scholarly journals Fullerene Derivatives Strongly Inhibit HIV-1 Replication by Affecting Virus Maturation without Impairing Protease Activity

2016 ◽  
Vol 60 (10) ◽  
pp. 5731-5741 ◽  
Author(s):  
Zachary S. Martinez ◽  
Edison Castro ◽  
Chang-Soo Seong ◽  
Maira R. Cerón ◽  
Luis Echegoyen ◽  
...  
Keyword(s):  
T Cells ◽  
Life Cycle ◽  
Reverse Transcriptase ◽  
Immunoblot Analysis ◽  
Reverse Transcriptase Activity ◽  
Rna Packaging ◽  
Fullerene Derivatives ◽  
Contrast Analysis ◽  
Hiv 1

ABSTRACTThree compounds (1, 2, and 3) previously reported to inhibit HIV-1 replication and/orin vitroactivity of reverse transcriptase were studied, but only fullerene derivatives 1 and 2 showed strong antiviral activity on the replication of HIV-1 in human CD4+T cells. However, these compounds did not inhibit infection by single-round infection vesicular stomatitis virus glycoprotein G (VSV-G)-pseudotyped viruses, indicating no effect on the early steps of the viral life cycle. In contrast, analysis of single-round infection VSV-G-pseudotyped HIV-1 produced in the presence of compound 1 or 2 showed a complete lack of infectivity in human CD4+T cells, suggesting that the late stages of the HIV-1 life cycle were affected. Quantification of virion-associated viral RNA and p24 indicates that RNA packaging and viral production were unremarkable in these viruses. However, Gag and Gag-Pol processing was affected, as evidenced by immunoblot analysis with an anti-p24 antibody and the measurement of virion-associated reverse transcriptase activity, ratifying the effect of the fullerene derivatives on virion maturation of the HIV-1 life cycle. Surprisingly, fullerenes 1 and 2 did not inhibit HIV-1 protease in anin vitroassay at the doses that potently blocked viral infectivity, suggesting a protease-independent mechanism of action. Highlighting the potential therapeutic relevance of fullerene derivatives, these compounds block infection by HIV-1 resistant to protease and maturation inhibitors.

scholarly journals Fullerene Derivatives Prevent Packaging of Viral Genomic RNA into HIV-1 Particles by Binding Nucleocapsid Protein

Viruses ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2451
Author(s):  
Ivana Křížová ◽  
Alžběta Dostálková ◽  
Edison Castro ◽  
Jan Prchal ◽  
Romana Hadravová ◽  
...  
Keyword(s):  
Reverse Transcription ◽  
Biological Activities ◽  
Reverse Transcriptase Activity ◽  
Genomic Rna ◽  
Rna Packaging ◽  
Fullerene Derivatives ◽  
Viral Genomic Rna ◽  
Anti Hiv ◽  
Hiv 1

Fullerene derivatives with hydrophilic substituents have been shown to exhibit a range of biological activities, including antiviral ones. For a long time, the anti-HIV activity of fullerene derivatives was believed to be due to their binding into the hydrophobic pocket of HIV-1 protease, thereby blocking its activity. Recent work, however, brought new evidence of a novel, protease-independent mechanism of fullerene derivatives’ action. We studied in more detail the mechanism of the anti-HIV-1 activity of N,N-dimethyl[70]fulleropyrrolidinium iodide fullerene derivatives. By using a combination of in vitro and cell-based approaches, we showed that these C70 derivatives inhibited neither HIV-1 protease nor HIV-1 maturation. Instead, our data indicate effects of fullerene C70 derivatives on viral genomic RNA packaging and HIV-1 cDNA synthesis during reverse transcription—without impairing reverse transcriptase activity though. Molecularly, this could be explained by a strong binding affinity of these fullerene derivatives to HIV-1 nucleocapsid domain, preventing its proper interaction with viral genomic RNA, thereby blocking reverse transcription and HIV-1 infectivity. Moreover, the fullerene derivatives’ oxidative activity and fluorescence quenching, which could be one of the reasons for the inconsistency among reported anti-HIV-1 mechanisms, are discussed herein.

scholarly journals A Novel Leu92 Mutant of HIV-1 Reverse Transcriptase with a Selective Deficiency in Strand Transfer Causes a Loss of Viral Replication

2015 ◽  
Vol 89 (16) ◽  
pp. 8119-8129 ◽  
Author(s):  
Eytan Herzig ◽  
Nickolay Voronin ◽  
Nataly Kucherenko ◽  
Amnon Hizi
Keyword(s):  
Life Cycle ◽  
Viral Replication ◽  
Reverse Transcriptase ◽  
Dna Polymerase ◽  
Reverse Transcription ◽  
Polymerase Activity ◽  
Rnase H ◽  
Strand Transfer ◽  
Hiv 1

