scholarly journals Post-Catalytic Complexes with Emtricitabine or Stavudine and HIV-1 Reverse Transcriptase Reveal New Mechanistic Insights for Nucleotide Incorporation and Drug Resistance

Molecules ◽  
2020 ◽  
Vol 25 (20) ◽  
pp. 4868
Author(s):  
Nicole Bertoletti ◽  
Albert H. Chan ◽  
Raymond F. Schinazi ◽  
Karen S. Anderson
Keyword(s):  
Crystal Structure ◽  
Reverse Transcriptase ◽  
Highly Active Antiretroviral Therapy ◽  
Molecular Mechanisms ◽  
X Ray Crystallography ◽  
Highly Active ◽  
Nucleotide Incorporation ◽  
Almost All ◽  
Immunodeficiency Syndrome ◽  
Hiv 1

Human immunodeficiency virus 1 (HIV-1) infection is a global health issue since neither a cure nor a vaccine is available. However, the highly active antiretroviral therapy (HAART) has improved the life expectancy for patients with acquired immunodeficiency syndrome (AIDS). Nucleoside reverse transcriptase inhibitors (NRTIs) are in almost all HAART and target reverse transcriptase (RT), an essential enzyme for the virus. Even though NRTIs are highly effective, they have limitations caused by RT resistance. The main mechanisms of RT resistance to NRTIs are discrimination and excision. Understanding the molecular mechanisms for discrimination and excision are essential to develop more potent and selective NRTIs. Using protein X-ray crystallography, we determined the first crystal structure of RT in its post-catalytic state in complex with emtricitabine, (-)FTC or stavudine (d4T). Our structural studies provide the framework for understanding how RT discriminates between NRTIs and natural nucleotides, and for understanding the requirement of (-)FTC to undergo a conformation change for successful incorporation by RT. The crystal structure of RT in post-catalytic complex with d4T provides a “snapshot” for considering the possible mechanism of how RT develops resistance for d4T via excision. The findings reported herein will contribute to the development of next generation NRTIs.

Tenofovir Disoproxil Fumarate

2003 ◽  
Vol 37 (6) ◽  
pp. 849-859 ◽  
Author(s):  
Shellee A Grim ◽  
Frank Romanelli
Keyword(s):  
Reverse Transcriptase ◽  
Tenofovir Disoproxil Fumarate ◽  
Highly Active Antiretroviral Therapy ◽  
Data Extraction ◽  
Single Agent ◽  
Transcriptase Inhibitor ◽  
Medline Search ◽  
Highly Active ◽  
Cell Counts ◽  
Hiv 1

OBJECTIVE: To review the pharmacology, virology, pharmacokinetics, efficacy, safety, resistance profile, and clinical use of tenofovir disoproxil fumarate. DATA SOURCES: A MEDLINE search was performed (1966–August 2002) using the following terms: tenofovir, tenofovir disoproxil fumarate, PMPA (9-( R)-[2-(phosphonomethoxy)propyl]adenine), and Viread. Abstracts from HIV-related meetings were reviewed. DATA EXTRACTION AND STUDY SELECTION: Publications and meeting abstracts regarding tenofovir were reviewed. The most recent and pertinent items were included. DATA SYNTHESIS: Tenofovir disoproxil fumarate is a nucleotide prodrug that is diphosphorylated to its active moiety, tenofovir diphosphate. In this form, tenofovir acts as a reverse transcriptase inhibitor to inhibit HIV-1 replication. In clinical trials, tenofovir was effective at suppressing HIV-1 RNA and boosting CD4+ cell counts. Tenofovir has a long intracellular half-life, which permits once-daily dosing. Since tenofovir does not interact with the cytochrome P450 pathway, it exhibits minimal drug interactions, with the exception of didanosine. Compared with other reverse transcriptase inhibitors, tenofovir may have advantages in terms of toxicity and medication adherence profiles. Ongoing studies are also analyzing tenofovir's activity against hepatitis B virus. CONCLUSIONS: Tenofovir has been shown to be active against HIV-1 in combination with other antiretrovirals. The drug's benefit as a single-agent intensifier of highly active antiretroviral therapy in treatment-experienced patients has been established, and preliminary data for treatment-naïve patients are encouraging.

