scholarly journals Identification and Characterization of BMS-955176, a Second-Generation HIV-1 Maturation Inhibitor with Improved Potency, Antiviral Spectrum, and Gag Polymorphic Coverage

2016 ◽  
Vol 60 (7) ◽  
pp. 3956-3969 ◽  
Author(s):  
Beata Nowicka-Sans ◽  
Tricia Protack ◽  
Zeyu Lin ◽  
Zhufang Li ◽  
Sharon Zhang ◽  
...  
Keyword(s):  
Human Serum ◽  
Second Generation ◽  
Mononuclear Cells ◽  
Integrase Inhibitor ◽  
Wild Type Virus ◽  
Peripheral Blood Mononuclear ◽  
Subtype B ◽  
Maturation Inhibitor ◽  
Hiv 1

ABSTRACTBMS-955176 is a second-generation human immunodeficiency virus type 1 (HIV-1) maturation inhibitor (MI). A first-generation MI, bevirimat, showed clinical efficacy in early-phase studies, but ∼50% of subjects had viruses with reduced susceptibility associated with naturally occurring polymorphisms in Gag near the site of MI action. MI potency was optimized using a panel of engineered reporter viruses containing site-directed polymorphic changes in Gag that reduce susceptibility to bevirimat (including V362I, V370A/M/Δ, and T371A/Δ), leading incrementally to the identification of BMS-955176. BMS-955176 exhibits potent activity (50% effective concentration [EC50], 3.9 ± 3.4 nM [mean ± standard deviation]) toward a library (n= 87) ofgag/prrecombinant viruses representing 96.5% of subtype B polymorphic Gag diversity near the CA/SP1 cleavage site. BMS-955176 exhibited a median EC50of 21 nM toward a library of subtype B clinical isolates assayed in peripheral blood mononuclear cells (PBMCs). Potent activity was maintained against a panel of reverse transcriptase, protease, and integrase inhibitor-resistant viruses, with EC50s similar to those for the wild-type virus. A 5.4-fold reduction in EC50occurred in the presence of 40% human serum plus 27 mg/ml of human serum albumin (HSA), which corresponded well to anin vitromeasurement of 86% human serum binding. Time-of-addition and pseudotype reporter virus studies confirm a mechanism of action for the compound that occurs late in the virus replication cycle. BMS-955176 inhibits HIV-1 protease cleavage at the CA/SP1 junction within Gag in virus-like particles (VLPs) and in HIV-1-infected cells, and it binds reversibly and with high affinity to assembled Gag in purified HIV-1 VLPs. Finally,in vitrocombination studies showed no antagonistic interactions with representative antiretrovirals (ARVs) of other mechanistic classes. In conclusion, BMS-955176 is a second-generation MI with potentin vitroanti-HIV-1 activity and a greatly improved preclinical profile compared to that of bevirimat.

scholarly journals Design and Profiling of GS-9148, a Novel Nucleotide Analog Active against Nucleoside-Resistant Variants of Human Immunodeficiency Virus Type 1, and Its Orally Bioavailable Phosphonoamidate Prodrug, GS-9131