ABSTRACTThe process of reverse transcription (RTN) in retroviruses is essential to the viral life cycle. This key process is catalyzed exclusively by the viral reverse transcriptase (RT) that copies the viral RNA into DNA by its DNA polymerase activity, while concomitantly removing the original RNA template by its RNase H activity. During RTN, the combination between DNA synthesis and RNA hydrolysis leads to strand transfers (or template switches) that are critical for the completion of RTN. The balance between these RT-driven activities was considered to be the sole reason for strand transfers. Nevertheless, we show here that a specific mutation in HIV-1 RT (L92P) that does not affect the DNA polymerase and RNase H activities abolishes strand transfer. There is also a good correlation between this complete loss of the RT's strand transfer to the loss of the DNA clamp activity of the RT, discovered recently by us. This finding indicates a mechanistic linkage between these two functions and that they are both direct and unique functions of the RT (apart from DNA synthesis and RNA degradation). Furthermore, when the RT's L92P mutant was introduced into an infectious HIV-1 clone, it lost viral replication, due to inefficient intracellular strand transfers during RTN, thus supporting thein vitrodata. As far as we know, this is the first report on RT mutants that specifically and directly impair RT-associated strand transfers. Therefore, targeting residue Leu92 may be helpful in selectively blocking this RT activity and consequently HIV-1 infectivity and pathogenesis.IMPORTANCEReverse transcription in retroviruses is essential for the viral life cycle. This multistep process is catalyzed by viral reverse transcriptase, which copies the viral RNA into DNA by its DNA polymerase activity (while concomitantly removing the RNA template by its RNase H activity). The combination and balance between synthesis and hydrolysis lead to strand transfers that are critical for reverse transcription completion. We show here for the first time that a single mutation in HIV-1 reverse transcriptase (L92P) selectively abolishes strand transfers without affecting the enzyme's DNA polymerase and RNase H functions. When this mutation was introduced into an infectious HIV-1 clone, viral replication was lost due to an impaired intracellular strand transfer, thus supporting thein vitrodata. Therefore, finding novel drugs that target HIV-1 reverse transcriptase Leu92 may be beneficial for developing new potent and selective inhibitors of retroviral reverse transcription that will obstruct HIV-1 infectivity.

scholarly journals In Vitro Interactions between Apricitabine and Other Deoxycytidine Analogues

2007 ◽  
Vol 51 (8) ◽  
pp. 2948-2953 ◽  
Author(s):  
R. Bethell ◽  
J. De Muys ◽  
J. Lippens ◽  
A. Richard ◽  
B. Hamelin ◽  
...  
Keyword(s):  
Reverse Transcriptase ◽  
High Performance ◽  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
Transcriptase Inhibitor ◽  
Reverse Transcriptase Activity ◽  
Peripheral Blood Mononuclear ◽  
Reverse Transcriptase Inhibitor ◽  
Hiv 1

ABSTRACT Apricitabine is a novel deoxycytidine analogue reverse transcriptase inhibitor that is under development for the treatment of human immunodeficiency virus type 1 (HIV-1) infection. Apricitabine is phosphorylated to its active triphosphate by deoxycytidine kinase, which is also responsible for the intracellular phosphorylation of lamivudine (3TC) and emtricitabine (FTC); hence, in vitro studies were performed to investigate possible interactions between apricitabine and these agents. Human peripheral blood mononuclear cells (PBMC) were incubated for 24 h with various concentrations of 3H-labeled or unlabeled apricitabine, 3TC, or FTC. Intracellular concentrations of parent compounds and their phosphorylated derivatives were measured by high-performance liquid chromatography. In other experiments, viral reverse transcriptase activity was measured in PBMC infected with HIV-1 bearing M184V in the presence of various concentrations of apricitabine and 3TC. [3H]apricitabine and [3H]3TC were metabolized intracellularly to form mono-, di-, and triphosphates. 3TC and FTC (1 to 10 μM) produced concentration-dependent decreases in apricitabine phosphorylation; in contrast, apricitabine at concentrations of up to 30 μM had no effect on the phosphorylation of 3TC or FTC. The combination of apricitabine and 3TC reduced the antiviral activity of apricitabine against HIV-1: apricitabine concentrations producing 50% inhibition of viral reverse transcriptase were increased two- to fivefold in the presence of 3TC. These findings suggest that nucleoside reverse transcriptase inhibitors with similar modes of action may show biochemical interactions that affect their antiviral efficacy. It is therefore essential that potential interactions between combinations of new and existing agents be thoroughly investigated before such combinations are introduced into clinical practice.

