group. Individuals using protease inhibitor presented worse triglyceride serum levels compared to their healthy counterparts.INTRODUÇÃO: Crianças e adolescentes infectadas pelo HIV e tratadas com terapia antirretroviral de alta potência (TAAP, que inclui inibidor de protease (IP podem apresentar significante melhora clínica no estado nutricional e na qualidade de vida. O objetivo é relatar as alterações nutricionais e metabólicas em pacientes pediátricos expostos a TAAP e controles saud

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

Science.gov (United States)

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

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

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

Science.gov (United States)

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.

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

Science.gov (United States)

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

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

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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.

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

Directory of Open Access Journals (Sweden)

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.

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

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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

Determinants of IL-6 levels during HIV infection

DEFF Research Database (Denmark)

Borges, Alvaro H; O'Connor, Jemma L; Phillips, Andrew N

2014-01-01

. MATERIAL AND METHODS: Participants in three international HIV trials (SMART, ESPRIT and SILCAAT) with IL-6 plasma levels measured at baseline were included (N=9864). Factors independently associated with log2-transformed IL-6 level were identified by multivariate linear regression; exponentiated estimates......INTRODUCTION: Elevated IL-6 levels have been linked to increased risk of cardiovascular disease (CVD), cancer and death. Compared to the general population, treated HIV+ persons have 50-100% higher IL-6 levels, but few data on the determinants of IL-6 levels during HIV infection currently exist...

Novinky v léčbě HIV infekce

Czech Academy of Sciences Publication Activity Database

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

Proteases and protease inhibitors of urinary extracellular vesicles in diabetic nephropathy.

Science.gov (United States)

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.

Proteases and Protease Inhibitors of Urinary Extracellular Vesicles in Diabetic Nephropathy

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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.

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

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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.

Evaluation of sequence ambiguities of the HIV-1 pol gene as a method to identify recent HIV-1 infection in transmitted drug resistance surveys.

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Andersson, Emmi; Shao, Wei; Bontell, Irene; Cham, Fatim; Cuong, Do Duy; Wondwossen, Amogne; Morris, Lynn; Hunt, Gillian; Sönnerborg, Anders; Bertagnolio, Silvia; Maldarelli, Frank; Jordan, Michael R

2013-08-01

Identification of recent HIV infection within populations is a public health priority for accurate estimation of HIV incidence rates and transmitted drug resistance at population level. Determining HIV incidence rates by prospective follow-up of HIV-uninfected individuals is challenging and serological assays have important limitations. HIV diversity within an infected host increases with duration of infection. We explore a simple bioinformatics approach to assess viral diversity by determining the percentage of ambiguous base calls in sequences derived from standard genotyping of HIV-1 protease and reverse transcriptase. Sequences from 691 recently infected (≤1 year) and chronically infected (>1 year) individuals from Sweden, Vietnam and Ethiopia were analyzed for ambiguity. A significant difference (p<0.0001) in the proportion of ambiguous bases was observed between sequences from individuals with recent and chronic infection in both HIV-1 subtype B and non-B infection, consistent with previous studies. In our analysis, a cutoff of <0.47% ambiguous base calls identified recent infection with a sensitivity and specificity of 88.8% and 74.6% respectively. 1,728 protease and reverse transcriptase sequences from 36 surveys of transmitted HIV drug resistance performed following World Health Organization guidance were analyzed for ambiguity. The 0.47% ambiguity cutoff was applied and survey sequences were classified as likely derived from recently or chronically infected individuals. 71% of patients were classified as likely to have been infected within one year of genotyping but results varied considerably amongst surveys. This bioinformatics approach may provide supporting population-level information to identify recent infection but its application is limited by infection with more than one viral variant, decreasing viral diversity in advanced disease and technical aspects of population based sequencing. Standardization of sequencing techniques and base calling

Prevalence of genotypic HIV-1 drug resistance in Thailand, 2002

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Watitpun Chotip

2003-03-01

Full Text Available Abstract Background The prices of reverse transcriptase (RT inhibitors in Thailand have been reduced since December 1, 2001. It is expected that reduction in the price of these inhibitors may influence the drug resistance mutation pattern of HIV-1 among infected people. This study reports the frequency of HIV-1 genetic mutation associated with drug resistance in antiretroviral-treated patients from Thailand. Methods Genotypic resistance testing was performed on samples collected in 2002 from 88 HIV-1 infected individuals. Automated DNA sequencing was used to genotype the HIV-1 polymerase gene isolated from patients' plasma. Results Resistance to protease inhibitors, nucleoside and non-nucleoside reverse transcriptase inhibitors were found in 10 (12%, 42 (48% and 19 (21% patients, respectively. The most common drug resistance mutations in the protease gene were at codon 82 (8%, 90 (7% and 54 (6%, whereas resistant mutations at codon 215 (45%, 67 (40%, 41 (38% and 184 (27% were commonly found in the RT gene. This finding indicates that genotypic resistance to nucleoside reverse transcriptase inhibitors was prevalent in 2002. The frequency of resistant mutations corresponding to non-nucleoside reverse transcriptase inhibitors was three times higher-, while resistant mutation corresponding to protease inhibitors was two times lower than those frequencies determined in 2001. Conclusion This study shows that the frequencies of RT inhibitor resistance mutations have been increased after the reduction in the price of RT inhibitors since December 2001. We believe that this was an important factor that influenced the mutation patterns of HIV-1 protease and RT genes in Thailand.

The Effect of Exogenous Protease in Broiler Diets on the Apparent Ileal Digestibility of Amino Acids and on Protease Activity in Jejunum

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Vojtěch Rada

2016-01-01

Full Text Available The objective of this study was to evaluate the effect of a mono-component commercial serine protease supplement in broiler diets on apparent ileal amino acid digestibility and protease activity. A total of 150 male (28 d old ROSS 308 were randomly placed into 30 battery pens and divided into 5 treatment groups with 6 replicates each. The experiment was performed for 7 days. Five dietary treatments were used: 2 standard protein diets without (SP and with protease (SP + P formulated 20.7 % CP, 2 lower-protein diets (19.9 % CP without (LP and with protease (LP + P and one lower‑protein diet with protease and with doubled rapeseed meal (RSM content (SP-RSM + P compared with the other treatments. Lower-protein diets were formulated with a 4 % decrease in the relative CP value compared with the standard protein diet. Enzyme protease was added to the diets at a concentration of 200 ppm (15,000 PROT units per kg. The diets contained 0.3 % Cr2O3 to facilitate the estimation of apparent AA digestibility and overall apparent ileal crude protein digestibility. Mono-component protease had no effect on apparent ileal AA digestibility or jejunum protease activity if diets contained the same level of RSM. The supplement of exogenous protease did not affect (P > 0.05 the apparent ileal AA digestibility coefficients if a higher RSM level was used. The CP level influenced (P < 0.05 only the coefficients of the apparent ileal AA digestibility of Pro and Arg. The RSM level (P < 0.01 had significant effects on protease activity in the jejunum.

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

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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.

Respiratory Failure Associated with the Lipodystrophy Syndrome in an HIV-Positive Patient with Compromised Lung Function

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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.

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

NARCIS (Netherlands)

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

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

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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.

Individual- and contextual-level factors associated with client-initiated HIV testing

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Claudia Renata dos Santos Barros

Full Text Available ABSTRACT: Background: Knowing the reasons for seeking HIV testing is central for HIV prevention. Despite the availability of free HIV counseling and testing in Brazil, coverage remains lacking. Methods: Survey of 4,760 respondents from urban areas was analyzed. Individual-level variables included sociodemographic characteristics; sexual and reproductive health; HIV/AIDS treatment knowledge and beliefs; being personally acquainted with a person with HIV/AIDS; and holding discriminatory ideas about people living with HIV. Contextual-level variables included the Human Development Index (HDI of the municipality; prevalence of HIV/AIDS; and availability of local HIV counseling and testing (CT services. The dependent variable was client-initiated testing. Multilevel Poisson regression models with random intercepts were used to assess associated factors. Results: Common individual-level variables among men and women included being personally acquainted with a person with HIV/AIDS and age; whereas discordant variables included those related to sexual and reproductive health and experiencing sexual violence. Among contextual-level factors, availability of CT services was variable associated with client-initiated testing among women only. The contextual-level variable “HDI of the municipality” was associated with client-initiated testing among women. Conclusion: Thus, marked gender differences in HIV testing were found, with a lack of HIV testing among married women and heterosexual men, groups that do not spontaneously seek testing.

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

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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.

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

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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

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

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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.

Cell-based fluorescence assay for human immunodeficiency virus type 1 protease activity

Czech Academy of Sciences Publication Activity Database

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

Factors associated with D-dimer levels in HIV-infected individuals

DEFF Research Database (Denmark)

Borges, Alvaro H; O'Connor, Jemma L; Phillips, Andrew N

2014-01-01

BACKGROUND: Higher plasma D-dimer levels are strong predictors of mortality in HIV+ individuals. The factors associated with D-dimer levels during HIV infection, however, remain poorly understood. METHODS: In this cross-sectional study, participants in three randomized controlled trials...... with measured D-dimer levels were included (N = 9,848). Factors associated with D-dimer were identified by linear regression. Covariates investigated were: age, gender, race, body mass index, nadir and baseline CD4+ count, plasma HIV RNA levels, markers of inflammation (C-reactive protein [CRP], interleukin-6...... viruses, was positively correlated with D-dimer. Other factors independently associated with higher D-dimer levels were black race, higher plasma HIV RNA levels, being off ART at baseline, and increased levels of CRP, IL-6 and cystatin C. In contrast, higher baseline CD4+ counts and higher high...

Cloned Bacillus subtilis alkaline protease (aprA) gene showing high level of keratinolytic activity.

Science.gov (United States)

Zaghloul, T I

1998-01-01

The Bacillus subtilis alkaline protease(aprA) gene was previously cloned on a pUBHO-derivative plasmid. High levels of expression and gene stability were demonstrated when B. subtilis cells were grown on the laboratory medium 2XSG. B. subtilis cells harboring the multicopy aprA gene were grown on basal medium, supplemented with 1 % chicken feather as a source of energy, carbon, and nitrogen. Proteolytic and keratinolytic activities were monitored throughout the cultivation time. A high level of keratinolytic activity was obtained, and this indicates that alkaline protease is acting as a keratinase. Furthermore, considerable amounts of soluble proteins and free amino acids were obtained as a result of the enzymatic hydrolysis of feather. Biodegradation of feather waste using these cells represents an alternative way to improve the nutritional value of feather, since feather waste is currently utilized on a limited basis as a dietary protein supplement for animal feedstuffs. Moreover, the release of free amino acids from feather and the secreted keratinase enzyme would promote industries based on feather waste.

High Levels of Inflammatory Cytokines in the Reproductive Tract of Women with BV and Engaging in Intravaginal Douching: A Cross-Sectional Study of Participants in the Women Interagency HIV Study.

Science.gov (United States)

Alcaide, Maria L; Rodriguez, Violeta J; Brown, Megan R; Pallikkuth, Suresh; Arheart, Kristopher; Martinez, Octavio; Roach, Margaret; Fichorova, Raina N; Jones, Deborah L; Pahwa, Savita; Fischl, Margaret A

2017-04-01

High levels of inflammatory cytokines in the genital tract suggest mucosal vulnerability and increased risk of HIV and sexually transmitted infection (STI) acquisition. Intravaginal douching is associated with bacterial vaginosis (BV) in women in the United States, and both douching and BV are linked to HIV and STI acquisition. This study evaluates inflammatory cytokines in the genital tract to increase understanding of the effects of both BV and intravaginal douching to the vaginal mucosa. A cross-sectional study of participants in the Miami WIHS investigated 72 reproductive age women (45 HIV + and 27 high-risk HIV - ) who completed intravaginal douching questionnaires and underwent collection of vaginal swabs and cervicovaginal lavages (CVLs). BV was assessed using the Nugent score. Inflammatory cytokines in the CVLs (interleukin [IL]-6, IL-8, IL-1α, IL-1β, soluble intracellular adhesion molecule-1 [sICAM-1], interferon [IFN]α2, chemokine C ligand 5 (CCL5), vascular endothelial growth factor (VEGF), monocyte chemotactic protein-1 (MCP1), tumor necrosis factor alpha (TNFα), and secretory leukocyte protease inhibitor [SLPI]) were measured. Fourteen (19%) women reported intravaginal douching; 24 (33%) had BV. BV, intravaginal douching, and HIV were associated with higher levels of inflammatory cytokines. After controlling for demographic and risk factors and HIV status, women who had BV and douched had higher levels of inflammatory cytokines than those without BV and who did not douche, or who only had BV or only douched. These findings suggest that BV and douching are associated with greater mucosal inflammation and may facilitate HIV acquisition and transmission. Although longitudinal studies are needed to determine temporal associations and causality, interventions to decrease rates of intravaginal douching and BV could significantly decrease women's risks of acquiring STIs and HIV and limit the spread of HIV.

HIV infection duration, social support and the level of trauma symptoms in a sample of HIV-positive Polish individuals.

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Rzeszutek, Marcin; Oniszczenko, Włodzimierz; Żebrowska, Magdalena; Firląg-Burkacka, Ewa

2015-01-01

The aim of this study was to investigate the relationship between the average HIV infection duration and the level of quantitatively rated post-traumatic stress disorder (PTSD) symptoms and social support dimensions in a sample of 562 Polish HIV+ adults. Possible moderating effects of social support on the relationship between the average HIV infection duration and the level of PTSD symptoms were also analysed. The results of this study suggest that the average HIV infection duration may intensify PTSD symptoms and deteriorate the perceived availability of social support in HIV+ individuals. However, a positive relationship between HIV infection duration and the level of trauma symptoms was observed only in the group of HIV+ individuals with low perceived available social support, but not in the group of HIV-infected individuals with high perceived available social support. This research provided some new insight into the psychological and social aspects of living with HIV. In particular, our results suggest that although HIV infection duration may intensify trauma symptoms and deteriorate social support, perceived available social support may act as a buffer against HIV-related trauma symptoms.

Peripheral blood mononuclear cells HIV DNA levels impact intermittently on neurocognition.

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Lucette A Cysique

Full Text Available To determine the contribution of peripheral blood mononuclear cells' (PBMCs HIV DNA levels to HIV-associated dementia (HAD and non-demented HIV-associated neurocognitive disorders (HAND in chronically HIV-infected adults with long-term viral suppression on combined antiretroviral treatment (cART.Eighty adults with chronic HIV infection on cART (>97% with plasma and CSF HIV RNA <50 copies/mL were enrolled into a prospective observational cohort and underwent assessments of neurocognition and pre-morbid cognitive ability at two visits 18 months apart. HIV DNA in PBMCs was measured by real-time PCR at the same time-points.At baseline, 46% had non-demented HAND; 7.5% had HAD. Neurocognitive decline occurred in 14% and was more likely in those with HAD (p<.03. Low pre-morbid cognitive ability was uniquely associated with HAD (p<.05. Log10 HIV DNA copies were stable between study visits (2.26 vs. 2.22 per 106 PBMC. Baseline HIV DNA levels were higher in those with lower pre-morbid cognitive ability (p<.04, and higher in those with no ART treatment during HIV infection 1st year (p = .03. Baseline HIV DNA was not associated with overall neurocognition. However, % ln HIV DNA change was associated with decline in semantic fluency in unadjusted and adjusted analyses (p = .01-.03, and motor-coordination (p = .02-.12 to a lesser extent.PBMC HIV DNA plays a role in HAD pathogenesis, and this is moderated by pre-morbid cognitive ability in the context of long-term viral suppression. While the HIV DNA levels in PBMC are not associated with current non-demented HAND, increasing HIV DNA levels were associated with a decline in neurocognitive functions associated with HAND progression.

EFFECT OF SHORT-TERM ART INTERRUPTION ON LEVELS OF INTEGRATED HIV DNA.

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Strongin, Zachary; Sharaf, Radwa; VanBelzen, D Jake; Jacobson, Jeffrey M; Connick, Elizabeth; Volberding, Paul; Skiest, Daniel J; Gandhi, Rajesh T; Kuritzkes, Daniel R; O'Doherty, Una; Li, Jonathan Z

2018-03-28

Analytic treatment interruption (ATI) studies are required to evaluate strategies aimed at achieving ART-free HIV remission, but the impact of ATI on the viral reservoir remains unclear. We validated a DNA size selection-based assay for measuring levels of integrated HIV DNA and applied it to assess the effects of short-term ATI on the HIV reservoir. Samples from participants from four AIDS Clinical Trials Group (ACTG) ATI studies were assayed for integrated HIV DNA levels. Cryopreserved PBMCs were obtained for 12 participants with available samples pre-ATI and approximately 6 months after ART resumption. Four participants also had samples available during the ATI. The median duration of ATI was 12 weeks. Validation of the HIV Integrated DNA size-Exclusion (HIDE) assay was performed using samples spiked with unintegrated HIV DNA, HIV-infected cell lines, and participant PBMCs. The HIDE assay eliminated 99% of unintegrated HIV DNA species and strongly correlated with the established Alu- gag assay. For the majority of individuals, integrated DNA levels increased during ATI and subsequently declined upon ART resumption. There was no significant difference in levels of integrated HIV DNA between the pre- and post-ATI time points, with the median ratio of post:pre-ATI HIV DNA levels of 0.95. Using a new integrated HIV DNA assay, we found minimal change in the levels of integrated HIV DNA in participants who underwent an ATI followed by 6 months of ART. This suggests that short-term ATI can be conducted without a significant impact on levels of integrated proviral DNA in the peripheral blood. IMPORTANCE Interventions aimed at achieving sustained antiretroviral therapy (ART)-free HIV remission require treatment interruption trials to assess their efficacy. However, these trials are accompanied by safety concerns related to the expansion of the viral reservoir. We validated an assay that uses an automated DNA size-selection platform for quantifying levels of integrated

In-cell protease assay systems based on trans-localizing molecular beacon proteins using HCV protease as a model system.

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Jeong Hee Kim

Full Text Available This study describes a sensitive in-cell protease detection system that enables direct fluorescence detection of a target protease and its inhibition inside living cells. This live-cell imaging system provides a fluorescent molecular beacon protein comprised of an intracellular translocation signal sequence, a protease-specific cleavage sequence, and a fluorescent tag sequence(s. The molecular beacon protein is designed to change its intracellular localization upon cleavage by a target protease, i.e., from the cytosol to a subcellular organelle or from a subcellular organelle to the cytosol. Protease activity can be monitored at the single cell level, and accordingly the entire cell population expressing the protease can be accurately enumerated. The clear cellular change in fluorescence pattern makes this system an ideal tool for various life science and drug discovery research, including high throughput and high content screening applications.

HIV and pregnancy: Maternal and neonatal evolution

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Diego Cecchini

2011-10-01

Full Text Available Data regarding epidemiological aspects, antiretroviral drug safety, and outcomes of HIV-infected pregnant women and their newborns are limited in Argentina. We underwent a retrospective analysis of registries of HIV-infected pregnant women assisted at Helios Salud, Buenos Aires, Argentina (1997-2006. Variables associated with preterm delivery and neonatal complications were analyzed by univariate and logistic regression analyses. A total of 204 mother-child binomium were included. Maternal age (median: 29 years; 32.5% without prior diagnosis of HIV-infection. Baseline median CD4 T-cell count: 417 cell/μl; 98% received antiretroviral drugs during pregnancy [2 nucleoside analogs plus either nevirapine (55% or a protease inhibitor (32%]. Overall incidence of toxicity was 12.5%: rash (8%, anemia (3.5% and hepatotoxicity (1%. Rash was associated with exposure to nevirapine. Eighty one percent and 50% reached HIV-viral loads <1000 and <50 copies/ml at the end of pregnancy, respectively. Twenty six percent had obstetric complications and 16% had preterm delivery. Of the newborns, 1.6% had congenital defects and 9% had neonatal complications. Overall neonatal mortality was 1% and perinatal transmission was 0.7%. Protease inhibitor use and obstetric complications were associated to preterm delivery while obstetric complications were associated with neonatal complications. In our population, hepatotoxicity was low despite frequent use of nevirapine. Protease inhibitor use was associated to preterm delivery. A favorable virological response and a low rate of perinatal transmission was observed, what supports the consensus that antiretroviral therapy benefits during pregnancy outweigh risks of maternal and neonatal adverse events.

Ninety-nine is not enough: molecular characterization of inhibitor-resistant human immunodeficiency virus type 1 protease mutants with insertions in the flap region

Czech Academy of Sciences Publication Activity Database

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

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

Science.gov (United States)

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.

The effect of fluconazole on ritonavir and saquinavir pharmacokinetics in HIV-1-infected individuals

NARCIS (Netherlands)

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,

Supplementation of broiler diets with high levels of microbial protease and phytase enables partial replacement of commercial soybean meal with raw, full-fat soybean.

Science.gov (United States)

Erdaw, M M; Perez-Maldonado, R A; Iji, P A

2018-02-22

A 3 × 3 + 1 factorial, involving three levels of protease (0, 15,000 or 30,000 PROT/kg) and three levels of phytase (1,000, 2,000 or 3,000 FYT/kg), was used to evaluate the effect of replacing commercial soybean meal (SBM) with raw, full-fat soybean (RFSB) at 75 g/kg of diet for broilers. A control diet was used for comparison. Each treatment was replicated six times, with nine birds per replicate. The concentration of trypsin inhibitors (TIs) in the test diets was approximately 10,193.4 TIU/kg. Regardless of enzyme supplementation, feed intake (FI) and body weight gain (BWG) of birds in the control group were superior to those on the test diets. Birds that received the protease-free test diets had reduced FI and BWG, but when supplemented with protease, were similar to the control diet in BWG, FI (except 0-35 days) and feed conversion ratio (FCR). When the test diet was supplemented with elevated levels (extradose) of protease and phytase, the BWG was improved during 0-10 days (p = .05) and 0-24 days (p replace SBM in broiler diets, provided the diets are supplemented with elevated levels of protease and phytase. © 2018 Blackwell Verlag GmbH.

Lipoprotein(a) and HIV: Allele-Specific Apolipoprotein(a) Levels Predict Carotid Intima-Media Thickness in HIV-Infected Young Women in the Women's Interagency HIV Study.

Science.gov (United States)

Enkhmaa, Byambaa; Anuurad, Erdembileg; Zhang, Wei; Li, Chin-Shang; Kaplan, Robert; Lazar, Jason; Merenstein, Dan; Karim, Roksana; Aouizerat, Brad; Cohen, Mardge; Butler, Kenneth; Pahwa, Savita; Ofotokun, Igho; Adimora, Adaora A; Golub, Elizabeth; Berglund, Lars

2017-05-01

In the general population, lipoprotein(a) [Lp(a)] has been established as an independent causal risk factor for cardiovascular disease. Lp(a) levels are to a major extent regulated by a size polymorphism in the apolipoprotein(a) [apo(a)] gene. The roles of Lp(a)/apo(a) in human immunodeficiency virus (HIV)-related elevated cardiovascular disease risk remain unclear. The associations between total plasma Lp(a) level, allele-specific apo(a) level, an Lp(a) level carried by individual apo(a) alleles, and common carotid artery intima-media thickness were assessed in 150 HIV-infected and 100 HIV-uninfected women in the WIHS (Women's Interagency HIV Study). Linear regression analyses with and without adjustments were used. The cohort was young (mean age, ≈31 years), with the majority being Blacks (≈70%). The prevalence of a small size apo(a) (≤22 Kringle repeats) or a high Lp(a) level (≥30 mg/dL) was similar by HIV status. Total plasma Lp(a) level ( P =0.029) and allele-specific apo(a) level carried by the smaller apo(a) sizes ( P =0.022) were significantly associated with carotid artery intima-media thickness in the HIV-infected women only. After accounting for confounders (age, race, smoking, body mass index, blood pressure, hepatitis C virus coinfection, menopause, plasma lipids, treatment status, CD4 + T cell count, and HIV/RNA viral load), the association remained significant for both Lp(a) ( P =0.035) and allele-specific apo(a) level carried by the smaller apo(a) sizes ( P =0.010) in the HIV-infected women. Notably, none of the other lipids/lipoproteins was associated with carotid artery intima-media thickness. Lp(a) and allele-specific apo(a) levels predict carotid artery intima-media thickness in HIV-infected young women. Further research is needed to identify underlying mechanisms of an increased Lp(a) atherogenicity in HIV infection. © 2017 American Heart Association, Inc.

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

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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.

Protease and protease inhibitory activity in pregnant and postpartum involuting uterus

International Nuclear Information System (INIS)

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

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

Science.gov (United States)

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.

Diagnosis, antiretroviral therapy, and emergence of resistance to antiretroviral agents in HIV-2 infection: a review

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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.

[Renal transplantation in HIV-infected patients in Spain].

Science.gov (United States)

Mazuecos, A; Pascual, J; Gómez, E; Sola, E; Cofán, F; López, F; Puig-Hooper, C E; Baltar, J M; González-Molina, M; Oppenheimer, F; Marcén, R; Rivero, M

2006-01-01

HIV infection has experienced dramatic improvement in morbidity and mortality with the highly active antiretroviral therapy (HAART). This prompted a reevaluation of organ-solid transplantation as a treatment option for HIV-infected patients. Some trials in the United States have shown that one- and 2-year graft and patient survival is comparable to HIV-negative transplant population. In Europe the experience is still scarce. The aim of this study is to analyse the outcome and the clinical characteristics of HIV-infected patients who received kidney transplantation in Spain in the HAART era. Ten patients were transplanted in our country since 2001. Only one patient was black. The main cause of end-stage renal disease reported was glomerulonephritis. Six of the recipients were coinfected by hepatitis C virus. Inclusion criteria included undetectable HIV viral load and CD4 counts greater than 200/pL. Immunosuppression consisted of steroids, tacrolimus and mycophenolate mofetil, with antibody induction in 4 cases. The median and mean follow-up was 11 and 16.3+/-15.6 (3-46) months, respectively. One recipient lost his graft because of early renal venous thrombosis. The remaining patients are functioning graft with mean serum creatinina level of 1.5 +/- 0.5 mg/dl. Biopsy-proven acute rejection was diagnosed in 4 recipients and was reversed in all cases with antirejection treatment. The plasma HIV RNA levels have remained controlled and CD4 counts have been stable in excess of 200 cell/microL. None of patients have developed AIDS complications. Recipients receiving protease inhibitor-based HAART regimens required significant dosing modification to maintain appropriate tacrolimus levels. Our results show that renal transplantation can be a safe and effective treatment in select HIV-infected patients. Like other series, the acute rejection rate was higher than in non-HIV recipients. The reasons of this rejection incidence remain unknown.

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

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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.

The association between HIV (treatment), pregnancy serum lipid concentrations and pregnancy outcomes: a systematic review.

Science.gov (United States)

Harmsen, Marissa J; Browne, Joyce L; Venter, Francois; Klipstein-Grobusch, Kerstin; Rijken, Marcus J

2017-07-11

Observed adverse effects of antiretroviral therapy (ART) on the lipid profile could be of significance in pregnancy. This systematic review aims to summarize studies that investigated the association between HIV, ART and serum lipids during pregnancy and adverse pregnancy outcomes. A systematic search was conducted in five electronic databases to obtain articles that measured serum lipid concentrations or the incidence of dyslipidaemia in HIV-infected pregnant women. Included articles were assessed for quality according to the Cochrane Risk of Bias Tool. The extracted data was analysed through descriptive analysis. Of the 1264 articles screened, 17 articles were included in this review; eleven reported the incidence of dyslipidaemia, and twelve on maternal serum lipid concentrations under the influence of HIV-infection and ART. No articles reported pregnancy outcomes in relation to serum lipids. Articles were of acceptable quality, but heterogenic in methods and study design. Lipid levels in HIV-infected women increased 1.5-3 fold over the trimesters of pregnancy, and remained within the physiological reference range. The percentage of women with dyslipidaemia was variable between the studies [0-88.9%] and highest in the groups on first generation protease inhibitors and for women on ART at conception. This systematic review observed physiologic concentrations of serum lipids for HIV-infected women receiving ART during pregnancy. Serum lipids were increased in users of first generation protease inhibitors and for those on treatment at conception. There was no information available about pregnancy outcomes. Future studies are needed which include HIV-uninfected control groups, control for potential confounders, and overcome limitations associated with included studies.

