Small-Molecule Inhibition of Human Immunodeficiency Virus Type 1 Infection by Virus Capsid Destabilization

ABSTRACT Resistance of human immunodeficiency virus type 1 (HIV-1) to small-molecule CCR5 inhibitors is well demonstrated, but resistance to macromolecular CCR5 inhibitors (e.g., PSC-RANTES) that act by both CCR5 internalization and receptor blockade had not been reported until recently (3). The report of a single simian-human immunodeficiency virus SHIVSF162-p3 variant with one V3 and one gp41 sequence change in gp160 that conferred both altered replicative fitness and resistance to PSC-RANTES was therefore surprising. We introduced the same two mutations into both the parental HIV-1SF162 and the macaque-adapted SHIVSF162-p3 and found minor differences in entry fitness but no changes in sensitivity to inhibition by either PSC-RANTES or the small-molecule allosteric inhibitor TAK-779. We attribute the earlier finding to confounding fitness effects with inhibitor sensitivity.

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N-Substituted Pyrrole Derivatives as Novel Human Immunodeficiency Virus Type 1 Entry Inhibitors That Interfere with the gp41 Six-Helix Bundle Formation and Block Virus Fusion

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.48.11.4349-4359.2004 ◽

2004 ◽

Vol 48 (11) ◽

pp. 4349-4359 ◽

Cited By ~ 180

Author(s):

Shibo Jiang ◽

Hong Lu ◽

Shuwen Liu ◽

Qian Zhao ◽

Yuxian He ◽

...

Keyword(s):

Human Immunodeficiency Virus ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Small Molecule ◽

Cooh Group ◽

Hydrophobic Pocket ◽

Fusion Inhibitors ◽

Immunodeficiency Virus ◽

Hiv 1

ABSTRACT A recently approved peptidic human immunodeficiency virus type 1 (HIV-1) fusion inhibitor, T-20 (Fuzeon; Trimeris Inc.), has shown significant promise in clinical application for treating HIV-1-infected individuals who have failed to respond to the currently available antiretroviral drugs. However, T-20 must be injected twice daily and is too expensive. Therefore, it is essential to develop orally available small molecule HIV-1 fusion inhibitors. By screening a chemical library consisting of “drug-like” compounds, we identified two N-substituted pyrroles, designated NB-2 and NB-64, that inhibited HIV-1 replication at a low micromolar range. The absence of the COOH group in NB-2 and NB-64 resulted in a loss of anti-HIV-1 activity, suggesting that this acid group plays an important role in mediating the antiviral activity. NB-2 and NB-64 inhibited HIV-1 fusion and entry by interfering with the gp41 six-helix bundle formation and disrupting the α-helical conformation. They blocked a d-peptide binding to the hydrophobic pocket on surface of the gp41 internal trimeric coiled-coil domain. Computer-aided molecular docking analysis has shown that they fit inside the hydrophobic pocket and that their COOH group interacts with a positively charged residue (K574) around the pocket to form a salt bridge. These results suggest that NB-2 and NB-64 may bind to the gp41 hydrophobic pocket through hydrophobic and ionic interactions and block the formation of the fusion-active gp41 core, thereby inhibiting HIV-1-mediated membrane fusion and virus entry. Therefore, NB-2 and NB-64 can be used as lead compounds toward designing and developing more potent small molecule HIV-1 fusion inhibitors targeting gp41.

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Isolation and Characterization of Human Immunodeficiency Virus Type 1 Resistant to the Small-Molecule CCR5 Antagonist TAK-652

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01079-06 ◽

2006 ◽

Vol 51 (2) ◽

pp. 707-715 ◽

Cited By ~ 62

Author(s):

Masanori Baba ◽

Hiroshi Miyake ◽

Xin Wang ◽

Mika Okamoto ◽

Katsunori Takashima

Keyword(s):

