Novel Bent Conformation of CD4 Induced by HIV-1 Inhibitor Indirectly Prevents Productive Viral Attachment

As the initial barrier to viral entry, the plasma membrane along with the membrane trafficking machinery and cytoskeleton are of fundamental importance in the viral cycle. However, little is known about the contribution of plasma membrane dynamics during early human immunodeficiency virus type 1 (HIV-1) infection. Considering that ADP ribosylation factor 6 (Arf6) regulates cellular invasion via several microorganisms by coordinating membrane trafficking, our aim was to study the function of Arf6-mediated membrane dynamics on HIV-1 entry and infection of T lymphocytes. We observed that an alteration of the Arf6–guanosine 5′-diphosphate/guanosine 5′-triphosphate (GTP/GDP) cycle, by GDP-bound or GTP-bound inactive mutants or by specific Arf6 silencing, inhibited HIV-1 envelope–induced membrane fusion, entry, and infection of T lymphocytes and permissive cells, regardless of viral tropism. Furthermore, cell-to-cell HIV-1 transmission of primary human CD4+T lymphocytes was inhibited by Arf6 knockdown. Total internal reflection fluorescence microscopy showed that Arf6 mutants provoked the accumulation of phosphatidylinositol-(4,5)-biphosphate–associated structures on the plasma membrane of permissive cells, without affecting CD4-viral attachment but impeding CD4-dependent HIV-1 entry. Arf6 silencing or its mutants did not affect fusion, entry, and infection of vesicular stomatitis virus G–pseudotyped viruses or ligand-induced CXCR4 or CCR5 endocytosis, both clathrin-dependent processes. Therefore we propose that efficient early HIV-1 infection of CD4+T lymphocytes requires Arf6-coordinated plasma membrane dynamics that promote viral fusion and entry.

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Pharmacokinetics of Temsavir, the Active Moiety of the Prodrug Fostemsavir, in Subjects with Hepatic Impairment

Open Forum Infectious Diseases ◽

10.1093/ofid/ofx163.1086 ◽

2017 ◽

Vol 4 (suppl_1) ◽

pp. S430-S430 ◽

Cited By ~ 4

Author(s):

Heather Sevinsky ◽

Mindy Magee ◽

Peter Ackerman ◽

Robert Adamczyk ◽

Jennifer Karkas ◽

...

Keyword(s):

Hepatic Impairment ◽

Geometric Mean ◽

Hepatic Function ◽

Open Label ◽

Post Dose ◽

Viral Attachment ◽

Linear Mixed Effects ◽

Active Moiety ◽

Impaired Hepatic Function ◽

Hiv 1

Abstract Background Fostemsavir (FTR) is a prodrug of temsavir (TMR), a first-in-class attachment inhibitor that binds directly to HIV-1 gp120, preventing initial viral attachment and entry into host CD4+ T cells. TMR is primarily metabolized via hydrolytic and oxidative pathways; impaired hepatic function may alter TMR pharmacokinetics (PK). Methods AI438053 (NCT02467335) was an open-label, nonrandomized study in healthy subjects (HS) and subjects with hepatic impairment (HI), defined by Child-Pugh (CP) score: mild (CPA), moderate (CPB), or severe (CPC). HS were matched for age, body weight, and sex. Subjects received a single oral dose of FTR 600 mg fasted and serial PK samples for TMR were collected up to 96 hours post-dose. Unbound TMR at 1 and 3 hours post-dose was determined. Total and unbound PK parameters were derived by noncompartmental methods. Geometric mean ratios (GMR) and 90% confidence intervals (CI) for HI vs.. HS were derived using linear mixed-effects models. Subjects were monitored for adverse events (AEs). Results 18 subjects with HI (N = 6/CP group) and 12 HS received FTR and completed the study. Total and unbound TMR exposures increased with increasing HI severity (see Table). Total and unbound TMR CLT/F decreased with increasing HI severity. Mean % protein binding of TMR was 81.0% in HS and 79.9%, 81.9%, and 76.5% in CPA, CPB, and CPC HI, respectively, and was independent of TMR concentration. There were no deaths, serious AEs, or discontinuations during the treatment period. Conclusion TMR exposures increase with increasing severity of HI. The increase in TMR exposures in patients with mild or moderate HI is not expected to alter the safety profile of FTR. The risk/benefit of higher TMR exposures in severe HI is under evaluation. Disclosures H. Sevinsky, ViiV Healthcare: Employee, Salary; M. Magee, GlaxoSmithKline: Employee and Shareholder, Salary; P. Ackerman, ViiV Healthcare/GSK: Employee and Shareholder, Salary and Stock; R. Adamczyk, Bristol-Myers Squibb: Employee, Salary; J. Karkas, Bristol Myers Squibb: Employee and Shareholder, Salary; S. Lubin, Bristol-Myers Squibb: Employee, Salary; P. Ravindran, Bristol-Myers Squibb: Employee, Salary; C. Llamoso, ViiV Healthcare: Employee, Salary; T. Eley, Bristol-Myers Squibb: Former Employee during study conduct, Salary; K. Moore, ViiV Healthcare: Employee, Salary

