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Viruses Sep 2017A paucity of information is available on the activity of protease inhibitors (PI) in chronically-infected monocyte-derived macrophages (MDM) and on the kinetics of...
A paucity of information is available on the activity of protease inhibitors (PI) in chronically-infected monocyte-derived macrophages (MDM) and on the kinetics of viral-rebound after PI removal in vitro. To fill this gap, the activity of different concentrations of amprenavir (AMP) was evaluated in chronically-infected MDM by measuring p24-production every day up to 12 days after drug administration and up to seven days after drug removal. Clinically-relevant concentrations of AMP (4 and 20 μM) drastically decreased p24 amount released from chronically-infected MDM from Day 2 up to Day 12 after drug administration. The kinetics of viral-rebound after AMP-removal (4 and 20 μM) showed that, despite an initial increase, p24-production over time never reached the level observed for untreated-MDM, suggesting a persistent intracellular drug activity. In line with this, after AMP-removal, human immunodeficiency virus 1 (HIV-1) infectivity and intracellular the p24/p55 ratio (reflecting virion-maturation) were remarkably lower than observed for untreated MDM. Overall, AMP shows high efficacy in blocking HIV-1 replication in chronically-infected MDM, persisting even after drug-removal. This highlights the role of protease inhibitors in preventing the establishment of this important HIV-1 reservoir, thus reducing viral-dissemination in different anatomical compartments.
Topics: Carbamates; Cells, Cultured; Furans; HIV Protease Inhibitors; HIV-1; Humans; Macrophages; Monocytes; Sulfonamides; Virus Replication
PubMed: 28956865
DOI: 10.3390/v9100277 -
Scientific Reports Sep 2017We 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...
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.
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 (EC: 0.0014-0.0028 μM) with minimal cytotoxicity (CC: 39.0 μM). Similarly, GRL-09510 efficiently blocked the replication of HIV-1 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-2. Under the selection condition, where HIV-1 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.
Topics: Antiviral Agents; Cell Survival; Crystallography, X-Ray; Drug Resistance, Viral; Furans; HIV Protease; HIV Protease Inhibitors; HIV-1; Humans; Microbial Sensitivity Tests; Models, Molecular; Protein Binding; Serial Passage
PubMed: 28947797
DOI: 10.1038/s41598-017-12052-9 -
OncoTargets and Therapy 2017Refractory pediatric leukemia remains one of the leading causes of death in children. Intensification of current chemotherapy regimens to improve the outcome in these...
PURPOSE
Refractory pediatric leukemia remains one of the leading causes of death in children. Intensification of current chemotherapy regimens to improve the outcome in these children is often limited by the effects of drug resistance and cumulative toxicity. Hence, the search for newer agents and novel therapeutic approaches are urgently needed to formulate the next-generation early-phase clinical trials for these patients.
MATERIALS AND METHODS
A comprehensive library of antimicrobials, including eight HIV protease inhibitors (nelfinavir [NFV], saquinavir, indinavir, ritonavir, amprenavir, atazanavir, lopinavir, and darunavir), was tested against a panel of pediatric leukemia cells by in vitro growth inhibition studies. Detailed target modulation studies were carried out by Western blot analyses. In addition, drug synergy experiments with conventional and novel antitumor agents were completed to identify effective treatment regimens for future clinical trials.
RESULTS
Several of the HIV protease inhibitors showed cytotoxicity at physiologically relevant concentrations (half-maximal inhibitory concentration values ranging from 1-24 µM). In particular, NFV was found to exhibit the most potent antileukemic properties across all cell lines tested. Mechanistic studies show that NFV leads to the induction of autophagy and apoptosis possibly through the induction of endoplasmic reticulum stress. Furthermore, interference with cell signaling pathways, including Akt and mTOR, was also noted. Finally, drug combination studies have identified agents with potential for synergy with NFV in its antileukemic activity. These include JQ1 (BET inhibitor), AT101 (Bcl-2 family inhibitor), and sunitinib (TK inhibitor).
CONCLUSION
Here, we show data demonstrating the potential of a previously unexplored group of drugs to address an unmet therapeutic need in pediatric oncology. The data presented provide preclinical supportive evidence and rationale for future studies of these agents for refractory leukemia in children.
PubMed: 28553123
DOI: 10.2147/OTT.S136484 -
Journal of Medicinal Chemistry Mar 2017HIV-1 protease inhibitors are crucial for treatment of HIV-1/AIDS, but their effectiveness is thwarted by rapid emergence of drug resistance. To better understand...
HIV-1 protease inhibitors are crucial for treatment of HIV-1/AIDS, but their effectiveness is thwarted by rapid emergence of drug resistance. To better understand binding of clinical inhibitors to resistant HIV-1 protease, we used room-temperature joint X-ray/neutron (XN) crystallography to obtain an atomic-resolution structure of the protease triple mutant (V32I/I47V/V82I) in complex with amprenavir. The XN structure reveals a D ion located midway between the inner Oδ1 oxygen atoms of the catalytic aspartic acid residues. Comparison of the current XN structure with our previous XN structure of the wild-type HIV-1 protease-amprenavir complex suggests that the three mutations do not significantly alter the drug-enzyme interactions. This is in contrast to the observations in previous 100 K X-ray structures of these complexes that indicated loss of interactions by the drug with the triple mutant protease. These findings, thus, uncover limitations of structural analysis of drug binding using X-ray structures obtained at 100 K.
