Addressing Antiretroviral Drug Resistance with Host-Targeting Drugs-First Steps towards Developing a Host-Targeting HIV-1 Assembly Inhibitor.

The concerning increase in HIV-1 resistance argues for prioritizing the development of host-targeting antiviral drugs because such drugs can offer high genetic barriers to the selection of drug-resistant viral variants. Targeting host proteins could also yield drugs that act on viral life cycle events that have proven elusive to inhibition, such as intracellular events of HIV-1 immature capsid assembly. Here, we review small molecule inhibitors identified primarily through HIV-1 self-assembly screens and describe how all act either narrowly post-entry or broadly on early and late events of the HIV-1 life cycle. We propose that a different screening approach could identify compounds that specifically inhibit HIV-1 Gag assembly, as was observed when a potent rabies virus inhibitor was identified using a host-catalyzed rabies assembly screen. As an example of this possibility, we discuss an antiretroviral small molecule recently identified using a screen that recapitulates the host-catalyzed HIV-1 capsid assembly pathway. This chemotype potently blocks HIV-1 replication in T cells by specifically inhibiting immature HIV-1 capsid assembly but fails to select for resistant viral variants over 37 passages, suggesting a host protein target. Development of such small molecules could yield novel host-targeting antiretroviral drugs and provide insight into chronic diseases resulting from dysregulation of host machinery targeted by these drugs.

Natural Bioactives as Potential Therapeutic Modalities Against NeuroAIDS.

With the introduction of antiretroviral therapy, the worldwide AIDS-related deaths have decreased, and life expectancy has increased, including the prevalence of AIDS-related neurological disorders or neuroAIDS. HIV-associated neurocognitive disorders such as mild neurocognitive disorder and asymptomatic neurocognitive impairment have largely remained stable or increased among the HIV-infected individuals in the combination antiretroviral therapy era. The emerging evidence that antiretrovirals with high CNS penetration effectiveness score contribute to the neurotoxicity and HIV-associated neurocognitive disorders has ushered the search for natural, nontoxic bioactive constituents having pre-established neuroprotective, anti-inflammatory, and restorative neurocognitive activity. In this review, we have highlighted the probable mechanism of neuroAIDS infection, the problem with the existing antiretroviral therapy, along with various bioactive constituents with in vivo, in vitro, or ex vivo evidence of their neuroprotective activity that can be used as an adjuvant with the current combination antiretroviral therapy regimen or can even serve as an alternate to the antiretrovirals for treatment of HIV associated neurocognitive disorder.

UPLC-MS/MS method for the simultaneous quantification of bictegravir and 13 others antiretroviral drugs plus cobicistat and ritonavir boosters in human plasma.

A sensitive and rapid ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method has been developed and validated for 14 antiretroviral drugs and 2 boosters in human plasma. Plasma (100 µL) was precipitated with a solution of acetonitrile containing labelled internal standards. The compounds were separated with a total chromatic run time of 6 min using an Acclaim TM RSLC 120 C18 column (2.1 × 100 mm, 2.2 µm). The method was fully validated according to the European Medecines Agency guidelines. Linearity of all analytes concentrations was validated up to 5000 ng/mL. Lower limits of quantification were ranged from 2.5 ng/mL to 10 ng/mL according to compounds. Intra-day and inter-day precision ranged from 0.2% to 8.9% and accuracies were below 13%. This UPLC-MS/MS method can be applied to clinical pharmacology research and therapeutic drug monitoring in patients living with HIV.

Retention characteristics of some antibiotic and anti-retroviral compounds in hydrophilic interaction chromatography using isocratic elution, and gradient elution with repeatable partial equilibration.

The separation of some zwitterionic, basic and neutral antibiotic and antiretroviral compounds was studied using hydrophilic interaction chromatography (HILIC) on bare silica, bonded amide and urea superficially porous phases. The differences in the selectivity and retentivity of these stationary phases were evaluated for compounds with widely different physicochemical properties (logD -3.43 to 2.41 at wwpH 3.0). The mobile phase was acetonitrile-ammonium formate buffered at low wwpH. Compounds containing quinolone and serine groups showed poor peak shapes on all columns, attributed to metal-oxide interactions with system metals. Peak shapes were improved by addition of citrate buffers. Gradient elution, particularly with regard to column equilibration, was also studied due to the large differences in retention factors observed under isocratic conditions. Full equilibration in HILIC was slow for both ionogenic and neutral solutes, requiring as much as ∼40 column volumes. However, highly repeatable partial equilibration, suitable for gradient elution, was achieved in only a few minutes. Pronounced selectivity differences in the separations were shown dependent on the partial equilibration time.

