1
|
Moaveni AK, Amiri M, Shademan B, Farhadi A, Behroozi J, Nourazarian A. Advances and challenges in gene therapy strategies for pediatric cancer: a comprehensive update. Front Mol Biosci 2024; 11:1382190. [PMID: 38836106 PMCID: PMC11149429 DOI: 10.3389/fmolb.2024.1382190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Accepted: 03/27/2024] [Indexed: 06/06/2024] Open
Abstract
Pediatric cancers represent a tragic but also promising area for gene therapy. Although conventional treatments have improved survival rates, there is still a need for targeted and less toxic interventions. This article critically analyzes recent advances in gene therapy for pediatric malignancies and discusses the challenges that remain. We explore the innovative vectors and delivery systems that have emerged, such as adeno-associated viruses and non-viral platforms, which show promise in addressing the unique pathophysiology of pediatric tumors. Specifically, we examine the field of chimeric antigen receptor (CAR) T-cell therapies and their adaptation for solid tumors, which historically have been more challenging to treat than hematologic malignancies. We also discuss the genetic and epigenetic complexities inherent to pediatric cancers, such as tumor heterogeneity and the dynamic tumor microenvironment, which pose significant hurdles for gene therapy. Ethical considerations specific to pediatric populations, including consent and long-term follow-up, are also analyzed. Additionally, we scrutinize the translation of research from preclinical models that often fail to mimic pediatric cancer biology to the regulatory landscapes that can either support or hinder innovation. In summary, this article provides an up-to-date overview of gene therapy in pediatric oncology, highlighting both the rapid scientific progress and the substantial obstacles that need to be addressed. Through this lens, we propose a roadmap for future research that prioritizes the safety, efficacy, and complex ethical considerations involved in treating pediatric patients. Our ultimate goal is to move from incremental advancements to transformative therapies.
Collapse
Affiliation(s)
- Amir Kian Moaveni
- Pediatric Urology and Regenerative Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Maryam Amiri
- Pediatric Urology and Regenerative Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Behrouz Shademan
- Stem Cell Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Arezoo Farhadi
- Department of Genetics and Molecular Medicine, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran
| | - Javad Behroozi
- Department of Cell and Molecular Biology, Faculty of Biological Sciences, Kharazmi University, Tehran, Iran
| | - Alireza Nourazarian
- Department of Basic Medical Sciences, Khoy University of Medical Sciences, Khoy, Iran
| |
Collapse
|
2
|
Edelstein J, Fritz M, Lai SK. Challenges and opportunities in gene editing of B cells. Biochem Pharmacol 2022; 206:115285. [PMID: 36241097 DOI: 10.1016/j.bcp.2022.115285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 09/28/2022] [Accepted: 09/30/2022] [Indexed: 01/29/2023]
Abstract
B cells have long been an underutilized target in immune cell engineering, despite a number of unique attributes that could address longstanding challenges in medicine. Notably, B cells evolved to secrete large quantities of antibodies for prolonged periods, making them suitable platforms for long-term protein delivery. Recent advances in gene editing technologies, such as CRISPR-Cas, have improved the precision and efficiency of engineering and expanded potential applications of engineered B cells. While most work on B cell editing has focused on ex vivo modification, a body of recent work has also advanced the possibility of in vivo editing applications. In this review, we will discuss both past and current approaches to B cell engineering, and its promising applications in immunology research and therapeutic gene editing.
Collapse
Affiliation(s)
- Jasmine Edelstein
- Division of Pharmacoengineering and Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, USA
| | - Marshall Fritz
- Division of Pharmacoengineering and Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, USA
| | - Samuel K Lai
- Division of Pharmacoengineering and Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, USA; Department of Biomedical Engineering, University of North Carolina, Chapel Hill, NC, USA; Department of Immunology and Microbiology, University of North Carolina, Chapel Hill, NC, USA.
| |
Collapse
|
3
|
Shen Q, Wu C, Freniere C, Tripler TN, Xiong Y. Nuclear Import of HIV-1. Viruses 2021; 13:2242. [PMID: 34835048 PMCID: PMC8619967 DOI: 10.3390/v13112242] [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: 09/30/2021] [Revised: 10/26/2021] [Accepted: 11/01/2021] [Indexed: 12/12/2022] Open
Abstract
The delivery of the HIV-1 genome into the nucleus is an indispensable step in retroviral infection of non-dividing cells, but the mechanism of HIV-1 nuclear import has been a longstanding debate due to controversial experimental evidence. It was commonly believed that the HIV-1 capsid would need to disassemble (uncoat) in the cytosol before nuclear import because the capsid is larger than the central channel of nuclear pore complexes (NPCs); however, increasing evidence demonstrates that intact, or nearly intact, HIV-1 capsid passes through the NPC to enter the nucleus. With the protection of the capsid, the HIV-1 core completes reverse transcription in the nucleus and is translocated to the integration site. Uncoating occurs while, or after, the viral genome is released near the integration site. These independent discoveries reveal a compelling new paradigm of this important step of the HIV-1 life cycle. In this review, we summarize the recent studies related to HIV-1 nuclear import, highlighting the spatial-temporal relationship between the nuclear entry of the virus core, reverse transcription, and capsid uncoating.
Collapse
Affiliation(s)
| | | | | | | | - Yong Xiong
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06511, USA; (Q.S.); (C.W.); (C.F.); (T.N.T.)
| |
Collapse
|
4
|
Wang Y, Bruggeman KF, Franks S, Gautam V, Hodgetts SI, Harvey AR, Williams RJ, Nisbet DR. Is Viral Vector Gene Delivery More Effective Using Biomaterials? Adv Healthc Mater 2021; 10:e2001238. [PMID: 33191667 DOI: 10.1002/adhm.202001238] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 10/03/2020] [Indexed: 12/16/2022]
Abstract
Gene delivery has been extensively investigated for introducing foreign genetic material into cells to promote expression of therapeutic proteins or to silence relevant genes. This approach can regulate genetic or epigenetic disorders, offering an attractive alternative to pharmacological therapy or invasive protein delivery options. However, the exciting potential of viral gene therapy has yet to be fully realized, with a number of clinical trials failing to deliver optimal therapeutic outcomes. Reasons for this include difficulty in achieving localized delivery, and subsequently lower efficacy at the target site, as well as poor or inconsistent transduction efficiency. Thus, ongoing efforts are focused on improving local viral delivery and enhancing its efficiency. Recently, biomaterials have been exploited as an option for more controlled, targeted and programmable gene delivery. There is a growing body of literature demonstrating the efficacy of biomaterials and their potential advantages over other delivery strategies. This review explores current limitations of gene delivery and the progress of biomaterial-mediated gene delivery. The combination of biomaterials and gene vectors holds the potential to surmount major challenges, including the uncontrolled release of viral vectors with random delivery duration, poorly localized viral delivery with associated off-target effects, limited viral tropism, and immune safety concerns.
Collapse
Affiliation(s)
- Yi Wang
- Laboratory of Advanced Biomaterials Research School of Engineering The Australian National University Canberra ACT 2601 Australia
| | - Kiara F. Bruggeman
- Laboratory of Advanced Biomaterials Research School of Engineering The Australian National University Canberra ACT 2601 Australia
| | - Stephanie Franks
- Laboratory of Advanced Biomaterials Research School of Engineering The Australian National University Canberra ACT 2601 Australia
| | - Vini Gautam
- Department of Biomedical Engineering The University of Melbourne Melbourne Victoria 3010 Australia
| | - Stuart I. Hodgetts
- School of Human Sciences The University of Western Australia Perth WA 6009 Australia
- Perron Institute for Neurological and Translational Science Perth WA 6009 Australia
| | - Alan R. Harvey
- School of Human Sciences The University of Western Australia Perth WA 6009 Australia
- Perron Institute for Neurological and Translational Science Perth WA 6009 Australia
| | - Richard J. Williams
- The Institute for Mental and Physical Health and Clinical Translation (IMPACT) School of Medicine Deakin University Waurn Ponds VIC 3216 Australia
- Biofab3D St. Vincent's Hospital Fitzroy 3065 Australia
| | - David R. Nisbet
- Laboratory of Advanced Biomaterials Research School of Engineering The Australian National University Canberra ACT 2601 Australia
- Biofab3D St. Vincent's Hospital Fitzroy 3065 Australia
| |
Collapse
|
5
|
Shukla E, Chauhan R. Host-HIV-1 Interactome: A Quest for Novel Therapeutic Intervention. Cells 2019; 8:cells8101155. [PMID: 31569640 PMCID: PMC6830350 DOI: 10.3390/cells8101155] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 09/09/2019] [Accepted: 09/09/2019] [Indexed: 12/15/2022] Open
Abstract
The complex nature and structure of the human immunodeficiency virus has rendered the cure for HIV infections elusive. The advances in antiretroviral treatment regimes and the development of highly advanced anti-retroviral therapy, which primarily targets the HIV enzymes, have dramatically changed the face of the HIV epidemic worldwide. Despite this remarkable progress, patients treated with these drugs often witness inadequate efficacy, compound toxicity and non-HIV complications. Considering the limited inventory of druggable HIV proteins and their susceptibility to develop drug resistance, recent attempts are focussed on targeting HIV-host interactomes that are essential for viral reproduction. Noticeably, unlike other viruses, HIV subverts the host nuclear pore complex to enter into and exit through the nucleus. Emerging evidence suggests a crucial role of interactions between HIV-1 proteins and host nucleoporins that underlie the import of the pre-integration complex into the nucleus and export of viral RNAs into the cytoplasm during viral replication. Nevertheless, the interaction of HIV-1 with nucleoporins has been poorly described and the role of nucleoporins during nucleocytoplasmic transport of HIV-1 still remains unclear. In this review, we highlight the advances and challenges in developing a more effective antiviral arsenal by exploring critical host-HIV interactions with a special focus on nuclear pore complex (NPC) and nucleoporins.
