Novel Acylguanidine-Based Inhibitor of HIV-1

ABSTRACTThe emergence of transmissible HIV-1 strains with resistance to antiretroviral drugs highlights a continual need for new therapies. Here we describe a novel acylguanidine-containing compound, 1-(2-(azepan-1-yl)nicotinoyl)guanidine (or SM111), that inhibitsin vitroreplication of HIV-1, including strains resistant to licensed protease, reverse transcriptase, and integrase inhibitors, without major cellular toxicity. At inhibitory concentrations, intracellular p24Gagproduction was unaffected, but virion release (measured as extracellular p24Gag) was reduced and virion infectivity was substantially impaired, suggesting that SM111 acts at a late stage of viral replication. SM111-mediated inhibition of HIV-1 was partially overcome by a Vpu I17R mutation alone or a Vpu W22* truncation in combination with Env N136Y. These mutations enhanced virion infectivity and Env expression on the surface of infected cells in the absence and presence of SM111 but also impaired Vpu's ability to downregulate CD4 and BST2/tetherin. Taken together, our results support acylguanidines as a class of HIV-1 inhibitors with a distinct mechanism of action compared to that of licensed antiretrovirals. Further research on SM111 and similar compounds may help to elucidate knowledge gaps related to Vpu's role in promoting viral egress and infectivity.IMPORTANCENew inhibitors of HIV-1 replication may be useful as therapeutics to counteract drug resistance and as reagents to perform more detailed studies of viral pathogenesis. SM111 is a small molecule that blocks the replication of wild-type and drug-resistant HIV-1 strains by impairing viral release and substantially reducing virion infectivity, most likely through its ability to prevent Env expression at the infected cell surface. Partial resistance to SM111 is mediated by mutations in Vpu and/or Env, suggesting that the compound affects host/viral protein interactions that are important during viral egress. Further characterization of SM111 and similar compounds may allow more detailed pharmacological studies of HIV-1 egress and provide opportunities to develop new treatments for HIV-1.

Download Full-text

Stage-Dependent Inhibition of HIV-1 Replication by Antiretroviral Drugs in Cell Culture

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01537-09 ◽

2009 ◽

Vol 54 (3) ◽

pp. 1047-1054 ◽

Cited By ~ 35

Author(s):

Daniel A. Donahue ◽

Richard D. Sloan ◽

Björn D. Kuhl ◽

Tamara Bar-Magen ◽

Susan M. Schader ◽

...

Keyword(s):

Viral Load ◽

Viral Replication ◽

Reverse Transcription ◽

Antiretroviral Drugs ◽

Proteolytic Processing ◽

Viral Inhibition ◽

Dependent Inhibition ◽

Infected Cells ◽

Hiv 1

ABSTRACT Recent clinical trials have shown that the use of the HIV-1 integrase (IN) inhibitor raltegravir (RAL) results in drops in the viral load that are more rapid than those achieved by use of the reverse transcriptase (RT) inhibitor efavirenz. Previously, mathematical modeling of viral load decay that takes into account the stage of viral replication targeted by a drug has yielded data that closely approximate the clinical trial results. This model predicts greater inhibition of viral replication by drugs that act later in the viral replication cycle. In the present study, we have added drugs that target entry, reverse transcription, integration, or proteolytic processing to acutely infected cells and have shown modest viral inhibition by entry inhibitors, intermediate levels of inhibition by RT and IN inhibitors, and high levels of inhibition by protease inhibitors relative to the levels of growth for the no-drug controls. When dual or triple combinations of these drugs were added to acutely infected cells, we found that the levels of inhibition achieved by any given combination were comparable to those achieved by the latest-acting drug in the combination. In single-round infections in which the kinetics of reverse transcription and integration had been determined by quantitative PCR, addition of IN inhibitors at various times postinfection resulted in levels of inhibition equal to or greater than those achieved by addition of RT inhibitors. Collectively, our data provide in vitro evidence of the stage-dependent inhibition of HIV-1 by clinically relevant drugs. We discuss how stage-dependent inhibition helps to explain the unique viral load decay dynamics observed clinically with RAL.

