DOCSLIB.ORG

Defining Rules Governing Recognition and Fc-Mediated Effector Functions to the HIV-1 Co-Receptor Binding Site William D

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Defining Rules Governing Recognition and Fc-Mediated Effector Functions to the HIV-1 Co-Receptor Binding Site William D Tolbert et al. BMC Biology (2020) 18:91 https://doi.org/10.1186/s12915-020-00819-y RESEARCH ARTICLE Open Access Defining rules governing recognition and Fc-mediated effector functions to the HIV-1 co-receptor binding site William D. Tolbert1,2†, Rebekah Sherburn1,2†, Neelakshi Gohain2†, Shilei Ding3,4, Robin Flinko2, Chiara Orlandi2, Krishanu Ray1, Andrés Finzi3,4,5, George K. Lewis2 and Marzena Pazgier1,2* Abstract Background: The binding of HIV-1 Envelope glycoproteins (Env) to host receptor CD4 exposes vulnerable conserved epitopes within the co-receptor binding site (CoRBS) which are required for the engagement of either CCR5 or CXCR4 co-receptor to allow HIV-1 entry. Antibodies against this region have been implicated in the protection against HIV acquisition in non-human primate (NHP) challenge studies and found to act synergistically with antibodies of other specificities to deliver effective Fc-mediated effector function against HIV-1-infected cells. Here, we describe the structure and function of N12-i2, an antibody isolated from an HIV-1-infected individual, and show how the unique structural features of this antibody allow for its effective Env recognition and Fc-mediated effector function. Results: N12-i2 binds within the CoRBS utilizing two adjacent sulfo-tyrosines (TYS) for binding, one of which binds to a previously unknown TYS binding pocket formed by gp120 residues of high sequence conservation among HIV-1 strains. Structural alignment with gp120 in complex with the co-receptor CCR5 indicates that the new pocket corresponds to TYS at position 15 of CCR5. In addition, structure-function analysis of N12-i2 and other CoRBS-specific antibodies indicates a link between modes of antibody binding within the CoRBS and Fc-mediated effector activities. The efficiency of antibody-dependent cellular cytotoxicity (ADCC) correlated with both the level of antibody binding and the mode of antibody attachment to the epitope region, specifically with the way the Fc region was oriented relative to the target cell surface. Antibodies with poor Fc access mediated the poorest ADCC whereas those with their Fc region readily accessible for interaction with effector cells mediated the most potent ADCC. Conclusion: Our data identify a previously unknown binding site for TYS within the assembled CoRBS of the HIV-1 virus. In addition, our combined structural-modeling-functional analyses provide new insights into mechanisms of Fc- effector function of antibodies against HIV-1, in particular, how antibody binding to Env antigen affects the efficiency of ADCC response. Keywords: HIV-1, Env, Co-receptor binding site, ADCC, N12-i2 * Correspondence: [email protected] †William D. Tolbert, Rebekah Sherburn and Neelakshi Gohain contributed equally to this work. 1Infectious Disease Division, Department of Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814-4712, USA 2Division of Vaccine Research of Institute of Human Virology, University of Maryland School of Medicine, Baltimore, USA Full list of author information is available at the end of the article © The Author(s). 2020 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data. Tolbert et al. BMC Biology (2020) 18:91 Page 2 of 20 Background Historically, such antibodies were classified solely based The human immunodeficiency virus (HIV-1) contains on their direct neutralizing activities; not much was only one viral glycoprotein on its surface; the envelope known about their involvement in Fc-mediated processes. (Env) spike, which is responsible for both target cell rec- Capable of direct neutralization of mostly Tier 1 viruses, ognition and virus-host fusion. The Env spike consists of in the absence of complement or effector cells, CoRBS a non-covalent trimeric assembly of exterior gp120 and Abs were viewed as moderately to weakly neutralizing and transmembrane gp41 glycoproteins [1, 2]. During viral overall not capable of neutralizing most circulating iso- entry, the recognition step is mediated by the specific lates [9, 29, 30]. Furthermore, the neutralization potency interaction of the exterior gp120 subunit with the pri- in this class was shown to directly correlate with unusual mary receptor at the target cell surface, CD4 [3]. CD4 antibody structural features with the most effective neu- binding induces conformational changes in the trimer, tralizers having