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Emert-Sedlak LA, Tice CM, Shi H, Alvarado JJ, Shu ST, Reitz AB, Smithgall TE. PROTAC-mediated degradation of HIV-1 Nef efficiently restores cell-surface CD4 and MHC-I expression and blocks HIV-1 replication. Cell Chem Biol 2024; 31:658-668.e14. [PMID: 38508197 PMCID: PMC11031313 DOI: 10.1016/j.chembiol.2024.02.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 12/20/2023] [Accepted: 02/20/2024] [Indexed: 03/22/2024]
Abstract
The HIV-1 Nef accessory factor enhances the viral life cycle in vivo, promotes immune escape of HIV-infected cells, and represents an attractive antiretroviral drug target. However, Nef lacks enzymatic activity and an active site, complicating traditional occupancy-based drug development. Here we describe the development of proteolysis targeting chimeras (PROTACs) for the targeted degradation of Nef. Nef-binding compounds, based on an existing hydroxypyrazole core, were coupled to ligands for ubiquitin E3 ligases via flexible linkers. The resulting bivalent PROTACs induced formation of a ternary complex between Nef and the cereblon E3 ubiquitin ligase thalidomide-binding domain in vitro and triggered Nef degradation in a T cell expression system. Nef-directed PROTACs efficiently rescued Nef-mediated MHC-I and CD4 downregulation in T cells and suppressed HIV-1 replication in donor PBMCs. Targeted degradation is anticipated to reverse all HIV-1 Nef functions and may help restore adaptive immune responses against HIV-1 reservoir cells in vivo.
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Affiliation(s)
- Lori A Emert-Sedlak
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Colin M Tice
- Fox Chase Therapeutics Discovery, Inc., Pennsylvania Biotechnology Center, Doylestown, PA 18902, USA
| | - Haibin Shi
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - John J Alvarado
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Sherry T Shu
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Allen B Reitz
- Fox Chase Therapeutics Discovery, Inc., Pennsylvania Biotechnology Center, Doylestown, PA 18902, USA
| | - Thomas E Smithgall
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA.
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2
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Crater JM, Dunn D, Nixon DF, O’Brien RLF. HIV-1 Mediated Cortical Actin Disruption Mirrors ARP2/3 Defects Found in Primary T Cell Immunodeficiencies. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.07.27.550856. [PMID: 38405733 PMCID: PMC10888893 DOI: 10.1101/2023.07.27.550856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
During cell movement, cortical actin balances mechanical and osmotic forces to maintain cell function while providing the scaffold for cell shape. Migrating CD4+ T cells have a polarized structure with a leading edge containing dynamic branched and linear F-actin structures that bridge intracellular components to surface adhesion molecules. These actin structures are complemented with a microtubular network beaded with membrane bound organelles in the trailing uropod. Disruption of actin structures leads to dysregulated migration and changes in morphology of affected cells. In HIV-1 infection, CD4+ T cells have dysregulated movement. However, the precise mechanisms by which HIV-1 affects CD4+ T cell movement are unknown. Here, we show that HIV-1 infection of primary CD4+ T cells causes at least four progressive morphological differences as a result of virally induced cortical cytoskeleton disruption, shown by ultrastructural and time lapse imaging. Infection with a ΔNef virus partially abrogated the dysfunctional phenotype in infected cells and partially restored a wild-type shape. The pathological morphologies after HIV-1 infection phenocopy leukocytes which contain genetic determinants of specific T cell Inborn Errors of Immunity (IEI) or Primary Immunodeficiencies (PID) that affect the actin cytoskeleton. To identify potential actin regulatory pathways that may be linked to the morphological deformities, uninfected CD4+ T cell morphology was characterized following addition of small molecule chemical inhibitors. The ARP2/3 inhibitor CK-666 recapitulated three of the four abnormal morphologies we observed in HIV-1 infected cells. Restoring ARP2/3 function and cortical actin integrity in people living with HIV-1 infection is a new avenue of investigation to eradicate HIV-1 infected cells from the body.
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Affiliation(s)
- Jacqueline M. Crater
- Department of Medicine, Division of Infectious Diseases, Weill Cornell Medicine, New York, NY, USA
| | - Daniel Dunn
- Department of Medicine, Division of Infectious Diseases, Weill Cornell Medicine, New York, NY, USA
| | - Douglas F. Nixon
- Department of Medicine, Division of Infectious Diseases, Weill Cornell Medicine, New York, NY, USA
| | - Robert L. Furler O’Brien
- Department of Medicine, Division of Infectious Diseases, Weill Cornell Medicine, New York, NY, USA
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3
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Yang S, Chen Y, Gu J, Harris A, Su RC, Ho EA. pH-sensitive dual-preventive siRNA-based nanomicrobicide reactivates autophagy and inhibits HIV infection in vaginal CD4+ cells. J Control Release 2024; 366:849-863. [PMID: 38176469 DOI: 10.1016/j.jconrel.2023.12.043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 12/13/2023] [Accepted: 12/24/2023] [Indexed: 01/06/2024]
Abstract
Women are more susceptible to HIV transmission through unprotected heterosexual intercourse due to biological and social vulnerabilities. Intravaginal delivery of siRNAs targeting viral genes, host genes, or in combination has shown promising outcomes against HSV, HPV and HIV. Therefore, in this study, we designed, developed and evaluated a pH-sensitive RNAi-based combination nanomicrobide for the prevention/reduction of vaginal transmission of HIV. The nanomicrobide was composed of siRNA-PEI encapsulated PLGA-PEG nanoparticles (siRNA NP) loaded in a HEC gel dosage form with siRNA targeting host gene CCR5 and the viral gene Nef as a dual preventive strategy. Knocking down CCR5, a co-receptor for HIV could prevent HIV from attaching to and entering host cells and knocking down Nef could reactivate autophagy that was inhibited by Nef to improve the elimination of intracellular virus that escaped the first line of defense. The siRNA NP showed a desirable particle size and zeta potential for intravaginal delivery and a pH-dependent release profile whereby low amounts of siRNA was released under acidic vaginal conditions (vaginal fluid simulant; VFS, pH 4.2) (6.0 ± 0.4% released over 15 days) but significantly higher amounts of siRNA was released under neutral pH conditions (phosphate buffered saline; PBS, pH 7.4) (22.9 ± 0.4% released over 15 days). The CCR5-Nef-specific siRNA NP efficiently knocked down CCR5 and Nef protein expression by 43% and 63%, respectively, reactivated Nef-blocked autophagy and inhibited the replication of HIV in vitro (71.8% reduction in p24 expression). After being formulated into a gel dosage form, siRNA NP could be readily released from the gel, penetrate the vaginal epithelial layer, get taken up into the target cells and knockdown Nef and CCR5 without causing cytotoxicity in a vaginal mucosal co-culture model. Functionalization of siRNA NP with anti-CD4 antibody and loaded into a 0.5% HEC gel improved vaginal distribution and uptake of siRNA in a mouse model with distribution of siRNA restricted to the reproductive tract without any unwanted systemic uptake. The 0.5% HEC gel loaded with siRNA NP-(m)CD4 significantly downregulated approximately 40% of CCR5 protein in the lower vagina and 36% of CCR5 protein in the upper vaginal and cervical region. In contrast, 0.5% HEC gel loaded with siRNA NP-IgG did not result in significant gene knockdown.
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Affiliation(s)
- Sidi Yang
- Laboratory for Drug Delivery and Biomaterials, School of Pharmacy, Faculty of Science, University of Waterloo, Canada; College of Pharmacy, Rady Faculty of Health Sciences, University of Manitoba, Canada
| | - Yufei Chen
- Laboratory for Drug Delivery and Biomaterials, School of Pharmacy, Faculty of Science, University of Waterloo, Canada; College of Pharmacy, Rady Faculty of Health Sciences, University of Manitoba, Canada
| | - Jijin Gu
- College of Pharmacy, Rady Faculty of Health Sciences, University of Manitoba, Canada
| | - Angela Harris
- Department of Medical Microbiology & Infectious Diseases, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Canada; National HIV and Retrovirology Laboratory, JC Wilt Infectious Disease Research Centre, Public Health Agency of Canada, Canada
| | - Ruey-Chyi Su
- Department of Medical Microbiology & Infectious Diseases, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Canada; National HIV and Retrovirology Laboratory, JC Wilt Infectious Disease Research Centre, Public Health Agency of Canada, Canada
| | - Emmanuel A Ho
- Laboratory for Drug Delivery and Biomaterials, School of Pharmacy, Faculty of Science, University of Waterloo, Canada; Waterloo Institute for Nanotechnology, University of Waterloo, Canada.
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4
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Iwamoto Y, Ye AA, Shirazinejad C, Hurley JH, Drubin DG. Kinetic investigation reveals an HIV-1 Nef-dependent increase in AP-2 recruitment and productivity at endocytic sites. Mol Biol Cell 2024; 35:ar9. [PMID: 37938925 PMCID: PMC10881171 DOI: 10.1091/mbc.e23-04-0126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 10/24/2023] [Accepted: 11/02/2023] [Indexed: 11/10/2023] Open
Abstract
The HIV-1 accessory protein Nef hijacks clathrin adaptors to degrade or mislocalize host proteins involved in antiviral defenses. Here, using quantitative live-cell microscopy in genome-edited Jurkat cells, we investigate the impact of Nef on clathrin-mediated endocytosis (CME), a major pathway for membrane protein internalization in mammalian cells. Nef is recruited to CME sites on the plasma membrane, and this recruitment is associated with an increase in the recruitment and lifetime of the CME coat protein AP-2 and the late-arriving CME protein dynamin2. Furthermore, we find that CME sites that recruit Nef are more likely to recruit dynamin2 and transferrin, suggesting that Nef recruitment to CME sites promotes site maturation to ensure high efficiency in host protein downregulation. Implications of these observations for HIV-1 infection are discussed.
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Affiliation(s)
- Yuichiro Iwamoto
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720
| | - Anna A. Ye
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720
| | - Cyna Shirazinejad
- Biophysics Graduate Group, University of California, Berkeley, Berkeley, CA 94720
| | - James H. Hurley
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720
- California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, CA 94720
- Biophysics Graduate Group, University of California, Berkeley, Berkeley, CA 94720
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA 94720
| | - David G. Drubin
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720
- California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, CA 94720
- Biophysics Graduate Group, University of California, Berkeley, Berkeley, CA 94720
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5
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Lamers SL, Fogel GB, Liu ES, Nolan DJ, Rose R, McGrath MS. HIV-1 subtypes maintain distinctive physicochemical signatures in Nef domains associated with immunoregulation. INFECTION, GENETICS AND EVOLUTION : JOURNAL OF MOLECULAR EPIDEMIOLOGY AND EVOLUTIONARY GENETICS IN INFECTIOUS DISEASES 2023; 115:105514. [PMID: 37832752 PMCID: PMC10842591 DOI: 10.1016/j.meegid.2023.105514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 10/09/2023] [Accepted: 10/10/2023] [Indexed: 10/15/2023]
Abstract
BACKGROUND HIV subtype is associated with varied rates of disease progression. The HIV accessory protein, Nef, continues to be present during antiretroviral therapy (ART) where it has numerous immunoregulatory effects. In this study, we analyzed Nef sequences from HIV subtypes A1, B, C, and D using a machine learning approach that integrates functional amino acid information to identify if unique physicochemical features are associated with Nef functional/structural domains in a subtype-specific manner. METHODS 2253 sequences representing subtypes A1, B, C, and D were aligned and domains with known functional properties were scored based on amino acid physicochemical properties. Following feature generation, we used statistical pruning and evolved neural networks (ENNs) to determine if we could successfully classify subtypes. Next, we used ENNs to identify the top five key Nef physicochemical features applied to specific immunoregulatory domains that differentiated subtypes. A signature pattern analysis was performed to the assess amino acid diversity in sub-domains that differentiated each subtype. RESULTS In validation studies, ENNs successfully differentiated each subtype at A1 (87.2%), subtype B (89.5%), subtype C (91.7%), and subtype D (85.1%). Our feature-based domain scoring, followed by t-tests, and a similar ENN identified subtype-specific domain-associated features. Subtype A1 was associated with alterations in Nef CD4 binding domain; subtype B was associated with alterations with the AP-2 Binding domain; subtype C was associated with alterations in a structural Alpha Helix domain; and, subtype D was associated with alterations in a Beta-Sheet domain. CONCLUSIONS Recent studies have focused on HIV Nef as a driver of immunoregulatory disease in those HIV infected and on ART. Nef acts through a complex mixture of interactions that are directly linked to the key features of the subtype-specific domains we identified with the ENN. The study supports the hypothesis that varied Nef subtypes contribute to subtype-specific disease progression.
