1
|
Habib A, Liang Y, Zhu N. Exosomes multifunctional roles in HIV-1: insight into the immune regulation, vaccine development and current progress in delivery system. Front Immunol 2023; 14:1249133. [PMID: 37965312 PMCID: PMC10642161 DOI: 10.3389/fimmu.2023.1249133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 10/17/2023] [Indexed: 11/16/2023] Open
Abstract
Human Immunodeficiency Virus (HIV-1) is known to establish a persistent latent infection. The use of combination antiretroviral therapy (cART) can effectively reduce the viral load, but the treatment can be costly and may lead to the development of drug resistance and life-shortening side effects. It is important to develop an ideal and safer in vivo target therapy that will effectively block viral replication and expression in the body. Exosomes have recently emerged as a promising drug delivery vehicle due to their low immunogenicity, nanoscale size (30-150nm), high biocompatibility, and stability in the targeted area. Exosomes, which are genetically produced by different types of cells such as dendritic cells, neurons, T and B cells, epithelial cells, tumor cells, and mast cells, are designed for efficient delivery to targeted cells. In this article, we review and highlight recent developments in the strategy and application of exosome-based HIV-1 vaccines. We also discuss the use of exosome-based antigen delivery systems in vaccine development. HIV-1 antigen can be loaded into exosomes, and this modified cargo can be delivered to target cells or tissues through different loading approaches. This review also discusses the immunological prospects of exosomes and their role as biomarkers in disease progression. However, there are significant administrative and technological obstacles that need to be overcome to fully harness the potential of exosome drug delivery systems.
Collapse
Affiliation(s)
- Arslan Habib
- Laboratory of Molecular Immunology, State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China
| | - Yulai Liang
- Laboratory of Molecular Immunology, State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China
| | - Naishuo Zhu
- Laboratory of Molecular Immunology, State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China
- Institute of Biomedical Sciences, School of Life Sciences, Fudan University, Shanghai, China
| |
Collapse
|
2
|
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.
Collapse
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
| |
Collapse
|
3
|
Hooy RM, Iwamoto Y, Tudorica DA, Ren X, Hurley JH. Self-assembly and structure of a clathrin-independent AP-1:Arf1 tubular membrane coat. SCIENCE ADVANCES 2022; 8:eadd3914. [PMID: 36269825 PMCID: PMC9586487 DOI: 10.1126/sciadv.add3914] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 09/01/2022] [Indexed: 05/28/2023]
Abstract
The adaptor protein (AP) complexes not only form the inner layer of clathrin coats but also have clathrin-independent roles in membrane traffic whose mechanisms are unknown. HIV-1 Nef hijacks AP-1 to sequester major histocompatibility complex class I (MHC-I), evading immune detection. We found that AP-1:Arf1:Nef:MHC-I forms a coat on tubulated membranes without clathrin and determined its structure. The coat assembles via Arf1 dimer interfaces. AP-1-positive tubules are enriched in cells upon clathrin knockdown. Nef localizes preferentially to AP-1 tubules in cells, explaining how Nef sequesters MHC-I. Coat contact residues are conserved across Arf isoforms and the Arf-dependent AP complexes AP-1, AP-3, and AP-4. Thus, AP complexes can self-assemble with Arf1 into tubular coats without clathrin or other scaffolding factors. The AP-1:Arf1 coat defines the structural basis of a broader class of tubulovesicular membrane coats as an intermediate in clathrin vesicle formation from internal membranes and as an MHC-I sequestration mechanism in HIV-1 infection.
Collapse
Affiliation(s)
- Richard M. Hooy
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
- California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Yuichiro Iwamoto
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
- California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Dan A. Tudorica
- California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, CA 94720, USA
- Graduate Group in Biophysics, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Xuefeng Ren
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
- California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, CA 94720, USA
| | - James H. Hurley
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
- California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, CA 94720, USA
- Graduate Group in Biophysics, University of California, Berkeley, Berkeley, CA 94720, USA
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA 94720, USA
| |
Collapse
|
4
|
Plasma-Enabled Smart Nanoexosome Platform as Emerging Immunopathogenesis for Clinical Viral Infection. Pharmaceutics 2022; 14:pharmaceutics14051054. [PMID: 35631640 PMCID: PMC9145689 DOI: 10.3390/pharmaceutics14051054] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 05/08/2022] [Accepted: 05/11/2022] [Indexed: 02/01/2023] Open
Abstract
Smart nanoexosomes are nanosized structures enclosed in lipid bilayers that are structurally similar to the viruses released by a variety of cells, including the cells lining the respiratory system. Of particular importance, the interaction between smart nanoexosomes and viruses can be used to develop antiviral drugs and vaccines. It is possible that nanoexosomes will be utilized and antibodies will be acquired more successfully for the transmission of an immune response if reconvalescent plasma (CP) is used instead of reconvalescent plasma exosomes (CPExo) in this concept. Convalescent plasma contains billions of smart nanoexosomes capable of transporting a variety of molecules, including proteins, lipids, RNA and DNA among other viral infections. Smart nanoexosomes are released from virus-infected cells and play an important role in mediating communication between infected and uninfected cells. Infections use the formation, production and release of smart nanoexosomes to enhance the infection, transmission and intercellular diffusion of viruses. Cell-free smart nanoexosomes produced by mesenchymal stem cells (MSCs) could also be used as cell-free therapies in certain cases. Smart nanoexosomes produced by mesenchymal stem cells can also promote mitochondrial function and heal lung injury. They can reduce cytokine storms and restore the suppression of host antiviral defenses weakened by viral infections. This study examines the benefits of smart nanoexosomes and their roles in viral transmission, infection, treatment, drug delivery and clinical applications. We also explore some potential future applications for smart nanoexosomes in the treatment of viral infections.
Collapse
|
5
|
Prévost J, Richard J, Gasser R, Medjahed H, Kirchhoff F, Hahn BH, Kappes JC, Ochsenbauer C, Duerr R, Finzi A. Detection of the HIV-1 Accessory Proteins Nef and Vpu by Flow Cytometry Represents a New Tool to Study Their Functional Interplay within a Single Infected CD4 + T Cell. J Virol 2022; 96:e0192921. [PMID: 35080425 PMCID: PMC8941894 DOI: 10.1128/jvi.01929-21] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 01/16/2022] [Indexed: 11/20/2022] Open
Abstract
The HIV-1 Nef and Vpu accessory proteins are known to protect infected cells from antibody-dependent cellular cytotoxicity (ADCC) responses by limiting exposure of CD4-induced (CD4i) envelope (Env) epitopes at the cell surface. Although both proteins target the host receptor CD4 for degradation, the extent of their functional redundancy is unknown. Here, we developed an intracellular staining technique that permits the intracellular detection of both Nef and Vpu in primary CD4+ T cells by flow cytometry. Using this method, we show that the combined expression of Nef and Vpu predicts the susceptibility of HIV-1-infected primary CD4+ T cells to ADCC by HIV+ plasma. We also show that Vpu cannot compensate for the absence of Nef, thus providing an explanation for why some infectious molecular clones that carry a LucR reporter gene upstream of Nef render infected cells more susceptible to ADCC responses. Our method thus represents a new tool to dissect the biological activity of Nef and Vpu in the context of other host and viral proteins within single infected CD4+ T cells. IMPORTANCE HIV-1 Nef and Vpu exert several biological functions that are important for viral immune evasion, release, and replication. Here, we developed a new method allowing simultaneous detection of these accessory proteins in their native form together with some of their cellular substrates. This allowed us to show that Vpu cannot compensate for the lack of a functional Nef, which has implications for studies that use Nef-defective viruses to study ADCC responses.
Collapse
Affiliation(s)
- Jérémie Prévost
- Centre de Recherche du CHUM, Montreal, Quebec, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, Quebec, Canada
| | - Jonathan Richard
- Centre de Recherche du CHUM, Montreal, Quebec, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, Quebec, Canada
| | - Romain Gasser
- Centre de Recherche du CHUM, Montreal, Quebec, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, Quebec, Canada
| | | | - Frank Kirchhoff
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
| | - Beatrice H. Hahn
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - John C. Kappes
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Christina Ochsenbauer
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Ralf Duerr
- Department of Microbiology, New York University School of Medicine, New York, New York, USA
| | - Andrés Finzi
- Centre de Recherche du CHUM, Montreal, Quebec, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, Quebec, Canada
- Department of Microbiology and Immunology, McGill University, Montreal, Quebec, Canada
| |
Collapse
|
6
|
Yu S, Ge H, Li S, Qiu HJ. Modulation of Macrophage Polarization by Viruses: Turning Off/On Host Antiviral Responses. Front Microbiol 2022; 13:839585. [PMID: 35222345 PMCID: PMC8874017 DOI: 10.3389/fmicb.2022.839585] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 01/12/2022] [Indexed: 11/17/2022] Open
Abstract
Macrophages are professional antigen-presenting cells and serve as the first line of defense against invading pathogens. Macrophages are polarized toward the proinflammatory classical (M1) or anti-inflammatory alternative (M2) phenotype upon viral infections. M1-polarized macrophages exert critical roles in antiviral responses via different mechanisms. Within the long competitive history between viruses and hosts, viruses have evolved various immune evasion strategies, inhibiting macrophage acquisition of an antiviral phenotype, impairing the antiviral responses of activated macrophages, and/or exploiting macrophage phenotypes for efficient replication. This review focuses on the sophisticated regulation of macrophage polarization utilized by viruses and is expected to provide systematic insights into the regulatory mechanisms of macrophage polarization by viruses and further facilitate the design of therapeutic targets for antivirals.
Collapse
|
7
|
Navarrete-Muñoz MA, Llorens C, Benito JM, Rallón N. Extracellular Vesicles as a New Promising Therapy in HIV Infection. Front Immunol 2022; 12:811471. [PMID: 35058938 PMCID: PMC8765339 DOI: 10.3389/fimmu.2021.811471] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 12/15/2021] [Indexed: 12/22/2022] Open
Abstract
Combination antiretroviral therapy (cART) effectively blocks HIV replication but cannot completely eliminate HIV from the body mainly due to establishment of a viral reservoir. To date, clinical strategies designed to replace cART for life and alternatively to eliminate the HIV reservoir have failed. The reduced expression of viral antigens in the latently infected cells is one of the main reasons behind the failure of the strategies to purge the HIV reservoir. This situation has forced the scientific community to search alternative therapeutic strategies to control HIV infection. In this regard, recent findings have pointed out extracellular vesicles as therapeutic agents with enormous potential to control HIV infection. This review focuses on their role as pro-viral and anti-viral factors, as well as their potential therapeutic applications.
Collapse
Affiliation(s)
- Maria A. Navarrete-Muñoz
- HIV and Viral Hepatitis Research Laboratory, Instituto de Investigación Sanitaria Fundación Jiménez Díaz (IIS-FJD), Universidad Autónoma de Madrid (UAM), Madrid, Spain
- Hospital Universitario Rey Juan Carlos, Móstoles, Spain
- Biotechvana, Madrid Scientific Park Foundation, Madrid, Spain
| | - Carlos Llorens
- Biotechvana, Madrid Scientific Park Foundation, Madrid, Spain
| | - José M. Benito
- HIV and Viral Hepatitis Research Laboratory, Instituto de Investigación Sanitaria Fundación Jiménez Díaz (IIS-FJD), Universidad Autónoma de Madrid (UAM), Madrid, Spain
- Hospital Universitario Rey Juan Carlos, Móstoles, Spain
| | - Norma Rallón
- HIV and Viral Hepatitis Research Laboratory, Instituto de Investigación Sanitaria Fundación Jiménez Díaz (IIS-FJD), Universidad Autónoma de Madrid (UAM), Madrid, Spain
- Hospital Universitario Rey Juan Carlos, Móstoles, Spain
| |
Collapse
|
8
|
Griffin BD, Corredor JC, Pei Y, Nagy É. Downregulation of Cell Surface Major Histocompatibility Complex Class I Expression Is Mediated by the Left-End Transcription Unit of Fowl Adenovirus 9. Viruses 2021; 13:v13112211. [PMID: 34835017 PMCID: PMC8619926 DOI: 10.3390/v13112211] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Revised: 10/27/2021] [Accepted: 10/27/2021] [Indexed: 01/16/2023] Open
Abstract
Major histocompatibility complex class I (MHC-I) molecules play a critical role in the host’s antiviral response by presenting virus-derived antigenic peptides to cytotoxic T lymphocytes (CTLs), enabling the clearance of virus-infected cells. Human adenoviruses evade CTL-mediated cell lysis, in part, by interfering directly with the MHC-I antigen presentation pathway through the expression of E3-19K, which binds both MHC-I and the transporter associated with antigen processing protein and sequestering MHC-I within the endoplasmic reticulum. Fowl adenoviruses have no homologues of E3-19K. Here, we show that representative virus isolates of the species Fowl aviadenovirus C, Fowl aviadenovirus D, and Fowl aviadenovirus E downregulate the cell surface expression of MHC-I in chicken hepatoma cells, resulting in 71%, 11%, and 14% of the baseline expression level, respectively, at 12 h post-infection. Furthermore, this work reports that FAdV-9 downregulates cell surface MHC-I through a minimum of two separate mechanisms—a lysosomal-independent mechanism that requires the presence of the fowl adenovirus early 1 (FE1) transcription unit located within the left terminal genomic region between nts 1 and 6131 and a lysosomal-dependent mechanism that does not require the presence of FE1. These results establish a new functional role for the FE1 transcription unit in immune evasion. These studies provide important new information about the immune evasion of FAdVs and will enhance our understanding of the pathogenesis of inclusion body hepatitis and advance the progress made in next-generation FAdV-based vectors.