long, tyrosine-O-sulfated CDR H3s [31– leading to the formation of the gp120 bridging sheet 35]. It was shown that CoRBS Abs containing tyrosines which, together with the stem of the gp120 third variable modified by post-translational O-sulfation were able to region (V3), constitutes the Env interaction site for co- mimic the interaction mediated by the N-terminus of receptor binding (CoRBS), allowing either CCR5 or CCR5, which contains up to four O-sulfo-tyrosines, with a CXCR4 to bind [4, 5]. Together, CD4-triggering and en- minimum of two required for HIV-1 cell entry [34, 36]. gagement of a co-receptor enable fusion of the viral and We recently performed a systematic analysis of a panel host cell membranes. The transitional structures arising of 33 CD4i monoclonal antibodies (mAbs) directed at the within the Env spike post-CD4 attachment in the HIV-1 CoRBS, Cluster C region, and defined their fine epitope entry process are referred to as “CD4-induced” (CD4i) specificities, neutralization, and ADCC potencies [15, 19]. and constitute effective targets for humoral immune re- We detected, consistent with previous reports [9, 29, 30, sponses [6–10]. These CD4i targets include highly con- 32–35], a substantial neutralization diversity among anti- served epitopes that are located within/proximal to the bodies directed at Cluster C epitopes, with the most po- assembled CoRBS [11–14] and epitopes elsewhere in the tent being those that bind epitopes overlapping the protein, including the C1/C2 region of gp120 [6–8, 15– classical 17b epitope and having tyrosine-O-sulfated CDR 18]. The CoRBS and C1C2 epitopes are commonly re- H3s. Most interestingly, our studies were the first to sys- ferred to as Cluster C and Cluster A epitope regions, re- tematically rank the breadth and potency of CoRBS epi- spectively [15, 19]. CD4i epitope targets, including the topes as functional ADCC targets. We showed that most Cluster C and A regions, are not fully exposed on the mAbs specific for these epitopes mediated significant free Env spike, and anti-Env antibodies specific for these ADCC against target cells coated with AT-2 inactivated regions show enhanced affinity for the gp120-CD4 com- viral particles [15]. Interestingly, the CoRBS antibodies plex as compared to un-triggered gp120 [20]. The struc- were also recently found to act synergistically with Cluster ture of gp120 in complex with both CD4 and CCR5 has A antibodies to promote FcγRIIIa engagement and to me- recently been solved by cryo-electron microscopy and diate ADCC of CD4+ HIV-infected cells and HIV-infected revealed that CCR5 most likely acts to stabilize the cells pre-treated with small CD4 mimetics [19, 37, 38]. gp120 in CD4-bound conformation and to moor the Here, we selected the mAb N12-i2, a representative anti- complex close to the cell surface [21]. body of the Cluster C panel [15], and described the molecu- Several lines of evidence point towards the involvement lar details of its interaction with the Env antigen. N12-i2, of the CD4i antibody class in protection against HIV-1 ac- similar to other CoRBS-specific antibodies, binds within the quisition or/and post-infection control during natural in- assembled co-receptor binding site but utilizes a unique fection and in vaccine settings [17, 22–24]. The CD4i binding mode that involves two sulfoTYSs, one of which oc- Cluster A antibodies were implicated in the protective ef- cupies a newly defined TYS binding pocket. Furthermore, in fect of the RV144 vaccine regimen in humans [25, 26]and order to better understand the mechanisms governing Fc- a mix of Cluster A and CoRBS antibodies induced by the effector mechanism to the CoRBS epitopes, we examined if covalently constrained gp120-CD4 complex vaccine (full- the fine epitope specificity and mode of binding of N12-i2 length single chain (FLSC) vaccine [27]) afforded heterol- and other CoRBS-specific antibodies contribute to the ef- ogous protection against SHIV162p3 and SIVmac251 in fectiveness of Env engagement and Fc-mediated effector ac- non-human primate (NHP) challenge studies [23, 28]. tivities in the elimination of CEM-NKR cells sensitized with Interestingly, Cluster A antibodies impacted the virus HIV-1 gp120 BaL or infected with the ADA virus. solely through Fc-mediated effector mechanisms, without direct neutralizing activity and were capable of cytolytic Results activity through antibody-dependent cellular cytotoxicity N12-i2 targets the co-receptor binding site of HIV-1 Env (ADCC) [15]. In contrast, less is known about the exact As initially assessed [15], N12-i2 recognizes the transi- mechanisms of the protective action of CoRBS antibodies.
