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Sample records for hiv-1 drug resistant

  1. Persistence of HIV-1 transmitted drug resistance mutations.

    PubMed

    Castro, Hannah; Pillay, Deenan; Cane, Patricia; Asboe, David; Cambiano, Valentina; Phillips, Andrew; Dunn, David T

    2013-11-01

    There are few data on the persistence of individual human immunodeficiency virus type 1 (HIV-1) transmitted drug resistance (TDR) mutations in the absence of selective drug pressure. We studied 313 patients in whom TDR mutations were detected at their first resistance test and who had a subsequent test performed while ART-naive. The rate at which mutations became undetectable was estimated using exponential regression accounting for interval censoring. Most thymidine analogue mutations (TAMs) and T215 revertants (but not T215F/Y) were found to be highly stable, with NNRTI and PI mutations being relatively less persistent. Our estimates are important for informing HIV transmission models.

  2. HIV-1 drug resistance in HIV-1-infected children in the United Kingdom from 1998 to 2004.

    PubMed

    Chakraborty, Rana; Smith, Colette J; Dunn, David; Green, Hannah; Duong, Trinh; Doerholt, Katja; Riordon, Andrew; Lyall, Hermione; Tookey, Pat; Butler, Karina; Sabin, Caroline A; Gibb, Di; Pillay, Deenan

    2008-05-01

    We reviewed HIV-1 genotypes from 200 of 979 (20%) HIV-infected children in the U.K. Collaborative HIV in Pediatric Study (CHIPS) cohort (343 resistance tests). Three of 44 samples had major primary resistance mutations before antiretroviral therapy. Three-class resistance was noted in 42 samples (14.1%). Our study also highlighted underutilization of testing and the need for prompt genotyping after drug discontinuation which may have lead to an underestimation of HIV-1 resistance.

  3. Sparse Representation for Prediction of HIV-1 Protease Drug Resistance.

    PubMed

    Yu, Xiaxia; Weber, Irene T; Harrison, Robert W

    2013-01-01

    HIV rapidly evolves drug resistance in response to antiviral drugs used in AIDS therapy. Estimating the specific resistance of a given strain of HIV to individual drugs from sequence data has important benefits for both the therapy of individual patients and the development of novel drugs. We have developed an accurate classification method based on the sparse representation theory, and demonstrate that this method is highly effective with HIV-1 protease. The protease structure is represented using our newly proposed encoding method based on Delaunay triangulation, and combined with the mutated amino acid sequences of known drug-resistant strains to train a machine-learning algorithm both for classification and regression of drug-resistant mutations. An overall cross-validated classification accuracy of 97% is obtained when trained on a publically available data base of approximately 1.5×10(4) known sequences (Stanford HIV database http://hivdb.stanford.edu/cgi-bin/GenoPhenoDS.cgi). Resistance to four FDA approved drugs is computed and comparisons with other algorithms demonstrate that our method shows significant improvements in classification accuracy.

  4. Modeling HIV-1 Drug Resistance as Episodic Directional Selection

    PubMed Central

    Murrell, Ben; de Oliveira, Tulio; Seebregts, Chris; Kosakovsky Pond, Sergei L.; Scheffler, Konrad

    2012-01-01

    The evolution of substitutions conferring drug resistance to HIV-1 is both episodic, occurring when patients are on antiretroviral therapy, and strongly directional, with site-specific resistant residues increasing in frequency over time. While methods exist to detect episodic diversifying selection and continuous directional selection, no evolutionary model combining these two properties has been proposed. We present two models of episodic directional selection (MEDS and EDEPS) which allow the a priori specification of lineages expected to have undergone directional selection. The models infer the sites and target residues that were likely subject to directional selection, using either codon or protein sequences. Compared to its null model of episodic diversifying selection, MEDS provides a superior fit to most sites known to be involved in drug resistance, and neither one test for episodic diversifying selection nor another for constant directional selection are able to detect as many true positives as MEDS and EDEPS while maintaining acceptable levels of false positives. This suggests that episodic directional selection is a better description of the process driving the evolution of drug resistance. PMID:22589711

  5. Combining classifiers for HIV-1 drug resistance prediction.

    PubMed

    Srisawat, Anantaporn; Kijsirikul, Boonserm

    2008-01-01

    This paper applies and studies the behavior of three learning algorithms, i.e. the Support Vector machine (SVM), the Radial Basis Function Network (the RBF network), and k-Nearest Neighbor (k-NN) for predicting HIV-1 drug resistance from genotype data. In addition, a new algorithm for classifier combination is proposed. The results of comparing the predictive performance of three learning algorithms show that, SVM yields the highest average accuracy, the RBF network gives the highest sensitivity, and k-NN yields the best in specificity. Finally, the comparison of the predictive performance of the composite classifier with three learning algorithms demonstrates that the proposed composite classifier provides the highest average accuracy.

  6. Insights into the mechanism of drug resistance. X-ray structure analysis of multi-drug resistant HIV-1 protease ritonavir complex

    SciTech Connect

    Liu, Zhigang; Yedidi, Ravikiran S.; Wang, Yong; Dewdney, Tamaria G.; Reiter, Samuel J.; Brunzelle, Joseph S.; Kovari, Iulia A.; Kovari, Ladislau C.

    2013-01-08

    Ritonavir (RTV) is a first generation HIV-1 protease inhibitor with rapidly emerging drug resistance. Mutations at residues 46, 54, 82 and 84 render the HIV-1 protease drug resistant against RTV. We report the crystal structure of multi-drug resistant (MDR) 769 HIV-1 protease (carrying resistant mutations at residues 10, 36, 46, 54, 62, 63, 71, 82, 84 and 90) complexed with RTV and the in vitro enzymatic IC50 of RTV against MDR HIV-1 protease. The structural and functional studies demonstrate significant drug resistance of MDR HIV-1 protease against RTV, arising from reduced hydrogen bonds and Van der Waals interactions between RTV and MDR HIV-1 protease.

  7. 2015 Update of the Drug Resistance Mutations in HIV-1.

    PubMed

    Wensing, Annemarie M; Calvez, Vincent; Günthard, Huldrych F; Johnson, Victoria A; Paredes, Roger; Pillay, Deenan; Shafer, Robert W; Richman, Douglas D

    2015-01-01

    The 2015 edition of the IAS-USA drug resistance mutations list updates the figures last published in July 2014. The mutations listed are those that have been identified by specific criteria for evidence and drugs described. The figures are designed to assist practitioners in identifying key mutations associated with resistance to antiretroviral drugs and, therefore, in making clinical decisions regarding antiretroviral therapy.

  8. 2017 Update of the Drug Resistance Mutations in HIV-1.

    PubMed

    Wensing, Annemarie M; Calvez, Vincent; Günthard, Huldrych F; Johnson, Victoria A; Paredes, Roger; Pillay, Deenan; Shafer, Robert W; Richman, Douglas D

    The 2017 edition of the IAS-USA drug resistance mutations list updates the figures last published in November 2015. The mutations listed are those that have been identified by specific criteria for evidence and drugs described. The figures are designed to assist practitioners in identifying key mutations associated with resistance to antiretroviral drugs and, therefore, in making clinical decisions regarding antiretroviral therapy.

  9. Computational mutation scanning and drug resistance mechanisms of HIV-1 protease inhibitors.

    PubMed

    Hao, Ge-Fei; Yang, Guang-Fu; Zhan, Chang-Guo

    2010-07-29

    The drug resistance of various clinically available HIV-1 protease inhibitors has been studied using a new computational protocol, that is, computational mutation scanning (CMS), leading to valuable insights into the resistance mechanisms and structure-resistance correction of the HIV-1 protease inhibitors associated with a variety of active site and nonactive site mutations. By using the CMS method, the calculated mutation-caused shifts of the binding free energies linearly correlate very well with those derived from the corresponding experimental data, suggesting that the CMS protocol may be used as a generalized approach to predict drug resistance associated with amino acid mutations. Because it is essentially important for understanding the structure-resistance correlation and for structure-based drug design to develop an effective computational protocol for drug resistance prediction, the reasonable and computationally efficient CMS protocol for drug resistance prediction should be valuable for future structure-based design and discovery of antiresistance drugs in various therapeutic areas.

  10. Estimation of the HIV-1 backward mutation rate from transmitted drug-resistant strains.

    PubMed

    Kitayimbwa, J M; Mugisha, J Y T; Saenz, R A

    2016-12-01

    One of the serious threats facing the administration of antiretroviral therapy to human immunodeficiency virus (HIV-1) infected patients is the reported increasing prevalence of transmitted drug resistance. However, given that HIV-1 drug-resistant strains are often less fit than the wild-type strains, it is expected that drug-resistant strains that are present during the primary phase of the HIV-1 infection are replaced by the fitter wild-type strains. This replacement of HIV-1 resistant mutations involves the emergence of wild-type strains by a process of backward mutation. How quickly the replacement happens is dependent on the class of HIV-1 mutation group. We estimate the backward mutation rates and relative fitness of various mutational groups known to confer HIV-1 drug resistance. We do this by fitting a stochastic model to data for individuals who were originally infected by an HIV-1 strain carrying any one of the known drug resistance-conferring mutations and observed over a period of time to see whether the resistant strain is replaced. To do this, we seek a distribution, generated from simulations of the stochastic model, that best describes the observed (clinical data) replacement times of a given mutation. We found that Lamivudine/Emtricitabine-associated mutations have a distinctly higher, backward mutation rate and low relative fitness compared to the other classes (as has been reported before) while protease inhibitors-associated mutations have a slower backward mutation rate and high relative fitness. For the other mutation classes, we found more uncertainty in their estimates.

  11. Assessing transmissibility of HIV-1 drug resistance mutations from treated and from drug-naive individuals

    PubMed Central

    Winand, Raf; Theys, Kristof; Eusébio, Mónica; Aerts, Jan; Camacho, Ricardo J.; Gomes, Perpetua; Suchard, Marc A.; Vandamme, Anne-Mieke; Abecasis, Ana B.

    2015-01-01

    Objectives: Surveillance drug resistance mutations (SDRMs) in drug-naive patients are typically used to survey HIV-1-transmitted drug resistance (TDR). We test here how SDRMs in patients failing treatment, the original source of TDR, contribute to assessing TDR, transmissibility and transmission source of SDRMs. Design: This is a retrospective observational study analyzing a Portuguese cohort of HIV-1-infected patients. Methods: The prevalence of SDRMs to protease inhibitors, nucleoside reverse transcriptase inhibitors (NRTIs) and nonnucleoside reverse transcriptase inhibitors (NNRTIs) in drug-naive and treatment-failing patients was measured for 3554 HIV-1 subtype B patients. Transmission ratio (prevalence in drug-naive/prevalence in treatment-failing patients), average viral load and robust linear regression with outlier detection (prevalence in drug-naive versus in treatment-failing patients) were analyzed and used to interpret transmissibility. Results: Prevalence of SDRMs in drug-naive and treatment-failing patients were linearly correlated, but some SDRMs were classified as outliers – above (PRO: D30N, N88D/S, L90 M, RT: G190A/S/E) or below (RT: M184I/V) expectations. The normalized regression slope was 0.073 for protease inhibitors, 0.084 for NRTIs and 0.116 for NNRTIs. Differences between SDRMs transmission ratios were not associated with differences in viral loads. Conclusion: The significant linear correlation between prevalence of SDRMs in drug-naive and in treatment-failing patients indicates that the prevalence in treatment-failing patients can be useful to predict levels of TDR. The slope is a cohort-dependent estimate of rate of TDR per drug class and outlier detection reveals comparative persistence of SDRMs. Outlier SDRMs with higher transmissibility are more persistent and more likely to have been acquired from drug-naive patients. Those with lower transmissibility have faster reversion dynamics after transmission and are associated with

  12. HIV-1 genetic diversity and antiretroviral drug resistance among individuals from Roraima state, northern Brazil

    PubMed Central

    Leão, Renato Augusto Carvalho; Granja, Fabiana; Naveca, Felipe Gomes

    2017-01-01

    The HIV-1 epidemic in Brazil has spread towards the Northern country region, but little is known about HIV-1 subtypes and prevalence of HIV strains with resistance mutations to antiretrovirals in some of the Northern states. HIV-1 protease (PR) and reverse transcriptase (RT) sequences were obtained from 73 treatment-naive and -experienced subjects followed between 2013 and 2014 at a public health reference unit from Roraima, the northernmost Brazilian state. The most prevalent HIV-1 clade observed in the study population was the subtype B (91%), followed by subtype C (9%). Among 12 HIV-1 strains from treatment-naïve patients, only one had a transmitted drug resistance mutation for NNRTI. Among 59 treatment-experienced patients, 12 (20%) harbored HIV-1 strains with acquired drug resistance mutations (ADRM) that reduce the susceptibility to two classes of antiretroviral drugs (NRTI and NNRTI or NRTI and PI), and five (8%) harbored HIV-1 strains with ADRM that reduced susceptibility to only one class of antiretroviral drugs (NNRTI or PI). No patients harboring HIV strains with reduced susceptibility to all three classes of antiretroviral drugs were detected. A substantial fraction of treatment-experienced patients with (63%) and without (70%) ADRM had undetectable plasma viral loads (<40 copies/ml) at the time of sampling. Among treatment-experienced with plasma viral loads above 2,000 copies/ml, 44% displayed no ADRM. This data showed that the HIV-1 epidemic in Roraima displayed a much lower level of genetic diversity and a lower prevalence of ADRM than that described in other Brazilian states. PMID:28301548

  13. An international multicenter study on HIV-1 drug resistance testing by 454 ultra-deep pyrosequencing.

    PubMed

    Simen, Birgitte B; Braverman, Michael S; Abbate, Isabella; Aerssens, Jeroen; Bidet, Yannick; Bouchez, Olivier; Gabriel, Christian; Izopet, Jacques; Kessler, Harald H; Stelzl, Evelyn; Di Giallonardo, Francesca; Schlapbach, Ralph; Radonic, Aleksander; Paredes, Roger; Recordon-Pinson, Patricia; Sakwa, James; St John, Elizabeth P; Schmitz-Agheguian, Gudrun G; Metzner, Karin J; Däumer, Martin P

    2014-08-01

    The detection of mutant spectra within the viral quasispecies is critical for therapeutic management of HIV-1 infections. Routine clinical application of ultrasensitive genotyping requires reproducibility and concordance within and between laboratories. The goal of the study was to evaluate a new protocol on HIV-1 drug resistance testing by 454 ultra-deep pyrosequencing (454-UDS) in an international multicenter study. Sixteen blinded HIV-1 subtype B samples were provided for 454-UDS as both RNA and cDNA with viral titers of 88,600-573,000 HIV-1 RNA copies/ml. Eight overlapping amplicons spanning protease (PR) codons 10-99 and reverse transcriptase (RT) codons 1-251 were generated using molecular barcoded primers. 454-UDS was performed using the 454 Life Sciences/Roche GS FLX platform. PR and RT sequences were analyzed using 454 Life Sciences Amplicon Variant Analyzer (AVA) software. Quantified variation data were analyzed for intra-laboratory reproducibility and inter-laboratory concordance. Routine population sequencing was performed using the ViroSeq HIV-1 genotyping system. Eleven laboratories and the reference laboratory 454 Life Sciences sequenced the HIV-1 sample set. Data presented are derived from seven laboratories and the reference laboratory since severe study protocol execution errors occurred in four laboratories leading to exclusion. The median sequencing depth across all sites was 1364 reads per position (IQR=809-2065). 100% of the ViroSeq-reported mutations were also detected by 454-UDS. Minority HIV-1 drug resistance mutations, defined as HIV-1 drug resistance mutations identified at frequencies of 1-25%, were only detected by 454-UDS. Analysis of 10 preselected majority and minority mutations were consistently found across sites. The analysis of drug-resistance mutations detected between 1 and 10% demonstrated high intra- and inter-laboratory consistency in frequency estimates for both RNA and prepared cDNA samples, indicating robustness of the

  14. HIV-1 Genetic Diversity and Drug Resistance Mutations Among Treatment-Naive Adult Patients in Suriname.

    PubMed

    Abdoel Wahid, Firoz; Sno, Rachel; Darcissac, Edith; Lavergne, Anne; Adhin, Malti R; Lacoste, Vincent

    2016-12-01

    The molecular epidemiologic profile of HIV-1 in Suriname was determined through protease (PR) and reverse transcriptase (RT) sequences obtained from HIV-1 strains collected from 100 drug-naive HIV-1-infected persons. Subtype determination revealed that most viruses were of subtype B (94.9%) in both PR and RT genomic regions, followed by B/D recombinants (5.1%). Analysis of drug resistance mutations showed only one transmitted dug resistance mutation (TDRM) (V75M) in a single strain. The genetic data obtained can serve as a baseline for Suriname to monitor emerging mutations. This study reveals that the HIV-1 epidemic in Suriname is still characterized by a low TDRM rate (1%) and a low level of subtype diversity. However, both genes display a high genetic polymorphism. This high polymorphism may ultimately lead to drug resistance. Continuous monitoring of the baseline resistance is therefore a prerequisite to safeguard effective long-term treatment for people living with HIV-1 in Suriname.

  15. HIV-1 Drug Resistance Mutations: Potential Applications for Point-of-Care Genotypic Resistance Testing

    PubMed Central

    Rhee, Soo-Yon; Jordan, Michael R.; Raizes, Elliot; Chua, Arlene; Parkin, Neil; Kantor, Rami; Van Zyl, Gert U.; Mukui, Irene; Hosseinipour, Mina C.; Frenkel, Lisa M.; Ndembi, Nicaise; Hamers, Raph L.; Rinke de Wit, Tobias F.; Wallis, Carole L.; Gupta, Ravindra K.; Fokam, Joseph; Zeh, Clement; Schapiro, Jonathan M.; Carmona, Sergio; Katzenstein, David; Tang, Michele; Aghokeng, Avelin F.; De Oliveira, Tulio; Wensing, Annemarie M. J.; Gallant, Joel E.; Wainberg, Mark A.; Richman, Douglas D.; Fitzgibbon, Joseph E.; Schito, Marco; Bertagnolio, Silvia; Yang, Chunfu; Shafer, Robert W.

    2015-01-01

    The increasing prevalence of acquired and transmitted HIV-1 drug resistance is an obstacle to successful antiretroviral therapy (ART) in the low- and middle-income countries (LMICs) hardest hit by the HIV-1 pandemic. Genotypic drug resistance testing could facilitate the choice of initial ART in areas with rising transmitted drug resistance (TDR) and enable care-providers to determine which individuals with virological failure (VF) on a first- or second-line ART regimen require a change in treatment. An inexpensive near point-of-care (POC) genotypic resistance test would be useful in settings where the resources, capacity, and infrastructure to perform standard genotypic drug resistance testing are limited. Such a test would be particularly useful in conjunction with the POC HIV-1 viral load tests that are currently being introduced in LMICs. A POC genotypic resistance test is likely to involve the use of allele-specific point mutation assays for detecting drug-resistance mutations (DRMs). This study proposes that two major nucleoside reverse transcriptase inhibitor (NRTI)-associated DRMs (M184V and K65R) and four major NNRTI-associated DRMs (K103N, Y181C, G190A, and V106M) would be the most useful for POC genotypic resistance testing in LMIC settings. One or more of these six DRMs was present in 61.2% of analyzed virus sequences from ART-naïve individuals with intermediate or high-level TDR and 98.8% of analyzed virus sequences from individuals on a first-line NRTI/NNRTI-containing regimen with intermediate or high-level acquired drug resistance. The detection of one or more of these DRMs in an ART-naïve individual or in a individual with VF on a first-line NRTI/NNRTI-containing regimen may be considered an indication for a protease inhibitor (PI)-containing regimen or closer virological monitoring based on cost-effectiveness or country policy. PMID:26717411

  16. Perinatal acquisition of drug-resistant HIV-1 infection: mechanisms and long-term outcome

    PubMed Central

    Delaugerre, Constance; Chaix, Marie-Laure; Blanche, Stephane; Warszawski, Josiane; Cornet, Dorine; Dollfus, Catherine; Schneider, Veronique; Burgard, Marianne; Faye, Albert; Mandelbrot, Laurent; Tubiana, Roland; Rouzioux, Christine

    2009-01-01

    Background Primary-HIV-1-infection in newborns that occurs under antiretroviral prophylaxis that is a high risk of drug-resistance acquisition. We examine the frequency and the mechanisms of resistance acquisition at the time of infection in newborns. Patients and Methods We studied HIV-1-infected infants born between 01 January 1997 and 31 December 2004 and enrolled in the ANRS-EPF cohort. HIV-1-RNA and HIV-1-DNA samples obtained perinatally from the newborn and mother were subjected to population-based and clonal analyses of drug resistance. If positive, serial samples were obtained from the child for resistance testing. Results Ninety-two HIV-1-infected infants were born during the study period. Samples were obtained from 32 mother-child pairs and from another 28 newborns. Drug resistance was detected in 12 newborns (20%): drug resistance to nucleoside reverse transcriptase inhibitors was seen in 10 cases, non-nucleoside reverse transcriptase inhibitors in two cases, and protease inhibitors in one case. For 9 children, the detection of the same resistance mutations in mothers' samples (6 among 10 available) and in newborn lymphocytes (6/8) suggests that the newborn was initially infected by a drug-resistant strain. Resistance variants were either transmitted from mother-to-child or selected during subsequent temporal exposure under suboptimal perinatal prophylaxis. Follow-up studies of the infants showed that the resistance pattern remained stable over time, regardless of antiretroviral therapy, suggesting the early cellular archiving of resistant viruses. The absence of resistance in the mother of the other three children (3/10) and neonatal lymphocytes (2/8) suggests that the newborns were infected by a wild-type strain without long-term persistence of resistance when suboptimal prophylaxis was stopped. Conclusion This study confirms the importance of early resistance genotyping of HIV-1-infected newborns. In most cases (75%), drug resistance was archived in

  17. [Comparison of three genotyping methods for the detection of HIV-1 resistance to antiretroviral drugs].

    PubMed

    Suárez, A; Picazo, J; Alonso, R; Bouza, E; Delgado, R; Rodríguez-Noriega, A; Bernal, A; García, A

    2002-03-01

    Highly active antiretroviral therapy has dramatically improved the life expectancy of human immunodeficiency virus (HIV)-infected patients, but mutations in the HIV-1 reverse transcriptase (RT) and protease (P) genes confer drug failure. Evaluation of drug resistance genotyping in HIV-1 has proven to be useful for the selection of drug combinations with maximum antiretroviral activity. The aim of this study was to evaluate the optimal procedure to determine the resistance profile in the laboratory. Plasma from 90 antiretroviral-treated patients was analyzed by reverse hybridization, which identifies the presence of wild-types or mutations at the 19 key codons for protease and RT regions, and was compared with two other methods of direct cDNA sequencing. A total of 408 mutations were detected by InnoLiPA HIV-1, (Line Probe Assay, Innogenetics, Belgium), 572 by TrueGene HIV-1 Genotyping System (Visible Genetics, Canada), and 721 by ViroSeq HIV-1 Genotyping System (Perkin Elmer/Applied Biosystems, California). Hybridization detected a significantly higher number of primary mutations which are associated with a high level of drug resistance (p <0.001). Hybridization also detected a higher number of mixtures of wild-type and mutant viruses. There was a good concordance among the three methods, although it was higher between the two sequencing methods. Sequencing determines a higher number of mutations, but hybridization better identifies primary mutations correlated with a high level of drug resistance. Hybridization is more suitable for detecting mixed populations and is easier to implement in clinical laboratories but does not eliminate the need for sequence analysis for detection of drug-resistant HIV.

  18. Declining prevalence of HIV-1 drug resistance in antiretroviral treatment-exposed individuals in Western Europe.

    PubMed

    De Luca, Andrea; Dunn, David; Zazzi, Maurizio; Camacho, Ricardo; Torti, Carlo; Fanti, Iuri; Kaiser, Rolf; Sönnerborg, Anders; Codoñer, Francisco M; Van Laethem, Kristel; Vandamme, Anne-Mieke; Bansi, Loveleen; Ghisetti, Valeria; van de Vijver, David A M C; Asboe, David; Prosperi, Mattia C F; Di Giambenedetto, Simona

    2013-04-15

    HIV-1 drug resistance represents a major obstacle to infection and disease control. This retrospective study analyzes trends and determinants of resistance in antiretroviral treatment (ART)-exposed individuals across 7 countries in Europe. Of 20 323 cases, 80% carried at least one resistance mutation: these declined from 81% in 1997 to 71% in 2008. Predicted extensive 3-class resistance was rare (3.2% considering the cumulative genotype) and peaked at 4.5% in 2005, decreasing thereafter. The proportion of cases exhausting available drug options dropped from 32% in 2000 to 1% in 2008. Reduced risk of resistance over calendar years was confirmed by multivariable analysis.

  19. Change in the Prevalence of HIV-1 and the Rate of Transmitted Drug-Resistant HIV-1 in Haiphong, Northern Vietnam.

    PubMed

    Pham, Hung Viet; Ishizaki, Azumi; Nguyen, Cuong Hung; Saina, Matilda Chelimo; Hoang, Huyen Thi Thanh; Tran, Vuong Thi; Bi, Xiuqiong; Pham, Thuc Van; Ichimura, Hiroshi

    2015-07-01

    We previously reported a significant decrease in HIV-1 prevalence, with no increase in drug-resistant HIV-1 among injecting drug users (IDU), female sex workers (FSW), and blood donors (BD), in Haiphong, Vietnam, from 2007 to 2009. In 2012, 388 IDU, 51 FSW, and 200 BD were recruited for further analysis. None had a history of antiretroviral treatment. From 2007 to 2012, HIV-1 prevalence was reduced from 35.9% to 18.6% (p<0.001), 23.1% to 9.8% (p<0.05), and 2.9% to 1% (p=0.29) in IDU, FSW, and BD, respectively. Of 79 anti-HIV-1 antibody-positive samples, 61 were successfully analyzed for the pol-reverse transcriptase (RT) region. All HIV-1 strains were CRF01_AE. Nonnucleoside RT inhibitor-resistant mutations, Y181C/I, were detected in three subjects; one had the nucleoside RT inhibitor-resistant mutations L74V and M184V and one had E138K. The prevalence of transmitted drug-resistant HIV-1 in Haiphong increased slightly from 1.8% in 2007 to 6.6% in 2012 (p=0.06).

  20. HIV-1 Variants and Drug Resistance in Pregnant Women from Bata (Equatorial Guinea): 2012-2013

    PubMed Central

    Alvarez, Patricia; Fernández McPhee, Carolina; Prieto, Luis; Martín, Leticia; Obiang, Jacinta; Avedillo, Pedro; Vargas, Antonio; Rojo, Pablo; Benito, Agustín; Ramos, José Tomás; Holguín, África

    2016-01-01

    Objectives This is the first study describing drug resistance mutations (DRM) and HIV-1 variants among infected pregnant women in Equatorial Guinea (GQ), a country with high (6.2%) and increasing HIV prevalence. Methods Dried blood spots (DBS) were collected from November 2012 to December 2013 from 69 HIV-1 infected women participating in a prevention of mother-to-child transmission program in the Hospital Regional of Bata and Primary Health Care Centre María Rafols, Bata, GQ. The transmitted (TDR) or acquired (ADR) antiretroviral drug resistance mutations at partial pol sequence among naive or antiretroviral therapy (ART)-exposed women were defined following WHO or IAS USA 2015 lists, respectively. HIV-1 variants were identified by phylogenetic analyses. Results A total of 38 of 69 HIV-1 specimens were successfully amplified and sequenced. Thirty (79%) belonged to ART-experienced women: 15 exposed to nucleoside reverse transcriptase inhibitors (NRTI) monotherapy, and 15 to combined ART (cART) as first regimen including two NRTI and one non-NRTI (NNRTI) or one protease inhibitor (PI). The TDR rate was only found for PI (3.4%). The ADR rate was 37.5% for NNRTI, 8.7% for NRTI and absent for PI or NRTI+NNRTI. HIV-1 group M non-B variants caused most (97.4%) infections, mainly (78.9%) recombinants: CRF02_AG (55.2%), CRF22_A101 (10.5%), subtype C (10.5%), unique recombinants (5.3%), and A3, D, F2, G, CRF06_cpx and CRF11_cpx (2.6% each). Conclusions The high rate of ADR to retrotranscriptase inhibitors (mainly to NNRTIs) observed among pretreated pregnant women reinforces the importance of systematic DRM monitoring in GQ to reduce HIV-1 resistance transmission and to optimize first and second-line ART regimens when DRM are present. PMID:27798676

  1. HIV-1 subtypes and drug resistance profiles in a cohort of heterosexual patients in Istanbul, Turkey.

    PubMed

    Köksal, Muammer Osman; Beka, Hayati; Lübke, Nadine; Verheyen, Jens; Eraksoy, Haluk; Cagatay, Atahan; Kaiser, Rolf; Akgül, Baki; Agacfidan, Ali

    2015-08-01

    Turkey is seeing a steady rise in rates of HIV infection in the country. The number of individuals with HIV/AIDS was greater than 7000 in 2014 according to data released by the Ministry of Health, and heterosexual contacts were reported to be the main transmission routes. Istanbul has the highest number of reported cases of HIV infection. The aim of the study was to determine the prevalence of HIV-1 drug resistance in 50 heterosexual patients from Istanbul. The most prevalent subtype was found to be subtype B (56.2 %). Resistance-associated mutations were found in 14 patients with 6/14 patients being therapy-experienced and 8/14 therapy naive at the time point of analysis. With increasing number of patients who require treatment and the rapid up-scaling of the antiretroviral therapy in Turkey, HIV-1 drug resistance testing is recommended before starting treatment in order to achieve better clinical outcomes.

  2. Multiple drug resistant mechanisms against darunavir, amprenavir, and nelfinavir of HIV-1 PR

    NASA Astrophysics Data System (ADS)

    Liu, Xiaoqing; Dai, Qi; Xiu, Zhilong

    2013-02-01

    Acquired immune deficiency syndrome (AIDS) is a disease of the human immune system caused by the human immunodeficiency virus (HIV), which is infecting more humans and is expanding faster in the world. The illness interferes with the immune system, making people with AIDS much more likely to get infections, including opportunistic infections and tumors that do not affect people with working immune systems. HIV-1 PR is one of the major targets of anti-AIDS drug discovery. It is, therefore, necessary to develop some inhibitors against HIV-1 PR. In this work, we executed molecular dynamics (MDs) simulation of HIV-1 PR with drugs darunavir (DRV), amprenavir (APV), nelfinavir (NFV), and examined the resistant mechanism of L10I, G48V, I54V, and L90M mutations of this PR, aiming at designing promising drugs. The comparative analysis suggests that the existences of dodecahydroisoquinoline ring at P1' subsite, 4-aminophenylsulfonamide at P2' subsite, and bis-tetrahydrofuranylurethane at P2 subsite are helpful for maintaining the high affinity of the inhibitor for the protease and exhibiting high potency against multiple drug resistance (MDR) mutant protease.

  3. Simple PCR Assays Improve the Sensitivity of HIV-1 Subtype B Drug Resistance Testing and Allow Linking of Resistance Mutations

    PubMed Central

    Johnson, Jeffrey A.; Li, Jin-Fen; Wei, Xierong; Lipscomb, Jonathan; Bennett, Diane; Brant, Ashley; Cong, Mian-er; Spira, Thomas; Shafer, Robert W.; Heneine, Walid

    2007-01-01

    Background The success of antiretroviral therapy is known to be compromised by drug-resistant HIV-1 at frequencies detectable by conventional bulk sequencing. Currently, there is a need to assess the clinical consequences of low-frequency drug resistant variants occurring below the detection limit of conventional genotyping. Sensitive detection of drug-resistant subpopulations, however, requires simple and practical methods for routine testing. Methodology We developed highly-sensitive and simple real-time PCR assays for nine key drug resistance mutations and show that these tests overcome substantial sequence heterogeneity in HIV-1 clinical specimens. We specifically used early wildtype virus samples from the pre-antiretroviral drug era to measure background reactivity and were able to define highly-specific screening cut-offs that are up to 67-fold more sensitive than conventional genotyping. We also demonstrate that sequencing the mutation-specific PCR products provided a direct and novel strategy to further detect and link associated resistance mutations, allowing easy identification of multi-drug-resistant variants. Resistance mutation associations revealed in mutation-specific amplicon sequences were verified by clonal sequencing. Significance Combined, sensitive real-time PCR testing and mutation-specific amplicon sequencing provides a powerful and simple approach that allows for improved detection and evaluation of HIV-1 drug resistance mutations. PMID:17653265

  4. Dolutegravir Interactions with HIV-1 Integrase-DNA: Structural Rationale for Drug Resistance and Dissociation Kinetics

    PubMed Central

    DeAnda, Felix; Hightower, Kendra E.; Nolte, Robert T.; Hattori, Kazunari; Yoshinaga, Tomokazu; Kawasuji, Takashi; Underwood, Mark R.

    2013-01-01

    Signature HIV-1 integrase mutations associated with clinical raltegravir resistance involve 1 of 3 primary genetic pathways, Y143C/R, Q148H/K/R and N155H, the latter 2 of which confer cross-resistance to elvitegravir. In accord with clinical findings, in vitro drug resistance profiling studies with wild-type and site-directed integrase mutant viruses have shown significant fold increases in raltegravir and elvitegravir resistance for the specified viral mutants relative to wild-type HIV-1. Dolutegravir, in contrast, has demonstrated clinical efficacy in subjects failing raltegravir therapy due to integrase mutations at Y143, Q148 or N155, which is consistent with its distinct in vitro resistance profile as dolutegravir’s antiviral activity against these viral mutants is equivalent to its activity against wild-type HIV-1. Kinetic studies of inhibitor dissociation from wild-type and mutant integrase-viral DNA complexes have shown that dolutegravir also has a distinct off-rate profile with dissociative half-lives substantially longer than those of raltegravir and elvitegravir, suggesting that dolutegravir’s prolonged binding may be an important contributing factor to its distinct resistance profile. To provide a structural rationale for these observations, we constructed several molecular models of wild-type and clinically relevant mutant HIV-1 integrase enzymes in complex with viral DNA and dolutegravir, raltegravir or elvitegravir. Here, we discuss our structural models and the posited effects that the integrase mutations and the structural and electronic properties of the integrase inhibitors may have on the catalytic pocket and inhibitor binding and, consequently, on antiviral potency in vitro and in the clinic. PMID:24146996

  5. Trends and predictors of HIV-1 acquired drug resistance in Minas Gerais, Brazil: 2002-2012.

    PubMed

    Duani, Helena; Aleixo, Agdemir Waleria; Tupinambás, Unaí

    Several studies show that the prevalence of multidrug-resistant HIV-1 virus is declining over time. A retrospective cohort study was carried out to evaluate the trends of drug resistance in antiretroviral treatment-exposed individuals in a state of a middle-income country, Minas Gerais, southeast region of Brazil. We analyzed 2115 HIV-1 sequences from 2002 up to 2012, from 52 cities of Minas Gerais. The groups were analyzed according to the definitions: "IAS - 3 class mutations", if ≥1 drug resistance mutation from IAS 2015 list (DRM) was present in each class; "No fully susceptible drugs" as the absence of any fully susceptible drug in Stanford algorithm; and "GSS≥2″, when a maximum calculated GSS (genotypic susceptibility score) was ≥2 or ≥3, counting only drugs available in Brazil and USA at given calendar years. Time trends of resistance were analyzed by Cochran-Armitage test. We observed a decrease in the rate resistance mutations for PI, NRTI, "IAS - 3 class mutations", and "No fully susceptible drugs" over these 11 years, from 69.2% to 20.7%, 92.3% to 90.2%, 46.2% to 22.5%, and 12.8% to 5.7%, respectively (p<0.05). Resistance to NNRTI increased from 74.4% to 81.6%, mainly because of K103N mutation. The GSS score ≥2 increased during the years from 35.9% to 87.3% (p<0.001). We demonstrate that resistance to PI and to the three main classes simultaneously are declining, although the number of patients on of antiretroviral therapy has doubled in the last ten years in Brazil (125,000 in 2002 to 400,000 in 2014). Broader resistance testing and the availability of more therapeutic options might have influenced this decline. The increase in NNRTI resistance can limit this class as first line treatment in Brazil in the future.

  6. Extreme entropy-enthalpy compensation in a drug-resistant variant of HIV-1 protease.

    PubMed

    King, Nancy M; Prabu-Jeyabalan, Moses; Bandaranayake, Rajintha M; Nalam, Madhavi N L; Nalivaika, Ellen A; Özen, Ayşegül; Haliloğlu, Türkan; Yilmaz, Neşe Kurt; Schiffer, Celia A

    2012-09-21

    The development of HIV-1 protease inhibitors has been the historic paradigm of rational structure-based drug design, where structural and thermodynamic analyses have assisted in the discovery of novel inhibitors. While the total enthalpy and entropy change upon binding determine the affinity, often the thermodynamics are considered in terms of inhibitor properties only. In the current study, profound changes are observed in the binding thermodynamics of a drug-resistant variant compared to wild-type HIV-1 protease, irrespective of the inhibitor bound. This variant (Flap+) has a combination of flap and active site mutations and exhibits extremely large entropy-enthalpy compensation compared to wild-type protease, 5-15 kcal/mol, while losing only 1-3 kcal/mol in total binding free energy for any of six FDA-approved inhibitors. Although entropy-enthalpy compensation has been previously observed for a variety of systems, never have changes of this magnitude been reported. The co-crystal structures of Flap+ protease with four of the inhibitors were determined and compared with complexes of both the wild-type protease and another drug-resistant variant that does not exhibit this energetic compensation. Structural changes conserved across the Flap+ complexes, which are more pronounced for the flaps covering the active site, likely contribute to the thermodynamic compensation. The finding that drug-resistant mutations can profoundly modulate the relative thermodynamic properties of a therapeutic target independent of the inhibitor presents a new challenge for rational drug design.

  7. Clinical Determinants of HIV-1B Between-Host Evolution and their Association with Drug Resistance in Pediatric Patients

    PubMed Central

    Rojas, Patricia; Ramos, José Tomás; Holguín, África

    2016-01-01

    Understanding the factors that modulate the evolution of virus populations is essential to design efficient control strategies. Mathematical models predict that factors affecting viral within-host evolution may also determine that at the between-host level. Although HIV-1 within-host evolution has been associated with clinical factors used to monitor AIDS progression, such as patient age, CD4 cells count, viral load, and antiretroviral experience, little is known about the role of these clinical factors in determining between-host HIV-1 evolution. Moreover, whether the relative importance of such factors in HIV-1 evolution vary in adult and children patients, in which the course of infection is different, has seldom been analysed. To address these questions, HIV-1 subtype B (HIV-1B) pol sequences of 163 infected children and 450 adults of Madrid, Spain, were used to estimate genetic diversity, rates of synonymous and non-synonymous mutations, selection pressures and frequency of drug-resistance mutations (DRMs). The role and relative importance of patient age, %CD4, CD4/mm3, viral load, and antiretroviral experience in HIV-1B evolution was analysed. In the pediatric HIV-1B population, three clinical factors were primary predictors of virus evolution: Higher HIV-1B genetic diversity was observed with increasing children age, decreasing CD4/mm3 and upon antiretroviral experience. This was mostly due to higher rates of non-synonymous mutations, which were associated with higher frequency of DRMs. Using this data, we have also constructed a simple multivariate model explaining between 55% and 66% of the variance in HIV-1B evolutionary parameters in pediatric populations. On the other hand, the analysed clinical factors had little effect in adult-infecting HIV-1B evolution. These findings highlight the different evolutionary dynamics of HIV-1B in children and adults, and contribute to understand the factors shaping HIV-1B evolution and the appearance of drug-resistance

  8. Antiretroviral drug resistance and phylogenetic diversity of HIV-1 in Chile.

    PubMed

    Ríos, Maritza; Delgado, Elena; Pérez-Alvarez, Lucía; Fernández, Jorge; Gálvez, Paula; de Parga, Elena Vázquez; Yung, Verónica; Thomson, Michael M; Nájera, Rafael

    2007-06-01

    This study reports the analysis of human immunodeficiency virus type 1 (HIV-1) protease (PR) and reverse transcriptase (RT) coding sequences from 136 HIV-1-infected subjects from Chile, 66 (49%) of them under antiretroviral (ARV) treatment. The prevalence of mutations conferring high or intermediate resistance levels to ARVs was 77% among treated patients and 2.5% among drug-naïve subjects. The distribution of resistance prevalence in treated patients by drug class was 61% to nucleoside RT inhibitors, 84% to nonnucleoside RT inhibitors, and 46% to PR inhibitors. Phylogenetic analysis revealed that 115 (85%) subjects were infected with subtype B viruses, 1 with a subtype F1 virus, and 20 (15%) carried BF intersubtype recombinants. Most BF recombinants grouped into two clusters, one related to CRF12_BF, while the other could represent a new circulating recombinant form (CRF). In conclusion, this is the first report analysing the prevalence of ARV resistance which includes patients under HAART from Chile. Additionally, phylogenetic analysis of the PR-RT coding sequences reveals the presence of BF intersubtype recombinants.

  9. A cell-free enzymatic activity assay for the evaluation of HIV-1 drug resistance to protease inhibitors

    PubMed Central

    Matsunaga, Satoko; Masaoka, Takashi; Sawasaki, Tatsuya; Morishita, Ryo; Iwatani, Yasumasa; Tatsumi, Masashi; Endo, Yaeta; Yamamoto, Naoki; Sugiura, Wataru; Ryo, Akihide

    2015-01-01

    Due to their high frequency of genomic mutations, human retroviruses often develop resistance to antiretroviral drugs. The emergence of drug-resistant human immunodeficiency virus type 1 (HIV-1) is a significant obstacle to the effective long-term treatment of HIV infection. The development of a rapid and versatile drug-susceptibility assay would enable acquisition of phenotypic information and facilitate determination of the appropriate choice of antiretroviral agents. In this study, we developed a novel in vitro method, termed the Cell-free drug susceptibility assay (CFDSA), for monitoring phenotypic information regarding the drug resistance of HIV-1 protease (PR). The CFDSA utilizes a wheat germ cell-free protein production system to synthesize enzymatically active HIV-1 PRs directly from PCR products amplified from HIV-1 molecular clones or clinical isolates in a rapid one-step procedure. Enzymatic activity of PRs can be readily measured by AlphaScreen (Amplified Luminescent Proximity Homogeneous Assay Screen) in the presence or absence of clinically used protease inhibitors (PIs). CFDSA measurement of drug resistance was based on the fold resistance to the half-maximal inhibitory concentration (IC50) of various PIs. The CFDSA could serve as a non-infectious, rapid, accessible, and reliable alternative to infectious cell-based phenotypic assays for evaluation of PI-resistant HIV-1. PMID:26583013

  10. Sequence and structure based models of HIV-1 protease and reverse transcriptase drug resistance

    PubMed Central

    2013-01-01

    Background Successful management of chronic human immunodeficiency virus type 1 (HIV-1) infection with a cocktail of antiretroviral medications can be negatively affected by the presence of drug resistant mutations in the viral targets. These targets include the HIV-1 protease (PR) and reverse transcriptase (RT) proteins, for which a number of inhibitors are available on the market and routinely prescribed. Protein mutational patterns are associated with varying degrees of resistance to their respective inhibitors, with extremes that can range from continued susceptibility to cross-resistance across all drugs. Results Here we implement statistical learning algorithms to develop structure- and sequence-based models for systematically predicting the effects of mutations in the PR and RT proteins on resistance to each of eight and eleven inhibitors, respectively. Employing a four-body statistical potential, mutant proteins are represented as feature vectors whose components quantify relative environmental perturbations at amino acid residue positions in the respective target structures upon mutation. Two approaches are implemented in developing sequence-based models, based on use of either relative frequencies or counts of n-grams, to generate vectors for representing mutant proteins. To the best of our knowledge, this is the first reported study on structure- and sequence-based predictive models of HIV-1 PR and RT drug resistance developed by implementing a four-body statistical potential and n-grams, respectively, to generate mutant attribute vectors. Performance of the learning methods is evaluated on the basis of tenfold cross-validation, using previously assayed and publicly available in vitro data relating mutational patterns in the targets to quantified inhibitor susceptibility changes. Conclusion Overall performance results are competitive with those of a previously published study utilizing a sequence-based strategy, while our structure- and sequence

  11. Evaluations of an in-house drug resistance method for HIV-1 drug resistance using ViroSeq™ 2.0 genotyping system as a gold standard.

    PubMed

    Chaturbhuj, Devidas N; Deshmukh, Pravin S; Hingankar, Nitin K; Siddhaarth, K; Deshpande, Sohan N; Sen, Sourav; Kabra, Sandhya; Paranjape, Ramesh S; Tripathy, Srikanth P

    2013-04-01

    An in-house method was evaluated for its efficiency to detect the HIV-1 drug resistance mutations. This method was compared with the ViroSeq™ Genotyping System 2.0 (Celera Diagnostics, US) a gold standard. Sixty-five stored plasma samples, previously tested for HIV-1 drug resistance using the ViroSeq™ method were used to evaluate the in-house method. Out of the sixty five plasma samples, sixty were HIV-1 positive clinical samples; four samples from the Virology Quality Assessment (VQA) program and one positive control from the ViroSeq™ kit were used in this study. The sequences generated by the ViroSeq™ and an in-house method showed 99.5±0.5% and 99.7±0.4% (mean±SD) nucleotide and amino acid identity, respectively. Out of 214 Stanford HIVdb listed HIV-1 drug resistance mutations in the protease and reverse transcriptase regions, concordance was observed in 203 (94.9%), partial discordance in 11 (5.1%) and complete discordance was absent. The in-house primers are broadly sensitive in genotyping multiple HIV-1 group M subtypes. The amplification sensitivity of the in-house method was 1000 copies/ml. The evaluation of the in-house method provides results comparable with that of ViroSeq™ method thus, making the in-house method suitable for HIV-1 drug resistance testing in the developing countries.

  12. Energetic basis for drug resistance of HIV-1 protease mutants against amprenavir

    NASA Astrophysics Data System (ADS)

    Kar, Parimal; Knecht, Volker

    2012-02-01

    Amprenavir (APV) is a high affinity (0.15 nM) HIV-1 protease (PR) inhibitor. However, the affinities of the drug resistant protease variants V32I, I50V, I54V, I54M, I84V and L90M to amprenavir are decreased 3 to 30-fold compared to the wild-type. In this work, the popular molecular mechanics Poisson-Boltzmann surface area method has been used to investigate the effectiveness of amprenavir against the wild-type and these mutated protease variants. Our results reveal that the protonation state of Asp25/Asp25' strongly affects the dynamics, the overall affinity and the interactions of the inhibitor with individual residues. We emphasize that, in contrast to what is often assumed, the protonation state may not be inferred from the affinities but requires pKa calculations. At neutral pH, Asp25 and Asp25' are ionized or protonated, respectively, as suggested from pKa calculations. This protonation state was thus mainly considered in our study. Mutation induced changes in binding affinities are in agreement with the experimental findings. The decomposition of the binding free energy reveals the mechanisms underlying binding and drug resistance. Drug resistance arises from an increase in the energetic contribution from the van der Waals interactions between APV and PR (V32I, I50V, and I84V mutant) or a rise in the energetic contribution from the electrostatic interactions between the inhibitor and its target (I54M and I54V mutant). For the V32I mutant, also an increased free energy for the polar solvation contributes to the drug resistance. For the L90M mutant, a rise in the van der Waals energy for APV-PR interactions is compensated by a decrease in the polar solvation free energy such that the net binding affinity remains unchanged. Detailed understanding of the molecular forces governing binding and drug resistance might assist in the design of new inhibitors against HIV-1 PR variants that are resistant against current drugs.

  13. Affordable in-house antiretroviral drug resistance assay with good performance in non-subtype B HIV-1

    PubMed Central

    Wallis, Carole L.; Papathanasopoulos, Maria A.; Lakhi, Shabir; Karita, Etienne; Kamali, Anatoli; Kaleebu, Pontiano; Sanders, Eduard; Anzala, Omu; Bekker, Linda-Gail; Stevens, Gwynn; Rinke de Wit, Tobias F.; Stevens, Wendy

    2010-01-01

    The introduction of antiretroviral therapy in resource-poor settings is effective in suppressing HIV-1 replication and prolonging life of infected individuals. This has led to a demand for affordable HIV-1 drug resistance assays, since treatment failure due to development of drug resistance is common. This study developed and evaluated an affordable “in–house” genotyping assay to monitor HIV-1 drug resistance in Africa, particularly South Africa. An “in-house” assay using automated RNA extraction, and subtype C specific PCR and sequencing primers was developed and successfully evaluated 396 patient samples (viral load ranges 1,000->1.6million RNA copies/ml). The “in-house” assay was validated by comparing sequence data and drug resistance profiles from 90 patient and 10 external quality control samples to data from the ViroSeqTM HIV-1 Genotyping kit. The “in-house” assay was more efficient, amplifying all 100 samples, compared to 91 samples using Viroseq. The “in house” sequences were 99.2%) homologous to the ViroSeq sequences, and identical drug resistance mutation profiles were observed in 96 samples. Furthermore, the “in-house” assay genotyped 260 of 295 samples from seven African sites, where 47% were non-subtype C. Overall, the newly validated “in-house” drug resistance assay is suited for use in Africa as it overcomes the obstacle of subtype diversity. PMID:19917318

  14. Protein promiscuity: drug resistance and native functions--HIV-1 case.

    PubMed

    Fernández, Ariel; Tawfik, Dan S; Berkhout, Ben; Sanders, Rogier; Kloczkowski, Andrzej; Sen, Taner; Jernigan, Bob

    2005-06-01

    The association of a drug with its target protein has the effect of blocking the protein activity and is termed a promiscuous function to distinguish from the protein's native function (Tawfik and associates, Nat. Genet. 37, 73-6, 2005). Obviously, a protein has not evolved naturally for drug association or drug resistance. Promiscuous protein functions exhibit unique traits of evolutionary adaptability, or evolvability, which is dependent on the induction of novel phenotypic traits by a small number of mutations. These mutations might have small effects on native functions, but large effects on promiscuous function; for example, an evolving protein could become increasingly drug resistant while maintaining its original function. Ariel Fernandez, in his opinion piece, notes that drug-binding "promiscuity" can hardly be dissociated from native functions; a dominant approach to drug discovery is the protein-native-substrate transition-state mimetic strategy. Thus, man-made ligands (e.g. drugs) have been successfully crafted to restrain enzymatic activity by focusing on the very same structural features that determine the native function. Using the successful inhibition of HIV-1 protease as an example, Fernandez illustrates how drug designers have employed naturally evolved features of the protein to suppress its activity. Based on these arguments, he dismisses the notion that drug binding is quintessentially promiscuous, even though in principle, proteins did not evolve to associate with man made ligands. In short, Fernandez argues that there may not be separate protein domains that one could term promiscuous domains. While acknowledging that drugs may bind promiscuously or in a native-like manner a la Fernandez, Tawfik maintains the role of evolutionary adaptation, even when a drug binds native-like. In the case of HIV-1 protease, drugs bind natively, and the initial onset of mutations results in drug resistance in addition to a dramatic decline in enzymatic

  15. Transition states of native and drug-resistant HIV-1 protease are the same

    PubMed Central

    Kipp, D. Randal; Hirschi, Jennifer S.; Wakata, Aya; Goldstein, Harris; Schramm, Vern L.

    2012-01-01

    HIV-1 protease is an important target for the treatment of HIV/AIDS. However, drug resistance is a persistent problem and new inhibitors are needed. An approach toward understanding enzyme chemistry, the basis of drug resistance, and the design of powerful inhibitors is to establish the structure of enzymatic transition states. Enzymatic transition structures can be established by matching experimental kinetic isotope effects (KIEs) with theoretical predictions. However, the HIV-1 protease transition state has not been previously resolved using these methods. We have measured primary 14C and 15N KIEs and secondary 3H and 18O KIEs for native and multidrug-resistant HIV-1 protease (I84V). We observed 14C KIEs (14V/K) of 1.029 ± 0.003 and 1.025 ± 0.005, 15N KIEs (15V/K) of 0.987 ± 0.004 and 0.989 ± 0.003, 18O KIEs (18V/K) of 0.999 ± 0.003 and 0.993 ± 0.003, and 3H KIEs (3V/K) KIEs of 0.968 ± 0.001 and 0.976 ± 0.001 for the native and I84V enzyme, respectively. The chemical reaction involves nucleophilic water attack at the carbonyl carbon, proton transfer to the amide nitrogen leaving group, and C-N bond cleavage. A transition structure consistent with the KIE values involves proton transfer from the active site Asp-125 (1.32 Å) with partial hydrogen bond formation to the accepting nitrogen (1.20 Å) and partial bond loss from the carbonyl carbon to the amide leaving group (1.52 Å). The KIEs measured for the native and I84V enzyme indicate nearly identical transition states, implying that a true transition-state analogue should be effective against both enzymes. PMID:22493227

  16. Drug-resistant molecular mechanism of CRF01_AE HIV-1 protease due to V82F mutation

    NASA Astrophysics Data System (ADS)

    Liu, Xiaoqing; Xiu, Zhilong; Hao, Ce

    2009-05-01

    Human immunodeficiency virus type 1 protease (HIV-1 PR) is one of the major targets of anti-AIDS drug discovery. The circulating recombinant form 01 A/E (CRF01_AE, abbreviated AE) subtype is one of the most common HIV-1 subtypes, which is infecting more humans and is expanding rapidly throughout the world. It is, therefore, necessary to develop inhibitors against subtype AE HIV-1 PR. In this work, we have performed computer simulation of subtype AE HIV-1 PR with the drugs lopinavir (LPV) and nelfinavir (NFV), and examined the mechanism of resistance of the V82F mutation of this protease against LPV both structurally and energetically. The V82F mutation at the active site results in a conformational change of 79's loop region and displacement of LPV from its proper binding site, and these changes lead to rotation of the side-chains of residues D25 and I50'. Consequently, the conformation of the binding cavity is deformed asymmetrically and some interactions between PR and LPV are destroyed. Additionally, by comparing the interactive mechanisms of LPV and NFV with HIV-1 PR we discovered that the presence of a dodecahydroisoquinoline ring at the P1' subsite, a [2-(2,6-dimethylphenoxy)acetyl]amino group at the P2' subsite, and an N2 atom at the P2 subsite could improve the binding affinity of the drug with AE HIV-1 PR. These findings are helpful for promising drug design.

  17. HemaSpot, a Novel Blood Storage Device for HIV-1 Drug Resistance Testing.

    PubMed

    Brooks, K; DeLong, A; Balamane, M; Schreier, L; Orido, M; Chepkenja, M; Kemboi, E; D'Antuono, M; Chan, P A; Emonyi, W; Diero, L; Coetzer, M; Kantor, R

    2016-01-01

    HemaSpot, a novel dried-blood storage filter device, was used for HIV-1 pol resistance testing in 30 fresh United States blood samples and 54 previously frozen Kenyan blood samples. Genotyping succeeded in 79% and 58% of samples, respectively, improved with shorter storage and higher viral load, and had good (86%) resistance mutation concordance to plasma.

  18. Transmitted Drug Resistance Mutations in Antiretroviral-Naïve Injection Drug Users with Chronic HIV-1 Infection in Iran

    PubMed Central

    Memarnejadian, Arash; Menbari, Shahoo; Vahabpour, Rouhollah; Aghasadeghi, Mohammad Reza; Mostafavi, Ehsan; Abdi, Mohammad

    2015-01-01

    The growing incidence and transmission of drug resistant HIV-1 strains due to widespread use of antiretroviral therapy (ART) can jeopardize the success of first-line ART. While there is a known moderate prevalence of transmitted drug resistance (TDR) among newly infected Iranians, no data exist about the rate of these primary resistance mutations among the ART-naïve, chronically infected individuals who are, in fact, the main candidates for ART initiation. To address this issue, we collected blood samples from 40 ART-naïve injection drug-users (IDUs) with chronic HIV-1 infection (seroconversion time ranging from 2 to 9 years) living in Sanandaj, Iran, followed by sequencing of the protease and reverse-transcriptase regions from their HIV-1 genome. Phylogenetic analyses of the sequenced regions revealed that all samples were CRF35_AD. Transmitted resistance mutations were interpreted as surveillance drug-resistant mutations (SDRMs) based on the world health organization (WHO) algorithm. The frequency of SDRMs to any class of antiretroviral drugs was 15%, which included mutations to nucleoside reverse transcriptase inhibitors (NRTIs, 10%), with M41L and M184V as the most common (5%), and non-nucleoside reverse transcriptase inhibitors (NNRTIs, 5%), with K103N as the only detected mutation (5%). Although not in the WHO SDRMs list, several minor protease inhibitor resistant mutations listed in the International Antiviral Society-USA panel were identified, of which M36I, H69K, L89M/V/I (each one 100%) and K20R/T (92.5%) can be considered as polymorphic signatures for CRF35_AD.The relatively high rate of TDR mutations in our study raises concerns about the risk of treatment failure in chronically infected IDUs of Sanandaj city. These results suggest that routine resistance testing should be considered before the therapy initiation in this area. Additional surveillance studies are required to generalize this deduction to other cities of Iran. PMID:25962088

  19. Neutralizing antibody and anti-retroviral drug sensitivities of HIV-1 isolates resistant to small molecule CCR5 inhibitors

    SciTech Connect

    Pugach, Pavel; Ketas, Thomas J.; Michael, Elizabeth; Moore, John P.

    2008-08-01

    The small molecule CCR5 inhibitors are a new class of drugs for treating infection by human immunodeficiency virus type 1 (HIV-1). They act by binding to the CCR5 co-receptor and preventing its use during HIV-1-cell fusion. Escape mutants can be raised against CCR5 inhibitors in vitro and will arise when these drugs are used clinically. Here, we have assessed the responses of CCR5 inhibitor-resistant viruses to other anti-retroviral drugs that act by different mechanisms, and their sensitivities to neutralizing antibodies (NAbs). The rationale for the latter study is that the resistance pathway for CCR5 inhibitors involves changes in the HIV-1 envelope glycoproteins (Env), which are also targets for NAbs. The escape mutants CC101.19 and D1/85.16 were selected for resistance to AD101 and vicriviroc (VVC), respectively, from the primary R5 HIV-1 isolate CC1/85. Each escape mutant was cross-resistant to other small molecule CCR5 inhibitors (aplaviroc, maraviroc, VVC, AD101 and CMPD 167), but sensitive to protein ligands of CCR5: the modified chemokine PSC-RANTES and the humanized MAb PRO-140. The resistant viruses also retained wild-type sensitivity to the nucleoside reverse transcriptase inhibitor (RTI) zidovudine, the non-nucleoside RTI nevirapine, the protease inhibitor atazanavir and other attachment and fusion inhibitors that act independently of CCR5 (BMS-806, PRO-542 and enfuvirtide). Of note is that the escape mutants were more sensitive than the parental CC1/85 isolate to a subset of neutralizing monoclonal antibodies and to some sera from HIV-1-infected people, implying that sequence changes in Env that confer resistance to CCR5 inhibitors can increase the accessibility of some NAb epitopes. The need to preserve NAb resistance may therefore be a constraint upon how escape from CCR5 inhibitors occurs in vivo.

  20. Neutralizing antibody and anti-retroviral drug sensitivities of HIV-1 isolates resistant to small molecule CCR5 inhibitors

    PubMed Central

    Pugach, Pavel; Ketas, Thomas J.; Michael, Elizabeth; Moore, John P.

    2008-01-01

    The small molecule CCR5 inhibitors are a new class of drugs for treating infection by human immunodeficiency virus type 1 (HIV-1). They act by binding to the CCR5 co-receptor and preventing its use during HIV-1-cell fusion. Escape mutants can be raised against CCR5 inhibitors in vitro and will arise when these drugs are used clinically. Here, we have assessed the responses of CCR5 inhibitor-resistant viruses to other anti-retroviral drugs that act by different mechanisms, and their sensitivities to neutralizing antibodies (NAbs). The rationale for the latter study is that the resistance pathway for CCR5 inhibitors involves changes in the HIV-1 envelope glycoproteins (Env), which are also targets for NAbs. The escape mutants CC101.19 and D1/85.16 were selected for resistance to AD101 and vicriviroc (VVC), respectively, from the primary R5 HIV-1 isolate CC1/85. Each escape mutant was cross resistant to other small molecule CCR5 inhibitors (aplaviroc, maraviroc, VVC, AD101 and CMPD 167), but sensitive to protein ligands of CCR5: the modified chemokine PSC-RANTES and the humanized MAb PRO 140. The resistant viruses also retained wild-type sensitivity to the nucleoside reverse transcriptase inhibitor (RTI) zidovudine, the non-nucleoside RTI nevirapine, the protease inhibitor atazanavir and other attachment and fusion inhibitors that act independently of CCR5 (BMS-806, PRO-542 and enfuvirtide). Of note is that the escape mutants were more sensitive than the parental CC1/85 isolate to a subset of neutralizing monoclonal antibodies and to some sera from HIV-1-infected people, implying that sequence changes in Env that confer resistance to CCR5 inhibitors can increase the accessibility of some NAb epitopes. The need to preserve NAb resistance may therefore be a constraint upon how escape from CCR5 inhibitors occurs in vivo. PMID:18519143

  1. MinVar: A rapid and versatile tool for HIV-1 drug resistance genotyping by deep sequencing.

    PubMed

    Huber, Michael; Metzner, Karin J; Geissberger, Fabienne D; Shah, Cyril; Leemann, Christine; Klimkait, Thomas; Böni, Jürg; Trkola, Alexandra; Zagordi, Osvaldo

    2017-02-01

    Genotypic monitoring of drug-resistance mutations (DRMs) in HIV-1 infected individuals is strongly recommended to guide selection of the initial antiretroviral therapy (ART) and changes of drug regimens. Traditionally, mutations conferring drug resistance are detected by population sequencing of the reverse transcribed viral RNA encoding the HIV-1 enzymes target by ART, followed by manual analysis and interpretation of Sanger sequencing traces. This process is labor intensive, relies on subjective interpretation from the operator, and offers limited sensitivity as only mutations above 20% frequency can be reliably detected. Here we present MinVar, a pipeline for the analysis of deep sequencing data, which allows reliable and automated detection of DRMs down to 5%. We evaluated MinVar with data from amplicon sequencing of defined mixtures of molecular virus clones with known DRM and plasma samples of viremic HIV-1 infected individuals and we compared it to VirVarSeq, another virus variant detection tool exclusively working on Illumina deep sequencing data. MinVar was designed to be compatible with a diverse range of sequencing platforms and allows the detection of DRMs and insertions/deletions from deep sequencing data without the need to perform additional bioinformatics analysis, a prerequisite to a widespread implementation of HIV-1 genotyping using deep sequencing in routine diagnostic settings.

  2. HIV-1 genetic diversity and transmitted drug resistance frequency among Iranian treatment-naive, sexually infected individuals.

    PubMed

    Vahabpour, Rouhollah; Bokharaei-Salim, Farah; Kalantari, Saeed; Garshasbi, Saba; Monavari, Seyed Hamidreza; Esghaei, Maryam; Memarnejadian, Arash; Fakhim, Atousa; Keyvani, Hossein

    2017-02-08

    In recent years, the patterns of human immunodeficiency virus 1 (HIV-1) transmission in Iran have been changing gradually from drug injection to unprotected sexual contact. This study sought to investigate the phylogenetic trends and characteristics of transmitted drug resistance (TDR) mutations of HIV-1 in a population that is mainly infected through homo/heterosexual contacts. Sixty newly diagnosed antiretroviral-naive individuals with HIV infection living in Tehran were recruited to this survey, and among them, 42 subjects were established to be infected through sexual intercourse. Following amplification and sequencing of the main part of the HIV-1 pol region, phylogenetic and drug-resistance mutation (DRM) analysis was successfully performed on these 42 patients. Phylogenetic analysis showed that the majority of the subjects were infected with subtype CRF35_AD (88%), followed by subtype B, with 7.1%, and subtype CRF01_AE, with 4.7%. A total of 7.1% of the subjects were found to be infected with HIV-1 variants with surveillance drug-resistant mutations (SDRMs) according to the last world health organisation (WHO) algorithm. All of the identified SDRMs belonged to the non-nucleoside reverse transcriptase inhibitors (NNRTIs) class, including K103 N and V106A, which were found in three patients. Two minor HIV protease-inhibitor-related mutations (L10I and G73S) were detected in two patients, but these mutations are not included in the WHO SDRMs list. The dominance of HIV-1 subtype CRF35_AD was observed among subjects of this study who were infected through sexual contact. The moderate prevalence of SDRMs (7.1%) in this population emphasises the fact that the risk of treatment failure in HIV-infected individuals might increase in the future, and preventive measures should be considered by health authorities.

  3. Human APOBEC3G drives HIV-1 evolution and the development of drug resistance

    SciTech Connect

    Bhattacharya, Tamoy; Kim, Eun - Young; Koning, Fransje; Malim, Michael; Wolinsky, Steven M

    2008-01-01

    Human APOBEC3G (hA3G) is an innate virus restriction factor that induces deamination of specific cytidine residues in single-stranded human immunodeficiency virus type 1 (HIV-1) DNA. Whereas destructive hA3G editing leads to a profound loss of HIV-1 infectivity, more limited editing could be a source of adaptation and diversification. Here we show that the presence of hA3G in T-cells can drive the development of diversity in HIV-1 populations and that under selection pressure imposed by the nucleotide analog reverse transcriptase inhibitor 3TC ((-)2',3'-dideoxy-3'-thiacytidine), a single point mutation that confers 3TC resistance, methionine 184 to isoleucine (M1841), emerges rapidly and reaches fixation. These results provide strong evidence that mutation by hA3G is an important source of genetic variation on which natural selection acts to shape the structure of the viral population and drive the tempo of HIV-1 evolution.

  4. More effective drugs lead to harder selective sweeps in the evolution of drug resistance in HIV-1

    PubMed Central

    Feder, Alison F; Rhee, Soo-Yon; Holmes, Susan P; Shafer, Robert W; Petrov, Dmitri A; Pennings, Pleuni S

    2016-01-01

    In the early days of HIV treatment, drug resistance occurred rapidly and predictably in all patients, but under modern treatments, resistance arises slowly, if at all. The probability of resistance should be controlled by the rate of generation of resistance mutations. If many adaptive mutations arise simultaneously, then adaptation proceeds by soft selective sweeps in which multiple adaptive mutations spread concomitantly, but if adaptive mutations occur rarely in the population, then a single adaptive mutation should spread alone in a hard selective sweep. Here, we use 6717 HIV-1 consensus sequences from patients treated with first-line therapies between 1989 and 2013 to confirm that the transition from fast to slow evolution of drug resistance was indeed accompanied with the expected transition from soft to hard selective sweeps. This suggests more generally that evolution proceeds via hard sweeps if resistance is unlikely and via soft sweeps if it is likely. DOI: http://dx.doi.org/10.7554/eLife.10670.001 PMID:26882502

  5. Ab initio molecular dynamics studies on HIV-1 reverse transcriptase triphosphate binding site: implications for nucleoside-analog drug resistance.

    PubMed Central

    Alber, F.; Carloni, P.

    2000-01-01

    Quantum-chemical methods are used to shed light on the functional role of residues involved in the resistance of HIV-1 reverse transcriptase against nucleoside-analog drugs. Ab initio molecular dynamics simulations are carried out for models representing the adduct between the triphosphate substrate and the nucleoside binding site. The triphosphate is considered either deprotonated or protonated at the gamma-position. Although the protonated form already experiences large rearrangements in the ps time scale, the fully deprotonated state exhibits a previously unrecognized low-barrier hydrogen bond between Lys65 and gamma-phosphate. Absence of this interaction in Lys65-->Arg HIV-1 RT might play a prominent role in the resistance of this mutant for nucleoside analogs (Gu Z et al., 1994b, Antimicrob Agents Chemother 38:275-281; Zhang D et al., 1994, Antimicrob Agents Chemother 38:282-287). Water molecules present in the active site, not detected in the X-ray structure, form a complex H-bond network. Among these waters, one may be crucial for substrate recognition as it bridges Gln151 and Arg72 with the beta-phosphate. Absence of this stabilizing interaction in Gln151-->Met HIV-1 RT mutant may be a key factor for the known drug resistance of this mutant toward dideoxy-type drugs and AZT (Shirasaka T et al., 1995, Proc Natl Acad Sci USA 92:2398-2402: Iversen AK et al., 1996, J Virol 70:1086-1090). PMID:11206075

  6. Design, Synthesis, Biological and Structural Evaluations of Novel HIV-1 Protease Inhibitors to Combat Drug Resistance

    PubMed Central

    Parai, Maloy Kumar; Huggins, David J.; Cao, Hong; Nalam, Madhavi N. L.; Ali, Akbar; Schiffer, Celia A.; Tidor, Bruce; Rana, Tariq M.

    2012-01-01

    A series of new HIV-1 protease inhibitors (PIs) were designed using a general strategy that combines computational structure-based design with substrate-envelope constraints. The PIs incorporate various alcohol-derived P2 carbamates with acyclic and cyclic heteroatomic functionalities into the (R)-hydroxyethylamine isostere. Most of the new PIs show potent binding affinities against wild-type HIV-1 protease and three multidrug resistant (MDR) variants, in particular inhibitors containing 2,2-dichloroacetamide, pyrrolidinone, imidazolidinone, and oxazolidinone moieties at P2 are the most potent with Ki values in the picomolar range. Several new PIs exhibit nanomolar antiviral potencies against patient-derived wild-type viruses from HIV-1 clades A, B, and C and two MDR variants. Crystal structure analyses of four potent inhibitors revealed that carbonyl groups of the new P2 moieties promote extensive hydrogen bond interactions with the invariant Asp-29 residue of the protease. These structure-activity relationship findings can be utilized to design new PIs with enhanced enzyme inhibitory and antiviral potencies. PMID:22708897

  7. Influence of Drug Resistance Mutations on the Activity of HIV-1 Subtypes A and B Integrases: a Comparative Study

    PubMed Central

    Shadrina, O. A.; Zatsepin, T. S.; Agapkina, Yu. Yu.; Isaguliants, M. G.; Gottikh, M. B.

    2015-01-01

    Integration of human immunodeficiency virus (HIV-1) DNA into the genome of an infected cell is one of the key steps in the viral replication cycle. The viral enzyme integrase (IN), which catalyzes the integration, is an attractive target for the development of new antiviral drugs. However, the HIV-1 therapy often results in the IN gene mutations inducing viral resistance to integration inhibitors. To assess the impact of drug resistance mutations on the activity of IN of HIV-1 subtype A strain FSU-A, which is dominant in Russia, variants of the consensus IN of this subtype containing the primary resistance mutations G118R and Q148K and secondary compensatory substitutions E138K and G140S were prepared and characterized. Comparative study of these enzymes with the corresponding mutants of IN of HIV-1 subtype B strains HXB-2 was performed. The mutation Q148K almost equally reduced the activity of integrases of both subtypes. Its negative effect was partially compensated by the secondary mutations E138K and G140S. Primary substitution G118R had different influence on the activity of proteins of the subtypes A and B, and the compensatory effect of the secondary substitution E138K also depended on the viral subtype. Comparison of the mutants resistance to the known strand transfer inhibitors raltegravir and elvitegravir, and a new inhibitor XZ-259 (a dihydro-1H-isoindol derivative), showed that integrases of both subtypes with the Q148K mutation were insensitive to raltegravir and elvitegravir but were effectively inhibited by XZ-259. The substitution G118R slightly reduced the efficiency of IN inhibition by raltegravir and elvitegravir and caused no resistance to XZ_259. PMID:25927004

  8. Development, Validation and Clinical Evaluation of a Low Cost In-House HIV-1 Drug Resistance Genotyping Assay for Indian Patients

    PubMed Central

    Acharya, Arpan; Vaniawala, Salil; Shah, Parth; Misra, Rabindra Nath; Wani, Minal; Mukhopadhyaya, Pratap N.

    2014-01-01

    Human Immunodeficiency Virus-1 (HIV-1) drug resistance genotyping assay is a part of clinical management of HIV-1 positive individuals under treatment with highly active antiretroviral therapy (HAART). Routine monitoring of drug resistance mutations in resource limited settings like India is not possible due to high cost of commercial drug resistance assays. In this study we developed an in-house, cost effective HIV-1 drug resistance genotyping assay for Indian patients and validated it against the US-FDA-approved ViroSeq HIV-1 drug resistance testing system. A reference panel of 20 clinical samples was used to develop and validate the assay against ViroSeq HIV-1 drug resistance testing system which was subsequently used to genotype a clinical panel of 225 samples. The Stanford HIV database was used to identify drug resistant mutations. The analytical sensitivity of the assay was 1000 HIV-1 RNA copies/ml of plasma sample while precision and reproducibility was 99.68±0.16% and 99.76±0.18% respectively. One hundred and one drug resistant mutations were detected by the in-house assay compared to 104 by ViroSeq system in the reference panel. The assay had 91.55% success rate in genotyping the clinical panel samples and was able to detect drug resistant mutations related to nucleoside reverse transcriptase inhibitor (NRTI), non-nucleoside reverse-transcriptase inhibitor (NNRTI) as well as protease inhibitor (PI) classes of antiretroviral drugs. It was found to be around 71.9% more cost effective compared to ViroSeq genotyping system. This evaluation of the assay on the clinical panel demonstrates its potential for monitoring clinical HIV-1 drug resistance mutations and population-based surveillance in resource limited settings like India. PMID:25157501

  9. Dose-response curve slope is a missing dimension in the analysis of HIV-1 drug resistance.

    PubMed

    Sampah, Maame Efua S; Shen, Lin; Jilek, Benjamin L; Siliciano, Robert F

    2011-05-03

    HIV-1 drug resistance is a major clinical problem. Resistance is evaluated using in vitro assays measuring the fold change in IC(50) caused by resistance mutations. Antiretroviral drugs are used at concentrations above IC(50), however, and inhibition at clinical concentrations can only be predicted from IC(50) if the shape of the dose-response curve is also known. Curve shape is influenced by cooperative interactions and is described mathematically by the slope parameter or Hill coefficient (m). Implicit in current analysis of resistance is the assumption that mutations shift dose-response curves to the right without affecting the slope. We show here that m is altered by resistance mutations. For reverse transcriptase and fusion inhibitors, single resistance mutations affect both slope and IC(50). For protease inhibitors, single mutations primarily affect slope. For integrase inhibitors, only IC(50) is affected. Thus, there are fundamental pharmacodynamic differences in resistance to different drug classes. Instantaneous inhibitory potential (IIP), the log inhibition of single-round infectivity at clinical concentrations, takes into account both slope and IC(50), and thus provides a direct measure of the reduction in susceptibility produced by mutations and the residual activity of drugs against resistant viruses. The standard measure, fold change in IC(50), does not correlate well with changes in IIP when mutations alter slope. These results challenge a fundamental assumption underlying current analysis of HIV-1 drug resistance and suggest that a more complete understanding of how resistance mutations reduce antiviral activity requires consideration of a previously ignored parameter, the dose-response curve slope.

  10. Surveillance of HIV-1 pol transmitted drug resistance in acutely and recently infected antiretroviral drug-naïve persons in rural western Kenya

    PubMed Central

    Maman, David; Auma, Erick; Were, Kennedy; Fredrick, Harrison; Owiti, Prestone; Opollo, Valarie; Etard, Jean-François; Mukui, Irene; Kim, Andrea A.; Zeh, Clement

    2017-01-01

    HIV-1 transmitted drug resistance (TDR) is of increasing public health concern in sub-Saharan Africa with the rollout of antiretroviral (ARV) therapy. Such data are, however, limited in Kenya, where HIV-1 drug resistance testing is not routinely performed. From a population-based household survey conducted between September and November 2012 in rural western Kenya, we retrospectively assessed HIV-1 TDR baseline rates, its determinants, and genetic diversity among drug-naïve persons aged 15–59 years with acute HIV-1 infections (AHI) and recent HIV-1 infections (RHI) as determined by nucleic acid amplification test and both Limiting Antigen and BioRad avidity immunoassays, respectively. HIV-1 pol sequences were scored for drug resistance mutations using Stanford HIVdb and WHO 2009 mutation guidelines. HIV-1 subtyping was computed in MEGA6. Eighty seven (93.5%) of the eligible samples were successfully sequenced. Of these, 8 had at least one TDR mutation, resulting in a TDR prevalence of 9.2% (95% CI 4.7–17.1). No TDR was observed among persons with AHI (n = 7). TDR prevalence was 4.6% (95% CI 1.8–11.2) for nucleoside reverse transcriptase inhibitors (NRTIs), 6.9% (95% CI 3.2–14.2) for non- nucleoside reverse transcriptase inhibitors (NNRTIs), and 1.2% (95% CI 0.2–6.2) for protease inhibitors. Three (3.4% 95% CI 0.8–10.1) persons had dual-class NRTI/NNRTI resistance. Predominant TDR mutations in the reverse transcriptase included K103N/S (4.6%) and M184V (2.3%); only M46I/L (1.1%) occurred in the protease. All the eight persons were predicted to have different grades of resistance to the ARV regimens, ranging from potential low-level to high-level resistance. HIV-1 subtype distribution was heterogeneous: A (57.5%), C (6.9%), D (21.8%), G (2.3%), and circulating recombinant forms (11.5%). Only low CD4 count was associated with TDR (p = 0.0145). Our findings warrant the need for enhanced HIV-1 TDR monitoring in order to inform on population

  11. HIV-1 Epidemiology, Genetic Diversity, and Primary Drug Resistance in the Tyumen Oblast, Russia

    PubMed Central

    Astakhova, Ekaterina M.; Gashnikova, Mariya P.; Bocharov, Evgeniy F.; Petrova, Svetlana V.; Pun'ko, Olga A.; Popkov, Alexander V.; Totmenin, Aleksey V.