2007 ◽  
Vol 52 (2) ◽  
pp. 655-665 ◽  
Author(s):  
Tomas Cihlar ◽  
Adrian S. Ray ◽  
Constantine G. Boojamra ◽  
Lijun Zhang ◽  
Hon Hui ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Mononuclear Cells ◽  
Biological Properties ◽  
Peripheral Blood Mononuclear ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT GS-9148 [(5-(6-amino-purin-9-yl)-4-fluoro-2,5-dihydro-furan-2-yloxymethyl)phosphonic acid] is a novel ribose-modified human immunodeficiency virus type 1 (HIV-1) nucleotide reverse transcriptase (RT) inhibitor (NRTI) selected from a series of nucleoside phosphonate analogs for its favorable in vitro biological properties including (i) a low potential for mitochondrial toxicity, (ii) a minimal cytotoxicity in renal proximal tubule cells and other cell types, (iii) synergy in combination with other antiretrovirals, and (iv) a unique resistance profile against multiple NRTI-resistant HIV-1 strains. Notably, antiviral resistance analysis indicated that neither the K65R, L74V, or M184V RT mutation nor their combinations had any effect on the antiretroviral activity of GS-9148. Viruses carrying four or more thymidine analog mutations showed a substantially smaller change in GS-9148 activity relative to that observed with most marketed NRTIs. GS-9131, an ethylalaninyl phosphonoamidate prodrug designed to maximize the intracellular delivery of GS-9148, is a potent inhibitor of multiple subtypes of HIV-1 clinical isolates, with a mean 50% effective concentration of 37 nM. Inside cells, GS-9131 is readily hydrolyzed to GS-9148, which is further phosphorylated to its active diphosphate metabolite (A. S. Ray, J. E. Vela, C. G. Boojamra, L. Zhang, H. Hui, C. Callebaut, K. Stray, K.-Y. Lin, Y. Gao, R. L. Mackman, and T. Cihlar, Antimicrob. Agents Chemother. 52:648-654, 2008). GS-9148 diphosphate acts as a competitive inhibitor of RT with respect to dATP (Ki = 0.8 μM) and exhibits low inhibitory potency against host polymerases including DNA polymerase γ. Oral administration of GS-9131 to beagle dogs at a dose of 3 mg/kg of body weight resulted in high and persistent levels of GS-9148 diphosphate in peripheral blood mononuclear cells (with a maximum intracellular concentration of >9 μM and a half-life of >24 h). This favorable preclinical profile makes GS-9131 an attractive clinical development candidate for the treatment of patients infected with NRTI-resistant HIV.

scholarly journals F18, a Novel Small-Molecule Nonnucleoside Reverse Transcriptase Inhibitor, Inhibits HIV-1 Replication Using Distinct Binding Motifs as Demonstrated by Resistance Selection and Docking Analysis

2011 ◽  
Vol 56 (1) ◽  
pp. 341-351 ◽  
Author(s):  
Xiaofan Lu ◽  
Li Liu ◽  
Xu Zhang ◽  
Terrence Chi Kong Lau ◽  
Stephen Kwok Wing Tsui ◽  
...  
Keyword(s):  
Reverse Transcriptase ◽  
Small Molecule ◽  
Mononuclear Cells ◽  
Binding Motif ◽  
Drug Resistant ◽  
Peripheral Blood Mononuclear ◽  
Docking Analysis ◽  
Hiv 1 ◽  
Calanolide A

ABSTRACTNonnucleoside reverse transcriptase inhibitors (NNRTIs) are one of the key components of antiretroviral therapy drug regimen against human immunodeficiency virus type 1 (HIV-1) replication. We previously described a newly synthesized small molecule, 10-chloromethyl-11-demethyl-12-oxo-calanolide A (F18), a (+)-calanolide A analog, as a novel anti-HIV-1 NNRTI (H. Xue et al., J. Med. Chem. 53:1397–1401, 2010). Here, we further investigated its antiviral range, drug resistance profile, and underlying mechanism of action. F18 consistently displayed potent activity against primary HIV-1 isolates, including various subtypes of group M, circulating recombinant form (CRF) 01_AE, and laboratory-adapted drug-resistant viruses. Moreover, F18 displayed distinct profiles against 17 NNRTI-resistant pseudoviruses, with an excellent potency especially against one of the most prevalent strains with the Y181C mutation (50% effective concentration, 1.0 nM), which was in stark contrast to the extensively used NNRTIs nevirapine and efavirenz. Moreover, we induced F18-resistant viruses byin vitroserial passages and found that the mutation L100I appeared to be the dominant contributor to F18 resistance, further suggesting a binding motif different from that of nevirapine and efavirenz. F18 was nonantagonistic when used in combination with other antiretrovirals against both wild-type and drug-resistant viruses in infected peripheral blood mononuclear cells. Interestingly, F18 displayed a highly synergistic antiviral effect with nevirapine against nevirapine-resistant virus (Y181C). Furthermore,in silicodocking analysis suggested that F18 may bind to the HIV-1 reverse transcriptase differently from other NNRTIs. This study presents F18 as a new potential drug for clinical use and also presents a new mechanism-based design for future NNRTI.