Collapse
Affiliation(s)
| | | | | | - Éva Nagy
- Correspondence: ; Tel.: +1-519-824-4120
| |
Collapse
|
9
|
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.
Collapse
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
| |
Collapse
|
10
|
Kruize Z, van Nuenen AC, van Wijk SW, Girigorie AF, van Dort KA, Booiman T, Kootstra NA. Nef Obtained from Individuals with HIV-1 Vary in Their Ability to Antagonize SERINC3- and SERINC5-Mediated HIV-1 Restriction. Viruses 2021; 13:v13030423. [PMID: 33800773 PMCID: PMC8000780 DOI: 10.3390/v13030423] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 02/25/2021] [Accepted: 03/02/2021] [Indexed: 12/14/2022] Open
Abstract
Nef is a multifunctional viral protein that has the ability to downregulate cell surface molecules, including CD4 and major histocompatibility complex class I (MHC-I) and, as recently shown, also members of the serine incorporator family (SERINC). Here, we analyzed the impact of naturally occurring mutations in HIV-1 Nef on its ability to counteract SERINC restriction and the clinical course of infection. HIV-1 Nef sequences were obtained from 123 participants of the Amsterdam Cohort Studies and showed multiple amino acid variations and mutations. Most of the primary Nef proteins showed increased activity to counteract SERINC3 and SERINC5 as compared to NL4-3 Nef. Several mutations in Nef were associated with either an increased or decreased infectivity of Bal26-pseudotyped HIV-1 produced in the presence of SERINC3 or SERINC5. The 8R, 157N and R178G Nef mutations were shown to have an effect on disease progression. Survival analysis showed an accelerated disease progression of individuals infected with HIV-1 carrying arginine or asparagine at position 8 or 157 in Nef, respectively, or the R178G Nef mutation. Here, we observed that naturally occurring mutations in Nef affect the ability of Nef to counteract SERINC3- and SERINC5-mediated inhibition of viral infectivity. The majority of these Nef mutations had no significant effect on HIV-1 pathogenesis and only the 8R, 157N and R178G mutations were associated with disease course.
Collapse
|
11
|
Macken WL, Godwin A, Wheway G, Stals K, Nazlamova L, Ellard S, Alfares A, Aloraini T, AlSubaie L, Alfadhel M, Alajaji S, Wai HA, Self J, Douglas AGL, Kao AP, Guille M, Baralle D. Biallelic variants in COPB1 cause a novel, severe intellectual disability syndrome with cataracts and variable microcephaly. Genome Med 2021; 13:34. [PMID: 33632302 PMCID: PMC7908744 DOI: 10.1186/s13073-021-00850-w] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 02/11/2021] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Coat protein complex 1 (COPI) is integral in the sorting and retrograde trafficking of proteins and lipids from the Golgi apparatus to the endoplasmic reticulum (ER). In recent years, coat proteins have been implicated in human diseases known collectively as "coatopathies". METHODS Whole exome or genome sequencing of two families with a neuro-developmental syndrome, variable microcephaly and cataracts revealed biallelic variants in COPB1, which encodes the beta-subunit of COPI (β-COP). To investigate Family 1's splice donor site variant, we undertook patient blood RNA studies and CRISPR/Cas9 modelling of this variant in a homologous region of the Xenopus tropicalis genome. To investigate Family 2's missense variant, we studied cellular phenotypes of human retinal epithelium and embryonic kidney cell lines transfected with a COPB1 expression vector into which we had introduced Family 2's mutation. RESULTS We present a new recessive coatopathy typified by severe developmental delay and cataracts and variable microcephaly. A homozygous splice donor site variant in Family 1 results in two aberrant transcripts, one of which causes skipping of exon 8 in COPB1 pre-mRNA, and a 36 amino acid in-frame deletion, resulting in the loss of a motif at a small interaction interface between β-COP and β'-COP. Xenopus tropicalis animals with a homologous mutation, introduced by CRISPR/Cas9 genome editing, recapitulate features of the human syndrome including microcephaly and cataracts. In vitro modelling of the COPB1 c.1651T>G p.Phe551Val variant in Family 2 identifies defective Golgi to ER recycling of this mutant β-COP, with the mutant protein being retarded in the Golgi. CONCLUSIONS This adds to the growing body of evidence that COPI subunits are essential in brain development and human health and underlines the utility of exome and genome sequencing coupled with Xenopus tropicalis CRISPR/Cas modelling for the identification and characterisation of novel rare disease genes.
Collapse
Affiliation(s)
- William L Macken
- Wessex Clinical Genetics Service, Princess Anne Hospital, University Hospital Southampton NHS Foundation Trust, Coxford Rd, Southampton, SO165YA, UK
| | - Annie Godwin
- European Xenopus Resource Centre, University of Portsmouth School of Biological Sciences, King Henry Building, King Henry I Street, Portsmouth, PO1 2DY, UK
| | - Gabrielle Wheway
- Faculty of Medicine, University of Southampton, Duthie Building, Southampton General Hospital, Tremona Road, Southampton, SO16 6YD, UK
| | - Karen Stals
- Exeter Genomics Laboratory, Level 3 RILD building, Royal Devon & Exeter NHS Foundation Trust, Barrack Road, Exeter, EX2 5DW, UK
| | - Liliya Nazlamova
- Faculty of Medicine, University of Southampton, Duthie Building, Southampton General Hospital, Tremona Road, Southampton, SO16 6YD, UK
| | - Sian Ellard
- Exeter Genomics Laboratory, Level 3 RILD building, Royal Devon & Exeter NHS Foundation Trust, Barrack Road, Exeter, EX2 5DW, UK
- University of Exeter Medical School, RILD building, Royal Devon & Exeter NHS Foundation Trust, Barrack Road, Exeter, EX2 5DW, UK
| | - Ahmed Alfares
- Department of Pediatrics, College of Medicine, Qassim University, Qassim, Saudi Arabia
- Department of Pathology and Laboratory Medicine, King Abdulaziz Medical City, Riyadh, Saudi Arabia
| | - Taghrid Aloraini
- Department of Pathology and Laboratory Medicine, King Abdulaziz Medical City, Riyadh, Saudi Arabia
| | - Lamia AlSubaie
- Division of Genetics, Department of Pediatrics, King Abdullah Specialized Children Hospital, King Abdulaziz Medical City, Ministry of National Guard Health Affairs (MNGHA), Riyadh, Saudi Arabia
- King Abdullah International Medical Research Centre, Ministry of National Guard Health Affairs (MNGHA), Riyadh, Saudi Arabia
| | - Majid Alfadhel
- Division of Genetics, Department of Pediatrics, King Abdullah Specialized Children Hospital, King Abdulaziz Medical City, Ministry of National Guard Health Affairs (MNGHA), Riyadh, Saudi Arabia
- King Abdullah International Medical Research Centre, Ministry of National Guard Health Affairs (MNGHA), Riyadh, Saudi Arabia
- King Saud bin Abdulaziz University for Health Sciences, Ministry of National Guard Health Affairs (MNGHA), Riyadh, Saudi Arabia
| | - Sulaiman Alajaji
- King Saud bin Abdulaziz University for Health Sciences, Ministry of National Guard Health Affairs (MNGHA), Riyadh, Saudi Arabia
- Division of Allergy and Clinical Immunology, Department of Pediatrics, King Abdullah Specialized Children Hospital, King Abdulaziz Medical City, Ministry of National Guard Health Affairs (MNGHA), Riyadh, Saudi Arabia
| | - Htoo A Wai
- Faculty of Medicine, University of Southampton, Duthie Building, Southampton General Hospital, Tremona Road, Southampton, SO16 6YD, UK
| | - Jay Self
- Faculty of Medicine, University of Southampton, Duthie Building, Southampton General Hospital, Tremona Road, Southampton, SO16 6YD, UK
| | - Andrew G L Douglas
- Wessex Clinical Genetics Service, Princess Anne Hospital, University Hospital Southampton NHS Foundation Trust, Coxford Rd, Southampton, SO165YA, UK
- Faculty of Medicine, University of Southampton, Duthie Building, Southampton General Hospital, Tremona Road, Southampton, SO16 6YD, UK
| | - Alexander P Kao
- Zeiss Global Centre, School of Mechanical and Design Engineering, University of Portsmouth, Portsmouth, PO1 3DJ, UK
| | - Matthew Guille
- European Xenopus Resource Centre, University of Portsmouth School of Biological Sciences, King Henry Building, King Henry I Street, Portsmouth, PO1 2DY, UK.
| | - Diana Baralle
- Wessex Clinical Genetics Service, Princess Anne Hospital, University Hospital Southampton NHS Foundation Trust, Coxford Rd, Southampton, SO165YA, UK.
- Faculty of Medicine, University of Southampton, Duthie Building, Southampton General Hospital, Tremona Road, Southampton, SO16 6YD, UK.
| |
Collapse
|
12
|
Chen H, Li K, Li Y, Xie P, He J, Zhang H. An integrative pan-cancer analysis of COPB1 based on data mining. Cancer Biomark 2021; 30:13-27. [PMID: 32986658 DOI: 10.3233/cbm-200398] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
BACKGROUND Cancer will become the leading cause of death worldwide in the 21st century, meanwhile, immunotherapy is the most popular cancer treatment method in recent years. COPI Coat Complex Subunit Beta 1 (COPB1) relates to human innate immunity. However, the role of COPB1 in pan-cancer remains unclear. OBJECTIVE The purpose of this study was to explore the relationship between COPB1 mRNA expression and tumor infiltrating lymphocytes and immune examination sites in pan-cancer. METHODS Data from multiple online databases were collected. The BioGPS, UALCAN Database, COSMIC, cBioPortal, Cancer Regulome tools, Kaplan-Meier Plotter and TIMER website were utilized to perform the analysis. RESULTS Upregulation of COPB1 has been widely observed in tumor tissues compared with normal tissues. Although COPB1 has poor prognosis in pan-cancer, COPB1 high expression was beneficial to the survival of ESCA patients. Unlike ESCA, COPB1 expression in STAD was positively correlated with tumor infiltrating lymphocytes, including B cells, CD8+ T cells, neutrophils, macrophages, and dendritic cells. Finally, we also found that the expression of COPB1 in STAD was positively correlated with PD-L1 and CTLA4. CONCLUSIONS COPB1 may be a prognostic biomarker for pan-carcinoma, and also provide an immune anti-tumor strategy for STAD based on the expression of COPB1.
Collapse
|
13
|
Recent Progress on Exosomes in RNA Virus Infection. Viruses 2021; 13:v13020256. [PMID: 33567490 PMCID: PMC7915723 DOI: 10.3390/v13020256] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 02/02/2021] [Accepted: 02/04/2021] [Indexed: 12/16/2022] Open
Abstract
Recent research indicates that most tissue and cell types can secrete and release membrane-enclosed small vesicles, known as exosomes, whose content reflects the physiological/pathological state of the cells from which they originate. These exosomes participate in the communication and cell-to-cell transfer of biologically active proteins, lipids, and nucleic acids. Studies of RNA viruses have demonstrated that exosomes release regulatory factors from infected cells and deliver other functional host genetic elements to neighboring cells, and these functions are involved in the infection process and modulate the cellular responses. This review provides an overview of the biogenesis, composition, and some of the most striking functions of exosome secretion and identifies physiological/pathological areas in need of further research. While initial indications suggest that exosome-mediated pathways operate in vivo, the exosome mechanisms involved in the related effects still need to be clarified. The current review focuses on the role of exosomes in RNA virus infections, with an emphasis on the potential contributions of exosomes to pathogenesis.
Collapse
|
14
|
Ecker M, Redpath GMI, Nicovich PR, Rossy J. Quantitative visualization of endocytic trafficking through photoactivation of fluorescent proteins. Mol Biol Cell 2021; 32:892-902. [PMID: 33534630 PMCID: PMC8108533 DOI: 10.1091/mbc.e20-10-0669] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Endocytic trafficking controls the density of molecules at the plasma membrane and by doing so, the cell surface profile, which in turn determines how cells interact with their environment. A full apprehension of any cellular process necessitates understanding how proteins associated with the plasma membrane are endocytosed, how they are sorted after internalization, and if and how they are recycled to the plasma membrane. To date, it is still difficult to experimentally gain access to this information, even more to do it in a quantitative way. Here we present a toolset based on photoactivation of fluorescent proteins that enabled us to generate quantitative information on endocytosis, incorporation into sorting and recycling endosomes, delivery from endosomes to the plasma membrane, and on the type of vesicles performing intracellular transport. We illustrate these approaches by revealing striking differences in the endocytic trafficking of T-cell receptor and CD4, which bind to the same molecule at the surface of antigen-presenting cells during T-cell activation.