Human Immunodeficiency Virus ◽

Amino Acid ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Small Molecule ◽

Cross Resistance ◽

Isolation And Characterization ◽

Immunodeficiency Virus ◽

Hiv 1

ABSTRACT TAK-652, a novel small-molecule chemokine receptor antagonist, is a highly potent and selective inhibitor of CCR5-using (R5) human immunodeficiency virus type 1 (HIV-1) replication in vitro. Since TAK-652 is orally bioavailable and has favorable pharmacokinetic profiles in humans, it is considered a promising candidate for an entry inhibitor of HIV-1. To investigate the resistance to TAK-652, peripheral blood mononuclear cells were infected with the R5 HIV-1 primary isolate KK and passaged in the presence of escalating concentrations of the compound for more than 1 year. After 67 weeks of cultivation, the escape virus emerged even in the presence of a high concentration of TAK-652. This virus displayed more than 200,000-fold resistance to TAK-652 compared with the wild type. The escape virus appeared to have cross-resistance to the structurally related compound TAK-779 but retained full susceptibility to TAK-220, which is from a different class of CCR5 antagonists. Furthermore, the escape virus was unable to use CXCR4 as a coreceptor. Analysis for Env amino acid sequences of escape viruses at certain points of passage revealed that amino acid changes accumulated with an increasing number of passages. Several amino acid changes not only in the V3 region but also in other Env regions seemed to be required for R5 HIV-1 to acquire complete resistance to TAK-652.

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Biochemical and Genetic Characterizations of a Novel Human Immunodeficiency Virus Type 1 Inhibitor That Blocks gp120-CD4 Interactions

Journal of Virology ◽

10.1128/jvi.77.19.10528-10536.2003 ◽

2003 ◽

Vol 77 (19) ◽

pp. 10528-10536 ◽

Cited By ~ 112

Author(s):

Qi Guo ◽

Hsu-Tso Ho ◽

Ira Dicker ◽

Li Fan ◽

Nannan Zhou ◽

...

Keyword(s):

Human Immunodeficiency Virus ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Small Molecule ◽

Viral Entry ◽

Binding Pocket ◽

Gp120 Protein ◽

Immunodeficiency Virus ◽

Hiv 1

ABSTRACT BMS-378806 is a recently discovered small-molecule human immunodeficiency virus type 1 (HIV-1) attachment inhibitor with good antiviral activity and pharmacokinetic properties. Here, we demonstrate that the compound targets viral entry by inhibiting the binding of the HIV-1 envelope gp120 protein to cellular CD4 receptors via a specific and competitive mechanism. BMS-378806 binds directly to gp120 at a stoichiometry of approximately 1:1, with a binding affinity similar to that of soluble CD4. The potential BMS-378806 target site was localized to a specific region within the CD4 binding pocket of gp120 by using HIV-1 gp120 variants carrying either compound-selected resistant substitutions or gp120-CD4 contact site mutations. Mapping of resistance substitutions to the HIV-1 envelope, and the lack of compound activity against a CD4-independent viral infection confirm the gp120-CD4 interactions as the target in infected cells. BMS-378806 therefore serves as a prototype for this new class of antiretroviral agents and validates gp120 as a viable target for small-molecule inhibitors.

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Structure-Based Identification of Small Molecule Antiviral Compounds Targeted to the gp41 Core Structure of the Human Immunodeficiency Virus Type 1

Journal of Medicinal Chemistry ◽

10.1021/jm990154t ◽

1999 ◽

Vol 42 (17) ◽

pp. 3203-3209 ◽

Cited By ~ 99

Author(s):

Asim Kumar Debnath ◽

Lin Radigan ◽

Shibo Jiang

Keyword(s):

Human Immunodeficiency Virus ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Small Molecule ◽

Core Structure ◽

Antiviral Compounds ◽

Immunodeficiency Virus

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Resistance of a human immunodeficiency virus type 1 isolate to a small molecule CCR5 inhibitor can involve sequence changes in both gp120 and gp41

Virology ◽

10.1016/j.virol.2010.12.052 ◽

2011 ◽

Vol 413 (1) ◽

pp. 47-59 ◽

Cited By ~ 17

Author(s):

Cleo G. Anastassopoulou ◽

Thomas J. Ketas ◽

Rafael S. Depetris ◽

Antonia M. Thomas ◽

Per Johan Klasse ◽

...

Keyword(s):

Human Immunodeficiency Virus ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Small Molecule ◽

Immunodeficiency Virus ◽

Ccr5 Inhibitor

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Genetic and Phenotypic Analyses of Human Immunodeficiency Virus Type 1 Escape from a Small-Molecule CCR5 Inhibitor

Journal of Virology ◽

10.1128/jvi.78.6.2790-2807.2004 ◽

2004 ◽

Vol 78 (6) ◽

pp. 2790-2807 ◽

Cited By ~ 160

Author(s):

Shawn E. Kuhmann ◽

Pavel Pugach ◽

Kevin J. Kunstman ◽

Joann Taylor ◽

Robyn L. Stanfield ◽

...

