A Tight-Binding Mode of Inhibition Is Essential for Anti-Human Immunodeficiency Virus Type 1 Virucidal Activity of Nonnucleoside Reverse Transcriptase Inhibitors

Motakis, Dimitrios; Parniak, Michael A.

doi:10.1128/aac.46.6.1851-1856.2002

Cited by 58 publications

(64 citation statements)

References 22 publications

(9 reference statements)

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“…The values of NERT inhibition for virus budded in the presence of EFV were not different before and after the wash procedure, suggesting that this NNRTI remains bound to the RT molecules inside the viral particles. These results agree with reports that named NNRTIs as rapid-equilibrium and tightly binding inhibitors (16,28). NVP is a rapid-equilibrium inhibitor and requires an excess of the drug over the enzyme concentration (27).…”

Section: Discussionsupporting

confidence: 83%

Development of a New Methodology for Screening of Human Immunodeficiency Virus Type 1 Microbicides Based on Real-Time PCR Quantification

Aguiar

Costa

Pereira

et al. 2007

Antimicrob Agents Chemother

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Potential topical retrovirucides or vaginal microbicides against human immunodeficiency virus type 1 (HIV-1) include nonnucleoside reverse transcriptase inhibitors (NNRTIs). To be successful, such agents have to be highly active against cell-free virions. In the present study, we developed a new real-time PCR-based assay to measure the natural endogenous reverse transcription (NERT) activity directly on intact HIV-1 particles in the presence of reverse transcriptase (RT) inhibitors. We further evaluated the permeability to nevirapine (NVP) and efavirenz (EFV) and their retention within nascent viral particles. We also demonstrated the NVP and EFV inhibitory effects on NERT activity and the impact of resistance mutations measured directly by this new strategy. Furthermore, the results showed a clear correlation between NERT activity and classical infectivity assays. The 50% inhibitory concentrations (IC 50 s) of NVP and EFV were demonstrated to be up to 100-fold higher for cell-free than for cell-associated virions, suggesting that cell-free virions are less permeable to these drugs. Our results suggest that NVP and EFV penetrate both the envelope and the capsid of HIV-1 particles and readily inactivate cell-free virions. However, the characteristics of these NNRTIs, such as lower permeability and lower retention during washing procedures, in cell-free virions reduce their efficacies as microbicides. Here, we demonstrate the usefulness of the NERT real-time PCR as an assay for screening novel antiretroviral compounds with unique mechanisms of action.

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Section: Discussionsupporting

confidence: 83%

Development of a New Methodology for Screening of Human Immunodeficiency Virus Type 1 Microbicides Based on Real-Time PCR Quantification

Aguiar

Costa

Pereira

et al. 2007

Antimicrob Agents Chemother

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“…This class of hydrophobic, tight-binding NNRTI compounds (that includes UC-781, TMC120, DABO, and MIV-150) readily crosses membrane barriers and irreversibly inactivates RT (13). UC-781 was originally developed by Uniroyal Chemical (now Crompton) (1) as an antiretroviral agent; however, poor bioavailability prevented its development as a therapeutic treatment.…”

mentioning

confidence: 99%

The Nonnucleoside Reverse Transcriptase Inhibitor UC-781 Inhibits Human Immunodeficiency Virus Type 1 Infection of Human Cervical Tissue and Dissemination by Migratory Cells

Fletcher

Kiselyeva

Wallace

et al. 2005

J Virol

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Heterosexual transmission of human immunodeficiency virus remains the major route of transmission worldwide; thus, there is an urgent need for additional prevention strategies, particularly those that could be controlled by women. Using cellular and tissue explant models, we have evaluated the potential activity of thiocarboxanilide nonnucleoside analogue reverse transcriptase inhibitor UC-781 as a vaginal microbicide. We were able to demonstrate a potent dose-dependent effect against R5 and X4 infections of T cells. In human cervical explant cultures, UC-781 was not only able to inhibit direct infection of mucosal tissue but was able to prevent dissemination of virus by migratory cells. UC-781 formulated into a carbopol gel (0.1%) retained significant activity against both direct tissue infection and transinfection mediated by migratory cells. Furthermore, UC-781 demonstrated prolonged inhibitory effects able to prevent both localized and disseminated infections up to 6 days post compound treatment. Additional studies were carried out to determine the concentration of compound that might be required to block a primary infection within draining lymph nodes. While a greater dose of compound was required to inhibit both X4 and R5 infections of lymphoid versus cervical explants, this was equivalent to a 1:3,000 dilution of the 0.1% formulation. Furthermore, a 2-h exposure to the compound prevented infection of lymphoid tissue when challenged up to 2 days later. The prolonged protection observed following pretreatment of both genital and lymphoid tissues with UC-781 suggests that this class of inhibitors may have unique advantages over other classes of potential microbicide candidates.

