scholarly journals Effects of Drug Resistance Mutations L100I and V106A on the Binding of Pyrrolobenzoxazepinone Nonnucleoside Inhibitors to the Human Immunodeficiency Virus Type 1 Reverse Transcriptase Catalytic Complex

2004 ◽  
Vol 48 (5) ◽  
pp. 1570-1580 ◽  
Author(s):  
Giada A. Locatelli ◽  
Giuseppe Campiani ◽  
Reynel Cancio ◽  
Elena Morelli ◽  
Anna Ramunno ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Drug Resistance ◽  
Reverse Transcriptase ◽  
Human Immunodeficiency Virus Type ◽  
Wild Type ◽  
Resistance Mutations ◽  
Drug Resistance Mutations ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT We have previously described a novel class of nonnucleoside reverse transcriptase (RT) inhibitors, the pyrrolobenzoxazepinone (PBO) and the pyridopyrrolooxazepinone (PPO) derivatives, which were effective inhibitors of human immunodeficiency virus type 1 (HIV-1) RT, either wild type or carrying known drug resistance mutations (G. Campiani et al., J. Med. Chem. 42:4462-4470, 1999). The lead compound of the PPO class, (R)-(−)-PPO464, was shown to selectively target the ternary complex formed by the viral RT with its substrates nucleic acid and nucleotide (G. Maga et al., J. Biol. Chem. 276:44653-44662, 2001). In order to better understand the structural basis for this selectivity, we exploited some PBO analogs characterized by various substituents at C-3 and by different inhibition potencies and drug resistance profiles, and we studied their interaction with HIV-1 RT wild type or carrying the drug resistance mutations L100I and V106A. Our kinetic and thermodynamic analyses showed that the formation of the complex between the enzyme and the nucleotide increased the inhibition potency of the compound PBO354 and shifted the free energy (energy of activation, ΔG#) for inhibitor binding toward more negative values. The V106A mutation conferred resistance to PBO 354 by increasing its dissociation rate from the enzyme, whereas the L100I mutation mainly decreased the association rate. This latter mutation also caused a severe reduction in the catalytic efficiency of the RT. These results provide a correlation between the efficiency of nucleotide utilization by RT and its resistance to PBO inhibition.

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.

Subtype Classification by Polymerase and Gag Genes of HIV-1 Iranian Sequences Registered in the NCBI GenBank

2020 ◽  
Vol 17 ◽  
Author(s):  
Behzad Dehghani ◽  
Zahra Hasanshahi ◽  
Tayebeh Hashempour ◽  
Parvin Afsar Kazerooni
Keyword(s):  
Human Immunodeficiency Virus ◽  
Drug Resistance ◽  
Human Immunodeficiency Virus Type ◽  
Resistance Mutations ◽  
Drug Resistance Mutations ◽  
Online Tools ◽  
Immunodeficiency Virus ◽  
Reliable Software ◽  
Hiv 1

Background: The rate of Human Immunodeficiency Virus type 1 (HIV-1) infection in Iran has increased dramatically in the last few years. Objective: The aim of this study was to investigate the HIV subtype amongst all Iranian HIV sequences, using 8 online websites. Methods: In this study, 637 sequences of polymerase, and gag genes of HIV-1 were obtained from NCBI. HIV-1 subtyping was done, using 8 reliable software. Results: The final results of the 8 online tools indicated that the majority of sequences were HIV-1 subtype CRF35 AD. However, it appeared that in some genes a few programs could not determine specific subtypes and in some cases they described different subtypes. Conclusion: Considering the CRF35 AD diagram, it was clear that integrase was not an appropriate region to define this subtype. Also the full length of gag gene should be used for subtyping. For CRF1, AE envelop gene is a reliable region to define this subtype. Stanford software was used to determine the drug resistance prevalence and in 5.7% of the sequences, drug resistance mutations were found.

scholarly journals Worldwide Evaluation of DNA Sequencing Approaches for Identification of Drug Resistance Mutations in the Human Immunodeficiency Virus Type 1 Reverse Transcriptase

1999 ◽  
Vol 37 (7) ◽  
pp. 2291-2296 ◽  
Author(s):  
Rob Schuurman ◽  
Lisa Demeter ◽  
Patricia Reichelderfer ◽  
Jolanda Tijnagel ◽  
Tom de Groot ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Drug Resistance ◽  
Dna Sequencing ◽  
Wild Type ◽  
Resistance Mutations ◽  
Drug Resistance Mutations ◽  
Immunodeficiency Virus ◽  
Hiv 1