Download Full-text

In vitro characterization of engineered red blood cells as viral traps against HIV-1 and SARS-CoV-2

Molecular Therapy — Methods & Clinical Development ◽

10.1016/j.omtm.2021.03.003 ◽

2021 ◽

Vol 21 ◽

pp. 161-170 ◽

Cited By ~ 1

Author(s):

Magnus A.G. Hoffmann ◽

Collin Kieffer ◽

Pamela J. Bjorkman

Keyword(s):

Red Blood Cells ◽

Blood Cells ◽

In Vitro Characterization ◽

Hiv 1

Download Full-text

Extended Interactions between HIV-1 Viral RNA and tRNALys3 Are Important to Maintain Viral RNA Integrity

International Journal of Molecular Sciences ◽

10.3390/ijms22010058 ◽

2020 ◽

Vol 22 (1) ◽

pp. 58

Author(s):

Thomas Gremminger ◽

Zhenwei Song ◽

Juan Ji ◽

Avery Foster ◽

Kexin Weng ◽

...

Keyword(s):

Reverse Transcription ◽

Potential Interaction ◽

Viral Rna ◽

Primer Binding Site ◽

Rna Integrity ◽

Immunodeficiency Virus ◽

Infected Cells ◽

Extended Interaction ◽

Hiv 1

The reverse transcription of the human immunodeficiency virus 1 (HIV-1) initiates upon annealing of the 3′-18-nt of tRNALys3 onto the primer binding site (PBS) in viral RNA (vRNA). Additional intermolecular interactions between tRNALys3 and vRNA have been reported, but their functions remain unclear. Here, we show that abolishing one potential interaction, the A-rich loop: tRNALys3 anticodon interaction in the HIV-1 MAL strain, led to a decrease in viral infectivity and reduced the synthesis of reverse transcription products in newly infected cells. In vitro biophysical and functional experiments revealed that disruption of the extended interaction resulted in an increased affinity for reverse transcriptase (RT) and enhanced primer extension efficiency. In the absence of deoxyribose nucleoside triphosphates (dNTPs), vRNA was degraded by the RNaseH activity of RT, and the degradation rate was slower in the complex with the extended interaction. Consistently, the loss of vRNA integrity was detected in virions containing A-rich loop mutations. Similar results were observed in the HIV-1 NL4.3 strain, and we show that the nucleocapsid (NC) protein is necessary to promote the extended vRNA: tRNALys3 interactions in vitro. In summary, our data revealed that the additional intermolecular interaction between tRNALys3 and vRNA is likely a conserved mechanism among various HIV-1 strains and protects the vRNA from RNaseH degradation in mature virions.

Download Full-text

Generation and characterization of a human monoclonal antibody that neutralizes diverse HIV-1 isolates in vitro

AIDS ◽

10.1097/00002030-199201000-00002 ◽

1992 ◽

Vol 6 (1) ◽

pp. 17-24 ◽

Cited By ~ 9

Author(s):

Douglas F. Lake ◽

Takashi Kawamura ◽

Takami Tomiyama ◽

W. Edward Robinson ◽

Yoh-ichi Matsumoto ◽

...

Keyword(s):

Monoclonal Antibody ◽

Human Monoclonal Antibody ◽

Hiv 1

Download Full-text

The Late-Domain-Containing Protein p6 Is the Predominant Phosphoprotein of Human Immunodeficiency Virus Type 1 Particles

Journal of Virology ◽

10.1128/jvi.76.3.1015-1024.2002 ◽

2002 ◽

Vol 76 (3) ◽

pp. 1015-1024 ◽

Cited By ~ 36

Author(s):

Barbara Müller ◽

Tilo Patschinsky ◽

Hans-Georg Kräusslich

Keyword(s):

Human Immunodeficiency Virus ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Metabolic Labeling ◽