    2016-01-01

    Introduction. Specific molecular epidemic features of HIV infection in Tyumen Oblast (TO), Russia, were studied. Methods. The genome sequences encoding HIV-1 protease-reverse transcriptase, integrase, and major envelope protein were examined for 72 HIV-1 specimens isolated from the TO resident infected in 2000–2015. Results. The recorded prevalence of HIV-1 subtype A (A1) is 93.1%; HIV-1 subtype B continues to circulate in MSM risk group (1.4%). Solitary instances of HIV-1 recombinant forms, CRF63_02A1 (1.4%) and CRF03_AB (1.4%), were detected as well as two cases of HIV-1 URF63_A1 (2.8%). Phylogenetic analysis showed no HIV-1 clustering according to the duration of infection and risk groups but revealed different epidemic networks confirming that HIV infection spread within local epidemic foci. A high incidence of CXCR4-tropic HIV-1 variants and a higher rate of secondary mutations influencing the virus fitness (K20R, L10V, and I) are observed among the virus specimens isolated from newly infected individuals. Conclusions. The current HIV-1 epidemic in TO develops within the local epidemic networks. Similar to the previous period, HIV-1 subtype A is predominant in TO with sporadic cases of importation of HIV-1 recombinant forms circulating in adjacent areas. PMID:27957489

  12. HIV-1 Epidemiology, Genetic Diversity, and Primary Drug Resistance in the Tyumen Oblast, Russia.

    PubMed

    Gashnikova, Natalya M; Astakhova, Ekaterina M; Gashnikova, Mariya P; Bocharov, Evgeniy F; Petrova, Svetlana V; Pun'ko, Olga A; Popkov, Alexander V; Totmenin, Aleksey V

    2016-01-01

    Introduction. Specific molecular epidemic features of HIV infection in Tyumen Oblast (TO), Russia, were studied. Methods. The genome sequences encoding HIV-1 protease-reverse transcriptase, integrase, and major envelope protein were examined for 72 HIV-1 specimens isolated from the TO resident infected in 2000-2015. Results. The recorded prevalence of HIV-1 subtype A (A1) is 93.1%; HIV-1 subtype B continues to circulate in MSM risk group (1.4%). Solitary instances of HIV-1 recombinant forms, CRF63_02A1 (1.4%) and CRF03_AB (1.4%), were detected as well as two cases of HIV-1 URF63_A1 (2.8%). Phylogenetic analysis showed no HIV-1 clustering according to the duration of infection and risk groups but revealed different epidemic networks confirming that HIV infection spread within local epidemic foci. A high incidence of CXCR4-tropic HIV-1 variants and a higher rate of secondary mutations influencing the virus fitness (K20R, L10V, and I) are observed among the virus specimens isolated from newly infected individuals. Conclusions. The current HIV-1 epidemic in TO develops within the local epidemic networks. Similar to the previous period, HIV-1 subtype A is predominant in TO with sporadic cases of importation of HIV-1 recombinant forms circulating in adjacent areas.

  13. HIV-1 Genetic Characteristics and Transmitted Drug Resistance among Men Who Have Sex with Men in Kunming, China

    PubMed Central

    Chen, Min; Ma, Yanling; Su, Yingzhen; Yang, Li; Zhang, Renzhong; Yang, Chaojun; Chen, Huichao; Yan, Wenyun; Shi, Yuhua; Dong, Lijuan; Chen, Ling; Jia, Manhong; Lu, Lin

    2014-01-01

    Background Yunnan has been severely affected by HIV/AIDS in China. Recently, the reported prevalence of HIV-1 among men who have sex with men (MSM) in Yunnan was high in China. To monitor dynamic HIV-1 epidemic among Yunnan MSM, HIV-1 genetic characteristics and transmitted drug resistance (TDR) were investigated. Methods Blood samples from 131 newly HIV-1 diagnosed MSM were continuously collected at fixed sites from January 2010 to December 2012 in Kunming City, Yunnan Province. Partial gag, pol and env genes were sequenced. Phylogenetic, evolutionary and genotypic drug resistance analyses were performed. Results Multiple genotypes were identified among MSM in Kunming, including CRF01_AE (64.9%), CRF07_BC (25.2%), unique recombinant forms (URFs, 5.3%), subtype B (3.1%) and CRF08_BC (1.5%). CRF01_AE and CRF07_BC were the predominant strains. The mean of genetic distance within CRF01_AE were larger than that within CRF07_BC. The estimated introducing time of CRF01_AE in Yunnan MSM (1996.9) is earlier than that of CRF07_BC (2002.8). In this study, subtype B was first identified in Yunnan MSM. CRF08_BC seems to be the distinctive strain in Yunnan MSM, which was seldom found among MSM outside Yunnan. The proportion of URFs increased, which further contributed to genetic diversity among MSM. Strikingly, genetic relatedness was found among these strains with MSM isolates from multiple provinces, which suggested that a nationwide transmission network may exist. TDR-associated mutations were identified in 4.6% individuals. The multivariate analysis revealed that non-native MSM and divorced/widowed MSM were independently associated with a higher TDR rate. Conclusion This work revealed diverse HIV-1 genetics, national transmission networks and a baseline level of TDR in MSM. These findings enhance our understanding of the distribution and evolution of HIV-1 in MSM, and are valuable for developing HIV prevention strategies for MSM. PMID:24489829

  14. Moderate Levels of Pre-Treatment HIV-1 Antiretroviral Drug Resistance Detected in the First South African National Survey

    PubMed Central

    Steegen, Kim; Carmona, Sergio; Bronze, Michelle; Papathanasopoulos, Maria A.; van Zyl, Gert; Goedhals, Dominique; MacLeod, William; Sanne, Ian; Stevens, Wendy S.

    2016-01-01

    Background In order to assess the level of transmitted and/or pre-treatment antiretroviral drug resistance to HIV-1, the World Health Organization (WHO) recommends that regular surveys are conducted. This study’s objective was to assess the frequency of HIV-1 antiretroviral drug resistance in patients initiating antiretroviral treatment (ART) in the public sector throughout South Africa. Methods A prospective cross-sectional survey was conducted using probability proportional to size sampling. This method ensured that samples from each province were proportionally collected, based on the number of patients receiving ART in each region. Samples were collected between March 2013 and October 2014. Pol sequences were obtained using RT-PCR and Sanger sequencing and submitted to the Stanford Calibrated Population Resistance tool v6.0. Results A total of 277 sequences were available for analysis. Most participants were female (58.8%) and the median age was 34 years (IQR: 29–42). The median baseline CD4-count was 149 cells/mm3 (IQR: 62–249) and, based on self-reporting, participants had been diagnosed as HIV-positive approximately 44 days prior to sample collection (IQR: 23–179). Subtyping revealed that 98.2% were infected with HIV-1 subtype C. Overall, 25 out of 277 patients presented with ≥1 surveillance drug resistance mutation (SDRM, 9.0%, 95% CI: 6.1–13.0%). Non-nucleoside reverse transcriptase inhibitor (NNRTI) mutations were the most numerous mutations detected (n = 23). Only two patients presented with a protease inhibitor (PI) mutation. In four patients ≥4 SDRMs were detected, which might indicate that these patients were not truly ART-naïve or were infected with a multi-resistant virus. Conclusions These results show that the level of antiretroviral drug resistance in ART-naïve South Africans has reached moderate levels, as per the WHO classification. Therefore, regular surveys of pre-treatment drug resistance levels in all regions of South Africa

  15. Different Frequencies of Drug Resistance Mutations among HIV-1 Subtypes Circulating in China: A Comprehensive Study

    PubMed Central

    Sui, Hongshuai; Gui, Tao; Jia, Lei; Guo, Wei; Han, Jingwan; Liu, Yongjian; Bao, Zuoyi; Li, Hanping; Li, Jingyun; Li, Lin

    2014-01-01

    The rapid spreading of HIV drug resistance is threatening the overall success of free HAART in China. Much work has been done on drug-resistant mutations, however, most of which were based on subtype B. Due to different genetic background, subtypes difference would have an effect on the development of drug-resistant mutations, which has already been proved by more and more studies. In China, the main epidemic subtypes are CRF07_BC, CRF08_BC, Thai B and CRF01_AE. The depiction of drug resistance mutations in those subtypes will be helpful for the selection of regimens for Chinese. In this study, the distributions difference of amino acids at sites related to HIV drug resistance were compared among subtype B, CRF01_AE, CRF07_BC and CRF08_BC strains prevalent in China. The amino acid composition of sequences belonging to different subtypes, which were obtained from untreated and treated individuals separately, were also compared. The amino acids proportions of 19 sites in RT among subtype B, CRF01_AE and CRF08_BC have significant difference in drug resistance groups (chi-square test, p<0.05). Genetic barriers analysis revealed that sites 69, 138, 181, 215 and 238 were significantly different among subtypes (Kruskal Wallis test, p<0.05). All subtypes shared three highest prevalent drug resistance sites 103, 181 and 184 in common. Many drug resistant sites in protease show surprising high proportions in almost all subtypes in drug-naïve patients. This is the first comprehensive study in China on different development of drug resistance among different subtypes. The detailed data will lay a foundation for HIV treatment regimens design and improve HIV therapy in China. PMID:24663120

  16. Update on HIV-1 acquired and transmitted drug resistance in Africa.

    PubMed

    Ssemwanga, Deogratius; Lihana, Raphael W; Ugoji, Chinenye; Abimiku, Alash'le; Nkengasong, John; Dakum, Patrick; Ndembi, Nicaise

    2015-01-01

    The last ten years have witnessed a significant scale-up and access to antiretroviral therapy in Africa, which has improved patient quality of life and survival. One major challenge associated with increased access to antiretroviral therapy is the development of antiretroviral resistance due to inconsistent drug supply and/or poor patient adherence. We review the current state of both acquired and transmitted drug resistance in Africa over the past ten years (2001-2011) to identify drug resistance associated with the different drug regimens used on the continent and to help guide affordable strategies for drug resistance surveillance. A total of 161 references (153 articles, six reports and two conference abstracts) were reviewed. Antiretroviral resistance data was available for 40 of 53 African countries. A total of 5,541 adult patients from 99 studies in Africa were included in this analysis. The pooled prevalence of drug resistance mutations in Africa was 10.6%, and Central Africa had the highest prevalence of 54.9%. The highest prevalence of nucleoside reverse transcriptase inhibitor mutations was in the west (55.3%) and central (54.8%) areas; nonnucleoside reverse transcriptase inhibitor mutations were highest in East Africa (57.0%) and protease inhibitors mutations highest in Southern Africa (16.3%). The major nucleoside reverse transcriptase inhibitor mutation in all four African regions was M184V. Major nonnucleoside reverse transcriptase inhibitor as well as protease inhibitor mutations varied by region. The prevalence of drug resistance has remained low in several African countries although the emergence of drug resistance mutations varied across countries. Continued surveillance of antiretroviral therapy resistance remains crucial in gauging the effectiveness of country antiretroviral therapy programs and strategizing on effective and affordable strategies for successful treatment.

  17. HIV-1 Antiretroviral Drug Resistance in Pregnant Women in Jamaica A Preliminary Report

    PubMed Central

    Amarakoon, II; Ramkissoon, A; Pierre, R; Eyzaguirre, LM; Carr, JK; Blattner, WA; Roye, ME

    2014-01-01

    ABSTRACT This preliminary report sought to provide insight into the genetic diversity of human immunodeficiency virus drug resistance (HIVDR) in Jamaica. This was done by investigating the genetic diversity associated with drug resistance in pregnant women living with HIV attending antenatal clinics in Kingston, Jamaica. Blood samples were collected and viral RNA were extracted and analysed. The protease and reverse transcriptase (Pro-RT) genes were amplified using the nested polymerase chain reaction (PCR) method. Polymerase chain reaction amplicons were obtained for nine (56%) of 16 patients, of which five (55%) were antiretroviral (ARV) drug naïve and four (45%) were treatment experienced. Three minor protease inhibitor resistant-conferring mutations (A71AT, A71V, A71T) and five mutations conferring high to low-level resistance (K219EK, T69S, K103S, G190A and K103N) were detected in the RT region. More than 50% of the resistance mutations found were detected in ARV drug naïve individuals, implying that viruses are being transmitted with the ARV resistance. These preliminary results will inform the health practitioners of the level of drug resistance that is being transmitted as well as strengthen the need to initiate a national baseline survey on HIVDR in Jamaica. PMID:25803373

  18. HIV-1 Drug Resistance in the iPrEx Preexposure Prophylaxis Trial

    PubMed Central

    Liegler, Teri; Abdel-Mohsen, Mohamed; Bentley, L. Gordon; Atchison, Robert; Schmidt, Timothy; Javier, Jacqueline; Mehrotra, Megha; Eden, Christopher; Glidden, David V.; McMahan, Vanessa; Anderson, Peter L.; Li, Peilin; Wong, Joseph K.; Buchbinder, Susan; Guanira, Juan V.; Grant, Robert M.

    2014-01-01

    Background. The iPrEx study demonstrated that combination oral emtricitabine and tenofovir disoproxil fumarate (FTC/TDF) as preexposure prophylaxis (PrEP) protects against HIV acquisition in men who have sex with men and transgender women. Selection for drug resistance could offset PrEP benefits. Methods. Phenotypic and genotypic clinical resistance assays characterized major drug resistant mutations. Minor variants with FTC/TDF mutations K65R, K70E, M184V/I were measured using 454 deep sequencing and a novel allele-specific polymerase chain reaction (AS-PCR) diagnostic tolerant to sequence heterogeneity. Results. Control of primer-binding site heterogeneity resulted in improved accuracy of minor variant measurements by AS-PCR. Of the 48 on-study infections randomized to FTC/TDF, none showed FTC/TDF mutations by clinical assays despite detectable drug levels in 8 participants. Two randomized to FTC/TDF had minor variant M184I detected at 0.53% by AS-PCR or 0.75% by deep sequencing, only 1 of which had low but detectable drug levels. Among those with acute infection at randomization to FTC/TDF, M184V or I mutations that were predominant at seroconversion waned to background levels within 24 weeks after discontinuing drug. Conclusions. Drug resistance was rare in iPrEx on-study FTC/TDF-randomized seroconverters, and only as low-frequency minor variants. FTC resistance among those initiating PrEP with acute infection waned rapidly after drug discontinuation. Clinical Trials Registration. NCT00458393. PMID:24740633

  19. Low Prevalence of Transmitted Drug Resistance in Patients Newly Diagnosed with HIV-1 Infection in Sweden 2003–2010

    PubMed Central

    Karlsson, Annika; Björkman, Per; Bratt, Göran; Ekvall, Håkan; Gisslén, Magnus; Sönnerborg, Anders; Mild, Mattias; Albert, Jan

    2012-01-01

    Transmitted drug resistance (TDR) is a clinical and epidemiological problem because it may contribute to failure of antiretroviral treatment. The prevalence of TDR varies geographically, and its prevalence in Sweden during the last decade has not been reported. Plasma samples from 1,463 patients newly diagnosed with HIV-1 infection between 2003 and 2010, representing 44% of all patients diagnosed in Sweden during this period, were analyzed using the WHO 2009 list of mutations for surveillance of TDR. Maximum likelihood phylogenetic analyses were used to determine genetic subtype and to investigate the relatedness of the sequences. Eighty-two patients showed evidence of TDR, representing a prevalence of 5.6% (95% CI: 4.5%–6.9%) without any significant time trends or differences between patients infected in Sweden or abroad. Multivariable logistic regression showed that TDR was positively associated with men who have sex with men (MSM) and subtype B infection and negatively associated with CD4 cell counts. Among patients with TDR, 54 (68%) had single resistance mutations, whereas five patients had multi-drug resistant HIV-1. Phylogenetic analyses identified nine significantly supported clusters involving 29 of the patients with TDR, including 23 of 42 (55%) of the patients with TDR acquired in Sweden. One cluster contained 18 viruses with a M41L resistance mutation, which had spread among MSM in Stockholm over a period of at least 16 years (1994–2010). Another cluster, which contained the five multidrug resistant viruses, also involved MSM from Stockholm. The prevalence of TDR in Sweden 2003–2010 was lower than in many other European countries. TDR was concentrated among MSM, where clustering of TDR strains was observed, which highlights the need for continued and improved measures for targeted interventions. PMID:22448246

  20. Mechanism of Drug Resistance Revealed by the Crystal Structure of the Unliganded HIV-1 Protease with F53L Mutation

    SciTech Connect

    Liu, Fengling; Kovalevsky, Andrey Y.; Louis, John M.; Boross, Peter I.; Wang, Yuan-Fang; Harrison, Robert W.; Weber, Irene T.

    2010-12-03

    Mutations in HIV-1 protease (PR) that produce resistance to antiviral PR inhibitors are a major problem in AIDS therapy. The mutation F53L arising from antiretroviral therapy was introduced into the flexible flap region of the wild-type PR to study its effect and potential role in developing drug resistance. Compared to wild-type PR, PR{sub F53L} showed lower (15%) catalytic efficiency, 20-fold weaker inhibition by the clinical drug indinavir, and reduced dimer stability, while the inhibition constants of two peptide analog inhibitors were slightly lower than those for PR. The crystal structure of PR{sub F53L} was determined in the unliganded form at 1.35 {angstrom} resolution in space group P4{sub 1}2{sub 1}2. The tips of the flaps in PR{sub F53L} had a wider separation than in unliganded wild-type PR, probably due to the absence of hydrophobic interactions of the side-chains of Phe53 and Ile50{prime}. The changes in interactions between the flaps agreed with the reduced stability of PR{sub F53L} relative to wild-type PR. The altered flap interactions in the unliganded form of PR{sub F53L} suggest a distinct mechanism for drug resistance, which has not been observed in other common drug-resistant mutants.

  1. HIV-1 Genetic Diversity and Transmitted Drug Resistance Among Recently Infected Individuals at Men Who Have Sex with Men Sentinel Surveillance Points in Hebei Province, China.

    PubMed

    Lu, Xinli; Kang, Xianjiang; Chen, Suliang; Zhao, Hongru; Liu, Yongjian; Zhao, Cuiying; Zhang, Yuqi; Li, Jingyun; Cui, Ze; Wang, Xianfeng

    2015-10-01

    For this study, 50 HIV-1 plasma samples of recently infected men who have sex with men (MSM) were amplified and sequenced. Multiple subtypes were identified by phylogenetic analyses of HIV-1 gag, env, and pol gene regions, including CRF01_AE (56.0%), CRF07_BC (30.0%), subtype B (12.0%), and unique recombinant forms (URFs, 6.0%). CRF01_AE was the most frequent genotype in the epidemic. Three recombination patterns of URFs were identified: 01BC, 01B, and 01C. The rate of HIV-1 transmitted drug resistance (TDR) mutation (M46L) was 2.08% (1/48). URFs and TDR first identified in this study suggest that HIV-1 prevalence is more and more complicated, and HIV-1 drug-resistant strains have begun to spread among at risk populations in Hebei. Our findings can provide vital information for an efficient surveillance system and strategic HIV prevention and control measures in China by revealing the evolutionary status and HIV-1 TDR of HIV-1 strains among recently infected MSM in Hebei Province.

  2. Use of Dried Plasma Spots for HIV-1 Viral Load Determination and Drug Resistance Genotyping in Mexican Patients.

    PubMed

    Rodriguez-Auad, Juan Pablo; Rojas-Montes, Othon; Maldonado-Rodriguez, Angelica; Alvarez-Muñoz, Ma Teresa; Muñoz, Onofre; Torres-Ibarra, Rocio; Vazquez-Rosales, Guillermo; Lira, Rosalia

    2015-01-01

    Monitoring antiretroviral therapy using measurements of viral load (VL) and the genotyping of resistance mutations is not routinely performed in low- to middle-income countries because of the high costs of the commercial assays that are used. The analysis of dried plasma spot (DPS) samples on filter paper may represent an alternative for resource-limited settings. Therefore, we evaluated the usefulness of analyzing DPS samples to determine VL and identify drug resistance mutations (DRM) in a group of HIV-1 patients. The VL was measured from 22 paired plasma and DPS samples. In these samples, the average VL was 4.7 log10 copies/mL in liquid plasma and 4.1 log10 copies/mL in DPS, with a correlation coefficient of R = 0.83. A 1.1 kb fragment of HIV pol could be amplified in 14/22 (63.6%) of the DPS samples and the same value was amplified in plasma samples. A collection of ten paired DPS and liquid plasma samples was evaluated for the presence of DRM; an excellent correlation was found in the identification of DRM between the paired samples. All HIV-1 pol sequences that were obtained corresponded to HIV subtype B. The analysis of DPS samples offers an attractive alternative for monitoring ARV therapy in resource-limited settings.

  3. Use of Dried Plasma Spots for HIV-1 Viral Load Determination and Drug Resistance Genotyping in Mexican Patients

    PubMed Central

    Rodriguez-Auad, Juan Pablo; Rojas-Montes, Othon; Maldonado-Rodriguez, Angelica; Alvarez-Muñoz, Ma. Teresa; Muñoz, Onofre; Torres-Ibarra, Rocio; Vazquez-Rosales, Guillermo

    2015-01-01

    Monitoring antiretroviral therapy using measurements of viral load (VL) and the genotyping of resistance mutations is not routinely performed in low- to middle-income countries because of the high costs of the commercial assays that are used. The analysis of dried plasma spot (DPS) samples on filter paper may represent an alternative for resource-limited settings. Therefore, we evaluated the usefulness of analyzing DPS samples to determine VL and identify drug resistance mutations (DRM) in a group of HIV-1 patients. The VL was measured from 22 paired plasma and DPS samples. In these samples, the average VL was 4.7 log10 copies/mL in liquid plasma and 4.1 log10 copies/mL in DPS, with a correlation coefficient of R = 0.83. A 1.1 kb fragment of HIV pol could be amplified in 14/22 (63.6%) of the DPS samples and the same value was amplified in plasma samples. A collection of ten paired DPS and liquid plasma samples was evaluated for the presence of DRM; an excellent correlation was found in the identification of DRM between the paired samples. All HIV-1 pol sequences that were obtained corresponded to HIV subtype B. The analysis of DPS samples offers an attractive alternative for monitoring ARV therapy in resource-limited settings. PMID:26779533

  4. Identification of Drug Resistant Mutations in HIV-1 CRF07_BC Variants Selected by Nevirapine In Vitro

    PubMed Central

    Wu, Hao; Zhang, Hao-Jie; Zhang, Xiao-min; Xu, Hui-fang; Wang, Ming; Huang, Jian-dong; Zheng, Bo-Jian

    2012-01-01

    Since the antiretroviral therapy (ART) was introduced to patients infected by human immunodeficiency virus (HIV), the HIV related mortality and morbidity have been significantly reduced. The major obstacle for long-term successful anti-HIV treatment is the emergence of drug resistant mutants. Current data of drug resistance was mainly obtained on HIV-1 subtype B but rarely on non-B virus, even more rare with newly emerged circulating recombinant forms (CRFs). The lack of such data limits the rational management of ART for the increasing number of patients infected by non-subtype B virus. In this study, a HIV-1 CRF07_BC strain CNGZD was isolated from a HIV patient and its genome was sequenced and deposited in GenBank (JQ423923). Potential drug resistant mutants of this CRF07_BC virus strain were selected in PBMCs cultures in the presence of Nevirapine (NVP), which is the most frequently used antiretroviral drug in China. Four combination profiles of mutations were identified in the NVP-selected mutants, which were initiated with A98G, V108I, Y181C and I135T/I382L and followed by more than two other mutations at the end of the selections, respectively. A total of seven previously reported mutations (A98G, V106M, V108I, I135T, Y181C, V189I, K238N) and seven novel mutations (P4H, T48I, I178M, V314A, I382L/V, T386A) in the reverse transcriptase gene were found in these NVP-selected mutants. Phenotypic analysis in the NVP-selected mutants showed that all the mutations, except P4H, contribute to NVP resistance. Among them, V106M and Y181C reduce NVP susceptibility for more than 20-fold, while the other mutations cause less than 20 folds drug resistance. Although the information obtained in this in vitro selection study may not fully cover resistant mutations which will actually occur in patients, it has still provided useful information for rational management of ART in patients infected with HIV CRF_BC subtype. PMID:22984494

  5. High prevalence of HIV-1 drug resistance among patients on first-line antiretroviral treatment in Lomé, Togo

    PubMed Central

    2011-01-01

    Background With widespread use of antiretroviral (ARV) drugs in Africa, one of the major potential challenges is the risk of emergence of ARV drug-resistant HIV strains. Our objective is to evaluate the virological failure and genotypic drug-resistance mutations in patients receiving first-line highly active antiretroviral therapy (HAART) in routine clinics that use the World Health Organization public health approach to monitor antiretroviral treatment (ART) in Togo. Methods Patients on HAART for one year (10-14 months) were enrolled between April and October 2008 at three sites in Lomé, the capital city of Togo. Plasma viral load was measured with the NucliSENS EasyQ HIV-1 assay (Biomérieux, Lyon, France) and/or a Generic viral load assay (Biocentric, Bandol, France). Genotypic drug-resistance testing was performed with an inhouse assay on plasma samples from patients with viral loads of more than 1000 copies/ml. CD4 cell counts and demographic data were also obtained from medical records. Results A total of 188 patients receiving first-line antiretroviral treatment were enrolled, and 58 (30.8%) of them experienced virologic failure. Drug-resistance mutations were present in 46 patients, corresponding to 24.5% of all patients enrolled in the study. All 46 patients were resistant to non-nucleoside reverse-transcriptase inhibitors (NNRTIs): of these, 12 were resistant only to NNRTIs, 25 to NNRTIs and lamivudine/emtricitabine, and eight to all three drugs of their ARV regimes. Importantly, eight patients were already predicted to be resistant to etravirine, the new NNRTI, and three patients harboured the K65R mutation, inducing major resistance to tenofovir. Conclusions In Togo, efforts to provide access to ARV therapy for infected persons have increased since 2003, and scaling up of ART started in 2007. The high number of resistant strains observed in Togo shows clearly that the emergence of HIV drug resistance is of increasing concern in countries where ART is

  6. Prevalence of drug resistance mutations in HAART patients infected with HIV-1 CRF06_cpx in Estonia.

    PubMed

    Avi, Radko; Pauskar, Merit; Karki, Tõnis; Kallas, Eveli; Jõgeda, Ene-Ly; Margus, Tõnu; Huik, Kristi; Lutsar, Irja

    2016-03-01

    HIV-1 drug resistance mutations (DRMs) and substitutions were assessed after the failure of the first line non-nucleoside reverse transcriptase inhibitors (NNRTIs) + 2 nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs) treatment regimens (efavirenz [EFV] + lamivudine[3TC] + zidovudine [ZDV] vs. EFV + 3TC + ddI) among the HIV-1 CRF06_cpx infected subjects in Estonia. HIV-1 genomic RNA was sequenced; DRMs and amino acid substitutions were compared in 44 treatment naïve and 45 first-line NNRTI + 2 NRTI treatment failed patients consisting of EFV + 3TC + ZDV (n = 17) and EFV + 3TC + didanosine[ddI] (n = 21) therapy failed sub-populations. At least one DRM was found in 78% of treatment experienced patients. The most common NRTI mutations were M184V (80%), L74V (31%), L74I (17%), K219E (9%), and M184I (9%), NNRTI mutations were K103N (83%), P225H (14%), L100I (11%), and Y188L (11%), reflecting generally the similar pattern of DRMs to that seen in treatment failed subtype B viruses. Sub-population analysis revealed that EFV + 3TC + ddI failed patients had more DRMs compared to EFV + 3TC + ZDV failed patients, especially the ddI DRM L74IV and several additional NNRTI DRMs. Additionally, CRF06_cpx specific mutation E179V and substitutions R32K, K122E, and V200AE were also detected in treatment experienced population. After the failure of the first-line EFV + 3TC + ddI therapy HIV-1 CRF06_cpx viruses develop additional NRTI and NNRTI mutations compared to EFV + 3TC + ZDV regimen. Therefore the usage of EFV + 3TC + ddI in this subtype decreases the options for next regimens containing abacavir, and NNRTI class agents.

  7. Field Study of Dried Blood Spot Specimens for HIV-1 Drug Resistance Genotyping

    PubMed Central

    Parry, C. M.; Diallo, K.; Mwebaza, S.; Batamwita, R.; DeVos, J.; Bbosa, N.; Lyagoba, F.; Magambo, B.; Jordan, M. R.; Downing, R.; Zhang, G.; Kaleebu, P.; Bertagnolio, S.

    2014-01-01

    Dried blood spots (DBS) are an alternative specimen type for HIV drug resistance genotyping in resource-limited settings. Data relating to the impact of DBS storage and shipment conditions on genotyping efficiency under field conditions are limited. We compared the genotyping efficiencies and resistance profiles of DBS stored and shipped at different temperatures to those of plasma specimens collected in parallel from patients receiving antiretroviral therapy in Uganda. Plasma and four DBS cards from anti-coagulated venous blood and a fifth card from finger-prick blood were prepared from 103 HIV patients with a median viral load (VL) of 57,062 copies/ml (range, 1,081 to 2,964,191). DBS were stored at ambient temperature for 2 or 4 weeks or frozen at −80°C and shipped from Uganda to the United States at ambient temperature or frozen on dry ice for genotyping using a broadly sensitive in-house method. Plasma (97.1%) and DBS (98.1%) stored and shipped frozen had similar genotyping efficiencies. DBS stored frozen (97.1%) or at ambient temperature for 2 weeks (93.2%) and shipped at ambient temperature also had similar genotyping efficiencies. Genotyping efficiency was reduced for DBS stored at ambient temperature for 4 weeks (89.3%, P = 0.03) or prepared from finger-prick blood and stored at ambient temperature for 2 weeks (77.7%, P < 0.001) compared to DBS prepared from venous blood and handled similarly. Resistance profiles were similar between plasma and DBS specimens. This report delineates the optimal DBS collection, storage, and shipping conditions and opens a new avenue for cost-saving ambient-temperature DBS specimen shipments for HIV drug resistance (HIVDR) surveillances in resource-limited settings. PMID:24871219

  8. Combinations of reverse transcriptase, protease, and integrase inhibitors can be synergistic in vitro against drug-sensitive and RT inhibitor-resistant molecular clones of HIV-1.

    PubMed

    Beale, K K; Robinson, W E

    2000-06-01

    Combinations of anti-HIV agents including one or two reverse transcriptase inhibitors with a protease inhibitor are potent and effective. However, toxicities, costs and the emergence of drug-resistant organisms have compromised their long-term efficacy in people. A next, likely, target for anti-HIV therapy is HIV-1 integrase. Viral integration, catalyzed by integrase, is absolutely required for HIV replication. L-chicoric acid is a potent and selective inhibitor of HIV-1 integrase that also inhibits HIV-1 replication in cell culture. As a first step in understanding the potential role for integrase inhibitors in clinical medicine, the activities of L-chicoric acid alone and in combination with 2', 3'-dideoxycytidine, zidovudine, and a protease inhibitor, nelfinavir, were tested in vitro against molecular clones of HIV-1 resistant to reverse transcriptase inhibitors. L-chicoric acid was equally effective against a wild-type clone of HIV-1, HIV(NL4-3), or against HIV-1 resistant to either zidovudine or dideoxycytidine. L-chicoric acid was largely synergistic with zidovudine and synergistic with both dideoxycytidine and nelfinavir.

  9. Stability of dried blood spots for HIV-1 drug resistance analysis.

    PubMed

    Hearps, Anna C; Ryan, Claire E; Morris, Lisa M; Plate, Megan M; Greengrass, Vicki; Crowe, Suzanne M

    2010-03-01

    The wide scale application of dried blood spots (DBS) as a collection tool for low-cost HIV drug resistance testing requires a greater understanding of the accuracy of DBS for genotype analysis and the stability of DBS under various environmental conditions. Analysis of a 50microl DBS via a single amplicon, nested PCR-based in-house assay (the Burnet genotyping assay) showed an average nucleotide concordance of 98.9% with plasma samples, although only 65% of nucleotide mixtures detected in plasma were also detected within DBS. The analysis of three DBS resulted in the detection of a greater number of nucleotide mixtures (72 and 109 mixtures detected within one and three DBS, respectively, n=10). Two DBS extraction protocols (silica particle; NucliSENS, bioMerieux and spin column extraction; High Pure, Roche) were assessed and found to be equivalent (79% and 84% recovery success respectively, n=19). FTA Elute paper (Whatman) was an inferior DBS collection medium compared to Whatman 903 paper. DBS appeared relatively tolerant to multiple freeze/thaw cycles, with 79% of DBS subjected to ten freeze/thaw cycles successfully amplified compared to 93% of DBS defrosted once (n=14). High temperature (37 degrees C) and high humidity (>90%) substantially impaired DBS recovery within two weeks of storage (38%, n=8), whilst storage at -20 degrees C or 4 degrees C adequately preserved DBS for this period (100% recovery, n=8). Therefore, whilst DBS are suitable for HIV drug resistance surveillance, the use of multiple DBS may be required to ensure accurate detection of minor HIV quasispecies and short-term storage of samples at either 4 degrees C or -20 degrees C is recommended.

  10. Trends in Prevalence of HIV-1 Drug Resistance in a Public Clinic in Maputo, Mozambique

    PubMed Central

    Bila, Dulce Celina Adolfo; Boullosa, Lídia Teodoro; Abreu, Celina Monteiro; Jani, Ilesh Vinodrai; Tanuri, Amilcar

    2015-01-01

    Background An observational study was conducted in Maputo, Mozambique, to investigate trends in prevalence of HIV drug resistance (HIVDR) in antiretroviral (ART) naïve subjects initiating highly active antiretroviral treatment (HAART). Methodology/Principal Findings To evaluate the pattern of drug resistance mutations (DRMs) found in adults on ART failing first-line HAART [patients with detectable viral load (VL)]. Untreated subjects [Group 1 (G1; n=99)] and 274 treated subjects with variable length of exposure to ARV´s [6–12 months, Group 2 (G2;n=93); 12-24 months, Group 3 (G3;n=81); >24 months (G4;n=100)] were enrolled. Virological and immunological failure (VF and IF) were measured based on viral load (VL) and T lymphocyte CD4+ cells (TCD4+) count and genotypic resistance was also performed. Major subtype found was C (untreated: n=66, 97,06%; treated: n=36, 91.7%). Maximum virological suppression was observed in G3, and significant differences intragroup were observed between VF and IF in G4 (p=0.022). Intergroup differences were observed between G3 and G4 for VF (p=0.023) and IF between G2 and G4 (p=0.0018). Viral suppression (<50 copies/ml) ranged from 84.9% to 90.1%, and concordant VL and DRM ranged from 25% to 57%. WHO cut-off for determining VF as given by 2010 guidelines (>5000 copies/ml) identified 50% of subjects carrying DRM compared to 100% when lower VL cut-off was used (<50 copies/ml). Length of exposure to ARVs was directly proportional to the complexity of DRM patterns. In Mozambique, VL suppression was achieved in 76% of individuals after 24 months on HAART. This is in agreement with WHO target for HIVDR prevention target (70%). Conclusions We demonstrated that the best way to determine therapeutic failure is VL compared to CD4 counts. The rationalized use of VL testing is needed to ensure timely detection of treatment failures preventing the occurrence of TDR and new infections. PMID:26151752

  11. HIV gp120 H375 is unique to HIV-1 subtype CRF01_AE and confers strong resistance to the entry inhibitor BMS-599793, a candidate microbicide drug.

    PubMed

    Schader, Susan M; Colby-Germinario, Susan P; Quashie, Peter K; Oliveira, Maureen; Ibanescu, Ruxandra-Ilinca; Moisi, Daniela; Mespléde, Thibault; Wainberg, Mark A

    2012-08-01

    BMS-599793 is a small molecule entry inhibitor that binds to human immunodeficiency virus type 1 (HIV-1) gp120, resulting in the inhibition of CD4-dependent entry into cells. Since BMS-599793 is currently considered a candidate microbicide drug, we evaluated its efficacy against a number of primary patient HIV isolates from different subtypes and circulating recombinant forms (CRFs) and showed that activity varied between ∼3 ρM and 7 μM at 50% effective concentrations (EC(50)s). Interestingly, CRF01_AE HIV-1 isolates consistently demonstrated natural resistance against this compound. Genotypic analysis of >1,600 sequences (Los Alamos HIV sequence database) indicated that a single amino acid polymorphism in Env, H375, may account for the observed BMS-599793 resistance in CRF01_AE HIV-1. Results of site-directed mutagenesis experiments confirmed this hypothesis, and in silico drug docking simulations identified a drug resistance mechanism at the molecular level. In addition, CRF01_AE viruses were shown to be resistant to multiple broadly neutralizing monoclonal antibodies. Thus, our results not only provide insight into how Env polymorphisms may contribute to entry inhibitor resistance but also may help to elucidate how HIV can evade some broadly neutralizing antibodies. Furthermore, the high frequency of H375 in CRF01_AE HIV-1, and its apparent nonoccurrence in other subtypes, could serve as a means for rapid identification of CRF01_AE infections.

  12. Outbreak of infections by hepatitis B virus genotype A and transmission of genetic drug resistance in patients coinfected with HIV-1 in Japan.

    PubMed

    Fujisaki, Seiichiro; Yokomaku, Yoshiyuki; Shiino, Teiichiro; Koibuchi, Tomohiko; Hattori, Junko; Ibe, Shiro; Iwatani, Yasumasa; Iwamoto, Aikichi; Shirasaka, Takuma; Hamaguchi, Motohiro; Sugiura, Wataru

    2011-03-01

    The major routes of hepatitis B virus (HBV) infection in Japan has been mother-to-child transmission (MTCT) and blood transfusion. However, HBV cases transmitted through sexual contact are increasing, especially among HIV-1-seropositive patients. To understand the molecular epidemiology of HBV in HBV/HIV-1 coinfection, we analyzed HBV genotypes and HIV-1 subtypes in HBV/HIV-1-coinfected patients at Nagoya Medical Center from 2003 to 2007. Among 394 HIV-1-infected Japanese men having sex with men (MSM) who were newly diagnosed during the study period, 31 (7.9%) tested positive for the hepatitis B virus surface antigen. HBV sequence analyses were successful in 26 cases, with 21 (80.7%) and 5 (19.3%) cases determined as genotypes A and C, respectively. Our finding that HBV genotype A was dominant in HIV-1-seropositive patients alerts clinicians to an alternative outbreak of HBV genotype A in the HIV-1-infected MSM population and a shift in HBV genotype from C to A in Japan. The narrow genetic diversity in genotype A cases suggests that genotype A has been recently introduced into the MSM population and that sexual contacts among MSM were more active than speculated from HIV-1 tree analyses. In addition, we found a lamivudine resistance mutation in one naïve case, suggesting a risk of drug-resistant HBV transmission. As genotype A infection has a higher risk than infection with other genotypes for individuals to become HBV carriers, prevention programs are urgently needed for the target population.

  13. HIV-1 Diversity and Drug Resistance Mutations among People Seeking HIV Diagnosis in Voluntary Counseling and Testing Sites in Rio de Janeiro, Brazil

    PubMed Central

    Velasco-de-Castro, Carlos A.; Grinsztejn, Beatriz; Veloso, Valdiléa G.; Bastos, Francisco I.; Pilotto, José H.; Fernandes, Nilo; Morgado, Mariza G.

    2014-01-01

    The remarkable viral diversity remains a big challenge to the development of HIV vaccines and optimal therapy worldwide. In the latest years, as a consequence of the large expansion of highly active antiretroviral therapy (HAART) availability worldwide, an increase in transmitted drug resistance mutations (TDRM) has been observed, varying according the region. This study assessed HIV-1 diversity and TDRM profile over time among newly HIV-1 diagnosed individuals from Rio de Janeiro, Brazil. Blood samples were collected from individuals seeking HIV diagnosis in four voluntary counseling and testing (VCTs) sites located in the Rio de Janeiro Metropolitan Area, in 2005–2007. Recent (RS) and long-term (LTS) HIV-1 seroconverters were distinguished using BED-CEIA. Pol viral sequences were obtained for 102 LTS identified in 2005 and 144 RS from 2005–2007. HIV-1 subtype and pol recombinant genomes were determined using Rega HIV-1 Subtyping Tool and by phylogenetic inferences and bootscanning analyses. Surveillance of HIV-1 TDRM to protease and reverse transcriptase inhibitors were performed according to the Calibrated Population Resistance (CPR) Tool 6.0. Overall, subtype B remains the most prevalent in Rio de Janeiro in both LTS and RS HIV-1 infected individuals. An increased proportion of recombinant samples was detected over time, especially in RS heterosexual men, due to the emergence of CRF02_AG and URF samples bearing a subtype K fragment. The prevalence of HIV-1 samples carrying TDRM was high and similar between LTS and RS (15.7% vs 14.6%) or age (<25yo 17.9% vs >25yo 16.6%) along the study period. The high resistance levels detected in both populations are of concern, especially considering the dynamics of HIV-1 diversity over time. Our results suggest that the incorporation of resistance testing prior to HAART initiation should be highly considered, as well as permanent surveillance, aiming to carefully monitoring HIV-1 diversity, with focus on CRF

  14. Capacity building and predictors of success for HIV-1 drug resistance testing in the Asia-Pacific region and Africa

    PubMed Central

    Land, Sally; Zhou, Julian; Cunningham, Philip; Sohn, Annette H; Singtoroj, Thida; Katzenstein, David; Mann, Marita; Sayer, David; Kantor, Rami

    2013-01-01

    Background The TREAT Asia Quality Assessment Scheme (TAQAS) was developed as a quality assessment programme through expert education and training, for laboratories in the Asia-Pacific and Africa that perform HIV drug-resistance (HIVDR) genotyping. We evaluated the programme performance and factors associated with high-quality HIVDR genotyping. Methods Laboratories used their standard protocols to test panels of human immunodeficiency virus (HIV)-positive plasma samples or electropherograms. Protocols were documented and performance was evaluated according to a newly developed scoring system, agreement with panel-specific consensus sequence, and detection of drug-resistance mutations (DRMs) and mixtures of wild-type and resistant virus (mixtures). High-quality performance was defined as detection of ≥95% DRMs. Results Over 4.5 years, 23 participating laboratories in 13 countries tested 45 samples (30 HIV-1 subtype B; 15 non-B subtypes) in nine panels. Median detection of DRMs was 88–98% in plasma panels and 90–97% in electropherogram panels. Laboratories were supported to amend and improve their test outcomes as appropriate. Three laboratories that detected <80% DRMs in early panels demonstrated subsequent improvement. Sample complexity factors – number of DRMs (p<0.001) and number of DRMs as mixtures (p<0.001); and laboratory performance factors – detection of mixtures (p<0.001) and agreement with consensus sequence (p<0.001), were associated with high performance; sample format (plasma or electropherogram), subtype and genotyping protocol were not. Conclusion High-quality HIVDR genotyping was achieved in the TAQAS collaborative laboratory network. Sample complexity and detection of mixtures were associated with performance quality. Laboratories conducting HIVDR genotyping are encouraged to participate in quality assessment programmes. PMID:23845227

  15. Increasing HIV-1 pretreatment drug resistance among antiretroviral-naïve adults initiating treatment between 2006 and 2014 in Nairobi, Kenya.

    PubMed

    Chung, Michael H; Silverman, Rachel; Beck, Ingrid A; Yatich, Nelly; Dross, Sandra; McKernan-Mullin, Jennifer; Bii, Stephen; Tapia, Kenneth; Stern, Joshua; Chohan, Bhavna; Sakr, Samah R; Kiarie, James N; Frenkel, Lisa M

    2016-06-19

    Antiretroviral-naïve adults initiating antiretroviral therapy in Nairobi, Kenya were tested for HIV-1 drug resistance at codons K103N, Y181C, G190A, M184V, and K65R using an oligonucleotide ligation assay. Prevalence of pretreatment drug resistance increased from 3.89% in 2006 to 10.93% in 2014 (P < 0.001), and 95% of those with resistance had at least one nonnucleoside reverse transcriptase inhibitor mutation. Resistance to tenofovir (K65R) was found in 2014 but not in 2006.

  16. Profile of the HIV Epidemic in Cape Verde: Molecular Epidemiology and Drug Resistance Mutations among HIV-1 and HIV-2 Infected Patients from Distinct Islands of the Archipelago

    PubMed Central

    de Pina-Araujo, Isabel Inês M.; Guimarães, Monick L.; Bello, Gonzalo; Vicente, Ana Carolina P.; Morgado, Mariza G.

    2014-01-01

    HIV-1 and HIV-2 have been detected in Cape Verde since 1987, but little is known regarding the genetic diversity of these viruses in this archipelago, located near the West African coast. In this study, we characterized the molecular epidemiology of HIV-1 and HIV-2 and described the occurrence of drug resistance mutations (DRM) among antiretroviral therapy naïve (ARTn) patients and patients under treatment (ARTexp) from different Cape Verde islands. Blood samples, socio-demographic and clinical-laboratory data were obtained from 221 HIV-positive individuals during 2010–2011. Phylogenetic and bootscan analyses of the pol region (1300 bp) were performed for viral subtyping. HIV-1 and HIV-2 DRM were evaluated for ARTn and ARTexp patients using the Stanford HIV Database and HIV-GRADE e.V. Algorithm Homepage, respectively. Among the 221 patients (169 [76.5%] HIV-1, 43 [19.5%] HIV-2 and 9 [4.1%] HIV-1/HIV-2 co-infections), 67% were female. The median ages were 34 (IQR = 1–75) and 47 (IQR = 12–84) for HIV-1 and HIV-2, respectively. HIV-1 infections were due to subtypes G (36.6%), CRF02_AG (30.6%), F1 (9.7%), URFs (10.4%), B (5.2%), CRF05_DF (3.0%), C (2.2%), CRF06_cpx (0.7%), CRF25_cpx (0.7%) and CRF49_cpx (0.7%), whereas all HIV-2 infections belonged to group A. Transmitted DRM (TDRM) was observed in 3.4% (2/58) of ARTn HIV-1-infected patients (1.7% NRTI, 1.7% NNRTI), but not among those with HIV-2. Among ARTexp patients, DRM was observed in 47.8% (33/69) of HIV-1 (37.7% NRTI, 37.7% NNRTI, 7.4% PI, 33.3% for two classes) and 17.6% (3/17) of HIV-2-infections (17.6% NRTI, 11.8% PI, 11.8% both). This study indicates that Cape Verde has a complex and unique HIV-1 molecular epidemiological scenario dominated by HIV-1 subtypes G, CRF02_AG and F1 and HIV-2 subtype A. The occurrence of TDRM and the relatively high level of DRM among treated patients are of concern. Continuous monitoring of patients on ART, including genotyping, are public policies to be

  17. Profile of the HIV epidemic in Cape Verde: molecular epidemiology and drug resistance mutations among HIV-1 and HIV-2 infected patients from distinct islands of the archipelago.

    PubMed

    de Pina-Araujo, Isabel Inês M; Guimarães, Monick L; Bello, Gonzalo; Vicente, Ana Carolina P; Morgado, Mariza G

    2014-01-01

    HIV-1 and HIV-2 have been detected in Cape Verde since 1987, but little is known regarding the genetic diversity of these viruses in this archipelago, located near the West African coast. In this study, we characterized the molecular epidemiology of HIV-1 and HIV-2 and described the occurrence of drug resistance mutations (DRM) among antiretroviral therapy naïve (ARTn) patients and patients under treatment (ARTexp) from different Cape Verde islands. Blood samples, socio-demographic and clinical-laboratory data were obtained from 221 HIV-positive individuals during 2010-2011. Phylogenetic and bootscan analyses of the pol region (1300 bp) were performed for viral subtyping. HIV-1 and HIV-2 DRM were evaluated for ARTn and ARTexp patients using the Stanford HIV Database and HIV-GRADE e.V. Algorithm Homepage, respectively. Among the 221 patients (169 [76.5%] HIV-1, 43 [19.5%] HIV-2 and 9 [4.1%] HIV-1/HIV-2 co-infections), 67% were female. The median ages were 34 (IQR = 1-75) and 47 (IQR = 12-84) for HIV-1 and HIV-2, respectively. HIV-1 infections were due to subtypes G (36.6%), CRF02_AG (30.6%), F1 (9.7%), URFs (10.4%), B (5.2%), CRF05_DF (3.0%), C (2.2%), CRF06_cpx (0.7%), CRF25_cpx (0.7%) and CRF49_cpx (0.7%), whereas all HIV-2 infections belonged to group A. Transmitted DRM (TDRM) was observed in 3.4% (2/58) of ARTn HIV-1-infected patients (1.7% NRTI, 1.7% NNRTI), but not among those with HIV-2. Among ARTexp patients, DRM was observed in 47.8% (33/69) of HIV-1 (37.7% NRTI, 37.7% NNRTI, 7.4% PI, 33.3% for two classes) and 17.6% (3/17) of HIV-2-infections (17.6% NRTI, 11.8% PI, 11.8% both). This study indicates that Cape Verde has a complex and unique HIV-1 molecular epidemiological scenario dominated by HIV-1 subtypes G, CRF02_AG and F1 and HIV-2 subtype A. The occurrence of TDRM and the relatively high level of DRM among treated patients are of concern. Continuous monitoring of patients on ART, including genotyping, are public policies to be implemented.

  18. Clinical and virologic follow-up in perinatally HIV-1-infected children and adolescents in Madrid with triple-class antiretroviral drug-resistant viruses.

    PubMed

    Rojas Sánchez, P; de Mulder, M; Fernandez-Cooke, E; Prieto, L; Rojo, P; Jiménez de Ory, S; José Mellado, M; Navarro, M; Tomas Ramos, J; Holguín, Á

    2015-06-01

    Drug resistance mutations compromise the success of antiretroviral treatment in human immunodeficiency virus type 1 (HIV-1)-infected children. We report the virologic and clinical follow-up of the Madrid cohort of perinatally HIV-infected children and adolescents after the selection of triple-class drug-resistant mutations (TC-DRM). We identified patients from the cohort carrying HIV-1 variants with TC-DRM to nucleoside reverse transcriptase inhibitors, nonnucleoside reverse transcriptase inhibitors and protease inhibitors according to IAS-USA-2013. We recovered pol sequences or resistance profiles from 2000 to 2011 and clinical-immunologic-virologic data from the moment of TC-DRM detection until December 2013. Viruses harbouring TC-DRM were observed in 48 (9%) of the 534 children and adolescents from 2000 to 2011, rising to 24.4% among those 197 with resistance data. Among them, 95.8% were diagnosed before 2003, 91.7% were Spaniards, 89.6% carried HIV-1-subtype B and 75% received mono/dual therapy as first regimen. The most common TC-DRM present in ≥50% of them were D67NME, T215FVY, M41L and K103N (retrotranscriptase) and L90M (protease). The susceptibility to darunavir, tipranavir, etravirine and rilpivirine was 67.7%, 43.7%, 33.3% and 33.3%, respectively, and all reported high resistance to didanosine, abacavir and nelfinavir. Despite the presence of HIV-1 resistance mutations to the three main antiretroviral families in our paediatric cohort, some drugs maintained their susceptibility, mainly the new protease inhibitors (tipranavir and darunavir) and nonnucleoside reverse transcriptase inhibitors (etravirine and rilpivirine). These data will help to improve the clinical management of HIV-infected children with triple resistance in Spain.

  19. HIV-1 Drug Resistance and Second-line Treatment in Children Randomized to Switch at Low versus Higher RNA Thresholds

    PubMed Central

    Harrison, Linda; Melvin, Ann; Fiscus, Susan; Saidi, Yacine; Nastouli, Eleni; Harper, Lynda; Compagnucci, Alexandra; Babiker, Abdel; McKinney, Ross; Gibb, Diana; Tudor-Williams, Gareth

    2015-01-01

    Background The PENPACT-1 trial compared virologic thresholds to determine when to switch to second-line antiretroviral therapy (ART). Using PENPACT-1 data, we aimed to describe HIV-1 drug resistance accumulation on first-line ART by virologic threshold. Methods PENPACT-1 had a 2x2 factorial design, randomizing HIV-infected children to start protease inhibitor (PI) versus non-nucleoside reverse transcriptase inhibitor (NNRTI) based ART, and switch at a 1000c/ml versus 30000c/ml threshold. Switch-criteria were: not achieving the threshold by week 24, confirmed rebound above the threshold thereafter, or CDC-C event. Resistance tests were performed on samples ≥1000c/ml before switch, re-suppression and at 4-year/trial-end. Results Sixty-seven children started PI-based ART and were randomized to switch at 1000c/ml (PI-1000), 64 PIs and 30000c/ml (PI-30000), 67 NNRTIs and 1000c/ml (NNRTI-1000), and 65 NNRTI and 30000c/ml (NNRTI-30000). Ninety-four (36%) children reached the 1000c/ml switch-criteria during 5 years follow-up. In 30000c/ml threshold arms, median time from 1000c/ml to 30000c/ml switch-criteria was 58 (PI) versus 80 (NNRTI) weeks (P=0.81). In NNRTI-30000 more NRTI resistance mutations accumulated than other groups. NNRTI mutations were selected before switching at 1000c/ml (23% NNRTI-1000, 27% NNRTI-30000). Sixty-two children started abacavir+lamivudine, 166 lamivudine+zidovudine or stavudine, and 35 other NRTIs. The abacavir+lamivudine group acquired fewest NRTI mutations. Of 60 switched to second-line, 79% PI-1000, 63% PI-30000, 64% NNRTI-1000 and 100% NNRTI-30000 were <400c/ml 24 weeks later. Conclusion Children on first-line NNRTI-based ART who were randomized to switch at a higher virologic threshold developed the most resistance, yet re-suppressed on second-line. An abacavir+lamivudine NRTI combination seemed protective against development of NRTI resistance. PMID:26322666

  20. Phylogenetic analysis of HIV-1 subtypes and drug resistance profile among treatment-naïve people in Kuwait.

    PubMed

    Chehadeh, Wassim; Albaksami, Osama; Altawalah, Haya; Ahmad, Suhail; Madi, Nada; John, Sonia E; Abraham, Priya S; Al-Nakib, Widad

    2015-09-01

    Mutations associated with resistance to antiretroviral therapy are a major cause of failure to treatment, and surveillance for the emergence of HIV resistance became a component of all antiretroviral treatment programs. As transmission of resistant viruses to newly infected persons is possible, we aimed to determine the prevalence of primary mutations associated with antiretroviral resistance among treatment-naïve patients, with respect to HIV subtype. Viral RNA was extracted from plasma samples of 43 treatment-naïve patients. Protease (PR) and reverse transcriptase (RT) regions were amplified and sequenced using the TRUGENE HIV-1 Genotyping Assay. A phylogenetic analysis was performed for HIV subtype assignment. Complete sequence information could be obtained for 35 patients. A total of ten different HIV-1 subtypes and recombinant forms were found in Kuwait with predominance of subtypes B, C, and CRF01_AE. A62V and A98G were non-polymorphic resistance-associated mutations (RAMs) detected in the RT region of two and three patients, respectively. Non-polymorphic mutations associated with resistance to protease inhibitors were not detected. Our results support continuous surveillance of RAMs in newly infected individuals to assess the effectiveness of first-line antiretroviral regimen available in Kuwait.

  1. Design, Synthesis, and Biological and Structural Evaluations of Novel HIV-1 Protease Inhibitors To Combat Drug Resistance

    SciTech Connect

    Parai, Maloy Kumar; Huggins, David J.; Cao, Hong; Nalam, Madhavi N.L.; Ali, Akbar; Schiffer, Celia A.; Tidor, Bruce; Rana, Tariq M.

    2012-09-11

    A series of new HIV-1 protease inhibitors (PIs) were designed using a general strategy that combines computational structure-based design with substrate-envelope constraints. The PIs incorporate various alcohol-derived P2 carbamates with acyclic and cyclic heteroatomic functionalities into the (R)-hydroxyethylamine isostere. Most of the new PIs show potent binding affinities against wild-type HIV-1 protease and three multidrug resistant (MDR) variants. In particular, inhibitors containing the 2,2-dichloroacetamide, pyrrolidinone, imidazolidinone, and oxazolidinone moieties at P2 are the most potent with Ki values in the picomolar range. Several new PIs exhibit nanomolar antiviral potencies against patient-derived wild-type viruses from HIV-1 clades A, B, and C and two MDR variants. Crystal structure analyses of four potent inhibitors revealed that carbonyl groups of the new P2 moieties promote extensive hydrogen bond interactions with the invariant Asp29 residue of the protease. These structure-activity relationship findings can be utilized to design new PIs with enhanced enzyme inhibitory and antiviral potencies.

  2. Prevalence of Transmitted Drug-Resistance Mutations and Polymorphisms in HIV-1 Reverse Transcriptase, Protease, and gp41 Sequences Among Recent Seroconverters in Southern Poland

    PubMed Central

    Smoleń-Dzirba, Joanna; Rosińska, Magdalena; Kruszyński, Piotr; Bratosiewicz-Wąsik, Jolanta; Wojtyczka, Robert; Janiec, Janusz; Szetela, Bartosz; Beniowski, Marek; Bociąga-Jasik, Monika; Jabłonowska, Elżbieta; Wąsik, Tomasz J.

    2017-01-01

    Background Monitoring of drug resistance-related mutations among patients with recent HIV-1 infection offers an opportunity to describe current patterns of transmitted drug resistance (TDR) mutations. Material/Methods Of 298 individuals newly diagnosed from March 2008 to February 2014 in southern Poland, 47 were deemed to have recent HIV-1 infection by the limiting antigen avidity immunoassay. Proviral DNA was amplified and sequenced in the reverse transcriptase, protease, and gp41 coding regions. Mutations were interpreted according to the Stanford Database algorithm and/or the International Antiviral Society USA guidelines. TDR mutations were defined according to the WHO surveillance list. Results Among 47 patients with recent HIV-1 infection only 1 (2%) had evidence of TDR mutation. No major resistance mutations were found, but the frequency of strains with ≥1 accessory resistance-associated mutations was high, at 98%. Accessory mutations were present in 11% of reverse transcriptase, 96% of protease, and 27% of gp41 sequences. Mean number of accessory resistance mutations in the reverse transcriptase and protease sequences was higher in viruses with no compensatory mutations in the gp41 HR2 domain than in strains with such mutations (p=0.031). Conclusions Despite the low prevalence of strains with TDR mutations, the frequency of accessory mutations was considerable, which may reflect the history of drug pressure among transmitters or natural viral genetic diversity, and may be relevant for future clinical outcomes. The accumulation of the accessory resistance mutations within the pol gene may restrict the occurrence of compensatory mutations related to enfuvirtide resistance or vice versa. PMID:28167814

  3. Prevalence of Transmitted Drug-Resistance Mutations and Polymorphisms in HIV-1 Reverse Transcriptase, Protease, and gp41 Sequences Among Recent Seroconverters in Southern Poland.

    PubMed

    Smoleń-Dzirba, Joanna; Rosińska, Magdalena; Kruszyński, Piotr; Bratosiewicz-Wąsik, Jolanta; Wojtyczka, Robert; Janiec, Janusz; Szetela, Bartosz; Beniowski, Marek; Bociąga-Jasik, Monika; Jabłonowska, Elżbieta; Wąsik, Tomasz J; The Cascade Collaboration In EuroCoord, And

    2017-02-07

    BACKGROUND Monitoring of drug resistance-related mutations among patients with recent HIV-1 infection offers an opportunity to describe current patterns of transmitted drug resistance (TDR) mutations. MATERIAL AND METHODS Of 298 individuals newly diagnosed from March 2008 to February 2014 in southern Poland, 47 were deemed to have recent HIV-1 infection by the limiting antigen avidity immunoassay. Proviral DNA was amplified and sequenced in the reverse transcriptase, protease, and gp41 coding regions. Mutations were interpreted according to the Stanford Database algorithm and/or the International Antiviral Society USA guidelines. TDR mutations were defined according to the WHO surveillance list. RESULTS Among 47 patients with recent HIV-1 infection only 1 (2%) had evidence of TDR mutation. No major resistance mutations were found, but the frequency of strains with ≥1 accessory resistance-associated mutations was high, at 98%. Accessory mutations were present in 11% of reverse transcriptase, 96% of protease, and 27% of gp41 sequences. Mean number of accessory resistance mutations in the reverse transcriptase and protease sequences was higher in viruses with no compensatory mutations in the gp41 HR2 domain than in strains with such mutations (p=0.031). CONCLUSIONS Despite the low prevalence of strains with TDR mutations, the frequency of accessory mutations was considerable, which may reflect the history of drug pressure among transmitters or natural viral genetic diversity, and may be relevant for future clinical outcomes. The accumulation of the accessory resistance mutations within the pol gene may restrict the occurrence of compensatory mutations related to enfuvirtide resistance or vice versa.

  4. High rates of virological failure and drug resistance in perinatally HIV-1-infected children and adolescents receiving lifelong antiretroviral therapy in routine clinics in Togo

    PubMed Central

    Salou, Mounerou; Dagnra, Anoumou Y; Butel, Christelle; Vidal, Nicole; Serrano, Laetitia; Takassi, Elom; Konou, Abla A; Houndenou, Spero; Dapam, Nina; Singo-Tokofaï, Assetina; Pitche, Palokinam; Atakouma, Yao; Prince-David, Mireille; Delaporte, Eric; Peeters, Martine

    2016-01-01

    Introduction Antiretroviral treatment (ART) has been scaled up over the last decade but compared to adults, children living with HIV are less likely to receive ART. Moreover, children and adolescents are more vulnerable than adults to virological failure (VF) and emergence of drug resistance. In this study we determined virological outcome in perinatally HIV-1-infected children and adolescents receiving ART in Togo. Methods HIV viral load (VL) testing was consecutively proposed to all children and adolescents who were on ART for at least 12 months when attending HIV healthcare services for their routine follow-up visit (June to September 2014). Plasma HIV-1 VL was measured using the m2000 RealTime HIV-1 assay (Abbott Molecular, Des Plaines, IL, USA). Genotypic drug resistance was done for all samples with VL>1000 copies/ml. Results and discussion Among 283 perinatally HIV-1-infected children and adolescents included, 167 (59%) were adolescents and 116 (41%) were children. The median duration on ART was 48 months (interquartile range: 28 to 68 months). For 228 (80.6%), the current ART combination consisted of two nucleoside reverse transcriptase inhibitors (NRTIs) (zidovudine and lamivudine) and one non-nucleoside reverse transcriptase inhibitor (NNRTI) (nevirapine or efavirenz). Only 28 (9.9%) were on a protease inhibitor (PI)-based regimen. VL was below the detection limit (i.e. 40 copies/ml) for 102 (36%), between 40 and 1000 copies/ml for 35 (12.4%) and above 1000 copies/ml for 146 (51.6%). Genotypic drug-resistance testing was successful for 125/146 (85.6%); 110/125 (88.0%) were resistant to both NRTIs and NNRTIs, 1/125 (0.8%) to NRTIs only, 4/125 (3.2%) to NNRTIs only and three harboured viruses resistant to reverse transcriptase and PIs. Overall, 86% (108/125) of children and adolescents experiencing VF and successfully genotyped, corresponding thus to at least 38% of the study population, had either no effective ART or had only a single effective drug in

  5. A Novel Drug-Resistant HIV-1 Circulating Recombinant Form CRF76_01B Identified by Near Full-Length Genome Analysis.

    PubMed

    Ogawa, Satoko; Hachiya, Atsuko; Hosaka, Masumi; Matsuda, Masakazu; Ode, Hirotaka; Shigemi, Urara; Okazaki, Reiko; Sadamasu, Kenji; Nagashima, Mami; Toyokawa, Takao; Tateyama, Masao; Tanaka, Yasuhito; Sugiura, Wataru; Yokomaku, Yoshiyuki; Iwatani, Yasumasa

    2016-03-01

    HIV-1 CRF01_AE and subtype B (B) have dominated and their different circulating recombinant forms (CRFs) have emerged in East and Southeast Asian countries. Here, we report a novel drug-resistant HIV-1 CRF. Five independent recombinant specimens exhibiting discordant subtype results for the gag, pol, and env sequences were isolated. These recombinants had the CRF01_AE (gag p17)/B (pol PR-RT and IN)/CRF01_AE (env C2-V3) pattern similar to CRF69_01B. Sequence analysis of four near full-length HIV-1 genomes revealed a unique phylogenetic cluster distinct from previously reported CRFs. Of the four recombinants, three shared an identical mosaic structure including seven breakpoints in the gag, pol, vif, and env regions, designated CRF76_01B. The one remaining recombinant had additional recombination breakpoints in the vpu region and exhibited another unique recombinant form composed of CRF76_01B and B. These findings provide important insight into the transmission dynamics of HIV-1 in Asia that may be important for its effective prevention.

  6. An Efficient Microarray-Based Genotyping Platform for the Identification of Drug-Resistance Mutations in Majority and Minority Subpopulations of HIV-1 Quasispecies

    PubMed Central

    Martín, Verónica; Perales, Celia; Fernández-Algar, María; Dos Santos, Helena G.; Garrido, Patricia; Pernas, María; Parro, Víctor; Moreno, Miguel; García-Pérez, Javier; Alcamí, José; Torán, José Luis; Abia, David; Domingo, Esteban

    2016-01-01

    The response of human immunodeficiency virus type 1 (HIV-1) quasispecies to antiretroviral therapy is influenced by the ensemble of mutants that composes the evolving population. Low-abundance subpopulations within HIV-1 quasispecies may determine the viral response to the administered drug combinations. However, routine sequencing assays available to clinical laboratories do not recognize HIV-1 minority variants representing less than 25% of the population. Although several alternative and more sensitive genotyping techniques have been developed, including next-generation sequencing (NGS) methods, they are usually very time consuming, expensive and require highly trained personnel, thus becoming unrealistic approaches in daily clinical practice. Here we describe the development and testing of a HIV-1 genotyping DNA microarray that detects and quantifies, in majority and minority viral subpopulations, relevant mutations and amino acid insertions in 42 codons of the pol gene associated with drug- and multidrug-resistance to protease (PR) and reverse transcriptase (RT) inhibitors. A customized bioinformatics protocol has been implemented to analyze the microarray hybridization data by including a new normalization procedure and a stepwise filtering algorithm, which resulted in the highly accurate (96.33%) detection of positive/negative signals. This microarray has been tested with 57 subtype B HIV-1 clinical samples extracted from multi-treated patients, showing an overall identification of 95.53% and 89.24% of the queried PR and RT codons, respectively, and enough sensitivity to detect minority subpopulations representing as low as 5–10% of the total quasispecies. The developed genotyping platform represents an efficient diagnostic and prognostic tool useful to personalize antiviral treatments in clinical practice. PMID:27959928

  7. An Efficient Microarray-Based Genotyping Platform for the Identification of Drug-Resistance Mutations in Majority and Minority Subpopulations of HIV-1 Quasispecies.

    PubMed

    Martín, Verónica; Perales, Celia; Fernández-Algar, María; Dos Santos, Helena G; Garrido, Patricia; Pernas, María; Parro, Víctor; Moreno, Miguel; García-Pérez, Javier; Alcamí, José; Torán, José Luis; Abia, David; Domingo, Esteban; Briones, Carlos

    2016-01-01

    The response of human immunodeficiency virus type 1 (HIV-1) quasispecies to antiretroviral therapy is influenced by the ensemble of mutants that composes the evolving population. Low-abundance subpopulations within HIV-1 quasispecies may determine the viral response to the administered drug combinations. However, routine sequencing assays available to clinical laboratories do not recognize HIV-1 minority variants representing less than 25% of the population. Although several alternative and more sensitive genotyping techniques have been developed, including next-generation sequencing (NGS) methods, they are usually very time consuming, expensive and require highly trained personnel, thus becoming unrealistic approaches in daily clinical practice. Here we describe the development and testing of a HIV-1 genotyping DNA microarray that detects and quantifies, in majority and minority viral subpopulations, relevant mutations and amino acid insertions in 42 codons of the pol gene associated with drug- and multidrug-resistance to protease (PR) and reverse transcriptase (RT) inhibitors. A customized bioinformatics protocol has been implemented to analyze the microarray hybridization data by including a new normalization procedure and a stepwise filtering algorithm, which resulted in the highly accurate (96.33%) detection of positive/negative signals. This microarray has been tested with 57 subtype B HIV-1 clinical samples extracted from multi-treated patients, showing an overall identification of 95.53% and 89.24% of the queried PR and RT codons, respectively, and enough sensitivity to detect minority subpopulations representing as low as 5-10% of the total quasispecies. The developed genotyping platform represents an efficient diagnostic and prognostic tool useful to personalize antiviral treatments in clinical practice.

  8. Epidemiological Surveillance of HIV-1 Transmitted Drug Resistance in Spain in 2004-2012: Relevance of Transmission Clusters in the Propagation of Resistance Mutations

    PubMed Central

    Vega, Yolanda; Delgado, Elena; Fernández-García, Aurora; Cuevas, Maria Teresa; Thomson, Michael M.; Montero, Vanessa; Sánchez, Monica; Sánchez, Ana Maria; Pérez-Álvarez, Lucia

    2015-01-01

    Our objectives were to carry out an epidemiological surveillance study on transmitted drug resistance (TDR) among individuals newly diagnosed of HIV-1 infection during a nine year period in Spain and to assess the role of transmission clusters (TC) in the propagation of resistant strains. An overall of 1614 newly diagnosed individuals were included in the study from January 2004 through December 2012. Individuals come from two different Spanish regions: Galicia and the Basque Country. Resistance mutations to reverse transcriptase inhibitors (RTI) and protease inhibitors (PI) were analyzed according to mutations included in the surveillance drug-resistance mutations list updated in 2009. TC were defined as those comprising viruses from five or more individuals whose sequences clustered in maximum likelihood phylogenetic trees with a bootstrap value ≥90%. The overall prevalence of TDR to any drug was 9.9%: 4.9% to nucleoside RTIs (NRTIs), 3.6% to non-nucleoside RTIs (NNRTIs), and 2.7% to PIs. A significant decrease of TDR to NRTIs over time was observed [from 10% in 2004 to 2% in 2012 (p=0.01)]. Sixty eight (42.2%) of 161 sequences with TDR were included in 25 TC composed of 5 or more individuals. Of them, 9 clusters harbored TDR associated with high level resistance to antiretroviral drugs. T215D revertant mutation was transmitted in a large cluster comprising 25 individuals. The impact of epidemiological networks on TDR frequency may explain its persistence in newly diagnosed individuals. The knowledge of the populations involved in TC would facilitate the design of prevention programs and public health interventions. PMID:26010948

  9. Epidemiological Surveillance of HIV-1 Transmitted Drug Resistance in Spain in 2004-2012: Relevance of Transmission Clusters in the Propagation of Resistance Mutations.

    PubMed

    Vega, Yolanda; Delgado, Elena; Fernández-García, Aurora; Cuevas, Maria Teresa; Thomson, Michael M; Montero, Vanessa; Sánchez, Monica; Sánchez, Ana Maria; Pérez-Álvarez, Lucia

    2015-01-01

    Our objectives were to carry out an epidemiological surveillance study on transmitted drug resistance (TDR) among individuals newly diagnosed of HIV-1 infection during a nine year period in Spain and to assess the role of transmission clusters (TC) in the propagation of resistant strains. An overall of 1614 newly diagnosed individuals were included in the study from January 2004 through December 2012. Individuals come from two different Spanish regions: Galicia and the Basque Country. Resistance mutations to reverse transcriptase inhibitors (RTI) and protease inhibitors (PI) were analyzed according to mutations included in the surveillance drug-resistance mutations list updated in 2009. TC were defined as those comprising viruses from five or more individuals whose sequences clustered in maximum likelihood phylogenetic trees with a bootstrap value ≥90%. The overall prevalence of TDR to any drug was 9.9%: 4.9% to nucleoside RTIs (NRTIs), 3.6% to non-nucleoside RTIs (NNRTIs), and 2.7% to PIs. A significant decrease of TDR to NRTIs over time was observed [from 10% in 2004 to 2% in 2012 (p=0.01)]. Sixty eight (42.2%) of 161 sequences with TDR were included in 25 TC composed of 5 or more individuals. Of them, 9 clusters harbored TDR associated with high level resistance to antiretroviral drugs. T215D revertant mutation was transmitted in a large cluster comprising 25 individuals. The impact of epidemiological networks on TDR frequency may explain its persistence in newly diagnosed individuals. The knowledge of the populations involved in TC would facilitate the design of prevention programs and public health interventions.

  10. Use of amplification refractory mutation system PCR assay as a simple and effective tool to detect HIV-1 drug resistance mutations.

    PubMed

    Nanfack, Aubin J; Agyingi, Lucy; Noubiap, Jean Jacques N; Ngai, Johnson N; Colizzi, Vittorio; Nyambi, Phillipe N

    2015-05-01

    Access to genotyping assays to determine successful antiretroviral treatment (ART) is limited in resource-constrained settings by high cost, suggesting the need for a cost-effective and simplified method to identify HIV-1 drug resistance (HIVDR) mutations. In this study, an amplification refractory mutation system (ARMS)-PCR assay was developed and used to investigate the most frequent HIVDR mutations affecting first-line ART in settings where WHO ART guidelines are applied. Seventy-five HIV-positive (HIV(+)) samples from Cameroon were used to assess the performance of this assay. Sequencing of HIV-1 reverse transcriptase was simultaneously performed for comparison, and discordant samples were tested with a Trugene HIV-1 genotyping kit. The ARMS-PCR assay was able to detect M184V, T215Y/F, K103N, and Y181C mutations with sensitivities of 96.8%, 85.7%, 91.3%, and 70%, respectively, and specificities of 90.6%, 95%, 100%, 96.9%, respectively, compared with data on sequencing. The results indicated the highest positive predictive value for K103N (100%) and the highest negative predictive value for M184V (97.5%). ARMS-PCR's limits of detection for mutations M184V, T215Y/F, K103N, and Y181C were <75 copies/ml, 143 copies/ml, 143 copies/ml, and 836 copies/ml, respectively. ARMS-PCR efficiently identified mutations in individuals harboring different HIV-1 clades (CRF02_AG and non-CRF02_AG). In addition, this approach was more cost-effective than other genotyping assays. The high throughput, the cost-effectiveness, and the simplicity of the ARMS-PCR assay make it a suitable tool to monitor HIVDR patterns in resource-constrained settings with broad HIV-1 genetic diversity.

  11. Characterizing the Diverse Mutational Pathways Associated with R5-Tropic Maraviroc Resistance: HIV-1 That Uses the Drug-Bound CCR5 Coreceptor

    PubMed Central

    Jiang, Xiaowei; Feyertag, Felix; Meehan, Conor J.; McCormack, Grace P.; Travers, Simon A.; Craig, Charles; Westby, Mike; Lewis, Marilyn

    2015-01-01

    ABSTRACT Entry inhibitors represent a potent class of antiretroviral drugs that target a host cell protein, CCR5, an HIV-1 entry coreceptor, and not viral protein. Lack of sensitivity can occur due to preexisting virus that uses the CXCR4 coreceptor, while true resistance occurs through viral adaptation to use a drug-bound CCR5 coreceptor. To understand this R5 resistance pathway, we analyzed >500 envelope protein sequences and phenotypes from viruses of 20 patients from the clinical trials MOTIVATE 1 and 2, in which treatment-experienced patients received maraviroc plus optimized background therapy. The resistant viral population was phylogenetically distinct and associated with a genetic bottleneck in each patient, consistent with de novo emergence of resistance. Recombination analysis showed that the C2-V3-C3 region tends to genotypically correspond to the recombinant's phenotype, indicating its primary importance in conferring resistance. Between patients, there was a notable lack of commonality in the specific sites conferring resistance, confirming the unusual nature of R5-tropic resistance. We used coevolutionary and positive-selection analyses to characterize the genotypic determinants of resistance and found that (i) there are complicated covariation networks, indicating frequent coevolutionary/compensatory changes in the context of protein structure; (ii) covarying sites under positive selection are enriched in resistant viruses; (iii) CD4 binding sites form part of a unique covariation network independent of the V3 loop; and (iv) the covariation network formed between the V3 loop and other regions of gp120 and gp41 intersects sites involved in glycosylation and protein secretion. These results demonstrate that while envelope sequence mutations are the key to conferring maraviroc resistance, the specific changes involved are context dependent and thus inherently unpredictable. IMPORTANCE The entry inhibitor drug maraviroc makes the cell coreceptor CCR5

  12. Drug resistance-related mutations T369V/I in the connection subdomain of HIV-1 reverse transcriptase severely impair viral fitness.

    PubMed

    Wang, Zheng; Zhang, Junli; Li, Fan; Ji, Xiaolin; Liao, Lingjie; Ma, Liying; Xing, Hui; Feng, Yi; Li, Dan; Shao, Yiming

    2017-03-06

    Fitness is a key parameter in the measurement of transmission capacity of individual drug-resistant HIV. Drug-resistance related mutations (DRMs) T369V/I and A371V in the connection subdomain (CN) of reverse transcriptase (RT) occur at higher frequencies in the individuals experiencing antiretroviral therapy failure. Here, we evaluated the effects of T369V/I and A371V on viral fitness, in the presence or in the absence of thymidine analogue resistance-associated mutations (TAMs) and assessed the effect of potential RT structure-related mechanism on change in viral fitness. Mutations T369V/I, A371V, alone or in combination with TAMs were introduced into a modified HIV-1 infectious clone AT1 by site-directed mutagenesis. Then, experiments on mutant and wild-type virus AT2 were performed separately using a growth-competition assay, and then the relative fitness was calculated. Structural analysis of RT was conducted using Pymol software. Results showed that T369V/I severely impaired the relative virus fitness, and A371V compensated for the viral fitness reduction caused by TAMs. Structural modeling of RT suggests that T369V/I substitutions disrupt powerful hydrogen bonds formed by T369 and V365 in p51 and p66. This study indicates that the secondary DRMs within CN might efficiently damage viral fitness, and provides valuable information for clinical surveillance and prevention of HIV-1 strains carrying these DRMs.

  13. Insights into the mechanism of drug resistance: X-ray structure analysis of G48V/C95F tethered HIV-1 protease dimer/saquinavir complex

    SciTech Connect

    Prashar, Vishal; Bihani, Subhash C.; Das, Amit; Rao, D.R.; Hosur, M.V.

    2010-06-11

    The mutation G48V in HIV-1 protease is a major resistance mutation against the drug saquinavir. Recently, G48V mutation is found to co-exist with the mutation C95F in AIDS patients treated with saquinavir. We report here the three-dimensional crystal structure of G48V/C95F tethered HIV-1 protease/saquinavir complex. The structure indicates following as the possible causes of drug resistance: (1) loss of direct van der Waals interactions between saquinavir and enzyme residues PHE-53 and PRO-1081, (2) loss of water-mediated hydrogen bonds between the carbonyl oxygen atoms in saquinavir and amide nitrogen atoms of flap residues 50 and 1050, (3) changes in inter-monomer interactions, which could affect the energetics of domain movements associated with inhibitor-binding, and (4) significant reduction in the stability of the mutant dimer. The present structure also provides a rationale for the clinical observation that the resistance mutations C95F/G48V/V82A occur as a cluster in AIDS patients.