Structural Features and Anti-Human Immunodeficiency Virus (HIV) Activity of the Isomers of 1-(2′,6′-Difluorophenyl)-1H,3H-Thiazolo[3,4-a]Benzimidazole, a Potent Non-Nucleoside HIV-1 Reverse Transcriptase Inhibitor

1997 ◽  
Vol 8 (4) ◽  
pp. 363-370 ◽  
Author(s):  
A Chimirri ◽  
S Grasso ◽  
C Molica ◽  
A-M Monforte ◽  
P Monforte ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Reverse Transcriptase ◽  
Transcriptase Inhibitor ◽  
Structural Features ◽  
Reverse Transcriptase Activity ◽  
Shift Reagent ◽  
Cross Resistance ◽  
Immunodeficiency Virus ◽  
Hiv 1

The structural features, including the absolute configuration, of the enantiomers of 1-(2′,6′-difluorophenyl)-1 H,3 H-thiazolo[3,4- a]benzimidazole (TBZ; NSC 625487), the lead compound of a new class of human immunodeficiency virus type 1 (HIV-1) non-nucleoside reverse transcriptase inhibitors (NNRTIs), are described. Diffractometric analysis revealed that TBZ, like other NNRTIs, assumes a butterfly-like conformation in which the phenyl ring at C1 is in an orthogonal orientation relative to the thiazolobenzimidazole system, and the 2′,6′-fluorine atoms form two intramolecular hydrogen bonds with H1 and one of the methylene protons at C3, respectively. The stereochemistry in solution, as confirmed by lanthanide shift reagent-assisted ‘H NMR, paralleled the situation present in the solid state. The in vitro anti-HIV activity of the two enantiomers was also evaluated and the results obtained showed that the R-(+) is more active than the S-(−) isomer in inhibiting HIV-1 replication. Resistance and cross-resistance to other NNRTIs as well as inhibitory effects on HIV-1 reverse transcriptase activity are also reported.

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 CD73+ CD127high Long-Term Memory CD4 T Cells Are Highly Proliferative in Response to Recall Antigens and Are Early Targets in HIV-1 Infection

2021 ◽  
Vol 22 (2) ◽  
pp. 912
Author(s):  
Nabila Seddiki ◽  
John Zaunders ◽  
Chan Phetsouphanh ◽  
Vedran Brezar ◽  
Yin Xu ◽  
...  
Keyword(s):  
T Cells ◽  
Peripheral Blood ◽  
Cd4 T Cells ◽  
Significant Proportion ◽  
Long Term Memory ◽  
Ki 67 ◽  
Memory Cd4 T Cells ◽  
Hiv 1

HIV-1 infection rapidly leads to a loss of the proliferative response of memory CD4+ T lymphocytes, when cultured with recall antigens. We report here that CD73 expression defines a subset of resting memory CD4+ T cells in peripheral blood, which highly express the α-chain of the IL-7 receptor (CD127), but not CD38 or Ki-67, yet are highly proliferative in response to mitogen and recall antigens, and to IL-7, in vitro. These cells also preferentially express CCR5 and produce IL-2. We reasoned that CD73+ memory CD4+ T cells decrease very early in HIV-1 infection. Indeed, CD73+ memory CD4+ T cells comprised a median of 7.5% (interquartile range: 4.5–10.4%) of CD4+ T cells in peripheral blood from healthy adults, but were decreased in primary HIV-1 infection to a median of 3.7% (IQR: 2.6–6.4%; p = 0.002); and in chronic HIV-1 infection to 1.9% (IQR: 1.1–3%; p < 0.0001), and were not restored by antiretroviral therapy. Moreover, we found that a significant proportion of CD73+ memory CD4+ T cells were skewed to a gut-homing phenotype, expressing integrins α4 and β7, CXCR3, CCR6, CD161 and CD26. Accordingly, 20% of CD4+ T cells present in gut biopsies were CD73+. In HIV+ subjects, purified CD73+ resting memory CD4+ T cells in PBMC were infected with HIV-1 DNA, determined by real-time PCR, to the same level as for purified CD73-negative CD4+ T cells, both in untreated and treated subjects. Therefore, the proliferative CD73+ subset of memory CD4+ T cells is disproportionately reduced in HIV-1 infection, but, unexpectedly, their IL-7 dependent long-term resting phenotype suggests that residual infected cells in this subset may contribute significantly to the very long-lived HIV proviral DNA reservoir in treated subjects.

A Method for Combined Immunoaffinity Purification and Assay of HIV-1 Reverse Transcriptase Activity Useful for Crude Samples

1996 ◽  
Vol 235 (2) ◽  
pp. 141-152 ◽  
Author(s):  
J. Lennerstrand ◽  
A.-S. Rytting ◽  
C. Örvell ◽  
J.S. Gronowitz ◽  
C.F.R. Källander
Keyword(s):  
Reverse Transcriptase ◽  
Reverse Transcriptase Activity ◽  
Transcriptase Activity ◽  
Immunoaffinity Purification ◽  
Hiv 1
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