Biochemical and structural comparisons of non-nucleoside reverse transcriptase inhibitors against feline and human immunodeficiency viruses.

BACKGROUND: Feline immunodeficiency virus (FIV) causes an acquired immunodeficiency-like syndrome in cats. FIV is latent. No effective treatment has been developed for treatment the infected cats. The first and second generations non-nucleoside reverse transcriptase inhibitors (NNRTIs) for HIV treatment, nevirapine (NVP) and efavirenz (EFV), and rilpivirine (RPV), were used to investigate the potential of NNRTIs for treatment of FIV infection. OBJECTIVE: This study aims to use experimental and in silico approaches to investigate the potential of NNRTIs, NVP, EFV, and RPV, for inhibition of FIV reverse transcriptase (FIV-RT). METHODS: The FIV-RT and human immunodeficiency virus reverse transcriptase (HIV-RT) were expressed and purified using chromatography approaches. The purified proteins were used to determine the IC50 values with NVP, EFV, and RPV. Surface plasmon resonance (SPR) analysis was used to calculate the binding affinities of NNRTIs to HIV-RT and FIV-RT. The molecular docking and molecular dynamic simulations were used to demonstrate the mechanism of FIV-RT and HIV-RT with first and second generation NNRTI complexes. RESULTS: The IC50 values of NNRTIs NVP, EFV, and RPV against FIV-RT were in comparable ranges to HIV-RT. The SPR analysis showed that NVP, EFV, and RPV could bind to both enzymes. Computational calculation also supports that these NNRTIs can bind with both FIV-RT and HIV-RT. CONCLUSIONS: Our results suggest the first and second generation NNRTIs (NVP, EFV, and RPV) could inhibit both FIV-RT and HIV-RT.

HIV-1 drug resistance among individuals who seroconverted in the ASPIRE dapivirine ring trial.

INTRODUCTION: A potential concern with the use of dapivirine (DPV) for HIV prevention is the selection of a drug-resistant virus that could spread and reduce the effectiveness of non-nucleoside reverse transcriptase (NNRTI)-based first-line antiretroviral therapy. We evaluated HIV-1 seroconversions in MTN-020/ASPIRE for selection of drug resistance and evaluated the genetic basis for observed reductions in susceptibility to DPV. METHODS: MTN-020/ASPIRE was a placebo-controlled, Phase III safety and effectiveness study of DPV ring for HIV-1 prevention conducted at 15 sites in South Africa, Zimbabwe, Malawi and Uganda between 2012 and 2015. Plasma from individuals who seroconverted in ASPIRE was analysed for HIV-1 drug resistance using both population Sanger sequencing and next-generation sequencing (NGS) with unique molecular identifiers to report mutations at ≥1% frequency. DPV susceptibility of plasma-derived recombinant HIV-1 containing bulk-cloned full-length reverse transcriptase sequences from MTN-020/ASPIRE seroconversions was determined in TZM-bl cells. Statistical significance was calculated using the Fisher's exact test. RESULTS: Plasma from all 168 HIV seroconversions were successfully tested by Sanger sequencing; 57 of 71 DPV arm and 82 of 97 placebo (PLB) arm participants had NGS results at 1% sensitivity. Overall, 18/168 (11%) had NNRTI mutations including K101E, K103N/S, V106M, V108I, E138A/G, V179D/I/T and H221Y. Five samples from both arms had low-frequency NNRTI mutations that were not detected by Sanger sequencing. The frequency of NNRTI mutations from the DPV arm (11%) was not different from the PLB arm (10%; p = 0.80). The E138A mutation was detected in both the DPV (3 of 71 [4.2%]) and PLB arm (5 of 97 [5.2%]) and conferred modest reductions in DPV susceptibility in some reverse transcriptase backgrounds but not others. CONCLUSIONS: HIV-1 drug resistance including NNRTI resistance did not differ between the DPV and placebo arms of the MTN-020/ASPIRE study, indicating that drug resistance was not preferentially acquired or selected by the DPV ring and that the preventive benefit of DPV ring outweighs resistance risk.

