scholarly journals Human Immunodeficiency Virus Type 1 Reverse Transcriptase Mutation Selection during In Vitro Exposure to Tenofovir Alone or Combined with Abacavir or Lamivudine

2004 ◽  
Vol 48 (4) ◽  
pp. 1413-1415 ◽  
Author(s):  
Chris Stone ◽  
Mounir Ait-Khaled ◽  
Charles Craig ◽  
Philip Griffin ◽  
Margaret Tisdale
Keyword(s):  
Human Immunodeficiency Virus ◽  
Reverse Transcriptase ◽  
Transcriptase Inhibitor ◽  
Wild Type Virus ◽  
Virus Genotype ◽  
Human Immunodeficiency Virus Strain ◽  
Immunodeficiency Virus ◽  
In The Wild ◽  
Inhibitor Resistance

ABSTRACT Mutations selected or deselected during passage of human immunodeficiency virus strain HXB2 or resistant variants with tenofovir (TFV), abacavir (ABC), and lamivudine (3TC) differed depending on the drug combination and virus genotype. In the wild-type virus, TFV-ABC and TFV-3TC selected K65R (with reduced susceptibility to all three inhibitors) and then Y115F. TFV-containing regimens might increase K65R selection, which confers multiple nucleoside reverse transcriptase inhibitor resistance.

scholarly journals Anti-Human Immunodeficiency Virus Type 1 Activity of the Nonnucleoside Reverse Transcriptase Inhibitor GW678248 in Combination with Other Antiretrovirals against Clinical Isolate Viruses and In Vitro Selection for Resistance

2005 ◽  
Vol 49 (11) ◽  
pp. 4465-4473 ◽  
Author(s):  
Richard J. Hazen ◽  
Robert J. Harvey ◽  
Marty H. St. Clair ◽  
Robert G. Ferris ◽  
George A. Freeman ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Reverse Transcriptase ◽  
Transcriptase Inhibitor ◽  
Amino Acid Substitutions ◽  
Nonnucleoside Reverse Transcriptase Inhibitor ◽  
Immunodeficiency Virus ◽  
Antiviral Activities ◽  
Approved Drugs ◽  
Reverse Transcriptase Inhibitor

ABSTRACT GW678248, a novel nonnucleoside reverse transcriptase inhibitor, has been evaluated for anti-human immunodeficiency virus activity in a variety of in vitro assays against laboratory strains and clinical isolates. When GW678248 was tested in combination with approved drugs in the nucleoside and nucleotide reverse transcriptase inhibitor classes or the protease inhibitor class, the antiviral activities were either synergistic or additive. When GW678248 was tested in combination with approved drugs in the nonnucleoside reverse transcriptase inhibitor class, the antiviral activities were either additive or slightly antagonistic. Clinical isolates from antiretroviral drug-experienced patients were selected for evaluation of sensitivity to GW678248 in a recombinant virus assay. Efavirenz (EFV) and nevirapine (NVP) had ≥10-fold increases in their 50% inhibitory concentrations (IC50s) for 85% and 98% of the 55 selected isolates, respectively, whereas GW678248 had a ≥10-fold increase in the IC50 for only 17% of these isolates. Thus, 81 to 83% of the EFV- and/or NVP-resistant viruses from this data set were susceptible to GW678248. Virus populations resistant to GW678248 were selected by in vitro dose-escalating serial passage. Resistant progeny viruses recovered after eight passages had amino acid substitutions V106I, E138K, and P236L in the reverse transcriptase-coding region in one passage series and amino acid substitutions K102E, V106A, and P236L in a second passage series.

scholarly journals Association of Virologic Failure and Nonnucleoside Reverse Transcriptase Inhibitor Resistance Found in Antiretroviral-Naive Children Infected With Human Immunodeficiency Virus and Given Efavirenz-Based Treatment

