scholarly journals A highly potent and safe pyrrolopyridine-based allosteric HIV-1 integrase inhibitor targeting host LEDGF/p75-integrase interaction site

2021 ◽  
Vol 17 (7) ◽  
pp. e1009671
Author(s):  
Tatsuya Maehigashi ◽  
Seohyun Ahn ◽  
Uk-Il Kim ◽  
Jared Lindenberger ◽  
Adrian Oo ◽  
...  
Keyword(s):  
Therapeutic Index ◽  
Integrase Inhibitor ◽  
Binding Pocket ◽  
Viral Particles ◽  
Viral Maturation ◽  
Biochemical Analyses ◽  
Rna Interaction ◽  
Anti Hiv Agents ◽  
Hiv 1

Allosteric integrase inhibitors (ALLINIs) are a class of experimental anti-HIV agents that target the noncatalytic sites of the viral integrase (IN) and interfere with the IN-viral RNA interaction during viral maturation. Here, we report a highly potent and safe pyrrolopyridine-based ALLINI, STP0404, displaying picomolar IC50 in human PBMCs with a >24,000 therapeutic index against HIV-1. X-ray structural and biochemical analyses revealed that STP0404 binds to the host LEDGF/p75 protein binding pocket of the IN dimer, which induces aberrant IN oligomerization and blocks the IN-RNA interaction. Consequently, STP0404 inhibits proper localization of HIV-1 RNA genomes in viral particles during viral maturation. Y99H and A128T mutations at the LEDGF/p75 binding pocket render resistance to STP0404. Extensive in vivo pharmacological and toxicity investigations demonstrate that STP0404 harbors outstanding therapeutic and safety properties. Overall, STP0404 is a potent and first-in-class ALLINI that targets LEDGF/p75 binding site and has advanced to a human trial.

scholarly journals A unique conformational escape reaction of HIV-1 against an allosteric integrase inhibitor

2019 ◽  
Author(s):  
Tomofumi Nakamura ◽  
Teruya Nakamura ◽  
Masayuki Amano ◽  
Toshikazu Miyakawa ◽  
Yuriko Yamagata ◽  
...  
Keyword(s):  
Rna Binding ◽  
Integrase Inhibitor ◽  
Catalytic Core ◽  
Viral Particles ◽  
Dimerization Interface ◽  
Conformational Alteration ◽  
Escape Reaction ◽  
Viral Maturation ◽  
Anti Hiv ◽  
Hiv 1

AbstractHIV-1 integrase (IN) contributes to HIV-1 RNA binding, which is required for viral maturation. Non-catalytic site integrase inhibitors (NCINIs) have been developed as allosteric IN inhibitors, which perform anti-HIV-1 activity by disrupting IN multimerization. Here, we show that IN undergoes a novel conformational alteration to escape from NCINIs. We observed that NCINI-resistant HIV-1 variants have accumulated amino acid (AA) mutations in the IN-encoding region. We employed HPLC and thermal stability assays to show that the AA mutations affect the folding and dimerization interface of the IN catalytic core domains, resulting in severely decreased multimerization of full-length IN proteins (IN under-multimerization). The under-multimerization of IN was finally restored by HIV-1 RNA in the viral particles. Our study demonstrates that HIV-1 countervails NCINIs by IN under-multimerization as a novel escape mechanism. Our findings provide information on the understanding of IN multimerization and influence the development of unique anti-HIV-1 strategies.

scholarly journals G2-S16 Polyanionic Carbosilane Dendrimer Can Reduce HIV-1 Reservoir Formation by Inhibiting Macrophage Cell to Cell Transmission

2021 ◽  
Vol 22 (16) ◽  
pp. 8366
Author(s):  
Ignacio Relaño-Rodríguez ◽  
María de la Sierra Espinar-Buitrago ◽  
Vanessa Martín-Cañadilla ◽  
Rafael Gómez-Ramírez ◽  
María Ángeles Muñoz-Fernández
Keyword(s):  
T Cells ◽  
Developed Countries ◽  
Main Role ◽  
Viral Particles ◽  
Carbosilane Dendrimer ◽  
Science Community ◽  
New Compounds ◽  
Hiv 1