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Platelet Factor 4 Inhibits and Enhances HIV-1 Infection in a Concentration-Dependent Manner by Modulating Viral Attachment

AIDS Research and Human Retroviruses ◽

10.1089/aid.2015.0344 ◽

2016 ◽

Vol 32 (7) ◽

pp. 705-717 ◽

Cited By ~ 9

Author(s):

Zahra F. Parker ◽

Ann H. Rux ◽

Amber M. Riblett ◽

Fang-Hua Lee ◽

Lubica Rauova ◽

...

Keyword(s):

Platelet Factor 4 ◽

Dependent Manner ◽

Concentration Dependent Manner ◽

Platelet Factor ◽

Viral Attachment ◽

Hiv 1

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θ Defensins Protect Cells from Infection by Herpes Simplex Virus by Inhibiting Viral Adhesion and Entry

Journal of Virology ◽

10.1128/jvi.78.10.5147-5156.2004 ◽

2004 ◽

Vol 78 (10) ◽

pp. 5147-5156 ◽

Cited By ~ 147

Author(s):

Bushra Yasin ◽

Wei Wang ◽

Mabel Pang ◽

Natalia Cheshenko ◽

Teresa Hong ◽

...

Keyword(s):

Herpes Simplex ◽

Nuclear Translocation ◽

Temperature Shift ◽

Virus Surface ◽

Herpes Simplex Viruses ◽

Viral Attachment ◽

High Affinity ◽

Simplex Virus ◽

Hiv 1

ABSTRACT We tested the ability of 20 synthetic θ defensins to protect cells from infection by type 1 and type 2 herpes simplex viruses (HSV-1 and -2, respectively). The peptides included rhesus θ defensins (RTDs) 1 to 3, originally isolated from rhesus macaque leukocytes, and three peptides (retrocyclins 1 to 3) whose sequences were inferred from human θ-defensin (DEFT) pseudogenes. We also tested 14 retrocyclin analogues, including the retro, enantio, and retroenantio forms of retrocyclin 1. Retrocyclins 1 and 2 and RTD 3 protected cervical epithelial cells from infection by both HSV serotypes, but only retrocyclin 2 did so without causing cytotoxicity or requiring preincubation with the virus. Surface plasmon resonance studies revealed that retrocyclin 2 bound to immobilized HSV-2 glycoprotein B (gB2) with high affinity (Kd , 13.3 nM) and that it did not bind to enzymatically deglycosylated gB2. Temperature shift experiments indicated that retrocyclin 2 and human α defensins human neutrophil peptide 1 (HNP 1) to HNP 3 protected human cells from HSV-2 by different mechanisms. Retrocyclin 2 blocked viral attachment, and its addition during the binding or penetration phases of HSV-2 infection markedly diminished nuclear translocation of VP16 and expression of ICP4. In contrast, HNPs 1 to 3 had little effect on binding but reduced both VP16 transport and ICP4 expression if added during the postbinding (penetration) period. We recently reported that θ defensins are miniature lectins that bind gp120 of human immunodeficiency virus type 1 (HIV-1) with high affinity and inhibit the entry of R5 and X4 isolates of HIV-1. Given its small size (18 residues), minimal cytotoxicity, lack of activity against vaginal lactobacilli, and effectiveness against both HSV-2 and HIV-1, retrocyclin 2 provides an intriguing prototype for future topical microbicide development.