[Study of the specific toxic effects of the substance 1-[2-(2-benzoylphenoxy)ethyl]-6-methyluracil, the original non-nucleoside inhibitor of human immunodeficiency virus type 1 (Retroviridae; Orthoretrovirinae; Lentivirus: Human immunodeficiency virus 1) reverse transcriptase].

INTRODUCTION: Combination antiretroviral therapy is currently the main component of treatment for human immunodeficiency virus (HIV) infected patients. At the same time, the high mutational potential of the virus and the frequency of side effects of existing drugs dictate the need for the development and preclinical study of new, more effective and safer compounds.The aim of the study is to evaluate the specific types of toxicity of a new non-nucleoside inhibitor of human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RNA-dependent DNA revertase) (NNRTI) based on the substance 1-[2-(2-benzoylphenoxy)ethyl]-6-methyluracil, a benzophenone derivative. MATERIAL AND METHODS: The study investigated reproductive toxicity, embryotoxicity, immunotoxicity, genotoxic (in micronucleus test in and comet assay) and allergenic properties of the test itemcompound. It was tested on three species of animals in two doses: the estimated therapeutic dose (1 TD) and its tenfold equivalent (10 TD). Taking into account the metabolic coefficients, the doses for rats (Rattus) were 9 and 90 mg/kg, for mice (Mus musculus), 21 and 210 mg/kg, and for guinea pigs (Cavia porcellus), 8 and 80 mg/kg, respectively. RESULTS AND DISCUSSION: According to the obtained results, a favorable safety profile of the tested compound was established. Negative effects on the immune system, reproductive function, the body of pregnant animals and the fetus were not observed, as well as the compound did not have genotoxic and allergenic properties. CONCLUSION: These data allows to consider the studied compound as a promising therapeutic candidate for the treatment of HIV-1 infection.

Mini Review - Epigenetics: Quest for no-escape to HIV, a persistent pathogen.

Acquired Immune Deficiency Syndrome (AIDS) is a disease infection mix, which is primarily because of 'deficient' immune system. Human Immune-deficiency Virus (HIV) makes the immune system susceptible to many infections by infiltrating it. Many researchers believe that HIV is a mutated form of Simian Immune-deficiency Virus (SIV). After being clinically discovered in 1981 in America, it is said to have caused 36 million deaths. Treatment of AIDS has been a 'burning ' issue ever since its discovery. There is no cure for AIDS! Although, Recombinant Transcriptase Inhibitors (RTis) are being considered a major treatment against HIV that can not only lessen the effect of HIV but also can prolong the life of HIV positive patients. More recent advancement includes 'transplantation of transgenic stem cells' in HIV positive patients. As latency of HIV provirus in host genome is the preeminent weapon of this virus against RTis that compel it to hide from host immune system and a persistent pathogen thereof. Thus, epigenetic activation of latent provirus pool by methyl inhibitors along with non¬toxic chemical drugs seems to be a more promising treatment to avoid the burden of lifelong RTI.

Discovery of dapivirine, a nonnucleoside HIV-1 reverse transcriptase inhibitor, as a broad-spectrum antiviral against both influenza A and B viruses.

The emergence of multidrug-resistant influenza viruses poses a persistent threat to public health. The current prophylaxis and therapeutic interventions for influenza virus infection have limited efficacy due to the continuous antigenic drift and antigenic shift of influenza viruses. As part of our ongoing effort to develop the next generation of influenza antivirals with broad-spectrum antiviral activity and a high genetic barrier to drug resistance, in this study we report the discovery of dapivirine, an FDA-approved HIV nonnucleoside reverse transcriptase inhibitor, as a broad-spectrum antiviral against multiple strains of influenza A and B viruses with low micromolar efficacy. Mechanistic studies revealed that dapivirine inhibits the nuclear entry of viral ribonucleoproteins at the early stage of viral replication. As a result, viral RNA and protein synthesis were inhibited. Furthermore, dapivirine has a high in vitro genetic barrier to drug resistance, and its antiviral activity is synergistic with oseltamivir carboxylate. In summary, the in vitro antiviral results of dapivirine suggest it is a promising candidate for the development of the next generation of dual influenza and HIV antivirals.