Immunodeficiency Virus ◽

Infected Cells ◽

A Minor ◽

Hiv 1

ABSTRACT The Gag-derived protein p6 of human immunodeficiency virus type 1 (HIV-1) plays a crucial role in the release of virions from the membranes of infected cells. It is presumed that p6 and functionally related proteins from other viruses act as adapters, recruiting cellular factors to the budding site. This interaction is mediated by so-called late domains within the viral proteins. Previous studies had suggested that virus release from the plasma membrane shares elements with the cellular endocytosis machinery. Since protein phosphorylation is known to be a regulatory mechanism in these processes, we have investigated the phosphorylation of HIV-1 structural proteins. Here we show that p6 is the major phosphoprotein of HIV-1 particles. After metabolic labeling of infected cells with [ortho- 32P]phosphate, we found that phosphorylated p6 from infected cells and from virus particles consisted of several forms, suggesting differential phosphorylation at multiple sites. Apparently, phosphorylation occurred shortly before or after the release of p6 from Gag and involved only a minor fraction of the total virion-associated p6 molecules. Phosphoamino acid analysis indicated phosphorylation at Ser and Thr, as well as a trace of Tyr phosphorylation, supporting the conclusion that multiple phosphorylation events do occur. In vitro experiments using purified virus revealed that endogenous or exogenously added p6 was efficiently phosphorylated by virion-associated cellular kinase(s). Inhibition experiments suggested that a cyclin-dependent kinase or a related kinase, most likely ERK2, was involved in p6 phosphorylation by virion-associated enzymes.

Download Full-text

PMTCT of HIV-1 in Burkina Faso: evaluation of residual vertical transmission by PCR, molecular characterization of subtypes and determination of antiretroviral drugs resistance

BMC Infectious Diseases ◽

10.1186/1471-2334-14-s2-p59 ◽

2014 ◽

Vol 14 (S2) ◽

Cited By ~ 1

Author(s):

T Sagna ◽

C Bisseye ◽

TS Kagone ◽

FW Djigma ◽

D Ouermi ◽

...

Keyword(s):

Burkina Faso ◽

Molecular Characterization ◽

Vertical Transmission ◽

Antiretroviral Drugs ◽

Hiv 1

Download Full-text

Discovery and Characterization of a Novel CD4-Binding Adnectin with Potent Anti-HIV Activity

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00508-17 ◽

2017 ◽

Vol 61 (8) ◽

Cited By ~ 7

Author(s):

David Wensel ◽

Yongnian Sun ◽

Zhufang Li ◽

Sharon Zhang ◽

Caryn Picarillo ◽

...

Keyword(s):

Conformational Changes ◽

Viral Entry ◽

High Affinity ◽

Glycosylation Sites ◽

Spectrum Activity ◽

Anti Hiv ◽

Hiv 1 ◽

Broad Spectrum Activity

ABSTRACT A novel fibronectin-based protein (Adnectin) HIV-1 inhibitor was generated using in vitro selection. This inhibitor binds to human CD4 with a high affinity (3.9 nM) and inhibits viral entry at a step after CD4 engagement and preceding membrane fusion. The progenitor sequence of this novel inhibitor was selected from a library of trillions of Adnectin variants using mRNA display and then further optimized for improved antiviral and physical properties. The final optimized inhibitor exhibited full potency against a panel of 124 envelope (gp160) proteins spanning 11 subtypes, indicating broad-spectrum activity. Resistance profiling studies showed that this inhibitor required 30 passages (151 days) in culture to acquire sufficient resistance to result in viral titer breakthrough. Resistance mapped to the loss of multiple potential N-linked glycosylation sites in gp120, suggesting that inhibition is due to steric hindrance of CD4-binding-induced conformational changes.

Download Full-text

Infection of CD8+CD45RO+ Memory T-Cells by HIV-1 and Their Proliferative Response

The Open AIDS Journal ◽

10.2174/1874613600802010043 ◽

2008 ◽

Vol 2 (1) ◽

pp. 43-57 ◽

Cited By ~ 7

Author(s):

Naveed Gulzar ◽

Sowyma Balasubramanian ◽

Greg Harris ◽

Jaime Sanchez-Dardon ◽

Karen F.T. Copeland

Keyword(s):