Collapse
Affiliation(s)
- Ekta Shukla
- National Center for Cell Science, S.P Pune University, Pune-411007, Maharashtra, India.
| | - Radha Chauhan
- National Center for Cell Science, S.P Pune University, Pune-411007, Maharashtra, India.
| |
Collapse
|
6
|
Nup153 Unlocks the Nuclear Pore Complex for HIV-1 Nuclear Translocation in Nondividing Cells. J Virol 2018; 92:JVI.00648-18. [PMID: 29997211 DOI: 10.1128/jvi.00648-18] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 06/20/2018] [Indexed: 12/27/2022] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) displays the unique ability to infect nondividing cells. The capsid of HIV-1 is the viral determinant for viral nuclear import. To understand the cellular factors involved in the ability of HIV-1 to infect nondividing cells, we sought to find capsid mutations that allow the virus to infect dividing but not nondividing cells. Because the interaction of capsid with the nucleoporin protein 153 (Nup153) is important for nuclear import of HIV-1, we solved new crystal structures of hexameric HIV-1 capsid in complex with a Nup153-derived peptide containing a phenylalanine-glycine repeat (FG repeat), which we used to guide structure-based mutagenesis of the capsid-binding interface. HIV-1 viruses with mutations in these capsid residues were tested for their ability to infect dividing and nondividing cells. HIV-1 viruses with capsid N57 substitutions infected dividing but not nondividing cells. Interestingly, HIV-1 viruses with N57 mutations underwent reverse transcription but not nuclear translocation. The mutant capsids also lost the ability to interact with Nup153 and CPSF6. The use of small molecules PF74 and BI-2 prevented the interaction of FG-containing nucleoporins (Nups), such as Nup153, with the HIV-1 core. Analysis of integration sites in HIV-1 viruses with N57 mutations revealed diminished integration into transcriptionally active genes in a manner resembling that of HIV-1 in CPSF6 knockout cells or that of HIV-1-N74D. The integration pattern of the N57 mutant HIV-1 can be explained by loss of capsid interaction with CPSF6, whereas capsid interaction with Nup153 is required for HIV-1 to infect nondividing cells. Additionally, the observed viral integration profiles suggested that integration site selection is a multiparameter process that depends upon nuclear factors and the state of the cellular chromatin.IMPORTANCE One of the key advantages that distinguish lentiviruses, such as HIV-1, from all other retroviruses is its ability to infect nondividing cells. Interaction of the HIV-1 capsid with Nup153 and CPSF6 is important for nuclear entry and integration; however, the contribution of each of these proteins to nuclear import and integration is not clear. Using genetics, we demonstrated that these proteins contribute to different processes: Nup153 is essential for the HIV-1 nuclear import in nondividing cells, and CPSF6 is important for HIV-1 integration. In addition, nuclear factors such as CPSF6 and the state of the chromatin are known to be important for integration site selection; nevertheless, the preferential determinant influencing integration site selection is not known. This work demonstrates that integration site selection is a multiparameter process that depends upon nuclear factors and the state of the cellular chromatin.
Collapse
|
7
|
N-terminally truncated POM121C inhibits HIV-1 replication. PLoS One 2017; 12:e0182434. [PMID: 28873410 PMCID: PMC5584925 DOI: 10.1371/journal.pone.0182434] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Accepted: 07/18/2017] [Indexed: 11/19/2022] Open
Abstract
Recent studies have identified host cell factors that regulate early stages of HIV-1 infection including viral cDNA synthesis and orientation of the HIV-1 capsid (CA) core toward the nuclear envelope, but it remains unclear how viral DNA is imported through the nuclear pore and guided to the host chromosomal DNA. Here, we demonstrate that N-terminally truncated POM121C, a component of the nuclear pore complex, blocks HIV-1 infection. This truncated protein is predominantly localized in the cytoplasm, does not bind to CA, does not affect viral cDNA synthesis, reduces the formation of 2-LTR and diminished the amount of integrated proviral DNA. Studies with an HIV-1-murine leukemia virus (MLV) chimeric virus carrying the MLV-derived Gag revealed that Gag is a determinant of this inhibition. Intriguingly, mutational studies have revealed that the blockade by N-terminally-truncated POM121C is closely linked to its binding to importin-β/karyopherin subunit beta 1 (KPNB1). These results indicate that N-terminally-truncated POM121C inhibits HIV-1 infection after completion of reverse transcription and before integration, and suggest an important role for KPNB1 in HIV-1 replication.
Collapse
|
8
|
Chen NY, Zhou L, Gane PJ, Opp S, Ball NJ, Nicastro G, Zufferey M, Buffone C, Luban J, Selwood D, Diaz-Griffero F, Taylor I, Fassati A. HIV-1 capsid is involved in post-nuclear entry steps. Retrovirology 2016; 13:28. [PMID: 27107820 PMCID: PMC4842275 DOI: 10.1186/s12977-016-0262-0] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Accepted: 04/14/2016] [Indexed: 11/17/2022] Open
Abstract
Background HIV-1 capsid influences viral uncoating and nuclear import. Some capsid is detected in the nucleus but it is unclear if it has any function. We reported that the antibiotic Coumermycin-A1 (C-A1) inhibits HIV-1 integration and that a capsid mutation confers resistance to C-A1, suggesting that capsid might affect post-nuclear entry steps. Results Here we report that C-A1 inhibits HIV-1 integration in a capsid-dependent way. Using molecular docking, we identify an extended binding pocket delimited by two adjacent capsid monomers where C-A1 is predicted to bind. Isothermal titration calorimetry confirmed that C-A1 binds to hexameric capsid. Cyclosporine washout assays in Jurkat CD4+ T cells expressing engineered human TRIMCyp showed that C-A1 causes faster and greater escape from TRIMCyp restriction. Sub-cellular fractionation showed that small amounts of capsid accumulated in the nuclei of infected cells and C-A1 reduced the nuclear capsid. A105S and N74D capsid mutant viruses did not accumulate capsid in the nucleus, irrespective of C-A1 treatment. Depletion of Nup153, a nucleoporin located at the nuclear side of the nuclear pore that binds to HIV-1 capsid, made the virus less susceptible to TRIMCyp restriction, suggesting that Nup153 may help maintain some integrity of the viral core in the nucleus. Furthermore C-A1 increased binding of CPSF6, a nuclear protein, to capsid. Conclusions Our results indicate that capsid is involved in post-nuclear entry steps preceding integration. Electronic supplementary material The online version of this article (doi:10.1186/s12977-016-0262-0) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Nan-Yu Chen
- Division of Infection and Immunity, University College London, Cruciform Building, 90 Gower Street, London, WC1E 6BT, UK.,Division of Infectious Diseases, Department of Internal Medicine, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, 5 Fuhsing Street, Kueishan, Taoyuan, 333, Taiwan
| | - Lihong Zhou
- Division of Infection and Immunity, University College London, Cruciform Building, 90 Gower Street, London, WC1E 6BT, UK.,Genome Damage and Stability Centre, University of Sussex, Science Park Road, Falmer, Brighton, BN1 9RQ, UK
| | - Paul J Gane
- Medicinal Chemistry Group, University College London, Cruciform Building, Gower Street, London, WC1E 6BT, UK.,Chemical Computing Group, St. John's Innovation Centre, Cowley Road, Cambridge, CB4 0WS, UK
| | - Silvana Opp
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Neil J Ball
- Mill Hill Laboratory, The Francis Crick Institute, The Ridgeway, Mill Hill, London, NW7 1AA, UK
| | - Giuseppe Nicastro
- Mill Hill Laboratory, The Francis Crick Institute, The Ridgeway, Mill Hill, London, NW7 1AA, UK
| | - Madeleine Zufferey
- Department of Microbiology and Molecular Medicine, University of Geneva, 1 Rue Michel Servet, CH-1211, Geneva, Switzerland.,Program in Molecular Medicine, University of Massachusetts Medical School, 373 Plantation Street, Biotech 2, Suite 319, Worcester, MA, 01605, USA
| | - Cindy Buffone
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Jeremy Luban
- Department of Microbiology and Molecular Medicine, University of Geneva, 1 Rue Michel Servet, CH-1211, Geneva, Switzerland.,Program in Molecular Medicine, University of Massachusetts Medical School, 373 Plantation Street, Biotech 2, Suite 319, Worcester, MA, 01605, USA.,Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, 373 Plantation Street, Biotech 2, Suite 319, Worcester, MA, 01605, USA
| | - David Selwood
- Medicinal Chemistry Group, University College London, Cruciform Building, Gower Street, London, WC1E 6BT, UK
| | - Felipe Diaz-Griffero
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Ian Taylor
- Mill Hill Laboratory, The Francis Crick Institute, The Ridgeway, Mill Hill, London, NW7 1AA, UK
| | - Ariberto Fassati
- Division of Infection and Immunity, University College London, Cruciform Building, 90 Gower Street, London, WC1E 6BT, UK.
| |
Collapse
|
9
|
Hill AB, Chen M, Chen CK, Pfeifer BA, Jones CH. Overcoming Gene-Delivery Hurdles: Physiological Considerations for Nonviral Vectors. Trends Biotechnol 2016; 34:91-105. [PMID: 26727153 PMCID: PMC5800990 DOI: 10.1016/j.tibtech.2015.11.004] [Citation(s) in RCA: 115] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Revised: 11/16/2015] [Accepted: 11/17/2015] [Indexed: 12/13/2022]
Abstract
With the use of contemporary tools and techniques, it has become possible to more precisely tune the biochemical mechanisms associated with using nonviral vectors for gene delivery. Consequently, nonviral vectors can incorporate numerous vector compositions and types of genetic cargo to develop diverse genetic therapies. Despite these advantages, gene-delivery strategies using nonviral vectors have poorly translated into clinical success due to preclinical experimental design considerations that inadequately predict therapeutic efficacy. Furthermore, the manufacturing and distribution processes are critical considerations for clinical application that should be considered when developing therapeutic platforms. In this review, we evaluate potential avenues towards improving the transition of gene-delivery technologies from in vitro assessment to human clinical therapy.
Collapse
Affiliation(s)
- Andrew B Hill
- Abcombi Biosciences Inc, Buffalo, NY, USA; McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, TX, USA
| | - Mingfu Chen
- Department of Chemical and Biological Engineering, University at Buffalo, The State University of New York, Buffalo, BY, USA
| | - Chih-Kuang Chen
- Department of Fiber and Composite Materials, Feng Chia University, Taichung, Taiwan, ROC
| | - Blaine A Pfeifer
- Abcombi Biosciences Inc, Buffalo, NY, USA; Department of Chemical and Biological Engineering, University at Buffalo, The State University of New York, Buffalo, BY, USA.
| | - Charles H Jones
- Abcombi Biosciences Inc, Buffalo, NY, USA; Department of Chemical and Biological Engineering, University at Buffalo, The State University of New York, Buffalo, BY, USA.
| |
Collapse
|
10
|
Bin Hamid F, Kim J, Shin CG. Cellular and viral determinants of retroviral nuclear entry. Can J Microbiol 2015; 62:1-15. [PMID: 26553381 DOI: 10.1139/cjm-2015-0350] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Retroviruses must integrate their cDNA into the host genome to generate proviruses. Viral DNA-protein complexes interact with cellular proteins and produce pre-integration complexes, which carry the viral genome and cross the nuclear pore channel to enter the nucleus and integrate viral DNA into host chromosomal DNA. If the reverse transcripts fail to integrate, linear or circular DNA species such as 1- and 2-long terminal repeats are generated. Such complexes encounter numerous cellular proteins in the cytoplasm, which restrict viral infection and protect the nucleus. To overcome host cell defenses, the pathogens have evolved several evasion strategies. Viral proteins often contain nuclear localization signals, allowing entry into the nucleus. Among more than 1000 proteins identified as required for HIV infection by RNA interference screening, karyopherins, cleavage and polyadenylation specific factor 6, and nucleoporins have been predominantly studied. This review discusses current opinions about the synergistic relationship between the viral and cellular factors involved in nuclear import, with focus on the unveiled mysteries of the host-pathogen interaction, and highlights novel approaches to pinpoint therapeutic targets.