Collapse
Affiliation(s)
- Manuela Ecker
- EMBL Australia Node in Single Molecule Science, School of Medical Sciences and the ARC Centre of Excellence in Advanced Molecular Imaging, University of New South Wales, Sydney, NSW 2052, Australia
| | - Gregory M I Redpath
- EMBL Australia Node in Single Molecule Science, School of Medical Sciences and the ARC Centre of Excellence in Advanced Molecular Imaging, University of New South Wales, Sydney, NSW 2052, Australia
| | | | - Jérémie Rossy
- EMBL Australia Node in Single Molecule Science, School of Medical Sciences and the ARC Centre of Excellence in Advanced Molecular Imaging, University of New South Wales, Sydney, NSW 2052, Australia.,Biotechnology Institute Thurgau (BITg) at the University of Konstanz, 8280 Kreuzlingen, Switzerland.,Department of Biology, University of Konstanz, 78457 Konstanz, Germany
| |
Collapse
|
15
|
Rezaie J, Aslan C, Ahmadi M, Zolbanin NM, Kashanchi F, Jafari R. The versatile role of exosomes in human retroviral infections: from immunopathogenesis to clinical application. Cell Biosci 2021; 11:19. [PMID: 33451365 PMCID: PMC7810184 DOI: 10.1186/s13578-021-00537-0] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 01/09/2021] [Indexed: 02/06/2023] Open
Abstract
Eukaryotic cells produce extracellular vesicles (EVs) mediating intercellular communication. These vesicles encompass many bio-molecules such as proteins, nucleic acids, and lipids that are transported between cells and regulate pathophysiological actions in the recipient cell. Exosomes originate from multivesicular bodies inside cells and microvesicles shed from the plasma membrane and participate in various pathological conditions. Retroviruses such as Human Immunodeficiency Virus -type 1 (HIV-1) and Human T-cell leukemia virus (HTLV)-1 engage exosomes for spreading and infection. Exosomes from virus-infected cells transfer viral components such as miRNAs and proteins that promote infection and inflammation. Additionally, these exosomes deliver virus receptors to target cells that make them susceptible to virus entry. HIV-1 infected cells release exosomes that contribute to the pathogenesis including neurological disorders and malignancy. Exosomes can also potentially carry out as a modern approach for the development of HIV-1 and HTLV-1 vaccines. Furthermore, as exosomes are present in most biological fluids, they hold the supreme capacity for clinical usage in the early diagnosis and prognosis of viral infection and associated diseases. Our current knowledge of exosomes' role from virus-infected cells may provide an avenue for efficient retroviruses associated with disease prevention. However, the exact mechanism involved in retroviruses infection/ inflammation remains elusive and related exosomes research will shed light on the mechanisms of pathogenesis.
Collapse
Affiliation(s)
- Jafar Rezaie
- Solid Tumor Research Center, Cellular and Molecular Medicine Research Institute, Urmia University of Medical Sciences, Shafa St, Ershad Blvd., P.O. Box: 1138, 57147, Urmia, Iran
| | - Cynthia Aslan
- Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
- Department of Immunology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mahdi Ahmadi
- Tuberculosis and Lung Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Naime Majidi Zolbanin
- Department of Pharmacology and Toxicology, School of Pharmacy, Urmia University of Medical Sciences, Urmia, Iran
| | - Fatah Kashanchi
- School of Systems Biology, Laboratory of Molecular Virology, George Mason University, Discovery Hall Room 182, 10900 University Blvd., Manassas, VA, 20110, USA.
| | - Reza Jafari
- Solid Tumor Research Center, Cellular and Molecular Medicine Research Institute, Urmia University of Medical Sciences, Shafa St, Ershad Blvd., P.O. Box: 1138, 57147, Urmia, Iran.
| |
Collapse
|
16
|
Martins SDT, Alves LR. Extracellular Vesicles in Viral Infections: Two Sides of the Same Coin? Front Cell Infect Microbiol 2020; 10:593170. [PMID: 33335862 PMCID: PMC7736630 DOI: 10.3389/fcimb.2020.593170] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Accepted: 10/30/2020] [Indexed: 12/11/2022] Open
Abstract
Extracellular vesicles are small membrane structures containing proteins and nucleic acids that are gaining a lot of attention lately. They are produced by most cells and can be detected in several body fluids, having a huge potential in therapeutic and diagnostic approaches. EVs produced by infected cells usually have a molecular signature that is very distinct from healthy cells. For intracellular pathogens like viruses, EVs can have an even more complex function, since the viral biogenesis pathway can overlap with EV pathways in several ways, generating a continuum of particles, like naked virions, EVs containing infective viral genomes and quasi-enveloped viruses, besides the classical complete viral particles that are secreted to the extracellular space. Those particles can act in recipient cells in different ways. Besides being directly infective, they also can prime neighbor cells rendering them more susceptible to infection, block antiviral responses and deliver isolated viral molecules. On the other hand, they can trigger antiviral responses and cytokine secretion even in uninfected cells near the infection site, helping to fight the infection and protect other cells from the virus. This protective response can also backfire, when a massive inflammation facilitated by those EVs can be responsible for bad clinical outcomes. EVs can help or harm the antiviral response, and sometimes both mechanisms are observed in infections by the same virus. Since those pathways are intrinsically interlinked, understand the role of EVs during viral infections is crucial to comprehend viral mechanisms and respond better to emerging viral diseases.
Collapse
Affiliation(s)
- Sharon de Toledo Martins
- Gene Expression Regulation Laboratory, Carlos Chagas Institute, ICC-Fiocruz, Curitiba, Brazil.,Biological Sciences Sector, Federal University of Paraná (UFPR), Curitiba, Brazil
| | - Lysangela Ronalte Alves
- Gene Expression Regulation Laboratory, Carlos Chagas Institute, ICC-Fiocruz, Curitiba, Brazil
| |
Collapse
|
17
|
Zhang HG, Guo J, Yuan Y, Zuo Y, Liu J, Zhu L, Miao Y, Chen X, Jin L, Huang F, Ren T, He J, Shi W, Wen Z, Zhu C, Zheng H, Dong C, Qian F. Ubiquitin E3 Ligase c-Cbl Is a Host Negative Regulator of Nef Protein of HIV-1. Front Microbiol 2020; 11:597972. [PMID: 33329486 PMCID: PMC7710902 DOI: 10.3389/fmicb.2020.597972] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2020] [Accepted: 10/28/2020] [Indexed: 11/23/2022] Open
Abstract
Nef is an accessory protein encoded by human immunodeficiency virus type-1 (HIV-1) and plays important roles in regulating HIV-1 infection and viral replication. Interestingly, HIV-1 Nef can promote degradation of numerous host proteins to disrupt cellular antiviral immune response. However, how HIV-1 Nef is degraded by host factors remains largely unexplored. Here, we identified c-Cbl as a host ubiquitin E3 ligase of HIV-1 Nef. We found that c-Cbl interacts with Nef and reduces protein levels of HIV-1 Nef. Further studies demonstrated that c-Cbl promoted Lys48-linked polyubiquitination of HIV-1 Nef, thus attenuating protein stability of HIV-1 Nef. Importantly, cellular c-Cbl ubiquitinated and degraded Nef proteins produced by HIV-1 NL4-3 virions, and ultimately attenuated HIV-1 virulence for infection of THP1 cells. This study reveals a ubiquitination and proteasome-dependent degradation mechanism of HIV-1 Nef protein, and could provide potential strategies for fighting against HIV-1.
Collapse
Affiliation(s)
- Hong-Guang Zhang
- Institutes of Biology and Medical Sciences, Soochow University, Suzhou, China.,Jiangsu Key Laboratory of Infection and Immunity, Soochow University, Suzhou, China
| | - Jing Guo
- Institutes of Biology and Medical Sciences, Soochow University, Suzhou, China.,Jiangsu Key Laboratory of Infection and Immunity, Soochow University, Suzhou, China
| | - Yukang Yuan
- Institutes of Biology and Medical Sciences, Soochow University, Suzhou, China.,Jiangsu Key Laboratory of Infection and Immunity, Soochow University, Suzhou, China
| | - Yibo Zuo
- Institutes of Biology and Medical Sciences, Soochow University, Suzhou, China.,Jiangsu Key Laboratory of Infection and Immunity, Soochow University, Suzhou, China
| | - Jin Liu
- The Second Affiliated Hospital of Soochow University, The Affiliated Infectious Diseases Hospital of Soochow University, Suzhou, China
| | - Li Zhu
- The Second Affiliated Hospital of Soochow University, The Affiliated Infectious Diseases Hospital of Soochow University, Suzhou, China
| | - Ying Miao
- Institutes of Biology and Medical Sciences, Soochow University, Suzhou, China.,Jiangsu Key Laboratory of Infection and Immunity, Soochow University, Suzhou, China
| | - Xiangjie Chen
- Institutes of Biology and Medical Sciences, Soochow University, Suzhou, China.,Jiangsu Key Laboratory of Infection and Immunity, Soochow University, Suzhou, China
| | - Lincong Jin
- Institutes of Biology and Medical Sciences, Soochow University, Suzhou, China.,Jiangsu Key Laboratory of Infection and Immunity, Soochow University, Suzhou, China
| | - Fan Huang
- Institutes of Biology and Medical Sciences, Soochow University, Suzhou, China.,Jiangsu Key Laboratory of Infection and Immunity, Soochow University, Suzhou, China
| | - Tengfei Ren
- Institutes of Biology and Medical Sciences, Soochow University, Suzhou, China.,Jiangsu Key Laboratory of Infection and Immunity, Soochow University, Suzhou, China
| | - Jiuyi He
- Institutes of Biology and Medical Sciences, Soochow University, Suzhou, China.,Jiangsu Key Laboratory of Infection and Immunity, Soochow University, Suzhou, China
| | - Weifeng Shi
- Department of Laboratory Medicine, The Third Affiliated Hospital of Soochow University, Changzhou, China
| | - Zhenke Wen
- Institutes of Biology and Medical Sciences, Soochow University, Suzhou, China
| | - Chuanwu Zhu
- The Second Affiliated Hospital of Soochow University, The Affiliated Infectious Diseases Hospital of Soochow University, Suzhou, China
| | - Hui Zheng
- Institutes of Biology and Medical Sciences, Soochow University, Suzhou, China.,Jiangsu Key Laboratory of Infection and Immunity, Soochow University, Suzhou, China
| | - Chunsheng Dong
- Institutes of Biology and Medical Sciences, Soochow University, Suzhou, China.,Jiangsu Key Laboratory of Infection and Immunity, Soochow University, Suzhou, China
| | - Feng Qian
- The Second Affiliated Hospital of Soochow University, The Affiliated Infectious Diseases Hospital of Soochow University, Suzhou, China
| |
Collapse
|
18
|
|
19
|
Hassanpour M, Rezaie J, Nouri M, Panahi Y. The role of extracellular vesicles in COVID-19 virus infection. INFECTION, GENETICS AND EVOLUTION : JOURNAL OF MOLECULAR EPIDEMIOLOGY AND EVOLUTIONARY GENETICS IN INFECTIOUS DISEASES 2020; 85:104422. [PMID: 32544615 PMCID: PMC7293471 DOI: 10.1016/j.meegid.2020.104422] [Citation(s) in RCA: 147] [Impact Index Per Article: 36.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Revised: 06/10/2020] [Accepted: 06/11/2020] [Indexed: 12/11/2022]
Abstract
Extracellular vesicles releasing from various types of cells contribute to intercellular communication via delivering bio-molecules like nucleic acids, proteins, and lipids to recipient cells. Exosomes are 30-120 nm extracellular vesicles that participate in several pathological conditions. Virus-infected cells release exosomes that are implicated in infection through transferring viral components such as viral-derived miRNAs and proteins. As well, exosomes contain receptors for viruses that make recipient cells susceptible to virus entry. Since December 2019, SARS-CoV-2 (COVID-19) infection has become a worldwide urgent public health concern. There is currently no vaccine or specific antiviral treatment existing for COVID-19 virus infection. Hence, it is critical to find a safe and effective therapeutic tool to patients with severe COVID-19 virus infection. Extracellular vesicles may contribute to spread this virus as they transfer such receptors as CD9 and ACE2, which make recipient cells susceptible to virus docking. Upon entry, COVID-19 virus may be directed into the exosomal pathway, and its component is packaged into exosomes for secretion. Exosome-based strategies for the treatment of COVID-19 virus infection may include following items: inhibition of exosome biogenesis and uptake, exosome-therapy, exosome-based drug delivery system, and exosome-based vaccine. Mesenchymal stem cells can suppress nonproductive inflammation and improve/repair lung cells including endothelial and alveolar cells, which damaged by COVID-19 virus infection. Understanding molecular mechanisms behind extracellular vesicles related COVID-19 virus infection may provide us with an avenue to identify its entry, replication, spreading, and infection to overcome its adverse effects.