Topics: Catalysis; Crystallography, X-Ray; HIV Protease; Neutrons; Protein Conformation
PubMed: 28195728
DOI: 10.1021/acs.jmedchem.6b01767 -
Antimicrobial Agents and Chemotherapy Dec 2016We report here that GRL-10413, a novel nonpeptidic HIV-1 protease inhibitor (PI) containing a modified P1 moiety and a hydroxyethylamine sulfonamide isostere, is highly...
A Modified P1 Moiety Enhances In Vitro Antiviral Activity against Various Multidrug-Resistant HIV-1 Variants and In Vitro Central Nervous System Penetration Properties of a Novel Nonpeptidic Protease Inhibitor, GRL-10413.
We report here that GRL-10413, a novel nonpeptidic HIV-1 protease inhibitor (PI) containing a modified P1 moiety and a hydroxyethylamine sulfonamide isostere, is highly active against laboratory HIV-1 strains and primary clinical isolates (50% effective concentration [EC] of 0.00035 to 0.0018 μM), with minimal cytotoxicity (50% cytotoxic concentration [CC] = 35.7 μM). GRL-10413 blocked the infectivity and replication of HIV-1 variants selected by use of atazanavir, lopinavir, or amprenavir (APV) at concentrations of up to 5 μM (EC = 0.0021 to 0.0023 μM). GRL-10413 also maintained its strong antiviral activity against multidrug-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 against APV. In addition, GRL-10413 showed favorable central nervous system (CNS) penetration properties as assessed with an in vitro blood-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 multidrug-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.
Topics: Animals; Blood-Brain Barrier; Carbamates; Cell Line; Central Nervous System; Crystallography, X-Ray; Darunavir; Drug Evaluation, Preclinical; Drug Resistance, Multiple, Viral; Ethylamines; Furans; HIV Protease; HIV Protease Inhibitors; HIV-1; Humans; Lopinavir; Microbial Sensitivity Tests; Peptides; Rats; Structure-Activity Relationship; Sulfonamides; Virus Replication
PubMed: 27620483
DOI: 10.1128/AAC.01428-16 -
Journal of the International AIDS... 2016Studies have shown that transgender women (TGW) are disproportionately affected by HIV, with an estimated HIV prevalence of 19.1% among TGW worldwide. After receiving a... (Review)
Review
INTRODUCTION
Studies have shown that transgender women (TGW) are disproportionately affected by HIV, with an estimated HIV prevalence of 19.1% among TGW worldwide. After receiving a diagnosis, HIV-positive TGW have challenges accessing effective HIV treatment, as demonstrated by lower rates of virologic suppression and higher HIV-related mortality. These adverse HIV outcomes have been attributed to the multiple sociocultural and structural barriers that negatively affect their engagement within the HIV care continuum. Guidelines for feminizing hormonal therapy among TGW recommend combinations of oestrogens and androgen blockers. Pharmacokinetic studies have shown that certain antiretroviral therapy (ART) agents, such as protease inhibitors (PIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs) and cobicistat, interact with ethinyl estradiol, the key oestrogen component of oral contraceptives (OCPs). The goal of this article is to provide an overview of hormonal regimens used by TGW, to summarize the known drug-drug interactions (DDIs) between feminizing hormonal regimens and ART, and to provide clinical care recommendations.
METHODS
The authors identified English language articles examining DDIs between oestrogen therapy, androgen blockers and ART published between 1995 and 2015 using PubMed, Cumulative Index to Nursing and Allied Health Literature and EBSCOhost.
RESULTS AND DISCUSSION
Published articles predominantly addressed interactions between ethinyl estradiol and NNRTIs and PIs. No studies examined interactions between ART and the types and doses of oestrogens found in feminizing regimens. DDIs that may have the potential to result in loss of virologic suppression included ethinyl estradiol and amprenavir, unboosted fosamprenavir and stavudine. No clinically significant DDIs were noted with other anti-retroviral agents or androgen blockers.
CONCLUSIONS
There are insufficient data to address DDIs between ART and feminizing hormone regimens used by TGW. There is an urgent need for further research in this area, specifically pharmacokinetic studies to study the direction and degree of interactions between oral, injectable and transdermal estradiol and ART. Clinicians need to be vigilant about possible interactions and monitor hormone levels if concerns arise. More research is also needed on the provision of hormone therapy and gender-affirming care on the long-term health outcomes of HIV-positive TGW.