Human immunodeficiency virus (HIV-1) is still a major problem, not only in developing countries but is also re-emerging in several developed countries, thus the development of new compounds able to inhibit the virus, either for prophylaxis or treatment, is still needed. Nanotechnology has provided the science community with several new tools for biomedical applications. G2-S16 is a polyanionic carbosilane dendrimer capable of inhibiting HIV-1 in vitro and in vivo by interacting directly with viral particles. One of the main barriers for HIV-1 eradication is the reservoirs created in primoinfection. These reservoirs, mainly in T cells, are untargetable by actual drugs or immune system. Thus, one approach is inhibiting HIV-1 from reaching these reservoir cells. In this context, macrophages play a main role as they can deliver viral particles to T cells establishing reservoirs. We showed that G2-S16 dendrimer is capable of inhibiting the infection from infected macrophages to healthy T CD4/CD8 lymphocytes by eliminating HIV-1 infectivity inside macrophages, so they are not able to carry infectious particles to other body locations, thus preventing the reservoirs from forming.

scholarly journals Human Immunodeficiency Virus Type 1 Vif Protein Is an Integral Component of an mRNP Complex of Viral RNA and Could Be Involved in the Viral RNA Folding and Packaging Process

2000 ◽  
Vol 74 (18) ◽  
pp. 8252-8261 ◽  
Author(s):  
Hui Zhang ◽  
Roger J. Pomerantz ◽  
Geethanjali Dornadula ◽  
Yong Sun
Keyword(s):  
Human Immunodeficiency Virus ◽  
Rna Binding ◽  
Viral Rna ◽  
Immunodeficiency Virus ◽  
Mrnp Complex ◽  
Rna Interaction ◽  
Vif Protein ◽  
Hiv 1

ABSTRACT Virion infectivity factor (Vif) is a protein encoded by human immunodeficiency virus types 1 and 2 (HIV-1 and -2) and simian immunodeficiency virus, plus other lentiviruses, and is essential for viral replication either in vivo or in culture for nonpermissive cells such as peripheral blood lymphoid cells, macrophages, and H9 T cells. Defects in the vif gene affect virion morphology and reverse transcription but not the expression of viral components. It has been shown that Vif colocalizes with Gag in cells and Vif binds to the NCp7 domain of Gag in vitro. However, it seems that Vif is not specifically packaged into virions. The molecular mechanism(s) for Vif remains unknown. In this report, we demonstrate that HIV-1 Vif is an RNA-binding protein and specifically binds to HIV-1 genomic RNA in vitro. Further, Vif binds to HIV-1 RNA in the cytoplasm of virus-producing cells to form a 40S mRNP complex. Coimmunoprecipitation and in vivo UV cross-linking assays indicated that Vif directly interact with HIV-1 RNA in the virus-producing cells. Vif-RNA binding could be displaced by Gag-RNA binding, suggesting that Vif protein in the mRNP complex may mediate viral RNA interaction with HIV-1 Gag precursors. Furthermore, we have demonstrated that these Vif mutants that lose the RNA binding activity in vitro do not supportvif-deficient HIV-1 replication in H9 T cells, suggesting that the RNA binding capacity of Vif is important for its function. Further studies regarding Vif-RNA interaction in virus-producing cells will be important for studying the function of Vif in the HIV-1 life cycle.

scholarly journals Regulation of the RNA and DNA nuclease activities required for Pyrococcus furiosus Type III-B CRISPR–Cas immunity

2020 ◽  
Vol 48 (8) ◽  
pp. 4418-4434 ◽  
Author(s):  
Kawanda Foster ◽  
Sabine Grüschow ◽  
Scott Bailey ◽  
Malcolm F White ◽  
Michael P Terns
Keyword(s):  
Rna Binding ◽  
Pyrococcus Furiosus ◽  
Type Iii ◽  
Second Messenger Signaling ◽  
Biochemical Analyses ◽  
Rna Interaction ◽  
Dual Mechanism ◽  
Target Rna ◽  
Rna And Dna