[Diversity of HIV-1 subtypes and primary HIV-1 drug resistance among 302 newly confirmed HIV infections/AIDS in Henan province, China].

OBJECTIVE: To investigate HIV-1 subtype diversity and the frequency of primary drug resistance in newly confirmed HIV infections/AIDS, and the ratio of recently infected cases in Henan. METHODS: Newly confirmed HIV infections/AIDS from June 2013 to October 2013 and from June 2014 to October 2014 in the municipal CDC and county CDC of six cities in Henan province (Nanyang, Luohe, Pingdingshan, Shangqiu, Xuchang and Zhengzhou) were included in this study. Information on demographics, route of infection and antiviral therapy regimen were obtained from report cards, and at follow-up visits. After collection of blood samples from 402 individuals for confirmatory diagnostic tests, 100 were excluded because of hemolysis or insufficient samples in 11 cases, and incomplete amplification results in 89 cases. Recent HIV infection was determined by the BED capture immunoassay. An in-house method were used for genotypic drug resistance tests and sequence analysis. RESULTS: Among the 302 individuals included, the mean age was (44.0±15.5) years, and 160 (53.0%) and 142 (47.0%) cases were confirmed in 2013 and 2014, respectively. The ratio of recent infections was 29.5% (89 cases), inside, the ratio of recent infections were 31.3% (20/64), 40.5% (30/74), 21.3% (32/150), 3/8 and 4/6 in 01_AE, 07_BC, B, 01_B and other subtypes (B/C, C, 01_BC and 08_BC) (χ(2)=13.48, P=0.009). The frequency of the B subtype was higher in former infections, at 55.4% (118/213), than in recent infections, at 36% (32/89) (χ(2)=9.49, P=0.002). In contrast, the ratios of both 07_BC and other subtypes were lower in former infections (20.7% (44/213) and 1% (2/213), respectively) than recent infections (33.7% (30/89), χ(2)=5.78, P=0.016 and 5% (4/89), χ(2)=4.08; P=0.044, respectively). The frequency of primary HIV-1 drug resistance was 6.0% (18 cases) in 302 subjects. The frequency of resistance to nucleoside reverse transcriptase inhibitor (NRTI) and non-nucleoside reverse transcriptase inhibitor (NNRTI) drugs was 2.7% (8 cases) and 3.6% (11 cases), respectively. Primary HIV-1 drug resistance was more frequent in subtypes B and 07_BC, at 8.7% (13 cases) and 5.4% (4 cases), respectively. CONCLUSION: Newly confirmed HIV infections/AIDS in Henan province harbored certain proportion of none-B subtypes, the frequency of primary resistance tended to be high in HIV-1B infection. The molecular epidemiology of HIV and the development of primary drug resistance should be regularly monitored.

In Vitro Exposure to PC-1005 and Cervicovaginal Lavage Fluid from Women Vaginally Administered PC-1005 Inhibits HIV-1 and HSV-2 Infection in Human Cervical Mucosa.

