1
|
Acton OJ, Sheppard D, Kunzelmann S, Caswell SJ, Nans A, Burgess AJO, Kelly G, Morris ER, Rosenthal PB, Taylor IA. Platform-directed allostery and quaternary structure dynamics of SAMHD1 catalysis. Nat Commun 2024; 15:3775. [PMID: 38710701 PMCID: PMC11074143 DOI: 10.1038/s41467-024-48237-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Accepted: 04/25/2024] [Indexed: 05/08/2024] Open
Abstract
SAMHD1 regulates cellular nucleotide homeostasis, controlling dNTP levels by catalysing their hydrolysis into 2'-deoxynucleosides and triphosphate. In differentiated CD4+ macrophage and resting T-cells SAMHD1 activity results in the inhibition of HIV-1 infection through a dNTP blockade. In cancer, SAMHD1 desensitizes cells to nucleoside-analogue chemotherapies. Here we employ time-resolved cryogenic-EM imaging and single-particle analysis to visualise assembly, allostery and catalysis by this multi-subunit enzyme. Our observations reveal how dynamic conformational changes in the SAMHD1 quaternary structure drive the catalytic cycle. We capture five states at high-resolution in a live catalytic reaction, revealing how allosteric activators support assembly of a stable SAMHD1 tetrameric core and how catalysis is driven by the opening and closing of active sites through pairwise coupling of active sites and order-disorder transitions in regulatory domains. This direct visualisation of enzyme catalysis dynamics within an allostery-stabilised platform sets a precedent for mechanistic studies into the regulation of multi-subunit enzymes.
Collapse
Affiliation(s)
- Oliver J Acton
- Macromolecular Structure Laboratory, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
- Structural Biology of Cells and Viruses Laboratory, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
- AstraZeneca, The Discovery Centre, 1 Francis Crick Avenue, Cambridge, CB2 0AA, UK
| | - Devon Sheppard
- Macromolecular Structure Laboratory, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
| | - Simone Kunzelmann
- Structural Biology Science Technology Platform, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
| | - Sarah J Caswell
- Macromolecular Structure Laboratory, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
- AstraZeneca, The Discovery Centre, 1 Francis Crick Avenue, Cambridge, CB2 0AA, UK
| | - Andrea Nans
- Structural Biology Science Technology Platform, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
| | - Ailidh J O Burgess
- Macromolecular Structure Laboratory, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
| | - Geoff Kelly
- The Medical Research Council Biomedical NMR Centre, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
| | - Elizabeth R Morris
- Macromolecular Structure Laboratory, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
- Department of Biosciences, University of Durham, Durham, DH1 3LE, UK
| | - Peter B Rosenthal
- Structural Biology of Cells and Viruses Laboratory, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK.
| | - Ian A Taylor
- Macromolecular Structure Laboratory, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK.
| |
Collapse
|
2
|
Lin C, Kuffour EO, Li T, Gertzen CGW, Kaiser J, Luedde T, König R, Gohlke H, Münk C. The ISG15-Protease USP18 Is a Pleiotropic Enhancer of HIV-1 Replication. Viruses 2024; 16:485. [PMID: 38675828 PMCID: PMC11053637 DOI: 10.3390/v16040485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Revised: 03/19/2024] [Accepted: 03/20/2024] [Indexed: 04/28/2024] Open
Abstract
The innate immune response to viruses is formed in part by interferon (IFN)-induced restriction factors, including ISG15, p21, and SAMHD1. IFN production can be blocked by the ISG15-specific protease USP18. HIV-1 has evolved to circumvent host immune surveillance. This mechanism might involve USP18. In our recent studies, we demonstrate that HIV-1 infection induces USP18, which dramatically enhances HIV-1 replication by abrogating the antiviral function of p21. USP18 downregulates p21 by accumulating misfolded dominant negative p53, which inactivates wild-type p53 transactivation, leading to the upregulation of key enzymes involved in de novo dNTP biosynthesis pathways and inactivated SAMHD1. Despite the USP18-mediated increase in HIV-1 DNA in infected cells, it is intriguing to note that the cGAS-STING-mediated sensing of the viral DNA is abrogated. Indeed, the expression of USP18 or knockout of ISG15 inhibits the sensing of HIV-1. We demonstrate that STING is ISGylated at residues K224, K236, K289, K347, K338, and K370. The inhibition of STING K289-linked ISGylation suppresses its oligomerization and IFN induction. We propose that human USP18 is a novel factor that potentially contributes in multiple ways to HIV-1 replication.
Collapse
Affiliation(s)
- Chaohui Lin
- Clinic of Gastroenterology, Hepatology and Infectious Diseases, Medical Faculty, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany; (C.L.); (E.O.K.); (T.L.); (T.L.)
| | - Edmund Osei Kuffour
- Clinic of Gastroenterology, Hepatology and Infectious Diseases, Medical Faculty, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany; (C.L.); (E.O.K.); (T.L.); (T.L.)
| | - Taolan Li
- Clinic of Gastroenterology, Hepatology and Infectious Diseases, Medical Faculty, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany; (C.L.); (E.O.K.); (T.L.); (T.L.)
| | - Christoph G. W. Gertzen
- Institute for Pharmaceutical and Medicinal Chemistry, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany; (C.G.W.G.); (J.K.); (H.G.)
| | - Jesko Kaiser
- Institute for Pharmaceutical and Medicinal Chemistry, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany; (C.G.W.G.); (J.K.); (H.G.)
| | - Tom Luedde
- Clinic of Gastroenterology, Hepatology and Infectious Diseases, Medical Faculty, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany; (C.L.); (E.O.K.); (T.L.); (T.L.)
| | - Renate König
- Host-Pathogen Interactions, Paul-Ehrlich-Institut, 63225 Langen, Germany;
| | - Holger Gohlke
- Institute for Pharmaceutical and Medicinal Chemistry, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany; (C.G.W.G.); (J.K.); (H.G.)
- Institute of Bio- and Geosciences (IBG-4: Bioinformatics), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Carsten Münk
- Clinic of Gastroenterology, Hepatology and Infectious Diseases, Medical Faculty, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany; (C.L.); (E.O.K.); (T.L.); (T.L.)
| |
Collapse
|
3
|
Tang Y, Behrens RT, St Gelais C, Wu S, Vivekanandan S, Razin E, Fang P, Wu L, Sherer N, Musier-Forsyth K. Human lysyl-tRNA synthetase phosphorylation promotes HIV-1 proviral DNA transcription. Nucleic Acids Res 2023; 51:12111-12123. [PMID: 37933844 PMCID: PMC10711549 DOI: 10.1093/nar/gkad941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 09/18/2023] [Accepted: 10/11/2023] [Indexed: 11/08/2023] Open
Abstract
Human lysyl-tRNA synthetase (LysRS) was previously shown to be re-localized from its normal cytoplasmic location in a multi-aminoacyl-tRNA synthetase complex (MSC) to the nucleus of HIV-1 infected cells. Nuclear localization depends on S207 phosphorylation but the nuclear function of pS207-LysRS in the HIV-1 lifecycle is unknown. Here, we show that HIV-1 replication was severely reduced in a S207A-LysRS knock-in cell line generated by CRISPR/Cas9; this effect was rescued by S207D-LysRS. LysRS phosphorylation up-regulated HIV-1 transcription, as did direct transfection of Ap4A, an upstream transcription factor 2 (USF2) activator that is synthesized by pS207-LysRS. Overexpressing an MSC-derived peptide known to stabilize LysRS MSC binding inhibited HIV-1 replication. Transcription of HIV-1 proviral DNA and other USF2 target genes was reduced in peptide-expressing cells. We propose that nuclear pS207-LysRS generates Ap4A, leading to activation of HIV-1 transcription. Our results suggest a new role for nuclear LysRS in facilitating HIV-1 replication and new avenues for antiviral therapy.
