Indinavir/ritonavir remains an important component of HAART for the treatment of HIV/AIDS, particularly in resource-limited settings

Investigating the role of hypothetical protein (AAB33144.1) in HIV-1 virus pathogenicity: A comparative study with FDA-Approved inhibitor compounds through In silico analysis and molecular docking

Aim and objective

Due to the a lot of unexplored proteins in HIV-1, this research aimed to explore the functional roles of a hypothetical protein (AAB33144.1) that might play a key role in HIV-1 pathogenicity.

Methods

The homologous protein was identified along with building and validating the 3D structure by searching several bioinformatics tools.

Results

Retroviral aspartyl protease and retropepsin like functional domains and motifs, folding pattern (cupredoxins), and subcellular localization in cytoplasmic membrane were determined as biological activity. Besides, the functional annotation revealed that the chosen hypothetical protein possessed protease-like activity. To validate our generated protein 3D structure, molecular docking was performed with five compounds where nelfinavir showed (-8.2 kcal/mol) best binding affinity against HXB2 viral protease (PDB ID: 7SJX) and main protease (PDB ID: 4EYR) protein.

Conclusions

This study suggests that the annotated hypothetical protein related to protease action, which may be useful in viral genetics and drug discovery.

Cocaine use may modify HIV/ART-associated myocardial steatosis and hepatic steatosis

BACKGROUND

It has been recognized that myocardial and hepatic steatosis may be more prevalent in HIV-infected individuals on antiretroviral therapy (ART); however, factors associated with these conditions have not been thoroughly investigated. The goals of this study were (1) to identify the risk factors for myocardial and hepatic steatosis in HIV-infected African Americans (AAs) and explore whether ART use is independently associated with myocardial and hepatic steatosis, and (2) to examine whether and how cocaine use influences any associations of ART use with myocardial and hepatic steatosis.

METHODS

Between June 2010 and December 2013, 220 HIV-infected AAs in Baltimore, Maryland, were enrolled in a study investigating HIV/ART-associated myocardial and hepatic damage. Proton magnetic resonance spectroscopy was performed to quantify myocardial and hepatic triglyceride contents. Sociodemographic, medical and laboratory data were also obtained. Robust regression model was employed to perform primary statistical analysis.

RESULTS

Robust regression analyses showed that (1) duration of protease inhibitor (PI) use was independently associated with myocardial and hepatic triglyceride contents, (2) duration of PI use was independently associated with myocardial triglyceride in cocaine users (p=0.025), but not in cocaine never-users (p=0.84), and (3) duration of PI use was independently associated with hepatic triglyceride in cocaine users, but not in cocaine never-users (p=0.52).

CONCLUSIONS

Cocaine use may trigger/exacerbate the toxicity of PI in ART-associated myocardial and hepatic steatosis, suggesting that cocaine abstinence/reduced use may retard these ART-associated comorbidities. Clinical trials should be conducted to examine whether reduced cocaine use improves HIV/AIDS-associated myocardial and hepatic steatosis.

UPLC-MS/MS quantification of nanoformulated ritonavir, indinavir, atazanavir, and efavirenz in mouse serum and tissues

Animal pharmacokinetic and tissue distribution assays of antiretroviral therapeutic drugs require accurate drug quantification in biological fluids and tissues. Here we report a simple, rapid, and sensitive ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for quantification of commonly used antiretroviral drugs ritonavir (RTV), indinavir (IDV), atazanavir (ATV), and efavirenz (EFV) in mouse serum and tissues (liver, kidney, lung, and spleen). These antiretroviral drugs are currently the cornerstones of common therapeutic regimens for human immunodeficiency virus (HIV) infection. Chromatographic separation was achieved using a gradient mobile phase (5% acetonitrile in methanol and 7.5mM ammonium acetate (pH 4.0)) on an ACQUITY UPLC(®)BEH Shield RP 18 column. All compounds eluted within a 7 min run time. Lopinavir was used as an internal standard. Detection was achieved by dual positive and negative ionization modes on a quadrupole linear ion trap hybrid mass spectrometer with an electrospray ionization (ESI) source. The dynamic range was 0.2-1000 ng/mL for RTV, IDV, and ATV, and 0.5-1000 for EFV. The method was validated and showed high and consistent intra-day and inter-day accuracy and precision for all analytes. This method is used to support the preclinical development studies of targeted- and sustained-release combination ART (nanoART). The current data demonstrate a 1.5-4 fold increase in serum and tissue AUC of nanoformulated ATV, RTV, and EFV administered to mice when compared to native drug. In addition, the tested formulation enhanced exposure of the same anti-HIV drugs in mouse tissues.

HIV Protease Inhibitors: Effect on the Opportunistic Protozoan Parasites

The impact of highly active antiretroviral therapy (HAART) in the natural history of AIDS disease has been allowed to prolong the survival of people with HIV infection, particularly whose with increased HIV viral load. Additionally, the antiretroviral therapy could exert a certain degree of protection against parasitic diseases. A number of studies have been evidenced a decrease in the incidence of opportunistic parasitic infections in the era of HAART. Although these changes have been attributed to the restoration of cell-mediated immunity, induced by either non-nucleoside reverse transcriptase inhibitors or HIV protease inhibitors, in combination with at least two nucleoside reverse transcriptase inhibitors included in HAART, there are evidence that the control of these parasitic infections in HIV-positive persons under HAART, is also induced by the inhibition of the proteases of the parasites. This review focuses on the principal available data related with therapeutic HIV-protease inhibitors and their in vitro and in vivo effects on the opportunistic protozoan parasites.

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

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.