Load more

Recommended publications
  • The Nef-Infectivity Enigma: Mechanisms of Enhanced Lentiviral Infection Jolien Vermeire§, Griet Vanbillemont§, Wojciech Witkowski and Bruno Verhasselt*
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by PubMed Central 474 Current HIV Research, 2011, 9, 474-489 The Nef-Infectivity Enigma: Mechanisms of Enhanced Lentiviral Infection Jolien Vermeire§, Griet Vanbillemont§, Wojciech Witkowski and Bruno Verhasselt* Department of Clinical Chemistry, Microbiology, and Immunology, Ghent University, Belgium Abstract: The Nef protein is an essential factor for lentiviral pathogenesis in humans and other simians. Despite a multitude of functions attributed to this protein, the exact role of Nef in disease progression remains unclear. One of its most intriguing functions is the ability of Nef to enhance the infectivity of viral particles. In this review we will discuss current insights in the mechanism of this well-known, yet poorly understood Nef effect. We will elaborate on effects of Nef, on both virion biogenesis and the early stage of the cellular infection, that might be involved in infectivity enhancement. In addition, we provide an overview of different HIV-1 Nef domains important for optimal infectivity and briefly discuss some possible sources of the frequent discrepancies in the field. Hereby we aim to contribute to a better understanding of this highly conserved and therapeutically attractive Nef function. Keywords: Nef, HIV, infectivity, viral replication, mutation analysis, envelope protein, cholesterol, proteasome. 1. INTRODUCTION 2. THE MULTIFACETED NEF PROTEIN Despite the globally declining number of new human As early as 1991, infections of rhesus monkeys with nef- immunodeficiency virus (HIV) infections [1] and the hopeful deleted simian immunodeficiency virus (SIV) revealed a observation that cure from HIV infection does not seem dramatic reduction of viral loads and disease progression in impossible [2], the HIV pandemic still remains a very absence of nef [6].
    [Show full text]
  • HIV-1 Rev Downregulates Tat Expression and Viral Replication Via Modulation of NAD(P)H:Quinine Oxidoreductase 1 (NQO1)
    ARTICLE Received 25 Jul 2014 | Accepted 22 Apr 2015 | Published 10 Jun 2015 DOI: 10.1038/ncomms8244 HIV-1 Rev downregulates Tat expression and viral replication via modulation of NAD(P)H:quinine oxidoreductase 1 (NQO1) Sneh Lata1,*, Amjad Ali2,*, Vikas Sood1,2,w, Rameez Raja2 & Akhil C. Banerjea2 HIV-1 gene expression and replication largely depend on the regulatory proteins Tat and Rev, but it is unclear how the intracellular levels of these viral proteins are regulated after infection. Here we report that HIV-1 Rev causes specific degradation of cytoplasmic Tat, which results in inhibition of HIV-1 replication. The nuclear export signal (NES) region of Rev is crucial for this activity but is not involved in direct interactions with Tat. Rev reduces the levels of ubiquitinated forms of Tat, which have previously been reported to be important for its transcriptional properties. Tat is stabilized in the presence of NAD(P)H:quinine oxidoreductase 1 (NQO1), and potent degradation of Tat is induced by dicoumarol, an NQO1 inhibitor. Furthermore, Rev causes specific reduction in the levels of endogenous NQO1. Thus, we propose that Rev is able to induce degradation of Tat indirectly by downregulating NQO1 levels. Our findings have implications in HIV-1 gene expression and latency. 1 Department of Microbiology, University College of Medical Sciences and Guru Teg Bahadur Hospital, Delhi 110095, India. 2 Laboratory of Virology, National Institute of Immunology, New Delhi 110067, India. * These authors contributed equally to this work. w Present address: Translational Health Science and Technology Institute, Faridabad, Haryana 121004, India. Correspondence and requests for materials should be addressed to A.C.B.
