Wild-type Human Immunodeficiency Virus Research Articles

Virus specificity and nucleoporin requirements for MX2 activity are affected by GTPase function and capsid-CypA interactions.

Human myxovirus resistance 2 (MX2/MXB) is an interferon-induced GTPase that inhibits human immunodeficiency virus-1 (HIV-1) infection by preventing nuclear import of the viral preintegration complex. The HIV-1 capsid (CA) is the major viral determinant for sensitivity to MX2, and complex interactions between MX2, CA, nucleoporins (Nups), cyclophilin A (CypA), and other cellular proteins influence the outcome of viral infection. To explore the interactions between MX2, the viral CA, and CypA, we utilized a CRISPR-Cas9/AAV approach to generate CypA knock-out cell lines as well as cells that express CypA from its endogenous locus, but with specific point mutations that would abrogate CA binding but should not affect enzymatic activity or cellular function. We found that infection of CypA knock-out and point mutant cell lines with wild-type HIV-1 and CA mutants recapitulated the phenotypes observed upon cyclosporine A (CsA) addition, indicating that effects of CsA treatment are the direct result of blocking CA-CypA interactions and are therefore independent from potential interactions between CypA and MX2 or other cellular proteins. Notably, abrogation of GTP hydrolysis by MX2 conferred enhanced antiviral activity when CA-CypA interactions were abolished, and this effect was not mediated by the CA-binding residues in the GTPase domain, or by phosphorylation of MX2 at position T151. We additionally found that elimination of GTPase activity also altered the Nup requirements for MX2 activity. Our data demonstrate that the antiviral activity of MX2 is affected by CypA-CA interactions in a virus-specific and GTPase activity-dependent manner. These findings further highlight the importance of the GTPase domain of MX2 in regulation of substrate specificity and interaction with nucleocytoplasmic trafficking pathways.

Structure-directed expansion of biphenyl-pyridone derivatives as potent non-nucleoside reverse transcriptase inhibitors with significantly improved potency and safety

Following our previous work on human immunodeficiency virus-1 (HIV-1) non-nucleoside reverse transcriptase inhibitors (NNRTIs), a series of novel biphenyl-pyridone derivatives were synthesized and evaluated for their anti-HIV-1 activity to expand their structure–activity relationship. Some of them exhibited low nanomolar activity toward wild-type HIV-1 and clinically relevant single/double mutant strains. The most active compound B1 was 231-fold more potent (EC50 = 17 nmol/L) than the lead compound 2 (EC50 = 3.93 µmol/L) against wild-type (WT) HIV-1. This compound was approximately 3.5-fold less cytotoxic (CC50 = 100.58 µmol/L) than compound 2 (CC50 = 28.24 µmol/L), presenting a higher selectivity index (SI) value of 5923. Compared with 2, the antiviral potency of B1 was significantly increased against five single mutant strains (L100I, K103N, E138K, Y181C and Y188L) and two double mutant strains (F227L+V106A and K103N+Y181C). Especially, K103N, Y181C and K103N+Y181C were more sensitive to B1 than both 2 and doravirine. Besides, the enzymatic inhibitory activity of B1 against wild-type HIV-1 reverse transcriptase was approximately 32-fold higher (IC50 = 100 nmol/L) than 2 (IC50 = 3.21 µmol/L). Molecular docking studies and dynamic simulations were conducted to explain their potent activity. Taken together, this research represents an important step toward the discovery of novel biphenyl-pyridone drug candidates for HIV therapy.