Keyword(s):

Human Immunodeficiency Virus ◽

Amino Acid ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Small Molecule ◽

Escape Mutant ◽

V3 Loop ◽

Immunodeficiency Virus ◽

Hiv 1

ABSTRACT We have described previously the generation of an escape variant of human immunodeficiency virus type 1 (HIV-1), under the selection pressure of AD101, a small molecule inhibitor that binds the CCR5 coreceptor (A. Trkola, S. E. Kuhmann, J. M. Strizki, E. Maxwell, T. Ketas, T. Morgan, P. Pugach, S. X. L. Wojcik, J. Tagat, A. Palani, S. Shapiro, J. W. Clader, S. McCombie, G. R. Reyes, B. M. Baroudy, and J. P. Moore, Proc. Natl. Acad. Sci. USA 99:395-400, 2002). The escape mutant, CC101.19, continued to use CCR5 for entry, but it was at least 20,000-fold more resistant to AD101 than the parental virus, CC1/85. We have now cloned the env genes from the the parental and escape mutant isolates and made chimeric infectious molecular clones that fully recapitulate the phenotypes of the corresponding isolates. Sequence analysis of the evolution of the escape mutants suggested that the most relevant changes were likely to be in the V3 loop of the gp120 glycoprotein. We therefore made a series of mutant viruses and found that full AD101 resistance was conferred by four amino acid changes in V3. Each change individually caused partial resistance when they were introduced into the V3 loop of a CC1/85 clone, but their impact was dependent on the gp120 context in which they were made. We assume that these amino acid changes alter how the HIV-1 Env complex interacts with CCR5. Perhaps unexpectedly, given the complete dependence of the escape mutant on CCR5 for entry, monomeric gp120 proteins expressed from clones of the fully resistant isolate failed to bind to CCR5 on the surface of L1.2-CCR5 cells under conditions where gp120 proteins from the parental virus and a partially AD101-resistant virus bound strongly. Hence, the full impact of the V3 substitutions may only be apparent at the level of the native Env complex.

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Inhibitory Effects of Small-Molecule CCR5 Antagonists on Human Immunodeficiency Virus Type 1 Envelope-Mediated Membrane Fusion and Viral Replication

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.45.12.3538-3543.2001 ◽

2001 ◽

Vol 45 (12) ◽

pp. 3538-3543 ◽

Cited By ~ 16

Author(s):

Katsunori Takashima ◽

Hiroshi Miyake ◽

Rika A. Furuta ◽

Jun-Ichi Fujisawa ◽

Yuji Iizawa ◽

...

Keyword(s):

Human Immunodeficiency Virus ◽

Viral Replication ◽

Membrane Fusion ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Small Molecule ◽

Inhibitory Effects ◽

Immunodeficiency Virus ◽

Hiv 1

ABSTRACT We established a human immunodeficiency virus type 1 (HIV-1) envelope (Env)-mediated membrane fusion assay and examined the small-molecule CCR5 antagonist TAK-779 and its derivatives for their inhibitory effects on HIV-1 Env-mediated membrane fusion and viral replication. The membrane fusion assay is based on HIV-1 long terminal repeat-directed β-d-galactosidase reporter gene expression in CD4- and CCR5-expressed HeLa (MAGI-CCR5) cells after cocultivation with effector 293T cells expressing HIV-1 Env. Inhibition of HIV-1 replication was also determined in MAGI-CCR5 cells infected with the corresponding cell-free HIV-1. TAK-779 effectively suppressed R5 HIV-1 (strain JR-FL) Env-mediated membrane fusion as well as viral replication. Its 50% inhibitory concentrations (IC50s) for membrane fusion and viral replication were 0.87 ± 0.11 and 1.4 ± 0.1 nM, respectively. These values corresponded well to the IC50 for 125I-RANTES (regulated on activation, T cell expressed, and secreted) binding to CCR5 (1.4 nM). The inhibitory effects of 18 TAK-779 derivatives on membrane fusion differed from one compound to another. However, there was a close correlation among their inhibitory effects on membrane fusion, viral replication, and RANTES binding. The correlation coefficient between their IC50s for membrane fusion and viral replication was 0.881. Furthermore, since this assay depends on Env expressed in the effector cells, it is also applicable to the evaluation of CXCR4 antagonists. These results indicate that the HIV-1 Env-mediated membrane fusion assay is a useful tool for the evaluation of entry inhibitors.

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