Topics: Anti-HIV Agents; Drug Interactions; Estrogens; Ethinyl Estradiol; Female; HIV Infections; HIV-1; Hormones; Humans; Transgender Persons
PubMed: 27431475
DOI: 10.7448/IAS.19.3.20810 -
Biochemistry Apr 2016We have systematically validated the activity and inhibition of a HIV-1 protease (PR) variant bearing 17 mutations (PR(S17)), selected to represent high resistance by...
Binding of Clinical Inhibitors to a Model Precursor of a Rationally Selected Multidrug Resistant HIV-1 Protease Is Significantly Weaker Than That to the Released Mature Enzyme.
We have systematically validated the activity and inhibition of a HIV-1 protease (PR) variant bearing 17 mutations (PR(S17)), selected to represent high resistance by machine learning on genotype-phenotype data. Three of five mutations in PR(S17) correlating with major drug resistance, M46L, G48V, and V82S, and five of 11 natural variations differ from the mutations in two clinically derived extreme mutants, PR20 and PR22 bearing 19 and 22 mutations, respectively. PR(S17), which forms a stable dimer (<10 nM), is ∼10- and 2-fold less efficient in processing the Gag polyprotein than the wild type and PR20, respectively, but maintains the same cleavage order. Isolation of a model precursor of PR(S17) flanked by the 56-amino acid transframe region (TFP-p6pol) at its N-terminus, which is impossible upon expression of an analogous PR20 precursor, allowed systematic comparison of inhibition of TFP-p6pol-PR(S17) and mature PR(S17). Resistance of PR(S17) to eight protease inhibitors (PIs) relative to PR (Ki) increases by 1.5-5 orders of magnitude from 0.01 to 8.4 μM. Amprenavir, darunavir, atazanavir, and lopinavir, the most effective of the eight PIs, inhibit precursor autoprocessing at the p6pol/PR site with IC50 values ranging from ∼7.5 to 60 μM. Thus, this process, crucial for stable dimer formation, shows inhibition ∼200-800-fold weaker than that of the mature PR(S17). TFP/p6pol cleavage, which occurs faster, is inhibited even more weakly by all PIs except darunavir (IC50 = 15 μM); amprenavir shows a 2-fold increase in IC50 (∼15 μM), and atazanavir and lopinavir show increased IC50 values of >42 and >70 μM, respectively.
Topics: Drug Resistance, Viral; HIV Infections; HIV Protease; HIV Protease Inhibitors; HIV-1; Humans; Point Mutation; Protein Multimerization; gag Gene Products, Human Immunodeficiency Virus
PubMed: 27039930
DOI: 10.1021/acs.biochem.6b00012 -
AIDS (London, England) Jul 2016Although several antiretroviral drugs, including the d-drugs stavudine (d4T) and didanosine (ddI), may cause biomarker-defined hepatotoxicity, their association with...
OBJECTIVES
Although several antiretroviral drugs, including the d-drugs stavudine (d4T) and didanosine (ddI), may cause biomarker-defined hepatotoxicity, their association with clinically defined end-stage liver disease (ESLD) and hepatocellular carcinoma (HCC) remains unknown.
DESIGN
Prospective cohort study.
METHODS
Data collection on adverse events of anti-HIV drugs study (D:A:D) participants were followed until the first of ESLD (variceal bleeding, hepatic encephalopathy, hepatorenal syndrome or liver transplantation), HCC (histology or α-fetoprotein along with imaging), death, 6 months after last visit or 1 February 2014. Associations between ESLD/HCC and cumulative use of individual antiretrovirals were investigated using Poisson regression adjusting for potential confounders.
RESULTS
During a median follow-up of 8.4 years, 319 ESLD/HCC cases occurred [incidence 1.01/1000 person-years (95% confidence interval 0.90-1.12)] with a 1-year mortality rate of 62.6%. After adjustment, cumulative (per 5 years) exposure to d4T [relative rate 1.46 (95% confidence interval 1.20-1.77)], ddI [1.32 (1.07-1.63)], tenofovir [TDF, 1.46 (1.11-1.93)] and (fos)amprenavir [APV; 1.47 (1.01-2.15)] was associated with increased ESLD/HCC rates. Longer exposure to emtricitabine [0.51 (0.32-0.83)] and nevirapine [0.76 (0.58-0.98)] were associated with lower ESLD/HCC rates. The ddI/d4T-associated increased ESLD/HCC rate only started to decline 6 years after cessation.
CONCLUSION
Cumulative use of d4T, ddI, TDF and APV were independently associated with increased ESLD/HCC rates, and intensified monitoring of liver function should hence be considered among all individuals exposed for longer time periods. The use of d-drugs should furthermore be avoided, where there are alternatives available, and focus should be put on those with longer-term d-drugs exposure who remain at increased ESLD/HCC risk. The unexpected, and viral hepatitis-independent, TDF association calls for further investigations.
Topics: Adult; Anti-Retroviral Agents; Carcinoma, Hepatocellular; End Stage Liver Disease; Female; HIV Infections; Humans; Liver Neoplasms; Male; Middle Aged; Prospective Studies; Risk Assessment
PubMed: 26752282
DOI: 10.1097/QAD.0000000000001018