Full Viral Suppression, Low-Level Viremia, and Quantifiable Plasma HIV-RNA at the End of Pregnancy in HIV-Infected Women on Antiretroviral Treatment.

Science.gov (United States)

Baroncelli, Silvia; Pirillo, Maria F; Tamburrini, Enrica; Guaraldi, Giovanni; Pinnetti, Carmela; Degli Antoni, Anna; Galluzzo, Clementina M; Stentarelli, Chiara; Amici, Roberta; Floridia, Marco

2015-07-01

There is limited information on full viral suppression and low-level HIV-RNA viremia in HIV-infected women at the end of pregnancy. We investigated HIV-RNA levels close to delivery in women on antiretroviral treatment in order to define rates of complete suppression, low-level viremia, and quantifiable HIV-RNA, exploring as potential determinants some clinical and viroimmunological variables. Plasma samples from a national study in Italy, collected between 2003 and 2012, were used. According to plasma HIV-RNA levels, three groups were defined: full suppression (target not detected), low-level viremia (target detected but HIV-RNA (≥37 copies/ml). Multivariable logistic regression was used to define determinants of full viral suppression and of quantifiable HIV-RNA. Among 107 women evaluated at a median gestational age of 35 weeks, 90 (84.1%) had HIV-RNA HIV-RNA was 109 copies/ml (IQR 46-251), with only one case showing resistance (mutation M184V; rate: 9.1%). In multivariable analyses, women with higher baseline HIV-RNA levels and with hepatitis C virus (HCV) coinfection were significantly more likely to have quantifiable HIV-RNA in late pregnancy. Full viral suppression was significantly more likely with nonnucleoside reverse transcriptase inhibitor (NNRTI)-based regimens and significantly less likely with higher HIV-RNA in early pregnancy. No cases of HIV transmission occurred. In conclusion, HIV-infected pregnant women showed a high rate of viral suppression and a low resistance rate before delivery. In most cases no target HIV-RNA was detected in plasma, suggesting a low risk of subsequent virological rebound and development of resistance. Women with high levels of HIV-RNA in early pregnancy and those who have concomitant HCV infection should be considered at higher risk of having quantifiable HIV-RNA at the end of pregnancy.

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

Science.gov (United States)

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

Earthworm Protease

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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.

Earthworm Protease

International Nuclear Information System (INIS)

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.

Mucosal serpin A1 and A3 levels in HIV highly exposed sero-negative women are affected by the menstrual cycle and hormonal contraceptives but are independent of epidemiological confounders.

Science.gov (United States)

Rahman, Syeda; Rabbani, Rasheda; Wachihi, Charles; Kimani, Joshua; Plummer, Francis A; Ball, Terry B; Burgener, Adam

2013-01-01

Serpins (serine protease inhibitors) are associated with protection against HIV infection. Here, we characterized mucosal serpin expression in the genital tract of HIV highly exposed sero-negative (HESN) women meeting our epidemiological definition of HIV resistance in relation to epidemiological variables. Cervicovaginal lavage (CVL) fluid and plasma were collected from 84 HIV-resistant, 54 HIV-uninfected, and 66 HIV-infected female commercial sex workers. Serpin A1 and A3 concentrations were measured by ELISA and compared with clinical information. Mucosal serpin A1 was elevated during proliferative phase over secretory phase (P = 0.017*), while A3 remained similar (P = 0.25). Plasma and mucosal serpin A1/A3 levels were not associated with each other and appeared compartment specific (r = 0.21, r = 0.056). Serpin A1/A3 expression did not associate with age (r = 0.009, r = -0.06), duration of sex work (r = 0.13, r = -0.10), clients per day (r = -0.11, r = -0.02), concurrent STIs (P = 0.36, P = 0.15), but was lower in women using hormonal contraceptives (P = 0.034, P = 0.008). Mucosal serpin A1/A3 levels in HIV-infected individuals were not significantly different with disease status as determined by plasma CD4(+) T-cell counts (P = 0.94, P = 0.30). This study shows the relationship of serpins to the menstrual cycle and hormonal contraceptives, as well as their independence to epidemiological sexual confounders. This information provides a broader understanding of innate components of the mucosal immune system in women. © 2012 John Wiley & Sons A/S.

A network-level explanation for the differences in HIV prevalence in ...

African Journals Online (AJOL)

A network-level explanation for the differences in HIV prevalence in South Africa's ... or ethnic groups may help explain the differential spread of HIV in South Africa. ... Keywords: concurrency, epidemiology, ethnicity, HIV/AIDS, race, social ...

Changes in Serum Proteins and Creatinine levels in HIV Infected ...

African Journals Online (AJOL)

This study examined the level of total serum proteins and globulins in HIV infected Nigerians. 64 patients with HIV infection and 10 apparently healthy subjects were recruited from 3 hospitals in Lagos Metropolis. They were examined for the presence of TB and malaria. Serum total protein, albumin and creatinine levels ...

Increasing procaspase 8 expression using repurposed drugs to induce HIV infected cell death in ex vivo patient cells.

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Rahul Sampath

Full Text Available HIV persists because a reservoir of latently infected CD4 T cells do not express viral proteins and are indistinguishable from uninfected cells. One approach to HIV cure suggests that reactivating HIV will activate cytotoxic pathways; yet when tested in vivo, reactivating cells do not die sufficiently to reduce cell-associated HIV DNA levels. We recently showed that following reactivation from latency, HIV infected cells generate the HIV specific cytotoxic protein Casp8p41 which is produced by HIV protease cleaving procaspase 8. However, cell death is prevented, possibly due to low procaspase 8 expression. Here, we tested whether increasing procaspase 8 levels in CD4 T cells will produce more Casp8p41 following HIV reactivation, causing more reactivated cells to die. Screening 1277 FDA approved drugs identified 168 that increased procaspase 8 expression by at least 1.7-fold. Of these 30 were tested for anti-HIV effects in an acute HIVIIIb infection model, and 9 drugs at physiologic relevant levels significantly reduced cell-associated HIV DNA. Primary CD4 T cells from ART suppressed HIV patients were treated with one of these 9 drugs and reactivated with αCD3/αCD28. Four drugs significantly increased Casp8p41 levels following HIV reactivation, and decreased total cell associated HIV DNA levels (flurbiprofen: p = 0.014; doxycycline: p = 0.044; indomethacin: p = 0.025; bezafibrate: P = 0.018 without effecting the viability of uninfected cells. Thus procaspase 8 levels can be increased pharmacologically and, in the context of HIV reactivation, increase Casp8p41 causing death of reactivating cells and decreased HIV DNA levels. Future studies will be required to define the clinical utility of this or similar approaches.

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

Science.gov (United States)

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

Osteonecrosis en pacientes infectados por HIV Osteonecrosis in HIV-infected patients

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Edgardo G. Bottaro

2004-08-01

Full Text Available Según la literatura, la osteonecrosis tiene una mayor incidencia en los pacientes infectados con HIV que en la población general. Ello sería resultado de la confluencia de factores de riesgo clásicos y de otros propios de esta población o más prevalentes en ella, como el tratamiento con inhibidores de proteasa, la dislipemia producto de su consumo, la presencia de anticuerpos anticardiolipina séricos, la hipercoagulabilidad, la restauración inmune y las vasculitis. Presentamos una serie de 13 pacientes infectados con HIV con osteonecrosis. El motivo de consulta fue dolor en grandes articulaciones. Cuatro eran alcoholistas, 8 tabaquistas y 9 tenían dislipemia. Once habían recibido esteroides en algún momento de la vida aunque sólo uno estaba recibiéndolos al momento del inicio del dolor. En 2 se detectaron anticuerpos anticardiolipina séricos. Doce tenían sida y recibían tratamiento antirretroviral de alta eficacia (11 con inhibidores de proteasa. Ellos lograron una adecuada recuperación inmunológica. Consideramos necesario incluir la osteonecrosis como diagnóstico diferencial de artralgia persistente en pacientes infectados con HIV e investigar infección por HIV en todo paciente con osteonecrosis sin claros factores predisponentes.Osteonecrosis, also known as avascular necrosis, is chiefly characterized by death of bone caused by vascular compromise. The true incidence of osteonecrosis in HIV-infected patients is not well known and the pathogenesis remains undefined. Hypothetical risk factors peculiar to HIV-infected individuals that might play a role in the pathogenesis of osteonecrosis include the introduction of protease inhibitors and resulting hyperlipidemia, the presence of anticardiolipin antibodies in serum leading to a hypercoagulable state, immune recovery and vasculitis. Hereby we present a series of 13 HIV-infected patients with osteonecrosis. The most common symptom upon presentation was arthralgia. The majority

Inhibition of protease activity by antisense RNA improves recombinant protein production in Nicotiana tabacum cv. Bright Yellow 2 (BY-2) suspension cells.

Science.gov (United States)

Mandal, Manoj K; Fischer, Rainer; Schillberg, Stefan; Schiermeyer, Andreas

2014-08-01

Recombinant proteins produced in plant suspension cultures are often degraded by endogenous plant proteases when secreted into the medium, resulting in low yields. To generate protease-deficient tobacco BY-2 cell lines and to retrieve the sequence information, we cloned four different protease cDNAs from tobacco BY-2 cells (NtAP, NtCP, NtMMP1, and NtSP), which represent the major catalytic classes. The simultaneous expression of antisense RNAs against these endogenous proteases led to the establishment of cell lines with reduced levels of endogenous protease expression and activity at late stages of the cultivation cycle. One of the cell lines showing reduced proteolytic activity in the culture medium was selected for the expression of the recombinant full-length IgG1(κ) antibody 2F5, recognizing the gp41 surface protein of HIV-1. This cell line showed significantly reduced degradation of the 2F5 heavy chain, resulting in four-fold higher accumulation of the intact antibody heavy chain when compared to transformed wild type cells expressing the same antibody. N-terminal sequencing data revealed that the antibody has two cleavage sites within the CDR-H3 and one site at the end of the H4-framework region. These cleavage sites are found to be vulnerable to serine proteases. The data provide a basis for further improvement of plant cells for the production of recombinant proteins in plant cell suspension cultures. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Decreased chronic morbidity but elevated HIV associated cytokine levels in HIV-infected older adults receiving HIV treatment: benefit of enhanced access to care?

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Portia C Mutevedzi

Full Text Available The association of HIV with chronic morbidity and inflammatory markers (cytokines in older adults (50+years is potentially relevant for clinical care, but data from African populations is scarce.To examine levels of chronic morbidity by HIV and ART status in older adults (50+years and subsequent associations with selected pro-inflammatory cytokines and body mass index.Ordinary, ordered and generalized ordered logistic regression techniques were employed to compare chronic morbidity (heart disease (angina, arthritis, stroke, hypertension, asthma and diabetes and cytokines (Interleukins-1 and -6, C-Reactive Protein and Tumor Necrosis Factor-alpha by HIV and ART status on a cross-sectional random sample of 422 older adults nested within a defined rural South African population based demographic surveillance.Using a composite measure of all morbidities, controlling for age, gender, BMI, smoking and wealth quintile, HIV-infected individuals on ART had 51% decreased odds (95% CI:0.26-0.92 of current morbidity compared to HIV-uninfected. In adjusted regression, compared to HIV-uninfected, the proportional odds (aPOR of having elevated inflammation markers of IL6 (>1.56 pg/mL was nearly doubled in HIV-infected individuals on (aPOR 1.84; 95%CI: 1.05-3.21 and not on (aPOR 1.94; 95%CI: 1.11-3.41 ART. Compared to HIV-uninfected, HIV-infected individuals on ART had >twice partial proportional odds (apPOR=2.30;p=0.004 of having non-clinically significant raised hsCRP levels(>1 ug/mL; ART-naïve HIV-infected individuals had >double apPOR of having hsCRP levels indicative of increased heart disease risk(>3.9 ug/mL;p=0.008.Although HIV status was associated with increased inflammatory markers, our results highlight reduced morbidity in those receiving ART and underscore the need of pro-actively extending these services to HIV-uninfected older adults, beyond mere provision at fixed clinics. Providing health services through regular community chronic disease

Lipid profile of HIV-infected patients in relation to antiretroviral therapy: a review.

Science.gov (United States)

Souza, Suelen Jorge; Luzia, Liania Alves; Santos, Sigrid Sousa; Rondó, Patrícia Helen Carvalho

2013-01-01

This study reviewed the lipid profile of human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) patients in relation to use of antiretroviral therapy (ART), and its different classes of drugs. A total of 190 articles published in peer-reviewed journals were retrieved from PubMed and LILACS databases; 88 of them met the selection criteria and were included in the review. Patients with HIV/AIDS without ART presented an increase of triglycerides and decreases of total cholesterol, low density lipoprotein (LDL-c), and high density lipoprotein (HDL-c) levels. Distinct ART regimens appear to promote different alterations in lipid metabolism. Protease inhibitors, particularly indinavir and lopinavir, were commonly associated with hypercholesterolemia, high LDL-c, low HDL-c, and hypertriglyceridemia. The protease inhibitor atazanavir is apparently associated with a more advantageous lipid profile. Some nucleoside reverse-transcriptase inhibitors (didanosine, stavudine, and zidovudine) induced lipoatrophy and hypertriglyceridemia, whereas abacavir increased the risk of cardiovascular diseases even in the absence of apparent lipid disorders, and tenofovir resulted in lower levels of cholesterol and triglycerides. Although non-nucleoside reverse-transcriptase inhibitors predisposed to hypertriglyceridemia and hypercholesterolemia, nevirapine was particularly associated with high HDL-c levels, a protective factor against cardiovascular diseases. Therefore, the infection itself, different classes of drugs, and some drugs from the same class of ART appear to exert distinct alterations in lipid metabolism. Copyright © 2013 Elsevier Editora Ltda. All rights reserved.

Predicted levels of HIV drug resistance

DEFF Research Database (Denmark)

Cambiano, Valentina; Bertagnolio, Silvia; Jordan, Michael R

2014-01-01

-term effects. METHODS: The previously validated HIV Synthesis model was calibrated to South Africa. Resistance was modeled at the level of single mutations, transmission potential, persistence, and effect on drug activity. RESULTS: We estimate 652 000 people (90% uncertainty range: 543 000-744 000) are living...... are maintained, in 20 years' time HIV incidence is projected to have declined by 22% (95% confidence interval, CI -23 to -21%), and the number of people carrying NNRTI resistance to be 2.9-fold higher. If enhancements in diagnosis and retention in care occur, and ART is initiated at CD4 cell count less than 500......  cells/μl, HIV incidence is projected to decline by 36% (95% CI: -37 to -36%) and the number of people with NNRTI resistance to be 4.1-fold higher than currently. Prevalence of people with viral load more than 500  copies/ml carrying NRMV is not projected to differ markedly according to future ART...

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

DEFF Research Database (Denmark)

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...

Levels and patterns of HIV RNA viral load in untreated pregnant women

DEFF Research Database (Denmark)

NN, NN; Patel, Deven; Thorne, Claire

2008-01-01

OBJECTIVE: To assess pregnancy levels and patterns of HIV RNA in the absence of antiretroviral therapy, while appropriately adjusting for potential confounders, including maternal immune status and race. METHODS: Data on > or = 1 antenatal HIV RNA measurements were available for 333 untreated HIV......-infected pregnant women enrolled in the European Collaborative Study. CD4 counts and HIV RNA measurements were routinely collected from 1992 and 1998, respectively. Linear mixed effects models based on 246 women for whom complete data were available examined changes in HIV RNA levels over pregnancy, with a nested...... random effects term accounting for measurement variability within women and period of sample collection. RESULTS: The change in HIV RNA over pregnancy varied significantly by race (p=0.005): from the second trimester until delivery, HIV RNA decreased significantly by an estimated 0.019 log(10) copies...

Changes in indinavir exposure over time : a case study in six HIV-1-infected children

NARCIS (Netherlands)

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

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

Czech Academy of Sciences Publication Activity Database

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

A novel protease activity assay using a protease-responsive chaperone protein

International Nuclear Information System (INIS)

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.

A novel protease activity assay using a protease-responsive chaperone protein

Energy Technology Data Exchange (ETDEWEB)

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.

OsteOpaenia and OsteOnecrOsis in HiV infectiOn: repOrt Of tWO ...

African Journals Online (AJOL)

diseases and aroused interest in the interaction of HiV and aging the pathogenesis of the .... prolonged use of corticosteroids in patient case report. 1, with HiV viral ... calcium deposition. this would help rationalise the selection of protease ...

Population-based monitoring of emerging HIV-1 drug resistance on antiretroviral therapy and associated factors in a sentinel site in Cameroon: low levels of resistance but poor programmatic performance.

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Serge C Billong

Full Text Available BACKGROUND: Scale-up of antiretroviral therapy (ART in resource-limited settings has drastically reduced HIV-related morbidity and mortality. However, challenges in long-term ART, adherence and HIV drug resistance (HIVDR itself, require monitoring to limit HIVDR emergence among ART-experienced populations, in order to ensure regimen efficacy. METHODS: A longitudinal study was conducted from 2009-2011 in a cohort of 141 HIV-infected adult patients (aged >21 at the national social insurance centre hospital in Yaounde, Cameroon. As per-WHO HIVDR protocol, HIV-1 protease-reverse transcriptase genotyping was performed at baseline and at endpoint (12 months on first-line ART using ViroSeq™ Genotyping kit. RESULTS: At baseline, a prevalence of 3.6% (5/139 HIVDR was observed [protease inhibitors M46I (1/5, G73A (1/5, L90LM (1/5; nucleoside reverse transcriptase inhibitors: M184V (1/5, T215F (1/5; non-nucleoside reverse transcriptase inhibitors: K103N (1/5, Y181Y/C (2/5, M230ML (1/5]. At endpoint, 54.0% (76 patients were followed-up, 9.2% (13 died, and 3.5% (5 transferred, 38.5% (47 lost to follow-up (LTFU. 69.7% (53/76 of those followed-up had viremia <40 copies/ml and 90.8% (69/76 <1000 copies/ml. 4/7 patients with viremia ≥1000 copies/ml harbored HIVDR (prevalence: 5.3%; 4/76, with M184V/I (4/4 and K103K/N (3/4 being the most prevalent mutations. LTFU was favored by costs for consultation/laboratory tests, drug shortages, workload (physician/patient ratio: 1/180 and community disengagement. CONCLUSIONS: Low levels of HIVDR at baseline and at endpoint suggest a probable effectiveness of ART regimens used in Cameroon. However the possible high rate of HIVDR among LTFUs limited the strengths of our findings. Evaluating HIVDR among LTFU, improving adherence, task shifting, subsidizing/harmonizing costs for routine follow-up, are urgent measures to ensure an improved success of the country ART performance.

Liquefaction of Semen Generates and Later Degrades a Conserved Semenogelin Peptide That Enhances HIV Infection

Science.gov (United States)

Liu, Haichuan; Usmani, Shariq M.; Neidleman, Jason; Müller, Janis A.; Avila-Herrera, Aram; Gawanbacht, Ali; Zirafi, Onofrio; Chu, Simon; Dong, Ming; Kumar, Senthil T.; Smith, James F.; Pollard, Katherine S.; Fändrich, Marcus; Kirchhoff, Frank; Münch, Jan; Witkowska, H. Ewa; Greene, Warner C.

2014-01-01

ABSTRACT Semen enhances HIV infection in vitro, but how long it retains this activity has not been carefully examined. Immediately postejaculation, semen exists as a semisolid coagulum, which then converts to a more liquid form in a process termed liquefaction. We demonstrate that early during liquefaction, semen exhibits maximal HIV-enhancing activity that gradually declines upon further incubation. The decline in HIV-enhancing activity parallels the degradation of peptide fragments derived from the semenogelins (SEMs), the major components of the coagulum that are cleaved in a site-specific and progressive manner upon initiation of liquefaction. Because amyloid fibrils generated from SEM fragments were recently demonstrated to enhance HIV infection, we set out to determine whether any of the liquefaction-generated SEM fragments associate with the presence of HIV-enhancing activity. We identify SEM1 from amino acids 86 to 107 [SEM1(86-107)] to be a short, cationic, amyloidogenic SEM peptide that is generated early in the process of liquefaction but that, conversely, is lost during prolonged liquefaction due to the activity of serine proteases. Synthetic SEM1(86-107) amyloids directly bind HIV-1 virions and are sufficient to enhance HIV infection of permissive cells. Furthermore, endogenous seminal levels of SEM1(86-107) correlate with donor-dependent variations in viral enhancement activity, and antibodies generated against SEM1(86-107) recognize endogenous amyloids in human semen. The amyloidogenic potential of SEM1(86-107) and its virus-enhancing properties are conserved among great apes, suggesting an evolutionarily conserved function. These studies identify SEM1(86-107) to be a key, HIV-enhancing amyloid species in human semen and underscore the dynamic nature of semen's HIV-enhancing activity. IMPORTANCE Semen, the most common vehicle for HIV transmission, enhances HIV infection in vitro, but how long it retains this activity has not been investigated. Semen

Antiretroviral drug susceptibility among drug-naive adults with recent HIV infection in Rakai, Uganda.

Science.gov (United States)

Eshleman, Susan H; Laeyendecker, Oliver; Parkin, Neil; Huang, Wei; Chappey, Colombe; Paquet, Agnes C; Serwadda, David; Reynolds, Steven J; Kiwanuka, Noah; Quinn, Thomas C; Gray, Ronald; Wawer, Maria

2009-04-27

To analyze antiretroviral drug susceptibility in HIV from recently infected adults in Rakai, Uganda, prior to the availability of antiretroviral drug treatment. Samples obtained at the time of HIV seroconversion (1998-2003) were analyzed using the GeneSeq HIV and PhenoSense HIV assays (Monogram Biosciences, Inc., South San Francisco, California, USA). Test results were obtained for 104 samples (subtypes: 26A, 1C, 66D, 9A/D, 1C/D, 1 intersubtype recombinant). Mutations used for genotypic surveillance of transmitted antiretroviral drug resistance were identified in six samples: three had nucleoside reverse transcriptase inhibitor (NRTI) surveillance mutations (two had M41L, one had K219R), and three had protease inhibitor surveillance mutations (I47V, F53L, N88D); none had nonnucleoside reverse transcriptase inhibitor (NNRTI) surveillance mutations. Other resistance-associated mutations were identified in some samples. However, none of the samples had a sufficient number of mutations to predict reduced antiretroviral drug susceptibility. Ten (9.6%) of the samples had reduced phenotypic susceptibility to at least one drug (one had partial susceptibility to didanosine, one had nevirapine resistance, and eight had resistance or partial susceptibility to at least one protease inhibitor). Fifty-three (51%) of the samples had hypersusceptibility to at least one drug (seven had zidovudine hypersusceptibility, 28 had NNRTI hypersusceptibility, 34 had protease inhibitor hypersusceptibility). Delavirdine hypersusceptibility was more frequent in subtype A than D. In subtype D, efavirenz hypersusceptibility was associated with substitutions at codon 11 in HIV-reverse transcriptase. Phenotyping detected reduced antiretroviral drug susceptibility and hypersusceptibility in HIV from some antiretroviral-naive Ugandan adults that was not predicted by genotyping. Phenotyping may complement genotyping for analysis of antiretroviral drug susceptibility in populations with nonsubtype B

CHANGES IN LEVELS OF ACTIVITY OF SERINE PROTEASES ACCOMPANY THE EXPOSURE OF COMMON BEAN (PHASEOLUS VULGARIS L. TO WATER DEFICIT

Directory of Open Access Journals (Sweden)

M. Budič

2008-09-01

Full Text Available A wide variety of proteolytic enzymes exist in plants. On their levels depends protein turnover, a fundamental component in plant development and adaptation to environmental conditions. Cysteine proteases have frequently been reported to be influenced by drought, but only a few serine proteases (SP, among them the trypsin-like enzyme and two aminopeptidases from bean leaves (Bartels and Sunkar, 2005; Hieng et al., 2004. Our starting point was to identify proteolytic activities assigned to SPs that change with drought and then to characterize the corresponding proteases. A quantitative, analytical one-step method was used to separate endopeptidases and aminopeptidases active against a range of substrates in leaf extracts of plants grown in the field (FC. The influence of drought was determined for those of these activities which were confirmed as SPs, based on their inhibition by specific inhibitors. Under water deficit in plants grown under controlled conditions (CC their levels changed in different ways. The levels of SP activities in FC plants, observed during a period of relative drought, were similar to those measured in mildly stressed CC plants. The partial characterisations of some of these SPs will be presented. Our results point to a number of roles for different SPs in the plant response to water stress, which could range from enhanced protein turnover to limited proteolysis at specific sites.

Impaired glucose metabolism in HIV-infected pregnant women: a retrospective analysis.

LENUS (Irish Health Repository)

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.

Characterization of the Mamestra configurata (Lepidoptera: Noctuidae) larval midgut protease complement and adaptation to feeding on artificial diet, Brassica species, and protease inhibitor.

Science.gov (United States)

Erlandson, Martin A; Hegedus, Dwayne D; Baldwin, Douglas; Noakes, Amy; Toprak, Umut

2010-10-01

The midgut protease profiles from 5th instar Mamestra configurata larvae fed various diets (standard artificial diet, low protein diet, low protein diet with soybean trypsin inhibitor [SBTI], or Brassica napus) were characterized by one-dimensional enzymography in gelatin gels. The gut protease profile of larvae fed B. napus possessed protease activities of molecular masses of approximately 33 and 55 kDa, which were not present in the guts of larvae fed artificial diet. Similarly, larvae fed artificial diet had protease activities of molecular masses of approximately 21, 30, and 100 kDa that were absent in larvae fed B. napus. Protease profiles changed within 12 to 24 h after switching larvae from artificial diet to plant diet and vice versa. The gut protease profiles from larvae fed various other brassicaceous species and lines having different secondary metabolite profiles did not differ despite significant differences in larval growth rates on the different host plants. Genes encoding putative digestive proteolytic enzymes, including four carboxypeptidases, five aminopeptidases, and 48 serine proteases, were identified in cDNA libraries from 4th instar M. configurata midgut tissue. Many of the protease-encoding genes were expressed at similar levels on all diets; however, three chymoptrypsin-like genes (McSP23, McSP27, and McSP37) were expressed at much higher levels on standard artificial diet and diet containing SBTI as was the trypsin-like gene McSP34. The expression of the trypsin-like gene McSP50 was highest on B. napus. The adaptation of M. configurata digestive biochemistry to different diets is discussed in the context of the flexibility of polyphagous insects to changing diet sources.

Nasal Nitric Oxide Levels in HIV Infection: A Cross-Sectional Study

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Cecilia T. Costiniuk

2018-01-01

Full Text Available Introduction. Low levels of nasal NO have been associated with increased propensity to rhinosinusitis and respiratory tract infections. Our objective was to describe nasal NO levels in HIV-infected individuals versus healthy controls and determine possible risk factors for reduced nasal NO levels. Materials and Methods. HIV-infected individuals and healthy controls were recruited. Participants underwent nasal NO testing by standardized methods using a CLD88 chemiluminescence analyzer and completed the Sinonasal Outcome Test-20 (SNOT-20 on symptoms of rhinosinusitis. Results. Participants included 41 HIV-infected individuals with suppressed VL on antiretroviral therapy (ART group, 5 HIV-infected individuals with detectable VL off ART (viremic group, and 12 healthy controls (HC group. Mean nasal NO level was 253 (±77 nL/min in the ART group, 213 (±48 nL/min in the viremic group, and 289 (±68 nL/min in the HC group (p=0.133; ANOVA. There was no correlation between nasal NO level and VL in viremic individuals (r=-0.200; p=0.747. Differences were observed in mean total points on the SNOT-20 which were 19 (±16/100, 18 (±26/100, and 4 (±4/100 in the ART, viremic, and HC groups, respectively (p=0.013; ANOVA. Conclusion. Healthy individuals, HIV patients on ART, and viremic individuals off ART display similar nasal NO levels. However, rhinosinusitis symptoms remain prominent despite ART-treatment.