Molecular Docking Structure-Activity Relationship, ADMET Evaluation and Pharmacokinetics Studies of Anti-HIV Agents and Methyl-Diarylpyrimidines Non-Nucleoside Reverse Transcriptase Inhibitors

In this study, the interaction between human immunodeficiency virus reverse transcriptase and methyldiarylpyrimidines containing a hydroxyimino, hydrazine, hydroxyl, cyclopropylamino, cyano or chloro etc. substituent was studied by molecular docking simulation, molecular docking was accomplished with AutoDock4.2 and absorption, distribution, metabolism, excretion and toxicity-structure-activity relationship and Swiss absorption, distribution, metabolism and excretion servers were used to predict the pharmacokinetics and absorption, distribution, metabolism, excretion and toxicity properties of all compounds. As a result, molecular docking analysis revealed that there are extensive interactions between the diarylpyrimidine derivatives and Lys101, Tyr188, Val179, Lys103, Glu138, Leu234, Phe227 and Trp229 residues in the active site of human immunodeficiency virus-1 reverse transcriptase. The formation of hydrogen bonds between diarylpyrimidines and the residues Lys101 and Glu138 play important roles in inhibiting the activity of human immunodeficiency virus. All compounds respect the conditions mentioned in Lipinski’s rule and have acceptable absorption, distribution, metabolism, excretion and toxicity properties. The preliminary structure-activity relationship was also investigated. A preliminary structureactivity relationship analysis of these target molecules highlighted a preference for the smaller or more flexible group’s substitution in the linker between the left ring and the pyrimidine skeleton for enhancing the anti-human immunodeficiency virus-1 activity. The acrylonitrile C4-substituent substantially improved the potency against wild-type human immunodeficiency virus-1 and several mutant strains, and the 2nd position is the most preferred position to improve antiviral activity. This information might be helpful for further diarylpyrimidine optimizations.

Advances and challenges in antiretroviral therapy for acquired immunodeficiency syndrome.

Advances and challenges in antiretroviral therapy for acquired immunodeficiency syndrome.

Preliminary SAR and biological evaluation of potent HIV-1 protease inhibitors with pyrimidine bases as novel P2 ligands to enhance activity against DRV-resistant HIV-1 variants

Introducing pyrimidine bases, the basic components of nucleic acid, to P2 ligands might enhance the potency of Human Immunodeficiency Virus-1 (HIV-1) protease inhibitors because of the carbonyl and amino groups promoting the formation of extensive hydrogen bonding interactions. In this work, we provide evidence that inhibitor 10e, with N-2-(2,4-Dioxo-3,4-dihydropyrimidin-1(2H)-yl) acetamide as the P2 ligand and a 4-methoxylphenylsulfonamide as the P2′ ligand, displayed remarkable enzyme inhibitory and antiviral activity, with the IC50 2.53 nM in vitro and a promising inhibition ratio with 68% against wild-type HIV-1 in vivo, with low cytotoxicity. This inhibitor also exhibited appreciable antiviral activity against DRV-resistant HIV-1 variants, which was of great value for further study.

Switching to Tenofovir Alafenamide in Elvitegravir-Based Regimens: Pharmacokinetics and Antiviral Activity in Cerebrospinal Fluid.

Tenofovir alafenamide fumarate (TAF) co-formulated with elvitegravir (EVG; E), cobicistat (C), and emtricitabine (F), a recommended antiretroviral regimen, was evaluated for distribution and antiviral activity in cerebrospinal fluid (CSF) as well as neurocognitive (NC) performance change in participants switching from E/C/F/tenofovir disoproxil fumarate (TDF) to E/C/F/TAF. This was a 24-week, single-arm, open-label study in treatment-experienced adults living with human immunodeficiency virus (HIV). Nine participants switched from E/C/F/TDF (150/150/200/300 mg once daily) to E/C/F/TAF (150/150/200/10 mg once daily) at week 12. CSF and total plasma concentrations of EVG, TDF, TAF, tenofovir (TFV), and HIV RNA levels were measured at baseline and week 24. NC performance was estimated by the Montreal Cognitive Assessment. EVG concentrations in CSF and the CSF:plasma ratio remained stable (P = .203) over time. Following the switch, TFV concentrations in CSF and plasma declined (P = .004), although the TFV CSF:plasma ratio increased (P = .004). At week 24, median TAF plasma concentration was 11.05 ng/mL (range, 2.84-147.1 ng/mL) 2 hours postdose but was below assay sensitivity 6 hours after dosing. TAF was below assay sensitivity in all CSF specimens. HIV RNA was ≤40 copies/mL in all CSF and plasma specimens. Three participants (33%) had NC impairment at baseline and 2 (22%) remained impaired at week 24. Switch to E/C/F/TAF was associated with reductions in TFV concentrations in CSF but stable EVG concentrations that exceeded the 50% inhibitory concentration for wild-type HIV, suggesting that EVG achieves therapeutic concentrations in the central nervous system. No virologic failure or significant NC changes were detected following the switch. NCT02251236.