Abstract Type III CRISPR–Cas prokaryotic immune systems provide anti-viral and anti-plasmid immunity via a dual mechanism of RNA and DNA destruction. Upon target RNA interaction, Type III crRNP effector complexes become activated to cleave both target RNA (via Cas7) and target DNA (via Cas10). Moreover, trans-acting endoribonucleases, Csx1 or Csm6, can promote the Type III immune response by destroying both invader and host RNAs. Here, we characterize how the RNase and DNase activities associated with Type III-B immunity in Pyrococcus furiosus (Pfu) are regulated by target RNA features and second messenger signaling events. In vivo mutational analyses reveal that either the DNase activity of Cas10 or the RNase activity of Csx1 can effectively direct successful anti-plasmid immunity. Biochemical analyses confirmed that the Cas10 Palm domains convert ATP into cyclic oligoadenylate (cOA) compounds that activate the ribonuclease activity of Pfu Csx1. Furthermore, we show that the HEPN domain of the adenosine-specific endoribonuclease, Pfu Csx1, degrades cOA signaling molecules to provide an auto-inhibitory off-switch of Csx1 activation. Activation of both the DNase and cOA generation activities require target RNA binding and recognition of distinct target RNA 3′ protospacer flanking sequences. Our results highlight the complex regulatory mechanisms controlling Type III CRISPR immunity.

scholarly journals Antiviral Activity of Bictegravir and Cabotegravir against Integrase Inhibitor-Resistant SIVmac239 and HIV-1

2017 ◽  
Vol 61 (12) ◽  
Author(s):  
Said A. Hassounah ◽  
Ahmad Alikhani ◽  
Maureen Oliveira ◽  
Simrat Bharaj ◽  
Ruxandra-Ilinca Ibanescu ◽  
...  
Keyword(s):  
Treatment Strategies ◽  
Fold Increase ◽  
Integrase Inhibitor ◽  
Antiretroviral Drugs ◽  
Strand Transfer ◽  
Single Cycle ◽  
Genetic Barrier ◽  
Hiv 1

ABSTRACT Animal models are essential to study novel antiretroviral drugs, resistance-associated mutations (RAMs), and treatment strategies. Bictegravir (BIC) is a novel potent integrase strand transfer inhibitor (INSTI) that has shown promising results against HIV-1 infection in vitro and in vivo and against clinical isolates with resistance against INSTIs. BIC has a higher genetic barrier to the development of resistance than two clinically approved INSTIs, termed raltegravir and elvitegravir. Another clinically approved INSTI, dolutegravir (DTG) also possesses a high genetic barrier to resistance, while a fourth compound, termed cabotegravir (CAB), is currently in late phases of clinical development. Here we report the susceptibilities of simian immunodeficiency virus (SIV) and HIV-1 integrase (IN) mutants containing various RAMs to BIC, CAB, and DTG. BIC potently inhibited SIV and HIV-1 in single cycle infection with 50% effective concentrations (EC50s) in the low nM range. In single cycle SIV infections, none of the E92Q, T97A, Y143R, or N155H substitutions had a significant effect on susceptibility to BIC (≤4-fold increase in EC50), whereas G118R and R263K conferred ∼14-fold and ∼6-fold increases in EC50, respectively. In both single and multiple rounds of HIV-1 infections, BIC remained active against the Y143R, N155H, R263K, R263K/M50I, and R263K/E138K mutants (≤4-fold increase in EC50). In multiple rounds of infection, the G140S/Q148H combination of substitutions decreased HIV-1 susceptibility to BIC 4.8-fold compared to 16.8- and 7.4-fold for CAB and DTG, respectively. BIC possesses an excellent resistance profile in regard to HIV and SIV and could be useful in nonhuman primate models of HIV infection.

scholarly journals Synthesis of 1-benzyl-3-(3,5-dimethylbenzyl)Uracil Derivatives with Potential Anti-HIV Activity

2011 ◽  
Vol 22 (2) ◽  
pp. 57-65 ◽  
Author(s):  
Yohei Isono ◽  
Norikazu Sakakibara ◽  
Paula Ordonez ◽  
Takayuki Hamasaki ◽  
Masanori Baba ◽  
...  
Keyword(s):  
Reverse Transcriptase ◽  
Transcriptase Inhibitor ◽  
Structural Modifications ◽  
Half Maximal Effective Concentration ◽  
Reverse Transcriptase Inhibitor ◽  
Anti Hiv Agents ◽  
Substituted 1 ◽  
Anti Hiv ◽  
Hiv 1