Towards novel therapeutics for HIV through fragment-based screening and drug design.

Science.gov (United States)

Tiefendbrunn, Theresa; Stout, C David

2014-01-01

Fragment-based drug discovery has been applied with varying levels of success to a number of proteins involved in the HIV (Human Immunodeficiency Virus) life cycle. Fragment-based approaches have led to the discovery of novel binding sites within protease, reverse transcriptase, integrase, and gp41. Novel compounds that bind to known pockets within CCR5 have also been identified via fragment screening, and a fragment-based approach to target the TAR-Tat interaction was explored. In the context of HIV-1 reverse transcriptase (RT), fragment-based approaches have yielded fragment hits with mid-μM activity in an in vitro activity assay, as well as fragment hits that are active against drug-resistant variants of RT. Fragment-based drug discovery is a powerful method to elucidate novel binding sites within proteins, and the method has had significant success in the context of HIV proteins.

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

Czech Academy of Sciences Publication Activity Database

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

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

Science.gov (United States)

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.

Full Viral Suppression, Low-Level Viremia, and Quantifiable Plasma HIV-RNA at the End of Pregnancy in HIV-Infected Women on Antiretroviral Treatment

OpenAIRE

Baroncelli, Silvia; Pirillo, Maria F.; Tamburrini, Enrica; Guaraldi, Giovanni; Pinnetti, Carmela; Antoni, Anna Degli; Galluzzo, Clementina M.; Stentarelli, Chiara; Amici, Roberta; Floridia, Marco

2015-01-01

There is limited information on full viral suppression and low-level HIV-RNA viremia in HIV-infected women at the end of pregnancy. We investigated HIV-RNA levels close to delivery in women on antiretroviral treatment in order to define rates of complete suppression, low-level viremia, and quantifiable HIV-RNA, exploring as potential determinants some clinical and viroimmunological variables. Plasma samples from a national study in Italy, collected between 2003 and 2012, were used. According ...

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

NARCIS (Netherlands)

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

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

Science.gov (United States)

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).

A Molecular Approach to Nested RT-PCR Using a New Set of Primers for the Detection of the Human Immunodeficiency Virus Protease Gene.

Science.gov (United States)

Zarei, Mohammad; Ravanshad, Mehrdad; Bagban, Ashraf; Fallahi, Shahab

2016-07-01

The human immunodeficiency virus (HIV-1) is the etiologic agent of AIDS. The disease can be transmitted via blood in the window period prior to the development of antibodies to the disease. Thus, an appropriate method for the detection of HIV-1 during this window period is very important. This descriptive study proposes a sensitive, efficient, inexpensive, and easy method to detect HIV-1. In this study 25 serum samples of patients under treatment and also 10 positive and 10 negative control samples were studied. Twenty-five blood samples were obtained from HIV-1-infected individuals who were receiving treatment at the acquired immune deficiency syndrome (AIDS) research center of Imam Khomeini hospital in Tehran. The identification of HIV-1-positive samples was done by using reverse transcription to produce copy deoxyribonucleic acid (cDNA) and then optimizing the nested polymerase chain reaction (PCR) method. Two pairs of primers were then designed specifically for the protease gene fragment of the nested real time-PCR (RT-PCR) samples. Electrophoresis was used to examine the PCR products. The results were analyzed using statistical tests, including Fisher's exact test, and SPSS17 software. The 325 bp band of the protease gene was observed in all the positive control samples and in none of the negative control samples. The proposed method correctly identified HIV-1 in 23 of the 25 samples. These results suggest that, in comparison with viral cultures, antibody detection by enzyme linked immunosorbent assay (ELISAs), and conventional PCR methods, the proposed method has high sensitivity and specificity for the detection of HIV-1.

Fluorometric assay for phenotypic differentiation of drug-resistant HIV mutants

OpenAIRE

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...

Prevalence of Metabolic Syndrome in Patients with HIV in the Era of Highly Active Antiretroviral Therapy.

Science.gov (United States)

Lombo, Bernardo; Alkhalil, Imran; Golden, Marjorie P; Fotjadhi, Irma; Ravi, Sreedhar; Virata, Michael; Lievano, Marta; Diez, Jose; Ghantous, Andre; Donohue, Thomas

2015-05-01

Since the introduction of combination antiretroviral therapy (cART) as the standard of care for HIV disease, there has been a precipitous decline in the death rate due to HIV/ AIDS. The purpose of this study was to report the prevalence of metabolic syndrome in HIV infected patients. Retrospective, cross-sectional, observational study of 259 patients with HIV infection treated with cART from an urban community hospital. Metabolic syndrome prevalence was defined using the International Diabetes Federation (IDF) and the U.S. National Cholesterol Education Program Adult Treatment Panel III (ATP III) criteria. Study patients were included regardless of the duration of cART. The prevalence of metabolic syndrome was 27% using IDF criteria and 26% using ATP III criteria. Logistic regression analysis found an association between treatment with the protease inhibitor darunavir and metabolic syndrome. (OR 3.32 with 95% confidence interval between 1.54 and 7.15). There is a high prevalence of metabolic syndrome and obesity in HIV patients treated with cART, especially those taking the protease inhibitor darunavir.

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

Directory of Open Access Journals (Sweden)

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.

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

NARCIS (Netherlands)

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

Future-oriented tweets predict lower county-level HIV prevalence in the United States.

Science.gov (United States)

Ireland, Molly E; Schwartz, H Andrew; Chen, Qijia; Ungar, Lyle H; Albarracín, Dolores

2015-12-01

Future orientation promotes health and well-being at the individual level. Computerized text analysis of a dataset encompassing billions of words used across the United States on Twitter tested whether community-level rates of future-oriented messages correlated with lower human immunodeficiency virus (HIV) rates and moderated the association between behavioral risk indicators and HIV. Over 150 million tweets mapped to U.S. counties were analyzed using 2 methods of text analysis. First, county-level HIV rates (cases per 100,000) were regressed on aggregate usage of future-oriented language (e.g., will, gonna). A second data-driven method regressed HIV rates on individual words and phrases. Results showed that counties with higher rates of future tense on Twitter had fewer HIV cases, independent of strong structural predictors of HIV such as population density. Future-oriented messages also appeared to buffer health risk: Sexually transmitted infection rates and references to risky behavior on Twitter were associated with higher HIV prevalence in all counties except those with high rates of future orientation. Data-driven analyses likewise showed that words and phrases referencing the future (e.g., tomorrow, would be) correlated with lower HIV prevalence. Integrating big data approaches to text analysis and epidemiology with psychological theory may provide an inexpensive, real-time method of anticipating outbreaks of HIV and etiologically similar diseases. (PsycINFO Database Record (c) 2015 APA, all rights reserved).

Nucleic Acid Aptamers Against Proteases

DEFF Research Database (Denmark)

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...

CD4 T cells remain the major source of HIV-1 during end stage disease.

NARCIS (Netherlands)

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

Knowledge Level and Attitude of Health Care Workers About HIV/AIDS

Directory of Open Access Journals (Sweden)

Ayse Ižnci

2013-10-01

Full Text Available Aim: In this study,it was aimed to investigate the level of knowledge and attitudes of healty care workers about HIV/AIDS. Material and Method: Data on knowledge and attitude of health care workers about HIV/AIDS was collected with a questionnaire. Results:This research was carried out on 230 health care workers (36 doctors, 194 nurses to investigate their knowledge and attidudes on HIV/AIDS. All of the participants knew that HIV/AIDS is an infectious disease,while 90.4 % of the participants stated that HIV/AIDS can be transmitted sexually.76.5 % of the participants stated they found their work risky for HIV/AIDS. Discussion:These findings have provided a data for educational programs designed for healty care workers. We belive that education programs for healty care workers will be effecive to control HIV/AIDS.

Hyper production of alkaline protease by mutagenized bacillus subtilis

International Nuclear Information System (INIS)

Qureshi, A.M.; Tanseem, F.

2010-01-01

The purpose of this work was to augment the alkaline protease production from Bacillus subtilis by using chemical mutagen (MMS) and UV mutagenesis. A number of mutants were isolated which produce high levels of extra cellular proteases. Analysis of culture supernatants of these mutants had shown that the total amounts of proteolysis activity were increased from 1 to 2 fold over the wild strain. Clones showing promote response were further characterized by analyzing different parameters; like of Temperature, pH substrate concentration and incubation period, to study the activity of protease enzyme. (author)

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

Science.gov (United States)

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.

Escherichia coli contains a soluble ATP-dependent protease (Ti) distinct from protease La

Energy Technology Data Exchange (ETDEWEB)

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.

Escherichia coli contains a soluble ATP-dependent protease (Ti) distinct from protease La

International Nuclear Information System (INIS)

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

Human serum protein and C-reactive protein levels among HIV ...

African Journals Online (AJOL)

Human serum protein and C-reactive protein levels were determined among HIV patients visiting St Camillus Hospital, Uromi, Edo State, Nigeria, between January to March, 2013. Fifty (50) HIV patients (20 males; 30 females) and 50 control subjects (24 males; 26 females) were enrolled for this study. The clinical status of ...

Fluorometric assay for phenotypic differentiation of drug-resistant HIV mutants

Science.gov (United States)

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

Bacterial proteases and virulence

DEFF Research Database (Denmark)

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...

Cerebrospinal fluid HIV-1 RNA levels in asymptomatic patients with early stage chronic HIV-1 infection: support for the hypothesis of local virus replication.

Science.gov (United States)

García, F; Niebla, G; Romeu, J; Vidal, C; Plana, M; Ortega, M; Ruiz, L; Gallart, T; Clotet, B; Miró, J M; Pumarola, T; Gatell, J M

1999-08-20

To assess HIV-1 RNA levels in cerebrospinal fluid (CSF) and their potential correlation with plasma viral load and central nervous system (CNS) HIV-1 infection markers in stable asymptomatic patients with a CD4 T cell count >500x10(6) cells/l. Consecutive patients screened for two trials were eligible for lumbar puncture assessment. At day 0, simultaneous samples of CSF and plasma were obtained and levels of total proteins, albumin, IgG, antibodies against HIV-1 p24 antigen, HIV-1 RNA (using the polymerase chain technique) and white cells were measured. The integrity of the blood-brain barrier was preserved (albumin index > or =7) in 59 out of 70 patients (84%). Intrathecal production of antibodies against HIV-1 p24 antigen was demonstrated in 55 out of 70 individuals (78%). Viral load in CSF was significantly lower than plasma values (3.13+/-0.95 versus 4.53+/-0.53, P = 0.0001). HIV-1 RNA was not detected in CSF in only three of the 70 patients (4%). Overall, there was a significant correlation between plasma and CSF HIV-1 RNA levels (r = 0.43, P = 0.0001); however, in 29 patients (41%) there were significant differences (>1.5 log10 copies/ml) between the viral loads in plasma and CSF. In the multivariate analysis, a high level of protein and white cells in CSF, but not the HIV-1 RNA plasma level, were factors independently associated with a higher level of HIV-1 RNA in CSF (P = 0.0001). HIV-1 RNA can be detected almost always in CSF of asymptomatic patients in early stages of HIV-1 infection including those with a preserved integrity of the blood-brain barrier. The important discrepancies between plasma and CSF viral load, and the independent association between CSF abnormalities and CSF viral load, support the hypothesis of local production of HIV-1.

Effects of neighbourhood-level educational attainment on HIV prevalence among young women in Zambia.

Science.gov (United States)

Kayeyi, Nkomba; Sandøy, Ingvild F; Fylkesnes, Knut

2009-08-25

Investigations of the association between socio-economic position indicators and HIV in East, Central and Southern Africa have chiefly focused on factors that pertain to individual-level characteristics. This study investigated the effect of neighbourhood educational attainment on HIV prevalence among young women in selected urban and rural areas in Zambia. This study re-analysed data from a cross-sectional population survey conducted in Zambia in 2003. The analyses were restricted to women aged 15-24 years (n = 1295). Stratified random cluster sampling was used to select 10 urban and 10 rural clusters. A measure for neighbourhood-level educational attainment was constructed by aggregating individual-level years-in-school. Multi-level mixed effects regression models were run to examine the neighbourhood-level educational effect on HIV prevalence after adjusting for individual-level underlying variables (education, currently a student, marital status) and selected proximate determinants (ever given birth, sexual activity, lifetime sexual partners). HIV prevalence among young women aged 15-24 years was 12.5% in the urban and 6.8% in the rural clusters. Neighbourhood educational attainment was found to be a strong determinant of HIV infection in both urban and rural population, i.e. HIV prevalence decreased substantially by increasing level of neighbourhood education. The likelihood of infection in low vs. high educational attainment of neighbourhoods was 3.4 times among rural women and 1.8 times higher among the urban women after adjusting for age and other individual-level underlying variables, including education. However, the association was not significant for urban young women after this adjustment. After adjusting for level of education in the neighbourhood, the effect of the individual-level education differed by residence, i.e. a strong protective effect among urban women whereas tending to be a risk factor among rural women. The findings suggested structural

Lopinavir/ritonavir in the treatment of HIV-1 infection: a review

Directory of Open Access Journals (Sweden)

Ashish Chandwani

2008-09-01

Full Text Available Ashish Chandwani1, Jonathan Shuter21Division of Infectious Diseases, Montefiore Medical Center and the Albert Einstein College of Medicine, Bronx, NY, USA; 2AIDS Center and Division of Infectious Diseases, Montefiore Medical Center and the Albert Einstein College of Medicine, Bronx, NY, USAAbstract: Lopinavir/ritonavir is the first and only coformulated HIV-1 protease inhibitor (PI. Large clinical trials have demonstrated lopinavir/ritonavir’s clinical efficacy in both antiretroviral-naïve and -experienced patients. The immunologic and virologic benefits of treatment with this agent have been proven in HIV-infected adults, adolescents, and children. Smaller studies support the use of lopinavir/ritonavir monotherapy as a therapeutic option in certain patients. The drug is characterized by a high genetic barrier to resistance, and appears to be more forgiving of non-adherence than earlier, unboosted PIs. The most frequent side effects observed are diarrhea, nausea, and vomiting. These gastrointestinal adverse effects are generally mild to moderate. Metabolic derangements, including hyperlipidemia and glucose intolerance, have also been observed in lopinavir/ritonavir recipients. As the menu of available antiretroviral agents continues to expand, lopinavir/ritonavir remains a proven and effective drug for the treatment of HIV infection.Keywords: lopinavir/ritonavir, protease inhibitor, HIV, antiretroviral, Kaletra®

Frequency of Subclinical Atherosclerosis in Brazilian HIV-Infected Patients.

Science.gov (United States)

Salmazo, Péricles Sidnei; Bazan, Silméia Garcia Zanati; Shiraishi, Flávio Gobbis; Bazan, Rodrigo; Okoshi, Katashi; Hueb, João Carlos

2018-04-09

AIDS as well as atherosclerosis are important public health problems. The longer survival among HIV-infected is associated with increased number of cardiovascular events in this population, and this association is not fully understood. To identify the frequency of subclinical atherosclerosis in HIV-infected patients compared to control subjects; to analyze associations between atherosclerosis and clinical and laboratory variables, cardiovascular risk factors, and the Framingham coronary heart disease risk score (FCRS). Prospective cross-sectional case-control study assessing the presence of subclinical atherosclerosis in 264 HIV-infected patients and 279 controls. Clinical evaluation included ultrasound examination of the carotid arteries, arterial stiffness by pulse wave velocity (PWV) and augmentation index (AIx), laboratory analysis of peripheral blood, and cardiovascular risk according to FCRS criteria. The significance level adopted in the statistical analysis was p media thickness was higher in the HIV group than in controls (p media thickness, was not associated with carotid plaque frequency, and did not alter the mechanical characteristics of the arterial system (PWV and AIx). HIV-infected patients are at increased risk of atherosclerosis in association with classical cardiovascular risk factors. Treatment with protease inhibitors does not promote functional changes in the arteries, and shows no association with increased frequency of atherosclerotic plaques in carotid arteries. The FCRS may be inappropriate for this population.

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

Science.gov (United States)

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.

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

Directory of Open Access Journals (Sweden)

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.

Community-level income inequality and HIV prevalence among persons who inject drugs in Thai Nguyen, Vietnam.

Science.gov (United States)

Lim, Travis W; Frangakis, Constantine; Latkin, Carl; Ha, Tran Viet; Minh, Nguyen Le; Zelaya, Carla; Quan, Vu Minh; Go, Vivian F

2014-01-01

Socioeconomic status has a robust positive relationship with several health outcomes at the individual and population levels, but in the case of HIV prevalence, income inequality may be a better predictor than absolute level of income. Most studies showing a relationship between income inequality and HIV have used entire countries as the unit of analysis. In this study, we examine the association between income inequality at the community level and HIV prevalence in a sample of persons who inject drugs (PWID) in a concentrated epidemic setting. We recruited PWID and non-PWID community participants in Thai Nguyen, Vietnam, and administered a cross-sectional questionnaire; PWID were tested for HIV. We used ecologic regression to model HIV burden in our PWID study population on GINI indices of inequality calculated from total reported incomes of non-PWID community members in each commune. We also modeled HIV burden on interaction terms between GINI index and median commune income, and finally used a multi-level model to control for community level inequality and individual level income. HIV burden among PWID was significantly correlated with the commune GINI coefficient (r = 0.53, p = 0.002). HIV burden was also associated with GINI coefficient (β = 0.082, p = 0.008) and with median commune income (β = -0.018, p = 0.023) in ecological regression. In the multi-level model, higher GINI coefficient at the community level was associated with higher odds of individual HIV infection in PWID (OR = 1.46 per 0.01, p = 0.003) while higher personal income was associated with reduced odds of infection (OR = 0.98 per $10, p = 0.022). This study demonstrates a context where income inequality is associated with HIV prevalence at the community level in a concentrated epidemic. It further suggests that community level socioeconomic factors, both contextual and compositional, could be indirect determinants of HIV infection in PWID.

Community-Level Income Inequality and HIV Prevalence among Persons Who Inject Drugs in Thai Nguyen, Vietnam

Science.gov (United States)

Lim, Travis W.; Frangakis, Constantine; Latkin, Carl; Ha, Tran Viet; Minh, Nguyen Le; Zelaya, Carla; Quan, Vu Minh; Go, Vivian F.

2014-01-01

Socioeconomic status has a robust positive relationship with several health outcomes at the individual and population levels, but in the case of HIV prevalence, income inequality may be a better predictor than absolute level of income. Most studies showing a relationship between income inequality and HIV have used entire countries as the unit of analysis. In this study, we examine the association between income inequality at the community level and HIV prevalence in a sample of persons who inject drugs (PWID) in a concentrated epidemic setting. We recruited PWID and non-PWID community participants in Thai Nguyen, Vietnam, and administered a cross-sectional questionnaire; PWID were tested for HIV. We used ecologic regression to model HIV burden in our PWID study population on GINI indices of inequality calculated from total reported incomes of non-PWID community members in each commune. We also modeled HIV burden on interaction terms between GINI index and median commune income, and finally used a multi-level model to control for community level inequality and individual level income. HIV burden among PWID was significantly correlated with the commune GINI coefficient (r = 0.53, p = 0.002). HIV burden was also associated with GINI coefficient (β = 0.082, p = 0.008) and with median commune income (β = −0.018, p = 0.023) in ecological regression. In the multi-level model, higher GINI coefficient at the community level was associated with higher odds of individual HIV infection in PWID (OR = 1.46 per 0.01, p = 0.003) while higher personal income was associated with reduced odds of infection (OR = 0.98 per $10, p = 0.022). This study demonstrates a context where income inequality is associated with HIV prevalence at the community level in a concentrated epidemic. It further suggests that community level socioeconomic factors, both contextual and compositional, could be indirect determinants of HIV infection in PWID. PMID

Protease Expression Levels in Prostate Cancer Tissue Can Explain Prostate Cancer-Associated Seminal Biomarkers—An Explorative Concept Study

Directory of Open Access Journals (Sweden)

Jochen Neuhaus

2017-05-01

Full Text Available Previously, we described prostate cancer (PCa detection (83% sensitivity; 67% specificity in seminal plasma by CE-MS/MS. Moreover, advanced disease was distinguished from organ-confined tumors with 80% sensitivity and 82% specificity. The discovered biomarkers were naturally occurring fragments of larger seminal proteins, predominantly semenogelin 1 and 2, representing endpoints of the ejaculate liquefaction. Here we identified proteases putatively involved in PCa specific protein cleavage, and examined gene expression and tissue protein levels, jointly with cell localization in normal prostate (nP, benign prostate hyperplasia (BPH, seminal vesicles and PCa using qPCR, Western blotting and confocal laser scanning microscopy. We found differential gene expression of chymase (CMA1, matrix metalloproteinases (MMP3, MMP7, and upregulation of MMP14 and tissue inhibitors (TIMP1 and TIMP2 in BPH. In contrast tissue protein levels of MMP14 were downregulated in PCa. MMP3/TIMP1 and MMP7/TIMP1 ratios were decreased in BPH. In seminal vesicles, we found low-level expression of most proteases and, interestingly, we also detected TIMP1 and low levels of TIMP2. We conclude that MMP3 and MMP7 activity is different in PCa compared to BPH due to fine regulation by their inhibitor TIMP1. Our findings support the concept of seminal plasma biomarkers as non-invasive tool for PCa detection and risk stratification.

Protease Expression Levels in Prostate Cancer Tissue Can Explain Prostate Cancer-Associated Seminal Biomarkers-An Explorative Concept Study.

Science.gov (United States)

Neuhaus, Jochen; Schiffer, Eric; Mannello, Ferdinando; Horn, Lars-Christian; Ganzer, Roman; Stolzenburg, Jens-Uwe

2017-05-04

Previously, we described prostate cancer (PCa) detection (83% sensitivity; 67% specificity) in seminal plasma by CE-MS/MS. Moreover, advanced disease was distinguished from organ-confined tumors with 80% sensitivity and 82% specificity. The discovered biomarkers were naturally occurring fragments of larger seminal proteins, predominantly semenogelin 1 and 2, representing endpoints of the ejaculate liquefaction. Here we identified proteases putatively involved in PCa specific protein cleavage, and examined gene expression and tissue protein levels, jointly with cell localization in normal prostate (nP), benign prostate hyperplasia (BPH), seminal vesicles and PCa using qPCR, Western blotting and confocal laser scanning microscopy. We found differential gene expression of chymase (CMA1), matrix metalloproteinases (MMP3, MMP7), and upregulation of MMP14 and tissue inhibitors (TIMP1 and TIMP2) in BPH. In contrast tissue protein levels of MMP14 were downregulated in PCa. MMP3/TIMP1 and MMP7/TIMP1 ratios were decreased in BPH. In seminal vesicles, we found low-level expression of most proteases and, interestingly, we also detected TIMP1 and low levels of TIMP2. We conclude that MMP3 and MMP7 activity is different in PCa compared to BPH due to fine regulation by their inhibitor TIMP1. Our findings support the concept of seminal plasma biomarkers as non-invasive tool for PCa detection and risk stratification.

HIV Drug Resistance Surveillance in Honduras after a Decade of Widespread Antiretroviral Therapy.

Science.gov (United States)

Avila-Ríos, Santiago; García-Morales, Claudia; Tapia-Trejo, Daniela; Meza, Rita I; Nuñez, Sandra M; Parham, Leda; Flores, Norma A; Valladares, Diana; Pineda, Luisa M; Flores, Dixiana; Motiño, Roxana; Umanzor, Víctor; Carbajal, Candy; Murillo, Wendy; Lorenzana, Ivette; Palou, Elsa Y; Reyes-Terán, Gustavo

2015-01-01

We assessed HIV drug resistance (DR) in individuals failing ART (acquired DR, ADR) and in ART-naïve individuals (pre-ART DR, PDR) in Honduras, after 10 years of widespread availability of ART. 365 HIV-infected, ART-naïve, and 381 ART-experienced Honduran individuals were enrolled in 5 reference centres in Tegucigalpa, San Pedro Sula, La Ceiba, and Choluteca between April 2013 and April 2015. Plasma HIV protease-RT sequences were obtained. HIVDR was assessed using the WHO HIVDR mutation list and the Stanford algorithm. Recently infected (RI) individuals were identified using a multi-assay algorithm. PDR to any ARV drug was 11.5% (95% CI 8.4-15.2%). NNRTI PDR prevalence (8.2%) was higher than NRTI (2.2%) and PI (1.9%, p500 vs. Honduras remains at the intermediate level, after 10 years of widespread availability of ART. Evidence of ADR influencing the presence of PDR was observed by phylogenetic analyses and ADR/PDR mutation frequency correlations.

HIV or HIV-Therapy? Causal attributions of symptoms and their impact on treatment decisions among women and men with HIV

Directory of Open Access Journals (Sweden)

Kremer H

2009-04-01

Full Text Available Abstract Objectives Among people with HIV, we examined symptom attribution to HIV or HIV-therapy, awareness of potential side effects and discontinuation of treatment, as well as sex/gender differences. Methods HIV-patients (N = 168, 46% female completed a comprehensive symptom checklist (attributing each endorsed symptom to HIV, HIV-therapy, or other causes, reported reasons for treatment discontinuations and potential ART-related laboratory abnormalities. Results Main symptom areas were fatigue/sleep/energy, depression/mood, lipodystrophy, and gastrointestinal, dermatological, and neurological problems. Top HIV-attributed symptoms were lack of stamina/energy in both genders, night sweats, depression, mood swings in women; and fatigue, lethargy, difficulties concentrating in men. Women attributed symptoms less frequently to HIV than men, particularly fa-tigue(p Top treatment-attributed symptoms were lipodystrophy and gastrointestinal problems in both genders. Symptom attribution to HIV-therapy did not differ between genders. Over the past six months, 22% switched/interrupted ART due to side effects. In women, side effect-related treatment decisions were more complex, involving more side effects and substances. Remarkably, women took predominantly protease inhibitor-sparing regimens (p = .05. Both genders reported only 15% of potential ART-related laboratory abnormalities but more than 50% had laboratory abnormalities. Notably, women had fewer elevated renal parameters (p Conclusions Men may attribute symptoms more often to HIV and maintain a treatment-regimen despite side effects, whereas women may be more prudent in avoiding treatment side effects. Lacking awareness of laboratory abnormalities in both genders potentially indicates gaps in physician-patient communication. Gender differences in causal attributions of symptoms/side effects may influence treatment decisions.

Lipodystrophy syndrome among HIV infected children on highly ...

African Journals Online (AJOL)

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 ...

Sexuality and HIV/AIDS: an exploration of older heterosexual women's knowledge levels.

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Ross, Pamela; Humble, Áine M; Blum, Ilya

2013-01-01

Sexuality research tends to ignore older populations, and little is known about older women's sexual health knowledge. To fill this research gap, 186 Canadian heterosexual women 50 years and older were surveyed about their knowledge regarding sexuality and HIV/AIDS. Respondents had moderate levels of overall knowledge of sexual health and aging, correctly answering, on average, 60% of the 35 questions. They had lower levels of HIV/AIDS knowledge, correctly answering just over 50% of the 25 questions. Results indicate the need for social awareness and education in this group regarding both general sexual health later in life and HIV/AIDS.

Decline of HIV antigen levels in cerebrospinal fluid during treatment with low-dose zidovudine

NARCIS (Netherlands)

de Gans, J.; Lange, J. M.; Derix, M. M.; de Wolf, F.; Eeftinck Schattenkerk, J. K.; Danner, S. A.; Ongerboer de Visser, B. W.; Cload, P.; Goudsmit, J.