scholarly journals Novel, Live Attenuated Simian Immunodeficiency Virus Constructs Containing Major Deletions in Leader RNA Sequences

2001 ◽  
Vol 75 (6) ◽  
pp. 2776-2785 ◽  
Author(s):  
Yongjun Guan ◽  
James B. Whitney ◽  
Chen Liang ◽  
Mark A. Wainberg
Keyword(s):  
Tissue Culture ◽  
Simian Immunodeficiency Virus ◽  
Mononuclear Cells ◽  
Polyacrylamide Gel Electrophoresis ◽  
Wild Type Virus ◽  
Replication Capacity ◽  
Peripheral Blood Mononuclear ◽  
Immunodeficiency Virus

ABSTRACT We have constructed a series of simian immunodeficiency virus (SIV) mutants containing deletions within a 97-nucleotide (nt) region of the leader sequence. Deletions in this region markedly decreased the replication capacity in tissue culture, i.e., in both the C8166 and CEMx174 cell lines, as well as in rhesus macaque peripheral blood mononuclear cells. In addition, these deletions adversely affected the packaging of viral genomic RNA into virions, the processing of Gag precursor proteins, and patterns of viral proteins in virions, as assessed by biochemical labeling and polyacrylamide gel electrophoresis. Different levels of attenuation were achieved by varying the size and position of deletions within this 97-nt region, and among a series of constructs that were generated, it was possible to rank in vitro virulence relative to that of wild-type virus. In all of these cases, the most severe impact on viral replication was observed when the deletions that were made were located at the 3′ rather than 5′ end of the leader region. The potential of viral reversion over protracted periods was investigated by repeated viral passage in CEMx174 cells. The results showed that several of these constructs showed no signs of reversion after more than 6 months in tissue culture. Thus, a series of novel, attenuated SIV constructs have been developed that are significantly impaired in replication capacity yet retain all viral genes. One of these viruses, termed SD4, may be appropriate for study with rhesus macaques, in order to determine whether reversions will occur in vivo and to further study this virus as a candidate for attenuated vaccination.

scholarly journals Anti-phospholipid human monoclonal antibodies inhibit CCR5-tropic HIV-1 and induce β-chemokines

2010 ◽  
Vol 207 (4) ◽  
pp. 763-776 ◽  
Author(s):  
M. Anthony Moody ◽  
Hua-Xin Liao ◽  
S. Munir Alam ◽  
Richard M. Scearce ◽  
M. Kelly Plonk ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Peripheral Blood Mononuclear Cells ◽  
Peripheral Blood ◽  
Mononuclear Cells ◽  
Virus Entry ◽  
Human Monoclonal Antibodies ◽  
Peripheral Blood Mononuclear ◽  
Blood Mononuclear Cells ◽  
Hiv 1

Traditional antibody-mediated neutralization of HIV-1 infection is thought to result from the binding of antibodies to virions, thus preventing virus entry. However, antibodies that broadly neutralize HIV-1 are rare and are not induced by current vaccines. We report that four human anti-phospholipid monoclonal antibodies (mAbs) (PGN632, P1, IS4, and CL1) inhibit HIV-1 CCR5-tropic (R5) primary isolate infection of peripheral blood mononuclear cells (PBMCs) with 80% inhibitory concentrations of <0.02 to ∼10 µg/ml. Anti-phospholipid mAbs inhibited PBMC HIV-1 infection in vitro by mechanisms involving binding to monocytes and triggering the release of MIP-1α and MIP-1β. The release of these β-chemokines explains both the specificity for R5 HIV-1 and the activity of these mAbs in PBMC cultures containing both primary lymphocytes and monocytes.