Collapse
Affiliation(s)
- Yingke Tang
- Department of Chemistry and Biochemistry, Ohio State University, Columbus, OH, USA
- Center for Retrovirus Research, Ohio State University, Columbus, OH, USA
- Center for RNA Biology, Ohio State University, Columbus, OH, USA
| | - Ryan T Behrens
- McArdle Laboratory for Cancer Research, Institute for Molecular Virology, & Carbone Cancer Center, University of Wisconsin, Madison, WI, USA
| | - Corine St Gelais
- Center for Retrovirus Research, Ohio State University, Columbus, OH, USA
- Center for RNA Biology, Ohio State University, Columbus, OH, USA
- Department of Veterinary Biosciences, Ohio State University, Columbus, OH, USA
| | - Siqi Wu
- State Key Laboratory of Chemical Biology, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, China
| | - Saravanan Vivekanandan
- Cellular and Molecular Mechanisms of Inflammation Program, National University of Singapore and The Hebrew University of Jerusalem (NUS–HUJ), Singapore
| | - Ehud Razin
- Department of Biochemistry and Molecular Biology, Institute for Medical Research Israel-Canada, The Hebrew University of Jerusalem, Israel
| | - Pengfei Fang
- State Key Laboratory of Chemical Biology, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, China
| | - Li Wu
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Nathan Sherer
- McArdle Laboratory for Cancer Research, Institute for Molecular Virology, & Carbone Cancer Center, University of Wisconsin, Madison, WI, USA
| | - Karin Musier-Forsyth
- Department of Chemistry and Biochemistry, Ohio State University, Columbus, OH, USA
- Center for Retrovirus Research, Ohio State University, Columbus, OH, USA
- Center for RNA Biology, Ohio State University, Columbus, OH, USA
| |
Collapse
|
4
|
James CD, Youssef A, Prabhakar AT, Otoa R, Witt A, Lewis RL, Bristol ML, Wang X, Zhang K, Li R, Morgan IM. Human Papillomavirus 16 replication converts SAMHD1 into a homologous recombination factor and promotes its recruitment to replicating viral DNA. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.13.566899. [PMID: 38014153 PMCID: PMC10680734 DOI: 10.1101/2023.11.13.566899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
We have demonstrated that SAMHD1 (sterile alpha motif and histidine-aspartic domain HD-containing protein 1) is a restriction factor for the HPV16 life cycle. Here we demonstrate that in HPV negative cervical cancer C33a cells and human foreskin keratinocytes immortalized by HPV16 (HFK+HPV16), SAMHD1 is recruited to E1-E2 replicating DNA. Homologous recombination (HR) factors are required for HPV16 replication and viral replication promotes phosphorylation of SAMHD1, which converts it from a dNTPase to an HR factor independent from E6/E7 expression. A SAMHD1 phosphor-mimic (SAMHD1 T592D) reduces E1-E2 mediated DNA replication in C33a cells and has enhanced recruitment to the replicating DNA. In HFK+HPV16 cells SAMHD1 T592D is recruited to the viral DNA and attenuates cellular growth, but does not attenuate growth in isogenic HFK cells immortalized by E6/E7 alone. SAMHD1 T592D also attenuates the development of viral replication foci following keratinocyte differentiation. The results indicated that enhanced SAMHD1 phosphorylation could be therapeutically beneficial in cells with HPV16 replicating genomes. Protein phosphatase 2A (PP2A) can dephosphorylate SAMHD1 and PP2A function can be inhibited by endothall. We demonstrate that endothall reduces E1-E2 replication and promotes SAMHD1 recruitment to E1-E2 replicating DNA, mimicking the SAMHD1 T592D phenotypes. Finally, we demonstrate that in head and neck cancer cell lines with HPV16 episomal genomes endothall attenuates their growth and promotes recruitment of SAMHD1 to the viral genome. The results suggest that targeting cellular phosphatases has therapeutic potential for the treatment of HPV infections and cancers. Importance Human papillomaviruses are causative agents in around 5% of all human cancers. The development of anti-viral therapeutics depends upon an increased understanding of the viral life cycle. Here we demonstrate that HPV16 replication converts SAMHD1 into an HR factor via phosphorylation. This phosphorylation promotes recruitment of SAMHD1 to viral DNA to assist with replication. A SAMHD1 mutant that mimics phosphorylation is hyper-recruited to viral DNA and attenuates viral replication. Expression of this mutant in HPV16 immortalized cells attenuates the growth of these cells, but not cells immortalized by the viral oncogenes E6/E7 alone. Finally, we demonstrate that the phosphatase inhibitor endothall promotes hyper-recruitment of endogenous SAMHD1 to HPV16 replicating DNA and can attenuate the growth of both HPV16 immortalized human foreskin keratinocytes and HPV16 positive head and neck cancer cell lines. We propose that phosphatase inhibitors represent a novel tool for combating HPV infections and disease.
Collapse
|
5
|
McCown C, Yu CH, Ivanov DN. Allosteric substrate activation of SAMHD1 shapes deoxynucleotide triphosphate imbalances by interconnecting the depletion and biosynthesis of different dNTPs. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.14.567083. [PMID: 38014186 PMCID: PMC10680743 DOI: 10.1101/2023.11.14.567083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
SAMHD1 is a dNTPase that impedes replication of HIV-1 in myeloid cells and resting T lymphocytes. Here we elucidate the substrate activation mechanism of SAMHD1 that depends on dNTP binding at allosteric sites and the concomitant tetramerization of the enzyme. The study reveals that SAMHD1 activation involves an inactive tetrameric intermediate with partial occupancy of the allosteric sites. The equilibrium between the inactive and active tetrameric states, which is coupled to cooperative binding/dissociation of at least two allosteric dNTP ligands, controls the dNTPase activity of the enzyme, which, in addition, depends on the identity of the dNTPs occupying the four allosteric sites of the active tetramer. We show how such allosteric regulation determines deoxynucleotide triphosphate levels established in the dynamic equilibria between dNTP production and SAMHD1-catalyzed depletion. Notably, the mechanism enables a distinctive functionality of SAMHD1, which we call facilitated dNTP depletion, whereby elevated biosynthesis of some dNTPs results in more efficient depletion of others. The regulatory relationship between the biosynthesis and depletion of different dNTPs sheds light on the emerging role of SAMHD1 in the biology of dNTP homeostasis with implications for HIV/AIDS, innate antiviral immunity, T cell disorders, telomere maintenance and therapeutic efficacy of nucleoside analogs.