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Affiliation(s)
| | | | - Enoch S Liu
- Natural Selection, San Diego, California, USA
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6
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Emert-Sedlak LA, Tice CM, Shi H, Alvarado JJ, Shu ST, Reitz AB, Smithgall TE. PROTAC-mediated Degradation of HIV-1 Nef Efficiently Restores Cell-surface CD4 and MHC-I Expression and Blocks HIV-1 Replication. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.14.553289. [PMID: 37645900 PMCID: PMC10462000 DOI: 10.1101/2023.08.14.553289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
The HIV-1 Nef accessory factor is critical to the viral life cycle in vivo where it promotes immune escape of HIV-infected cells and viral persistence. While these features identify Nef as an attractive antiretroviral drug target, Nef lacks enzymatic activity and an active site, complicating development of occupancy-based drugs. Here we describe the development of proteolysis targeting chimeras (PROTACs) for the targeted degradation of Nef. Nef-binding compounds, based on a previously reported hydroxypyrazole core, were coupled to ligands for ubiquitin E3 ligases via flexible linkers. The resulting bivalent PROTACs induced formation of a ternary complex between Nef and the Cereblon E3 ubiquitin ligase, resulting in ubiquitylation of Nef and proteolytic degradation. Nef-directed PROTACs efficiently rescued Nef-mediated MHC-I and CD4 downregulation in T cells and suppressed HIV-1 replication in donor PBMCs. Targeted degradation of Nef is anticipated to reverse all HIV-1 Nef functions and may help restore adaptive immune responses against HIV-1 reservoir cells in vivo .
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7
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Heinrich F, Thomas CE, Alvarado JJ, Eells R, Thomas A, Doucet M, Whitlatch KN, Aryal M, Lösche M, Smithgall TE. Neutron Reflectometry and Molecular Simulations Demonstrate HIV-1 Nef Homodimer Formation on Model Lipid Bilayers. J Mol Biol 2023; 435:168009. [PMID: 36773691 PMCID: PMC10079580 DOI: 10.1016/j.jmb.2023.168009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 01/16/2023] [Accepted: 02/03/2023] [Indexed: 02/12/2023]
Abstract
The HIV-1 Nef protein plays a critical role in viral infectivity, high-titer replication in vivo, and immune escape of HIV-infected cells. Nef lacks intrinsic biochemical activity, functioning instead through interactions with diverse host cell signaling proteins and intracellular trafficking pathways. Previous studies have established an essential role for Nef homodimer formation at the plasma membrane for most if not all its functions. Here we combined neutron reflectometry of full-length myristoylated Nef bound to model lipid bilayers with molecular simulations based on previous X-ray crystal structures of Nef homodimers. This integrated approach provides direct evidence that Nef associates with the membrane as a homodimer with its structured core region displaced from the membrane for partner protein engagement. Parallel studies of a dimerization-defective mutant, Nef-L112D, demonstrate that the helical dimerization interface present in previous crystal structures stabilizes the membrane-bound dimer. X-ray crystallography of the Nef-L112D mutant in complex with the SH3 domain of the Nef-associated host cell kinase Hck revealed a monomeric 1:1 complex instead of the 2:2 dimer complex formed with wild-type Nef. Importantly, the crystal structure of the Nef-L112D core and SH3 interface are virtually identical to the wild-type complex, indicating that this mutation does not affect the overall Nef fold. These findings support the intrinsic capacity of Nef to homodimerize at lipid bilayers using structural features present in X-ray crystal structures of dimeric complexes.
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Affiliation(s)
- Frank Heinrich
- Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213, USA; NIST Center for Neutron Research, Gaithersburg, MD 20899, USA
| | - Catherine E Thomas
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - John J Alvarado
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Rebecca Eells
- Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Alyssa Thomas
- Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Mathieu Doucet
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Kindra N Whitlatch
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Manish Aryal
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Mathias Lösche
- Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213, USA; NIST Center for Neutron Research, Gaithersburg, MD 20899, USA
| | - Thomas E Smithgall
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA.
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8
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Ghaly M, Proulx J, Borgmann K, Park IW. Novel role of HIV-1 Nef in regulating the ubiquitination of cellular proteins. Front Cell Infect Microbiol 2023; 13:1106591. [PMID: 36968110 PMCID: PMC10031067 DOI: 10.3389/fcimb.2023.1106591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 01/16/2023] [Indexed: 03/10/2023] Open
Abstract
Our recent data established that HIV-1 Nef is pivotal in determining the fate of cellular proteins by modulating ubiquitination. However, it is unknown which proteins are ubiquitinated in the presence of Nef, a question critical for understanding the proliferation/restriction strategies of HIV-1 in infected cells. To identify cellular proteins ubiquitinated by Nef, we conducted a proteomic analysis of cellular proteins in the presence and absence of Nef. Proteomic analysis in HEK293T cells indicated that 93 proteins were upregulated and 232 were downregulated in their ubiquitination status by Nef. Computational analysis classified these proteins based on molecular function, biological process, subcellular localization, and biological pathway. Of those proteins, we found a majority of molecular functions to be involved in binding and catalytic activity. With respect to biological processes, a significant portion of the proteins identified were related to cellular and metabolic processes. Subcellular localization analysis showed the bulk of proteins to be localized to the cytosol and cytosolic compartments, which is consistent with the known function and location of Nef during HIV-1 infection. As for biological pathways, the wide range of affected proteins was denoted by the multiple modes to fulfill function, as distinguished from a strictly singular means, which was not detected. Among these ubiquitinated proteins, six were found to directly interact with Nef, wherein two were upregulated and four downregulated. We also identified 14 proteins involved in protein stability through directly participating in the Ubiquitin Proteasome System (UPS)-mediated proteasomal degradation pathway. Of those proteins, we found six upregulated and eight downregulated. Taken together, these analyses indicate that HIV-1 Nef is integral to regulating the stability of various cellular proteins via modulating ubiquitination. The molecular mechanisms directing Nef-triggered regulation of cellular protein ubiquitination are currently under investigation.
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9
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Olety B, Usami Y, Wu Y, Peters P, Göttlinger H. AP-2 Adaptor Complex-Dependent Enhancement of HIV-1 Replication by Nef in the Absence of the Nef/AP-2 Targets SERINC5 and CD4. mBio 2023; 14:e0338222. [PMID: 36622146 PMCID: PMC9973267 DOI: 10.1128/mbio.03382-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 12/08/2022] [Indexed: 01/10/2023] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) Nef hijacks the clathrin adaptor complex 2 (AP-2) to downregulate the viral receptor CD4 and the antiviral multipass transmembrane proteins SERINC3 and SERINC5, which inhibit the infectivity of progeny virions when incorporated. In Jurkat Tag T lymphoid cells lacking SERINC3 and SERINC5, Nef is no longer required for full progeny virus infectivity and for efficient viral replication. However, in MOLT-3 T lymphoid cells, HIV-1 replication remains highly dependent on Nef even in the absence of SERINC3 and SERINC5. Using a knockout (KO) approach, we now show that the Nef-mediated enhancement of HIV-1 replication in MOLT-3 cells does not depend on the Nef-interacting kinases LCK and PAK2. Furthermore, Nef substantially enhanced HIV-1 replication even in triple-KO MOLT-3 cells that simultaneously lacked the three Nef/AP-2 targets, SERINC3, SERINC5, and CD4, and were reconstituted with a Nef-resistant CD4 to permit HIV-1 entry. Nevertheless, the ability of Nef mutants to promote HIV-1 replication in the triple-KO cells correlated strictly with the ability to bind AP-2. In addition, knockdown and reconstitution experiments confirmed the involvement of AP-2. These observations raise the possibility that MOLT-3 cells express a novel antiviral factor that is downregulated by Nef in an AP-2-dependent manner. IMPORTANCE The HIV-1 Nef protein hijacks a component of the cellular endocytic machinery called AP-2 to downregulate the viral receptor CD4 and the antiviral cellular membrane proteins SERINC3 and SERINC5. In the absence of Nef, SERINC3 and SERINC5 are taken up into viral particles, which reduces their infectivity. Surprisingly, in a T cell line called MOLT-3, Nef remains crucial for HIV-1 spreading in the absence of SERINC3 and SERINC5. We now show that this effect of Nef also does not depend on the cellular signaling molecules and Nef interaction partners LCK and PAK2. Nef was required for efficient HIV-1 spreading even in triple-knockout cells that completely lacked Nef/AP-2-sensitive CD4, in addition to the Nef/AP-2 targets SERINC3 and SERINC5. Nevertheless, our results indicate that the enhancement of HIV-1 spreading by Nef in the triple-knockout cells remained AP-2 dependent, which suggests the presence of an unknown antiviral factor that is sensitive to Nef/AP-2-mediated downregulation.
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Affiliation(s)
- Balaji Olety
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA
| | - Yoshiko Usami
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA
| | - Yuanfei Wu
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA
| | - Paul Peters
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA
| | - Heinrich Göttlinger
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA
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10
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Firrito C, Bertelli C, Rosa A, Chande A, Ananth S, van Dijk H, Fackler OT, Stoneham C, Singh R, Guatelli J, Pizzato M. A Conserved Acidic Residue in the C-Terminal Flexible Loop of HIV-1 Nef Contributes to the Activity of SERINC5 and CD4 Downregulation. Viruses 2023; 15:652. [PMID: 36992361 PMCID: PMC10057511 DOI: 10.3390/v15030652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 02/22/2023] [Accepted: 02/27/2023] [Indexed: 03/05/2023] Open
Abstract
The host transmembrane protein SERINC5 is incorporated into retrovirus particles and inhibits HIV-1 infectivity. The lentiviral Nef protein counteracts SERINC5 by downregulating it from the cell surface and preventing its incorporation into virions. The ability of Nef to antagonize the host factor varies in magnitude between different HIV-1 isolates. After having identified a subtype H nef allele unable to promote HIV-1 infectivity in the presence of SERINC5, we investigated the molecular determinants responsible for the defective counteraction of the host factor. Chimeric molecules with a subtype C Nef highly active against SERINC5 were constructed to locate Nef residues crucial for the activity against SERINC5. An Asn at the base of the C-terminal loop of the defective nef allele was found in place of a highly conserved acidic residue (D/E 150). The conversion of Asn to Asp restored the ability of the defective Nef to downregulate SERINC5 and promote HIV-1 infectivity. The substitution was also found to be crucial for the ability of Nef to downregulate CD4, but not for Nef activities that do not rely on the internalization of receptors from the cell surface, suggesting a general implication in promoting clathrin-mediated endocytosis. Accordingly, bimolecular fluorescence complementation revealed that the conserved acidic residue contributes to the recruitment of AP2 by Nef. Altogether, our results confirm that Nef downregulates SERINC5 and CD4 by engaging a similar machinery and indicates that, in addition to the di-leucine motif, other residues in the C-terminal flexible loop are important for the ability of the protein to sustain clathrin-mediated endocytosis.
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Affiliation(s)
- Claudia Firrito
- Department of Cellular, Computational and integrative Biology, University of Trento, 38123 Trento, Italy
| | - Cinzia Bertelli
- Department of Cellular, Computational and integrative Biology, University of Trento, 38123 Trento, Italy
| | - Annachiara Rosa
- Department of Cellular, Computational and integrative Biology, University of Trento, 38123 Trento, Italy
| | - Ajit Chande
- Department of Cellular, Computational and integrative Biology, University of Trento, 38123 Trento, Italy
| | - Swetha Ananth
- Department of Infectious Diseases, Integrative Virology, University Hospital Heidelberg, 69120 Heidelberg, Germany
| | - Hannah van Dijk
- Department of Infectious Diseases, Integrative Virology, University Hospital Heidelberg, 69120 Heidelberg, Germany
| | - Oliver T. Fackler
- Department of Infectious Diseases, Integrative Virology, University Hospital Heidelberg, 69120 Heidelberg, Germany
- German Center for Infection Research (DZIF), 69120 Heidelberg, Germany
| | - Charlotte Stoneham
- Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA
- VA San Diego Healthcare System, San Diego, CA 92161, USA
| | - Rajendra Singh
- Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA
- VA San Diego Healthcare System, San Diego, CA 92161, USA
| | - John Guatelli
- Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA
- VA San Diego Healthcare System, San Diego, CA 92161, USA
| | - Massimo Pizzato
- Department of Cellular, Computational and integrative Biology, University of Trento, 38123 Trento, Italy
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11
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Chakravarty A, Yang PL. Targeted protein degradation as an antiviral approach. Antiviral Res 2023; 210:105480. [PMID: 36567024 PMCID: PMC10178900 DOI: 10.1016/j.antiviral.2022.105480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 12/01/2022] [Indexed: 12/24/2022]
Abstract
Targeted protein degradation (TPD) has emerged as a new modality in drug discovery. In this approach, small molecules are used to drive degradation of the target protein of interest. Whereas most direct-acting antivirals (DAAs) inhibit or derange the activity of their viral protein targets and have occupancy-driven pharmacology, small molecules with a TPD-based mechanism have event-driven pharmacology exerted through their ability to induce target degradation. These contrasting mechanisms can result in significant differences in drug efficacy and pharmacodynamics that may be useful in the development of new classes of antivirals. While now being widely pursued in cancer biology and autoimmune disease, TPD has not yet been widely applied as an antiviral strategy. Here, we briefly review TPD pharmacology along with the current status of tools available for developing small molecules that achieve antiviral activity through a TPD mechanism. We also highlight aspects of TPD that may be especially useful in the development of antivirals and that we hope will motivate pursuit of TPD-based antivirals by the antivirals research community.
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Affiliation(s)
- Antara Chakravarty
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Priscilla L Yang
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA, 94305, USA.