Hollow mesoporous structured molecularly imprinted polymer as adsorbent in pipette-tip solid-phase extraction for the determination of antiretrovirals from plasma of HIV-infected patients.

In this work a hollow mesoporous structured molecularly imprinted polymer was synthetized and used as adsorbent in pipette-tip solid-phase extraction for the determination of lamivudine (3TC), zidovudine (AZT) and efavirenz (EFZ) from plasma of human immunodeficiency virus (HIV) infected patients by high-performance liquid chromatography (HPLC). All parameters that influence the recovery of the pipette tip based on hollow mesoporous molecularly imprinted polymer solid-phase extraction (PT-HM-MIP-SPE) method were systematically studied and discussed in detail. The adsorbent material was prepared using methacrylic acid and 4-vinylpyridine as functional monomers, ethylene glycol dimethacrylate as crosslinker, acetonitrile as solvent, 4,4'-azobis(4-cyanovaleric acid) as radical initiator, benzalkonium chloride as surfactant, 3TC, and AZT as templates. The simultaneous separation of 3TC, AZT and EFZ by HPLC-UV was performed using a Gemini C18 Phenomenex® column (250 mm × 4.6 mm, 5 µm) and mobile phase consisting of acetonitrile: water pH 3.2 (68:32, v/v), flow rate of 1.0 mL/min and λ = 260 nm. The method was linear over the concentration range from 0.25 to 10 µg/mL for 3TC and EFZ, and 0.05 to 2.0 µg mL-1 for AZT, with correlation coefficients larger than 0.99 for all analytes. Recovery ± relative standard deviations (RSDs %) were 41.99 ± 2.38%, 82.29 ± 1.63%, and 83.72 ± 7.52% for 3TC, AZT, and EFZ, respectively. The RSDs and relative errors (REs) were lower than 15% for intra and interday assays. The method has been successfully applied for monitoring HIV-infected patients outside the therapeutic dosage.

Simultaneous determination and validation of emtricitabine, rilpivirine and tenofovir from biological samples using LC and CE methods.

A combination of antiretroviral agents is frequently used in effective treatment of the human immunodeficiency virus infection. In this study, two different separation methods are presented for the simultaneous determination of emtricitabine, rilpivirine and tenofovir from raw materials and urine samples. Developed liquid chromatography and capillary electrophoresis methods were thoroughly optimized for high analytical performances. Optimization of multiple variables at the same time by performing a minimum number of experiments was achieved by the Box-Behnken design, which is an experimental design in response surface methodology, in capillary electrophoresis. The results of the experimental design ensure minimum analysis time with well-separated analytes. Separation conditions, such as different stationary phases, pH level, organic modifiers and temperatures in liquid chromatography method, were also optimized. In particular, among stationary phases, the core-shell column especially enhanced the effectiveness of separation in liquid chromatography. Both methods were fully validated and applied to real samples. The main advantage of the developed methods is the separation of the drug combination in a short time with high efficiency and without any time-consuming steps.

La adherencia al tratamiento antirretroviral en pacientes con VIH/sida y estrategias para su optimización. Un enfoque integrafdor / The adherence to antiretroviral therapy in patients with HIV/AIDS and the strategies for its optimization: an integrated approach