Collapse
|
6
|
Glumakova K, Ivanov G, Vedernikova V, Shyrokova L, Lebedev T, Stomakhin A, Zenchenko A, Oslovsky V, Drenichev M, Prassolov V, Spirin P. Nucleoside Analog 2',3'-Isopropylidene-5-Iodouridine as Novel Efficient Inhibitor of HIV-1. Pharmaceutics 2023; 15:2389. [PMID: 37896149 PMCID: PMC10610023 DOI: 10.3390/pharmaceutics15102389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 09/18/2023] [Accepted: 09/23/2023] [Indexed: 10/29/2023] Open
Abstract
Nucleoside reverse transcriptase inhibitors are the first class of drugs to be approved by the FDA for the suppression of HIV-1 and are widely used for this purpose in combination with drugs of other classes. Despite the progress in HIV-1 treatment, there is still the need to develop novel efficient antivirals. Here the efficiency of HIV-1 inhibition by a set of original 5-substituted uridine nucleosides was studied. We used the replication deficient human immunodeficiency virus (HIV-1)-based lentiviral particles and identified that among the studied compounds, 2',3'-isopropylidene-5-iodouridine was shown to cause anti-HIV-1 activity. Importantly, no toxic action of this compound against the cells of T-cell origin was found. We determined that this compound is significantly more efficient at suppressing HIV-1 compared to Azidothymidine (AZT) when taken at the high non-toxic concentrations. We did not find any profit when using AZT in combination with 2',3'-isopropylidene-5-iodouridine. 2',3'-Isopropylidene-5-iodouridine acts synergistically to repress HIV-1 when combined with the CDK4/6 inhibitor Palbociclib in low non-toxic concentration. No synergistic antiviral action was detected when AZT was combined with Palbociclib. We suggest 2',3'-isopropylidene-5-iodouridine as a novel perspective non-toxic compound that may be used for HIV-l suppression.
Collapse
Affiliation(s)
- Ksenia Glumakova
- Department of Cancer Cell Biology, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilova 32, 119991 Moscow, Russia; (K.G.); (G.I.); (V.V.); (T.L.); (A.S.); (A.Z.); (V.O.); (M.D.)
- Moscow Institute of Physics and Technology, National Research University, Institutskiy per. 9, 141701 Dolgoprudny, Russia
| | - Georgy Ivanov
- Department of Cancer Cell Biology, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilova 32, 119991 Moscow, Russia; (K.G.); (G.I.); (V.V.); (T.L.); (A.S.); (A.Z.); (V.O.); (M.D.)
| | - Valeria Vedernikova
- Department of Cancer Cell Biology, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilova 32, 119991 Moscow, Russia; (K.G.); (G.I.); (V.V.); (T.L.); (A.S.); (A.Z.); (V.O.); (M.D.)
- Moscow Institute of Physics and Technology, National Research University, Institutskiy per. 9, 141701 Dolgoprudny, Russia
| | - Lena Shyrokova
- Department of Experimental Medical Science, Lund University, 221 84 Lund, Sweden;
| | - Timofey Lebedev
- Department of Cancer Cell Biology, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilova 32, 119991 Moscow, Russia; (K.G.); (G.I.); (V.V.); (T.L.); (A.S.); (A.Z.); (V.O.); (M.D.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilova 32, 119991 Moscow, Russia
| | - Andrei Stomakhin
- Department of Cancer Cell Biology, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilova 32, 119991 Moscow, Russia; (K.G.); (G.I.); (V.V.); (T.L.); (A.S.); (A.Z.); (V.O.); (M.D.)
| | - Anastasia Zenchenko
- Department of Cancer Cell Biology, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilova 32, 119991 Moscow, Russia; (K.G.); (G.I.); (V.V.); (T.L.); (A.S.); (A.Z.); (V.O.); (M.D.)
| | - Vladimir Oslovsky
- Department of Cancer Cell Biology, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilova 32, 119991 Moscow, Russia; (K.G.); (G.I.); (V.V.); (T.L.); (A.S.); (A.Z.); (V.O.); (M.D.)
| | - Mikhail Drenichev
- Department of Cancer Cell Biology, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilova 32, 119991 Moscow, Russia; (K.G.); (G.I.); (V.V.); (T.L.); (A.S.); (A.Z.); (V.O.); (M.D.)
| | - Vladimir Prassolov
- Department of Cancer Cell Biology, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilova 32, 119991 Moscow, Russia; (K.G.); (G.I.); (V.V.); (T.L.); (A.S.); (A.Z.); (V.O.); (M.D.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilova 32, 119991 Moscow, Russia
| | - Pavel Spirin
- Department of Cancer Cell Biology, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilova 32, 119991 Moscow, Russia; (K.G.); (G.I.); (V.V.); (T.L.); (A.S.); (A.Z.); (V.O.); (M.D.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilova 32, 119991 Moscow, Russia
| |
Collapse
|
7
|
Wang XF, Zhang X, Ma W, Li J, Wang X. Host cell restriction factors of equine infectious anemia virus. Virol Sin 2023; 38:485-496. [PMID: 37419416 PMCID: PMC10436108 DOI: 10.1016/j.virs.2023.07.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 07/03/2023] [Indexed: 07/09/2023] Open
Abstract
Equine infectious anemia virus (EIAV) is a member of the lentivirus genus in the Retroviridae family and is considered an animal model for HIV/AIDS research. An attenuated EIAV vaccine, which was successfully developed in the 1970s by classical serial passage techniques, is the first and only lentivirus vaccine that has been widely used to date. Restriction factors are cellular proteins that provide an early line of defense against viral replication and spread by interfering with various critical steps in the viral replication cycle. However, viruses have evolved specific mechanisms to overcome these host barriers through adaptation. The battle between the viruses and restriction factors is actually a natural part of the viral replication process, which has been well studied in human immunodeficiency virus type 1 (HIV-1). EIAV has the simplest genome composition of all lentiviruses, making it an intriguing subject for understanding how the virus employs its limited viral proteins to overcome restriction factors. In this review, we summarize the current literature on the interactions between equine restriction factors and EIAV. The features of equine restriction factors and the mechanisms by which the EIAV counteract the restriction suggest that lentiviruses employ diverse strategies to counteract innate immune restrictions. In addition, we present our insights on whether restriction factors induce alterations in the phenotype of the attenuated EIAV vaccine.