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Extracellular vesicles from symbiotic vaginal lactobacilli inhibit HIV-1 infection of human tissues

Nature Communications ◽

10.1038/s41467-019-13468-9 ◽

2019 ◽

Vol 10 (1) ◽

Cited By ~ 13

Author(s):

Rogers A. Ñahui Palomino ◽

Christophe Vanpouille ◽

Luca Laghi ◽

Carola Parolin ◽

Kamran Melikov ◽

...

Keyword(s):

Extracellular Vesicles ◽

Viral Entry ◽

Ex Vivo ◽

Target Cells ◽

Isolated Cells ◽

Viral Attachment ◽

Vaginal Lactobacilli ◽

Male To Female ◽

Hiv 1

AbstractThe vaginal microbiota, dominated by Lactobacillus spp., plays a key role in preventing HIV-1 transmission. Here, we investigate whether the anti-HIV effect of lactobacilli is mediated by extracellular vesicles (EVs) released by these bacteria. Human cervico-vaginal and tonsillar tissues ex vivo, and cell lines were infected with HIV-1 and treated with EVs released by lactobacilli isolated from vaginas of healthy women. EVs released by L. crispatus BC3 and L. gasseri BC12 protect tissues ex vivo and isolated cells from HIV-1 infection. This protection is associated with a decrease of viral attachment to target cells and viral entry due to diminished exposure of Env that mediates virus-cell interactions. Inhibition of HIV-1 infection is associated with the presence in EVs of several proteins and metabolites. Our findings demonstrate that the protective effect of Lactobacillus against HIV-1 is, in part, mediated by EVs released by these symbiotic bacteria. If confirmed in vivo, this finding may lead to new strategies to prevent male-to-female sexual HIV-1 transmission.

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Pharmacokinetic Interactions between BMS-626529, the Active Moiety of the HIV-1 Attachment Inhibitor Prodrug BMS-663068, and Ritonavir or Ritonavir-Boosted Atazanavir in Healthy Subjects

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.04914-14 ◽

2015 ◽

Vol 59 (7) ◽

pp. 3816-3822 ◽

Cited By ~ 12

Author(s):

Li Zhu ◽

Matthew Hruska ◽

Carey Hwang ◽

Vaishali Shah ◽

Michael Furlong ◽

...

Keyword(s):

Healthy Subjects ◽

Systemic Exposure ◽

Open Label ◽

Time Curve ◽

Once Daily ◽

Viral Attachment ◽

Cyp3a4 Substrate ◽

Cyp3a4 Inhibitors ◽

To Receive ◽

Hiv 1

ABSTRACTBMS-663068 is a prodrug of BMS-626529, a first-in-class attachment inhibitor that binds directly to HIV-1 gp120, preventing initial viral attachment and entry into host CD4+T cells. This open-label, multiple-dose, four-sequence, crossover study addressed potential two-way drug-drug interactions following coadministration of BMS-663068 (BMS-626529 is a CYP3A4 substrate), atazanavir (ATV), and ritonavir (RTV) (ATV and RTV are CYP3A4 inhibitors). Thirty-six healthy subjects were randomized 1:1:1:1 to receive one of four treatment sequences with three consecutive treatments: BMS-663068 at 600 mg twice daily (BID), BMS-663068 at 600 mg BID plus RTV at 100 mg once daily (QD), ATV at 300 mg QD plus RTV at 100 mg QD (RTV-boosted ATV [ATV/r]), or BMS-663068 at 600 mg BID plus ATV at 300 mg QD plus RTV at 100 mg QD. Compared with the results obtained by administration of BMS-663068 alone, coadministration of BMS-663068 with ATV/r increased the BMS-626529 maximum concentration in plasma (Cmax) and the area under the concentration-time curve in one dosing interval (AUCtau) by 68% and 54%, respectively. Similarly, coadministration of BMS-663068 with RTV increased the BMS-626529Cmaxand AUCtauby 53% and 45%, respectively. Compared with the results obtained by administration of ATV/r alone, ATV and RTV systemic exposures remained similar following coadministration of BMS-663068 with ATV/r. BMS-663068 was generally well tolerated, and there were no adverse events (AEs) leading to discontinuation, serious AEs, or deaths. Moderate increases in BMS-626529 systemic exposure were observed following coadministration of BMS-663068 with ATV/r or RTV. However, the addition of ATV to BMS-663068 plus RTV did not further increase BMS-626529 systemic exposure. ATV and RTV exposures remained similar following coadministration of BMS-663068 with either ATV/r or RTV. BMS-663068 was generally well tolerated alone or in combination with either RTV or ATV/r.