    [Show full text]
  • Opportunistic Intruders: How Viruses Orchestrate ER Functions to Infect Cells
    REVIEWS Opportunistic intruders: how viruses orchestrate ER functions to infect cells Madhu Sudhan Ravindran*, Parikshit Bagchi*, Corey Nathaniel Cunningham and Billy Tsai Abstract | Viruses subvert the functions of their host cells to replicate and form new viral progeny. The endoplasmic reticulum (ER) has been identified as a central organelle that governs the intracellular interplay between viruses and hosts. In this Review, we analyse how viruses from vastly different families converge on this unique intracellular organelle during infection, co‑opting some of the endogenous functions of the ER to promote distinct steps of the viral life cycle from entry and replication to assembly and egress. The ER can act as the common denominator during infection for diverse virus families, thereby providing a shared principle that underlies the apparent complexity of relationships between viruses and host cells. As a plethora of information illuminating the molecular and cellular basis of virus–ER interactions has become available, these insights may lead to the development of crucial therapeutic agents. Morphogenesis Viruses have evolved sophisticated strategies to establish The ER is a membranous system consisting of the The process by which a virus infection. Some viruses bind to cellular receptors and outer nuclear envelope that is contiguous with an intri‑ particle changes its shape and initiate entry, whereas others hijack cellular factors that cate network of tubules and sheets1, which are shaped by structure. disassemble the virus particle to facilitate entry. After resident factors in the ER2–4. The morphology of the ER SEC61 translocation delivering the viral genetic material into the host cell and is highly dynamic and experiences constant structural channel the translation of the viral genes, the resulting proteins rearrangements, enabling the ER to carry out a myriad An endoplasmic reticulum either become part of a new virus particle (or particles) of functions5.
    [Show full text]
  • A Novel Ebola Virus VP40 Matrix Protein-Based Screening for Identification of Novel Candidate Medical Countermeasures
    viruses Communication A Novel Ebola Virus VP40 Matrix Protein-Based Screening for Identification of Novel Candidate Medical Countermeasures Ryan P. Bennett 1,† , Courtney L. Finch 2,† , Elena N. Postnikova 2 , Ryan A. Stewart 1, Yingyun Cai 2 , Shuiqing Yu 2 , Janie Liang 2, Julie Dyall 2 , Jason D. Salter 1 , Harold C. Smith 1,* and Jens H. Kuhn 2,* 1 OyaGen, Inc., 77 Ridgeland Road, Rochester, NY 14623, USA; [email protected] (R.P.B.); [email protected] (R.A.S.); [email protected] (J.D.S.) 2 NIH/NIAID/DCR/Integrated Research Facility at Fort Detrick (IRF-Frederick), Frederick, MD 21702, USA; courtney.fi[email protected] (C.L.F.); [email protected] (E.N.P.); [email protected] (Y.C.); [email protected] (S.Y.); [email protected] (J.L.); [email protected] (J.D.) * Correspondence: [email protected] (H.C.S.); [email protected] (J.H.K.); Tel.: +1-585-697-4351 (H.C.S.); +1-301-631-7245 (J.H.K.) † These authors contributed equally to this work. Abstract: Filoviruses, such as Ebola virus and Marburg virus, are of significant human health concern. From 2013 to 2016, Ebola virus caused 11,323 fatalities in Western Africa. Since 2018, two Ebola virus disease outbreaks in the Democratic Republic of the Congo resulted in 2354 fatalities. Although there is progress in medical countermeasure (MCM) development (in particular, vaccines and antibody- based therapeutics), the need for efficacious small-molecule therapeutics remains unmet. Here we describe a novel high-throughput screening assay to identify inhibitors of Ebola virus VP40 matrix protein association with viral particle assembly sites on the interior of the host cell plasma membrane.