Collapse
Affiliation(s)
- Xue-Feng Wang
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin 150069, China
| | - Xiangmin Zhang
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin 150069, China
| | - Weiwei Ma
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin 150069, China
| | - Jiwei Li
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin 150069, China
| | - Xiaojun Wang
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin 150069, China.
| |
Collapse
|
8
|
Lin Y, Yang B, Huang Y, Zhang Y, Jiang Y, Ma L, Shen YQ. Mitochondrial DNA-targeted therapy: A novel approach to combat cancer. CELL INSIGHT 2023; 2:100113. [PMID: 37554301 PMCID: PMC10404627 DOI: 10.1016/j.cellin.2023.100113] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 07/14/2023] [Accepted: 07/16/2023] [Indexed: 08/10/2023]
Abstract
Mitochondrial DNA (mtDNA) encodes proteins and RNAs that are essential for mitochondrial function and cellular homeostasis, and participates in important processes of cellular bioenergetics and metabolism. Alterations in mtDNA are associated with various diseases, especially cancers, and are considered as biomarkers for some types of tumors. Moreover, mtDNA alterations have been found to affect the proliferation, progression and metastasis of cancer cells, as well as their interactions with the immune system and the tumor microenvironment (TME). The important role of mtDNA in cancer development makes it a significant target for cancer treatment. In recent years, many novel therapeutic methods targeting mtDNA have emerged. In this study, we first discussed how cancerogenesis is triggered by mtDNA mutations, including alterations in gene copy number, aberrant gene expression and epigenetic modifications. Then, we described in detail the mechanisms underlying the interactions between mtDNA and the extramitochondrial environment, which are crucial for understanding the efficacy and safety of mtDNA-targeted therapy. Next, we provided a comprehensive overview of the recent progress in cancer therapy strategies that target mtDNA. We classified them into two categories based on their mechanisms of action: indirect and direct targeting strategies. Indirect targeting strategies aimed to induce mtDNA damage and dysfunction by modulating pathways that are involved in mtDNA stability and integrity, while direct targeting strategies utilized molecules that can selectively bind to or cleave mtDNA to achieve the therapeutic efficacy. This study highlights the importance of mtDNA-targeted therapy in cancer treatment, and will provide insights for future research and development of targeted drugs and therapeutic strategies.
Collapse
Affiliation(s)
- Yumeng Lin
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Research Unit of Oral Carcinogenesis and Management, Chinese Academy of Medical Sciences, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan 610041, PR China
| | - Bowen Yang
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Research Unit of Oral Carcinogenesis and Management, Chinese Academy of Medical Sciences, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan 610041, PR China
| | - Yibo Huang
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Research Unit of Oral Carcinogenesis and Management, Chinese Academy of Medical Sciences, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan 610041, PR China
| | - You Zhang
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Research Unit of Oral Carcinogenesis and Management, Chinese Academy of Medical Sciences, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan 610041, PR China
| | - Yu Jiang
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Research Unit of Oral Carcinogenesis and Management, Chinese Academy of Medical Sciences, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan 610041, PR China
| | - Longyun Ma
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Research Unit of Oral Carcinogenesis and Management, Chinese Academy of Medical Sciences, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan 610041, PR China
| | - Ying-Qiang Shen
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Research Unit of Oral Carcinogenesis and Management, Chinese Academy of Medical Sciences, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan 610041, PR China
| |
Collapse
|
9
|
Sharifi HJ, Paine DN, Fazzari VA, Tipple AF, Patterson E, de Noronha CMC. Sulforaphane Reduces SAMHD1 Phosphorylation To Protect Macrophages from HIV-1 Infection. J Virol 2022; 96:e0118722. [PMID: 36377871 PMCID: PMC9749475 DOI: 10.1128/jvi.01187-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 10/24/2022] [Indexed: 11/16/2022] Open
Abstract
The cellular protein SAMHD1 is important for DNA repair, suppressing LINE elements, controlling deoxynucleoside triphosphate (dNTP) concentrations, maintaining HIV-1 latency, and preventing excessive type I interferon responses. SAMHD1 is also a potent inhibitor of HIV-1 and other significant viral pathogens. Infection restriction is due in part to the deoxynucleoside triphosphatase (dNTPase) activity of SAMHD1 but is also mediated through a dNTPase-independent mechanism that has been described but not explored. The phosphorylation of SAMHD1 at threonine 592 (T592) controls many of its functions. Retroviral restriction, irrespective of dNTPase activity, is linked to unphosphorylated T592. Sulforaphane (SFN), an isothiocyanate, protects macrophages from HIV infection by mobilizing the transcription factor and antioxidant response regulator Nrf2. Here, we show that SFN and other clinically relevant Nrf2 mobilizers reduce SAMHD1 T592 phosphorylation to protect macrophages from HIV-1. We further show that SFN, through Nrf2, triggers the upregulation of the cell cycle control protein p21 in human monocyte-derived macrophages to contribute to SAMHD1 activation. We additionally present data that support another, potentially redox-dependent mechanism employed by SFN to contribute to SAMHD1 activation through reduced phosphorylation. This work establishes the use of exogenous Nrf2 mobilizers as a novel way to study virus restriction by SAMHD1 and highlights the Nrf2 pathway as a potential target for the therapeutic control of SAMHD1 cellular and antiviral functions. IMPORTANCE Here, we show, for the first time, that the treatment of macrophages with Nrf2 mobilizers, known activators of antioxidant responses, increases the fraction of SAMHD1 without a regulatory phosphate at position 592. We demonstrate that this decreases infection of macrophages by HIV-1. Phosphorylated SAMHD1 is important for DNA repair, the suppression of LINE elements, the maintenance of HIV-1 in a latent state, and the prevention of excessive type I interferon responses, while unphosphorylated SAMHD1 blocks HIV infection. SAMHD1 impacts many viruses and is involved in various cancers, so knowledge of how it works and how it is regulated has broad implications for the development of therapeutics. Redox-modulating therapeutics are already in clinical use or under investigation for the treatment of many conditions. Thus, understanding the impact of redox modifiers on controlling SAMHD1 phosphorylation is important for many areas of research in microbiology and beyond.
Collapse
Affiliation(s)
- H. John Sharifi
- Albany College of Pharmacy and Health Sciences, Albany, New York, USA
| | - Dakota N. Paine
- Albany College of Pharmacy and Health Sciences, Albany, New York, USA
| | | | | | - Emilee Patterson
- Department of Immunology and Microbial Disease, Albany Medical College, Albany, New York, USA
| | - Carlos M. C. de Noronha
- Department of Immunology and Microbial Disease, Albany Medical College, Albany, New York, USA
| |
Collapse
|
10
|
Williams ESCP, Szaniawski MA, Martins LJ, Innis EA, Alcamí J, Hanley TM, Spivak AM, Coiras M, Planelles V. Dasatinib: effects on the macrophage phospho proteome with a focus on SAMHD1 and HIV-1 infection. CLINICAL RESEARCH IN HIV/AIDS 2022; 8:1053. [PMID: 36589263 PMCID: PMC9802671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Macrophages are one of the main cellular targets of human immunodeficiency virus type 1 (HIV-1). Macrophage infection by HIV-1 is inefficient due to the presence of the viral restriction factor sterile alpha motif and histidine aspartic acid domain containing protein 1 (SAMHD1). Ex vivo human monocyte-derived macrophages (MDMs) express SAMHD1 in an equilibrium between active (unphosphorylated) and inactive (phosphorylated) states. We and others have shown that treatment of MDMs with the FDA-approved tyrosine kinase inhibitor, dasatinib, ablates SAMHD1 phosphorylation, thus skewing the balance towards a cellular state that is refractory to HIV-1 infection. We hypothesized that dasatinib inhibits a putative tyrosine kinase that is upstream of SAMHD1. In search for this tyrosine kinase, we probed several candidates and were unable to identify a single target that, when inhibited, was sufficient to explain the dephosphorylation of SAMHD1 we observe upon treatment with dasatinib. On the other hand, we probed the ability of dasatinib to directly inhibit the serine/threonine cyclin dependent kinases 1, 2, 4 and 6 and confirmed that dasatinib directly inhibits these kinases. Therefore, our results show that inhibition of the proximal CDKs 1, 2, 4 and 6 by dasatinib is clearly detectable, leads to blockade of infection by HIV-1, and may be sufficient to explain the activity of dasatinib against SAMHD1 phosphorylation.