1988-01-01

Six HIV-antigenaemic patients with AIDS or AIDS-related complex were studied to assess the effect of treatment with low-dose zidovudine (250 mg) in 6-hourly doses on HIV antigen (HIV-Ag) levels in cerebrospinal fluid (CSF). HIV-Ag was detected in CSF of three patients before treatment. These

CIHR Canadian HIV Trials Network Coinfection and Concurrent Diseases Core: Canadian guidelines for management and treatment of HIV/hepatitis C coinfection in adults

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Hull, Mark; Klein, Marina; Shafran, Stephen; Tseng, Alice; Giguère, Pierre; Côté, Pierre; Poliquin, Marc; Cooper, Curtis

2013-01-01

BACKGROUND: Hepatitis C virus (HCV) coinfection occurs in 20% to 30% of Canadians living with HIV, and is responsible for a heavy burden of morbidity and mortality. HIV-HCV management is more complex due to the accelerated progression of liver disease, the timing and nature of antiretroviral and HCV therapy, mental health and addictions management, socioeconomic obstacles and drug-drug interactions between new HCV direct-acting antiviral therapies and antiretroviral regimens. OBJECTIVE: To develop national standards for the management of HCV-HIV coinfected adults in the Canadian context. METHODS: A panel with specific clinical expertise in HIV-HCV co-infection was convened by The CIHR HIV Trials Network to review current literature, existing guidelines and protocols. Following broad solicitation for input, consensus recommendations were approved by the working group, and were characterized using a Class (benefit verses harm) and Level (strength of certainty) quality-of-evidence scale. RESULTS: All HIV-HCV coinfected individuals should be assessed for HCV therapy. Individuals unable to initiate HCV therapy should initiate antiretroviral therapy to slow liver disease progression. Standard of care for genotype 1 is pegylated interferon and weight-based ribavirin dosing plus an HCV protease inhibitor; traditional dual therapy for 24 weeks (for genotype 2/3 with virological clearance at week 4); or 48 weeks (for genotypes 2–6). Therapy deferral for individuals with mild liver disease may be considered. HIV should not be considered a barrier to liver transplantation in coinfected patients. DISCUSSION: Recommendations may not supersede individual clinical judgement. PMID:24489565

Oxidized lipoproteins are associated with markers of inflammation and immune activation in HIV-1 infection

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Kelesidis, T; Jackson, N; McComsey, GA; Wang, X; Elashoff, D; Dube, MP; Brown, TT; Yang, OO; Stein, JH; Currier, JS

2016-01-01

Objective The pathogenesis of immune dysfunction in chronic HIV-1 infection is unclear, and a potential role for oxidized lipids has been suggested. We hypothesize that both oxidized low- and high-density lipoproteins (HDLox, LDLox) contribute to HIV-1 related immune dysfunction. Study In the AIDS Clinical Trials Group (ACTG) A5260, 234 HIV-infected antiretroviral therapy (ART)-naïve participants were randomized to receive tenofovir-emtricitabine plus protease inhibitors or raltegravir and had HIV-1 RNA lipoproteins may contribute to persistent immune activation on ART. PMID:27603288

Avascular necrosis of the femoral head in HIV infected patients

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Marcos Almeida Matos

Full Text Available Avascular necrosis (AVN of the femoral head is an emerging complication in HIV infected patients. It has been suggested that the increased incidence of AVN in this population may be caused by an increased prevalence of predisposing factors for osteonecrosis, including protease inhibitors, hyperlipidemia, corticosteroid use, alcohol and intravenous drug abuse. The aim of this study was to assess the risk factors for avascular necrosis developing in the femoral head of HIV infected individuals. This study consisted of meta-analysis of the secondary data extracted from current literature. The selected articles allowed two study groups to be drawn up for comparison. Group 1 comprised 324 individuals infected by the HIV virus, who did not present femoral head AVN. Group 2 comprised 32 HIV positive patients, who presented femoral head AVN. The parameters used for analysis were as follows: age, gender, sexual preference, use of intravenous drugs, time of diagnosis, CD4+ cell count, use of antiretroviral agents and duration, serum cholesterol and serum triglycerides. The present study found a statistically significant association between hypertriglyceridemia, hypercholesterolemia, sexual preference and intravenous drug abuse. The authors concluded that femoral head osteonecrosis is associated with hyperlipidemia (hypercholesterolemia and hypertriglyceridemia and intravenous drug abuse. This study supports the hypothesis that protease inhibitors play a role in the development of osteonecrosis through a tendency to cause hyperlipidemia.

Identification of HIV Mutation as Diagnostic Biomarker through Next Generation Sequencing.

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Shaw, Wen Hui; Lin, Qianqian; Muhammad, Zikry Zhiwei Bin Roslee; Lee, Jia Jun; Khong, Wei Xin; Ng, Oon Tek; Tan, Eng Lee; Li, Peng

2016-07-01

Current clinical detection of Human immunodeficiency virus 1 (HIV-1) is used to target viral genes and proteins. However, the immunoassay, such as viral culture or Polymerase Chain Reaction (PCR), lacks accuracy in the diagnosis, as these conventional assays rely on the stable genome and HIV-1 is a highly-mutated virus. Next generation sequencing (NGS) promises to be transformative for the practice of infectious disease, and the rapidly reducing cost and processing time mean that this will become a feasible technology in diagnostic and research laboratories in the near future. The technology offers the superior sensitivity to detect the pathogenic viruses, including unknown and unexpected strains. To leverage the NGS technology in order to improve current HIV-1 diagnosis and genotyping methods. Ten blood samples were collected from HIV-1 infected patients which were diagnosed by RT PCR at Singapore Communicable Disease Centre, Tan Tock Seng Hospital from October 2014 to March 2015. Viral RNAs were extracted from blood plasma and reversed into cDNA. The HIV-1 cDNA samples were cleaned up using a PCR purification kit and the sequencing library was prepared and identified through MiSeq. Two common mutations were observed in all ten samples. The common mutations were identified at genome locations 1908 and 2104 as missense and silent mutations respectively, conferring S37N and S3S found on aspartic protease and reverse transcriptase subunits. The common mutations identified in this study were not previously reported, therefore suggesting the potential for them to be used for identification of viral infection, disease transmission and drug resistance. This was especially the case for, missense mutation S37N which could cause an amino acid change in viral proteases thus reducing the binding affinity of some protease inhibitors. Thus, the unique common mutations identified in this study could be used as diagnostic biomarkers to indicate the origin of infection as being

Current concepts of metabolic abnormalities in HIV patients: focus on lipodystrophy.

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Kolter, Donald P

2003-12-01

HIV infection is associated with a number of metabolic abnormalities, including lipodystrophy, a difficult-to-define disorder whose characteristics include hyperlipidemia, insulin resistance, and fat redistribution. Current data suggest that lipodystrophy is caused by multiple factors. Dual-nucleoside reverse transcriptase inhibitor therapy combined with protease inhibitor therapy has been shown to increase the risk of metabolic abnormalities, but susceptibility independent of drug effects has also been shown. While many of the treatments for the broad range of signs and symptoms of lipodystrophy bring about improvements in patient status, none have been demonstrated to bring about a return to baseline levels.

Knowledge of Diabetes mellitus-HIV Co-Infection Among Health ...

African Journals Online (AJOL)

Advent of drug combinations in Highly Active Antiretroviral Therapy (HAART) has been a major achievement in the management of HIV/AIDS. However, some of the drugs involved e.g. protease inhibitors have as side effects metabolic disorders like diabetes mellitus DM and dyslipidemia due to affectation of the pancreas ...

Inhibitory effects of (-)-epigallocatechin gallate on the life cycle of human immunodeficiency virus type 1 (HIV-1).

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Yamaguchi, Koushi; Honda, Mitsuo; Ikigai, Hajime; Hara, Yukihiko; Shimamura, Tadakatsu

2002-01-01

Epigallocatechin gallate (EGCg), the major tea catechin, is known as a potent anti-bacterial agent. In addition, anti-tumor promoting, anti-inflammatory, anti-oxidative and antiviral activities have been reported. In the present study, we investigated possible anti-human immunodeficiency virus type-1 (HIV-1) activity of EGCg and its mechanisms of action in the viral life cycle. EGCg impinges on each step of the HIV life cycle. Thus, destruction of the viral particles, viral attachment to cells, post-adsorption entry into cells, reverse transcription (RT), viral production from chronically-infected cells, and the level of expression of viral mRNA, were analyzed using T-lymphoid (H9) and monocytoid (THP-1) cell systems, and antiviral protease activity was measured using a cell-free assay. Inhibitory effects of EGCg on specific binding of the virions to the cellular surfaces and changes in the steady state viral regulation (mRNA expression) due to EGCg were not observed. However, EGCg had a destructive effect on the viral particles, and post-adsorption entry and RT in acutely infected monocytoid cells were significantly inhibited at concentrations of EGCg greater than 1 microM, and protease kinetics were suppressed at a concentration higher than 10 microM in the cell-free study. Viral production by THP-1 cells chronically-infected with HIV-1 was also inhibited in a dose-dependent manner and the inhibitory effect was enhanced by liposome modification of EGCg. As expected, increased viral mRNA production was observed in lipopolysaccharide (LPS)-activated chronically HIV-1-infected cells. This production was significantly inhibited by EGCg treatment of THP-1 cells. In contrast, production of HIV-1 viral mRNA in unstimulated or LPS-stimulated T-lymphoid cells (H9) was not inhibited by EGCg. Anti-HIV viral activity of EGCg may thus result from an interaction with several steps in the HIV-1 life cycle.

Insecticide resistance and intracellular proteases.

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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.

Hormonal levels among HIV-1-seropositive women compared with high-risk HIV-seronegative women during the menstrual cycle. Women's Health Study (WHS) 001 and WHS 001a Study Team.

Science.gov (United States)

Cu-Uvin, S; Wright, D J; Anderson, D; Kovacs, A; Watts, D H; Cohn, J; Landay, A; Reichelderfer, P S

2000-10-01

There is a paucity of normative data on hormonal levels among HIV-infected women. Hormonal levels may influence fertility and HIV-related immunological and virological factors. The objective of this study was to determine progesterone and estradiol levels during the menstrual cycle in HIV-seropositive women compared with high-risk seronegative women. The study enrolled 55 HIV-infected and 10 high-risk uninfected women with self-reported regular menstrual cycles (25-30-day cycles). Progesterone and estradiol levels were determined on a weekly basis for 8 weeks. The analysis included evaluations from the first complete menstrual cycle for the 54 HIV-infected and 9 uninfected women who had at least one complete cycle. The median age was 35 years for HIV-infected women and 36 years for uninfected women. The median CD4+ count for HIV-seropositive women was 210 cells/mm3. The median menstrual cycle length was 28 days (range 22-49 days) for HIV-infected women and 25 days (range 24-44 days) for uninfected women. The maximum progesterone level during the luteal phase was normal (>3.0 ng/ml) for 52 (96%) of 54 HIV-seropositive women and 7 (78%) of 9 HIV-seronegative women (p = 0.09, Fisher's exact test). The median maximum progesterone level was 12.2 ng/ml in HIV-seropositive women and 7.2 ng/ml in HIV-seronegative women (p = 0.07, Wilcoxon test). The median maximum estradiol value during the follicular phase was 148 pg/ml for HIV-seropositive women and 111 pg/ml for HIV-seronegative women (p = 0.04, Wilcoxon test). Among HIV-infected women, there were no significant differences in progesterone and estradiol levels by antiretroviral therapy, baseline plasma viral load, or median CD4+ cell count. We conclude that HIV-infected women with self-reported normal menstrual cycles have normal levels of progesterone and estradiol during the menstrual cycle.

Effectiveness of tipranavir versus darunavir as a salvage therapy in HIV-1 treatment-experienced patients.

Science.gov (United States)

Domínguez-Hermosillo, Juan Carlos; Mata-Marin, José Antonio; Herrera-González, Norma Estela; Chávez-García, Marcelino; Huerta-García, Gloria; Nuñez-Rodríguez, Nohemí; García-Gámez, José Gerardo; Jiménez-Romero, Anai; Gaytán-Martínez, Jesús Enrique

2016-09-30

Although both tipranavir (TPV) and darunavir (DRV) represent important options for the management of patients with multi-protease inhibitor (PI)-resistant human immunodeficiency virus (HIV), currently there are no studies comparing the effectiveness and safety of these two drugs in the Mexican population. The aim of this study was to compare the effectiveness of TPV versus DRV as a salvage therapy in HIV-1 treatment-experienced patients. This was a comparative, prospective, cohort study. Patients with HIV and triple-class drug resistance evaluated at the Hospital de Infectología "La Raza", National Medical Center, were included. All patients had the protease and retrotranscriptase genotype; resistance mutation interpretation was done using the Stanford database. A total of 35 HIV-1 triple-class drug-resistant patients were analyzed. All of them received tenofovir and raltegravir, 22 received darunavir/ritonavir (DRV/r), and 13 received tipranavir/ritonavir (TPV/r) therapies. The median baseline RNA HIV-1 viral load and CD4+ cell count were 4.34 log (interquartile range [IQR], 4.15-4.72) and 267 cells/mm3 (IQR, 177-320) for the DRV/r group, and 4.14 log (IQR, 3.51-4.85) and 445 cells/mm3 (IQR, 252-558) for the TPV/r group. At week 24 of treatment, 91% of patients receiving DRV/r and 100% of patients receiving TPV/r had an RNA HIV-1 viral load HIV-1 patients who were highly experienced in antiretroviral therapy.

Stakeholder conceptualisation of multi-level HIV and AIDS determinants in a Black epicentre.

Science.gov (United States)

Brawner, Bridgette M; Reason, Janaiya L; Hanlon, Kelsey; Guthrie, Barbara; Schensul, Jean J

2017-09-01

HIV has reached epidemic proportions among African Americans in the USA but certain urban contexts appear to experience a disproportionate disease burden. Geographic information systems mapping in Philadelphia indicates increased HIV incidence and prevalence in predominantly Black census tracts, with major differences across adjacent communities. What factors shape these geographic HIV disparities among Black Philadelphians? This descriptive study was designed to refine and validate a conceptual model developed to better understand multi-level determinants of HIV-related risk among Black Philadelphians. We used an expanded ecological approach to elicit reflective perceptions from administrators, direct service providers and community members about individual, social and structural factors that interact to protect against or increase the risk for acquiring HIV within their community. Gender equity, social capital and positive cultural mores (e.g., monogamy, abstinence) were seen as the main protective factors. Historical negative contributory influences of racial residential segregation, poverty and incarceration were among the most salient risk factors. This study was a critical next step toward initiating theory-based, multi-level community-based HIV prevention initiatives.

Labor migration, externalities and ethics: theorizing the meso-level determinants of HIV vulnerability.

Science.gov (United States)

Hirsch, Jennifer S

2014-01-01

This paper discusses labor migration as an example of how focusing on the meso-level highlights the social processes through which structural factors produce HIV risk. Situating that argument in relation to existing work on economic organization and HIV risk as well as research on labor migration and HIV vulnerabilities, the paper demonstrates how analyzing the processes through which labor migration creates vulnerability can shift attention away from the proximate behavioral determinants of HIV risk and toward the community and policy levels. Further, it presents the concepts of externalities and the ethics of consumption, which underline how both producers and consumers benefit from low-waged migrant labor, and thus are responsible for the externalization of HIV risk characteristic of supply chains that rely on migrant labor. These concepts point to strategies through which researchers and advocates could press the public and private sectors to improve the conditions in which migrants live and work, with implications for HIV as well as other health outcomes. Copyright © 2013 Elsevier Ltd. All rights reserved.

Management of HIV During Pregnancy

OpenAIRE

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...

Plasma levels of Transforming Growth Factor Beta in HIV-1 patients with oral candidiasis

Science.gov (United States)

Izadi, A; Asadikaram, G; Nakhaee, N; Hadizadeh, S; Ayatollahi Mousavi, A

2015-01-01

Background and Purpose: TGF-β is a potent regulator and suppressor of the immune system and overproduction of this cytokine may contribute to immunosuppression in HIV-infected patients. Increasing population of immunosuppressed patients has resulted in increasingly frequent of fungal infections, including oral candidiasis. The aim of this study was to evaluate the plasma levels of TGF-β under in vivo conditions. Materials and Methods: Seventy- two samples were obtained from the oral cavities of HIV-positive Iranian patients and cultured on Sabouraud’s dextrose agar and CHROMagar. Also blood samples were obtained to assess TGF-β levels using ELISA technique. Results: Thirty-three out of 72 oral samples yielded candida isolates, Candida albicans in 14 and non-albicans candida in 19.Fungal infection decreased significantly more TGF-β level than non-fungal infection also HIV negative were significantly more TGF-β than HIV positive. Conclusion: Our findings suggest a significant interaction between fungal infection and HIV on expression of Transforming Growth Factor Beta. PMID:28680977

Comparative effectiveness of fish oil versus fenofibrate, gemfibrozil, and atorvastatin on lowering triglyceride levels among HIV-infected patients in routine clinical care.

Science.gov (United States)

Muñoz, Monica A; Liu, Wei; Delaney, Joseph A C; Brown, Elizabeth; Mugavero, Michael J; Mathews, W Chris; Napravnik, Sonia; Willig, James H; Eron, Joseph J; Hunt, Peter W; Kahn, James O; Saag, Michael S; Kitahata, Mari M; Crane, Heidi M

2013-11-01

The goal of this study was to compare the effectiveness of fish oil, fenofibrate, gemfibrozil, and atorvastatin on reducing triglyceride (TG) levels among a large cohort of HIV-infected patients in clinical care. Retrospective observational cohort study. The primary endpoint was absolute change in TG levels measured using the last TG value pretreatment and the first TG value posttreatment. A pre-post quasi-experimental design was used to estimate the change in TG because of initiating fish oil. Linear regression models examined the comparative effectiveness of treatment with fish oil versus gemfibrozil, fenofibrate, or atorvastatin for TG reduction. Models were adjusted for baseline differences in age, sex, race, CD4⁺ cell count, diabetes, body mass index, protease inhibitor use, and time between TG measures. A total of 493 patients (mean age, 46 years; 95% male) were included (46 patients receiving gemfibrozil; 80, fenofibrate; 291, atorvastatin; and 76, fish oil) with a mean baseline TG of 347 mg/dL. New use of fish oil decreased TG [ΔTG, -45 mg/dL; 95% confidence interval (CI): -80 to -11] in the pre-post study. Compared with fish oil (reference), fibrates were more effective (ΔTG, -66; 95% CI: -120 to -12) in reducing TG levels, whereas atorvastatin was not (ΔTG, -39; 95% CI: -86 to 9). In HIV-infected patients in routine clinical care, fish oil is less effective than fibrates (but not atorvastatin) at lowering TG values. Fish oil may still represent an attractive alternative for patients with moderately elevated TGs, particularly among patients who may not want or tolerate fibrates.

Hepatitis C virus NS3 protease genotyping and drug concentration determination during triple therapy with telaprevir or boceprevir for chronic infection with genotype 1 viruses, southeastern France.

Science.gov (United States)

Aherfi, Sarah; Solas, Caroline; Motte, Anne; Moreau, Jacques; Borentain, Patrick; Mokhtari, Saadia; Botta-Fridlund, Danielle; Dhiver, Catherine; Portal, Isabelle; Ruiz, Jean-Marie; Ravaux, Isabelle; Bregigeon, Sylvie; Poizot-Martin, Isabelle; Stein, Andreas; Gérolami, René; Brouqui, Philippe; Tamalet, Catherine; Colson, Philippe

2014-11-01

Telaprevir and boceprevir, the two first hepatitis C virus (HCV) NS3 protease inhibitors (PIs), considerably increase rates of sustained virologic response in association with pegylated interferon and ribavirin in chronic HCV genotype 1 infections. The 30 first patients treated by telaprevir or boceprevir including anti-HCV therapies since 2011 in Marseille University hospitals, France, were monitored. HCV loads and plasmatic concentrations of telaprevir and boceprevir were determined on sequential blood samples. HCV NS3 protease gene population sequencing was performed at baseline of treatment and in case of treatment failure. Fifteen patients (including 7 co-infected with HIV) received telaprevir and the other 15 patients (including 4 co-infected with HIV) received boceprevir. At baseline, HCV NS3 protease from six patients harbored amino acid substitutions associated with PI-resistance. Treatment failure occurred at week 12 for 7 patients. Amino acid substitutions associated with PI-resistance were observed in six of these cases. HCV NS3 R155K and T54A/S mutants, all of genotype 1a, were found from four patients. Median (interquartile range) plasma concentrations were 3,092 ng/ml (2,320-3,525) for telaprevir and 486 ng/ml (265-619) for boceprevir. For HIV-HCV co-infected patients, median concentrations were 3,162 ng/ml (2,270-4,232) for telaprevir and 374 ng/ml (229-519) for boceprevir. Plasma drug concentration monitoring revealed undetectable concentrations for two patients at week 4, and probable non-adherence to therapy for another patient. These findings indicate that routine HCV NS3 protease sequencing and plasma PI concentration monitoring might be helpful to characterize cases of therapy failure, at a cost dramatically low compared to that of anti-HCV therapy. © 2014 Wiley Periodicals, Inc.

Identification of SlpB, a Cytotoxic Protease from Serratia marcescens.

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Shanks, Robert M Q; Stella, Nicholas A; Hunt, Kristin M; Brothers, Kimberly M; Zhang, Liang; Thibodeau, Patrick H

2015-07-01

The Gram-negative bacterium and opportunistic pathogen Serratia marcescens causes ocular infections in healthy individuals. Secreted protease activity was characterized from 44 ocular clinical isolates, and a higher frequency of protease-positive strains was observed among keratitis isolates than among conjunctivitis isolates. A positive correlation between protease activity and cytotoxicity to human corneal epithelial cells in vitro was determined. Deletion of prtS in clinical keratitis isolate K904 reduced, but did not eliminate, cytotoxicity and secreted protease production. This indicated that PrtS is necessary for full cytotoxicity to ocular cells and implied the existence of another secreted protease(s) and cytotoxic factors. Bioinformatic analysis of the S. marcescens Db11 genome revealed three additional open reading frames predicted to code for serralysin-like proteases noted here as slpB, slpC, and slpD. Induced expression of prtS and slpB, but not slpC and slpD, in strain PIC3611 rendered the strain cytotoxic to a lung carcinoma cell line; however, only prtS induction was sufficient for cytotoxicity to a corneal cell line. Strain K904 with deletion of both prtS and slpB genes was defective in secreted protease activity and cytotoxicity to human cell lines. PAGE analysis suggests that SlpB is produced at lower levels than PrtS. Purified SlpB demonstrated calcium-dependent and AprI-inhibited protease activity and cytotoxicity to airway and ocular cell lines in vitro. Lastly, genetic analysis indicated that the type I secretion system gene, lipD, is required for SlpB secretion. These genetic data introduce SlpB as a new cytotoxic protease from S. marcescens. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Child Mortality Levels and Trends by HIV Status in Blantyre, Malawi: 1989-2009

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Taha, Taha E.; Dadabhai, Sufia S.; Sun, Jin; Rahman, M. Hafizur; Kumwenda, Johnstone; Kumwenda, Newton

2012-01-01

Introduction Continuous evaluation of child survival is needed in sub-Saharan Africa where HIV prevalence among women of reproductive age continues to be high. We examined mortality levels and trends over a period of ~20 years among HIV-unexposed and exposed children in Blantyre, Malawi. Methods Data from five prospective cohort studies conducted at a single research site from 1989-2009 were analyzed. In these studies, children born to HIV-infected and uninfected mothers were enrolled at birth and followed longitudinally for at least two years. Information on socio-demographic, HIV infection status, survival and associated risk factors was collected in all studies. Mortality rates were estimated using birth-cohort analyses stratified by maternal and infant HIV status. Multivariate Cox regression models were used to determine risk factors associated with mortality. Results The analysis included 8,286 children. From 1989-1995, overall mortality rates (per 100 person-years) in these clinic-based cohorts remained comparable among HIV-uninfected children born to HIV-uninfected mothers (range 3.3-6.9) or to HIV-infected mothers (range 2.5-7.5). From 1989-2009, overall mortality remained high among all children born to HIV-infected mothers (range 6.3-19.3), and among children who themselves became infected (range 15.6-57.4, 1994-2009). Only lower birth weight was consistently and significantly (P<0.05) associated with higher child mortality. Conclusions HIV infection among mothers and children contributed to high levels of child mortality in the African setting in the pre-treatment era. In addition to services that prevent mother-to-child transmission of HIV, other programs are needed to improve child survival by lowering HIV-unrelated mortality through innovative interventions that strengthen health infrastructure. PMID:22692091

Influence of HLA-C Expression Level on HIV Control

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Apps, Richard; Qi, Ying; Carlson, Jonathan M.; Chen, Haoyan; Gao, Xiaojiang; Thomas, Rasmi; Yuki, Yuko; Del Prete, Greg Q.; Goulder, Philip; Brumme, Zabrina L.; Brumme, Chanson J.; John, Mina; Mallal, Simon; Nelson, George; Bosch, Ronald; Heckerman, David; Stein, Judy L.; Soderberg, Kelly A.; Moody, M. Anthony; Denny, Thomas N.; Zeng, Xue; Fang, Jingyuan; Moffett, Ashley; Lifson, Jeffrey D.; Goedert, James J.; Buchbinder, Susan; Kirk, Gregory D.; Fellay, Jacques; McLaren, Paul; Deeks, Steven G.; Pereyra, Florencia; Walker, Bruce; Michael, Nelson L.; Weintrob, Amy; Wolinsky, Steven; Liao, Wilson; Carrington, Mary

2013-01-01

A variant upstream of human leukocyte antigen C (HLA-C) shows the most significant genome-wide effect on HIV control in European Americans and is also associated with the level of HLA-C expression. We characterized the differential cell surface expression levels of all common HLA-C allotypes and tested directly for effects of HLA-C expression on outcomes of HIV infection in 5243 individuals. Increasing HLA-C expression was associated with protection against multiple outcomes independently of individual HLA allelic effects in both African and European Americans, regardless of their distinct HLA-C frequencies and linkage relationships with HLA-B and HLA-A. Higher HLA-C expression was correlated with increased likelihood of cytotoxic T lymphocyte responses and frequency of viral escape mutation. In contrast, high HLA-C expression had a deleterious effect in Crohn’s disease, suggesting a broader influence of HLA expression levels in human disease. PMID:23559252

Coronary and peripheral endothelial function in HIV patients studied with positron emission tomography and flow-mediated dilation: relation to hypercholesterolemia

Energy Technology Data Exchange (ETDEWEB)

Lebech, Anne-Mette [Copenhagen University Hospital, Department of Infectious Diseases, Hvidovre (Denmark); Hvidovre University Hospital, Department of Infectious Diseases, Hvidovre (Denmark); Kristoffersen, Ulrik Sloth; Kjaer, Andreas [Rigshospitalet University Hospital, Department of Clinical Physiology, Nuclear Medicine and PET, Copenhagen (Denmark); University of Copenhagen, Cluster for Molecular Imaging, Copenhagen (Denmark); Wiinberg, Niels; Petersen, Claus Leth [Frederiksberg University Hospital, Department of Clinical Physiology and Nuclear Medicine, Frederiksberg (Denmark); Kofoed, Kristian; Andersen, Ove [Copenhagen University Hospital, Department of Infectious Diseases, Hvidovre (Denmark); Copenhagen University Hospital, Clinical Research Unit, Hvidovre (Denmark); Hesse, Birger [Rigshospitalet University Hospital, Department of Clinical Physiology, Nuclear Medicine and PET, Copenhagen (Denmark); Gerstoft, Jan [Rigshospitalet University Hospital, Department of Infectious Diseases, Copenhagen (Denmark)

2008-11-15

The mechanisms underlying increased cardiovascular risk in HIV patients in antiretroviral therapy (ART) are not known. Our aim was to study the endothelial function of the coronary arteries by cardiac perfusion positron emission tomography (PET), in HIV patients with normal or high cholesterol levels. Flow mediated dilation (FMD) of the brachial artery and circulating endothelial markers were also assessed. HIV patients in ART with total cholesterol {<=} 5.5 mmol/L (215 mg/dL; n = 13) or total cholesterol {>=} 6.5 mmol/L (254 mg/dL; n = 12) and healthy controls (n = 14) were included. {sup 13}NH{sub 3} perfusion PET, FMD, and measurement of plasma levels of E-Selectin, ICAM-1, VCAM-1, tPAI-1, and hs-CRP were performed. Baseline myocardial perfusion and the coronary flow reserve measured by PET (3.2 {+-} 0.3, 3.2 {+-} 0.3 and 3.0 {+-} 0.3; ns) was similar in HIV patients with normal or high total cholesterol and controls. FMD did not differ between the groups and was 4.6 {+-} 1.1%, 5.1 {+-} 1.2%, and 4.6 {+-} 0.8%, respectively. Increased levels of plasma E-Selectin, ICAM-1, tPAI-1, and hs-CRP were found in HIV patients when compared to controls (p < 0.05). E-Selectin and ICAM-1 levels were higher in HIV patients receiving protease inhibitors (PI) compared to those not receiving PI (p < 0.05). None of the measured endothelial biomarkers differed between the normal and high cholesterol HIV groups. In ART-treated HIV patients with a low overall cardiovascular risk, no sign of endothelial dysfunction was found not even in hypercholesterolemic patients. Also, the increased level of plasma endothelial markers found in HIV patients was not related to hypercholesterolemia. (orig.)