    [Show full text]
  • Lentivirus and Lentiviral Vectors Fact Sheet
    Lentivirus and Lentiviral Vectors Family: Retroviridae Genus: Lentivirus Enveloped Size: ~ 80 - 120 nm in diameter Genome: Two copies of positive-sense ssRNA inside a conical capsid Risk Group: 2 Lentivirus Characteristics Lentivirus (lente-, latin for “slow”) is a group of retroviruses characterized for a long incubation period. They are classified into five serogroups according to the vertebrate hosts they infect: bovine, equine, feline, ovine/caprine and primate. Some examples of lentiviruses are Human (HIV), Simian (SIV) and Feline (FIV) Immunodeficiency Viruses. Lentiviruses can deliver large amounts of genetic information into the DNA of host cells and can integrate in both dividing and non- dividing cells. The viral genome is passed onto daughter cells during division, making it one of the most efficient gene delivery vectors. Most lentiviral vectors are based on the Human Immunodeficiency Virus (HIV), which will be used as a model of lentiviral vector in this fact sheet. Structure of the HIV Virus The structure of HIV is different from that of other retroviruses. HIV is roughly spherical with a diameter of ~120 nm. HIV is composed of two copies of positive ssRNA that code for nine genes enclosed by a conical capsid containing 2,000 copies of the p24 protein. The ssRNA is tightly bound to nucleocapsid proteins, p7, and enzymes needed for the development of the virion: reverse transcriptase (RT), proteases (PR), ribonuclease and integrase (IN). A matrix composed of p17 surrounds the capsid ensuring the integrity of the virion. This, in turn, is surrounded by an envelope composed of two layers of phospholipids taken from the membrane of a human cell when a newly formed virus particle buds from the cell.
    [Show full text]
  • HIV-1) CD4 Receptor and Its Central Role in Promotion of HIV-1 Infection
    MICROBIOLOGICAL REVIEWS, Mar. 1995, p. 63–93 Vol. 59, No. 1 0146-0749/95/$04.0010 Copyright q 1995, American Society for Microbiology The Human Immunodeficiency Virus Type 1 (HIV-1) CD4 Receptor and Its Central Role in Promotion of HIV-1 Infection STEPHANE BOUR,* ROMAS GELEZIUNAS,† AND MARK A. WAINBERG* McGill AIDS Centre, Lady Davis Institute-Jewish General Hospital, and Departments of Microbiology and Medicine, McGill University, Montreal, Quebec, Canada H3T 1E2 INTRODUCTION .........................................................................................................................................................63 RETROVIRAL RECEPTORS .....................................................................................................................................64 Receptors for Animal Retroviruses ........................................................................................................................64 CD4 Is the Major Receptor for HIV-1 Infection..................................................................................................65 ROLE OF THE CD4 CORECEPTOR IN T-CELL ACTIVATION........................................................................65 Structural Features of the CD4 Coreceptor..........................................................................................................65 Interactions of CD4 with Class II MHC Determinants ......................................................................................66 CD4–T-Cell Receptor Interactions during T-Cell Activation
    [Show full text]
  • Structural Basis of CD4 Downregulation by HIV-1 Nef
    ARTICLES https://doi.org/10.1038/s41594-020-0463-z Structural basis of CD4 downregulation by HIV-1 Nef Yonghwa Kwon1, Robyn M. Kaake2,3, Ignacia Echeverria4, Marissa Suarez5, Mohammad Karimian Shamsabadi 1, Charlotte Stoneham5,6, Peter W. Ramirez6, Jacob Kress1, Rajendra Singh5,6, Andrej Sali4,7, Nevan Krogan 2,3, John Guatelli5,6 and Xiaofei Jia 1 ✉ The HIV-1 Nef protein suppresses multiple immune surveillance mechanisms to promote viral pathogenesis and is an attractive target for the development of novel therapeutics. A key function of Nef is to remove the CD4 receptor from the cell surface by hijacking clathrin- and adaptor protein complex 2 (AP2)-dependent endocytosis. However, exactly how Nef does this has been elusive. Here, we describe the underlying mechanism as revealed by a 3.0-Å crystal structure of a fusion protein comprising Nef and the cytoplasmic domain of CD4 bound to the tetrameric AP2 complex. An intricate combination of conformational changes occurs in both Nef and AP2 to enable CD4 binding and downregulation. A pocket on Nef previously identified as crucial for recruiting class I MHC is also responsible for recruiting CD4, revealing a potential approach to inhibit two of Nef’s activities and sensitize the virus to immune clearance. he HIV-1 protein Nef is a critical factor in viral pathogenesis1. domains of membrane cargos. Two sorting motifs are commonly Expression of Nef in vivo is required for high viral loads and recognized by APs. The tyrosine-based motifs (YxxΦ, where Φ is for progression to AIDS2. Individuals infected with HIV-1 a bulky hydrophobic residue) bind to the μ subunits of APs, while T 3,4 encoding defective nef genes do not develop AIDS for decades .