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12
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Ramirez PW, Vollbrecht T, Acosta FM, Suarez M, Angerstein AO, Wallace J, O' Connell RM, Guatelli J. Nef enhances HIV-1 replication and infectivity independently of SERINC5 in CEM T cells. Virology 2023; 578:154-162. [PMID: 36577173 PMCID: PMC10484624 DOI: 10.1016/j.virol.2022.12.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 12/14/2022] [Accepted: 12/15/2022] [Indexed: 12/25/2022]
Abstract
A primary function of HIV-1 Nef is the enhancement of viral infectivity and replication. Whether counteraction of the antiretroviral proteins SERINC3 and SERINC5 is the cause of this positive influence on viral growth-rate and infectivity remains unclear. Here, we utilized CRISPR/Cas9 to knockout SERINC3 and SERINC5 in a leukemic CD4-positive T cell line (CEM) that displays nef-related infectivity and growth-rate phenotypes. Viral replication was attenuated in CEM cells infected with HIV-1 lacking Nef (HIV-1ΔNef). This attenuated growth-rate phenotype was observed regardless of whether the coding regions of the serinc3 or serinc5 genes were intact. Moreover, knockout of serinc5 alone or of both serinc5 and serinc3 together failed to restore the infectivity of HIV1ΔNef virions produced from infected CEM cells. Our results corroborate a similar study using another T-lymphoid cell line (MOLT-3) and indicate that the antagonism of SERINC3 and SERINC5 does not fully explain the virology of HIV-1 lacking Nef.
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Affiliation(s)
- Peter W Ramirez
- Department of Biological Sciences, California State University Long Beach, Long Beach, CA, USA.
| | - Thomas Vollbrecht
- Department of Medicine, University of California San Diego, La Jolla, CA, USA; VA San Diego Healthcare System, San Diego, CA, USA
| | - Francisco M Acosta
- Department of Biological Sciences, California State University Long Beach, Long Beach, CA, USA
| | | | - Aaron O Angerstein
- Department of Medicine, University of California San Diego, La Jolla, CA, USA; VA San Diego Healthcare System, San Diego, CA, USA
| | - Jared Wallace
- Division of Microbiology and Immunology, Department of Pathology, The University of Utah, Salt Lake City, UT, USA
| | - Ryan M O' Connell
- Division of Microbiology and Immunology, Department of Pathology, The University of Utah, Salt Lake City, UT, USA
| | - John Guatelli
- Department of Medicine, University of California San Diego, La Jolla, CA, USA; VA San Diego Healthcare System, San Diego, CA, USA
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13
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Kandel SR, Luo X, He JJ. Nef inhibits HIV transcription and gene expression in astrocytes and HIV transmission from astrocytes to CD4 + T cells. J Neurovirol 2022; 28:552-565. [PMID: 36001227 DOI: 10.1007/s13365-022-01091-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 07/07/2022] [Accepted: 07/27/2022] [Indexed: 01/13/2023]
Abstract
HIV infects astrocytes in a restricted manner but leads to abundant expression of Nef, a major viral factor for HIV replication and disease progression. However, the roles of Nef in HIV gene expression and replication in astrocytes and viral transfer from astrocytes to CD4+ T cells remain largely unclear. In this study, we attempted to address these issues by transfecting human primary astrocytes with HIV molecular clones with intact Nef and without Nef (a nonsense Nef mutant) and comparing gene expression and replication in astrocytes and viral transfer from astrocytes to CD4+ T cells MT4. First, we found that lack of Nef expression led to increased extracellular virus production from astrocytes and intracellular viral protein and RNA expression in astrocytes. Using a HIV LTR-driven luciferase reporter gene assay, we showed that ectopic Nef expression alone inhibited the HIV LTR promoter activity in astrocytes. Consistent with the previously established function of Nef, we showed that the infectivity of HIV derived from astrocytes with Nef expression was significantly higher than that with no Nef expression. Next, we performed the co-culture assay to determine HIV transfer from astrocytes transfected to MT4. We showed that lack of Nef expression led to significant increase in HIV transfer from astrocytes to MT4 using two HIV clones. We also used Nef-null HIV complemented with Nef in trans in the co-culture assay and demonstrated that Nef expression led to significantly decreased HIV transfer from astrocytes to MT4. Taken together, these findings support a negative role of Nef in HIV replication and pathogenesis in astrocytes.
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Affiliation(s)
- Suresh R Kandel
- Department of Microbiology and Immunology, Chicago Medical School, Rosalind Franklin University, North Chicago, IL, 60064, USA.,Center for Cancer Cell Biology, Immunology and Infection, Rosalind Franklin University, North Chicago, IL, 60064, USA.,School of Graduate and Postdoctoral Studies, Rosalind Franklin University, 3333 Green Bay Road, North Chicago, IL, 60064, USA
| | - Xiaoyu Luo
- Gladstone Institute of Virology, University of California at San Francisco, San Francisco, CA, 94158, USA
| | - Johnny J He
- Department of Microbiology and Immunology, Chicago Medical School, Rosalind Franklin University, North Chicago, IL, 60064, USA. .,Center for Cancer Cell Biology, Immunology and Infection, Rosalind Franklin University, North Chicago, IL, 60064, USA. .,School of Graduate and Postdoctoral Studies, Rosalind Franklin University, 3333 Green Bay Road, North Chicago, IL, 60064, USA.
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14
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Extracellular vesicles carrying HIV-1 Nef induce long-term hyperreactivity of myeloid cells. Cell Rep 2022; 41:111674. [DOI: 10.1016/j.celrep.2022.111674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 08/31/2022] [Accepted: 10/25/2022] [Indexed: 11/23/2022] Open
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15
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Aryal M, Lin D, Regan K, Du S, Shi H, Alvarado JJ, Ilina TV, Andreotti AH, Smithgall TE. The HIV-1 protein Nef activates the Tec family kinase Btk by stabilizing an intermolecular SH3-SH2 domain interaction. Sci Signal 2022; 15:eabn8359. [PMID: 36126115 PMCID: PMC9830684 DOI: 10.1126/scisignal.abn8359] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The Nef protein produced by the viruses HIV-1 and SIV drives efficient viral replication partially by inducing constitutive activation of host cell tyrosine kinases, including members of the Src and Tec families. Here, we uncovered the mechanism by which both HIV-1 and SIV Nef enhanced the activity of the Tec family kinase Btk in vitro and in cells. A Nef mutant that could not bind to the SH3 domain of Src family kinases activated Btk to the same extent as did wild-type Nef, demonstrating that Nef activated Src and Tec family kinases by distinct mechanisms. The Btk SH3-SH2 region formed a homodimer requiring the CD loop in the SH2 domain, which was stabilized by the binding of Nef homodimers. Alanine substitution of Pro327 in the CD loop of the Btk SH2 domain destabilized SH3-SH2 dimers, abolished the interaction with Nef, and prevented activation by Nef in vitro. In cells, Nef stabilized and activated wild-type but not P327A Btk homodimers at the plasma membrane. These data reveal that the interaction with Nef stabilizes Btk dimers through the SH3-SH2 interface to promote kinase activity and show that the HIV-1 Nef protein evolved distinct mechanisms to activate Src and Tec family tyrosine kinases to enhance viral replication.
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Affiliation(s)
- Manish Aryal
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh PA, 15219 USA
| | - David Lin
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, 50011 USA
| | - Kiera Regan
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh PA, 15219 USA
| | - Shoucheng Du
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh PA, 15219 USA
| | - Haibin Shi
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh PA, 15219 USA
| | - John J. Alvarado
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh PA, 15219 USA
| | - Tatiana V. Ilina
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh PA, 15260 USA
| | - Amy H. Andreotti
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, 50011 USA
| | - Thomas E. Smithgall
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh PA, 15219 USA,To whom correspondence should be addressed: Thomas E. Smithgall, Ph.D., Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Bridgeside Point II, Suite 523, 450 Technology Drive, Pittsburgh, PA 15219, Tel. 412-648-8106, Fax 412-624-8997,
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16
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Emert-Sedlak LA, Shi H, Tice CM, Chen L, Alvarado JJ, Shu ST, Du S, Thomas CE, Wrobel JE, Reitz AB, Smithgall TE. Antiretroviral Drug Discovery Targeting the HIV-1 Nef Virulence Factor. Viruses 2022; 14:v14092025. [PMID: 36146831 PMCID: PMC9503669 DOI: 10.3390/v14092025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 09/06/2022] [Accepted: 09/08/2022] [Indexed: 11/16/2022] Open
Abstract
While antiretroviral drugs have transformed the lives of HIV-infected individuals, chronic treatment is required to prevent rebound from viral reservoir cells. People living with HIV also are at higher risk for cardiovascular and neurocognitive complications, as well as cancer. Finding a cure for HIV-1 infection is therefore an essential goal of current AIDS research. This review is focused on the discovery of pharmacological inhibitors of the HIV-1 Nef accessory protein. Nef is well known to enhance HIV-1 infectivity and replication, and to promote immune escape of HIV-infected cells by preventing cell surface MHC-I display of HIV-1 antigens. Recent progress shows that Nef inhibitors not only suppress HIV-1 replication, but also restore sufficient MHC-I to the surface of infected cells to trigger a cytotoxic T lymphocyte response. Combining Nef inhibitors with latency reversal agents and therapeutic vaccines may provide a path to clearance of viral reservoirs.
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Affiliation(s)
- Lori A. Emert-Sedlak
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Haibin Shi
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Colin M. Tice
- Fox Chase Chemical Diversity Center, Inc., Pennsylvania Biotechnology Center, Doylestown, PA 18902, USA
| | - Li Chen
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - John J. Alvarado
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Sherry T. Shu
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Shoucheng Du
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Catherine E. Thomas
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Jay E. Wrobel
- Fox Chase Chemical Diversity Center, Inc., Pennsylvania Biotechnology Center, Doylestown, PA 18902, USA
| | - Allen B. Reitz
- Fox Chase Chemical Diversity Center, Inc., Pennsylvania Biotechnology Center, Doylestown, PA 18902, USA
| | - Thomas E. Smithgall
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
- Correspondence:
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Abstract
PURPOSE OF REVIEW The quest for HIV-1 cure could take advantage of the study of rare individuals that control viral replication spontaneously (elite controllers) or after an initial course of antiretroviral therapy (posttreatment controllers, PTCs). In this review, we will compare back-to-back the immunological and virological features underlying viral suppression in elite controllers and PTCs, and explore their possible contributions to the HIV-1 cure research. RECENT FINDINGS HIV-1 control in elite controllers shows hallmarks of an effective antiviral response, favored by genetic background and possibly associated to residual immune activation. The immune pressure in elite controllers might select against actively transcribing intact proviruses, allowing the persistence of a small and poorly inducible reservoir. Evidence on PTCs is less abundant but preliminary data suggest that antiviral immune responses may be less pronounced. Therefore, these patients may rely on distinct mechanisms, not completely elucidated to date, suppressing HIV-1 transcription and replication. SUMMARY PTCs and elite controllers may control HIV replication using distinct pathways, the elucidation of which may contribute to design future interventional strategies aiming to achieve a functional cure.
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18
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Sviridov D, Miller YI, Bukrinsky MI. Trained Immunity and HIV Infection. Front Immunol 2022; 13:903884. [PMID: 35874772 PMCID: PMC9304701 DOI: 10.3389/fimmu.2022.903884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 06/20/2022] [Indexed: 11/13/2022] Open
Abstract
Findings that certain infections induce immunity not only against the causing agent, but also against an unrelated pathogen have intrigued investigators for many years. Recently, underlying mechanisms of this phenomenon have started to come to light. It was found that the key cells responsible for heterologous protection are innate immune cells such as natural killer cells (NKs), dendritic cells, and monocytes/macrophages. These cells are 'primed' by initial infection, allowing them to provide enhanced response to subsequent infection by the same or unrelated agent. This phenomenon of innate immune memory was termed 'trained immunity'. The proposed mechanism for trained immunity involves activation by the first stimulus of metabolic pathways that lead to epigenetic changes, which maintain the cell in a "trained" state, allowing enhanced responses to a subsequent stimulus. Innate immune memory can lead either to enhanced responses or to suppression of subsequent responses ('tolerance'), depending on the strength and length of the initial stimulation of the immune cells. In the context of HIV infection, innate memory induced by infection is not well understood. In this Hypothesis and Theory article, we discuss evidence for HIV-induced trained immunity in human monocytes, its possible mechanisms, and implications for HIV-associated co-morbidities.
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Affiliation(s)
- Dmitri Sviridov
- Laboratory of Lipoproteins and Atherosclerosis, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC, Australia
| | - Yury I. Miller
- Department of Medicine, University of California, San Diego, San Diego, CA, United States
| | - Michael I. Bukrinsky
- Department of Microbiology, Immunology and Tropical Medicine, School of Medicine and Health Sciences, The George Washington University, Washington, DC, United States
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De La Torre-Tarazona E, Ayala-Suárez R, Díez-Fuertes F, Alcamí J. Omic Technologies in HIV: Searching Transcriptional Signatures Involved in Long-Term Non-Progressor and HIV Controller Phenotypes. Front Immunol 2022; 13:926499. [PMID: 35844607 PMCID: PMC9284212 DOI: 10.3389/fimmu.2022.926499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 05/31/2022] [Indexed: 11/13/2022] Open
Abstract
This article reviews the main discoveries achieved by transcriptomic approaches on HIV controller (HIC) and long-term non-progressor (LTNP) individuals, who are able to suppress HIV replication and maintain high CD4+ T cell levels, respectively, in the absence of antiretroviral therapy. Different studies using high throughput techniques have elucidated multifactorial causes implied in natural control of HIV infection. Genes related to IFN response, calcium metabolism, ribosome biogenesis, among others, are commonly differentially expressed in LTNP/HIC individuals. Additionally, pathways related with activation, survival, proliferation, apoptosis and inflammation, can be deregulated in these individuals. Likewise, recent transcriptomic studies include high-throughput sequencing in specific immune cell subpopulations, finding additional gene expression patterns associated to viral control and/or non-progression in immune cell subsets. Herein, we provide an overview of the main differentially expressed genes and biological routes commonly observed on immune cells involved in HIV infection from HIC and LTNP individuals, analyzing also different technical aspects that could affect the data analysis and the future perspectives and gaps to be addressed in this field.