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

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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.

European recommendations for the clinical use of HIV drug resistance testing: 2011 update

DEFF Research Database (Denmark)

Vandamme, Anne-Mieke; Camacho, Ricardo J; Ceccherini-Silberstein, Francesca

2011-01-01

, and other drug targets (integrase and envelope) if such drugs were part of the failing regimen; (iii) consider testing for CCR5 tropism at virologic failure or when a change of therapy has to be made in absence of detectable viral load, and in the latter case test DNA or last detectable plasma RNA; (iv...... the following recommendations concerning the indications for resistance testing: for HIV-1 (i) test earliest sample for protease and reverse transcriptase drug resistance in drug-naive patients with acute or chronic infection; (ii) test protease and reverse transcriptase drug resistance at virologic failure...... is needed after treatment failure. The Panel recommends genotyping in most situations, using updated and clinically evaluated interpretation systems. It is mandatory that laboratories performing HIV resistance tests take part regularly in external quality assurance programs, and that they consider storing...

High levels of T lymphocyte activation in Leishmania-HIV-1 co-infected individuals despite low HIV viral load

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Grinsztejn Beatriz

2010-12-01

Full Text Available Abstract Background Concomitant infections may influence HIV progression by causing chronic activation leading to decline in T-cell function. In the Americas, visceral (AVL and tegumentary leishmaniasis (ATL have emerged as important opportunistic infections in HIV-AIDS patients and both of those diseases have been implicated as potentially important co-factors in disease progression. We investigated whether leishmaniasis increases lymphocyte activation in HIV-1 co-infected patients. This might contribute to impaired cellular immune function. Methods To address this issue we analyzed CD4+ T absolute counts and the proportion of CD8+ T cells expressing CD38 in Leishmania/HIV co-infected patients that recovered after anti-leishmanial therapy. Results We found that, despite clinical remission of leishmaniasis, AVL co-infected patients presented a more severe immunossupression as suggested by CD4+ T cell counts under 200 cells/mm3, differing from ATL/HIV-AIDS cases that tends to show higher lymphocytes levels (over 350 cells/mm3. Furthermore, five out of nine, AVL/HIV-AIDS presented low CD4+ T cell counts in spite of low or undetectable viral load. Expression of CD38 on CD8+ T lymphocytes was significantly higher in AVL or ATL/HIV-AIDS cases compared to HIV/AIDS patients without leishmaniasis or healthy subjects. Conclusions Leishmania infection can increase the degree of immune system activation in individuals concomitantly infected with HIV. In addition, AVL/HIV-AIDS patients can present low CD4+ T cell counts and higher proportion of activated T lymphocytes even when HIV viral load is suppressed under HAART. This fact can cause a misinterpretation of these laboratorial markers in co-infected patients.

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.

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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.

Proteases and antiproteases in chronic neutrophilic lung disease - relevance to drug discovery.

LENUS (Irish Health Repository)

Greene, Catherine M

2009-10-01

Chronic inflammatory lung diseases such as cystic fibrosis and emphysema are characterized by higher-than-normal levels of pulmonary proteases. While these enzymes play important roles such as bacterial killing, their dysregulated expression or activity can adversely impact on the inflammatory process. The existence of efficient endogenous control mechanisms that can dampen or halt this overexuberant protease activity in vivo is essential for the effective resolution of inflammatory lung disease. The function of pulmonary antiproteases is to fulfil this role. Interestingly, in addition to their antiprotease activity, protease inhibitors in the lung also often possess other intrinsic properties that contribute to microbial killing or termination of the inflammatory process. This review will outline important features of chronic inflammation that are regulated by pulmonary proteases and will describe the various mechanisms by which antiproteases attempt to counterbalance exaggerated protease-mediated inflammatory events. These proteases, antiproteases and their modifiers represent interesting targets for therapeutic intervention.

Study of Body Composition and Metabolic Parameters in HIV-1 Male Patients

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Gurudath Gundurao Sreekantamurthy

2014-01-01

Full Text Available Background. HIV patients on highly active antiretroviral therapy (HAART containing protease inhibitors (PIs had been often associated with lipodystrophy. However, there are only few studies on association of nucleoside and nonnucleoside reverse transcriptase inhibitors (NRTI and NNRTI with lipodystrophy. Study Design. One hundred and one HIV male patients were categorised into ART naïve (n=22, zidovudine (n=22, stavudine (n=18, tenofovir (n=15, and PIs (n=24 based HAART. Their clinicoepidemiological data had been entered in preformed pro forma. The body composition, using TANITA machine and metabolic parameters like lipid profile, blood sugars was analysed. Results. Clinically, lipoatrophy of face was most prevalent in HIV patients on stavudine (15 patients, 83.3% and PIs (20 patients, 83.3% based HAART. The mean BMI among study population was in normal range. Excess visceral fat was most prevalent among patients on PIs, 4 patients (16.7%. The waist-hip ratio was significantly higher in PIs (P=0.01 based HAART. There was no significant difference among different study populations in terms of BMI (P=0.917, body water (P=0.318, body fat (P=0.172, bone mass (P=0.200, and muscle mass (P=0.070. Hypertriglyceridiemia was found in stavudine, tenofovir, and protease inhibitors regimens. Low levels of high density lipoprotein (HDL was found zidovudine, stavudine, and PIs regimens. Fasting and postprandial hyperglycaemia was found PIs and impaired glucose tolerance in stavudine regimen. Conclusion. Patients on PIs were associated with truncal obesity and lipoatrophy of face, along with dyslipidemia and hyperglycaemia. Stavudine based regimen is associated with hypertriglyceridiemia and low HDL along with lipoatrophy of face.

Individual and Population Level Impact of Key HIV Risk Factors on HIV Incidence Rates in Durban, South Africa.

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Gita Ramjee

Full Text Available We aimed to estimate the individual and joint impact of age, marital status and diagnosis with sexually transmitted infections (STIs on HIV acquisition among young women at a population level in Durban, KwaZulu-Natal, South Africa. A total of 3,978 HIV seronegative women were recruited for four biomedical intervention trials from 2002-2009. Point and interval estimates of partial population attributable risk (PAR were used to quantify the proportion of HIV seroconversions which can be prevented if a combination of risk factors is eliminated from a target population. More than 70% of the observed HIV acquisitions were collectively attributed to the three risk factors: younger age (<25 years old, unmarried and not cohabiting with a stable/regular partner and diagnosis with STIs. Addressing these risks requires targeted structural, behavioural, biomedical and cultural interventions in order to impact on unacceptably high HIV incidence rates among young women and the population as a whole.

Proteases and caspase-like activity in the yeast Saccharomyces cerevisiae.

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Wilkinson, Derek; Ramsdale, Mark

2011-10-01

A variety of proteases have been implicated in yeast PCD (programmed cell death) including the metacaspase Mca1 and the separase Esp1, the HtrA-like serine protease Nma111, the cathepsin-like serine carboxypeptideases and a range of vacuolar proteases. Proteasomal activity is also shown to have an important role in determining cell fate, with both pro- and anti-apoptotic roles. Caspase 3-, 6- and 8-like activities are detected upon stimulation of yeast PCD, but not all of this activity is associated with Mca1, implicating other proteases with caspase-like activity in the yeast cell death response. Global proteolytic events that accompany PCD are discussed alongside a consideration of the conservation of the death-related degradome (both at the level of substrate choice and cleavage site). The importance of both gain-of-function changes in the degradome as well as loss-of-function changes are highlighted. Better understanding of both death-related proteases and their substrates may facilitate the design of future antifungal drugs or the manipulation of industrial yeasts for commercial exploitation.

Low prevalence of primary HIV resistance in western Massachusetts.

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Iarikov, Dmitri E; Irizarry-Acosta, Melina; Martorell, Claudia; Hoffman, Robert P; Skiest, Daniel J

2010-01-01

Most studies of primary antiretroviral (ARV) resistance have been conducted in large metropolitan areas with reported rates of 8% to 25%. We collected data on 99 HIV-1-infected antiretroviral-naive patients from several sites in Springfield, MA, who underwent genotypic resistance assay between 2004 and 2008. Only major resistance mutations per International AIDS Society-USA (IAS-USA) drug resistance mutations list were considered. The prevalence of resistance was 5% (5 of 99). Three patients had one nonnucleoside reverse transcriptase inhibitor (NNRTI) mutation: 103N, 103N, and 190A, 1 patient had a protease inhibitor (PI) mutation: 90M; and 1 patient had 3-class resistance with NNRTI: 181C, 190A, PI: 90M, and nucleoside analogue reverse transcriptase inhibitor (NRTI): 41L, 210W. Mean time from HIV diagnosis to resistance testing was shorter in patients with resistance versus those without: 9 (range 0.3-42 months) versus 27 (range 0.1-418 months), P = .11. There was a trend to lower mean CD4 count in those with resistance, 170 versus 318 cells/mm(3), P = .06. No differences were noted in gender, age, HIV risk category, or HIV RNA level. The low prevalence of primary resistance may be explained by differences in demographic and risk factors or may reflect the time from infection to resistance testing. Our findings emphasize the importance of continued resistance surveillance.

Proteolytic crosstalk in multi-protease networks

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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.

HIV-1 diversity and drug-resistant mutations in infected individuals in Changchun, China.

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Ming Yan

Full Text Available OBJECTIVES: Human immunodeficiency virus type 1 (HIV-1 infection has been detected in all provinces of China. Although epidemiological and phylogenetic studies have been conducted in many regions, such analyses are lacking from Jilin province in northeastern China. METHOD: Epidemiological and phylogenetic analyses, as well as detection of drug-resistant mutations, were conducted on 57 HIV-1 infected patients from Changchun city identified and confirmed through annual surveillance by local Centers for Disease Control in Jilin province of northeastern China in 2012. RESULTS: Sexual contact was determined to be the major pathway for HIV-1 transmission in Jilin, where hetero- and homosexual activities contributed almost equally. Phylogenetic analyses detected multiple subtypes of HIV-1 including subtype G circulating in Jilin, with multiple origins for each of them. Both subtype B and CRF01_AE were dominant, and evidence of subtype B transmitting between different high-risk groups was observed. Mutations in the viral protease at position 71 indicated the presence of a selective pressure. Several drug-resistant mutations were detected, although they were predicted with low-level resistance to antiviral treatments. CONCLUSIONS: Information from this study fills the gap in knowledge of HIV-1 transmission in Changchun city, Jilin province, China. By revealing the origin and evolutionary status of local HIV-1 strains, this work contributes to ongoing efforts in the control and prevention of AIDS.

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

DEFF Research Database (Denmark)

Ullum, H; Katzenstein, T; Aladdin, H

1999-01-01

The present study examines the influence of effective anti-retroviral treatment on immune function, evaluated by a broad array of immunological tests. We followed 12 individuals infected with human immunodeficiency virus (HIV) for 6 months after initiation of combination anti-retroviral treatment...

Higher levels of Zidovudine resistant HIV in the colon compared to blood and other gastrointestinal compartments in HIV infection

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van Marle Guido

2010-09-01

Full Text Available Abstract Background The gut-associated lymphoid tissue (GALT is the largest lymphoid organ infected by human immunodeficiency virus type 1 (HIV-1. It serves as a viral reservoir and host-pathogen interface in infection. This study examined whether different parts of the gut and peripheral blood lymphocytes (PBL contain different drug-resistant HIV-1 variants. Methods Gut biopsies (esophagus, stomach, duodenum and colon and PBL were obtained from 8 HIV-1 infected preHAART (highly active antiretroviral therapy patients at three visits over 18 months. Patients received AZT, ddI or combinations of AZT/ddI. HIV-1 Reverse transcriptase (RT-coding sequences were amplified from viral DNA obtained from gut tissues and PBL, using nested PCR. The PCR fragments were cloned and sequenced. The resulting sequences were subjected to phylogenetic analyses, and antiretroviral drug mutations were identified. Results Phylogenetic and drug mutation analyses revealed differential distribution of drug resistant mutations in the gut within patients. The level of drug-resistance conferred by the RT sequences was significantly different between different gut tissues and PBL, and varied with antiretroviral therapy. The sequences conferring the highest level of drug-resistance to AZT were found in the colon. Conclusion This study confirms that different drug-resistant HIV-1 variants are present in different gut tissues, and it is the first report to document that particular gut tissues may select for drug resistant HIV-1 variants.

HIDROLISIS IKAN BERNILAI EKONOMI RENDAH SECARA ENZIMATIS MENGGUNAKAN PROTEASE BIDURI [Enzymatic Hydrolysis of Low Economic Value Fishes using Biduri’s Protease

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Yuli Witono1*

2015-07-01

Full Text Available Fish protein hydrolyzate is a product obtained from the decomposition of fish proteins into short-chain compounds due to the hydrolysis process either by enzymes, acids, or bases. The purpose of this study was to optimize the production of fish protein hydrolyzate from the low economic value fishes including 'bibisan' (Apogon albimaculosus, 'baji-baji' (Platycephalidae cymbacephalus, and the 'lidah' (Cynoglossus lingua obtained from Talango Island, Madura. Production of fish protein hydrolyzate was conducted using (Calotropis gigantea protease at various concentrations (0, 0.7, 1.4, and 2.1 Unit/g and at various hydrolysis times (0, 1.5, and 3 h. The experimental design was a Completely Randomized Design with two factors and the experiments were carried out in triplicates. The results showed that interactions between protease concentrations and hydrolysis times significantly affected (at 5% level test the soluble proteins, maillard products, and the level of rancidity measured as thiobarbituric acid (TBA. The best fish hydrolyzate product based on the soluble protein parameter was resulted from 2.1 unit/g of biduri’s protease with a hydrolysis time of 1.5 h. The hydrolyzate produced had 3.51% of soluble proteins, a maillard value of 0.63, and rancidity levels of 12.21 mmol TBA/kg.

Prevalence of drug resistance mutations and non-B subtypes in newly diagnosed HIV-1 patients in Denmark

DEFF Research Database (Denmark)

Jørgensen, Louise B; Christensen, Marianne B; Gerstoft, Jan

2003-01-01

The aim of this study was to monitor the prevalence of drug resistance mutations in newly diagnosed HIV-1 positive individuals in Denmark. In addition we assessed the prevalence of non-B subtypes based on phylogenetic analysis of the pol gene. Plasma samples from 104 newly diagnosed HIV-1 positive...... patients were obtained in the year 2000. The entire protease gene and 320 amino acids of the reverse transcriptase gene were genotyped. Sequences were obtained from 97 patients. No subjects displayed primary resistance mutations in the protease gene, whereas all carried 1 or more secondary mutations....... Resistance mutations in the RT-gene associated with NRTI-resistance were found in 1 patient, who was infected with zidovudine resistant HIV-1 harbouring the M41L mutation in combination with T215S and L210S. The T215S mutation has been showed to be associated with reversion of zidovudine resistance. The T215...

Genome-wide identification and structure-function studies of proteases and protease inhibitors in Cicer arietinum (chickpea).

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Sharma, Ranu; Suresh, C G

2015-01-01

Proteases are a family of enzymes present in almost all living organisms. In plants they are involved in many biological processes requiring stress response in situations such as water deficiency, pathogen attack, maintaining protein content of the cell, programmed cell death, senescence, reproduction and many more. Similarly, protease inhibitors (PIs) are involved in various important functions like suppression of invasion by pathogenic nematodes, inhibition of spores-germination and mycelium growth of Alternaria alternata and response to wounding and fungal attack. As much as we know, no genome-wide study of proteases together with proteinaceous PIs is reported in any of the sequenced genomes till now. Phylogenetic studies and domain analysis of proteases were carried out to understand the molecular evolution as well as gene and protein features. Structural analysis was carried out to explore the binding mode and affinity of PIs for cognate proteases and prolyl oligopeptidase protease with inhibitor ligand. In the study reported here, a significant number of proteases and PIs were identified in chickpea genome. The gene expression profiles of proteases and PIs in five different plant tissues revealed a differential expression pattern in more than one plant tissue. Molecular dynamics studies revealed the formation of stable complex owing to increased number of protein-ligand and inter and intramolecular protein-protein hydrogen bonds. The genome-wide identification, characterization, evolutionary understanding, gene expression, and structural analysis of proteases and PIs provide a framework for future analysis when defining their roles in stress response and developing a more stress tolerant variety of chickpea. Copyright © 2014 Elsevier Ltd. All rights reserved.

A role in immunity for Arabidopsis cysteine protease RD21, the ortholog of the tomato immune protease C14.

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Takayuki Shindo

Full Text Available Secreted papain-like Cys proteases are important players in plant immunity. We previously reported that the C14 protease of tomato is targeted by cystatin-like EPIC proteins that are secreted by the oomycete pathogen Phytophthora infestans (Pinf during infection. C14 has been under diversifying selection in wild potato species coevolving with Pinf and reduced C14 levels result in enhanced susceptibility for Pinf. Here, we investigated the role C14-EPIC-like interactions in the natural pathosystem of Arabidopsis with the oomycete pathogen Hyaloperonospora arabidopsidis (Hpa. In contrast to the Pinf-solanaceae pathosystem, the C14 orthologous protease of Arabidopsis, RD21, does not evolve under diversifying selection in Arabidopsis, and rd21 null mutants do not show phenotypes upon compatible and incompatible Hpa interactions, despite the evident lack of a major leaf protease. Hpa isolates express highly conserved EPIC-like proteins during infections, but it is unknown if these HpaEPICs can inhibit RD21 and one of these HpaEPICs even lacks the canonical cystatin motifs. The rd21 mutants are unaffected in compatible and incompatible interactions with Pseudomonas syringae pv. tomato, but are significantly more susceptible for the necrotrophic fungal pathogen Botrytis cinerea, demonstrating that RD21 provides immunity to a necrotrophic pathogen.

Correlation between saliva IgA level and T cell CD4+ in HIV/AIDS patients

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Irna Sufiawati

2007-07-01

Full Text Available Background: HIV infection appears to have direct effects on oral mucosal immunity, cellular and humoral. Antibody secretion, especially salivary immunoglobulin A (IgA, is a useful indicator of mucosal immune function. This immune system component is recognized as an important first-line of defence against pathogens which colonize and invade mucosal surfaces in the oral cavity. Objectives: The purpose of this study was to investigate salivary IgA levels and to determine its correlation with CD4+ T-cell counts among HIV-infected patients in Pokdisus AIDS Cipto Mangunkusomo Hospital Jakarta. Methods: The design study was using a cross-sectional study. Whole paraffin-wax-stimulated saliva was collected from 103 HIV-infected patients and 30 healthy individuals. Saliva was collected using the spitting method. Salivary IgA levels were determined by the immunoturbidimetry method using the Behring Turbitimer Analyser. CD4+ T-cell counts were analyzed by flow cytometry. Results: Salivary IgA levels were 141.55 ± 83.23 (HIV group and 97.24 ± 38.25 (healthy individuals. The Mann-Whitney U test showed salivary IgA levels were significantly higher in HIV/AIDS subjects compared with healthy individuals (p0.1. Conclusion: This study indicates that total salivary IgA levels were significantly higher in the HIV-infected patients compared to control, and salivary IgA level seems not to be related significantly to CD4+ T-cell counts.

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

DEFF Research Database (Denmark)

Worm, S W; Kamara, D A; Reiss, P

2012-01-01

Concerns have arisen about possible effects of protease inhibitors (PIs) on cardiac conductivity. We found no significant association between current or recent PI exposure and sudden death or nonhemorrhagic stroke (adjusted rate ratio, 1.22; 95% confidence interval, .95-1.57), whereas cumulative...

Natural inhibitors of tumor-associated proteases

International Nuclear Information System (INIS)

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)

ALKALINE PROTEASE, AMYLASE AND CELLULASE ACTIVITIES OF YELLOW RASBORA, Rasbora lateristriataBlkr., AT DIFFERENT FEEDING LEVELS

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Untung Susilo

2016-11-01

Full Text Available Alkaline proteases, amylase and cellulase activities of digestive organ of yellow rasbora, Rasbora lateristriata Blkr., was evaluated with four different feeding levels of 0.34g protein+0.03g fiber, 1.01g protein+0.10g fiber, 1.69g protein+0.16g fiber and 2.36g protein+0.23g fiber/day/100 g fish biomass. A total of 280 fish with average body weight of 0.71±0.06g were used in this study. The results showed that the difference in the feeding levels resulted in a significant difference in trypsin and chymotrypsin  activities (P .05. In conclusion, protein digestion capacity increased, but not to the digestion of starch and fiber in response to different feeding levels and the optimal feeding level for yellow rasbora was 1,01g protein+0,10g fiber/day/100 g fish biomass.

Protease activation involved in resistance of human cells to x-ray cell killing

International Nuclear Information System (INIS)

Zhang, Hong-Chang; Takahashi, Shuji; Karata, Kiyonobu; Kita, Kazuko; Suzuki, Nobuo

2003-01-01

Little is known of proteases that play roles in the early steps of X-ray irradiation response. In the present study, we first searched for proteases whose activity is induced in human RSa-R cells after X-ray irradiation. The activity was identified as fibrinolytic, using 125 I-labeled fibrin as a substrate. Protease samples were prepared by lysation of cells with a buffer containing MEGA-8. RSa-R cells showed an increased level of protease activity 10 min after X-ray (up to 3 Gy) irradiation. We next examined whether this protease inducibility is causally related with the X-ray susceptibility of cells. Leupeptin, a serine-cysteine protease inhibitor, inhibited the protease activity in samples obtained from X-ray-irradiated RSa-R cells. Treatment of RSa-R cells with the inhibitor before and after X-ray irradiation resulted in an increased susceptibility of the cells to X-ray cell killing. However, the treatment of cells with other inhibitors tested did not modulate the X-ray susceptibility. These results suggest that leupeptin-sensitive proteases are involved in the resistance of human cells to X-ray cell killing. (author)

Diversity of both the cultivable protease-producing bacteria and bacterial extracellular proteases in the coastal sediments of King George Island, Antarctica.

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Ming-Yang Zhou

Full Text Available Protease-producing bacteria play a vital role in degrading sedimentary organic nitrogen. However, the diversity of these bacteria and their extracellular proteases in most regions remain unknown. In this paper, the diversity of the cultivable protease-producing bacteria and of bacterial extracellular proteases in the sediments of Maxwell Bay, King George Island, Antarctica was investigated. The cultivable protease-producing bacteria reached 10(5 cells/g in all 8 sediment samples. The cultivated protease-producing bacteria were mainly affiliated with the phyla Actinobacteria, Firmicutes, Bacteroidetes, and Proteobacteria, and the predominant genera were Bacillus (22.9%, Flavobacterium (21.0% and Lacinutrix (16.2%. Among these strains, Pseudoalteromonas and Flavobacteria showed relatively high protease production. Inhibitor analysis showed that nearly all the extracellular proteases from the bacteria were serine proteases or metalloproteases. These results begin to address the diversity of protease-producing bacteria and bacterial extracellular proteases in the sediments of the Antarctic Sea.

Structure of protease-cleaved Escherichia coli α-2-macroglobulin reveals a putative mechanism of conformational activation for protease entrapment

International Nuclear Information System (INIS)

Fyfe, Cameron D.; Grinter, Rhys; Josts, Inokentijs; Mosbahi, Khedidja; Roszak, Aleksander W.; Cogdell, Richard J.; Wall, Daniel M.; Burchmore, Richard J. S.; Byron, Olwyn; Walker, Daniel

2015-01-01

The X-ray structure of protease-cleaved E. coli α-2-macroglobulin is described, which reveals a putative mechanism of activation and conformational change essential for protease inhibition. Bacterial α-2-macroglobulins have been suggested to function in defence as broad-spectrum inhibitors of host proteases that breach the outer membrane. Here, the X-ray structure of protease-cleaved Escherichia coli α-2-macroglobulin is described, which reveals a putative mechanism of activation and conformational change essential for protease inhibition. In this competitive mechanism, protease cleavage of the bait-region domain results in the untethering of an intrinsically disordered region of this domain which disrupts native interdomain interactions that maintain E. coli α-2-macroglobulin in the inactivated form. The resulting global conformational change results in entrapment of the protease and activation of the thioester bond that covalently links to the attacking protease. Owing to the similarity in structure and domain architecture of Escherichia coli α-2-macroglobulin and human α-2-macroglobulin, this protease-activation mechanism is likely to operate across the diverse members of this group

Structure of protease-cleaved Escherichia coli α-2-macroglobulin reveals a putative mechanism of conformational activation for protease entrapment

Energy Technology Data Exchange (ETDEWEB)

Fyfe, Cameron D.; Grinter, Rhys; Josts, Inokentijs; Mosbahi, Khedidja [University of Glasgow, Glasgow G12 8QQ, Scotland (United Kingdom); Roszak, Aleksander W. [University of Glasgow, Glasgow G12 8QQ, Scotland (United Kingdom); University of Glasgow, Glasgow G12 8QQ, Scotland (United Kingdom); Cogdell, Richard J.; Wall, Daniel M.; Burchmore, Richard J. S.; Byron, Olwyn; Walker, Daniel, E-mail: daniel.walker@glasgow.ac.uk [University of Glasgow, Glasgow G12 8QQ, Scotland (United Kingdom)

2015-06-30

The X-ray structure of protease-cleaved E. coli α-2-macroglobulin is described, which reveals a putative mechanism of activation and conformational change essential for protease inhibition. Bacterial α-2-macroglobulins have been suggested to function in defence as broad-spectrum inhibitors of host proteases that breach the outer membrane. Here, the X-ray structure of protease-cleaved Escherichia coli α-2-macroglobulin is described, which reveals a putative mechanism of activation and conformational change essential for protease inhibition. In this competitive mechanism, protease cleavage of the bait-region domain results in the untethering of an intrinsically disordered region of this domain which disrupts native interdomain interactions that maintain E. coli α-2-macroglobulin in the inactivated form. The resulting global conformational change results in entrapment of the protease and activation of the thioester bond that covalently links to the attacking protease. Owing to the similarity in structure and domain architecture of Escherichia coli α-2-macroglobulin and human α-2-macroglobulin, this protease-activation mechanism is likely to operate across the diverse members of this group.

Three monoclonal antibodies against the serpin protease nexin-1 prevent protease translocation

DEFF Research Database (Denmark)

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...

First line treatment response in patients with transmitted HIV drug resistance and well defined time point of HIV infection: updated results from the German HIV-1 seroconverter study.