Collapse
Affiliation(s)
- Faysal Bin Hamid
- Department of Systems Biotechnology, Chung-Ang University, Ansung 456-756, Republic of Korea.,Department of Systems Biotechnology, Chung-Ang University, Ansung 456-756, Republic of Korea
| | - Jinsun Kim
- Department of Systems Biotechnology, Chung-Ang University, Ansung 456-756, Republic of Korea.,Department of Systems Biotechnology, Chung-Ang University, Ansung 456-756, Republic of Korea
| | - Cha-Gyun Shin
- Department of Systems Biotechnology, Chung-Ang University, Ansung 456-756, Republic of Korea.,Department of Systems Biotechnology, Chung-Ang University, Ansung 456-756, Republic of Korea
| |
Collapse
|
11
|
Abstract
HIV-1 replication has been intensively investigated over the past 30 years. Hsp90 is one of the most abundant proteins in human cells, important in the formation and function of several protein complexes that maintain cell homeostasis. Remarkably, the impact of Hsp90 on HIV-1 infection has started to be appreciated only recently. Hsp90 has been shown to (a) promote HIV-1 gene expression in acutely infected cells, (b) localize at the viral promoter DNA, (c) mediate enhanced replication in conditions of hyperthermia and (d) activate the P-TEFb complex, which is essential for efficient HIV-1 transcription. Hsp90 has been implicated in buffering deleterious mutations of the viral core and in the regulation of innate and acquired immune responses to HIV-1 infection. Therefore, Hsp90 is an important host factor promoting several steps of the HIV-1 life cycle. Several small Hsp90 inhibitors are in Phase II clinical trials for human cancers and might potentially be used to inhibit HIV-1 infection at multiple levels.
Collapse
|
12
|
Le Sage V, Mouland AJ, Valiente-Echeverría F. Roles of HIV-1 capsid in viral replication and immune evasion. Virus Res 2014; 193:116-29. [PMID: 25036886 DOI: 10.1016/j.virusres.2014.07.010] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Revised: 07/04/2014] [Accepted: 07/07/2014] [Indexed: 02/07/2023]
Abstract
The primary roles of the human immunodeficiency virus type 1 (HIV-1) capsid (CA) protein are to encapsidate and protect the viral RNA genome. It is becoming increasing apparent that HIV-1 CA is a multifunctional protein that acts early during infection to coordinate uncoating, reverse transcription, nuclear import of the pre-integration complex and integration of double stranded viral DNA into the host genome. Additionally, numerous recent studies indicate that CA is playing a crucial function in HIV-1 immune evasion. Here we summarize the current knowledge on HIV-1 CA and its interactions with the host cell to promote infection. The fact that CA engages in a number of different protein-protein interactions with the host makes it an interesting target for the development of new potent antiviral agents.
Collapse
Affiliation(s)
- Valerie Le Sage
- HIV-1 RNA Trafficking Laboratory, Lady Davis Institute, Jewish General Hospital, Montréal, Québec H3T1E2, Canada; Department of Medicine, Division of Experimental Medicine, McGill University, Montréal, Québec H3A 1A3, Canada
| | - Andrew J Mouland
- HIV-1 RNA Trafficking Laboratory, Lady Davis Institute, Jewish General Hospital, Montréal, Québec H3T1E2, Canada; Department of Medicine, Division of Experimental Medicine, McGill University, Montréal, Québec H3A 1A3, Canada; Department of Microbiology and Immunology, McGill University, Montréal, Québec, H3A2B4, Canada
| | - Fernando Valiente-Echeverría
- HIV-1 RNA Trafficking Laboratory, Lady Davis Institute, Jewish General Hospital, Montréal, Québec H3T1E2, Canada; Department of Medicine, Division of Experimental Medicine, McGill University, Montréal, Québec H3A 1A3, Canada.
| |
Collapse
|
13
|
Hu K. Vectorology and factor delivery in induced pluripotent stem cell reprogramming. Stem Cells Dev 2014; 23:1301-15. [PMID: 24625220 PMCID: PMC4046209 DOI: 10.1089/scd.2013.0621] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Accepted: 03/13/2014] [Indexed: 12/26/2022] Open
Abstract
Induced pluripotent stem cell (iPSC) reprogramming requires sustained expression of multiple reprogramming factors for a limited period of time (10-30 days). Conventional iPSC reprogramming was achieved using lentiviral or simple retroviral vectors. Retroviral reprogramming has flaws of insertional mutagenesis, uncontrolled silencing, residual expression and re-activation of transgenes, and immunogenicity. To overcome these issues, various technologies were explored, including adenoviral vectors, protein transduction, RNA transfection, minicircle DNA, excisable PiggyBac (PB) transposon, Cre-lox excision system, negative-sense RNA replicon, positive-sense RNA replicon, Epstein-Barr virus-based episomal plasmids, and repeated transfections of plasmids. This review provides summaries of the main vectorologies and factor delivery systems used in current reprogramming protocols.
Collapse
Affiliation(s)
- Kejin Hu
- Department of Biochemistry and Molecular Genetics, UAB Stem Cell Institute, School of Medicine, University of Alabama at Birmingham , Birmingham, Alabama
| |
Collapse
|
14
|
Hossain A, Ali K, Shin CG. Nuclear localization signals in prototype foamy viral integrase for successive infection and replication in dividing cells. Mol Cells 2014; 37:140-8. [PMID: 24598999 PMCID: PMC3935627 DOI: 10.14348/molcells.2014.2331] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Revised: 12/11/2013] [Accepted: 12/13/2013] [Indexed: 11/27/2022] Open
Abstract
We identified four basic amino acid residues as nuclear localization signals (NLS) in the C-terminal domain of the prototype foamy viral (PFV) integrase (IN) protein that were essential for viral replication. We constructed seven point mutants in the C-terminal domain by changing the lysine and arginine at residues 305, 308, 313, 315, 318, 324, and 329 to threonine or proline, respectively, to identify residues conferring NLS activity. Our results showed that mutation of these residues had no effect on expression assembly, release of viral particles, or in vitro recombinant IN enzymatic activity. However, mutations at residues 305 (R → T), 313(R → T), 315(R → P), and 329(R → T) lead to the production of defective viral particles with loss of infectivity, whereas non-defective mutations at residues 308(R → T), 318(K → T), and 324(K → T) did not show any adverse effects on subsequent production or release of viral particles. Sub-cellular fractionation and immunostaining for viral protein PFV-IN and PFV-Gag localization revealed predominant cytoplasmic localization of PFV-IN in defective mutants, whereas cytoplasmic and nuclear localization of PFV-IN was observed in wild type and non-defective mutants. However sub-cellular localization of PFV-Gag resulted in predominant nuclear localization and less presence in the cytoplasm of the wild type and non-defective mutants. But defective mutants showed only nuclear localization of Gag. Therefore, we postulate that four basic arginine residues at 305, 313, 315 and 329 confer the karyoplilic properties of PFV-IN and are essential for successful viral integration and replication.
Collapse
Affiliation(s)
- Alamgir Hossain
- Department of Biotechnology, Chung-Ang University, Ansung 456-756,
Korea
| | - Khadem Ali
- Department of Biotechnology, Chung-Ang University, Ansung 456-756,
Korea
| | - Cha-Gyun Shin
- Department of Biotechnology, Chung-Ang University, Ansung 456-756,
Korea
| |
Collapse
|
15
|
Shaw A, Cornetta K. Design and Potential of Non-Integrating Lentiviral Vectors. Biomedicines 2014; 2:14-35. [PMID: 28548058 PMCID: PMC5423482 DOI: 10.3390/biomedicines2010014] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2013] [Revised: 01/22/2014] [Accepted: 01/23/2014] [Indexed: 01/29/2023] Open
Abstract
Lentiviral vectors have demonstrated promising results in clinical trials that target cells of the hematopoietic system. For these applications, they are the vectors of choice since they provide stable integration into cells that will undergo extensive expansion in vivo. Unfortunately, integration can have unintended consequences including dysregulated cell growth. Therefore, lentiviral vectors that do not integrate are predicted to have a safer profile compared to integrating vectors and should be considered for applications where transient expression is required or for sustained episomal expression such as in quiescent cells. In this review, the system for generating lentiviral vectors will be described and used to illustrate how alterations in the viral integrase or vector Long Terminal Repeats have been used to generate vectors that lack the ability to integrate. In addition to their safety advantages, these non-integrating lentiviral vectors can be used when persistent expression would have adverse consequences. Vectors are currently in development for use in vaccinations, cancer therapy, site-directed gene insertions, gene disruption strategies, and cell reprogramming. Preclinical work will be described that illustrates the potential of this unique vector system in human gene therapy.