2019 ◽  
Vol 9 (2) ◽  
pp. 261-264
Author(s):  
Nikki Higa ◽  
Amy Pelz ◽  
Donald Birch ◽  
Ingrid A Beck ◽  
Tatiana Sils ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Reverse Transcriptase ◽  
Nucleoside Reverse Transcriptase Inhibitor ◽  
Virologic Failure ◽  
Transcriptase Inhibitor ◽  
Nnrti Resistance ◽  
Nonnucleoside Reverse Transcriptase Inhibitor ◽  
Immunodeficiency Virus ◽  
Inhibitor Resistance ◽  
Reverse Transcriptase Inhibitor

Abstract Among 66 antiretroviral-naive children aged <3 years with human immunodeficiency virus (HIV) or coinfected with HIV and tuberculosis and initiating efavirenz-based antiretroviral therapy (ART), non–nucleoside reverse transcriptase inhibitor (NNRTI) resistance was detected before ART in 5 (7.6%). Virologic failure occurred in 2 of these children; they were last tested at 16 and 24 weeks of ART. Pre-ART NNRTI resistance was not associated with virologic failure.

scholarly journals A Mutation in the 3′ Region of the Human Immunodeficiency Virus Type 1 Reverse Transcriptase (Y318F) Associated with Nonnucleoside Reverse Transcriptase Inhibitor Resistance

2002 ◽  
Vol 76 (13) ◽  
pp. 6836-6840 ◽  
Author(s):  
P. Richard Harrigan ◽  
Mahboob Salim ◽  
David K. Stammers ◽  
Brian Wynhoven ◽  
Zabrina L. Brumme ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Reverse Transcriptase ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Transcriptase Inhibitor ◽  
Nnrti Resistance ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT The Y318F substitution in the 3′ region of human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) has been linked to nonnucleoside RT inhibitor (NNRTI) resistance in vitro. A systematic search of a large phenotypic-genotypic database (Virco) linked the Y318F substitution with a >10-fold decrease in NNRTI susceptibility in >85% of clinically derived isolates. There was a significant association between Y318F and use of delavirdine (P = 10−11) and nevirapine (P = 10−6) but not efavirenz (P = 0.3). Site-directed HIV-1 Y318F mutants in an HXB2 background displayed 42-fold-decreased susceptibility to delavirdine but <3-fold-decreased susceptibility to nevirapine or efavirenz. Combinations of Y318F with K103N, Y181C, or both resulted in decreased efavirenz susceptibility of 43-, 3.3-, and 84-fold, respectively, as well as >100- and >60-fold decreases in delavirdine and nevirapine susceptibility, respectively. These results indicate the importance of the Y318F substitution in HIV-1 drug resistance.

scholarly journals Molecular Umbrellas: a Novel Class of Candidate Topical Microbicides To Prevent Human Immunodeficiency Virus and Herpes Simplex Virus Infections

2007 ◽  
Vol 81 (14) ◽  
pp. 7636-7646 ◽  
Author(s):  
Rebecca Pellett Madan ◽  
Pedro M. M. Mesquita ◽  
Natalia Cheshenko ◽  
Bingwen Jing ◽  
Vikas Shende ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Reverse Transcriptase ◽  
Transcriptase Inhibitor ◽  
Immunodeficiency Virus ◽  
Topical Microbicides ◽  
Simplex Virus ◽  
Hsv Infections