Our recent phase 1 trial demonstrated that PC-1005 gel containing 50 µM MIV-150, 14 mM zinc acetate dihydrate, and carrageenan (CG) applied daily vaginally for 14 days is safe and well tolerated. Importantly, cervicovaginal lavage fluid samples (CVLs) collected 4 or 24 h after the last gel application inhibited HIV-1 and human papillomavirus (HPV) in cell-based assays in a dose-dependent manner (MIV-150 for HIV-1 and CG for HPV). Herein we aimed to determine the anti-HIV and anti-herpes simplex virus 2 (anti-HSV-2) activity of PC-1005 in human cervical explants after in vitro exposure to the gel and to CVLs from participants in the phase 1 trial. Single HIV-1BaL infection and HIV-1BaL-HSV-2 coinfection explant models were utilized. Coinfection with HSV-2 enhanced tissue HIV-1BaL infection. In vitro exposure to PC-1005 protected cervical mucosa against HIV-1BaL (up to a 1:300 dilution) in single-challenge and cochallenge models. CG gel (PC-525) provided some barrier effect against HIV-1BaL at the 1:100 dilution in a single-challenge model but not in the cochallenge model. Both PC-1005 and PC-525 at the 1:100 dilution inhibited HSV-2 infection, pointing to a CG-mediated protection. MIV-150 and CG in CVLs inhibited HIV (single-challenge or cochallenge models) and HSV-2 infections in explants in a dose-dependent manner (P < 0.05). Stronger inhibition of HIV-1 infection by CVLs collected 4 h after the last gel administration was observed compared to infection detected in the presence of baseline CVLs. The anti-HIV and anti-HSV-2 activity of PC-1005 gel in vitro and CVLs in human ectocervical explants supports the further development of PC-1005 gel as a broad-spectrum on-demand microbicide.

Pharmacodynamic Activity of Dapivirine and Maraviroc Single Entity and Combination Topical Gels for HIV-1 Prevention.

PURPOSE: Dapivirine (DPV), a non-nucleoside reverse transcriptase inhibitor, and maraviroc (MVC), a CCR5 antagonist, were formulated into aqueous gels designed to prevent mucosal HIV transmission. METHODS: 0.05% DPV, 0.1% MVC, 0.05% DPV/0.1% MVC and placebo gels were evaluated for pH, viscosity, osmolality, and in vitro release. In vitro assays and mucosal tissues were used to evaluate anti-HIV activity. Viability (Lactobacilli only) and epithelial integrity in cell lines and mucosal tissues defined safety. RESULTS: The gels were acidic and viscous. DPV gel had an osmolality of 893 mOsm/kg while the other gels had an osmolality of <100 mOsm/kg. MVC release was similar from the single and combination gels (~5 µg/cm(2)/min(1/2)), while DPV release was 10-fold less from the single as compared to the combination gel (0.4331 µg/cm(2)/min(1/2)). Titrations of the gels showed 10-fold more drug was needed to protect ectocervical than colonic tissue. The combination gel showed ~10- and 100-fold improved activity as compared to DPV and MVC gel, respectively. All gels were safe. CONCLUSIONS: The DPV/MVC gel showed a benefit blocking HIV infection of mucosal tissue compared to the single entity gels. Combination products with drugs affecting unique steps in the viral replication cycle would be advantageous for HIV prevention.

Non-nucleoside reverse transcriptase inhibitors: a review on pharmacokinetics, pharmacodynamics, safety and tolerability.

INTRODUCTION: Human immunodeficiency virus (HIV) type-1 non-nucleoside and nucleoside reverse transcriptase inhibitors (NNRTIs) are key drugs of highly active antiretroviral therapy (HAART) in the clinical management of acquired immune deficiency syndrome (AIDS)/HIV infection. DISCUSSION: First-generation NNRTIs, nevirapine (NVP), delavirdine (DLV) and efavirenz (EFV) are drugs with a low genetic barrier and poor resistance profile, which has led to the development of new generations of NNRTIs. Second-generation NNRTIs, etravirine (ETR) and rilpivirine (RPV) have been approved by the Food and Drug Administration and European Union, and the next generation of drugs is currently being clinically developed. This review describes recent clinical data, pharmacokinetics, metabolism, pharmacodynamics, safety and tolerability of commercialized NNRTIs, including the effects of sex, race and age differences on pharmacokinetics and safety. Moreover, it summarizes the characteristics of next-generation NNRTIs: lersivirine, GSK 2248761, RDEA806, BILR 355 BS, calanolide A, MK-4965, MK-1439 and MK-6186. CONCLUSIONS: This review presents a wide description of NNRTIs, providing useful information for researchers interested in this field, both in clinical use and in research.