Collapse
Affiliation(s)
- Mehdi Hassanpour
- Stem Cell Research Center, Tabriz University of Medical Sciences, Tabriz, Iran,Department of Clinical Biochemistry, Laboratory Medicine, School of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran,Stem Cell and Regenerative Medicine Institute, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Jafar Rezaie
- Solid Tumor Research Center, Cellular and Molecular Medicine Research Institute, Urmia University of Medical Sciences, Urmia, Iran,Correspondence to: J. Rezaie, Solid Tumor Research Center, Research Institute on Cellular and Molecular Medicine, Urmia University of Medical Sciences, Shafa St, Ershad Blvd., P.O. BoX: 1138, 57147 Urmia, Iran
| | - Mohammad Nouri
- Stem Cell Research Center, Tabriz University of Medical Sciences, Tabriz, Iran,Department of Clinical Biochemistry, Laboratory Medicine, School of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran,Stem Cell and Regenerative Medicine Institute, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Yunes Panahi
- Pharmacy Department, Faculty of Pharmacy, Baqiyatallah University of Medical Sciences, Tehran, Iran,Correspondence to: Y. Panahi, Clinical Pharmacy Department, Faculty of Pharmacy, Baqiyatallah University of Medical Sciences, Tehran 1435916471, Iran
| |
Collapse
|
20
|
McNamara RP, Dittmer DP. Extracellular vesicles in virus infection and pathogenesis. Curr Opin Virol 2020; 44:129-138. [PMID: 32846272 PMCID: PMC7755726 DOI: 10.1016/j.coviro.2020.07.014] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Revised: 07/18/2020] [Accepted: 07/20/2020] [Indexed: 12/11/2022]
Abstract
Viruses are obligate intracellular parasites that usurp cellular signaling networks to promote pathogen spread and disease progression. Signaling through extracellular vesicles (EVs) is an emerging field of study in the virus-host interaction network. EVs relay information both locally and distally through incorporated contents, typically without tripping innate immune sensors. Therefore, this extracellular signaling axis presents itself as a tantalizing target for promoting a favorable niche for the pathogen(s) takeover of the host, particularly for chronic infections. From the incorporation of virus-encoded molecules such as micro RNAs and proteins/enzymes to the envelopment of entire infectious particles, evolutionary distinct viruses have shown a remarkable ability to converge on this means of communication. In this review, we will cover the recent advances in this field and explore how EV can be used as potential biomarkers for chronic, persistent, or latent virus infections.
Collapse
Affiliation(s)
- Ryan P McNamara
- Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, United States; Department of Microbiology and Immunology, The University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, United States
| | - Dirk P Dittmer
- Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, United States; Department of Microbiology and Immunology, The University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, United States.
| |
Collapse
|
21
|
Painter MM, Zimmerman GE, Merlino MS, Robertson AW, Terry VH, Ren X, McLeod MR, Gomez-Rodriguez L, Garcia KA, Leonard JA, Leopold KE, Neevel AJ, Lubow J, Olson E, Piechocka-Trocha A, Collins DR, Tripathi A, Raghavan M, Walker BD, Hurley JH, Sherman DH, Collins KL. Concanamycin A counteracts HIV-1 Nef to enhance immune clearance of infected primary cells by cytotoxic T lymphocytes. Proc Natl Acad Sci U S A 2020; 117:23835-23846. [PMID: 32900948 PMCID: PMC7519347 DOI: 10.1073/pnas.2008615117] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Nef is an HIV-encoded accessory protein that enhances pathogenicity by down-regulating major histocompatibility class I (MHC-I) expression to evade killing by cytotoxic T lymphocytes (CTLs). A potent Nef inhibitor that restores MHC-I is needed to promote immune-mediated clearance of HIV-infected cells. We discovered that the plecomacrolide family of natural products restored MHC-I to the surface of Nef-expressing primary cells with variable potency. Concanamycin A (CMA) counteracted Nef at subnanomolar concentrations that did not interfere with lysosomal acidification or degradation and were nontoxic in primary cell cultures. CMA specifically reversed Nef-mediated down-regulation of MHC-I, but not CD4, and cells treated with CMA showed reduced formation of the Nef:MHC-I:AP-1 complex required for MHC-I down-regulation. CMA restored expression of diverse allotypes of MHC-I in Nef-expressing cells and inhibited Nef alleles from divergent clades of HIV and simian immunodeficiency virus, including from primary patient isolates. Lastly, we found that restoration of MHC-I in HIV-infected cells was accompanied by enhanced CTL-mediated clearance of infected cells comparable to genetic deletion of Nef. Thus, we propose CMA as a lead compound for therapeutic inhibition of Nef to enhance immune-mediated clearance of HIV-infected cells.
Collapse
Affiliation(s)
- Mark M Painter
- Graduate Program in Immunology, University of Michigan, Ann Arbor, MI 48109
| | | | - Madeline S Merlino
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109
| | - Andrew W Robertson
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109
- Natural Products Discovery Core, Life Sciences Institute, University of Michigan Ann Arbor, MI 48109
| | - Valeri H Terry
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109
| | - Xuefeng Ren
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720
- California Institute for Quantitative Biosciences, University of California, Berkeley, CA 94720
| | - Megan R McLeod
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109
| | - Lyanne Gomez-Rodriguez
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109
- Graduate Program in Chemical Biology, University of Michigan, Ann Arbor, MI 48109
| | - Kirsten A Garcia
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109
| | - Jolie A Leonard
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109
| | - Kay E Leopold
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109
| | - Andrew J Neevel
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109
| | - Jay Lubow
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI 48109
| | - Eli Olson
- Graduate Program in Immunology, University of Michigan, Ann Arbor, MI 48109
| | - Alicja Piechocka-Trocha
- Ragon Institute of MGH, MIT and Harvard, Cambridge, MA 02139
- Howard Hughes Medical Institute, Chevy Chase, MD 20815
| | - David R Collins
- Ragon Institute of MGH, MIT and Harvard, Cambridge, MA 02139
- Howard Hughes Medical Institute, Chevy Chase, MD 20815
| | - Ashootosh Tripathi
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109
- Natural Products Discovery Core, Life Sciences Institute, University of Michigan Ann Arbor, MI 48109
- Department of Medicinal Chemistry, University of Michigan, Ann Arbor, MI 48109
| | - Malini Raghavan
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI 48109
| | - Bruce D Walker
- Ragon Institute of MGH, MIT and Harvard, Cambridge, MA 02139
- Howard Hughes Medical Institute, Chevy Chase, MD 20815
| | - James H Hurley
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720
- California Institute for Quantitative Biosciences, University of California, Berkeley, CA 94720
| | - David H Sherman
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI 48109
- Department of Medicinal Chemistry, University of Michigan, Ann Arbor, MI 48109
| | - Kathleen L Collins
- Graduate Program in Immunology, University of Michigan, Ann Arbor, MI 48109;
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI 48109
- Cellular and Molecular Biology Graduate Program, University of Michigan, Ann Arbor, MI 48109
| |
Collapse
|
22
|
Proulx J, Borgmann K, Park IW. Post-translational modifications inducing proteasomal degradation to counter HIV-1 infection. Virus Res 2020; 289:198142. [PMID: 32882242 DOI: 10.1016/j.virusres.2020.198142] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2020] [Revised: 08/20/2020] [Accepted: 08/21/2020] [Indexed: 12/14/2022]
Abstract
Post-translational modifications (PTMs) are integral to regulating a wide variety of cellular processes in eukaryotic cells, such as regulation of protein stability, alteration of celluar location, protein activity modulation, and regulation of protein interactions. HIV-1, like other eukaryotic viruses, and its infected host exploit the proteasomal degradation system for their respective proliferation and survival, using various PTMs, including but not limited to ubiquitination, SUMOylation, NEDDylation, interferon-stimulated gene (ISG)ylation. Essentially all viral proteins within the virions -- and in the HIV-1-infected cells -- interact with their cellular counterparts for this degradation, utilizing ubiquitin (Ub), and the Ub-like (Ubl) modifiers less frequently, to eliminate the involved proteins throughout the virus life cycle, from the entry step to release of the assembled virus particles. Such interplay is pivotal for, on the one hand, the cell to restrict proliferation of the infecting virus, and on the other, for molecular counteraction by the virus to overcome this cellular protein-imposed restriction. Recent reports indicate that not only viral/cellular proteins but also viral/viral protein interactions play vital roles in regulating viral protein stability. We hence give an overview of the molecular processes of PTMs involved in proteasomal degradation of the viral and cellular proteins, and the viral/viral and viral/cellular protein interplay in restriction and competition for HIV-1 vs. host cell survival. Insights in this realm could open new avenues for developing therapeutics against HIV-1 via targeting specific steps of the proteasome degradation pathway during the HIV-1 life cycle.
Collapse
Affiliation(s)
- Jessica Proulx
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX, 76107, United States
| | - Kathleen Borgmann
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX, 76107, United States
| | - In-Woo Park
- Microbiology, Immunology, and Genetics, University of North Texas Health Science Center, Fort Worth, TX, 76107, United States.
| |
Collapse
|
23
|
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.
Collapse
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.
| |
Collapse
|
24
|
Ali A, Farooqui SR, Rai J, Singh J, Kumar V, Mishra R, Banerjea AC. HIV-1 Nef promotes ubiquitination and proteasomal degradation of p53 tumor suppressor protein by using E6AP. Biochem Biophys Res Commun 2020; 529:1038-1044. [PMID: 32819562 DOI: 10.1016/j.bbrc.2020.05.188] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 05/25/2020] [Indexed: 01/19/2023]
Abstract
Human Immunodeficiency Virus-1 (HIV-1) Nef promotes p53 protein degradation to protect HIV-1 infected cells from p53 induced apoptosis. We found that Nef mediated p53 degradation is accomplished through ubiquitin proteasome pathway in an Mdm2-independent manner. By GST pulldown and immunoprecipitation assays, we have shown that Nef interacts with E3 ubiquitin ligase E6AP in both Nef transfected HEK-293T cells and HIV-1 infected MOLT3 cells. The p53 ubiquitination and degradation was found to be enhanced by Nef with E6AP but not by Nef with E6AP-C843A, a dominant negative E6AP mutant. We show that Nef binds with E6AP and promotes E6AP dependent p53 ubiquitination. Further, Nef inhibits apoptosis of p53 null H1299 cells after exogenous expression of p53 protein. The p53 dependent apoptosis of H1299 cells was further reduced after the expression of Nef with E6AP. However, Nef mediated reduction in p53 induced apoptosis of H1299 cells was restored when Nef was co-expressed with E6AP-C843A. Thus, Nef and E6AP co-operate to promote p53 ubiquitination and degradation in order to suppress p53 dependent apoptosis. CHME3 cells, which are a natural host of HIV-1, also show p53 ubiquitination and degradation by Nef and E6AP. These results establish that Nef induces p53 degradation via cellular E3 ligase E6AP to inhibit apoptosis during HIV-1 infection.
Collapse
Affiliation(s)
- Amjad Ali
- Virology Lab, National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, 110067, India; Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA, USA 01605.
| | - Sabihur Rahman Farooqui
- Virology Lab, National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, 110067, India.
| | - Jagdish Rai
- IFSC, Panjab University, Chandigarh, 160014, India.
| | - Jyotsna Singh
- Virology Lab, National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, 110067, India.
| | - Vivek Kumar
- Virology Lab, National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, 110067, India.
| | - Ritu Mishra
- Virology Lab, National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, 110067, India.
| | - Akhil C Banerjea
- Virology Lab, National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, 110067, India.
| |
Collapse
|
25
|
Extracellular Vesicles in Viral Infections of the Nervous System. Viruses 2020; 12:v12070700. [PMID: 32605316 PMCID: PMC7411781 DOI: 10.3390/v12070700] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 06/19/2020] [Accepted: 06/25/2020] [Indexed: 02/07/2023] Open
Abstract
Almost all types of cells release extracellular vesicles (EVs) into the extracellular space. EVs such as exosomes and microvesicles are membrane-bound vesicles ranging in size from 30 to 1000 nm in diameter. Under normal conditions, EVs mediate cell to cell as well as inter-organ communication via the shuttling of their cargoes which include RNA, DNA and proteins. Under pathological conditions, however, the number, size and content of EVs are found to be altered and have been shown to play crucial roles in disease progression. Emerging studies have demonstrated that EVs are involved in many aspects of viral infection-mediated neurodegenerative diseases. In the current review, we will describe the interactions between EV biogenesis and the release of virus particles while also reviewing the role of EVs in various viral infections, such as HIV-1, HTLV, Zika, CMV, EBV, Hepatitis B and C, JCV, and HSV-1. We will also discuss the potential uses of EVs and their cargoes as biomarkers and therapeutic vehicles for viral infections.