Combining 25-Hydroxycholesterol with an HIV Fusion Inhibitor Peptide: Interaction with Biomembrane Model Systems and Human Blood Cells.

The fusion between the viral and the target cell membrane is a crucial step in the life cycle of enveloped viruses. The blocking of this process is a well-known therapeutic approach that led to the development of the fusion inhibitor peptide enfuvirtide, clinically used against human immunodeficiency virus (HIV) type 1. Despite this significant advance on viral treatment, the appearance of resistance has limited its clinical use. Such a limitation has led to the development of other fusion inhibitor peptides, such as C34, that present the same structural domain as enfuvirtide (heptad repeat sequence) but have different functional domains (pocket-binding domain in the case of C34 and lipid-binding domain in the case of enfuvirtide). Recently, the antiviral properties of 25-hydroxycholesterol were demonstrated, which boosted the interest in this oxysterol. The combination of two distinct antiviral molecules, C34 and 25-hydroxycholesterol, may help to suppress the emergence of resistant viruses. In this work, we characterized the interaction of the C34-25-hydroxycholesterol conjugate with biomembrane model systems and human blood cells. Lipid vesicles and monolayers with defined lipid compositions were used as biomembrane model systems. The conjugate interacts preferentially with membranes rich in sphingomyelin (a lipid enriched in lipid rafts) and presents a poor partition to membranes composed solely of phosphatidylcholine and cholesterol. We hypothesize that cholesterol causes a repulsive effect that is overcome in the presence of sphingomyelin. Importantly, the peptide shows a preference for human peripheral blood mononuclear cells relative to erythrocytes, which shows its potential to target CD4+ cells. Antiviral activity results against different wild-type and drug-resistant HIV strains further demonstrated the potential of C34-HC as a good candidate for future studies.

Discovery of potent HIV-1 non-nucleoside reverse transcriptase inhibitors by exploring the structure-activity relationship of solvent-exposed regions I.

Two novel series of human immunodeficiency virus-1 (HIV-1) non-nucleoside reverse transcriptase inhibitors (NNRTIs) bearing a thiophene[3,2-d]pyrimidine scaffold and sulfonamide linker in the right wing have been identified, which demonstrated activity against the wild-type (WT) HIV-1 strain in MT-4 cells with inhibitory concentrations ranging from micromolar to submicromolar. Especially, against the mutant strains K103N and E138K, most compounds exhibited more potent activity than against WT HIV-1. Compound 7 (EC50 =0.014, 0.031μM) achieved the most potent activity against the two mutants, being more effective than that of nevirapine (NVP, EC50 =7.572, 0.190μM) and comparable to that of etravirine (ETV, EC50 =0.004, 0.014μM). Molecular docking experiments on the novel analogs have also suggested that the extensive network of main chain hydrogen bonds are important in the binding mode, which may provide valuable insights for further optimization.

Synthesis and anti-human immunodeficiency virus activity of substituted ( o,o-difluorophenyl)-linked-pyrimidines as potent non-nucleoside reverse transcriptase inhibitors.

