scholarly journals PO 8411 MOLECULAR CHARACTERISATION OF GP41 AND GP120 V3 LOOP IN HIV-1C PATIENTS FAILING SALVAGE THERAPY IN BOTSWANA

2019 ◽  
Vol 4 (Suppl 3) ◽  
pp. A34.1-A34
Author(s):  
Nokuthula S Ndlovu ◽  
Kaelo Seatla
Keyword(s):  
Viral Entry ◽  
Salvage Therapy ◽  
False Positive Rate ◽  
V3 Loop ◽  
Coreceptor Usage ◽  
Drug Resistant ◽  
Resistance Mutations ◽  
Global Challenge ◽  
Cxcr4 Coreceptor ◽  
Hiv 1

BackgroundTriple class drug-resistant HIV-1 infection remains a global challenge in individuals with extensive antiretroviral treatment (ART) experience, in terms of high mortality and probability of onward transmission. New therapeutic options within old and new drug classes are therefore essential. We determined if patients failing salvage therapy in Botswana are eligible for maraviroc (MVC) and enfuvirtide (T20) viral entry inhibitors based on the coreceptor usage and drug-resistant mutations in envelope gp120 and gp41.MethodsA total of 38 deep salvage patients were included in the analysis. We amplified and sequenced gp41 and V3 regions of HIV-1 envelope. Drug resistance mutations were analysed according to the IAS-USA 2017 reference mutation lists. Coreceptor usage was determined using PSSM and Geno2Pheno using a false-positive rate (FPR) of 10%.ResultsAmong 38 participants, 34 (89%) were successfully sequenced and amplified gp41 and 26 (68%) gp120 V3 loop sequences were obtained. Major T20 mutation G36S was obtained in 1/34 samples (5.8%) within the study population. Polymorphisms I169V(97%), I135L(100%), E151A(70.6%) and N42S(70.6%) were detected in HR1 and HR2 of gp41. CXCR4 coreceptor associated use, mutation L34M in gp41 HR1 was detected in 2 samples (5%). Analysis of coreceptor usage showed (17/26) 65.4% use of CCR5, and a (9/26) 34.6% use of the CXCR4 coreceptor.ConclusionA moderately high proportion of treatment-experienced (deep salvage) participants had CXCR4 coreceptor using strains. The use of maraviroc in Botswana would require coreceptor tropism testing. Non-T20 treatment experience in Botswana reduces the prevalence of the major mutations that confer resistance to the drug. T20 is therefore a potential alternative drug for patients failing salvage therapy in Botswana.

scholarly journals HIV Drug Resistance Mutations in Patients with HIV and HIV-TB Coinfection After Failure of First-Line Therapy: A Prevalence Study in a Resource-Limited Setting

2019 ◽  
Vol 18 ◽  
pp. 232595821984906
Author(s):  
Nawaid Hussain Khan ◽  
Mikashmi Kohli ◽  
Kartik Gupta ◽  
Bimal Kumar Das ◽  
Ravindra Mohan Pandey ◽  
...  
Keyword(s):  
Reverse Transcriptase ◽  
Drug Resistant ◽  
Resistance Mutations ◽  
Reverse Transcriptase Inhibitors ◽  
Nucleoside Reverse Transcriptase Inhibitors ◽  
First Line Therapy ◽  
Resource Limited ◽  
High Prevalence ◽  
Hiv 1 ◽  
Limited Setting

Introduction: The present study aimed to report the prevalent HIV-1 drug-resistant mutations in patients with HIV-1 alone and tuberculosis (TB) coinfection alone to improve our understanding of the mutation patterns and aid treatment decisions. Methods: Patients with HIV-1 and HIV-TB on treatment for more than 1 year with suspected failure were recruited. Sequencing of protease and two-thirds of the region of reverse transcriptase gene was done for drug-resistant mutations. Results: In the HIV-TB group (n = 25), 88%, 92%, and 12% had mutations to nucleoside reverse transcriptase inhibitors (NRTIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs), and protease inhibitors (PIs), respectively. In the HIV-alone group (n = 25), 84%, 100%, and 4% had mutations to NRTIs, NNRTIs, and PIs, respectively. M184V, M41L, D67N, G190A, A98G, and K103N were the most common mutations seen. Conclusion: There is a high prevalence of drug-resistant mutations in HIV and HIV-TB coinfected patients.

scholarly journals L74V increases the reverse transcriptase content of HIV-1 virions with non-nucleoside reverse transcriptase drug-resistant mutations L100I+K103N and K101E+G190S, which results in increased fitness