Transmitted drug resistance among antiretroviral-naive patients with established HIV type 1 infection in Santo Domingo, Dominican Republic and review of the Latin American and Caribbean literature.

Emergence of HIV resistance is a concerning consequence of global scale-up of antiretroviral therapy (ART). To date, there is no published information about HIV resistance from the Dominican Republic. The study's aim was to determine the prevalence of transmitted drug resistance (TDR) to reverse transcriptase and protease inhibitors in a sample of chronically HIV-1-infected patients in one clinic in Santo Domingo. The data are presented in the context of a review of the TDR literature from Latin America and the Caribbean. Genotype testing was successfully performed on 103 treatment-naive adults planning to initiate antiretroviral therapy; the World Health Organization (WHO) list of surveillance drug resistance mutations (SDRM) was used to determine the presence of TDR mutations. WHO SDRM were identified in eight patients (7.8%); none had received sdNVP. There were no significant differences in epidemiologic or clinical variables between those with or without WHO SDRM. The prevalence of WHO SDRM was 1.0% and 6.8% for nucleoside reverse transcriptase inhibitors and nonnucleoside reverse transcriptase inhibitors, respectively. No WHO SDRMs for protease inhibitors were identified. Among 12 studies of TDR in the region with a sample size of at least 100 subjects, the reported prevalence of SDRM ranged from 2.8% to 8.1%. The most commonly identified SDRM was K103N. This information adds to our understanding of the epidemiology of TDR in the region and the possible role such mutations could play in undermining first-line treatment. Ongoing surveillance is clearly needed to better understand the TDR phenomenon in the Caribbean.

[The newest developments in anti-HIV-1 drugs].

In the two decades since AZT was first approved for clinical use in 1987, 24 additional antiretroviral agents have been approved. They include 7 nucleoside analogs, a nucleotide analog and 4 non-nucleoside reverse transcriptase inhibitors, 10 protease inhibitors, 2 entry inhibitors and an integrase inhibitor. More than 20 investigational agents are currently being studied in clinical trials. Highly active antiretroviral therapy (HAART), which involves a combination of anti-HIV-1 drugs, is extremely effective in suppressing HIV-1 replication and increasing CD4+ number and results in substantial reductions in HIV-1-related morbidity and mortality. In last 20 years, much has been learned about resistance to antiretroviral drugs, drug interactions and metabolic complications of antiviral drug use. Drugs are now selected on the basis of resistance tests and on the risk of specific drug complications in individual patients. As a result, decisions about the therapy of HIV/AIDS have become personalized and are made on a patient-by-patient basis. With appropriate medical management, a person with HIV-1 now has the possibility of a nearly normal life expectancy.

QSAR models for 2-amino-6-arylsulfonylbenzonitriles and congeners HIV-1 reverse transcriptase inhibitors based on linear and nonlinear regression methods.

A quantitative structure-activity relationship study of a series of HIV-1 reverse transcriptase inhibitors (2-amino-6-arylsulfonylbenzonitriles and their thio and sulfinyl congeners) was performed. Topological and geometrical, as well as quantum mechanical energy-related and charge distribution-related descriptors generated from CODESSA, were selected to describe the molecules. Principal component analysis (PCA) was used to select the training set. Six techniques: multiple linear regression (MLR), multivariate adaptive regression splines (MARS), radial basis function neural networks (RBFNN), general regression neural networks (GRNN), projection pursuit regression (PPR) and support vector machine (SVM) were used to establish QSAR models for two data sets: anti-HIV-1 activity and HIV-1 reverse transcriptase binding affinity. Results showed that PPR and SVM models provided powerful capacity of prediction.

Revealing interaction mode between HIV-1 reverse transcriptase and diaryltriazine analog inhibitor.