A panel (ENVA-1) of well-defined blinded samples containing wild-type and mutant human immunodeficiency virus type 1 (HIV-1) reverse transcriptase was analyzed by automated DNA sequencing in 23 laboratories worldwide. Drug resistance mutations at codons 41, 215, and 184 were present in the panel samples at different ratios to the wild type. The presence of mutant genotypes was determined qualitatively and quantitatively. All laboratories reported the presence of sequence heterogeneities at codons 41, 215, and 184 in one or more of the panel samples, though not all reported the correct codon genotypes. Two laboratories reported a mutant genotype in samples containing only the wild type, whereas two and three laboratories failed to detect the mutant genotypes at codons 41 and 215, respectively, in a completely mutant DNA population. Mutations present at relative concentrations of 25% of the total DNA population were successfully identified by 13 of 23, 10 of 23, and 16 of 23 labs for codons 41, 215, and 184Val, respectively. For more than 80% of those laboratories that qualitatively detected the presence of a mutation correctly, the estimated wild type/mutant ratio was less than 25% different from the input ratio in those samples containing 25 to 50% or 75% mutant input. This first multicenter study on the quality of DNA sequencing approaches for identifying HIV-1 drug resistance mutations revealed large interlaboratory differences in the quality of the results. The application of these procedures in their current state would in several cases lead to inaccurate or even incorrect diagnostic results. Therefore, proper quality control and standardization are urgently needed.

scholarly journals Genotypic Testing for Human Immunodeficiency Virus Type 1 Drug Resistance

2002 ◽  
Vol 15 (2) ◽  
pp. 247-277 ◽  
Author(s):  
Robert W. Shafer
Keyword(s):  
Human Immunodeficiency Virus ◽  
Drug Resistance ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Resistance Mutations ◽  
Drug Resistance Mutations ◽  
Immunodeficiency Virus ◽  
Rt Inhibitors ◽  
Hiv 1

SUMMARY There are 16 approved human immunodeficiency virus type 1 (HIV-1) drugs belonging to three mechanistic classes: protease inhibitors, nucleoside and nucleotide reverse transcriptase (RT) inhibitors, and nonnucleoside RT inhibitors. HIV-1 resistance to these drugs is caused by mutations in the protease and RT enzymes, the molecular targets of these drugs. Drug resistance mutations arise most often in treated individuals, resulting from selective drug pressure in the presence of incompletely suppressed virus replication. HIV-1 isolates with drug resistance mutations, however, may also be transmitted to newly infected individuals. Three expert panels have recommended that HIV-1 protease and RT susceptibility testing should be used to help select HIV drug therapy. Although genotypic testing is more complex than typical antimicrobial susceptibility tests, there is a rich literature supporting the prognostic value of HIV-1 protease and RT mutations. This review describes the genetic mechanisms of HIV-1 drug resistance and summarizes published data linking individual RT and protease mutations to in vitro and in vivo resistance to the currently available HIV drugs.

scholarly journals The Thiocarboxanilide Nonnucleoside Inhibitor UC781 Restores Antiviral Activity of 3′-Azido-3′-Deoxythymidine (AZT) against AZT-Resistant Human Immunodeficiency Virus Type 1

1999 ◽  
Vol 43 (2) ◽  
pp. 259-263 ◽  
Author(s):  
Gadi Borkow ◽  
Dominique Arion ◽  
Mark A. Wainberg ◽  
Michael A. Parniak
Keyword(s):  
Human Immunodeficiency Virus ◽  
Antiviral Activity ◽  
Reverse Transcriptase ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Wild Type Virus ◽  
Wild Type ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT N-[4-Chloro-3-(3-methyl-2-butenyloxy)phenyl]-2-methyl-3-furancarbothioamide (UC781) is an exceptionally potent nonnucleoside inhibitor of human immunodeficiency virus type 1 (HIV-1) reverse transcriptase. We found that a 1:1 molar combination of UC781 and 3′-azido-3′-deoxythymidine (AZT) showed high-level synergy in inhibiting the replication of AZT-resistant virus, implying that UC781 can restore antiviral activity to AZT against AZT-resistant HIV-1. Neither the nevirapine plus AZT nor the 2′,5′-bis-O-(t-butyldimethylsilyl)-3′-spiro-5"-(4"-amino-1",2"-oxathiole-2",2"-dioxide plus AZT combinations had this effect. Studies with purified HIV-1 reverse transcriptase (from a wild type and an AZT-resistant mutant) showed that UC781 was a potent inhibitor of the pyrophosphorolytic cleavage of nucleotides from the 3′ end of the DNA polymerization primer, a process that we have proposed to be critical for the phenotypic expression of AZT resistance. Combinations of UC781 plus AZT did not act in synergy to inhibit the replication of either wild-type virus or UC781-resistant HIV-1. Importantly, the time to the development of viral resistance to combinations of UC781 plus AZT is significantly delayed compared to the time to the development of resistance to either drug alone.

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