  14. The HIVdb system for HIV-1 genotypic resistance interpretation.

    PubMed

    Tang, Michele W; Liu, Tommy F; Shafer, Robert W

    2012-01-01

    The Stanford HIV Drug Resistance Database hosts a freely available online genotypic resistance interpretation system called HIVdb to help clinicians and laboratories interpret HIV-1 genotypic resistance tests. These tests are designed to assess susceptibility to nucleoside and nonnucleoside reverse transcriptase inhibitors (NRTI and NNRTI), protease inhibitors and integrase inhibitors. The HIVdb genotypic resistance interpretation system output consists of (1) a list of penalty scores for each antiretroviral (ARV) resistance mutation in a submitted sequence, (2) estimates of decreased NRTI, NNRTI, protease and integrase inhibitor susceptibility, and (3) comments about each ARV resistance mutation in the submitted sequence. The application's strengths are its convenience for submitting sequences, its quality control analysis, its transparency and its extensive comments. The Sierra Web service is an extension that enables laboratories analyzing many sequences to individualize the format of their results. The algorithm specification interface compiler makes it possible for HIVdb to provide results using a variety of different HIV-1 genotypic resistance interpretation algorithms.

  15. Antiretroviral prophylaxis of perinatal HIV-1 transmission and the potential impact of antiretroviral resistance.

    PubMed

    Nolan, Monica; Fowler, Mary Glenn; Mofenson, Lynne M

    2002-06-01

    Since 1994, trials of zidovudine, zidovudine and lamivudine, and nevirapine have demonstrated that these antiretroviral drugs can substantially reduce the risk of perinatal HIV-1 transmission. With reductions in drug price, identification of simple, effective antiretroviral regimens to prevent perinatal HIV-1 transmission, and an increasing international commitment to support health care infrastructure, antiretrovirals for both perinatal HIV-1 prevention and HIV-1 treatment will likely become more widely available to HIV-1-infected persons in resource-limited countries. In the United States, widespread antiretroviral usage has been associated with increased antiretroviral drug resistance. This raises concern that drug resistance may reduce the effectiveness of perinatal antiretroviral prophylaxis as well as therapeutic intervention strategies. The purpose of this article is to review what is known about resistance and risk of perinatal HIV transmission, assess the interaction between antiretroviral resistance and the prevention of perinatal HIV-1 transmission, and discuss implications for current global prevention and treatment strategies.

  16. HIV-1 Antiretroviral Drug Resistance Mutations in Treatment Naïve and Experienced Panamanian Subjects: Impact on National Use of EFV-Based Schemes

    PubMed Central

    Mendoza, Yaxelis; Castillo Mewa, Juan; Martínez, Alexander A.; Zaldívar, Yamitzel; Sosa, Néstor; Arteaga, Griselda; Armién, Blas; Bautista, Christian T.; García-Morales, Claudia; Tapia-Trejo, Daniela; Ávila-Ríos, Santiago; Reyes-Terán, Gustavo; Bello, Gonzalo; Pascale, Juan M.

    2016-01-01

    The use of antiretroviral therapy in HIV infected subjects prevents AIDS-related illness and delayed occurrence of death. In Panama, rollout of ART started in 1999 and national coverage has reached 62.8% since then. The objective of this study was to determine the level and patterns of acquired drug resistance mutations of clinical relevance (ADR-CRM) and surveillance drug resistance mutations (SDRMs) from 717 HIV-1 pol gene sequences obtained from 467 ARV drug-experienced and 250 ARV drug-naïve HIV-1 subtypes B infected subjects during 2007–2013, respectively. The overall prevalence of SDRM and of ADR-CRM during the study period was 9.2% and 87.6%, respectively. The majority of subjects with ADR-CRM had a pattern of mutations that confer resistance to at least two classes of ARV inhibitors. The non-nucleoside reverse transcriptase inhibitor (NNRTI) mutations K103N and P225H were more prevalent in both ARV drug-naïve and ARV drug-experienced subjects. The nucleoside reverse transcriptase inhibitor (NRTI) mutation M184V was more frequent in ARV drug-experienced individuals, while T215YFrev and M41L were more frequent in ARV drug-naïve subjects. Prevalence of mutations associated to protease inhibitors (PI) was lower than 4.1% in both types of subjects. Therefore, there is a high level of resistance (>73%) to Efavirenz/Nevirapine, Lamivudine and Azidothymidine in ARV drug-experienced subjects, and an intermediate to high level of resistance (5–10%) to Efavirenz/Nevirapine in ARV drug-naïve subjects. During the study period, we observed an increasing trend in the prevalence of ADR-CRM in subjects under first-line schemes, but not significant changes in the prevalence of SDRM. These results reinforce the paramount importance of a national surveillance system of ADR-CRM and SDRM for national management policies of subjects living with HIV. PMID:27119150

  17. Multi-drug resistance profile of PR20 HIV-1 protease is attributed to distorted conformational and drug binding landscape: molecular dynamics insights.

    PubMed

    Chetty, Sarentha; Bhakat, Soumendranath; Martin, Alberto J M; Soliman, Mahmoud E S

    2016-01-01

    The PR20 HIV-1 protease, a variant with 20 mutations, exhibits high levels of multi-drug resistance; however, to date, there has been no report detailing the impact of these 20 mutations on the conformational and drug binding landscape at a molecular level. In this report, we demonstrate the first account of a comprehensive study designed to elaborate on the impact of these mutations on the dynamic features as well as drug binding and resistance profile, using extensive molecular dynamics analyses. Comparative MD simulations for the wild-type and PR20 HIV proteases, starting from bound and unbound conformations in each case, were performed. Results showed that the apo conformation of the PR20 variant of the HIV protease displayed a tendency to remain in the open conformation for a longer period of time when compared to the wild type. This led to a phenomena in which the inhibitor seated at the active site of PR20 tends to diffuse away from the binding site leading to a significant change in inhibitor-protein association. Calculating the per-residue fluctuation (RMSF) and radius of gyration, further validated these findings. MM/GBSA showed that the occurrence of 20 mutations led to a drop in the calculated binding free energies (ΔGbind) by ~25.17 kcal/mol and ~5 kcal/mol for p2-NC, a natural peptide substrate, and darunavir, respectively, when compared to wild type. Furthermore, the residue interaction network showed a diminished inter-residue hydrogen bond network and changes in inter-residue connections as a result of these mutations. The increased conformational flexibility in PR20 as a result of loss of intra- and inter-molecular hydrogen bond interactions and other prominent binding forces led to a loss of protease grip on ligand. It is interesting to note that the difference in conformational flexibility between PR20 and WT conformations was much higher in the case of substrate-bound conformation as compared to DRV. Thus, developing analogues of DRV by

  18. Molecular dynamics studies of the inhibitor C34 binding to the wild-type and mutant HIV-1 gp41: inhibitory and drug resistant mechanism.

    PubMed

    Ma, Xueting; Tan, Jianjun; Su, Min; Li, Chunhua; Zhang, Xiaoyi; Wang, Cunxin

    2014-01-01

    Mutations on NHR (N-terminal heptad repeat) associated with resistance to fusion inhibitor were observed. In addition, mutations on CHR (C-terminal heptad repeat) accompanied NHR mutations of gp41 are noted in many cases, like N43D/S138A double mutation. In this work, we explored the drug resistant mechanism of N43D mutation and the role of S138A second mutation in drug resistance. The binding modes of the wild type gp41 and the two mutants, N43D and N43D/S138A, with the HIV-1 fusion inhibitor C34, a 34-residue peptide mimicking CHR of gp41, were carried out by using molecular dynamics simulations. Based on the MD simulations, N43D mutation affects not only the stability of C34 binding, but also the binding energy of the inhibitor C34. Because N43D mutation may also affect the stable conformation of 6-HB, we introduced S138A second mutation into CHR of gp41 and determined the impact of this mutation. Through the comparative analysis of MD results of the N43D mutant and the N43D/S138A mutant, we found that CHR with S138A mutation shown more favorable affinity to NHR. Compelling differences in structures have been observed for these two mutants, particularly in the binding modes and in the hydrophobic interactions of the CHR (C34) located near the hydrophobic groove of the NHR. Because the conformational stability of 6-HB is important to HIV-1 infection, we suggested a hypothetical mechanism for the drug resistance: N43D single mutation not only impact the binding of inhibitor, but also affect the affinity between NHR and CHR of gp41, thus may reduce the rate of membrane fusion; compensatory mutation S138A would induce greater hydrophobic interactions between NHR and CHR, and render the CHR more compatible to NHR than inhibitors.

  19. Biochemical characterization of a multi-drug resistant HIV-1 subtype AG reverse transcriptase: antagonism of AZT discrimination and excision pathways and sensitivity to RNase H inhibitors

    PubMed Central

    Schneider, Anna; Corona, Angela; Spöring, Imke; Jordan, Mareike; Buchholz, Bernd; Maccioni, Elias; Di Santo, Roberto; Bodem, Jochen; Tramontano, Enzo; Wöhrl, Birgitta M.

    2016-01-01

    We analyzed a multi-drug resistant (MR) HIV-1 reverse transcriptase (RT), subcloned from a patient-derived subtype CRF02_AG, harboring 45 amino acid exchanges, amongst them four thymidine analog mutations (TAMs) relevant for high-level AZT (azidothymidine) resistance by AZTMP excision (M41L, D67N, T215Y, K219E) as well as four substitutions of the AZTTP discrimination pathway (A62V, V75I, F116Y and Q151M). In addition, K65R, known to antagonize AZTMP excision in HIV-1 subtype B was present. Although MR-RT harbored the most significant amino acid exchanges T215Y and Q151M of each pathway, it exclusively used AZTTP discrimination, indicating that the two mechanisms are mutually exclusive and that the Q151M pathway is obviously preferred since it confers resistance to most nucleoside inhibitors. A derivative was created, additionally harboring the TAM K70R and the reversions M151Q as well as R65K since K65R antagonizes excision. MR-R65K-K70R-M151Q was competent of AZTMP excision, whereas other combinations thereof with only one or two exchanges still promoted discrimination. To tackle the multi-drug resistance problem, we tested if the MR-RTs could still be inhibited by RNase H inhibitors. All MR-RTs exhibited similar sensitivity toward RNase H inhibitors belonging to different inhibitor classes, indicating the importance of developing RNase H inhibitors further as anti-HIV drugs. PMID:26850643

  20. Surveillance of Transmitted HIV-1 Drug Resistance in Gauteng and KwaZulu-Natal Provinces, South Africa, 2005–2009

    PubMed Central

    Ledwaba, J.; Basson, A. E.; Moyes, J.; Cohen, C.; Singh, B.; Bertagnolio, S.; Jordan, M. R.; Puren, A.; Morris, L.

    2012-01-01

    Surveillance of human immunodeficiency virus type 1 transmitted drug resistance (TDR) was conducted among pregnant women in South Africa over a 5-year period after the initiation of a large national antiretroviral treatment program. Analysis of TDR data from 9 surveys conducted between 2005 and 2009 in 2 provinces of South Africa suggests that while TDR remains low (<5%) in Gauteng Province, it may be increasing in KwaZulu-Natal, with the most recent survey showing moderate (5%–15%) levels of resistance to the nonnucleoside reverse transcriptase inhibitor drug class. PMID:22544199

  1. HIV-1 drug resistance genotyping from antiretroviral therapy (ART) naïve and first-line treatment failures in Djiboutian patients

    PubMed Central

    2012-01-01

    Abstract In this study we report the prevalence of antiretroviral drug resistant HIV-1 genotypes of virus isolated from Djiboutian patients who failed first-line antiretroviral therapy (ART) and from ART naïve patients. Patients and methods A total of 35 blood samples from 16 patients who showed first-line ART failure (>1000 viral genome copies/ml) and 19 ART-naïve patients were collected in Djibouti from October 2009 to December 2009. Both the protease (PR) and reverse transcriptase (RT) genes were amplified and sequenced using National Agency for AIDS Research (ANRS) protocols. The Stanford HIV database algorithm was used for interpretation of resistance data and genotyping. Results Among the 16 patients with first-line ART failure, nine (56.2%) showed reverse transcriptase inhibitor-resistant HIV-1 strains: two (12.5%) were resistant to nucleoside (NRTI), one (6.25%) to non-nucleoside (NNRTI) reverse transcriptase inhibitors, and six (37.5%) to both. Analysis of the DNA sequencing data indicated that the most common mutations conferring drug resistance were M184V (38%) for NRTI and K103N (25%) for NNRTI. Only NRTI primary mutations K101Q, K103N and the PI minor mutation L10V were found in ART naïve individuals. No protease inhibitor resistant strains were detected. In our study, we found no detectable resistance in ∼ 44% of all patients who experienced therapeutic failure which was explained by low compliance, co-infection with tuberculosis and malnutrition. Genotyping revealed that 65.7% of samples were infected with subtype C, 20% with CRF02_AG, 8.5% with B, 2.9% with CRF02_AG/C and 2.9% with K/C. Conclusion The results of this first study about drug resistance mutations in first-line ART failures show the importance of performing drug resistance mutation test which guides the choice of a second-line regimen. This will improve the management of HIV-infected Djiboutian patients. Virtual slides The virtual slide(s) for this article can be found here

  2. How conformational changes can affect catalysis, inhibition and drug resistance of enzymes with induced-fit binding mechanism such as the HIV-1 protease.

    PubMed

    Weikl, Thomas R; Hemmateenejad, Bahram

    2013-05-01

    A central question is how the conformational changes of proteins affect their function and the inhibition of this function by drug molecules. Many enzymes change from an open to a closed conformation upon binding of substrate or inhibitor molecules. These conformational changes have been suggested to follow an induced-fit mechanism in which the molecules first bind in the open conformation in those cases where binding in the closed conformation appears to be sterically obstructed such as for the HIV-1 protease. In this article, we present a general model for the catalysis and inhibition of enzymes with induced-fit binding mechanism. We derive general expressions that specify how the overall catalytic rate of the enzymes depends on the rates for binding, for the conformational changes, and for the chemical reaction. Based on these expressions, we analyze the effect of mutations that mainly shift the conformational equilibrium on catalysis and inhibition. If the overall catalytic rate is limited by product unbinding, we find that mutations that destabilize the closed conformation relative to the open conformation increase the catalytic rate in the presence of inhibitors by a factor exp(ΔΔGC/RT) where ΔΔGC is the mutation-induced shift of the free-energy difference between the conformations. This increase in the catalytic rate due to changes in the conformational equilibrium is independent of the inhibitor molecule and, thus, may help to understand how non-active-site mutations can contribute to the multi-drug-resistance that has been observed for the HIV-1 protease. A comparison to experimental data for the non-active-site mutation L90M of the HIV-1 protease indicates that the mutation slightly destabilizes the closed conformation of the enzyme. This article is part of a Special Issue entitled: The emerging dynamic view of proteins: Protein plasticity in allostery, evolution and self-assembly.

  3. Single Genome Analysis for the Detection of Linked Multiclass Drug Resistance Mutations in HIV-1-Infected Children After Failure of Protease Inhibitor-Based First-Line Therapy.

    PubMed

    Lange, Camille Marie; Hué, Stéphane; Violari, Avy; Cotton, Mark; Gibb, Diana; Babiker, Abdel; Otwombe, Kennedy; Panchia, Ravindre; Dobbels, Els; Jean-Philippe, Patrick; McIntyre, James A; Pillay, Deenan; Gupta, Ravindra Kumar

    2015-06-01

    The WHO recommends protease inhibitor (PI)-based antiretroviral therapy (ART) for vertically infected children after failed nevirapine (NVP) prophylaxis. Emergence of PI resistance on the backdrop of preexisting non-nucleoside reverse transcriptase inhibitor (NNRTI) resistance could compromise long-term treatment options in such children. We characterized multiclass drug resistance using single genome sequencing (SGS) in children with viremia while receiving PI-based ART. We applied SGS of HIV-1 protease (PR) and reverse transcriptase to longitudinal samples from a cohort of the Children with HIV Early Antiretroviral Therapy trial with viral loads >1000 copies per milliliter after 40 weeks of early ART. Bulk sequencing revealed NVP-selected resistance in 50% of these children, whereas SGS revealed NVP-selected resistance in 70%. Two children had baseline NRTI and PI mutations, suggesting previous maternal ART. Linked multiclass drug resistance after PI-based ART was detected by SGS in 2 of 10 children. In one child, the majority species contained M184V in reverse transcriptase linked to L10F, M46I/L, I54V, and V82A in PR and a triple-class drug-resistant variant with these mutations linked to the NNRTI mutation V108I. In the second child, the majority species contained M184V and V82A linked within viral genomes. We conclude that when PI-based ART is initiated soon after birth after single dose-NVP prophylaxis, PI and NRTI resistance can occur in the majority species as expected and also be selected on the same genomes as preexisting NNRTI-resistant mutations. These observations highlight a future therapeutic challenge for vertically infected children where antiretroviral drug classes are limited.

  4. A Follow-Up of the Multicenter Collaborative Study on HIV-1 Drug Resistance and Tropism Testing Using 454 Ultra Deep Pyrosequencing

    PubMed Central

    St. John, Elizabeth P.; Simen, Birgitte B.; Turenchalk, Gregory S.; Braverman, Michael S.; Abbate, Isabella; Aerssens, Jeroen; Bouchez, Olivier; Gabriel, Christian; Izopet, Jacques; Meixenberger, Karolin; Di Giallonardo, Francesca; Schlapbach, Ralph; Paredes, Roger; Sakwa, James; Schmitz-Agheguian, Gudrun G.; Thielen, Alexander; Victor, Martin

    2016-01-01

    Background Ultra deep sequencing is of increasing use not only in research but also in diagnostics. For implementation of ultra deep sequencing assays in clinical laboratories for routine diagnostics, intra- and inter-laboratory testing are of the utmost importance. Methods A multicenter study was conducted to validate an updated assay design for 454 Life Sciences’ GS FLX Titanium system targeting protease/reverse transcriptase (RTP) and env (V3) regions to identify HIV-1 drug-resistance mutations and determine co-receptor use with high sensitivity. The study included 30 HIV-1 subtype B and 6 subtype non-B samples with viral titers (VT) of 3,940–447,400 copies/mL, two dilution series (52,129–1,340 and 25,130–734 copies/mL), and triplicate samples. Amplicons spanning PR codons 10–99, RT codons 1–251 and the entire V3 region were generated using barcoded primers. Analysis was performed using the GS Amplicon Variant Analyzer and geno2pheno for tropism. For comparison, population sequencing was performed using the ViroSeq HIV-1 genotyping system. Results The median sequencing depth across the 11 sites was 1,829 reads per position for RTP (IQR 592–3,488) and 2,410 for V3 (IQR 786–3,695). 10 preselected drug resistant variants were measured across sites and showed high inter-laboratory correlation across all sites with data (P<0.001). The triplicate samples of a plasmid mixture confirmed the high inter-laboratory consistency (mean% ± stdev: 4.6 ±0.5, 4.8 ±0.4, 4.9 ±0.3) and revealed good intra-laboratory consistency (mean% range ± stdev range: 4.2–5.2 ± 0.04–0.65). In the two dilutions series, no variants >20% were missed, variants 2–10% were detected at most sites (even at low VT), and variants 1–2% were detected by some sites. All mutations detected by population sequencing were also detected by UDS. Conclusions This assay design results in an accurate and reproducible approach to analyze HIV-1 mutant spectra, even at variant frequencies

  5. Potent Antiviral HIV-1 Protease Inhibitor GRL-02031 Adapts to the Structures of Drug Resistant Mutants with Its P1;#8242;-Pyrrolidinone Ring

    SciTech Connect

    Chang, Yu-Chung E.; Yu, XiaXia; Zhang, Ying; Tie, Yunfeng; Wang, Yuan-Fang; Yashchuk, Sofiya; Ghosh, Arun K.; Harrison, Robert W.; Weber, Irene T.

    2012-11-14

    GRL-02031 (1) is an HIV-1 protease (PR) inhibitor containing a novel P1' (R)-aminomethyl-2-pyrrolidinone group. Crystal structures at resolutions of 1.25-1.55 {angstrom} were analyzed for complexes of 1 with the PR containing major drug resistant mutations, PR{sub I47V}, PR{sub L76V}, PR{sub V82A}, and PR{sub N88D}. Mutations of I47V and V82A alter residues in the inhibitor-binding site, while L76V and N88D are distal mutations having no direct contact with the inhibitor. Substitution of a smaller amino acid in PR{sub I47V} and PR{sub L76V} and the altered charge of PR{sub N88D} are associated with significant local structural changes compared to the wild-type PR{sub WT}, while substitution of alanine in PR{sub V82A} increases the size of the S1' subsite. The P1' pyrrolidinone group of 1 accommodates to these local changes by assuming two different conformations. Overall, the conformation and interactions of 1 with PR mutants resemble those of PR{sub WT} with similar inhibition constants in good agreement with the antiviral potency on multidrug resistant HIV-1.

  6. Global epidemiology of drug resistance after failure of WHO recommended first-line regimens for adult HIV-1 infection: a multicentre retrospective cohort study

    PubMed Central

    2016-01-01

    Summary Background Antiretroviral therapy (ART) is crucial for controlling HIV-1 infection through wide-scale treatment as prevention and pre-exposure prophylaxis (PrEP). Potent tenofovir disoproxil fumarate-containing regimens are increasingly used to treat and prevent HIV, although few data exist for frequency and risk factors of acquired drug resistance in regions hardest hit by the HIV pandemic. We aimed to do a global assessment of drug resistance after virological failure with first-line tenofovir-containing ART. Methods The TenoRes collaboration comprises adult HIV treatment cohorts and clinical trials of HIV drug resistance testing in Europe, Latin and North America, sub-Saharan Africa, and Asia. We extracted and harmonised data for patients undergoing genotypic resistance testing after virological failure with a first-line regimen containing tenofovir plus a cytosine analogue (lamivudine or emtricitabine) plus a non-nucleotide reverse-transcriptase inhibitor (NNRTI; efavirenz or nevirapine). We used an individual participant-level meta-analysis and multiple logistic regression to identify covariates associated with drug resistance. Our primary outcome was tenofovir resistance, defined as presence of K65R/N or K70E/G/Q mutations in the reverse transcriptase (RT) gene. Findings We included 1926 patients from 36 countries with treatment failure between 1998 and 2015. Prevalence of tenofovir resistance was highest in sub-Saharan Africa (370/654 [57%]). Pre-ART CD4 cell count was the covariate most strongly associated with the development of tenofovir resistance (odds ratio [OR] 1·50, 95% CI 1·27–1·77 for CD4 cell count <100 cells per μL). Use of lamivudine versus emtricitabine increased the risk of tenofovir resistance across regions (OR 1·48, 95% CI 1·20–1·82). Of 700 individuals with tenofovir resistance, 578 (83%) had cytosine analogue resistance (M184V/I mutation), 543 (78%) had major NNRTI resistance, and 457 (65%) had both. The mean plasma

  7. Factors Associated with the Development of Drug Resistance Mutations in HIV-1 Infected Children Failing Protease Inhibitor-Based Antiretroviral Therapy in South Africa

    PubMed Central

    Melikian, George; van Dyk, Gisela; Thomas, Winifred; du Plessis, Nicolette M.; Avenant, Theunis

    2015-01-01

    Objective Limited data are available from the developing world on antiretroviral drug resistance in HIV-1 infected children failing protease inhibitor-based antiretroviral therapy, especially in the context of a high tuberculosis burden. We describe the proportion of children with drug resistance mutations after failed protease inhibitor-based antiretroviral therapy as well as associated factors. Methods Data from children initiated on protease inhibitor-based antiretroviral therapy with subsequent virological failure referred for genotypic drug resistance testing between 2008 and 2012 were retrospectively analysed. Frequencies of drug resistance mutations were determined and associations with these mutations identified through logistic regression analysis. Results The study included 65 young children (median age 16.8 months [IQR 7.8; 23.3]) with mostly advanced clinical disease (88.5% WHO stage 3 or 4 disease), severe malnutrition (median weight-for-age Z-score -2.4 [IQR -3.7;-1.5]; median height-for-age Z-score -3.1 [IQR -4.3;-2.4]), high baseline HIV viral load (median 6.04 log10, IQR 5.34;6.47) and frequent tuberculosis co-infection (66%) at antiretroviral therapy initiation. Major protease inhibitor mutations were found in 49% of children and associated with low weight-for-age and height-for-age (p = 0.039; p = 0.05); longer duration of protease inhibitor regimens and virological failure (p = 0.001; p = 0.005); unsuppressed HIV viral load at 12 months of antiretroviral therapy (p = 0.001); tuberculosis treatment at antiretroviral therapy initiation (p = 0.048) and use of ritonavir as single protease inhibitor (p = 0.038). On multivariate analysis, cumulative months on protease inhibitor regimens and use of ritonavir as single protease inhibitor remained significant (p = 0.008; p = 0.033). Conclusion Major protease inhibitor resistance mutations were common in this study of HIV-1-infected children, with the timing of tuberculosis treatment and subsequent

  8. CCR5 antibodies HGS004 and HGS101 preferentially inhibit drug-bound CCR5 infection and restore drug sensitivity of Maraviroc-resistant HIV-1 in primary cells

    SciTech Connect

    Latinovic, Olga; Reitz, Marvin; Le, Nhut M.; Foulke, James S.; Faetkenheuer, Gerd; Lehmann, Clara; Redfield, Robert R.; Heredia, Alonso

    2011-03-01

    R5 HIV-1 strains resistant to the CCR5 antagonist Maraviroc (MVC) can use drug-bound CCR5. We demonstrate that MVC-resistant HIV-1 exhibits delayed kinetics of coreceptor engagement and fusion during drug-bound versus free CCR5 infection of cell lines. Antibodies directed against the second extracellular loop (ECL2) of CCR5 had greater antiviral activity against MVC-bound compared to MVC-free CCR5 infection. However, in PBMCs, only ECL2 CCR5 antibodies HGS004 and HGS101, but not 2D7, inhibited infection by MVC resistant HIV-1 more potently with MVC-bound than with free CCR5. In addition, HGS004 and HGS101, but not 2D7, restored the antiviral activity of MVC against resistant virus in PBMCs. In flow cytometric studies, CCR5 binding by the HGS mAbs, but not by 2D7, was increased when PBMCs were treated with MVC, suggesting MVC increases exposure of the relevant epitope. Thus, HGS004 and HGS101 have antiviral mechanisms distinct from 2D7 and could help overcome MVC resistance.

  9. Molecular Dynamics Studies of the Inhibitor C34 Binding to the Wild-Type and Mutant HIV-1 gp41: Inhibitory and Drug Resistant Mechanism

    PubMed Central

    Ma, Xueting; Tan, Jianjun; Su, Min; Li, Chunhua; Zhang, Xiaoyi; Wang, Cunxin

    2014-01-01

    Mutations on NHR (N-terminal heptad repeat) associated with resistance to fusion inhibitor were observed. In addition, mutations on CHR (C-terminal heptad repeat) accompanied NHR mutations of gp41 are noted in many cases, like N43D/S138A double mutation. In this work, we explored the drug resistant mechanism of N43D mutation and the role of S138A second mutation in drug resistance. The binding modes of the wild type gp41 and the two mutants, N43D and N43D/S138A, with the HIV-1 fusion inhibitor C34, a 34-residue peptide mimicking CHR of gp41, were carried out by using molecular dynamics simulations. Based on the MD simulations, N43D mutation affects not only the stability of C34 binding, but also the binding energy of the inhibitor C34. Because N43D mutation may also affect the stable conformation of 6-HB, we introduced S138A second mutation into CHR of gp41 and determined the impact of this mutation. Through the comparative analysis of MD results of the N43D mutant and the N43D/S138A mutant, we found that CHR with S138A mutation shown more favorable affinity to NHR. Compelling differences in structures have been observed for these two mutants, particularly in the binding modes and in the hydrophobic interactions of the CHR (C34) located near the hydrophobic groove of the NHR. Because the conformational stability of 6-HB is important to HIV-1 infection, we suggested a hypothetical mechanism for the drug resistance: N43D single mutation not only impact the binding of inhibitor, but also affect the affinity between NHR and CHR of gp41, thus may reduce the rate of membrane fusion; compensatory mutation S138A would induce greater hydrophobic interactions between NHR and CHR, and render the CHR more compatible to NHR than inhibitors. PMID:25393106

  10. HIV-1 drug resistance mutations emerging on darunavir therapy in PI-naive and -experienced patients in the UK

    PubMed Central

    El Bouzidi, Kate; White, Ellen; Mbisa, Jean L.; Sabin, Caroline A.; Phillips, Andrew N.; Mackie, Nicola; Pozniak, Anton L.; Tostevin, Anna; Pillay, Deenan; Dunn, David T.

    2016-01-01

    Background Darunavir is considered to have a high genetic barrier to resistance. Most darunavir-associated drug resistance mutations (DRMs) have been identified through correlation of baseline genotype with virological response in clinical trials. However, there is little information on DRMs that are directly selected by darunavir in clinical settings. Objectives We examined darunavir DRMs emerging in clinical practice in the UK. Patients and methods Baseline and post-exposure protease genotypes were compared for individuals in the UK Collaborative HIV Cohort Study who had received darunavir; analyses were stratified for PI history. A selection analysis was used to compare the evolution of subtype B proteases in darunavir recipients and matched PI-naive controls. Results Of 6918 people who had received darunavir, 386 had resistance tests pre- and post-exposure. Overall, 2.8% (11/386) of these participants developed emergent darunavir DRMs. The prevalence of baseline DRMs was 1.0% (2/198) among PI-naive participants and 13.8% (26/188) among PI-experienced participants. Emergent DRMs developed in 2.0% of the PI-naive group (4 mutations) and 3.7% of the PI-experienced group (12 mutations). Codon 77 was positively selected in the PI-naive darunavir cases, but not in the control group. Conclusions Our findings suggest that although emergent darunavir resistance is rare, it may be more common among PI-experienced patients than those who are PI-naive. Further investigation is required to explore whether codon 77 is a novel site involved in darunavir susceptibility. PMID:27856703

  11. Trends and predictors of transmitted drug resistance (TDR) and clusters with TDR in a local Belgian HIV-1 epidemic.

    PubMed

    Pineda-Peña, Andrea-Clemencia; Schrooten, Yoeri; Vinken, Lore; Ferreira, Fossie; Li, Guangdi; Trovão, Nídia Sequeira; Khouri, Ricardo; Derdelinckx, Inge; De Munter, Paul; Kücherer, Claudia; Kostrikis, Leondios G; Nielsen, Claus; Littsola, Kirsi; Wensing, Annemarie; Stanojevic, Maja; Paredes, Roger; Balotta, Claudia; Albert, Jan; Boucher, Charles; Gomez-Lopez, Arley; Van Wijngaerden, Eric; Van Ranst, Marc; Vercauteren, Jurgen; Vandamme, Anne-Mieke; Van Laethem, Kristel

    2014-01-01

    We aimed to study epidemic trends and predictors for transmitted drug resistance (TDR) in our region, its clinical impact and its association with transmission clusters. We included 778 patients from the AIDS Reference Center in Leuven (Belgium) diagnosed from 1998 to 2012. Resistance testing was performed using population-based sequencing and TDR was estimated using the WHO-2009 surveillance list. Phylogenetic analysis was performed using maximum likelihood and Bayesian techniques. The cohort was predominantly Belgian (58.4%), men who have sex with men (MSM) (42.8%), and chronically infected (86.5%). The overall TDR prevalence was 9.6% (95% confidence interval (CI): 7.7-11.9), 6.5% (CI: 5.0-8.5) for nucleoside reverse transcriptase inhibitors (NRTI), 2.2% (CI: 1.4-3.5) for non-NRTI (NNRTI), and 2.2% (CI: 1.4-3.5) for protease inhibitors. A significant parabolic trend of NNRTI-TDR was found (p = 0.019). Factors significantly associated with TDR in univariate analysis were male gender, Belgian origin, MSM, recent infection, transmission clusters and subtype B, while multivariate and Bayesian network analysis singled out subtype B as the most predictive factor of TDR. Subtype B was related with transmission clusters with TDR that included 42.6% of the TDR patients. Thanks to resistance testing, 83% of the patients with TDR who started therapy had undetectable viral load whereas half of the patients would likely have received a suboptimal therapy without this test. In conclusion, TDR remained stable and a NNRTI up-and-down trend was observed. While the presence of clusters with TDR is worrying, we could not identify an independent, non-sequence based predictor for TDR or transmission clusters with TDR that could help with guidelines or public health measures.

  12. Pretreatment HIV Drug Resistance and HIV-1 Subtype C Are Independently Associated With Virologic Failure: Results From the Multinational PEARLS (ACTG A5175) Clinical Trial

    PubMed Central

    Kantor, Rami; Smeaton, Laura; Vardhanabhuti, Saran; Hudelson, Sarah E.; Wallis, Carol L.; Tripathy, Srikanth; Morgado, Mariza G.; Saravanan, Shanmugham; Balakrishnan, Pachamuthu; Reitsma, Marissa; Hart, Stephen; Mellors, John W.; Halvas, Elias; Grinsztejn, Beatriz; Hosseinipour, Mina C.; Kumwenda, Johnstone; La Rosa, Alberto; Lalloo, Umesh G.; Lama, Javier R.; Rassool, Mohammed; Santos, Breno R.; Supparatpinyo, Khuanchai; Hakim, James; Flanigan, Timothy; Kumarasamy, Nagalingeswaran; Campbell, Thomas B.; Eshleman, Susan H.

    2015-01-01

    Background. Evaluation of pretreatment HIV genotyping is needed globally to guide treatment programs. We examined the association of pretreatment (baseline) drug resistance and subtype with virologic failure in a multinational, randomized clinical trial that evaluated 3 antiretroviral treatment (ART) regimens and included resource-limited setting sites. Methods. Pol genotyping was performed in a nested case-cohort study including 270 randomly sampled participants (subcohort), and 218 additional participants failing ART (case group). Failure was defined as confirmed viral load (VL) >1000 copies/mL. Cox proportional hazards models estimated resistance–failure association. Results. In the representative subcohort (261/270 participants with genotypes; 44% women; median age, 35 years; median CD4 cell count, 151 cells/µL; median VL, 5.0 log10 copies/mL; 58% non-B subtypes), baseline resistance occurred in 4.2%, evenly distributed among treatment arms and subtypes. In the subcohort and case groups combined (466/488 participants with genotypes), used to examine the association between resistance and treatment failure, baseline resistance occurred in 7.1% (9.4% with failure, 4.3% without). Baseline resistance was significantly associated with shorter time to virologic failure (hazard ratio [HR], 2.03; P = .035), and after adjusting for sex, treatment arm, sex–treatment arm interaction, pretreatment CD4 cell count, baseline VL, and subtype, was still independently associated (HR, 2.1; P = .05). Compared with subtype B, subtype C infection was associated with higher failure risk (HR, 1.57; 95% confidence interval [CI], 1.04–2.35), whereas non-B/C subtype infection was associated with longer time to failure (HR, 0.47; 95% CI, .22–.98). Conclusions. In this global clinical trial, pretreatment resistance and HIV-1 subtype were independently associated with virologic failure. Pretreatment genotyping should be considered whenever feasible. Clinical Trials

  13. Short Communication: Population-Based Surveillance of HIV-1 Drug Resistance in Cameroonian Adults Initiating Antiretroviral Therapy According to the World Health Organization Guidelines.

    PubMed

    Fokam, Joseph; Takou, Désiré; Santoro, Maria Mercedes; Akonie, Haniel Ze; Kouanfack, Charles; Ceccherini-Silberstein, Francesca; Colizzi, Vittorio; Perno, Carlo-Federico; Ndjolo, Alexis

    2016-04-01

    With ongoing earlier enrollment on and rapid scale-up of antiretroviral therapy (ART) in Cameroon, there are increasing risks of transmitted HIV drug resistance (HIVDR) at population levels. We, therefore, evaluated the threshold of HIVDR in a population initiating ART, to inform on the effectiveness of first-line regimens, considering HIV-1 diversity, plasma viral load (PVL), and CD4-based disease progression. A total of 53 adults [median (interquartile range, IQR) CD4: 162 cell/mm(3) (48-284); median (IQR) PVL: 5.34 log10 RNA (4.17-6.42) copies/ml] initiating ART in 2014 at the Yaoundé Central Hospital were enrolled for HIV-1 protease-reverse transcriptase sequencing. Drug resistance mutations (DRMs) were interpreted using the 2009 World Health Organization (WHO) list versus the Stanford HIVdb algorithm version 7.0. Level of DRMs was low (3.77%) versus moderate (7.55%), respectively, following the WHO list (T69D, K103N) versus Stanford HIVdb (T69D, A98G, K103N, K238T), respectively. Prevailing clade was CRF02_AG (71.70%). Based on Stanford HIVdb, a slightly higher proportion of patients with DRMs were found among ones infected with CRF02_AG than in those non-CRF02_AG infected (7.89% vs. 6.67%, p = 1.000), with lower PVL (7.69% <5.5 vs. 0% ≥5.5 log10 RNA copies/ml, p = .488) and with higher CD4 counts (9.52% CD4 ≥200 vs. 3.33% CD4 <200 cells/mm(3), p = .749). Thresholds of DRMs suggest that standard first-line regimens currently used in Cameroon may remain effective at population levels, despite scale-up of ART in the country, pending adherence, and closed virological monitoring. With an intent-to-diagnose approach, the discrepant levels of DRMs support using Stanford HIVdb to evaluate initial ART, while revising the WHO list for surveillance.

  14. The evolution of HIV-1 group M genetic variability in Southern Cameroon is characterized by several emerging recombinant forms of CRF02_AG and viruses with drug resistance mutations.

    PubMed

    Agyingi, Lucy; Mayr, Luzia M; Kinge, Thompson; Orock, George Enow; Ngai, Johnson; Asaah, Bladine; Mpoame, Mbida; Hewlett, Indira; Nyambi, Phillipe

    2014-03-01

    The HIV epidemic in Cameroon is marked by a broad genetic diversity dominated by circulating recombinant forms (CRFs). Studies performed more than a decade ago in urban settings of Southern Cameroon revealed a dominance of the CRF02_AG and clade A variants in >90% of the infected subjects; however, little is known about the evolving viral variants circulating in this region. To document circulating HIV viral diversity, four regions of the viral genome (gag, PR, reverse transcriptase, env) in 116 HIV-1 positive individuals in Limbe, Southern Cameroon, were PCR-amplified. Sequences obtained at the RT and protease regions were analyzed for mutations that conferred drug resistance using the Stanford Drug Resistance Database. The present study reveals a broad genetic diversity characterized by several unique recombinant forms (URF) accounting for 36% of infections, 48.6% of patients infected with CRF02_AG, and the emergence of CRF22_01A1 in 7.2% of patients. Three out of 15 (20%) treated patients and 13 out of 93 (13.9%) drug naïve patients harbor drug resistance mutations to RT inhibitors, while 3.2% of drug naïve patients harbor drug resistance mutations associated with protease inhibitors. The high proportion (13.9%) of drug resistance mutations among the drug naïve patients reveals the ongoing transmission of these viruses in this region of Cameroon and highlights the need for drug resistance testing before starting treatment for patients infected with HIV-1.

  15. Field Evaluation of Dried Blood Spots for Routine HIV-1 Viral Load and Drug Resistance Monitoring in Patients Receiving Antiretroviral Therapy in Africa and Asia

    PubMed Central

    Monleau, Marjorie; Eymard-Duvernay, Sabrina; Dagnra, Anoumou; Kania, Dramane; Ngo-Giang-Huong, Nicole; Touré-Kane, Coumba; Truong, Lien X. T.; Chaix, Marie-Laure; Delaporte, Eric; Ayouba, Ahidjo; Peeters, Martine

    2014-01-01

    Dried blood spots (DBS) can be used in developing countries to alleviate the logistic constraints of using blood plasma specimens for viral load (VL) and HIV drug resistance (HIVDR) testing, but they should be assessed under field conditions. Between 2009 and 2011, we collected paired plasma-DBS samples from treatment-experienced HIV-1-infected adults in Burkina Faso, Cameroon, Senegal, Togo, Thailand, and Vietnam. The DBS were stored at an ambient temperature for 2 to 4 weeks and subsequently at −20°C before testing. VL testing was performed on the plasma samples and DBS using locally available methods: the Abbott m2000rt HIV-1 test, generic G2 real-time PCR, or the NucliSENS EasyQ version 1.2 test. In the case of virological failure (VF), i.e., a plasma VL of ≥1,000 copies/ml, HIVDR genotyping was performed on paired plasma-DBS samples. Overall, we compared 382 plasma-DBS sample pairs for DBS VL testing accuracy. The sensitivities of the different assays in different laboratories for detecting VF using DBS varied from 75% to 100% for the m2000rt test in labs B, C, and D, 91% to 93% for generic G2 real-time PCR in labs A and F, and 85% for the NucliSENS test in lab E. The specificities varied from 82% to 97% for the m2000rt and NucliSENS tests and reached only 60% for the generic G2 test. The NucliSENS test showed good agreement between plasma and DBS VL but underestimated the DBS VL. The lowest agreement was observed for the generic G2 test. Genotyping was successful for 96/124 (77%) DBS tested, and 75/96 (78%) plasma-DBS pairs had identical HIVDR mutations. Significant discrepancies in resistance interpretations were observed in 9 cases, 6 of which were from the same laboratory. DBS can be successfully used as an alternative to blood plasma samples for routine VL and HIVDR monitoring in African and Asian settings. However, the selection of an adequate VL measurement method and the definition of the VF threshold should be considered, and laboratory

  16. Design, Synthesis and Biological Evaluation of 1-[(2-benzyloxyl/alkoxyl) methyl]-5-halo-6-aryluracils as Potent HIV-1 Non-Nucleoside Reverse Transcriptase Inhibitors with Improved Drug Resistance Profile

    PubMed Central

    Wang, Xiaowei; Zhang, Jianfang; Huang, Yang; Wang, Ruiping; Zhang, Liang; Qiao, Kang; Li, Li; Liu, Chang; Ouyang, Yabo; Xu, Weisi; Zhang, Zhili; Zhang, Liangren; Shao, Yiming; Jiang, Shibo; Ma, Liying; Liu, Junyi

    2012-01-01

    Since the emergence of drug-resistant mutants has limited the efficacy of non-nucleoside reverse transcriptase inhibitors (NNRTIs), it is essential to develop new antivirals with better drug-resistance and pharmacokinetic profiles. Here we designed and synthesized a series of 1-[(2-benzyloxyl/alkoxyl)methyl]-5-halo-6-aryluracils, the HEPT analogues, and evaluated their biological activity using Nevirapine and 18 (TNK-651) as reference compounds. Most of these compounds, especially 6b, 7b, 9b, 11b and 7c, exhibited highly potent anti-HIV-1 activity against both wild-type and NNRTI-resistant HIV-1 strains. The compound 7b, that had the highest selectivity index (SI = 38,215), is more potent than Nevirapine and 18. These results suggest that introduction of halogen at the C-5 position may contribute to the effectiveness of these compounds against RTI-resistant variants. In addition, m-substituents on the C-6 aromatic moiety could significantly enhance activity against NNRTI-resistant HIV-1 strains. These compounds can be further developed as next-generation NNRTIs with improved antiviral efficacy and drug-resistance profile. PMID:22283377

  17. Emergent HIV-1 Drug Resistance Mutations Were Not Present at Low-Frequency at Baseline in Non-Nucleoside Reverse Transcriptase Inhibitor-Treated Subjects in the STaR Study

    PubMed Central

    Porter, Danielle P.; Daeumer, Martin; Thielen, Alexander; Chang, Silvia; Martin, Ross; Cohen, Cal; Miller, Michael D.; White, Kirsten L.

    2015-01-01

    At Week 96 of the Single-Tablet Regimen (STaR) study, more treatment-naïve subjects that received rilpivirine/emtricitabine/tenofovir DF (RPV/FTC/TDF) developed resistance mutations compared to those treated with efavirenz (EFV)/FTC/TDF by population sequencing. Furthermore, more RPV/FTC/TDF-treated subjects with baseline HIV-1 RNA >100,000 copies/mL developed resistance compared to subjects with baseline HIV-1 RNA ≤100,000 copies/mL. Here, deep sequencing was utilized to assess the presence of pre-existing low-frequency variants in subjects with and without resistance development in the STaR study. Deep sequencing (Illumina MiSeq) was performed on baseline and virologic failure samples for all subjects analyzed for resistance by population sequencing during the clinical study (n = 33), as well as baseline samples from control subjects with virologic response (n = 118). Primary NRTI or NNRTI drug resistance mutations present at low frequency (≥2% to 20%) were detected in 6.6% of baseline samples by deep sequencing, all of which occurred in control subjects. Deep sequencing results were generally consistent with population sequencing but detected additional primary NNRTI and NRTI resistance mutations at virologic failure in seven samples. HIV-1 drug resistance mutations emerging while on RPV/FTC/TDF or EFV/FTC/TDF treatment were not present at low frequency at baseline in the STaR study. PMID:26690199

  18. Emergent HIV-1 Drug Resistance Mutations Were Not Present at Low-Frequency at Baseline in Non-Nucleoside Reverse Transcriptase Inhibitor-Treated Subjects in the STaR Study.

    PubMed

    Porter, Danielle P; Daeumer, Martin; Thielen, Alexander; Chang, Silvia; Martin, Ross; Cohen, Cal; Miller, Michael D; White, Kirsten L

    2015-12-07

    At Week 96 of the Single-Tablet Regimen (STaR) study, more treatment-naïve subjects that received rilpivirine/emtricitabine/tenofovir DF (RPV/FTC/TDF) developed resistance mutations compared to those treated with efavirenz (EFV)/FTC/TDF by population sequencing. Furthermore, more RPV/FTC/TDF-treated subjects with baseline HIV-1 RNA >100,000 copies/mL developed resistance compared to subjects with baseline HIV-1 RNA ≤100,000 copies/mL. Here, deep sequencing was utilized to assess the presence of pre-existing low-frequency variants in subjects with and without resistance development in the STaR study. Deep sequencing (Illumina MiSeq) was performed on baseline and virologic failure samples for all subjects analyzed for resistance by population sequencing during the clinical study (n = 33), as well as baseline samples from control subjects with virologic response (n = 118). Primary NRTI or NNRTI drug resistance mutations present at low frequency (≥2% to 20%) were detected in 6.6% of baseline samples by deep sequencing, all of which occurred in control subjects. Deep sequencing results were generally consistent with population sequencing but detected additional primary NNRTI and NRTI resistance mutations at virologic failure in seven samples. HIV-1 drug resistance mutations emerging while on RPV/FTC/TDF or EFV/FTC/TDF treatment were not present at low frequency at baseline in the STaR study.

  19. HIV-1 virologic failure and acquired drug resistance among first-line antiretroviral experienced adults at a rural HIV clinic in coastal Kenya: a cross-sectional study

    PubMed Central

    2014-01-01

    Background An increasing number of people on antiretroviral therapy (ART) in sub-Saharan Africa has led to declines in HIV related morbidity and mortality. However, virologic failure (VF) and acquired drug resistance (ADR) may negatively affect these gains. This study describes the prevalence and correlates of HIV-1 VF and ADR among first-line ART experienced adults at a rural HIV clinic in Coastal Kenya. Methods HIV-infected adults on first-line ART for ≥6 months were cross-sectionally recruited between November 2008 and March 2011. The primary outcome was VF, defined as a one-off plasma viral load of ≥400 copies/ml. The secondary outcome was ADR, defined as the presence of resistance associated mutations. Logistic regression and Fishers exact test were used to describe correlates of VF and ADR respectively. Results Of the 232 eligible participants on ART over a median duration of 13.9 months, 57 (24.6% [95% CI: 19.2 – 30.6]) had VF. Fifty-five viraemic samples were successfully amplified and sequenced. Of these, 29 (52.7% [95% CI: 38.8 – 66.3]) had at least one ADR, with 25 samples having dual-class resistance mutations. The most prevalent ADR mutations were the M184V (n = 24), K103N/S (n = 14) and Y181C/Y/I/V (n = 8). Twenty-six of the 55 successfully amplified viraemic samples (47.3%) did not have any detectable resistance mutation. Younger age (15–34 vs. ≥35 years: adjusted odd ratios [95% CI], p-value: 0.3 [0.1–0.6], p = 0.002) and unsatisfactory adherence (<95% vs. ≥95%: 3.0 [1.5–6.5], p = 0.003) were strong correlates of VF. Younger age, unsatisfactory adherence and high viral load were also strong correlates of ADR. Conclusions High levels of VF and ADR were observed in younger patients and those with unsatisfactory adherence. Youth-friendly ART initiatives and strengthened adherence support should be prioritized in this Coastal Kenyan setting. To prevent unnecessary/premature switches, targeted HIV drug resistance

  20. The L76V Drug Resistance Mutation Decreases the Dimer Stability and Rate of Autoprocessing of HIV-1 Protease by Reducing Internal Hydrophobic Contacts

    SciTech Connect

    Louis, John M.; Zhang, Ying; Sayer, Jane M.; Wang, Yuan-Fang; Harrison, Robert W.; Weber, Irene T.

    2011-09-06

    The mature HIV-1 protease (PR) bearing the L76V drug resistance mutation (PR{sub L76V}) is significantly less stable, with a >7-fold higher dimer dissociation constant (K{sub d}) of 71 {+-} 24 nM and twice the sensitivity to urea denaturation (UC{sub 50} = 0.85 M) relative to those of PR. Differential scanning calorimetry showed decreases in T{sub m} of 12 C for PR{sub L76V} in the absence of inhibitors and 5-7 C in the presence of inhibitors darunavir (DRV), saquinavir (SQV), and lopinavir (LPV), relative to that of PR. Isothermal titration calorimetry gave a ligand dissociation constant of 0.8 nM for DRV, {approx}160-fold higher than that of PR, consistent with DRV resistance. Crystal structures of PR{sub L76V} in complexes with DRV and SQV were determined at resolutions of 1.45-1.46 {angstrom}. Compared to the corresponding PR complexes, the mutated Val76 lacks hydrophobic interactions with Asp30, Lys45, Ile47, and Thr74 and exhibits closer interactions with Val32 and Val56. The bound DRV lacks one hydrogen bond with the main chain of Asp30 in PR{sub L76V} relative to PR, possibly accounting for the resistance to DRV. SQV shows slightly improved polar interactions with PR{sub L76V} compared to those with PR. Although the L76V mutation significantly slows the N-terminal autoprocessing of the precursor TFR-PR{sub L76V} to give rise to the mature PR{sub L76V}, the coselected M46I mutation counteracts the effect by enhancing this rate but renders the TFR-PRM46I/L76V precursor less responsive to inhibition by 6 {micro}M LPV while preserving inhibition by SQV and DRV. The correlation of lowered stability, higher K{sub d}, and impaired autoprocessing with reduced internal hydrophobic contacts suggests a novel molecular mechanism for drug resistance.

  1. A multifaceted analysis of HIV-1 protease multidrug resistance phenotypes

    PubMed Central

    2011-01-01

    Background Great strides have been made in the effective treatment of HIV-1 with the development of second-generation protease inhibitors (PIs) that are effective against historically multi-PI-resistant HIV-1 variants. Nevertheless, mutation patterns that confer decreasing susceptibility to available PIs continue to arise within the population. Understanding the phenotypic and genotypic patterns responsible for multi-PI resistance is necessary for developing PIs that are active against clinically-relevant PI-resistant HIV-1 variants. Results In this work, we use globally optimal integer programming-based clustering techniques to elucidate multi-PI phenotypic resistance patterns using a data set of 398 HIV-1 protease sequences that have each been phenotyped for susceptibility toward the nine clinically-approved HIV-1 PIs. We validate the information content of the clusters by evaluating their ability to predict the level of decreased susceptibility to each of the available PIs using a cross validation procedure. We demonstrate the finding that as a result of phenotypic cross resistance, the considered clinical HIV-1 protease isolates are confined to ~6% or less of the clinically-relevant phenotypic space. Clustering and feature selection methods are used to find representative sequences and mutations for major resistance phenotypes to elucidate their genotypic signatures. We show that phenotypic similarity does not imply genotypic similarity, that different PI-resistance mutation patterns can give rise to HIV-1 isolates with similar phenotypic profiles. Conclusion Rather than characterizing HIV-1 susceptibility toward each PI individually, our study offers a unique perspective on the phenomenon of PI class resistance by uncovering major multidrug-resistant phenotypic patterns and their often diverse genotypic determinants, providing a methodology that can be applied to understand clinically-relevant phenotypic patterns to aid in the design of novel inhibitors that

  2. Prevalence of HIV-1 resistant strains in recent seroconverters.

    PubMed

    Balotta, C; Berlusconi, A; Pan, A; Violin, M; Riva, C; Gori, A; Corvasce, S; Mazzucchelli, R; Facchi, G; Velleca, R; Senese, D; Dehò, L; Galli, M; Rusconi, S; Moroni, M

    2000-01-01

    Twenty-nine HIV-1 recently infected subjects were retrospectively studied to investigate both the prevalence of nucleoside reverse transcriptase inhibitors (NRTI)-related mutations at primary infection and the proportion of naturally occurring mutations in protease inhibitor (PI)-naive patients. Neither HIV-1 plasma viremia nor CD4 absolute count at baseline could distinguish patients with NRTI pre-existing mutations from those with wild-type virus. An increasing proportion of ZDV-related mutations was observed over time with an overall frequency of 20.7% in the study period. Only 1 out of 6 patients (16.7%) with ZDV-related mutations showed a phenotypically ZDV resistant isolate. A striking proportion of polymorphic changes was present in the protease region of pol gene in newly infected individuals. As many as 80% of seroconverters presented at least one naturally occurring substitution. Some PI-associated substitutions, thought to be compensatory in protease enzymatic function, could confer intermediate to high PI-resistance. Their role following PI administration remains to be elucidated. Our data suggest that the choice of drugs should be oriented by both genotypic and phenotypic evaluations to tailor individual regimens in seroconverters.

  3. Rare emergence of drug resistance in HIV-1 treatment-naïve patients after 48 weeks of treatment with elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide.

    PubMed

    Margot, Nicolas A; Kitrinos, Kathryn M; Fordyce, Marshall; McCallister, Scott; Miller, Michael D; Callebaut, Christian

    2016-03-01

    Tenofovir alafenamide (TAF), a novel prodrug of the NtRTI tenofovir (TFV), delivers TFV-diphosphate (TFV-DP) to target cells more efficiently than the current prodrug, tenofovir disoproxil fumarate (TDF), with a 90% reduction in TFV plasma exposure. TAF, within the fixed dose combination of elvitegravir /cobicistat / emtricitabine (FTC)/TAF (E/C/F/TAF), has been evaluated in one Phase 2 and two Phase 3 randomized, double-blinded studies in HIV-infected treatment-naive patients, comparing E/C/F/TAF to E/C/F/TDF. In these studies, the TAF-containing group demonstrated non-inferior efficacy to the TDF-containing comparator group with 91.9% of E/C/F/TAF patients having <50 copies/mL of HIV-1 RNA at week 48. An integrated resistance analysis across these three studies was conducted, including HIV-1 genotypic analysis at screening, and genotypic/phenotypic analysis for patients with HIV-1 RNA>400 copies/mL at virologic failure. Pre-existing primary resistance-associated mutations (RAMs) were observed at screening among the 1903 randomized and treated patients: 7.5% had NRTI-RAMs, 18.2% had NNRTI-RAMs, and 3.4% had primary PI-RAMs. Pre-treatment RAMs did not influence treatment response at Week 48. In the E/C/F/TAF group, resistance development was rare; seven patients (0.7%, 7/978) developed NRTI-RAMs, five of whom (0.5%, 5/978) also developed primary INSTI-RAMs. In the E/C/F/TDF group, resistance development was also rare; seven patients (0.8%, 7/925) developed NRTI-RAMs, four of whom (0.4%, 4/925) also developed primary INSTI-RAMs. An additional analysis by deep sequencing in virologic failures revealed minimal differences compared to population sequencing. Overall, resistance development was rare in E/C/F/TAF-treated patients, and the pattern of emergent mutations was similar to E/C/F/TDF.

  4. Comparison of Ahlstrom grade 226, Munktell TFN, and Whatman 903 filter papers for dried blood spot specimen collection and subsequent HIV-1 load and drug resistance genotyping analysis.

    PubMed

    Rottinghaus, Erin; Bile, Ebi; Modukanele, Mosetsanagape; Maruping, Maruping; Mine, Madisa; Nkengasong, John; Yang, Chunfu

    2013-01-01

    Dried blood spots (DBS) collected onto filter paper have eased the difficulty of blood collection in resource-limited settings. Currently, Whatman 903 (W-903) filter paper is the only filter paper that has been used for HIV load and HIV drug resistance (HIVDR) testing. We therefore evaluated two additional commercially available filter papers, Ahlstrom grade 226 (A-226) and Munktell TFN (M-TFN), for viral load (VL) testing and HIVDR genotyping using W-903 filter paper as a comparison group. DBS specimens were generated from 344 adult patients on antiretroviral therapy (ART) in Botswana. The VL was measured with NucliSENS EasyQ HIV-1 v2.0, and genotyping was performed for those specimens with a detectable VL (≥ 2.90 log(10) copies/ml) using an in-house method. Bland-Altman analysis revealed a strong concordance in quantitative VL analysis between W-903 and A-226 (bias = -0.034 ± 0.246 log(10) copies/ml [mean difference ± standard deviation]) and W-903 and M-TFN (bias = -0.028 ± 0.186 log(10) copies/ml) filter papers, while qualitative VL analysis for virological failure determination, defined as a VL of ≥ 3.00 log(10) copies/ml, showed low sensitivities for A-266 (71.54%) and M-TFN (65.71%) filter papers compared to W-903 filter paper. DBS collected on M-TFN filter paper had the highest genotyping efficiency (100%) compared to W-903 and A-226 filter papers (91.7%) and appeared more sensitive in detecting major HIVDR mutations. DBS collected on A-226 and M-TFN filter papers performed similarly to DBS collected on W-903 filter paper for quantitative VL analysis and HIVDR detection. Together, the encouraging genotyping results and the variability observed in determining virological failure from this small pilot study warrant further investigation of A-226 and M-TFN filter papers as specimen collection devices for HIVDR monitoring surveys.

  5. Assessing the HIV-1 Epidemic in Brazilian Drug Users: A Molecular Epidemiology Approach

    PubMed Central

    Guimarães, Monick Lindenmeyer; Marques, Bianca Cristina Leires; Bertoni, Neilane; Teixeira, Sylvia Lopes Maia; Morgado, Mariza Gonçalves; Bastos, Francisco Inácio

    2015-01-01

    Person who inject illicit substances have an important role in HIV-1 blood and sexual transmission and together with person who uses heavy non-injecting drugs may have less than optimal adherence to anti-retroviral treatment and eventually could transmit resistant HIV variants. Unfortunately, molecular biology data on such key population remain fragmentary in most low and middle-income countries. The aim of the present study was to assess HIV infection rates, evaluate HIV-1 genetic diversity, drug resistance, and to identify HIV transmission clusters in heavy drug users (DUs). For this purpose, DUs were recruited in the context of a Respondent-Driven Sampling (RDS) study in different Brazilian cities during 2009. Overall, 2,812 individuals were tested for HIV, and 168 (6%) of them were positive, of which 19 (11.3%) were classified as recent seroconverters, corresponding to an estimated incidence rate of 1.58%/year (95% CI 0.92–2.43%). Neighbor joining phylogenetic trees from env and pol regions and bootscan analyses were employed to subtype the virus from132 HIV-1-infected individuals. HIV-1 subtype B was prevalent in most of the cities under analysis, followed by BF recombinants (9%-35%). HIV-1 subtype C was the most prevalent in Curitiba (46%) and Itajaí (86%) and was also detected in Brasília (9%) and Campo Grande (20%). Pure HIV-1F infections were detected in Rio de Janeiro (9%), Recife (6%), Salvador (6%) and Brasília (9%). Clusters of HIV transmission were assessed by Maximum likelihood analyses and were cross-compared with the RDS network structure. Drug resistance mutations were verified in 12.2% of DUs. Our findings reinforce the importance of the permanent HIV-1 surveillance in distinct Brazilian cities due to viral resistance and increasing subtype heterogeneity all over Brazil, with relevant implications in terms of treatment monitoring, prophylaxis and vaccine development. PMID:26536040

  6. Prediction of HIV-1 protease inhibitor resistance using a protein-inhibitor flexible docking approach.

    PubMed

    Jenwitheesuk, Ekachai; Samudrala, Ram

    2005-01-01

    Emergence of drug resistance remains one of the most challenging issues in the treatment of HIV-1 infection. Here we focus on resistance to HIV-1 protease inhibitors (PIs) at a molecular level, which can be analysed genotypically or phenotypically. Genotypic assays are based on the analysis of mutations associated with reduced drug susceptibility, but are problematic because of the numerous mutations and mutational patterns that confer drug resistance. Phenotypic resistance or susceptibility can be experimentally evaluated by measuring the amount of free drug bound to HIV-1 protease molecules, but this procedure is expensive and time-consuming. To overcome these problems, we have developed a docking protocol that takes protein-inhibitor flexibility into account to predict phenotypic drug resistance. For six FDA-approved Pls and a total of 1792 HIV-1 protease sequence mutants, we used a combination of inhibitor flexible docking and molecular dynamics (MD) simulations to calculate protein-inhibitor binding energies. Prediction results were expressed as fold changes of the calculated inhibitory constant (Ki), and the samples predicted to have fold-increase in calculated Ki above the fixed cut-off were defined as drug resistant. Our combined docking and MD protocol achieved accuracies ranging from 72-83% in predicting resistance/susceptibility for five of the six drugs evaluated. Evaluating the method only on samples where our predictions concurred with established knowledge-based methods resulted in increased accuracies of 83-94% for the six drugs. The results suggest that a physics-based approach, which is readily applicable to any novel PI and/or mutant, can be used judiciously with knowledge-based approaches that require experimental training data to devise accurate models of HIV-1 Pl resistance prediction.

  7. The higher barrier of darunavir and tipranavir resistance for HIV-1 protease

    SciTech Connect

    Wang, Yong; Liu, Zhigang; Brunzelle, Joseph S.; Kovari, Iulia A.; Dewdney, Tamaria G.; Reiter, Samuel J.; Kovari, Ladislau C.

    2011-11-17

    Darunavir and tipranavir are two inhibitors that are active against multi-drug resistant (MDR) HIV-1 protease variants. In this study, the invitro inhibitory efficacy was tested against a MDR HIV-1 protease variant, MDR 769 82T, containing the drug resistance mutations of 46L/54V/82T/84V/90M. Crystallographic and enzymatic studies were performed to examine the mechanism of resistance and the relative maintenance of potency. The key findings are as follows: (i) The MDR protease exhibits decreased susceptibility to all nine HIV-1 protease inhibitors approved by the US Food and Drug Administration (FDA), among which darunavir and tipranavir are the most potent; (ii) the threonine 82 mutation on the protease greatly enhances drug resistance by altering the hydrophobicity of the binding pocket; (iii) darunavir or tipranavir binding facilitates closure of the wide-open flaps of the MDR protease; and (iv) the remaining potency of tipranavir may be preserved by stabilizing the flaps in the inhibitor-protease complex while darunavir maintains its potency by preserving protein main chain hydrogen bonds with the flexible P2 group. These results could provide new insights into drug design strategies to overcome multi-drug resistance of HIV-1 protease variants.

  8. Clinical and resistance consequences of misquantification of plasma and cerebrospinal fluid human immunodeficiency virus type 1 (HIV-1) RNA in samples from an HIV-1 subtype G-infected patient.

    PubMed

    Delaugerre, Constance; Denis, Blandine; Peytavin, Gilles; Palmer, Pierre; Mourez, Thomas; Le Goff, Jerôme; Molina, Jean-Michel; Simon, François

    2009-11-01

    Human immunodeficiency virus (HIV) load is the main marker used to monitor antiviral treatment efficacy and resistance. We report a case of underquantification of HIV type 1 (HIV-1) RNA in plasma and cerebrospinal fluid from an HIV-1 subtype G-infected woman, leading to delayed diagnosis of HIV encephalitis and to the emergence of drug resistance.

  9. Increasing HIV-1 Drug Resistance Between 2010 and 2012 in Adults Participating in Population-Based HIV Surveillance in Rural KwaZulu-Natal, South Africa

    PubMed Central

    Danaviah, Siva; Lessells, Richard; Elshareef, Muna; Tanser, Frank; Wilkinson, Eduan; Pillay, Sureshnee; Mthiyane, Hloniphile; Mwambi, Henry; Pillay, Deenan; de Oliveira, Tulio

    2016-01-01

    Abstract As more human immunodeficiency virus (HIV)–infected patients access combination antiretroviral therapy (cART), higher proportions of newly infected patients may be infected with drug-resistant viruses. Regular surveillance of transmitted drug resistance (TDR) is required in southern Africa where high rates of transmission persist despite rapid expansion of ART. Dried blood spot samples from cART-naive participants from two rounds of an annual population-based HIV surveillance program in rural KwaZulu-Natal were tested for HIV RNA, and samples with HIV RNA >10,000 copies/ml were genotyped for drug resistance. The 2009 surveillance of drug resistance mutation (SDRM) list was used for drug resistance interpretation. The data were added to previously published data from the same program, and the χ2 test for trend was used to test for trend in estimated prevalence of any TDR. Seven hundred and one participants' data were analyzed: 67 (2010), 381 (2011), and 253 (2012). No TDR was detected in 2010. Years 2011 and 2012 had 18 participants with SDRMs 4.7% and 7.1%, respectively (p = .02, χ2 test for trend). The nonnucleoside reverse transcriptase inhibitor mutation, K103N, was the most common mutation, occurring in 27 (3.8%) of the participants, while nucleoside reverse transcriptase inhibitor (NRTI) SDRMs were detected in 10 (1.4%) of the participants, of whom eight had only a single NRTI SDRM. The increase in levels of drug resistance observed in this population could be a signal of increasing transmission of drug-resistant HIV. Thus, continued surveillance is critical to inform public health policies around HIV treatment and prevention. PMID:27002368

  10. Generation of Rhesus Macaque-Tropic HIV-1 Clones That Are Resistant to Major Anti-HIV-1 Restriction Factors

    PubMed Central

    Nomaguchi, Masako; Yokoyama, Masaru; Kono, Ken; Nakayama, Emi E.; Shioda, Tatsuo; Doi, Naoya; Fujiwara, Sachi; Saito, Akatsuki; Akari, Hirofumi; Miyakawa, Kei; Ryo, Akihide; Ode, Hirotaka; Iwatani, Yasumasa; Miura, Tomoyuki; Igarashi, Tatsuhiko

    2013-01-01

    Human immunodeficiency virus type 1 (HIV-1) replication in macaque cells is restricted mainly by antiviral cellular APOBEC3, TRIM5α/TRIM5CypA, and tetherin proteins. For basic and clinical HIV-1/AIDS studies, efforts to construct macaque-tropic HIV-1 (HIV-1mt) have been made by us and others. Although rhesus macaques are commonly and successfully used as infection models, no HIV-1 derivatives suitable for in vivo rhesus research are available to date. In this study, to obtain novel HIV-1mt clones that are resistant to major restriction factors, we altered Gag and Vpu of our best HIV-1mt clone described previously. First, by sequence- and structure-guided mutagenesis, three amino acid residues in Gag-capsid (CA) (M94L/R98S/G114Q) were found to be responsible for viral growth enhancement in a macaque cell line. Results of in vitro TRIM5α susceptibility testing of HIV-1mt carrying these substitutions correlated well with the increased viral replication potential in macaque peripheral blood mononuclear cells (PBMCs) with different TRIM5 alleles, suggesting that the three amino acids in HIV-1mt CA are involved in the interaction with TRIM5α. Second, we replaced the transmembrane domain of Vpu of this clone with the corresponding region of simian immunodeficiency virus SIVgsn166 Vpu. The resultant clone, MN4/LSDQgtu, was able to antagonize macaque but not human tetherin, and its Vpu effectively functioned during viral replication in a macaque cell line. Notably, MN4/LSDQgtu grew comparably to SIVmac239 and much better than any of our other HIV-1mt clones in rhesus macaque PBMCs. In sum, MN4/LSDQgtu is the first HIV-1 derivative that exhibits resistance to the major restriction factors in rhesus macaque cells. PMID:23966385

  11. Drug-eluting fibers for HIV-1 inhibition and contraception.

    PubMed

    Ball, Cameron; Krogstad, Emily; Chaowanachan, Thanyanan; Woodrow, Kim A

    2012-01-01

    Multipurpose prevention technologies (MPTs) that simultaneously prevent sexually transmitted infections (STIs) and unintended pregnancy are a global health priority. Combining chemical and physical barriers offers the greatest potential to design effective MPTs, but integrating both functional modalities into a single device has been challenging. Here we show that drug-eluting fiber meshes designed for topical drug delivery can function as a combination chemical and physical barrier MPT. Using FDA-approved polymers, we fabricated nanofiber meshes with tunable fiber size and controlled degradation kinetics that facilitate simultaneous release of multiple agents against HIV-1, HSV-2, and sperm. We observed that drug-loaded meshes inhibited HIV-1 infection in vitro and physically obstructed sperm penetration. Furthermore, we report on a previously unknown activity of glycerol monolaurate (GML) to potently inhibit sperm motility and viability. The application of drug-eluting nanofibers for HIV-1 prevention and sperm inhibition may serve as an innovative platform technology for drug delivery to the lower female reproductive tract.

  12. Drug-Eluting Fibers for HIV-1 Inhibition and Contraception

    PubMed Central

    Ball, Cameron; Krogstad, Emily; Chaowanachan, Thanyanan; Woodrow, Kim A.

    2012-01-01

    Multipurpose prevention technologies (MPTs) that simultaneously prevent sexually transmitted infections (STIs) and unintended pregnancy are a global health priority. Combining chemical and physical barriers offers the greatest potential to design effective MPTs, but integrating both functional modalities into a single device has been challenging. Here we show that drug-eluting fiber meshes designed for topical drug delivery can function as a combination chemical and physical barrier MPT. Using FDA-approved polymers, we fabricated nanofiber meshes with tunable fiber size and controlled degradation kinetics that facilitate simultaneous release of multiple agents against HIV-1, HSV-2, and sperm. We observed that drug-loaded meshes inhibited HIV-1 infection in vitro and physically obstructed sperm penetration. Furthermore, we report on a previously unknown activity of glycerol monolaurate (GML) to potently inhibit sperm motility and viability. The application of drug-eluting nanofibers for HIV-1 prevention and sperm inhibition may serve as an innovative platform technology for drug delivery to the lower female reproductive tract. PMID:23209601

  13. Natural polymorphisms and unusual mutations in HIV-1 protease with potential antiretroviral resistance: a bioinformatic analysis

    PubMed Central

    2014-01-01

    Background The correlations of genotypic and phenotypic tests with treatment, clinical history and the significance of mutations in viruses of HIV-infected patients are used to establish resistance mutations to protease inhibitors (PIs). Emerging mutations in human immunodeficiency virus type 1 (HIV-1) protease confer resistance to PIs by inducing structural changes at the ligand interaction site. The aim of this study was to establish an in silico structural relationship between natural HIV-1 polymorphisms and unusual HIV-1 mutations that confer resistance to PIs. Results Protease sequences isolated from 151 Mexican HIV-1 patients that were naïve to, or subjected to antiretroviral therapy, were examined. We identified 41 unrelated resistance mutations with a prevalence greater than 1%. Among these mutations, nine exhibited positive selection, three were natural polymorphisms (L63S/V/H) in a codon associated with drug resistance, and six were unusual mutations (L5F, D29V, L63R/G, P79L and T91V). The D29V mutation, with a prevalence of 1.32% in the studied population, was only found in patients treated with antiretroviral drugs. Using in silico modelling, we observed that D29V formed unstable protease complexes when were docked with lopinavir, saquinavir, darunavir, tipranavir, indinavir and atazanavir. Conclusions The structural correlation of natural polymorphisms and unusual mutations with drug resistance is useful for the identification of HIV-1 variants with potential resistance to PIs. The D29V mutation likely confers a selection advantage in viruses; however, in silico, presence of this mutation results in unstable enzyme/PI complexes, that possibly induce resistance to PIs. PMID:24629078

  14. Drug-Induced Reactivation of Apoptosis Abrogates HIV-1 Infection

    PubMed Central

    Hanauske-Abel, Hartmut M.; Saxena, Deepti; Palumbo, Paul E.; Hanauske, Axel-Rainer; Luchessi, Augusto D.; Cambiaghi, Tavane D.; Hoque, Mainul; Spino, Michael; Gandolfi, Darlene D'Alliessi; Heller, Debra S.; Singh, Sukhwinder; Park, Myung Hee; Cracchiolo, Bernadette M.; Tricta, Fernando; Connelly, John; Popowicz, Anthony M.; Cone, Richard A.; Holland, Bart; Pe’ery, Tsafi; Mathews, Michael B.

    2013-01-01

    HIV-1 blocks apoptosis, programmed cell death, an innate defense of cells against viral invasion. However, apoptosis can be selectively reactivated in HIV-infected cells by chemical agents that interfere with HIV-1 gene expression. We studied two globally used medicines, the topical antifungal ciclopirox and the iron chelator deferiprone, for their effect on apoptosis in HIV-infected H9 cells and in peripheral blood mononuclear cells infected with clinical HIV-1 isolates. Both medicines activated apoptosis preferentially in HIV-infected cells, suggesting that the drugs mediate escape from the viral suppression of defensive apoptosis. In infected H9 cells, ciclopirox and deferiprone enhanced mitochondrial membrane depolarization, initiating the intrinsic pathway of apoptosis to execution, as evidenced by caspase-3 activation, poly(ADP-ribose) polymerase proteolysis, DNA degradation, and apoptotic cell morphology. In isolate-infected peripheral blood mononuclear cells, ciclopirox collapsed HIV-1 production to the limit of viral protein and RNA detection. Despite prolonged monotherapy, ciclopirox did not elicit breakthrough. No viral re-emergence was observed even 12 weeks after drug cessation, suggesting elimination of the proviral reservoir. Tests in mice predictive for cytotoxicity to human epithelia did not detect tissue damage or activation of apoptosis at a ciclopirox concentration that exceeded by orders of magnitude the concentration causing death of infected cells. We infer that ciclopirox and deferiprone act via therapeutic reclamation of apoptotic proficiency (TRAP) in HIV-infected cells and trigger their preferential elimination. Perturbations in viral protein expression suggest that the antiretroviral activity of both drugs stems from their ability to inhibit hydroxylation of cellular proteins essential for apoptosis and for viral infection, exemplified by eIF5A. Our findings identify ciclopirox and deferiprone as prototypes of selectively cytocidal

  15. Molecular Gymnastics: Mechanisms of HIV-1 Resistance to CCR5 Antagonists and Impact on Virus Phenotypes.

    PubMed

    Roche, Michael; Borm, Katharina; Flynn, Jacqueline K; Lewin, Sharon R; Churchill, Melissa J; Gorry, Paul R

    2016-01-01

    Human immunodeficiency virus type 1 (HIV-1) enters host cells through the binding of its envelope glycoproteins (Env) to the host cell receptor CD4 and then subsequent binding to a chemokine coreceptor, either CCR5 or CXCR4. CCR5 antagonists are a relatively recent class addition to the armamentarium of anti-HIV-1 drugs. These compounds act by binding to a hydrophobic pocket formed by the transmembrane helices of CCR5 and altering the conformation of the extracellular domains, such that they are no longer recognized by Env. Maraviroc is the first drug within this class to be licenced for use in HIV-1 therapy regimens. HIV resistance to CCR5 antagonists occurs either through outgrowth of pre-existing CXCR4-using viruses, or through acquisition of the ability of CCR5-using HIV-1 to use the antagonist bound form of CCR5. In the latter scenario, the mechanism underlying resistance is through complex alterations in the way that resistant Envs engage CCR5. These significant changes are unlikely to occur without consequence to the viral entry phenotype and may also open up new avenues to target CCR5 antagonist resistant viruses. This review discusses the mechanism of action of CCR5 antagonists, how HIV resistance to CCR5 antagonists occurs, and the subsequent effects on Env function.

  16. Detection of HIV-1 Drug Resistance in Women Following Administration of a Single Dose of Nevirapine: Comparison of Plasma RNA to Cellular DNA by Consensus Sequencing and by Oligonucleotide Ligation Assay▿

    PubMed Central

    Wagner, Thor A.; Kress, Catherine M.; Beck, Ingrid; Techapornroong, Malee; Wittayapraparat, Pakorn; Tansuphasawasdikul, Somboon; Jourdain, Gonzague; Ngo-Giang-Huong, Nicole; Lallemant, Marc; Frenkel, Lisa M.

    2010-01-01

    A single dose of nevirapine (sdNVP) to prevent mother-to-child transmission of HIV-1 increases the risk of failure of subsequent NVP-containing antiretroviral therapy (ART), especially when initiated within 6 months of sdNVP administration, emphasizing the importance of understanding the decay of nevirapine-resistant mutants. Nevirapine-resistant HIV-1 genotypes (with the mutations K103N, Y181C, and/or G190A) from 21 women were evaluated 10 days and 6 weeks after sdNVP administration and at the initiation of ART. Resistance was assayed by consensus sequencing and by a more sensitive assay (oligonucleotide ligation assay [OLA]) using plasma-derived HIV-1 RNA and cell-associated HIV-1 DNA. OLA detected nevirapine resistance in more specimens than consensus sequencing did (63% versus 33%, P < 0.01). When resistance was detected only by OLA (n = 45), the median mutant concentration was 18%, compared to 61% when detected by both sequencing and OLA (n = 51) (P < 0.0001). The proportion of women whose nevirapine resistance was detected by OLA 10 days after sdNVP administration was higher when we tested their HIV-1 RNA (95%) than when we tested their HIV-1 DNA (88%), whereas at 6 weeks after sdNVP therapy, the proportion was greater with DNA (85%) than with RNA (67%) and remained higher with DNA (33%) than with RNA (11%) at the initiation of antiretroviral treatment (median, 45 weeks after sdNVP therapy). Fourteen women started NVP-ART more than 6 months after sdNVP therapy; resistance was detected by OLA in 14% of the women but only in their DNA. HIV-1 resistance to NVP following sdNVP therapy persists longer in cellular DNA than in plasma RNA, as determined by a sensitive assay using sufficient copies of virus, suggesting that DNA may be superior to RNA for detecting resistance at the initiation of ART. PMID:20181911

  17. Identification of differentially expressed proteins in the cervical mucosa of HIV-1-resistant sex workers.

    PubMed

    Burgener, Adam; Boutilier, Julie; Wachihi, Charles; Kimani, Joshua; Carpenter, Michael; Westmacott, Garrett; Cheng, Keding; Ball, Terry B; Plummer, Francis

    2008-10-01

    Novel tools are necessary to understand mechanisms of altered susceptibility to HIV-1 infection in women of the Pumwani Sex Worker cohort, Kenya. In this cohort, more than 140 of the 2000 participants have been characterized to be relatively resistant to HIV-1 infection. Given that sexual transmission of HIV-1 occurs through mucosal surfaces such as that in the cervicovaginal environment, our hypothesis is that innate immune factors in the genital tract may play a role in HIV-1 infection resistance. Understanding this mechanism may help develop microbicides and/or vaccines against HIV-1. A quantitative proteomics technique (2D-DIGE: two-dimensional difference in-gel electrophoresis) was used to examine cervical mucosa of HIV-1 resistant women ( n = 10) for biomarkers of HIV-1 resistance. Over 15 proteins were found to be differentially expressed between HIV-1-resistant women and control groups ( n = 29), some which show a greater than 8-fold change. HIV-1-resistant women overexpressed several antiproteases, including those from the serpin B family, and also cystatin A, a known anti-HIV-1 factor. Immunoblotting for a selection of the identified proteins confirmed the DIGE volume differences. Validation of these results on a larger sample of individuals will provide further evidence these biomarkers are associated with HIV-1 resistance and could help aid in the development of effective microbicides against HIV-1.