Collapse
|
26
|
Two Functional Variants of AP-1 Complexes Composed of either γ2 or γ1 Subunits Are Independently Required for Major Histocompatibility Complex Class I Downregulation by HIV-1 Nef. J Virol 2020; 94:JVI.02039-19. [PMID: 31915283 DOI: 10.1128/jvi.02039-19] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Accepted: 01/01/2020] [Indexed: 11/20/2022] Open
Abstract
The HIV-1 accessory protein Nef downregulates the cell surface expression of major histocompatibility complex class I (MHC-I) molecules to facilitate virus spreading. The Nef-induced downregulation of MHC-I molecules such as HLA-A requires the clathrin adaptor protein 1 (AP-1) complex. The cooperative interaction of Nef, AP-1, and the cytosolic tail (CT) of HLA-A leads to a redirection of HLA-A targeting from the trans-Golgi network (TGN) to lysosomes for degradation. Although the γ-adaptin subunit of AP-1 has two distinct isoforms (γ1 and γ2), which may form two AP-1 complex variants, so far, only the importance of AP-1γ1 in MHC-I downregulation by Nef has been investigated. Here, we report that the AP-1γ2 isoform also participates in this process. We found that AP-1γ2 forms a complex with Nef and HLA-A2_CT and that this interaction depends on the Y320 residue in HLA-A2_CT and Nef expression. Moreover, Nef targets AP-1γ1 and AP-1γ2 to different compartments in T cells, and the depletion of either AP-1 variant impairs the Nef-mediated reduction of total endogenous HLA-A levels and rescues HLA-A levels on the cell surface. Finally, immunofluorescence and immunoelectron microscopy analyses reveal that the depletion of γ2 in T cells compromises both the Nef-mediated retention of HLA-A molecules in the TGN and targeting to multivesicular bodies/late endosomes. Altogether, these results show that in addition to AP-1γ1, Nef also requires the AP-1γ2 variant for efficient MHC-I downregulation.IMPORTANCE HIV-1 Nef mediates evasion of the host immune system by inhibiting MHC-I surface presentation of viral antigens. To achieve this goal, Nef modifies the intracellular trafficking of MHC-I molecules in several ways. Despite being the subject of intense study, the molecular details underlying these modifications are not yet fully understood. Adaptor protein 1 (AP-1) plays an essential role in the Nef-mediated downregulation of MHC-I molecules such as HLA-A in different cell types. However, AP-1 has two functionally distinct variants composed of either γ1 or γ2 subunit isoforms. Because previous studies on the role of AP-1 in MHC-I downregulation by Nef focused on AP-1γ1, an important open question is the participation of AP-1γ2 in this process. Here, we show that AP-1γ2 is also essential for Nef-mediated depletion of surface HLA-A molecules in T cells. Our results indicate that Nef hijacks AP-1γ2 to modify HLA-A intracellular transport, redirecting these proteins to lysosomes for degradation.
Collapse
|
27
|
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.
Collapse
|
28
|
van Stigt Thans T, Akko JI, Niehrs A, Garcia-Beltran WF, Richert L, Stürzel CM, Ford CT, Li H, Ochsenbauer C, Kappes JC, Hahn BH, Kirchhoff F, Martrus G, Sauter D, Altfeld M, Hölzemer A. Primary HIV-1 Strains Use Nef To Downmodulate HLA-E Surface Expression. J Virol 2019; 93:e00719-19. [PMID: 31375574 PMCID: PMC6798123 DOI: 10.1128/jvi.00719-19] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 07/19/2019] [Indexed: 02/08/2023] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) has evolved elaborate ways to evade immune cell recognition, including downregulation of classical HLA class I (HLA-I) from the surfaces of infected cells. Recent evidence identified HLA-E, a nonclassical HLA-I, as an important part of the antiviral immune response to HIV-1. Changes in HLA-E surface levels and peptide presentation can prompt both CD8+ T-cell and natural killer (NK) cell responses to viral infections. Previous studies reported unchanged or increased HLA-E levels on HIV-1-infected cells. Here, we examined HLA-E surface levels following infection of CD4+ T cells with primary HIV-1 strains and observed that a subset downregulated HLA-E. Two primary strains of HIV-1 that induced the strongest reduction in surface HLA-E expression were chosen for further testing. Expression of single Nef or Vpu proteins in a T-cell line, as well as tail swap experiments exchanging the cytoplasmic tail of HLA-A2 with that of HLA-E, demonstrated that Nef modulated HLA-E surface levels and targeted the cytoplasmic tail of HLA-E. Furthermore, infection of primary CD4+ T cells with HIV-1 mutants showed that a lack of functional Nef (and Vpu to some extent) impaired HLA-E downmodulation. Taken together, the results of this study demonstrate for the first time that HIV-1 can downregulate HLA-E surface levels on infected primary CD4+ T cells, potentially rendering them less vulnerable to CD8+ T-cell recognition but at increased risk of NKG2A+ NK cell killing.IMPORTANCE For almost two decades, it was thought that HIV-1 selectively downregulated the highly expressed HLA-I molecules HLA-A and HLA-B from the cell surface in order to evade cytotoxic-T-cell recognition, while leaving HLA-C and HLA-E molecules unaltered. It was stipulated that HIV-1 infection thereby maintained inhibition of NK cells via inhibitory receptors that bind HLA-C and HLA-E. This concept was recently revised when a study showed that primary HIV-1 strains reduce HLA-C surface levels, whereas the cell line-adapted HIV-1 strain NL4-3 lacks this ability. Here, we demonstrate that infection with distinct primary HIV-1 strains results in significant downregulation of surface HLA-E levels. Given the increasing evidence for HLA-E as an important modulator of CD8+ T-cell and NKG2A+ NK cell functions, this finding has substantial implications for future immunomodulatory approaches aimed at harnessing cytotoxic cellular immunity against HIV.
Collapse
Affiliation(s)
| | - Janet I Akko
- Heinrich Pette Institute, Leibniz Institute for Experimental Virology, Hamburg, Germany
- German Center for Infection Research (DZIF), Site Hamburg-Lübeck-Borstel-Riems, Germany
| | - Annika Niehrs
- Heinrich Pette Institute, Leibniz Institute for Experimental Virology, Hamburg, Germany
- German Center for Infection Research (DZIF), Site Hamburg-Lübeck-Borstel-Riems, Germany
| | | | - Laura Richert
- Heinrich Pette Institute, Leibniz Institute for Experimental Virology, Hamburg, Germany
- Université Bordeaux, Inserm, Bordeaux Population Health Research Center, UMR 1219, Inria SISTM, Bordeaux, France
| | - Christina M Stürzel
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
| | - Christopher T Ford
- Heinrich Pette Institute, Leibniz Institute for Experimental Virology, Hamburg, Germany
| | - Hui Li
- Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Christina Ochsenbauer
- Department of Medicine, Division of Hematology and Oncology, and CFAR, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - John C Kappes
- Department of Medicine, Division of Hematology and Oncology, and CFAR, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Beatrice H Hahn
- Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Frank Kirchhoff
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
| | - Glòria Martrus
- Heinrich Pette Institute, Leibniz Institute for Experimental Virology, Hamburg, Germany
| | - Daniel Sauter
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
| | - Marcus Altfeld
- Heinrich Pette Institute, Leibniz Institute for Experimental Virology, Hamburg, Germany
- German Center for Infection Research (DZIF), Site Hamburg-Lübeck-Borstel-Riems, Germany
- Institute for Immunology, University Medical Center Eppendorf, Hamburg, Germany
| | - Angelique Hölzemer
- Heinrich Pette Institute, Leibniz Institute for Experimental Virology, Hamburg, Germany
- German Center for Infection Research (DZIF), Site Hamburg-Lübeck-Borstel-Riems, Germany
- First Department of Internal Medicine, University Medical Center Eppendorf, Hamburg, Germany
| |
Collapse
|
29
|
Urbanelli L, Buratta S, Tancini B, Sagini K, Delo F, Porcellati S, Emiliani C. The Role of Extracellular Vesicles in Viral Infection and Transmission. Vaccines (Basel) 2019; 7:vaccines7030102. [PMID: 31466253 PMCID: PMC6789493 DOI: 10.3390/vaccines7030102] [Citation(s) in RCA: 113] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 08/12/2019] [Accepted: 08/22/2019] [Indexed: 12/12/2022] Open
Abstract
Extracellular vesicles (EVs) have been found to be released by any type of cell and can be retrieved in every circulating body fluid, namely blood (plasma, serum), saliva, milk, and urine. EVs were initially considered a cellular garbage disposal tool, but later it became evident that they are involved in intercellular signaling. There is evidence that viruses can use EV endocytic routes to enter uninfected cells and hijack the EV secretory pathway to exit infected cells, thus illustrating that EVs and viruses share common cell entry and biogenesis mechanisms. Moreover, EVs play a role in immune response against viral pathogens. EVs incorporate and spread both viral and host factors, thereby prompting or inhibiting immune responses towards them via a multiplicity of mechanisms. The involvement of EVs in immune responses, and their potential use as agents modulating viral infection, will be examined. Although further studies are needed, the engineering of EVs could package viral elements or host factors selected for their immunostimulatory properties, to be used as vaccines or tolerogenic tools in autoimmune diseases.
Collapse
Affiliation(s)
- Lorena Urbanelli
- Department of Chemistry, Biology and Biotechnology, University of Perugia, Via del Giochetto, 06123 Perugia, Italy.
| | - Sandra Buratta
- Department of Chemistry, Biology and Biotechnology, University of Perugia, Via del Giochetto, 06123 Perugia, Italy
| | - Brunella Tancini
- Department of Chemistry, Biology and Biotechnology, University of Perugia, Via del Giochetto, 06123 Perugia, Italy
| | - Krizia Sagini
- Department of Chemistry, Biology and Biotechnology, University of Perugia, Via del Giochetto, 06123 Perugia, Italy
| | - Federica Delo
- Department of Chemistry, Biology and Biotechnology, University of Perugia, Via del Giochetto, 06123 Perugia, Italy
| | - Serena Porcellati
- Department of Chemistry, Biology and Biotechnology, University of Perugia, Via del Giochetto, 06123 Perugia, Italy
| | - Carla Emiliani
- Department of Chemistry, Biology and Biotechnology, University of Perugia, Via del Giochetto, 06123 Perugia, Italy
- Centro di Eccellenza sui Materiali Innovativi Nanostrutturati (CEMIN), University of Perugia, Via del Giochetto, 06123 Perugia, Italy
| |
Collapse
|
30
|
Barton JP, Rajkoomar E, Mann JK, Murakowski DK, Toyoda M, Mahiti M, Mwimanzi P, Ueno T, Chakraborty AK, Ndung'u T. Modelling and in vitro testing of the HIV-1 Nef fitness landscape. Virus Evol 2019; 5:vez029. [PMID: 31392033 PMCID: PMC6680064 DOI: 10.1093/ve/vez029] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
An effective vaccine is urgently required to curb the HIV-1 epidemic. We have previously described an approach to model the fitness landscape of several HIV-1 proteins, and have validated the results against experimental and clinical data. The fitness landscape may be used to identify mutation patterns harmful to virus viability, and consequently inform the design of immunogens that can target such regions for immunological control. Here we apply such an analysis and complementary experiments to HIV-1 Nef, a multifunctional protein which plays a key role in HIV-1 pathogenesis. We measured Nef-driven replication capacities as well as Nef-mediated CD4 and HLA-I down-modulation capacities of thirty-two different Nef mutants, and tested model predictions against these results. Furthermore, we evaluated the models using 448 patient-derived Nef sequences for which several Nef activities were previously measured. Model predictions correlated significantly with Nef-driven replication and CD4 down-modulation capacities, but not HLA-I down-modulation capacities, of the various Nef mutants. Similarly, in our analysis of patient-derived Nef sequences, CD4 down-modulation capacity correlated the most significantly with model predictions, suggesting that of the tested Nef functions, this is the most important in vivo. Overall, our results highlight how the fitness landscape inferred from patient-derived sequences captures, at least in part, the in vivo functional effects of mutations to Nef. However, the correlation between predictions of the fitness landscape and measured parameters of Nef function is not as accurate as the correlation observed in past studies for other proteins. This may be because of the additional complexity associated with inferring the cost of mutations on the diverse functions of Nef.