ABSTRACT Molecular umbrella compounds may function as novel topical microbicides to prevent human immunodeficiency virus (HIV) and herpes simplex virus (HSV) infections. In a preliminary structure-activity investigation, one umbrella compound, designated Spm8CHAS, was identified which inhibited both HIV and HSV infections with no cellular toxicity. The objectives of the current studies were to define its spectrum of antiviral activity, characterize its mechanism of action, and explore the possibility of combining Spm8CHAS with HIV-specific reverse transcriptase inhibitors. Spm8CHAS inhibited infections by laboratory and clinical R5 and X4 clade B and clade C HIV strains in cell culture. Ectocervical tissue explants exposed to HIV-1BaL in the presence of Spm8CHAS were completely protected (50% inhibitory concentration [IC50], 13.6 μg/ml), and transfer of virus to target T cells via migratory cells was abolished (IC50, 3.8 μg/ml). Spm8CHAS inhibited HSV-2 infection of epithelial cells 10,000-fold if present throughout the infection. Notably, adding Spm8CHAS to cultures following HSV entry significantly reduced viral infection, indicating that the drug also acts postentry. Subsequent studies indicated that Spm8CHAS blocks cell-to-cell spread of HSV. Confocal microscopy using a fluorescently labeled analog of Spm8CHAS demonstrated that this conjugate crosses the plasma cell membrane and is transported to the nucleus. Combinations of Spm8CHAS with UC-781 or 9-[R-2-(phosphonylmethoxy)propyl] adenine monohydrate in vitro exhibited additive anti-HIV activity with preserved anti-HSV activity. The abilities of Spm8CHAS to inhibit primary isolates of HIV, block HSV infection postentry, and cross cell membranes support the development of a combination microbicide containing Spm8CHAS with an HIV-specific reverse transcriptase inhibitor to prevent both HIV and HSV infections by multiple mechanisms.

scholarly journals Novel mutation (K70E) in human immunodeficiency virus type 1 reverse transcriptase confers decreased susceptibility to 9-[2-(phosphonomethoxy)ethyl]adenine in vitro.

1996 ◽  
Vol 40 (9) ◽  
pp. 2212-2216 ◽  
Author(s):  
J M Cherrington ◽  
A S Mulato ◽  
M D Fuller ◽  
M S Chen
Keyword(s):  
Human Immunodeficiency Virus ◽  
Reverse Transcriptase ◽  
Novel Mutation ◽  
Fold Increase ◽  
Wild Type Virus ◽  
Wild Type ◽  
Hiv Reverse Transcriptase ◽  
Immunodeficiency Virus

9-[2-(phosphonomethoxy)ethyl]adenine (PMEA), an acyclic nucleoside phosphonate analog, is active against several retroviruses and herpesviruses and has shown anti-human immunodeficiency virus (HIV) activity in clinical trials. Serial passage of HIV type 1 (strain IIIb, in MT2 cells in increasing concentrations of PMEA resulted in viruses with > 12-fold increases in their 50% inhibitory concentrations of PMEA compared with that for strain IIIb. Sequence analyses of these PMEA-selected viruses demonstrated the presence of a novel lysine-to-glutamic acid mutation at amino acid 70 (K70E) in HIV reverse transcriptase. A recombinant virus carrying the K70E mutation was constructed and showed a 10-fold increase in its 50% inhibitory concentrations of PMEA and 2',3'-dideoxy-3'-thiacytidine but showed wild-type susceptibility levels to 2',3'-dideoxycytosine, 2',3'-dideoxyinosine,2',3'-didehydro-2'3'-dideoxythymidine, 3'-azido-3'-deoxythymidine, foscarnet, and two additional phosphonates, 9-[(R)-2-(phosphonomethoxy)propyl]adenine and 9-[2,5-dihydro-5-(phosphonomethoxy)-2-furanyl]adenine. Additionally, the K70E recombinant showed a minor reduction in growth kinetics compared with those of the wild-type virus in vitro.

scholarly journals In Vitro Antiretroviral Activity and In Vitro Toxicity Profile of SPD754, a New Deoxycytidine Nucleoside Reverse Transcriptase Inhibitor for Treatment of Human Immunodeficiency Virus Infection

2006 ◽  
Vol 50 (2) ◽  
pp. 625-631 ◽  
Author(s):  
Z. Gu ◽  
B. Allard ◽  
J. M. de Muys ◽  
J. Lippens ◽  
R. F. Rando ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Reverse Transcriptase ◽  
Amino Acid Position ◽  
Transcriptase Inhibitor ◽  
In Vitro Toxicity ◽  
Mitochondrial Toxicity ◽  
Immunodeficiency Virus ◽  
Reverse Transcriptase Inhibitor ◽  
Hiv 1