With the worldwide number of human immunodeficiency virus positive patients stagnant and the increasing emergence of viral strains resistant to current treatment, the development of novel anti-human immunodeficiency virus drug candidates is a perpetual quest of medicinal chemists. Herein, we report a novel group of diarylpyrimidines, non-nucleoside reverse transcriptase inhibitors, which represents an important class of current anti-human immunodeficiency virus therapy. Series of diarylpyrimidines containing o,o-difluorophenyl (A-arm), 4-cyanophenylamino (B-arm), and a small substituent (e.g. NH2, OMe) at positions 2, 4, and 6 of the pyrimidine ring were prepared. The A-arm was modified in the para position (F or OMe) and linked to the central pyrimidine core with a variable spacer (CO, O, NH). Antiviral activities of 20 compounds were measured against wild type human immunodeficiency virus-1 and mutant reverse transcriptase strains (K103N, Y181C) using a cytoprotection assay. To the most promising structural motives belong the o,o-difluoro-p-methoxy A-arm in position 4, and the amino group in position 6 of pyrimidine. Single digit nanomolar activities with no significant toxicity (CC50 > 17,000 nM) were found for compounds 35 (EC50 = 2 nM), 37 (EC50 = 3 nM), and 13 (EC50 = 4 nM) having O, NH, and CO linkers, respectively.

An in silico pharmacological approach toward the discovery of potent inhibitors to combat drug resistance HIV-1 protease variants.

Protease inhibitors (PIs) are crucial drugs in highly active antiretroviral therapy for human immunodeficiency virus-1 (HIV-1) infections. However, resistance owing to mutations challenge the long-term efficacy in the medication of HIV-1-infected individuals. Lopinavir (LPV) and darunavir (DRV), two second-generation drugs are the most potent among PIs, hustling the drug resistance when mutations occur in the active and nonactive site of the protease (PR). Herein, we strive for compounds that can stifle the function of wild-type (WT) HIV-1 PR along with four major single mutants (I54M, V82T, I84V, and L90M) instigating resistance to the PIs using in silico approach. Six common compounds are retrieved from six databases using combined pharmacophore-based and structure-based virtual screening methodology. LPV and DRV are docked and the binding free energy is calculated to set the cut-off value for selecting compounds. Further, to gain insight into the stability of the complexes the molecular dynamics simulation (MDS) is carried out, which uncovers two lead molecules namely NCI-524545 and ZINC12866729. Both the lead molecules connect with WT and mutant HIV-1 PRs through strong and stable hydrogen bond interactions when compared with LPV and DRV throughout the trajectory analysis. Interestingly, NCI-524545 and ZINC12866729 exhibit direct interactions with I50/50' by replacing the conserved water molecule as evidenced by MDS, which indicates the credible potency of these compounds. Hence, weconcluded that NCI-524545 and ZINC12866729 have great puissant to restrain the role of drug resistance HIV-1 PR variants, which can also show better activity through in vivo and in vitro conditions.

540. Investigating the Mechanism of a Unique Human Immunodeficiency Virus-1 (HIV-1) Entry Inhibitor, MF275

BackgroundHIV-1 entry into cells is mediated by sequential binding of target cell CD4 and CCR5 or CXCR4 to the metastable envelope (Env) trimer of gp120-gp41 heterodimers (Figure 1). We determined that MF275, a single diastereomer of the small molecule entry inhibitor PF-68742, is necessary and sufficient to inhibit entry of a subset of HIV-1 strains. We investigated the mechanism of MF275.MethodsRecombinant luciferase-expressing HIV-1 pseudotyped by wild-type or mutant HIV-1 Envs was incubated with MF275, other entry inhibitors, and/or antibodies. The virus-inhibitor mixture was added to CD4+ CCR5+ or CD4− CCR5+ target cells and luciferase activity measured.ResultsUnlike other entry inhibitors, MF275 not only reversibly inhibited the infection of CD4+ CCR5+ cells by some HIV-1 strains, but also irreversibly enhanced the infection of CD4− CCR5+ cells by others. In both cases, the strain susceptibility profiles were unique from those of CD4-mimetics, BMS-378806, and maraviroc. Furthermore, MF275 activity was not affected by mutations conferring resistance to other entry inhibitors and vice versa. In line with its activating activity, MF275 sensitized susceptible Envs to neutralization by a variety of broadly neutralizing antibodies against different epitopes. Changes in the gp120 C5 and gp41 FP regions conferred resistance to MF275 inhibition but not activation. Furthermore, sensitivity to other entry inhibitors in the presence of MF275 indicated that inhibition and activation target different conformational intermediates along the entry pathway, with the former targeting the prehairpin intermediate.ConclusionMF275 is unique among HIV-1 entry inhibitors. Depending on the conformation of the target Env, which appears related to the gp120-gp41 interface, MF275 mediates inhibition or activation via distinct mechanisms (Figure 2). Further characterization of the MF275 mechanisms and binding site/s will advance understanding of the HIV-1 entry pathway as well as assist optimization of its clinical utility as an antiretroviral in multi-class drug resistance and potentially as an adjunct to vaccines. Disclosures All authors: No reported disclosures.