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Affiliation(s)
- Erick De La Torre-Tarazona
- Acquired Immunodeficiency Syndrome (AIDS) Immunopathology Unit, National Center for Microbiology, Institute of Health Carlos III, Majadahonda, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Infecciosas, Instituto de Salud Carlos III (ISCIII), Madrid, Spain
| | - Rubén Ayala-Suárez
- Acquired Immunodeficiency Syndrome (AIDS) Immunopathology Unit, National Center for Microbiology, Institute of Health Carlos III, Majadahonda, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Infecciosas, Instituto de Salud Carlos III (ISCIII), Madrid, Spain
- Departamento de Biomedicina y Biotecnología, Universidad de Alcalá, Alcalá de Henares, Spain
| | - Francisco Díez-Fuertes
- Acquired Immunodeficiency Syndrome (AIDS) Immunopathology Unit, National Center for Microbiology, Institute of Health Carlos III, Majadahonda, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Infecciosas, Instituto de Salud Carlos III (ISCIII), Madrid, Spain
- *Correspondence: Francisco Díez-Fuertes,
| | - José Alcamí
- Acquired Immunodeficiency Syndrome (AIDS) Immunopathology Unit, National Center for Microbiology, Institute of Health Carlos III, Majadahonda, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Infecciosas, Instituto de Salud Carlos III (ISCIII), Madrid, Spain
- Human Immunodeficiency Virus (HIV) Unit, Hospital Clínic de Barcelona, Barcelona, Spain
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20
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Cho YK, Kim JE, Lee J. Impact of HIV-1 subtypes on gross deletion in the nef gene after Korean Red Ginseng treatment. J Ginseng Res 2022; 46:731-737. [PMID: 36312730 PMCID: PMC9597433 DOI: 10.1016/j.jgr.2022.02.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 02/16/2022] [Accepted: 02/22/2022] [Indexed: 11/29/2022] Open
Abstract
Background Methods Results Conclusion
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21
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Lian X, Gao C, Sun X, Jiang C, Einkauf KB, Seiger KW, Chevalier JM, Yuki Y, Martin M, Hoh R, Peluso MJ, Carrington M, Ruiz-Mateos E, Deeks SG, Rosenberg ES, Walker BD, Lichterfeld M, Yu XG. Signatures of immune selection in intact and defective proviruses distinguish HIV-1 elite controllers. Sci Transl Med 2021; 13:eabl4097. [PMID: 34910552 PMCID: PMC9202005 DOI: 10.1126/scitranslmed.abl4097] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Increasing evidence suggests that durable drug-free control of HIV-1 replication is enabled by effective cellular immune responses that may induce an attenuated viral reservoir configuration with a weaker ability to drive viral rebound. Here, we comprehensively tracked effects of antiviral immune responses on intact and defective proviral sequences from elite controllers (ECs), analyzing both classical escape mutations and HIV-1 chromosomal integration sites as biomarkers of antiviral immune selection pressure. We observed that, within ECs, defective proviruses were commonly located in permissive genic euchromatin positions, which represented an apparent contrast to autologous intact proviruses that were frequently located in heterochromatin regions; this suggests differential immune selection pressure on intact versus defective proviruses in ECs. In comparison to individuals receiving antiretroviral therapy, intact and defective proviruses from ECs showed reduced frequencies of escape mutations in cytotoxic T cell epitopes and antibody contact regions, possibly due to the small and poorly inducible reservoir that may be insufficient to drive effective viral escape in ECs. About 15% of ECs harbored nef deletions in intact proviruses, consistent with increased viral vulnerability to host immunity in the setting of nef dysfunction. Together, these results suggest a distinct signature of immune footprints in proviral sequences from ECs.
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Affiliation(s)
- Xiaodong Lian
- Ragon Institute of MGH, MIT and Harvard, Cambridge, MA 02139, USA
- Infectious Disease Division, Brigham and Women’s Hospital, Boston, MA 02115, USA
| | - Ce Gao
- Ragon Institute of MGH, MIT and Harvard, Cambridge, MA 02139, USA
- Infectious Disease Division, Brigham and Women’s Hospital, Boston, MA 02115, USA
| | - Xiaoming Sun
- Ragon Institute of MGH, MIT and Harvard, Cambridge, MA 02139, USA
| | - Chenyang Jiang
- Ragon Institute of MGH, MIT and Harvard, Cambridge, MA 02139, USA
- Infectious Disease Division, Brigham and Women’s Hospital, Boston, MA 02115, USA
| | - Kevin B. Einkauf
- Ragon Institute of MGH, MIT and Harvard, Cambridge, MA 02139, USA
- Infectious Disease Division, Brigham and Women’s Hospital, Boston, MA 02115, USA
| | - Kyra W. Seiger
- Ragon Institute of MGH, MIT and Harvard, Cambridge, MA 02139, USA
- Infectious Disease Division, Brigham and Women’s Hospital, Boston, MA 02115, USA
| | - Joshua M. Chevalier
- Ragon Institute of MGH, MIT and Harvard, Cambridge, MA 02139, USA
- Infectious Disease Division, Brigham and Women’s Hospital, Boston, MA 02115, USA
| | - Yuko Yuki
- Basic Science Program, Frederick National Laboratory for Cancer Research, National Cancer Institute, Frederick, MD and Laboratory of Integrative Cancer Immunology, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Maureen Martin
- Basic Science Program, Frederick National Laboratory for Cancer Research, National Cancer Institute, Frederick, MD and Laboratory of Integrative Cancer Immunology, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Rebecca Hoh
- University of California at San Francisco, San Francisco, CA 94143, USA
| | - Michael J. Peluso
- University of California at San Francisco, San Francisco, CA 94143, USA
| | - Mary Carrington
- Ragon Institute of MGH, MIT and Harvard, Cambridge, MA 02139, USA
- Basic Science Program, Frederick National Laboratory for Cancer Research, National Cancer Institute, Frederick, MD and Laboratory of Integrative Cancer Immunology, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Ezequiel Ruiz-Mateos
- Clinical Unit of Infectious Diseases, Microbiology and Preventive Medicine, Institute of Biomedicine of Seville (IBiS), Virgen del Rocío University Hospital, CSIC, University of Seville, Seville 41013, Spain
| | - Steven G. Deeks
- University of California at San Francisco, San Francisco, CA 94143, USA
| | - Eric S. Rosenberg
- Infectious Disease Division, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Bruce D. Walker
- Ragon Institute of MGH, MIT and Harvard, Cambridge, MA 02139, USA
- Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
- Institute for Medical Engineering and Sciences and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Mathias Lichterfeld
- Ragon Institute of MGH, MIT and Harvard, Cambridge, MA 02139, USA
- Infectious Disease Division, Brigham and Women’s Hospital, Boston, MA 02115, USA
| | - Xu G. Yu
- Ragon Institute of MGH, MIT and Harvard, Cambridge, MA 02139, USA
- Infectious Disease Division, Brigham and Women’s Hospital, Boston, MA 02115, USA
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22
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Hodge AL, Baxter AA, Poon IKH. Gift bags from the sentinel cells of the immune system: The diverse role of dendritic cell-derived extracellular vesicles. J Leukoc Biol 2021; 111:903-920. [PMID: 34699107 DOI: 10.1002/jlb.3ru1220-801r] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Dendritic cells (DCs) are professional APCs of the immune system that continuously sample their environment and function to stimulate an adaptive immune response by initiating Ag-specific immunity or tolerance. Extracellular vesicles (EVs), small membrane-bound structures, are released from DCs and have been discovered to harbor functional peptide-MHC complexes, T cell costimulatory molecules, and other molecules essential for Ag presentation, immune cell regulation, and stimulating immune responses. As such, DC-derived EVs are being explored as potential immunotherapeutic agents. DC-derived EVs have also been implicated to function as a trafficking mechanism of infectious particles aiding viral propagation. This review will explore the unique features that enable DC-derived EVs to regulate immune responses and interact with recipient cells, their roles within Ag-presentation and disease settings, as well as speculating on a potential immunological role of apoptotic DC-derived EVs.
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Affiliation(s)
- Amy L Hodge
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria, Australia
| | - Amy A Baxter
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria, Australia
| | - Ivan K H Poon
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria, Australia
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23
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Heidarzadeh M, Gürsoy-Özdemir Y, Kaya M, Eslami Abriz A, Zarebkohan A, Rahbarghazi R, Sokullu E. Exosomal delivery of therapeutic modulators through the blood-brain barrier; promise and pitfalls. Cell Biosci 2021; 11:142. [PMID: 34294165 PMCID: PMC8296716 DOI: 10.1186/s13578-021-00650-0] [Citation(s) in RCA: 64] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Accepted: 07/05/2021] [Indexed: 12/16/2022] Open
Abstract
Nowadays, a large population around the world, especially the elderly, suffers from neurological inflammatory and degenerative disorders/diseases. Current drug delivery strategies are facing different challenges because of the presence of the BBB, which limits the transport of various substances and cells to brain parenchyma. Additionally, the low rate of successful cell transplantation to the brain injury sites leads to efforts to find alternative therapies. Stem cell byproducts such as exosomes are touted as natural nano-drug carriers with 50-100 nm in diameter. These nano-sized particles could harbor and transfer a plethora of therapeutic agents and biological cargos to the brain. These nanoparticles would offer a solution to maintain paracrine cell-to-cell communications under healthy and inflammatory conditions. The main question is that the existence of the intact BBB could limit exosomal trafficking. Does BBB possess some molecular mechanisms that facilitate the exosomal delivery compared to the circulating cell? Although preliminary studies have shown that exosomes could cross the BBB, the exact molecular mechanism(s) beyond this phenomenon remains unclear. In this review, we tried to compile some facts about exosome delivery through the BBB and propose some mechanisms that regulate exosomal cross in pathological and physiological conditions.
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Affiliation(s)
- Morteza Heidarzadeh
- Koç University Research Center for Translational Medicine (KUTTAM), Rumeli Feneri, 34450, Sariyer, Istanbul, Turkey
| | - Yasemin Gürsoy-Özdemir
- Koç University Research Center for Translational Medicine (KUTTAM), Rumeli Feneri, 34450, Sariyer, Istanbul, Turkey.,Neurology Department, Koç University School of Medicine, Rumeli Feneri, 34450, Sariyer, Istanbul, Turkey
| | - Mehmet Kaya
- Koç University Research Center for Translational Medicine (KUTTAM), Rumeli Feneri, 34450, Sariyer, Istanbul, Turkey.,Physiology Department, Koç University School of Medicine, Rumeli Feneri, 34450, Sariyer, Istanbul, Turkey
| | - Aysan Eslami Abriz
- Department of Medical Nanotechnology, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Amir Zarebkohan
- Department of Medical Nanotechnology, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Reza Rahbarghazi
- Stem Cell Research Center, Tabriz University of Medical Sciences, Tabriz, Iran. .,Department of Applied Cell Sciences, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran.
| | - Emel Sokullu
- Koç University Research Center for Translational Medicine (KUTTAM), Rumeli Feneri, 34450, Sariyer, Istanbul, Turkey. .,Biophysics Department, Koç University School of Medicine, Rumeli Feneri, 34450, Sariyer, Istanbul, Turkey.
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24
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Tavares LA, Januário YC, daSilva LLP. HIV-1 Hijacking of Host ATPases and GTPases That Control Protein Trafficking. Front Cell Dev Biol 2021; 9:622610. [PMID: 34307340 PMCID: PMC8295591 DOI: 10.3389/fcell.2021.622610] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 06/07/2021] [Indexed: 12/22/2022] Open
Abstract
The human immunodeficiency virus (HIV-1) modifies the host cell environment to ensure efficient and sustained viral replication. Key to these processes is the capacity of the virus to hijack ATPases, GTPases and the associated proteins that control intracellular protein trafficking. The functions of these energy-harnessing enzymes can be seized by HIV-1 to allow the intracellular transport of viral components within the host cell or to change the subcellular distribution of antiviral factors, leading to immune evasion. Here, we summarize how energy-related proteins deviate from their normal functions in host protein trafficking to aid the virus in different phases of its replicative cycle. Recent discoveries regarding the interplay among HIV-1 and host ATPases and GTPases may shed light on potential targets for pharmacological intervention.