Collapse
Affiliation(s)
| | - Matthew A Szaniawski
- University of Utah School of Medicine, Department of Pathology, Salt Lake City, UT
| | - Laura J Martins
- University of Utah School of Medicine, Department of Pathology, Salt Lake City, UT
| | - Emily A Innis
- University of Utah School of Medicine, Department of Pathology, Salt Lake City, UT
| | - José Alcamí
- AIDS Immunopathology Unit, National Center of Microbiology, Instituto de Salud Carlos III, Madrid, Spain
| | - Timothy M Hanley
- University of Utah School of Medicine, Department of Pathology, Salt Lake City, UT
| | - Adam M Spivak
- University of Utah School of Medicine, Department of Pathology, Salt Lake City, UT
| | - Mayte Coiras
- AIDS Immunopathology Unit, National Center of Microbiology, Instituto de Salud Carlos III, Madrid, Spain
| | - Vicente Planelles
- University of Utah School of Medicine, Department of Pathology, Salt Lake City, UT
| |
Collapse
|
11
|
Kapoor-Vazirani P, Rath SK, Liu X, Shu Z, Bowen NE, Chen Y, Haji-Seyed-Javadi R, Daddacha W, Minten EV, Danelia D, Farchi D, Duong DM, Seyfried NT, Deng X, Ortlund EA, Kim B, Yu DS. SAMHD1 deacetylation by SIRT1 promotes DNA end resection by facilitating DNA binding at double-strand breaks. Nat Commun 2022; 13:6707. [PMID: 36344525 PMCID: PMC9640623 DOI: 10.1038/s41467-022-34578-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 10/29/2022] [Indexed: 11/09/2022] Open
Abstract
Sterile alpha motif and HD domain-containing protein 1 (SAMHD1) has a dNTPase-independent function in promoting DNA end resection to facilitate DNA double-strand break (DSB) repair by homologous recombination (HR); however, it is not known if upstream signaling events govern this activity. Here, we show that SAMHD1 is deacetylated by the SIRT1 sirtuin deacetylase, facilitating its binding with ssDNA at DSBs, to promote DNA end resection and HR. SIRT1 complexes with and deacetylates SAMHD1 at conserved lysine 354 (K354) specifically in response to DSBs. K354 deacetylation by SIRT1 promotes DNA end resection and HR but not SAMHD1 tetramerization or dNTPase activity. Mechanistically, K354 deacetylation by SIRT1 promotes SAMHD1 recruitment to DSBs and binding to ssDNA at DSBs, which in turn facilitates CtIP ssDNA binding, leading to promotion of genome integrity. These findings define a mechanism governing the dNTPase-independent resection function of SAMHD1 by SIRT1 deacetylation in promoting HR and genome stability.
Collapse
Affiliation(s)
- Priya Kapoor-Vazirani
- grid.189967.80000 0001 0941 6502Department of Radiation Oncology and Winship Cancer Institute, Emory University School of Medicine, Atlanta, GA 30322 USA
| | - Sandip K. Rath
- grid.189967.80000 0001 0941 6502Department of Radiation Oncology and Winship Cancer Institute, Emory University School of Medicine, Atlanta, GA 30322 USA
| | - Xu Liu
- grid.189967.80000 0001 0941 6502Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322 USA
| | - Zhen Shu
- grid.189967.80000 0001 0941 6502Department of Radiation Oncology and Winship Cancer Institute, Emory University School of Medicine, Atlanta, GA 30322 USA
| | - Nicole E. Bowen
- grid.189967.80000 0001 0941 6502Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322 USA
| | - Yitong Chen
- grid.189967.80000 0001 0941 6502Department of Radiation Oncology and Winship Cancer Institute, Emory University School of Medicine, Atlanta, GA 30322 USA
| | - Ramona Haji-Seyed-Javadi
- grid.189967.80000 0001 0941 6502Department of Radiation Oncology and Winship Cancer Institute, Emory University School of Medicine, Atlanta, GA 30322 USA
| | - Waaqo Daddacha
- grid.410427.40000 0001 2284 9329Department of Biochemistry and Molecular Biology, Medical College of Georgia at Augusta University, Augusta, GA 30912 USA
| | - Elizabeth V. Minten
- grid.189967.80000 0001 0941 6502Department of Radiation Oncology and Winship Cancer Institute, Emory University School of Medicine, Atlanta, GA 30322 USA
| | - Diana Danelia
- grid.189967.80000 0001 0941 6502Department of Radiation Oncology and Winship Cancer Institute, Emory University School of Medicine, Atlanta, GA 30322 USA
| | - Daniela Farchi
- grid.189967.80000 0001 0941 6502Department of Radiation Oncology and Winship Cancer Institute, Emory University School of Medicine, Atlanta, GA 30322 USA
| | - Duc M. Duong
- grid.189967.80000 0001 0941 6502Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322 USA
| | - Nicholas T. Seyfried
- grid.189967.80000 0001 0941 6502Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322 USA
| | - Xingming Deng
- grid.189967.80000 0001 0941 6502Department of Radiation Oncology and Winship Cancer Institute, Emory University School of Medicine, Atlanta, GA 30322 USA
| | - Eric A. Ortlund
- grid.189967.80000 0001 0941 6502Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322 USA
| | - Baek Kim
- grid.189967.80000 0001 0941 6502Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322 USA
| | - David S. Yu
- grid.189967.80000 0001 0941 6502Department of Radiation Oncology and Winship Cancer Institute, Emory University School of Medicine, Atlanta, GA 30322 USA
| |
Collapse
|
12
|
Han M, Woottum M, Mascarau R, Vahlas Z, Verollet C, Benichou S. Mechanisms of HIV-1 cell-to-cell transfer to myeloid cells. J Leukoc Biol 2022; 112:1261-1271. [PMID: 35355323 DOI: 10.1002/jlb.4mr0322-737r] [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: 01/17/2022] [Revised: 03/09/2022] [Indexed: 12/24/2022] Open
Abstract
In addition to CD4+ T lymphocytes, cells of the myeloid lineage such as macrophages, dendritic cells (DCs), and osteoclasts (OCs) are emerging as important target cells for HIV-1, as they likely participate in all steps of pathogenesis, including sexual transmission and early virus dissemination in both lymphoid and nonlymphoid tissues where they can constitute persistent virus reservoirs. At least in vitro, these myeloid cells are poorly infected by cell-free viral particles. In contrast, intercellular virus transmission through direct cell-to-cell contacts may be a predominant mode of virus propagation in vivo leading to productive infection of these myeloid target cells. HIV-1 cell-to-cell transfer between CD4+ T cells mainly through the formation of the virologic synapse, or from infected macrophages or dendritic cells to CD4+ T cell targets, have been extensively described in vitro. Recent reports demonstrate that myeloid cells can be also productively infected through virus homotypic or heterotypic cell-to-cell transfer between macrophages or from virus-donor-infected CD4+ T cells, respectively. These modes of infection of myeloid target cells lead to very efficient spreading in these poorly susceptible cell types. Thus, the goal of this review is to give an overview of the different mechanisms reported in the literature for cell-to-cell transfer and spreading of HIV-1 in myeloid cells.