    [Show full text]
  • Genetic Variation and Function of the HIV-1 Tat Protein
    Medical Microbiology and Immunology (2019) 208:131–169 https://doi.org/10.1007/s00430-019-00583-z REVIEW Genetic variation and function of the HIV-1 Tat protein Cassandra Spector1,2 · Anthony R. Mele1,2 · Brian Wigdahl1,2,3 · Michael R. Nonnemacher1,2,3 Received: 23 August 2018 / Accepted: 11 February 2019 / Published online: 5 March 2019 © Springer-Verlag GmbH Germany, part of Springer Nature 2019 Abstract Human immunodeficiency virus type 1 (HIV-1) encodes a transactivator of transcription (Tat) protein, which has several functions that promote viral replication, pathogenesis, and disease. Amino acid variation within Tat has been observed to alter the functional properties of Tat and, depending on the HIV-1 subtype, may produce Tat phenotypes differing from viruses’ representative of each subtype and commonly used in in vivo and in vitro experimentation. The molecular properties of Tat allow for distinctive functional activities to be determined such as the subcellular localization and other intracellular and extracellular functional aspects of this important viral protein influenced by variation within the Tat sequence. Once Tat has been transported into the nucleus and becomes engaged in transactivation of the long terminal repeat (LTR), vari- ous Tat variants may differ in their capacity to activate viral transcription. Post-translational modification patterns based on these amino acid variations may alter interactions between Tat and host factors, which may positively or negatively affect this process. In addition, the ability of HIV-1 to utilize or not utilize the transactivation response (TAR) element within the LTR, based on genetic variation and cellular phenotype, adds a layer of complexity to the processes that govern Tat-mediated proviral DNA-driven transcription and replication.
    [Show full text]
  • 4149662.Pdf (4.408Mb)
    136 HIV-1 Nef regulates activity of endoplasmic reticulum chaperone calnexin The Harvard community has made this article openly available. Please share how this access benefits you. Your story matters Citation Jennelle, Lucas, Ruth Hunegnaw, Larisa Dubrovsky, Tatiana Pushkarsky, Michael L. Fitzgerald, Dmitri Sviridov, and Michael Bukrinsky*. 2014. “136 HIV-1 Nef regulates activity of endoplasmic reticulum chaperone calnexin.” Journal of Acquired Immune Deficiency Syndromes (1999) 65 (Suppl 2): 57. doi:10.1097/01.qai.0000446716.85972.b0. http:// dx.doi.org/10.1097/01.qai.0000446716.85972.b0. Published Version doi:10.1097/01.qai.0000446716.85972.b0 Citable link http://nrs.harvard.edu/urn-3:HUL.InstRepos:12987392 Terms of Use This article was downloaded from Harvard University’s DASH repository, and is made available under the terms and conditions applicable to Other Posted Material, as set forth at http:// nrs.harvard.edu/urn-3:HUL.InstRepos:dash.current.terms-of- use#LAA TH 1515TH ANNANNUALUAL INTERNATIONAL MEETING INTERNATIONAL Center forHIV/AIDSPreventionandTreatment the Institute ofHumanVirology SEPTEMBER 8–12,2013|MOSCOW Global Virus Network Global Virus IHV is an Institute at the at Institute an IHV is and in partnershipwith The Moscow L INTERNATIONAL MEETING UA Institute of Human Virology in partnership with the Global Virus Network and The Moscow ANNUAL ANN Contents H T Center for HIV/AIDS Prevention and Treatment TH 5 1 15 SEPTEMBER 8 –12, 2013 | MOSCOW CONTENTS EVENTS SCHEDULE SPEAKER SCHEDULE ABSTRACTS INDEX CONTENTS Click on
    [Show full text]
  • LEDGF/P75 Functions Downstream from Preintegration Complex Formation to Effect Gene-Specific HIV-1 Integration
    Downloaded from genesdev.cshlp.org on October 1, 2021 - Published by Cold Spring Harbor Laboratory Press LEDGF/p75 functions downstream from preintegration complex formation to effect gene-specific HIV-1 integration Ming-Chieh Shun,1,4 Nidhanapati K. Raghavendra,1,4 Nick Vandegraaff,1,4,5 Janet E. Daigle,1 Siobhan Hughes,2 Paul Kellam,3 Peter Cherepanov,2,7 and Alan Engelman1,6 1Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Division of AIDS, Harvard Medical School, Boston, Massachusetts 02115, USA; 2Division of Medicine, Imperial College London, St. Mary’s Campus, London W2 1PG, United Kingdom; 3Department of Infection, University College London, London W1T 4JF, United Kingdom LEDGF/p75 directly interacts with lentiviral integrase proteins and can modulate their enzymatic activities and chromosomal association. A novel genetic knockout model was established that allowed us for the first time to analyze HIV-1 integration in the absence of LEDGF/p75 protein. Supporting a crucial role for the cofactor in viral replication, HIV-1 vector integration and reporter gene expression were significantly reduced in LEDGF-null cells. Yet, integrase processed the viral cDNA termini normally and maintained its local target DNA sequence preference during integration. Preintegration complexes extracted from knockout cells moreover supported normal levels of DNA strand transfer activity in vitro. In contrast, HIV-1 lost its strong bias toward integrating into transcription units, displaying instead increased affinity for promoter regions and CpG islands. Our results reveal LEDGF/p75 as a critical targeting factor, commandeering lentiviruses from promoter- and/or CpG island-proximal pathways that are favored by other members of Retroviridae.
