scholarly journals Flavonol 7-O-Glucoside Herbacitrin Inhibits HIV-1 Replication through Simultaneous Integrase and Reverse Transcriptase Inhibition

2019 ◽  
Vol 2019 ◽  
pp. 1-6 ◽  
Author(s):  
Éva Áy ◽  
Attila Hunyadi ◽  
Mária Mezei ◽  
János Minárovits ◽  
Judit Hohmann

Here we report the evaluation of the antiretroviral effect of two flavonoid 7-O-glucosides, herbacitrin (1) and gossypitrin (2), together with quercetin (3), a well-studied flavonol. Antiviral activity of the flavonoids was assessed by analyzing HIV-1 p24 core protein levels in the supernatants of HIV-1 infected MT-4 and MT-2 cell cultures. The compounds showed mild to weak cytotoxic activities on the host cells; herbacitrin was the strongest in this regard (CC50=27.8 and 63.64 μM on MT-4 and MT-2 cells, respectively). In nontoxic concentrations, herbacitrin and quercetin reduced HIV-1 replication, whereas gossypitrin was ineffective. Herbacitrin was found to inhibit reverse transcriptase at 21.5 μM, while it was a more potent integrase inhibitor already active at 2.15 μM. Therefore, our observations suggest that herbacitrin exerts antiretroviral activity through simultaneously acting on these two targets of HIV-1 and that integrase inhibition might play a major role in this activity.

2010 ◽  
Vol 2010 ◽  
pp. 1-10 ◽  
Author(s):  
Iris Cadima-Couto ◽  
Joao Goncalves

APOBEC proteins appeared in the cellular battle against HIV-1 as part of intrinsic cellular immunity. The antiretroviral activity of some of these proteins is overtaken by the action of HIV-1 Viral Infectivity Factor (Vif) protein. Since the discovery of APOBEC3G (A3G) as an antiviral factor, many advances have been made to understand its mechanism of action in the cell and how Vif acts in order to counteract its activity. The mainstream concept is that Vif overcomes the innate antiviral activity of A3G by direct protein binding and promoting its degradation via the cellular ubiquitin/proteasomal pathway. Vif may also inhibit A3G through mechanisms independent of proteasomal degradation. Binding of Vif to A3G is essential for its degradation since disruption of this interaction is predicted to stimulate intracellular antiviral immunity. In this paper we will discuss the different binding partners between both proteins as one of the major challenges for the development of new antiviral drugs.


2020 ◽  
Author(s):  
Ki Hoon Park ◽  
Minjee Kim ◽  
Seoung Eun Bae ◽  
Hee Jung Lee ◽  
Kyung-Chang Kim ◽  
...  

Abstract Background: Integrase (IN) is an essential protein for HIV replication that catalyzes insertion of the reverse-transcribed viral genome into the host chromosome during the early steps of viral infection. Highly active anti-retroviral therapy (HAART) is a HIV/AIDS treatment method that combines three or more antiviral drugs often formulated from compounds that inhibit the activities of viral reverse transcriptase and protease enzymes. Early IN inhibitors (INIs) mainly serve as integrase strand transfer inhibitors (INSTI) that disrupt strand transfer by binding the catalytic core domain (CCD) of IN. However, mutations of IN can confer resistance to INSTI. Therefore, non-catalytic integrase inhibitors (NCINI) have been developed as next-generation INIs. Methods: In this study, we evaluated and compared the activity of INSTI and NCINI according to the analysis method. Antiviral activity was compared using p24 ELISA with MT2 cell and TZM-bl luciferase system with TZM-bl cell. Each drug was serially diluted and treated to MT2 and TZM-b1 cells, infected with HIV-1 AD8 strain and incubated for 5 and 2 days, respectively. Additionally, to analyze properties of INSTI and NCINI, transfer inhibition assay and 3'-processing inhibition assay were performed. Results: During screening of INIs using the p24 ELISA and TZM-bl luciferase systems, we found an inconsistent result with INSTI and NCINI drugs. Following infection of MT2 and TZM-bl cells with T-tropic HIV-1 strain, both INSTI and NCINI treatments induced significant p24 reduction in MT2 cells. However, NCINI showed no antiviral activity in the TZM-bl luciferase system, indicating that this widely used and convenient antiretroviral assay is not suitable for screening of NCINI compounds that target the second round of HIV-1 replication. Conclusion: Accordingly, we recommend application of other assay procedures, such as p24 ELISA or reverse transcription activity, in lieu of the TZM-bl luciferase system for preliminary NCINI drug screening. Utilization of appropriate analytical methods based on underlying mechanisms is necessary for accurate assessment of drug efficacy.