scholarly journals The HEPT Analogue WPR-6 Is Active against a Broad Spectrum of Nonnucleoside Reverse Transcriptase Drug-Resistant HIV-1 Strains of Different Serotypes

2015 ◽  
Vol 59 (8) ◽  
pp. 4882-4888 ◽  
Author(s):  
Weisi Xu ◽  
Jianxiong Zhao ◽  
Jianping Sun ◽  
Qianqian Yin ◽  
Yan Wang ◽  
...  
Keyword(s):  
Reverse Transcriptase ◽  
Highly Active Antiretroviral Therapy ◽  
Therapeutic Index ◽  
Transcriptase Inhibitor ◽  
Resistance Mutations ◽  
Highly Active ◽  
Hiv Drugs ◽  
Reverse Transcriptase Inhibitor ◽  
Hiv 1

ABSTRACTNonnucleoside reverse transcriptase inhibitors (NNRTIs) are important components of the highly active antiretroviral therapy (HAART) used to treat human immunodeficiency type 1 virus (HIV-1). However, because of the emergence of drug resistance and the adverse effects of current anti-HIV drugs, it is essential to develop novel NNRTIs with an excellent safety profile, improved activity against NNRTI-resistant viruses, and enhanced activity against clinical isolates of different subtypes. Here, we have identified 1-[(benzyloxy)methyl]-6-(3,5-dimethylbenzyl)-5-iodopyrimidine-2,4(1H,3H)-dione (WPR-6), a novel NNRTI with a 50% effective concentration (EC50) of 2 to 4 nM against laboratory-adapted HIV-1 strain SF33 and an EC50of 7 to 14 nM against nucleoside reverse transcriptase inhibitor-resistant HIV-1 strain 7391 with a therapeutic index of >1 × 104. A panel of five representative clinical virus isolates of different subtypes circulating predominantly in China was highly sensitive to WPR-6, with EC50s ranging from 1 to 6 nM. In addition, WPR-6 showed excellent antiviral potency against the most prevalent NNRTI-resistant viruses containing the K103N and Y181C mutations. To determine whether WPR-6 selects for novel resistant mutants,in vitroresistance selection was conducted with laboratory-adapted HIV-1 strain SF33 on MT-4 cells. The results demonstrated that V106I and Y188L were the two dominant NNRTI-associated resistance mutations detected in the breakthrough viruses. Taken together, thesein vitrodata indicate that WPR-6 has greater efficacy than the reference HEPT analogue TNK651 and the marketed drug nevirapine against HIV-1. However, to develop it as a new NNRTI, further improvement of its pharmacological properties is warranted.

scholarly journals Suppression of Virus Load by Highly Active Antiretroviral Therapy in Rhesus Macaques Infected with a Recombinant Simian Immunodeficiency Virus Containing Reverse Transcriptase from Human Immunodeficiency Virus Type 1

2005 ◽  
Vol 79 (12) ◽  
pp. 7349-7354 ◽  
Author(s):  
Thomas W. North ◽  
Koen K. A. Van Rompay ◽  
Joanne Higgins ◽  
Timothy B. Matthews ◽  
Debra A. Wadford ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Antiretroviral Therapy ◽  
Reverse Transcriptase ◽  
Highly Active Antiretroviral Therapy ◽  
Rhesus Macaques ◽  
Once Daily ◽  
Highly Active ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT We have modeled highly active antiretroviral therapy (HAART) for AIDS in rhesus macaques infected with a chimera (RT-SHIV) of simian immunodeficiency virus containing reverse transcriptase from human immunodeficiency virus type-1 (HIV-1). Seven RT-SHIV-infected macaques were treated with a combination of efavirenz (200 mg orally once daily), lamivudine (8 mg/kg subcutaneously once daily), and tenofovir (30 mg/kg subcutaneously once daily). Plasma viral RNA levels in all animals were reduced by more than 1,000-fold after 4 weeks and, in six of the seven animals, were reduced to undetectable levels after 10 weeks. Virus loads increased slightly between 12 and 16 weeks of treatment, associated with problems with the administration of efavirenz. After a change in the method of efavirenz administration, virus loads declined again and remained undetectable in the majority of animals for the duration of therapy. Treatment was stopped for three animals after 36 weeks of therapy, and virus loads increased rapidly. Posttreatment RT-SHIV isolates had no mutations associated with resistance to any of the three drugs. Efavirenz treatment was stopped, but lamivudine and tenofovir treatment for two other macaques was continued. The virus load in one of these two animals rebounded; virus from this animal was initially free of drug-resistance mutations but acquired the K65R mutation in reverse transcriptase at 11 weeks after efavirenz treatment was withdrawn. These results mimic HAART of HIV-1-infected humans. The RT-SHIV/rhesus macaque model should be useful for studies of tissue reservoirs and sites of residual replication that are not possible or practical with humans.