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Affiliation(s)
- Lucas A Tavares
- Department of Cell and Molecular Biology, Center for Virology Research, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Yunan C Januário
- Department of Cell and Molecular Biology, Center for Virology Research, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Luis L P daSilva
- Department of Cell and Molecular Biology, Center for Virology Research, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
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25
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Shu ST, Li WF, Smithgall TE. Visualization of Host Cell Kinase Activation by Viral Proteins Using GFP Fluorescence Complementation and Immunofluorescence Microscopy. Bio Protoc 2021; 11:e4068. [PMID: 34327265 DOI: 10.21769/bioprotoc.4068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 03/29/2021] [Accepted: 04/01/2021] [Indexed: 11/02/2022] Open
Abstract
Non-receptor protein-tyrosine kinases regulate cellular responses to many external signals and are important drug discovery targets for cancer and infectious diseases. While many assays exist for the assessment of kinase activity in vitro, methods that report changes in tyrosine kinase activity in single cells have the potential to provide information about kinase responses at the cell population level. In this protocol, we combined bimolecular fluorescence complementation (BiFC), an established method for the assessment of protein-protein interactions, and immunofluorescence staining with phosphospecific antibodies to characterize changes in host cell tyrosine kinase activity in the presence of an HIV-1 virulence factor, Nef. Specifically, two Tec family kinases (Itk and Btk) as well as Nef were fused to complementary, non-fluorescent fragments of the Venus variant of YFP. Each kinase was expressed in 293T cells in the presence or absence of Nef and immunostained for protein expression and activity with anti-phosphotyrosine (pTyr) antibodies. Multi-color confocal microscopy revealed the interaction of Nef with each kinase (BiFC), kinase activity, and kinase protein expression. Strong BiFC signals were observed when Nef was co-expressed with both Itk and Btk, indicative of interaction, and a strong anti-pTyr immunoreactivity was also seen. The BiFC, pTyr, and kinase expression signals co-localized to the plasma membrane, consistent with Nef-mediated kinase activation in this subcellular compartment. Image analysis allowed calculation of pTyr-to-kinase protein ratios, which showed a range of responses in individual cells across the population that shifted upward in the presence of Nef and back down in the presence of a kinase inhibitor. This method has the potential to reveal changes in steady-state non-receptor tyrosine kinase activity and subcellular localization in a cell population in response to other protein-kinase interactions, information that is not attainable from immunoblotting or other in vitro methods.
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Affiliation(s)
- Sherry T Shu
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Wing Fai Li
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Thomas E Smithgall
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
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26
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Influence of Different Glycoproteins and of the Virion Core on SERINC5 Antiviral Activity. Viruses 2021; 13:v13071279. [PMID: 34209034 PMCID: PMC8310182 DOI: 10.3390/v13071279] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 06/22/2021] [Accepted: 06/28/2021] [Indexed: 11/25/2022] Open
Abstract
Host plasma membrane protein SERINC5 is incorporated into budding retrovirus particles where it blocks subsequent entry into susceptible target cells. Three structurally unrelated proteins encoded by diverse retroviruses, human immunodeficiency virus type 1 (HIV-1) Nef, equine infectious anemia virus (EIAV) S2, and ecotropic murine leukemia virus (MLV) GlycoGag, disrupt SERINC5 antiviral activity by redirecting SERINC5 from the site of virion assembly on the plasma membrane to an internal RAB7+ endosomal compartment. Pseudotyping retroviruses with particular glycoproteins, e.g., vesicular stomatitis virus glycoprotein (VSV G), renders the infectivity of particles resistant to inhibition by virion-associated SERINC5. To better understand viral determinants for SERINC5-sensitivity, the effect of SERINC5 was assessed using HIV-1, MLV, and Mason-Pfizer monkey virus (M-PMV) virion cores, pseudotyped with glycoproteins from Arenavirus, Coronavirus, Filovirus, Rhabdovirus, Paramyxovirus, and Orthomyxovirus genera. SERINC5 restricted virions pseudotyped with glycoproteins from several retroviruses, an orthomyxovirus, a rhabdovirus, a paramyxovirus, and an arenavirus. Infectivity of particles pseudotyped with HIV-1, amphotropic-MLV (A-MLV), or influenza A virus (IAV) glycoproteins, was decreased by SERINC5, whether the core was provided by HIV-1, MLV, or M-PMV. In contrast, particles pseudotyped with glycoproteins from M-PMV, parainfluenza virus 5 (PIV5), or rabies virus (RABV) were sensitive to SERINC5, but only with particular retroviral cores. Resistance to SERINC5 did not correlate with reduced SERINC5 incorporation into particles, route of viral entry, or absolute infectivity of the pseudotyped virions. These findings indicate that some non-retroviruses may be sensitive to SERINC5 and that, in addition to the viral glycoprotein, the retroviral core influences sensitivity to SERINC5.
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27
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Yarandi SS, Duggan MR, Sariyer IK. Emerging Role of Nef in the Development of HIV Associated Neurological Disorders. J Neuroimmune Pharmacol 2021; 16:238-250. [PMID: 33123948 PMCID: PMC8081738 DOI: 10.1007/s11481-020-09964-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 10/08/2020] [Indexed: 01/13/2023]
Abstract
Despite adherence to treatment, individuals living with HIV have an increased risk for developing cognitive impairments, referred to as HIV-associated neurological disorders (HAND). Due to continued growth in the HIV population, particularly amongst the aging cohort, the neurobiological mechanisms of HAND are increasingly relevant. Similar to other viral proteins (e.g. Tat, Gp120, Vpr), the Negative Factor (Nef) is associated with numerous adverse effects in the CNS as well as cognitive impairments. In particular, emerging data indicate the consequences of Nef may be facilitated by the modulation of cellular autophagy as well as its inclusion into extracellular vesicles (EVs). The present review examines evidence for the molecular mechanisms by which Nef might contribute to neuronal dysfunction underlying HAND, with a specific focus on autophagy and EVs. Based on the these data, we propose an integrated model by which Nef may contribute to underlying neuronal dysfunction in HAND and highlight potentially novel therapeutic targets for HAND. Graphical abstract.
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Affiliation(s)
- Shadan S Yarandi
- Department of Neuroscience and Center for Neurovirology, Temple University Lewis Katz School of Medicine, 3500 North Broad Street, Medical Education and Research Building Room 753, 7th Floor, Philadelphia, PA, 19140, USA
| | - Michael R Duggan
- Department of Neuroscience and Center for Neurovirology, Temple University Lewis Katz School of Medicine, 3500 North Broad Street, Medical Education and Research Building Room 753, 7th Floor, Philadelphia, PA, 19140, USA
| | - Ilker K Sariyer
- Department of Neuroscience and Center for Neurovirology, Temple University Lewis Katz School of Medicine, 3500 North Broad Street, Medical Education and Research Building Room 753, 7th Floor, Philadelphia, PA, 19140, USA.
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28
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Abstract
The CD8+ T cell noncytotoxic antiviral response (CNAR) was discovered during studies of asymptomatic HIV-infected subjects more than 30 years ago. In contrast to CD8+ T cell cytotoxic lymphocyte (CTL) activity, CNAR suppresses HIV replication without target cell killing. This activity has characteristics of innate immunity: it acts on all retroviruses and thus is neither epitope specific nor HLA restricted. The HIV-associated CNAR does not affect other virus families. It is mediated, at least in part, by a CD8+ T cell antiviral factor (CAF) that blocks HIV transcription. A variety of assays used to measure CNAR/CAF and the effects on other retrovirus infections are described. Notably, CD8+ T cell noncytotoxic antiviral responses have now been observed with other virus families but are mediated by different cytokines. Characterizing the protein structure of CAF has been challenging despite many biologic, immunologic, and molecular studies. It represents a low-abundance protein that may be identified by future next-generation sequencing approaches. Since CNAR/CAF is a natural noncytotoxic activity, it could provide promising strategies for HIV/AIDS therapy, cure, and prevention.
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Affiliation(s)
- Maelig G Morvan
- Division of Hematology/Oncology, Department of Medicine, University of California, San Francisco, San Francisco, California, USA
| | - Fernando C Teque
- Division of Hematology/Oncology, Department of Medicine, University of California, San Francisco, San Francisco, California, USA
| | | | - Jay A Levy
- Division of Hematology/Oncology, Department of Medicine, University of California, San Francisco, San Francisco, California, USA
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29
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Synergy and allostery in ligand binding by HIV-1 Nef. Biochem J 2021; 478:1525-1545. [PMID: 33787846 PMCID: PMC8079166 DOI: 10.1042/bcj20201002] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 03/29/2021] [Accepted: 03/31/2021] [Indexed: 11/27/2022]
Abstract
The Nef protein of human and simian immunodeficiency viruses boosts viral pathogenicity through its interactions with host cell proteins. By combining the polyvalency of its large unstructured regions with the binding selectivity and strength of its folded core domain, Nef can associate with many different host cell proteins, thereby disrupting their functions. For example, the combination of a linear proline-rich motif and hydrophobic core domain surface allows Nef to bind tightly and specifically to SH3 domains of Src family kinases. We investigated whether the interplay between Nef's flexible regions and its core domain could allosterically influence ligand selection. We found that the flexible regions can associate with the core domain in different ways, producing distinct conformational states that alter the way in which Nef selects for SH3 domains and exposes some of its binding motifs. The ensuing crosstalk between ligands might promote functionally coherent Nef-bound protein ensembles by synergizing certain subsets of ligands while excluding others. We also combined proteomic and bioinformatics analyses to identify human proteins that select SH3 domains in the same way as Nef. We found that only 3% of clones from a whole-human fetal library displayed Nef-like SH3 selectivity. However, in most cases, this selectivity appears to be achieved by a canonical linear interaction rather than by a Nef-like ‘tertiary' interaction. Our analysis supports the contention that Nef's mode of hijacking SH3 domains is a virus-specific adaptation with no or very few cellular counterparts. Thus, the Nef tertiary binding surface is a promising virus-specific drug target.
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30
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Patient-Derived HIV-1 Nef Alleles Reveal Uncoupling of CD4 Downregulation and SERINC5 Antagonism Functions of the Viral Pathogenesis Factor. J Acquir Immune Defic Syndr 2021; 85:e23-e26. [PMID: 32541384 DOI: 10.1097/qai.0000000000002418] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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31
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Immunologic Control of HIV-1: What Have We Learned and Can We Induce It? Curr HIV/AIDS Rep 2021; 18:211-220. [PMID: 33709324 DOI: 10.1007/s11904-021-00545-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/25/2021] [Indexed: 02/08/2023]
Abstract
PURPOSE OF REVIEW A large amount of data now exists on the virus-specific immune response associated with spontaneous or induced immunologic control of lentiviruses. This review focuses on how the current understanding of HIV-specific immunity might be leveraged into induction of immunologic control and what further research is needed to accomplish this goal. RECENT FINDINGS During chronic infection, the function most robustly associated with immunologic control of HIV-1 is CD8+ T cell cytotoxic capacity. This function has proven difficult to restore in HIV-specific CD8+ T cells of chronically infected progressors in vitro and in vivo. However, progress has been made in inducing an effective CD8+ T cell response prior to lentiviral infection in the macaque model and during acute lentiviral infection in non-human primates. Further study will likely accelerate the ability to induce an effective CD8+ T cell response as part of prophylactic or therapeutic strategies.
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32
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Salamango DJ, Harris RS. Dual Functionality of HIV-1 Vif in APOBEC3 Counteraction and Cell Cycle Arrest. Front Microbiol 2021; 11:622012. [PMID: 33510734 PMCID: PMC7835321 DOI: 10.3389/fmicb.2020.622012] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 12/11/2020] [Indexed: 01/02/2023] Open
Abstract
Accessory proteins are a key feature that distinguishes primate immunodeficiency viruses such as human immunodeficiency virus type I (HIV-1) from other retroviruses. A prime example is the virion infectivity factor, Vif, which hijacks a cellular co-transcription factor (CBF-β) to recruit a ubiquitin ligase complex (CRL5) to bind and degrade antiviral APOBEC3 enzymes including APOBEC3D (A3D), APOBEC3F (A3F), APOBEC3G (A3G), and APOBEC3H (A3H). Although APOBEC3 antagonism is essential for viral pathogenesis, and a more than sufficient functional justification for Vif’s evolution, most viral proteins have evolved multiple functions. Indeed, Vif has long been known to trigger cell cycle arrest and recent studies have shed light on the underlying molecular mechanism. Vif accomplishes this function using the same CBF-β/CRL5 ubiquitin ligase complex to degrade a family of PPP2R5 phospho-regulatory proteins. These advances have helped usher in a new era of accessory protein research and fresh opportunities for drug development.
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Affiliation(s)
- Daniel J Salamango
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, United States.,Masonic Cancer Center, University of Minnesota, Minneapolis, MN, United States.,Institute for Molecular Virology, University of Minnesota, Minneapolis, MN, United States
| | - Reuben S Harris
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, United States.,Masonic Cancer Center, University of Minnesota, Minneapolis, MN, United States.,Institute for Molecular Virology, University of Minnesota, Minneapolis, MN, United States.,Howard Hughes Medical Institute, University of Minnesota, Minneapolis, MN, United States
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33
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34
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Impaired ability of Nef to counteract SERINC5 is associated with reduced plasma viremia in HIV-infected individuals. Sci Rep 2020; 10:19416. [PMID: 33173092 PMCID: PMC7656250 DOI: 10.1038/s41598-020-76375-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Accepted: 10/28/2020] [Indexed: 01/23/2023] Open
Abstract
HIV-1 Nef plays an essential role in enhancing virion infectivity by antagonizing the host restriction molecule SERINC5. Because Nef is highly polymorphic due to the selective forces of host cellular immunity, we hypothesized that certain immune-escape polymorphisms may impair Nef’s ability to antagonize SERINC5 and thereby influence viral fitness in vivo. To test this hypothesis, we identified 58 Nef polymorphisms that were overrepresented in HIV-infected patients in Japan sharing the same HLA genotypes. The number of immune-associated Nef polymorphisms was inversely correlated with the plasma viral load. By breaking down the specific HLA allele-associated mutations, we found that a number of the HLA-B*51:01-associated Y120F and Q125H mutations were most significantly associated with a reduced plasma viral load. A series of biochemical experiments showed that the double mutations Y120F/Q125H, but not either single mutation, impaired Nef’s ability to antagonize SERINC5 and was associated with decreasing virion infectivity and viral replication in primary lymphocytes. In contrast, other Nef functions such as CD4, CCR5, CXCR4 and HLA class I downregulation and CD74 upregulation remained unchanged. Taken together, our results suggest that the differential ability of Nef to counteract SERINC5 by naturally occurring immune-associated mutations was associated with the plasma viral load in vivo.