Collapse
Affiliation(s)
- John P Barton
- Departments of Chemical Engineering, Physics, and Chemistry, Institute for Medical Engineering & Science, Massachusetts Institute of Technology, Cambridge, MA, USA.,Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Boston, MA, USA
| | - Erasha Rajkoomar
- HIV Pathogenesis Programme, Doris Duke Medical Research Institute, Nelson R. Mandela School of Medicine, University of KwaZulu-Natal, Durban, South Africa
| | - Jaclyn K Mann
- HIV Pathogenesis Programme, Doris Duke Medical Research Institute, Nelson R. Mandela School of Medicine, University of KwaZulu-Natal, Durban, South Africa
| | - Dariusz K Murakowski
- Departments of Chemical Engineering, Physics, and Chemistry, Institute for Medical Engineering & Science, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Mako Toyoda
- Center for AIDS Research, Kumamoto University, Kumamoto, Japan
| | | | | | - Takamasa Ueno
- Center for AIDS Research, Kumamoto University, Kumamoto, Japan.,International Research Center for Medical Sciences (IRCMS), Kumamoto University, Kumamoto, Japan
| | - Arup K Chakraborty
- Departments of Chemical Engineering, Physics, and Chemistry, Institute for Medical Engineering & Science, Massachusetts Institute of Technology, Cambridge, MA, USA.,Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Boston, MA, USA
| | - Thumbi Ndung'u
- Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Boston, MA, USA.,HIV Pathogenesis Programme, Doris Duke Medical Research Institute, Nelson R. Mandela School of Medicine, University of KwaZulu-Natal, Durban, South Africa.,Africa Health Research Institute, Durban, South Africa.,Max Planck Institute for Infection Biology, Chariteplatz, D-10117 Berlin, Germany
| |
Collapse
|
31
|
Identification of Novel Subcellular Localization and Trafficking of HIV-1 Nef Variants from Reference Strains G (F1.93.HH8793) and H (BE.93.VI997). Viruses 2018; 10:v10090493. [PMID: 30217018 PMCID: PMC6164931 DOI: 10.3390/v10090493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 08/30/2018] [Accepted: 09/11/2018] [Indexed: 11/17/2022] Open
Abstract
The human immunodeficiency virus type 1 (HIV-1) accessory protein Nef, plays an essential role in disease progression and pathogenesis via hijacking the host cellular membrane-trafficking machinery. Interestingly, HIV-1 group-M subtypes display differences in the rate of disease progression. However, few reports investigated how the cellular behaviors and activities of Nef isolates from reference strains may differ between HIV-1 group-M subtypes. Here, we characterize how differing cellular distributions of Nef proteins across group-M subtypes may impact protein function using immunofluorescence microscopy and flow cytometric analysis. We demonstrate that Nef variants isolated from HIV-1 group-M subtypes display differences in expression, with low expressing Nef proteins from reference strains of subtypes G (F1.93.HH8793) and H (BE.93.VI997) also displaying decreased functionality. Additionally, we demonstrate variations in the subcellular distribution and localization of these Nef proteins. Nef from subtype G (F1.93.HH8793) and H (BE.93.VI997) reference strains also failed to colocalize with the trans-Golgi network, and were not differentially localized to cellular markers of multivesicular bodies or lysosomes. Strikingly, our results demonstrate that HIV-1 Nef proteins from reference strains G (F1.93.HH8793) and H (BE.93.VI997) highly colocalize with labeled mitochondrial compartments.
Collapse
|
32
|
Chen L, Keppler OT, Schölz C. Post-translational Modification-Based Regulation of HIV Replication. Front Microbiol 2018; 9:2131. [PMID: 30254620 PMCID: PMC6141784 DOI: 10.3389/fmicb.2018.02131] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 08/20/2018] [Indexed: 12/13/2022] Open
Abstract
Human immunodeficiency virus (HIV) relies heavily on the host cellular machinery for production of viral progeny. To exploit cellular proteins for replication and to overcome host factors with antiviral activity, HIV has evolved a set of regulatory and accessory proteins to shape an optimized environment for its replication and to facilitate evasion from the immune system. Several cellular pathways are hijacked by the virus to modulate critical steps during the viral life cycle. Thereby, post-translational modifications (PTMs) of viral and cellular proteins gain increasingly attention as modifying enzymes regulate virtually every step of the viral replication cycle. This review summarizes the current knowledge of HIV-host interactions influenced by PTMs with a special focus on acetylation, ubiquitination, and phosphorylation of proteins linked to cellular signaling and viral replication. Insights into these interactions are surmised to aid development of new intervention strategies.
Collapse
Affiliation(s)
- Lin Chen
- Max von Pettenkofer-Institute and Gene Center, Virology, National Reference Center for Retroviruses, Faculty of Medicine, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Oliver T Keppler
- Max von Pettenkofer-Institute and Gene Center, Virology, National Reference Center for Retroviruses, Faculty of Medicine, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Christian Schölz
- Max von Pettenkofer-Institute and Gene Center, Virology, National Reference Center for Retroviruses, Faculty of Medicine, Ludwig-Maximilians-University Munich, Munich, Germany
| |
Collapse
|
33
|
Rodrigues M, Fan J, Lyon C, Wan M, Hu Y. Role of Extracellular Vesicles in Viral and Bacterial Infections: Pathogenesis, Diagnostics, and Therapeutics. Am J Cancer Res 2018; 8:2709-2721. [PMID: 29774070 PMCID: PMC5957004 DOI: 10.7150/thno.20576] [Citation(s) in RCA: 128] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Accepted: 01/15/2018] [Indexed: 02/05/2023] Open
Abstract
Extracellular vesicles (EVs), or exosomes, are nanovesicles of endocytic origin that carry host and pathogen-derived protein, nucleic acid, and lipid cargos. They are secreted by most cell types and play important roles in normal cell-to-cell communications but can also spread pathogen- and host-derived molecules during infections to alter immune responses and pathophysiological processes. New research is beginning to decipher how EVs influence viral and bacterial pathogenesis. In this review, we will describe how EVs influence viral and bacterial pathogenesis by spreading pathogen-derived factors and how they can promote and inhibit the immune response to these pathogens. We will also discuss the emerging potential of EVs as diagnostic and therapeutic tools.
Collapse
|
34
|
HLA Class I Downregulation by HIV-1 Variants from Subtype C Transmission Pairs. J Virol 2018; 92:JVI.01633-17. [PMID: 29321314 DOI: 10.1128/jvi.01633-17] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 12/23/2017] [Indexed: 02/08/2023] Open
Abstract
HIV-1 downregulates human leukocyte antigen A (HLA-A) and HLA-B from the surface of infected cells primarily to evade CD8 T cell recognition. HLA-C was thought to remain on the cell surface and bind inhibitory killer immunoglobulin-like receptors, preventing natural killer (NK) cell-mediated suppression. However, a recent study found HIV-1 primary viruses have the capacity to downregulate HLA-C. The goal of this study was to assess the heterogeneity of HLA-A, HLA-B, and HLA-C downregulation among full-length primary viruses from six chronically infected and six newly infected individuals from transmission pairs and to determine whether transmitted/founder variants exhibit common HLA class I downregulation characteristics. We measured HLA-A, HLA-B, HLA-C, and total HLA class I downregulation by flow cytometry of primary CD4 T cells infected with 40 infectious molecular clones. Primary viruses mediated a range of HLA class I downregulation capacities (1.3- to 6.1-fold) which could differ significantly between transmission pairs. Downregulation of HLA-C surface expression on infected cells correlated with susceptibility to in vitro NK cell suppression of virus release. Despite this, transmitted/founder variants did not share a downregulation signature and instead were more similar to the quasispecies of matched donor partners. These data indicate that a range of viral abilities to downregulate HLA-A, HLA-B, and HLA-C exist within and between individuals that can have functional consequences on immune recognition.IMPORTANCE Subtype C HIV-1 is the predominant subtype involved in heterosexual transmission in sub-Saharan Africa. Authentic subtype C viruses that contain natural sequence variations throughout the genome often are not used in experimental systems due to technical constraints and sample availability. In this study, authentic full-length subtype C viruses, including transmitted/founder viruses, were examined for the ability to disrupt surface expression of HLA class I molecules, which are central to both adaptive and innate immune responses to viral infections. We found that the HLA class I downregulation capacity of primary viruses varied, and HLA-C downregulation capacity impacted viral suppression by natural killer cells. Transmitted viruses were not distinct in the capacity for HLA class I downregulation or natural killer cell evasion. These results enrich our understanding of the phenotypic variation existing among natural HIV-1 viruses and how that might impact the ability of the immune system to recognize infected cells in acute and chronic infection.
Collapse
|
35
|
Faust TB, Binning JM, Gross JD, Frankel AD. Making Sense of Multifunctional Proteins: Human Immunodeficiency Virus Type 1 Accessory and Regulatory Proteins and Connections to Transcription. Annu Rev Virol 2017; 4:241-260. [PMID: 28961413 DOI: 10.1146/annurev-virology-101416-041654] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Viruses are completely dependent upon cellular machinery to support replication and have therefore developed strategies to co-opt cellular processes to optimize infection and counter host immune defenses. Many viruses, including human immunodeficiency virus type 1 (HIV-1), encode a relatively small number of genes. Viruses with limited genetic content often encode multifunctional proteins that function at multiple stages of the viral replication cycle. In this review, we discuss the functions of HIV-1 regulatory (Tat and Rev) and accessory (Vif, Vpr, Vpu, and Nef) proteins. Each of these proteins has a highly conserved primary activity; however, numerous additional activities have been attributed to these viral proteins. We explore the possibility that HIV-1 proteins leverage their multifunctional nature to alter host transcriptional networks to elicit a diverse set of cellular responses. Although these transcriptional effects appear to benefit the virus, it is not yet clear whether they are strongly selected for during viral evolution or are a ripple effect from the primary function. As our detailed knowledge of these viral proteins improves, we will undoubtedly uncover how the multifunctional nature of these HIV-1 regulatory and accessory proteins, and in particular their transcriptional functions, work to drive viral pathogenesis.
Collapse
Affiliation(s)
- Tyler B Faust
- Department of Biochemistry and Biophysics, University of California, San Francisco, California 94158; ,
| | - Jennifer M Binning
- Department of Pharmaceutical Chemistry, University of California, San Francisco, California 94158; ,
| | - John D Gross
- Department of Pharmaceutical Chemistry, University of California, San Francisco, California 94158; ,
| | - Alan D Frankel
- Department of Biochemistry and Biophysics, University of California, San Francisco, California 94158; ,
| |
Collapse
|
36
|
Shu ST, Emert-Sedlak LA, Smithgall TE. Cell-based Fluorescence Complementation Reveals a Role for HIV-1 Nef Protein Dimerization in AP-2 Adaptor Recruitment and CD4 Co-receptor Down-regulation. J Biol Chem 2016; 292:2670-2678. [PMID: 28031466 DOI: 10.1074/jbc.m116.770016] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Revised: 12/21/2016] [Indexed: 02/03/2023] Open
Abstract
The HIV-1 Nef accessory factor enhances viral infectivity, immune evasion, and AIDS progression. Nef triggers rapid down-regulation of CD4 via the endocytic adaptor protein 2 (AP-2) complex, a process linked to enhanced viral infectivity and immune escape. Here, we describe a bimolecular fluorescence complementation (BiFC) assay to visualize the interaction of Nef with AP-2 and CD4 in living cells. Interacting protein pairs were fused to complementary non-fluorescent fragments of YFP and co-expressed in 293T cells. Nef interactions with both CD4 and AP-2 resulted in complementation of YFP and a bright fluorescent signal by confocal microcopy that localized to the cell periphery. Co-expression of the AP-2 α subunit enhanced the Nef·AP-2 σ2 subunit BiFC signal and vice versa, suggesting that the AP-2 α-σ2 hemicomplex interacts cooperatively with Nef. Mutagenesis of Nef amino acids Arg-134, Glu-174, and Asp-175, which stabilize Nef for AP-2 α-σ2 binding in a recent co-crystal structure, substantially reduced AP-2 interaction without affecting CD4 binding. A dimerization-defective mutant of Nef failed to interact with either CD4 or AP-2 in the BiFC assay, indicating that Nef quaternary structure is required for CD4 and AP-2 recruitment as well as CD4 down-regulation. A small molecule previously shown to bind the Nef dimerization interface also reduced Nef interactions with AP-2 and CD4 and restored CD4 expression to the surface of HIV-infected cells. Our findings provide a mechanistic explanation for previous observations that dimerization-defective Nef mutants fail to down-regulate CD4 and validate the Nef dimerization interface as a target site for antiretroviral drug development.