HIV-1 reverse transcriptase is a key enzyme playing an important role in the HIV-1 life cycle for the replication of the RNA genome into DNA form. Lys103Asn (K103N) mutant frequently is observed in HIV-1 reverse transcriptase. Therefore, a series of novel non-nucleoside reverse transcriptase inhibitors were designed and synthesized. In vitro experimental results show that diaryltriazine analogs have potent anti-HIV activity with moderate to high selectivity. In order to design anti-HIV drug, docking and molecular dynamics simulation were used to investigate the binding mode between ligand and HIV-1 reverse transcriptase. The results suggest that the analogs might have a similar interaction mechanism with HIV-1 reverse transcriptase. Then comparative molecular field analysis and comparative molecular similarity indices analysis were used to construct quantitative structure-activity models. These models were evaluated by eight test set compounds. These models are helpful in making quantitative prediction of their activity for new lead compounds before resorting in vitro and in vivo experimentation.

Pre-incubation of cell-free HIV-1 group M isolates with non-nucleoside reverse transcriptase inhibitors blocks subsequent viral replication in co-cultures of dendritic cells and T cells.

In order to study the inhibitory effect of various reverse transcriptase inhibitors (RTIs) on cell-free HIV, we adapted a recently described in vitro system, based on co-cultures of dendritic cells and resting CD4 T cells, modelling early target cells during sexual transmission. The compounds tested included the second-generation non-nucleoside RTI (NNRTI) TMC-120 (R147681, dapivirine) and TMC-125 (R165335, travertine), as well as the reference nucleoside RTI AZT (zidovudine), the nucleotide RTI PMPA (tenofovir) and the NNRTI UC-781. The virus strains included the reference strain HIV-1Ba-L and six primary isolates, representative of the HIV-1 group M pandemic. They all display the non-syncytium-inducing and CCR5 receptor-using (NSI/R5) phenotype, important in transmission. Cell-free virus was immobilized on a poly-L-lysine (PLL)-treated microwell plate and incubated with compound for 1 h. Afterwards, the compound was thoroughly washed away; target cells were added and cultured for 2 weeks, followed by an extended culture with highly susceptible mitogen-activated T cells. Viral production in the cultures was measured on supernatant with HIV antigen ELISA. Negative results were confirmed by showing absence of proviral DNA in the cells. TMC-120 and TMC-125 inhibited replication of HIV-1Ba-L with average EC50 values of 38 nM and 117 nM, respectively, whereas the EC50 of UC-781 was 517 nM. Complete suppression of virus and provirus was observed at compound concentrations of 100, 300 and 1000 nM, respectively. Inhibition of all primary isolates followed the same pattern as HIV-1Ba-L. In contrast, pre-treating the virus with the nucleotide RTI PMPA and AZT failed to inhibit infection even at a concentration of 100000 nM. These data clearly suggest that NNRTIs inactivate RT enzymatic activity of different viral clades (predominant in the epidemic) and might be proposed for further testing as a sterilizing microbicide worldwide.

Newer aminopyrimidinimino isatin analogues as non-nucleoside HIV-1 reverse transcriptase inhibitors for HIV and other opportunistic infections of AIDS: design, synthesis and biological evaluation.

Human immuno deficiency virus (HIV) weakens the immune system so that many opportunistic infections (OIs) like tuberculosis, hepatitis, bacterial infections etc can develop. In this paper, we designed aminopyrimidinimino isatin lead compound as a novel non-nucleoside reverse transcriptase inhibitor (NNRTI) with broad-spectrum chemotherapeutic properties for the effective treatment of AIDS and AIDS-related OIs. Compound 1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-[[N4-[3'-(4'-amino-5'-trimethoxybenzyl pyrimidin-2'-yl)imino-1'-(5-methylisatinyl)]methyl]-N1-piperazinyl]-3-quinoline carboxylic acid (10) emerged as the most potent broad-spectrum chemotherapeutic agent active against HIV, HCV, Mycobacterium tuberculosis and various pathogenic bacteria.

2H-Pyrrolo[3,4-b] [1,5]benzothiazepine derivatives as potential inhibitors of HIV-1 reverse transcriptase.