2013 ◽  
Vol 94 (7) ◽  
pp. 1597-1607 ◽  
Author(s):  
Jiong Wang ◽  
Dongge Li ◽  
Robert A. Bambara ◽  
Hongmei Yang ◽  
Carrie Dykes
Keyword(s):  
Reverse Transcriptase ◽  
Resistance Mutation ◽  
Transcriptase Inhibitor ◽  
Rnase H ◽  
Drug Resistant ◽  
Resistance Mutations ◽  
Nnrti Resistance ◽  
Reverse Transcriptase Inhibitor ◽  
Subsequent Addition ◽  
Hiv 1

The fitness of non-nucleoside reverse transcriptase inhibitor (NNRTI) drug-resistant reverse transcriptase (RT) mutants of HIV-1 correlates with the amount of RT in the virions and the RNase H activity of the RT. We wanted to understand the mechanism by which secondary NNRTI-resistance mutations, L100I and K101E, and the nucleoside resistance mutation, L74V, alter the fitness of K103N and G190S viruses. We measured the amount of RT in virions and the polymerization and RNase H activities of mutant RTs compared to wild-type, K103N and G190S. We found that L100I, K101E and L74V did not change the polymerization or RNase H activities of K103N or G190S RTs. However, L100I and K101E reduced the amount of RT in the virions and subsequent addition of L74V restored RT levels back to those of G190S or K103N alone. We conclude that fitness changes caused by L100I, K101E and L74V derive from their effects on RT content.

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

2016 ◽  
Vol 60 (6) ◽  
pp. 3380-3397 ◽  
Author(s):  
Fred Kyeyune ◽  
Richard M. Gibson ◽  
Immaculate Nankya ◽  
Colin Venner ◽  
Samar Metha ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Treatment Failure ◽  
Sanger Sequencing ◽  
Antiretroviral Treatment ◽  
Low Frequency ◽  
Drug Resistant ◽  
Viral Quasispecies ◽  
Resistance Mutations ◽  
Drug Resistance Mutations ◽  
Hiv 1

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 sensitive methods to detect minority HIV-1 variants.

scholarly journals Two Coselected Distal Mutations in HIV-1 Reverse Transcriptase (RT) Alter Susceptibility to Nonnucleoside RT Inhibitors and Nucleoside Analogs

2019 ◽  
Vol 93 (11) ◽  
Author(s):  
Paul L. Boyer ◽  
Kevin Melody ◽  
Steven J. Smith ◽  
Linda L. Dunn ◽  
Chris Kline ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Reverse Transcriptase ◽  
Active Site ◽  
Nucleoside Analogs ◽  
Transcriptase Inhibitor ◽  
Drug Resistant ◽  
Resistance Mutations ◽  
Hydrophobic Region ◽  
Nnrti Resistance ◽  
Hiv 1

ABSTRACTTwo mutations, G112D and M230I, were selected in the reverse transcriptase (RT) of human immunodeficiency virus type 1 (HIV-1) by a novel nonnucleoside reverse transcriptase inhibitor (NNRTI). G112D is located near the HIV-1 polymerase active site; M230I is located near the hydrophobic region where NNRTIs bind. Thus, M230I could directly interfere with NNRTI binding but G112D could not. Biochemical and virological assays were performed to analyze the effects of these mutations individually and in combination. M230I alone caused a reduction in susceptibility to NNRTIs, while G112D alone did not. The G112D/M230I double mutant was less susceptible to NNRTIs than was M230I alone. In contrast, both mutations affected the ability of RT to incorporate nucleoside analogs. We suggest that the mutations interact with each other via the bound nucleic acid substrate; the nucleic acid forms part of the polymerase active site, which is near G112D. The positioning of the nucleic acid is influenced by its interactions with the “primer grip” region and could be influenced by the M230I mutation.IMPORTANCEAlthough antiretroviral therapy (ART) is highly successful, drug-resistant variants can arise that blunt the efficacy of ART. New inhibitors that are broadly effective against known drug-resistant variants are needed, although such compounds might select for novel resistance mutations that affect the sensitivity of the virus to other compounds. Compound 13 selects for resistance mutations that differ from traditional NNRTI resistance mutations. These mutations cause increased sensitivity to NRTIs, such as AZT.

scholarly journals Impact of pretreatment low-abundance HIV-1 drug-resistant variants on virological failure among HIV-1/TB-co-infected individuals