INTRODUCCIÓN. La producción científica demuestra que es necesaria una adherencia al tratamiento antirretroviral (TAR) del 95 %, que perdure en el tiempo, para conseguir reducir la carga viral plasmática (CVP), aumentar los linfocitos CD4, disminuir el riesgo de infecciones oportunistas y reacciones adversas. La valoración y fomento de la adherencia al TAR es, por lo tanto, un factor clave y prioritario en la práctica asistencial. Para ello existen diversos instrumentos para conseguir optimizar la adherencia y disminuir las complicaciones asociadas como la morbilidad, y así aumentar la calidad de vida de los pacientes con VIH/sida. OBJETIVOS. Analizar la adherencia al TAR y las diferentes estrategias utilizadas para su optimización en pacientes con VIH/sida. MATERIAL Y MÉTODO. Diseño: revisión bibliográfica. Se realizaron dos búsquedas en 4 bases de datos distintas, una para revisar los artículos que analizaran la adherencia al TAR en pacientes con VIH/sida y otra para revisar los artículos que analizaran las estrategias que optimizan la adherencia al TAR. Los resultados se procesaron mediante el programa Microsoft Excel 2007, y el análisis estadístico se realizó mediante el programa SPSS 15.0. RESULTADOS. En lo referente a la adherencia al TAR en pacientes con VIH/sida, un 64.19 % de ellos presenta una adherencia óptima al tratamiento. El 40.74 % de los estudios establece que la intervención multidisciplinar aumenta considerablemente la adherencia, y ella la sigue, con un 25.9 %, el apoyo social-familiar-psicológico. CONCLUSIONES. Uno de cada tres pacientes analizados no presenta una adherencia óptima al TAR. La intervención multidisciplinar se configura como la estrategia de mayor eficacia para optimizar la adherencia al TAR (AU)

INTRODUCTION. The scientific production has demonstrated that adherence to antiretroviral therapy (ART) is needed at 95 %, lasting over time, to achieve the reduction of plasma viral load (PVL), increase CD4 lymphocytes, decrease the risk of opportunistic infections and the adverse reactions. The assessment and development of adherence to ART is therefore a key factor and a principal priority in healthcare practice. To that end, there are different tools to achieve the optimizing adherence, reduce complications associated with morbidity and hence to increase the life quality of patients with human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS). OBJECTIVES. To analyze the adherence to ART and the various strategies used for its optimization in patients with HIV/AIDS. MATERIAL AND METHOD. Design: bibliographic review. Two searches were performed in four different data base, one to overhaul the articles that will analyze the adherence to ART in patients with HIV/AIDS and the other one to review the articles that will analyze the strategies which optimize the adherence to ART. The results were prosecuted through Microsoft 2007 program and the statistical analysis was performed through SPSS 15.0. RESULTS. The adherence to ART in patients with HIV/AIDS amounts in which 64,19% of them present an optimal adherence to the treatment. 40,74% of the studies establish that the multidisciplinary intervention significally increases the adherence, continued with a 25,9% of the social support/familiar/psychological. CONCLUSIONS. One out of three patients which are analyzed does not show an optimal adherence to ART. The multidisciplinary intervention is configured as the most effective strategy to optimize the adherence to ART (AU)

The antiretroviral drug pipeline: prospects and implications for future treatment research.

PURPOSE OF REVIEW: A number of investigational antiretroviral drugs in clinical development could alter the future treatment landscape for resource-limited settings and contribute to optimized therapy for HIV infection. RECENT FINDINGS: Several nucleoside reverse transcriptase inhibitors (NRTIs) are in development, including festinavir (BMS-986001), a thymidine analogue similar to stavudine but with reduced potential for toxicity, CMX-157, a hexadecyloxypropyl conjugate of tenofovir and tenofovir alafenamide (GS-7340), a prodrug of tenofovir achieving much higher intracellular triphosphate concentrations with a lower dose than tenofovir disoproxil fumarate. MK-1439 is a well tolerated once-daily non-NRTI (NNRTI) with activity against most NNRTI-associated resistance mutations. Albuvirtide is a long-acting parenteral fusion inhibitor related to enfuvirtide, and BMS-663068 is an oral HIV attachment/entry inhibitor. Ibalizumab (formerly TNX-355) is an mAb that binds to CD4 and lowers HIV plasma viral RNA in infected patients. Cenicriviroc is a CCR5-antagonist that also has activity against the inflammatory chemokine CCR2. The integrase strand transfer inhibitor (InSTI) dolutegravir was recently approved in the U.S. and is an attractive component of future regimens because of efficacy, tolerability, apparent safety and once-daily dosing; it also maintains some activity against raltegravir and elvitegravir-resistant mutants. The dolutegravir analogue GSK-1265744 appears to be equipotent and is being developed as a long-lasting injectable parenteral agent. The selective cytochrome P450 3A4 inhibitor cobicistat is a better tolerated alternative to ritonavir for pharmacokinetic 'boosting', but may also result in clinically undesirable drug interactions. SUMMARY: There are several investigational antiretroviral drugs with significant promise for inclusion in future primary and secondary combination regimens.