Boosted protease inhibitors as a therapeutic option in the treatment of HIV-infected children

OBJECTIVE

Paediatric HIV treatment must address various special considerations. Administration of pharmacokinetically enhanced protease inhibitors (PIs) can improve paediatric therapeutic outcomes. The objective of this study was to review the use of boosted PI regimens in children.

METHODS

Systematic literature searches of published manuscripts and conference databases using generic drug names and specific keywords were performed to ensure thorough and balanced reporting of available data.

RESULTS

Boosted PI regimens offer multiple options across a range of ages and are efficacious in naïve and experienced children; safety and tolerability are similar to those observed in adults. Novel boosted PI simplification approaches may foster adherence and diminish resistance.

CONCLUSIONS

Boosted PIs are key components of first- and second-line treatments in children. Identifying factors associated with the response to highly active antiretroviral therapy in children may ultimately permit individualized therapies.

Gilbert's syndrome and hyperbilirubinemia in protease inhibitor therapy--an extended haplotype of genetic variants increases risk in indinavir treatment

BACKGROUND/AIMS

Gilbert's syndrome is a frequent genetic conjugation abnormality associated with adverse drug effects. Genetic UDP glucuronosyltransferase (UGT)1A gene variants can influence gene transcription, inducibility and glucuronidation activity. Protease inhibitors used in human immunodeficiency virus (HIV) infection and chronic viral hepatitis can inhibit UGTs. Indinavir (IDV) can lead to hyperbilirubinemia in Gilbert's syndrome (UGT1A1*28), which does not explain interindividual severity differences and may thus involve additional UGT1A variants.

METHODS

One hundred and twenty-five HIV patients receiving IDV and 427 healthy blood donors were genotyped for the presence of UGT1A1*28, UGT1A3 -66T/C, UGT1A7 -57T/G, UGT1A7(N129K/R131K) using Taqman 5' nuclease assays.

RESULTS

Hyperbilirubinemia was observed in 42%. UGT1A1*28 frequencies did not differ between HIV patients and controls but were significantly higher in hyperbilirubinemic patients. The frequency of homozygous carriers of the 4 UGT1A marker haplotype increased with hyperbilirubinemia affecting all patients with bilirubin levels >85 micromol/l.

CONCLUSIONS

In IDV treatment the risk of severe hyperbilirubinemia is associated with genetic variants of the UGT1A3 and UGT1A7 genes in addition to Gilbert's syndrome (UGT1A1*28). This haplotype is a useful predictor of protease inhibitor-induced side effects.

Methadone pharmacokinetics are independent of cytochrome P4503A (CYP3A) activity and gastrointestinal drug transport: insights from methadone interactions with ritonavir/indinavir

BACKGROUND

Methadone clearance is highly variable, and drug interactions are problematic. Both have been attributed to CYP3A, but actual mechanisms are unknown. Drug interactions can provide such mechanistic information. Ritonavir/indinavir, one of the earliest protease inhibitor combinations, may inhibit CYP3A. We assessed ritonavir/indinavir effects on methadone pharmacokinetics and pharmacodynamics, intestinal and hepatic CYP3A activity, and intestinal transporters (P-glycoprotein) activity. CYP3A and transporters were assessed with alfentanil and fexofenadine, respectively.

METHODS

Twelve healthy human immunodeficiency virus-negative volunteers underwent a sequential three-part crossover. On three consecutive days, they received oral alfentanil/fexofenadine, intravenous alfentanil, and intravenous plus oral (deuterium-labeled) methadone, repeated after acute (3 days) and steady-state (2 weeks) ritonavir/indinavir. Plasma and urine analytes were measured by mass spectrometry. Opioid effects were assessed by miosis.

RESULTS

Alfentanil apparent oral clearance was inhibited more than 97% by both acute and steady-state ritonavir/indinavir, and systemic clearance was inhibited more than 90% due to diminished hepatic and intestinal extraction. Ritonavir/indinavir increased fexofenadine area under the plasma concentration-time curve four- to five-fold, suggesting significant inhibition of gastrointestinal P-glycoprotein. Ritonavir/indinavir slightly increased methadone N-demethylation, but it had no significant effects on methadone plasma concentrations or on systemic or apparent oral clearance, renal clearance, hepatic extraction or clearance, or bioavailability. Ritonavir/indinavir had no significant effects on methadone plasma concentration-effect relationships.

CONCLUSIONS

Inhibition of both hepatic and intestinal CYP3A activity is responsible for ritonavir/indinavir drug interactions. Methadone disposition was unchanged, despite profound inhibition of CYP3A activity, suggesting little or no role for CYP3A in clinical methadone metabolism and clearance. Methadone bioavailability was unchanged, despite inhibition of gastrointestinal P-glycoprotein activity, suggesting that this transporter does not limit methadone intestinal absorption.

Indinavir influences biological function of dendritic cells and stimulates antifungal immunity

In this study, we analyzed the possibility that Indinavir (IDV), a well-known protease inhibitor (PI) used in highly active antiretroviral therapy, could affect immune response against the opportunistic fungus Cryptococcus neoformans. In particular, the quality of dendritic cell (DC) response was analyzed. The results reported here show that IDV treatment induces an expansion of DC with CD8alpha phenotype in spleens of infected hosts. Splenic CD11c+ DC expressed elevated costimulatory molecules such as CD40 and CD80, showed an increased expression of mRNA for proinflammatory cytokines, and secreted abundant IL-12. Integration of all aforementioned regulatory effects results in development of an efficient, T cell-protective response that reflects a consistent reduction in fungus colonization at a cerebral level. These results could help to elucidate the immunoregulatory activity of PI and point out the beneficial effects of IDV in regulating DC functions and antifungal activity. Therefore, although new PI are being introduced in the clinical setting, nevertheless, given its low cost and proven efficacy, IDV could still be considered a potential key compound in the treatment of HIV in resource-limited settings.