A number of 2H-pyrrolo[3,4-b] [1,5]benzothiazepine derivatives (PBTAs) 7-25 and the related synthetic intermediates 3-pyrrolyl aryl sulfones (PASs) 26-32 were designed, synthesized and tested as potential anti-HIV-1 agents targeted at the reverse transcriptase (RT). The PBTAs were conceived as tricyclic analogs of nevirapine, pyrrolo[1,2-b] [1,2,5]benzothiadiazepine 5 (PBTD) and pyrrolo[2,1-d] [1,2,5]benzothiadiazepine 6, NNRTIs endowed with potent anti-HIV-1 activities. The majority of tested PBTAs were active against HIV-1-induced cytopathicity in MT-4 cells at concentrations ranging from 0.3 to 40 microM. In particular, compound 10 was the most potent derivative with EC50 = 0.3 microM, comparable to that of nevirapine used as reference drug. In the 3-pyrrolyl aryl sulfones (26-32) series only three sulfones were found active against HIV-1 replication cycle. The following preliminary SAR could be depicted for the title derivatives: i) the conformationally restrained PBTAs are more potent than the corresponding open counterparts (PASs); ii) the DMA group give the highest anti-HIV-1 potency in the PBTAs series; iii) PBTAs and the corresponding thiones are equipotent; iv) an unsubstituted amino group, as part of p-chloroanilino moiety, is a strong determinant for the antiviral activity in the PASs series. The most potent derivatives in cell-based assays were proven to target the RT in enzyme assays. Unfortunately, none of the test compounds inhibited the multiplication of clinically relevant drug-resistant viruses (mutants of HIV-1 carrying K103N and Y181C mutations) at concentrations lower than 30 microM. However, the good results obtained against replication of wt HIV-1, lead us to consider compound 10 as a lead compound for further investigation in this field. In particular, our efforts will be directed to modifications of 10 devoted to obtain new derivatives active against HIV-1 mutant strains.

Effects of tRNA 3 Lys aminoacylation on the initiation of HIV-1 reverse transcription.

HIV-1 utilizes cellular tRNA(3)(Lys) to prime the initiation of reverse transcription. The selective incorporation of cytoplasmic tRNA(3)(Lys) into HIV-1 particles was recently shown to involve the lysyl-tRNA synthetase, and hence, the encapsidated tRNA(3)(Lys) is likely to be aminoacylated. Here, we tested the effect of aminoacylation on the initiation of reverse transcription. We show that HIV-1 reverse transcriptase is unable to extend lysyl-tRNA(3)(Lys). In addition, the viral polymerase does not significantly enhance the rate of tRNA deacylation, in contrast with previous studies on avian retroviruses. Thus, aminoacylation of the primer tRNA might prevent the initiation of HIV-1 reverse transcription from taking place before viral budding and maturation.

Comparative study of non nucleoside inhibitors with HIV-1 reverse transcriptase based on 3D-QSAR and docking.

The intermolecular interaction between two types of non nucleoside reverse transcriptase inhibitors (NNRTIs), HEPT and TIBO, and HIV reverse transcriptase receptor (HIVRT) was investigated. The result of docking study showed that two types of NNRTIs presented similar interaction mechanism with HIVRT. The most active compound of every type of inhibitors could form one hydrogen bond with the residue Lys101 and has hydrophobic interaction with residues Tyr181, Tyr188 and Tyr318, etc. Three 3D-QSAR models including two partial correlation models (one for each family of HEPT and TIBO) and a mixed model gathering two families were constructed. Comparative study of these models indicated that the mixed model offered the strongest prediction ability. For this model, the cross-validated q2 values were 0.720 and 0.675, non-cross-validated r2 values were 0.940 and 0.920 for CoMFA and CoMSIA, respectively. It has been validated by using a test set of 27 inhibitors. Compared with previously reported works, our model showed better prediction ability. It could help us to insight the interaction between NNRTIs and HIVRT, and to design new anti-HIV NNRTIs inhibitors.