  18. Virological Failure and HIV-1 Drug Resistance Mutations among Naive and Antiretroviral Pre-Treated Patients Entering the ESTHER Program of Calmette Hospital in Cambodia

    PubMed Central

    Limsreng, Setha; Him, Sovanvatey; Nouhin, Janin; Hak, Chanroeurn; Srun, Chanvatey; Viretto, Gerald; Ouk, Vara; Delfraissy, Jean Francois; Ségéral, Olivier

    2014-01-01

    Introduction In resource limited settings, patients entering an antiretroviral therapy (ART) program comprise ART naive and ART pre-treated patients who may show differential virological outcomes. Methods This retrospective study, conducted in 2010–2012 in the HIV clinic of Calmette Hospital located in Phnom Penh (Cambodia) assessed virological failure (VF) rates and patterns of drug resistance of naive and pre-treated patients. Naive and ART pre-treated patients were included when a Viral Load (VL) was performed during the first year of ART for naive subjects or at the first consultation for pre-treated individuals. Patients showing Virological failure (VF) (>1,000 copies/ml) underwent HIV DR genotyping testing. Interpretation of drug resistance mutations was done according to 2013 version 23 ANRS algorithms. Results On a total of 209 patients, 164 (78.4%) were naive and 45 (21.5%) were ART pre-treated. Their median initial CD4 counts were 74 cells/mm3 (IQR: 30–194) and 279 cells/mm3 (IQR: 103–455) (p<0.001), respectively. Twenty seven patients (12.9%) exhibited VF (95% CI: 8.6–18.2%), including 10 naive (10/164, 6.0%) and 17 pre-treated (17/45, 37.8%) patients (p<0.001). Among these viremic patients, twenty-two (81.4%) were sequenced in reverse transcriptase and protease coding regions. Overall, 19 (86.3%) harbored ≥1 drug resistance mutations (DRMs) whereas 3 (all belonging to pre-treated patients) harbored wild-types viruses. The most frequent DRMs were M184V (86.3%), K103N (45.5%) and thymidine analog mutations (TAMs) (40.9%). Two (13.3%) pre-treated patients harbored viruses that showed a multi-nucleos(t)ide resistance including Q151M, K65R, E33A/D, E44A/D mutations. Conclusion In Cambodia, VF rates were low for naive patients but the emergence of DRMs to NNRTI and 3TC occurred relatively quickly in this subgroup. In pre-treated patients, VF rates were much higher and TAMs were relatively common. HIV genotypic assays before ART initiation and for

  19. Structural Studies of a Rationally Selected Multi-Drug Resistant HIV-1 Protease Reveal Synergistic Effect of Distal Mutations on Flap Dynamics.

    PubMed

    Agniswamy, Johnson; Louis, John M; Roche, Julien; Harrison, Robert W; Weber, Irene T

    2016-01-01

    We report structural analysis of HIV protease variant PRS17 which was rationally selected by machine learning to represent wide classes of highly drug-resistant variants. Crystal structures were solved of PRS17 in the inhibitor-free form and in complex with antiviral inhibitor, darunavir. Despite its 17 mutations, PRS17 has only one mutation (V82S) in the inhibitor/substrate binding cavity, yet exhibits high resistance to all clinical inhibitors. PRS17 has none of the major mutations (I47V, I50V, I54ML, L76V and I84V) associated with darunavir resistance, but has 10,000-fold weaker binding affinity relative to the wild type PR. Comparable binding affinity of 8000-fold weaker than PR is seen for drug resistant mutant PR20, which bears 3 mutations associated with major resistance to darunavir (I47V, I54L and I84V). Inhibitor-free PRS17 shows an open flap conformation with a curled tip correlating with G48V flap mutation. NMR studies on inactive PRS17 D25N unambiguously confirm that the flaps adopt mainly an open conformation in solution very similar to that in the inhibitor-free crystal structure. In PRS17, the hinge loop cluster of mutations, E35D, M36I and S37D, contributes to the altered flap dynamics by a mechanism similar to that of PR20. An additional K20R mutation anchors an altered conformation of the hinge loop. Flap mutations M46L and G48V in PRS17/DRV complex alter the Phe53 conformation by steric hindrance between the side chains. Unlike the L10F mutation in PR20, L10I in PRS17 does not break the inter-subunit ion pair or diminish the dimer stability, consistent with a very low dimer dissociation constant comparable to that of wild type PR. Distal mutations A71V, L90M and I93L propagate alterations to the catalytic site of PRS17. PRS17 exhibits a molecular mechanism whereby mutations act synergistically to alter the flap dynamics resulting in significantly weaker binding yet maintaining active site contacts with darunavir.

  20. Structural Studies of a Rationally Selected Multi-Drug Resistant HIV-1 Protease Reveal Synergistic Effect of Distal Mutations on Flap Dynamics

    SciTech Connect

    Agniswamy, Johnson; Louis, John M.; Roche, Julien; Harrison, Robert W.; Weber, Irene T.; Sluis-Cremer, Nicolas

    2016-12-16

    We report structural analysis of HIV protease variant PRS17 which was rationally selected by machine learning to represent wide classes of highly drug-resistant variants. Crystal structures were solved of PRS17 in the inhibitor-free form and in complex with antiviral inhibitor, darunavir. Despite its 17 mutations, PRS17 has only one mutation (V82S) in the inhibitor/substrate binding cavity, yet exhibits high resistance to all clinical inhibitors. PRS17 has none of the major mutations (I47V, I50V, I54ML, L76V and I84V) associated with darunavir resistance, but has 10,000-fold weaker binding affinity relative to the wild type PR. Comparable binding affinity of 8000-fold weaker than PR is seen for drug resistant mutant PR20, which bears 3 mutations associated with major resistance to darunavir (I47V, I54L and I84V). Inhibitor-free PRS17 shows an open flap conformation with a curled tip correlating with G48V flap mutation. NMR studies on inactive PRS17 D25N unambiguously confirm that the flaps adopt mainly an open conformation in solution very similar to that in the inhibitor-free crystal structure. In PRS17, the hinge loop cluster of mutations, E35D, M36I and S37D, contributes to the altered flap dynamics by a mechanism similar to that of PR20. An additional K20R mutation anchors an altered conformation of the hinge loop. Flap mutations M46L and G48V in PRS17/DRV complex alter the Phe53 conformation by steric hindrance between the side chains. Unlike the L10F mutation in PR20, L10I in PRS17 does not break the inter-subunit ion pair or diminish the dimer stability, consistent with a very low dimer dissociation constant comparable to that of wild type PR. Distal mutations A71V, L90M and I93L propagate alterations to the catalytic site of PRS17. PRS17 exhibits a molecular mechanism whereby mutations act synergistically to alter the flap dynamics resulting in significantly weaker binding yet maintaining active site contacts with darunavir.

  1. Structural Studies of a Rationally Selected Multi-Drug Resistant HIV-1 Protease Reveal Synergistic Effect of Distal Mutations on Flap Dynamics

    PubMed Central

    Agniswamy, Johnson; Louis, John M.; Roche, Julien; Harrison, Robert W.

    2016-01-01

    We report structural analysis of HIV protease variant PRS17 which was rationally selected by machine learning to represent wide classes of highly drug-resistant variants. Crystal structures were solved of PRS17 in the inhibitor-free form and in complex with antiviral inhibitor, darunavir. Despite its 17 mutations, PRS17 has only one mutation (V82S) in the inhibitor/substrate binding cavity, yet exhibits high resistance to all clinical inhibitors. PRS17 has none of the major mutations (I47V, I50V, I54ML, L76V and I84V) associated with darunavir resistance, but has 10,000-fold weaker binding affinity relative to the wild type PR. Comparable binding affinity of 8000-fold weaker than PR is seen for drug resistant mutant PR20, which bears 3 mutations associated with major resistance to darunavir (I47V, I54L and I84V). Inhibitor-free PRS17 shows an open flap conformation with a curled tip correlating with G48V flap mutation. NMR studies on inactive PRS17 D25N unambiguously confirm that the flaps adopt mainly an open conformation in solution very similar to that in the inhibitor-free crystal structure. In PRS17, the hinge loop cluster of mutations, E35D, M36I and S37D, contributes to the altered flap dynamics by a mechanism similar to that of PR20. An additional K20R mutation anchors an altered conformation of the hinge loop. Flap mutations M46L and G48V in PRS17/DRV complex alter the Phe53 conformation by steric hindrance between the side chains. Unlike the L10F mutation in PR20, L10I in PRS17 does not break the inter-subunit ion pair or diminish the dimer stability, consistent with a very low dimer dissociation constant comparable to that of wild type PR. Distal mutations A71V, L90M and I93L propagate alterations to the catalytic site of PRS17. PRS17 exhibits a molecular mechanism whereby mutations act synergistically to alter the flap dynamics resulting in significantly weaker binding yet maintaining active site contacts with darunavir. PMID:27992544

  2. Low-frequency drug-resistant HIV-1 and risk of virological failure to first-line NNRTI-based ART: a multicohort European case–control study using centralized ultrasensitive 454 pyrosequencing

    PubMed Central

    Cozzi-Lepri, Alessandro; Noguera-Julian, Marc; Di Giallonardo, Francesca; Schuurman, Rob; Däumer, Martin; Aitken, Sue; Ceccherini-Silberstein, Francesca; D'Arminio Monforte, Antonella; Geretti, Anna Maria; Booth, Clare L.; Kaiser, Rolf; Michalik, Claudia; Jansen, Klaus; Masquelier, Bernard; Bellecave, Pantxika; Kouyos, Roger D.; Castro, Erika; Furrer, Hansjakob; Schultze, Anna; Günthard, Huldrych F.; Brun-Vezinet, Francoise; Paredes, Roger; Metzner, Karin J.; Paredes, Roger; Metzner, Karin J.; Cozzi-Lepri, Alessandro; Schuurman, Rob; Brun-Vezinet, Francoise; Günthard, Huldrych; Ceccherini-Silberstein, Francesca; Kaiser, Rolf; Geretti, Anna Maria; Brockmeyer, Norbert; Masquelier, Bernard; Dabis, F.; Bruyand, M.; Chêne, G.; Dabis, F.; Lawson-Ayayi, S.; Thiébaut, R.; Wittkop, L.; André, K.; Bonnal, F.; Bonnet, F.; Bernard, N.; Caunègre, L.; Cazanave, C.; Ceccaldi, J.; Chossat, I.; Courtaud, K.; Dauchy, F. A.; De Witte, S.; Dupon, M.; Dupont, A.; Duffau, P.; Dutronc, H.; Farbos, S.; Gaborieau, V.; Gemain, M. C.; Gerard, Y.; Greib, C.; Hessamfar, M.; Lacoste, D.; Lataste, P.; Lazaro, E.; Longy-Boursier, M.; Malvy, D.; Meraud, J. P.; Mercié, P.; Monlun, E.; Morlat, P.; Neau, D.; Ochoa, A.; Pellegrin, J. L.; Pistone, T.; Receveur, M. C.; Schmeltz, J. Roger; Tchamgoué, S.; Vandenhende, M. A.; Vareil, M.O.; Viallard, J. F.; Moreau, J. F.; Pellegrin, I.; Fleury, H.; Lafon, M. E.; Masquelier, B.; Reigadas, S.; Trimoulet, P.; Bouchet, S.; Breilh, D.; Molimard, M.; Titier, K.; Haramburu, F.; Miremont-Salamé., G.; Blaizeau, M. J.; Decoin, M.; Delaune, J.; Delveaux, S.; D'Ivernois, C.; Hanapier, C.; Leleux, O.; Lenaud, E.; Uwamaliya-Nziyumvira, B.; Sicard, X.; Geffard, S.; Le Marec, F.; Conte, V.; Frosch, A.; Leray, J.; Palmer, G.; Touchard, D.; Bonnet, F.; Breilh, D.; Chêne, G.; Dabis, F.; Dupon, M.; Fleury, H.; Malvy, D.; Mercié, P.; Morlat, P.; Neau, D.; Pellegrin, I.; Pellegrin, J. L.; Bouchet, S.; Gaborieau, V.; Lacoste, D.; Tchamgoué, S.; Thiébaut, R.; Losso, M.; Kundro, M.; Ramos Mejia, J. M.; Vetter, N.; Zangerle, R.; Karpov, I.; Vassilenko, A.; Mitsura, V. M.; Suetnov, O.; Clumeck, N.; De Wit, S.; Delforge, M.; Florence, E.; Vandekerckhove, L.; Hadziosmanovic, V.; Kostov, K.; Begovac, J.; Machala, L.; Jilich, D.; Sedlacek, D.; Nielsen, J.; Kronborg, G.; Benfield, T.; Larsen, M.; Gerstoft, J.; Katzenstein, T.; Hansen, A.-B. E.; Skinhøj, P.; Pedersen, C.; Ostergaard, L.; Dragsted, U. B.; Nielsen, L. N.; Zilmer, K.; Smidt, Jelena; Ristola, M.; Katlama, C.; Viard, J. P.; Girard, P. M.; Vanhems, P.; Pradier, C.; Dabis, F.; Neau, D.; Duvivier, C.; Rockstroh, J.; Schmidt, R.; van Lunzen, J.; Degen, O.; Stellbrink, H. J.; Bickel, M.; Bogner, J.; Fätkenheuer, G.; Kosmidis, J.; Gargalianos, P.; Xylomenos, G.; Perdios, J.; Sambatakou, H.; Banhegyi, D.; Gottfredsson, M.; Mulcahy, F.; Yust, I.; Turner, D.; Burke, M.; Pollack, S.; HassounRambam, G.; Elinav, H.; HaouziHadassah, M.; EspositoI, R.; Mazzotta, F.; Vullo, V.; Moroni, M.; Andreoni, M.; Angarano, G.; Antinori, A.; Castelli, F.; Cauda, R.; Di Perri, G.; Galli, M.; Iardino, R.; Ippolito, G.; Lazzarin, A.; Perno, C. F.; von Schloesser, F.; Viale, P.; Monforte, A. D'Arminio; Antinori, A.; Castagna, A.; Ceccherini-Silberstein, F.; Cozzi-Lepri, A.; Girardi, E.; Lo Caputo, S.; Mussini, C.; Puoti, M.; Andreoni, M.; Ammassari, A.; Antinori, A.; Balotta, C.; Bonfanti, P.; Bonora, S.; Borderi, M.; Capobianchi, M. R.; Castagna, A.; Ceccherini-Silberstein, F.; Cingolani, A.; Cinque, P.; Cozzi-Lepri, A.; De Luca, A.; Di Biagio, A.; Girardi, E.; Gianotti, N.; Gori, A.; Guaraldi, G.; Lapadula, G.; Lichtner, M.; Lo Caputo, S.; Madeddu, G.; Maggiolo, F.; Marchetti, G.; Marcotullio, S.; Monno, L.; Mussini, C.; Puoti, M.; Quiros Roldan, E.; Rusconi, S.; Cozzi-Lepri, A.; Cicconi, P.; Fanti, I.; Formenti, T.; Galli, L.; Lorenzini, P.; Carletti, F.; Carrara, S.; Castrogiovanni, A.; Di Caro, A.; Petrone, F.; Prota, G.; Quartu, S.; Giacometti, A.; Costantini, A.; Mazzoccato, S.; Angarano, G.; Monno, L.; Santoro, C.; Maggiolo, F.; Suardi, C.; Viale, P.; Vanino, E.; Verucchi, G.; Castelli, F.; Quiros Roldan, E.; Minardi, C.; Quirino, T.; Abeli, C.; Manconi, P. E.; Piano, P.; Vecchiet, J.; Falasca, K.; Sighinolfi, L.; Segala, D.; Mazzotta, F.; Lo Caputo, S.; Cassola, G.; Viscoli, C.; Alessandrini, A.; Piscopo, R.; Mazzarello, G.; Mastroianni, C.; Belvisi, V.; Bonfanti, P.; Caramma, I.; Chiodera, A.; Castelli, A. P.; Galli, M.; Lazzarin, A.; Rizzardini, G.; Puoti, M.; D'Arminio Monforte, A.; Ridolfo, A. L.; Piolini, R.; Castagna, A.; Salpietro, S.; Carenzi, L.; Moioli, M. C.; Tincati, C.; Marchetti, G.; Mussini, C.; Puzzolante, C.; Gori, A.; Lapadula, G.; Abrescia, N.; Chirianni, A.; Guida, M. G.; Gargiulo, M.; Baldelli, F.; Francisci, D.; Parruti, G.; Ursini, T.; Magnani, G.; Ursitti, M. A.; Cauda, R.; Andreoni, M.; Antinori, A.; Vullo, V.; Cingolani, A.; d'Avino, A.; Gallo, L.; Nicastri, E.; Acinapura, R.; Capozzi, M.; Libertone, R.; Tebano, G.; Cattelan, A.; Sasset, L.; Mura, M. S.; Madeddu, G.; De Luca, A.; Rossetti, B.; Caramello, P.; Di Perri, G.; Orofino, G. C.; Bonora, S.; Sciandra, M.; Bassetti, M.; Londero, A.; Pellizzer, G.; Manfrin, V.; Brockmeyer, N. H.; Skaletz-Rorowski, A.; Dupke, S.; Baumgarten, A.; Carganico, A.; Köppe, S.; Kreckel, P.; Lauenroth-Mai, E.; Freiwald-Rausch, M.; Gölz, J.; Moll, A.; Zeitz, M.; Hower, M.; Reuter, S.; Jensen, B.; Harrer, T.; Esser, S.; Brodt, H. R.; Plettenberg, A.; Stöhr, A.; Buhk, T.; Stellbrink, H. J.; Stoll, M.; Schmidt, R.; Kuhlmann, B.; Mosthaf, F. A.; Rieke, A.; Becker, W.; Volkert, R.; Jäger, H.; Hartl, H.; Mutz, A.; Ulmer, A.; Müller, M.; Aubert, V.; Barth, J.; Battegay, M.; Bernasconi, E.; Böni, J.; Bucher, H. C.; Burton-Jeangros, C.; Calmy, A.; Cavassini, M.; Egger, M.; Elzi, L.; Fehr, J.; Fellay, J.; Furrer, H.; Fux, C. A.; Gorgievski, M.; Günthard, H.; Haerry, D.; Hasse, B.; Hirsch, H. H.; Hösli, I.; Kahlert, C.; Kaiser, L.; Keiser, O.; Klimkait, T.; Kovari, H.; Kouyos, R.; Ledergerber, B.; Martinetti, G.; Martinez de Tejada, B.; Metzner, K.; Müller, N.; Nadal, D.; Pantaleo, G.; Rauch, A.; Regenass, S.; Rickenbach, M.; Rudin, C.; Schmid, P.; Schultze, D.; Schöni-Affolter, F.; Schüpbach, J.; Speck, R.; Staehelin, C.; Tarr, P.; Telenti, A.; Trkola, A.; Vernazza, P.; Weber, R.; Yerly, S.

    2015-01-01

    Objectives It is still debated if pre-existing minority drug-resistant HIV-1 variants (MVs) affect the virological outcomes of first-line NNRTI-containing ART. Methods This Europe-wide case–control study included ART-naive subjects infected with drug-susceptible HIV-1 as revealed by population sequencing, who achieved virological suppression on first-line ART including one NNRTI. Cases experienced virological failure and controls were subjects from the same cohort whose viraemia remained suppressed at a matched time since initiation of ART. Blinded, centralized 454 pyrosequencing with parallel bioinformatic analysis in two laboratories was used to identify MVs in the 1%–25% frequency range. ORs of virological failure according to MV detection were estimated by logistic regression. Results Two hundred and sixty samples (76 cases and 184 controls), mostly subtype B (73.5%), were used for the analysis. Identical MVs were detected in the two laboratories. 31.6% of cases and 16.8% of controls harboured pre-existing MVs. Detection of at least one MV versus no MVs was associated with an increased risk of virological failure (OR = 2.75, 95% CI = 1.35–5.60, P = 0.005); similar associations were observed for at least one MV versus no NRTI MVs (OR = 2.27, 95% CI = 0.76–6.77, P = 0.140) and at least one MV versus no NNRTI MVs (OR = 2.41, 95% CI = 1.12–5.18, P = 0.024). A dose–effect relationship between virological failure and mutational load was found. Conclusions Pre-existing MVs more than double the risk of virological failure to first-line NNRTI-based ART. PMID:25336166

  3. A Modified P1 Moiety Enhances in vitro Antiviral Activity against Various Multi-Drug-Resistant HIV-1 Variants and in vitro CNS Penetration Properties of a Novel Nonpeptidic Protease Inhibitor, GRL-10413

    SciTech Connect

    Amano, Masayuki; Salcedo-Gómez, Pedro Miguel; Zhao, Rui; Yedidi, Ravikiran S.; Das, Debananda; Bulut, Haydar; Delino, Nicole S.; Reddy, Sheri Venkata; Ghosh, Arun K.; Mitsuya, Hiroaki

    2016-09-12

    We here report that GRL-10413, a novel non-peptidic HIV-1 protease inhibitor (PI) containing a modified P1 moiety and a sulfonamide isostere, is highly active against laboratory HIV-1 strains and primary clinical isolates (EC50: 0.00035 - 0.0018 μM) with minimal cytotoxicity (CC50: 35.7 μM). GRL-10413 blocked the infectivity and replication of HIV-1NL4-3variants selected by up to 5 μM concentrations of atazanavir, lopinavir, or amprenavir (EC50: 0.0021 - 0.0023 μM). GRL-10413 also maintained its strong antiviral activity against multi-drug-resistant clinical HIV-1 variants isolated from patients, who no longer responded to various antiviral regimens after long-term antiretroviral therapy. The development of resistance against GRL-10413 was significantly delayed compared to that of APV. In addition, GRL-10413 showed a favorable central nervous system (CNS) penetration property as assessed with anin vitroblood brain barrier (BBB) reconstruction system. Analysis of the crystal structure of HIV-1 protease in complex with GRL-10413 demonstrated that the modified P1 moiety of GRL-10413 has a greater hydrophobic surface area and makes greater van der Waals contacts with active-site amino acids of protease than in the case of darunavir. Moreover, the chlorine substituent in the P1 moiety interacts with protease in two distinct configurations. The present data demonstrate that GRL-10413 has desirable features for treating patients infected with wild-type and/or multi-drug-resistant HIV-1 variants with favorable CNS-penetration capability and that the newly modified P1-moiety may confer desirable features in designing novel anti-HIV-1 PIs.

  4. Contribution of the 80s loop of HIV-1 protease to the multidrug-resistance mechanism: crystallographic study of MDR769 HIV-1 protease variants

    PubMed Central

    Yedidi, Ravikiran S.; Proteasa, Georghe; Martinez, Jorge L.; Vickrey, John F.; Martin, Philip D.; Wawrzak, Zdzislaw; Liu, Zhigang; Kovari, Iulia A.; Kovari, Ladislau C.

    2011-01-01

    The flexible flaps and the 80s loops (Pro79–Ile84) of HIV-1 protease are crucial in inhibitor binding. Previously, it was reported that the crystal structure of multidrug-resistant 769 (MDR769) HIV-1 protease shows a wide-open conformation of the flaps owing to conformational rigidity acquired by the accumulation of mutations. In the current study, the effect of mutations on the conformation of the 80s loop of MDR769 HIV-1 protease variants is reported. Alternate conformations of Pro81 (proline switch) with a root-mean-square deviation of 3–4.8 Å in the Cα atoms of the I10V mutant and a side chain with a ‘flipped-out’ conformation in the A82F mutant cause distortion in the S1/S1′ binding pockets that affects inhibitor binding. The A82S and A82T mutants show local changes in the electrostatics of inhibitor binding owing to the mutation from nonpolar to polar residues. In summary, the crystallo­graphic studies of four variants of MDR769 HIV-1 protease presented in this article provide new insights towards understanding the drug-resistance mechanism as well as a basis for design of future protease inhibitors with enhanced potency. PMID:21636892

  5. Contribution of the 80s loop of HIV-1 protease to the multidrug-resistance mechanism: crystallographic study of MDR769 HIV-1 protease variants

    SciTech Connect

    Yedidi, Ravikiran S.; Proteasa, Georghe; Martinez, Jorge L.; Vickrey, John F.; Martin, Philip D.; Wawrzak, Zdzislaw; Liu, Zhigang; Kovari, Iulia A.; Kovari, Ladislau C.

    2011-09-06

    The flexible flaps and the 80s loops (Pro79-Ile84) of HIV-1 protease are crucial in inhibitor binding. Previously, it was reported that the crystal structure of multidrug-resistant 769 (MDR769) HIV-1 protease shows a wide-open conformation of the flaps owing to conformational rigidity acquired by the accumulation of mutations. In the current study, the effect of mutations on the conformation of the 80s loop of MDR769 HIV-1 protease variants is reported. Alternate conformations of Pro81 (proline switch) with a root-mean-square deviation of 3-4.8 {angstrom} in the C{alpha} atoms of the I10V mutant and a side chain with a 'flipped-out' conformation in the A82F mutant cause distortion in the S1/S1' binding pockets that affects inhibitor binding. The A82S and A82T mutants show local changes in the electrostatics of inhibitor binding owing to the mutation from nonpolar to polar residues. In summary, the crystallographic studies of four variants of MDR769 HIV-1 protease presented in this article provide new insights towards understanding the drug-resistance mechanism as well as a basis for design of future protease inhibitors with enhanced potency.

  6. The molecular mechanism of human resistance to HIV-1 infection in persistently infected individuals--a review, hypothesis and implications.

    PubMed

    Becker, Yechiel

    2005-08-01

    Resistance to HIV-1 infection in Europeans is associated with a mutation in the gene that codes for the CCR5 protein that is present in Th2 cells and serves as a coreceptor for HIV-1 R5 strain. A deletion of 32 amino acids from the cytokine receptor prevents infection. This mutation prevails in Europeans and is absent in Africans. However, duplication of a gene that codes for a chemokine that binds to the CCR5 was discovered in Africans (mean gene copy 6 while in non-Africans the mean gene copy is 3). Higher expression of these genes protects T cells against HIV-1 infection in vitro. It should be noted that resistance to HIV-1 R5 variant does not protect against HIV-1 R4 variant. It was reported that a minority of highly HIV-1 exposed African professional sex workers (APSW) were resistant to the virus infection during a 10 years period. Recently, the analysis of the cytokines in the serum of the persistently infected seronegative women revealed that the latter hypo-expresses the cytokine IL-4. Since the molecular events during HIV-1 infection are associated with a marked increase in the levels of IL-4 and IgE in the sera of the infected individuals, it suggests that AIDS is an allergy. Thus, a very low level of IL-4 production may abrogate the virus infection. Studies on the human IL-4 gene revealed that together with the IL-4 mRNA a spliced variant with a deletion of exon 2 is synthesized. The latter is a natural antagonist of IL-4 and when expressed in an individual at a level higher than IL-4, the person will resist a microbial infection (e.g. Mycobacterium tuberculosis) or asthma. The present hypothesis suggests that the HIV-1 resistant APSWs produce more IL-4 delta 2 molecules than IL-4 molecules. The binding of IL-4 delta 2 to IL-4 receptors on T and B cells prevents their functions and the infection by HIV-1. The implications of these studies are that treatment of HIV-1 infected people with drugs that will block the IL-4 receptors will stop HIV-1 infections

  7. Coevolutionary analysis of resistance-evading peptidomimetic inhibitors of HIV-1 protease.

    PubMed

    Rosin, C D; Belew, R K; Morris, G M; Olson, A J; Goodsell, D S

    1999-02-16

    We have developed a coevolutionary method for the computational design of HIV-1 protease inhibitors selected for their ability to retain efficacy in the face of protease mutation. For HIV-1 protease, typical drug design techniques are shown to be ineffective for the design of resistance-evading inhibitors: An inhibitor that is a direct analogue of one of the natural substrates will be susceptible to resistance mutation, as will inhibitors designed to fill the active site of the wild-type or a mutant enzyme. Two design principles are demonstrated: (i) For enzymes with broad substrate specificity, such as HIV-1 protease, resistance-evading inhibitors are best designed against the immutable properties of the active site-the properties that must be conserved in any mutant protease to retain the ability to bind and cleave all of the native substrates. (ii) Robust resistance-evading inhibitors can be designed by optimizing activity simultaneously against a large set of mutant enzymes, incorporating as much of the mutational space as possible.

  8. Coevolutionary analysis of resistance-evading peptidomimetic inhibitors of HIV-1 protease

    PubMed Central

    Rosin, Christopher D.; Belew, Richard K.; Morris, Garrett M.; Olson, Arthur J.; Goodsell, David S.

    1999-01-01

    We have developed a coevolutionary method for the computational design of HIV-1 protease inhibitors selected for their ability to retain efficacy in the face of protease mutation. For HIV-1 protease, typical drug design techniques are shown to be ineffective for the design of resistance-evading inhibitors: An inhibitor that is a direct analogue of one of the natural substrates will be susceptible to resistance mutation, as will inhibitors designed to fill the active site of the wild-type or a mutant enzyme. Two design principles are demonstrated: (i) For enzymes with broad substrate specificity, such as HIV-1 protease, resistance-evading inhibitors are best designed against the immutable properties of the active site—the properties that must be conserved in any mutant protease to retain the ability to bind and cleave all of the native substrates. (ii) Robust resistance-evading inhibitors can be designed by optimizing activity simultaneously against a large set of mutant enzymes, incorporating as much of the mutational space as possible. PMID:9990030

  9. Investigation on the mechanism for the binding and drug resistance of wild type and mutations of G86 residue in HIV-1 protease complexed with Darunavir by molecular dynamic simulation and free energy calculation.

    PubMed

    Li, Dan; Zhang, Ying; Zhao, Run-Ning; Fan, Song; Han, Ju-Guang

    2014-02-01

    Residue Gly86 is considered as the highly conversed residue in the HIV-1 protease. In our work, the detailed binding free energies for the wild-type (WT) and mutated proteases binding to the TMC-114 are estimated to investigate the protein-inhibitor binding and drug resistance mechanism by molecule dynamic simulations and molecular mechanics Poisson Boltzmann surface area (MM-PBSA) method. The binding affinities between the mutants and inhibitor are different than that in the wild-type complex and the major resistance to Darunavir (DRV) of G86A and G86S originate from the electrostatic energy and entropy, respectively. Furthermore, free energy decomposition analysis for the WT and mutated complexes on the basis of per-residue indicates that the mutagenesis influences the energy contribution of the residue located at three regions: active site region (residue 24-32), the flap region, and the region around the mutated residue G86 (residue 79-88), especially the flap region. Finally, further hydrogen bonds and structure analysis are carried out to detect the relationship between the energy and conformation. In all, the G86 mutations change the flap region's conformation. The experimental results are in good agreement with available results.

  10. Crystal engineering of HIV-1 reverse transcriptase for structure-based drug design.

    PubMed

    Bauman, Joseph D; Das, Kalyan; Ho, William C; Baweja, Mukta; Himmel, Daniel M; Clark, Arthur D; Oren, Deena A; Boyer, Paul L; Hughes, Stephen H; Shatkin, Aaron J; Arnold, Eddy

    2008-09-01

    HIV-1 reverse transcriptase (RT) is a primary target for anti-AIDS drugs. Structures of HIV-1 RT, usually determined at approximately 2.5-3.0 A resolution, are important for understanding enzyme function and mechanisms of drug resistance in addition to being helpful in the design of RT inhibitors. Despite hundreds of attempts, it was not possible to obtain the structure of a complex of HIV-1 RT with TMC278, a nonnucleoside RT inhibitor (NNRTI) in advanced clinical trials. A systematic and iterative protein crystal engineering approach was developed to optimize RT for obtaining crystals in complexes with TMC278 and other NNRTIs that diffract X-rays to 1.8 A resolution. Another form of engineered RT was optimized to produce a high-resolution apo-RT crystal form, reported here at 1.85 A resolution, with a distinct RT conformation. Engineered RTs were mutagenized using a new, flexible and cost effective method called methylated overlap-extension ligation independent cloning. Our analysis suggests that reducing the solvent content, increasing lattice contacts, and stabilizing the internal low-energy conformations of RT are critical for the growth of crystals that diffract to high resolution. The new RTs enable rapid crystallization and yield high-resolution structures that are useful in designing/developing new anti-AIDS drugs.

  11. Crystal Engineering of HIV-1 Reverse Transcriptase for structure-Based Drug Design

    SciTech Connect

    Bauman,J.; Das, K.; Ho, W.; Baweja, M.; Himmel, D.; Clark, A.; Oren, D.; Shatkin, A.; Arnold, E.

    2008-01-01

    HIV-1 reverse transcriptase (RT) is a primary target for anti-AIDS drugs. Structures of HIV-1 RT, usually determined at {approx}2.5-3.0 Angstroms resolution, are important for understanding enzyme function and mechanisms of drug resistance in addition to being helpful in the design of RT inhibitors. Despite hundreds of attempts, it was not possible to obtain the structure of a complex of HIV-1 RT with TMC278, a nonnucleoside RT inhibitor (NNRTI) in advanced clinical trials. A systematic and iterative protein crystal engineering approach was developed to optimize RT for obtaining crystals in complexes with TMC278 and other NNRTIs that diffract X-rays to 1.8 Angstroms resolution. Another form of engineered RT was optimized to produce a high-resolution apo-RT crystal form, reported here at 1.85 Angstroms resolution, with a distinct RT conformation. Engineered RTs were mutagenized using a new, flexible and cost effective method called methylated overlap-extension ligation independent cloning. Our analysis suggests that reducing the solvent content, increasing lattice contacts, and stabilizing the internal low-energy conformations of RT are critical for the growth of crystals that diffract to high resolution. The new RTs enable rapid crystallization and yield high-resolution structures that are useful in designing/developing new anti-AIDS drugs.

  12. Novel HIV-1 Protease Inhibitors (PIs) Containing a Bicyclic P2 Functional Moiety, Tetrahydropyrano-Tetrahydrofuran, That Are Potent against Multi-PI-Resistant HIV-1 Variants▿ †

    PubMed Central

    Ide, Kazuhiko; Aoki, Manabu; Amano, Masayuki; Koh, Yasuhiro; Yedidi, Ravikiran S.; Das, Debananda; Leschenko, Sofiya; Chapsal, Bruno; Ghosh, Arun K.; Mitsuya, Hiroaki

    2011-01-01

    We identified GRL-1388 and -1398, potent nonpeptidic human immunodeficiency virus type 1 (HIV-1) protease inhibitors (PIs) containing a bicyclic P2 functional moiety, tetrahydropyrano-tetrahydrofuran (Tp-THF). GRL-1388 was as potent as darunavir (DRV) against various drug-resistant HIV-1 laboratory strains with 50% effective concentration (EC50s) of 2.6 to 32.6 nM. GRL-1398 was significantly more potent against such variants than DRV with EC50s of 0.1 to 5.7 nM. GRL-1388 and -1398 were also potent against multiple-PI-resistant clinical HIV-1 variants (CLHIV-1MDR) with EC50s ranging from 2.7 to 21.3 nM and from 0.3 to 4.8 nM, respectively. A highly DRV-resistant HIV-1 variant selected in vitro remained susceptible to GRL-1398 with the EC50 of 21.9 nM, while the EC50 of DRV was 214.1 nM. When HIV-1NL4-3 was selected with GRL-1398, four amino acid substitutions—leucine to phenylalanine at a position 10 (L10F), A28S, L33F, and M46I—emerged, ultimately enabling the virus to replicate in the presence of >1.0 μM the compound beyond 57 weeks of selection. When a mixture of 10 different CLHIV-1MDR strains was selected, the emergence of resistant variants was more substantially delayed with GRL-1398 than with GRL-1388 and DRV. Modeling analyses revealed that GRL-1398 had greater overall hydrogen bonding and hydrophobic interactions than GRL-1388 and DRV and that GRL-1388 and -1398 had hydrogen bonding interactions with the main chain of the active-site amino acids (Asp29 and Asp30) of protease. The present findings warrant that GRL-1398 be further developed as a potential drug for treating individuals with HIV-1 infection. PMID:21282450

  13. In Vitro Selection and Characterization of HIV-1 Variants with Increased Resistance to Sifuvirtide, a Novel HIV-1 Fusion Inhibitor*

    PubMed Central

    Liu, Zhonghua; Shan, Mei; Li, Li; Lu, Lu; Meng, Shu; Chen, Cheng; He, Yuxian; Jiang, Shibo; Zhang, Linqi

    2011-01-01

    Sifuvirtide, a novel fusion inhibitor against human immunodeficiency virus type I (HIV-1), which is more potent than enfuvirtide (T20) in cell culture, is currently under clinical investigation for the treatment of HIV-1 infection. We now report that in vitro selection of HIV-1 variants resistant to sifuvirtide in the presence of increasing concentrations of sifuvirtide has led to several specific mutations in the gp41 region that had not been previously reported. Many of these substitutions were confined to the N-terminal heptad repeat region at positions 37, 38, 41, and 43, either singly or in combination. A downstream substitution at position 126 (N126K) in the C-terminal heptad repeat region was also found. Site-directed mutagenesis studies have further identified the critical amino acid substitutions and combinations thereof in conferring the resistant genotypes. Furthermore, the mutant viruses demonstrated variable degrees of cross-resistance to enfuvirtide, some of which are preferentially more resistant to sifuvirtide. Impaired infectivity was also found for many of the mutant viruses. Biophysical and structural analyses of the key substitutions have revealed several potential novel mechanisms against sifuvirtide. Our results may help to predict potential resistant patterns in vivo and facilitate the further clinical development and therapeutic utility of sifuvirtide. PMID:21098485

  14. Computational study of the resistance shown by the Subtype B / HIV-1 Protease to currently known inhibitors †

    PubMed Central

    Genoni, Alessandro; Morra, Giulia; Merz, Kenneth M.; Colombo, Giorgio

    2010-01-01

    Human Immunodeficiency Virus type 1 Protease (HIV-1 PR) is an essential enzyme in the HIV-1 life cycle. As such, this protein represents a major drug target in AIDS therapy, but emerging resistance to anti-retroviral inhibitor cocktails, due to high viral mutation rates, represents a significant challenge in AIDS treatment. Many mutations are not located within the active site or binding pocket, nor they do significantly modify the 3D structural organization of the enzyme; hence, the mechanism(s) by which they alter inhibitor affinity for the Protease remains uncertain. In this article, we present an all-atom computational analysis of the dynamic residue-residue coordination between the active site residues and the rest of the protein and of the energetic properties of different HIV-1 PR complexes. We analyze both the wild type form and mutated forms that induce drug resistance. In particular, the results show differences between the wild type and the mutants in their mechanism of dynamic coordination, in the signal propagation between the active site residues and the rest of the protein and in the energy-networks responsible for the stabilization of the bound inhibitor conformation. Finally, we propose a dynamic and energetic explanation for HIV-1 Protease drug resistance and, through this model, we identify a possible new site that could be helpful in the design of a new family of HIV-1 PR allosteric inhibitors. PMID:20415450

  15. Comparison of drug resistance scores for tipranavir in protease inhibitor-naive patients infected with HIV-1 B and non-B subtypes.

    PubMed

    Stürmer, Martin; Stephan, Christoph; Gute, Peter; Knecht, Gaby; Bickel, Markus; Brodt, Hans-Reinhard; Doerr, Hans W; Gürtler, Lutz; Lecocq, Pierre; van Houtte, Margriet

    2011-11-01

    Genotypes of samples from protease inhibitor-naïve patients in Frankfurt's HIV Cohort were analyzed with five tipranavir resistance prediction algorithms. Mean scores were higher in non-B than in B subtypes. The proportion of non-B subtypes increased with increasing scores, except in weighted algorithms. Virtual and in vitro phenotype analyses of samples with increased scores showed no reduced tipranavir susceptibility. Current algorithms appear suboptimal for interpretation of resistance to tipranavir in non-B subtypes; increased scores might reflect algorithm bias rather than "natural resistance."

  16. Design and synthesis of HIV-1 protease inhibitors for a long-acting injectable drug application.

    PubMed

    Kesteleyn, Bart; Amssoms, Katie; Schepens, Wim; Hache, Geerwin; Verschueren, Wim; Van De Vreken, Wim; Rombauts, Klara; Meurs, Greet; Sterkens, Patrick; Stoops, Bart; Baert, Lieven; Austin, Nigel; Wegner, Jörg; Masungi, Chantal; Dierynck, Inge; Lundgren, Stina; Jönsson, Daniel; Parkes, Kevin; Kalayanov, Genadiy; Wallberg, Hans; Rosenquist, Asa; Samuelsson, Bertil; Van Emelen, Kristof; Thuring, Jan Willem

    2013-01-01

    The design and synthesis of novel HIV-1 protease inhibitors (PIs) (1-22), which display high potency against HIV-1 wild-type and multi-PI-resistant HIV-mutant clinical isolates, is described. Lead optimization was initiated from compound 1, a Phe-Phe hydroxyethylene peptidomimetic PI, and was directed towards the discovery of new PIs suitable for a long-acting (LA) injectable drug application. Introducing a heterocyclic 6-methoxy-3-pyridinyl or a 6-(dimethylamino)-3-pyridinyl moiety (R(3)) at the para-position of the P1' benzyl fragment generated compounds with antiviral potency in the low single digit nanomolar range. Halogenation or alkylation of the metabolic hot spots on the various aromatic rings resulted in PIs with high stability against degradation in human liver microsomes and low plasma clearance in rats. Replacing the chromanolamine moiety (R(1)) in the P2 protease binding site by a cyclopentanolamine or a cyclohexanolamine derivative provided a series of high clearance PIs (16-22) with EC(50)s on wild-type HIV-1 in the range of 0.8-1.8 nM. PIs 18 and 22, formulated as nanosuspensions, showed gradual but sustained and complete release from the injection site over two months in rats, and were therefore identified as interesting candidates for a LA injectable drug application for treating HIV/AIDS.

  17. Structural basis of HIV-1 resistance to AZT by excision

    SciTech Connect

    Tu, Xiongying; Das, Kalyan; Han, Qianwei; Bauman, Joseph D.; Clark, Jr., Arthur D.; Hou, Xiaorong; Frenkel, Yulia V.; Gaffney, Barbara L.; Jones, Roger A.; Boyer, Paul L.; Hughes, Stephen H.; Sarafianos, Stefan G.; Arnold, Eddy

    2011-11-23

    Human immunodeficiency virus (HIV-1) develops resistance to 3'-azido-2',3'-deoxythymidine (AZT, zidovudine) by acquiring mutations in reverse transcriptase that enhance the ATP-mediated excision of AZT monophosphate from the 3' end of the primer. The excision reaction occurs at the dNTP-binding site, uses ATP as a pyrophosphate donor, unblocks the primer terminus and allows reverse transcriptase to continue viral DNA synthesis. The excision product is AZT adenosine dinucleoside tetraphosphate (AZTppppA). We determined five crystal structures: wild-type reverse transcriptase-double-stranded DNA (RT-dsDNA)-AZTppppA; AZT-resistant (AZTr; M41L D67N K70R T215Y K219Q) RT-dsDNA-AZTppppA; AZTr RT-dsDNA terminated with AZT at dNTP- and primer-binding sites; and AZTr apo reverse transcriptase. The AMP part of AZTppppA bound differently to wild-type and AZTr reverse transcriptases, whereas the AZT triphosphate part bound the two enzymes similarly. Thus, the resistance mutations create a high-affinity ATP-binding site. The structure of the site provides an opportunity to design inhibitors of AZT-monophosphate excision.

  18. The demise of multidrug-resistant HIV-1: the national time trend in Portugal

    PubMed Central

    Vercauteren, Jurgen; Theys, Kristof; Carvalho, Ana Patricia; Valadas, Emília; Duque, Luis Miguel; Teófilo, Eugénio; Faria, Telo; Faria, Domitília; Vera, José; Águas, Maria João; Peres, Susana; Mansinho, Kamal; Vandamme, Anne-Mieke; Camacho, Ricardo Jorge; Mansinho, Kamal; Cláudia Miranda, Ana; Aldir, Isabel; Ventura, Fernando; Nina, Jaime; Borges, Fernando; Valadas, Emília; Doroana, Manuela; Antunes, Francisco; João Aleixo, Maria; João Águas, Maria; Botas, Júlio; Branco, Teresa; Vera, José; Vaz Pinto, Inês; Poças, José; Sá, Joana; Duque, Luis; Diniz, António; Mineiro, Ana; Gomes, Flora; Santos, Carlos; Faria, Domitília; Fonseca, Paula; Proença, Paula; Tavares, Luís; Guerreiro, Cristina; Narciso, Jorge; Faria, Telo; Teófilo, Eugénio; Pinheiro, Sofia; Germano, Isabel; Caixas, Umbelina; Faria, Nancy; Paula Reis, Ana; Bentes Jesus, Margarida; Amaro, Graça; Roxo, Fausto; Abreu, Ricardo; Neves, Isabel

    2013-01-01

    Objectives Despite a decreasing mortality and morbidity in treated HIV-1 patients, highly active antiretroviral treatment (HAART) can still fail due to the development of drug resistance. Especially, multidrug-resistant viruses pose a threat to efficient therapy. We studied the changing prevalence of multidrug resistance (MDR) over time in a cohort of HIV-1-infected patients in Portugal. Patients and methods We used data of 8065 HIV-1-infected patients followed from July 2001 up to April 2012 in 22 hospitals located in Portugal. MDR at a specific date of sampling was defined as no more than one fully active drug (excluding integrase and entry inhibitors) at that time authorized by the Portuguese National Authority of Medicines and Health Products (INFARMED), as interpreted with the Rega algorithm version 8.0.2. A generalized linear mixed model was used to study the time trend of the prevalence of MDR. Results We observed a statistically significant decrease in the prevalence of MDR over the last decade, from 6.9% (95% CI: 5.7–8.4) in 2001–03, 6.0% (95% CI: 4.9–7.2) in 2003–05, 3.7% (95% CI: 2.8–4.8) in 2005–07 and 1.6% (95% CI: 1.1–2.2) in 2007–09 down to 0.6% (95% CI: 0.3–0.9) in 2009–12 [OR = 0.80 (95% CI: 0.75–0.86); P < 0.001]. In July 2011 the last new case of MDR was seen. Conclusions The prevalence of multidrug-resistant HIV-1 is decreasing over time in Portugal, reflecting the increasing efficiency of HAART and the availability of new drugs. Therefore, in designing a new drug, safety and practical aspects, e.g. less toxicity and ease of use, may need more attention than focusing mainly on efficacy against resistant strains. PMID:23228933

  19. Drug Resistance

    MedlinePlus

    HIV Treatment Drug Resistance (Last updated 3/2/2017; last reviewed 3/2/2017) Key Points As HIV multiplies in the ... the risk of drug resistance. What is HIV drug resistance? Once a person becomes infected with HIV, ...

  20. Maraviroc (Celsentri) for multidrug-resistant human immunodeficiency virus (HIV)-1.

    PubMed

    Ndegwa, S

    2007-12-01

    (1) Maraviroc belongs to a new class of antiretroviral drugs designed to block entry of HIV-1 into CD4+ T-cells via the CCR5 coreceptor. It is indicated for combination therapy in treatment-experienced adults infected with CCR5-tropic HIV-1 that is resistant to multiple antiretroviral agents. (2) Results from two randomized controlled trials (RCTs) indicate that in treatment experienced patients, maraviroc, combined with optimized background therapy (OBT), significantly decreases the level of HIV-1 RNA in the blood (viral load) when compared with OBT alone. The number of patients achieving undetectable viral loads and CD4+ cell count increases were also significantly higher in those receiving maraviroc. (3) Most patients experiencing treatment failure with maraviroc exhibit tropism changes from CCR5-tropic to CXCR4-using virus, but there is no evidence of disease progression. (4) Adverse effects reported with maraviroc include cough, fever, upper respiratory tract infections, rash, muscle and joint pain, abdominal pain, and postural hypotension (dizziness). No significant increases in cardiovascular events, hepatotoxicity, infections or malignancies have been reported with short-term maraviroc therapy. Several post-marketing studies will assess maraviroc's long-term safety for immune function, liver function, malignancy, cardiac events, and risks associated with changes in tropism. (5) Results from an ongoing trial in treatment naive patients suggest that maraviroc may not be superior in terms of viral suppression to standard therapy, but may significantly increase the number of CD4+ T-cells.

  1. Snapshot of the equilibrium dynamics of a drug bound to HIV-1 reverse transcriptase

    NASA Astrophysics Data System (ADS)

    Kuroda, Daniel G.; Bauman, Joseph D.; Challa, J. Reddy; Patel, Disha; Troxler, Thomas; Das, Kalyan; Arnold, Eddy; Hochstrasser, Robin M.

    2013-03-01

    The anti-AIDS drug rilpivirine undergoes conformational changes to bind HIV-1 reverse transcriptase (RT), which is an essential enzyme for the replication of HIV. These changes allow it to retain potency against mutations that otherwise would render the enzyme resistant. Here we report that water molecules play an essential role in this binding process. Femtosecond experiments and theory expose the molecular level dynamics of rilpivirine bound to HIV-1 RT. Two nitrile substituents, one on each arm of the drug, are used as vibrational probes of the structural dynamics within the binding pocket. Two-dimensional vibrational echo spectroscopy reveals that one nitrile group is unexpectedly hydrogen-bonded to a mobile water molecule, not identified in previous X-ray structures. Ultrafast nitrile-water dynamics are confirmed by simulations. A higher (1.51 Å) resolution X-ray structure also reveals a water-drug interaction network. Maintenance of a crucial anchoring hydrogen bond may help retain the potency of rilpivirine against pocket mutations despite the structural variations they cause.

  2. Molecular and phylogenetic analysis of HIV-1 variants circulating among injecting drug users in Mashhad-Iran.

    PubMed

    Naderi, H R; Tagliamonte, M; Tornesello, M L; Ciccozzi, M; Rezza, G; Farid, R; Buonaguro, F M; Buonaguro, L

    2006-09-19

    Genetic and phylogenetic information on the HIV-1 epidemic in Middle-East Countries, and in particular in Iran, are extremely limited. By March 2004, the Iranian Ministry of Health officially reported a cumulative number of 6'532 HIV positive individuals and 214 AIDS cases in the Iranian HIV-1 epidemic. The intra-venous drug users (IDUs) represent the group at highest risk for HIV-1 infection in Iran, accounting for almost 63% of all HIV-infected population. In this regards, a molecular phylogenetic study has been performed on a sentinel cohort of HIV-1 seropositive IDUs enrolled at the end of 2005 at the University of Mashhad, the largest city North East of Tehran. The study has been performed on both gag and env subgenomic regions amplified by Polymerase Chain Reaction (PCR) from peripheral blood mononuclear cells (PBMCs) and characterized by direct DNA sequence analysis. The results reported here show that the HIV-1 subtype A is circulating in this IDUs sentinel cohort. Moreover, the single phylogenetic cluster as well as the intra-group low nucleotide divergence is indicative of a recent outbreak. Unexpectedly, the Iranian samples appear to be phylogenetically derived from African Sub-Saharan subtype A viruses, raising stirring speculations on HIV-1 introduction into the IDUs epidemic in Mashhad. This sentinel study could represent the starting point for a wider molecular survey of the HIV-1 epidemics in Iran to evaluate in detail the distribution of genetic subtypes and possible natural drug-resistant variants, which are extremely helpful information to design diagnostic and therapeutic strategies.

  3. Interaction between Tat and Drugs of Abuse during HIV-1 Infection and Central Nervous System Disease

    PubMed Central

    Maubert, Monique E.; Pirrone, Vanessa; Rivera, Nina T.; Wigdahl, Brian; Nonnemacher, Michael R.

    2016-01-01

    In many individuals, drug abuse is intimately linked with HIV-1 infection. In addition to being associated with one-third of all HIV-1 infections in the United States, drug abuse also plays a role in disease progression and severity in HIV-1-infected patients, including adverse effects on the central nervous system (CNS). Specific systems within the brain are known to be damaged in HIV-1-infected individuals and this damage is similar to that observed in drug abuse. Even in the era of anti-retroviral therapy (ART), CNS pathogenesis occurs with HIV-1 infection, with a broad range of cognitive impairment observed, collectively referred to as HIV-1-associated neurocognitive disorders (HAND). A number of HIV-1 proteins (Tat, gp120, Nef, Vpr) have been implicated in the etiology of pathogenesis and disease as a result of the biologic activity of the extracellular form of each of the proteins in a number of tissues, including the CNS, even in ART-suppressed patients. In this review, we have made Tat the center of attention for a number of reasons. First, it has been shown to be synthesized and secreted by HIV-1-infected cells in the CNS, despite the most effective suppression therapies available to date. Second, Tat has been shown to alter the functions of several host factors, disrupting the molecular and biochemical balance of numerous pathways contributing to cellular toxicity, dysfunction, and death. In addition, the advantages and disadvantages of ART suppression with regard to controlling the genesis and progression of neurocognitive impairment are currently under debate in the field and are yet to be fully determined. In this review, we discuss the individual and concerted contributions of HIV-1 Tat, drug abuse, and ART with respect to damage in the CNS, and how these factors contribute to the development of HAND in HIV-1-infected patients. PMID:26793168

  4. Host Double Strand Break Repair Generates HIV-1 Strains Resistant to CRISPR/Cas9.

    PubMed

    Yoder, Kristine E; Bundschuh, Ralf

    2016-07-12

    CRISPR/Cas9 genome editing has been proposed as a therapeutic treatment for HIV-1 infection. CRISPR/Cas9 induced double strand breaks (DSBs) targeted to the integrated viral genome have been shown to decrease production of progeny virus. Unfortunately HIV-1 evolves rapidly and may readily produce CRISPR/Cas9 resistant strains. Here we used next-generation sequencing to characterize HIV-1 strains that developed resistance to six different CRISPR/Cas9 guide RNAs (gRNAs). Reverse transcriptase (RT) derived base substitution mutations were commonly found at sites encoding unpaired bases of RNA stem-loop structures. In addition to RT mutations, insertion and/or deletion (indel) mutations were common. Indels localized to the CRISPR/Cas9 cleavage site were major contributors to CRISPR gRNA resistance. While most indels at non-coding regions were a single base pair, 3 base pair indels were observed when a coding region of HIV-1 was targeted. The DSB repair event may preserve the HIV-1 reading frame, while destroying CRISPR gRNA homology. HIV-1 may be successfully edited by CRISPR/Cas9, but the virus remains competent for replication and resistant to further CRISPR/Cas9 targeting at that site. These observations strongly suggest that host DSB repair at CRISPR/Cas9 cleavage sites is a novel and important pathway that may contribute to HIV-1 therapeutic resistance.

  5. Host Double Strand Break Repair Generates HIV-1 Strains Resistant to CRISPR/Cas9

    PubMed Central

    Yoder, Kristine E.; Bundschuh, Ralf

    2016-01-01

    CRISPR/Cas9 genome editing has been proposed as a therapeutic treatment for HIV-1 infection. CRISPR/Cas9 induced double strand breaks (DSBs) targeted to the integrated viral genome have been shown to decrease production of progeny virus. Unfortunately HIV-1 evolves rapidly and may readily produce CRISPR/Cas9 resistant strains. Here we used next-generation sequencing to characterize HIV-1 strains that developed resistance to six different CRISPR/Cas9 guide RNAs (gRNAs). Reverse transcriptase (RT) derived base substitution mutations were commonly found at sites encoding unpaired bases of RNA stem-loop structures. In addition to RT mutations, insertion and/or deletion (indel) mutations were common. Indels localized to the CRISPR/Cas9 cleavage site were major contributors to CRISPR gRNA resistance. While most indels at non-coding regions were a single base pair, 3 base pair indels were observed when a coding region of HIV-1 was targeted. The DSB repair event may preserve the HIV-1 reading frame, while destroying CRISPR gRNA homology. HIV-1 may be successfully edited by CRISPR/Cas9, but the virus remains competent for replication and resistant to further CRISPR/Cas9 targeting at that site. These observations strongly suggest that host DSB repair at CRISPR/Cas9 cleavage sites is a novel and important pathway that may contribute to HIV-1 therapeutic resistance. PMID:27404981

  6. Biochemical Mechanism of HIV-1 Resistance to Rilpivirine*

    PubMed Central

    Singh, Kamalendra; Marchand, Bruno; Rai, Devendra K.; Sharma, Bechan; Michailidis, Eleftherios; Ryan, Emily M.; Matzek, Kayla B.; Leslie, Maxwell D.; Hagedorn, Ariel N.; Li, Zhe; Norden, Pieter R.; Hachiya, Atsuko; Parniak, Michael A.; Xu, Hong-Tao; Wainberg, Mark A.; Sarafianos, Stefan G.

    2012-01-01

    Rilpivirine (RPV) is a second generation nonnucleoside reverse transcriptase (RT) inhibitor (NNRTI) that efficiently inhibits HIV-1 resistant to first generation NNRTIs. Virological failure during therapy with RPV and emtricitabine is associated with the appearance of E138K and M184I mutations in RT. Here we investigate the biochemical mechanism of RT inhibition and resistance to RPV. We used two transient kinetics approaches (quench-flow and stopped-flow) to determine how subunit-specific mutations in RT p66 or p51 affect association and dissociation of RPV to RT as well as their impact on binding of dNTP and DNA and the catalytic incorporation of nucleotide. We compared WT with four subunit-specific RT mutants, p66M184I/p51WT, p66E138K/p51E138K, p66E138K/M184I/p51E138K, and p66M184I/p51E138K. Ile-184 in p66 (p66184I) decreased the catalytic efficiency of RT (kpol/Kd.dNTP), primarily through a decrease in dNTP binding (Kd.dNTP). Lys-138 either in both subunits or in p51 alone abrogated the negative effect of p66184I by restoring dNTP binding. Furthermore, p51138K reduced RPV susceptibility by altering the ratio of RPV dissociation to RPV association, resulting in a net reduction in RPV equilibrium binding affinity (Kd.RPV = koff.RPV/kon.RPV). Quantum mechanics/molecular mechanics hybrid molecular modeling revealed that p51E138K affects access to the RPV binding site by disrupting the salt bridge between p51E138 and p66K101. p66184I caused repositioning of the Tyr-183 active site residue and decreased the efficiency of RT, whereas the addition of p51138K restored Tyr-183 to a WT-like conformation, thus abrogating the Ile-184-induced functional defects. PMID:22955279

  7. A uniquely prevalent nonnucleoside reverse transcriptase inhibitor resistance mutation in Russian subtype A HIV-1 viruses

    PubMed Central

    Kolomeets, Anna N.; Varghese, Vici; Lemey, Philippe; Bobkova, Marina R.; Shafer, Robert W.

    2015-01-01

    Background The subtype A variant in the Former Soviet Union (AFSU) causes most of Russia’s HIV-1 infections. However, the spectrum of drug-resistance mutations (DRMs) in antiretroviral experienced patients with this variant has not been studied. Methods Between 2010 and 2013, genotypic resistance testing was performed on plasma samples from 366 antiretroviral-experienced patients in Siberia. Results Three-hundred patients (82%) had subtype AFSU and 55 (15%) had CRF02_AG viruses. The pattern of DRMs was consistent with patient antiretroviral history with one exception. G190S was the most common nonnucleoside reverse transcriptase inhibitor (NNRTI) resistance mutation, occurring in 55 (33%) subtype AFSU viruses from 167 NNRTI-experienced patients compared with none of 37 CRF02_AG viruses from NNRTI-experienced patients (P < 0.001). The next most common subtype AFSU NNRTI-resistance mutation, K103N, occurred in 25 (15%) viruses. Wild-type glycine (G) at position 190 is encoded by GGC in more than 99% of published AFSU strains. By contrast, G190 is encoded by GGA or GGG in 97% of other subtypes and in subtype A strains outside of the FSU. Therefore, G190S results from a single G→A transition: G (GGC) → S (AGC) almost exclusively in subtype AFSU viruses. Conclusion The predisposition of subtype AFSU to G190S is concerning because G→A is the most common HIV-1 mutation and because G190S causes higher levels of nevirapine and efavirenz resistance than K103N. This study exemplifies the need for characterizing the genetic mechanisms of resistance in diverse populations and warrants studies to verify that NRTI/NNRTI regimens are as efficacious in treating subtype AFSU as viruses belonging to other subtypes. PMID:25259833

  8. Evolution of CCR5 Antagonist Resistance in an HIV-1 Subtype C Clinical Isolate

    PubMed Central

    Henrich, Timothy J.; Tsibris, Athe M.N.; Lewine, Nicolas R.P.; Konstantinidis, Ioannis; Leopold, Kay E.; Sagar, Manish; Kuritzkes, Daniel R.

    2011-01-01

    Objectives We previously reported vicriviroc (VCV) resistance in an HIV-infected subject and used deep sequencing and clonal analyses to track the evolution of V3 sequence forms over 28 weeks of therapy. Here, we test the contribution of gp120 mutations to CCR5 antagonist resistance and investigate why certain minority V3 variants emerged as the dominant species under drug pressure. Methods 19 site-directed HIV-1 mutants were generated that contained gp120 VCV-resistance mutations. Viral sensitivities to VCV, maraviroc, TAK-779 and HGS004 were determined. Results Three patterns of susceptibilities were observed: sigmoid inhibition curves with IC50s similar to pre-treatment virus (07J-week 0 [W0]), single mutants with decreased IC50s compared to 07J-W0, and mutants that contained ≥5 of 7 VCV-resistance mutations with flattened inhibition curves and decreased or negative percent maximal inhibition. Substitutions such as S306P, which sensitized virus to CCR5 antagonists when present as single mutations, were not detected in the baseline virus population but were necessary for maximal resistance when incorporated into V3 backbones that included pre-existing VCV resistance mutations. Conclusion CCR5 antagonist resistance was reproduced only when a majority of V3 mutations were present. Minority V3 loop variants may serve as a scaffold upon which additional mutations lead to complete VCV resistance. PMID:20856130

  9. Cocaine modulates HIV-1 integration in primary CD4+ T cells: implications in HIV-1 pathogenesis in drug-abusing patients.

    PubMed

    Addai, Amma B; Pandhare, Jui; Paromov, Victor; Mantri, Chinmay K; Pratap, Siddharth; Dash, Chandravanu

    2015-04-01

    Epidemiologic studies suggest that cocaine abuse worsens HIV-1 disease progression. Increased viral load has been suggested to play a key role for the accelerated HIV disease among cocaine-abusing patients. The goal of this study was to investigate whether cocaine enhances proviral DNA integration as a mechanism to increase viral load. We infected CD4(+) T cells that are the primary targets of HIV-1 in vivo and treated the cells with physiologically relevant concentrations of cocaine (1 µM-100 µM). Proviral DNA integration in the host genome was measured by nested qPCR. Our results illustrated that cocaine from 1 µM through 50 µM increased HIV-1 integration in CD4(+) T cells in a dose-dependent manner. As integration can be modulated by several early postentry steps of HIV-1 infection, we examined the direct effects of cocaine on viral integration by in vitro integration assays by use of HIV-1 PICs. Our data illustrated that cocaine directly increases viral DNA integration. Furthermore, our MS analysis showed that cocaine is able to enter CD4(+) T cells and localize to the nucleus-. In summary, our data provide strong evidence that cocaine can increase HIV-1 integration in CD4(+) T cells. Therefore, we hypothesize that increased HIV-1 integration is a novel mechanism by which cocaine enhances viral load and worsens disease progression in drug-abusing HIV-1 patients.

  10. Correlation of Naturally Occurring HIV-1 Resistance to DEB025 with Capsid Amino Acid Polymorphisms

    PubMed Central

    Gallay, Philippe A.; Ptak, Roger G.; Bobardt, Michael D.; Dumont, Jean-Maurice; Vuagniaux, Grégoire; Rosenwirth, Brigitte

    2013-01-01

    DEB025 (alisporivir) is a synthetic cyclosporine with inhibitory activity against human immunodeficiency virus type-1 (HIV-1) and hepatitis C virus (HCV). It binds to cyclophilin A (CypA) and blocks essential functions of CypA in the viral replication cycles of both viruses. DEB025 inhibits clinical HIV-1 isolates in vitro and decreases HIV-1 virus load in the majority of patients. HIV-1 isolates being naturally resistant to DEB025 have been detected in vitro and in nonresponder patients. By sequence analysis of their capsid protein (CA) region, two amino acid polymorphisms that correlated with DEB025 resistance were identified: H87Q and I91N, both located in the CypA-binding loop of the CA protein of HIV-1. The H87Q change was by far more abundant than I91N. Additional polymorphisms in the CypA-binding loop (positions 86, 91 and 96), as well as in the N-terminal loop of CA were detected in resistant isolates and are assumed to contribute to the degree of resistance. These amino acid changes may modulate the conformation of the CypA-binding loop of CA in such a way that binding and/or isomerase function of CypA are no longer necessary for virus replication. The resistant HIV-1 isolates thus are CypA-independent. PMID:23524389

  11. A prospective on drug abuse-associated epigenetics and HIV-1 replication.

    PubMed

    Pandhare, Jui; Dash, Chandravanu

    2011-05-23

    Drugs of abuse serve as cofactors to susceptibility to HIV infection and disease progression. Although clinical reports indicate association between HIV/AIDS and drug use, the molecular mechanism of infection susceptibility and disease progression remains unclear. Drugs such as cocaine exert their addictive effects in part by epigenetic mechanisms. Given that epigenetic modifications play an important role in HIV-1 life cycle, it is essential to unravel whether drug abuse-associated epigenetic changes may contribute to HIV/AIDS. In this article we will provide a prospective on the impact of epigenetic mechanisms on HIV-1 life cycle.

  12. Vpu-Mediated Counteraction of Tetherin Is a Major Determinant of HIV-1 Interferon Resistance

    PubMed Central

    Kmiec, Dorota; Iyer, Shilpa S.; Stürzel, Christina M.; Sauter, Daniel; Hahn, Beatrice H.

    2016-01-01

    ABSTRACT Human immunodeficiency virus type 1 (HIV-1) groups M, N, O, and P are the result of independent zoonotic transmissions of simian immunodeficiency viruses (SIVs) infecting great apes in Africa. Among these, only Vpu proteins of pandemic HIV-1 group M strains evolved potent activity against the restriction factor tetherin, which inhibits virus release from infected cells. Thus, effective Vpu-mediated tetherin antagonism may have been a prerequisite for the global spread of HIV-1. To determine whether this particular function enhances primary HIV-1 replication and interferon resistance, we introduced mutations into the vpu genes of HIV-1 group M and N strains to specifically disrupt their ability to antagonize tetherin, but not other Vpu functions, such as degradation of CD4, down-modulation of CD1d and NTB-A, and suppression of NF-κB activity. Lack of particular human-specific adaptations reduced the ability of HIV-1 group M Vpu proteins to enhance virus production and release from primary CD4+ T cells at high levels of type I interferon (IFN) from about 5-fold to 2-fold. Interestingly, transmitted founder HIV-1 strains exhibited higher virion release capacity than chronic control HIV-1 strains irrespective of Vpu function, and group M viruses produced higher levels of cell-free virions than an N group HIV-1 strain. Thus, efficient virus release from infected cells seems to play an important role in the spread of HIV-1 in the human population and requires a fully functional Vpu protein that counteracts human tetherin. PMID:27531907

  13. The Envelope Gene of Transmitted HIV-1 Resists a Late Interferon Gamma-Induced Block

    PubMed Central

    Rihn, Suzannah J.; Foster, Toshana L.; Busnadiego, Idoia; Aziz, Muhamad Afiq; Hughes, Joseph; Neil, Stuart J. D.

    2017-01-01

    ABSTRACT Type I interferon (IFN) signaling engenders an antiviral state that likely plays an important role in constraining HIV-1 transmission and contributes to defining subsequent AIDS pathogenesis. Type II IFN (IFN-γ) also induces an antiviral state but is often primarily considered to be an immunomodulatory cytokine. We report that IFN-γ stimulation can induce an antiviral state that can be both distinct from that of type I interferon and can potently inhibit HIV-1 in primary CD4+ T cells and a number of human cell lines. Strikingly, we find that transmitted/founder (TF) HIV-1 viruses can resist a late block that is induced by type II IFN, and the use of chimeric IFN-γ-sensitive/resistant viruses indicates that interferon resistance maps to the env gene. Simultaneously, in vitro evolution also revealed that just a single amino acid substitution in the envelope can confer substantial resistance to IFN-mediated inhibition. Thus, the env gene of transmitted HIV-1 confers resistance to a late block that is phenotypically distinct from blocks previously described to be resisted by env and is therefore mediated by unknown IFN-γ-stimulated factor(s) in human CD4+ T cells and cell lines. This important unidentified block could play a key role in constraining HIV-1 transmission. IMPORTANCE The human immune system can hinder invading pathogens through interferon (IFN) signaling. One consequence of this signaling is that cells enter an antiviral state, increasing the levels of hundreds of defenses that can inhibit the replication and spread of viruses. The majority of HIV-1 infections result from a single virus particle (the transmitted/founder) that makes it past these defenses and colonizes the host. Thus, the founder virus is hypothesized to be a relatively interferon-resistant entity. Here, we show that certain HIV-1 envelope genes have the unanticipated ability to resist specific human defenses mediated by different types of interferons. Strikingly, the envelope

  14. Minority HIV-1 resistant variants in recent infection and in patients who failed first-line antiretroviral therapy with no detectable resistance-associated mutations in Thailand.

    PubMed

    Le Nguyen, Hai; Pitakpolrat, Patrawadee; Sirivichayakul, Sunee; Delaugerre, Constance; Ruxrungtham, Kiat

    2012-05-01

    Through the Thai National AIDS Program, approximately 200,000 patients infected with HIV are on antiretroviral (ARV) therapy. Although studies have shown low prevalence of primary HIV-1 resistance transmission in Thailand and in Southeast Asia where subtype CRF01_AE is predominant, minority HIV-1 drug resistance has not been studied. Two groups of patients, whose conventional genotyping results showed no drug resistance-associated mutations, were investigated: 104 homosexual men recently infected with HIV-1, naïve to ARV treatment and 22 first-line non-nucleoside reverse transcriptase inhibitor (NNRTI)-based failure patients. Pyrosequencing (PSQ) assay was developed to detect and quantify minority Y181C and M184V variants from the patients' plasma samples. The sensitivity of PSQ to detect minority Y181C and M184V variants was approximately 1%. 1/104 (0.5%) and 3/101 (3%) samples were found harboring Y181C and M184V in the group of homosexual men recently infected with HIV-1. In patients with first-line treatment failure, one had a minority M184V mutation (4.5%). The prevalence of Y181C and M184V minority variants in homosexual men recently infected and naïve to treatment was low in Thailand. Systematic monitoring of primary resistance transmission in Thailand and this region is essential to guide whether genotypic resistance test is required prior to commencing the first-line highly active antiretroviral therapy (HAART).

  15. Mechanisms associated with HIV-1 resistance to acyclovir by the V75I mutation in reverse transcriptase.

    PubMed

    Tchesnokov, Egor P; Obikhod, Aleksandr; Massud, Ivana; Lisco, Andrea; Vanpouille, Christophe; Brichacek, Beda; Balzarini, Jan; McGuigan, Christopher; Derudas, Marco; Margolis, Leonid; Schinazi, Raymond F; Götte, Matthias

    2009-08-07

    It has recently been demonstrated that the anti-herpetic drug acyclovir (ACV) also displays antiviral activity against the human immunodeficiency virus type 1 (HIV-1). The triphosphate form of ACV is accepted by HIV-1 reverse transcriptase (RT), and subsequent incorporation leads to classical chain termination. Like all approved nucleoside analogue RT inhibitors (NRTIs), the selective pressure of ACV is associated with the emergence of resistance. The V75I mutation in HIV-1 RT appears to be dominant in this regard. By itself, this mutation is usually not associated with resistance to currently approved NRTIs. Here we studied the underlying biochemical mechanism. We demonstrate that V75I is also selected under the selective pressure of a monophosphorylated prodrug that was designed to bypass the bottleneck in drug activation to the triphosphate form (ACV-TP). Pre-steady-state kinetics reveal that V75I discriminates against the inhibitor at the level of catalysis, whereas binding of the inhibitor remains largely unaffected. The incorporated ACV-monophosphate (ACV-MP) is vulnerable to excision in the presence of the pyrophosphate donor ATP. V75I compromises binding of the next nucleotide that can otherwise provide a certain degree of protection from excision. Collectively, the results of this study suggest that ACV is sensitive to two different resistance pathways, which warrants further investigation regarding the detailed resistance profile of ACV. Such studies will be crucial in assessing the potential clinical utility of ACV and its derivatives in combination with established NRTIs.

  16. Structure of the HIV-1 reverse transcriptase Q151M mutant: insights into the inhibitor resistance of HIV-1 reverse transcriptase and the structure of the nucleotide-binding pocket of Hepatitis B virus polymerase

    SciTech Connect

    Nakamura, Akiyoshi; Tamura, Noriko; Yasutake, Yoshiaki

    2015-10-23

    The structure of the HIV-1 reverse transcriptase Q151M mutant was determined at a resolution of 2.6 Å in space group P321. Hepatitis B virus polymerase (HBV Pol) is an important target for anti-HBV drug development; however, its low solubility and stability in vitro has hindered detailed structural studies. Certain nucleotide reverse transcriptase (RT) inhibitors (NRTIs) such as tenofovir and lamivudine can inhibit both HBV Pol and Human immunodeficiency virus 1 (HIV-1) RT, leading to speculation on structural and mechanistic analogies between the deoxynucleotide triphosphate (dNTP)-binding sites of these enzymes. The Q151M mutation in HIV-1 RT, located at the dNTP-binding site, confers resistance to various NRTIs, while maintaining sensitivity to tenofovir and lamivudine. The residue corresponding to Gln151 is strictly conserved as a methionine in HBV Pol. Therefore, the structure of the dNTP-binding pocket of the HIV-1 RT Q151M mutant may reflect that of HBV Pol. Here, the crystal structure of HIV-1 RT Q151M, determined at 2.6 Å resolution, in a new crystal form with space group P321 is presented. Although the structure of HIV-1 RT Q151M superimposes well onto that of HIV-1 RT in a closed conformation, a slight movement of the β-strands (β2–β3) that partially create the dNTP-binding pocket was observed. This movement might be caused by the introduction of the bulky thioether group of Met151. The structure also highlighted the possibility that the hydrogen-bonding network among amino acids and NRTIs is rearranged by the Q151M mutation, leading to a difference in the affinity of NRTIs for HIV-1 RT and HBV Pol.

  17. Two subtypes of HIV-1 among injection-drug users in southern China.

    PubMed

    Yu, X F; Chen, J; Shao, Y; Beyrer, C; Lai, S

    1998-04-25

    The rate of HIV-1 infection has increased steadily in China by about 80% annually and by the end of September 1997, 8277 HIV-1 cases had been reported, of whom more than 75% were IV drug users (IVDUs). UNAIDS, however, has estimated that up to 200,000 people could actually be infected with HIV-1 in China. Guangxi Province borders Yunnan province in the west and Vietnam to the south, and is a major transit area for heroin trafficking from the opium-growing region of Laos and Myanmar. Phylogenetic analyses of HIV-1 env sequences (C2-V3) obtained from 14 IVDUs found that 9 subjects from Pingxiang City were infected with subtype E and 5 from Baise City with subtype C. The 9 subtype E and 5 subtype C HIV-1 sequences were clustered together within each group, with significant bootstrap values of 100% and 95%, respectively. The subtype E sequences were more closely related to HIV-1 subtype E from Thailand than to those from Africa, and the subtype C sequences were clustered more closely to those from India than to those from Africa. Study results suggest 2 epidemiologically unrelated epidemics and 2 different sources; subtype C probably transmitted from Yunnan to Baise City through drug trafficking and IVDU interaction, and subtype E coming into China from Vietnam.