1999 ◽  
Vol 43 (2) ◽  
pp. 259-263 ◽  
Author(s):  
Gadi Borkow ◽  
Dominique Arion ◽  
Mark A. Wainberg ◽  
Michael A. Parniak

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.


2014 ◽  
Vol 58 (6) ◽  
pp. 3233-3244 ◽  
Author(s):  
Craig Fenwick ◽  
Ma'an Amad ◽  
Murray D. Bailey ◽  
Richard Bethell ◽  
Michael Bös ◽  
...  

ABSTRACTBI 224436 is an HIV-1 integrase inhibitor with effective antiviral activity that acts through a mechanism that is distinct from that of integrase strand transfer inhibitors (INSTIs). This 3-quinolineacetic acid derivative series was identified using an enzymatic integrase long terminal repeat (LTR) DNA 3′-processing assay. A combination of medicinal chemistry, parallel synthesis, and structure-guided drug design led to the identification of BI 224436 as a candidate for preclinical profiling. It has antiviral 50% effective concentrations (EC50s) of <15 nM against different HIV-1 laboratory strains and cellular cytotoxicity of >90 μM. BI 224436 also has a low, ∼2.1-fold decrease in antiviral potency in the presence of 50% human serum and, by virtue of a steep dose-response curve slope, exhibits serum-shifted EC95values ranging between 22 and 75 nM. Passage of virus in the presence of inhibitor selected for either A128T, A128N, or L102F primary resistance substitutions, all mapping to a conserved allosteric pocket on the catalytic core of integrase. BI 224436 also retains full antiviral activity against recombinant viruses encoding INSTI resistance substitutions N155S, Q148H, and E92Q. In drug combination studies performed in cellular antiviral assays, BI 224436 displays an additive effect in combination with most approved antiretrovirals, including INSTIs. BI 224436 has drug-likein vitroabsorption, distribution, metabolism, and excretion (ADME) properties, including Caco-2 cell permeability, solubility, and low cytochrome P450 inhibition. It exhibited excellent pharmacokinetic profiles in rat (clearance as a percentage of hepatic flow [CL], 0.7%; bioavailability [F], 54%), monkey (CL, 23%;F, 82%), and dog (CL, 8%;F, 81%). Based on the excellent biological and pharmacokinetic profile, BI 224436 was advanced into phase 1 clinical trials.


2019 ◽  
Vol 63 (5) ◽  
Author(s):  
Robert A. Smith ◽  
Dana N. Raugi ◽  
Vincent H. Wu ◽  
Christopher G. Zavala ◽  
Jennifer Song ◽  
...  

ABSTRACTWe compared the activity of the integrase inhibitor bictegravir against HIV-1 and HIV-2 using a culture-based, single-cycle assay. Values of 50% effective concentrations ranged from 1.2 to 2.5 nM for 9 HIV-1 isolates and 1.4 to 5.6 nM for 15 HIV-2 isolates. HIV-2 integrase mutants G140S/Q148R and G140S/Q148H were 34- and 110-fold resistant to bictegravir, respectively; other resistance-associated mutations conferred ≤5-fold changes in bictegravir susceptibility. Our findings indicate that bictegravir-based antiretroviral therapy should be evaluated in HIV-2-infected individuals.