Transcriptional inaccuracy threshold attenuates differences in RNA-dependent DNA synthesis fidelity between retroviral reverse transcriptases

In M13mp2 lacZα forward mutation assays measuring intrinsic fidelity of DNA-dependent DNA synthesis, wild-type human immunodeficiency virus type 1 (HIV-1) RTs of group M/subtype B previously showed >10-fold higher error rates than murine leukaemia virus (MLV) and avian myeloblastosis virus (AMV) RTs. An adapted version of the assay was used to obtain error rates of RNA-dependent DNA synthesis for several RTs, including wild-type HIV-1BH10, HIV-1ESP49, AMV and MLV RTs, and the high-fidelity mutants of HIV-1ESP49 RT K65R and K65R/V75I. Our results showed that there were less than two-fold differences in fidelity between the studied RTs with error rates ranging within 2.5 × 10−5 and 3.5 × 10−5. These results were consistent with the existence of a transcriptional inaccuracy threshold, generated by the RNA polymerase while synthesizing the RNA template used in the assay. A modest but consistent reduction of the inaccuracy threshold was achieved by lowering the pH and Mg2+ concentration of the transcription reaction. Despite assay limitations, we conclude that HIV-1BH10 and HIV-1ESP49 RTs are less accurate when copying DNA templates than RNA templates. Analysis of the RNA-dependent mutational spectra revealed a higher tendency to introduce large deletions at the initiation of reverse transcription by all HIV-1 RTs except the double-mutant K65R/V75I.

Next-generation sequencing-based analysis of reverse transcriptase fidelity

In this study, we devised a simple and rapid method to analyze fidelity of reverse transcriptase (RT) using next-generation sequencing (NGS). The method comprises a cDNA synthesis reaction from standard RNA with a primer containing a tag of 14 randomized bases and the RT to be tested, PCR using high-fidelity DNA polymerase, and NGS. By comparing the sequence of each read with the reference sequence, mutations were identified. The mutation can be identified to be due to an error introduced by either cDNA synthesis, PCR, or NGS based on whether the sequence reads with the same tag contain the same mutation or not. The error rates in cDNA synthesis with Moloney murine leukemia virus (MMLV) RT thermostable variant MM4 or the recently developed 16-tuple variant of family B DNA polymerase with RT activity, RTX, from Thermococcus kodakarensis, were 0.75–1.0 × 10−4 errors/base, while that in the reaction with the wild-type human immunodeficiency virus type 1 (HIV-1) RT was 2.6 × 10−4 errors/base. Overall, our method could precisely evaluate the fidelity of various RTs with different reaction conditions in a high-throughput manner without the use of expensive optics and troublesome adaptor ligation.

Combination antiretroviral therapy and cell-cell spread of wild-type and drug-resistant human immunodeficiency virus-1.