Phenols with anti-HIV activity from Daphne acutiloba.

The present paper describes the study of the phytochemical properties and anti-HIV activity of the phenolic isolates of the plateau medicinal plant Daphne acutiloba Rehd. (Thymelaeceae). Two new lignans named daphnenin (1) and daphnetone (2), along with 11 known ones, were isolated, and their structures were elucidated by 1D and 2DNMR spectroscopy aswell as HR­ESI­MS. In the anti-HIV activity study, daphnenin (1) and caffeic acid n-octadecyl ester (13) showed definite anti-HIVactivity with EC(50) values of 0.39 and 0.16 µg/mL, respectively.

High-content screening for compounds that affect mtDNA-encoded protein levels in eukaryotic cells.

Compounds that interfere with the synthesis of either mitochondrial DNA or mtDNA-encoded proteins reduce the levels of 13 proteins essential for oxidative phosphorylation, leading to a decrease in mitochondrial adenosine triphosphate (ATP) production. Toxicity caused by these compounds is seldom identified in 24- to 72-h cytotoxicity assays due to the low turnover rates of both mtDNA and mtDNA-encoded proteins. To address this problem, the authors developed a 96-well format, high-content screening (HCS) assay that measures, in eukaryotic cells, the level of Complex IV-subunit 1, an mtDNA-encoded protein synthesized on mitochondrial ribosomes, and the level of Complex V-alpha subunit, a nuclear DNA-encoded protein synthesized on cytosolic ribosomes. The effect of several antibiotics and antiretrovirals on these 2 proteins was assessed, in transformed human liver epithelial cells, 6 days after compound treatment. The results confirmed effects of drugs known to reduce mtDNA-encoded protein levels and also revealed novel information showing that several fluoroquinolones and a macrolide, josamycin, impaired expression of mtDNA-encoded proteins. The HCS assay was robust with an average Z' factor of 0.62. The assay enables large-scale screening of compounds to identify those that potentially affect mtDNA-encoded protein levels and can be implemented within a screening paradigm to minimize compound attrition.

Dammarenolic acid, a secodammarane triterpenoid from Aglaia sp. shows potent anti-retroviral activity in vitro.

Screening of a panel of purified compounds isolated from Aglaia sp. (Meliaceae) for inhibition of early steps in the lentiviral replication cycle led to the identification of the 3, 4-secodammarane triterpenoid, ignT1, which inhibited HIV-1 infection potently (IC(50)=0.48microg/ml), while cytotoxic effects and inhibition of cell proliferation were only observed at concentrations exceeding 10.69microg/ml. Time of addition experiments revealed similar kinetics to the non-nucleoside RT-inhibitor (NNRTI), Nevirapine, although the latter was significantly less cytotoxic. However, unlike Nevirapine, dammarenolic acid also potently inhibited the in vitro replication of other retroviruses, including Simian immunodeficiency virus and Murine leukemic virus in vector-based antiviral screening studies. Interestingly, the methyl ester analogue of dammarenolic acid-methyldammarenolate had no anti-HIV-1 activity. Cell cycle analysis revealed that ignT1 arrests HeLa cells at the S and G2/M phase. These results strongly suggest that dammarenolic acid could be a promising lead compound for the development of novel anti-retrovirals.

Crystallization and preliminary x-ray diffraction analysis of a novel mannose-binding lectin with antiretroviral properties from Polygonatum cyrtonema hua.

A novel antiretroviral protein Polygonatum cyrtonema lectin (PCL) belonging to the monocot mannose-binding lectin (MMBL) superfamily has been crystallized using hanging-drop vapor-diffusion method. The crystals diffract to 2.0 A resolution and belong to space group P2(1), with unit-cell parameters of a=39.308 A, b=48.317 A, c=112.221 A, and beta=90.12 degrees . Preliminary analysis indicates that the asymmetric unit contains four PCL molecules with a solvent content of about 45%. A set of X-ray data has been collected for the crystal structure determination.

Isolation of an active Lv1 gene from cattle indicates that tripartite motif protein-mediated innate immunity to retroviral infection is widespread among mammals.