  18. Relative resistance of HIV-1 founder viruses to control by interferon-alpha

    PubMed Central

    2013-01-01

    Background Following mucosal human immunodeficiency virus type 1 (HIV-1) transmission, type 1 interferons (IFNs) are rapidly induced at sites of initial virus replication in the mucosa and draining lymph nodes. However, the role played by IFN-stimulated antiviral activity in restricting HIV-1 replication during the initial stages of infection is not clear. We hypothesized that if type 1 IFNs exert selective pressure on HIV-1 replication in the earliest stages of infection, the founder viruses that succeed in establishing systemic infection would be more IFN-resistant than viruses replicating during chronic infection, when type 1 IFNs are produced at much lower levels. To address this hypothesis, the relative resistance of virus isolates derived from HIV-1-infected individuals during acute and chronic infection to control by type 1 IFNs was analysed. Results The replication of plasma virus isolates generated from subjects acutely infected with HIV-1 and molecularly cloned founder HIV-1 strains could be reduced but not fully suppressed by type 1 IFNs in vitro. The mean IC50 value for IFNα2 (22 U/ml) was lower than that for IFNβ (346 U/ml), although at maximally-inhibitory concentrations both IFN subtypes inhibited virus replication to similar extents. Individual virus isolates exhibited differential susceptibility to inhibition by IFNα2 and IFNβ, likely reflecting variation in resistance to differentially up-regulated IFN-stimulated genes. Virus isolates from subjects acutely infected with HIV-1 were significantly more resistant to in vitro control by IFNα than virus isolates generated from the same individuals during chronic, asymptomatic infection. Viral IFN resistance declined rapidly after the acute phase of infection: in five subjects, viruses derived from six-month consensus molecular clones were significantly more sensitive to the antiviral effects of IFNs than the corresponding founder viruses. Conclusions The establishment of systemic HIV-1 infection by

  19. Antiviral Activity of Bictegravir (GS-9883), a Novel Potent HIV-1 Integrase Strand Transfer Inhibitor with an Improved Resistance Profile

    PubMed Central

    Tsiang, Manuel; Jones, Gregg S.; Goldsmith, Joshua; Mulato, Andrew; Hansen, Derek; Kan, Elaine; Tsai, Luong; Bam, Rujuta A.; Stepan, George; Stray, Kirsten M.; Niedziela-Majka, Anita; Yant, Stephen R.; Yu, Helen; Kukolj, George; Cihlar, Tomas; Lazerwith, Scott E.; Jin, Haolun

    2016-01-01

    Bictegravir (BIC; GS-9883), a novel, potent, once-daily, unboosted inhibitor of HIV-1 integrase (IN), specifically targets IN strand transfer activity (50% inhibitory concentration [IC50] of 7.5 ± 0.3 nM) and HIV-1 integration in cells. BIC exhibits potent and selective in vitro antiretroviral activity in both T-cell lines and primary human T lymphocytes, with 50% effective concentrations ranging from 1.5 to 2.4 nM and selectivity indices up to 8,700 relative to cytotoxicity. BIC exhibits synergistic in vitro antiviral effects in pairwise combinations with tenofovir alafenamide, emtricitabine, or darunavir and maintains potent antiviral activity against HIV-1 variants resistant to other classes of antiretrovirals. BIC displayed an in vitro resistance profile that was markedly improved compared to the integrase strand transfer inhibitors (INSTIs) raltegravir (RAL) and elvitegravir (EVG), and comparable to that of dolutegravir (DTG), against nine INSTI-resistant site-directed HIV-1 mutants. BIC displayed statistically improved antiviral activity relative to EVG, RAL, and DTG against a panel of 47 patient-derived HIV-1 isolates with high-level INSTI resistance; 13 of 47 tested isolates exhibited >2-fold lower resistance to BIC than DTG. In dose-escalation experiments conducted in vitro, BIC and DTG exhibited higher barriers to resistance than EVG, selecting for HIV-1 variants with reduced phenotypic susceptibility at days 71, 87, and 20, respectively. A recombinant virus with the BIC-selected M50I/R263K dual mutations in IN exhibited only 2.8-fold reduced susceptibility to BIC compared to wild-type virus. All BIC-selected variants exhibited low to intermediate levels of cross-resistance to RAL, DTG, and EVG (<8-fold) but remained susceptible to other classes of antiretrovirals. A high barrier to in vitro resistance emergence for both BIC and DTG was also observed in viral breakthrough studies in the presence of constant clinically relevant drug concentrations. The

  20. CCR5 gene disruption via lentiviral vectors expressing Cas9 and single guided RNA renders cells resistant to HIV-1 infection.

    PubMed

    Wang, Weiming; Ye, Chaobaihui; Liu, Jingjing; Zhang, Di; Kimata, Jason T; Zhou, Paul

    2014-01-01

    CCR5, a coreceptor for HIV-1 entry, is a major target for drug and genetic intervention against HIV-1. Genetic intervention strategies have knocked down CCR5 expression levels by shRNA or disrupted the CCR5 gene using zinc finger nucleases (ZFN) or Transcription activator-like effector nuclease (TALEN). In the present study, we silenced CCR5 via CRISPR associated protein 9 (Cas9) and single guided RNAs (sgRNAs). We constructed lentiviral vectors expressing Cas9 and CCR5 sgRNAs. We show that a single round transduction of lentiviral vectors expressing Cas9 and CCR5 sgRNAs into HIV-1 susceptible human CD4+ cells yields high frequencies of CCR5 gene disruption. CCR5 gene-disrupted cells are not only resistant to R5-tropic HIV-1, including transmitted/founder (T/F) HIV-1 isolates, but also have selective advantage over CCR5 gene-undisrupted cells during R5-tropic HIV-1 infection. Importantly, using T7 endonuclease I assay we did not detect genome mutations at potential off-target sites that are highly homologous to these CCR5 sgRNAs in stably transduced cells even at 84 days post transduction. Thus we conclude that silencing of CCR5 via Cas9 and CCR5-specific sgRNAs could be a viable alternative strategy for engineering resistance against HIV-1.

  1. C-5-Modified Tetrahydropyrano-Tetrahydofuran-Derived Protease Inhibitors (PIs) Exert Potent Inhibition of the Replication of HIV-1 Variants Highly Resistant to Various PIs, including Darunavir

    PubMed Central

    Aoki, Manabu; Hayashi, Hironori; Yedidi, Ravikiran S.; Martyr, Cuthbert D.; Takamatsu, Yuki; Aoki-Ogata, Hiromi; Nakamura, Teruya; Nakata, Hirotomo; Das, Debananda; Yamagata, Yuriko; Ghosh, Arun K.

    2015-01-01

    vitro. Here, we identified three novel HIV-1 protease inhibitors (PIs) containing a tetrahydropyrano-tetrahydrofuran (Tp-THF) moiety with a C-5 hydroxyl (GRL-015, -085, and -097) which potently suppress the replication of HIVDRVR. Moreover, the emergence of HIV-1 strains resistant to the three compounds was considerably delayed compared to the case of DRV. The C-5 hydroxyl formed a strong hydrogen bonding interaction with the carbonyl oxygen atom of Gly48 of protease as examined in the structural analyses. Interestingly, a compound with Tp-THF lacking the hydroxyl moiety substantially decreased activity against HIVDRVR. The three novel compounds should be further developed as potential drugs for treating individuals harboring wild-type and multi-PI-resistant HIV variants as well as HIVDRVR. PMID:26581995

  2. From the traditional Chinese medicine plant Schisandra chinensis new scaffolds effective on HIV-1 reverse transcriptase resistant to non-nucleoside inhibitors.

    PubMed

    Xu, Lijia; Grandi, Nicole; Del Vecchio, Claudia; Mandas, Daniela; Corona, Angela; Piano, Dario; Esposito, Francesca; Parolin, Cristina; Tramontano, Enzo

    2015-04-01

    HIV-1 reverse transcriptase (RT) is still an extremely attractive pharmaceutical target for the identification of new inhibitors possibly active on drug resistant strains. Medicinal plants are a rich source of chemical diversity and can be used to identify novel scaffolds to be further developed by chemical modifications. We investigated the ability of the main lignans from Schisandra chinensis (Turcz.) Baill. fruits, commonly used in Traditional Chinese Medicine, to affect HIV-1 RT functions. We purified 6 lignans from Schisandra chinensis fruits and assayed their effects on HIV-1 RT and viral replication. Among the S. chinensis fruit lignans, Schisandrin B and Deoxyschizandrin selectively inhibited the HIV-1 RT-associated DNA polymerase activity. Structure activity relationship revealed the importance of cyclooctadiene ring substituents for efficacy. In addition, Schisandrin B was also able to impair HIV-1 RT drug resistant mutants and the early phases of viral replication. We identified Schisandrin B and Deoxyschizandrin as new scaffold for the further development of novel HIV-1 RT inhibitors.

  3. HIV-1 Drug Discovery: Targeting Folded RNA Structures With Branched Peptides

    PubMed Central

    Wynn, Jessica E.

    2015-01-01

    Human immunodeficiency virus type 1 (HIV-1) is an RNA virus that is prone to high rates of mutation. While the disease is managed with current antiretroviral therapies, drugs with a new mode of action are needed. A strategy towards this goal is aimed at targeting the native three-dimensional fold of conserved RNA structures. This perspective highlights medium-sized peptides and peptidomimetics used to target two conserved RNA structures of HIV-1. In particular, branched peptides have the capacity to bind in a multivalent fashion, utilizing a large surface area to achieve the necessary affinity and selectivity toward the target RNA. PMID:25958855

  4. Site-specific host gene modification by zinc finger nucleases: pointing the way to drug free control of HIV-1?

    PubMed Central

    Sasson, Sarah C; Kelleher, Anthony D

    2014-01-01

    Anti-retroviral therapy (ART) for human immunodeficiency virus-1 (HIV-1) infection has transformed its clinical course with spectacular reductions in morbidity and mortality, turning this once fatal diagnosis into a manageable chronic infection. However, ART has its limitations. Current ART does not eliminate the virus. Interruption of therapy results in rapid rebound of the virus, and such rebounds are associated with excess morbidity and mortality. This means that therapy once started is for life. This raises the issues of drug resistance due to suboptimal compliance, cumulative toxicities and mounting costs. Efforts to control the virus through novel interventions, particularly through cell or gene therapy have had a resurgence of interest as a single patient was apparently cured by an allogeneic stem cell transplantation from a donor who carried homozygous mutations that disable expression of the HIV-1 co-receptor CCR5. This paper reviews the state of play of gene therapy for HIV infection in the context of a recent paper showing the safety and feasibility of an approach that involves the ex vivo disruption of the ccr5 gene in autologous CD4 T cells using a virally delivered zinc finger nuclease, before their expansion and reinfusion. Although there are still considerable challenges, this approach may point towards a future drug free therapy for HIV-1 infection. PMID:25505967

  5. Antiretroviral drugs do not interfere with bryostatin-mediated HIV-1 latency reversal.

    PubMed

    Martínez-Bonet, Marta; Clemente, Maria Isabel; Álvarez, Susana; Díaz, Laura; García-Alonso, Dolores; Muñoz, Eduardo; Moreno, Santiago; Muñoz-Fernández, Maria Ángeles

    2015-11-01

    Although an effective combination of antiretroviral therapy (cART) controls HIV-1 viraemia in infected patients, viral latency established soon after infection hinders HIV-1 eradication. It has been shown that bryostatin-1 (BRY) inhibits HIV-infection in vitro and reactivates the latent virus through the protein kinase C-NF-κB pathway. We determined the in vitro potential effect of BRY in combination with currently used antiretroviral drugs. BRY alone or in combination with maraviroc (MVC)/Atripla (ATP) was tested for its capacity to reactivate latent virus and inhibit new infections. JLTRG-R5 cells and two latent HIV-1-infected cell lines, J89GFP and THP89GFP, were used as latency models. To quantify HIV infection, the reporter cell line TZM-bl was used. We found that BRY reactivates HIV-1 even in combination with MVC or ATP. Antiretroviral combinations with BRY do not interfere with BRY activity (i.e., the reactivation of latently infected cells) or with the antiviral activity of antiretroviral drugs. In addition, BRY-mediated down-modulation of surface CD4 and CXCR4 was not affected when it was used in combination with other antiretrovirals, and no hyperactivation or high-proliferation effects were observed in primary T cells. Moreover, the BRY treatment was able to reactivate HIV-1 in CD4+ T cells from HIV-1-infected patients under cART. Thus, we propose the use of BRY to purge the viral reservoir and recommend its combination with current antiretroviral treatments.

  6. Evolutionary analysis identifies an MX2 haplotype associated with natural resistance to HIV-1 infection.

    PubMed

    Sironi, Manuela; Biasin, Mara; Cagliani, Rachele; Gnudi, Federica; Saulle, Irma; Ibba, Salomè; Filippi, Giulia; Yahyaei, Sarah; Tresoldi, Claudia; Riva, Stefania; Trabattoni, Daria; De Gioia, Luca; Lo Caputo, Sergio; Mazzotta, Francesco; Forni, Diego; Pontremoli, Chiara; Pineda, Juan Antonio; Pozzoli, Uberto; Rivero-Juarez, Antonio; Caruz, Antonio; Clerici, Mario

    2014-09-01

    The protein product of the myxovirus resistance 2 (MX2) gene restricts HIV-1 and simian retroviruses. We demonstrate that MX2 evolved adaptively in mammals with distinct sites representing selection targets in distinct branches; selection mainly involved residues in loop 4, previously shown to carry antiviral determinants. Modeling data indicated that positively selected sites form a continuous surface on loop 4, which folds into two antiparallel α-helices protruding from the stalk domain. A population genetics-phylogenetics approach indicated that the coding region of MX2 mainly evolved under negative selection in the human lineage. Nonetheless, population genetic analyses demonstrated that natural selection operated on MX2 during the recent history of human populations: distinct selective events drove the frequency increase of two haplotypes in the populations of Asian and European ancestry. The Asian haplotype carries a susceptibility allele for melanoma; the European haplotype is tagged by rs2074560, an intronic variant. Analyses performed on three independent European cohorts of HIV-1-exposed seronegative individuals with different geographic origin and distinct exposure route showed that the ancestral (G) allele of rs2074560 protects from HIV-1 infection with a recessive effect (combined P = 1.55 × 10(-4)). The same allele is associated with lower in vitro HIV-1 replication and increases MX2 expression levels in response to IFN-α. Data herein exploit evolutionary information to identify a novel host determinant of HIV-1 infection susceptibility.

  7. "Second generation" of TSAO compounds directed against HIV-1 TSAO-resistant strains.

    PubMed

    Lobatón, E; Velázquez, S; Pérez-Pérez, M J; Jimeno, M L; San-Félix, A; De Clercq, E; Balzarini, J; Camarasa, M J

    2001-01-01

    A "second generation" of TSAO molecules directed against TSAO-resistant strains have been prepared. The presence of two neighboring carbonyl groups at the 4" position of the 3'-spiro moiety seems to be important for the anti-HIV-1 activity against both wild type and TSAO-resistant strains. NMR conformational studies in solution and theoretical calculations of the novel compounds have also been carried out.

  8. Polymorphisms in the HIV-1 gp41 env gene, natural resistance to enfuvirtide (T-20) and pol resistance among pregnant Brazilian women.

    PubMed

    Reis, Mônica Nogueira da Guarda; de Alcântara, Keila Correa; Cardoso, Ludimila Paula Vaz; Stefani, Mariane Martins Araújo

    2014-01-01

    The selective pressure of antiretroviral drugs (ARVs) targeting HIV-1 pol can promote drug resistance mutations in other genomic regions, such as env. Drug resistance among women should be monitored to avoid horizontal and mother-to-child transmission. To describe natural resistance to T-20 (enfuvirtide), gp41 env polymorphisms, mutations in pol and HIV-1 subtypes, 124 pregnant women were recruited. For 98 patients, the gp41 env, protease (PR) and reverse transcriptase (RT) fragments were sequenced. The patients were ARV naïve (n = 30), taking mother-to-child transmission prophylaxis (n = 50), or being treated with highly active ARV therapy/HAART (n = 18). The Stanford and IAS/USA databases and other sources were used to analyze PR/RT, gp41 env resistance mutations. The HIV-1 genetic diversity was analyzed by REGA/phylogenetic analyses. The patients' median age was 25 years (range, 16-42), 18.4% had AIDS. The frequency of natural resistance to T-20 (N42D, L44M, and R46M-low-impact mutations) was 6.1% (6/98); 20.4% (20/98) had compensatory mutations in HR2. The prevalence of transmitted drug resistance in the pol was 13.3% (4/30), and the prevalence of secondary drug resistance was 33.3% (6/18). Two patients were infected with multidrug resistant/MDR viruses. The analysis of HIV-1 subtypes (PR/RT/gp41) revealed that 61.2% (60/98) were subtype B, 12.2% (12/98) were subtype C, 4.1% (4/98) were subtype F1, and 22.4% (22/98) were possible recombinants (BF1 = 20.4%; BC = 2%). Natural resistance to T-20 was not associated with pol resistance or previous ARV use. The high rate of secondary resistance, including MDR, indicates that the number of women that may need T-20 salvage therapy may be higher than anticipated.

  9. Prediction of HIV-1 protease inhibitor resistance by Molecular Modeling Protocols (MMPs) using GenMol software.

    PubMed

    Pèpe, G; Courcambeck, J; Perbost, R; Jouanna, P; Halfon, P

    2008-11-01

    This paper investigates the contribution of Molecular Modeling to (i) predict and (ii) understand more fundamentally HIV drug resistance. Based on a new automated GenMol module, these goals are approached by Molecular Modeling Protocols (MMPs), respectively, (i) the Molecular Modeling Phenotype Protocol (MMPP) and (ii) the Molecular Modeling Phenotype-Genotype Protocol (MMGPP). Section 2 recalls clinical practice with a reference case study and Section 3 presents atomistic simulation tools. Section 4 is the heart of the paper. In Section 4.1, MMPP drug resistance prediction is based on correlations between fold resistances versus binding energies on 2959 HIV-1 complexes with 6 protease inhibitors. Based on a drug sensitivity twofold criterion, modeling prediction is able to replace long and costly phenotype tests. In Section 4.2, MMGPP enlightens drug resistance by investigating steric and energetic residues/inhibitor interaction. Section 5 gives a synthesis on modeling contribution to drug resistance prediction. In conclusion, the most promising trend consists of MMP automats that are able to suggest a real time diagnosis taking into account the history of each patient, to enrich databases and to develop therapy strategy and new drugs.

  10. HIV-1 subtype A infection in a community of intravenous drug users in Pakistan

    PubMed Central

    Khan, Saeed; Rai, Mohammad A; Khanani, Mohammad R; Khan, Muhammad N; Ali, Syed H

    2006-01-01

    Background Data on the subtypes of HIV in a population help in predicting the potential foci of epidemic, tracking the routes of infection and following the patterns of the virus' genetic divergence. Globally, the most prevalent HIV infection is the HIV-1 subtype C. In Asia, predominant subtypes of HIV-1 are B, C, and CRF-01AE. During the last few years, HIV prevalence in Pakistan has taken the form of a concentrated epidemic in at least two high risk groups, namely, Intravenous Drug Users (IDUs) and Male Sex Workers (MSWs). Factors that have facilitated the proliferation of HIV infection include transmission through a large number of repatriates and needle-sharing intravenous drug users, unscreened blood transfusions, and sexual illiteracy. The HIV subtypes infecting Pakistani populations have not been explored to date. In this study, we analyzed HIV-1 subtypes from in a high-risk community of IDUs in Karachi, the largest city of Pakistan. Methods Samples were collected from 34 IDUs after their informed consent. In addition, the study subjects were administered a questionnaire regarding their sexual behavior and travel history. For HIV analysis, DNA was extracted from the samples and analyzed for HIV types and subtypes using subtype-specific primers in a nested polymerase chain reaction (PCR). The results from this PCR were further confirmed using the Heteroduplex Mobility Assay (HMA). Results We found HIV-1 subtype A in all the 34 samples analyzed. A few of the study subjects were found to have a history of travel and stay in the United Arab Emirates. The same subjects also admitted to having contact with commercial sex workers during their stay abroad. Conclusion Our study therefore shows clade A HIV-1 to be prevalent among the IDUs in Karachi. As the prevalence of HIV in Pakistan continues to rise, more work needs to be done to track the infection, and to analyze the strains of HIV spreading through the country. PMID:17105667

  11. Analysis of the Zidovudine Resistance Mutations T215Y, M41L, and L210W in HIV-1 Reverse Transcriptase.

    PubMed

    Boyer, Paul L; Das, Kalyan; Arnold, Eddy; Hughes, Stephen H

    2015-12-01

    Although anti-human immunodeficiency virus type 1 (HIV-1) therapies have become more sophisticated and more effective, drug resistance continues to be a major problem. Zidovudine (azidothymidine; AZT) was the first nucleoside reverse transcriptase (RT) inhibitor (NRTI) approved for the treatment of HIV-1 infections and is still being used, particularly in the developing world. This drug targets the conversion of single-stranded RNA to double-stranded DNA by HIV-1 RT. However, resistance to the drug quickly appeared both in viruses replicating in cells in culture and in patients undergoing AZT monotherapy. The primary resistance pathway selects for mutations of T215 that change the threonine to either a tyrosine or a phenylalanine (T215Y/F); this resistance pathway involves an ATP-dependent excision mechanism. The pseudo-sugar ring of AZT lacks a 3' OH; RT incorporates AZT monophosphate (AZTMP), which blocks the end of the viral DNA primer. AZT-resistant forms of HIV-1 RT use ATP in an excision reaction to unblock the 3' end of the primer strand, allowing its extension by RT. The T215Y AZT resistance mutation is often accompanied by two other mutations, M41L and L210W. In this study, the roles of these mutations, in combination with T215Y, were examined to determine whether they affect polymerization and excision by HIV-1 RT. The M41L mutation appears to help restore the DNA polymerization activity of RT containing the T215Y mutation and also enhances AZTMP excision. The L210W mutation plays a similar role, but it enhances excision by RTs that carry the T215Y mutation when ATP is present at a low concentration.

  12. Complex subtype diversity of HIV-1 among drug users in major Kenyan cities.

    PubMed

    Gounder, Kamini; Oyaro, Micah; Padayachi, Nagavelli; Zulu, Thando Mbali; de Oliveira, Tulio; Wylie, John; Ndung'u, Thumbi

    2017-01-09

    Drug users are increasingly recognized as a key population driving HIV spread in sub-Saharan Africa. To determine HIV-1 subtypes circulating in this population group and explore possible geographic differences, we analyzed HIV-1 sequences among drug users from Nairobi, Mombasa and Kisumu in Kenya. We sequenced gag and env from 55 drug users. Subtype analysis from 220 gag clonal sequences from 54/55 participants (median=4/participant) showed that 44.4% were A, 16.7% were C, 3.7% were D and 35.2% were intersubtype recombinants. Of 156 env clonal sequences from 48/55 subjects (median=3/participant), 45.8% were subtype A, 14.6% were C, 6.3% were D and 33.3% were recombinants. Comparative analysis of both genes showed that 30 (63.8%) participants had concordant subtypes while 17 (36.2%) were discordant. We identified one genetically-linked transmission pair and 2 cases of dual infection. These data are indicative of extensive HIV-1 intersubtype recombination in Kenya and suggest decline in subtype D prevalence.

  13. Full quantum mechanical study of binding of HIV-1 protease drugs

    NASA Astrophysics Data System (ADS)

    Zhang, Da W.; Zhang, John Z. H.

    Fully quantum mechanical studies of detailed binding interactions between HIV-1 protease and six FDA (Food and Drug Administration)-approved drugs (saquinavir, indinavir, ritonavir, nelfinavir, amprenavir, and lopinavir) are carried out using a recently developed MFCC (molecular fractionation with conjugate caps) method. The MFCC calculation produces a quantum mechanical interaction spectrum for any protease drug binding complex. Detailed quantitative analysis on binding of lopinavir to specific residues of the protease is given from the current study. The present calculation shows that the dominant binding of lopinavir to the protease is through the formation of a strong hydrogen bond between the central hydroxyl group of the drug to the aspartate oxygen of Asp25 in one of the two chains of the protease (A chain). This is closely followed by hydrogen binding of the drug to Asp29 in the B chain and somewhat weak hydrogen bonding to Asp30, Gly27, Gly48, and Ile50 in both chains. By partitioning all six drugs into four building blocks besides the central component containing the hydroxyl group, MFCC calculation finds that block III has essentially no binding interaction with the protease and the major binding interactions of these drugs are from blocks II and IV, in addition to the dominant central hydroxyl group. This detailed quantitative information on drug binding to the protease is very useful in rational design of new and improved inhibitors of HIV-1 protease and its mutants.

  14. Discovery of TSAO derivatives with an unusual HIV-1 activity/resistance profile.

    PubMed

    de Castro, Sonia; García-Aparicio, Carlos; Van Laethem, Kristel; Gago, Federico; Lobatón, Esther; De Clercq, Erik; Balzarini, Jan; Camarasa, María-José; Velázquez, Sonsoles

    2006-08-01

    The very first TSAO derivative that lacks the 4''-amino group at the 3'-spiro moiety (compound 3) has been prepared and the effect of this modification on the activity/resistance profile has been evaluated. This molecule proved HIV-1 specific (NNRTI-characteristic). A mixture of wild-type and V106V/A or L234L/I mutations were found in the RT of some, but not all compound 3-resistant virus strains. Compound 3 does not select for the TSAO-specific E138K mutation in the RT. However, the compound markedly lost its antiviral potential against a variety of virus strains that contain NNRTI-characteristic mutations in RT including E138K. The deaminated TSAO compound must fit differently in the HIV-1 RT enzyme than its prototype TSAO-m(3)T.

  15. Effects of varying concentrations of bleach on in vitro HIV-1 replication and the relevance to injection drug use.

    PubMed

    Contoreggi, C; Jones, S; Simpson, P; Lange, W R; Meyer, W A

    2000-01-01

    The use of bleach (hypochlorite) as a disinfectant for drug injection equipment in the intravenous-drug-using population was recommended early in the HIV-1/AIDS epidemic. Epidemiological studies have challenged the use of bleach as an effective measure to prevent HIV-1 transmission. However, in vitro HIV-1 coculture studies have shown that a high concentration of bleach is an effective cytotoxic and potentially virucidal agent. In this study, we demonstrate that HIV-1 peripheral blood mononuclear cell cocultures containing low concentrations of hypochlorite in the media showed earlier conversion to HIV-1 positivity, as measured by the presence of p24 antigen. HIV-1 cocultures with high concentrations of hypochlorite in the culture media, which appeared to be highly cytotoxic, and HIV-1 cocultures without bleach in the media did not exhibit this early p24 antigen positivity. Hypochlorite chemically disinfects by releasing free chlorine that is a potent oxidant. In injection drug equipment, a low residual concentration of bleach is likely to remain in cleaned equipment despite rinsing with water. Low concentrations of oxidants have been shown to enhance tissue inflammation, in vivo, as well as HIV-1 replication in vitro. Previous studies have shown that despite vigorous cleaning of blood-contaminated injection syringes with bleach followed by water, microaggregates of residual blood remained in bleach-cleaned blood-contaminated syringes. Hypothetically, oxidant effects of the residual bleach in the bleach-cleaned syringes could enhance the possibility of infection by remaining HIV-1 contained in a contaminated syringe. We suggest that the likelihood of an injection drug user contracting HIV-1 through the sharing of a bleach-cleaned blood-contaminated syringe may be increased by the cotransmission of residual bleach and its localized tissue-inflammatory effects; however, this has not been statistically proven in epidemiological studies.

  16. Mechanisms of HIV-1 subtype C resistance to GRFT, CV-N and SVN

    PubMed Central

    Alexandre, Kabamba B.; Moore, Penny L.; Nonyane, Molati; Gray, Elin S.; Ranchobe, Nthabeleng; Chakauya, Ereck; McMahon, James B.; O’Keefe, Barry R.; Chikwamba, Rachel; Morris, Lynn

    2013-01-01

    We examined the ability of HIV-1 subtype C to develop resistance to the inhibitory lectins, griffithsin (GRFT), cyanovirin-N (CV-N) and scytovirin (SVN), which bind multiple mannose-rich glycans on gp120. Four primary HIV-1 strains cultured under escalating concentrations of these lectins became increasingly resistant tolerating 2 to 12 times their 50% inhibitory concentrations. Sequence analysis of gp120 showed that most had deletions of 1 to 5 mannose-rich glycans. Glycosylation sites at positions 230, 234, 241, 289 located in the C2 region and 339, 392 and 448 in the C3-C4 region were affected. Furthermore, deletions and insertions of up to 5 amino acids in the V4 region were observed in 3 of the 4 isolates. These data suggest that loss of glycosylation sites on gp120 as well as rearrangement of glycans in V4 are mechanisms involved in HIV-1 subtype C escape from GRFT, CV-N and SVN. PMID:24074568

  17. Can the HIV-1 splicing machinery be targeted for drug discovery?

    PubMed

    Dlamini, Zodwa; Hull, Rodney

    2017-01-01

    HIV-1 is able to express multiple protein types and isoforms from a single 9 kb mRNA transcript. These proteins are also expressed at particular stages of viral development, and this is achieved through the control of alternative splicing and the export of these transcripts from the nucleus. The nuclear export is controlled by the HIV protein Rev being required to transport incompletely spliced and partially spliced mRNA from the nucleus where they are normally retained. This implies a close relationship between the control of alternate splicing and the nuclear export of mRNA in the control of HIV-1 viral proliferation. This review discusses both the processes. The specificity and regulation of splicing in HIV-1 is controlled by the use of specific splice sites as well as exonic splicing enhancer and exonic splicing silencer sequences. The use of these silencer and enhancer sequences is dependent on the serine arginine family of proteins as well as the heterogeneous nuclear ribonucleoprotein family of proteins that bind to these sequences and increase or decrease splicing. Since alternative splicing is such a critical factor in viral development, it presents itself as a promising drug target. This review aims to discuss the inhibition of splicing, which would stall viral development, as an anti-HIV therapeutic strategy. In this review, the most recent knowledge of splicing in human immunodeficiency viral development and the latest therapeutic strategies targeting human immunodeficiency viral splicing are discussed.

  18. Can the HIV-1 splicing machinery be targeted for drug discovery?

    PubMed Central

    Dlamini, Zodwa; Hull, Rodney

    2017-01-01

    HIV-1 is able to express multiple protein types and isoforms from a single 9 kb mRNA transcript. These proteins are also expressed at particular stages of viral development, and this is achieved through the control of alternative splicing and the export of these transcripts from the nucleus. The nuclear export is controlled by the HIV protein Rev being required to transport incompletely spliced and partially spliced mRNA from the nucleus where they are normally retained. This implies a close relationship between the control of alternate splicing and the nuclear export of mRNA in the control of HIV-1 viral proliferation. This review discusses both the processes. The specificity and regulation of splicing in HIV-1 is controlled by the use of specific splice sites as well as exonic splicing enhancer and exonic splicing silencer sequences. The use of these silencer and enhancer sequences is dependent on the serine arginine family of proteins as well as the heterogeneous nuclear ribonucleoprotein family of proteins that bind to these sequences and increase or decrease splicing. Since alternative splicing is such a critical factor in viral development, it presents itself as a promising drug target. This review aims to discuss the inhibition of splicing, which would stall viral development, as an anti-HIV therapeutic strategy. In this review, the most recent knowledge of splicing in human immunodeficiency viral development and the latest therapeutic strategies targeting human immunodeficiency viral splicing are discussed. PMID:28331370

  19. A novel mutation, D404N, in the connection subdomain of reverse transcriptase of HIV-1 CRF08_BC subtype confers cross-resistance to NNRTIs

    PubMed Central

    Zhang, Xiao-Min; Wu, Hao; Zhang, Qiwei; Lau, Terrence Chi-Kong; Chu, Hin; Chen, Zhi-Wei; Jin, Dong-Yan; Zheng, Bo-Jian

    2015-01-01

    Objectives Growing evidence suggests that mutations in the connection domain of the HIV-1 reverse transcriptase (RT) can contribute to viral resistance to RT inhibitors. This work was designed to determine the effects of a novel mutation, D404N, in the connection subdomain of RT of HIV-1 CRF08_BC subtype on drug resistance, viral replication capacity (RC) and RT activity. Methods Mutation D404N, alone or together with the other reported mutations, was introduced into an HIV-1 CRF08_BC subtype infectious clone by site-directed mutagenesis. Viral susceptibility to nine RT inhibitors, viral RC and the DNA polymerase activity of viral RT of the constructed virus mutants were investigated. A modelling study using the server SWISS-MODEL was conducted to explore the possible structure-related drug resistance mechanism of the mutation D404N. Results Single mutations D404N and H221Y conferred low-level resistance to nevirapine, efavirenz, rilpivirine and zidovudine. Double mutations Y181C/D404N and Y181C/H221Y significantly reduced susceptibility to NNRTIs. The most pronounced resistance to NNRTIs was observed with the triple mutation Y181C/D404N/H221Y. Virus containing D404N as the only mutation displayed ∼50% RC compared with the WT virus. The modelling study suggested that the D404N mutation might abolish the hydrogen bonds between residues 404 and K30 in p51 or K431 in p66, leading to impaired RT subunit structure and enhanced drug resistance. Conclusions These results indicate that D404N is a novel NNRTI-associated mutation in the HIV-1 subtype CRF08_BC and provides information valuable for the monitoring of clinical RTI resistance. PMID:25637519

  20. In Vitro Selection of HIV-1 CRF08_BC Variants Resistant to Reverse Transcriptase Inhibitors

    PubMed Central

    Wu, Hao; Zhang, Xiao-Min; Zhang, Hao-Jie; Zhang, Qiwei; Chen, Zhiwei; Huang, Jian-Dong

    2015-01-01

    Abstract Human immunodeficiency virus type 1 (HIV-1) circulating recombinant form 08_BC (CRF08_BC), carrying the recombinant reverse transcriptase (RT) gene from subtypes B and C, has recently become highly prevalent in Southern China. As the number of patients increases, it is important to characterize the drug resistance mutations of CRF08_BC, especially against widely used antiretrovirals. In this study, clinically isolated virus (2007CNGX-HK), confirmed to be CRF08_BC with its sequence deposited in GenBank (KF312642), was propagated in human peripheral blood mononuclear cells (PBMCs) with increasing concentrations of nevirapine (NVP), efavirenz (EFV), or lamivudine (3TC). Three different resistance patterns led by initial mutations of Y181C, E138G, and Y188C were detected after the selection with NVP. Initial mutations, in combination with other previously reported substitutions (K20R, D67N, V90I, K101R/E, V106I/A, V108I, F116L, E138R, A139V, V189I, G190A, D218E, E203K, H221Y, F227L, N348I, and T369I) or novel mutations (V8I, S134N, C162Y, L228I, Y232H, E396G, and D404N), developed during NVP selection. EFV-associated variations contained two initial mutations (L100I and Y188C) and three other mutations (V106L, F116Y, and A139V). Phenotypic analyses showed that E138R, Y181C, and G190A contributed high-level resistance to NVP, while L100I and V106L significantly reduced virus susceptibility to EFV. Y188C was 20-fold less sensitive to both NVP and EFV. As expected, M184I alone, or with V90I or D67N, decreased 3TC susceptibility by over 1,000-fold. Although the mutation profile obtained in culture may be different from the patients, these results may still provide useful information to monitor and optimize the antiretroviral regimens. PMID:25482475

  1. Molecular Dynamics Study of HIV-1 RT-DNA-Nevirapine Complexes Explains NNRTI Inhibition, and Resistance by Connection Mutations

    PubMed Central

    Vijayan, R.S.K.; Arnold, Eddy; Das, Kalyan

    2015-01-01

    HIV-1 reverse transcriptase (RT) is a multifunctional enzyme that is targeted by nucleoside analogs (NRTIs) and nonnucleoside inhibitors (NNRTIs). NNRTIs are allosteric inhibitors of RT, and constitute an integral part of the highly active antiretroviral therapy (HAART) regimen. Under selective pressure, HIV-1 acquires resistance against NNRTIs primarily by selecting mutations around the NNRTI pocket. Complete RT sequencing of clinical isolates revealed that spatially distal mutations arising in connection and the RNase H domain also confer NNRTI resistance and contribute to NRTI resistance. However, the precise structural mechanism by which the connection domain mutations confer NNRTI resistance is poorly understood. We performed 50-ns MD simulations, followed by essential dynamics, free-energy landscape analyses and network analyses of RT-DNA, RT-DNA-nevirapine, and N348I/T369I mutant RT-DNA-nevirapine complexes. MD simulation studies revealed altered global motions and restricted conformational landscape of RT upon nevirapine binding. Analysis of protein structure network parameters demonstrated a dissortative hub pattern in the RT-DNA complex and an assortative hub pattern in the RT-DNA-nevirapine complex suggesting enhanced rigidity of RT upon nevirapine binding. The connection subdomain mutations N348I/T369I did not induce any significant structural change; rather, these mutations modulate the conformational dynamics and alter the long-range allosteric communication network between the connection subdomain and NNRTI pocket. Insights from the present study provide a structural basis for the biochemical and clinical findings on drug resistance caused by the connection and RNase H mutations. PMID:24174331

  2. Identification of a novel resistance (E40F) and compensatory (K43E) substitution in HIV-1 reverse transcriptase

    PubMed Central

    Huigen, Marleen CDG; van Ham, Petronella M; de Graaf, Loek; Kagan, Ron M; Boucher, Charles AB; Nijhuis, Monique

    2008-01-01

    Background HIV-1 nucleoside reverse transcriptase inhibitors (NRTIs) have been used in the clinic for over twenty years. Interestingly, the complete resistance pattern to this class has not been fully elucidated. Novel mutations in RT appearing during treatment failure are still being identified. To unravel the role of two of these newly identified changes, E40F and K43E, we investigated their effect on viral drug susceptibility and replicative capacity. Results A large database (Quest Diagnostics database) was analysed to determine the associations of the E40F and K43E changes with known resistance mutations. Both amino acid changes are strongly associated with the well known NRTI-resistance mutations M41L, L210W and T215Y. In addition, a strong positive association between these changes themselves was observed. A panel of recombinant viruses was generated by site-directed mutagenesis and phenotypically analysed. To determine the effect on replication capacity, competition and in vitro evolution experiments were performed. Introduction of E40F results in an increase in Zidovudine resistance ranging from nine to fourteen fold depending on the RT background and at the same time confers a decrease in viral replication capacity. The K43E change does not decrease the susceptibility to Zidovudine but increases viral replication capacity, when combined with E40F, demonstrating a compensatory role for this codon change. Conclusion In conclusion, we have identified a novel resistance (E40F) and compensatory (K43E) change in HIV-1 RT. Further research is indicated to analyse the clinical importance of these changes. PMID:18271957

  3. Antiviral molecules correlate with vitamin D pathway genes and are associated with natural resistance to HIV-1 infection.

    PubMed

    Aguilar-Jimenez, Wbeimar; Zapata, Wildeman; Rugeles, María T

    2016-01-01

    The relationship between the immunomodulatory effects of Vitamin D (VitD) and the expression of anti-HIV-1 molecules has not been explored in HIV-1-exposed seronegative individuals (HESNs). Higher mRNA levels of cathelicidin and HAD-4 in oral-mucosa and peripheral-blood, along with higher CYP24A1 mRNA in vaginal-mucosa and lower TLR2 mRNA in endocervical-mucosa were found in HESNs compared to non-exposed controls. Furthermore, the mRNA of anti-HIV molecules Elafin, TRIM5, Cathelicidin, HAD-4 and RNase7, previously associated with natural resistance to HIV-1 infection, positively correlated with the mRNA expression of VDR in HESNs, suggesting the potential participation of VitD in natural resistance to HIV-1.

  4. Natural history of HIV-1 infection and predictors of survival in a cohort of HIV-1 seropositive injecting drug users.

    PubMed Central

    Brown, L. S.; Siddiqui, N. S.; Chu, A. F.

    1996-01-01

    Injecting drug users represent a pivotal and increasing component of acquired immunodeficiency syndrome (AIDS) case reporting in the United States. This article describes the natural history of human immunodeficiency virus (HIV) disease in a New York City cohort of 328 HIV-infected injecting drug users. The study sample of nearly two-thirds men (predominately African Americans and Latino Americans) underwent follow-up from December 1988 through December 1993. Male injecting drug users reported a longer injecting drug use history and were more likely to share needles/works than female injecting drug users. Eighty-nine of 328 study subjects died during the 5 years of observation. Comparing African Americans and Latinos, race/ethnicity was not related to survival. Survival was related to baseline CD4 count and hemoglobin level. Zidovudine use and PCP prophylaxis did not predict survival. Because of the continuing and increasing impact of HIV disease on injecting drug users and communities of color, there remains an unquestionable need to develop effective prevention programs, to understand the natural history of HIV disease, and to develop appropriate therapeutic interventions to treat those with HIV disease. PMID:8583491

  5. [Genetic characteristics of viral quasispecies of HIV-1 CRF07_BC among intravenous drug users].

    PubMed

    Xin, Ruo-Lei; Ma, Ze-Qin; Cheng, Chun-Lin; Xing, Hui; Hong, Kun-Xue; Ruan, Yu-Hua; Li, Jia; Lu, Hong-Yan; Shao, Yi-Ming; He, Xiang

    2013-05-01

    To explore the genetic characteristics of viral quasispecies in HIV-1 CRF07_BC infections among intravenous drug users (IDU), the gp120 fragments of HIV-1 env gene were amplified from plasma samples collected from 6 CRF07_BC infected persons using single genome amplification and sequencing (SGA/ SGS) method, and 11 to 28 sequences were obtained from these samples, respectively, A neighbor-joining phylogenetic tree was reconstructed to describe the genetic characteristics of viral quasispecies. The Simplot, segments' phylogenetic trees and diversity plots based on average pairwise distance (APD) were used to identify the recombination events between quasispecies. The SGA sequences derived from single specimen formed a large monophyletic cluster in the neighbor-joining phylogenetic tree and showed the complex topologic structures of viral quasispecies. Of the 6 CRF07_BC infected patients, only one possessed the high genetic homogeneity, whereas the other five individuals showed high heterogeneity, with two to four subclusters inside the monophyletic cluster for each specimen. In addition, the recombinant events were identified among viral quasispecies from 3 cases. The results show SGA technique and phylogenetic analyses are useful tool to investigate the intrahost CRF07_BC gp120 complex quasispecies variation and high genetic diversity.

  6. Authentic HIV-1 integrase inhibitors

    PubMed Central

    Liao, Chenzhong; Marchand, Christophe; Burke, Terrence R; Pommier, Yves; Nicklaus, Marc C

    2010-01-01

    HIV-1 integrase (IN) is indispensable for HIV-1 replication and has become a validated target for developing anti-AIDS agents. In two decades of development of IN inhibition-based anti-HIV therapeutics, a significant number of compounds were identified as IN inhibitors, but only some of them showed antiviral activity. This article reviews a number of patented HIV-1 IN inhibitors, especially those that possess high selectivity for the strand transfer reaction. These compounds generally have a polar coplanar moiety, which is assumed to chelate two magnesium ions in the binding site. Resistance to those compounds, when given to patients, can develop as a result of IN mutations. We refer to those compounds as authentic IN inhibitors. Continued drug development has so far delivered one authentic IN inhibitor to the market (raltegravir in 2007). Current and future attention will be focused on the development of novel authentic IN inhibitors with the goal of overcoming viral resistance. PMID:21426159

  7. Antimicrobial (Drug) Resistance Prevention

    MedlinePlus

    ... Visitor Information Contact Us Research > NIAID's Role in Research > Antimicrobial (Drug) Resistance > Understanding share with facebook share with twitter ... Prevention, Antimicrobial (Drug) Resistance Antimicrobial (Drug) Resistance Antimicrobial ... To prevent antimicrobial resistance, you and your healthcare ...

  8. Antigenicity-defined conformations of an extremely neutralization-resistant HIV-1 envelope spike.

    PubMed

    Cai, Yongfei; Karaca-Griffin, Selen; Chen, Jia; Tian, Sai; Fredette, Nicholas; Linton, Christine E; Rits-Volloch, Sophia; Lu, Jianming; Wagh, Kshitij; Theiler, James; Korber, Bette; Seaman, Michael S; Harrison, Stephen C; Carfi, Andrea; Chen, Bing

    2017-04-10

    The extraordinary genetic diversity of the HIV-1 envelope spike [Env; trimeric (gp160)3, cleaved to (gp120/gp41)3] poses challenges for vaccine development. Envs of different clinical isolates exhibit different sensitivities to antibody-mediated neutralization. Envs of difficult-to-neutralize viruses are thought to be more stable and conformationally homogeneous trimers than those of easy-to-neutralize viruses, thereby providing more effective concealment of conserved, functionally critical sites. In this study we have characterized the antigenic properties of an Env derived from one of the most neutralization-resistant HIV-1 isolates, CH120.6. Sequence variation at neutralizing epitopes does not fully account for its exceptional resistance to antibodies. The full-length, membrane-bound CH120.6 Env is indeed stable and conformationally homogeneous. Its antigenicity correlates closely with its neutralization sensitivity, and major changes in antigenicity upon CD4 engagement appear to be restricted to the coreceptor site. The CH120.6 gp140 trimer, the soluble and uncleaved ectodomain of (gp160)3, retains many antigenic properties of the intact Env, consistent with a conformation close to that of Env spikes on a virion, whereas its monomeric gp120 exposes many nonneutralizing or strain-specific epitopes. Thus, trimer organization and stability are important determinants not only for occluding many epitopes but also for conferring resistance to neutralization by all but a small set of antibodies. Env preparations derived from neutralization-resistant viruses may induce irrelevant antibody responses less frequently than do other Envs and may be excellent templates for developing soluble immunogens.

  9. Co-infections and transmission networks of HCV, HIV-1 and HPgV among people who inject drugs

    PubMed Central

    Tien Ng, Kim; Takebe, Yutaka; Bee Chook, Jack; Zhen Chow, Wei; Gan Chan, Kok; Abed Al-Darraji, Haider Abdulrazzaq; Kamarulzaman, Adeeba; Keng Tee, Kok

    2015-01-01

    Co-infections with human immunodeficiency virus type 1 (HIV-1) and human pegivirus (HPgV) are common in hepatitis C virus (HCV)-infected individuals. However, analysis on the evolutionary dynamics and transmission network profiles of these viruses among individuals with multiple infections remains limited. A total of 228 injecting drug users (IDUs), either HCV- and/or HIV-1-infected, were recruited in Kuala Lumpur, Malaysia. HCV, HIV-1 and HPgV genes were sequenced, with epidemic growth rates assessed by the Bayesian coalescent method. Based on the sequence data, mono-, dual- and triple-infection were detected in 38.8%, 40.6% and 20.6% of the subjects, respectively. Fifteen transmission networks involving HCV (subtype 1a, 1b, 3a and 3b), HIV-1 (CRF33_01B) and HPgV (genotype 2) were identified and characterized. Genealogical estimates indicated that the predominant HCV, HIV-1 and HPgV genotypes were introduced into the IDUs population through multiple sub-epidemics that emerged as early as 1950s (HCV), 1980s (HIV-1) and 1990s (HPgV). By determining the difference in divergence times between viral lineages (ΔtMRCA), we also showed that the frequency of viral co-transmission is low among these IDUs. Despite increased access to therapy and other harm reduction interventions, the continuous emergence and coexistence of new transmission networks suggest persistent multiple viral transmissions among IDUs. PMID:26459957

  10. High Prevalence of HIV-1 Intersubtype B′/C Recombinants among Injecting Drug Users in Dehong, China

    PubMed Central

    Han, Xiaoxu; An, Minghui; Zhao, Bin; Duan, Song; Yang, Shaomin; Xu, Junjie; Zhang, Min; McGoogan, Jennifer M.; Takebe, Yutaka; Shang, Hong

    2013-01-01

    Objective To examine the distribution of HIV-1 genotypes among injecting drug users (IDUs) from Dehong, Yunnan province. Materials and Methods Blood samples from a total of 95 HIV-positive IDUs were retrospectively analyzed. Samples were collected between 2005 and 2009 from four cities in Dehong prefecture, western Yunnan province, the geographical origin of the HIV epidemic in China. HIV-1 gag, partial pol, vpr-env fragment, half-genome, or near-full-length sequences were analyzed to determine the HIV-1 genotypes of each subject. Results were compared with findings from past studies of IDUs in Dehong and in neighboring Myanmar. Results We observed a high prevalence of B′/C recombinants (82.4%) among IDUs in Dehong, the structural profiles of which do not match those previously reported in Dehong or in Myanmar. Furthermore, statistically significant differences in geographical and temporal distributions of HIV-1 genotypes were characterized by a predominance of HIV-1 B′/C recombinant forms among older subjects(p = 0.034), subjects from Longchuan district (p = 0.022), and subjects diagnosed between 2000 and 2004 (p = 0.004). Conclusions The increasing prevalence of multiple, new B′/C recombinant forms suggest that HIV-1 intersubtype recombination is substantial and ongoing in western Yunnan. This reflects the high-risk behavior of IDUs in this region and argues the need for stronger monitoring and prevention measures in Dehong and other high-prevalence areas around China. PMID:23741489

  11. Application of 3D-QSAR techniques in anti-HIV-1 drug design--an overview.

    PubMed

    Debnath, Asim Kumar

    2005-01-01

    Despite the availability of several classes of drugs against acquired immunodeficiency syndrome (AIDS) caused by human immunodeficiency virus type 1(HIV-1), this deadly disease showing very little sign of containment, especially in Sub-Saharan Africa and South-East Asia. More than 20 million people died since the first diagnosis of AIDS more than twenty years ago and almost 40 million people are currently living with HIV/AIDS. Structure-based drug design effort was immensely successful in identifying several drugs that are currently available for the treatment of HIV-1. Many applications have been reported on the use of quantitative structure-activity relationship (QSAR) studies to understand the drug-receptor interactions and help in the design of more effective analogs. Extensive application was also reported on the application of 3D-QSAR techniques, such as, Comparative Molecular Field Analysis (CoMFA), Comparative Molecular Similarity Analysis (CoMSIA), pharmacophore generation using Catalyst/HypoGen, free-energy binding analysis, GRID/GOLPE, HINT-based techniques, etc. in anti-HIV-1 drug discovery programs in academia and industry. We have attempted to put together a comprehensive overview on the 3D-QSAR applications in anti-HIV-1 drug design reported in the literature during the last decade.

  12. HIV-1 resistance to neutralizing antibodies: Determination of antibody concentrations leading to escape mutant evolution.

    PubMed

    Magnus, Carsten; Reh, Lucia; Trkola, Alexandra

    2016-06-15

    Broadly neutralizing antibodies against human immunodeficiency virus type 1 (HIV-1) are considered vital components of novel therapeutics and blueprints for vaccine research. Yet escape to even the most potent of these antibodies is imminent in natural infection. Measures to define antibody efficacy and prevent mutant selection are thus urgently needed. Here, we derive a mathematical framework to predict the concentration ranges for which antibody escape variants can outcompete their viral ancestors, referred to as mutant selection window (MSW). When determining the MSW, we focus on the differential efficacy of neutralizing antibodies against HIV-1 in two canonical infection routes, free-virus infection and cell-cell transmission. The latter has proven highly effective in vitro suggesting its importance for both in vivo spread as well as for escaping targeted intervention strategies. We observed a range of MSW patterns that highlight the potential of mutants to arise in both transmission pathways and over wide concentration ranges. Most importantly, we found that only when the arising mutant has both, residual sensitivity to the neutralizing antibody and reduced infectivity compared to the parental virus, antibody dosing outside of the MSW to restrict mutant selection is possible. Emergence of mutants that provide complete escape and have no considerable fitness loss cannot be prevented by adjusting antibody doses. The latter may in part explain the ubiquitous resistance to neutralizing antibodies observed in natural infection and antibody treatment. Based on our findings, combinations of antibodies targeting different epitopes should be favored for antibody-based interventions as this may render complete resistance less likely to occur and also increase chances that multiple escapes result in severe fitness loss of the virus making longer-term antibody treatment more feasible.

  13. Resistance to type 1 interferons is a major determinant of HIV-1 transmission fitness

    PubMed Central

    Iyer, Shilpa S.; Bibollet-Ruche, Frederic; Sherrill-Mix, Scott; Learn, Gerald H.; Plenderleith, Lindsey; Smith, Andrew G.; Barbian, Hannah J.; Russell, Ronnie M.; Gondim, Marcos V. P.; Bahari, Catherine Y.; Shaw, Christiana M.; Li, Yingying; Decker, Timothy; Haynes, Barton F.; Shaw, George M.; Sharp, Paul M.; Borrow, Persephone; Hahn, Beatrice H.

    2017-01-01

    Sexual transmission of HIV-1 is an inefficient process, with only one or few variants of the donor quasispecies establishing the new infection. A critical, and as yet unresolved, question is whether the mucosal bottleneck selects for viruses with increased transmission fitness. Here, we characterized 300 limiting dilution-derived virus isolates from the plasma, and in some instances genital secretions, of eight HIV-1 donor and recipient pairs. Although there were no differences in the amount of virion-associated envelope glycoprotein, recipient isolates were on average threefold more infectious (P = 0.0001), replicated to 1.4-fold higher titers (P = 0.004), were released from infected cells 4.2-fold more efficiently (P < 0.00001), and were significantly more resistant to type I IFNs than the corresponding donor isolates. Remarkably, transmitted viruses exhibited 7.8-fold higher IFNα2 (P < 0.00001) and 39-fold higher IFNβ (P < 0.00001) half-maximal inhibitory concentrations (IC50) than did donor isolates, and their odds of replicating in CD4+ T cells at the highest IFNα2 and IFNβ doses were 35-fold (P < 0.00001) and 250-fold (P < 0.00001) greater, respectively. Interestingly, pretreatment of CD4+ T cells with IFNβ, but not IFNα2, selected donor plasma isolates that exhibited a transmitted virus-like phenotype, and such viruses were also detected in the donor genital tract. These data indicate that transmitted viruses are phenotypically distinct, and that increased IFN resistance represents their most distinguishing property. Thus, the mucosal bottleneck selects for viruses that are able to replicate and spread efficiently in the face of a potent innate immune response. PMID:28069935

  14. Emerging pathogens: Dynamics, mutation and drug resistance

    SciTech Connect

    Perelson, A.S.; Goldstein, B.; Korber, B.T.

    1997-10-01

    This is the final report of a one-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). The objectives of this project were to develop models of the spread of pathogens, such as HIV-1 and influenza, in humans, and then to use the models to address the possibility of designing appropriate drug therapies that may limit the ability of the pathogen to escape treatment by mutating into a drug resistant form. We have developed a model of drug-resistance to amantidine and rimantadine, the two major antiviral drugs used to treat influenza, and have used the model to suggest treatment strategies during an epidemic.

  15. Drug-Based Lead Discovery: The Novel Ablative Antiretroviral Profile of Deferiprone in HIV-1-Infected Cells and in HIV-Infected Treatment-Naive Subjects of a Double-Blind, Placebo-Controlled, Randomized Exploratory Trial

    PubMed Central

    Saxena, Deepti; Spino, Michael; Tricta, Fernando; Connelly, John; Cracchiolo, Bernadette M.; Hanauske, Axel-Rainer; D’Alliessi Gandolfi, Darlene; Mathews, Michael B.; Karn, Jonathan; Holland, Bart; Park, Myung Hee; Pe’ery, Tsafi; Palumbo, Paul E.; Hanauske-Abel, Hartmut M.

    2016-01-01

    Antiretrovirals suppress HIV-1 production yet spare the sites of HIV-1 production, the HIV-1 DNA-harboring cells that evade immune detection and enable viral resistance on-drug and viral rebound off-drug. Therapeutic ablation of pathogenic cells markedly improves the outcome of many diseases. We extend this strategy to HIV-1 infection. Using drug-based lead discovery, we report the concentration threshold-dependent antiretroviral action of the medicinal chelator deferiprone and validate preclinical findings by a proof-of-concept double-blind trial. In isolate-infected primary cultures, supra-threshold concentrations during deferiprone monotherapy caused decline of HIV-1 RNA and HIV-1 DNA; did not allow viral breakthrough for up to 35 days on-drug, indicating resiliency against viral resistance; and prevented, for at least 87 days off-drug, viral rebound. Displaying a steep dose-effect curve, deferiprone produced infection-independent deficiency of hydroxylated hypusyl-eIF5A. However, unhydroxylated deoxyhypusyl-eIF5A accumulated particularly in HIV-infected cells; they preferentially underwent apoptotic DNA fragmentation. Since the threshold, ascertained at about 150 μM, is achievable in deferiprone-treated patients, we proceeded from cell culture directly to an exploratory trial. HIV-1 RNA was measured after 7 days on-drug and after 28 and 56 days off-drug. Subjects who attained supra-threshold concentrations in serum and completed the protocol of 17 oral doses, experienced a zidovudine-like decline of HIV-1 RNA on-drug that was maintained off-drug without statistically significant rebound for 8 weeks, over 670 times the drug’s half-life and thus clearance from circulation. The uniform deferiprone threshold is in agreement with mapping of, and crystallographic 3D-data on, the active site of deoxyhypusyl hydroxylase (DOHH), the eIF5A-hydroxylating enzyme. We propose that deficiency of hypusine-containing eIF5A impedes the translation of mRNAs encoding proline

  16. Effects of PRE and POST Therapy Drug-Pressure Selected Mutations on HIV-1 Protease Conformational Sampling

    PubMed Central

    Carter, Jeffrey D.; Gonzales, Estrella G.; Huang, Xi; Smith, Adam N.; deVera, Ian Mitchelle S.; D’Amore, Peter W.; Rocca, James R.; Goodenow, Maureen; Dunn, Ben M.; Fanucci, Gail E.

    2015-01-01

    Conformational sampling of pre- and post-therapy subtype B HIV-1 protease sequences derived from a pediatric subject infected via maternal transmission with HIV-1 were characterized by double electron-electron resonance spectroscopy. The conformational ensemble of the PRE construct resembles native-like inhibitor bound states. In contrast, the POST construct, which contains accumulated drug-pressure selected mutations, has a predominantly semi-open conformational ensemble, with increased populations of open-like states. The single point mutant L63P, which is contained in PRE and POST, has decreased dynamics, particularly in the flap region, and also displays a closed-like conformation of inhibitor-bound states. These findings support our hypothesis that secondary mutations accumulate in HIV-1 protease to shift conformational sampling to stabilize open-like conformations, while maintaining the predominant semi-open conformation for activity. PMID:24983495

  17. The R263K Dolutegravir Resistance-Associated Substitution Progressively Decreases HIV-1 Integration

    PubMed Central

    Mesplède, Thibault; Leng, Jing; Pham, Hanh Thi; Liang, Jiaming; Quan, Yudong; Han, Yingshan

    2017-01-01

    ABSTRACT Human immunodeficiency virus (HIV) infection persists despite decades of active antiretroviral therapy (ART), effectively preventing viral eradication. Treatment decreases plasma viral RNA, but viral DNA persists, mostly integrated within the genome of nucleated blood cells. Viral DNA blood levels correlate with comorbidities and the rapidity of viral rebound following treatment interruption. To date, no intervention aiming at decreasing HIV DNA levels below those attained through ART has been successful. This includes use of some integrase inhibitors either as part of ART or in treatment intensification studies. We have argued that using the integrase inhibitor dolutegravir (DTG) in similar studies may yield better results, but this remains to be studied. In treatment-experienced individuals, the most frequent substitution associated with failure with dolutegravir is R263K in integrase. R263K decreases integration both in cell-free and tissue culture assays. We investigated here how integrated DNA levels evolve over time during prolonged infections with R263K viruses. To investigate a potential defect in reverse transcription with R263K, the levels of reverse transcripts were measured by quantitative PCR. We measured HIV type 1 (HIV-1) integration in Jurkat cells over the course of 4-week infections using Alu-mediated quantitative PCR. The results show that R263K did not decrease reverse transcription. Prolonged infections with R263K mutant viruses led to less HIV-1 integrated DNA over time compared to wild-type viruses. These tissue culture results help to explain the absence of the R263K substitution in most individuals experiencing failure with DTG and support studies aiming at longitudinally measuring the levels of integrated DNA in individuals treated with this drug. PMID:28377526

  18. Genome editing of CXCR4 by CRISPR/cas9 confers cells resistant to HIV-1 infection.

    PubMed

    Hou, Panpan; Chen, Shuliang; Wang, Shilei; Yu, Xiao; Chen, Yu; Jiang, Meng; Zhuang, Ke; Ho, Wenzhe; Hou, Wei; Huang, Jian; Guo, Deyin

    2015-10-20

    Genome editing via CRISPR/Cas9 has become an efficient and reliable way to make precise, targeted changes to the genome of living cells. CXCR4 is a co-receptor for the human immunodeficiency virus type 1 (HIV-1) infection and has been considered as an important therapeutic target for AIDS. CXCR4 mediates viral entry into human CD4(+) cells by binding to envelope protein, gp120. Here, we show that human CXCR4 gene is efficiently disrupted by CRISPR/Cas9-mediated genome editing, leading to HIV-1 resistance of human primary CD4(+) T cells. We also show that the Cas9-mediated ablation of CXCR4 demonstrated high specificity and negligible off-target effects without affecting cell division and propagation. The precise and efficient genome editing of CXCR4 will provide a new strategy for therapeutic application against HIV-1 infection.

  19. Low-Frequency Drug Resistance in HIV-Infected Ugandans on Antiretroviral Treatment Is Associated with Regimen Failure

    PubMed Central

    Kyeyune, Fred; Gibson, Richard M.; Nankya, Immaculate; Venner, Colin; Metha, Samar; Akao, Juliet; Ndashimye, Emmanuel; Kityo, Cissy M.; Salata, Robert A.; Mugyenyi, Peter

    2016-01-01

    Most patients failing antiretroviral treatment in Uganda continue to fail their treatment regimen even if a dominant drug-resistant HIV-1 genotype is not detected. In a recent retrospective study, we observed that approximately 30% of HIV-infected individuals in the Joint Clinical Research Centre (Kampala, Uganda) experienced virologic failure with a susceptible HIV-1 genotype based on standard Sanger sequencing. Selection of minority drug-resistant HIV-1 variants (not detectable by Sanger sequencing) under antiretroviral therapy pressure can lead to a shift in the viral quasispecies distribution, becoming dominant members of the virus population and eventually causing treatment failure. Here, we used a novel HIV-1 genotyping assay based on deep sequencing (DeepGen) to quantify low-level drug-resistant HIV-1 variants in 33 patients failing a first-line antiretroviral treatment regimen in the absence of drug-resistant mutations, as screened by standard population-based Sanger sequencing. Using this sensitive assay, we observed that 64% (21/33) of these individuals had low-frequency (or minority) drug-resistant variants in the intrapatient HIV-1 population, which correlated with treatment failure. Moreover, the presence of these minority HIV-1 variants was associated with higher intrapatient HIV-1 diversity, suggesting a dynamic selection or fading of drug-resistant HIV-1 variants from the viral quasispecies in the presence or absence of drug pressure, respectively. This study identified low-frequency HIV drug resistance mutations by deep sequencing in Ugandan patients failing antiretroviral treatment but lacking dominant drug resistance mutations as determined by Sanger sequencing methods. We showed that these low-abundance drug-resistant viruses could have significant consequences for clinical outcomes, especially if treatment is not modified based on a susceptible HIV-1 genotype by Sanger sequencing. Therefore, we propose to make clinical decisions using more

  20. Strain-Specific V3 and CD4 Binding Site Autologous HIV-1 Neutralizing Antibodies Select Neutralization-Resistant Viruses.

    PubMed

    Moody, M Anthony; Gao, Feng; Gurley, Thaddeus C; Amos, Joshua D; Kumar, Amit; Hora, Bhavna; Marshall, Dawn J; Whitesides, John F; Xia, Shi-Mao; Parks, Robert; Lloyd, Krissey E; Hwang, Kwan-Ki; Lu, Xiaozhi; Bonsignori, Mattia; Finzi, Andrés; Vandergrift, Nathan A; Alam, S Munir; Ferrari, Guido; Shen, Xiaoying; Tomaras, Georgia D; Kamanga, Gift; Cohen, Myron S; Sam, Noel E; Kapiga, Saidi; Gray, Elin S; Tumba, Nancy L; Morris, Lynn; Zolla-Pazner, Susan; Gorny, Miroslaw K; Mascola, John R; Hahn, Beatrice H; Shaw, George M; Sodroski, Joseph G; Liao, Hua-Xin; Montefiori, David C; Hraber, Peter T; Korber, Bette T; Haynes, Barton F

    2015-09-09

    The third variable (V3) loop and the CD4 binding site (CD4bs) of the HIV-1 envelope are frequently targeted by neutralizing antibodies (nAbs) in infected individuals. In chronic infection, HIV-1 escape mutants repopulate the plasma, and V3 and CD4bs nAbs emerge that can neutralize heterologous tier 1 easy-to-neutralize but not tier 2 difficult-to-neutralize HIV-1 isolates. However, neutralization sensitivity of autologous plasma viruses to this type of nAb response has not been studied. We describe the development and evolution in vivo of antibodies distinguished by their target specificity for V3 and CD4bs epitopes on autologous tier 2 viruses but not on heterologous tier 2 viruses. A surprisingly high fraction of autologous circulating viruses was sensitive to these antibodies. These findings demonstrate a role for V3 and CD4bs antibodies in constraining the native envelope trimer in vivo to a neutralization-resistant phenotype, explaining why HIV-1 transmission generally occurs by tier 2 neutralization-resistant viruses.

  1. Implementation of a multiregion hybridization assay to characterize HIV-1 strains detected among injecting drug users in Manipur, India.

    PubMed

    Sarkar, Roni; Sengupta, Satarupa; Mullick, Ranajoy; Singh, N Brajachand; Sarkar, Kamalesh; Chakrabarti, Sekhar

    2009-01-01

    We have implemented the latest technology of a multiregion hybridization assay (MHAbce, version 2) for the molecular characterization of HIV-1 among injecting drug users (IDUs) of Manipur, India. This study provides a more detailed analysis on the basis of probes designed from eight different genomic regions of HIV-1, to achieve a clear picture of HIV-1 genomic diversity in Manipur. Out of 30 samples, 15 were found to be of subtype C, 1 of subtype B, 5 with dual-probe reactivity, 8 with multigenomic recombination pattern and 1 sample showed both dual-probe reactivity and multigenomic variations. In contrast, the heteroduplex mobility assay (HMA) with respect to gag and env genes revealed 21 samples to be of subtype C (gag C/env C), 3 samples of subtype B (gag B/env B) and 6 samples of B/C recombinants (gag C/env B). MHAbce illustrates the occurrence of inter- and intragenomic variants and dual infection in an IDU population from India. It also indicates the possibility of the presence of new circulating recombinant forms of HIV-1 strains, which might have been difficult to trace by HMA alone.

  2. Generation and Characterization of HIV-1 Transmitted and Founder Virus Consensus Sequence from Intravenous Drug Users in Xinjiang, China.

    PubMed

    Li, Fan; Ma, Liying; Feng, Yi; Hu, Jing; Ni, Na; Ruan, Yuhua; Shao, Yiming

    2017-03-02

    HIV-1 transmission in intravenous drug users (IDUs) has been characterized by high genetic multiplicity and suggests a greater challenge for HIV-1 infection blocking. We investigated a total of 749 sequences of full-length gp160 gene obtained by single genome sequencing (SGS) from 22 HIV-1 early infected IDUs in Xinjiang province, northwest China, and generated a transmitted and founder virus (T/F virus) consensus sequence (IDU.CON). The T/F virus was classified as subtype CRF07_BC and predicted to be CCR5-tropic virus. The variable region (V1, V2, and V4 loop) of IDU.CON showed length variation compared with the heterosexual T/F virus consensus sequence (HSX.CON) and homosexual T/F virus consensus sequence (MSM.CON). A total of 26 N-linked glycosylation sites were discovered in the IDU.CON sequence, which is less than that of MSM.CON and HSX.CON. Characterization of T/F virus from IDUs highlights the genetic make-up and complexity of virus near the moment of transmission or in early infection preceding systemic dissemination and is important toward the development of an effective HIV-1 preventive methods, including vaccines.

  3. Incompatible Natures of the HIV-1 Envelope in Resistance to the CCR5 Antagonist Cenicriviroc and to Neutralizing Antibodies

    PubMed Central

    Enomoto, Ikumi; Baba, Masanori

    2015-01-01

    Cenicriviroc is a CCR5 antagonist which prevents human immunodeficiency virus type 1 (HIV-1) from cellular entry. The CCR5-binding regions of the HIV-1 envelope glycoprotein are important targets for neutralizing antibodies (NAbs), and mutations conferring cenicriviroc resistance may therefore affect sensitivity to NAbs. Here, we used the in vitro induction of HIV-1 variants resistant to cenicriviroc or NAbs to examine the relationship between resistance to cenicriviroc and resistance to NAbs. The cenicriviroc-resistant variant KK652-67 (strain KK passaged 67 times in the presence of increasing concentrations of cenicriviroc) was sensitive to neutralization by NAbs against the V3 loop, the CD4-induced (CD4i) region, and the CD4-binding site (CD4bs), whereas the wild-type (WT) parental HIV-1 strain KKWT from which cenicriviroc-resistant strain KK652-67 was obtained was resistant to these NAbs. The V3 region of KK652-67 was important for cenicriviroc resistance and critical to the high sensitivity of the V3, CD4i, and CD4bs epitopes to NAbs. Moreover, induction of variants resistant to anti-V3 NAb 0.5γ and anti-CD4i NAb 4E9C from cenicriviroc-resistant strain KK652-67 resulted in reversion to the cenicriviroc-sensitive phenotype comparable to that of the parental strain, KKWT. Resistance to 0.5γ and 4E9C was caused by the novel substitutions R315K, G324R, and E381K in the V3 and C3 regions near the substitutions conferring cenicriviroc resistance. Importantly, these amino acid changes in the CCR5-binding region were also responsible for reversion to the cenicriviroc-sensitive phenotype. These results suggest the presence of key amino acid residues where resistance to cenicriviroc is incompatible with resistance to NAbs. This implies that cenicriviroc and neutralizing antibodies may restrict the emergence of variants resistant to each other. PMID:26525792

  4. Incompatible Natures of the HIV-1 Envelope in Resistance to the CCR5 Antagonist Cenicriviroc and to Neutralizing Antibodies.

    PubMed

    Kuwata, Takeo; Enomoto, Ikumi; Baba, Masanori; Matsushita, Shuzo

    2015-11-02

    Cenicriviroc is a CCR5 antagonist which prevents human immunodeficiency virus type 1 (HIV-1) from cellular entry. The CCR5-binding regions of the HIV-1 envelope glycoprotein are important targets for neutralizing antibodies (NAbs), and mutations conferring cenicriviroc resistance may therefore affect sensitivity to NAbs. Here, we used the in vitro induction of HIV-1 variants resistant to cenicriviroc or NAbs to examine the relationship between resistance to cenicriviroc and resistance to NAbs. The cenicriviroc-resistant variant KK652-67 (strain KK passaged 67 times in the presence of increasing concentrations of cenicriviroc) was sensitive to neutralization by NAbs against the V3 loop, the CD4-induced (CD4i) region, and the CD4-binding site (CD4bs), whereas the wild-type (WT) parental HIV-1 strain KKWT from which cenicriviroc-resistant strain KK652-67 was obtained was resistant to these NAbs. The V3 region of KK652-67 was important for cenicriviroc resistance and critical to the high sensitivity of the V3, CD4i, and CD4bs epitopes to NAbs. Moreover, induction of variants resistant to anti-V3 NAb 0.5γ and anti-CD4i NAb 4E9C from cenicriviroc-resistant strain KK652-67 resulted in reversion to the cenicriviroc-sensitive phenotype comparable to that of the parental strain, KKWT. Resistance to 0.5γ and 4E9C was caused by the novel substitutions R315K, G324R, and E381K in the V3 and C3 regions near the substitutions conferring cenicriviroc resistance. Importantly, these amino acid changes in the CCR5-binding region were also responsible for reversion to the cenicriviroc-sensitive phenotype. These results suggest the presence of key amino acid residues where resistance to cenicriviroc is incompatible with resistance to NAbs. This implies that cenicriviroc and neutralizing antibodies may restrict the emergence of variants resistant to each other.

  5. Dolutegravir in Antiretroviral-Experienced Patients With Raltegravir- and/or Elvitegravir-Resistant HIV-1: 24-Week Results of the Phase III VIKING-3 Study

    PubMed Central

    Castagna, Antonella; Maggiolo, Franco; Penco, Giovanni; Wright, David; Mills, Anthony; Grossberg, Robert; Molina, Jean-Michel; Chas, Julie; Durant, Jacques; Moreno, Santiago; Doroana, Manuela; Ait-Khaled, Mounir; Huang, Jenny; Min, Sherene; Song, Ivy; Vavro, Cindy; Nichols, Garrett; Yeo, Jane M.; Aberg, J.; Akil, B.; Arribas, J. R.; Baril, J.-G.; Blanco Arévalo, J. L.; Blanco Quintana, F.; Blick, G.; Boix Martínez, V.; Bouchaud, O.; Branco, T.; Bredeek, U. F.; Castro Iglesias, M.; Clumeck, N.; Conway, B.; DeJesus, E.; Delassus, J.-L.; De Truchis, P.; Di Perri, G.; Di Pietro, M.; Duggan, J.; Duvivier, C.; Elion, R.; Eron, J.; Fish, D.; Gathe, J.; Haubrich, R.; Henderson, H.; Hicks, C.; Hocqueloux, L.; Hodder, S.; Hsiao, C.-B.; Katlama, C.; Kozal, M.; Kumar, P.; Lalla-Reddy, S.; Lazzarin, A.; Leoncini, F.; Llibre, J. M.; Mansinho, K.; Morlat, P.; Mounzer, K.; Murphy, M.; Newman, C.; Nguyen, T.; Nseir, B.; Philibert, P.; Pialoux, G.; Poizot-Martin, I.; Ramgopal, M.; Richmond, G.; Salmon Ceron, D.; Sax, P.; Scarsella, A.; Sension, M.; Shalit, P.; Sighinolfi, L.; Sloan, L.; Small, C.; Stein, D.; Tashima, K.; Tebas, P.; Torti, C.; Tribble, M.; Troisvallets, D.; Tsoukas, C.; Viciana Fernández, P.; Ward, D.; Wheeler, D.; Wilkin, T.; Yeni, G.-P.; Louise Martin-Carpenter, J.; Uhlenbrauck, Gina

    2014-01-01

    Background. The pilot phase IIb VIKING study suggested that dolutegravir (DTG), a human immunodeficiency virus (HIV) integrase inhibitor (INI), would be efficacious in INI-resistant patients at the 50 mg twice daily (BID) dose. Methods. VIKING-3 is a single-arm, open-label phase III study in which therapy-experienced adults with INI-resistant virus received DTG 50 mg BID while continuing their failing regimen (without raltegravir or elvitegravir) through day 7, after which the regimen was optimized with ≥1 fully active drug and DTG continued. The primary efficacy endpoints were the mean change from baseline in plasma HIV-1 RNA at day 8 and the proportion of subjects with HIV-1 RNA <50 c/mL at week 24. Results. Mean change in HIV-1 RNA at day 8 was −1.43 log10 c/mL, and 69% of subjects achieved <50 c/mL at week 24. Multivariate analyses demonstrated a strong association between baseline DTG susceptibility and response. Response was most reduced in subjects with Q148 + ≥2 resistance-associated mutations. DTG 50 mg BID had a low (3%) discontinuation rate due to adverse events, similar to INI-naive subjects receiving DTG 50 mg once daily. Conclusions. DTG 50 mg BID–based therapy was effective in this highly treatment-experienced population with INI-resistant virus. Clinical Trials Registration. www.clinicaltrials.gov (NCT01328041) and http://www.gsk-clinicalstudywww.gsk-clinicalstudyregister.com (112574). PMID:24446523

  6. Short-term declines in CD4 levels associated with cocaine use in HIV-1 seropositive, minority injecting drug users.

    PubMed Central

    Siddiqui, N. S.; Brown, L. S.; Makuch, R. W.

    1993-01-01

    This study evaluates the association of cocaine use with short-term change in CD4 counts among human immunodeficiency virus type 1 (HIV-1) seropositive, minority injecting drug users prior to the introduction of zidovudine (AZT). Ninety-eight HIV-1 seropositive subjects were recruited from six inner-city, methadone maintenance clinics. A baseline assessment included a short questionnaire regarding drug behavior and quantitation of CD4 cell counts. These measures were repeated on all subjects 3 to 4 months later. Thirty-eight subjects reported using cocaine between baseline and 4-month follow-up evaluations. Males and African Americans were more likely to be cocaine users (P < .01). Cocaine users were more likely to engage in heroin and needle use (P < .001). Cocaine users experienced a significant decline in CD4 cells compared with nonusers (P = .013); no marked difference in CD4 decline was noted between heroin users and nonusers (P = .19). Multivariate analysis showed that a decline in CD4 counts was 2.82 times more likely to occur in cocaine users than in cocaine nonusers (90% two-sided confidence interval of 1.08, 7.37). These findings support the hypothesis of a possible link between cocaine use and short-term CD4 decline in HIV-1 seropositive injecting drug users. PMID:8478971

  7. Mutation of a Single Residue Renders Human Tetherin Resistant to HIV-1 Vpu-Mediated Depletion

    PubMed Central

    Schaller, Torsten; Verschoor, Ernst; Pillay, Deenan; Towers, Greg J.

    2009-01-01

    The recently identified restriction factor tetherin/BST-2/CD317 is an interferon-inducible trans-membrane protein that restricts HIV-1 particle release in the absence of the HIV-1 countermeasure viral protein U (Vpu). It is known that Tantalus monkey CV1 cells can be rendered non-permissive to HIV-1 release upon stimulation with type 1 interferon, despite the presence of Vpu, suggesting species-specific sensitivity of tetherin proteins to viral countermeasures such as Vpu. Here we demonstrate that Tantalus monkey tetherin restricts HIV-1 by nearly two orders of magnitude, but in contrast to human tetherin the Tantalus protein is insensitive to HIV-1 Vpu. We have investigated tetherin's sensitivity to Vpu using positive selection analyses, seeking evidence for evolutionary conflict between tetherin and viral countermeasures. We provide evidence that tetherin has undergone positive selection during primate evolution. Mutation of a single amino acid (showing evidence of positive selection) in the trans-membrane cap of human tetherin to that in Tantalus monkey (T45I) substantially impacts on sensitivity to HIV-1 Vpu, but not on antiviral activity. Finally, we provide evidence that cellular steady state levels of tetherin are substantially reduced by Vpu, and that the T45I mutation abrogates this effect. This study provides evidence that tetherin is important in protecting mammals against viral infection, and that the HIV-1 Vpu–mediated countermeasure is specifically adapted to act against human tetherin. It also emphasizes the power of selection analyses to illuminate the molecular details of host–virus interactions. This work suggests that tetherin binding agents might protect it from viral encoded countermeasures and thus make powerful antivirals. PMID:19461879

  8. Nevirapine-Resistant HIV-1 DNA in Breast Milk After Single-Dose Nevirapine With or Without Zidovudine for Prevention of Mother-to-Child Transmission

    PubMed Central

    Gantt, Soren; Payant, Rachel; Carlsson, Jacquelyn; Micek, Mark A.; Blanco, Ana Judith; Beck, Ingrid A.; Matunha, Laurinda; Montoya, Pablo; Matediana, Eduardo; Gloyd, Stephen; Frenkel, Lisa M.