Collapse
Affiliation(s)
- Mingyu Han
- Institut Cochin, Inserm U1016, Paris, France.,Centre National de la Recherche Scientifique CNRS UMR8104, Paris, France.,Faculty of Health, University of Paris Cité, Paris, France
| | - Marie Woottum
- Institut Cochin, Inserm U1016, Paris, France.,Centre National de la Recherche Scientifique CNRS UMR8104, Paris, France.,Faculty of Health, University of Paris Cité, Paris, France
| | - Rémi Mascarau
- Institut de Pharmacologie et Biologie Structurale, IPBS, Université de Toulouse, CNRS, Toulouse, France.,International Research Project (IRP) CNRS, Toulouse, France.,International Research Project (IRP), CNRS, Buenos Aires, Argentina
| | - Zoï Vahlas
- Institut de Pharmacologie et Biologie Structurale, IPBS, Université de Toulouse, CNRS, Toulouse, France.,International Research Project (IRP) CNRS, Toulouse, France.,International Research Project (IRP), CNRS, Buenos Aires, Argentina
| | - Christel Verollet
- Institut de Pharmacologie et Biologie Structurale, IPBS, Université de Toulouse, CNRS, Toulouse, France.,International Research Project (IRP) CNRS, Toulouse, France.,International Research Project (IRP), CNRS, Buenos Aires, Argentina
| | - Serge Benichou
- Institut Cochin, Inserm U1016, Paris, France.,Centre National de la Recherche Scientifique CNRS UMR8104, Paris, France.,Faculty of Health, University of Paris Cité, Paris, France
| |
Collapse
|
13
|
Bowen NE, Oo A, Kim B. Mechanistic Interplay between HIV-1 Reverse Transcriptase Enzyme Kinetics and Host SAMHD1 Protein: Viral Myeloid-Cell Tropism and Genomic Mutagenesis. Viruses 2022; 14:v14081622. [PMID: 35893688 PMCID: PMC9331428 DOI: 10.3390/v14081622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 07/21/2022] [Accepted: 07/22/2022] [Indexed: 11/23/2022] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) has been the primary interest among studies on antiviral discovery, viral replication kinetics, drug resistance, and viral evolution. Following infection and entry into target cells, the HIV-1 core disassembles, and the viral RT concomitantly converts the viral RNA into double-stranded proviral DNA, which is integrated into the host genome. The successful completion of the viral life cycle highly depends on the enzymatic DNA polymerase activity of RT. Furthermore, HIV-1 RT has long been known as an error-prone DNA polymerase due to its lack of proofreading exonuclease properties. Indeed, the low fidelity of HIV-1 RT has been considered as one of the key factors in the uniquely high rate of mutagenesis of HIV-1, which leads to efficient viral escape from immune and therapeutic antiviral selective pressures. Interestingly, a series of studies on the replication kinetics of HIV-1 in non-dividing myeloid cells and myeloid specific host restriction factor, SAM domain, and HD domain-containing protein, SAMHD1, suggest that the myeloid cell tropism and high rate of mutagenesis of HIV-1 are mechanistically connected. Here, we review not only HIV-1 RT as a key antiviral target, but also potential evolutionary and mechanistic crosstalk among the unique enzymatic features of HIV-1 RT, the replication kinetics of HIV-1, cell tropism, viral genetic mutation, and host SAMHD1 protein.
Collapse
Affiliation(s)
- Nicole E. Bowen
- Department of Pediatrics, School of Medicine, Emory University, Atlanta, GA 30329, USA; (N.E.B.); (A.O.)
| | - Adrian Oo
- Department of Pediatrics, School of Medicine, Emory University, Atlanta, GA 30329, USA; (N.E.B.); (A.O.)
| | - Baek Kim
- Department of Pediatrics, School of Medicine, Emory University, Atlanta, GA 30329, USA; (N.E.B.); (A.O.)
- Center for Drug Discovery, Children’s Healthcare of Atlanta, Atlanta, GA 30329, USA
- Correspondence:
| |
Collapse
|
14
|
Han M, Cantaloube-Ferrieu V, Xie M, Armani-Tourret M, Woottum M, Pagès JC, Colin P, Lagane B, Benichou S. HIV-1 cell-to-cell spread overcomes the virus entry block of non-macrophage-tropic strains in macrophages. PLoS Pathog 2022; 18:e1010335. [PMID: 35622876 PMCID: PMC9182568 DOI: 10.1371/journal.ppat.1010335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 06/09/2022] [Accepted: 05/09/2022] [Indexed: 11/19/2022] Open
Abstract
Macrophages (MΦ) are increasingly recognized as HIV-1 target cells involved in the pathogenesis and persistence of infection. Paradoxically, in vitro infection assays suggest that virus isolates are mostly T-cell-tropic and rarely MΦ-tropic. The latter are assumed to emerge under CD4+ T-cell paucity in tissues such as the brain or at late stage when the CD4 T-cell count declines. However, assays to qualify HIV-1 tropism use cell-free viral particles and may not fully reflect the conditions of in vivo MΦ infection through cell-to-cell viral transfer. Here, we investigated the capacity of viruses expressing primary envelope glycoproteins (Envs) with CCR5 and/or CXCR4 usage from different stages of infection, including transmitted/founder Envs, to infect MΦ by a cell-free mode and through cell-to-cell transfer from infected CD4+ T cells. The results show that most viruses were unable to enter MΦ as cell-free particles, in agreement with the current view that non-M-tropic viruses inefficiently use CD4 and/or CCR5 or CXCR4 entry receptors on MΦ. In contrast, all viruses could be effectively cell-to-cell transferred to MΦ from infected CD4+ T cells. We further showed that viral transfer proceeded through Env-dependent cell-cell fusion of infected T cells with MΦ targets, leading to the formation of productively infected multinucleated giant cells. Compared to cell-free infection, infected T-cell/MΦ contacts showed enhanced interactions of R5 M- and non-M-tropic Envs with CD4 and CCR5, resulting in a reduced dependence on receptor expression levels on MΦ for viral entry. Altogether, our results show that virus cell-to-cell transfer overcomes the entry block of isolates initially defined as non-macrophage-tropic, indicating that HIV-1 has a more prevalent tropism for MΦ than initially suggested. This sheds light into the role of this route of virus cell-to-cell transfer to MΦ in CD4+ T cell rich tissues for HIV-1 transmission, dissemination and formation of tissue viral reservoirs.