scholarly journals Lersivirine, a Nonnucleoside Reverse Transcriptase Inhibitor with Activity against Drug-Resistant Human Immunodeficiency Virus Type 1

2010 ◽  
Vol 54 (10) ◽  
pp. 4451-4463 ◽  
Author(s):  
Romuald Corbau ◽  
Julie Mori ◽  
Chris Phillips ◽  
Lesley Fishburn ◽  
Alex Martin ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Reverse Transcriptase ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Highly Active Antiretroviral Therapy ◽  
Transcriptase Inhibitor ◽  
Highly Active ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT The nonnucleoside reverse transcriptase inhibitors (NNRTIs) are key components of highly active antiretroviral therapy (HAART) for the treatment of human immunodeficiency virus type 1 (HIV-1). A major problem with the first approved NNRTIs was the emergence of mutations in the HIV-1 reverse transcriptase (RT), in particular K103N and Y181C, which led to resistance to the entire class. We adopted an iterative strategy to synthesize and test small molecule inhibitors from a chemical series of pyrazoles against wild-type (wt) RT and the most prevalent NNRTI-resistant mutants. The emerging candidate, lersivirine (UK-453,061), binds the RT enzyme in a novel way (resulting in a unique resistance profile), inhibits over 60% of viruses bearing key RT mutations, with 50% effective concentrations (EC50s) within 10-fold of those for wt viruses, and has excellent selectivity against a range of human targets. Altogether lersivirine is a highly potent and selective NNRTI, with excellent efficacy against NNRTI-resistant viruses.

scholarly journals Advances in Continuous Microfluidics-Based Technologies for the Study of HIV Infection

Viruses ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 982 ◽  
Author(s):  
Joëlle Eid ◽  
Marylène Mougel ◽  
Marius Socol
Keyword(s):  
Highly Active Antiretroviral Therapy ◽  
Wide Spectrum ◽  
Microfluidic Chips ◽  
Basic Study ◽  
Highly Active ◽  
Aids Progression ◽  
Acquired Immunodeficiency ◽  
Immunodeficiency Syndrome ◽  
Aids Diagnosis ◽  
Hiv 1

HIV-1 is the causative agent of acquired immunodeficiency syndrome (AIDS). It affects millions of people worldwide and the pandemic persists despite the implementation of highly active antiretroviral therapy. A wide spectrum of techniques has been implemented in order to diagnose and monitor AIDS progression over the years. Besides the conventional approaches, microfluidics has provided useful methods for monitoring HIV-1 infection. In this review, we introduce continuous microfluidics as well as the fabrication and handling of microfluidic chips. We provide a review of the different applications of continuous microfluidics in AIDS diagnosis and progression and in the basic study of the HIV-1 life cycle.

scholarly journals Loss of the Perforin Cytotoxic Pathway Predisposes Mice to Experimental Cytomegalovirus Retinitis

2003 ◽  
Vol 77 (6) ◽  
pp. 3402-3408 ◽  
Author(s):  
Richard D. Dix ◽  
Eckhard R. Podack ◽  
Scott W. Cousins
Keyword(s):  
T Lymphocytes ◽  
Highly Active Antiretroviral Therapy ◽  
Retinal Disease ◽  
Murine Cytomegalovirus ◽  
Mrna Levels ◽  
Reverse Transcription Pcr ◽  
Highly Active ◽  
Series Of Experiments ◽  
Immunodeficiency Syndrome ◽  
Hiv 1