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Fabia Zu Knyphausen

Full Text Available BACKGROUND: Transmission of drug-resistant HIV-1 (TDR can impair the virologic response to antiretroviral combination therapy. Aim of the study was to assess the impact of TDR on treatment success of resistance test-guided first-line therapy in the German HIV-1 Seroconverter Cohort for patients infected with HIV between 1996 and 2010. An update of the prevalence of TDR and trend over time was performed. METHODS: Data of 1,667 HIV-infected individuals who seroconverted between 1996 and 2010 were analysed. The WHO drug resistance mutations list was used to identify resistance-associated HIV mutations in drug-naïve patients for epidemiological analysis. For treatment success analysis the Stanford algorithm was used to classify a subset of 323 drug-naïve genotyped patients who received a first-line cART into three resistance groups: patients without TDR, patients with TDR and fully active cART and patients with TDR and non-fully active cART. The frequency of virologic failure 5 to 12 months after treatment initiation was determined. RESULTS: Prevalence of TDR was stable at a high mean level of 11.9% (198/1,667 in the HIV-1 Seroconverter Cohort without significant trend over time. Nucleotide reverse transcriptase inhibitor resistance was predominant (6.0% and decreased significantly over time (OR = 0.92, CI = 0.87-0.98, p = 0.01. Non-nucleoside reverse transcriptase inhibitor (2.4%; OR = 1.00, CI = 0.92-1.09, p = 0.96 and protease inhibitor resistance (2.0%; OR = 0.94, CI = 0.861.03, p = 0.17 remained stable. Virologic failure was observed in 6.5% of patients with TDR receiving fully active cART, 5,6% of patients with TDR receiving non-fully active cART and 3.2% of patients without TDR. The difference between the three groups was not significant (p = 0.41. CONCLUSION: Overall prevalence of TDR remained stable at a rather high level. No significant differences in the frequency of virologic failure were

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

Science.gov (United States)

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.

Hepatitis C viremia is associated with cytomegalovirus IgG antibody levels in HIV-infected women.

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Mark H Kuniholm

Full Text Available Individuals with HIV infection exhibit high cytomegalovirus (CMV IgG levels, but there are few data regarding the association of hepatitis C virus (HCV with the immune response against CMV.Associations of HCV with CMV seropositivity and CMV IgG levels were studied in 635 HIV-infected women, 187 of whom were HCV-seropositive, with adjustment in multivariable models for age, race/ethnicity, and HIV disease characteristics. Eighty one percent of the women reported receipt of highly active antiretroviral therapy (HAART prior to or at CMV testing.In adjusted models women with chronic HCV had higher CMV IgG levels than those without HCV RNA (β = 2.86, 95% CI:0.89 - 4.83; P = 0.004. The association of HCV RNA with CMV IgG differed by age (P(interaction = 0.0007, with a strong association observed among women in the low and middle age tertiles (≤ 45.3 years of age; β = 6.21, 95% CI:3.30 - 9.11, P<0.0001 but not among women in the high age tertile. CMV IgG levels were not associated with non-invasive measures of liver disease, APRI and FIB-4, or with HCV RNA level and adjustment for Epstein-Barr virus (EBV IgG levels did not affect the association between HCV and CMV.CMV IgG levels are higher in HCV/HIV co-infected women than in HIV mono-infected women. Further research on the association of HCV with CMV IgG is indicated because prior studies have found CMV IgG to be associated with morbidity and mortality in the general population and subclinical carotid artery disease in HIV-infected patients.

Seminal Plasma HIV-1 RNA Concentration Is Strongly Associated with Altered Levels of Seminal Plasma Interferon-γ, Interleukin-17, and Interleukin-5

Science.gov (United States)

Hoffman, Jennifer C.; Anton, Peter A.; Baldwin, Gayle Cocita; Elliott, Julie; Anisman-Posner, Deborah; Tanner, Karen; Grogan, Tristan; Elashoff, David; Sugar, Catherine; Yang, Otto O.

2014-01-01

Abstract Seminal plasma HIV-1 RNA level is an important determinant of the risk of HIV-1 sexual transmission. We investigated potential associations between seminal plasma cytokine levels and viral concentration in the seminal plasma of HIV-1-infected men. This was a prospective, observational study of paired blood and semen samples from 18 HIV-1 chronically infected men off antiretroviral therapy. HIV-1 RNA levels and cytokine levels in seminal plasma and blood plasma were measured and analyzed using simple linear regressions to screen for associations between cytokines and seminal plasma HIV-1 levels. Forward stepwise regression was performed to construct the final multivariate model. The median HIV-1 RNA concentrations were 4.42 log10 copies/ml (IQR 2.98, 4.70) and 2.96 log10 copies/ml (IQR 2, 4.18) in blood and seminal plasma, respectively. In stepwise multivariate linear regression analysis, blood HIV-1 RNA level (pplasma HIV-1 RNA level. After controlling for blood HIV-1 RNA level, seminal plasma HIV-1 RNA level was positively associated with interferon (IFN)-γ (p=0.03) and interleukin (IL)-17 (p=0.03) and negatively associated with IL-5 (p=0.0007) in seminal plasma. In addition to blood HIV-1 RNA level, cytokine profiles in the male genital tract are associated with HIV-1 RNA levels in semen. The Th1 and Th17 cytokines IFN-γ and IL-17 are associated with increased seminal plasma HIV-1 RNA, while the Th2 cytokine IL-5 is associated with decreased seminal plasma HIV-1 RNA. These results support the importance of genital tract immunomodulation in HIV-1 transmission. PMID:25209674

Purification and biochemical characterization of the haloalkaliphilic archaeon Natronococcus occultus extracellular serine protease

DEFF Research Database (Denmark)

Studdert, C A; Herrera Seitz, M K; Plasencia, I

2001-01-01

A serine protease was purified from Natronococcus occultus stationary phase culture medium (328-fold, yield 19%) and characterized at the biochemical level. The enzyme has a native molecular mass of 130 kDa, has chymotrypsin-like activity, is stable and active in a broad pH range (5.5-12), is rat......A serine protease was purified from Natronococcus occultus stationary phase culture medium (328-fold, yield 19%) and characterized at the biochemical level. The enzyme has a native molecular mass of 130 kDa, has chymotrypsin-like activity, is stable and active in a broad pH range (5.......5-12), is rather thermophilic (optimal activity at 60 degrees C in 1-2 M NaCl) and is dependent on high salt concentrations for activity and stability (1-2 M NaCl or KCl). Polyclonal antibodies were raised against the purified protease. In Western blots, they presented no cross-reactivity with culture medium from...... other halobacteria nor with commercial proteases except subtilisin. The amino acid sequences of three tryptic peptides obtained from Natronococcus occultus protease did not show significant similarity to other known proteolytic enzymes. This fact, in addition to its high molecular mass suggests...

An Event-Level Analysis of Condomless Anal Intercourse with a HIV-Discordant or HIV Status-Unknown Partner Among Black Men Who Have Sex with Men from a Multi-site Study.

Science.gov (United States)

Yang, Cui; Latkin, Carl; Tobin, Karin; Seal, David; Koblin, Beryl; Chander, Geetanjali; Siconolfi, Daniel; Flores, Stephen; Spikes, Pilgrim

2018-05-19

Despite the high HIV incidence and prevalence among black men who have sex with men (BMSM), little research has examined partner characteristics, partner seeking venue, sexual position, substance use, and sexual risk behavior at the sex event-level among BMSM. Using the baseline data from a multi-site study of 807 BMSM stratified by their HIV status, the goal of this study was to conduct a detailed event-level analysis of 1577 male anal sex events to assess the factors associated with condomless anal intercourse (CLAI) with a HIV-discordant or HIV status-unknown partner. We found CLAI with an HIV-discordant or unknown HIV status partner among HIV-negative BMSM was negatively associated with having sex with a main partner, and was positively associated with taking both receptive and insertive sexual positions during sex. As compared to a sex partner met at bar, night club or dance club, HIV-positive BMSM were less likely to engage in CLAI with HIV-discordant and unknown HIV status partner met at party or friend's house or at community organizations. HIV-positive BMSM had lower odds of engaging in CLAI with HIV-discordant and unknown HIV status partner if they had insertive sexual position or both receptive and insertive sexual positions. These results underscore the importance of delineating unique sex event-level factors associated with sexual risk behavior depending on individuals' HIV status. Our findings suggest event-level partner characteristics, sexual position, and partner seeking venues may contribute to disparities in HIV incidence.

Processing Proteases

DEFF Research Database (Denmark)

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...

Rationale and uses of a public HIV drug-resistance database.

Science.gov (United States)

Shafer, Robert W

2006-09-15

Knowledge regarding the drug resistance of human immunodeficiency virus (HIV) is critical for surveillance of drug resistance, development of antiretroviral drugs, and management of infections with drug-resistant viruses. Such knowledge is derived from studies that correlate genetic variation in the targets of therapy with the antiretroviral treatments received by persons from whom the variant was obtained (genotype-treatment), with drug-susceptibility data on genetic variants (genotype-phenotype), and with virological and clinical response to a new treatment regimen (genotype-outcome). An HIV drug-resistance database is required to represent, store, and analyze the diverse forms of data underlying our knowledge of drug resistance and to make these data available to the broad community of researchers studying drug resistance in HIV and clinicians using HIV drug-resistance tests. Such genotype-treatment, genotype-phenotype, and genotype-outcome correlations are contained in the Stanford HIV RT and Protease Sequence Database and have specific usefulness.

RC1339/APRc from Rickettsia conorii is a novel aspartic protease with properties of retropepsin-like enzymes.

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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

HIV Drug Resistance-Associated Mutations in Antiretroviral Naïve HIV-1-Infected Latin American Children

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Luis E. Soto-Ramirez

2010-01-01

Full Text Available Our goal was to describe the presence of HIV drug resistance among HIV-1-infected, antiretroviral (ARV naïve children and adolescents in Latin America and to examine resistance in these children in relation to drug exposure in the mother. Genotyping was performed on plasma samples obtained at baseline from HIV-1-infected participants in a prospective cohort study in Brazil, Argentina, and Mexico (NISDI Pediatric Study. Of 713 HIV-infected children enrolled, 69 were ARV naïve and eligible for the analysis. At enrollment, mean age was 7.3 years; 81.2% were infected with HIV perinatally. Drug resistance mutations (DRMs were detected in 6 (8.7%; 95% confidence interval 3.1–18.2% ARV-naïve subjects; none of the mothers of these 6 received ARVs during their pregnancies and none of the children received ARV prophylaxis. Reverse transcriptase mutations K70R and K70E were detected in 3 and 2 subjects, respectively; protease mutation I50 V was detected in 1 subject. Three of the 6 children with DRMs initiated ARV therapy during followup, with a good response in 2. The overall rate of primary drug resistance in this pediatric HIV-infected population was low, and no subjects had more than 1 DRM. Mutations associated with resistance to nucleoside reverse transcriptase inhibitors were the most prevalent.

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

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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.

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

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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

HIV transmitted drug resistance in adult and pediatric populations in Panama Farmacorresistencia transmitida del VIH en poblaciones adultas y pediátricas en Panamá

OpenAIRE

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...

A qualitative analysis of multi-level barriers to HIV testing among women in Lebanon.

Science.gov (United States)

Clark, Kirsty A; Keene, Danya E; Pachankis, John E; Fattal, Omar; Rizk, Nesrine; Khoshnood, Kaveh

2017-09-01

While the number of HIV cases in the Middle East and North Africa region is low compared to other regions, recent studies show that incidence is increasing especially among high-risk populations; in particular, little is known about women and HIV in the region. Through semi-structured interviews with sexual healthcare providers and staff at non-governmental organisations, we sought to understand barriers to HIV testing among women in Lebanon. Using snowball sampling, key informants were recruited from greater Beirut (12 physicians, 9 non-governmental organisation staff). Data were analysed using a grounded theory framework. Findings identified barriers to HIV testing among women at each level of an adapted social-ecological model (i.e. social-cultural barriers, policy barriers, interpersonal healthcare provider barriers and intrapersonal barriers). Primary findings include the culture of sex as taboo; lack of sexual health education among women; fear of disclosing HIV testing and diagnosis; financial barriers linked to stigmatising insurance policies; and provider attitudes towards women. Findings can be used to inform HIV-related sexual health interventions at multiple levels for women in Lebanon and the greater region.

A biotechnology perspective of fungal proteases

Directory of Open Access Journals (Sweden)

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.

Effect of menstrual cycle on HIV-1 levels in the peripheral blood and genital tract. WHS 001 Study Team.

Science.gov (United States)

Reichelderfer, P S; Coombs, R W; Wright, D J; Cohn, J; Burns, D N; Cu-Uvin, S; Baron, P A; Coheng, M H; Landay, A L; Beckner, S K; Lewis, S R; Kovacs, A A

2000-09-29

To assess the variation in HIV-1 over the menstrual cycle, including RNA levels in the female genital tract, plasma HIV-1-RNA levels, CD4 cell counts, and culturable virus. A prospective analysis of 55 HIV-1-infected women. Blood and genital tract specimens were collected weekly over 8 weeks, spanning two complete menstrual cycles. Applying repeated-measures models that used menses as the reference level, the variation in viral RNA levels was compared in endocervical canal fluid and cells (collected by Sno-strips and cytobrush, respectively) and ectocervicovaginal lavage (CVL) fluid. Repeated-measures models were also used to assess the variation in plasma CD4 cell counts and viral load. Shedding patterns differed among the three sampling methods, independent of genital tract co-infections. Genital tract HIV-1-RNA levels from CVL fluid and endocervical canal cytobrush specimens were highest during menses and lowest immediately thereafter (P = 0.001 and P = 0.04). The HIV-1-RNA level in endocervical canal fluid was highest in the week preceding menses (P = 0.003). The menstrual cycle had no effect on blood levels of RNA (P = 0.62), culturable virus (P = 0.34), or CD4 cell counts (P = 0.55). HIV-1-RNA levels were higher in endocervical canal fluid than in peripheral blood plasma during the late luteal phase (P = 0.03). HIV-1-RNA levels vary with the menstrual cycle in the female genital tract but not the blood compartment. HIV-1-RNA levels are higher in endocervical canal fluid than in blood plasma. These findings may have important implications for sex-specific pathogenesis, heterosexual transmission, and contraceptive hormone interventions in HIV-1-infected women.

Hepatitis C Viremia Is Associated with Cytomegalovirus IgG Antibody Levels in HIV-Infected Women

Science.gov (United States)

Kuniholm, Mark H.; Parrinello, Christina M.; Anastos, Kathryn; Augenbraun, Michael; Plankey, Michael; Nowicki, Marek; Peters, Marion; Golub, Elizabeth T.; Lurain, Nell; Landay, Alan L.; Strickler, Howard D.; Kaplan, Robert C.

2013-01-01

Background Individuals with HIV infection exhibit high cytomegalovirus (CMV) IgG levels, but there are few data regarding the association of hepatitis C virus (HCV) with the immune response against CMV. Methods Associations of HCV with CMV seropositivity and CMV IgG levels were studied in 635 HIV-infected women, 187 of whom were HCV-seropositive, with adjustment in multivariable models for age, race/ethnicity, and HIV disease characteristics. Eighty one percent of the women reported receipt of highly active antiretroviral therapy (HAART) prior to or at CMV testing. Results In adjusted models women with chronic HCV had higher CMV IgG levels than those without HCV RNA (β = 2.86, 95% CI:0.89 – 4.83; P = 0.004). The association of HCV RNA with CMV IgG differed by age (P interaction = 0.0007), with a strong association observed among women in the low and middle age tertiles (≤45.3 years of age; β = 6.21, 95% CI:3.30 – 9.11, P<0.0001) but not among women in the high age tertile. CMV IgG levels were not associated with non-invasive measures of liver disease, APRI and FIB-4, or with HCV RNA level and adjustment for Epstein-Barr virus (EBV) IgG levels did not affect the association between HCV and CMV. Conclusions CMV IgG levels are higher in HCV/HIV co-infected women than in HIV mono-infected women. Further research on the association of HCV with CMV IgG is indicated because prior studies have found CMV IgG to be associated with morbidity and mortality in the general population and subclinical carotid artery disease in HIV-infected patients. PMID:23613990

Antiretroviral Drug Use in a Cohort of HIV-Uninfected Women in the United States: HIV Prevention Trials Network 064.

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Iris Chen

Full Text Available Antiretroviral (ARV drug use was analyzed in HIV-uninfected women in an observational cohort study conducted in 10 urban and periurban communities in the United States with high rates of poverty and HIV infection. Plasma samples collected in 2009-2010 were tested for the presence of 16 ARV drugs. ARV drugs were detected in samples from 39 (2% of 1,806 participants: 27/181 (15% in Baltimore, MD and 12/179 (7% in Bronx, NY. The ARV drugs detected included different combinations of non-nucleoside reverse transcriptase inhibitors and protease inhibitors (1-4 drugs/sample. These data were analyzed in the context of self-reported data on ARV drug use. None of the 39 women who had ARV drugs detected reported ARV drug use at any study visit. Further research is needed to evaluate ARV drug use by HIV-uninfected individuals.

Nef enhances HIV-1 infectivity via association with the virus assembly complex

International Nuclear Information System (INIS)

Qi Mingli; Aiken, Christopher

2008-01-01

The HIV-1 accessory protein Nef enhances virus infectivity by facilitating an early post-entry step of infection. Nef acts in the virus producer cell, leading to a beneficial modification to HIV-1 particles. Nef itself is incorporated into HIV-1 particles, where it is cleaved by the viral protease during virion maturation. To probe the role of virion-associated Nef in HIV-1 infection, we generated a fusion protein consisting of the host protein cyclophilin A (CypA) linked to the amino terminus of Nef. The resulting CypA-Nef protein enhanced the infectivity of Nef-defective HIV-1 particles and was specifically incorporated into the virions via association with Gag during particle assembly. Pharmacologic or genetic inhibition of CypA-Nef binding to Gag prevented incorporation of CypA-Nef into virions and inhibited infectivity enhancement. Our results indicate that infectivity enhancement by Nef requires its association with a component of the assembling HIV-1 particle

High genetic variability of HIV-1 in female sex workers from Argentina

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Carr Jean K

2007-08-01

Full Text Available Abstract Background A cross-sectional study on 625 Female Sex Workers (FSWs was conducted between 2000 and 2002 in 6 cities in Argentina. This study describes the genetic diversity and the resistance profile of the HIV-infected subjects. Results Seventeen samples from HIV positive FSWs were genotyped by env HMA, showing the presence of 9 subtype F, 6 subtype B and 2 subtype C. Sequence analysis of the protease/RT region on 16 of these showed that 10 were BF recombinants, three were subtype B, two were subtype C, and one sample presented a dual infection with subtype B and a BF recombinant. Full-length genomes of five of the protease/RT BF recombinants were also sequenced, showing that three of them were CRF12_BF. One FSW had a dual HIV-1 infection with subtype B and a BF recombinant. The B sections of the BF recombinant clustered closely with the pure B sequence isolated from the same patient. Major resistance mutations to antiretroviral drugs were found in 3 of 16 (18.8% strains. Conclusion The genetic diversity of HIV strains among FSWs in Argentina was extensive; about three-quarters of the samples were infected with diverse BF recombinants, near twenty percent had primary ART resistance and one sample presented a dual infection. Heterosexual transmission of genetically diverse, drug resistant strains among FSWs and their clients represents an important and underestimated threat, in Argentina.

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

Czech Academy of Sciences Publication Activity Database

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

2015-01-01

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

A predominance of R5-like HIV genotypes in vaginal secretions is associated with elevated plasma HIV-1 RNA levels and the absence of anti-retroviral therapy

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Lacour Nedra

2008-07-01

Full Text Available Abstract HIV expressed in genital secretions provides the inoculum from which transmitting variants are selected, both in sexual transmission and mother-to-infant transmission during partuition. Characterization of HIV levels and genotypes found in vaginal secretions and the impact of anti-retroviral therapy (ART on this virus can provide valuable insight for the prevention of HIV transmission. Vaginal HIV was evaluated in a cohort of 43 women attending a New Orleans HIV outpatient clinic. Predominant vaginal genotypes were characterized as R5- or X4-like by heteroduplex tracking analyses of the envelope V3 region. Most women (67.4% shed R5-like genotypes in vaginal secretions which was associated with elevated plasma HIV levels (≥ 10,000 copies HIV-RNA/mL and absence of ART. Because R5-like genotypes are more frequently associated with transmission, these observations suggest that the majority of women shedding HIV in genital secretions present a transmission risk. The levels of vaginal virus were similar between both groups, but shedding of X4-like genotypes was associated with lower plasma viral loads and the use of ART, suggesting that ART use may impact the genotypes of virus found in the female genital compartment.

Intracellular alkaline proteases produced by thermoacidophiles: detection of protease heterogeneity by gelatin zymography and polymerase chain reaction (PCR)

Energy Technology Data Exchange (ETDEWEB)

Kocab, S.; Erdem, B. [Middle East Technical University, Ankara (Turkey). Dept. of Biological Sciences

2002-08-01

In this study 24 thermoacidophilic archeal and bacterial strains isolated from hot-springs and hot-soils were screened for their ability to produce intracellular alkaline proteases. The protease activities of the strains, based on azocasein hydrolysis, showed a variation from 0.6 to 5.1 U. The cell extracts of three most potent producers were further examined and it was found that their proteases exhibited maximum activity at 60-70{sup o}C and showed a pH optimum over a range of pH 7.0-8.5. Gelatin zymography revealed that two of the selected archeal strains produced multiple active SDS-resistant proteases. On the other hand, PCR amplification of alkaline serine protease gene sequences of total DNA from all isolates yielded four distinct amplification fragments of 650, 450, 400 and 300 bp, which might have been derived from different serine protease genes. (author)

the effect of cd4 count level on the middle ear dynamics of hiv

African Journals Online (AJOL)

2014-01-01

Jan 1, 2014 ... THE EFFECT OF CD4 COUNT LEVEL ON THE MIDDLE EAR DYNAMICS OF HIV INFECTED PATIENTS .... compliance and pressure values were the ones causing ... of sound wave than in the control group (non-HIV infected ...

Incorporation of chimeric HIV-SIV-Env and modified HIV-Env proteins into HIV pseudovirions

International Nuclear Information System (INIS)

Devitt, Gerard; Emerson, Vanessa; Holtkotte, Denise; Pfeiffer, Tanya; Pisch, Thorsten; Bosch, Valerie

2007-01-01

Low level incorporation of the viral glycoprotein (Env) into human immunodeficiency virus (HIV) particles is a major drawback for vaccine strategies against HIV/AIDS in which HIV particles are used as immunogen. Within this study, we have examined two strategies aimed at achieving higher levels of Env incorporation into non-infectious pseudovirions (PVs). First, we have generated chimeric HIV/SIV Env proteins containing the truncated C-terminal tail region of simian immunodeficiency virus (SIV)mac239-Env767 stop , which mediates strongly increased incorporation of SIV-Env into SIV particles. In a second strategy, we have employed a truncated HIV-Env protein (Env-Tr752 N750K ) which we have previously demonstrated to be incorporated into HIV virions, generated in infected T-cells, to a higher level than that of Wt-HIV-Env. Although the chimeric HIV/SIV Env proteins were expressed at the cell surface and induced increased levels of cell-cell fusion in comparison to Wt-HIV-Env, they did not exhibit increased incorporation into either HIV-PVs or SIV-PVs. Only Env-Tr752 N750K exhibited significantly higher (threefold) levels of incorporation into HIV-PVs, an improvement, which, although not dramatic, is worthwhile for the large-scale preparation of non-infectious PVs for vaccine studies aimed at inducing Env humoral responses

Novel dual small-molecule HIV inhibitors: scaffolds and discovery strategies.

Science.gov (United States)

Song, Anran; Yu, Haiqing; Wang, Changyuan; Zhu, Xingqi; Liu, Kexin; Ma, Xiaodong

2015-01-01

Searching for safe and effective treatments for HIV infection is still a great challenge worldwide in spite of the 27 marketed anti-HIV drugs and the powerful highly active antiretroviral therapy (HAART). As a promising prospect for generation of new HIV therapy drugs, multiple ligands (MDLs) were greatly focused on recently due to their lower toxicity, simplified dosing and patient adherence than single-target drugs. Till now, by disrupting two active sites or steps of HIV replications, a number of HIV dual inhibitors, such as CD4-gssucap120 inhibitors, CXCR4-gp20 inhibitors, RT-CXCR4 inhibitors, RT-protease inhibitors, RT-integrase inhibitors, and RTassociated functions inhibitors have been identified. Generally, these dual inhibitors were discovered mainly through screening approaches and design strategies. Of these compounds, the molecules bearing small skeletons exhibited strong anti-HIV activity and aroused great attention recently. Reviewing the progress of the dual small-molecule HIV inhibitors from the point of view of their scaffolds and discovery strategies will provide valuable information for producing more effective anti-HIV drugs. In this regard, novel dual small-molecule HIV inhibitors were illustrated, and their discovery paradigms as the major contents were also summarized in this manuscript.

Genital herpes simplex virus type 2 infection in humanized HIV-transgenic mice triggers HIV shedding and is associated with greater neurological disease.

Science.gov (United States)

Nixon, Briana; Fakioglu, Esra; Stefanidou, Martha; Wang, Yanhua; Dutta, Monica; Goldstein, Harris; Herold, Betsy C

2014-02-15

Epidemiological studies consistently demonstrate synergy between herpes simplex virus type 2 (HSV-2) and human immunodeficiency virus type 1 (HIV-1). Higher HIV-1 loads are observed in coinfected individuals, and conversely, HIV-1 is associated with more-severe herpetic disease. A small animal model of coinfection would facilitate identification of the biological mechanisms underlying this synergy and provide the opportunity to evaluate interventions. Mice transgenic for HIV-1 provirus and human cyclin T1 under the control of a CD4 promoter (JR-CSF/hu-cycT1) were intravaginally infected with HSV-2 and evaluated for disease progression, HIV shedding, and mucosal immune responses. HSV-2 infection resulted in higher vaginal HIV loads and genital tissue expression of HIV RNA, compared with HSV-uninfected JR-CSF/hu-cycT1 mice. There was an increase in genital tract inflammatory cells, cytokines, chemokines, and interferons in response to HSV-2, although the kinetics of the response were delayed in HIV-transgenic, compared with control mice. Moreover, the JR-CSF/hu-cycT1 mice exhibited earlier and more-severe neurological disease. The latter was associated with downregulation of secretory leukocyte protease inhibitor expression in neuronal tissue, a molecule with antiinflammatory, antiviral, and neuroprotective properties. JR-CSF/hu-cycT1 mice provide a valuable model to study HIV/HSV-2 coinfection and identify potential mechanisms by which HSV-2 facilitates HIV-1 transmission and HIV modulates HSV-2-mediated disease.

Prevalence and patterns of HIV transmitted drug resistance in Guatemala.

Science.gov (United States)

Avila-Ríos, Santiago; Mejía-Villatoro, Carlos R; García-Morales, Claudia; Soto-Nava, Maribel; Escobar, Ingrid; Mendizabal, Ricardo; Girón, Amalia; García, Leticia; Reyes-Terán, Gustavo

2011-12-01

To assess human immunodeficiency virus (HIV) diversity and the prevalence of transmitted drug resistance (TDR) in Guatemala. One hundred forty-five antiretroviral treatment-naïve patients referred to the Roosevelt Hospital in Guatemala City were enrolled from October 2010 to March 2011. Plasma HIV pol sequences were obtained and TDR was assessed with the Stanford algorithm and the World Health Organization (WHO) TDR surveillance mutation list. HIV subtype B was highly prevalent in Guatemala (96.6%, 140/145), and a 2.8% (4/145) prevalence of BF1 recombinants and 0.7% (1/145) prevalence of subtype C viruses were found. TDR prevalence for the study period was 8.3% (12/145) with the Stanford database algorithm (score > 15) and the WHO TDR surveillance mutation list. Most TDR cases were associated with non-nucleoside reverse transcriptase inhibitors (NNRTIs) (83.3%, 10/12); a low prevalence of nucleoside reverse transcriptase inhibitors and protease inhibitors was observed in the cohort (Guatemala. TDR prevalence in Guatemala was at the intermediate level. Most TDR cases were associated with NNRTIs. Further and continuous TDR surveillance is necessary to gain more indepth knowledge about TDR spread and trends in Guatemala and to optimize treatment outcomes in the country.