Collapse
Affiliation(s)
- Sherry T Shu
- From the Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15219
| | - Lori A Emert-Sedlak
- From the Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15219
| | - Thomas E Smithgall
- From the Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15219
| |
Collapse
|
37
|
Identification of Binding Mode and Prospective Structural Features of Novel Nef Protein Inhibitors as Potential Anti-HIV Drugs. Cell Biochem Biophys 2016; 75:49-64. [DOI: 10.1007/s12013-016-0774-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Accepted: 11/28/2016] [Indexed: 12/16/2022]
|
38
|
Tavares LA, da Silva EML, da Silva-Januário ME, Januário YC, de Cavalho JV, Czernisz ÉS, Mardones GA, daSilva LLP. CD4 downregulation by the HIV-1 protein Nef reveals distinct roles for the γ1 and γ2 subunits of the AP-1 complex in protein trafficking. J Cell Sci 2016; 130:429-443. [PMID: 27909244 DOI: 10.1242/jcs.192104] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 11/16/2016] [Indexed: 12/20/2022] Open
Abstract
The HIV accessory protein Nef is a major determinant of viral pathogenesis that facilitates viral particle release, prevents viral antigen presentation and increases infectivity of new virus particles. These functions of Nef involve its ability to remove specific host proteins from the surface of infected cells, including the CD4 receptor. Nef binds to the adaptor protein 2 (AP-2) and CD4 in clathrin-coated pits, forcing CD4 internalization and its subsequent targeting to lysosomes. Herein, we report that this lysosomal targeting requires a variant of AP-1 containing isoform 2 of γ-adaptin (AP1G2, hereafter γ2). Depletion of the γ2 or μ1A (AP1M1) subunits of AP-1, but not of γ1 (AP1G1), precludes Nef-mediated lysosomal degradation of CD4. In γ2-depleted cells, CD4 internalized by Nef accumulates in early endosomes and this alleviates CD4 removal from the cell surface. Depletion of γ2 also hinders EGFR-EGF-complex targeting to lysosomes, an effect that is not observed upon γ1 depletion. Taken together, our data provide evidence that the presence of γ1 or γ2 subunits delineates two distinct variants of AP-1 complexes, with different functions in protein sorting.
Collapse
Affiliation(s)
- Lucas A Tavares
- Department of Cell and Molecular Biology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo 14049-900, Brazil
| | - Eulália M L da Silva
- Department of Cell and Molecular Biology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo 14049-900, Brazil
| | - Mara E da Silva-Januário
- Department of Cell and Molecular Biology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo 14049-900, Brazil
| | - Yunan C Januário
- Department of Cell and Molecular Biology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo 14049-900, Brazil
| | - Julianne V de Cavalho
- Department of Cell and Molecular Biology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo 14049-900, Brazil
| | - Érika S Czernisz
- Department of Cell and Molecular Biology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo 14049-900, Brazil
| | - Gonzalo A Mardones
- Department of Physiology, School of Medicine, and Center for Interdisciplinary Studies of the Nervous System (CISNe), Universidad Austral de Chile, Valdivia 5110566, Chile
| | - Luis L P daSilva
- Department of Cell and Molecular Biology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo 14049-900, Brazil
| |
Collapse
|
39
|
HIV-1 Nef sequesters MHC-I intracellularly by targeting early stages of endocytosis and recycling. Sci Rep 2016; 6:37021. [PMID: 27841315 PMCID: PMC5107982 DOI: 10.1038/srep37021] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Accepted: 10/24/2016] [Indexed: 11/25/2022] Open
Abstract
A defining characteristic of HIV-1 infection is the ability of the virus to persist within the host. Specifically, MHC-I downregulation by the HIV-1 accessory protein Nef is of critical importance in preventing infected cells from cytotoxic T-cell mediated killing. Nef downregulates MHC-I by modulating the host membrane trafficking machinery, resulting in the endocytosis and eventual sequestration of MHC-I within the cell. In the current report, we utilized the intracellular protein-protein interaction reporter system, bimolecular fluorescence complementation (BiFC), in combination with super-resolution microscopy, to track the Nef/MHC-I interaction and determine its subcellular localization in cells. We demonstrate that this interaction occurs upon Nef binding the MHC-I cytoplasmic tail early during endocytosis in a Rab5-positive endosome. Disruption of early endosome regulation inhibited Nef-dependent MHC-I downregulation, demonstrating that Nef hijacks the early endosome to sequester MHC-I within the cell. Furthermore, super-resolution imaging identified that the Nef:MHC-I BiFC complex transits through both early and late endosomes before ultimately residing at the trans-Golgi network. Together we demonstrate the importance of the early stages of the endocytic network in the removal of MHC-I from the cell surface and its re-localization within the cell, which allows HIV-1 to optimally evade host immune responses.
Collapse
|
40
|
HIV Nef- and Notch1-dependent Endocytosis of ADAM17 Induces Vesicular TNF Secretion in Chronic HIV Infection. EBioMedicine 2016; 13:294-304. [PMID: 27773542 PMCID: PMC5264432 DOI: 10.1016/j.ebiom.2016.10.027] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Revised: 10/11/2016] [Accepted: 10/18/2016] [Indexed: 12/30/2022] Open
Abstract
Tumor necrosis factor (TNF) is a key cytokine in HIV replication and pathogenesis. For reasons that are not entirely clear, the cytokine remains upregulated despite anti-retroviral therapy (ART). Here we demonstrate that HIV Nef induces an alternative TNF secretion mechanism that remains active in chronic infection. Ingestion of Nef-containing plasma extracellular vesicles (pEV) from ART patients by primary immune cells, but also Nef expression, induced intracellular proTNF cleavage and secretion of vesicular TNF endosomes. Key event was the Nef-mediated routing of the TNF-converting enzyme ADAM17 into Rab4 + early endosomes and the Rab27 + secretory pathway. Analysis of lymph-node tissue by multi-epitope-ligand-cartography (MELC) confirmed a vesicular TNF secretion phenotype that co-localized with persistent Nef expression, and implicated Notch1 as an essential co-factor. Surprisingly Notch1 had no transcriptional effect but was required for the endosomal trafficking of ADAM17. We conclude that Nef expression and Nef-containing pEV mobilize TNF from endosomal compartments in acute and chronic infection. Nef/ADAM17 containing extracellular vesicles induce an endosomal TNF secretion type in primary target cells. The mechanism required the shuttling of ADAM17 into Rab4 + endosomal compartments in a Notch1-dependent manner. The mechanism could be demonstrated in tissue by multi-epitope-ligand-cartography (MELC) technology.
Despite antiviral therapy, plasma levels of TNF remain upregulated and likely play a role in many comorbidities seen in chronic HIV infection. We found that this is due to high levels of HIV-induced plasma extracellular vesicles (pEV) containing the TNF processing ADAM17 protease. Interestingly these vesicles induced a different TNF secretion type. Whereas TNF is usually shed from the plasma membrane, pEV mobilized intracellular TNF storage compartments, secreting endosomal vesicles. We could confirm this mechanism analyzing lymph node tissue sections by a novel immunostaining technology. Our report supports our previous publication implying ongoing viral activity despite successful antiretroviral therapy.
Collapse
|
41
|
Cell Surface Downregulation of NK Cell Ligands by Patient-Derived HIV-1 Vpu and Nef Alleles. J Acquir Immune Defic Syndr 2016; 72:1-10. [PMID: 26656785 DOI: 10.1097/qai.0000000000000917] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
OBJECTIVE HIV-1 Vpu and Nef proteins downregulate cell surface levels of natural killer (NK) cell ligands but functional consequences of individual downregulation events are unclear. We tested how well-conserved NK cell ligand downregulation is among Vpu and Nef variants isolated from chronic HIV patients. METHODS Proviral vpu and nef sequences were amplified from 27 chronic HIV patients, subcloned, and tested for their ability to downregulate cell surface receptors. RESULTS Cell surface downregulation of CD4, CD317/tetherin, and major histocompatibility complex class 1 that exert biological functions other than NK cell activation were well conserved among patient-derived Vpu and Nef variants. Among NK cell ligands, NK-T-B-antigen, poliovirus receptor, and UL16-binding protein were identified as main targets for Vpu and Nef, the downregulation of which by at least 1 viral protein was highly conserved. NK cell ligands displayed specific sensitivity to Vpu (NK-T-B-antigen) or Nef (poliovirus receptor), and downregulation of cell surface UL16-binding protein was identified as a novel and highly conserved activity of HIV-1 Vpu but not Nef. CONCLUSIONS The conservation of downregulation of major NK cell ligands by either HIV-1 Vpu or Nef suggests an important pathophysiological role of this activity, which may impact the acute but not the chronic phase of HIV infection.
Collapse
|
42
|
D186/D190 is an allele-dependent determinant of HIV-1 Nef function. Virology 2016; 498:44-56. [PMID: 27560372 DOI: 10.1016/j.virol.2016.08.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 08/12/2016] [Accepted: 08/13/2016] [Indexed: 01/23/2023]
Abstract
The HIV-1 pathogenesis factor Nef interacts with numerous ligands to affect cellular vesicular transport, signal transduction and cytoskeletal dynamics. While most Nef functions depend on multivalent protein interaction motifs, disrupting actin dynamics requires a motif that specifically recruits the host kinase PAK2. An adjacent aspartate was recently predicted to mediate Nef-β-catenin interactions. We report here that β-catenin can be co-immunoprecipitated with Nef.GFP from Jurkat T cell lysates. This association is conserved among lentiviral Nef proteins but does not involve classical Nef protein interaction motifs, including the critical aspartate. While aspartate-to-alanine mutations impaired cell surface receptor downregulation and interference with actin dynamics and cell motility by HIV-1 NA7 Nef, analogous mutations did not affect HIV-1 SF2 Nef function. These allelic differences were determined by a proximal lysine/arginine polymorphism. These results emphasize differences between Nef alleles regarding the functional role of individual residues and underscore the need for allele-specific structure-function analyses.
Collapse
|
43
|
Histone Deacetylase Inhibitors Enhance CD4 T Cell Susceptibility to NK Cell Killing but Reduce NK Cell Function. PLoS Pathog 2016; 12:e1005782. [PMID: 27529554 PMCID: PMC4986965 DOI: 10.1371/journal.ppat.1005782] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 06/30/2016] [Indexed: 11/19/2022] Open
Abstract
In the search for a cure for HIV-1 infection, histone deacetylase inhibitors (HDACi) are being investigated as activators of latently infected CD4 T cells to promote their targeting by cytotoxic T-lymphocytes (CTL). However, HDACi may also inhibit CTL function, suggesting different immunotherapy approaches may need to be explored. Here, we study the impact of different HDACi on both Natural Killer (NK) and CTL targeting of HIV-1 infected cells. We found HDACi down-regulated HLA class I expression independently of HIV-1 Nef which, without significantly compromising CTL function, led to enhanced targeting by NK cells. HDACi-treated HIV-1-infected CD4 T cells were also more effectively cleared than untreated controls during NK co-culture. However, HDACi impaired NK function, reducing degranulation and killing capacity. Depending on the HDACi and dose, this impairment could counteract the benefit gained by treating infected target cells. These data suggest that following HDACi-induced HLA class I down-regulation NK cells kill HIV-1-infected cells, although HDACi-mediated NK cell inhibition may negate this effect. Our data emphasize the importance of studying the effects of potential interventions on both targets and effectors. Antiretroviral therapy successfully controls HIV-1 viraemia and can restore life expectancy to within normal limits. However, antiretroviral therapy is not a cure as HIV-1 persists in a treatment-resistant latent reservoir. Therapy also comes with a high cost, side effects, and a lifetime commitment to pills. Therefore, there is growing interest in finding a cure. One proposed strategy is to use novel agents to stimulate HIV-1 transcription in latently-infected cells, after which the cells could be targeted and cleared by the immune system. Of current interest are the latency-reversing histone deacetylase inhibitors (HDACi), with CD8 T cells and NK cells potentially serving as the HIV-1 killing agents. However, previous studies suggested HDACi negatively affected CD8 T cell function, compromising their role as killers. Here we studied whether NK cells might serve as effective killers of HDACi treated CD4 T cells, especially as HDACi may induce HLA class I down-regulation. We found that although treating infected cells with HDACi resulted in HLA class I down-regulation and enhanced their visibility to NK cells, HDACi inhibited NK cell function overall, suggesting additional killing strategies will be required.
Collapse
|
44
|
Pereira EA, daSilva LLP. HIV-1 Nef: Taking Control of Protein Trafficking. Traffic 2016; 17:976-96. [PMID: 27161574 DOI: 10.1111/tra.12412] [Citation(s) in RCA: 89] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 05/05/2016] [Accepted: 05/05/2016] [Indexed: 12/25/2022]
Abstract
The Nef protein of the human immunodeficiency virus is a crucial determinant of viral pathogenesis and disease progression. Nef is abundantly expressed early in infection and is thought to optimize the cellular environment for viral replication. Nef controls expression levels of various cell surface molecules that play important roles in immunity and virus life cycle, by directly interfering with the itinerary of these proteins within the endocytic and late secretory pathways. To exert these functions, Nef physically interacts with host proteins that regulate protein trafficking. In recent years, considerable progress was made in identifying host-cell-interacting partners for Nef, and the molecular machinery used by Nef to interfere with protein trafficking has started to be unraveled. Here, we briefly review the knowledge gained and discuss new findings regarding the mechanisms by which Nef modifies the intracellular trafficking pathways to prevent antigen presentation, facilitate viral particle release and enhance the infectivity of HIV-1 virions.