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35
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Kaw S, Ananth S, Tsopoulidis N, Morath K, Coban BM, Hohenberger R, Bulut OC, Klein F, Stolp B, Fackler OT. HIV-1 infection of CD4 T cells impairs antigen-specific B cell function. EMBO J 2020; 39:e105594. [PMID: 33146906 PMCID: PMC7737609 DOI: 10.15252/embj.2020105594] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 09/28/2020] [Accepted: 10/01/2020] [Indexed: 12/12/2022] Open
Abstract
Failures to produce neutralizing antibodies upon HIV‐1 infection result in part from B‐cell dysfunction due to unspecific B‐cell activation. How HIV‐1 affects antigen‐specific B‐cell functions remains elusive. Using an adoptive transfer mouse model and ex vivo HIV infection of human tonsil tissue, we found that expression of the HIV‐1 pathogenesis factor NEF in CD4 T cells undermines their helper function and impairs cognate B‐cell functions including mounting of efficient specific IgG responses. NEF interfered with T cell help via a specific protein interaction motif that prevents polarized cytokine secretion at the T‐cell–B‐cell immune synapse. This interference reduced B‐cell activation and proliferation and thus disrupted germinal center formation and affinity maturation. These results identify NEF as a key component for HIV‐mediated dysfunction of antigen‐specific B cells. Therapeutic targeting of the identified molecular surface in NEF will facilitate host control of HIV infection.
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Affiliation(s)
- Sheetal Kaw
- Department of Infectious Diseases, Integrative Virology, University Hospital Heidelberg, Heidelberg, Germany
| | - Swetha Ananth
- Department of Infectious Diseases, Integrative Virology, University Hospital Heidelberg, Heidelberg, Germany.,German Centre for Infection Research (DZIF), Partner Site Heidelberg, Heidelberg, Germany
| | - Nikolaos Tsopoulidis
- Department of Infectious Diseases, Integrative Virology, University Hospital Heidelberg, Heidelberg, Germany
| | - Katharina Morath
- Department of Infectious Diseases, Integrative Virology, University Hospital Heidelberg, Heidelberg, Germany
| | - Bahar M Coban
- Department of Infectious Diseases, Integrative Virology, University Hospital Heidelberg, Heidelberg, Germany.,German Centre for Infection Research (DZIF), Partner Site Heidelberg, Heidelberg, Germany
| | - Ralph Hohenberger
- Department of Otorhinolaryngology, University Hospital Heidelberg, Heidelberg, Germany
| | - Olcay C Bulut
- German Centre for Infection Research (DZIF), Partner Site Heidelberg, Heidelberg, Germany.,Department of Otorhinolaryngology, Head and Neck Surgery, SLK Klinikum Am Gesundbrunnen, Heilbronn, Germany
| | - Florian Klein
- Laboratory of Experimental Immunology, Institute of Virology, University Hospital of Cologne, Cologne, Germany.,German Centre for Infection Research (DZIF), Partner Site Köln, Köln, Germany
| | - Bettina Stolp
- Department of Infectious Diseases, Integrative Virology, University Hospital Heidelberg, Heidelberg, Germany
| | - Oliver T Fackler
- Department of Infectious Diseases, Integrative Virology, University Hospital Heidelberg, Heidelberg, Germany.,German Centre for Infection Research (DZIF), Partner Site Heidelberg, Heidelberg, Germany
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36
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Tamalet C, Devaux C, Dubourg G, Colson P. Resistance to human immunodeficiency virus infection: a rare but neglected state. Ann N Y Acad Sci 2020; 1485:22-42. [PMID: 33009659 DOI: 10.1111/nyas.14452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 06/25/2020] [Accepted: 07/07/2020] [Indexed: 11/29/2022]
Abstract
The natural history of human immunodeficiency virus (HIV) infection is well understood. In most individuals sexually exposed to HIV, the risk of becoming infected depends on the viral load and on sexual practices and gender. However, a low percentage of individuals who practice frequent unprotected sexual intercourse with HIV-infected partners remain uninfected. Although the systematic study of these individuals has made it possible to identify HIV resistance factors including protective genetic patterns, such epidemiological situations remain paradoxical and not fully understood. In vitro experiments have demonstrated that peripheral blood mononuclear cells (PBMCs) from HIV-free, unexposed blood donors are not equally susceptible to HIV infection; in addition, PBMCs from highly exposed seronegative individuals are generally resistant to infection by primary HIV clinical isolates. We review the literature on permissiveness of PBMCs from healthy blood donors and uninfected hyperexposed individuals to sustained infection and replication of HIV-1 in vitro. In addition, we focus on recent evidence indicating that the gut microbiota may either contribute to natural resistance to or delay replication of HIV infected individuals.
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Affiliation(s)
- Catherine Tamalet
- IHU Méditerranée Infection and Aix-Marseille University, Institut de Recherche pour le Développement (IRD), Assistance Publique-Hôpitaux de Marseille (AP-HM), Microbes Evolution Phylogeny and Infections (MEPHI), Marseille, France
| | - Christian Devaux
- IHU Méditerranée Infection and Aix-Marseille University, Institut de Recherche pour le Développement (IRD), Assistance Publique-Hôpitaux de Marseille (AP-HM), Microbes Evolution Phylogeny and Infections (MEPHI), Marseille, France
| | - Gregory Dubourg
- IHU Méditerranée Infection and Aix-Marseille University, Institut de Recherche pour le Développement (IRD), Assistance Publique-Hôpitaux de Marseille (AP-HM), Microbes Evolution Phylogeny and Infections (MEPHI), Marseille, France
| | - Philippe Colson
- IHU Méditerranée Infection and Aix-Marseille University, Institut de Recherche pour le Développement (IRD), Assistance Publique-Hôpitaux de Marseille (AP-HM), Microbes Evolution Phylogeny and Infections (MEPHI), Marseille, France
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37
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Jin SW, Alsahafi N, Kuang XT, Swann SA, Toyoda M, Göttlinger H, Walker BD, Ueno T, Finzi A, Brumme ZL, Brockman MA. Natural HIV-1 Nef Polymorphisms Impair SERINC5 Downregulation Activity. Cell Rep 2020; 29:1449-1457.e5. [PMID: 31693887 PMCID: PMC6925589 DOI: 10.1016/j.celrep.2019.10.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Revised: 07/26/2019] [Accepted: 10/01/2019] [Indexed: 11/30/2022] Open
Abstract
HIV-1 Nef enhances virion infectivity by counteracting host restriction factor SERINC5; however, the impact of natural Nef polymorphisms on this function is largely unknown. We characterize SERINC5 downregulation activity of 91 primary HIV-1 subtype B nef alleles, including isolates from 45 elite controllers and 46 chronic progressors. Controller-derived Nef clones display lower ability to downregulate SERINC5 (median 80% activity) compared with progressor-derived clones (median 96% activity) (p = 0.0005). We identify 18 Nef polymorphisms associated with differential function, including two CTL escape mutations that contribute to lower SERINC5 downregulation: K94E, driven by HLA-B∗08, and H116N, driven by the protective allele HLA-B∗57. HIV-1 strains encoding Nef K94E and/or H116N display lower infectivity and replication capacity in the presence of SERINC5. Our results demonstrate that natural polymorphisms in HIV-1 Nef can impair its ability to internalize SERINC5, indicating that variation in this recently described function may contribute to differences in viral pathogenesis.
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Affiliation(s)
- Steven W Jin
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada
| | - Nirmin Alsahafi
- Centre de Recherche du CHUM, Montreal, QC, Canada; Department of Microbiology and Immunology, McGill University, Montreal, QC, Canada
| | - Xiaomei T Kuang
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada
| | - Shayda A Swann
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada
| | - Mako Toyoda
- Center for AIDS Research, Kumamoto University, Kumamoto, Japan
| | - Heinrich Göttlinger
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Bruce D Walker
- Ragon Institute of MGH, MIT, and Harvard, Cambridge, MA, USA; Howard Hughes Medical Institute, Cambridge, MA, USA
| | - Takamasa Ueno
- Center for AIDS Research, Kumamoto University, Kumamoto, Japan
| | - Andrés Finzi
- Centre de Recherche du CHUM, Montreal, QC, Canada; Department of Microbiology and Immunology, McGill University, Montreal, QC, Canada; Department of Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, QC, Canada
| | - Zabrina L Brumme
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada; British Columbia Centre for Excellence in HIV/AIDS, Vancouver, BC, Canada
| | - Mark A Brockman
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada; Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada; British Columbia Centre for Excellence in HIV/AIDS, Vancouver, BC, Canada.
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38
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Staudt RP, Smithgall TE. Nef homodimers down-regulate SERINC5 by AP-2-mediated endocytosis to promote HIV-1 infectivity. J Biol Chem 2020; 295:15540-15552. [PMID: 32873704 DOI: 10.1074/jbc.ra120.014668] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 08/24/2020] [Indexed: 12/13/2022] Open
Abstract
SERINC5 is a multipass intrinsic membrane protein that suppresses HIV-1 infectivity when incorporated into budding virions. The HIV-1 Nef virulence factor prevents viral incorporation of SERINC5 by triggering its down-regulation from the producer cell membrane through an AP-2-dependent endolysosomal pathway. However, the mechanistic basis for SERINC5 down-regulation by Nef remains elusive. Here we demonstrate that Nef homodimers are important for SERINC5 down-regulation, trafficking to late endosomes, and exclusion from newly synthesized viral particles. Based on previous X-ray crystal structures, we mutated three conserved residues in the Nef dimer interface (Leu112, Tyr115, and Phe121) and demonstrated attenuated homodimer formation in a cell-based fluorescence complementation assay. Point mutations at each position reduced the infectivity of HIV-1 produced from transfected 293T cells, the Jurkat TAg T-cell line, and donor mononuclear cells in a SERINC5-dependent manner. In SERINC5-transfected 293T cells, virion incorporation of SERINC5 was increased by dimerization-defective Nef mutants, whereas down-regulation of SERINC5 from the membrane of transfected Jurkat cells by these mutants was significantly reduced. Nef dimer interface mutants also failed to trigger internalization of SERINC5 and localization to Rab7+ late endosomes in T cells. Importantly, fluorescence complementation assays demonstrated that dimerization-defective Nef mutants retained interaction with both SERINC5 and AP-2. These results show that down-regulation of SERINC5 and subsequent enhancement of viral infectivity require Nef homodimers and support a mechanism by which the Nef dimer bridges SERINC5 to AP-2 for endocytosis. Pharmacological disruption of Nef homodimers may control HIV-1 infectivity and viral spread by enhancing virion incorporation of SERINC5.
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Affiliation(s)
- Ryan P Staudt
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Thomas E Smithgall
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, School of Medicine, Pittsburgh, Pennsylvania, USA.
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Angerstein AO, Stoneham CA, Ramirez PW, Guatelli JC, Vollbrecht T. Sensitivity to monoclonal antibody 447-52D and an open env trimer conformation correlate poorly with inhibition of HIV-1 infectivity by SERINC5. Virology 2020; 548:73-81. [PMID: 32838948 PMCID: PMC7447835 DOI: 10.1016/j.virol.2020.06.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 05/25/2020] [Accepted: 06/12/2020] [Indexed: 11/25/2022]
Abstract
The host protein SERINC5 inhibits the infectivity of HIV-1 virions in an Env-dependent manner and is counteracted by Nef. The conformation of the Env trimer reportedly correlates with sensitivity to SERINC5. Here, we tested the hypothesis that the "open" conformation of the Env trimer revealed by sensitivity to the V3-loop specific antibody 447-52D directly correlates with sensitivity to SERINC5. Of five Envs tested, SF162 was the most sensitive to neutralization by 447-52D, but it was not the most sensitive to SERINC5; instead the Env of LAI was substantially more sensitive to SERINC5 than all the other Envs. Mutational opening of the trimer by substitution of two tyrosines that mediate interaction between the V2 and V3 loops sensitized the Envs of JRFL and LAI to 447-52D as previously reported, but only BaL was sensitized to SERINC5. These data suggest that trimer "openness" is not sufficient for sensitivity to SERINC5.