Kinetic intermediates en route to the final serpin-protease complex: studies of complexes of α1-protease inhibitor with trypsin.

Science.gov (United States)

Maddur, Ashoka A; Swanson, Richard; Izaguirre, Gonzalo; Gettins, Peter G W; Olson, Steven T

2013-11-01

Serpin protein protease inhibitors inactivate their target proteases through a unique mechanism in which a major serpin conformational change, resulting in a 70-Å translocation of the protease from its initial reactive center loop docking site to the opposite pole of the serpin, kinetically traps the acyl-intermediate complex. Although the initial Michaelis and final trapped acyl-intermediate complexes have been well characterized structurally, the intermediate stages involved in this remarkable transformation are not well understood. To better characterize such intermediate steps, we undertook rapid kinetic studies of the FRET and fluorescence perturbation changes of site-specific fluorophore-labeled derivatives of the serpin, α1-protease inhibitor (α1PI), which report the serpin and protease conformational changes involved in transforming the Michaelis complex to the trapped acyl-intermediate complex in reactions with trypsin. Two kinetically resolvable conformational changes were observed in the reactions, ascribable to (i) serpin reactive center loop insertion into sheet A with full protease translocation but incomplete protease distortion followed by, (ii) full conformational distortion and movement of the protease and coupled serpin conformational changes involving the F helix-sheet A interface. Kinetic studies of calcium effects on the labeled α1PI-trypsin reactions demonstrated both inactive and low activity states of the distorted protease in the final complex that were distinct from the intermediate distorted state. These studies provide new insights into the nature of the serpin and protease conformational changes involved in trapping the acyl-intermediate complex in serpin-protease reactions and support a previously proposed role for helix F in the trapping mechanism.

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

Science.gov (United States)

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.

Dual antiretroviral therapy for HIV infection.

Science.gov (United States)

Soriano, Vicente; Fernandez-Montero, Jose Vicente; Benitez-Gutierrez, Laura; Mendoza, Carmen de; Arias, Ana; Barreiro, Pablo; Peña, José M; Labarga, Pablo

2017-08-01

For two decades, triple combinations of antiretrovirals have been the standard treatment for HIV infection. The challenges of such lifelong therapy include long-term side effects, high costs and reduced drug adherence. The recent advent of more potent and safer antiretrovirals has renewed the interest for simpler HIV regimens. Areas covered: We discuss the pros and cons of dual antiretroviral therapies in both drug-naïve and in treatment-experienced patients with viral suppression (switch strategy). Expert opinion: Some dual antiretroviral regimens are safe and efficacious, particularly as maintenance therapy. At this time, combinations of dolutegravir plus rilpivirine represent the best dual regimen. Longer follow-up and larger study populations are needed before supporting dolutegravir plus lamivudine. In contrast, dual therapy based on maraviroc is less effective. Although dual regimens with boosted protease inhibitors plus either lamivudine or raltegravir may be effective, they are penalized by metabolic side effects and risk for drug interactions. The newest dual regimens could save money, reduce toxicity and spare drug options for the future. For the first time in HIV therapeutics, less can be more. Dual therapy switching has set up a new paradigm in HIV treatment that uses induction-maintenance.

Distinguishing HIV-1 drug resistance, accessory, and viral fitness mutations using conditional selection pressure analysis of treated versus untreated patient samples

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Lee Christopher

2006-05-01

Full Text Available Abstract Background HIV can evolve drug resistance rapidly in response to new drug treatments, often through a combination of multiple mutations 123. It would be useful to develop automated analyses of HIV sequence polymorphism that are able to predict drug resistance mutations, and to distinguish different types of functional roles among such mutations, for example, those that directly cause drug resistance, versus those that play an accessory role. Detecting functional interactions between mutations is essential for this classification. We have adapted a well-known measure of evolutionary selection pressure (Ka/Ks and developed a conditional Ka/Ks approach to detect important interactions. Results We have applied this analysis to four independent HIV protease sequencing datasets: 50,000 clinical samples sequenced by Specialty Laboratories, Inc.; 1800 samples from patients treated with protease inhibitors; 2600 samples from untreated patients; 400 samples from untreated African patients. We have identified 428 mutation interactions in Specialty dataset with statistical significance and we were able to distinguish primary vs. accessory mutations for many well-studied examples. Amino acid interactions identified by conditional Ka/Ks matched 80 of 92 pair wise interactions found by a completely independent study of HIV protease (p-value for this match is significant: 10-70. Furthermore, Ka/Ks selection pressure results were highly reproducible among these independent datasets, both qualitatively and quantitatively, suggesting that they are detecting real drug-resistance and viral fitness mutations in the wild HIV-1 population. Conclusion Conditional Ka/Ks analysis can detect mutation interactions and distinguish primary vs. accessory mutations in HIV-1. Ka/Ks analysis of treated vs. untreated patient data can distinguish drug-resistance vs. viral fitness mutations. Verification of these results would require longitudinal studies. The result

Humanized mice recapitulate key features of HIV-1 infection: a novel concept using long-acting anti-retroviral drugs for treating HIV-1.

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Marc Nischang

Full Text Available BACKGROUND: Humanized mice generate a lymphoid system of human origin subsequent to transplantation of human CD34+ cells and thus are highly susceptible to HIV infection. Here we examined the efficacy of antiretroviral treatment (ART when added to food pellets, and of long-acting (LA antiretroviral compounds, either as monotherapy or in combination. These studies shall be inspiring for establishing a gold standard of ART, which is easy to administer and well supported by the mice, and for subsequent studies such as latency. Furthermore, they should disclose whether viral breakthrough and emergence of resistance occurs similar as in HIV-infected patients when ART is insufficient. METHODS/PRINCIPAL FINDINGS: NOD/shi-scid/γ(cnull (NOG mice were used in all experimentations. We first performed pharmacokinetic studies of the drugs used, either added to food pellets (AZT, TDF, 3TC, RTV or in a LA formulation that permitted once weekly subcutaneous administration (TMC278: non-nucleoside reverse transcriptase inhibitor, TMC181: protease inhibitor. A combination of 3TC, TDF and TMC278-LA or 3TC, TDF, TMC278-LA and TMC181-LA suppressed the viral load to undetectable levels in 15/19 (79% and 14/14 (100% mice, respectively. In successfully treated mice, subsequent monotherapy with TMC278-LA resulted in viral breakthrough; in contrast, the two LA compounds together prevented viral breakthrough. Resistance mutations matched the mutations most commonly observed in HIV patients failing therapy. Importantly, viral rebound after interruption of ART, presence of HIV DNA in successfully treated mice and in vitro reactivation of early HIV transcripts point to an existing latent HIV reservoir. CONCLUSIONS/SIGNIFICANCE: This report is a unique description of multiple aspects of HIV infection in humanized mice that comprised efficacy testing of various treatment regimens, including LA compounds, resistance mutation analysis as well as viral rebound after treatment

Advances in protease engineering for laundry detergents.

Science.gov (United States)

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.

Potential roles for uncoupling proteins in HIV lipodystrophy.

Science.gov (United States)

Nolan, David; Pace, Craig

2004-07-01

The 'HIV lipodystrophy syndrome' consists of several distinct components, including lipoatrophy (pathological subcutaneous fat loss), lipohypertrophy (abdominal/visceral adiposity), and metabolic complications including insulin resistance and dyslipidemia. Lipoatrophy appears to represent an adipose tissue-specific form of mitochondrial toxicity associated strongly with stavudine NRTI therapy, whilst the 'metabolic syndrome' phenotype is associated with HIV protease inhibitor therapy. In this context, the role of uncoupling proteins (UCPs) in modulating resting energy expenditure in response to elevated fatty acid flux associated with the 'metabolic syndrome' is supported by clinical data as well as findings of elevated adipose tissue UCP expression. The role of UCPs in this syndrome therefore exemplifies the multifactorial nature of these antiretroviral therapy complications.

Human endogenous retrovirus K Gag coassembles with HIV-1 Gag and reduces the release efficiency and infectivity of HIV-1.

Science.gov (United States)

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.

High Prevalence of HIV Drug Resistance Among Newly Diagnosed Infants Aged <18 Months: Results From a Nationwide Surveillance in Nigeria.

Science.gov (United States)

Inzaule, Seth C; Osi, Samuels J; Akinbiyi, Gbenga; Emeka, Asadu; Khamofu, Hadiza; Mpazanje, Rex; Ilesanmi, Oluwafunke; Ndembi, Nicaise; Odafe, Solomon; Sigaloff, Kim C E; Rinke de Wit, Tobias F; Akanmu, Sulaimon

2018-01-01

WHO recommends protease-inhibitor-based first-line regimen in infants because of risk of drug resistance from failed prophylaxis used in prevention of mother-to-child transmission (PMTCT). However, cost and logistics impede implementation in sub-Saharan Africa, and >75% of children still receive nonnucleoside reverse transcriptase inhibitor-based regimen (NNRTI) used in PMTCT. We assessed the national pretreatment drug resistance prevalence of HIV-infected children aged resistance surveillance protocol. We used remnant dried blood spots collected between June 2014 and July 2015 from 15 early infant diagnosis facilities spread across all the 6 geopolitical regions of Nigeria. Sampling was through a probability proportional-to-size approach. HIV drug resistance was determined by population-based sequencing. Overall, in 48% of infants (205 of 430) drug resistance mutations (DRM) were detected, conferring resistance to predominantly NNRTIs (45%). NRTI and multiclass NRTI/NNRTI resistance were present at 22% and 20%, respectively, while resistance to protease inhibitors was at 2%. Among 204 infants with exposure to drugs for PMTCT, 57% had DRMs, conferring NNRTI resistance in 54% and multiclass NRTI/NNRTI resistance in 29%. DRMs were also detected in 34% of 132 PMTCT unexposed infants. A high frequency of PDR, mainly NNRTI-associated, was observed in a nationwide surveillance among newly diagnosed HIV-infected children in Nigeria. PDR prevalence was equally high in PMTCT-unexposed infants. Our results support the use of protease inhibitor-based first-line regimens in HIV-infected young children regardless of PMTCT history and underscore the need to accelerate implementation of the newly disseminated guideline in Nigeria.

Risk of triple-class virological failure in children with HIV: a retrospective cohort study

DEFF Research Database (Denmark)

Castro, Hannah; Judd, Ali; Gibb, Diana M

2011-01-01

In adults with HIV treated with antiretroviral drug regimens from within the three original drug classes (nucleoside or nucleotide reverse transcriptase inhibitors [NRTIs], non-NRTIs [NNRTIs], and protease inhibitors), virological failure occurs slowly, suggesting that long-term virological...... failure to the three original drugs classes in children....

4th International Workshop on Adverse Drug Reactions and Lipodystrophy in HIV. San Diego, California, USA 22-25 September 2002.

Science.gov (United States)

Nolan, David; Christiansen, Frank

2003-01-01

Highlights are presented from this annual workshop, which was devoted to the investigation of adverse effects associated with antiretroviral therapy for HIV infection. Topics covered included the lipodystrophy syndrome, which encompasses body composition changes (subcutaneous fat wasting, visceral fat accumulation) and metabolic abnormalities (insulin resistance and dyslipidaemia). The relevance of HIV protease inhibitor-induced metabolic abnormalities to cardiovascular disease is discussed. Research in the areas of hyperlactataemia, abacavir hypersensitivity, and bone mineral density in the context of HIV infection is also briefly reviewed.

Prevalence, awareness, treatment, and control rate of hypertension in HIV-infected patients: the HIV-HY study.

Science.gov (United States)

De Socio, Giuseppe Vittorio; Ricci, Elena; Maggi, Paolo; Parruti, Giustino; Pucci, Giacomo; Di Biagio, Antonio; Calza, Leonardo; Orofino, Giancarlo; Carenzi, Laura; Cecchini, Enisia; Madeddu, Giordano; Quirino, Tiziana; Schillaci, Giuseppe

2014-02-01

We aimed to assess the prevalence of hypertension in an unselected human immunodeficiency virus (HIV)-infected population and to identify factors associated with hypertension prevalence, treatment, and control. We used a multicenter, cross-sectional, nationwide study that sampled 1,182 unselected, consecutive, HIV-infected patients. Office blood pressure was accurately measured with standard procedures. Patients were 71% men and 92% white, with a median age of 47 years (range = 18-78); 6% were antiretroviral treatment naive. The overall prevalence of hypertension was 29.3%; high-normal pressure accounted for an additional 12.3%. Among hypertensive subjects, 64.9% were aware of their hypertensive condition, 52.9% were treated, and 33.0% were controlled (blood pressure < 140/90 mm Hg). Blood pressure-lowering medications were used in monotherapy in 54.3% of the subjects. Angiotensin-converting enzyme inhibitors and angiotensin receptor blockers were the most frequently used drugs (76.1%: monotherapy = 39.1%, combination treatment = 37.0%). In multivariable regression models, hypertension was independently predicted by traditional risk factors, including age ≥50 years, male sex, family history of cardiovascular disease, body mass index ≥25 kg/m2, previous cardiovascular events, diabetes, central obesity, and metabolic syndrome, as well as by duration of HIV infection, duration of antiretroviral therapy, and nadir CD4+ T-cell count <200/μl. The choice of protease inhibitors vs. nonnucleoside reverse transcriptase inhibitors as a third antiretroviral drug was irrelevant. Hypertension affects nearly 30% of HIV adult outpatients in Italy. More than one-third of the hypertensive subjects are unaware of their condition, and more than two-thirds are uncontrolled. A higher level of attention to the diagnosis and treatment of hypertension is mandatory in this setting.

Understanding serine proteases implications on Leishmania spp lifecycle.

Science.gov (United States)

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.

Individual-level socioeconomic status and community-level inequality as determinants of stigma towards persons living with HIV who inject drugs in Thai Nguyen, Vietnam

Science.gov (United States)

Lim, Travis; Zelaya, Carla; Latkin, Carl; Quan, Vu Minh; Frangakis, Constantine; Ha, Tran Viet; Minh, Nguyen Le; Go, Vivian

2013-01-01

Introduction HIV infection may be affected by multiple complex socioeconomic status (SES) factors, especially individual socioeconomic disadvantage and community-level inequality. At the same time, stigma towards HIV and marginalized groups has exacerbated persistent concentrated epidemics among key populations, such as persons who inject drugs (PWID) in Vietnam. Stigma researchers argue that stigma fundamentally depends on the existence of economic power differences in a community. In rapidly growing economies like Vietnam, the increasing gap in income and education levels, as well as an individual's absolute income and education, may create social conditions that facilitate stigma related to injecting drug use and HIV. Methods A cross-sectional baseline survey assessing different types of stigma and key socioeconomic characteristics was administered to 1674 PWID and 1349 community members living in physical proximity throughout the 32 communes in Thai Nguyen province, Vietnam. We created four stigma scales, including HIV-related and drug-related stigma reported by both PWID and community members. We then used ecologic Spearman's correlation, ordinary least-squares regression and multi-level generalized estimating equations to examine community-level inequality associations, individual-level SES associations and multi-level SES associations with different types of stigma, respectively. Results There was little urban–rural difference in stigma among communes. Higher income inequality was marginally associated with drug-related stigma reported by community members (p=0.087), and higher education inequality was significantly associated with higher HIV-related stigma reported by both PWID and community members (pstigma (HIV and drug related) reported by both PWID and community members. Part-time employed PWID reported more experiences and perceptions of drug-related stigma, while conversely unemployed community members reported enacting lower drug-related stigma

A genomic survey of proteases in Aspergilli

NARCIS (Netherlands)

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

Long-term effectiveness of highly active antiretroviral therapy (HAART) in perinatally HIV-infected children in Denmark

DEFF Research Database (Denmark)

Bracher, Linda; Valerius, Niels Henrik; Rosenfeldt, Vibeke

2007-01-01

children treated with HAART. Initial HAART included 2 nucleoside reverse-transcriptase inhibitors in combination with either a protease inhibitor (n =38) or a non-nucleoside reverse-transcriptase inhibitor (n =12). 19 (39%) patients were previously treated with mono- or dual therapy. Baseline......The long-term impact of highly active antiretroviral therapy (HAART) on HIV-1 infected children is not well known. The Danish Paediatric HIV Cohort Study includes all patients ... characteristics were median CD4 percentage 14% and HIV-RNA viral load 4.9 log(10). Within the first 12 weeks of therapy approximately 60% achieved HIV-RNA viral load children changed the components of HAART. The proportion of children with CD4...

Circulating levels of mannan-binding lectin (MBL) and MBL-associated serine protease 2 in endemic pemphigus foliaceus

DEFF Research Database (Denmark)

Messias-Reason, I; Bosco, DG; Nisihara, RM

2008-01-01

Endemic pemphigus foliaceus (EPF) is an autoimmune disease, which occurs in Brazil and other regions of South America. Mannose-binding lectin (MBL) and MBL-associated serine protease (MASP-2) play a key role in innate immunity, and its deficiency has been related to increased susceptibility...... to infection and autoimmune diseases. MBL and MASP-2 serum levels were measured in 114 patients with EPF and in 100 healthy individuals in Brazil. MBL and MASP-2 levels were measured by sandwich assays (time-resolved immunofluorimetic assay) using monoclonal antibodies. No difference was observed in the MBL...... level in patients with EPF compared with controls [mean +/- SEM 1230.07 +/- 132.18 ng/mL (median 789.0 ng/mL) vs. 1036.98 +/- 117.99 ng/mL (median 559.5 ng/mL), P = 0.32]. Non-significant lower MASP-2 levels were observed in EPF [274.34 +/- 15.66 ng/mL (median 239.5 ng/mL ) vs. 304.72 +/- 15.28 ng...

Cathepsin F cysteine protease of the human liver fluke, Opisthorchis viverrini.

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Porntip Pinlaor

Full Text Available The liver fluke Opisthorchis viverrini is classified as a class I carcinogen due to the association between cholangiocarcinoma and chronic O. viverrini infection. During its feeding activity within the bile duct, the parasite secretes several cathepsin F cysteine proteases that may induce or contribute to the pathologies associated with hepatobiliary abnormalities.Here, we describe the cDNA, gene organization, phylogenetic relationships, immunolocalization, and functional characterization of the cathepsin F cysteine protease gene, here termed Ov-cf-1, from O. viverrini. The full length mRNA of 1020 nucleotides (nt encoded a 326 amino acid zymogen consisting of a predicted signal peptide (18 amino acids, aa, prosegment (95 aa, and mature protease (213 aa. BLAST analysis using the Ov-CF-1 protein as the query revealed that the protease shared identity with cathepsin F-like cysteine proteases of other trematodes, including Clonorchis sinensis (81%, Paragonimus westermani (58%, Schistosoma mansoni and S. japonicum (52%, and with vertebrate cathepsin F (51%. Transcripts encoding the protease were detected in all developmental stages that parasitize the mammalian host. The Ov-cf-1 gene, of approximately 3 kb in length, included seven exons interrupted by six introns; the exons ranged from 69 to 267 bp in length, the introns from 43 to 1,060 bp. The six intron/exon boundaries of Ov-cf-1 were conserved with intron/exon boundaries in the human cathepsin F gene, although the gene structure of human cathepsin F is more complex. Unlike Ov-CF-1, human cathepsin F zymogen includes a cystatin domain in the prosegment region. Phylogenetic analysis revealed that the fluke, human, and other cathepsin Fs branched together in a clade discrete from the cathepsin L cysteine proteases. A recombinant Ov-CF-1 zymogen that displayed low-level activity was expressed in the yeast Pichia pastoris. Although the recombinant protease did not autocatalytically process and

Suboptimal inhibition of protease activity in human immunodeficiency virus type 1: Effects on virion morphogenesis and RNA maturation

International Nuclear Information System (INIS)

Moore, Michael D.; Fu, William; Soheilian, Ferri; Nagashima, Kunio; Ptak, Roger G.; Pathak, Vinay K.; Hu, Wei-Shau

2008-01-01

Protease activity within nascently released human immunodeficiency virus type 1 (HIV-1) particles is responsible for the cleavage of the viral polyproteins Gag and Gag-Pol into their constituent parts, which results in the subsequent condensation of the mature conical core surrounding the viral genomic RNA. Concomitant with viral maturation is a conformational change in the packaged viral RNA from a loosely associated dimer into a more thermodynamically stable form. In this study we used suboptimal concentrations of two protease inhibitors, lopinavir and atazanavir, to study their effects on Gag polyprotein processing and on the properties of the RNA in treated virions. Analysis of the treated virions demonstrated that even with high levels of inhibition of viral infectivity (IC 90 ), most of the Gag and Gag-Pol polyproteins were processed, although slight but significant increases in processing intermediates of Gag were detected. Drug treatments also caused a significant increase in the proportion of viruses displaying either immature or aberrant mature morphologies. The aberrant mature particles were characterized by an electron-dense region at the viral periphery and an electron-lucent core structure in the viral center, possibly indicating exclusion of the genomic RNA from these viral cores. Intriguingly, drug treatments caused only a slight decrease in overall thermodynamic stability of the viral RNA dimer, suggesting that the dimeric viral RNA was able to mature in the absence of correct core condensation

House dust mite major allergens Der p 1 and Der p 5 activate human airway-derived epithelial cells by protease-dependent and protease-independent mechanisms

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Timmerman J André B

2006-03-01

Full Text Available Abstract House dust mite allergens (HDM cause bronchoconstriction in asthma patients and induce an inflammatory response in the lungs due to the release of cytokines, chemokines and additional mediators. The mechanism how HDM components achieve this is largely unknown. The objective of this study was to assess whether HDM components of Dermatophagoides pteronissinus with protease activity (Der p 1 and unknown enzymatic activity (Der p 2, Der p 5 induce biological responses in a human airway-derived epithelial cell line (A549, and if so, to elucidate the underlying mechanism(s of action. A549 cells were incubated with HDM extract, Der p 1, recombinant Der p 2 and recombinant Der p 5. Cell desquamation was assessed by microscopy. The proinflammatory cytokines, IL-6 and IL-8, were measured by ELISA. Intracellular Ca2+ levels were assessed in A549 cells and in mouse fibroblasts expressing the human protease activated receptor (PAR1, PAR2 or PAR4. HDM extract, Der p 1 and Der p 5 dose-dependently increased the production of IL-6 and IL-8. Added simultaneously, Der p 1 and Der p 5 further increased the production of IL-6 and IL-8. The action of Der p 1 was blocked by cysteine-protease inhibitors, while that of Der p 5 couldn't be blocked by either serine- or cysteine protease inhibitors. Der p 5 only induced cell shrinking, whereas HDM extract and Der p1 also induced cell desquamation. Der p 2 had no effect on A549 cells. Der p 1's protease activity causes desquamation and induced the release of IL6 and IL-8 by a mechanism independent of Ca2+ mobilisation and PAR activation. Der p 5 exerts a protease-independent activation of A549 that involves Ca2+ mobilisation and also leads to the production of these cytokines. Together, our data indicate that allergens present in HDM extracts can trigger protease-dependent and protease-independent signalling pathways in A549 cells.

Cytomegalovirus protease targeted prodrug development.

Science.gov (United States)

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.

Role of Proteases in Chronic Obstructive Pulmonary Disease

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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.

tolerant alkaline protease from Bacillus coagulans PSB

African Journals Online (AJOL)

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.

Flazinamide, a novel β-carboline compound with anti-HIV actions

International Nuclear Information System (INIS)

Wang Yunhua; Tang Jianguo; Wang Ruirui; Yang Liumeng; Dong Zejun; Du Li; Shen Xu; Liu Jikai; Zheng Yongtang

2007-01-01

A β-carboline compound, flazin isolated from Suillus granulatus has been shown weak anti-HIV-1 activity. Based on the structure of flazin, flazinamide [1-(5'- hydromethyl-2'-furyl)-β-carboline-3-carboxamide] was synthesized and its anti-HIV activities were evaluated in the present study. The cytotoxicity of flazinamide was about 4.1-fold lower than that of flazin. Flazinamide potently reduced syncytium formation induced by HIV-1IIIB with EC50 value of 0.38 μM, the EC50 of flazinamide was about 6.2-fold lower than that of flazin. Flazinamide also inhibited HIV-2ROD and HIV-2CBL-20 infection with EC50 values of 0.57 and 0.89 μM, respectively. Flazinamide reduced p24 antigen expression in HIV-1IIIB acute infected C8166 and in clinical isolated strain HIV-1KM018 infected PBMC, with EC50 values of 1.45 and 0.77 μM, respectively. Flazinamide did not suppress HIV-1 replication in chronically infected H9 cells. Flazinamide blocked the fusion between normal cells and HIV-1 or HIV-2 chronically infected cells. It weakly inhibited activities of recombinant HIV-1 reverse transcriptase, protease or integrase at higher concentrations. In conclusion, the conversion of the carboxyl group in 3 position of flazin markedly enhanced the anti-viral activity (TI value increased from 12.1 to 312.2) and flazinamide might interfere in the early stage of HIV life cycle

Mosaic serine proteases in the mammalian central nervous system.

Science.gov (United States)

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.

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

DEFF Research Database (Denmark)

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

2016-01-01

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

Ubiquitin-specific protease 14 regulates cell proliferation and apoptosis in oral squamous cell carcinoma.

Science.gov (United States)

Chen, Xiangyun; Wu, Jingjing; Chen, Yitian; Ye, Dongxia; Lei, Hu; Xu, Hanzhang; Yang, Li; Wu, Yingli; Gu, Wenli

2016-10-01

Ubiquitin-specific protease 14, a deubiquitinating enzyme, has been implicated in the tumorigenesis and progression of several cancers, but its role in oral squamous cell carcinoma remains to be elucidated. The aim of this study was to explore the expression pattern and roles of Ubiquitin-specific protease 14 in the occurrence and development of oral squamous cell carcinoma. Interestingly, Ubiquitin-specific protease 14 was overexpressed in oral cancer tissues and cell lines at both mRNA and protein levels. b-AP15, a specific inhibitor of Ubiquitin-specific protease 14, significantly inhibited the growth of cancer cells and increased cell apoptosis in a dose-dependent manner. Moreover, knockdown of Ubiquitin-specific protease 14 by shRNA significantly inhibited the proliferation and migration of cancer cells in vitro. Finally, using a xenograft mouse model of oral squamous cell carcinoma, knockdown of Ubiquitin-specific protease 14 markedly inhibited tumor growth and triggered the cancer cell apoptosis in vivo, supporting previous results. In conclusion, for the first time we have demonstrated the expression pattern of Ubiquitin-specific protease 14 in oral squamous cell carcinoma and verified a relationship with tumor growth and metastasis. These results may highlight new therapeutic strategies for tumor treatment, application of Ubiquitin-specific protease 14 selective inhibitor, such as b-AP15, or knockdown by shRNA. Collectively, Ubiquitin-specific protease 14 could be a potential therapeutic target for oral squamous cell carcinoma patients. Copyright © 2016 Elsevier Ltd. All rights reserved.

Protease-resistant prions selectively decrease Shadoo protein.

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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.

Short circuit: Disaggregation of adrenocorticotropic hormone and cortisol levels in HIV-positive, methamphetamine-using men who have sex with men.