Collapse
Affiliation(s)
- Aaron Shaw
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
| | - Kenneth Cornetta
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
- Department of Medicine, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
| |
Collapse
|
16
|
Henning MS, Dubose BN, Burse MJ, Aiken C, Yamashita M. In vivo functions of CPSF6 for HIV-1 as revealed by HIV-1 capsid evolution in HLA-B27-positive subjects. PLoS Pathog 2014; 10:e1003868. [PMID: 24415937 PMCID: PMC3887095 DOI: 10.1371/journal.ppat.1003868] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Accepted: 11/22/2013] [Indexed: 11/21/2022] Open
Abstract
The host protein CPSF6 possesses a domain that can interact with the HIV-1 capsid (CA) protein. CPSF6 has been implicated in regulating HIV-1 nuclear entry. However, its functional significance for HIV-1 replication has yet to be firmly established. Here we provide evidence for two divergent functions of CPSF6 for HIV-1 replication in vivo. We demonstrate that endogenous CPSF6 exerts an inhibitory effect on naturally occurring HIV-1 variants in individuals carrying the HLA-B27 allele. Conversely, we find a strong selective pressure in these individuals to preserve CPSF6 binding, while escaping from the restrictive activity by CPSF6. This active maintenance of CPSF6 binding during HIV-1 CA evolution in vivo contrasts with the in vitro viral evolution, which can reduce CPSF6 binding to evade from CPSF6-mediated restriction. Thus, these observations argue for a beneficial role of CPSF6 for HIV-1 in vivo. CPSF6-mediated restriction renders HIV-1 less dependent or independent from TNPO3, RanBP2 and Nup153, host factors implicated in HIV-1 nuclear entry. However, viral evolution that maintains CPSF6 binding in HLA-B27+ subjects invariably restores the ability to utilize these host factors, which may be the major selective pressure for CPSF6 binding in vivo. Our study uncovers two opposing CA-dependent functions of CPSF6 in HIV-1 replication in vivo; however, the benefit for binding CPSF6 appears to outweigh the cost, providing support for a vital function of CPSF6 during HIV-1 replication in vivo. The viral capsid (CA) protein of HIV-1 determines both the ability to infect non-dividing cells and the utilization of host factors implicated in nuclear entry. Understanding how CA controls these two properties is critical. CPSF6, a CA-interacting host protein, may be important for these properties but its precise role remains unclear. Here we provide direct evidence for the involvement of endogenous CPSF6 during HIV-1 infection. We found that CPSF6 blocks CA mutants that are impaired for infection of non-dividing cells. This CPSF6-mediated inhibition also targets early escape variants that arise in HIV-1 infected HLA-B27+ patients. Moreover, this CPSF6-mediated inhibition, together with robust CTL response, appears to be critical for viral suppression, because viruses derived after late viral breakthrough in these individuals were no longer sensitive to the antiviral activity of CPSF6. However, we also report indirect evidence for a potentially beneficial role for CPSF6 in HIV-1 replication, because escape from this inhibition in vivo was paradoxically accompanied by a strict preservation of the CPSF6 binding pocket. These results highlight the unique characteristics of the HIV-CPSF6 interactions in which CPSF6 can be either beneficial or detrimental for viral replication in a CA-specific manner.
Collapse
Affiliation(s)
- Matthew S. Henning
- Aaron Diamond AIDS Research Center, New York, New York, United States of America
| | - Brittany N. Dubose
- Aaron Diamond AIDS Research Center, New York, New York, United States of America
| | - Mallori J. Burse
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Christopher Aiken
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Masahiro Yamashita
- Aaron Diamond AIDS Research Center, New York, New York, United States of America
- * E-mail:
| |
Collapse
|
17
|
Schambach A, Zychlinski D, Ehrnstroem B, Baum C. Biosafety features of lentiviral vectors. Hum Gene Ther 2013; 24:132-42. [PMID: 23311447 DOI: 10.1089/hum.2012.229] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Over the past decades, lentiviral vectors have evolved as a benchmark tool for stable gene transfer into cells with a high replicative potential. Their relatively flexible genome and ability to transduce many forms of nondividing cells, combined with the potential for cell-specific pseudotyping, provides a rich resource for numerous applications in experimental platforms and therapeutic settings. Here, we give an overview of important biosafety features of lentiviral vectors, with detailed discussion of (i) the principles of the lentiviral split-genome design used for the construction of packaging cells; (ii) the relevance of modifications introduced into the lentiviral long terminal repeat (deletion of enhancer/promoter sequences and introduction of insulators); (iii) the basic features of mRNA processing, including the Rev/Rev-responsive element (RRE) interaction and the modifications of the 3' untranslated region of lentiviral vectors with various post-transcriptional regulatory elements affecting transcriptional termination, polyadenylation, and differentiation-specific degradation of mRNA; and (iv) the characteristic integration pattern with the associated risk of transcriptional interference with cellular genes. We conclude with considerations regarding the importance of cell targeting via envelope modifications. Along this course, we address canonical biosafety issues encountered with any type of viral vector: the risks of shedding, mobilization, germline transmission, immunogenicity, and insertional mutagenesis.
Collapse
Affiliation(s)
- Axel Schambach
- Institute of Experimental Hematology, Hannover Medical School, D-30625 Hannover, Germany
| | | | | | | |
Collapse
|
18
|
Amie SM, Daly MB, Noble E, Schinazi RF, Bambara RA, Kim B. Anti-HIV host factor SAMHD1 regulates viral sensitivity to nucleoside reverse transcriptase inhibitors via modulation of cellular deoxyribonucleoside triphosphate (dNTP) levels. J Biol Chem 2013; 288:20683-91. [PMID: 23744077 DOI: 10.1074/jbc.m113.472159] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Newly identified anti-HIV host factor, SAMHD1, restricts replication of lentiviruses such as HIV-1, HIV-2, and simian immunodeficiency virus in macrophages by enzymatically hydrolyzing and depleting cellular dNTPs, which are the substrates of viral DNA polymerases. HIV-2 and some simian immunodeficiency viruses express viral protein X (VPX), which counteracts SAMHD1 and elevates cellular dNTPs, enhancing viral replication in macrophages. Because nucleoside reverse transcriptase inhibitors (NRTIs), the most commonly used anti-HIV drugs, compete against cellular dNTPs for incorporation into proviral DNA, we tested whether SAMHD1 directly affects the efficacy of NRTIs in inhibiting HIV-1. We found that reduction of SAMHD1 levels with the use of virus-like particles expressing Vpx- and SAMHD1-specific shRNA subsequently elevates cellular dNTPs and significantly decreases HIV-1 sensitivity to various NRTIs in macrophages. However, virus-like particles +Vpx treatment of activated CD4(+) T cells only minimally reduced NRTI efficacy. Furthermore, with the use of HPLC, we could not detect SAMHD1-mediated hydrolysis of NRTI-triphosphates, verifying that the reduced sensitivity of HIV-1 to NRTIs upon SAMHD1 degradation is most likely caused by the elevation in cellular dNTPs.
Collapse
Affiliation(s)
- Sarah M Amie
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, New York 14642, USA
| | | | | | | | | | | |
Collapse
|
19
|
The importance of becoming double-stranded: Innate immunity and the kinetic model of HIV-1 central plus strand synthesis. Virology 2013; 441:1-11. [PMID: 23561461 DOI: 10.1016/j.virol.2013.03.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Accepted: 03/14/2013] [Indexed: 12/23/2022]
Abstract
Central initiation of plus strand synthesis is a conserved feature of lentiviruses and certain other retroelements. This complication of the standard reverse transcription mechanism produces a transient "central DNA flap" in the viral cDNA, which has been proposed to mediate its subsequent nuclear import. This model has assumed that the important feature is the flapped DNA structure itself rather than the process that produces it. Recently, an alternative kinetic model was proposed. It posits that central plus strand synthesis functions to accelerate conversion to the double-stranded state, thereby helping HIV-1 to evade single-strand DNA-targeting antiviral restrictions such as APOBEC3 proteins, and perhaps to avoid innate immune sensor mechanisms. The model is consistent with evidence that lentiviruses must often synthesize their cDNAs when dNTP concentrations are limiting and with data linking reverse transcription and uncoating. There may be additional kinetic advantages for the artificial genomes of lentiviral gene therapy vectors.
Collapse
|
20
|
Nup153 and Nup98 bind the HIV-1 core and contribute to the early steps of HIV-1 replication. Virology 2013; 440:8-18. [PMID: 23523133 DOI: 10.1016/j.virol.2013.02.008] [Citation(s) in RCA: 115] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Revised: 01/31/2013] [Accepted: 02/02/2013] [Indexed: 12/13/2022]
Abstract
The early steps of HIV-1 replication involve the entry of HIV-1 into the nucleus, which is characterized by viral interactions with nuclear pore components. HIV-1 developed an evolutionary strategy to usurp the nuclear pore machinery and chromatin in order to integrate and efficiently express viral genes. In the current work, we studied the role of nucleoporins 153 and 98 (Nup153 and Nup98) in infection of human Jurkat lymphocytes by HIV-1. We showed that Nup153-depleted cells exhibited a defect in nuclear import, while depletion of Nup 98 caused a slight defect in HIV integration. To explore the biochemical viral determinants for the requirement of Nup153 and Nup98 during HIV-1 infection, we tested the ability of these nucleoporins to interact with HIV-1 cores. Our findings showed that both nucleoporins bind HIV-1 cores suggesting that this interaction is important for HIV-1 nuclear import and/or integration. Distribution analysis of integration sites in Nup153-depleted cells revealed a reduced tendency of HIV-1 to integrate in intragenic sites, which in part could account for the large infectivity defect observed in Nup153-depleted cells. Our work strongly supports a role for Nup153 in HIV-1 nuclear import and integration.
Collapse
|
21
|
Abstract
Primate immunodeficiency viruses are highly specialized lentiviruses that have evolved to successfully infect and persist for the lifetime of the host. Despite encountering numerous potent antiviral factors, HIVs and SIVs are successful pathogens due to the acquisition of equally potent countermeasures in the form of accessory genes. The accessory gene Vpx encoded by HIV-2 and a subset of SIVs have a profound effect on the ability of lentiviruses to infect non-dividing cells, such as macrophages. Although most virus replication occurs in activated CD4(+) T cells, myeloid lineage cells are natural targets of infection and play a central role in virus transmission, dissemination, and persistence. However, myeloid lineage cells are poorly sensitive to lentiviral infection due partly to the high-level expression of a host protein that regulates nucleic acid metabolism named SAMHD1. Degradation of SAMHD1 is induced by Vpx to eliminate this intrinsic antiviral factor. Importantly, SAMHD1 has also been implicated as a negative regulator of the innate immune response, so the interplay between SAMHD1 and Vpx is likely to have significant consequences for virus replication, persistence, and immune control.
Collapse
Affiliation(s)
- Mark Sharkey
- University of Miami Miller School of Medicine, Miami, FL 33136, USA.
| |
Collapse
|
22
|
Fassati A. Multiple roles of the capsid protein in the early steps of HIV-1 infection. Virus Res 2012; 170:15-24. [PMID: 23041358 DOI: 10.1016/j.virusres.2012.09.012] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2012] [Revised: 09/10/2012] [Accepted: 09/11/2012] [Indexed: 11/22/2022]
Abstract
The early steps of HIV-1 infection starting after virus entry into cells up to integration of its genome into host chromosomes are poorly understood. From seminal work showing that HIV-1 and oncoretroviruses follow different steps in the early stages post-entry, significant advances have been made in recent years and an important role for the HIV-1 capsid (CA) protein, the constituent of the viral core, has emerged. CA appears to orchestrate several events, such as virus uncoating, recognition by restriction factors and the innate immune system. It also plays a role in nuclear import and integration of HIV-1 and has become a novel target for antiretroviral drugs. Here we describe the different functions of CA and how they may be integrated into one or more coherent models that illuminate the early events in HIV-1 infection and their relations with the host cell.