ABSTRACT SPD754 (AVX754) is a deoxycytidine analogue nucleotide reverse transcriptase inhibitor (NRTI) in clinical development. These studies characterized the in vitro activity of SPD754 against NRTI-resistant human immunodeficiency virus type 1 (HIV-1) and non-clade B HIV-1 isolates, its activity in combination with other antiretrovirals, and its potential myelotoxicity and mitochondrial toxicity. SPD754 was tested against 50 clinical HIV-1 isolates (5 wild-type isolates and 45 NRTI-resistant isolates) in MT-4 cells using the Antivirogram assay. SPD754 susceptibility was reduced 1.2- to 2.2-fold against isolates resistant to zidovudine (M41L, T215Y/F, plus a median of three additional nucleoside analogue mutations [NAMs]) and/or lamivudine (M184V) and was reduced 1.3- to 2.8-fold against isolates resistant to abacavir (L74V, Y115F, and M184V plus one other NAM) or stavudine (V75T/M, M41L, T215F/Y, and four other NAMs). Insertions at amino acid position 69 and Q151M mutations (with or without M184V) reduced SPD754 susceptibility 5.2-fold and 14- to 16-fold, respectively (these changes gave values comparable to or less than the corresponding values for zidovudine, lamivudine, abacavir, and didanosine). SPD754 showed similar activity against isolates of group M HIV-1 clades, including A/G, B, C, D, A(E), D/F, F, and H. SPD754 showed additive effects in combination with other NRTIs, tenofovir, nevirapine, or saquinavir. SPD754 had no significant effects on cell viability or mitochondrial DNA in HepG2 or MT-4 cells during 28-day exposure at concentrations up to 200 μM. SPD754 showed a low potential for myelotoxicity against human bone marrow. In vitro, SPD754 retained activity against most NRTI-resistant HIV-1 clinical isolates and showed a low propensity to cause myelotoxicity and mitochondrial toxicity.

scholarly journals Mutations That Abrogate Human Immunodeficiency Virus Type 1 Reverse Transcriptase Dimerization Affect Maturation of the Reverse Transcriptase Heterodimer

2005 ◽  
Vol 79 (16) ◽  
pp. 10247-10257 ◽  
Author(s):  
Johanna Wapling ◽  
Katie L. Moore ◽  
Secondo Sonza ◽  
Johnson Mak ◽  
Gilda Tachedjian
Keyword(s):  
Human Immunodeficiency Virus ◽  
Reverse Transcriptase ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Wild Type Virus ◽  
Wild Type ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT The specific impact of mutations that abrogate human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) dimerization on virus replication is not known, as mutations shown previously to inhibit RT dimerization also impact Gag-Pol stability, resulting in pleiotropic effects on HIV-1 replication. We have previously characterized mutations at codon 401 in the HIV-1 RT tryptophan repeat motif that abrogate RT dimerization in vitro, leading to a loss in polymerase activity. The introduction of the RT dimerization-inhibiting mutations W401L and W401A into HIV-1 resulted in the formation of noninfectious viruses with reduced levels of both virion-associated and intracellular RT activity compared to the wild-type virus and the W401F mutant, which does not inhibit RT dimerization in vitro. Steady-state levels of the p66 and p51 RT subunits in viral lysates of the W401L and W401A mutants were reduced, but no significant decrease in Gag-Pol was observed compared to the wild type. In contrast, there was a decrease in processing of p66 to p51 in cell lysates for the dimerization-defective mutants compared to the wild type. The treatment of transfected cells with indinavir suggested that the HIV-1 protease contributed to the degradation of virion-associated RT subunits. These data demonstrate that mutations near the RT dimer interface that abrogate RT dimerization in vitro result in the production of replication-impaired viruses without detectable effects on Gag-Pol stability or virion incorporation. The inhibition of RT activity is most likely due to a defect in RT maturation, suggesting that RT dimerization represents a valid drug target for chemotherapeutic intervention.

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