Background: Nine novel uracil analogues were synthesized and evaluated as inhibitors of HIV-1. Methods: Key structural modifications included replacement of the 6-chloro group of 1-benzyl-6-chloro-3-(3,5-dimethylbenzyl)uracil by other functional groups or N1-alkylation of 3-(3,5-dimethylbenzyl)-5-fluorouracil. Results: These compounds showed only micromolar potency against HIV-1 in MT-4, though two of them; 6-azido-1-benzyl-3-(3,5-dimethylbenzyl) uracil and 6-amino-1-benzyl-3-(3,5-dimethylbenzyl) uracil were highly potent (half maximal effective concentration =0.067 and 0.069 μM) and selective (selectivity index =685 and 661), respectively. Structure–activity relationships among the newly synthesized uracil analogues suggest the importance of the H-bond formed between 6-amino group of 6-amino-1-benzyl-3-(3,5-dimethylbenzyl) uracil and amide group of HIV-1 reverse transcriptase. Conclusions: We discovered two 6-substituted 1-benzyl-3-(3,5-dimethylbenzyl) uracils, (6-azido-1-benzyl-3-(3,5-dimethylbenzyl) uracil and 6-amino-1-benzyl-3-(3,5-dimethylbenzyl) uracil) as novel anti-HIV agents. These compounds should be further pursued for their toxicity and pharmacokinetics in vivo as well as antiviral activity against non-nucleoside reverse transcriptase inhibitor-resistant strains.

scholarly journals HIV Viral Dynamic under Treatment with Intracellular Delay and Virus Decay as Interactive Parameters

2021 ◽  
Vol 22 (2) ◽  
pp. 291-306
Author(s):  
R. A. C. Prata ◽  
R. S. M. Jafelice ◽  
V. M. Cabral ◽  
F. S. Pedro ◽  
L. C. Barros
Keyword(s):  
Mathematical Model ◽  
Plasma Viral Load ◽  
Fuzzy Numbers ◽  
Rapid Reduction ◽  
Viral Particles ◽  
Immunodeficiency Virus ◽  
A Cell ◽  
Hiv 1

Treatment with antiviral drugs for human immunodeficiency virus type 1 (HIV-1) infection causes a rapid reduction in plasma viral load. Viral decline occurs in several stages and provides information on important kinetic constants of virus replication in vivo and pharmacodynamic properties. We present a mathematical model that not only considers the intracellular phase of the viral life cycle, defined as the time between the infection of a cell and the production of new viral particles, but we  also consider that this parameter together with the virus decay are interactive fuzzy numbers.

scholarly journals An ultrasensitive planar array p24 Gag ELISA to detect individual HIV-1 viral particles and infected cells

2021 ◽  
Author(s):  
Alberto Bosque ◽  
Callie Levinger ◽  
J Natalie Howard ◽  
Pingtao Tang ◽  
Amit Joshi
Keyword(s):  
Biological Fluids ◽  
Low Frequency ◽  
Viral Reservoirs ◽  
Hiv Persistence ◽  
Viral Particles ◽  
Planar Array ◽  
Infected Cells ◽  
Major Loss ◽  
Hiv 1

Abstract Human Immunodeficiency virus-1 (HIV-1) persistence in the presence of antiretroviral therapy (ART) has halted the development of curative strategies. Measuring HIV persistence is complex due to the low frequency of cells containing virus in vivo. Most of the commercially available assays to date measure nucleic acid. These assays have the advantage of being highly sensitive and allow for the analysis of sequence diversity, intactness of the HIV genome or evaluation of diverse RNA species. However, these assays are limited in evaluating translational competent viral reservoirs. In here, we developed an ultrasensitive p24 ELISA that uses the SimoaTM planar array technology that can detect as low as a single HIV-1 particle and a single HIV-1 infected cell. Furthermore, the assay is optimized to measure very low levels of p24 in different biological fluids without a major loss of sensitivity or reproducibility. Our results demonstrate that the ‘homebrew' planar p24 ELISA immunoassay is a broadly applicable new tool to evaluate HIV persistence in diverse biological fluids.