Collapse
Affiliation(s)
- Estela A Pereira
- Department of Cell and Molecular Biology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Luis L P daSilva
- Department of Cell and Molecular Biology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil
| |
Collapse
|
45
|
Kalamvoki M, Deschamps T. Extracellular vesicles during Herpes Simplex Virus type 1 infection: an inquire. Virol J 2016; 13:63. [PMID: 27048572 PMCID: PMC4822280 DOI: 10.1186/s12985-016-0518-2] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Accepted: 03/29/2016] [Indexed: 12/21/2022] Open
Abstract
Extracellular vesicles are defined as a heterogeneous group of vesicles that are released by prokaryotic to higher eukaryotic cells and by plant cells in an evolutionary conserved manner. The significance of these vesicles lies in their capacity to transfer selected cargo composed of proteins, lipids and nucleic acids to both recipient and parent cells and to influence various physiological and pathological functions. Microorganisms such as parasites, fungi and protozoa and even single cell organisms such as bacteria generate extracellular vesicles. In addition, several viruses have evolved strategies to hijack the extracellular vesicles for egress or to alter the surrounding environment. The thesis of this article is that: a) during HSV-1 infection vesicles are delivered from infected to uninfected cells that influence the infection; b) the cargo of these vesicles consists of viral and host transcripts (mRNAs, miRNAs and non-coding RNAs) and proteins including innate immune components, such as STING; and c) the viral vesicles carry the tetraspanins CD9, CD63 and CD81, which are considered as markers of exosomes. Therefore, we assume that the STING-carrying vesicles, produced during HSV-1 infection, are reminiscent to exosomes. The presumed functions of the exosomes released from HSV-1 infected cells include priming the recipient cells and accelerating antiviral responses to control the dissemination of the virus. This may be one strategy used by the virus to prevent the elimination by the host and establish persistent infection. In conclusion, the modification of the cargo of exosomes appears to be part of the strategy that HSV-1 has evolved to establish lifelong persistent infections into the human body to ensure successful dissemination between individuals.
Collapse
Affiliation(s)
- Maria Kalamvoki
- Department Microbiology, Molecular Genetics Immunology, University of Kansas Medical Center, 3901 Rainbow Blvd, Building Hixon, room 3009, Kansas City, KS, 66160, USA.
| | - Thibaut Deschamps
- Department Microbiology, Molecular Genetics Immunology, University of Kansas Medical Center, 3901 Rainbow Blvd, Building Hixon, room 3009, Kansas City, KS, 66160, USA
| |
Collapse
|
46
|
Remodeling of the Host Cell Plasma Membrane by HIV-1 Nef and Vpu: A Strategy to Ensure Viral Fitness and Persistence. Viruses 2016; 8:67. [PMID: 26950141 PMCID: PMC4810257 DOI: 10.3390/v8030067] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2016] [Revised: 02/09/2016] [Accepted: 02/16/2016] [Indexed: 02/07/2023] Open
Abstract
The plasma membrane protects the cell from its surroundings and regulates cellular communication, homing, and metabolism. Not surprisingly, the composition of this membrane is highly controlled through the vesicular trafficking of proteins to and from the cell surface. As intracellular pathogens, most viruses exploit the host plasma membrane to promote viral replication while avoiding immune detection. This is particularly true for the enveloped human immunodeficiency virus (HIV), which assembles and obtains its lipid shell directly at the plasma membrane. HIV-1 encodes two proteins, negative factor (Nef) and viral protein U (Vpu), which function primarily by altering the quantity and localization of cell surface molecules to increase virus fitness despite host antiviral immune responses. These proteins are expressed at different stages in the HIV-1 life cycle and employ a variety of mechanisms to target both unique and redundant surface proteins, including the viral receptor CD4, host restriction factors, immunoreceptors, homing molecules, tetraspanins and membrane transporters. In this review, we discuss recent progress in the study of the Nef and Vpu targeting of host membrane proteins with an emphasis on how remodeling of the cell membrane allows HIV-1 to avoid host antiviral immune responses leading to the establishment of systemic and persistent infection.
Collapse
|
47
|
Serena M, Giorgetti A, Busato M, Gasparini F, Diani E, Romanelli MG, Zipeto D. Molecular characterization of HIV-1 Nef and ACOT8 interaction: insights from in silico structural predictions and in vitro functional assays. Sci Rep 2016; 6:22319. [PMID: 26927806 PMCID: PMC4772117 DOI: 10.1038/srep22319] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 02/11/2016] [Indexed: 11/29/2022] Open
Abstract
HIV-1 Nef interacts with several cellular proteins, among which the human peroxisomal thioesterase 8 (ACOT8). This interaction may be involved in the endocytosis regulation of membrane proteins and might modulate lipid composition in membrane rafts. Nef regions involved in the interaction have been experimentally characterized, whereas structural details of the ACOT8 protein are unknown. The lack of structural information hampers the comprehension of the functional consequences of the complex formation during HIV-1 infection. We modelled, through in silico predictions, the ACOT8 structure and we observed a high charge complementarity between Nef and ACOT8 surfaces, which allowed the identification of the ACOT8 putative contact points involved in the interaction. The predictions were validated by in vitro assays through the development of ACOT8 deletion mutants. Coimmunoprecipitation and immunofluorescence analyses showed that ACOT8 Arg45-Phe55 and Arg86-Pro93 regions are involved in Nef association. In addition, K91S mutation abrogated the interaction with Nef, indicating that Lys91 plays a key role in the interaction. Finally, when associated with ACOT8, Nef may be preserved from degradation. These findings improve the comprehension of the association between HIV-1 Nef and ACOT8, helping elucidating the biological effect of their interaction.
Collapse
Affiliation(s)
- Michela Serena
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Strada le Grazie 8, 37134 Verona, Italy
| | - Alejandro Giorgetti
- Department of Biotechnology, University of Verona, Strada le Grazie 15, 37134 Verona, Italy
| | - Mirko Busato
- Department of Biotechnology, University of Verona, Strada le Grazie 15, 37134 Verona, Italy
| | - Francesca Gasparini
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Strada le Grazie 8, 37134 Verona, Italy.,Department of Biotechnology, University of Verona, Strada le Grazie 15, 37134 Verona, Italy
| | - Erica Diani
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Strada le Grazie 8, 37134 Verona, Italy
| | - Maria Grazia Romanelli
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Strada le Grazie 8, 37134 Verona, Italy
| | - Donato Zipeto
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Strada le Grazie 8, 37134 Verona, Italy
| |
Collapse
|
48
|
Landi A, Timermans CG, Naessens E, Vanderstraeten H, Stove V, Verhasselt B. The human immunodeficiency virus (HIV) Rev-binding protein (HRB) is a co-factor for HIV-1 Nef-mediated CD4 downregulation. J Gen Virol 2015; 97:778-785. [PMID: 26701340 DOI: 10.1099/jgv.0.000382] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1)-mediated CD4 downregulation is an important determinant of viral replication in vivo. Research on cellular co-factors involved in this process could lead to the identification of potential therapeutic targets. We found that CD4 surface levels were significantly higher in HIV-1-infected cells knocked-down for the HIV Rev-binding protein (HRB) compared with control cells. HRB knock-down affected CD4 downregulation induced by Nef but not by HIV-1 Vpu. Interestingly, the knock-down of the related protein HRBL (HRB-like), but not of the HRB interaction partner EPS15 (epidermal growth factor receptor pathway substrate 15), increased CD4 levels in Vpu-expressing cells significantly. Both of these proteins are known to be involved in HIV-1-mediated CD4 downregulation as co-factors of HIV-1 Nef. These results identify HRB as a previously unknown co-factor for HIV-1 Nef-mediated CD4 downregulation and highlight differences with the related protein HRBL, which affects the CD4 downregulation in a dual role as co-factor of both HIV-1 Nef and Vpu.
Collapse
Affiliation(s)
- Alessia Landi
- Department of Clinical Chemistry, Microbiology, and Immunology, Ghent University, Ghent, Belgium
| | | | - Evelien Naessens
- Department of Clinical Chemistry, Microbiology, and Immunology, Ghent University, Ghent, Belgium
| | - Hanne Vanderstraeten
- Department of Clinical Chemistry, Microbiology, and Immunology, Ghent University, Ghent, Belgium
| | - Veronique Stove
- Department of Clinical Chemistry, Microbiology, and Immunology, Ghent University, Ghent, Belgium
| | - Bruno Verhasselt
- Department of Clinical Chemistry, Microbiology, and Immunology, Ghent University, Ghent, Belgium
| |
Collapse
|
49
|
Raymond AD, Diaz P, Chevelon S, Agudelo M, Yndart-Arias A, Ding H, Kaushik A, Jayant RD, Nikkhah-Moshaie R, Roy U, Pilakka-Kanthikeel S, Nair MP. Microglia-derived HIV Nef+ exosome impairment of the blood-brain barrier is treatable by nanomedicine-based delivery of Nef peptides. J Neurovirol 2015; 22:129-39. [PMID: 26631079 DOI: 10.1007/s13365-015-0397-0] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Revised: 10/13/2015] [Accepted: 10/14/2015] [Indexed: 10/22/2022]
Abstract
The negative factor (Nef) of human immunodeficiency virus (HIV) is an accessory protein that is thought to be integral to HIV-associated immune- and neuroimmune pathogenesis. Here, we show that nef-transfected microglia-released Nef+ exosome (exNef) disrupts the apical blood-brain barrier (BBB) and that only nef-transfected microglia release Nef in exosomes. nef-gfp-transduced neurons and astrocytes release exosomes but did not release exNef in the extracellular space. Apical administration of exNef derived from nef-transfected 293T cells reduced transendothelial electrical resistance (TEER) and increased permeability of the BBB. Microglia-derived exNef applied to either the apical/basal BBB significantly reduced expression of the tight junction protein, ZO-1, suggesting a mechanism of exNef-mediated neuropathogenesis. Microglia exposed to exNef release elevated levels of Toll-like receptor-induced cytokines and chemokines IL-12, IL-8, IL-6, RANTES, and IL-17A. Magnetic nanoparticle delivery of Nef peptides containing the Nef myrisolation site across an in vitro BBB ultimately reduced nef-transfected microglia release of Nef exosomes and prevented the loss of BBB integrity and permeability as measured by TEER and dextran-FITC transport studies, respectively. Overall, we show that exNef is released from nef-gfp-transfected microglia; exNef disrupts integrity and permeability, and tight junctions of the BBB, and induces microglial cytokine/chemokine secretion. These exNef-mediated effects were significantly restricted by Nef peptides. Taken together, this study provides preliminary evidence of the role of exNef in HIV neuroimmune pathogenesis and the feasibility of a nanomedicine-based therapeutics targeting exNef to treat HIV-associated neuropathogenesis.
Collapse
Affiliation(s)
- A D Raymond
- Department of Immunology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, 33199, USA. .,Institute of Neuroimmune Pharmacology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, 33199, USA.
| | - P Diaz
- Department of Immunology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, 33199, USA
| | - S Chevelon
- Department of Immunology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, 33199, USA
| | - M Agudelo
- Department of Immunology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, 33199, USA
| | - A Yndart-Arias
- Department of Immunology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, 33199, USA.,Institute of Neuroimmune Pharmacology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, 33199, USA
| | - H Ding
- Institute of Neuroimmune Pharmacology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, 33199, USA
| | - A Kaushik
- Institute of Neuroimmune Pharmacology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, 33199, USA
| | - R Dev Jayant
- Institute of Neuroimmune Pharmacology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, 33199, USA
| | - R Nikkhah-Moshaie
- Department of Mechanical and Materials Engineering, College of Engineering and Computing, Florida International University, 10555 W. Flagler St., Miami, FL, 33174, USA
| | - U Roy
- Institute of Neuroimmune Pharmacology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, 33199, USA
| | - S Pilakka-Kanthikeel
- Department of Immunology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, 33199, USA
| | - M P Nair
- Department of Immunology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, 33199, USA.,Institute of Neuroimmune Pharmacology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, 33199, USA
| |
Collapse
|
50
|
AP-2 Is the Crucial Clathrin Adaptor Protein for CD4 Downmodulation by HIV-1 Nef in Infected Primary CD4+ T Cells. J Virol 2015; 89:12518-24. [PMID: 26423947 DOI: 10.1128/jvi.01838-15] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Accepted: 09/22/2015] [Indexed: 01/28/2023] Open
Abstract
HIV-1 Nef-mediated CD4 downmodulation involves various host factors. We investigated the importance of AP-1, AP-2, AP-3, V1H-ATPase, β-COP, and ACOT8 for CD4 downmodulation in HIV-1-infected short hairpin RNA (shRNA)-expressing CD4(+) T cells and characterized direct interaction with Nef by Förster resonance energy transfer (FRET). Binding of lentiviral Nefs to CD4 and AP-2 was conserved, and only AP-2 knockdown impaired Nef-mediated CD4 downmodulation from primary T cells. Altogether, among the factors tested, AP-2 is the most important player for Nef-mediated CD4 downmodulation.
Collapse
|