Human immunodeficiency virus-1 (HIV-1) disseminates between T cells either by cell-free infection or by highly efficient direct cell–cell spread. The high local multiplicity that characterizes cell–cell infection causes variability in the effectiveness of antiretroviral drugs applied as single agents. Whereas protease inhibitors (PIs) are effective inhibitors of HIV-1 cell–cell and cell-free infection, some reverse transcriptase inhibitors (RTIs) show reduced potency; however, antiretrovirals are not administered as single agents and are used clinically as combination antiretroviral therapy (cART). Here we explored the efficacy of PI- and RTI-based cART against cell–cell spread of wild-type and drug-resistant HIV-1 strains. Using a quantitative assay to measure cell–cell spread of HIV-1 between T cells, we evaluated the efficacy of different clinically relevant drug combinations. We show that combining PIs and RTIs improves the potency of inhibition of HIV-1 and effectively blocks both cell-free and cell–cell spread. Combining drugs that alone are poor inhibitors of cell–cell spread markedly improves HIV-1 inhibition, demonstrating that clinically relevant combinations of ART can inhibit this mode of HIV-1 spread. Furthermore, comparison of wild-type and drug-resistant viruses reveals that PI- and RTI-resistant viruses have a replicative advantage over wild-type virus when spreading by cell–cell means in the presence of cART, suggesting that in the context of inadequate drug combinations or drug resistance, cell–cell spread could potentially allow for ongoing viral replication.

2-thio-6-azauridine inhibits Vpu mediated BST-2 degradation.

Backgroud BST-2 is an interferon-induced host restriction factor that inhibits the release of diverse mammalian enveloped viruses from infected cells by physically trapping the newly formed virions onto the host cell surface. Human Immunodeficiency Virus-1 (HIV-1) encodes an accessory protein Vpu that antagonizes BST-2 by down-regulating BST-2 from the cell surface.ResultsUsing a cell-based ELISA screening system, we have discovered a lead compound, 2-thio-6-azauridine, that restores cell surface BST-2 level in the presence of Vpu. This compound has no effect on the expression of BST-2 and Vpu, but inhibits Vpu-mediated BST-2 down-regulation and exerts no effect on Vpu-induced down-regulation of CD4 or KSHV K5 protein induced BST-2 down-regulation. 2-thio-6-azauridine suppresses HIV-1 production in a BST-2-dependent manner. Further results indicate that 2-thio-6-azauridine does not interrupt the interaction of BST-2 with Vpu and β-TrCP2, but decreases BST-2 ubiquitination.ConclusionOur study demonstrates the feasibility of using small molecules to target Vpu function and sensitize wild type HIV-1 to BST-2-mediated host restriction.Electronic supplementary materialThe online version of this article (doi:10.1186/s12977-016-0247-z) contains supplementary material, which is available to authorized users.

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

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.

HIV inhibits endothelial reverse cholesterol transport through impacting subcellular Caveolin-1 trafficking.

BackgroundHuman immunodeficiency virus (HIV) infection leads to decreased reverse cholesterol transport (RCT) in macrophages, and Nef mediated down-regulation and redistribution of ATP-binding cassette transporter A1 (ABCA1) are identified as key factors for this effect. This may partially explain the increased risk of atherosclerosis in HIV infected individuals. Since endothelial dysfunction is key in the initial stages of atherosclerosis, we sought to determine whether RCT was affected in human aortic endothelial cells (HAECs).ResultsWe found that apoA-I does not significantly stimulate cholesterol efflux in HAECs while cholesterol efflux to high-density lipoprotein (HDL) was dramatically reduced in HAECs co-cultured with HIV infected cells. Studies with wild type and Nef defective HIV revealed no significant differences suggesting that multiple factors are working perhaps in concert with Nef to affect cholesterol efflux to HDL from HAECs. Interestingly, treating HAECs with recombinant Nef showed similar effect in HDL mediated cholesterol efflux as observed in HAECs co-cultured with HIV infected cells. Using a detergent-free based subcellular fractionation approach, we demonstrated that exposure of HAECs to HIV infected cells or Nef alone disrupts caveolin 1 (Cav-1) subcellular trafficking upon HDL stimulation. Moreover, Nef significantly enhanced tyrosine 14 phosphorylation of Cav-1 which may have an impact on recycling of Cav-1 and caveolae.ConclusionThese results suggest that HIV interferes with cholesterol efflux by HDL in HAECs through the disruption of Cav-1s’ cellular distribution and that multiple factors are involved, possibly including Nef, for the inhibition of HDL mediated cholesterol efflux and alteration of cellular distribution of Cav-1.Electronic supplementary materialThe online version of this article (doi:10.1186/s12977-015-0188-y) contains supplementary material, which is available to authorized users.