Cholecalciferol modulates the phenotype of differentiated monocyte-derived dendritic cells without altering HIV-1 transfer to CD4+ T cells

2019 ◽  
Vol 40 (1) ◽  
Author(s):  
Sandra M. Gonzalez ◽  
Wbeimar Aguilar-Jimenez ◽  
Natalia Alvarez ◽  
Maria T. Rugeles
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
Systemic Infection ◽  
Target Cells ◽  
Viral Particles ◽  
Hiv 1 ◽  
Lps Treatment ◽  
In Vitro Treatment

Abstract Background Dendritic cells (DCs) play a crucial role during HIV-1 transmission due to their ability to transfer virions to susceptible CD4+ T cells, particularly in the lymph nodes during antigen presentation which favors the establishment of systemic infection. As mature dendritic cells (mDCs) exhibit a greater ability to transfer virions, compared to immature DCs (iDCs), maintenance of an iDC phenotype could decrease viral transmission. The immunomodulatory vitamin D (VitD) has been shown to reduce activation and maturation of DCs; hence, we hypothesized that it would reduce viral transference by DCs. Materials and methods We evaluated the effect of in vitro treatment with a precursor of VitD, cholecalciferol, on the activation/maturation phenotype of differentiated monocyte-derived DCs and their ability to transfer HIV-1 to autologous CD4+ T cells. Results Our findings show that although cholecalciferol decreases the activation of iDCs, it did not impact the maturation phenotype after LPS treatment nor iDCs’ ability to transfer viral particles to target cells. Conclusion These findings suggest that despite cholecalciferol potentially modulates the phenotype of mucosal iDCs in vivo, such modulation might not impact the ability of these cells to transfer HIV-1 to target CD4+ T cells.

Inhibition of HIV-1 by DpT-Based Iron Chelators

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 79-79 ◽  
Author(s):  
Zufan Debebe ◽  
Krishna Kumar ◽  
Tatiana Ammosova ◽  
Xiaomei Niu ◽  
Des R Richardson ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Host Cell ◽  
Rna Polymerase Ii ◽  
Therapeutic Index ◽  
Iron Chelators ◽  
Iodide Uptake ◽  
Cyclin T1 ◽  
Cycle Dependent ◽  
Hiv 1

Abstract HIV-1 transcription is activated by HIV-1 Tat protein, which recruits transcriptional co-activators to the HIV-1 promoter. Elongation of HIV-1 transcription is mediated by the interaction of Tat with host cell cycle-dependent kinase 9 (CDK9)/cyclin T1, which phosphorylates the C-terminal domain of RNA polymerase II. Tat itself is phosphorylated by host cell cycle-dependent kinase 2 (CDK2) [1] and inhibition of CDK2 by tridentate iron chelators such as 2-hydroxy-1-naphthylaldehyde isonicotinoyl hydrazone, (311) or ICL670 (deferasirox) inhibits HIV-1 transcription [2]. In addition to the inhibition of CDK2, 311 and ICL670 also prevent association of CDK9 with cyclin T1 [2], which could lead to inhibition of CDK9 activity and also to inhibition of HIV-1 transcription. Recently, a group of novel di-2-pyridylketone thiosemicarbazone (DpT) based tridentate iron chelators were shown to exhibit marked antiproliferative activity in vivo [3]. Here we screened DpT-based and also 2-benzoylpyridine thiosemicarbazone (BpT)-based tridentate iron chelators and identified three chelators, Dp44mT, Bp4eT and Bp4aT, that inhibited HIV-1 transcription but were not cytotoxic as determined by propidium iodide uptake, LDH release and calcein-AM uptake. The inhibition of HIV-1 transcription was observed in CEM HIV-1 LTR-GFP cells infected with Adeno-Tat and in 293T cells transiently transfected with HIV-1-LTR LacZ and Tat-expressing vectors with IC50s in the mid-nanomolar range. These new iron chelators also inhibited HIV-1 replication in CEM and THP-1 cells at 10 mM concentration. Analysis of the molecular mechanism of HIV-1 inhibition revealed that the DpT- and BpT-based iron chelators inhibited the activities of both CDK9/cyclin T1 and CDK2. The CDK9/cyclin T1 complex was disrupted in the cells treated with iron chelators, suggesting a possible mechanism for the inhibition of CDK9. In conclusion, our findings provide further evidence that iron chelators may inhibit HIV-1 transcription by deregulating CDK2 and CDK9. The projected therapeutic index of the selected DpT-based iron chelators was over 103 suggesting their potential usefulness as future anti-retroviral therapeutics.

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