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Affiliation(s)
- Aaron O Angerstein
- Department of Biological Sciences, University of California San Diego, 9500 Gilman Dr, La Jolla, CA, 92093, USA; VA San Diego Healthcare System, 3350 La Jolla Village Dr, San Diego, CA, 92161, USA
| | - Charlotte A Stoneham
- VA San Diego Healthcare System, 3350 La Jolla Village Dr, San Diego, CA, 92161, USA; Department of Medicine, University of California San Diego, 9500 Gilman Dr, La Jolla, CA, 92093, USA
| | - Peter W Ramirez
- VA San Diego Healthcare System, 3350 La Jolla Village Dr, San Diego, CA, 92161, USA; Department of Medicine, University of California San Diego, 9500 Gilman Dr, La Jolla, CA, 92093, USA
| | - John C Guatelli
- VA San Diego Healthcare System, 3350 La Jolla Village Dr, San Diego, CA, 92161, USA; Department of Medicine, University of California San Diego, 9500 Gilman Dr, La Jolla, CA, 92093, USA
| | - Thomas Vollbrecht
- VA San Diego Healthcare System, 3350 La Jolla Village Dr, San Diego, CA, 92161, USA; Department of Medicine, University of California San Diego, 9500 Gilman Dr, La Jolla, CA, 92093, USA.
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40
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Kwon Y, Kaake RM, Echeverria I, Suarez M, Karimian Shamsabadi M, Stoneham C, Ramirez PW, Kress J, Singh R, Sali A, Krogan N, Guatelli J, Jia X. Structural basis of CD4 downregulation by HIV-1 Nef. Nat Struct Mol Biol 2020; 27:822-828. [PMID: 32719457 PMCID: PMC7483821 DOI: 10.1038/s41594-020-0463-z] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 06/16/2020] [Indexed: 02/06/2023]
Abstract
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.
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Affiliation(s)
- Yonghwa Kwon
- Department of Chemistry and Biochemistry, University of Massachusetts Dartmouth, Dartmouth, MA, USA
| | - Robyn M Kaake
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA, USA
- Gladstone Institutes, San Francisco, CA, USA
| | - Ignacia Echeverria
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA, USA
| | | | | | - Charlotte Stoneham
- The VA San Diego Healthcare System, San Diego, CA, USA
- Department of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Peter W Ramirez
- Department of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Jacob Kress
- Department of Chemistry and Biochemistry, University of Massachusetts Dartmouth, Dartmouth, MA, USA
| | - Rajendra Singh
- The VA San Diego Healthcare System, San Diego, CA, USA
- Department of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Andrej Sali
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA, USA
- Department of Pharmaceutical Chemistry and Quantitative Biosciences Institute, University of California, San Francisco, San Francisco, CA, USA
| | - Nevan Krogan
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA, USA
- Gladstone Institutes, San Francisco, CA, USA
| | - John Guatelli
- The VA San Diego Healthcare System, San Diego, CA, USA
- Department of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Xiaofei Jia
- Department of Chemistry and Biochemistry, University of Massachusetts Dartmouth, Dartmouth, MA, USA.
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Jin SW, Mwimanzi FM, Mann JK, Bwana MB, Lee GQ, Brumme CJ, Hunt PW, Martin JN, Bangsberg DR, Ndung’u T, Brumme ZL, Brockman MA. Variation in HIV-1 Nef function within and among viral subtypes reveals genetically separable antagonism of SERINC3 and SERINC5. PLoS Pathog 2020; 16:e1008813. [PMID: 32925973 PMCID: PMC7515180 DOI: 10.1371/journal.ppat.1008813] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 09/24/2020] [Accepted: 07/15/2020] [Indexed: 12/14/2022] Open
Abstract
HIV Nef counteracts cellular host restriction factors SERINC3 and SERINC5, but our understanding of how naturally occurring global Nef sequence diversity impacts these activities is limited. Here, we quantify SERINC3 and SERINC5 internalization function for 339 Nef clones, representing the major pandemic HIV-1 group M subtypes A, B, C and D. We describe distinct subtype-associated hierarchies for Nef-mediated internalization of SERINC5, for which subtype B clones display the highest activities on average, and of SERINC3, for which subtype B clones display the lowest activities on average. We further identify Nef polymorphisms that modulate its ability to counteract SERINC proteins, including substitutions in the N-terminal domain that selectively impair SERINC3 internalization. Our findings demonstrate that the SERINC antagonism activities of HIV Nef differ markedly among major viral subtypes and between individual isolates within a subtype, suggesting that variation in these functions may contribute to global differences in viral pathogenesis.
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Affiliation(s)
- Steven W. Jin
- Faculty of Health Sciences, Simon Fraser University, Burnaby, Canada
| | | | - Jaclyn K. Mann
- HIV Pathogenesis Programme, The Doris Duke Medical Research Institute, University of KwaZulu-Natal, Durban, South Africa
| | - Mwebesa Bosco Bwana
- Faculty of Medicine, Mbarara University of Science and Technology, Mbarara, Uganda
| | - Guinevere Q. Lee
- British Columbia Centre for Excellence in HIV/AIDS, Vancouver, Canada
| | - Chanson J. Brumme
- British Columbia Centre for Excellence in HIV/AIDS, Vancouver, Canada
- Department of Medicine, University of British Columbia, Vancouver, Canada
| | - Peter W. Hunt
- School of Medicine, University of California, San Francisco, United States of America
| | - Jeff N. Martin
- School of Medicine, University of California, San Francisco, United States of America
| | - David R. Bangsberg
- School of Public Health, Oregon Health Science University, Portland, United States of America
| | - Thumbi Ndung’u
- HIV Pathogenesis Programme, The Doris Duke Medical Research Institute, University of KwaZulu-Natal, Durban, South Africa
- Africa Health Research Institute, Durban, South Africa
- Ragon Institute of MGH, MIT, and Harvard University, Cambridge, United States of America
- Max Planck Institute for Infection Biology, Berlin, Germany
- Division of Infection and Immunity, University College London, London, United Kingdom
| | - Zabrina L. Brumme
- Faculty of Health Sciences, Simon Fraser University, Burnaby, Canada
- British Columbia Centre for Excellence in HIV/AIDS, Vancouver, Canada
| | - Mark A. Brockman
- Faculty of Health Sciences, Simon Fraser University, Burnaby, Canada
- British Columbia Centre for Excellence in HIV/AIDS, Vancouver, Canada
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, Canada
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Gomes STM, da Silva Graça Amoras E, Gomes ÉR, Queiroz MAF, Júnior ECS, de Vasconcelos Massafra JM, da Silva Lemos P, Júnior JLV, Ishak R, Vallinoto ACR. Immune escape mutations in HIV-1 controllers in the Brazilian Amazon region. BMC Infect Dis 2020; 20:546. [PMID: 32711474 PMCID: PMC7382849 DOI: 10.1186/s12879-020-05268-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 07/16/2020] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND Human immunodeficiency virus (HIV-1) infection is characterized by high viral replication and a decrease in CD4+ T cells (CD4+TC), resulting in AIDS, which can lead to death. In elite controllers and viremia controllers, viral replication is naturally controlled, with maintenance of CD4+TC levels without the use of antiretroviral therapy (ART). METHODS The aim of the present study was to describe virological and immunological risk factors among HIV-1-infected individuals according to characteristics of progression to AIDS. The sample included 30 treatment-naive patients classified into three groups based on infection duration (> 6 years), CD4+TC count and viral load: (i) 2 elite controllers (ECs), (ii) 7 viremia controllers (VCs) and (iii) 21 nonviremia controllers (NVCs). Nested PCR was employed to amplify the virus genome, which was later sequenced using the Ion PGM platform for subtyping and analysis of immune escape mutations. RESULTS Viral samples were classified as HIV-1 subtypes B and F. Greater selection pressure on mutations was observed in the group of viremia controllers, with a higher frequency of immunological escape mutations in the genes investigated, including two new mutations in gag. The viral sequences of viremia controllers and nonviremia controllers did not differ significantly regarding the presence of immune escape mutations. CONCLUSION The results suggest that progression to AIDS is not dependent on a single variable but rather on a set of characteristics and pressures exerted by virus biology and interactions with immunogenetic host factors.
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Affiliation(s)
- Samara Tatielle Monteiro Gomes
- Laboratory of Virology, Biological Science Institute, Federal University of Pará (ICB/UFPA), Ananindeua, Brazil
- Graduate Program in Biology of Infectious and Parasitic Agents, Biological Science Institute, Federal University of Pará, Ananindeua, Brazil
| | | | - Érica Ribeiro Gomes
- Laboratory of Virology, Biological Science Institute, Federal University of Pará (ICB/UFPA), Ananindeua, Brazil
| | - Maria Alice Freitas Queiroz
- Laboratory of Virology, Biological Science Institute, Federal University of Pará (ICB/UFPA), Ananindeua, Brazil
| | - Edivaldo Costa Sousa Júnior
- Health Surveillance Department, Ministry of Health (IEC-SVS/MS), Evandro Chagas Institute, Ananindeua, Brazil
| | | | - Poliana da Silva Lemos
- Health Surveillance Department, Ministry of Health (IEC-SVS/MS), Evandro Chagas Institute, Ananindeua, Brazil
| | - João Lídio Vianez Júnior
- Health Surveillance Department, Ministry of Health (IEC-SVS/MS), Evandro Chagas Institute, Ananindeua, Brazil
| | - Ricardo Ishak
- Laboratory of Virology, Biological Science Institute, Federal University of Pará (ICB/UFPA), Ananindeua, Brazil
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Wan Q, Song D, Li H, He ML. Stress proteins: the biological functions in virus infection, present and challenges for target-based antiviral drug development. Signal Transduct Target Ther 2020; 5:125. [PMID: 32661235 PMCID: PMC7356129 DOI: 10.1038/s41392-020-00233-4] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 05/26/2020] [Accepted: 06/13/2020] [Indexed: 02/06/2023] Open
Abstract
Stress proteins (SPs) including heat-shock proteins (HSPs), RNA chaperones, and ER associated stress proteins are molecular chaperones essential for cellular homeostasis. The major functions of HSPs include chaperoning misfolded or unfolded polypeptides, protecting cells from toxic stress, and presenting immune and inflammatory cytokines. Regarded as a double-edged sword, HSPs also cooperate with numerous viruses and cancer cells to promote their survival. RNA chaperones are a group of heterogeneous nuclear ribonucleoproteins (hnRNPs), which are essential factors for manipulating both the functions and metabolisms of pre-mRNAs/hnRNAs transcribed by RNA polymerase II. hnRNPs involve in a large number of cellular processes, including chromatin remodelling, transcription regulation, RNP assembly and stabilization, RNA export, virus replication, histone-like nucleoid structuring, and even intracellular immunity. Dysregulation of stress proteins is associated with many human diseases including human cancer, cardiovascular diseases, neurodegenerative diseases (e.g., Parkinson’s diseases, Alzheimer disease), stroke and infectious diseases. In this review, we summarized the biologic function of stress proteins, and current progress on their mechanisms related to virus reproduction and diseases caused by virus infections. As SPs also attract a great interest as potential antiviral targets (e.g., COVID-19), we also discuss the present progress and challenges in this area of HSP-based drug development, as well as with compounds already under clinical evaluation.
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Affiliation(s)
- Qianya Wan
- Department of Biomedical Sciences, City University of Hong Kong, Kowloon, Hong Kong, China
| | - Dan Song
- Department of Biomedical Sciences, City University of Hong Kong, Kowloon, Hong Kong, China
| | - Huangcan Li
- Department of Biomedical Sciences, City University of Hong Kong, Kowloon, Hong Kong, China
| | - Ming-Liang He
- Department of Biomedical Sciences, City University of Hong Kong, Kowloon, Hong Kong, China. .,CityU Shenzhen Research Institute, Shenzhen, China.
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Ruiz-Mateos E, Poveda E, Lederman MM. Antiretroviral Treatment for HIV Elite Controllers? Pathog Immun 2020; 5:121-133. [PMID: 32582872 PMCID: PMC7307444 DOI: 10.20411/pai.v5i1.364] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 04/20/2020] [Indexed: 12/12/2022] Open
Abstract
In most HIV-infected persons, the natural history of untreated infection is one of sustained viremia, progressive CD4 T cell depletion with resultant morbidity and mortality. The advent of effective combination antiretroviral therapy (ART) that controls HIV replication has altered this landscape dramatically. Yet a rare population of HIV-infected persons-elite controllers (EC)-can control HIV replication such that plasma levels of virus are "undetectable" without ART. The EC phenotype is heterogeneous, with some subjects durably controlling the virus-persistent elite controllers-and some eventually losing viral control-transient elite controllers. Overall, EC tend to have robust HIV-specific T cell responses and in some cases, mainly in transient elite controllers, elevated activation and inflammation indices that diminish with ART suggesting that endogenous defenses against this persistent pathogen come at the cost of heightened activation/inflammation. A limited data set suggests that cardiovascular disease risk as well as the occur-rence of other morbid events may be greater in the overall EC population than in treated HIV infection. ART in EC decreases activation indices but does not appear to increase circulating CD4 T cell numbers nor do we know if it alters clinical outcomes. Thus, it is difficult to recommend or discourage a decision to start ART in the EC population but the authors lean toward treatment particularly in those EC whose activation indices are high and those who are progressively losing circulating CD4 T cell numbers. Biomarkers that can reliably predict loss of virologic control and immune failure are needed.