scholarly journals Kinetics of Replication of a Partially Attenuated Virus and of the Challenge Virus during a Three-Year Intersubtype Feline Immunodeficiency Virus Superinfection Experiment in Cats

1999 ◽  
Vol 73 (2) ◽  
pp. 1518-1527 ◽  
Author(s):  
Mauro Pistello ◽  
Donatella Matteucci ◽  
Giancarlo Cammarota ◽  
Paola Mazzetti ◽  
Simone Giannecchini ◽  
...  
Keyword(s):  
Feline Immunodeficiency Virus ◽  
Mononuclear Cells ◽  
Acute Infection ◽  
Low Grade ◽  
Peripheral Blood Mononuclear ◽  
Subtype B ◽  
Immunodeficiency Virus ◽  
Attenuated Virus

ABSTRACT The effects of preinfecting cats with a partially attenuated feline immunodeficiency virus (FIV) on subsequent infection with a fully virulent FIV belonging to a different subtype were investigated. Eight specific-pathogen-free cats were preinfected with graded doses of a long-term in vitro-cultured cell-free preparation of FIV Petaluma (FIV-P, subtype A). FIV-P established a low-grade or a silent infection in the inoculated animals. Seven months later, the eight preinfected cats and two uninfected cats were challenged with in vivo-grown FIV-M2 (subtype B) and periodically monitored for immunological and virological status. FIV-P-preinfected cats were not protected from acute infection by FIV-M2, and the sustained replication of this virus was accompanied by a reduction of FIV-P viral loads in the peripheral blood mononuclear cells and plasma. However, from 2 years postchallenge (p.c.) until 3 years p.c., when the experiment was terminated, preinfected cats exhibited reduced total viral burdens, and some also exhibited a diminished decline of circulating CD4+ T lymphocytes relative to control cats infected with FIV-M2 alone. Interestingly, most of the virus detected in challenged cats at late times p.c. was of FIV-P origin, indicating that the preinfecting, attenuated virus had become largely predominant. By the end of follow-up, two challenged cats had no FIV-M2 detectable in the tissues examined. The possible mechanisms underlying the interplay between the two viral populations are discussed.

scholarly journals Derivation of simian tropic HIV-1 infectious clone reveals virus adaptation to a new host

2019 ◽  
Vol 116 (21) ◽  
pp. 10504-10509 ◽  
Author(s):  
Fabian Schmidt ◽  
Brandon F. Keele ◽  
Gregory Q. Del Prete ◽  
Dennis Voronin ◽  
Christine M. Fennessey ◽  
...  
Keyword(s):  
Mononuclear Cells ◽  
Infectious Clone ◽  
Host Protein ◽  
Peripheral Blood Mononuclear ◽  
New Host ◽  
Species Specific ◽  
Hiv 1 ◽  
Pigtail Macaques

To replicate in a new host, lentiviruses must adapt to exploit required host factors and evade species-specific antiviral proteins. Understanding how host protein variation drives lentivirus adaptation allowed us to expand the host range of HIV-1 to pigtail macaques. We have previously derived a viral swarm (in the blood of infected animals) that can cause AIDS in this new host. To further exploit this reagent, we generated infectious molecular clones (IMCs) from the viral swarm. We identified clones with high replicative capacity in pigtail peripheral blood mononuclear cells (PBMC) in vitro and used in vivo replication to select an individual IMC, named stHIV-A19 (for simian tropic HIV-1 clone A19), which recapitulated the phenotype obtained with the viral swarm. Adaptation of HIV-1 in macaques led to the acquisition of amino acid changes in viral proteins, such as capsid (CA), that are rarely seen in HIV-1–infected humans. Using stHIV-A19, we show that these CA changes confer a partial resistance to the host cell inhibitor Mx2 from pigtail macaques, but that complete resistance is associated with a fitness defect. Adaptation of HIV-1 to a new host will lead to a more accurate animal model and a better understanding of virus–host interactions.

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.

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