Collapse
Affiliation(s)
- Ariberto Fassati
- The Wohl Virion Centre and MRC Centre for Medical & Molecular Virology, Division of Infection and Immunity, University College London, Cruciform Building, 90 Gower Street, London WC1E 6BT, UK.
| |
Collapse
|
23
|
Di Nunzio F, Danckaert A, Fricke T, Perez P, Fernandez J, Perret E, Roux P, Shorte S, Charneau P, Diaz-Griffero F, Arhel NJ. Human nucleoporins promote HIV-1 docking at the nuclear pore, nuclear import and integration. PLoS One 2012; 7:e46037. [PMID: 23049930 PMCID: PMC3457934 DOI: 10.1371/journal.pone.0046037] [Citation(s) in RCA: 125] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2012] [Accepted: 08/27/2012] [Indexed: 11/19/2022] Open
Abstract
The nuclear pore complex (NPC) mediates nucleo-cytoplasmic transport of macromolecules and is an obligatory point of passage and functional bottleneck in the replication of some viruses. The Human Immunodeficiency Virus (HIV) has evolved the required mechanisms for active nuclear import of its genome through the NPC. However the mechanisms by which the NPC allows or even assists HIV translocation are still unknown. We investigated the involvement of four key nucleoporins in HIV-1 docking, translocation, and integration: Nup358/RanBP2, Nup214/CAN, Nup98 and Nup153. Although all induce defects in infectivity when depleted, only Nup153 actually showed any evidence of participating in HIV-1 translocation through the nuclear pore. We show that Nup358/RanBP2 mediates docking of HIV-1 cores on NPC cytoplasmic filaments by interacting with the cores and that the C-terminus of Nup358/RanBP2 comprising a cyclophilin-homology domain contributes to binding. We also show that Nup214/CAN and Nup98 play no role in HIV-1 nuclear import per se: Nup214/CAN plays an indirect role in infectivity read-outs through its effect on mRNA export, while the reduction of expression of Nup98 shows a slight reduction in proviral integration. Our work shows the involvement of nucleoporins in diverse and functionally separable steps of HIV infection and nuclear import.
Collapse
Affiliation(s)
- Francesca Di Nunzio
- Molecular Virology and Vaccinology Unit, CNRS URA 3015, Department of Virology, Institut Pasteur, Paris, France
| | | | - Thomas Fricke
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Patricio Perez
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Juliette Fernandez
- Molecular Virology and Vaccinology Unit, CNRS URA 3015, Department of Virology, Institut Pasteur, Paris, France
| | | | | | | | - Pierre Charneau
- Molecular Virology and Vaccinology Unit, CNRS URA 3015, Department of Virology, Institut Pasteur, Paris, France
| | - Felipe Diaz-Griffero
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Nathalie J. Arhel
- Molecular Virology and Vaccinology Unit, CNRS URA 3015, Department of Virology, Institut Pasteur, Paris, France
- * E-mail:
| |
Collapse
|
24
|
The Role of TNPO3 in HIV-1 Replication. Mol Biol Int 2012; 2012:868597. [PMID: 22888429 PMCID: PMC3409535 DOI: 10.1155/2012/868597] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2012] [Revised: 06/04/2012] [Accepted: 06/05/2012] [Indexed: 12/12/2022] Open
Abstract
TNPO3, transportin-SR2 or Tnp3, a member of the karyopherin β superfamily of proteins, is important for the ability of human immunodeficiency virus (HIV-1) to achieve productive infection, as TNPO3 depletion in human cells leads to a dramatic reduction of infection. Here we describe and discuss recent findings suggesting that TNPO3 assists HIV-1 replication in the nucleus and in fact that TNPO3 may assist PIC maturation in the nucleus. In addition, the viral determinant for the requirement of TNPO3 in HIV-1 infection is discussed. This paper summarizes the most significant recent discoveries about this important host factor and its role in HIV-1 replication.
Collapse
|
25
|
Abstract
Retroviruses are distinguished from other viruses by two characteristic steps in the viral replication cycle. The first is reverse transcription, which results in the production of a double-stranded DNA copy of the viral RNA genome, and the second is integration, which results in covalent attachment of the DNA copy to host cell DNA. The initial catalytic steps of the integration reaction are performed by the virus-encoded integrase (IN) protein. The chemistry of the IN-mediated DNA breaking and joining steps is well worked out, and structures of IN-DNA complexes have now clarified how the overall complex assembles. Methods developed during these studies were adapted for identification of IN inhibitors, which received FDA approval for use in patients in 2007. At the chromosomal level, HIV integration is strongly favored in active transcription units, which may promote efficient viral gene expression after integration. HIV IN binds to the cellular factor LEDGF/p75, which promotes efficient infection and tethers IN to favored target sites. The HIV integration machinery must also interact with many additional host factors during infection, including nuclear trafficking and pore proteins during nuclear entry, histones during initial target capture, and DNA repair proteins during completion of the DNA joining steps. Models for some of the molecular mechanisms involved have been proposed, but important details remain to be clarified.
Collapse
Affiliation(s)
- Robert Craigie
- Molecular Virology Section, NIDDK, National Institutes of Health, Bethesda, Maryland, USA.
| | | |
Collapse
|
26
|
Marcello A, Dhir S, Dieudonné M. Nuclear positional control of HIV transcription in 4D. Nucleus 2012; 1:8-11. [PMID: 21327098 DOI: 10.4161/nucl.1.1.10136] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2009] [Revised: 09/18/2009] [Accepted: 09/21/2009] [Indexed: 12/16/2022] Open
Abstract
Retroviruses integrate their genome into the chromatin of the host cell and are subject to the same control mechanisms governing transcription in the nucleus. There is increasing evidence that the spatial position of a gene within the nucleus in time affects its activity. Therefore it becomes important to study the chromatin environment in space and time of the HIV-1 provirus, particularly in cells where a tight transcriptional control allows the virus to hide away from antiviral treatment and immune response. We recently showed that the HIV-1 provirus is found at the nuclear periphery of latently infected lymphocytes associated in trans with centromeric heterochromatin. After induction of transcription, this association was lost, although the location of the transcribing provirus remained peripheral. Our results reveal a novel mechanism of transcriptional silencing involved in HIV-1 post-transcriptional latency and open wider perspectives for the general organization of chromatin in the nucleus.
Collapse
|
27
|
Cribier A, Ségéral E, Delelis O, Parissi V, Simon A, Ruff M, Benarous R, Emiliani S. Mutations affecting interaction of integrase with TNPO3 do not prevent HIV-1 cDNA nuclear import. Retrovirology 2011; 8:104. [PMID: 22176773 PMCID: PMC3286403 DOI: 10.1186/1742-4690-8-104] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2011] [Accepted: 12/16/2011] [Indexed: 12/23/2022] Open
Abstract
Background Integration of human immunodeficiency virus type 1 (HIV-1) into a host cell chromosome is an essential step under the control of the viral integrase (IN). Although this enzyme is necessary and sufficient to catalyze the integration reaction in vitro, cellular cofactors are involved in the process in vivo. The chromatin-associated factor LEDGF/p75 interacts with IN and promotes integration to transcription units of the host genome. HIV-1 IN also binds the karyopherin TNPO3, however the significance of this interaction during viral replication remains to be explored. Results Here we present a functional analysis of IN mutants impaired for LEDGF/p75 and TNPO3 interaction. Among them, IN W131A and IN Q168L, that were previously identified to be deficient for LEDGF/p75 interaction, were also partially impaired for TNPO3 binding. We observed that mutations abolishing IN ability to form tetramers resulted in a severe reduction in LEDGF/p75 binding. In sharp contrast, no correlation could be found between the ability of IN to multimerize and TNPO3 interaction. Most of the mutant viruses were essentially impaired for the integration step whereas the amount of 2-LTR circles, reflecting the nuclear import of the viral DNA, was not significantly affected. Conclusion Our functional analysis of HIV-1 IN mutants reveals distinct structural basis for TNPO3 interaction and suggests that the interaction between IN and TNPO3 is not a major determinant of nuclear import but could take place at a nuclear step prior to integration.
Collapse
|
28
|
Liu L, Oliveira NMM, Cheney KM, Pade C, Dreja H, Bergin AMH, Borgdorff V, Beach DH, Bishop CL, Dittmar MT, McKnight A. A whole genome screen for HIV restriction factors. Retrovirology 2011; 8:94. [PMID: 22082156 PMCID: PMC3228845 DOI: 10.1186/1742-4690-8-94] [Citation(s) in RCA: 109] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2011] [Accepted: 11/14/2011] [Indexed: 01/01/2023] Open
Abstract
Background Upon cellular entry retroviruses must avoid innate restriction factors produced by the host cell. For human immunodeficiency virus (HIV) human restriction factors, APOBEC3 (apolipoprotein-B-mRNA-editing-enzyme), p21 and tetherin are well characterised. Results To identify intrinsic resistance factors to HIV-1 replication we screened 19,121 human genes and identified 114 factors with significant inhibition of infection. Those with a known function are involved in a broad spectrum of cellular processes including receptor signalling, vesicle trafficking, transcription, apoptosis, cross-nuclear membrane transport, meiosis, DNA damage repair, ubiquitination and RNA processing. We focused on the PAF1 complex which has been previously implicated in gene transcription, cell cycle control and mRNA surveillance. Knockdown of all members of the PAF1 family of proteins enhanced HIV-1 reverse transcription and integration of provirus. Over-expression of PAF1 in host cells renders them refractory to HIV-1. Simian Immunodeficiency Viruses and HIV-2 are also restricted in PAF1 expressing cells. PAF1 is expressed in primary monocytes, macrophages and T-lymphocytes and we demonstrate strong activity in MonoMac1, a monocyte cell line. Conclusions We propose that the PAF1c establishes an anti-viral state to prevent infection by incoming retroviruses. This previously unrecognised mechanism of restriction could have implications for invasion of cells by any pathogen.
Collapse
Affiliation(s)
- Li Liu
- Centre for Immunology and Infectious Disease, Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London E1 2AT, UK
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
29
|
The inside out of lentiviral vectors. Viruses 2011; 3:132-159. [PMID: 22049307 PMCID: PMC3206600 DOI: 10.3390/v3020132] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2010] [Revised: 01/25/2011] [Accepted: 02/08/2011] [Indexed: 11/30/2022] Open
Abstract
Lentiviruses induce a wide variety of pathologies in different animal species. A common feature of the replicative cycle of these viruses is their ability to target non-dividing cells, a property that constitutes an extremely attractive asset in gene therapy. In this review, we shall describe the main basic aspects of the virology of lentiviruses that were exploited to obtain efficient gene transfer vectors. In addition, we shall discuss some of the hurdles that oppose the efficient genetic modification mediated by lentiviral vectors and the strategies that are being developed to circumvent them.