2020 ◽  
Vol 75 (11) ◽  
pp. 3319-3326
Author(s):  
Benjamin Chimukangara ◽  
Jennifer Giandhari ◽  
Richard Lessells ◽  
Nonhlanhla Yende-Zuma ◽  
Benn Sartorius ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Virological Failure ◽  
Statistical Significance ◽  
Drug Resistant ◽  
Resistance Mutations ◽  
Next Generation Sequencing Ngs ◽  
Ngs Data ◽  
The Impact ◽  
Hiv 1 ◽  
Control Study

Abstract Objectives To determine the impact of pretreatment low-abundance HIV-1 drug-resistant variants (LA-DRVs) on virological failure (VF) among HIV-1/TB-co-infected individuals treated with NNRTI first-line ART. Methods We conducted a case–control study of 170 adults with HIV-1/TB co-infection. Cases had at least one viral load (VL) ≥1000 RNA copies/mL after ≥6 months on NNRTI-based ART, and controls had sustained VLs <1000 copies/mL. We sequenced plasma viruses by Sanger and MiSeq next-generation sequencing (NGS). We assessed drug resistance mutations (DRMs) using the Stanford drug resistance database, and analysed NGS data for DRMs at ≥20%, 10%, 5% and 2% thresholds. We assessed the effect of pretreatment drug resistance (PDR) on VF. Results We analysed sequences from 45 cases and 125 controls. Overall prevalence of PDR detected at a ≥20% threshold was 4.7% (8/170) and was higher in cases than in controls (8.9% versus 3.2%), P = 0.210. Participants with PDR at ≥20% had almost 4-fold higher odds of VF (adjusted OR 3.7, 95% CI 0.8–18.3) compared with those without, P = 0.104. PDR prevalence increased to 18.2% (31/170) when LA-DRVs at ≥2% were included. Participants with pretreatment LA-DRVs only had 1.6-fold higher odds of VF (adjusted OR 1.6, 95% CI 0.6–4.3) compared with those without, P = 0.398. Conclusions Pretreatment DRMs and LA-DRVs increased the odds of developing VF on NNRTI-based ART, although without statistical significance. NGS increased detection of DRMs but provided no additional benefit in identifying participants at risk of VF at lower thresholds. More studies assessing mutation thresholds predictive of VF are required to inform use of NGS in treatment decisions.

scholarly journals DETERMINATION OF VIRAL TROPISM BY GENOTYPING AND PHENOTYPING ASSAYS IN BRAZILIAN HIV-1-INFECTED PATIENTS

2014 ◽  
Vol 56 (4) ◽  
pp. 287-290
Author(s):  
Liã Bárbara Arruda ◽  
Marilia Ladeira de Araújo ◽  
Maira Luccia Martinez ◽  
Claudio Roberto Gonsalez ◽  
Alberto José da Silva Duarte ◽  
...  
Keyword(s):  
Clinical Practice ◽  
Dna Sequences ◽  
False Positive Rate ◽  
Coreceptor Usage ◽  
Viral Strain ◽  
Positive Rate ◽  
Ccr5 Antagonists ◽  
Virus Strains ◽  
Hiv 1

The clinical application of CCR5 antagonists involves first determining the coreceptor usage by the infecting viral strain. Bioinformatics programs that predict coreceptor usage could provide an alternative method to screen candidates for treatment with CCR5 antagonists, particularly in countries with limited financial resources. Thus, the present study aims to identify the best approach using bioinformatics tools for determining HIV-1 coreceptor usage in clinical practice. Proviral DNA sequences and Trofile results from 99 HIV-1-infected subjects under clinical monitoring were analyzed in this study. Based on the Trofile results, the viral variants present were 81.1% R5, 21.4% R5X4 and 1.8% X4. Determination of tropism using a Geno2pheno[coreceptor] analysis with a false positive rate of 10% gave the most suitable performance in this sampling: the R5 and X4 strains were found at frequencies of 78.5% and 28.4%, respectively, and there was 78.6% concordance between the phenotypic and genotypic results. Further studies are needed to clarify how genetic diversity amongst virus strains affects bioinformatics-driven approaches for determining tropism. Although this strategy could be useful for screening patients in developing countries, some limitations remain that restrict the wider application of coreceptor usage tests in clinical practice.

scholarly journals Mechanism of Interaction of Novel Indolylarylsulfone Derivatives with K103N and Y181I Mutant HIV-1 Reverse Transcriptase in Complex with its Substrates