Collapse
Affiliation(s)
- Mingyu Han
- Institut Cochin, Inserm U1016, Paris, France
- CNRS, UMR8104, Paris, France
- Université de Paris, Paris, France
| | | | - Maorong Xie
- Institut Cochin, Inserm U1016, Paris, France
- CNRS, UMR8104, Paris, France
- Université de Paris, Paris, France
| | | | - Marie Woottum
- Institut Cochin, Inserm U1016, Paris, France
- CNRS, UMR8104, Paris, France
- Université de Paris, Paris, France
| | - Jean-Christophe Pagès
- Institut RESTORE, Université de Toulouse, CNRS U-5070, EFS, ENVT, Inserm U1301, Toulouse, France
| | - Philippe Colin
- Infinity, Université de Toulouse, CNRS, INSERM, UPS, Toulouse, France
| | - Bernard Lagane
- Infinity, Université de Toulouse, CNRS, INSERM, UPS, Toulouse, France
- * E-mail: (BL); (SB)
| | - Serge Benichou
- Institut Cochin, Inserm U1016, Paris, France
- CNRS, UMR8104, Paris, France
- Université de Paris, Paris, France
- * E-mail: (BL); (SB)
| |
Collapse
|
15
|
Lata S, Sood V, Banerjea AC. Human Immunodeficiency Virus Type 1 Vif Up-Regulates the Expression of Tat via AKT Signaling Pathway: Role of Ubiquitin Specific Protease 17. Front Microbiol 2022; 13:828430. [PMID: 35387085 PMCID: PMC8978020 DOI: 10.3389/fmicb.2022.828430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 01/10/2022] [Indexed: 11/18/2022] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) has RNA genome and depends on host cellular machinery for most of its activities. Host cellular proteins modulate the expression and activity of viral proteins to combat the virus. HIV-1 proteins are known to regulate each other for the benefit of virus by exploiting these modulations. Here, we report that HIV-1 Vif increases the levels of Tat via AKT signaling pathway. We show that HIV-1 Vif activates AKT signaling pathway by inducing phosphorylation of AKT. Mdm2, downstream target of AKT signaling, increases the levels of Tat protein in ubiquitin-dependent manner by inducing Ubiquitin Specific Protease 17 (USP17), which is a deubiquitinase and stabilizes Tat protein. Thus, HIV-1 proteins exploit AKT signaling pathway to promote viral replication.
Collapse
Affiliation(s)
- Sneh Lata
- Virology II, National Institute of Immunology, New Delhi, India
| | - Vikas Sood
- Department of Biochemistry, Jamia Hamdard University, New Delhi, India
| | | |
Collapse
|
16
|
Karuppusamy KV, Demosthenes JP, Venkatesan V, Christopher AC, Babu P, Azhagiri MK, Jacob A, Ramalingam VV, Rangaraj S, Murugesan MK, Marepally SK, Varghese GM, Srivastava A, Kannangai R, Thangavel S. The CCR5 Gene Edited CD34+CD90+ Hematopoietic Stem Cell Population Serves as an Optimal Graft Source for HIV Gene Therapy. Front Immunol 2022; 13:792684. [PMID: 35359982 PMCID: PMC8963924 DOI: 10.3389/fimmu.2022.792684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Accepted: 02/14/2022] [Indexed: 11/13/2022] Open
Abstract
Transplantation of allogenic hematopoietic stem and progenitor cells (HSPCs) with C-C chemokine receptor type 5 (CCR5) Δ32 genotype generates HIV-1 resistant immune cells. CCR5 gene edited autologous HSPCs can be a potential alternative to hematopoietic stem cell transplantation (HSCT) from HLA-matched CCR5 null donor. However, the clinical application of gene edited autologous HSPCs is critically limited by the quality of the graft, as HIV also infects the HSPCs. In this study, by using mobilized HSPCs from healthy donors, we show that the CD34+CD90+ hematopoietic stem cells (HSCs) express 7-fold lower CD4/CCR5 HIV receptors, higher levels of SAMHD1 anti-viral restriction factor, and possess lower susceptibility to HIV infection than the CD34+CD90- hematopoietic progenitor cells. Further, the treatment with small molecule cocktail of Resveratrol, UM729 and SR1(RUS) improved the in vivo engraftment potential of CD34+CD90+ HSCs. To demonstrate that CD34+CD90+ HSC population as an ideal graft for HIV gene therapy, we sort purified CD34+CD90+ HSCs, treated with RUS and then gene edited the CCR5 with single sgRNA. On transplantation, 100,000 CD34+CD90+ HSCs were sufficient for long-term repopulation of the entire bone marrow of NBSGW mice. Importantly, the gene editing efficiency of ~90% in the infused product was maintained in vivo, facilitating the generation of CCR5 null immune cells, resistant to HIV infection. Altogether, CCR5 gene editing of CD34+CD90+ HSCs provide an ideal gene manipulation strategy for autologous HSCT based gene therapy for HIV infection.
Collapse
Affiliation(s)
- Karthik V. Karuppusamy
- Centre for Stem Cell Research (CSCR), A Unit of InStem Bengaluru, Vellore, India
- Manipal Academy of Higher Education, Manipal, India
| | | | - Vigneshwaran Venkatesan
- Centre for Stem Cell Research (CSCR), A Unit of InStem Bengaluru, Vellore, India
- Manipal Academy of Higher Education, Manipal, India
| | - Abisha Crystal Christopher
- Centre for Stem Cell Research (CSCR), A Unit of InStem Bengaluru, Vellore, India
- Thiruvalluvar University, Vellore, India
| | - Prathibha Babu
- Centre for Stem Cell Research (CSCR), A Unit of InStem Bengaluru, Vellore, India
- Manipal Academy of Higher Education, Manipal, India
| | - Manojkumar K. Azhagiri
- Centre for Stem Cell Research (CSCR), A Unit of InStem Bengaluru, Vellore, India
- Manipal Academy of Higher Education, Manipal, India
| | - Annlin Jacob
- Centre for Stem Cell Research (CSCR), A Unit of InStem Bengaluru, Vellore, India
- Manipal Academy of Higher Education, Manipal, India
| | | | - Sumathi Rangaraj
- Centre for Stem Cell Research (CSCR), A Unit of InStem Bengaluru, Vellore, India
| | | | | | - George M. Varghese
- Department of Infectious Diseases, Christian Medical College, Vellore, India
| | - Alok Srivastava
- Centre for Stem Cell Research (CSCR), A Unit of InStem Bengaluru, Vellore, India
- Department of Hematology, Christian Medical College, Vellore, India
| | - Rajesh Kannangai
- Department of Clinical Virology, Christian Medical College, Vellore, India
| | - Saravanabhavan Thangavel
- Centre for Stem Cell Research (CSCR), A Unit of InStem Bengaluru, Vellore, India
- *Correspondence: Saravanabhavan Thangavel,
| |
Collapse
|
17
|
Bhatlekar S, Jacob S, Tugolukova E, Manne BK, Kosaka Y, Loher P, O'Connell RM, Planelles V, Rondina MT, Rigoutsos I, Bray PF. Interferon α-induced SAMHD1 regulates human cultured megakaryocyte apoptosis and proplatelet formation. Haematologica 2022; 107:558-561. [PMID: 34758609 PMCID: PMC8804568 DOI: 10.3324/haematol.2021.279864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 10/28/2021] [Indexed: 11/16/2022] Open
Affiliation(s)
- Seema Bhatlekar
- Program in Molecular Medicine and Department of Internal Medicine, University of Utah, Salt Lake City
| | - Shancy Jacob
- Program in Molecular Medicine and Department of Internal Medicine, University of Utah, Salt Lake City
| | - Emilia Tugolukova
- Program in Molecular Medicine and Department of Internal Medicine, University of Utah, Salt Lake City
| | - Bhanu K Manne
- Program in Molecular Medicine and Department of Internal Medicine, University of Utah, Salt Lake City, UT
| | - Yasuhiro Kosaka
- Program in Molecular Medicine and Department of Internal Medicine, University of Utah, Salt Lake City
| | - Phillipe Loher
- Computational Medicine Center, Thomas Jefferson University, Philadelphia
| | - Ryan M O'Connell
- Division of Microbiology and Immunology, Department of Pathology, and Huntsman Cancer Institute, University of Utah Health Sciences Center, University of Utah, Salt Lake City
| | - Vicente Planelles
- Division of Microbiology and Immunology, Department of Pathology, University of Utah, Salt Lake City
| | - Matthew T Rondina
- Program in Molecular Medicine and Department of Internal Medicine, University of Utah, Salt Lake City, UT; Department of Pathology, University of Utah, Salt Lake City, UT and the George E. Wahlen VAMC Department of Medicine and George E. Wahlen VAMC GRECC, Salt Lake City
| | - Isidore Rigoutsos
- Department of Pathology, University of Utah, Salt Lake City, UT and the George E. Wahlen VAMC Department of Medicine and George E. Wahlen VAMC GRECC, Salt Lake City
| | - Paul F Bray
- Program in Molecular Medicine and Department of Internal Medicine, University of Utah, Salt Lake City, UT; Division of Hematology and Hematologic Malignancies, Department of Internal Medicine, University of Utah, Salt Lake City.