Lopinavir/ritonavir en pacientes infectados por el virus de la inmunodeficiencia humana en situaciones especiales

Ritonavir-boosted lopinavir (LPV/r) is a protease inhibitor used for the treatment of human immunodeficiency virus (HIV) infection in both normal patients and in certain situations. In patients with renal failure, LPV/r does not require dosage adjustment because it is metabolized in the liver. Cohort studies have shown that the incidence of varying degrees of renal disease and/or crystalluria related to combination antiretroviral therapy with tenofovir and some protease inhibitors (PI) does not appear with LPV/r or that the incidence is much lower with this combination. Neurocognitive impairments are described in a high proportion of patients with HIV infection and viral replication or related inflammatory activity in the subarachnoid space. In these patients, LPV/r is one of the therapeutic options. A score has been published that rates antiretroviral drugs according to the concentration attained in the cerebrospinal fluid (CSF). LPV/r levels reached in CSF exceed the IC50 of wild-type HIV and has a valuable score (score 3) of the drugs currently used. The most important comorbid condition is chronic hepatitis, due to its frequency and because the biotransformation of LPV/r occurs in the liver. In these circumstances, it is important to evaluate the influence of liver failure on blood drug levels and how these values may cause liver toxicity. LPV/r dose modification has not been established in the presence of liver failure. LPV/r-induced liver toxicity has only been reported with a certain frequency when liver enzymes were elevated at baseline or in patients with chronic hepatitis C, although most cases of liver toxicity were mild.

Cerebrospinal fluid inhibitory quotients of antiretroviral drugs in HIV-infected patients are associated with compartmental viral control.

Despite the efficacy of highly active antiretroviral treatment (HAART), a large proportion of human immunodeficiency virus (HIV)-infected patients may develop moderate neurocognitive impairment. Antiretroviral drug passage into the central nervous system may be relevant for preventing and treating HIV-associated neurocognitive disorder; nevertheless, clear cerebrospinal fluid (CSF) pharmacodynamic targets are not known. HAART-treated adults with wild-type HIV were prospectively enrolled. CSF concentrations (measured by mass spectrophotometric methods) and inhibitory quotients (CSF concentrations divided by in vitro 50% and 95% inhibitory concentrations) were compared among different drugs and related to CSF HIV RNA levels. CSF escape was defined as CSF HIV RNA >50 copies/mL despite contemporary plasma HIV RNA below that threshold. One hundred twenty-seven patients (91 male [71.7%], 93 white [73.2%], with a median age of 46 years [interquartile range, 40.5-54.5 years]) provided 174 paired CSF and plasma samples. Twice-daily darunavir, once-daily darunavir, and efavirenz had the highest CSF 95% inhibitory quotients (18.5, 8.2, and 6.4, respectively). Higher nadir CD4 cell count (P = .01) and plasma HIV RNA <50 copies/mL (P < .001) were independent predictors of controlled CSF HIV RNA. Optimal drug exposure (CSF detectable drugs and 95% inhibitory quotient >1) was protective for CSF escape (P = .01). Cerebrospinal fluid 95% inhibitory quotients may be used to compare antiretroviral drug compartmental exposure; they deserve longitudinal studies to assess the adequacy of CSF drug concentrations in treated HIV-infected patients.

Novel indole based NNRTIs with improved potency against wild type and resistant HIV

The human immunodeficiency virus (HIV) pandemic remains a significant problem, especially in developing nations where the social and economic impacts are severe. Until a cure or vaccine for the disease is found, a constant supply of new compounds to fill the drug development pipeline is a requirement, given the tendency for the virus to rapidly develop resistance to current therapies. Here we disclose our efforts to improve upon the efficacy of cyclopropyl-indole derivatives developed as NNRTIs in our laboratories. To this end, modifications to the functionality occupying the small Val179 pocket have resulted in nearly two orders of magnitude increase in potency.