2011 ◽  
Vol 22 (3) ◽  
pp. 107-118 ◽  
Author(s):  
Alberta Samuele ◽  
Sara Bisi ◽  
Alexandra Kataropoulou ◽  
Giuseppe La Regina ◽  
Francesco Piscitelli ◽  
...  
Keyword(s):  
Reverse Transcriptase ◽  
Resistant Mutant ◽  
Drug Resistant ◽  
Resistance Mutations ◽  
Specific Effects ◽  
Steady State Kinetic ◽  
Drug Resistant Mutant ◽  
K103n Mutation ◽  
New Generation ◽  
Hiv 1

Background: Novel indolylarylsulfones (lASs), designed through rational structure-based molecular modelling and docking approaches, have been recently characterized as effective inhibitors of the wild-type and drug-resistant mutant HIV-1 reverse transcriptase (RT). Methods: Here, we studied the interaction of selected halo- and nitra-substituted IAS derivatives, with the RT enzyme carrying the single resistance mutations K103N and Y181I through steady-state kinetic experiments. Results: The studied compounds exhibited high selectivity to the mutant RT in complex with its substrates, behaving as uncompetitive inhibitors. The presence of the K103N mutation, and to a lesser extent the Y181I, stabilized the drug interactions with the viral RT, when both its substrates were bound. Conclusions: The characterization of these mutation-specific effects on inhibitor binding might be relevant to the design of more effective new generation non-nucleoside reverse transcriptase inhibitors, with better resilience towards drug resistant mutants.

scholarly journals Small Molecule HIV-1 Attachment Inhibitors: Discovery, Mode of Action and Structural Basis of Inhibition

Viruses ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 843
Author(s):  
Yen-Ting Lai
Keyword(s):  
Viral Entry ◽  
Mode Of Action ◽  
Host Cells ◽  
Structural Basis ◽  
Structural Studies ◽  
Mechanistic Studies ◽  
Resistance Mutations ◽  
Inhibitor Discovery ◽  
Surface Envelope ◽  
Hiv 1

Viral entry into host cells is a critical step in the viral life cycle. HIV-1 entry is mediated by the sole surface envelope glycoprotein Env and is initiated by the interaction between Env and the host receptor CD4. This interaction, referred to as the attachment step, has long been considered an attractive target for inhibitor discovery and development. Fostemsavir, recently approved by the FDA, represents the first-in-class drug in the attachment inhibitor class. This review focuses on the discovery of temsavir (the active compound of fostemsavir) and analogs, mechanistic studies that elucidated the mode of action, and structural studies that revealed atomic details of the interaction between HIV-1 Env and attachment inhibitors. Challenges associated with emerging resistance mutations to the attachment inhibitors and the development of next-generation attachment inhibitors are also highlighted.

scholarly journals Combination of Drugs and Drug-Resistant Reverse Transcriptase Results in a Multiplicative Increase of Human Immunodeficiency Virus Type 1 Mutant Frequencies

2002 ◽  
Vol 76 (18) ◽  
pp. 9253-9259 ◽  
Author(s):  
Louis M. Mansky ◽  
Dennis K. Pearl ◽  
Lisa C. Gajary
Keyword(s):  
Human Immunodeficiency Virus ◽  
Drug Resistance ◽  
Reverse Transcriptase ◽  
Drug Resistant ◽  
Resistance Mutations ◽  
Drug Resistance Mutations ◽  
Immunodeficiency Virus ◽  
Hiv 1 ◽  
Mutant Frequency

ABSTRACT Replication of drug-resistant human immunodeficiency virus type 1 (HIV-1) in the presence of drug can lead to the failure of antiretroviral drug treatment. Drug failure is associated with the accumulation of drug resistance mutations. Previous studies have shown that 3′-azido-3′-deoxythymidine (AZT), (−)2′,3′-dideoxy-3′-thiacytidine (3TC), and AZT-resistant HIV-1 reverse transcriptase (RT) can increase the virus in vivo mutation rate. In this study, the combined effects of drug-resistant RT and antiretroviral drugs on the HIV-1 mutant frequency were determined. In most cases, a multiplicative effect was observed with AZT-resistant or AZT/3TC dually resistant RT and several drugs (i.e., AZT, 3TC, hydroxyurea, and thymidine) and led to increases in the odds of recovering virus mutants to over 20 times that of the HIV-1 mutant frequency in the absence of drug or drug-resistance mutations. This observation indicates that HIV-1 can mutate at a significantly higher rate when drug-resistant virus replicates in the presence of drug. These increased mutant frequencies could have important implications for HIV-1 population dynamics and drug therapy regimens.

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