    2012-01-01

    Among 30 human immunodeficiency virus type 1 (HIV-1)–infected women who received single-dose nevirapine (NVP), 17 (57%) had NVP-resistant HIV-1 detected in breast milk. NVP resistance in breast milk persisted for at least 8 months postpartum and was apparently transmitted to at least 1 infant. NVP resistance was detected less often in women who also received zidovudine. PMID:23687579

  9. Novel HIV-1 Therapeutics through Targeting Altered Host Cell Pathways

    PubMed Central

    Coley, William; Kehn-Hall, Kylene; Van Duyne, Rachel; Kashanchi, Fatah

    2009-01-01

    The emergence of drug-resistant human immunodeficiency virus type I (HIV-1) strains presents a challenge for the design of new drugs. Anti-HIV compounds currently in use are the subject of advanced clinical trials using either HIV-1 reverse-transcriptase, viral protease, or integrase inhibitors. Recent studies show an increase in the number of HIV-1 variants resistant to anti-retroviral agents in newly infected individuals. Targeting host cell factors involved in the regulation of HIV-1 replication might be one way to combat HIV-1 resistance to the currently available anti-viral agents. A specific inhibition of HIV-1 gene expression could be expected from the development of compounds targeting host cell factors that participate in the activation of the HIV-1 LTR promoter. Here we will discuss how targeting the host can be accomplished either by using small molecules to alter the function of the host’s proteins such as p53 or cdk9, or by utilizing new advances in siRNA therapies to knock down essential host factors such as CCR5 and CXCR4. Finally, we will discuss how the viral protein interactomes should be performed to better design therapeutics against HIV-1. PMID:19732026

  10. Modeling antiretroviral drug responses for HIV-1 infected patients using differential equation models.

    PubMed

    Xiao, Yanni; Miao, Hongyu; Tang, Sanyi; Wu, Hulin

    2013-06-30

    We review mathematical modeling and related statistical issues of HIV dynamics primarily in response to antiretroviral drug therapy in this article. We start from a basic model of virus infection and then review a number of more advanced models with consideration of pharmacokinetic factors, adherence and drug resistance. Specifically, we illustrate how mathematical models can be developed and parameterized to understand the effects of long-term treatment and different treatment strategies on disease progression. In addition, we discuss a variety of parameter estimation methods for differential equation models that are applicable to either within- or between-host viral dynamics.

  11. Modeling Antiretroviral Drug Responses for HIV-1 infected Patients Using Differential Equation Models

    PubMed Central

    Xiao, Yanni; Miao, Hongyu; Tang, Sanyi; Wu, Hulin

    2014-01-01

    Summary We review mathematical modeling and related statistical issues of HIV dynamics primarily in response to antiretroviral drug therapy in this article. We start from a basic model of virus infection and then review a number of more advanced models with considering, e.g., pharmacokinetic factors, adherence and drug resistance. Specifically, we illustrate how mathematical models can be developed and parameterized to understand effects of long-term treatment and different treatment strategies on disease progression. In addition, we discuss a variety of parameter estimation methods for differential equation models that are applicable to either within- or between-host viral dynamics. PMID:23603208

  12. The HIV-1 capsid protein as a drug target: recent advances and future prospects.

    PubMed

    Domenech, Rosa; Neira, José L

    2013-12-01

    HIV-1, the agent responsible for AIDS, belongs to the retrovirus family. Assembly of the immature HIV-1 capsid occurs through the controlled polymerization of the Gag polyprotein, which is transported to the plasma membrane of infected cells, where morphogenesis of the immature, non-infectious virion occurs. Moreover, the mature capsid of HIV-1 is formed by the assembly of copies of the capsid protein (CA), which results, among other proteins, from cleavage of Gag. The C-terminal domain of CA (CTD) can homodimerize, and most of the dimerization interface is formed by a single α-helix from each monomer. Assembly of the HIV-1 capsid critically depends on CA-CA interactions, including CTD interaction with itself and with the N-terminal domain of CA (NTD). This review will report on recent advances for the search of small organic compounds and peptides that have been designed in the last four years to hamper CA assembly. Most of the molecules have been proved to interact with CA; such molecules aim to disrupt and/or alter the oligomerization capability of CTD and/or NTD.

  13. Outwitting Evolution: Fighting Drug Resistance in the Treatment of TB, Malaria and HIV

    PubMed Central

    Goldberg, Daniel E.; Siliciano, Robert F.; Jacobs, William R.

    2012-01-01

    Although caused by vastly different pathogens, the world’s three most serious infectious diseases, tuberculosis, malaria and HIV-1 infection, share the common problem of drug resistance. The pace of drug development has been very slow for tuberculosis and malaria and rapid for HIV-1. But for each disease, resistance to most drugs has appeared quickly after the introduction of the drug. Learning how to manage and prevent resistance is a major medical challenge that requires an understanding of the evolutionary dynamics of each pathogen. This review summarized the similarities and differences in the evolution of drug resistance for these three pathogens. PMID:22424234

  14. Resistance to human immunodeficiency virus type 1 (HIV-1) generated by lentivirus vector-mediated delivery of the CCR5{Delta}32 gene despite detectable expression of the HIV-1 co-receptors.

    PubMed

    Jin, Qingwen; Marsh, Jon; Cornetta, Kenneth; Alkhatib, Ghalib

    2008-10-01

    It has previously been demonstrated that there are two distinct mechanisms for genetic resistance to human immunodeficiency virus type 1 (HIV-1) conferred by the CCR5Delta32 gene: the loss of wild-type CCR5 surface expression and the generation of CCR5Delta32 protein, which interacts with CXCR4. To analyse the protective effects of long-term expression of the CCR5Delta32 protein, recombinant lentiviral vectors were used to deliver the CCR5Delta32 gene into human cell lines and primary peripheral blood mononuclear cells that had been immortalized by human T-cell leukemia virus type 1. Blasticidin S-resistant cell lines expressing the lentivirus-encoded CCR5Delta32 showed a significant reduction in HIV-1 Env-mediated fusion assays. It was shown that CD4(+) T lymphocytes expressing the lentivirus-encoded CCR5Delta32 gene were highly resistant to infection by a primary but not by a laboratory-adapted X4 strain, suggesting different infectivity requirements. In contrast to previous studies that analysed the CCR5Delta32 protective effects in a transient expression system, this study showed that long-term expression of CCR5Delta32 conferred resistance to HIV-1 despite cell-surface expression of the HIV co-receptors. The results suggest an additional unknown mechanism for generating the CCR5Delta32 resistance phenotype and support the hypothesis that the CCR5Delta32 protein acts as an HIV-suppressive factor by altering the stoichiometry of the molecules involved in HIV-1 entry. The lentiviral-CCR5Delta32 vectors offer a method of generating HIV-resistant cells by delivery of the CCR5Delta32 gene that may be useful for stem cell- or T-cell-based gene therapy for HIV-1 infection.

  15. Strain-Specific V3 and CD4 Binding Site Autologous HIV-1 Neutralizing Antibodies Select Neutralization-Resistant Viruses

    SciTech Connect

    Moody, M.  Anthony; Gao, Feng; Gurley, Thaddeus  C.; Amos, Joshua  D.; Kumar, Amit; Hora, Bhavna; Marshall, Dawn  J.; Whitesides, John  F.; Xia, Shi-Mao; Parks, Robert; Lloyd, Krissey  E.; Hwang, Kwan-Ki; Lu, Xiaozhi; Bonsignori, Mattia; Finzi, Andrés; Vandergrift, Nathan  A.; Alam, S.  Munir; Ferrari, Guido; Shen, Xiaoying; Tomaras, Georgia  D.; Kamanga, Gift; Cohen, Myron  S.; Sam, Noel  E.; Kapiga, Saidi; Gray, Elin S.; Tumba, Nancy  L.; Morris, Lynn; Zolla-Pazner, Susan; Gorny, Miroslaw  K.; Mascola, John  R.; Hahn, Beatrice H.; Shaw, George  M.; Sodroski, Joseph  G.; Liao, Hua-Xin; Montefiori, David C.; Hraber, Peter T.; Korber, Bette T.; Haynes, Barton F.

    2015-09-09

    The third variable (V3) loop and the CD4 binding site (CD4bs) of the viral envelope are frequently targeted by neutralizing antibodies (nAbs) in HIV-1-infected individuals. In chronic infection, virus escape mutants repopulate the plasma and V3 and CD4bs nAbs emerge that can neutralize heterologous tier 1 easy-to-neutralize, but not tier 2 difficult-to-neutralize HIV-1 isolates. However, neutralization sensitivity of autologous plasma viruses to this type of nAb response has not been studied. We describe the development and evolution in vivo of antibodies distinguished by their target specificity for V3and CD4bs epitopes on autologous tier 2 viruses but not on heterologous tier 2 viruses. A surprisingly high fraction of autologous circulating viruses was sensitive to these antibodies. These findings demonstrate a role for V3 and CD4bs antibodies in constraining the native envelope trimer in vivo to a neutralization-resistant phenotype, explaining why HIV-1 transmission generally occurs by tier 2 neutralization-resistant viruses.

  16. Strain-Specific V3 and CD4 Binding Site Autologous HIV-1 Neutralizing Antibodies Select Neutralization-Resistant Viruses

    DOE PAGES

    Moody, M.  Anthony; Gao, Feng; Gurley, Thaddeus  C.; ...

    2015-09-09

    The third variable (V3) loop and the CD4 binding site (CD4bs) of the viral envelope are frequently targeted by neutralizing antibodies (nAbs) in HIV-1-infected individuals. In chronic infection, virus escape mutants repopulate the plasma and V3 and CD4bs nAbs emerge that can neutralize heterologous tier 1 easy-to-neutralize, but not tier 2 difficult-to-neutralize HIV-1 isolates. However, neutralization sensitivity of autologous plasma viruses to this type of nAb response has not been studied. We describe the development and evolution in vivo of antibodies distinguished by their target specificity for V3and CD4bs epitopes on autologous tier 2 viruses but not on heterologous tiermore » 2 viruses. A surprisingly high fraction of autologous circulating viruses was sensitive to these antibodies. These findings demonstrate a role for V3 and CD4bs antibodies in constraining the native envelope trimer in vivo to a neutralization-resistant phenotype, explaining why HIV-1 transmission generally occurs by tier 2 neutralization-resistant viruses.« less

  17. Resistance-associated epitopes of HIV-1C-highly probable candidates for a multi-epitope vaccine.

    PubMed

    Sundaramurthi, Jagadish Chandrabose; Swaminathan, Soumya; Hanna, Luke Elizabeth

    2012-10-01

    Earlier studies have identified a large number of immunogenic epitopes in HIV-1. Efforts are required to prioritize these epitopes in order to identify the best candidates for formulating an effective multi-epitope vaccine for HIV. We modeled 155 known cytotoxic T lymphocyte epitopes of HIV-1 subtype C on the 3D structure of HLA-A*0201, HLA-B*2705, and HLA-B*5101 using MODPROPEP, as these alleles are known to be associated with resistance to HIV/slow progression to AIDS. Thirty-six epitopes were identified to bind to all the three HLA alleles with better binding affinity than the control peptides complexed with each HLA allele but not to any of the HLA alleles reported to be associated with susceptibility to HIV infection/rapid progression to disease. As increase in stability of the epitope-HLA complex results in increased immunogenicity, the short-listed epitopes could be suitable candidates for vaccine development. Twenty of the 36 epitopes were polyfunctional in nature adding to their immunological relevance for vaccine design. Further, 9 of the 20 polyfunctional epitopes were found to bind to all three resistance-associated HLA alleles using an additional method, adding worth to their potential as candidates for a vaccine formulation for HIV-1C.

  18. Resistance detected by pyrosequencing following zidovudine monotherapy for prevention of HIV-1 mother-to-child-transmission.

    PubMed

    Olson, Scott C; Ngo-Giang-Huong, Nicole; Beck, Ingrid; Deng, Wenjie; Britto, Paula; Shapiro, David E; Bumgarner, Roger E; Mullins, James I; Van Dyke, Russell B; Jourdain, Gonzague; Frenkel, Lisa M

    2015-07-31

    To prevent mother-to-child-transmission of HIV-1, the 2010 WHO guidelines recommended prenatal zidovudine (ZDV) monotherapy (option A). To determine if ZDV monotherapy selects for HIV resistance in antiretroviral-naive women during pregnancy, specimens from 50 individuals were examined using pyrosequencing. ZDV-resistance mutations were detected at delivery in seven women (14%, 95% confidence interval 6.6-26.5%). These data raise the question whether women administered ZDV monotherapy for prevention of mother-to-child-transmission could have higher risk of virologic failure when later started on combination antiretroviral therapy, as has been demonstrated following single-dose nevirapine prophylaxis.

  19. HIV-1 Genital Shedding is Suppressed in the Setting of High Genital Antiretroviral Drug Concentrations Throughout the Menstrual Cycle

    PubMed Central

    Sheth, Anandi N.; Evans-Strickfaden, Tammy; Haaland, Richard; Martin, Amy; Gatcliffe, Chelsea; Adesoye, Adebola; Omondi, Michael W.; Lupo, L. Davis; Danavall, Damien; Easley, Kirk; Chen, Cheng-Yen; Pau, Chou-Pong; Hart, Clyde; Ofotokun, Igho

    2014-01-01

    Background. It is not known if fluctuations in genital tract antiretroviral drug concentrations correlate with genital virus shedding in human immunodeficiency virus (HIV)–infected women on antiretroviral therapy (ART). Methods. Among 20 HIV-infected women on ART (tenofovir [TFV], emtricitabine [FTC], and ritonavir-boosted atazanavir [ATV]) with suppressed plasma virus loads, blood and cervicovaginal samples collected twice weekly for 3 weeks were tested for antiretroviral concentrations, HIV-1 RNA, and proviral DNA. Results. Cervicovaginal:plasma antiretroviral concentration ratios were highest for FTC (11.9, 95% confidence interval [CI], 8.66–16.3), then TFV (3.52, 95% CI, 2.27–5.48), and ATV (2.39, 95% CI, 1.69–3.38). Within- and between-person variations in plasma and genital antiretroviral concentrations were observed. Low amounts of genital HIV-1 RNA (<50 copies/mL) were detected in 45% of women at 16% of visits. Genital HIV-1 DNA was detected in 70% of women at 35% of visits. Genital virus detection was associated with higher concentrations of mucosal leukocytes but not with genital antiretroviral concentrations, menstrual cycle phase, bacterial vaginosis, genital bleeding, or plasma virus detection. Conclusions. Standard doses of ART achieved higher genital than plasma concentrations across the menstrual cycle. Therapeutic ART suppresses genital virus shedding throughout the menstrual cycle, even in the presence of factors reported to increase virus shedding. PMID:24643223

  20. Evolution of HIV-1 isolates that use a novel Vif-independent mechanism to resist restriction by human APOBEC3G.

    PubMed

    Haché, Guylaine; Shindo, Keisuke; Albin, John S; Harris, Reuben S

    2008-06-03

    The human APOBEC3G protein restricts the replication of Vif-deficient HIV-1 by deaminating nascent viral cDNA cytosines to uracils, leading to viral genomic strand G-to-A hypermutations. However, the HIV-1 Vif protein triggers APOBEC3G degradation, which helps to explain why this innate defense does not protect patients. The APOBEC3G-Vif interaction is a promising therapeutic target, but the benefit of the enabling of HIV-1 restriction in patients is unlikely to be known until Vif antagonists are developed. As a necessary prelude to such studies, cell-based HIV-1 evolution experiments were done to find out whether APOBEC3G can provide a long-term block to Vif-deficient virus replication and, if so, whether HIV-1 variants that resist restriction would emerge. APOBEC3G-expressing T cells were infected with Vif-deficient HIV-1. Virus infectivity was suppressed in 45/48 cultures for more than five weeks, but replication was eventually detected in three cultures. Virus-growth characteristics and sequencing demonstrated that these isolates were still Vif-deficient and that in fact, these viruses had acquired a promoter mutation and a Vpr null mutation. Resistance occurred by a novel tolerance mechanism in which the resistant viruses packaged less APOBEC3G and accumulated fewer hypermutations. These data support the development of antiretrovirals that antagonize Vif and thereby enable endogenous APOBEC3G to suppress HIV-1 replication.

  1. 4E10-Resistant HIV-1 Isolated from Four Subjects with Rare Membrane-Proximal External Region Polymorphisms

    PubMed Central

    Nakamura, Kyle J.; Gach, Johannes S.; Jones, Laura; Semrau, Katherine; Walter, Jan; Bibollet-Ruche, Frederic; Decker, Julie M.; Heath, Laura; Decker, William D.; Sinkala, Moses; Kankasa, Chipepo; Thea, Donald; Mullins, James; Kuhn, Louise; Zwick, Michael B.; Aldrovandi, Grace M.

    2010-01-01

    Human antibody 4E10 targets the highly conserved membrane-proximal external region (MPER) of the HIV-1 transmembrane glycoprotein, gp41, and has extraordinarily broad neutralizing activity. It is considered by many to be a prototype for vaccine development. In this study, we describe four subjects infected with viruses carrying rare MPER polymorphisms associated with resistance to 4E10 neutralization. In one case resistant virus carrying a W680G substitution was transmitted from mother to infant. We used site-directed mutagenesis to demonstrate that the W680G substitution is necessary for conferring the 4E10-resistant phenotype, but that it is not sufficient to transfer the phenotype to a 4E10-sensitive Env. Our third subject carried Envs with a W680R substitution causing variable resistance to 4E10, indicating that residues outside the MPER are required to confer the phenotype. A fourth subject possessed a F673L substitution previously associated with 4E10 resistance. For all three subjects with W680 polymorphisms, we observed additional residues in the MPER that co-varied with position 680 and preserved charged distributions across this region. Our data provide important caveats for vaccine development targeting the MPER. Naturally occurring Env variants described in our study also represent unique tools for probing the structure-function of HIV-1 envelope. PMID:20352106

  2. Development of Nevirapine Resistance in Children Exposed to the Prevention of Mother-to-Child HIV-1 Transmission Programme in Maputo, Mozambique

    PubMed Central

    Antunes, Francisco; Zindoga, Pereira; Gomes, Perpétua; Augusto, Orvalho; Mahumane, Isabel; Veloso, Luís; Valadas, Emília; Camacho, Ricardo

    2015-01-01

    Background Single-dose nevirapine (sd-NVP) has been the main option for prevention of mother-to-child transmission (PMTCT) of HIV-1 in low-resource settings. However, sd-NVP can induce the selection of HIV-1 resistant mutations in mothers and infants. In Mozambique, there are limited data regarding the profile of NVP resistance associated mutations (RAM) in the context of PMTCT. Objectives To assess the prevalence and the factors associated with NVP RAM among children born to HIV-1 infected mothers enrolled in the PMTCT programme adopted in Mozambique. Methods One hundred and fifty seven children aged 6 to 48 weeks were sequentially included (July 2011 to March 2012) at four centres in Maputo. Genotyping of RAM was performed in samples with HIV-1 RNA≥ 100 copies/μL (Viroseq). Sequencing was performed with ABI 3100 (Applied Biosystems). Logistic regression modelling was undertaken to identify the factors associated with NVP RAM. Results Seventy-nine children had their samples genotyped. Their median age was 7.0 (3–12) months and 92.4% received prophylaxis with sd-NVP at birth plus daily NVP. 35.4% of mothers received antiretrovirals (ARVs) for PMTCT. ARV RAM were detected in 43 (54.4%) of the children. 45.6% of these children had at least one NVP RAM. The most common mutations associated with NVP resistance were K103N (n = 16) and Y181C (n = 15). NVP RAM was significantly associated with mother exposure to PMTCT (crude odds ratio [OR] 30.3, 95% CI 4.93–186.34) and with mother’s CD4 count < 350 cells/mm3 (crude OR 3.08, 95% CI 1.02–9.32). In the multivariable analysis the mother’s exposure to PMTCT was the only variable significantly associated with NVP RAM (adjusted OR 48.65, 95% CI 9.33–253.66). Conclusions We found a high prevalence of NVP RAM among children who were exposed to the drug regimen for PMTCT in Mozambique. The mothers’ exposure to PMTCT significantly increased the risk of NVP RAM. PMID:26161559

  3. Crystal structures of multidrug-resistant HIV-1 protease in complex with two potent anti-malarial compounds

    SciTech Connect

    Yedidi, Ravikiran S.; Liu, Zhigang; Wang, Yong; Brunzelle, Joseph S.; Kovari, Iulia A.; Woster, Patrick M.; Kovari, Ladislau C.; Gupta, Deepak

    2012-06-19

    Two potent inhibitors (compounds 1 and 2) of malarial aspartyl protease, plasmepsin-II, were evaluated against wild type (NL4-3) and multidrug-resistant clinical isolate 769 (MDR) variants of human immunodeficiency virus type-1 (HIV-1) aspartyl protease. Enzyme inhibition assays showed that both 1 and 2 have better potency against NL4-3 than against MDR protease. Crystal structures of MDR protease in complex with 1 and 2 were solved and analyzed. Crystallographic analysis revealed that the MDR protease exhibits a typical wide-open conformation of the flaps (Gly48 to Gly52) causing an overall expansion in the active site cavity, which, in turn caused unstable binding of the inhibitors. Due to the expansion of the active site cavity, both compounds showed loss of direct contacts with the MDR protease compared to the docking models of NL4-3. Multiple water molecules showed a rich network of hydrogen bonds contributing to the stability of the ligand binding in the distorted binding pockets of the MDR protease in both crystal structures. Docking analysis of 1 and 2 showed a decrease in the binding affinity for both compounds against MDR supporting our structure-function studies. Thus, compounds 1 and 2 show promising inhibitory activity against HIV-1 protease variants and hence are good candidates for further development to enhance their potency against NL4-3 as well as MDR HIV-1 protease variants.

  4. Pharmacotherapy of HIV-1 Infection: Focus on CCR5 Antagonist Maraviroc

    PubMed Central

    Latinovic, Olga; Kuruppu, Janaki; Davis, Charles; Le, Nhut; Heredia, Alonso

    2009-01-01

    Sustained inhibition of HIV-1, the goal of antiretroviral therapy, is often impeded by the emergence of viral drug resistance. For patients infected with HIV-1 resistant to conventional drugs from the viral reverse transcriptase and protease inhibitor classes, the recently approved entry and integration inhibitors effectively suppress HIV-1 and offer additional therapeutic options. Entry inhibitors are particularly attractive because, unlike conventional antiretrovirals, they target HIV-1 extracellularly, thereby sparing cells from both viral- and drug-induced toxicities. The fusion inhibitor enfuvirtide and the CCR5 antagonist maraviroc are the first entry inhibitors licensed for patients with drug-resistant HIV-1, with maraviroc restricted to those infected with CCR5-tropic HIV-1 (R5 HIV-1) only. Vicriviroc (another CCR5 antagonist) is in Phase III clinical trials, whereas the CCR5 antibodies PRO 140 and HGS 004 are in early stages of clinical development. Potent antiviral synergy between maraviroc and CCR5 antibodies, coupled with distinct patterns of resistance, suggest their combinations might be particularly effective in patients. In addition, given that oral administration of maraviroc achieves high drug levels in cervicovaginal fluid, combinations of maraviroc and other CCR5 inhibitors could be effective in preventing HIV-1 transmission. Moreover, since CCR5 antagonists prevent rejection of transplanted organs, maraviroc could both suppress HIV-1 and prolong organ survival for the growing number of HIV-1 patients with kidney or liver failure necessitating organ transplantation. Thus, maraviroc offers an important treatment option for patients with drug-resistant R5 HIV-1, who presently account for >50% of drug-resistance cases. PMID:19920876

  5. Effects of sequence changes in the HIV-1 gp41 fusion peptide on CCR5 inhibitor resistance

    SciTech Connect

    Anastassopoulou, Cleo G.; Ketas, Thomas J.; Sanders, Rogier W.; Johan Klasse, Per; Moore, John P.

    2012-07-05

    A rare pathway of HIV-1 resistance to small molecule CCR5 inhibitors such as Vicriviroc (VCV) involves changes solely in the gp41 fusion peptide (FP). Here, we show that the G516V change is critical to VCV resistance in PBMC and TZM-bl cells, although it must be accompanied by either M518V or F519I to have a substantial impact. Modeling VCV inhibition data from the two cell types indicated that G516V allows both double mutants to use VCV-CCR5 complexes for entry. The model further identified F519I as an independent determinant of preference for the unoccupied, high-VCV affinity form of CCR5. From inhibitor-free reversion cultures, we also identified a substitution in the inner domain of gp120, T244A, which appears to counter the resistance phenotype created by the FP substitutions. Examining the interplay of these changes will enhance our understanding of Env complex interactions that influence both HIV-1 entry and resistance to CCR5 inhibitors.

  6. Activity of the HIV-1 Attachment Inhibitor BMS-626529, the Active Component of the Prodrug BMS-663068, against CD4-Independent Viruses and HIV-1 Envelopes Resistant to Other Entry Inhibitors

    PubMed Central

    Li, Zhufang; Zhou, Nannan; Sun, Yongnian; Ray, Neelanjana; Lataillade, Max; Hanna, George J.

    2013-01-01

    BMS-626529 is a novel small-molecule HIV-1 attachment inhibitor active against both CCR5- and CXCR4-tropic viruses. BMS-626529 functions by preventing gp120 from binding to CD4. A prodrug of this compound, BMS-663068, is currently in clinical development. As a theoretical resistance pathway to BMS-663068 could be the development of a CD4-independent phenotype, we examined the activity of BMS-626529 against CD4-independent viruses and investigated whether resistance to BMS-626529 could be associated with a CD4-independent phenotype. Finally, we evaluated whether cross-resistance exists between BMS-626529 and other HIV-1 entry inhibitors. Two laboratory-derived envelopes with a CD4-independent phenotype (one CXCR4 tropic and one CCR5 tropic), five envelopes from clinical isolates with preexisting BMS-626529 resistance, and several site-specific mutant BMS-626529-resistant envelopes were examined for their dependence on CD4 for infectivity or susceptibility to BMS-626529. Viruses resistant to other entry inhibitors (enfuvirtide, maraviroc, and ibalizumab) were also examined for susceptibility to BMS-626529. Both CD4-independent laboratory isolates retained sensitivity to BMS-626529 in CD4− cells, while HIV-1 envelopes from viruses resistant to BMS-626529 exhibited no evidence of a CD4-independent phenotype. BMS-626529 also exhibited inhibitory activity against ibalizumab- and enfuvirtide-resistant envelopes. While there appeared to be some association between maraviroc resistance and reduced susceptibility to BMS-626529, an absolute correlation cannot be presumed, since some CCR5-tropic maraviroc-resistant envelopes remained sensitive to BMS-626529. Clinical use of the prodrug BMS-663068 is unlikely to promote resistance via generation of CD4-independent virus. No cross-resistance between BMS-626529 and other HIV entry inhibitors was observed, which could allow for sequential or concurrent use with different classes of entry inhibitors. PMID:23774428

  7. Activity of the HIV-1 attachment inhibitor BMS-626529, the active component of the prodrug BMS-663068, against CD4-independent viruses and HIV-1 envelopes resistant to other entry inhibitors.

    PubMed

    Li, Zhufang; Zhou, Nannan; Sun, Yongnian; Ray, Neelanjana; Lataillade, Max; Hanna, George J; Krystal, Mark

    2013-09-01

    BMS-626529 is a novel small-molecule HIV-1 attachment inhibitor active against both CCR5- and CXCR4-tropic viruses. BMS-626529 functions by preventing gp120 from binding to CD4. A prodrug of this compound, BMS-663068, is currently in clinical development. As a theoretical resistance pathway to BMS-663068 could be the development of a CD4-independent phenotype, we examined the activity of BMS-626529 against CD4-independent viruses and investigated whether resistance to BMS-626529 could be associated with a CD4-independent phenotype. Finally, we evaluated whether cross-resistance exists between BMS-626529 and other HIV-1 entry inhibitors. Two laboratory-derived envelopes with a CD4-independent phenotype (one CXCR4 tropic and one CCR5 tropic), five envelopes from clinical isolates with preexisting BMS-626529 resistance, and several site-specific mutant BMS-626529-resistant envelopes were examined for their dependence on CD4 for infectivity or susceptibility to BMS-626529. Viruses resistant to other entry inhibitors (enfuvirtide, maraviroc, and ibalizumab) were also examined for susceptibility to BMS-626529. Both CD4-independent laboratory isolates retained sensitivity to BMS-626529 in CD4(-) cells, while HIV-1 envelopes from viruses resistant to BMS-626529 exhibited no evidence of a CD4-independent phenotype. BMS-626529 also exhibited inhibitory activity against ibalizumab- and enfuvirtide-resistant envelopes. While there appeared to be some association between maraviroc resistance and reduced susceptibility to BMS-626529, an absolute correlation cannot be presumed, since some CCR5-tropic maraviroc-resistant envelopes remained sensitive to BMS-626529. Clinical use of the prodrug BMS-663068 is unlikely to promote resistance via generation of CD4-independent virus. No cross-resistance between BMS-626529 and other HIV entry inhibitors was observed, which could allow for sequential or concurrent use with different classes of entry inhibitors.

  8. Preventing and managing antiretroviral drug resistance.

    PubMed

    Kuritzkes, Daniel R

    2004-05-01

    Development of resistance to antiretroviral drugs (ARVs) is a major impediment to optimum treatment of HIV-1 infection. Although resistance testing can help to select subsequent regimens when virologic failure occurs, cross-resistance, which affects all classes of ARVs, may make it more difficult to achieve optimum control of HIV. We have known for some time that our first choice of antiretroviral therapy offers the best chance to control HIV replication and that initial therapy should be selected with an eye on future options. Potency is the first line of defense against the development of resistance. Other factors that affect resistance development include: tolerability, potential for optimum adherence, and genetic and pharmacologic barriers to development of resistance. If resistance emerges, only a single drug may be affected initially, and a rapid change in ARVs may preserve the efficacy of other components. One cautionary note is that we can no longer assume that a patient's HIV is fully susceptible to all ARVs even in the initial regimen. Transmission of drug-resistant HIV means that the genetic composition may be that of an "experienced" virus with reduced susceptibility to ARVs. Resistance testing at the time of transmission is most likely to reveal this resistance, but over time the dominant genetic pattern may revert to wild-type, and be missed by resistance testing. Because "archived" resistant HIV may emerge quickly once treatment is initiated, we need to keep this in mind when selecting initial therapy.

  9. Design, Synthesis, and Preclinical Evaluations of Novel 4-Substituted 1,5-Diarylanilines as Potent HIV-1 Non-Nucleoside Reverse Transcriptase Inhibitor (NNRTI) Drug Candidates

    PubMed Central

    Sun, Lian-Qi; Zhu, Lei; Qian, Keduo; Qin, Bingjie; Huang, Li; Chen, Chin Ho; Lee, Kuo-Hsiung; Xie, Lan

    2012-01-01

    Twenty-one new 4-substituted diarylaniline compounds (DAANs) (Scheme 2, series 13, 14, and 15) were designed, synthesized, and evaluated against wild-type and drug resistant HIV-1 viral strains. As a result, approximately a dozen new DAANs showed high potency with low nano- to sub-nanomolar EC50 values ranging from 0.2 to 10 nM. The three most promising compounds 14e, 14h, and 15h exhibited high potency against wild-type and drug-resistant viral strains with EC50 values at the sub-nanomolar level (0.29–0.87 nM), and were comparable to or more potent than the new NNRTI drug riplivirine (2) in the same assays. Drug-like physicochemical property assessments revealed that the most active DAANs (EC50 <10 nM) have better aqueous solubility (>1–90 μg/mL at pH 7.4 and pH 2) and metabolic stability in vitro than 2, as well as desirable log P values (<5) and polar surface area (PSA) (<140 Å2). These promising results warrant further development of this novel compound class as potential potent anti-AIDS clinical trial candidates. PMID:22856541

  10. Effects of Short-Course Zidovudine on the Selection of Nevirapine-Resistant HIV-1 in Women Taking Single-Dose Nevirapine

    PubMed Central

    Micek, Mark A.; Blanco, Ana Judith; Carlsson, Jacquelyn; Beck, Ingrid A.; Dross, Sandra; Matunha, Laurinda; Seidel, Kristy; Montoya, Pablo; Gantt, Soren; Matediana, Eduardo; Jamisse, Lilia; Gloyd, Stephen; Frenkel, Lisa M.

    2012-01-01

    Single-dose nevirapine (sdNVP) given to prevent mother-to-child-transmission of HIV-1 selects NVP-resistance. Short-course zidovudine (ZDV) was hypothesized to lower rates of NVP-resistance. HIV-1 infected pregnant women administered sdNVP with or without short-course ZDV were assessed for HIV-1 mutations (K103N, Y181C, G190A, and V106M) prior to delivery and postpartum. Postpartum NVP-resistance was lower among 31 taking ZDV+sdNVP compared to 33 taking only sdNVP (35.5% vs 72.7%; χ2 P = .003). NVP mutants decayed to <2% in 24/35 (68.6%) at a median 6 months postpartum, with no differences based on ZDV use (logrank P = .99). Short-course ZDV was associated with reduced NVP-resistance mutations among women taking sdNVP. PMID:22492850

  11. Ethics and drug resistance.

    PubMed

    Selgelid, Michael J

    2007-05-01

    This paper reviews the dynamics behind, and ethical issues associated with, the phenomenon of drug resistance. Drug resistance is an important ethical issue partly because of the severe consequences likely to result from the increase in drug resistant pathogens if more is not done to control them. Drug resistance is also an ethical issue because, rather than being a mere quirk of nature, the problem is largely a product of drug distribution. Drug resistance results from the over-consumption of antibiotics by the wealthy; and it, ironically, results from the under-consumption of antibiotics, usually by the poor or otherwise marginalized. In both kinds of cases the phenomenon of drug resistance illustrates why health (care)--at least in the context of infectious disease--should be treated as a (global) public good. The point is that drug resistance involves 'externalities' affecting third parties. When one patient develops a resistant strain of disease because of her over- or under-consumption of medication, this more dangerous malady poses increased risk to others. The propriety of free-market distribution of goods subject to externalities is famously dubious--given that the 'efficiency' rationale behind markets assumes an absence of externalities. Market failure in the context of drug resistance is partly revealed by the fact that no new classes of antibiotics have been developed since 1970. I conclude by arguing that the case of drug resistance reveals additional reasons--to those traditionally appealed to by bioethicists--for treating health care as something special when making policy decisions about its distribution.

  12. Hybrid Ty1/HIV-1 elements used to detect inhibitors and monitor the activity of HIV-1 reverse transcriptase

    PubMed Central

    Nissley, Dwight V.; Boyer, Paul L.; Garfinkel, David J.; Hughes, Stephen H.; Strathern, Jeffrey N.

    1998-01-01

    We previously demonstrated that hybrid retrotransposons composed of the yeast Ty1 element and the reverse transcriptase (RT) of HIV-1 are active in the yeast Saccharomyces cerevisiae. The RT activity of these hybrid Ty1/HIV-1 (his3AI/AIDS RT; HART) elements can be monitored by using a simple genetic assay. HART element reverse transcription depends on both the polymerase and RNase H domains of HIV-1 RT. Here we demonstrate that the HART assay is sensitive to inhibitors of HIV-1 RT. (−)-(S)-8-Chloro-4,5,6,7-tetrahydro-5-methyl-6-(3-methyl-2-butenyl)imidazo[4,5,1-jk][1,4]-benzodiazepin-2(1H)-thione monohydrochloride (8 Cl-TIBO), a well characterized non-nucleoside RT inhibitor (NNRTI) of HIV-1 RT, blocks propagation of HART elements. HART elements that express NNRTI-resistant RT variants of HIV-1 are insensitive to 8 Cl-TIBO, demonstrating the specificity of inhibition in this assay. HART elements carrying NNRTI-resistant variants of HIV-1 RT can be used to identify compounds that are active against drug-resistant viruses. PMID:9811899

  13. Abacavir, an anti-HIV-1 drug, targets TDP1-deficient adult T cell leukemia.

    PubMed

    Tada, Kohei; Kobayashi, Masayuki; Takiuchi, Yoko; Iwai, Fumie; Sakamoto, Takashi; Nagata, Kayoko; Shinohara, Masanobu; Io, Katsuhiro; Shirakawa, Kotaro; Hishizawa, Masakatsu; Shindo, Keisuke; Kadowaki, Norimitsu; Hirota, Kouji; Yamamoto, Junpei; Iwai, Shigenori; Sasanuma, Hiroyuki; Takeda, Shunichi; Takaori-Kondo, Akifumi

    2015-04-01

    Adult T cell leukemia (ATL) is an aggressive T cell malignancy caused by human T cell leukemia virus type 1 (HTLV-1) and has a poor prognosis. We analyzed the cytotoxic effects of various nucleoside analog reverse transcriptase inhibitors (NRTIs) for HIV-1 on ATL cells and found that abacavir potently and selectively kills ATL cells. Although NRTIs have minimal genotoxicities on host cells, the therapeutic concentration of abacavir induced numerous DNA double-strand breaks (DSBs) in the chromosomal DNA of ATL cells. DSBs persisted over time in ATL cells but not in other cell lines, suggesting impaired DNA repair. We found that the reduced expression of tyrosyl-DNA phosphodiesterase 1 (TDP1), a repair enzyme, is attributable to the cytotoxic effect of abacavir on ATL cells. We also showed that TDP1 removes abacavir from DNA ends in vitro. These results suggest a model in which ATL cells with reduced TDP1 expression are unable to excise abacavir incorporated into genomic DNA, leading to irreparable DSBs. On the basis of the above mechanism, we propose abacavir as a promising chemotherapeutic agent for ATL.

  14. Neuronal Stress and Injury Caused by HIV-1, cART and Drug Abuse: Converging Contributions to HAND.

    PubMed

    Sanchez, Ana B; Kaul, Marcus

    2017-02-23

    Multiple mechanisms appear to contribute to neuronal stress and injury underlying HIV-associated neurocognitive disorders (HAND), which occur despite the successful introduction of combination antiretroviral therapy (cART). Evidence is accumulating that components of cART can itself be neurotoxic upon long-term exposure. In addition, abuse of psychostimulants, such as methamphetamine (METH), seems to compromise antiretroviral therapy and aggravate HAND. However, the combined effect of virus and recreational and therapeutic drugs on the brain is still incompletely understood. However, several lines of evidence suggest a shared critical role of oxidative stress, compromised neuronal energy homeostasis and autophagy in promotion and prevention of neuronal dysfunction associated with HIV-1 infection, cART and psychostimulant use. In this review, we present a synopsis of recent work related to neuronal stress and injury induced by HIV infection, antiretrovirals (ARVs) and the highly addictive psychostimulant METH.

  15. Neuronal Stress and Injury Caused by HIV-1, cART and Drug Abuse: Converging Contributions to HAND

    PubMed Central

    Sanchez, Ana B.; Kaul, Marcus

    2017-01-01

    Multiple mechanisms appear to contribute to neuronal stress and injury underlying HIV-associated neurocognitive disorders (HAND), which occur despite the successful introduction of combination antiretroviral therapy (cART). Evidence is accumulating that components of cART can itself be neurotoxic upon long-term exposure. In addition, abuse of psychostimulants, such as methamphetamine (METH), seems to compromise antiretroviral therapy and aggravate HAND. However, the combined effect of virus and recreational and therapeutic drugs on the brain is still incompletely understood. However, several lines of evidence suggest a shared critical role of oxidative stress, compromised neuronal energy homeostasis and autophagy in promotion and prevention of neuronal dysfunction associated with HIV-1 infection, cART and psychostimulant use. In this review, we present a synopsis of recent work related to neuronal stress and injury induced by HIV infection, antiretrovirals (ARVs) and the highly addictive psychostimulant METH. PMID:28241493

  16. Achieving HIV-1 Control through RNA-Directed Gene Regulation

    PubMed Central

    Klemm, Vera; Mitchell, Jye; Cortez-Jugo, Christina; Cavalieri, Francesca; Symonds, Geoff; Caruso, Frank; Kelleher, Anthony Dominic; Ahlenstiel, Chantelle

    2016-01-01

    HIV-1 infection has been transformed by combined anti-retroviral therapy (ART), changing a universally fatal infection into a controllable infection. However, major obstacles for an HIV-1 cure exist. The HIV latent reservoir, which exists in resting CD4+ T cells, is not impacted by ART, and can reactivate when ART is interrupted or ceased. Additionally, multi-drug resistance can arise. One alternate approach to conventional HIV-1 drug treatment that is being explored involves gene therapies utilizing RNA-directed gene regulation. Commonly known as RNA interference (RNAi), short interfering RNA (siRNA) induce gene silencing in conserved biological pathways, which require a high degree of sequence specificity. This review will provide an overview of the silencing pathways, the current RNAi technologies being developed for HIV-1 gene therapy, current clinical trials, and the challenges faced in progressing these treatments into clinical trials. PMID:27941595

  17. Antimicrobial (Drug) Resistance

    MedlinePlus

    ... NIAID invests in basic research to understand the biology of microbes, their behavior, and how drug resistance ... Nucleotide Polymorphism Phylogenetics & Ontology Proteomics & Protein Analysis Systems Biology Data Portals Software Applications BCBB Mobyle Interface Designer ( ...

  18. Nine Crystal Structures Determine the Substrate Envelope of the MDR HIV-1 Protease

    SciTech Connect

    Liu, Zhigang; Wang, Yong; Brunzelle, Joseph; Kovari, Iulia A.; Kovari, Ladislau C.

    2012-03-27

    Under drug selection pressure, emerging mutations render HIV-1 protease drug resistant, leading to the therapy failure in anti-HIV treatment. It is known that nine substrate cleavage site peptides bind to wild type (WT) HIV-1 protease in a conserved pattern. However, how the multidrug-resistant (MDR) HIV-1 protease binds to the substrate cleavage site peptides is yet to be determined. MDR769 HIV-1 protease (resistant mutations at residues 10, 36, 46, 54, 62, 63, 71, 82, 84, and 90) was selected for present study to understand the binding to its natural substrates. MDR769 HIV-1 protease was co-crystallized with nine substrate cleavage site hepta-peptides. Crystallographic studies show that MDR769 HIV-1 protease has an expanded substrate envelope with wide open flaps. Furthermore, ligand binding energy calculations indicate weaker binding in MDR769 HIV-1 protease-substrate complexes. These results help in designing the next generation of HIV-1 protease inhibitors by targeting the MDR HIV-1 protease.

  19. Latent HIV-1 can be reactivated by cellular superinfection in a Tat-dependent manner, which can lead to the emergence of multidrug-resistant recombinant viruses.

    PubMed

    Donahue, Daniel A; Bastarache, Sophie M; Sloan, Richard D; Wainberg, Mark A

    2013-09-01

    The HIV-1 latent reservoir represents an important source of genetic diversity that could contribute to viral evolution and multidrug resistance following latent virus reactivation. This could occur by superinfection of a latently infected cell. We asked whether latent viruses might be reactivated when their host cells are superinfected, and if so, whether they could contribute to the generation of recombinant viruses. Using populations of latently infected Jurkat cells, we found that latent viruses were efficiently reactivated upon superinfection. Pathways leading to latent virus reactivation via superinfection might include gp120-CD4/CXCR4-induced signaling, modulation of the cellular environment by Nef, and/or the activity of Tat produced upon superinfection. Using a range of antiviral compounds and genetic approaches, we show that gp120 and Nef are not required for latent virus reactivation by superinfection, but this process depends on production of functional Tat by the superinfecting virus. In a primary cell model of latency in unstimulated CD4 T cells, superinfection also led to latent virus reactivation. Drug-resistant latent viruses were also reactivated following superinfection in Jurkat cells and were able to undergo recombination with the superinfecting virus. Under drug-selective pressure, this generated multidrug-resistant recombinants that were identified by unique restriction digestion band patterns and by population-level sequencing. During conditions of poor drug adherence, treatment interruption or treatment failure, or in drug-impermeable sanctuary sites, reactivation of latent viruses by superinfection or other means could provide for the emergence or spread of replicatively fit viruses in the face of strong selective pressures.

  20. The Folding Free Energy Surface of HIV-1 Protease: Insights into the Thermodynamic Basis for Resistance to Inhibitors

    PubMed Central

    Noel, Amanda F.; Bilsel, Osman; Kundu, Agnita; Wu, Ying; Zitzewitz, Jill A.; Matthews, C. Robert

    2009-01-01

    Spontaneous mutations at numerous sites distant from the active site of HIV-1 protease enable resistance to inhibitors while retaining enzymatic activity. As a benchmark for probing the effects of these mutations on the conformational adaptability of this dimeric β-barrel protein, the folding free energy surface of a pseudo wild-type variant, HIV-PR*, was determined by a combination of equilibrium and kinetic experiments on the urea-induced unfolding/refolding reactions. The equilibrium unfolding reaction was well-described by a two-state model involving only the native dimeric form and the unfolded monomer. The global analysis of the kinetic folding mechanism reveals the presence of a fully-folded monomeric intermediate that associates to form the native dimeric structure. Independent analysis of a stable monomeric version of the protease demonstrated that a small amplitude fluorescence phase in refolding and unfolding, not included in the global analysis of the dimeric protein, reflects the presence of a transient intermediate in the monomer folding reaction. The partially-folded and fully-folded monomers are only marginally stable with respect to the unfolded state, and the dimerization reaction provides a modest driving force at micromolar concentrations of protein. The thermodynamic properties of this system are such that mutations can readily shift the equilibrium from the dimeric native state towards weakly-folded states that have a lower affinity for inhibitors, but that could be induced to bind to their target proteolytic sites. Presumably, subsequent secondary mutations increase the stability of the native dimeric state in these variants and, thereby, optimize the catalytic properties of the resistant HIV-1 protease. PMID:19150359

  1. A Newly Emerging HIV-1 Recombinant Lineage (CRF58_01B) Disseminating among People Who Inject Drugs in Malaysia

    PubMed Central

    Chow, Wei Zhen; Takebe, Yutaka; Syafina, Nur Ezreen; Prakasa, Malarvelli Soorya; Chan, Kok Gan; Al-Darraji, Haider Abdulrazzaq Abed; Koh, Clayton; Kamarulzaman, Adeeba; Tee, Kok Keng

    2014-01-01

    The HIV epidemic is primarily characterised by the circulation of HIV-1 group M (main) comprising of 11 subtypes and sub-subtypes (A1, A2, B–D, F1, F2, G, H, J, and K) and to date 55 circulating recombinant forms (CRFs). In Southeast Asia, active inter-subtype recombination involving three main circulating genotypes—subtype B (including subtype B′, the Thai variant of subtype B), CRF01_AE, and CRF33_01B—have contributed to the emergence of novel unique recombinant forms. In the present study, we conducted the molecular epidemiological surveillance of HIV-1 gag-RT genes among 258 people who inject drugs (PWIDs) in Kuala Lumpur, Malaysia, between 2009 and 2011 whereby a novel CRF candidate was recently identified. The near full-length genome sequences obtained from six epidemiologically unlinked individuals showed identical mosaic structures consisting of subtype B′ and CRF01_AE, with six unique recombination breakpoints in the gag-RT, pol, and env regions. Among the high-risk population of PWIDs in Malaysia, which was predominantly infected by CRF33_01B (>70%), CRF58_01B circulated at a low but significant prevalence (2.3%, 6/258). Interestingly, the CRF58_01B shared two unique recombination breakpoints with other established CRFs in the region: CRF33_01B, CRF48_01B, and CRF53_01B in the gag gene, and CRF15_01B (from Thailand) in the env gene. Extended Bayesian Markov chain Monte Carlo sampling analysis showed that CRF58_01B and other recently discovered CRFs were most likely to have originated in Malaysia, and that the recent spread of recombinant lineages in the country had little influence from neighbouring countries. The isolation, genetic characterization, and evolutionary features of CRF58_01B among PWIDs in Malaysia signify the increasingly complex HIV-1 diversity in Southeast Asia that may hold an implication on disease treatment, control, and prevention. PMID:24465513

  2. Characterization of Gp41 polymorphisms in the fusion peptide domain and T-20 (Enfuvirtide) resistance-associated regions in Korean HIV-1 isolates.

    PubMed

    Jang, Dai-Ho; Yoon, Cheol-Hee; Choi, Byeong-Sun; Chung, Yoon-Seok; Kim, Hye-Young; Chi, Sung-Gil; Kim, Sung Soon

    2014-03-01

    HIV-1 gp41 is an envelope protein that plays an essential role in virus entry. The mutation of gp41 affects HIV-1 entry and susceptibility to the fusion inhibitor T-20. Therefore, we analyzed the natural polymorphism of gp41 of 163 HIV-1 isolates from T-20-naïve Koreans infected with HIV-1. This study of gp41 polymorphisms showed that insertions in the fourth threonine (74.8%) and L7M substitutions (85.3%) were more frequent in the fusion peptide motif in Korean HIV-1 isolates compared with those from other countries. Minor T-20 resistance mutations such as L45M (1.2%), N126K (1.2%), and E137K (6.7%) were detected, but the critical T-20 resistance mutations were not detected in the gp41 HR1 and HR2 regions. In addition, the N42S mutation (12.9%) associated with T-20 hypersusceptibility was detected at a high frequency. These results may serve as useful data for studies considering T-20 for use in the development of a more effective anti-retroviral treatment in Korea.

  3. Immunophilins and HIV-1 V3 loop for structure-based anti-AIDS drug design.

    PubMed

    Andrianov, Alexander M

    2009-02-01

    The model of the structural complex of cyclophilin A (CycA) belonging to the immunophilins family with the HIV-MN gp120 V3 loop was generated, and the computer-aided design of the immunophilin-derived peptide able to mask the biologically crucial V3 segments was implemented. To this end, the following problems were solved: (i) the NMR-based conformational analysis of the HIV-MN V3 loop was put into effect, and its low energy structure fitting the input experimental observations was determined; (ii) molecular docking of this V3 structure with the X-ray conformation of CycA was carried out, and the energy refining the simulated structural complex was performed; (iii) the matrix of inter-atomic distances for the amino acids of the molecules forming part of the built over-molecular ensemble was computed, the types of interactions responsible for its stabilization were analyzed, and the CycA stretch, which accounts for the binding to V3, was identified; (iv) the most probable 3D structure for this stretch in the unbound state was predicted, and its collation with the X-ray structure for the corresponding site of CycA was performed; (v) the potential energy function and its constituents were studied for the structural complex generated by molecular docking of the V3 loop with the CycA peptide offering the virtual molecule that imitates the CycA segment, making a key contribution to the interactions of the native protein with the HIV-1 principal neutralizing determinant; (vi) as a result of the studies above, the designed molecule was shown to be capable of the efficacious blockading the functionally crucial V3 sites; and (vii) based on the joint analysis of the evidence obtained previously and in the present study, the composition of the peptide cocktail presenting the promising anti-AIDS pharmacological substance was developed. The molecules simulated here by molecular modeling methods may become the first representatives of a new class of the chemical compounds

  4. Mutations in variable domains of the HIV-1 envelope gene can have a significant impact on maraviroc and vicriviroc resistance

    PubMed Central

    2013-01-01

    Background Resistance to CCR5 inhibitors, such as maraviroc and vicriviroc is characterized by reduction of maximal percent inhibition which indicates the use of an inhibitor-bound conformation of CCR5 for human immunodeficiency virus-1(HIV-1) entry. It is accompanied by substitutions in gp120 and gp41. Variable domain 3 (V3) plays the most important role, but substitutions outside V3 could also be involved in phenotype resistance. In this work, we investigated how mutations in variable regions of the viral envelope protein gp120 can contribute to CCR5 inhibitor resistance. Methods Resistant isolates were selected by passaging CC1/85 and BaL viruses with sub-inhibitory MVC and VCV concentrations. Mutations in gp160 were identified and mutants containing V2 (V169M), V3 (L317W) and V4 (I408T) were constructed. Results MVC and VCV susceptibility and viral tropism were assessed by single cycle assay. Mutant I408T showed 4-fold change (FC) increase in the half maximal inhibitory concentration (IC50) to MVC, followed by L317W (1.52-FC), V169M (1.23-FC), V169M/I408T (4-FC) L317W/I408T (3-FC), V169M/L317W (1.30-FC), and V169M/L317W/I408T (3.31-FC). MPI reduction was observed for mutants I408T (85%), L317W (95%), V169M/I408T (84%), L317W/I408T (85%) and V169M/L317W/I408T (83%). For VCV, I408T increased the IC50 by 2-FC and few mutants showed MPI reduction less than 95%: I408T (94%), L317W/I408T (94%) and V169M/L317W/I408T (94%). All mutants remained R5-tropic and presented decreased infectivity. Conclusions These results suggest that mutations in the V4 loop of HIV-1 may contribute to MVC and VCV resistance alone or combined with mutations in V2 and V3 loops. PMID:23758814

  5. Nevirapine Resistance in Previously Nevirapine-Unexposed HIV-1-Infected Kenyan Infants Initiating Early Antiretroviral Therapy.

    PubMed

    Chohan, Bhavna H; Tapia, Kenneth; Benki-Nugent, Sarah; Khasimwa, Brian; Ngayo, Musa; Maleche-Obimbo, Elizabeth; Wamalwa, Dalton; Overbaugh, Julie; John-Stewart, Grace

    2015-08-01

    Nevirapine (NVP) resistance occurs frequently in infants following NVP use in prevention of mother-to-child transmission (PMTCT) regimens. However, among previously NVP-unexposed infants treated with NVP-antiretroviral therapy (ART), the development and impact of NVP resistance have not been well characterized. In a prospective clinical trial providing early ART to HIV-infected infants <5 months of age in Kenya (OPH03 study), we followed NVP-unexposed infants who initiated NVP-ART for 12 months. Viral loads were assessed and resistance determined using a population-based genotypic resistance assay. Of 99 infants screened, 33 had no prior NVP exposure, 22 of whom were initiated on NVP-ART. Among 19 infants with follow-up, seven (37%) infants developed resistance: one at 3 months and six at 6 months after ART initiation. The cumulative probability of NVP resistance was 5.9% at 3 months and 43.5% at 6 months. Baseline HIV RNA levels (p=0.7) and other characteristics were not associated with developing resistance. Post-ART, higher virus levels at visits preceding the detection of resistance were significantly associated with increased detection of resistance (p=0.004). Virus levels after 6 and 12 months of ART were significantly higher in infants with resistance than those without (p=0.007, p=0.030, respectively). Among infants without previous NVP exposure, development of NVP resistance was frequent and was associated with virologic failure during the first year of ART. Earlier development of NVP resistance in infants than in adults initiating NVP-ART may be due to longer viremia following ART or inadequate NVP levels resulting from NVP lead-in dosing. The development of NVP resistance may, in part, explain the superiority of protease inhibitor-based ART in infants.

  6. Nevirapine Resistance in Previously Nevirapine-Unexposed HIV-1-Infected Kenyan Infants Initiating Early Antiretroviral Therapy

    PubMed Central

    Chohan, Bhavna H.; Tapia, Kenneth; Benki-Nugent, Sarah; Khasimwa, Brian; Ngayo, Musa; Maleche-Obimbo, Elizabeth; Wamalwa, Dalton; Overbaugh, Julie

    2015-01-01

    Abstract Nevirapine (NVP) resistance occurs frequently in infants following NVP use in prevention of mother-to-child transmission (PMTCT) regimens. However, among previously NVP-unexposed infants treated with NVP-antiretroviral therapy (ART), the development and impact of NVP resistance have not been well characterized. In a prospective clinical trial providing early ART to HIV-infected infants<5 months of age in Kenya (OPH03 study), we followed NVP-unexposed infants who initiated NVP-ART for 12 months. Viral loads were assessed and resistance determined using a population-based genotypic resistance assay. Of 99 infants screened, 33 had no prior NVP exposure, 22 of whom were initiated on NVP-ART. Among 19 infants with follow-up, seven (37%) infants developed resistance: one at 3 months and six at 6 months after ART initiation. The cumulative probability of NVP resistance was 5.9% at 3 months and 43.5% at 6 months. Baseline HIV RNA levels (p=0.7) and other characteristics were not associated with developing resistance. Post-ART, higher virus levels at visits preceding the detection of resistance were significantly associated with increased detection of resistance (p=0.004). Virus levels after 6 and 12 months of ART were significantly higher in infants with resistance than those without (p=0.007, p=0.030, respectively). Among infants without previous NVP exposure, development of NVP resistance was frequent and was associated with virologic failure during the first year of ART. Earlier development of NVP resistance in infants than in adults initiating NVP-ART may be due to longer viremia following ART or inadequate NVP levels resulting from NVP lead-in dosing. The development of NVP resistance may, in part, explain the superiority of protease inhibitor-based ART in infants. PMID:25819584

  7. Mitochondrial DNA Haplogroup A Decreases the Risk of Drug Addiction but Conversely Increases the Risk of HIV-1 Infection in Chinese Addicts.

    PubMed

    Zhang, A-Mei; Hu, Qiu-Xiang; Liu, Feng-Liang; Bi, Rui; Yang, Bi-Qing; Zhang, Wen; Guo, Hao; Logan, Ian; Zheng, Yong-Tang; Yao, Yong-Gang

    2016-08-01

    Drug addiction is one of the most serious social problems in the world today and addicts are always at a high risk of acquiring HIV infection. Mitochondrial impairment has been reported in both drug addicts and in HIV patients undergoing treatment. In this study, we aimed to investigate whether mitochondrial DNA (mtDNA) haplogroup could affect the risk of drug addiction and HIV-1 infection in Chinese. We analyzed mtDNA sequence variations of 577 Chinese intravenous drug addicts (289 with HIV-1 infection and 288 without) and compared with 2 control populations (n = 362 and n = 850). We quantified the viral load in HIV-1-infected patients with and without haplogroup A status and investigated the potential effect of haplogroup A defining variants m.4824A > G and m.8794C > T on the cellular reactive oxygen species (ROS) levels by using an allotopic expression assay. mtDNA haplogroup A had a protective effect against drug addiction but appeared to confer an increased risk of HIV infection in addicts. HIV-1-infected addicts with haplogroup A had a trend for a higher viral load, although the mean viral load was similar between carriers of haplogroup A and those with other haplogroup. Hela cells overexpressing allele m.8794 T showed significantly decreased ROS levels as compared to cells with the allele m.8794C (P = 0.03). Our results suggested that mtDNA haplogroup A might protect against drug addiction but increase the risk of HIV-1 infection. The contradictory role of haplogroup A might be caused by an alteration in mitochondrial function due to a particular mtDNA ancestral variant.

  8. Glycan Microheterogeneity at the PGT135 Antibody Recognition Site on HIV-1 gp120 Reveals a Molecular Mechanism for Neutralization Resistance

    PubMed Central

    Pritchard, Laura K.; Spencer, Daniel I. R.; Royle, Louise; Vasiljevic, Snezana; Krumm, Stefanie A.; Doores, Katie J.

    2015-01-01

    Broadly neutralizing antibodies have been isolated that bind the glycan shield of the HIV-1 envelope spike. One such antibody, PGT135, contacts the intrinsic mannose patch of gp120 at the Asn332, Asn392, and Asn386 glycosylation sites. Here, site-specific glycosylation analysis of recombinant gp120 revealed glycan microheterogeneity sufficient to explain the existence of a minor population of virions resistant to PGT135 neutralization. Target microheterogeneity and antibody glycan specificity are therefore important parameters in HIV-1 vaccine design. PMID:25878100

  9. The Complex Interaction between Methamphetamine Abuse and HIV-1 pathogenesis

    PubMed Central

    Passaro, Ryan Colby; Pandhare, Jui; Qian, Han-Zhu; Dash, Chandravanu

    2016-01-01

    The global HIV/AIDS pandemic has claimed the lives of an estimated 35 million people. A significant barrier for combating this global pandemic is substance use since it is associated with HIV transmission, delayed diagnosis/initiation of therapy, and poor adherence to therapy. Clinical studies also suggest a link between substance use and HIV-disease progression/AIDS-associated mortality. Methamphetamine (METH) use is one of the fastest-growing substance use problems in the world. METH use enhances high-risk sexual behaviors, therefore increases the likelihood of HIV-1 acquisition. METH use is also associated with higher viral loads, immune dysfunction, and antiretroviral resistance. Moreover, METH use has also been correlated with rapid progression to AIDS. However, direct effects of METH on HIV-1 disease progression remains poorly understood because use of METH and other illicit drugs is often associated with reduced/non adherence to ART. Nevertheless, in vitro studies demonstrate that METH increases HIV-1 replication in cell cultures and animal models. Thus, it has been proposed that METH’s potentiating effects on HIV-1 replication may in part contribute to the worsening of HIV-1 pathogenesis. However, our recent data demonstrate that METH inhibits HIV-1 replication in CD4+ T cells and challenges this paradigm. Thus, the goal of this review is to systematically examine the published literature to better understand the complex interaction between METH abuse and HIV-1 disease progression. PMID:25850893

  10. Antimicrobial drug resistance.

    PubMed

    Martinez, Marilyn; Silley, Peter

    2010-01-01

    This chapter provides an overview of our current understanding of the mechanisms associated with the development of antimicrobial drug resistance, international differences in definitions of resistance, ongoing efforts to track shifts in drug susceptibility, and factors that can influence the selection of therapeutic intervention. The latter presents a matrix of complex variables that includes the mechanism of drug action, the pharmacokinetics (PK) of the antimicrobial agent in the targeted patient population, the pharmacodynamics (PD) of the bacterial response to the antimicrobial agent, the PK/PD relationship that will influence dose selection, and the integrity of the host immune system. Finally, the differences between bacterial tolerance and bacterial resistance are considered, and the potential for non-traditional anti-infective therapies is discussed.

  11. Poly(ethylene glycol) enclatherated pectin-mucin submicron matrices for intravaginal anti-HIV-1 drug delivery.

    PubMed

    Mashingaidze, Felix; Choonara, Yahya E; Kumar, Pradeep; du Toit, Lisa C; Maharaj, Vinesh; Buchmann, Eckhart; Pillay, Viness

    2016-04-30

    This paper explores the potential of polyethylene glycol enclatherated pectin-mucin (PEG-encl-PEC:MUC) submicron matrices (SMMs) as an intravaginal drug delivery system capable of delivering an anti-HIV-1 agent (zidovudine; AZT) over a prolonged duration. A three factor and three level (3(3)) Box-Behnken statistical design was employed to optimize the SMMs. Optimized PEG-encl-PEC:MUC SMMs prepared as a stable W/O emulsion (determined by the degree of reversible colloidal phenomena) were spherical with a mean particle size of 270.6 ± 5.533 nm and mean zeta potential of -34.4 ± 0.539 mV. The microencapsulation of AZT and the hydrogen bonding mediated shielding of AZT by SMMs was confirmed by Fourier Transform Infrared (FTIR) analysis. The thermochemical (differential scanning calorimetry and thermogravimetric analysis) data proposed that Ca(2+)-based macromolecular ionic crosslinking as well as the intermolecular interactions may be responsible for the thermal stability of the delivery system. The partially amorphous nature of drug-loaded SMMs, as confirmed by X-ray diffraction patterns, further strengthened the matricization of AZT into the pectin-mucin matrix. In vitro drug release studies from the SMMs showed approximately 91% zidovudine release in simulated vaginal fluid (SVF) and 94% in phosphate buffered saline (PBS) in 24h. The mean dissolution time (MDT) of zidovudine from the SMMs was 5.974 h. The attainment of required dimensional structure and drug release profiles from SMMs highlights the potential of their inclusion into a secondary carrier system for extended and controlled intravaginal stay.

  12. Treating HIV-1 Infection: What Might the Future Hold?

    PubMed Central

    Lichterfeld, Mathias; Zachary, Kimon C.

    2011-01-01

    Advances in antiretroviral combination therapy lasting the past two decades have transformed HIV-1 infection from a fatal disease into a chronic medical condition that in many cases does not compromise life quality. There are 25 different antiretroviral agents available currently, allowing for patient-centered, individualized management of HIV-1 infection, and ongoing progress in HIV-1 virology and antiretroviral pharmacology is likely to expand treatment options further in the future. Nevertheless, antiretroviral therapy continues to have limitations, including insufficient immunological reconstitution, selection of drug resistance, ongoing abnormal immune activation despite effective suppression of HIV-1 viremia, and the inability to target latently infected cells that are responsible for long-term viral persistence. Owing to these shortcomings, the theoretical ability of antiretroviral therapy to extend life expectancy to normal levels is not realized in many cases. Strategies to address these limitations are a matter of active ongoing research and will be summarized in this article. PMID:23251756

  13. Association of drug abuse with inhibition of HIV-1 immune responses: studies with long-term of HIV-1 non-progressors.

    PubMed

    Nair, Madhavan P N; Mahajan, S; Hewitt, R; Whitney, Z R B; Schwartz, S A

    2004-02-01

    Recreational drug use has been proposed to affect the course of human immunodeficiency virus (HIV) infections. To investigate the effects of substance abuse on HIV infections, we compared virus-specific cytotoxic T lymphocyte (CTL) responses and the expression of IL-16, TGF-beta1, and CXCR4 in three different cohorts of HIV-infected patients: (1) long-term nonprogressors (LT-NPs) of HIV infection who do not use recreational drugs; (2) nondrugs using normal progressors (NPs), and (3) drugs using NPs. Our results show that LT-NPs manifest increased CTL activity and IL-16 expression and decreased expression of TGF-beta1 and CXCR4 compared to NPs, regardless of recreational drug usage. Furthermore, drugs using NPs showed significantly lower levels of CTL and IL-16 expression and increased TGF-beta1 and CXCR4 expression compared to nondrugs using NPs. Our results suggest that recreational drug use may reduce CTL and IL-16 expression and increase the expression of TGF-beta1 and CXCR4, all of which may facilitate progression of HIV infections.

  14. Sequences in Glycoprotein gp41, the CD4 Binding Site, and the V2 Domain Regulate Sensitivity and Resistance of HIV-1 to Broadly Neutralizing Antibodies

    PubMed Central

    O'Rourke, Sara M.; Schweighardt, Becky; Phung, Pham; Mesa, Kathryn A.; Vollrath, Aaron L.; Tatsuno, Gwen P.; To, Briana; Sinangil, Faruk; Limoli, Kay; Wrin, Terri

    2012-01-01

    The swarm of quasispecies that evolves in each HIV-1-infected individual represents a source of closely related Env protein variants that can be used to explore various aspects of HIV-1 biology. In this study, we made use of these variants to identify mutations that confer sensitivity and resistance to the broadly neutralizing antibodies found in the sera of selected HIV-1-infected individuals. For these studies, libraries of Env proteins were cloned from infected subjects and screened for infectivity and neutralization sensitivity. The nucleotide sequences of the Env proteins were then compared for pairs of neutralization-sensitive and -resistant viruses. In vitro mutagenesis was used to identify the specific amino acids responsible for the neutralization phenotype. All of the mutations altering neutralization sensitivity/resistance appeared to induce conformational changes that simultaneously enhanced the exposure of two or more epitopes located in different regions of gp160. These mutations appeared to occur at unique positions required to maintain the quaternary structure of the gp160 trimer, as well as conformational masking of epitopes targeted by neutralizing antibodies. Our results show that sequences in gp41, the CD4 binding site, and the V2 domain all have the ability to act as global regulators of neutralization sensitivity. Our results also suggest that neutralization assays designed to support the development of vaccines and therapeutics targeting the HIV-1 Env protein should consider virus variation within individuals as well as virus variation between individuals. PMID:22933284

  15. Development of Tetravalent, Bispecific CCR5 Antibodies with Antiviral Activity against CCR5 Monoclonal Antibody-Resistant HIV-1 Strains▿

    PubMed Central

    Schanzer, Jürgen; Jekle, Andreas; Nezu, Junichi; Lochner, Adriane; Croasdale, Rebecca; Dioszegi, Marianna; Zhang, Jun; Hoffmann, Eike; Dormeyer, Wilma; Stracke, Jan; Schäfer, Wolfgang; Ji, Changhua; Heilek, Gabrielle; Cammack, Nick; Brandt, Michael; Umana, Pablo; Brinkmann, Ulrich

    2011-01-01

    In this study, we describe novel tetravalent, bispecific antibody derivatives that bind two different epitopes on the HIV coreceptor CCR5. The basic protein formats that we applied were derived from Morrison-type bispecific antibodies: whole IgGs to which we connected single-chain antibodies (scFvs) via (Gly4Ser)n sequences at either the C or N terminus of the light chain or heavy chain. By design optimization, including disulfide stabilization of scFvs or introduction of 30-amino-acid linkers, stable molecules could be obtained in amounts that were within the same range as or no less than 4-fold lower than those observed with monoclonal antibodies in transient expression assays. In contrast to monospecific CCR5 antibodies, bispecific antibody derivatives block two alternative docking sites of CCR5-tropic HIV strains on the CCR5 coreceptor. Consequently, these molecules showed 18- to 57-fold increased antiviral activities compared to the parent antibodies. Most importantly, one prototypic tetravalent CCR5 antibody had antiviral activity against virus strains resistant to the single parental antibodies. In summary, physical linkage of two CCR5 antibodies targeting different epitopes on the HIV coreceptor CCR5 resulted in tetravalent, bispecific antibodies with enhanced antiviral potency against wild-type and CCR5 antibody-resistant HIV-1 strains. PMID:21300827

  16. "Fusion and binding inhibition" key target for HIV-1 treatment and pre-exposure prophylaxis: targets, drug delivery and nanotechnology approaches.

    PubMed

    Malik, Tanushree; Chauhan, Gaurav; Rath, Goutam; Murthy, R S R; Goyal, Amit K

    2017-11-01

    More than 35 million people are living with HIV worldwide with approximately 2.3 million new infections per year. Cascade of events (cell entry, virus replication, assembly and release of newly formed virions) is involved in the HIV-1 transmission process. Every single step offers a potential therapeutic strategy to halt this progression and HIV fusion into the human host cell is one such stage. Controlling the initial event of HIV-1 transmission is the best way to control its dissemination especially when prophylaxis is concerned. Action is required either on the HIV's or host's cell surface which is logically more rational when compared with other intracellular acting moieties. Aim of this manuscript is to detail the significance and current strategies to halt this initial step, thus blocking the entry of HIV-1 for further infection. Both HIV-1 and the possible host cell's receptors/co-receptors are under focus while specifying the targets available for inhibiting this fusion. Current and under investigation moieties are categorized based on their versatile mechanisms. Advanced drug delivery and nanotechnology approaches present a key tool to exploit the therapeutic potential in a boosted way. Current drug delivery and the impact of nanotechnology in potentiating this strategy are detailed.

  17. Residential Eviction and Risk of Detectable Plasma HIV-1 RNA Viral Load Among HIV-Positive People Who Use Drugs.

    PubMed

    Kennedy, Mary Clare; Kerr, Thomas; McNeil, Ryan; Parashar, Surita; Montaner, Julio; Wood, Evan; Milloy, M-J

    2017-03-01

    We examined the relationship between residential eviction and exhibiting detectable plasma HIV-1 RNA viral load (VL) among a prospective cohort of antiretroviral therapy (ART)-exposed HIV-seropositive people who use illicit drugs (PWUD) in Vancouver, Canada. We used multivariable generalized estimating equations to estimate the effect of residential eviction on detectable VL and examine ART adherence as a mediating variable. Between June 2007 and May 2014, 705 ART-exposed participants were included in the study, among whom 500 (70.9 %) experienced at least one period of detectable VL. In a time-updated multivariable model, eviction independently increased the odds of detectable VL among those who were homeless [adjusted odds ratio (AOR) = 2.25; 95 % confidence interval (CI) 1.18-4.29] as well as not homeless (AOR = 1.76; 95 % CI 1.17-2.63) post eviction. The results of mediation analyses suggest that this association was mediated by incomplete ART adherence. These findings suggest the need for further development and evaluation of interventions to prevent evictions and promote ART adherence among PWUD facing eviction.

  18. Fidelity of classwide-resistant HIV-2 reverse transcriptase and differential contribution of K65R to the accuracy of HIV-1 and HIV-2 reverse transcriptases.

    PubMed

    Álvarez, Mar; Sebastián-Martín, Alba; García-Marquina, Guillermo; Menéndez-Arias, Luis

    2017-03-23

    Nucleoside reverse transcriptase (RT) inhibitors constitute the backbone of current therapies against human immunodeficiency virus type 1 and type 2 (HIV-1 and HIV-2, respectively). However, mutational pathways leading to the development of nucleoside analogue resistance are different in both types of HIV. In HIV-2, resistance to all approved nucleoside analogues is conferred by the combination of RT substitutions K65R, Q151M and M184V. Nucleotide incorporation kinetic analyses of mutant and wild-type (WT) HIV-2 RTs show that the triple-mutant has decreased catalytic efficiency due to the presence of M184V. Although similar effects were previously reported for equivalent mutations in HIV-1 RT, the HIV-2 enzymes were catalytically less efficient. Interestingly, in highly divergent HIV-1 RTs, K65R confers several-fold increased accuracy of DNA synthesis. We have determined the intrinsic fidelity of DNA synthesis of WT HIV-2 RT and mutants K65R and K65R/Q151M/M184V. Our results show that those changes in HIV-2 RT have a relatively small impact on nucleotide selectivity. Furthermore, we found that there were less than two-fold differences in error rates obtained with forward mutation assays using mutant and WT HIV-2 RTs. A different conformation of the β3-β4 hairpin loop in HIV-1 and HIV-2 RTs could probably explain the differential effects of K65R.

  19. Fidelity of classwide-resistant HIV-2 reverse transcriptase and differential contribution of K65R to the accuracy of HIV-1 and HIV-2 reverse transcriptases

    PubMed Central

    Álvarez, Mar; Sebastián-Martín, Alba; García-Marquina, Guillermo; Menéndez-Arias, Luis

    2017-01-01

    Nucleoside reverse transcriptase (RT) inhibitors constitute the backbone of current therapies against human immunodeficiency virus type 1 and type 2 (HIV-1 and HIV-2, respectively). However, mutational pathways leading to the development of nucleoside analogue resistance are different in both types of HIV. In HIV-2, resistance to all approved nucleoside analogues is conferred by the combination of RT substitutions K65R, Q151M and M184V. Nucleotide incorporation kinetic analyses of mutant and wild-type (WT) HIV-2 RTs show that the triple-mutant has decreased catalytic efficiency due to the presence of M184V. Although similar effects were previously reported for equivalent mutations in HIV-1 RT, the HIV-2 enzymes were catalytically less efficient. Interestingly, in highly divergent HIV-1 RTs, K65R confers several-fold increased accuracy of DNA synthesis. We have determined the intrinsic fidelity of DNA synthesis of WT HIV-2 RT and mutants K65R and K65R/Q151M/M184V. Our results show that those changes in HIV-2 RT have a relatively small impact on nucleotide selectivity. Furthermore, we found that there were less than two-fold differences in error rates obtained with forward mutation assays using mutant and WT HIV-2 RTs. A different conformation of the β3-β4 hairpin loop in HIV-1 and HIV-2 RTs could probably explain the differential effects of K65R. PMID:28333133

  20. Heterosexual Transmission of Subtype C HIV-1 Selects Consensus-Like Variants without Increased Replicative Capacity or Interferon-α Resistance

    PubMed Central

    Fenton-May, Angharad E.; Dilernia, Dario A.; Kilembe, William; Allen, Susan A.; Borrow, Persephone; Hunter, Eric

    2015-01-01

    Heterosexual transmission of HIV-1 is characterized by a genetic bottleneck that selects a single viral variant, the transmitted/founder (TF), during most transmission events. To assess viral characteristics influencing HIV-1 transmission, we sequenced 167 near full-length viral genomes and generated 40 infectious molecular clones (IMC) including TF variants and multiple non-transmitted (NT) HIV-1 subtype C variants from six linked heterosexual transmission pairs near the time of transmission. Consensus-like genomes sensitive to donor antibodies were selected for during transmission in these six transmission pairs. However, TF variants did not demonstrate increased viral fitness in terms of particle infectivity or viral replicative capacity in activated peripheral blood mononuclear cells (PBMC) and monocyte-derived dendritic cells (MDDC). In addition, resistance of the TF variant to the antiviral effects of interferon-α (IFN-α) was not significantly different from that of non-transmitted variants from the same transmission pair. Thus neither in vitro viral replicative capacity nor IFN-α resistance discriminated the transmission potential of viruses in the quasispecies of these chronically infected individuals. However, our findings support the hypothesis that within-host evolution of HIV-1 in response to adaptive immune responses reduces viral transmission potential. PMID:26378795

  1. Distinct circulating recombinant HIV-1 strains among injecting drug users and sex workers in Afghanistan.

    PubMed

    Sanders-Buell, Eric; Bose, Meera; Nasir, Abdul; Todd, Catherine S; Stanekzai, M Raza; Tovanabutra, Sodsai; Scott, Paul T; Strathdee, Steffanie A; Tjaden, Jeffrey; Michael, Nelson L; McCutchan, Francine E

    2010-05-01

    Little information is available regarding a circulating HIV genotype among high-risk groups in Afghanistan; we describe HIV genotypes among injecting drug users (IDUs) and sex workers (SWs) in four Afghan cities. Participants completed behavioral questionnaires and HIV testing. Western blot-confirmed specimens had peripheral mononuclear blood cells isolated for genotyping. Analysis of recombinants was done by bootscanning and manual sequence alignment. The single SW sample harbored a CRF01_AE strain. Of 10 IDUs available for analysis, all were CRF35_AD and from Hirat. Analyzed subregions (gag p17 and env C1-C5) revealed close homology between the Hirat specimens. Three distinct subclusters comprising two or three strains were identified, whereas two other strains were generally equidistant from previously identified Kabul strains. Results suggest that the nascent HIV epidemic among IDUs in Hirat is largely, if not entirely, subtype CRF35_AD, and the close homology suggests recent infection; harm reduction should be supported to avert further transmission.

  2. Selectivity for strand-transfer over 3′-processing and susceptibility to clinical resistance of HIV-1 integrase inhibitors are driven by key enzyme–DNA interactions in the active site

    PubMed Central

    Métifiot, Mathieu; Johnson, Barry C.; Kiselev, Evgeny; Marler, Laura; Zhao, Xue Zhi; Burke, Terrence R.; Marchand, Christophe; Hughes, Stephen H.; Pommier, Yves

    2016-01-01

    Integrase strand transfer inhibitors (INSTIs) are highly effective against HIV infections. Co-crystal structures of the prototype foamy virus intasome have shown that all three FDA-approved drugs, raltegravir (RAL), elvitegravir and dolutegravir (DTG), act as interfacial inhibitors during the strand transfer (ST) integration step. However, these structures give only a partial sense for the limited inhibition of the 3′-processing reaction by INSTIs and how INSTIs can be modified to overcome drug resistance, notably against the G140S-Q148H double mutation. Based on biochemical experiments with modified oligonucleotides, we demonstrate that both the viral DNA +1 and −1 bases, which flank the 3′-processing site, play a critical role for 3′-processing efficiency and inhibition by RAL and DTG. In addition, the G140S-Q148H (SH) mutant integrase, which has a reduced 3′-processing activity, becomes more active and more resistant to inhibition of 3′-processing by RAL and DTG in the absence of the −1 and +1 bases. Molecular modeling of HIV-1 integrase, together with biochemical data, indicate that the conserved residue Q146 in the flexible loop of HIV-1 integrase is critical for productive viral DNA binding through specific contacts with the virus DNA ends in the 3′-processing and ST reactions. The potency of integrase inhibitors against 3′-processing and their ability to overcome resistance is discussed. PMID:27369381

  3. Repeated HIV-1 resistance genotyping external quality assessments improve virology laboratory performance.

    PubMed

    Descamps, Diane; Delaugerre, Constance; Masquelier, Bernard; Ruffault, Annick; Marcelin, Anne-Geneviève; Izopet, Jacques; Chaix, Marie-Laure; Calvez, Vincent; Brun-Vézinet, Françoise; Costagliola, Dominique

    2006-02-01

    The performance of French virology laboratories belonging to the ANRS network has been assessed annually for 3 years. The performance of these laboratories was compared between the years 2002 and 2003. Ten and 7 coded samples were sent to 38 virology laboratories in 2002 and 45 virology laboratories in 2003, respectively. Each panel of coded samples included at least one HIV-negative control, a pair of duplicate specimens, samples with a wide range of viral loads, and samples with a large number of resistance mutations. The laboratories used their standard sequencing procedures and were asked to report the amino acids at codons associated with resistance mutations, based on the IAS-USA expert panel list. The reference amino acid sequences were defined as those most frequently reported by the participants. The specificity of detection of RT mutations was significantly better in 2003 (99.9%) than in 2002 (99.7%) (P = 0.05). There was no difference between 2002 and 2003 in the specificity of detection of protease mutations (99.6% and 99.8%) or the sensitivity of detection of RT mutations (98.8% and 98.2%). The sensitivity of detection of protease mutations improved significantly between 2002 and 2003 (97.6% and 99.0%, respectively; P = 0.037). The proportion of laboratories reporting fully accurate results, in terms of amplification, specificity, sensitivity, and reproducibility, tended to increase between 2002 and 2003 (P = 0.077). No errors were made by 19% of laboratories in 2002, compared to 42% in 2003. These results show the value of repeated external quality assessments.