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2500. Fostemsavir Drug–Drug Interaction Profile, an Attachment Inhibitor and Oral Prodrug of Temsavir, for Heavily Treatment Experienced HIV-1-Infected Patients

Open Forum Infectious Diseases ◽

10.1093/ofid/ofz360.2178 ◽

2019 ◽

Vol 6 (Supplement_2) ◽

pp. S867-S867 ◽

Cited By ~ 2

Author(s):

Katy P Moore ◽

A Savannah Mageau ◽

Mindy Magee ◽

Peter D Gorycki ◽

Peter Ackerman ◽

...

Keyword(s):

Organic Anion ◽

Viral Envelope ◽

Organic Anion Transporter ◽

Uridine Diphosphate ◽

Cancer Resistance ◽

Viral Attachment ◽

Transporter Protein ◽

Anion Transporter ◽

The Impact ◽

Hiv 1

Abstract Background Fostemsavir (FTR) is a first-in-class attachment inhibitor being evaluated in heavily treatment-experienced (HTE) HIV-1-infected patients. Active temsavir (TMR) binds to viral envelope glycoprotein 120 and prevents viral attachment and entry into host CD4+ T cells. TMR is primarily metabolized by esterase-mediated hydrolysis with contributions from cytochrome P450 (CYP) 3A4. TMR does not inhibit/induce major CYP or uridine diphosphate glucuronosyltransferase (UGT) enzymes and is a P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP) substrate. TMR and/or its metabolites inhibit BCRP and organic anion transporter protein 1B1/3 (OATP1B1/3). FTR DDI profile informs coadministration with antiretrovirals (ARV) and other therapeutic classes. Methods DDI data from 13 studies were compiled to inform the impact of 17 drugs or drug combinations on TMR and the impact of TMR on 15 drugs such as ARVs, rifamycins, opioid substitutes, statins, oral contraceptives (OC), and H2-antagonsits. Results FTR with CYP3A4, P-gp, and/or BCRP inhibitors increase TMR concentrations; but, do not pose clinical concern at therapeutic dose. TMR may be administered with weak/moderate inducers with or without coadministration of CYP3A4, P-gp, and/or BCRP inhibitors such as RTV or COBI. Coadministration with strong inducers is contraindicated. FTR may be coadministered with RBT with or without a PK enhancer. However, co-administration of FTR with RIF is contraindicated. FTR can be given with drugs that increase gastric pH; famotidine did not impact TMR PK. TMR may increase concentrations of drugs that are substrates of OATP1B1/3 and BCRP; therefore, most statins require dose reduction (e.g., rosuvastatin dose is limited to ≤10 mg QD). TMR increased EE exposure 40% with no impact on NE; therefore, FTR may be coadministered with OCs containing ≤30 µg EE. TMR had no clinically meaningful impact on TDF, DRV/RTV, ATV/RTV, ATV, RTV, ETR, MET, or BUP/norBUP PK (Table 1). Conclusion FTR can be coadministered with ARVs and most common treatments used to manage HIV co-infections or comorbidities without dose adjustment of either drug except for select HMG-CoA reductase inhibitors and EE-containing OCs. Strong CYP3A inducers are contraindicated. Disclosures All authors: No reported disclosures.