T Cells ◽

T Cell ◽

Cd8 T Cells ◽

Proliferative Response ◽

Cell Infection ◽

Cellular Target ◽

Potential Reservoir ◽

Infected Cells ◽

Hiv 1

CD8+ T-cells are involved in controlling HIV-1 infection by eliminating infected cells and secreting soluble factors that inhibit viral replication. To investigate the mechanism and significance of infection of CD8+ T-cells by HIV-1in vitro, we examined the susceptibility of these cells and their subsets to infection. CD8+ T-cells supported greater levels of replication with T-cell tropic strains of HIV-1, though viral production was lower than that observed in CD4+ T-cells. CD8+ T-cell infection was found to be productive through ELISA, RT-PCR and flow cytometric analyses. In addition, the CD8+CD45RO+ memory T-cell population supported higher levels of HIV-1 replication than CD8+CD45RA+ naïve T-cells. However, infection of CD8+CD45RO+ T-cells did not affect their proliferative response to the majority of mitogens tested. We conclude, with numerous lines of evidence detecting and measuring infection of CD8+ T-cells and their subsets, that this cellular target and potential reservoir may be central to HIV-1 pathogenesis.

Download Full-text

HIV-Infected Macrophages Are Infected and Killed by the Interferon-Sensitive Rhabdovirus MG1

Journal of Virology ◽

10.1128/jvi.01953-20 ◽

2021 ◽

Vol 95 (9) ◽

Author(s):

Teslin S. Sandstrom ◽

Nischal Ranganath ◽

Stephanie C. Burke Schinkel ◽

Syim Salahuddin ◽

Oussama Meziane ◽

...

Keyword(s):

Cancer Cells ◽

Oncolytic Viruses ◽

Type I Interferons ◽

Viral Reservoir ◽

Type I ◽

Antiviral Signaling ◽

Infected Cells ◽

Hiv 1

ABSTRACT The use of unique cell surface markers to target and eradicate HIV-infected cells has been a longstanding objective of HIV-1 cure research. This approach, however, overlooks the possibility that intracellular changes present within HIV-infected cells may serve as valuable therapeutic targets. For example, the identification of dysregulated antiviral signaling in cancer has led to the characterization of oncolytic viruses capable of preferentially killing cancer cells. Since impairment of cellular antiviral machinery has been proposed as a mechanism by which HIV-1 evades immune clearance, we hypothesized that HIV-infected macrophages (an important viral reservoir in vivo) would be preferentially killed by the interferon-sensitive oncolytic Maraba virus MG1. We first showed that HIV-infected monocyte-derived macrophages (MDM) were more susceptible to MG1 infection and killing than HIV-uninfected cells. As MG1 is highly sensitive to type I interferons (IFN-I), we then investigated whether we could identify IFN-I signaling differences between HIV-infected and uninfected MDM and found evidence of impaired IFN-α responsiveness within HIV-infected cells. Finally, to assess whether MG1 could target a relevant, primary cell reservoir of HIV-1, we investigated its effects in alveolar macrophages (AM) obtained from effectively treated individuals living with HIV-1. As observed with in vitro-infected MDM, we found that HIV-infected AM were preferentially eliminated by MG1. In summary, the oncolytic rhabdovirus MG1 appears to preferentially target and kill HIV-infected cells via impairment of antiviral signaling pathways and may therefore provide a novel approach to an HIV-1 cure. IMPORTANCE Human immunodeficiency virus type 1 (HIV-1) remains a treatable, but incurable, viral infection. The establishment of viral reservoirs containing latently infected cells remains the main obstacle in the search for a cure. Cure research has also focused on only one cellular target of HIV-1 (the CD4+ T cell) while largely overlooking others (such as macrophages) that contribute to HIV-1 persistence. In this study, we address these challenges by describing a potential strategy for the eradication of HIV-infected macrophages. Specifically, we show that an engineered rhabdovirus—initially developed as a cancer therapy—is capable of preferential infection and killing of HIV-infected macrophages, possibly via the same altered antiviral signaling seen in cancer cells. As this rhabdovirus is currently being explored in phase I/II clinical trials, there is potential for this approach to be readily adapted for use within the HIV-1 cure field.

Download Full-text