  4. New connections: Cell to cell HIV-1 transmission, resistance to broadly neutralizing antibodies, and an envelope sorting motif.

    PubMed

    Smith, S Abigail; Derdeyn, Cynthia A

    2017-03-01

    HIV-1 infection from cell to cell may provide an efficient mode of viral spread in vivo and could therefore present a significant challenge for preventative or therapeutic strategies based on broadly neutralizing antibodies. Indeed, Li et al show that the potency and magnitude of multiple HIV-1 broadly neutralizing antibody classes are decreased during cell to cell infection in a context dependent manner. A functional motif in gp41 appears to contribute to this differential susceptibility by modulating exposure of neutralization epitopes.

  5. Mutations in both env and gag genes are required for HIV-1 resistance to the polysulfonic dendrimer SPL2923, as corroborated by chimeric virus technology.

    PubMed

    Hantson, Anke; Fikkert, Valery; Van Remoortel, Barbara; Pannecouque, Chistophe; Cherepanov, Peter; Matthews, Barry; Holan, George; De Clercq, Erik; Vandamme, Anne-Mieke; Debyser, Zeger; Witvrouw, Myriam

    2005-01-01

    A drug-resistant NL4.3/SPL2923 strain has previously been generated by in vitro selection of HIV-1(NL4.3) in the presence of the polysulfonic dendrimer SPL2923 and mutations were reported in its gp120 gene (Witvrouw et al., 2000). Here, we further analysed the (cross) resistance profile of NL4.3/SPL2923. NL4.3/SPL2923 was found to contain additional mutations in gp41 and showed reduced susceptibility to SPL2923, dextran sulfate (DS) and enfuvirtide. To delineate to what extent the mutations in each env gene were accountable for the phenotypic (cross) resistance of NL4.3/SPL2923, the gp120-, gp41- and gp160-sequences derived from this strain were placed into a wild-type background using env chimeric virus technology (CVT). The cross resistance of NL4.3/SPL2923 towards DS was fully reproduced following gp160-recombination, while it was only partially reproduced following gp120- or gp41-recombination. The mutations in gp41 of NL4.3/SPL2923 were sufficient to reproduce the cross resistance to enfuvirtide. Unexpectedly, the reduced sensitivity towards SPL2923 was not fully reproduced after gp160-recombination. The search for mutations in NL4.3/SPL2923 in viral genes other than env revealed several mutations in the gene encoding the HIV p17 matrix protein (MA) and one mutation in the gene encoding the p24 capsid protein (CA). In order to analyse the impact of the gag mutations alone and in combination with the mutations in env on the phenotypic resistance towards SPL2923, we developed a novel p17- and p17/gp160-CVT. Phenotypic analysis of the NL4.3/SPL2923 p17- and p17/gp160-recombined strains indicated that the mutations in both env and gag have to be present to fully reproduce the resistance of NL4.3/SPL2923 towards SPL2923.

  6. Therapeutics for HIV-1 reactivation from latency.

    PubMed

    Sgarbanti, Marco; Battistini, Angela

    2013-08-01

    Intensive combined antiretroviral therapy successfully suppresses HIV-1 replication and AIDS disease progression making infection manageable, but it is unable to eradicate the virus that persists in long-lived, drug-insensitive and immune system-insensitive reservoirs thus asking for life-long treatments with problems of compliance, resistance, toxicity and cost. These limitations and recent insights into latency mechanisms have fueled a renewed effort in finding a cure for HIV-1 infection. Proposed eradication strategies involve reactivation of the latent reservoir upon induction of viral transcription followed by the elimination of reactivated virus-producing cells by viral cytopathic effect or host immune response. Several molecules identified by mechanism-directed approaches or in large-scale screenings have been proposed as latency reversing agents. Some of them have already entered clinical testing in humans but with mixed or unsatisfactory results.

  7. Prevalence of transmitted nucleoside analogue-resistant HIV-1 strains and pre-existing mutations in pol reverse transcriptase and protease region: outcome after treatment in recently infected individuals.

    PubMed

    Balotta, C; Berlusconi, A; Pan, A; Violin, M; Riva, C; Colombo, M C; Gori, A; Papagno, L; Corvasce, S; Mazzucchelli, R; Facchi, G; Velleca, R; Saporetti, G; Galli, M; Rusconi, S; Moroni, M

    2000-03-01

    We retrospectively studied 38 Italian recently HIV-1-infected subjects who seroconverted from 1994 to 1997 to investigate: (i) the prevalence of nucleoside reverse transcriptase inhibitors (NRTI)-related mutations at primary infection; (ii) the proportion of naturally occurring mutations in reverse transcriptase (RT) and protease regions of patients naive for non-nucleoside RT inhibitors (NNRTIs) and protease inhibitors (PIs); (iii) the drug-susceptibility to NRTIs and PIs in subjects with NRTI- and/or PI-related mutations; and (iv) the outcome of seroconverters treated with various NRTIs or NRTI/PI regimens. Baseline HIV-1 plasma viraemia and absolute CD4 count at baseline could not be used to distinguish patients with NRTI- and/or PI-related pre-existing mutations from those with wild-type virus (P = 0.693 and P = 0.542, respectively). The frequency of zidovudine-related mutations was 21% in the study period. The response to treatment was not significantly different in subjects with or without genotypic zidovudine-related mutations at primary infection (P = 0.744 for HIV-1 RNA and P = 0.102 for CD4 cells). Some natural variation (2.6%) was present within regions 98-108 and 179-190 of RT involved in NNRTI resistance. The high natural polymorphism in the protease region present in our patients was similar to that reported by others. In our study some PI-associated substitutions, thought to be compensatory in protease enzymatic function, could confer intermediate to high PI-resistance. As discrepancies between genotypic and phenotypic results may exist in recent seroconverters, our data suggest that the role of transmitted NRTI- and PI-resistant variants remain to be fully elucidated in vivo.

  8. Inhibitory effect of aqueous dandelion extract on HIV-1 replication and reverse transcriptase activity

    PubMed Central

    2011-01-01

    Background Acquired immunodeficiency syndrome (AIDS), which is caused by the human immunodeficiency virus (HIV), is an immunosuppressive disease that results in life-threatening opportunistic infections. The general problems in current therapy include the constant emergence of drug-resistant HIV strains, adverse side effects and the unavailability of treatments in developing countries. Natural products from herbs with the abilities to inhibit HIV-1 life cycle at different stages, have served as excellent sources of new anti-HIV-1 drugs. In this study, we aimed to investigate the anti-HIV-1 activity of aqueous dandelion extract. Methods The pseudotyped HIV-1 virus has been utilized to explore the anti-HIV-1 activity of dandelion, the level of HIV-1 replication was assessed by the percentage of GFP-positive cells. The inhibitory effect of the dandelion extract on reverse transcriptase activity was assessed by the reverse transcriptase assay kit. Results Compared to control values obtained from cells infected without treatment, the level of HIV-1 replication and reverse transcriptase activity were decreased in a dose-dependent manner. The data suggest that dandelion extract has a potent inhibitory activity against HIV-1 replication and reverse transcriptase activity. The identification of HIV-1 antiviral compounds from Taraxacum officinale should be pursued. Conclusions The dandelion extract showed strong activity against HIV-1 RT and inhibited both the HIV-1 vector and the hybrid-MoMuLV/MoMuSV retrovirus replication. These findings provide additional support for the potential therapeutic efficacy of Taraxacum officinale. Extracts from this plant may be regarded as another starting point for the development of an antiretroviral therapy with fewer side effects. PMID:22078030

  9. Endogenous CD317/Tetherin limits replication of HIV-1 and murine leukemia virus in rodent cells and is resistant to antagonists from primate viruses.

    PubMed

    Goffinet, Christine; Schmidt, Sarah; Kern, Christian; Oberbremer, Lena; Keppler, Oliver T

    2010-11-01

    Human CD317 (BST-2/tetherin) is an intrinsic immunity factor that blocks the release of retroviruses, filoviruses, herpesviruses, and arenaviruses. It is unclear whether CD317 expressed endogenously in rodent cells has the capacity to interfere with the replication of the retroviral rodent pathogen murine leukemia virus (MLV) or, in the context of small-animal model development, contributes to the well-established late-phase restriction of human immunodeficiency virus type 1 (HIV-1). Here, we show that small interfering RNA (siRNA)-mediated knockdown of CD317 relieved a virion release restriction and markedly enhanced the egress of HIV-1, HIV-2, and simian immunodeficiency virus (SIV) in rat cells, including primary macrophages. Moreover, rodent CD317 potently inhibited MLV release, and siRNA-mediated depletion of CD317 in a mouse T-cell line resulted in the accelerated spread of MLV. Several virus-encoded antagonists have recently been reported to overcome the restriction imposed by human or monkey CD317, including HIV-1 Vpu, envelope glycoproteins of HIV-2 and Ebola virus, Kaposi's sarcoma-associated herpesvirus K5, and SIV Nef. In contrast, both rat and mouse CD317 showed a high degree of resistance to these viral antagonists. These data suggest that CD317 is a broadly acting and conserved mediator of innate control of retroviral infection and pathogenesis that restricts the release of retroviruses and lentiviruses in rodents. The high degree of resistance of the rodent CD317 restriction factors to antagonists from primate viruses has implications for HIV-1 small-animal model development and may guide the design of novel antiviral interventions.

  10. Driving HIV-1 into a Vulnerable Corner by Taking Advantage of Viral Adaptation and Evolution

    PubMed Central

    Harada, Shigeyoshi; Yoshimura, Kazuhisa

    2017-01-01

    Anti-retroviral therapy (ART) is crucial for controlling human immunodeficiency virus type-1 (HIV-1) infection. Recently, progress in identifying and characterizing highly potent broadly neutralizing antibodies has provided valuable templates for HIV-1 therapy and vaccine design. Nevertheless, HIV-1, like many RNA viruses, exhibits genetically diverse populations known as quasispecies. Evolution of quasispecies can occur rapidly in response to selective pressures, such as that exerted by ART and the immune system. Hence, rapid viral evolution leading to drug resistance and/or immune evasion is a significant barrier to the development of effective HIV-1 treatments and vaccines. Here, we describe our recent investigations into evolutionary pressure exerted by anti-retroviral drugs and monoclonal neutralizing antibodies (NAbs) on HIV-1 envelope sequences. We also discuss sensitivities of HIV-1 escape mutants to maraviroc, a CCR5 inhibitor, and HIV-1 sensitized to NAbs by small-molecule CD4-mimetic compounds. These studies help to develop an understanding of viral evolution and escape from both anti-retroviral drugs and the immune system, and also provide fundamental insights into the combined use of NAbs and entry inhibitors. These findings of the adaptation and evolution of HIV in response to drug and immune pressure will inform the development of more effective antiviral therapeutic strategies. PMID:28360890

  11. Universal amplification, next-generation sequencing, and assembly of HIV-1 genomes.

    PubMed

    Gall, Astrid; Ferns, Bridget; Morris, Clare; Watson, Simon; Cotten, Matthew; Robinson, Mark; Berry, Neil; Pillay, Deenan; Kellam, Paul

    2012-12-01

    Whole HIV-1 genome sequences are pivotal for large-scale studies of inter- and intrahost evolution, including the acquisition of drug resistance mutations. The ability to rapidly and cost-effectively generate large numbers of HIV-1 genome sequences from different populations and geographical locations and determine the effect of minority genetic variants is, however, a limiting factor. Next-generation sequencing promises to bridge this gap but is hindered by the lack of methods for the enrichment of virus genomes across the phylogenetic breadth of HIV-1 and methods for the robust assembly of the virus genomes from short-read data. Here we report a method for the amplification, next-generation sequencing, and unbiased de novo assembly of HIV-1 genomes of groups M, N, and O, as well as recombinants, that does not require prior knowledge of the sequence or subtype. A sensitivity of at least 3,000 copies/ml was determined by using plasma virus samples of known copy numbers. We applied our novel method to compare the genome diversities of HIV-1 groups, subtypes, and genes. The highest level of diversity was found in the env, nef, vpr, tat, and rev genes and parts of the gag gene. Furthermore, we used our method to investigate mutations associated with HIV-1 drug resistance in clinical samples at the level of the complete genome. Drug resistance mutations were detected as both major variant and minor species. In conclusion, we demonstrate the feasibility of our method for large-scale HIV-1 genome sequencing. This will enable the phylogenetic and phylodynamic resolution of the ongoing pandemic and efficient monitoring of complex HIV-1 drug resistance genotypes.

  12. Drug-resistant tuberculous meningitis.

    PubMed

    Garg, Ravindra K; Jain, Amita; Malhotra, Hardeep S; Agrawal, Avinash; Garg, Rajiv

    2013-06-01

    Drug-resistant tuberculosis, including drug-resistant tuberculous meningitis, is an emerging health problem in many countries. An association with Beijing strains and drug resistance-related mutations, such as mutations in katG and rpoB genes, has been found. The pathology, clinical features and neuroimaging characteristics of drug-resistant tuberculous meningitis are similar to drug-responsive tuberculous meningitis. Detection of mycobacteria in cerebrospinal fluid (CSF) by conventional methods (smear examination or culture) is often difficult. Nucleic acid amplification assays are better methods owing to their rapidity and high sensitivity. The Xpert MTB/RIF assay (Cepheid, CA, USA) is a fully-automated test that has also been found to be effective for CSF samples. Treatment of multidrug-resistant tuberculous meningitis depends on the drug susceptibility pattern of the isolate and/or the previous treatment history of the patient. Second-line drugs with good penetration of the CSF should be preferred. Isoniazid monoresistant disease requires addition of another drug with better CSF penetration. Drug-resistant tuberculous meningitis is associated with a high mortality. HIV infected patients with drug-resistant tuberculous meningitis have severe clinical manifestations with exceptionally high mortality. Prevention of tuberculosis is the key to reduce drug-resistant tuberculous meningitis.

  13. Discovery of diarylpyridine derivatives as novel non-nucleoside HIV-1 reverse transcriptase inhibitors

    PubMed Central

    Tian, Xingtao; Qin, Bingjie; Lu, Hong; Lai, Weihong; Jiang, Shibo; Lee, Kuo-Hsiung; Ho Chen, Chin; Xie, Lan

    2009-01-01

    Two series (4 and 5) of diarylpyridine derivatives were designed, synthesized, and evaluated for anti-HIV-1 activity. The most promising compound, 5e, inhibited HIV-1 IIIB, NL4-3, and RTMDR1 with low nanomolar EC50 values and selectivity indexes of >10,000. The results of this study indicate that diarylpyridine can be used as a novel scaffold to derive a new class of potent NNRTIs, active against both wild-type and drug resistant HIV-1 strains. PMID:19666220

  14. Drugs and drug resistance in African trypanosomiasis.

    PubMed

    Delespaux, Vincent; de Koning, Harry P

    2007-01-01

    Despite the many decades of use of most of the current trypanocides, we know little of their mode of action. This may in part be because most of these will act on multiple targets once inside the cell, and they derive their selective action on the parasite from selective accumulation by the pathogen. Loss of this capacity for drug uptake by the trypanosome would thus be a major cause for drug resistance. We here discuss the use of current drugs against human and veterinary African trypanosomiasis, the prevalence, causes and mechanisms of drug resistance and new developments in trypanosomiasis therapy such as the introduction of nifurtimox and DB289.

  15. Conserved hydrogen bonds and water molecules in MDR HIV-1 protease substrate complexes.

    PubMed

    Liu, Zhigang; Wang, Yong; Yedidi, Ravikiran S; Dewdney, Tamaria G; Reiter, Samuel J; Brunzelle, Joseph S; Kovari, Iulia A; Kovari, Ladislau C

    2013-01-18

    The success of highly active antiretroviral therapy (HAART) in anti-HIV therapy is severely compromised by the rapidly developing drug resistance. HIV-1 protease inhibitors, part of HAART, are losing their potency and efficacy in inhibiting the target. Multi-drug resistant (MDR) 769 HIV-1 protease (resistant mutations at residues 10, 36, 46, 54, 62, 63, 71, 82, 84, 90) was selected for the present study to understand the binding to its natural substrates. The nine crystal structures of MDR769 HIV-1 protease substrate hepta-peptide complexes were analyzed in order to reveal the conserved structural elements for the purpose of drug design against MDR HIV-1 protease. Our structural studies demonstrated that highly conserved hydrogen bonds between the protease and substrate peptides, together with the conserved crystallographic water molecules, played a crucial role in the substrate recognition, substrate stabilization and protease stabilization. In addition, the absence of the key flap-ligand bridging water molecule might imply a different catalytic mechanism of MDR769 HIV-1 protease compared to that of wild type (WT) HIV-1 protease.

  16. Conserved hydrogen bonds and water molecules in MDR HIV-1 protease substrate complexes

    SciTech Connect

    Liu, Zhigang; Wang, Yong; Yedidi, Ravikiran S.; Dewdney, Tamaria G.; Reiter, Samuel J.; Brunzelle, Joseph S.; Kovari, Iulia A.; Kovari, Ladislau C.

    2012-12-19

    Success of highly active antiretroviral therapy (HAART) in anti-HIV therapy is severely compromised by the rapidly developing drug resistance. HIV-1 protease inhibitors, part of HAART, are losing their potency and efficacy in inhibiting the target. Multi-drug resistant (MDR) 769 HIV-1 protease (resistant mutations at residues 10, 36, 46, 54, 62, 63, 71, 82, 84, 90) was selected for the present study to understand the binding to its natural substrates. The nine crystal structures of MDR769 HIV-1 protease substrate hepta-peptide complexes were analyzed in order to reveal the conserved structural elements for the purpose of drug design against MDR HIV-1 protease. Our structural studies demonstrated that highly conserved hydrogen bonds between the protease and substrate peptides, together with the conserved crystallographic water molecules, played a crucial role in the substrate recognition, substrate stabilization and protease stabilization. Additionally, the absence of the key flap-ligand bridging water molecule might imply a different catalytic mechanism of MDR769 HIV-1 protease compared to that of wild type (WT) HIV-1 protease.

  17. HIV-1 pol diversity among female bar and hotel workers in Northern Tanzania.

    PubMed

    Kiwelu, Ireen E; Novitsky, Vladimir; Kituma, Elimsaada; Margolin, Lauren; Baca, Jeannie; Manongi, Rachel; Sam, Noel; Shao, John; McLane, Mary F; Kapiga, Saidi H; Essex, M

    2014-01-01

    A national ART program was launched in Tanzania in October 2004. Due to the existence of multiple HIV-1 subtypes and recombinant viruses co-circulating in Tanzania, it is important to monitor rates of drug resistance. The present study determined the prevalence of HIV-1 drug resistance mutations among ART-naive female bar and hotel workers, a high-risk population for HIV-1 infection in Moshi, Tanzania. A partial HIV-1 pol gene was analyzed by single-genome amplification and sequencing in 45 subjects (622 pol sequences total; median number of sequences per subject, 13; IQR 5-20) in samples collected in 2005. The prevalence of HIV-1 subtypes A1, C, and D, and inter-subtype recombinant viruses, was 36%, 29%, 9% and 27%, respectively. Thirteen different recombination patterns included D/A1/D, C/A1, A1/C/A1, A1/U/A1, C/U/A1, C/A1, U/D/U, D/A1/D, A1/C, A1/C, A2/C/A2, CRF10_CD/C/CRF10_CD and CRF35_AD/A1/CRF35_AD. CRF35_AD was identified in Tanzania for the first time. All recombinant viruses in this study were unique, suggesting ongoing recombination processes among circulating HIV-1 variants. The prevalence of multiple infections in this population was 16% (n = 7). Primary HIV-1 drug resistance mutations to RT inhibitors were identified in three (7%) subjects (K65R plus Y181C; N60D; and V106M). In some subjects, polymorphisms were observed at the RT positions 41, 69, 75, 98, 101, 179, 190, and 215. Secondary mutations associated with NNRTIs were observed at the RT positions 90 (7%) and 138 (6%). In the protease gene, three subjects (7%) had M46I/L mutations. All subjects in this study had HIV-1 subtype-specific natural polymorphisms at positions 36, 69, 89 and 93 that are associated with drug resistance in HIV-1 subtype B. These results suggested that HIV-1 drug resistance mutations and natural polymorphisms existed in this population before the initiation of the national ART program. With increasing use of ARV, these results highlight the importance of drug

  18. Lack of associations between HLA class II alleles and resistance to HIV-1 infection among white, non-Hispanic homosexual men.

    PubMed

    Liu, Chenglong; Carrington, Mary; Kaslow, Richard A; Gao, Xiaojiang; Rinaldo, Charles R; Jacobson, Lisa P; Margolick, Joseph B; Phair, John; O'Brien, Stephen J; Detels, Roger

    2004-10-01

    HLA class II alleles were molecularly typed for 100 high-risk seronegative men and 184 low-risk seroconverters from the Multicenter AIDS Cohort Study (MACS). Seven resistant individuals homozygous for CCR5 Delta32 deletions were excluded from analysis. In the univariate analysis, no significant HLA class II associations with resistance/susceptibility to HIV type 1 infection were identified. However, the transporter associated with antigen presentation 2 (TAP2) Ala 665 variant associated with resistance in earlier analyses in the MACS was in linkage disequilibrium with some HLA class II alleles. After adjusting for the established associations with HLA-A*0205 subgroup and TAP2 Ala 665 variant, no HLA class II alleles were independently associated with resistance/susceptibility to HIV-1 infection. Other genetic factors in the HLA class II-TAP region of the major histocompatibility complex might be involved.

  19. Tenascin-C is an innate broad-spectrum, HIV-1-neutralizing protein in breast milk.

    PubMed

    Fouda, Genevieve G; Jaeger, Frederick H; Amos, Joshua D; Ho, Carrie; Kunz, Erika L; Anasti, Kara; Stamper, Lisa W; Liebl, Brooke E; Barbas, Kimberly H; Ohashi, Tomoo; Moseley, Martin Arthur; Liao, Hua-Xin; Erickson, Harold P; Alam, S Munir; Permar, Sallie R

    2013-11-05

    Achieving an AIDS-free generation will require elimination of postnatal transmission of HIV-1 while maintaining the nutritional and immunologic benefits of breastfeeding for infants in developing regions. Maternal/infant antiretroviral prophylaxis can reduce postnatal HIV-1 transmission, yet toxicities and the development of drug-resistant viral strains may limit the effectiveness of this strategy. Interestingly, in the absence of antiretroviral prophylaxis, greater than 90% of infants exposed to HIV-1 via breastfeeding remain uninfected, despite daily mucosal exposure to the virus for up to 2 y. Moreover, milk of uninfected women inherently neutralizes HIV-1 and prevents virus transmission in animal models, yet the factor(s) responsible for this anti-HIV activity is not well-defined. In this report, we identify a primary HIV-1-neutralizing protein in breast milk, Tenascin-C (TNC). TNC is an extracellular matrix protein important in fetal development and wound healing, yet its antimicrobial properties have not previously been established. Purified TNC captured and neutralized multiclade chronic and transmitted/founder HIV-1 variants, and depletion of TNC abolished the HIV-1-neutralizing activity of milk. TNC bound the HIV-1 Envelope protein at a site that is induced upon engagement of its primary receptor, CD4, and is blocked by V3 loop- (19B and F39F) and chemokine coreceptor binding site-directed (17B) monoclonal antibodies. Our results demonstrate the ability of an innate mucosal host protein found in milk to neutralize HIV-1 via binding to the chemokine coreceptor site, potentially explaining why the majority of HIV-1-exposed breastfed infants are protected against mucosal HIV-1 transmission.

  20. Field evaluation of an open and polyvalent universal HIV-1/SIVcpz/SIVgor quantitative RT-PCR assay for HIV-1 viral load monitoring in comparison to Abbott RealTime HIV-1 in Cameroon.

    PubMed

    Guichet, Emilande; Aghokeng, Avelin; Eymard-Duvernay, Sabrina; Vidal, Nicole; Ayouba, Ahidjo; Mpoudi Ngole, Eitel; Delaporte, Eric; Ciaffi, Laura; Peeters, Martine

    2016-11-01

    With the increasing demand of HIV viral load (VL) tests in resource-limited countries (RLCs) there is a need for assays at affordable cost and able to quantify all known HIV-1 variants. VLs obtained with a recently developed open and polyvalent universal HIV-1/SIVcpz/SIVgor RT-qPCR were compared to Abbott RealTime HIV-1 assay in Cameroon. On 474 plasma samples, characterized by a wide range of VLs and a broad HIV-1 group M genetic diversity, 97.5% concordance was observed when using the lower detection limit of each assay. When using the threshold of 3.00 log10 copies/mL, according to WHO guidelines to define virological failure (VF) in RLCs, the concordance was 94.7%, 360/474 versus 339/474 patients were identified with VF with the new assay and Abbott RealTime HIV-1, respectively. Higher VLs were measured with the new assay, +0.47 log10 copies/mL (95% CI; 0.42-0.52) as shown with Bland-Altman analysis. Eleven samples from patients on VF with drug resistance were not detected by Abbott RealTime HIV-1 versus two only with the new assay. Overall, our study showed that the new assay can be easily implemented in a laboratory in RLCs with VL experience and showed good performance on a wide diversity of HIV-1 group M variants.

  1. Mechanisms of drug resistance: quinolone resistance

    PubMed Central

    Hooper, David C.; Jacoby, George A.

    2015-01-01

    Quinolone antimicrobials are synthetic and widely used in clinical medicine. Resistance emerged with clinical use and became common in some bacterial pathogens. Mechanisms of resistance include two categories of mutation and acquisition of resistance-conferring genes. Resistance mutations in one or both of the two drug target enzymes, DNA gyrase and DNA topoisomerase IV, are commonly in a localized domain of the GyrA and ParE subunits of the respective enzymes and reduce drug binding to the enzyme-DNA complex. Other resistance mutations occur in regulatory genes that control the expression of native efflux pumps localized in the bacterial membrane(s). These pumps have broad substrate profiles that include quinolones as well as other antimicrobials, disinfectants, and dyes. Mutations of both types can accumulate with selection pressure and produce highly resistant strains. Resistance genes acquired on plasmids can confer low-level resistance that promotes the selection of mutational high-level resistance. Plasmid-encoded resistance is due to Qnr proteins that protect the target enzymes from quinolone action, one mutant aminoglycoside-modifying enzyme that also modifies certain quinolones, and mobile efflux pumps. Plasmids with these mechanisms often encode additional antimicrobial resistances and can transfer multidrug resistance that includes quinolones. Thus, the bacterial quinolone resistance armamentarium is large. PMID:26190223

  2. Mechanisms of drug resistance: quinolone resistance.

    PubMed

    Hooper, David C; Jacoby, George A

    2015-09-01

    Quinolone antimicrobials are synthetic and widely used in clinical medicine. Resistance emerged with clinical use and became common in some bacterial pathogens. Mechanisms of resistance include two categories of mutation and acquisition of resistance-conferring genes. Resistance mutations in one or both of the two drug target enzymes, DNA gyrase and DNA topoisomerase IV, are commonly in a localized domain of the GyrA and ParE subunits of the respective enzymes and reduce drug binding to the enzyme-DNA complex. Other resistance mutations occur in regulatory genes that control the expression of native efflux pumps localized in the bacterial membrane(s). These pumps have broad substrate profiles that include quinolones as well as other antimicrobials, disinfectants, and dyes. Mutations of both types can accumulate with selection pressure and produce highly resistant strains. Resistance genes acquired on plasmids can confer low-level resistance that promotes the selection of mutational high-level resistance. Plasmid-encoded resistance is due to Qnr proteins that protect the target enzymes from quinolone action, one mutant aminoglycoside-modifying enzyme that also modifies certain quinolones, and mobile efflux pumps. Plasmids with these mechanisms often encode additional antimicrobial resistances and can transfer multidrug resistance that includes quinolones. Thus, the bacterial quinolone resistance armamentarium is large.

  3. Decreasing population selection rates of resistance mutation K65R over time in HIV-1 patients receiving combination therapy including tenofovir

    PubMed Central

    Theys, K.; Snoeck, J.; Vercauteren, J.; Abecasis, A. B.; Vandamme, A.-M.; Camacho, R. J.

    2013-01-01

    Objectives The use of tenofovir is highly associated with the emergence of mutation K65R, which confers broad resistance to nucleoside/nucleotide analogue reverse transcriptase inhibitors (NRTIs), especially when tenofovir is combined with other NRTIs also selecting for K65R. Although recent HIV-1 treatment guidelines discouraging these combinations resulted in reduced K65R selection with tenofovir, updated information on the impact of currently recommended regimens on the population selection rate of K65R is presently lacking. Methods In this study, we evaluated changes over time in the selection rate of resistance mutation K65R in a large population of 2736 HIV-1-infected patients failing combination antiretroviral treatment between 2002 and 2010. Results The K65R resistance mutation was detected in 144 patients, a prevalence of 5.3%. A large majority of observed K65R cases were explained by the use of tenofovir, reflecting its wide use in clinical practice. However, changing patterns over time in NRTIs accompanying tenofovir resulted in a persistent decreasing probability of K65R selection by tenofovir-based therapy. The currently recommended NRTI combination tenofovir/emtricitabine was associated with a low probability of K65R emergence. For any given dual NRTI combination including tenofovir, higher selection rates of K65R were consistently observed with a non-nucleoside reverse transcriptase inhibitor than with a protease inhibitor as the third agent. Discussion Our finding of a stable time trend of K65R despite elevated use of tenofovir illustrates increased potency of current HIV-1 therapy including tenofovir. PMID:23027713

  4. Lack of impact of pre-existing T97A HIV-1 integrase mutation on integrase strand transfer inhibitor resistance and treatment outcome

    PubMed Central

    Ram, Renee R.; Margot, Nicolas A.; Barnes, Tiffany L.; White, Kirsten L.; Callebaut, Christian; Miller, Michael D.

    2017-01-01

    T97A is an HIV-1 integrase polymorphism associated with integrase strand transfer inhibitor (INSTI) resistance. Using pooled data from 16 clinical studies, we investigated the prevalence of T97A (pre-existing and emergent) and its impact on INSTI susceptibility and treatment response in INSTI-naive patients who enrolled on elvitegravir (EVG)- or raltegravir (RAL)-based regimens. Prior to INSTI-based therapy, primary INSTI resistance-associated mutations (RAMs) were absent and T97A pre-existed infrequently (1.4%; 47 of 3367 integrase sequences); most often among non-B (5.3%) than B (0.9%) HIV-1 subtypes. During INSTI-based therapy, few patients experienced virologic failure with emergent INSTI RAMs (3%; 122 of 3881 patients), among whom T97A emerged infrequently in the presence (n = 6) or absence (n = 8) of primary INSTI RAMs. A comparison between pre-existing and emergent T97A patient populations (i.e., in the absence of primary INSTI RAMs) showed no significant differences in EVG or RAL susceptibility in vitro. Furthermore, among all T97A-containing viruses tested, only 38–44% exhibited reduced susceptibility to EVG and/or RAL (all of low magnitude; <11-fold), while all maintained susceptibility to dolutegravir. Of the patients with pre-existing T97A, 17 had available clinical follow-up: 16 achieved virologic suppression and 1 maintained T97A and INSTI sensitivity without further resistance development. Overall, T97A is an infrequent integrase polymorphism that is enriched among non-B HIV-1 subtypes and can confer low-level reduced susceptibility to EVG and/or RAL. However, detection of T97A does not affect response to INSTI-based therapy with EVG or RAL. These results suggest a very low risk of initiating INSTI-based therapy in patients with pre-existing T97A. PMID:28212411

  5. Clinical, virological and biochemical evidence supporting the association of HIV-1 reverse transcriptase polymorphism R284K and thymidine analogue resistance mutations M41L, L210W and T215Y in patients failing tenofovir/emtricitabine therapy

    PubMed Central

    2012-01-01

    Background Thymidine analogue resistance mutations (TAMs) selected under treatment with nucleoside analogues generate two distinct genotypic profiles in the HIV-1 reverse transcriptase (RT): (i) TAM1: M41L, L210W and T215Y, and (ii) TAM2: D67N, K70R and K219E/Q, and sometimes T215F. Secondary mutations, including thumb subdomain polymorphisms (e.g. R284K) have been identified in association with TAMs. We have identified mutational clusters associated with virological failure during salvage therapy with tenofovir/emtricitabine-based regimens. In this context, we have studied the role of R284K as a secondary mutation associated with mutations of the TAM1 complex. Results The cross-sectional study carried out with >200 HIV-1 genotypes showed that virological failure to tenofovir/emtricitabine was strongly associated with the presence of M184V (P < 10-10) and TAMs (P < 10-3), while K65R was relatively uncommon in previously-treated patients failing antiretroviral therapy. Clusters of mutations were identified, and among them, the TAM1 complex showed the highest correlation coefficients. Covariation of TAM1 mutations and V118I, V179I, M184V and R284K was observed. Virological studies showed that the combination of R284K with TAM1 mutations confers a fitness advantage in the presence of zidovudine or tenofovir. Studies with recombinant HIV-1 RTs showed that when associated with TAM1 mutations, R284K had a minimal impact on zidovudine or tenofovir inhibition, and in their ability to excise the inhibitors from blocked DNA primers. However, the mutant RT M41L/L210W/T215Y/R284K showed an increased catalytic rate for nucleotide incorporation and a higher RNase H activity in comparison with WT and mutant M41L/L210W/T215Y RTs. These effects were consistent with its enhanced chain-terminated primer rescue on DNA/DNA template-primers, but not on RNA/DNA complexes, and can explain the higher fitness of HIV-1 having TAM1/R284K mutations. Conclusions Our study shows the association

  6. Designing interventions to prevent HIV-1 infection by promoting use of condoms and spermicides among intravenous drug abusers and their sexual partners.

    PubMed

    Stone, A J; Morisky, D; Detels, R; Braxton, H

    1989-01-01

    This paper summarizes the results of a 2-day workshop to identify the most effective educational strategies to promote use of condoms and spermicides for preventing heterosexual transmission of HIV-1 virus from intravenous drug abusers (IVDA) to their steady, nonintravenous drug abusing (NIVDA) sexual partners. Representatives from health departments, drug abuse treatment centers, academic institutions, service organizations, and the community discussed issues relating to population characteristics, educational strategies and recruitment techniques. A consensus document that identifies the most effective recruitment and intervention strategies was developed. Recruitment issues include locations, recruitment targets, anticipated difficulties, and ethical considerations. The majority of workshop participants agreed that an intervention should target the couple (both IVDA and NIVDA). Intervention concerns encompass obtaining trust, maintaining participation, and identifying guidelines to maximize program impact.

  7. Incarceration is associated with used syringe lending among active injection drug users with detectable plasma HIV-1 RNA: a longitudinal analysis

    PubMed Central

    2013-01-01

    Background Informed by recent studies demonstrating the central role of plasma HIV-1 RNA viral load (VL) on HIV transmission, interventions to employ HIV antiretroviral treatment as prevention (TasP) are underway. To optimize these efforts, evidence is needed to identify factors associated with both non-suppressed VL and HIV risk behaviours. Thus, we sought to assess the possible role played by exposure to correctional facilities on VL non-suppression and used syringe lending among HIV-seropositive people who use injection drugs (PWID). Methods We used data from the ACCESS study, a community-recruited prospective cohort. We used longitudinal multivariate mixed-effects analyses to estimate the relationship between incarceration and plasma HIV-1 RNA > 500 copies/mL among antiretroviral therapy (ART)-exposed active PWID and, during periods of non-suppression, the relationship between incarceration and used syringe lending. Results Between May 1996 and March 2012, 657 ART-exposed PWID were recruited. Incarceration was independently associated with higher odds of VL non-suppression (Adjusted Odds Ratio [AOR] = 1.54, 95% Confidence Interval [95% CI]: 1.10, 2.16). In a separate multivariate model restricted to periods of VL non-suppression, incarceration was independently associated with lending used syringes (AOR = 1.81, 95% CI: 1.03, 3.18). Conclusions The current findings demonstrate that incarceration is associated with used syringe lending among active PWID with detectable plasma HIV-1 RNA. Our results provide a possible pathway for the commonly observed association between incarceration and increased risk of HIV transmission. Our results suggest that alternatives to incarceration of non-violent PWID and evidence-based combination HIV prevention interventions for PWID within correctional facilities are urgently needed. PMID:24289651

  8. Short communication: high prevalence of drug resistance in HIV type 1-infected children born in Honduras and Belize 2001 to 2004.

    PubMed

    Parham, Leda; de Rivera, Ivette Lorenzana; Murillo, Wendy; Naver, Lars; Largaespada, Natalia; Albert, Jan; Karlsson, Annika C

    2011-10-01

    Antiretroviral therapy has had a great impact on the prevention of mother-to-child transmission (MTCT) of HIV-1. However, development of drug resistance, which could be subsequently transmitted to the child, is a major concern. In Honduras and Belize the prevalence of drug resistance among HIV-1-infected children remains unknown. A total of 95 dried blood spot samples was obtained from HIV-1-infected, untreated children in Honduras and Belize born during 2001 to 2004, when preventive antiretroviral therapy was often suboptimal and consisted of monotherapy with nevirapine or zidovudine. Partial HIV-1 pol gene sequences were successfully obtained from 66 children (Honduras n=55; Belize n=11). Mutations associated with drug resistance were detected in 13% of the Honduran and 27% of the Belizean children. Most of the mutations detected in Honduras (43%) and all mutations detected in Belize were associated with resistance to nonnucleoside reverse transcriptase inhibitors, which was expected from the wide use of nevirapine to prevent MTCT during the study period. In addition, although several mothers reported that they had not received antiretroviral therapy, mutations associated with resistance to nucleoside reverse transcriptase inhibitors and protease inhibitors were found in Honduras. This suggests prior and unreported use of these drugs, or that these women had been infected with resistant virus. The present study demonstrates, for the first time, the presence of drug resistance-associated mutations in HIV-1-infected Honduran and Belizean children.

  9. Molecular mechanisms of resistance: free energy calculations of mutation effects on inhibitor binding to HIV-1 protease.

    PubMed Central

    Rick, S. W.; Topol, I. A.; Erickson, J. W.; Burt, S. K.

    1998-01-01

    The changes in the inhibitor binding constants due to the mutation of isoleucine to valine at position 84 of HIV-1 protease are calculated using molecular dynamics simulations. The calculations are done for three potent inhibitors--KNI-272, L-735,524 (indinavir or MK-639), and Ro 31-8959 (saquinavir). The calculations agree with the experimental data both in terms of an overall trend and in the magnitude of the resulting free energy change. HIV-1 protease is a homodimer, so each mutation causes two changes in the enzyme. The decrease in the binding free energy from each mutated side chain differs among the three inhibitors and correlates well with the size of the cavities induced in the protein interior near the mutated residue. The cavities are created as a result of a mutation to a smaller side chain, but the cavities are less than would be predicted from the wild-type structures, indicating that there is significant relaxation to partially fill the cavities. PMID:10082371

  10. Persistent HIV-1 replication maintains the tissue reservoir during therapy

    PubMed Central

    Bedford, Trevor; Kim, Eun-Young; Archer, John; Pond, Sergei L. Kosakovsky; Chung, Yoon-Seok; Penugonda, Sudhir; Chipman, Jeffrey; Fletcher, Courtney V.; Schacker, Timothy W.; Malim, Michael H.; Rambaut, Andrew; Haase, Ashley T.; McLean, Angela R.; Wolinsky, Steven M.

    2015-01-01

    Lymphoid tissue is a key reservoir established by HIV-1 during acute infection. It is a site of viral production, storage of viral particles in immune complexes, and viral persistence. Whilst combinations of antiretroviral drugs usually suppress viral replication and reduce viral RNA to undetectable levels in blood, it is unclear whether treatment fully suppresses viral replication in lymphoid tissue reservoirs. Here we show that virus evolution and trafficking between tissue compartments continues in patients with undetectable levels of virus in their bloodstream. A spatial dynamic model of persistent viral replication and spread explains why the development of drug resistance is not a foregone conclusion under conditions where drug concentrations are insufficient to completely block virus replication. These data provide fresh insights into the evolutionary and infection dynamics of the virus population within the host, revealing that HIV-1 can continue to replicate and refill the viral reservoir despite potent antiretroviral therapy. PMID:26814962

  11. Design, synthesis and evaluation of a potent substrate analog inhibitor identified by scanning Ala/Phe mutagenesis, mimicking substrate co-evolution, against multidrug-resistant HIV-1 protease

    SciTech Connect

    Yedidi, Ravikiran S.; Muhuhi, Joseck M.; Liu, Zhigang; Bencze, Krisztina Z.; Koupparis, Kyriacos; O’Connor, Carrie E.; Kovari, Iulia A.; Spaller, Mark R.; Kovari, Ladislau C.

    2013-09-06

    Highlights: •Inhibitors against MDR HIV-1 protease were designed, synthesized and evaluated. •Lead peptide (6a) showed potent inhibition (IC{sub 50}: 4.4 nM) of MDR HIV-1 protease. •(6a) Showed favorable binding isotherms against NL4-3 and MDR proteases. •(6a) Induced perturbations in the {sup 15}N-HSQC spectrum of MDR HIV-1 protease. •Molecular modeling suggested that (6a) may induce total flap closure inMDR protease. -- Abstract: Multidrug-resistant (MDR) clinical isolate-769, human immunodeficiency virus type-1 (HIV-1) protease (PDB ID: (1TW7)), was shown to exhibit wide-open flaps and an expanded active site cavity, causing loss of contacts with protease inhibitors. In the current study, the expanded active site cavity of MDR769 HIV-1 protease was screened with a series of peptide-inhibitors that were designed to mimic the natural substrate cleavage site, capsid/p2. Scanning Ala/Phe chemical mutagenesis approach was incorporated into the design of the peptide series to mimic the substrate co-evolution. Among the peptides synthesized and evaluated, a lead peptide (6a) with potent activity (IC{sub 50}: 4.4 nM) was identified against the MDR769 HIV-1 protease. Isothermal titration calorimetry data showed favorable binding profile for 6aagainst both wild type and MDR769 HIV-1 protease variants. Nuclear magnetic resonance spectrum of {sup 15}N-labeled MDR769 HIV-1 protease in complex with 6a showed some major perturbations in chemical shift, supporting the peptide induced conformational changes in protease. Modeling analysis revealed multiple contacts between 6a and MDR769 HIV-1 protease. The lead peptide-inhibitor, 6a, with high potency and good binding profile can be used as the basis for developing potent small molecule inhibitors against MDR variants of HIV.

  12. Hepatitis B virus and hepatitis C virus infection among HIV-1-infected injection drug users in Dali, China: prevalence and infection status in a cross-sectional study.

    PubMed

    Dong, Yuan; Qiu, Chao; Xia, Xueshan; Wang, Jing; Zhang, Haiyan; Zhang, Xiaoyan; Xu, Jianqing

    2015-04-01

    To assess the prevalence of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection and to investigate their mutual influences on infection status among human immunodeficiency virus type 1 (HIV-1)-seropositive injection drug users (IDUs). A cross-sectional study was conducted among HIV infected IDUs in Dali, China. The participants were tested for serological markers of HBV and HCV infection, alanine transaminase (ALT) activity and CD4(+) T cell count. HCV genotype was determined by sequencing. Of 529 patients, 498 (94.1 %) HIV infected IDUs agreed to participate. The overall prevalence of HCV infection (anti-HCV antibody positive) and spontaneous HCV clearance were 90.8 % (452/498) and 21.5 % (97/452), respectively. Of 411 subjects who had not received HBV vaccine, 296 (72.0 %) were positive for antibody against HBV core antigen (HBcAb), while 274 (66.7 %) were positive for both HCV antibody and HBcAb. HBV antigens were detected in 52 of the HBV-infected subjects (17.6 %). HCV clearance was associated with HBV antigenemia (p = 0.0002) and higher CD4(+) T cell count (p = 0.0294). Resolved HBV infection was associated with HCV genotype 3 (p = 0.0365). HBV and HCV infection are highly prevalent and mutually influence infection status in HIV-1 infected IDUs in Dali, China.

  13. HIV-1 Reverse Transcriptase Still Remains a New Drug Target: Structure, Function, Classical Inhibitors, and New Inhibitors with Innovative Mechanisms of Actions

    PubMed Central

    Esposito, Francesca; Corona, Angela; Tramontano, Enzo

    2012-01-01

    During the retrotranscription process, characteristic of all retroviruses, the viral ssRNA genome is converted into integration-competent dsDNA. This process is accomplished by the virus-coded reverse transcriptase (RT) protein, which is a primary target in the current treatments for HIV-1 infection. In particular, in the approved therapeutic regimens two classes of drugs target RT, namely, nucleoside RT inhibitors (NRTIs) and nonnucleoside RT inhibitors (NNRTIs). Both classes inhibit the RT-associated polymerase activity: the NRTIs compete with the natural dNTP substrate and act as chain terminators, while the NNRTIs bind to an allosteric pocket and inhibit polymerization noncompetitively. In addition to these two classes, other RT inhibitors (RTIs) that target RT by distinct mechanisms have been identified and are currently under development. These include translocation-defective RTIs, delayed chain terminators RTIs, lethal mutagenesis RTIs, dinucleotide tetraphosphates, nucleotide-competing RTIs, pyrophosphate analogs, RT-associated RNase H function inhibitors, and dual activities inhibitors. This paper describes the HIV-1 RT function and molecular structure, illustrates the currently approved RTIs, and focuses on the mechanisms of action of the newer classes of RTIs. PMID:22778958

  14. A novel mechanism for inhibition of HIV-1 reverse transcriptase.

    PubMed

    Skillman, A Geoffrey; Maurer, Karl W; Roe, Diana C; Stauber, Margaret J; Eargle, Dolan; Ewing, Todd J A; Muscate, Angelika; Davioud-Charvet, Elisabeth; Medaglia, Maxine V; Fisher, Robert J; Arnold, Edward; Gao, Hong Qiang; Buckheit, Robert; Boyer, Paul L; Hughes, Stephen H; Kuntz, Irwin D; Kenyon, George L

    2002-12-01

    The human immunodeficiency virus (HIV) epidemic is an important medical problem. Although combination drug regimens have produced dramatic decreases in viral load, current therapies do not provide a cure for HIV infection. We have used structure-based design and combinatorial medicinal chemistry to identify potent and selective HIV-1 reverse transcriptase (RT) inhibitors that may work by a mechanism distinct from that of current HIV drugs. The most potent of these compounds (compound 4, 2-naphthalenesulfonic acid, 4-hydroxy-7-[[[[5-hydroxy-6-[(4-cinnamylphenyl)azo]-7-sulfo-2-naphthalenyl]amino]carbonyl]amino]-3-[(4-cinnamylphenyl)azo], disodium salt) has an IC(50) of 90 nM for inhibition of polymerase chain extension, a K(d) of 40 nM for inhibition of DNA-RT binding, and an IC(50) of 25-100 nM for inhibition of RNaseH cleavage. The parent compound (1) was as effective against 10 nucleoside and non-nucleoside resistant HIV-1 RT mutants as it was against the wild-type enzyme. Compound 4 inhibited HIV-1 RT and murine leukemia virus (MLV) RT, but it did not inhibit T(4) DNA polymerase, T(7) DNA polymerase, or the Klenow fragment at concentrations up to 200 nM. Finally, compound 4 protected cells from HIV-1 infection at a concentration more than 40 times lower than the concentration at which it caused cellular toxicity.

  15. Development of HIV-1 fusion inhibitors targeting gp41.

    PubMed

    Lu, K; Asyifah, M R; Shao, F; Zhang, D

    2014-06-01

    The HIV-1 envelope protein glycoprotein 41 (gp41) is crucial in the HIV-1 infection process, therefore gp41 has emerged as an attractive target for drug design against AIDS. During the past few decades, tremendous efforts have been made on developing inhibitors that can prevent the HIV-1 entry process via suppressing functional gp41. In this review, the development of HIV-1 fusion inhibitors targeting gp41 including peptide inhibitors, small molecule inhibitors, vaccines and neutralized antibodies will be discussed.

  16. Efficient Modification of the CCR5 Locus in Primary Human T Cells With megaTAL Nuclease Establishes HIV-1 Resistance

    PubMed Central

    Romano Ibarra, Guillermo S; Paul, Biswajit; Sather, Blythe D; Younan, Patrick M; Sommer, Karen; Kowalski, John P; Hale, Malika; Stoddard, Barry; Jarjour, Jordan; Astrakhan, Alexander; Kiem, Hans-Peter; Rawlings, David J

    2016-01-01

    A naturally occurring 32-base pair deletion of the HIV-1 co-receptor CCR5 has demonstrated protection against HIV infection of human CD4+ T cells. Recent genetic engineering approaches using engineered nucleases to disrupt the gene and mimic this mutation show promise for HIV therapy. We developed a megaTAL nuclease targeting the third extracellular loop of CCR5 that we delivered to primary human T cells by mRNA transfection. The CCR5 megaTAL nuclease established resistance to HIV in cell lines and disrupted the expression of CCR5 on primary human CD4+ T cells with a high efficiency, achieving up to 80% modification of the locus in primary cells as measured by molecular analysis. Gene-modified cells engrafted at levels equivalent to unmodified cells when transplanted into immunodeficient mice. Furthermore, genetically modified CD4+ cells were preferentially expanded during HIV-1 infection in vivo in an immunodeficient mouse model. Our results demonstrate the feasibility of targeting CCR5 in primary T cells using an engineered megaTAL nuclease, and the potential to use gene-modified cells to reconstitute a patient's immune system and provide protection from HIV infection. PMID:27741222

  17. Severe Impairment of Endothelial Function with the HIV-1 Protease Inhibitor Indinavir is not Mediated by Insulin Resistance in Healthy Subjects

    PubMed Central

    Dubé, Michael P.; Gorski, J. Christopher; Shen, Changyu

    2010-01-01

    Endothelial dysfunction may contribute to increased cardiovascular events among HIV-1 infected patients receiving antiretroviral therapy. The HIV-1 protease inhibitor indinavir causes both vascular dysfunction and insulin resistance, but the relationship between the two disturbances is not established. Endothelium-dependent vasodilation (EDV), insulin-mediated vasodilation (IMV), and whole body and leg glucose uptake during a euglycemic hyperinsulinemic clamp (40 mU/m2/min) were measured before and after four weeks of indinavir in nine healthy men. EDV fell from 270 ± 67% above basal to 124 ± 30% (p=0.04) and IMV from 56 ± 14% above basal to 8 ± 8% (p=0.001) with indinavir. During the clamp, arteriovenous glucose difference and leg glucose uptake were not significantly different after indinavir and whole-body glucose uptake was only modestly reduced (8.0 ± 0.8 vs 7.2 ± 0.8 mg/kg/min, p=0.04). The change in EDV did not correlate with the change in whole-body glucose uptake after indinavir (r=0.21, p=0.6). Despite marked impairment of endothelial function and IMV with indinavir, only modest, inconsistent reductions in measures of insulin stimulated glucose uptake occurred. This suggests that indinavir's effects on glucose metabolism are not directly related to indinavir-associated endothelial dysfunction. Studies of the vascular effects of newer protease inhibitors are needed. PMID:18172783

  18. Effect of HIV-1 Subtype C integrase mutations implied using molecular modeling and docking data.

    PubMed

    Sachithanandham, Jaiprasath; Konda Reddy, Karnati; Solomon, King; David, Shoba; Kumar Singh, Sanjeev; Vadhini Ramalingam, Veena; Alexander Pulimood, Susanne; Cherian Abraham, Ooriyapadickal; Rupali, Pricilla; Sridharan, Gopalan; Kannangai, Rajesh

    2016-01-01

    The degree of sequence variation in HIV-1 integrase genes among infected patients and their impact on clinical response to Anti retroviral therapy (ART) is of interest. Therefore, we collected plasma samples from 161 HIV-1 infected individuals for subsequent integrase gene amplification (1087 bp). Thus, 102 complete integrase gene sequences identified as HIV-1 subtype-C was assembled. This sequence data was further used for sequence analysis and multiple sequence alignment (MSA) to assess position specific frequency of mutations within pol gene among infected individuals. We also used biophysical geometric optimization technique based molecular modeling and docking (Schrodinger suite) methods to infer differential function caused by position specific sequence mutations towards improved inhibitor selection. We thus identified accessory mutations (usually reduce susceptibility) leading to the resistance of some known integrase inhibitors in 14% of sequences in this data set. The Stanford HIV-1 drug resistance database provided complementary information on integrase resistance mutations to deduce molecular basis for such observation. Modeling and docking analysis show reduced binding by mutants for known compounds. The predicted binding values further reduced for models with combination of mutations among subtype C clinical strains. Thus, the molecular basis implied for the consequence of mutations in different variants of integrase genes of HIV-1 subtype C clinical strains from South India is reported. This data finds utility in the design, modification and development of a representative yet an improved inhibitor for HIV-1 integrase.

  19. Effect of HIV-1 Subtype C integrase mutations implied using molecular modeling and docking data

    PubMed Central

    Sachithanandham, Jaiprasath; Konda Reddy, Karnati; Solomon, King; David, Shoba; Kumar Singh, Sanjeev; Vadhini Ramalingam, Veena; Alexander Pulimood, Susanne; Cherian Abraham, Ooriyapadickal; Rupali, Pricilla; Sridharan, Gopalan; Kannangai, Rajesh

    2016-01-01

    The degree of sequence variation in HIV-1 integrase genes among infected patients and their impact on clinical response to Anti retroviral therapy (ART) is of interest. Therefore, we collected plasma samples from 161 HIV-1 infected individuals for subsequent integrase gene amplification (1087 bp). Thus, 102 complete integrase gene sequences identified as HIV-1 subtype-C was assembled. This sequence data was further used for sequence analysis and multiple sequence alignment (MSA) to assess position specific frequency of mutations within pol gene among infected individuals. We also used biophysical geometric optimization technique based molecular modeling and docking (Schrodinger suite) methods to infer differential function caused by position specific sequence mutations towards improved inhibitor selection. We thus identified accessory mutations (usually reduce susceptibility) leading to the resistance of some known integrase inhibitors in 14% of sequences in this data set. The Stanford HIV-1 drug resistance database provided complementary information on integrase resistance mutations to deduce molecular basis for such observation. Modeling and docking analysis show reduced binding by mutants for known compounds. The predicted binding values further reduced for models with combination of mutations among subtype C clinical strains. Thus, the molecular basis implied for the consequence of mutations in different variants of integrase genes of HIV-1 subtype C clinical strains from South India is reported. This data finds utility in the design, modification and development of a representative yet an improved inhibitor for HIV-1 integrase. PMID:28149058

  20. The current status and challenges in the development of fusion inhibitors as therapeutics for HIV-1 infection.

    PubMed

    Tan, Jian Jun; Ma, Xue Ting; Liu, Chang; Zhang, Xiao Yi; Wang, Cun Xin

    2013-01-01

    HIV-1 membrane fusion as a part of the process of viral entry in the target cells is facilitated by gp41 and gp120, which are encoded by Env gene of HIV-1. Based on the structure and the mechanism researches, new treatment options targeting HIV-1 entry process have been proposed. Enfuvirtide, which mimics amino acid sequences of viral envelope glycoprotein gp41, is the first HIV-1 fusion inhibitor approved by FDA. Although it fulfills vital functions by binding to gp41 and abolishing the membrane fusion reaction when used in combination, it could induce drug resistant virus variants. Currently, a number of design and modification schemes have been presented, a large number of prospective fusion peptides have emerged. For these fusion inhibitors, multiple mutations in gp41 have been associated with the loss of susceptibility to agents. This review reported the current developments and innovative designs of HIV-1 membrane fusion inhibitors.

  1. The impact of HIV-1 genetic diversity on the efficacy of a combinatorial RNAi-based gene therapy.

    PubMed

    Herrera-Carrillo, E; Berkhout, B

    2015-06-01

    A hurdle for human immunodeficiency virus (HIV-1) therapy is the genomic diversity of circulating viruses and the possibility that drug-resistant virus variants are selected. Although RNA interference (RNAi) is a powerful tool to stably inhibit HIV-1 replication by the expression of antiviral short hairpin RNAs (shRNAs) in transduced T cells, this approach is also vulnerable to pre-existing genetic variation and the development of viral resistance through mutation. To prevent viral escape, we proposed to combine multiple shRNAs against important regions of the HIV-1 RNA genome, which should ideally be conserved in all HIV-1 subtypes. The vulnerability of RNAi therapy to viral escape has been studied for a single subtype B strain, but it is unclear whether the antiviral shRNAs can inhibit diverse virus isolates and subtypes, including drug-resistant variants that could be present in treated patients. To determine the breadth of the RNAi gene therapy approach, we studied the susceptibility of HIV-1 subtypes A-E and drug-resistant variants. In addition, we monitored the evolution of HIV-1 escape variants. We demonstrate that the combinatorial RNAi therapy is highly effective against most isolates, supporting the future testing of this gene therapy in appropriate in vivo models.

  2. Psychoneuroimmunology and HIV-1.

    ERIC Educational Resources Information Center

    Antoni, Michael H.; And Others

    1990-01-01

    Presents evidence describing benefits of behavioral interventions such as aerobic exercise training on both psychological and immunological functioning among high risk human immunodeficiency virus-Type 1 (HIV-1) seronegative and very early stage seropositive homosexual men. HIV-1 infection is cast as chronic disease for which early…

  3. Blocking HIV-1 entry by a gp120 surface binding inhibitor

    PubMed Central

    Tsou, Lun K.; Chen, Chin-Ho; Dutschman, Ginger E.

    2012-01-01

    We report the mode of action of a proteomimetic compound that binds to the exterior surface of gp120 and blocks HIV-1 entry into cells. Using a one cycle time-of-addition study and antibody competition binding studies, we have determined that the compound blocks HIV-1 entry through modulation of key protein-protein interactions mediated by gp120. The compound exhibits anti-HIV-1 replication activities against several pseudotype viruses derived from primary isolates and the resistant strains isolated from existing drug candidates with equal potency. Together, these data provide evidence that the proteomimetic compound represents a novel class of HIV-1 viral entry inhibitor that functions through protein surface recognition in analogy to an antibody. PMID:22487177

  4. Identifying Recombination Hot Spots in the HIV-1 Genome

    PubMed Central

    Smyth, Redmond P.; Schlub, Timothy E.; Grimm, Andrew J.; Waugh, Caryll; Ellenberg, Paula; Chopra, Abha; Mallal, Simon; Cromer, Deborah

    2014-01-01

    ABSTRACT HIV-1 infection is characterized by the rapid generation of genetic diversity that facilitates viral escape from immune selection and antiretroviral therapy. Despite recombination's crucial role in viral diversity and evolution, little is known about the genomic factors that influence recombination between highly similar genomes. In this study, we use a minimally modified full-length HIV-1 genome and high-throughput sequence analysis to study recombination in gag and pol in T cells. We find that recombination is favored at a number of recombination hot spots, where recombination occurs six times more frequently than at corresponding cold spots. Interestingly, these hot spots occur near important features of the HIV-1 genome but do not occur at sites immediately around protease inhibitor or reverse transcriptase inhibitor drug resistance mutations. We show that the recombination hot and cold spots are consistent across five blood donors and are independent of coreceptor-mediated entry. Finally, we check common experimental confounders and find that these are not driving the location of recombination hot spots. This is the first study to identify the location of recombination hot spots between two similar viral genomes with great statistical power and under conditions that closely reflect natural recombination events among HIV-1 quasispecies. IMPORTANCE The ability of HIV-1 to evade the immune system and antiretroviral therapy depends on genetic diversity within the viral quasispecies. Retroviral recombination is an important mechanism that helps to generate and maintain this genetic diversity, but little is known about how recombination rates vary within the HIV-1 genome. We measured recombination rates in gag and pol and identified recombination hot and cold spots, demonstrating that recombination is not random but depends on the underlying gene sequence. The strength and location of these recombination hot and cold spots can be used to improve models of

  5. Characterization of the HIV-1 TAR RNA-Tat peptide and drug interactions by on-line acoustic wave sensor

    NASA Astrophysics Data System (ADS)

    Tassew, Nardos Gobena

    This thesis presents the application of the thickness shear-mode (TSM) acoustic wave sensor to the study of RNA-protein and RNA-drug interactions at the solid-liquid interface. The binding of the human immunodeficiency virus-type 1 Tat protein to the trans-activation responsive RNA element (TAR) has been studied using this sensor. Data from such measurements show that the sensor is able to discriminate between different Tat peptides derived from the parent protein based on size. The effects of mutations introduced at specific sites in the protein and RNA on the TAR-Tat binding have also been examined in detail. Reduced level of response in acoustic parameters due to mutations was observed indicating that the decrease in binding in response to site specific mutations can be acoustically detected. Data from acoustic wave sensor measurements indicate that the TAR-Tat binding is also affected by ionic strength. Both the frequency and motional resistance signals show periodic responses when varying concentrations of salt are introduced on a TAR-modified surface. The binding of the two molecules seems to be a function of the response of the nucleic acid to salt concentrations. The kinetics of binding of Tat peptides to TAR RNA and to a bulge mutant analogue (MTAR) is also examined from the rate of change of the series resonant frequency. Results from such analysis illustrate longer Tat peptides formed more stable complexes with TAR RNA and exhibited increased discrimination between mutant and wild type TAR. The binding of two aminoglycoside antibiotics, neomycin and streptomycin, to TAR RNA and their effectiveness in preventing TAR-Tat complex formation has been studied in detail. Binding affinity is directly correlated with the inhibitory potency of these molecules and the TSM sensor shows that neomycin exhibits at least a ten fold greater affinity to TAR and that it is also a more potent inhibitor than streptomycin. The results from this research involving TAR-Tat and

  6. The application of artificial neural networks for phenotypic drug resistance prediction: evaluation and comparison with other interpretation systems.

    PubMed

    Pasomsub, Ekawat; Sukasem, Chonlaphat; Sungkanuparph, Somnuek; Kijsirikul, Boonserm; Chantratita, Wasun

    2010-03-01

    Although phenotypic resistance testing provides more direct measurement of antiretroviral drug resistance than genotypic testing, it is costly and time-consuming. However, genotypic resistance testing has the advantages of being simpler and more accessible, and it might be possible to use the data obtained for predicting quantitative drug susceptibility to interpret complex mutation combinations. This study applied the Artificial Neural Network (ANN) system to predict the HIV-1 resistance phenotype from the genotype. A total of 7,598 pairs of HIV-1 sequences, with their corresponding phenotypic fold change values for 14 antiretroviral drugs, were trained, validated, and tested in ANN modeling. The results were compared with the HIV-SEQ and Geno2pheno interpretation systems. The prediction performance of the ANN models was measured by 10-fold cross-validation. The results indicated that by using the ANN, with an associated set of amino acid positions known to influence drug resistance for individual antiretroviral drugs, drug resistance was accurately predicted and generalized for individual HIV-1 subtypes. Therefore, high correlation with the experimental phenotype may help physicians choose optimal therapeutic regimens that might be an option, or supporting system, of FDA-approved genotypic resistance testing in heavily treatment-experienced patients.

  7. Drug resistance in eukaryotic microorganisms.

    PubMed

    Fairlamb, Alan H; Gow, Neil A R; Matthews, Keith R; Waters, Andrew P

    2016-06-24

    Eukaryotic microbial pathogens are major contributors to illness and death globally. Although much of their impact can be controlled by drug therapy as with prokaryotic microorganisms, the emergence of drug resistance has threatened these treatment efforts. Here, we discuss the challenges posed by eukaryotic microbial pathogens and how these are similar to, or differ from, the challenges of prokaryotic antibiotic resistance. The therapies used for several major eukaryotic microorganisms are then detailed, and the mechanisms that they have evolved to overcome these therapies are described. The rapid emergence of resistance and the restricted pipeline of new drug therapies pose considerable risks to global health and are particularly acute in the developing world. Nonetheless, we detail how the integration of new technology, biological understanding, epidemiology and evolutionary analysis can help sustain existing therapies, anticipate the emergence of resistance or optimize the deployment of new therapies.

  8. Drug resistance in eukaryotic microorganisms

    PubMed Central

    Fairlamb, Alan H.; Gow, Neil A. R.; Matthews, Keith R.; Waters, Andrew P.

    2016-01-01

    Eukaryotic microbial pathogens are major contributors to illness and death globally. Although much of their impact can be controlled by drug therapy as with prokaryotic microorganisms, the emergence of drug resistance has threatened these treatment efforts. Here, we discuss the challenges posed by eukaryotic microbial pathogens and how these are similar to, or differ from, the challenges of prokaryotic antibiotic resistance. The therapies used for several major eukaryotic microorganisms are then detailed, and the mechanisms that they have evolved to overcome these therapies are described. The rapid emergence of resistance and the restricted pipeline of new drug therapies pose considerable risks to global health and are particularly acute in the developing world. Nonetheless, we detail how the integration of new technology, biological understanding, epidemiology and evolutionary analysis can help sustain existing therapies, anticipate the emergence of resistance or optimize the deployment of new therapies. PMID:27572976

  9. Structure of HIV-1 nonnucleoside reverse transcriptase inhibitors derivatives of N-benzyl-benzimidazole with different substituents in position 4

    NASA Astrophysics Data System (ADS)

    Ziółkowska, Natasza E.; Michejda, Christopher J.; Bujacz, Grzegorz D.

    2010-01-01

    The constant development of new drugs against HIV-1 is necessary due to global expansion of AIDS and HIV-1 drug resistance. Nonnucleoside reverse transcriptase inhibitors of HIV-1 (NNRTIs) are potentially effective and nontoxic drugs in AIDS therapy. The crystal structures of six nonnucleoside inhibitors of HIV-1 reverse transcriptase (RT) derivatives of N-benzyl-benzimidazole are reported here. The investigated compounds belong to the group of so called "butterfly like" inhibitors with characteristic two π-electron moieties with an angled orientation. The structural data show the influence of the substituents of the benzimidazole ring on the geometry of the molecule and correlation between the structure of the inhibitor and its biological activity.

  10. Fluctuating partially native-like topologies in the acid denatured ensemble of autolysis resistant HIV-1 protease.

    PubMed

    Rout, Manoj Kumar; Hosur, Ramakrishna V

    2009-02-01

    Folding, in-vivo, starts from a denatured state and thus the nature of the denatured state would play an important role in directing the folding of a protein. We report here NMR characterization of the acid-denatured state of a mutant of HIV-1 protease, designed to prevent autolysis (Q7K, L33I, L63I) and to prevent cysteine oxidation (C67A and C95A). Secondary chemical shifts, TALOS analysis of chemical shifts and (15)N relaxation data (R(1), R(2), NOE) coupled with AABUF and hydrophobicity calculations, suggest formation of hydrophobic clusters and possibility of some partially native-like topologies in the acid denatured state of the protease. The structural and dynamics characteristics of the acid denatured PR seem to be considerably different from those of the guanidine or urea denatured states of some variants of PR. These would have implications for the folding and auto-processing of the enzyme in-vivo.

  11. In Vitro Characterization of GS-8374, a Novel Phosphonate-Containing Inhibitor of HIV-1 Protease with a Favorable Resistance Profile ▿ †

    PubMed Central

    Callebaut, Christian; Stray, Kirsten; Tsai, Luong; Williams, Matt; Yang, Zheng-Yu; Cannizzaro, Carina; Leavitt, Stephanie A.; Liu, Xiaohong; Wang, Kelly; Murray, Bernard P.; Mulato, Andrew; Hatada, Marcos; Priskich, Tina; Parkin, Neil; Swaminathan, Swami; Lee, William; He, Gong-Xin; Xu, Lianhong; Cihlar, Tomas

    2011-01-01

    GS-8374 is a novel bis-tetrahydrofuran HIV-1 protease (PR) inhibitor (PI) with a unique diethylphosphonate moiety. It was selected from a series of analogs containing various di(alkyl)phosphonate substitutions connected via a linker to the para position of a P-1 phenyl ring. GS-8374 inhibits HIV-1 PR with high potency (Ki = 8.1 pM) and with no known effect on host proteases. Kinetic and thermodynamic analysis of GS-8374 binding to PR demonstrated an extremely slow off rate for the inhibitor and favorable contributions of both the enthalpic and entropic components to the total free binding energy. GS-8374 showed potent antiretroviral activity in T-cell lines, primary CD4+ T cells (50% effective concentration [EC50] = 3.4 to 11.5 nM), and macrophages (EC50 = 25.5 nM) and exhibited low cytotoxicity in multiple human cell types. The antiviral potency of GS-8374 was only moderately affected by human serum protein binding, and its combination with multiple approved antiretrovirals showed synergistic effects. When it was tested in a PhenoSense assay against a panel of 24 patient-derived viruses with high-level PI resistance, GS-8374 showed lower mean EC50s and lower fold resistance than any of the clinically approved PIs. Similar to other PIs, in vitro hepatic microsomal metabolism of GS-8374 was efficiently blocked by ritonavir, suggesting a potential for effective pharmacokinetic boosting in vivo. In summary, results from this broad in vitro pharmacological profiling indicate that GS-8374 is a promising candidate to be further assessed as a new antiretroviral agent with potential for clinical efficacy in both treatment-naïve and -experienced patients. PMID:21245449

  12. Current progress in the development of RNAi-based therapeutics for HIV-1.

    PubMed

    Zhou, J; Rossi, J J

    2011-12-01

    Highly active antiretroviral therapy (HAART) treatment for HIV has changed the course of AIDS in societies in which the drugs are readily available. Despite the great success of HAART, drug resistance and toxicity issues still remain a concern for some individuals. Thus, a number of investigators have been exploring other approaches for inhibiting HIV-1 replication. One of the most potent of these is the use of RNA interference (RNAi). This review will focus solely on the use of RNAi for the treatment of HIV-1 infection, including the problems, progress and future prospects.

  13. Genetic diversity and drug resistance profiles in HIV type 1- and HIV type 2-infected patients from Cape Verde Islands.

    PubMed

    Oliveira, Vânia; Bártolo, Inês; Borrego, Pedro; Rocha, Cheila; Valadas, Emília; Barreto, Jorge; Almeida, Elsa; Antunes, Francisco; Taveira, Nuno

    2012-05-01

    Our aim was to characterize for the first time the genetic diversity of HIV in Cape Verde Islands as well as the drug resistance profiles in treated and untreated patients. Blood specimens were collected from 41 HIV-1 and 14 HIV-2 patients living in Santiago Island. Half of the patients were on antiretroviral treatment (ART). Pol and env gene sequences were obtained using in-house methods. Phylogenetic analysis was used for viral subtyping and the Stanford Algorithm was used for resistance genotyping. For HIV-1, the amplification of pol and env was possible in 27 patients (66%). HIV-1 patients were infected with subtypes G (13, 48%), B (2, 7%), F1 (2, 7%), and CRF02_AG (2, 7%), and complex recombinant forms including a new C/G variant (n=8, 30%). Drug resistance mutations were detected in the PR and RT of three (10%) treated patients. M41L and K103N transmitted drug resistance mutations were found in 2 of 17 (12%) untreated patients. All 14 HIV-2 isolates belonged to group A. The origin of 12 strains was impossible to determine whereas two strains were closely related to the historic ROD strain. In conclusion, in Cape Verde there is a long-standing HIV-2 epidemic rooted in ROD-like strains and a more recent epidemic of unknown origin. The HIV-1 epidemic is caused by multiple subtypes and complex recombinant forms. Drug resistance HIV-1 strains are present at moderate levels in both treated and untreated patients. Close surveillance in these two populations is crucial to prevent further transmission of drug-resistant strains.

  14. Synthesis of a Vpr-Binding Derivative for Use as a Novel HIV-1 Inhibitor.

    PubMed

    Hagiwara, Kyoji; Ishii, Hideki; Murakami, Tomoyuki; Takeshima, Shin-nosuke; Chutiwitoonchai, Nopporn; Kodama, Eiichi N; Kawaji, Kumi; Kondoh, Yasumitsu; Honda, Kaori; Osada, Hiroyuki; Tsunetsugu-Yokota, Yasuko; Suzuki, Masaaki; Aida, Yoko

    2015-01-01

    The emergence of multidrug-resistant viruses compromises the efficacy of anti-human immunodeficiency virus type 1 (HIV-1) therapy and limits treatment options. Therefore, new targets that can be used to develop novel antiviral agents need to be identified. We previously identified a potential parent compound, hematoxylin, which suppresses the nuclear import of HIV-1 via the Vpr-importin α interaction and inhibits HIV-1 replication in a Vpr-dependent manner by blocking nuclear import of the pre-integration complex. However, it was unstable. Here, we synthesized a stable derivative of hematoxylin that bound specifically and stably to Vpr and inhibited HIV-1 replication in macrophages. Furthermore, like hematoxylin, the derivative inhibited nuclear import of Vpr in an in vitro nuclear import assay, but had no effect on Vpr-induced G2/M phase cell cycle arrest or caspase activity. Interestingly, this derivative bound strongly to amino acid residues 54-74 within the C-terminal α-helical domain (αH3) of Vpr. These residues are highly conserved among different HIV strains, indicating that this region is a potential target for drug-resistant HIV-1 infection. Thus, we succeeded in developing a stable hematoxylin derivative that bound directly to Vpr, suggesting that specific inhibitors of the interaction between cells and viral accessory proteins may provide a new strategy for the treatment of HIV-1 infection.

  15. Combination of the CCL5-Derived Peptide R4.0 with Different HIV-1 Blockers Reveals Wide Target Compatibility and Synergic Cobinding to CCR5

    PubMed Central

    Secchi, Massimiliano; Vassena, Lia; Morin, Sébastien; Schols, Dominique

    2014-01-01

    R4.0, a synthetic CCL5/RANTES-derived peptide, exerts potent anti-HIV-1 activity via its nonactivating interaction with CCR5, the major HIV-1 coreceptor. CCR5 chronic activation may promote undesirable inflammatory effects and enhance viral infection; thus, receptor antagonism is a necessary requisite. HIV-1 gp120, CCL5, and maraviroc dock on CCR5 by sharing two receptor sites: the N terminus and the second extracellular loop. In combination studies, R4.0, CCL5, and maraviroc exhibited concomitant interactions with CCR5 and promoted synergic inhibition of HIV-1 in acute-infection assays. Furthermore, various degrees of additive/synergic HIV-1 inhibition were observed when R4.0 was tested in combination with drugs and lead compounds directed toward different viral targets (gp120, gp41, reverse transcriptase, and protease). In combination with tenofovir, R4.0 provides cross-clade synergic inhibition of primary HIV-1 isolates. Remarkably, an in vitro-generated maraviroc-resistant R5 HIV-1 strain was inhibited by R4.0 comparably to the wild-type strain, suggesting the presence of viral resistance barriers similar to those reported for CCL5. Overall, R4.0 appears to be a promising lead peptide with potential for combination in anti-HIV-1 therapy and in microbicide development to prevent sexual HIV-1 transmission. PMID:25114130

  16. Combination of the CCL5-derived peptide R4.0 with different HIV-1 blockers reveals wide target compatibility and synergic cobinding to CCR5.

    PubMed

    Secchi, Massimiliano; Vassena, Lia; Morin, Sébastien; Schols, Dominique; Vangelista, Luca

    2014-10-01

    R4.0, a synthetic CCL5/RANTES-derived peptide, exerts potent anti-HIV-1 activity via its nonactivating interaction with CCR5, the major HIV-1 coreceptor. CCR5 chronic activation may promote undesirable inflammatory effects and enhance viral infection; thus, receptor antagonism is a necessary requisite. HIV-1 gp120, CCL5, and maraviroc dock on CCR5 by sharing two receptor sites: the N terminus and the second extracellular loop. In combination studies, R4.0, CCL5, and maraviroc exhibited concomitant interactions with CCR5 and promoted synergic inhibition of HIV-1 in acute-infection assays. Furthermore, various degrees of additive/synergic HIV-1 inhibition were observed when R4.0 was tested in combination with drugs and lead compounds directed toward different viral targets (gp120, gp41, reverse transcriptase, and protease). In combination with tenofovir, R4.0 provides cross-clade synergic inhibition of primary HIV-1 isolates. Remarkably, an in vitro-generated maraviroc-resistant R5 HIV-1 strain was inhibited by R4.0 comparably to the wild-type strain, suggesting the presence of viral resistance barriers similar to those reported for CCL5. Overall, R4.0 appears to be a promising lead peptide with potential for combination in anti-HIV-1 therapy and in microbicide development to prevent sexual HIV-1 transmission.