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Model-Based Phase 3 Dose Selection for HIV-1 Attachment Inhibitor Prodrug BMS-663068 in HIV-1-Infected Patients: Population Pharmacokinetics/Pharmacodynamics of the Active Moiety, BMS-626529

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.02503-15 ◽

2016 ◽

Vol 60 (5) ◽

pp. 2782-2789 ◽

Cited By ~ 12

Author(s):

Ishani Landry ◽

Li Zhu ◽

Malaz Abu Tarif ◽

Matthew Hruska ◽

Brian M. Sadler ◽

...

Keyword(s):

Population Pharmacokinetics ◽

Clinical Investigation ◽

Central Compartment ◽

Pharmacodynamic Modeling ◽

Dose Selection ◽

Phase 3 ◽

Viral Attachment ◽

First Order ◽

Selection For ◽

Hiv 1

ABSTRACTBMS-663068 is an oral prodrug of the HIV-1 attachment inhibitor BMS-626529, which prevents viral attachment to host CD4+T cells by binding to HIV-1 gp120. To guide dose selection for the phase 3 program, pharmacokinetic/pharmacodynamic modeling was performed using data from two phase 2 studies with HIV-1-infected subjects (n= 244). BMS-626529 population pharmacokinetics were described by a two-compartment model with first-order elimination from the central compartment, zero-order release of prodrug from the extended-release formulation into a hypothetical absorption compartment, and first-order absorption into the central compartment. The covariates of BMS-663068 formulation type, lean body mass, baseline CD8+T-cell percentage, and ritonavir coadministration were found to be significant contributors to intersubject variability. Exposure-response analyses showed a relationship between the loge-transformed concentration at the end of a dosing interval (Ctau) normalized for the protein binding-adjusted BMS-626529 half-maximal (50%) inhibitory concentration (PBAIC50) and the change in the HIV-1 RNA level from the baseline level after 7 days of BMS-663068 monotherapy. The probability of achieving a decline in HIV-1 RNA level of >0.5 or >1.0 log10copies/ml as a function of the loge-transformed PBAIC50-adjustedCtauafter 7 days of monotherapy was 99 to 100% and 57 to 73%, respectively, for proposed BMS-663068 doses of 400 mg twice daily (BID), 600 mg BID (not studied in the phase 2b study), 800 mg BID, 600 mg once daily (QD), and 1,200 mg QD. On the basis of a slight advantage in efficacy of BID dosing over QD dosing, similar responses for the 600- and 800-mg BID doses, and prior clinical observations, BMS-663068 at 600 mg BID was predicted to have the optimal benefit-risk profile and selected for further clinical investigation. (The phase 2a proof-of-concept study AI438006 and the phase 2b study AI438011 are registered at ClinicalTrials.gov under numbers NCT01009814 and NCT01384734, respectively.)

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Ultrastructural observations of human monocytes infected with HIV-1

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100084843 ◽

1991 ◽

Vol 49 ◽

pp. 108-109

Author(s):

James K. Koehler ◽

Steven G. Reed ◽

Joao S. Silva

Keyword(s):

Gradient Centrifugation ◽

Virus Production ◽

Human Monocyte ◽

Red Cross ◽

Human Monocytes ◽

Blood Monocytes ◽

Hiv Replication ◽

Electron Microscopic ◽

Ultrastructural Studies ◽

Hiv 1

As part of a larger study involving the co-infection of human monocyte cultures with HIV and protozoan parasites, electron microscopic observations were made on the course of HIV replication and infection in these cells. Although several ultrastructural studies of the cytopathology associated with HIV infection have appeared, few studies have shown the details of virus production in “normal,” human monocytes/macrophages, one of the natural targets of the virus, and suspected of being a locus of quiescent virus during its long latent period. In this report, we detail some of the interactions of developing virons with the membranes and organelles of the monocyte host.Peripheral blood monocytes were prepared from buffy coats (Portland Red Cross) by Percoll gradient centrifugation, followed by adherence to cover slips. 90-95% pure monocytes were cultured in RPMI with 5% non-activated human AB serum for four days and infected with 100 TCID50/ml of HIV-1 for four hours, washed and incubated in fresh medium for 14 days.

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