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“…A variety of compounds have been proposed as potential topical anti-HIV microbicides (16,21,40,41,44,(54)(55)(56)(57). One of these is the nonnucleoside reverse transcriptase inhibitor (NNRTI) UC781, which we and others have shown to possess excellent anti-HIV-1 microbicidal activity against wild-type (wt) HIV-1 in vitro (7,10,15,22,39,42,43). However, a significant concern with NNRTI-based microbicides is that these might be ineffective against NNRTIresistant HIV-1 and thus might select for the transmission of NNRTI-resistant virus strains.…”

mentioning

confidence: 99%

In Vitro Microbicidal Activity of the Nonnucleoside Reverse Transcriptase Inhibitor (NNRTI) UC781 against NNRTI-Resistant Human Immunodeficiency Virus Type 1

Hossain

Parniak

2006

J Virol

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The nonnucleoside reverse transcriptase inhibitor (NNRTI) UC781 is under development as a microbicide to prevent sexual transmission of the human immunodeficiency virus type 1 (HIV-1). However, NNRTIresistant HIV-1 is increasingly prevalent in the infected population, and one of the concerns for NNRTI-based microbicides is that they will be ineffective against drug-resistant virus and may in fact selectively transmit NNRTI-resistant virus. We evaluated the microbicidal activity of UC781 against UC781-resistant (UCR), efavirenz-resistant (EFVR), and nevirapine-resistant (NVPR) strains in a variety of microbicide-relevant tests, including inactivation of cell-free virus, inhibition of cell-to-cell HIV-1 transmission, and the ability of UC781 pretreatment to protect cells from subsequent infection in the absence of exogenous drug. UC781 was 10-to 100-fold less effective against NNRTI-resistant HIV-1 compared to wild-type (wt) virus in each of these tests, with UC781 microbicidal activity against the various virus strains being wt > NVPR > UCR > EFVR. Breakthrough experiments using UC781-pretreated cells and mixtures of wt and NNRTI-resistant HIV-1 showed that UC781-pretreatment selected for NNRTI-resistant HIV-1. However, the efficacy of UC781 was dose dependent, and 25 M UC781 provided essentially equivalent microbicidal activity against NNRTI-resistant and wt virus. The amount of UC781 in topical microbicide formulations under current development is approximately 100-fold greater than this concentration, so transmission of NNRTI-resistant virus may not be an issue at these microbicide formulation levels of UC781. Nonetheless, the reduced microbicidal activity of UC781 against NNRTI-resistant HIV-1 suggests that additional antiviral agents should be included in NNRTIbased microbicide formulations.

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A Tight-Binding Mode of Inhibition Is Essential for Anti-Human Immunodeficiency Virus Type 1 Virucidal Activity of Nonnucleoside Reverse Transcriptase Inhibitors

Cited by 58 publications

References 22 publications

Development of a New Methodology for Screening of Human Immunodeficiency Virus Type 1 Microbicides Based on Real-Time PCR Quantification

Development of a New Methodology for Screening of Human Immunodeficiency Virus Type 1 Microbicides Based on Real-Time PCR Quantification

The Nonnucleoside Reverse Transcriptase Inhibitor UC-781 Inhibits Human Immunodeficiency Virus Type 1 Infection of Human Cervical Tissue and Dissemination by Migratory Cells

In Vitro Microbicidal Activity of the Nonnucleoside Reverse Transcriptase Inhibitor (NNRTI) UC781 against NNRTI-Resistant Human Immunodeficiency Virus Type 1

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