Collapse
|
30
|
Abstract
HIV uncoating is defined as the loss of viral capsid that occurs within the cytoplasm of infected cells before entry of the viral genome into the nucleus. It is an obligatory step of HIV-1 early infection and accompanies the transition between reverse transcription complexes (RTCs), in which reverse transcription occurs, and pre-integration complexes (PICs), which are competent to integrate into the host genome. The study of the nature and timing of HIV-1 uncoating has been paved with difficulties, particularly as a result of the vulnerability of the capsid assembly to experimental manipulation. Nevertheless, recent studies of capsid structure, retroviral restriction and mechanisms of nuclear import, as well as the recent expansion of technical advances in genome-wide studies and cell imagery approaches, have substantially changed our understanding of HIV uncoating. Although early work suggested that uncoating occurs immediately following viral entry in the cell, thus attributing a trivial role for the capsid in infected cells, recent data suggest that uncoating occurs several hours later and that capsid has an all-important role in the cell that it infects: for transport towards the nucleus, reverse transcription and nuclear import. Knowing that uncoating occurs at a later stage suggests that the viral capsid interacts extensively with the cytoskeleton and other cytoplasmic components during its transport to the nucleus, which leads to a considerable reassessment of our efforts to identify potential therapeutic targets for HIV therapy. This review discusses our current understanding of HIV uncoating, the functional interplay between infectivity and timely uncoating, as well as exposing the appropriate methods to study uncoating and addressing the many questions that remain unanswered.
Collapse
|
31
|
Vozzolo L, Loh B, Gane PJ, Tribak M, Zhou L, Anderson I, Nyakatura E, Jenner RG, Selwood D, Fassati A. Gyrase B inhibitor impairs HIV-1 replication by targeting Hsp90 and the capsid protein. J Biol Chem 2010; 285:39314-28. [PMID: 20937817 PMCID: PMC2998086 DOI: 10.1074/jbc.m110.155275] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Chemical genetics is an emerging approach to investigate the biology of host-pathogen interactions. We screened several inhibitors of ATP-dependent DNA motors and detected the gyrase B inhibitor coumermycin A1 (C-A1) as a potent antiretroviral. C-A1 inhibited HIV-1 integration and gene expression from acutely infected cell, but the two activities mapped to distinct targets. Target discovery identified Hsp90 as the C-A1 target affecting viral gene expression. Chromatin immunoprecipitation revealed that Hsp90 associates with the viral promoter and may directly regulate gene expression. Molecular docking suggested that C-A1 binds to two novel pockets at the C terminal domain of Hsp90. C-A1 inhibited Hsp90 dimer formation, suggesting that it impairs viral gene expression by preventing Hsp90 dimerization at the C terminus. The inhibition of HIV-1 integration imposed by C-A1 was independent of Hsp90 and mapped to the capsid protein, and a point mutation at residue 105 made the virus resistant to this block. HIV-1 susceptibility to the integration block mediated by C-A1 was influenced by cyclophilin A. Our chemical genetic approach revealed an unexpected function of capsid in HIV-1 integration and provided evidence for a role of Hsp90 in regulating gene expression in mammalian cells. Both activities were amenable to inhibition by small molecules and represent novel antiretroviral drug targets.
Collapse
Affiliation(s)
- Luciano Vozzolo
- Wohl Virion Centre, Division of Infection and Immunity, University College London, 46 Cleveland Street, W1T 4JF London, United Kingdom
| | | | | | | | | | | | | | | | | | | |
Collapse
|
32
|
Lee K, Ambrose Z, Martin TD, Oztop I, Mulky A, Julias JG, Vandegraaff N, Baumann JG, Wang R, Yuen W, Takemura T, Shelton K, Taniuchi I, Li Y, Sodroski J, Littman DR, Coffin JM, Hughes SH, Unutmaz D, Engelman A, KewalRamani VN. Flexible use of nuclear import pathways by HIV-1. Cell Host Microbe 2010; 7:221-33. [PMID: 20227665 DOI: 10.1016/j.chom.2010.02.007] [Citation(s) in RCA: 347] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2009] [Revised: 10/29/2009] [Accepted: 02/15/2010] [Indexed: 01/21/2023]
Abstract
HIV-1 replication requires transport of nascent viral DNA and associated virion proteins, the retroviral preintegration complex (PIC), into the nucleus. Too large for passive diffusion through nuclear pore complexes (NPCs), PICs use cellular nuclear transport mechanisms and nucleoporins (NUPs), the NPC components that permit selective nuclear-cytoplasmic exchange, but the details remain unclear. Here we identify a fragment of the cleavage and polyadenylation factor 6, CPSF6, as a potent inhibitor of HIV-1 infection. When enriched in the cytoplasm, CPSF6 prevents HIV-1 nuclear entry by targeting the viral capsid (CA). HIV-1 harboring the N74D mutation in CA fails to interact with CPSF6 and evades the nuclear import restriction. Interestingly, whereas wild-type HIV-1 requires NUP153, N74D HIV-1 mimics feline immunodeficiency virus nuclear import requirements and is more sensitive to NUP155 depletion. These findings reveal a remarkable flexibility in HIV-1 nuclear transport and highlight a single residue in CA as essential in regulating interactions with NUPs.
Collapse
Affiliation(s)
- KyeongEun Lee
- HIV Drug Resistance Program, National Cancer Institute, Frederick, MD 21702, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
33
|
Ayinde D, Maudet C, Transy C, Margottin-Goguet F. Limelight on two HIV/SIV accessory proteins in macrophage infection: is Vpx overshadowing Vpr? Retrovirology 2010; 7:35. [PMID: 20380700 PMCID: PMC2867959 DOI: 10.1186/1742-4690-7-35] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2009] [Accepted: 04/09/2010] [Indexed: 01/16/2023] Open
Abstract
HIV viruses encode a set of accessory proteins, which are important determinants of virulence due to their ability to manipulate the host cell physiology for the benefit of the virus. Although these viral proteins are dispensable for viral growth in many in vitro cell culture systems, they influence the efficiency of viral replication in certain cell types. Macrophages are early targets of HIV infection which play a major role in viral dissemination and persistence in the organism. This review focuses on two HIV accessory proteins whose functions might be more specifically related to macrophage infection: Vpr, which is conserved across primate lentiviruses including HIV-1 and HIV-2, and Vpx, a protein genetically related to Vpr, which is unique to HIV-2 and a subset of simian lentiviruses. Recent studies suggest that both Vpr and Vpx exploit the host ubiquitination machinery in order to inactivate specific cellular proteins. We review here why it remains difficult to decipher the role of Vpr in macrophage infection by HIV-1 and how recent data underscore the ability of Vpx to antagonize a restriction factor which counteracts synthesis of viral DNA in monocytic cells.
Collapse
Affiliation(s)
- Diana Ayinde
- Institut Cochin, Université Paris Descartes, CNRS (UMR 8104), Paris, France
| | | | | | | |
Collapse
|
34
|
Casey L, Wen X, de Noronha CMC. The functions of the HIV1 protein Vpr and its action through the DCAF1.DDB1.Cullin4 ubiquitin ligase. Cytokine 2010; 51:1-9. [PMID: 20347598 DOI: 10.1016/j.cyto.2010.02.018] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2009] [Revised: 01/30/2010] [Accepted: 02/24/2010] [Indexed: 01/21/2023]
Abstract
Among the proteins encoded by human and simian immunodeficiency viruses (HIV and SIV) at least three, Vif, Vpu and Vpr, subvert cellular ubiquitin ligases to block the action of anti-viral defenses. This review focuses on Vpr and its HIV2/SIV counterparts, Vpx and Vpr, which all engage the DDB1.Cullin4 ubiquitin ligase complex through the DCAF1 adaptor protein. Here, we discuss the multiple functions that have been linked to Vpr expression and summarize the current knowledge on the role of the ubiquitin ligase complex in carrying out a subset of these activities.
Collapse
Affiliation(s)
- Laurieann Casey
- Center for Immunology and Microbial Disease, Albany Medical College, 43 New Scotland Avenue, Albany, NY 12208, USA
| | | | | |
Collapse
|
35
|
The foamy virus genome remains unintegrated in the nuclei of G1/S phase-arrested cells, and integrase is critical for preintegration complex transport into the nucleus. J Virol 2009; 84:2832-42. [PMID: 20032182 DOI: 10.1128/jvi.02435-09] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Foamy viruses are a member of the spumavirus subfamily of retroviruses with unique mechanisms of virus replication. Foamy virus replication is cell cycle dependent; however, the genome is found in the nuclei of cells arrested in the G(1)/S phase. Despite the presence of genome in the nuclei of growth-arrested cells, there is no viral gene expression, thus explaining its dependency on cell cycle. This report shows that the foamy virus genome remains unintegrated in G(1)/S phase-arrested cells. The foamy virus genome is detected by confocal microscopy in the nuclei of both dividing and growth-arrested cells. Alu PCR revealed foamy virus-specific DNA amplification from genomic DNA isolated in cycling cells at 24 h postinfection. In arrested cells no foamy virus DNA band was detected in cells harvested at 1 or 7 days after infection, and a very faint band that is significantly less than DNA amplified from cycling cells was observed at day 15. After these cells were arrested at the G(1)/S phase for 1, 7, or 15 days they were allowed to cycle, at which time foamy virus-specific DNA amplification was readily observed. Taken together, these results suggest that the foamy virus genome persists in nondividing cells without integrating. We have also established evidence for the first time that the foamy virus genome and Gag translocation into the nucleus are dependent on integrase in cycling cells, implicating the role of integrase in transport of the preintegration complex into the nucleus. Furthermore, despite the presence of a nuclear localization signal sequence in Gag, we observed no foamy virus Gag importation into the nucleus in the absence of integrase.