    [Show full text]
  • A Point Mutation in HIV-1 Integrase Redirects Proviral Integration Into
    bioRxiv preprint doi: https://doi.org/10.1101/2021.01.12.426369; this version posted January 12, 2021. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. A point mutation in HIV-1 integrase redirects proviral integration into centromeric repeats Shelby Winansa,b,c and Stephen P. Goffa.b,c# aDepartment of Biochemistry and Molecular Biophysics Columbia University Medical Center, New York, NY bDepartment of Microbiology and Immunology Columbia University Medical Center, New York, NY cHoward Hughes Medical Institute, Columbia University, New York, NY #Lead Contact: address correspondence to Stephen P. Goff, [email protected] bioRxiv preprint doi: https://doi.org/10.1101/2021.01.12.426369; this version posted January 12, 2021. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. 1 Abstract 2 Retroviruses utilize the viral integrase (IN) protein to integrate a DNA copy of their 3 genome into the host chromosomal DNA. HIV-1 integration sites are highly biased towards 4 actively transcribed genes, likely mediated by binding of the IN protein to specific host 5 factors, particularly LEDGF, located at these gene regions. We here report a dramatic 6 redirection of integration site distribution induced by a single point mutation in HIV-1 IN.
    [Show full text]
  • Viral Surface Glycoproteins, Gp120 and Gp41, As Potential Drug Targets
    European Journal of Medicinal Chemistry 46 (2011) 979e992 Contents lists available at ScienceDirect European Journal of Medicinal Chemistry journal homepage: http://www.elsevier.com/locate/ejmech Invited review Viral surface glycoproteins, gp120 and gp41, as potential drug targets against HIV-1: Brief overview one quarter of a century past the approval of zidovudine, the first anti-retroviral drug Cátia Teixeira a,b,c, José R.B. Gomes b, Paula Gomes c,*, François Maurel a a ITODYS, Université Paris Diderot, CNRS e UMR7086, 15 Rue Jean Antoine de Baif, 75205 Paris Cedex 13, France b CICECO, Universidade de Aveiro, Campus Universitário de Santiago, P-3810-193 Aveiro, Portugal c Centro de Investigação em Química da Universidade do Porto, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, R. Campo Alegre, 687, P-4169-007 Porto, Portugal article info abstract Article history: The first anti-HIV drug, zidovudine (AZT), was approved by the FDA a quarter of a century ago, in 1985. Received 22 September 2010 Currently, anti-HIV drug-combination therapies only target HIV-1 protease and reverse transcriptase. Received in revised form Unfortunately, most of these molecules present numerous shortcomings such as viral resistances and 15 January 2011 adverse effects. In addition, these drugs are involved in later stages of infection. Thus, it is necessary to Accepted 25 January 2011 develop new drugs that are able to block the first steps of viral life cycle. Entry of HIV-1 is mediated by its Available online 3 February 2011 two envelope glycoproteins: gp120 and gp41. Upon gp120 binding to cellular receptors, gp41 undergoes a series of conformational changes from a non-fusogenic to a fusogenic conformation.
    [Show full text]