Lv1/TRIM5alpha (tripartite motif 5alpha) has recently emerged as an important factor influencing species-specific permissivity to retroviral infection in a range of primates, including humans. Old World monkey TRIM5alpha blocks human immunodeficiency virus type 1 (HIV-1) infectivity, and the human and New World monkey TRIM5alpha proteins are inactive against HIV-1 but active against divergent murine (N-tropic murine leukemia virus [MLV-N]) and simian (simian immunodeficiency virus from rhesus macaque [SIVmac]) retroviruses, respectively. Here we demonstrate antiviral activity of the first nonprimate TRIM protein, from cattle, active against divergent retroviruses, including HIV-1. The number of closely related human TRIM sequences makes assignment of the bovine sequence as a TRIM5alpha ortholog uncertain, and we therefore refer to it as bovine Lv1. Bovine Lv1 is closely related to primate TRIM5alpha proteins in the N-terminal RING and B-box 2 domains but significantly less homologous in the C-terminal B30.2 domain, particularly in the region shown to influence antiviral specificity. Intriguingly, some viruses restricted by bovine Lv1, including HIV-1 and MLV-N, are unable to synthesize viral DNA by reverse transcription, whereas restricted HIV-2 makes normal amounts of DNA. The data support the conclusion that TRIM protein-mediated restriction of retroviral infection is a more common attribute of mammals than previously appreciated.

In vitro and in vivo anti-retroviral activity of the substance purified from the aqueous extract of Chelidonium majus L.

We have isolated a substance with anti-retroviral activity from the freshly prepared crude extract of Chelidonium majus L. (greater celandine) by 9-aminoacridine precipitation method and ion exchange chromatography using Dowex-50W/H+ resin followed by the gel filtration on Sephadex-75 column. Elemental and phenol/sulfuric acid method analyses as well as the mass spectrometry of the purified substance indicated that it may represent a low-sulfated poly-glycosaminoglycan moiety with molecular weight of approximately 3800 Da. The substance prevented infection of human CD4+ T-cell lines AA2 and H9 with HIV-1 at concentration of 25 microg/mL as well as the cell-to-cell virus spread in H9 cells continuously infected with HIV-1, as determined by the measurement of reverse transcriptase activity and p24 content in cell cultures. Furthermore, we have shown in a murine AIDS model that the treatment with purified substance significantly prevented splenomegaly and the enlargement of cervical lymph nodes in C57Bl/6 mice chronically infected with the pool of murine leukemia retroviruses. The mechanism(s) of anti-retroviral activity of this substance have to be elucidated.

HIV-1 integrase inhibitors: 2003-2004 update.

The integration of viral cDNA into the host genome is an essential step in the HIV-1-life cycle and is mediated by the virally encoded enzyme, integrase (IN). Inhibition of this process provides an attractive strategy for antiviral drug design. The discovery of beta-diketo acid inhibitors played a major role in validating IN as a legitimate antiretroviral drug target. Over a decade of research, a plethora of IN inhibitors have been discovered and some showed antiviral activity consistent with their effect on IN. To date, at least two compounds have been tested in human but none are close to the FDA approval. In this review, we provide a comprehensive report of all small-molecule IN inhibitors discovered during the years 2003 and 2004. Compilation of such data will prove beneficial in developing QSAR, virtual screening, pharmacophore hypothesis generation, and validation.

Detection of clinical interactions between methadone and anti-retroviral compounds using an enantioselective capillary electrophoresis for methadone analysis.

A capillary electrophoresis method was developed to detect interactions between methadone and anti-retroviral compounds. Eight subjects, who underwent methadone maintenance treatment in the Province of Alicante (Spain), consented to participate in the present study. Of those, one subject was followed up for 123 days to detect drug-drug interactions. The enantiomers of methadone and those of its main metabolite were conveniently resolved within 4 min using a chiral electrophoresis buffer mixture which consisted of phosphate buffer, pH 5, plus 0.2% highly sulphated-(beta)-cyclodextrin. The effective mobility of the analytes was in the 0.061-0.140 cm(2)/(kV s) range at pH 5. The R-methadone plasma concentration range for seven patients was 91-318 ng/mL, it decreased from 186 to 46 ng/mL in a patient followed-up on commencement of the anti-retroviral therapy, returning to the previous higher levels after progressive dose increases. We conclude that monitoring R-methadone plasma levels can be a useful tool for the dose adjustment of methadone.