  17. A Growth Factor Attenuates HIV-1 Tat and Morphine Induced Damage to Human Neurons: Implication in HIV/AIDS-Drug Abuse Cases

    PubMed Central

    Malik, Shaily; Khalique, Hena; Buch, Shilpa; Seth, Pankaj

    2011-01-01

    The neuropathological abnormalities of human immunodeficiency virus (HIV)-1 patients abusing illicit drugs suggest extensive interactions between the two agents, thereby leading to increased rate of progression to neurodegeneration. The role of HIV-1 transactivating protein, Tat has been elucidated in mediating neuronal damage via apoptosis, a hallmark of HIV-associated dementia (HAD), however the underlying mechanisms involved in enhanced neurodegeneration by illicit drugs remain elusive. In this study, we demonstrated that morphine enhances HIV-Tat induced toxicity in human neurons and neuroblastoma cells. Enhanced toxicity by Tat and morphine was accompanied by increased numbers of TUNEL positive apoptotic neurons, elevated caspase-3 levels and decreased ratio of anti- and pro-apoptotic proteins, Bcl2/Bax. Tat and morphine together elicited high levels of reactive oxygen species that were NADPH dependent. Significant alterations in mitochondrial membrane homeostasis were also observed with co-exposure of these agents. Extensive studies of mitogen activated protein kinase (MAPK) signaling pathways revealed the involvement of c-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase-1/2 (ERK1/2) pathways in enhanced toxicity of Tat and morphine. In addition to this, we found that pre-treatment of cells with platelet derived growth factor (PDGF-BB) protected neurons from HIV-Tat and morphine induced damage. PDGF-BB alleviated ROS production, maintained mitochondrial membrane potential, decreased caspase-3 activation and hence protected the cells from undergoing apoptosis. PDGF-BB mediated protection against Tat and morphine involved the phosphatidylinositol–3 kinase (PI3K) pathway, as specific inhibitor of PI3K abrogated the protection conferred by PDGF-BB. This study demonstrates the mechanism of enhanced toxicity in human neurons subjected to co-exposure of HIV protein Tat and morphine, thus implying its importance in HIV positive drug abusers

  18. Suppression of HIV-1 Infectivity by Human Glioma Cells.

    PubMed

    Hoque, Sheikh Ariful; Tanaka, Atsushi; Islam, Salequl; Ahsan, Gias Uddin; Jinno-Oue, Atsushi; Hoshino, Hiroo

    2016-05-01

    HIV-1 infection to the central nervous system (CNS) is very common in AIDS patients. The predominant cell types infected in the brain are monocytes and macrophages, which are surrounded by several HIV-1-resistant cell types, such as astrocytes, oligodendrocytes, neurons, and microvascular cells. The effect of these HIV-1-resistant cells on HIV-1 infection is largely unknown. In this study, we examined the stability of HIV-1 cultured with several human glioblastoma cell lines, for example, NP-2, U87MG, T98G, and A172, to determine whether these HIV-1-resistant brain cells could enhance or suppress HIV-1 infection and thus modulate HIV-1 infection in the CNS. The HIV-1 titer was determined using the MAGIC-5A indicator cell line as well as naturally occurring CD4(+) T cells. We found that the stability of HIV-1 incubated with NP-2 or U87MG cells at 37°C was significantly shorter (half-life, 2.5-4 h) compared to that of HIV-1 incubated with T98G or A172 cells or in culture medium without cells (half-life, 8-18 h). The spent culture media (SCM) of NP-2 and U87MG cells had the ability to suppress both R5- and X4-HIV-1 infection by inhibiting HIV-1 attachment to target cells. This inhibitory effect was eliminated by the treatment of the SCM with chondroitinase ABC but not heparinase, suggesting that the inhibitory factor(s) secreted by NP-2 and U87MG cells was chiefly mediated by chondroitin sulfate (CS) or CS-like moiety. Thus, this study reveals that some but not all glioma cells secrete inhibitory molecules to HIV-1 infection that may contribute in lowering HIV-1 infection in the CNS in vivo.

  19. In Vivo validation of a bioinformatics based tool to identify reduced replication capacity in HIV-1.

    PubMed

    Kitchen, Christina M R; Krogstad, Paul; Kitchen, Scott G

    2010-01-01

    Although antiretroviral drug resistance is common in treated HIV infected individuals, it is not a consistent indicator of HIV morbidity and mortality. To the contrary, HIV resistance-associated mutations may lead to changes in viral fitness that are beneficial to infected individuals. Using a bioinformatics-based model to assess the effects of numerous drug resistance mutations, we determined that the D30N mutation in HIV-1 protease had the largest decrease in replication capacity among known protease resistance mutations. To test this in silico result in an in vivo environment, we constructed several drug-resistant mutant HIV-1 strains and compared their relative fitness utilizing the SCID-hu mouse model. We found HIV-1 containing the D30N mutation had a significant defect in vivo, showing impaired replication kinetics and a decreased ability to deplete CD4+ thymocytes, compared to the wild-type or virus without the D30N mutation. In comparison, virus containing the M184V mutation in reverse transcriptase, which shows decreased replication capacity in vitro, did not have an effect on viral fitness in vivo. Thus, in this study we have verified an in silico bioinformatics result with a biological assessment to identify a unique mutation in HIV-1 that has a significant fitness defect in vivo.

  20. Specific Elimination of Latently HIV-1 Infected Cells Using HIV-1 Protease-Sensitive Toxin Nanocapsules

    PubMed Central

    Wen, Jing; Yan, Ming; Liu, Yang; Li, Jie; Xie, Yiming; Lu, Yunfeng; Kamata, Masakazu; Chen, Irvin S. Y.

    2016-01-01

    Anti-retroviral drugs suppress HIV-1 plasma viremia to undetectable levels; however, latent HIV-1 persists in reservoirs within HIV-1-infected patients. The silent provirus can be activated through the use of drugs, including protein kinase C activators and histone deacetylase inhibitors. This “shock” approach is then followed by “kill” of the producing cells either through direct HIV-1-induced cell death or natural immune mechanisms. However, these mechanisms are relatively slow and effectiveness is unclear. Here, we develop an approach to specifically target and kill cells that are activated early in the process of virus production. We utilize a novel nanocapsule technology whereby the ricin A chain is encapsulated in an inactive form within a polymer shell. Specificity for release of the ricin A toxin is conferred by peptide crosslinkers that are sensitive to cleavage by HIV-1 protease. By using well-established latent infection models, J-Lat and U1 cells, we demonstrate that only within an HIV-1-producing cell expressing functional HIV-1 protease will the nanocapsule release its ricin A cargo, shutting down viral and cellular protein synthesis, and ultimately leading to rapid death of the producer cell. Thus, we provide proof of principle for a novel technology to kill HIV-1-producing cells without effects on non-target cells. PMID:27049645

  1. Specific Elimination of Latently HIV-1 Infected Cells Using HIV-1 Protease-Sensitive Toxin Nanocapsules.

    PubMed

    Wen, Jing; Yan, Ming; Liu, Yang; Li, Jie; Xie, Yiming; Lu, Yunfeng; Kamata, Masakazu; Chen, Irvin S Y

    2016-01-01

    Anti-retroviral drugs suppress HIV-1 plasma viremia to undetectable levels; however, latent HIV-1 persists in reservoirs within HIV-1-infected patients. The silent provirus can be activated through the use of drugs, including protein kinase C activators and histone deacetylase inhibitors. This "shock" approach is then followed by "kill" of the producing cells either through direct HIV-1-induced cell death or natural immune mechanisms. However, these mechanisms are relatively slow and effectiveness is unclear. Here, we develop an approach to specifically target and kill cells that are activated early in the process of virus production. We utilize a novel nanocapsule technology whereby the ricin A chain is encapsulated in an inactive form within a polymer shell. Specificity for release of the ricin A toxin is conferred by peptide crosslinkers that are sensitive to cleavage by HIV-1 protease. By using well-established latent infection models, J-Lat and U1 cells, we demonstrate that only within an HIV-1-producing cell expressing functional HIV-1 protease will the nanocapsule release its ricin A cargo, shutting down viral and cellular protein synthesis, and ultimately leading to rapid death of the producer cell. Thus, we provide proof of principle for a novel technology to kill HIV-1-producing cells without effects on non-target cells.

  2. Inefficient entry of vicriviroc-resistant HIV-1 via the inhibitor-CCR5 complex at low cell surface CCR5 densities

    PubMed Central

    Pugach, Pavel; Ray, Neelanjana; Klasse, Per Johan; Ketas, Thomas J.; Michael, Elizabeth; Doms, Robert W.; Lee, Benhur; Moore, John P.

    2009-01-01

    HIV-1 variants resistant to small molecule CCR5 inhibitors such as vicriviroc (VVC) have modified Env complexes that can use both the inhibitor-bound and -free forms of the CCR5 co-receptor to enter target cells. However, entry via the inhibitor-CCR5 complex is inefficient in some, but not all, cell types, particularly cell lines engineered to express CCR5. We investigated the effect of increasing CCR5 expression, and hence the density of the inhibitor-CCR5 complex when a saturating inhibitor (VVC) concentration was present, by using 293-Affinofile cells, in which CCR5 expression is up-regulated by the transcriptional activator, ponasterone. When CCR5 expression was low, the resistant virus entered the target cells to a lesser extent when VVC was present than absent. However, at a higher CCR5 level, there was much less entry inhibition at a constant, saturating VVC concentration. We conclude that the relative decrease in entry of a VVC-resistant virus in some cell types results from its less efficient use of the VVC-CCR5 complex, and that increasing the CCR5 expression level can compensate for this inefficiency. PMID:19303620

  3. Allosteric inhibition of HIV-1 integrase activity

    PubMed Central

    Engelman, Alan; Kessl, Jacques J.; Kvaratskhelia, Mamuka

    2013-01-01

    HIV-1 integrase is an important therapeutic target in the fight against HIV/AIDS. Integrase strand transfer inhibitors (INSTIs), which target the enzyme active site, have witnessed clinical success over the past 5 years, but the generation of drug resistance poses challenges to INSTI-based therapies moving forward. Integrase is a dynamic protein, and its ordered multimerization is critical to enzyme activity. The integrase tetramer, bound to viral DNA, interacts with host LEDGF/p75 protein to tether integration to active genes. Allosteric integrase inhibitors (ALLINIs) that compete with LEDGF/p75 for binding to integrase disrupt integrase assembly with viral DNA and allosterically inhibit enzyme function. ALLINIs display steep dose response curves and synergize with INSTIs ex vivo, highlighting this novel inhibitor class for clinical development. PMID:23647983

  4. Developments of indoles as anti-HIV-1 inhibitors.

    PubMed

    Xu, Hui; Lv, Min

    2009-01-01

    Since the first case of acquired immunodeficiency syndrome (AIDS) was reported in 1981, AIDS has always been a global health threat and the leading cause of deaths due to the rapid emergence of drug-resistance and unwanted metabolic side effects. Every day in 2007 an estimated 6850 people were newly infected with human immunodeficiency virus (HIV). Over the past 28 years the rapid worldwide spread of AIDS has prompted an intense research effort to discover compounds that could effectively inhibit HIV. The development of new, selective and safe inhibitors for the treatment of HIV, therefore, still remains a high priority for medical research. To the best of our knowledge, the indole derivatives have been considered as one class of promising HIV-1 inhibitors, such as delavirdine approved by the Food and Drug Administration (FDA) in 1997 for use in combination with other antiretrovirals in adults with HIV infection. In this review we focus on the synthesis and anti-HIV-1 activity of indole derivatives, in the meantime, the structure-activity relationship (SAR) for some derivatives are also surveyed. It will pave the way for the design of indole derivatives as anti-HIV-1 drugs in the future.

  5. Flap Conformations in HIV-1 Protease are Altered by Mutations

    NASA Astrophysics Data System (ADS)

    Fanucci, Gail; Blackburn, Mandy; Veloro, Angelo; Galiano, Luis; Fangu, Ding; Simmerling, Carlos

    2009-03-01

    HIV-1 protease (PR) is an enzyme that is a major drug target in the treatment of AIDS. Although the structure and function of HIV-1 PR have been studied for over 20 years, questions remain regarding the conformations and dynamics of the β-hairpin turns (flaps) that cover the active site cavity. Distance measurements with pulsed EPR spectroscopy of spin labeled constructs of HIV-1 PR have been used to characterize the flap conformations in the apo and inhibitor bound states. From the most probably distances and the breadth of the distance distribution profiles from analysis of the EPR data, insights regarding the flap conformations and flexibility are gained. The EPR results clearly show how drug pressure selected mutations alter the average conformation of the flaps and the degree of opening of the flaps. Molecular dynamics simulations successfully regenerate the experimentally determined distance distribution profiles, and more importantly, provide structural models for full interpretation of the EPR results. By combining experiment and theory to understand the role that altered flap flexibility/conformations play in the mechanism of drug resistance, key insights are gained toward the rational development of new inhibitors of this important enzyme.

  6. Human immunodeficiency virus type 1 (HIV-1) integrase: resistance to diketo acid integrase inhibitors impairs HIV-1 replication and integration and confers cross-resistance to L-chicoric acid.

    PubMed

    Lee, Deborah J; Robinson, W E

    2004-06-01

    The diketo acids are potent inhibitors of human immunodeficiency virus (HIV) integrase (IN). Mutations in IN, T66I, S153Y, and M154I, as well as T66I-S153Y and T66I-M154I double mutations, confer resistance to diketo acids (D. J. Hazuda et al., Science 287:646-650, 2000). The effects of these IN mutations on viral replication, enzymatic activity, and susceptibility to other HIV inhibitors are reported herein. By immunofluorescence assay and real-time PCR, all mutant viruses demonstrated a modest delay in viral spread compared to that of reference HIV. These viruses also showed a statistically significant defect in integration without defects in reverse transcription. Recombinant IN containing S153Y, T66I, and M154I-T66I mutations had an approximately twofold decrease in both disintegration and 3'-end-processing-strand transfer activities in vitro. In contrast, IN containing M154I demonstrated a greater than twofold increase in specific activity in both reactions. All mutant HIVs were resistant to l-chicoric acid, a dicaffeoyltartaric acid IN inhibitor, both in tissue culture and in biochemical assays, yet remained susceptible to the reverse transcriptase inhibitors zidovudine and nevirapine. Thus, IN mutations conferring resistance to the diketo acids can yield integration defects, attenuated catalysis in vitro, and cross-resistance to l-chicoric acid.

  7. [Molecular characterization of complex recombinant HIV-1 CRF06_cpx subtype detected in Turkey].

    PubMed

    Sayan, Murat; Kaptan, Figen; Ormen, Bahar; Türker, Nesrin

    2014-01-01

    A major proportion of the global HIV infections is caused by group M of HIV-1 genotype and to date approximately nine subtypes (A, B, C, D, F, G, H, J, K) and 50 circulating recombinant forms (CRFs) have been recognized. Recombinants between different HIV-1 group M subtypes are designated as CRF. The extension 'cpx', for complex, is given if the CRF consists of contributions from three or more different subtypes but the composition of the subtype is not given. The objective of this study was to present, for the first time an HIV-1 positive married couple infected with CRF06_cpx subtype in Izmir, Turkey. A 39-year-old male patient who admitted to hospital with the complaints of oral candidiasis and zona, was found to be anti-HIV positive. CD4+ T lymphocyte count was 21 cells/mm3 and plasma HIV-1 RNA level was 56.380 copies/ml. He reported unprotected heterosexual contact with multiple partners including African women during his stay in Saudi Arabia between 1996 and 2002. After his diagnosis, his 37-year-old wife was screened for HIV infection and she was also found anti-HIV positive, with CD4+ T cell count of 122 cells/mm3. However, her results of basal plasma HIV-1 RNA could not be obtained because of an internal control error. HIV-1 strains were analysed for subtyping, recombination and drug resistance mutations with pol gene region sequencing. HIV-1 sequences were subtyped as CRF06_cpx after phylogenetic analysis using neighbor-joining method. According to the recombination analysis, HIV-1 pol gene regions consisted of group M subtype G, A, D, and B in the male patient and G K, A, F, and D in the female patient. While L10I + L33F mutation associated with protease inhibitor (PI) resistance was detected in both of the patients, K219N mutation associated with nucleoside reverse transcriptase inhibitor (NRTI) resistance was detected only in the male patient. In conclusion, HIV-1 molecular epidemiology studies are important tools for tracking transmission patterns and

  8. HIV-1 Envelope Glycoprotein Resistance to Monoclonal Antibody 2G12 Is Subject-Specific and Context-Dependent in Macaques and Humans

    PubMed Central

    Malherbe, Delphine C.; Sanders, Rogier W.; van Gils, Marit J.; Park, Byung; Gomes, Michelle M.; Schuitemaker, Hanneke; Barnett, Susan; Haigwood, Nancy L.

    2013-01-01

    HIV-1 Envelope (Env) protein is the sole target of neutralizing antibodies (NAbs) that arise during infection to neutralize autologous variants. Under this immune pressure, HIV escape variants are continuously selected and over the course of infection Env becomes more neutralization resistant. Many common alterations are known to affect sensitivity to NAbs, including residues encoding potential N-linked glycosylation sites (PNGS). Knowledge of Env motifs associated with neutralization resistance is valuable for the design of an effective Env-based vaccine so we characterized Envs isolated longitudinally from a SHIVSF162P4 infected macaque for sensitivity to neutralizing monoclonal antibodies (MAbs) B12, 2G12, 4E10 and 2F5. The early Env, isolated from plasma at day 56 after infection, was the most sensitive and the late Env, from day 670, was the most resistant to MAbs. We identified four PNGS in these Envs that accumulated over time at positions 130, 139, 160 and 397. We determined that removal of these PNGS significantly increased neutralization sensitivity to 2G12, and conversely, we identified mutations by in silico analyses that contributed resistance to 2G12 neutralization. In order to expand our understanding of these PNGS, we analyzed Envs from clade B HIV-infected human subjects and identified additional glycan and amino acid changes that could affect neutralization by 2G12 in a context-dependent manner. Taken together, these in vitro and in silico analyses of clade B Envs revealed that 2G12 resistance is achieved by previously unrecognized PNGS substitutions in a context-dependent manner and by subject-specific pathways. PMID:24040404

  9. HIV-1 Eradication: Early Trials (and Tribulations).

    PubMed

    Spivak, Adam M; Planelles, Vicente

    2016-01-01

    Antiretroviral therapy (ART) has rendered HIV-1 infection a manageable illness for those with access to treatment. However, ART does not lead to viral eradication owing to the persistence of replication-competent, unexpressed proviruses in long-lived cellular reservoirs. The potential for long-term drug toxicities and the lack of access to ART for most people living with HIV-1 infection have fueled scientific interest in understanding the nature of this latent reservoir. Exploration of HIV-1 persistence at the cellular and molecular level in resting memory CD4(+) T cells, the predominant viral reservoir in patients on ART, has uncovered potential strategies to reverse latency. We review recent advances in pharmacologically based 'shock and kill' HIV-1 eradication strategies, including comparative analysis of early clinical trials.

  10. 4'-Thio-oligo-beta-D-ribonucleotides: synthesis of beta-4'-thio-oligouridylates, nuclease resistance, base pairing properties, and interaction with HIV-1 reverse transcriptase.

    PubMed Central

    Bellon, L; Barascut, J L; Maury, G; Divita, G; Goody, R; Imbach, J L

    1993-01-01

    We present the synthesis and the study of properties of a new series of modified oligonucleotides, namely 4'-thio-oligo-beta-D-ribonucleotides (4'-S-RNA). Homo-oligonucleotides of this class (4'-SU6 and 4'-SU12) were prepared from the previously known thionucleosides using the phosphoramidite methodology. The comparison of the substrate properties of 4'-SU6 and its natural analog U6 with respect to four nucleases indicates that the former is much more resistant than the latter. Such resistance to nucleases in addition to relatively high Tm values for 4'-SU12 hybridized with Poly(A) show that these new 4'-S-RNA are good candidates for potential antisense effects. The oligonucleotides 4'-SU6 and 4'-SU12 have been also evaluated as non sequence specific inhibitors of HIV-1 reverse transcriptase. All available evidences, based primarily on fluorescence measurements, are consistent with the binding of 4'-SU6 and 4'-SU12 to RT at a site which is different from the polymerase site of the enzyme. PMID:7683133

  11. Single Nucleotide Polymorphisms in Cellular Drug Transporters Are Associated with Intolerance to Antiretroviral Therapy in Brazilian HIV-1 Positive Individuals.

    PubMed

    Arruda, Mônica Barcellos; Campagnari, Francine; de Almeida, Tailah Bernardo; Couto-Fernandez, José Carlos; Tanuri, Amilcar; Cardoso, Cynthia Chester

    2016-01-01

    Adverse reactions are the main cause of treatment discontinuation among HIV+ individuals. Genes related to drug absorption, distribution, metabolism and excretion (ADME) influence drug bioavailability and treatment response. We have investigated the association between single nucleotide polymorphisms (SNPs) in 29 ADME genes and intolerance to therapy in a case-control study including 764 individuals. Results showed that 15 SNPs were associated with intolerance to nucleoside and 11 to non-nucleoside reverse transcriptase inhibitors (NRTIs and NNRTIs), and 8 to protease inhibitors (PIs) containing regimens under alpha = 0.05. After Bonferroni adjustment, two associations remained statistically significant. SNP rs2712816, at SLCO2B1 was associated to intolerance to NRTIs (ORGA/AA = 2.37; p = 0.0001), while rs4148396, at ABCC2, conferred risk of intolerance to PIs containing regimens (ORCT/TT = 2.64; p = 0.00009). Accordingly, haplotypes carrying rs2712816A and rs4148396T alleles were also associated to risk of intolerance to NRTIs and PIs, respectively. Our data reinforce the role of drug transporters in response to HIV therapy and may contribute to a future development of personalized therapies.

  12. Single Nucleotide Polymorphisms in Cellular Drug Transporters Are Associated with Intolerance to Antiretroviral Therapy in Brazilian HIV-1 Positive Individuals

    PubMed Central

    Arruda, Mônica Barcellos; Campagnari, Francine; de Almeida, Tailah Bernardo; Couto-Fernandez, José Carlos; Tanuri, Amilcar; Cardoso, Cynthia Chester

    2016-01-01

    Adverse reactions are the main cause of treatment discontinuation among HIV+ individuals. Genes related to drug absorption, distribution, metabolism and excretion (ADME) influence drug bioavailability and treatment response. We have investigated the association between single nucleotide polymorphisms (SNPs) in 29 ADME genes and intolerance to therapy in a case-control study including 764 individuals. Results showed that 15 SNPs were associated with intolerance to nucleoside and 11 to non-nucleoside reverse transcriptase inhibitors (NRTIs and NNRTIs), and 8 to protease inhibitors (PIs) containing regimens under alpha = 0.05. After Bonferroni adjustment, two associations remained statistically significant. SNP rs2712816, at SLCO2B1 was associated to intolerance to NRTIs (ORGA/AA = 2.37; p = 0.0001), while rs4148396, at ABCC2, conferred risk of intolerance to PIs containing regimens (ORCT/TT = 2.64; p = 0.00009). Accordingly, haplotypes carrying rs2712816A and rs4148396T alleles were also associated to risk of intolerance to NRTIs and PIs, respectively. Our data reinforce the role of drug transporters in response to HIV therapy and may contribute to a future development of personalized therapies. PMID:27648838

  13. Low risk of nevirapine resistance mutations in the prevention of mother-to-child transmission of HIV-1: Agence Nationale de Recherches sur le SIDA Ditrame Plus, Abidjan, Cote d'Ivoire.

    PubMed

    Chaix, Marie-Laure; Ekouevi, Didier Koumavi; Rouet, Francois; Tonwe-Gold, Besigin; Viho, Ida; Bequet, Laurence; Peytavin, Gilles; Toure, Hassane; Menan, Herve; Leroy, Valeriane; Dabis, Francois; Rouzioux, Christine

    2006-02-15

    The frequency of resistance mutations was estimated in the cohort of Agence Nationale de Recherches sur le SIDA Ditrame Plus, a study that evaluated the combination of short-course zidovudine (ZDV) plus lamivudine (3TC) and single-dose nevirapine (SD-NVP) followed by 3 days of postpartum ZDV plus 3TC for the prevention of mother-to-child transmission of human immunodeficiency virus type 1 (HIV-1). The frequency with which resistance mutations were detected in mothers at week 4 postpartum was 1.14% (95% confidence interval [CI], 0.03%-6.17%) for NVP and 8.33% (95% CI, 3.66%-15.76%) for 3TC. In multivariate analysis, 3TC resistance was associated with a longer duration of ZDV plus 3TC prepartum prophylaxis (P=.009). This regimen, which is feasible in resource-limited settings, prevents most peripartum HIV-1 transmission and minimizes the development of NVP resistance.

  14. Virtual Screening of Indonesian Herbal Database as HIV-1 Protease Inhibitor

    PubMed Central

    Yanuar, Arry; Suhartanto, Heru; Mun׳im, Abdul; Anugraha, Bram Hik; Syahdi, Rezi Riadhi

    2014-01-01

    HIV-1 (Human immunodeficiency virus type 1)׳s infection is considered as one of most harmful disease known by human, the survivability rate of the host reduced significantly when it developed into AIDS. HIV drug resistance is one of the main problems of its treatment and several drug designs have been done to find new leads compound as the cure. In this study, in silico virtual screening approach was used to find lead molecules from the library or database of natural compounds as HIV-1 protease inhibitor. Virtual screening against Indonesian Herbal Database with AutoDock was performed on HIV-1 protease. From the virtual screening, top ten compounds obtained were 8-Hydroxyapigenin 8-(2",4"-disulfatoglucuronide), Isoscutellarein 4'-methyl ether, Amaranthin, Torvanol A, Ursonic acid, 5-Carboxypyranocyanidin 3-O-(6"-O-malonyl-beta-glucopyranoside), Oleoside, Jacoumaric acid, Platanic acid and 5-Carboxypyranocyanidin 3-O-beta-glucopyranoside. PMID:24616554

  15. High genetic diversity of HIV-1 was found in men who have sex with men in Shijiazhuang, China.

    PubMed

    Li, Lin; Lu, Xinli; Li, Hanping; Chen, Lili; Wang, Zheng; Liu, Yongjian; Bao, Zuoyi; Li, Tianyi; Tian, Chong; Liu, Hongxin; Zhuang, Daomin; Liu, Siyang; Li, Jingyun

    2011-08-01

    Men who have sex with men (MSM) have become one of the populations with severely HIV prevalence in China. However, very few genetic studies have been done on HIV-1 spreading in this population. In this study, the genetic characterization of HIV-1 strains prevalent in the MSM in Shijiazhuang, China, was analyzed basing on the HIV-1 full-length gag, pol, and partial env gene. 21 drug-naïve HIV-1 sero-positive patients were enrolled into the study. Full length gag, pol, partial env genes and some near full length genomes were amplified with nest RT-PCR followed by sequencing. Multiple subtypes, including CRF01_AE (52.9%), subtype B (35.3%) and CRF07_BC (11.8%), were found in the population. Phylogenetic analysis showed close relationship between our strains with those from Beijing MSM but not those from paid blood donors of local area. Drug resistance surveillance evaluation showed no transmitted drug resistance (TDR). However, some drug-resistance related polymorphism sites (V181I and V106I) were popularly found in B subtype strains. The findings will contribute to understanding the distribution and evolution of HIV-1 in MSM and also help the behavior change intervention.

  16. High-intensity cannabis use associated with lower plasma HIV-1 RNA viral load among recently-infected people who use injection drugs

    PubMed Central

    Milloy, M-J; Marshall, Brandon; Kerr, Thomas; Richardson, Lindsey; Hogg, Robert; Guillemi, Silvia; Montaner, Julio SG; Wood, Evan

    2015-01-01

    Introduction and Aims Cannabis use is common among people who are living with HIV/AIDS. While there is growing pre-clinical evidence of the immunomodulatory and anti-viral effects of cannabinoids, their possible effects on HIV disease parameters in humans is largely unknown. Thus, we sought to investigate the possible effects of cannabis use on plasma HIV-1 RNA viral loads among recently-seroconverted illicit drug users. Design and Methods We used data from two linked longitudinal observational cohorts of people who use injection drugs. Using multivariable linear mixed-effects modeling, we analysed the relationship between pVL and high-intensity cannabis use among participants who seroconverted following recruitment. Results Between May, 1996 and March, 2012, 88 individuals seroconverted after recruitment and were included in these analyses. Median pVL in the first 365 days among all seroconverters was 4.66 log10 c/mL. In a multivariable model, at least daily cannabis use was associated with 0.51 log10 c/mL lower pVL (β = −0.51, Standard Error = 0.170, p-value = 0.003). Discussion Consistent with the findings from recent in vitro and in vivo studies, including one conducted among lentiviral-infected primates, we observed a strong association between cannabis use and lower pVL following seroconversion among illicit drug-using participants. Conclusion Our findings support the further investigation of the immunomodulatory or anti-viral effects of cannabinoids among individuals living with HIV/AIDS. PMID:25389027

  17. Design and characterization of swapped-domain constructs of HIV-1 glycoprotein-41 as receptors for drug discovery

    PubMed Central

    Walsh, Joseph D.; Chu, Shidong; Zhang, Shao-Qing; Gochin, Miriam

    2015-01-01

    Four new swapped-domain constructs of the ectodomain of human immunodeficiency virus type 1 glycoprotein-41 (gp41) were prepared. The gp41 ectodomain consists of 50-residue N-heptad repeat (NHR), 36-residue disulfide-bonded loop and 39-residue C-heptad repeat (CHR). It folds into a hairpin structure that forms a trimer along the NHR axis. The swapped-domain proteins feature CHR domains of length 39, 28 or 21 residues preceding a 4-residue loop and a 49- or 50-residue NHR domain. The effect of CHR truncation was to expose increasing lengths of the NHR groove, including the conserved hydrophobic pocket, an important drug target. A novel method for preparing proteins with extended exposed hydrophobic surfaces was demonstrated. Biophysical measurements, including analytical ultracentrifugation and ligand-detected Water-Ligand Observed via Gradient Spectroscopy and 1H–15N-HSQC NMR experiments, were used to confirm that the proteins formed stable trimers in solution with exposed binding surfaces. These proteins could play an important role as receptors in structure-based drug discovery. PMID:25792539

  18. Drug resistance in Giardia duodenalis.

    PubMed

    Ansell, Brendan R E; McConville, Malcolm J; Ma'ayeh, Showgy Y; Dagley, Michael J; Gasser, Robin B; Svärd, Staffan G; Jex, Aaron R

    2015-11-01

    Giardia duodenalis is a microaerophilic parasite of the human gastrointestinal tract and a major contributor to diarrheal and post-infectious chronic gastrointestinal disease world-wide. Treatment of G. duodenalis infection currently relies on a small number of drug classes. Nitroheterocyclics, in particular metronidazole, have represented the front line treatment for the last 40 years. Nitroheterocyclic-resistant G. duodenalis have been isolated from patients and created in vitro, prompting considerable research into the biomolecular mechanisms of resistance. These compounds are redox-active and are believed to damage proteins and DNA after being activated by oxidoreductase enzymes in metabolically active cells. In this review, we explore the molecular phenotypes of nitroheterocyclic-resistant G. duodenalis described to date in the context of the protist's unusual glycolytic and antioxidant systems. We propose that resistance mechanisms are likely to extend well beyond currently described resistance-associated enzymes (i.e., pyruvate ferredoxin oxidoreductases and nitroreductases), to include NAD(P)H- and flavin-generating pathways, and possibly redox-sensitive epigenetic regulation. Mechanisms that allow G. duodenalis to tolerate oxidative stress may lead to resistance against both oxygen and nitroheterocyclics, with implications for clinical control. The present review highlights the potential for systems biology tools and advanced bioinformatics to further investigate the multifaceted mechanisms of nitroheterocyclic resistance in this important pathogen.

  19. Genetic Characterization of a Novel HIV-1 Circulating Recombinant Form (CRF74_01B) Identified among Intravenous Drug Users in Malaysia: Recombination History and Phylogenetic Linkage with Previously Defined Recombinant Lineages.

    PubMed

    Cheong, Hui Ting; Chow, Wei Zhen; Takebe, Yutaka; Chook, Jack Bee; Chan, Kok Gan; Al-Darraji, Haider Abdulrazzaq Abed; Koh, Clayton; Kamarulzaman, Adeeba; Tee, Kok Keng

    2015-01-01

    In many parts of Southeast Asia, the HIV-1 epidemic has been driven by the sharing of needles and equipment among intravenous drug users (IDUs). Over the last few decades, many studies have proven time and again that the diversity of HIV-1 epidemics can often be linked to the route of infection transmission. That said, the diversity and complexity of HIV-1 molecular epidemics in the region have been increasing at an alarming rate, due in part to the high tendency of the viral RNA to recombine. This scenario was exemplified by the discovery of numerous circulating recombinant forms (CRFs), especially in Thailand and Malaysia. In this study, we characterized a novel CRF designated CRF74_01B, which was identified in six epidemiologically unlinked IDUs in Kuala Lumpur, Malaysia. The near-full length genomes were composed of CRF01_AE and subtype B', with eight breakpoints dispersed in the gag-pol and nef regions. Remarkably, this CRF shared four and two recombination hotspots with the previously described CRF33_01B and the less prevalent CRF53_01B, respectively. Genealogy-based Bayesian phylogenetic analysis of CRF74_01B genomic regions showed that it is closely related to both CRF33_01B and CRF53_01B. This observation suggests that CRF74_01B was probably a direct descendent from specific lineages of CRF33_01B, CRF53_01B and subtype B' that could have emerged in the mid-1990s. Additionally, it illustrated the active recombination processes between prevalent HIV-1 subtypes and recombinants in Malaysia. In summary, we report a novel HIV-1 genotype designated CRF74_01B among IDUs in Kuala Lumpur, Malaysia. The characterization of the novel CRF74_01B is of considerable significance towards the understanding of the genetic diversity and population dynamics of HIV-1 circulating in the region.

  20. Novel theoretically designed HIV-1 non-nucleoside reverse transcriptase inhibitors derived from nevirapine.

    PubMed

    Liu, Jinfeng; He, Xiao; Zhang, John Z H

    2014-10-01

    A common problem with non-nucleoside reverse transcriptase inhibitors (NNRTIs) of HIV-1 is the emergence of mutations in the HIV-1 RT, in particular Lys103 → Asn (K103N) and Tyr181 → Cys (Y181C), which lead to resistance to this entire class of inhibitors. In this study, we theoretically designed two new non-nucleoside HIV-1 RT inhibitors, Mnev-1 and Mnev-2, derived from nevirapine, in order to reduce the resistance caused by those HIV-1 RT mutations. The binding modes of Mnev-1 and Mnev-2 with the wild-type HIV-1 RT and its mutants (K103N and Y181C) were suggested by molecular docking followed by 20-ns molecular dynamics (MD) simulations in explicit water of those binding complexes (HIV-1 RTs with the new inhibitors). A molecular mechanics/generalized Born surface area (MM/GBSA) calculation was carried out for multiple snapshots extracted from the MD trajectory to estimate the binding free energy. The results of the calculations show that each of the new inhibitors forms a stable hydrogen bond with His235 during the MD simulations, leading to tighter binding of the new inhibitors with their targets. In addition, the repulsive interaction with Cys181 in the Y181C-nevirapine complex is not present in the novel inhibitors. The binding affinities predicted using the MM/GBSA calculations indicate that the new inhibitors could be effective at bypassing the drug resistance of these HIV-1 RT mutants.

  1. Repositioning HIV-1 integrase inhibitors for cancer therapeutics: 1,6-naphthyridine-7-carboxamide as a promising scaffold with drug-like properties.

    PubMed

    Zeng, Li-Fan; Wang, Yong; Kazemi, Roza; Xu, Shili; Xu, Zhong-Liang; Sanchez, Tino W; Yang, Liu-Meng; Debnath, Bikash; Odde, Srinivas; Xie, Hua; Zheng, Yong-Tang; Ding, Jian; Neamati, Nouri; Long, Ya-Qiu

    2012-11-26

    Among a large number of HIV-1 integrase (IN) inhibitors, the 8-hydroxy-[1,6]naphthyridines (i.e., L-870,810) were one of the promising class of antiretroviral drugs developed by Merck Laboratories. In spite of its remarkable potency and efficacy, unfortunately upon completion of phase I clinical studies, development of L-870,810 was halted. Because of its desirable pharmacological and pharmaceutical properties we were intrigued to design novel analogues of L-870,810 with goals to (1) improve upon limitations of naphthyridine-7-carboxamides as antiviral agents and (2) to reposition their use as innovative cytotoxic agents for cancer therapeutics. Herein, we report on the design and synthesis of a series of 1,6-naphthyridine-7-carboxamides with various substitutions at the 5- and 8-positions. All the new 5-substituted-8-hydroxy-[1,6]naphthyridines were potent IN inhibitors and the 5-substituted-8-amino-[1,6]naphthyridines were significantly cytotoxic. Further optimization of the 5,8-disubstituted-[1,6]naphthyridines with structural variation on 7-carboxamide delivered novel compounds with significant cytotoxicity in a panel of cancer cell lines and effective inhibition against select oncogenic kinases.

  2. The Efficacy of an anti-CD4 Monoclonal Antibody for HIV-1 Treatment

    PubMed Central

    Fessel, W. Jeffrey; Anderson, Brooke; Follansbee, Stephen E.; Winters, Mark A.; Lewis, Stanley; Weinheimer, Steven; Petropoulos, Christos J.; Shafer, Robert W.

    2015-01-01

    The availability of 24 antiretroviral (ARV) drugs within six distinct drug classes has transformed HIV-1 infection (AIDS) into a treatable chronic disease. However, the ability of HIV-1 to develop resistance to multiple classes continues to present challenges to the treatment of many ARV treatment-experienced patients. In this case report, we describe the response to ibalizumab, an investigational CD4-binding monoclonal antibody (mAb), in a patient with advanced immunodeficiency and high-level five-class antiretroviral resistance. After starting an ibalizumab-based salvage regimen, the patient had an approximately 4.0 log10 reduction in viral load. An inadvertently missed infusion at week 32 led to the rapid loss of virologic response and decreased susceptibility to the remainder of the patient’s salvage therapy regimen. Following the reinstitution of ibalizumab, phenotypic and genotypic resistance to ibalizumab was detected. Nonetheless, plasma HIV-1 RNA levels stabilized at ~2.0 log10 copies/ml below pre-ibalizumab levels. Continued ARV drug development may yield additional clinical and public health benefits. This report illustrates the promise of mAbs for HIV-1 therapy in highly treatment-experienced patients. Therapeutic mAbs may also have a role in pre-exposure prophylaxis in high-risk uninfected populations and may facilitate directly observed therapy (DOT) if two or more synergistic long acting agents become available. PMID:22001594

  3. The efficacy of an anti-CD4 monoclonal antibody for HIV-1 treatment.

    PubMed

    Fessel, W Jeffrey; Anderson, Brooke; Follansbee, Stephen E; Winters, Mark A; Lewis, Stanley T; Weinheimer, Steven P; Petropoulos, Christos J; Shafer, Robert W

    2011-12-01

    The availability of 24 antiretroviral (ARV) drugs within six distinct drug classes has transformed HIV-1 infection (AIDS) into a treatable chronic disease. However, the ability of HIV-1 to develop resistance to multiple classes continues to present challenges to the treatment of many ARV treatment-experienced patients. In this case report, we describe the response to ibalizumab, an investigational CD4-binding monoclonal antibody (mAb), in a patient with advanced immunodeficiency and high-level five-class antiretroviral resistance. After starting an ibalizumab-based salvage regimen, the patient had an approximately 4.0 log(10) reduction in viral load. An inadvertently missed infusion at week 32 led to the rapid loss of virologic response and decreased susceptibility to the remainder of the patient's salvage therapy regimen. Following the reinstitution of ibalizumab, phenotypic and genotypic resistance to ibalizumab was detected. Nonetheless, plasma HIV-1 RNA levels stabilized at ∼2.0 log(10) copies/ml below pre-ibalizumab levels. Continued ARV drug development may yield additional clinical and public health benefits. This report illustrates the promise of mAbs for HIV-1 therapy in highly treatment-experienced patients. Therapeutic mAbs may also have a role in pre-exposure prophylaxis in high-risk uninfected populations and may facilitate directly observed therapy (DOT) if two or more synergistic long acting agents become available.

  4. Viral Decay Dynamics and Mathematical Modeling of Treatment Response: Evidence of Lower in vivo Fitness of HIV-1 Subtype C

    PubMed Central

    Shet, Anita; Nagaraja, Pradeep

    2016-01-01

    Background: Despite the high prevalence of HIV-1 subtype C (HIV-1C) worldwide, information on HIV-1C viral dynamics and response to antiretroviral therapy (ART) is limited. We sought to measure viral load decay dynamics during treatment and estimate the within-host basic reproductive ratio, R0, and the critical efficacy, εc, for successful treatment of HIV-1C infection. Methods: Individuals initiated on first-line ART in India and monitored for 6 months of treatment were considered. Viral load, CD4+ count, and adherence data were collected at baseline, 4, 12, 16 and 24 weeks after ART initiation. Drug resistance genotyping was performed at baseline. R0 and εc were estimated using a mathematical model. Results: Among 257 patients with complete data, mean baseline viral load was 5.7 log10 copies per milliliter and median CD4+ count was 165 cells per cubic millimeter. Primary drug resistance was present in 3.1% at baseline. At 6 months, 87.5% had undetectable viral load, indicating excellent response to ART despite high baseline viremia. After excluding those with transmitted resistance, suboptimal adherence and viral rebound, data from 112 patients were analyzed using a mathematical model. We estimated the median R0 to be 5.3. The corresponding εc was ∼0.8. Conclusions: These estimates of R0 and εc are smaller than current estimates for HIV-1B, suggesting that HIV-1C exhibits lower in vivo fitness compared with HIV-1B, which allows successful treatment despite high baseline viral loads. The lower fitness, and potentially lower virulence, together with high viral loads may underlie the heightened transmission potential of HIV-1C and its growing global spread. PMID:27273158

  5. Off-label use of maraviroc in HIV-1-infected paediatric patients in clinical practice.

    PubMed

    Palladino, Claudia; Gómez, María Luisa Navarro; Soler-Palacín, Pere; González-Tomé, María Isabel; De Ory, Santiago J; Espiau, María; Hoyos, Santiago Pérez; León-Leal, Juan Antonio; Méndez, María; Moreno-Pérez, David; Guasch, Claudia Fortuny; Sierra, Antoni Mur; Guruceta, Itziar Pocheville; Guillén, Santiago Moreno; Briz, Verónica

    2015-10-23

    Maraviroc (MVC) is not approved for HIV-1-infected paediatric patients. This is the first assessment of the use of MVC-based salvage therapy in vertically HIV-1-infected paediatric patients in clinical settings. The results suggest that MVC-based salvage therapy is useful in children and adolescents with extensive resistance profile leading to maintained virological suppression in up to 88% of the patients with CCR5-tropic virus. The likelihood of treatment success might increase when MVC is combined with other active drugs.

  6. Methamphetamine inhibits HIV-1 replication in CD4+ T cells by modulating anti-HIV-1 miRNA expression.

    PubMed

    Mantri, Chinmay K; Mantri, Jyoti V; Pandhare, Jui; Dash, Chandravanu

    2014-01-01

    Methamphetamine is the second most frequently used illicit drug in the United States. Methamphetamine abuse is associated with increased risk of HIV-1 acquisition, higher viral loads, and enhanced HIV-1 pathogenesis. Although a direct link between methamphetamine abuse and HIV-1 pathogenesis remains to be established in patients, methamphetamine has been shown to increase HIV-1 replication in macrophages, dendritic cells, and cells of HIV transgenic mice. Intriguingly, the effects of methamphetamine on HIV-1 replication in human CD4(+) T cells that serve as the primary targets of infection in vivo are not clearly understood. Therefore, we examined HIV-1 replication in primary CD4(+) T cells in the presence of methamphetamine in a dose-dependent manner. Our results demonstrate that methamphetamine had a minimal effect on HIV-1 replication at concentrations of 1 to 50 μmol/L. However, at concentrations >100 μmol/L, it inhibited HIV-1 replication in a dose-dependent manner. We also discovered that methamphetamine up-regulated the cellular anti-HIV-1 microRNAs (miR-125b, miR-150, and miR-28-5p) in CD4(+) T cells. Knockdown experiments illustrated that up-regulation of the anti-HIV miRNAs inhibited HIV-1 replication. These results are contrary to the paradigm that methamphetamine accentuates HIV-1 pathogenesis by increasing HIV-1 replication. Therefore, our findings underline the complex interaction between drug use and HIV-1 and necessitate comprehensive understanding of the effects of methamphetamine on HIV-1 pathogenesis.

  7. Methamphetamine Inhibits HIV-1 Replication in CD4+ T Cells by Modulating Anti–HIV-1 miRNA Expression

    PubMed Central

    Mantri, Chinmay K.; Mantri, Jyoti V.; Pandhare, Jui; Dash, Chandravanu

    2015-01-01

    Methamphetamine is the second most frequently used illicit drug in the United States. Methamphetamine abuse is associated with increased risk of HIV-1 acquisition, higher viral loads, and enhanced HIV-1 pathogenesis. Although a direct link between methamphetamine abuse and HIV-1 pathogenesis remains to be established in patients, methamphetamine has been shown to increase HIV-1 replication in macrophages, dendritic cells, and cells of HIV transgenic mice. Intriguingly, the effects of methamphetamine on HIV-1 replication in human CD4+ T cells that serve as the primary targets of infection in vivo are not clearly understood. Therefore, we examined HIV-1 replication in primary CD4+ T cells in the presence of methamphetamine in a dose-dependent manner. Our results demonstrate that methamphetamine had a minimal effect on HIV-1 replication at concentrations of 1 to 50 μmol/L. However, at concentrations >100 μmol/L, it inhibited HIV-1 replication in a dose-dependent manner. We also discovered that methamphetamine up-regulated the cellular anti–HIV-1 microRNAs (miR-125b, miR-150, and miR-28-5p) in CD4+ T cells. Knockdown experiments illustrated that up-regulation of the anti-HIV miRNAs inhibited HIV-1 replication. These results are contrary to the paradigm that methamphetamine accentuates HIV-1 pathogenesis by increasing HIV-1 replication. Therefore, our findings underline the complex interaction between drug use and HIV-1 and necessitate comprehensive understanding of the effects of methamphetamine on HIV-1 pathogenesis. PMID:24434277

  8. Substance abuse, HIV-1 and hepatitis.

    PubMed

    Parikh, Nirzari; Nonnemacher, Michael R; Pirrone, Vanessa; Block, Timothy; Mehta, Anand; Wigdahl, Brian

    2012-10-01

    During the course of human immunodeficiency virus type 1 (HIV-1) disease, the virus has been shown to effectively escape the immune response with the subsequent establishment of latent viral reservoirs in specific cell populations within the peripheral blood (PB) and associated lymphoid tissues, bone marrow (BM), brain, and potentially other end organs. HIV-1, along with hepatitis B and C viruses (HBV and HCV), are known to share similar routes of transmission, including intravenous drug use, blood transfusions, sexual intercourse, and perinatal exposure. Substance abuse, including the use of opioids and cocaine, is a significant risk factor for exposure to HIV-1 and the development of acquired immune deficiency syndrome, as well as HBV and HCV exposure, infection, and disease. Thus, coinfection with HIV-1 and HBV or HCV is common and may be impacted by chronic substance abuse during the course of disease. HIV- 1 impacts the natural course of HBV and HCV infection by accelerating the progression of HBV/HCV-associated liver disease toward end-stage cirrhosis and quantitative depletion of the CD4+ T-cell compartment. HBV or HCV coinfection with HIV-1 is also associated with increased mortality when compared to either infection alone. This review focuses on the impact of substance abuse and coinfection with HBV and HCV in the PB, BM, and brain on the HIV-1 pathogenic process as it relates to viral pathogenesis, disease progression, and the associated immune response during the course of this complex interplay. The impact of HIV-1 and substance abuse on hepatitis virus-induced disease is also a focal point.

  9. Lentivector Knockdown of CCR5 in Hematopoietic Stem and Progenitor Cells Confers Functional and Persistent HIV-1 Resistance in Humanized Mice

    PubMed Central

    Myburgh, Renier; Ivic, Sandra; Pepper, Michael S.; Gers-Huber, Gustavo; Li, Duo; Audigé, Annette; Rochat, Mary-Aude; Jaquet, Vincent; Regenass, Stephan; Manz, Markus G.; Salmon, Patrick; Krause, Karl-Heinz

    2015-01-01

    ABSTRACT Gene-engineered CD34+ hematopoietic stem and progenitor cells (HSPCs) can be used to generate an HIV-1-resistant immune system. However, a certain threshold of transduced HSPCs might be required for transplantation into mice for creating an HIV-resistant immune system. In this study, we combined CCR5 knockdown by a highly efficient microRNA (miRNA) lentivector with pretransplantation selection of transduced HSPCs to obtain a rather pure population of gene engineered CD34+ cells. Low-level transduction of HSPCs and subsequent sorting by flow cytometry yielded >70% transduced cells. Mice transplanted with these cells showed functional and persistent resistance to a CCR5-tropic HIV strain: viral load was significantly decreased over months, and human CD4+ T cells were preserved. In one mouse, viral mutations, resulting presumably in a CXCR4-tropic strain, overcame HIV resistance. Our results suggest that HSPC-based CCR5 knockdown may lead to efficient control of HIV in vivo. We overcame a major limitation of previous HIV gene therapy in humanized mice in which only a proportion of the cells in chimeric mice in vivo are anti-HIV engineered. Our strategy underlines the promising future of gene engineering HIV-resistant CD34+ cells that produce a constant supply of HIV-resistant progeny. IMPORTANCE Major issues in experimental long-term in vivo HIV gene therapy have been (i) low efficacy of cell transduction at the time of transplantation and (ii) transduction resulting in multiple copies of heterologous DNA in target cells. In this study, we demonstrated the efficacy of a transplantation approach with a selection step for transduced cells that allows transplantation of an enriched population of HSPCs expressing a single (low) copy of a CCR5 miRNA. Efficient maintenance of CD4+ T cells and a low viral titer resulted only when at least 70% of the HIV target cells were genetically modified. These findings imply that clinical protocols of HIV gene therapy require a

  10. Serum adiponectin in HIV-1 and hepatitis C virus mono- and co-infected Kenyan injection drug users

    PubMed Central

    Ndombi, Eric M; Budambula, Valentine; Webale, Mark K; Musumba, Francis O; Wesongah, Jesca O; Mibei, Erick; Ahmed, Aabid A; Lihana, Raphael; Were, Tom

    2015-01-01

    Adiponectin is an important marker of anthropometric profiles of adipose tissue. However, association of adiponectin and adiposity in HIV mono- and co-infected and hepatitis (HCV) injection drug users (IDUs) has not been elucidated. Therefore, the relationship of total adiponectin levels with anthropometric indices of adiposity was examined in HIV mono-infected (anti-retroviral treatment, ART-naive, n=16 and -experienced, n=34); HCV mono-infected, n=36; HIV and HCV co-infected (ART-naive, n=5 and -experienced, n=13); uninfected, n=19 IDUs; and healthy controls, n=16 from coastal Kenya. Anthropometric indices of adiposity were recorded and total circulating adiponectin levels were measured in serum samples using enzyme-linked immunosorbent assay. Adiponectin levels differed significantly amongst the study groups (P<0.0001). Post-hoc analyses revealed decreased levels in HIV mono-infected ART-naive IDUs in comparison to uninfected IDUs (P<0.05) and healthy controls (P<0.05). However, adiponectin levels were elevated in HCV mono-infected IDUs relative to HIV mono-infected ART-naive (P<0.001) and -experienced (P<0.001) as well as HIV and HCV co-infected ART-naive (P<0.05) IDUs. Furthermore, adiponectin correlated with weight (ρ=0.687; P=0.003) and BMI (ρ=0.598; P=0.014) in HIV mono-infected ART-naive IDUs; waist circumference (ρ=−0.626; P<0.0001), hip (ρ=−0.561; P=0.001) circumference, and bust-to-waist ratio (ρ=0.561; P=0.001) in HIV mono-infected ART-experienced IDUs; waist girth (ρ=0.375; P=0.024) in HCV mono-infected IDUs; and waist-to-hip ratio (ρ=−0.872; P=0.048) in HIV and HCV co-infected ART-naive IDUs. Altogether, these results suggest suppression of adiponectin production in treatment-naive HIV mono-infected IDUs and that circulating adiponectin is a useful surrogate marker of altered adiposity in treatment-naive and -experienced HIV and HCV mono- and co-infected IDUs. PMID:26306727

  11. Identification of mechanistically distinct inhibitors of HIV-1 reverse transcriptase through fragment screening

    PubMed Central

    La, Jennifer; Latham, Catherine F.; Tinetti, Ricky N.; Johnson, Adam; Tyssen, David; Huber, Kelly D.; Sluis-Cremer, Nicolas; Simpson, Jamie S.; Headey, Stephen J.; Chalmers, David K.; Tachedjian, Gilda

    2015-01-01

    Fragment-based screening methods can be used to discover novel active site or allosteric inhibitors for therapeutic intervention. Using saturation transfer difference (STD) NMR and in vitro activity assays, we have identified fragment-sized inhibitors of HIV-1 reverse transcriptase (RT) with distinct chemical scaffolds and mechanisms compared to nonnucleoside RT inhibitors (NNRTIs) and nucleoside/nucleotide RT inhibitors (NRTIs). Three compounds were found to inhibit RNA- and DNA-dependent DNA polymerase activity of HIV-1 RT in the micromolar range while retaining potency against RT variants carrying one of three major NNRTI resistance mutations: K103N, Y181C, or G190A. These compounds also inhibit Moloney murine leukemia virus RT but not the Klenow fragment of Escherichia coli DNA polymerase I. Steady-state kinetic analyses demonstrate that one of these fragments is a competitive inhibitor of HIV-1 RT with respect to deoxyribonucleoside triphosphate (dNTP) substrate, whereas a second compound is a competitive inhibitor of RT polymerase activity with respect to the DNA template/primer (T/P), and consequently also inhibits RNase H activity. The dNTP competing RT inhibitor retains activity against the NRTI-resistant mutants K65R and M184V, demonstrating a drug resistance profile distinct from the nucleotide competing RT inhibitors indolopyridone-1 (INDOPY-1) and 4-dimethylamino-6-vinylpyrimidine-1 (DAVP-1). In antiviral assays, the T/P competing compound inhibits HIV-1 replication at a step consistent with an RT inhibitor. Screening of additional structurally related compounds to the three fragments led to the discovery of molecules with improved potency against HIV-1 RT. These fragment inhibitors represent previously unidentified scaffolds for development of novel drugs for HIV-1 prevention or treatment. PMID:26038551

  12. A novel and rapid assay for HIV-1 protease detection using magnetic bead mediation.

    PubMed

    Esseghaier, Chiheb; Ng, Andy; Zourob, Mohammed

    2013-03-15

    A simple sensing assay was established for label-free detection of HIV-1 protease. HIV-1 protease peptide substrate conjugated to magnetic beads via its N-terminus is directly fixed onto the sensor gold surface through the sulphur atom of cysteine. Surface plasmon resonance (SPR) was used to study the peptide substrate cleavage efficiency of the protease with magnetic beads of different sizes (1 μm and 30 nm). Cyclic voltammetry and faradic impedance spectroscopy were employed in order to characterize the functionalized gold electrode. It was found that the nano-sized beads are a more efficient sensing probe for the protease. Electrochemical biosensing showed a gradual decrease in charge transfer resistance after injection of the HIV-1 protease. The experimental data established a detection limit of 10 pg/ml, as well as demonstrated a drug screening assay. This HIV-1 protease biosensor represents a new detection approach which will lead to low-cost point-of-care devices for sensitive HIV-1 diagnosis, as well as high-throughput drug screening platforms.

  13. Epidemiological networks and drug resistance of HIV type 1 in Krasnoyarsk region, Russia.

    PubMed

    Rumyantseva, Olga A; Olkhovskiy, Igor A; Malysheva, Marina A; Ruzaeva, Ludmila A; Vasiliev, Alexander V; Kazennova, Elena V; Bobkova, Marina R; Lukashov, Vladimir V

    2009-09-01

    To study the molecular epidemiology of HIV-1 in Krasnoyarsk region, Russia, where HIV-1 has spread rapidly since 2000, we obtained pol sequences from individuals living in this region (n = 67) as well as in the geographically closely related Altay region (n = 13). In both regions, subtype A viruses specific for the former Soviet Union (IDU-A strains) were dominant (92.5%). Virus sequences clustered according to the geographic origin of the infected individuals rather than to their risk group, demonstrating the role of geographically defined epidemiological networks in the propagation of the HIV-1 epidemic in the region. Six viruses belonged to subtype B. Three of them were phylogenetically (and therefore epidemiologically) closely related to each other, demonstrating that even though IDU-A viruses dominate the epidemic, the spread of other virus strains does occur. Most viruses (75%) had an A62V mutation in reverse transcriptase, specific for HIV-1 strains in Russia. Remarkably, 26 of 47 (55%) patients under HAART with detectable virus loads did not have any known drug-resistant mutation, indicating the need to increase compliance to therapy.

  14. CCR5 Disruption in Induced Pluripotent Stem Cells Using CRISPR/Cas9 Provides Selective Resistance of Immune Cells to CCR5-tropic HIV-1 Virus.

    PubMed

    Kang, HyunJun; Minder, Petra; Park, Mi Ae; Mesquitta, Walatta-Tseyon; Torbett, Bruce E; Slukvin, Igor I

    2015-12-15

    The chemokine (C-C motif) receptor 5 (CCR5) serves as an HIV-1 co-receptor and is essential for cell infection with CCR5-tropic viruses. Loss of functional receptor protects against HIV infection. Here, we report the successful targeting of CCR5 in GFP-marked human induced pluripotent stem cells (iPSCs) using CRISPR/Cas9 with single and dual guide RNAs (gRNAs). Following CRISPER/Cas9-mediated gene editing using a single gRNA, 12.5% of cell colonies demonstrated CCR5 editing, of which 22.2% showed biallelic editing as determined by a Surveyor nuclease assay and direct sequencing. The use of dual gRNAs significantly increased the efficacy of CCR5 editing to 27% with a biallelic gene alteration frequency of 41%. To ensure the homogeneity of gene editing within cells, we used single cell sorting to establish clonal iPSC lines. Single cell-derived iPSC lines with homozygous CCR5 mutations displayed the typical characteristics of pluripotent stem cells and differentiated efficiently into hematopoietic cells, including macrophages. Although macrophages from both wild-type and CCR5-edited iPSCs supported CXCR4-tropic virus replication, macrophages from CCR5-edited iPSCs were uniquely resistant to CCR5-tropic virus challenge. This study demonstrates the feasibility of applying iPSC technology for the study of the role of CCR5 in HIV infection in vitro, and generation of HIV-resistant cells for potential therapeutic applications.

  15. Therapeutic targets for HIV-1 infection in the host proteome

    PubMed Central

    Liang, Winnie S; Maddukuri, Anil; Teslovich, Tanya M; de la Fuente, Cynthia; Agbottah, Emmanuel; Dadgar, Shabnam; Kehn, Kylene; Hautaniemi, Sampsa; Pumfery, Anne; Stephan, Dietrich A; Kashanchi, Fatah

    2005-01-01

    Background Despite the success of HAART, patients often stop treatment due to the inception of side effects. Furthermore, viral resistance often develops, making one or more of the drugs ineffective. Identification of novel targets for therapy that may not develop resistance is sorely needed. Therefore, to identify cellular proteins that may be up-regulated in HIV infection and play a role in infection, we analyzed the effects of Tat on cellular gene expression during various phases of the cell cycle. Results SOM and k-means clustering analyses revealed a dramatic alteration in transcriptional activity at the G1/S checkpoint. Tat regulates the expression of a variety of gene ontologies, including DNA-binding proteins, receptors, and membrane proteins. Using siRNA to knock down expression of several gene targets, we show that an Oct1/2 binding protein, an HIV Rev binding protein, cyclin A, and PPGB, a cathepsin that binds NA, are important for viral replication following induction from latency and de novo infection of PBMCs. Conclusion Based on exhaustive and stringent data analysis, we have compiled a list of gene products that may serve as potential therapeutic targets for the inhibition of HIV-1 replication. Several genes have been established as important for HIV-1 infection and replication, including Pou2AF1 (OBF-1), complement factor H related 3, CD4 receptor, ICAM-1, NA, and cyclin A1. There were also several genes whose role in relation to HIV-1 infection have not been established and may also be novel and efficacious therapeutic targets and thus necessitate further study. Importantly, targeting certain cellular protein kinases, receptors, membrane proteins, and/or cytokines/chemokines may result in adverse effects. If there is the presence of two or more proteins with similar functions, where only one protein is critical for HIV-1 transcription, and thus, targeted, we may decrease the chance of developing treatments with negative side effects. PMID:15780141

  16. Drug resistance mechanisms and novel drug targets for tuberculosis therapy.

    PubMed

    Islam, Md Mahmudul; Hameed, H M Adnan; Mugweru, Julius; Chhotaray, Chiranjibi; Wang, Changwei; Tan, Yaoju; Liu, Jianxiong; Li, Xinjie; Tan, Shouyong; Ojima, Iwao; Yew, Wing Wai; Nuermberger, Eric; Lamichhane, Gyanu; Zhang, Tianyu

    2017-01-20

    Drug-resistant tuberculosis (TB) poses a significant challenge to the successful treatment and control of TB worldwide. Resistance to anti-TB drugs has existed since the beginning of the chemotherapy era. New insights into the resistant mechanisms of anti-TB drugs have been provided. Better understanding of drug resistance mechanisms helps in the development of new tools for the rapid diagnosis of drug-resistant TB. There is also a pressing need in the development of new drugs with novel targets to improve the current treatment of TB and to prevent the emergence of drug resistance in Mycobacterium tuberculosis. This review summarizes the anti-TB drug resistance mechanisms, furnishes some possible novel drug targets in the development of new agents for TB therapy and discusses the usefulness using known targets to develop new anti-TB drugs. Whole genome sequencing is currently an advanced technology to uncover drug resistance mechanisms in M. tuberculosis. However, further research is required to unravel the significance of some newly discovered gene mutations in their contribution to drug resistance.

  17. High levels of virological failure with major genotypic resistance mutations in HIV-1-infected children after 5 years of care according to WHO-recommended 1st-line and 2nd-line antiretroviral regimens in the Central African Republic: A cross-sectional study.

    PubMed

    Mossoro-Kpinde, Christian Diamant; Gody, Jean-Chrysostome; Mboumba Bouassa, Ralph-Sydney; Mbitikon, Olivia; Jenabian, Mohammad-Ali; Robin, Leman; Matta, Mathieu; Zeitouni, Kamal; Longo, Jean De Dieu; Costiniuk, Cecilia; Grésenguet, Gérard; Touré Kane, Ndèye Coumba; Bélec, Laurent

    2017-03-01

    A large cohort of 220 HIV-1-infected children (median [range] age: 12 [4-17] years) was cared and followed up in the Central African Republic, including 198 in 1st-line and 22 in 2nd-line antiretroviral regimens. Patients were monitored clinically and biologically for HIV-1 RNA load and drug resistance mutations (DRMs) genotyping. A total of 87 (40%) study children were virological responders and 133 (60%) nonresponders. In children with detectable viral load, the majority (129; 97%) represented a virological failure. In children receiving 1st-line regimens in virological failure for whom genotypic resistance test was available, 45% displayed viruses harboring at least 1 DRM to NNRTI or NRTI, and 26% showed at least 1 major DRM to NNRTI or NRTI; more than half of children in 1st-line regimens were resistant to 1st-generation NNRTI and 24% of the children in 1st-line regimens had a major DRMs to PI. Virological failure and selection of DRMs were both associated with poor adherence. These observations demonstrate high rate of virological failure after 3 to 5 years of 1st-line or 2nd-line antiretroviral treatment, which is generally associated with DRMs and therapeutic failure. Overall, more than half (55%) of children receiving 1st-line antiretroviral treatment for a median of 3.4 years showed virological failure and antiretroviral-resistance and thus eligible to 2nd-line treatment. Furthermore, two-third (64%) of children under 2nd-line therapy were eligible to 3rd-line regimen. Taken together, these observations point the necessity to monitor antiretroviral-treated children by plasma HIV-1 RNA load to diagnose as early as possible the therapeutic failure and operate switch to a new therapeutic line.

  18. High levels of virological failure with major genotypic resistance mutations in HIV-1-infected children after 5 years of care according to WHO-recommended 1st-line and 2nd-line antiretroviral regimens in the Central African Republic

    PubMed Central

    Mossoro-Kpinde, Christian Diamant; Gody, Jean-Chrysostome; Mboumba Bouassa, Ralph-Sydney; Mbitikon, Olivia; Jenabian, Mohammad-Ali; Robin, Leman; Matta, Mathieu; Zeitouni, Kamal; Longo, Jean De Dieu; Costiniuk, Cecilia; Grésenguet, Gérard; Touré Kane, Ndèye Coumba; Bélec, Laurent

    2017-01-01

    Abstract A large cohort of 220 HIV-1-infected children (median [range] age: 12 [4–17] years) was cared and followed up in the Central African Republic, including 198 in 1st-line and 22 in 2nd-line antiretroviral regimens. Patients were monitored clinically and biologically for HIV-1 RNA load and drug resistance mutations (DRMs) genotyping. A total of 87 (40%) study children were virological responders and 133 (60%) nonresponders. In children with detectable viral load, the majority (129; 97%) represented a virological failure. In children receiving 1st-line regimens in virological failure for whom genotypic resistance test was available, 45% displayed viruses harboring at least 1 DRM to NNRTI or NRTI, and 26% showed at least 1 major DRM to NNRTI or NRTI; more than half of children in 1st-line regimens were resistant to 1st-generation NNRTI and 24% of the children in 1st-line regimens had a major DRMs to PI. Virological failure and selection of DRMs were both associated with poor adherence. These observations demonstrate high rate of virological failure after 3 to 5 years of 1st-line or 2nd-line antiretroviral treatment, which is generally associated with DRMs and therapeutic failure. Overall, more than half (55%) of children receiving 1st-line antiretroviral treatment for a median of 3.4 years showed virological failure and antiretroviral-resistance and thus eligible to 2nd-line treatment. Furthermore, two-third (64%) of children under 2nd-line therapy were eligible to 3rd-line regimen. Taken together, these observations point the necessity to monitor antiretroviral-treated children by plasma HIV-1 RNA load to diagnose as early as possible the therapeutic failure and operate switch to a new therapeutic line. PMID:28272247

  19. HIV Drug Resistance Surveillance Among Jamaican Men Who Have Sex with Men Should Be Prioritized for Reducing HIV Transmission

    PubMed Central

    Dennis, Ann M.; Nelson, Julie A.E.; Weir, Sharon S.; Figueroa, J. Peter

    2015-01-01

    Abstract The prevalence of human immunodeficiency virus type 1 (HIV-1) is highest among men who have sex with men (MSM) in Jamaica but no genotypic data are available on the virus strains that are responsible for the epidemic among this key population. HIV-1 polymerase (pol) genes from 65 MSM were sequenced and used to predict drug resistance mutations. An HIV drug resistance prevalence of 28% (minimum 13%) was observed among this cohort, with the most frequent mutations conferring resistance to efavirenz, nevirapine, and lamivudine. Phylogenetic analysis of the sequences revealed 10 times the number of linked HIV infections among this cohort than respondent reporting. HIV treatment and prevention efforts in Jamaica could benefit significantly from Pol genotyping of the HIV strains infecting socially vulnerable MSM prior to initiating antiretroviral therapy (ART), as this would guide suppressive ART and unearth HIV transmission clusters to enable more effective delivery of treatment and prevention programs. PMID:26133540

  20. Quorum sensing and microbial drug resistance.

    PubMed

    Yufan, Chen; Shiyin, Liu; Zhibin, Liang; Mingfa, Lv; Jianuan, Zhou; Lianhui, Zhang

    2016-10-20

    Microbial drug resistance has become a serious problem of global concern, and the evolution and regulatory mechanisms of microbial drug resistance has become a hotspot of research in recent years. Recent studies showed that certain microbial resistance mechanisms are regulated by quorum sensing system. Quorum sensing is a ubiquitous cell-cell communication system in the microbial world, which associates with cell density. High-density microbial cells produce sufficient amount of small signal molecules, activating a range of downstream cellular processes including virulence and drug resistance mechanisms, which increases bacterial drug tolerance and causes infections on host organisms. In this review, the general mechanisms of microbial drug resistance and quorum-sensing systems are summarized with a focus on the association of quorum sensing and chemical signaling systems with microbial drug resistance mechanisms, including biofilm formation and drug efflux pump. The potential use of quorum quenching as a new strategy to control microbial resistance is also discussed.

  1. Ibalizumab: an anti-CD4 monoclonal antibody for the treatment of HIV-1 infection.

    PubMed

    Bruno, Christopher J; Jacobson, Jeffrey M

    2010-09-01

    The majority of currently available agents for the treatment of HIV-1 infection act by targeting one of several intracellular steps in the viral life cycle. Despite improvements in efficacy and tolerability, the development of viral resistance to these agents is common and significant toxicity and adherence issues still occur. For this reason the development of safe, well tolerated antiviral agents that target a novel step in the viral life cycle remains important. Viral entry into host cells affords several potential extracellular targets for antiretroviral therapy. Ibalizumab, a humanized monoclonal antibody to CD4, the primary host cellular receptor for HIV-1 entry, has been shown to block HIV-1 entry in vitro. Early clinical trials have demonstrated significant antiviral efficacy with a >1 log(10) reduction in viral load when given as monotherapy. Its long half-life, which allows weekly dosing, and its administration as an intravenous infusion differentiate it from other currently available antiretroviral agents. These properties may prove useful in allowing improved drug delivery to patients who have had difficulty adhering to daily oral regimens. Its unique mode of action reduces the risk of cross-resistance with currently available antiretroviral agents, with the potential to expand the choices available to treat drug-resistant HIV-1.

  2. Diarylaniline Derivatives as a Distinct Class of HIV-1 Non-nucleoside Reverse Transcriptase Inhibitors

    PubMed Central

    Qin, Bingjie; Jiang, Xingkai; Lu, Hong; Tian, Xingtao; Barbault, Florent; Huang, Li; Qian, Keduo; Chen, Chin-Ho; Huang, Rong; Jiang, Shibo; Lee, Kuo-Hsiung; Xie, Lan

    2010-01-01

    By using structure-based drug design and isosteric replacement, diarylaniline and 1,5-diarylbenzene-1,2-diamine derivatives were synthesized and evaluated against wild type HIV-1 and drug-resistant viral strains, resulting in the discovery of diarylaniline derivatives as a distinct class of next-generation HIV-1 non-nucleoside reverse transcriptase inhibitor (NNRTI) agents. The most promising compound 37 showed significant EC50 values of 0.003-0.032 μM against HIV-1 wild-type strains and of 0.005-0.604 μM against several drug-resistant strains. Current results also revealed important structure-activity relationship (SAR) conclusions for diarylanilines and strongly support our hypothesis that an NH2 group on the central benzene ring ortho to the aniline moiety is crucial for interaction with K101 of the NNRTI binding site in HIV-1 RT, likely by forming H-bonds with K101. Furthermore, molecular modeling studies with molecular mechanism/general born surface area (MM/GBSA) technology demonstrated the rationality of our hypothesis. PMID:20527972

  3. Nonneutralizing Antibodies Induced by the HIV-1 gp41 NHR Domain Gain Neutralizing Activity in the Presence of the HIV Fusion Inhibitor Enfuvirtide: a Potential Therapeutic Vaccine Strategy.

    PubMed

    Wang, Qian; Bi, Wenwen; Zhu, Xiaojie; Li, Haoyang; Qi, Qianqian; Yu, Fei; Lu, Lu; Jiang, Shibo

    2015-07-01

    A key barrier against developing preventive and therapeutic human immunodeficiency virus (HIV) vaccines is the inability of viral envelope glycoproteins to elicit broad and potent neutralizing antibodies. However, in the presence of fusion inhibitor enfuvirtide, we show that the nonneutralizing antibodies induced by the HIV type 1 (HIV-1) gp41 N-terminal heptad repeat (NHR) domain (N63) exhibit potent and broad neutralizing activity against laboratory-adapted HIV-1 strains, including the drug-resistant variants, and primary HIV-1 isolates with different subtypes, suggesting the potential of developing gp41-targeted HIV therapeutic vaccines.

  4. Drugs That Fight HIV-1

    MedlinePlus

    ... tablet (Extended-release) 50 mg/5mL Viramune oral suspension 400 mg Viramune XR tablet (Extended-release) Rilpivirine * ... mg Prezista tablet 100 mg/mL Prezista oral suspension Fosamprenavir trade name: LEXIVA 700 mg Lexiva tablet ...

  5. Broadly neutralizing antibodies: An approach to control HIV-1 infection.

    PubMed

    Yaseen, Mahmoud Mohammad; Yaseen, Mohammad Mahmoud; Alqudah, Mohammad Ali

    2017-01-02

    Although available antiretroviral therapy (ART) has changed human immunodeficiency virus (HIV)-1 infection to a non-fatal chronic disease, the economic burden of lifelong therapy, severe adverse ART effects, daily ART adherence, and emergence of ART-resistant HIV-1 mutants require prospecting for alternative therapeutic modalities. Indeed, a growing body of evidence suggests that broadly neutralizing anti-HIV-1 antibodies (BNAbs) may offer one such feasible alternative. To evaluate their therapeutic potential in established HIV-1 infection, we sought to address recent advances in pre-clinical and clinical investigations in this area of HIV-1 research. In addition, we addressed the obstacles that may impede the success of such immunotherapeutic approach, suggested strategic solutions, and briefly compared this approach with the currently used ART to open new insights for potential future passive immunotherapy for HIV-1 infection.

  6. Treatment intensification does not reduce residual HIV-1 viremia in patients on highly active antiretroviral therapy.

    PubMed

    Dinoso, J B; Kim, S Y; Wiegand, A M; Palmer, S E; Gange, S J; Cranmer, L; O'Shea, A; Callender, M; Spivak, A; Brennan, T; Kearney, M F; Proschan, M A; Mican, J M; Rehm, C A; Coffin, J M; Mellors, J W; Siliciano, R F; Maldarelli, F

    2009-06-09

    In HIV-1-infected individuals on currently recommended antiretroviral therapy (ART), viremia is reduced to <50 copies of HIV-1 RNA per milliliter, but low-level residual viremia appears to persist over the lifetimes of most infected individuals. There is controversy over whether the residual viremia results from ongoing cycles of viral replication. To address this question, we conducted 2 prospective studies to assess the effect of ART intensification with an additional potent drug on residual viremia in 9 HIV-1-infected individuals on successful ART. By using an HIV-1 RNA assay with single-copy sensitivity, we found that levels of viremia were not reduced by ART intensification with any of 3 different antiretroviral drugs (efavirenz, lopinavir/ritonavir, or atazanavir/ritonavir). The lack of response was not associated with the presence of drug-resistant virus or suboptimal drug concentrations. Our results suggest that residual viremia is not the product of ongoing, complete cycles of viral replication, but rather of virus output from stable reservoirs of infection.

  7. Enhanced clearance of HIV-1-infected cells by broadly neutralizing antibodies against HIV-1 in vivo.

    PubMed

    Lu, Ching-Lan; Murakowski, Dariusz K; Bournazos, Stylianos; Schoofs, Till; Sarkar, Debolina; Halper-Stromberg, Ariel; Horwitz, Joshua A; Nogueira, Lilian; Golijanin, Jovana; Gazumyan, Anna; Ravetch, Jeffrey V; Caskey, Marina; Chakraborty, Arup K; Nussenzweig, Michel C

    2016-05-20

    Antiretroviral drugs and antibodies limit HIV-1 infection by interfering with the viral life cycle. In addition, antibodies also have the potential to guide host immune effector cells to kill HIV-1-infected cells. Examination of the kinetics of HIV-1 suppression in infected individuals by passively administered 3BNC117, a broadly neutralizing antibody, suggested that the effects of the antibody are not limited to free viral clearance and blocking new infection but also include acceleration of infected cell clearance. Consistent with these observations, we find that broadly neutralizing antibodies can target CD4(+) T cells infected with patient viruses and can decrease their in vivo half-lives by a mechanism that requires Fcγ receptor engagement in a humanized mouse model. The results indicate that passive immunotherapy can accelerate elimination of HIV-1-infected cells.

  8. Overcoming drug resistance through in silico prediction.

    PubMed

    Carbonell, Pablo; Trosset, Jean-Yves

    2014-03-01

    Prediction tools are commonly used in pre-clinical research to assist target selection, to optimize drug potency or to predict the pharmacological profile of drug candidates. In silico prediction and overcoming drug resistance is a new opportunity that creates a high interest in pharmaceutical research. This review presents two main in silico strategies to meet this challenge: a structure-based approach to study the influence of mutations on the drug-target interaction and a system-biology approach to identify resistance pathways for a given drug. In silico screening of synergies between therapeutic and resistant pathways through biological network analysis is an example of technique to escape drug resistance. Structure-based drug design and in silico system biology are complementary approaches to reach few objectives at once: increase efficiency, reduce toxicity and overcoming drug resistance.

  9. Inhibition of HIV-1 Maturation via Small Molecule Targeting of the Amino-Terminal Domain in the Viral Capsid Protein.

    PubMed

    Wang, Weifeng; Zhou, Jing; Halambage, Upul D; Jurado, Kellie A; Jamin, Augusta V; Wang, Yujie; Engelman, Alan N; Aiken, Christopher

    2017-02-15

    The HIV-1 capsid protein is an attractive therapeutic target owing to its multifunctionality in virus replication and the high fitness cost of amino acid substitutions in capsid to HIV-1 infectivity. To date, small molecule inhibitors have been identified that inhibit HIV-1 capsid assembly and/or impair its function in target cells. Here we describe the mechanism of action of the previously reported capsid-targeting HIV-1 inhibitor, BI compound 1 (C1). We show that C1 acts during HIV-1 maturation to prevent assembly of a mature viral capsid. However, unlike the maturation inhibitor Bevirimat, C1 did not significantly affect the kinetics or fidelity of Gag processing. HIV-1 particles produced in the presence of C1 contained unstable capsids that lacked associated electron density and exhibited impairments in early postentry stages of infection, most notably reverse transcription. C1 inhibited assembly of recombinant HIV-1 CA in vitro and induced aberrant crosslinks in mutant HIV-1 particles capable of spontaneous intersubunit disulfide bonds at the interhexamer interface in the capsid lattice. Resistance to C1 was conferred by a single amino acid substitution within the compound-binding site in the N-terminal domain of the CA protein. Our results demonstrate that the binding site for C1 represents a new pharmacological vulnerability in the capsid assembly stage of the HIV-1 life cycle.IMPORTANCE The HIV-1 capsid protein is an attractive but unexploited target for clinical drug development. Prior studies have identified HIV-1 capsid-targeting compounds that display different mechanisms of action, which in part reflects the requirement for capsid function at both the efferent and afferent phases of viral replication. Here we show that one such compound, Compound 1, interferes with assembly of the conical viral capsid during virion maturation, and results in perturbations at a specific protein-protein interface in the capsid lattice. We also identify and characterize a