Collapse
|
36
|
The requirement for cellular transportin 3 (TNPO3 or TRN-SR2) during infection maps to human immunodeficiency virus type 1 capsid and not integrase. J Virol 2009; 84:397-406. [PMID: 19846519 DOI: 10.1128/jvi.01899-09] [Citation(s) in RCA: 154] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Recent genome-wide screens have highlighted an important role for transportin 3 in human immunodeficiency virus type 1 (HIV-1) infection and preintegration complex (PIC) nuclear import. Moreover, HIV-1 integrase interacted with recombinant transportin 3 protein under conditions whereby Moloney murine leukemia virus (MLV) integrase failed to do so, suggesting that integrase-transportin 3 interactions might underscore active retroviral PIC nuclear import. Here we correlate infectivity defects in transportin 3 knockdown cells with in vitro protein binding affinities for an expanded set of retroviruses that include simian immunodeficiency virus (SIV), bovine immunodeficiency virus (BIV), equine infectious anemia virus (EIAV), feline immunodeficiency virus (FIV), and Rous sarcoma virus (RSV) to critically address the role of integrase-transportin 3 interactions in viral infection. Lentiviruses, with the exception of FIV, display a requirement for transportin 3 in comparison to MLV and RSV, yielding an infection-based dependency ranking of SIV > HIV-1 > BIV and EIAV > MLV, RSV, and FIV. In vitro pulldown and surface plasmon resonance assays, in contrast, define a notably different integrase-transportin 3 binding hierarchy: FIV, HIV-1, and BIV > SIV and MLV > EIAV. Our results therefore fail to support a critical role for integrase binding in dictating transportin 3 dependency during retrovirus infection. In addition to integrase, capsid has been highlighted as a retroviral nuclear import determinant. Accordingly, MLV/HIV-1 chimera viruses pinpoint the genetic determinant of sensitization to transportin 3 knockdown to the HIV-1 capsid protein. We therefore conclude that capsid, not integrase, is the dominant viral factor that dictates transportin 3 dependency during HIV-1 infection.
Collapse
|
37
|
Cellular restriction targeting viral capsids perturbs human immunodeficiency virus type 1 infection of nondividing cells. J Virol 2009; 83:9835-43. [PMID: 19625401 DOI: 10.1128/jvi.01084-09] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The ability of human immunodeficiency virus (HIV) to infect nondividing cells is a fundamental property by which HIV replicates in critical target cells, such as macrophages and resting CD4(+) T cells. Recent studies have revealed that the capsid (CA) protein is a dominant factor that determines retrovirus infectivity in nondividing cells, and several mutations in HIV type 1 (HIV-1) CA abrogate the ability of HIV-1 to infect nondividing cells. We present evidence for a connection between cellular restriction against viral capsids and the resistance of nondividing cells to retrovirus infection. TRIM proteins that are able to target incoming viral capsids restrict HIV-1 more potently in nondividing cells than in dividing cells, thus rendering HIV-1 infection dependent on cell division. Moreover, cyclophilin A, another cellular protein that binds to HIV-1 CA, regulates HIV-1 infection of nondividing cells. Together, these data demonstrate the importance of capsid-binding cellular proteins in the control of the cell cycle independence of HIV-1. We propose that cellular restrictions to retroviral infections are themselves cell cycle dependent.
Collapse
|
38
|
Integrase interacts with nucleoporin NUP153 to mediate the nuclear import of human immunodeficiency virus type 1. J Virol 2009; 83:6522-33. [PMID: 19369352 DOI: 10.1128/jvi.02061-08] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The ability to traverse an intact nuclear envelope and productively infect nondividing cells is a salient feature of human immunodeficiency virus type 1 (HIV-1) and other lentiviruses, but the viral factors and mechanism of nuclear entry have not been defined. HIV-1 integrase (IN) is implicated to play a role in the nuclear import of the virus, but the cellular pathway for IN trafficking and the role of IN in mediating the nuclear import of viral particles are unknown. Using a semipermeabilized cell assay, we observed that the nuclear import of IN was not the result of passive diffusion but occurred independently of cytosolic factors, metabolic energy, and the classical receptor-mediated, Ran-dependent import pathways. To determine if IN enters the nucleus by interacting with the nucleopore complex (NPC), we found that IN bound directly with the FxFG-rich C-terminal domain of nucleoporin 153 (NUP153C). When added in excess to the import assay, NUP153C inhibited the nuclear import of IN. Known binding partners of NUP153C competed with IN for binding with NUP153 and also inhibited the nuclear import of IN. In cultured cells, overexpression of NUP153C reduced the infectivity of an HIV-derived vector by interfering with the nuclear translocation of the viral cDNA. These results support a functional role for the IN-NUP153 interaction in HIV-1 replication and suggest that HIV-1 subviral particles gain access to the nucleus by interacting directly with the NPC via the binding of particle-associated IN to NUP153C.
Collapse
|
39
|
Zaitseva L, Cherepanov P, Leyens L, Wilson SJ, Rasaiyaah J, Fassati A. HIV-1 exploits importin 7 to maximize nuclear import of its DNA genome. Retrovirology 2009; 6:11. [PMID: 19193229 PMCID: PMC2660290 DOI: 10.1186/1742-4690-6-11] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2008] [Accepted: 02/04/2009] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Nuclear import of the HIV-1 reverse transcription complex (RTC) is critical for infection of non dividing cells, and importin 7 (imp7) has been implicated in this process. To further characterize the function of imp7 in HIV-1 replication we generated cell lines stably depleted for imp7 and used them in conjunction with infection, cellular fractionation and pull-down assays. RESULTS Imp7 depletion impaired HIV-1 infection but did not significantly affect HIV-2, simian immunodeficiency virus (SIVmac), or equine infectious anemia virus (EIAV). The lentiviral dependence on imp7 closely correlated with binding of the respective integrase proteins to imp7. HIV-1 RTC associated with nuclei of infected cells with remarkable speed and knock down of imp7 reduced HIV-1 DNA nuclear accumulation, delaying infection. Using an HIV-1 mutant deficient for reverse transcription, we found that viral RNA accumulated within nuclei of infected cells, indicating that reverse transcription is not absolutely required for nuclear import. Depletion of imp7 impacted on HIV-1 DNA but not RNA nuclear import and also inhibited DNA transfection efficiency. CONCLUSION Although imp7 may not be essential for HIV-1 infection, our results suggest that imp7 facilitates nuclear trafficking of DNA and that HIV-1 exploits imp7 to maximize nuclear import of its DNA genome. Lentiviruses other than HIV-1 may have evolved to use alternative nuclear import receptors to the same end.
Collapse
Affiliation(s)
- Lyubov Zaitseva
- Wohl Virion Centre, Division of Infection and Immunity, University College London (UCL), London, UK
- MRC Centre for Medical Molecular Virology, Division of Infection and Immunity, University College London (UCL), London, UK
| | - Peter Cherepanov
- Division of Medicine, St Mary's Campus, Imperial College London, Norfolk Place, London, W2 1PG, UK
| | - Lada Leyens
- Wohl Virion Centre, Division of Infection and Immunity, University College London (UCL), London, UK
- MRC Centre for Medical Molecular Virology, Division of Infection and Immunity, University College London (UCL), London, UK
| | - Sam J Wilson
- MRC Centre for Medical Molecular Virology, Division of Infection and Immunity, University College London (UCL), London, UK
- Centre for Post-genomic Virology, Division of Infection and Immunity, University College London, 46 Cleveland Street, London, W1T 4JF, UK
| | - Jane Rasaiyaah
- MRC Centre for Medical Molecular Virology, Division of Infection and Immunity, University College London (UCL), London, UK
- Centre for Post-genomic Virology, Division of Infection and Immunity, University College London, 46 Cleveland Street, London, W1T 4JF, UK
| | - Ariberto Fassati
- Wohl Virion Centre, Division of Infection and Immunity, University College London (UCL), London, UK
- MRC Centre for Medical Molecular Virology, Division of Infection and Immunity, University College London (UCL), London, UK
| |
Collapse
|
40
|
Narayanan NN, Grosic S, Tasma IM, Grant D, Shoemaker R, Bhattacharyya MK. Identification of candidate signaling genes including regulators of chromosome condensation 1 protein family differentially expressed in the soybean-Phytophthora sojae interaction. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2009; 118:399-412. [PMID: 18825360 DOI: 10.1007/s00122-008-0895-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2007] [Accepted: 09/06/2008] [Indexed: 05/07/2023]
Abstract
Stem and root rot caused by the oomycete pathogen, Phytophthora sojae, is a serious soybean disease. Use of Phytophthora resistance genes (Rps) in soybean cultivars has been very effective in controlling this pathogen. Resistance encoded by Rps genes is manifested through activation of defense responses. In order to identify candidate signaling genes involved in the expression of Phytophthora resistance in soybean, a cDNA library was prepared from infected etiolated hypocotyl tissues of a Phytophthora resistant soybean cultivar harvested 2 and 4 h following P. sojae inoculation. In silico subtraction of 101,833 expressed sequence tags (ESTs) originating from unstressed cDNA libraries from 4,737 ESTs of this library resulted in identification of 204 genes that were absent in the unstressed libraries. Of the 204 identified genes, seven were P. sojae genes. Putative function of 91 of the 204 genes could not be assigned based on sequence comparison. Macroarray analyses of all 204 genes led to identification of 60 genes including 15 signaling-related soybean genes and three P. sojae genes, transcripts of which were induced twofold in P. sojae-infected tissues as compared to that in water controls. Eight soybean genes were down-regulated twofold following P. sojae infection as compared to water controls. Differential expression of a few selected genes was confirmed by conducting Northern and RT-PCR analyses. We have shown that two putative regulators of chromosome condensation 1 (RCC1) family proteins were down-regulated in the incompatible interaction. This observation suggested that the nucleocytoplasmic transport function for trafficking protein and non-coding RNA is suppressed during expression of race-specific Phytophthora resistance. Characterization of a cDNA library generated from tissues harvested almost immediately following P. sojae-infection of a resistant cultivar allowed us to identify many candidate signaling genes that are presumably involved in regulating the expression of defense-related pathways for expression of Phytophthora resistance in soybean.
Collapse
|
41
|
Wellensiek BP, Ramakrishnan R, Sundaravaradan V, Mehta R, Harris DT, Ahmad N. Differential HIV-1 integration targets more actively transcribed host genes in neonatal than adult blood mononuclear cells. Virology 2008; 385:28-38. [PMID: 19100594 DOI: 10.1016/j.virol.2008.10.052] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2008] [Revised: 08/30/2008] [Accepted: 10/31/2008] [Indexed: 11/30/2022]
Abstract
We have recently shown an increased HIV-1 replication and gene expression in neonatal (cord) blood mononuclear cells compared with adult cells, which could be due to HIV-1 integration as it targets active host genes. Here we have characterized 468 HIV-1 integration sites within cord and adult blood T-lymphocytes and monocyte-derived macrophages (MDM) from five donors. Several functional classes of genes were identified by gene ontology to be over represented, including genes for cellular components, maintenance of intracellular environment, enzyme regulation, cellular metabolism, catalytic activity and cation transport. Numerous potential transcription factor binding sites at the sites of integration were identified. Furthermore, the genes at the site of integration, transcription factors which potentially bind upstream of the HIV-1 promoter and factors that assist HIV-1 integration were found to be expressed at higher levels in cord than adult cells. Taken together, these results suggest HIV-1 integration occurred in a more actively transcribed genes in neonatal cells compared with adult cells, which may help explain a higher level of HIV-1 gene expression and replication in neonatal compared with adult cells.