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Affiliation(s)
- Ezequiel Ruiz-Mateos
- Clinic Unit of Infectious Diseases; Microbiology and Preventive Medicine; Institute of Biomedicine of Seville; Virgen del Rocío University Hospital/CSIC/University of Seville, Spain
| | - Eva Poveda
- Group of Virology and Pathogenesis; Galicia Sur Health Research Institute (IIS Galicia Sur)-Complexo Hospitalario Universitario de Vigo; SERGAS-UVigo; Vigo, Spain
| | - Michael M. Lederman
- Division of Infectious Diseases; Center for AIDS Research; Case Western Reserve University and University Hospitals; Cleveland Medical Center; Cleveland, Ohio
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Li WF, Aryal M, Shu ST, Smithgall TE. HIV-1 Nef dimers short-circuit immune receptor signaling by activating Tec-family kinases at the host cell membrane. J Biol Chem 2020; 295:5163-5174. [PMID: 32144207 DOI: 10.1074/jbc.ra120.012536] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Revised: 03/04/2020] [Indexed: 01/08/2023] Open
Abstract
The HIV-1 virulence factor Nef promotes high-titer viral replication, immune escape, and pathogenicity. Nef interacts with interleukin-2-inducible T-cell kinase (Itk) and Bruton's tyrosine kinase (Btk), two Tec-family kinases expressed in HIV-1 target cells (CD4 T cells and macrophages, respectively). Using a cell-based bimolecular fluorescence complementation assay, here we demonstrate that Nef recruits both Itk and Btk to the cell membrane and induces constitutive kinase activation in transfected 293T cells. Nef homodimerization-defective mutants retained their interaction with both kinases but failed to induce activation, supporting a role for Nef homodimer formation in the activation mechanism. HIV-1 infection up-regulates endogenous Itk activity in SupT1 T cells and donor-derived peripheral blood mononuclear cells. However, HIV-1 strains expressing Nef variants with mutations in the dimerization interface replicated poorly and were significantly attenuated in Itk activation. We conclude that direct activation of Itk and Btk by Nef at the membrane in HIV-infected cells may override normal immune receptor control of Tec-family kinase activity to enhance the viral life cycle.
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Affiliation(s)
- Wing Fai Li
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, 450 Technology Drive, Pittsburgh, Pennsylvania 15219
| | - Manish Aryal
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, 450 Technology Drive, Pittsburgh, Pennsylvania 15219
| | - Sherry T Shu
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, 450 Technology Drive, Pittsburgh, Pennsylvania 15219
| | - Thomas E Smithgall
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, 450 Technology Drive, Pittsburgh, Pennsylvania 15219
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Ali A, Furler RL, Pedroza-Martins L, Colantonio AD, Anisman-Posner D, Bryson Y, Yang OO, Uittenbogaart CH. A Novel HIV-1 Nef Mutation in a Primary Pediatric Isolate Impairs MHC-Class I Downregulation and Cytopathicity. AIDS Res Hum Retroviruses 2020; 36:122-130. [PMID: 31571497 DOI: 10.1089/aid.2019.0160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
HIV-1-induced cytopathicity of thymocytes is a major cause of reduced peripheral T cells and rapid disease progression observed in HIV-1-infected infants. Understanding the virulence factors responsible for thymocyte depletion has paramount importance in addressing the pathogenesis of disease progression in children. In this study, thymocyte depletion was analyzed following infection with two primary CXCR4-tropic HIV-1 pediatric isolates (PI), PI-2 and PI-2.1, which were serially derived from an in utero-infected infant. Although highly similar to each other, PI-2 showed markedly decreased thymocyte depletion in vitro compared with PI-2.1. Further analysis showed a novel deletion in the Nef protein (NefΔK7S) of PI-2, which was absent in PI-2.1. This deletion inhibited Nef-mediated major histocompatibility complex class I (MHC-I) downregulation in infected thymocytes in vitro and in vivo; in contrast, the mutated Nef continued to downregulate CD4 surface expression in vitro. These results suggest that HIV-1 Nef contributes to thymic damage in infants through selective functions.
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Affiliation(s)
- Ayub Ali
- UCLA AIDS Institute, University of California, Los Angeles, Los Angeles, California
- Division of Infectious Diseases, Department of Medicine, University of California, Los Angeles, Los Angeles, California
| | - Robert L. Furler
- Division of Infectious Diseases, Department of Medicine, Weill Cornell Medicine, New York, New York
| | - Livia Pedroza-Martins
- ANRS, French National Agency for Research on AIDS and Viral Hepatitis, Paris, France
| | - Arnaud D. Colantonio
- UCLA AIDS Institute, University of California, Los Angeles, Los Angeles, California
- Department of Microbiology, Immunology & Molecular Genetics, University of California, Los Angeles, Los Angeles, California
| | - Deborah Anisman-Posner
- UCLA AIDS Institute, University of California, Los Angeles, Los Angeles, California
- Department of Microbiology, Immunology & Molecular Genetics, University of California, Los Angeles, Los Angeles, California
| | - Yvonne Bryson
- UCLA AIDS Institute, University of California, Los Angeles, Los Angeles, California
- Department of Pediatrics, University of California, Los Angeles, Los Angeles, California
| | - Otto O. Yang
- UCLA AIDS Institute, University of California, Los Angeles, Los Angeles, California
- Division of Infectious Diseases, Department of Medicine, University of California, Los Angeles, Los Angeles, California
| | - Christel H. Uittenbogaart
- UCLA AIDS Institute, University of California, Los Angeles, Los Angeles, California
- Department of Microbiology, Immunology & Molecular Genetics, University of California, Los Angeles, Los Angeles, California
- Department of Pediatrics, University of California, Los Angeles, Los Angeles, California
- Jonsson Comprehensive Cancer Center, University of California, Los Angeles, Los Angeles, California
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Multifunctional Roles of the N-Terminal Region of HIV-1 SF2Nef Are Mediated by Three Independent Protein Interaction Sites. J Virol 2019; 94:JVI.01398-19. [PMID: 31597760 DOI: 10.1128/jvi.01398-19] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 10/01/2019] [Indexed: 01/23/2023] Open
Abstract
HIV-1 Nef promotes virus spread and disease progression by altering host cell transport and signaling processes through interaction with multiple host cell proteins. The N-terminal region in HIV-1 Nef encompassing residues 12 to 39 has been implicated in many Nef activities, including disruption of CD4 T lymphocyte polarization and homing to lymph nodes, antagonism of SERINC5 restriction to virion infectivity, downregulation of cell surface CD4 and major histocompatibility complex class I (MHC-I), release of Nef-containing extracellular vesicles, and phosphorylation of Nef by recruitment of the Nef-associated kinase complex (NAKC). How this region mediates these pleiotropic functions is unclear. Characterization of a panel of alanine mutants spanning the N-terminal region to identify specific functional determinants revealed this region to be dispensable for effects of Nef from HIV-1 strain SF2 (HIV-1SF2Nef) on T cell actin organization and chemotaxis, retargeting of the host cell kinase Lck to the trans-Golgi network, and incorporation of Nef into extracellular vesicles. MHC-I downmodulation was specific to residue M20, and inhibition of T cell polarization by Nef required the integrity of the entire region. In contrast, downmodulation of cell surface CD4 and SERINC5 antagonism were mediated by a specific motif encompassing residues 32 to 39 that was also essential for efficient HIV replication in primary CD4 T lymphocytes. Finally, Nef phosphorylation via association with the NAKC was mediated by two EP repeats within residues 24 to 29 but was dispensable for other functions. These results identify the N-terminal region as a multifunctional interaction module for at least three different host cell ligands that mediate independent functions of HIV-1SF2Nef to facilitate immune evasion and virus spread.IMPORTANCE HIV-1 Nef critically determines virus spread and disease progression in infected individuals by acting as a protein interaction adaptor via incompletely defined mechanisms and ligands. Residues 12 to 39 near the N terminus of Nef have been described as an interaction platform for the Nef-associated kinase complex (NAKC) and were recently identified as essential determinants for a broad range of Nef activities. Here, we report a systematic mapping of this amino acid stretch that revealed the presence of three independent interaction motifs with specific ligands and activities. While downmodulation of cell surface MHC-I depends on M20, two EP repeats are the minimal binding site for the NAKC, and residues 32 to 39 mediate antagonism of the host cell restriction factor SERINC5 as well as downmodulation of cell surface CD4. These results reveal that the N-terminal region of HIV-1SF2Nef is a versatile and multifunctional protein interaction module that exerts essential functions of the pathogenicity factor via independent mechanisms.
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Hirao K, Andrews S, Kuroki K, Kusaka H, Tadokoro T, Kita S, Ose T, Rowland-Jones SL, Maenaka K. Structure of HIV-2 Nef Reveals Features Distinct from HIV-1 Involved in Immune Regulation. iScience 2019; 23:100758. [PMID: 31927483 PMCID: PMC6956826 DOI: 10.1016/j.isci.2019.100758] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 11/24/2019] [Accepted: 12/03/2019] [Indexed: 01/07/2023] Open
Abstract
The human immunodeficiency virus (HIV) accessory protein Nef plays a major role in establishing and maintaining infection, particularly through immune evasion. Many HIV-2-infected people experience long-term viral control and survival, resembling HIV-1 elite control. HIV-2 Nef has overlapping but also distinct functions from HIV-1 Nef. Here we report the crystal structure of HIV-2 Nef core. The di-leucine sorting motif forms a helix bound to neighboring molecules, and moreover, isothermal titration calorimetry demonstrated that the CD3 endocytosis motif can directly bind to HIV-2 Nef, ensuring AP-2-mediated endocytosis for CD3. The highly conserved C-terminal region forms a α-helix, absent from HIV-1. We further determined the structure of simian immunodeficiency virus (SIV) Nef harboring this region, demonstrating similar C-terminal α-helix, which may contribute to AP-1 binding for MHC-I downregulation. These results provide insights into the distinct pathogenesis of HIV-2 infection. Structure of HIV-2 Nef revealed a conserved C-terminal α-helix not present in HIV-1 C-terminal structure is conserved in SIV Nef, likely involved in MHC-I downregulation Di-leucine AP-2-mediated sorting motif forms a helix bound to the α1 and α2 helices ITC demonstrated that the CD3 endocytosis motif can directly bind to HIV-2 Nef
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Affiliation(s)
- Kengo Hirao
- Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan
| | - Sophie Andrews
- Nuffield Department of Medicine, University of Oxford, NDM Research Building, Oxford OX3 7FZ, UK
| | - Kimiko Kuroki
- Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan
| | - Hiroki Kusaka
- Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan
| | - Takashi Tadokoro
- Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan
| | - Shunsuke Kita
- Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan
| | - Toyoyuki Ose
- Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan; Faculty of Advanced Life Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Sarah L Rowland-Jones
- Nuffield Department of Medicine, University of Oxford, NDM Research Building, Oxford OX3 7FZ, UK.
| | - Katsumi Maenaka
- Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan.
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Abstract
The accessory protein Nef of human immunodeficiency virus (HIV) is a primary determinant of viral pathogenesis. Nef is abundantly expressed during infection and reroutes a variety of cell surface proteins to disrupt host immunity and promote the viral replication cycle. Nef counteracts host defenses by sequestering and/or degrading its targets via the endocytic and secretory pathways. Nef does this by physically engaging a number of host trafficking proteins. Substantial progress has been achieved in identifying the targets of Nef, and a structural and mechanistic understanding of Nef's ability to command the protein trafficking machinery has recently started to coalesce. Comparative analysis of HIV and simian immunodeficiency virus (SIV) Nef proteins in the context of recent structural advances sheds further light on both viral evolution and the mechanisms whereby trafficking is hijacked. This review describes how advances in cell and structural biology are uncovering in growing detail how Nef subverts the host immune system, facilitates virus release, and enhances viral infectivity.
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50
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Evans JP, Liu SL. Multifaceted Roles of TIM-Family Proteins in Virus-Host Interactions. Trends Microbiol 2019; 28:224-235. [PMID: 31732320 DOI: 10.1016/j.tim.2019.10.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 09/25/2019] [Accepted: 10/10/2019] [Indexed: 01/16/2023]
Abstract
To enhance infection, enveloped viruses exploit adhesion molecules expressed on the surface of host cells. Specifically, phosphatidylserine (PS) receptors - including members of the human T cell immunoglobulin and mucin domain (TIM)-family - have gained attention for their ability to mediate the entry of many enveloped viruses. However, recent evidence that TIM-1 can restrict viral release reveals a new role for these PS receptors. Additionally, viral factors such as the HIV-1 accessory protein Nef can antagonize this antiviral activity of TIM-1 while host restriction factors such as SERINC5 can enhance it. In this review, we examine the various roles of PS receptors, specifically TIM-family proteins, and the intricate relationship between host and viral factors. Elucidating the multifunctional roles of PS receptors in virus-host interaction is important for understanding viral pathogenesis and developing novel antiviral therapeutics.
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Affiliation(s)
- John P Evans
- Molecular, Cellular and Developmental Biology Program, The Ohio State University, Columbus, OH 43210, USA; Center for Retrovirus Research, The Ohio State University, Columbus, OH 43210, USA; Department of Veterinary Biosciences, The Ohio State University, Columbus, OH 43210, USA
| | - Shan-Lu Liu
- Center for Retrovirus Research, The Ohio State University, Columbus, OH 43210, USA; Department of Veterinary Biosciences, The Ohio State University, Columbus, OH 43210, USA; Department of Microbial Infection and Immunity, The Ohio State University, Columbus, OH 43210, USA; Viruses and Emerging Pathogens Program, Infectious Diseases Institute, The Ohio State University, Columbus, OH 43210, USA.
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