ABSTRACT AIDS-related human cytomegalovirus (HCMV) retinitis continues to be a chronic ophthalmologic problem among human immunodeficiency virus type 1 (HIV-1)-infected patients who do not respond to highly active antiretroviral therapy. Although HCMV retinitis occurs during HIV-1-induced immunosuppression, the precise effector mechanism(s) that fails during the immunopathogenesis of AIDS to allow onset and progression of HCMV retinal disease remains unclear. We therefore performed a series of experiments to explore the relative roles of distinct pathways of lymphocyte-mediated cytotoxicity in either resistance or susceptibility to experimental murine cytomegalovirus (MCMV) retinitis in mice. Whereas mutant C57BL/6 mice deficient in the Fas/FasL cytotoxic pathway (gld mice) were identical to normal C57BL/6 mice and exhibited absolute resistance to retinal necrosis following subretinal MCMV inoculation, knockout C57BL/6 mice deficient in the perforin cytotoxic pathway (PKO mice) were susceptible to MCMV retinitis. Susceptibility of PKO mice to MCMV retinitis correlated with increased ocular MCMV titers when compared with ocular MCMV titers of gld and normal mice. Since mice with retrovirus-induced immunodeficiency syndrome (MAIDS) exhibited a frequency and severity of MCMV retinitis that were equivalent to those observed in PKO mice, we hypothesized that susceptibility to MCMV retinitis during MAIDS correlates with a decrease in the perforin cytotoxic pathway. To test this hypothesis, we developed a quantitative competitive reverse transcription-PCR assay to measure mouse perforin mRNA levels in the splenic T lymphocytes and MCMV-inoculated eyes of normal mice or mice with MAIDS. Perforin mRNA levels in splenic T lymphocytes were significantly decreased during MAIDS, by ∼100-fold, from perforin mRNA levels in normal mice. Moreover, MCMV-inoculated eyes destined to develop retinitis during MAIDS also showed a significant decrease in perforin mRNA levels from the perforin mRNA levels of MCMV-inoculated eyes of normal mice destined to be resistant to retinitis. As expected, perforin mRNA could not be detected in unmanipulated and uninfected eyes of normal mice. These results provide the first evidence that the perforin cytotoxic pathway is more important than the Fas/FasL cytotoxic pathway in providing resistance to experimental MCMV retinitis and that loss of the perforin cytotoxic pathway predisposes to MCMV retinitis.

The Mechanical and Structural Effects of HIV Proteins on Murine Carotid Arteries

2011 ◽  
Author(s):  
Laura Hansen ◽  
Manu Platt ◽  
Roy L. Sutliff ◽  
Rudolph L. Gleason
Keyword(s):  
Cardiovascular Disease ◽  
Highly Active Antiretroviral Therapy ◽  
Intima Media Thickness ◽  
Biomechanical Properties ◽  
Cardiovascular Complications ◽  
Global Epidemic ◽  
Highly Active ◽  
Atherosclerotic Lesions ◽  
Immunodeficiency Syndrome ◽  
Hiv 1

Acquired immunodeficiency syndrome (AIDS) is considered a global epidemic with over 65 million people worldwide infected with the HIV-1 virus, the causative agent [1]. The development of highly active antiretroviral therapy (HAART) has significantly increased the life expectancy of people infected with the virus by slowing the progression to the development of AIDS. However, the treatment has also led to the emergence of early onset cardiovascular complications including myocardial infarction [2] and atherosclerotic lesions [3], as well as subclinical markers of atherosclerosis including increased carotid artery intima-media thickness [4], increased arterial stiffness [5–6], and endothelial dysfunction [6]. It appears that HAART and HIV-1-infection are independent risk factors for the development of atherosclerosis in adults [7]; however, the mechanism of disease progression remains unclear. There is a pressing need to identify mechanisms of early on-set cardiovascular disease associated with HIV-1 infection and HAART and to identify therapeutic strategies to reduce cardiovascular disease in HIV patients. The overall goal of this study is to test the hypothesis that over-expression of HIV proteins will lead to alterations in the biomechanical properties of large arteries.

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