Collapse
|
42
|
Abstract
HIV infection of macrophages is a critically important component of viral pathogenesis and progression to AIDS. Although the virus follows the same life cycle in macrophages and T lymphocytes, several aspects of the virus-host relationship are unique to macrophage infection. Examples of these are the long-term persistence of productive infection, sustained by the absence of cell death, and the ability of progeny virus to bud into and accumulate in endocytic compartments designated multivesicular bodies (MVBs). Recently, the hypothesis that viral exploitation of the macrophage endocytic machinery is responsible for perpetuating the chronic state of infection unique to this cell type has been challenged in several independent studies employing a variety of experimental strategies. This review examines the evidence supporting and refuting the canonical hypothesis and highlights recently identified cellular factors that may contribute to the unique aspects of the HIV-macrophage interaction.
Collapse
Affiliation(s)
- Carol A Carter
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, New York 11794, USA.
| | | |
Collapse
|
43
|
Abstract
In HIV-infected people, resting CD4+ T cells are the main reservoir of latent virus and the reason for the failure of drug therapy to cure HIV infection. Still, we do not have a complete understanding of the factors regulating HIV replication in these cells. A recent paper in Cell describes a new trick that the virus uses to infect resting T cells. Interaction between the viral gp120 and cellular HIV co-receptor, CXCR4, during viral entry initiates signaling that activates cofilin, the main regulator of actin polymerization. As a result of this activation, actin is depolymerized, thus destroying the natural barrier to HIV replication. I discuss implications of this study for our understanding of HIV biology and development of novel anti-HIV therapeutic approaches.
Collapse
Affiliation(s)
- Michael Bukrinsky
- George Washington University, Department of Microbiology, Immunology and Tropical Medicine, Washington, DC 20037, USA.
| |
Collapse
|
44
|
Andrake MD, Sauter MM, Boland K, Goldstein AD, Hussein M, Skalka AM. Nuclear import of Avian Sarcoma Virus integrase is facilitated by host cell factors. Retrovirology 2008; 5:73. [PMID: 18687138 PMCID: PMC2527327 DOI: 10.1186/1742-4690-5-73] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2008] [Accepted: 08/07/2008] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Integration of retroviral DNA into the host cell genome is an obligatory step in the virus life cycle. In previous reports we identified a sequence (amino acids 201-236) in the linker region between the catalytic core and C-terminal domains of the avian sarcoma virus (ASV) integrase protein that functions as a transferable nuclear localization signal (NLS) in mammalian cells. The sequence is distinct from all known NLSs but, like many, contains basic residues that are essential for activity. RESULTS Our present studies with digitonin-permeabilized HeLa cells show that nuclear import mediated by the NLS of ASV integrase is an active, saturable, and ATP-dependent process. As expected for transport through nuclear pore complexes, import is blocked by treatment of cells with wheat germ agglutinin. We also show that import of ASV integrase requires soluble cellular factors but does not depend on binding the classical adapter Importin-alpha. Results from competition studies indicate that ASV integrase relies on one or more of the soluble components that mediate transport of the linker histone H1. CONCLUSION These results are consistent with a role for ASV integrase and cytoplasmic cellular factors in the nuclear import of its viral DNA substrate, and lay the foundation for identification of host cell components that mediate this reaction.
Collapse
Affiliation(s)
- Mark D Andrake
- Institute for Cancer Research, Fox Chase Cancer Center, Philadelphia, PA 19111, USA.
| | | | | | | | | | | |
Collapse
|
45
|
Tobaly-Tapiero J, Bittoun P, Lehmann-Che J, Delelis O, Giron ML, de Thé H, Saïb A. Chromatin tethering of incoming foamy virus by the structural Gag protein. Traffic 2008; 9:1717-27. [PMID: 18627573 DOI: 10.1111/j.1600-0854.2008.00792.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Retroviruses hijack cellular machineries to productively infect their hosts. During the early stages of viral replication, proviral integration relies on specific interactions between components of the preintegration complex and host chromatin-bound proteins. Here, analyzing the fate of incoming primate foamy virus, we identify a short domain within the C-terminus of the structural Gag protein that efficiently binds host chromosomes, by interacting with H2A/H2B core histones. While viral particle production, virus entry and intracellular trafficking are not affected by mutation of this domain, chromosomal attachment of incoming subviral complexes is abolished, precluding proviral integration. We thus highlight a new function of the structural foamy Gag protein as the main tether between incoming subviral complexes and host chromatin prior to integration.
Collapse
Affiliation(s)
- Joelle Tobaly-Tapiero
- CNRS UMR 7151, Institut Universitaire d'Hématologie, Université Paris Diderot, Paris Cedex 10, France
| | | | | | | | | | | | | |
Collapse
|
46
|
Weiss RA. Special anniversary review: twenty-five years of human immunodeficiency virus research: successes and challenges. Clin Exp Immunol 2008; 152:201-10. [PMID: 18373700 PMCID: PMC2384092 DOI: 10.1111/j.1365-2249.2008.03645.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/18/2008] [Indexed: 01/09/2023] Open
Abstract
During 25 years of research since HIV-1 was first identified in Paris, there have been great advances in our understanding of the virus and of the immune system. Practical advances include the early development of diagnostic tests of infection that made blood donation safe, and since 1996, combination anti-retroviral therapy that has great reduced incidence of AIDS in HIV-infected people who have access to the drugs. HIV prevention through behavioural change has been successful, and we do not yet have any safe and efficacious microbicides or vaccines.
Collapse
Affiliation(s)
- R A Weiss
- Division of Infection and Immunity, University College London, London, UK.
| |
Collapse
|
47
|
Abstract
HIV integrates a DNA copy of its genome into a host cell chromosome in each replication cycle. The essential DNA cleaving and joining chemistry of integration is known, but there is less understanding of the process as it occurs in a cell, where two complex and dynamic macromolecular entities are joined: the viral pre-integration complex and chromatin. Among implicated cellular factors, much recent attention has coalesced around LEDGF/p75, a nuclear protein that may act as a chromatin docking factor or receptor for lentiviral pre-integration complexes. LEDGF/p75 tethers HIV integrase to chromatin, protects it from degradation, and strongly influences the genome-wide pattern of HIV integration. Depleting the protein from cells and/or over-expressing its integrase-binding domain blocks viral replication. Current goals are to establish the underlying mechanisms and to determine whether this knowledge can be exploited for antiviral therapy or for targeting lentiviral vector integration in human gene therapy.
Collapse
Affiliation(s)
- E M Poeschla
- Guggenheim 18, Mayo Clinic College of Medicine, 200 First Street SW, Rochester 55905, USA.
| |
Collapse
|
48
|
Engelman A, Cherepanov P. The lentiviral integrase binding protein LEDGF/p75 and HIV-1 replication. PLoS Pathog 2008; 4:e1000046. [PMID: 18369482 PMCID: PMC2275779 DOI: 10.1371/journal.ppat.1000046] [Citation(s) in RCA: 179] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/12/2007] [Indexed: 01/10/2023] Open
Abstract
Retroviral replication proceeds through a stable proviral DNA intermediate, and numerous host cell factors have been implicated in its formation. In particular, recent results have highlighted an important role for the integrase-interactor lens epithelium-derived growth factor (LEDGF)/p75 in lentiviral integration. Cells engineered to over-express fragments of LEDGF/p75 containing its integrase-binding domain but lacking determinants essential for chromatin association are refractory to HIV-1 infection. Furthermore, both the levels of HIV-1 integration and the genomic distribution of the resultant proviruses are significantly perturbed in cells devoid of endogenous LEDGF/p75 protein. A strong bias towards integration along transcription units is a characteristic feature of lentiviruses. In the absence of LEDGF/p75, HIV-1 in large part loses that preference, displaying concomitant integration surges in the vicinities of CpG islands and gene promoter regions, elements naturally targeted by other types of retroviruses. Together, these findings highlight that LEDGF/p75 is an important albeit not strictly essential cofactor of lentiviral DNA integration, and solidify a role for chromatin-associated LEDGF/p75 as a receptor for lentiviral preintegration complexes. By now one of the best characterized virus–host interactions, the integrase-LEDGF/p75 interface opens a range of opportunities for lentiviral vector targeting for gene therapy applications as well as for the development of novel classes of antiretroviral drugs.
Collapse
Affiliation(s)
- Alan Engelman
- Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Division of AIDS, Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail: (AE); (PC)
| | - Peter Cherepanov
- Division of Medicine, Imperial College London, St. Mary's Campus, London, United Kingdom
- * E-mail: (AE); (PC)
| |
Collapse
|
49
|
Evidence for direct involvement of the capsid protein in HIV infection of nondividing cells. PLoS Pathog 2008; 3:1502-10. [PMID: 17967060 PMCID: PMC2042020 DOI: 10.1371/journal.ppat.0030156] [Citation(s) in RCA: 161] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2007] [Accepted: 09/13/2007] [Indexed: 12/19/2022] Open
Abstract
HIV and other lentiviruses can productively infect nondividing cells, whereas most other retroviruses, such as murine leukemia virus, require cell division for efficient infection. However, the determinants for this phenotype have been controversial. Here, we show that HIV-1 capsid (CA) is involved in facilitating HIV infection of nondividing cells because amino acid changes on CA severely disrupt the cell-cycle independence of HIV. One mutant in the N-terminal domain of CA in particular has lost the cell-cycle independence in all cells tested, including primary macrophages. The defect in this mutant appears to be at a stage past nuclear entry. We also find that the loss of cell-cycle independence can be cell-type specific, which suggests that a cellular factor affects the ability of HIV to infect nondividing cells. Our data suggest that CA is directly involved at some step in the viral life cycle that is important for infection of nondividing cells. HIV and related viruses are unusual among retroviruses in their ability to replicate independently of cell-cycle progression of target cells. However, the determinants of this phenotype have been controversial. Here, we identified mutations on the surface of the capsid (CA) protein that reduce the ability of HIV to infect nondividing cells. These mutations also confer cell-cycle dependency on HIV, even in dividing cells. Interestingly, some CA mutants lose cell-cycle independence only in certain cell types. Thus, these findings suggest that a cellular factor targeting CA regulates HIV-1 infection in nondividing cells. Surprisingly, these mutations do not appear to affect nuclear localization of viral genomes, which points to a novel regulation of the cell-cycle independence of HIV by the CA protein.
Collapse
|
50
|
Giacca M. Gene therapy to induce cellular resistance to HIV-1 infection: lessons from clinical trials. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2008; 56:297-325. [PMID: 18086416 DOI: 10.1016/s1054-3589(07)56010-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Mauro Giacca
- Molecular Medicine Laboratory, International Centre for Genetic Engineering and Biotechnology (ICGEB), Padriciano 99, 34012 Trieste, Italy
| |
Collapse
|