Science.gov (United States)

Carrico, Adam W; Rodriguez, Violeta J; Jones, Deborah L; Kumar, Mahendra

2018-01-01

This study examined if methamphetamine use alone (METH + HIV-) and methamphetamine use in combination with HIV (METH + HIV+) were associated with hypothalamic-pituitary-adrenal (HPA) axis dysregulation as well as insulin resistance relative to a nonmethamphetamine-using, HIV-negative comparison group (METH-HIV-). Using an intact groups design, serum levels of HPA axis hormones in 46 METH + HIV- and 127 METH + HIV+ men who have sex with men (MSM) were compared to 136 METH-HIV- men. There were no group differences in prevailing adrenocorticotropic hormone (ACTH) or cortisol levels, but the association between ACTH and cortisol was moderated by METH + HIV+ group (β = -0.19, p < .05). Compared to METH-HIV- men, METH + HIV+ MSM displayed 10% higher log 10 cortisol levels per standard deviation lower ACTH. Both groups of methamphetamine-using MSM had lower insulin resistance and greater syndemic burden (i.e., sleep disturbance, severe depression, childhood trauma, and polysubstance use disorder) compared to METH-HIV- men. However, the disaggregated functional relationship between ACTH and cortisol in METH + HIV+ MSM was independent of these factors. Further research is needed to characterize the bio-behavioral pathways that explain dysregulated HPA axis functioning in HIV-positive, methamphetamine-using MSM. Copyright © 2017 John Wiley & Sons, Ltd.

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

Science.gov (United States)

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.

Designing cellulosic and nanocellulosic sensors for interface with a protease sequestrant wound-dressing prototype: implications of material selection for dressing and protease sensor design

Science.gov (United States)

An intelligent dressing is a self-adjusting material with multifunctional properties and/or a biosensor-interface designed to treat specific pathological issues of wounds at a molecular or cellular level. The ability to detect and treat excessive protease levels in wounds, one indicator of chronic w...

Dysregulation of protease and protease inhibitors in a mouse model of human pelvic organ prolapse.

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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.

Extracellular proteases of Trichoderma species. A review.

Science.gov (United States)

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.

Individual-level socioeconomic status and community-level inequality as determinants of stigma towards persons living with HIV who inject drugs in Thai Nguyen, Vietnam.

Science.gov (United States)

Lim, Travis; Zelaya, Carla; Latkin, Carl; Quan, Vu Minh; Frangakis, Constantine; Ha, Tran Viet; Minh, Nguyen Le; Go, Vivian

2013-11-13

HIV infection may be affected by multiple complex socioeconomic status (SES) factors, especially individual socioeconomic disadvantage and community-level inequality. At the same time, stigma towards HIV and marginalized groups has exacerbated persistent concentrated epidemics among key populations, such as persons who inject drugs (PWID) in Vietnam. Stigma researchers argue that stigma fundamentally depends on the existence of economic power differences in a community. In rapidly growing economies like Vietnam, the increasing gap in income and education levels, as well as an individual's absolute income and education, may create social conditions that facilitate stigma related to injecting drug use and HIV. A cross-sectional baseline survey assessing different types of stigma and key socioeconomic characteristics was administered to 1674 PWID and 1349 community members living in physical proximity throughout the 32 communes in Thai Nguyen province, Vietnam. We created four stigma scales, including HIV-related and drug-related stigma reported by both PWID and community members. We then used ecologic Spearman's correlation, ordinary least-squares regression and multi-level generalized estimating equations to examine community-level inequality associations, individual-level SES associations and multi-level SES associations with different types of stigma, respectively. There was little urban-rural difference in stigma among communes. Higher income inequality was marginally associated with drug-related stigma reported by community members (p=0.087), and higher education inequality was significantly associated with higher HIV-related stigma reported by both PWID and community members (pinequality and HIV-related stigma is superseded by the effect of individual-level education. The results of the study confirm that socioeconomic factors at both the individual level and community level affect different types of stigma in different ways. Attention should be paid to these

Labeling of multiple HIV-1 proteins with the biarsenical-tetracysteine system.

Directory of Open Access Journals (Sweden)

Cândida F Pereira

Full Text Available Due to its small size and versatility, the biarsenical-tetracysteine system is an attractive way to label viral proteins for live cell imaging. This study describes the genetic labeling of the human immunodeficiency virus type 1 (HIV-1 structural proteins (matrix, capsid and nucleocapsid, enzymes (protease, reverse transcriptase, RNAse H and integrase and envelope glycoprotein 120 with a tetracysteine tag in the context of a full-length virus. We measure the impact of these modifications on the natural virus infection and, most importantly, present the first infectious HIV-1 construct containing a fluorescently-labeled nucleocapsid protein. Furthermore, due to the high background levels normally associated with the labeling of tetracysteine-tagged proteins we have also optimized a metabolic labeling system that produces infectious virus containing the natural envelope glycoproteins and specifically labeled tetracysteine-tagged proteins that can easily be detected after virus infection of T-lymphocytes. This approach can be adapted to other viral systems for the visualization of the interplay between virus and host cell during infection.

Plasma CXCL10, sCD163 and sCD14 Levels Have Distinct Associations with Antiretroviral Treatment and Cardiovascular Disease Risk Factors.

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Alison Castley

Full Text Available We investigate the associations of three established plasma biomarkers in the context of HIV and treatment-related variables including a comprehensive cardiovascular disease risk assessment, within a large ambulatory HIV cohort. Patients were recruited in 2010 to form the Royal Perth Hospital HIV/CVD risk cohort. Plasma sCD14, sCD163 and CXCL10 levels were measured in 475 consecutive patients with documented CVD risk (age, ethnicity, gender, smoking, blood pressure, BMI, fasting metabolic profile and HIV treatment history including immunological/virological outcomes. The biomarkers assessed showed distinct associations with virological response: CXCL10 strongly correlated with HIV-1 RNA (p0.2. Associations between higher sCD163 and protease inhibitor therapy (p = 0.05 and lower sCD14 with integrase inhibitor therapy (p = 0.02 were observed. Levels of sCD163 were also associated with CVD risk factors (age, ethnicity, HDL, BMI, with a favourable influence of Framingham score <10% (p = 0.04. Soluble CD14 levels were higher among smokers (p = 0.002, with no effect of other CVD risk factors, except age (p = 0.045. Our findings confirm CXCL10, sCD163 and sCD14 have distinct associations with different aspects of HIV infection and treatment. Levels of CXCL10 correlated with routinely monitored variables, sCD163 levels reflect a deeper level of virological suppression and influence of CVD risk factors, while sCD14 levels were not associated with routinely monitored variables, with evidence of specific effects of smoking and integrase inhibitor therapy warranting further investigation.

Plasma CXCL10, sCD163 and sCD14 Levels Have Distinct Associations with Antiretroviral Treatment and Cardiovascular Disease Risk Factors

Science.gov (United States)

Castley, Alison; Williams, Leah; James, Ian; Guelfi, George; Berry, Cassandra; Nolan, David

2016-01-01

We investigate the associations of three established plasma biomarkers in the context of HIV and treatment-related variables including a comprehensive cardiovascular disease risk assessment, within a large ambulatory HIV cohort. Patients were recruited in 2010 to form the Royal Perth Hospital HIV/CVD risk cohort. Plasma sCD14, sCD163 and CXCL10 levels were measured in 475 consecutive patients with documented CVD risk (age, ethnicity, gender, smoking, blood pressure, BMI, fasting metabolic profile) and HIV treatment history including immunological/virological outcomes. The biomarkers assessed showed distinct associations with virological response: CXCL10 strongly correlated with HIV-1 RNA (p0.2). Associations between higher sCD163 and protease inhibitor therapy (p = 0.05) and lower sCD14 with integrase inhibitor therapy (p = 0.02) were observed. Levels of sCD163 were also associated with CVD risk factors (age, ethnicity, HDL, BMI), with a favourable influence of Framingham score <10% (p = 0.04). Soluble CD14 levels were higher among smokers (p = 0.002), with no effect of other CVD risk factors, except age (p = 0.045). Our findings confirm CXCL10, sCD163 and sCD14 have distinct associations with different aspects of HIV infection and treatment. Levels of CXCL10 correlated with routinely monitored variables, sCD163 levels reflect a deeper level of virological suppression and influence of CVD risk factors, while sCD14 levels were not associated with routinely monitored variables, with evidence of specific effects of smoking and integrase inhibitor therapy warranting further investigation. PMID:27355513

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

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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.

Deletion of aprA and nprA genes for alkaline protease A and neutral protease A from bacillus thuringiensis: effect on insecticidal crystal proteins.

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Tan, Y; Donovan, W P

2001-11-17

The aprA gene encoding alkaline protease A (AprA) was cloned from Bacillus thuringiensis subsp. kurstaki, and the cloned gene was used to construct aprA-deleted (aprA1) strains of B. thuringiensis. An aprA1 strain of B. thuringiensis that contained the wild-type gene for neutral protease A (nprA(+)) displayed levels of extracellular proteolytic activity that were similar to those of an aprA(+)nprA(+) strain. However, when EDTA was included in the protease assay to inhibit NprA activity the aprA1nprA(+) strain displayed only 2% of the extracellular proteolytic activity of the aprA(+)nprA(+) strain. A strain that was deleted for both aprA and nprA (aprA1nprA3 strain) failed to produce detectable levels of proteolytic activity either in the presence or absence of EDTA in the assay. Compared with the aprA(+)nprA(+) strain the aprA1nprA(+) strain yielded 10% more full-length Cry1Bb crystal protein and the aprA1nprA3 strain yielded 25% more full-length Cry1Bb protein. No significant differences were seen in the 50% lethal dose of Cry1Bb protein from aprA(+)nprA(+) and aprA1nprA3 strains against three species of lepidopteran insects. These results suggest that enhanced yield of certain crystal proteins can be obtained by deletion of the genes aprA and nprA which are the major extracellular proteases of B. thuringiensis.

Variability of HIV-1 genomes among children and adolescents from Sao Paulo, Brazil.

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Sabri Saeed Sanabani

Full Text Available BACKGROUND: Genetic variability is a major feature of the human immunodeficiency virus type 1 (HIV-1 and considered the key factor to frustrating efforts to halt the virus epidemic. In this study, we aimed to investigate the genetic variability of HIV-1 strains among children and adolescents born from 1992 to 2009 in the state of Sao Paulo, Brazil. METHODOLOGY: Plasma and peripheral blood mononuclear cells (PBMC were collected from 51 HIV-1-positive children and adolescents on ART followed between September 1992 and July 2009. After extraction, the genetic materials were used in a polymerase chain reaction (PCR to amplify the viral near full length genomes (NFLGs from 5 overlapped fragments. NFLGs and partial amplicons were directly sequenced and data were phylogenetically inferred. RESULTS: Of the 51 samples studied, the NFLGs and partial fragments of HIV-1 from 42 PBMCs and 25 plasma were successfully subtyped. Results based on proviral DNA revealed that 22 (52.4% patients were infected with subtype B, 16 (38.1% were infected with BF1 mosaic variants and 4 (9.5% were infected with sub-subtype F1. All the BF1 recombinants were unique and distinct from any previously identified unique or circulating recombinant forms in South America. Evidence of dual infections was detected in 3 patients coinfected with the same or distinct HIV-1 subtypes. Ten of the 31 (32.2% and 12 of the 21 (57.1% subjects with recovered proviral and plasma, respectively, protease sequences were infected with major mutants resistant to protease inhibitors. The V3 sequences of 14 patients with available sequences from PBMC/or plasma were predicted to be R5-tropic virus except for two patients who harbored an X4 strain. CONCLUSIONS: The high proportion of HIV-1 BF1 recombinant, coinfection rate and vertical transmission in Brazil merits urgent attention and effective measures to reduce the transmission of HIV among spouses and sex partners.

Antibodies from the sera of HIV-infected patients efficiently hydrolyze all human histones.

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Baranova, Svetlana V; Buneva, Valentina N; Nevinsky, Georgy A

2016-08-01

Histones and their post-translational modifications have key roles in chromatin remodeling and gene transcription. Besides intranuclear functions, histones act as damage-associated molecular pattern molecules when they are released into the extracellular space. Administration of exogenous histones to animals leads to systemic inflammatory and toxic responses through activating Toll-like receptors and inflammasome pathways. Here, using ELISA it was shown that sera of HIV-infected patients and healthy donors contain autoantibodies against histones. Autoantibodies with enzymic activities (abzymes) are a distinctive feature of autoimmune diseases. It was interesting whether antibodies from sera of HIV-infected patients can hydrolyze human histones. Electrophoretically and immunologically homogeneous IgGs were isolated from sera of HIV-infected patients by chromatography on several affinity sorbents. We present first evidence showing that 100% of IgGs purified from the sera of 32 HIV-infected patients efficiently hydrolyze from one to five human histones. Several rigid criteria have been applied to show that the histone-hydrolyzing activity is an intrinsic property of IgGs of HIV-infected patients. The relative efficiency of hydrolysis of histones (H1, H2a, H2b, H3, and H4) significantly varied for IgGs of different patients. IgGs from the sera of 40% of healthy donors also hydrolyze histones but with an average efficiency approximately 16-fold lower than that of HIV-infected patients. Similar to proteolytic abzymes from the sera of patients with several autoimmune diseases, histone-hydrolyzing IgGs from HIV-infected patients were inhibited by specific inhibitors of serine and of metal-dependent proteases, but an unexpected significant inhibition of the activity by specific inhibitor of thiol-like proteases was also observed. Because IgGs can efficiently hydrolyze histones, a negative role of abzymes in development of acquired immune deficiency syndrome cannot be

Exposure to ozone modulates human airway protease/antiprotease balance contributing to increased influenza A infection.

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Matthew J Kesic

Full Text Available Exposure to oxidant air pollution is associated with increased respiratory morbidities and susceptibility to infections. Ozone is a commonly encountered oxidant air pollutant, yet its effects on influenza infections in humans are not known. The greater Mexico City area was the primary site for the spring 2009 influenza A H1N1 pandemic, which also coincided with high levels of environmental ozone. Proteolytic cleavage of the viral membrane protein hemagglutinin (HA is essential for influenza virus infectivity. Recent studies suggest that HA cleavage might be cell-associated and facilitated by the type II transmembrane serine proteases (TTSPs human airway trypsin-like protease (HAT and transmembrane protease, serine 2 (TMPRSS2, whose activities are regulated by antiproteases, such as secretory leukocyte protease inhibitor (SLPI. Based on these observations, we sought to determine how acute exposure to ozone may modulate cellular protease/antiprotease expression and function, and to define their roles in a viral infection. We utilized our in vitro model of differentiated human nasal epithelial cells (NECs to determine the effects of ozone on influenza cleavage, entry, and replication. We show that ozone exposure disrupts the protease/antiprotease balance within the airway liquid. We also determined that functional forms of HAT, TMPRSS2, and SLPI are secreted from human airway epithelium, and acute exposure to ozone inversely alters their expression levels. We also show that addition of antioxidants significantly reduces virus replication through the induction of SLPI. In addition, we determined that ozone-induced cleavage of the viral HA protein is not cell-associated and that secreted endogenous proteases are sufficient to activate HA leading to a significant increase in viral replication. Our data indicate that pre-exposure to ozone disrupts the protease/antiprotease balance found in the human airway, leading to increased influenza susceptibility.

Purification and characterization of a serine protease (CESP) from mature coconut endosperm

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Panicker, Leelamma M; Usha, Rajamma; Roy, Samir; Mandal, Chhabinath

2009-01-01

Background In plants, proteases execute an important role in the overall process of protein turnover during seed development, germination and senescence. The limited knowledge on the proteolytic machinery that operates during seed development in coconut (Cocos nucifera L.) prompted us to search for proteases in the coconut endosperm. Findings We have identified and purified a coconut endosperm protease (CESP) to apparent homogeneity. CESP is a single polypeptide enzyme of approximate molecular mass of 68 kDa and possesses pH optimum of 8.5 for the hydrolysis of BAPNA. Studies relating to substrate specificity and pattern of inhibition by various protease inhibitors indicated that CESP is a serine protease with cleavage specificity to peptide bonds after arginine. Purified CESP was often autolysed to two polypeptides of 41.6 kDa (CESP1) and 26.7 kDa (CESP2) and is confirmed by immunochemistry. We have shown the expression of CESP in all varieties of coconut and in all stages of coconut endosperm development with maximum amount in fully matured coconut. Conclusion Since the involvement of proteases in the processing of pre-proteins and maintenance of intracellular protein levels in seeds are well known, we suspect this CESP might play an important role in the coconut endosperm development. However this need to be confirmed using further studies. PMID:19426537

Compliance/adherence and care management in HIV disease.

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Crespo-Fierro, M

1997-01-01

With the changing perspectives of the HIV epidemic and the introduction of protease inhibitors to treat human immunodeficiency virus (HIV) disease, the issue of compliance has gained considerable interest among health care providers. The idea that clients with HIV disease should succumb to a patriarchal system of medical care has been challenged by AIDS activists since the beginning of the epidemic. The concept that there is only one explanation for "noncompliance" is outdated. The reasons for noncompliance are multifaceted in nature and include psychosocial factors, complex medication and treatment regimens, ethnocultural concerns, and in many instances substance use. Therefore, the notion that there is one intervention to resolve noncompliance is at best archaic. Interventions to enhance compliance include supervised therapy, improving the nurse-client relationship, and patient education, all of which should be combined with ethnocultural interventions. Plans to enhance compliance must incorporate person-specific variables and should be tailored to individualized needs.

Rapid Detection of Thrombin and Other Protease Activity Directly in Whole Blood

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Yu, Johnson Chung Sing

Thrombin is a serine protease that plays a key role in the clotting cascade to promote hemostasis following injury to the endothelium. From a clinical diagnostic perspective, in-vivo thrombin activity is linked to various blood clotting disorders, as well as cardiovascular disease (DVT, arteriosclerosis, etc). Thus, the ability to rapidly measure protease activity directly in whole blood will provide important new diagnostics, and clinical researchers with a powerful tool to further elucidate the relationship between circulating protease levels and disease. The ultimate goal is to design novel point of care (POC) diagnostic devices that are capable of monitoring protease activities directly in whole blood and biological sample. A charge-changing substrate specific to the thrombin enzyme was engineered and its functionality was confirmed by a series of experiments. This led to the preliminary design, construction, and testing of two device platforms deemed fully functional for the electrophoretic separation and focusing of charged peptide fragments. The concept of using the existing charge-changing substrate platform for bacterial protease detection was also investigated. Certain strains of E coli are associated with severe symptoms such as abdominal cramps, bloody diarrhea, and vomiting. The OmpT protease is expressed on the outer membrane of E coli and plays a role in the cleavage of antimicrobial peptides, the degradation of recombinant heterologous proteins, and the activation of plasminogen in the host. Thus, a synthetic peptide substrate specific to the OmpT protease was designed and modeled for the purpose of detecting E coli in biological sample.

The changing molecular epidemiology of HIV in the Philippines.

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Salvaña, Edsel Maurice T; Schwem, Brian E; Ching, Patrick R; Frost, Simon D W; Ganchua, Sharie Keanne C; Itable, Jill R

2017-08-01

The Philippines has one of the fastest-growing HIV epidemics in the world. Possible reasons for this include increased testing, increased local transmission, and possibly more aggressive strains of HIV. This study sought to determine whether local molecular subtypes of HIV have changed. Viruses from 81 newly diagnosed, treatment-naive HIV patients were genotyped using protease and reverse transcriptase genes. Demographic characteristics and CD4 count data were collected. The cohort had an average age of 29 years (range 19-51 years), CD4+ count of 255 cells/mm 3 (range 2-744 cells/mm 3 ), and self-reported acquisition time of 2.42 years (range 0.17-8.17 years). All were male, including 79 men who have sex with men (MSM). The genotype distribution was 77% CRF01_AE, 22% B, and 1% C. Previous data from 1985-2000 showed that most Philippine HIV infections were caused by subtype B (71%, n=100), followed by subtype CRF01_AE (20%). Comparison with the present cohort showed a significant shift in subtype (pepidemiology of HIV in the Philippines has changed, with the more aggressive CRF01_AE now being the predominant subtype. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Association of a 3' untranslated region polymorphism in proprotein convertase subtilisin/kexin type 9 with HIV viral load and CD4+ levels in HIV/hepatitis C virus coinfected women.

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Kuniholm, Mark H; Liang, Hua; Anastos, Kathryn; Gustafson, Deborah; Kassaye, Seble; Nowicki, Marek; Sha, Beverly E; Pawlowski, Emilia J; Gange, Stephen J; Aouizerat, Bradley E; Pushkarsky, Tatiana; Bukrinsky, Michael I; Prasad, Vinayaka R

2017-11-28

To assess variation in genes that regulate cholesterol metabolism in relation to the natural history of HIV infection. Cross-sectional and longitudinal analysis of the Women's Interagency HIV Study. We examined 2050 single nucleotide polymorphisms (SNPs) in 19 genes known to regulate cholesterol metabolism in relation to HIV viral load and CD4 T-cell levels in a multiracial cohort of 1066 antiretroviral therapy-naive women. Six SNPs were associated with both HIV viral load and CD4 T-cell levels at a false discovery rate of 0.01. Bioinformatics tools did not predict functional activity for five SNPs, located in introns of nuclear receptor corepressor 2, retinoid X receptor alpha (RXRA), and tetratricopeptide repeat domain 39B. Rs17111557 located in the 3' untranslated region of proprotein convertase subtilisin/kexin type 9 (PCSK9) putatively affects binding of hsa-miR-548t-5p and hsa-miR-4796-3p, which could regulate PCSK9 expression levels. Interrogation of rs17111557 revealed stronger associations in the subset of women with HIV/hepatitis C virus (HCV) coinfection (n = 408, 38% of women). Rs17111557 was also associated with low-density lipoprotein cholesterol levels in HIV/HCV coinfected (β: -10.4; 95% confidence interval: -17.9, -2.9; P = 0.007), but not in HIV monoinfected (β:1.2; 95% confidence interval: -6.3, 8.6; P = 0.76) women in adjusted analysis. PCSK9 polymorphism may affect HIV pathogenesis, particularly in HIV/HCV coinfected women. A likely mechanism for this effect is PCSK9-mediated regulation of cholesterol metabolism. Replication in independent cohorts is needed to clarify the generalizability of the observed associations.

Obstacles to local-level AIDS competence in rural Zimbabwe: putting HIV prevention in context.

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Nhamo, Mercy; Campbell, Catherine; Gregson, Simon

2010-01-01

We explore the wider social context of an HIV-prevention programme in rural Zimbabwe. We make no comment on the programme itself, rather seeking to examine the wider community dynamics into which it was inserted, to highlight how pre-existing social dynamics may have influenced community "readiness" to derive optimal benefit from the intervention. Using the concept of "the AIDS competent community", we analysed 44 interviews and 11 focus groups with local people. Despite high levels of HIV/AIDS-related knowledge, there were several ways gender, poverty and low literacy may have undermined its perceived relevance to peoples' lives. Lack of opportunities for dialogue in the social milieu beyond the intervention may have limited opportunities for translating factual AIDS knowledge into action plans, or sharing hidden individual experiences of HIV/AIDS-affected family members or friends, given stigma and denial. The initiative of women and young people to respond effectively to AIDS was limited in a context dominated by adult males. People spoke of HIV/AIDS in a passive and fatalistic way, expecting outsiders to solve the problem. This tendency was exacerbated given the community's previous experiences of HIV/AIDS-related NGOs, which had often regarded local people as unpaid volunteer labour rather than building their capacity to make significant decisions and play leadership roles in health programmes. Despite obstacles, however, there were many potential community strengths and resources. There were high levels of HIV/AIDS-related knowledge. Public denial of HIV/AIDS masked huge reservoirs of private support and kindness to AIDS-affected family and friends. There were many strong community organisations and clubs, potentially forming the springboard for more empowered community responses to HIV/AIDS. HIV/AIDS programmers should pay greater attention to community readiness for interventions, especially around: (1) identifying and anticipating pre-existing obstacles to

Indispensable Role of Proteases in Plant Innate Immunity.

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Balakireva, Anastasia V; Zamyatnin, Andrey A

2018-02-23

Plant defense is achieved mainly through the induction of microbe-associated molecular patterns (MAMP)-triggered immunity (MTI), effector-triggered immunity (ETI), systemic acquired resistance (SAR), induced systemic resistance (ISR), and RNA silencing. Plant immunity is a highly complex phenomenon with its own unique features that have emerged as a result of the arms race between plants and pathogens. However, the regulation of these processes is the same for all living organisms, including plants, and is controlled by proteases. Different families of plant proteases are involved in every type of immunity: some of the proteases that are covered in this review participate in MTI, affecting stomatal closure and callose deposition. A large number of proteases act in the apoplast, contributing to ETI by managing extracellular defense. A vast majority of the endogenous proteases discussed in this review are associated with the programmed cell death (PCD) of the infected cells and exhibit caspase-like activities. The synthesis of signal molecules, such as salicylic acid, jasmonic acid, and ethylene, and their signaling pathways, are regulated by endogenous proteases that affect the induction of pathogenesis-related genes and SAR or ISR establishment. A number of proteases are associated with herbivore defense. In this review, we summarize the data concerning identified plant endogenous proteases, their effect on plant-pathogen interactions, their subcellular localization, and their functional properties, if available, and we attribute a role in the different types and stages of innate immunity for each of the proteases covered.

(IgA, IgG and IgM) levels and complement fixation activity in HIV

African Journals Online (AJOL)

The study was designed to evaluate the immunoglobulin A, G and M levels and complement fixation activity in HIV infected participants, who were not administered antiretroviral therapy (ART). Eighty (80) HIV infected participants, aged between 15 – 55 years (38 ±10 years), were recruited for the study. Forty five (45) of the ...

Gut proteases target Yersinia invasin in vivo

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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.

Molar incisor hypomineralization in HIV-infected children and adolescents.

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Andrade, Natália Silva; Pontes, Alessandra Silva; de Sousa Paz, Hélvis Enri; de Moura, Marcoeli Silva; Moura, Lúcia de Fátima Almeida de Deus; Lima, Marina de Deus Mourade

2017-01-01

The objective was to determine the prevalence of molar incisor hypomineralization (MIH) among individuals between 7 and 15 years old infected or noninfected with human immunodeficiency virus (HIV). The study was conducted with 33 HIV-infected individuals (study group; SG) and 66 non-HIV-infected schoolchildren (control group; CG), paired by gender and age. Data collection was based on medical records (SG), a questionnaire for caregivers and oral examination for diagnosis of MIH (European Academy of Pediatric Dentistry criteria) and caries (DMFT index and ICDAS). Data were analyzed with Mann-Whitney, chi-square, and Fisher's exact tests and logistic regression. In SG, MIH (45.5%) and caries (87.9%) had higher prevalence. MIH was associated with use of protease inhibitors in SG (OR: 2.14; 95% CI: 1.21 to 3.77) and incubator need in CG (OR: 2.80; 95% CI: 1.71 to 9.10). HIV-infected patients had a higher prevalence of MIH and dental caries in the permanent dentition. © 2016 Special Care Dentistry Association and Wiley Periodicals, Inc.

Structures of a bi-functional Kunitz-type STI family inhibitor of serine and aspartic proteases: Could the aspartic protease inhibition have evolved from a canonical serine protease-binding loop?

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Guerra, Yasel; Valiente, Pedro A; Pons, Tirso; Berry, Colin; Rudiño-Piñera, Enrique

2016-08-01

Bi-functional inhibitors from the Kunitz-type soybean trypsin inhibitor (STI) family are glycosylated proteins able to inhibit serine and aspartic proteases. Here we report six crystal structures of the wild-type and a non-glycosylated mutant of the bifunctional inhibitor E3Ad obtained at different pH values and space groups. The crystal structures show that E3Ad adopts the typical β-trefoil fold of the STI family exhibiting some conformational changes due to pH variations and crystal packing. Despite the high sequence identity with a recently reported potato cathepsin D inhibitor (PDI), three-dimensional structures obtained in this work show a significant conformational change in the protease-binding loop proposed for aspartic protease inhibition. The E3Ad binding loop for serine protease inhibition is also proposed, based on structural similarity with a novel non-canonical conformation described for the double-headed inhibitor API-A from the Kunitz-type STI family. In addition, structural and sequence analyses suggest that bifunctional inhibitors of serine and aspartic proteases from the Kunitz-type STI family are more similar to double-headed inhibitor API-A than other inhibitors with a canonical protease-binding loop. Copyright © 2016. Published by Elsevier Inc.

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

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