2019 ◽  
Vol 75 (3) ◽  
pp. 648-655 ◽  
Author(s):  
Scott L Letendre ◽  
Anthony Mills ◽  
Debbie Hagins ◽  
Susan Swindells ◽  
Franco Felizarta ◽  
...  

Abstract Background Long-acting (LA) formulations of cabotegravir, an HIV integrase inhibitor, and rilpivirine, an NNRTI, are in development as monthly or 2 monthly intramuscular (IM) injections for maintenance of virological suppression. Objectives To evaluate cabotegravir and rilpivirine CSF distribution and HIV-1 RNA suppression in plasma and CSF in HIV-infected adults participating in a substudy of the Phase 2b LATTE-2 study (NCT02120352). Methods Eighteen participants receiving cabotegravir LA 400 mg + rilpivirine LA 600 mg IM [every 4 weeks (Q4W), n = 3] or cabotegravir LA 600 mg + rilpivirine LA 900 mg IM [every 8 weeks (Q8W), n = 15] with plasma HIV-1 RNA &lt;50 copies/mL enrolled. Paired steady-state CSF and plasma concentrations were evaluable in 16 participants obtained 7 (±3) days after an injection visit. HIV-1 RNA in CSF and plasma were assessed contemporaneously using commercial assays. Results Median total CSF concentrations in Q4W and Q8W groups, respectively, were 0.011 μg/mL and 0.013 μg/mL for cabotegravir (0.30% and 0.34% of the paired plasma concentrations) and 1.84 ng/mL and 1.67 ng/mL for rilpivirine (1.07% and 1.32% of paired plasma concentrations). Cabotegravir and rilpivirine total CSF concentrations exceeded their respective in vitro EC50 for WT HIV-1 (0.10 ng/mL and 0.27 ng/mL, respectively). All 16 participants had HIV-1 RNA &lt;50 copies/mL in plasma and CSF, and 15 of 16 participants had HIV-1 RNA &lt;2 copies/mL in CSF. Conclusions A dual regimen of cabotegravir LA and rilpivirine LA achieved therapeutic concentrations in the CSF resulting in effective virological control in CSF.


2003 ◽  
Vol 47 (9) ◽  
pp. 2951-2957 ◽  
Author(s):  
Miguel Stevens ◽  
Christophe Pannecouque ◽  
Erik De Clercq ◽  
Jan Balzarini

ABSTRACT A new class of pyridine oxide derivatives as inhibitors of human immunodeficiency virus type 1 (HIV-1) and/or HIV-2 replication in cell culture has been identified. The compounds, which specifically inhibit HIV-1, behave as typical nonnucleoside reverse transcriptase inhibitors (NNRTIs). The most active congener of this group, JPL-133 (UC-B3096), has a 50% effective concentration of 0.05 μg/ml for HIV-1(IIIB) with a selectivity index of approximately 760 in CEM cell cultures. However, the cytostatic activity of most pyridine oxide derivatives highly depended on the nature of the cell line. All compounds, including those pyridine oxide derivatives that inhibit both HIV-1 and HIV-2 replication, select for NNRTI-characteristic mutations in the HIV-1 reverse transcriptase of HIV-infected cell cultures (i.e., Lys103Asn, Val108Ile, Glu138Lys, Tyr181Cys and Tyr188His). These amino acid mutations emerged mostly through transition of guanine to adenine or adenine to guanine in the corresponding codons of the reverse transcriptase (RT) gene. The HIV-1-specific pyridine oxide derivatives lost their antiviral activity against HIV-1 strains containing these mutations in the RT. However, most compounds retained pronounced antiviral potency against virus strains that contained other NNRTI-characteristic RT mutations, such as Leu100Ile and Val179Asp. Furthermore, the complete lack of inhibitory activity of the pyridine oxide derivatives against recombinant HIV-2 RT and partial retention of anti-HIV-1 activity against HIV-1 strains that contain a variety of HIV-1-characteristic mutations suggest that the pyridine oxide derivatives must have a second target of antiviral action independent from HIV-1 RT.


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