| |
Collapse
|
18
|
Barrett B, Nguyen DH, Xu J, Guo K, Shetty S, Jones ST, Mickens KL, Shepard C, Roers A, Behrendt R, Wu L, Kim B, Santiago ML. SAMHD1 Promotes the Antiretroviral Adaptive Immune Response in Mice Exposed to Lipopolysaccharide. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2022; 208:444-453. [PMID: 34893529 DOI: 10.4049/jimmunol.2001389] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 11/08/2021] [Indexed: 12/13/2022]
Abstract
SAMHD1 is a potent HIV-1 restriction factor that blocks reverse transcription in monocytes, dendritic cells and resting CD4+ T cells by decreasing intracellular dNTP pools. However, SAMHD1 may diminish innate immune sensing and Ag presentation, resulting in a weaker adaptive immune response. To date, the role of SAMHD1 on antiretroviral immunity remains unclear, as mouse SAMHD1 had no impact on murine retrovirus replication in prior in vivo studies. Here, we show that SAMHD1 significantly inhibits acute Friend retrovirus infection in mice. Pretreatment with LPS, a significant driver of inflammation during HIV-1 infection, further unmasked a role for SAMHD1 in influencing immune responses. LPS treatment in vivo doubled the intracellular dNTP levels in immune compartments of SAMHD1 knockout but not wild-type mice. SAMHD1 knockout mice exhibited higher plasma infectious viremia and proviral DNA loads than wild-type mice at 7 d postinfection (dpi), and proviral loads inversely correlated with a stronger CD8+ T cell response. SAMHD1 deficiency was also associated with weaker NK, CD4+ T and CD8+ T cell responses by 14 dpi and weaker neutralizing Ab responses by 28 dpi. Intriguingly, SAMHD1 influenced these cell-mediated immune (14 dpi) and neutralizing Ab (28 dpi) responses in male but not female mice. Our findings formally demonstrate SAMHD1 as an antiretroviral factor in vivo that could promote adaptive immune responses in a sex-dependent manner. The requirement for LPS to unravel the SAMHD1 immunological phenotype suggests that comorbidities associated with a "leaky" gut barrier may influence the antiviral function of SAMHD1 in vivo.
Collapse
Affiliation(s)
- BradleyS Barrett
- Department of Medicine, University of Colorado School of Medicine, Aurora, CO
| | - David H Nguyen
- Department of Medicine, University of Colorado School of Medicine, Aurora, CO
| | - Joella Xu
- Department of Pediatrics, School of Medicine, Emory University, Atlanta, GA
| | - Kejun Guo
- Department of Medicine, University of Colorado School of Medicine, Aurora, CO
| | - Shravida Shetty
- Department of Medicine, University of Colorado School of Medicine, Aurora, CO
| | - Sean T Jones
- Department of Medicine, University of Colorado School of Medicine, Aurora, CO.,Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO
| | - Kaylee L Mickens
- Department of Medicine, University of Colorado School of Medicine, Aurora, CO.,Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO
| | - Caitlin Shepard
- Department of Pediatrics, School of Medicine, Emory University, Atlanta, GA
| | - Axel Roers
- Institute for Immunology, Faculty of Medicine, Technical University Dresden, Dresden, Germany
| | - Rayk Behrendt
- Institute for Immunology, Faculty of Medicine, Technical University Dresden, Dresden, Germany
| | - Li Wu
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, IA; and
| | - Baek Kim
- Department of Pediatrics, School of Medicine, Emory University, Atlanta, GA.,Center for Drug Discovery, Children's Healthcare of Atlanta, Atlanta, GA
| | - Mario L Santiago
- Department of Medicine, University of Colorado School of Medicine, Aurora, CO; .,Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO
| |
Collapse
|
19
|
Mohamed A, Bakir T, Al-Hawel H, Al-Sharif I, Bakheet R, Kouser L, Murugaiah V, Al-Mozaini M. HIV-2 Vpx neutralizes host restriction factor SAMHD1 to promote viral pathogenesis. Sci Rep 2021; 11:20984. [PMID: 34697376 PMCID: PMC8545964 DOI: 10.1038/s41598-021-00415-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Accepted: 10/12/2021] [Indexed: 11/21/2022] Open
Abstract
SAMHD1, a human host factor found in myeloid cells which restricts HIV-1 replication. It depletes the dNTPs pool for viral cDNA syntheses, thus preventing the viral replication in the cells. The viral accessory protein, Vpx, exists only in SIVmac/HIV-2 particles. Vpx in SIVmac can induce proteosomal degradation of SAMHD1, which then leads to a decrease in the cytoplasmic dNTP pool. The protein-protein interaction between Vpx and SAMHD1 and its consequences are still unclear. Methods: In this study, we cloned, for the first time, Vpx gene from a HIV-2 infected patient and found up to 30% sequence variation compared to known HIV-2 strains. We then analyzed the role of SAMHD1 protein expression in transfected THP-1 and U937 cells by transfecting with the Vpx gene derived from SIVmac, HIV-2 from the NIH sample as well as HIV-2 from a Saudi patient. We found that Vpx gene expression led to reduced levels of intracellular SAMHD1. When the supernatants of the transfected cell lines were examined for secreted cytokines, chemokines and growth factors, Vpx expression seemed to be suppressive of pro-inflammatory response, and skewed the immune response towards an anti-inflammatory response. These results suggest that Vpx can act at two levels: clearance of intracellular restriction factor and suppression of cytokine storm: both aimed at long-term latency and host-pathogen stand-off, suggesting that Vpx is likely to be a potential therapeutic target.
Collapse
Affiliation(s)
- Ahlam Mohamed
- Immunocompromised Host Research Section, Department of Infection and Immunity, King Faisal Specialist Hospital and Research Centre, PO Box 3354 (MBC-03), Riyadh, 11211, Kingdom of Saudi Arabia
| | - Talal Bakir
- Department of Clinical Laboratories Sciences, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia
| | - Huda Al-Hawel
- Immunocompromised Host Research Section, Department of Infection and Immunity, King Faisal Specialist Hospital and Research Centre, PO Box 3354 (MBC-03), Riyadh, 11211, Kingdom of Saudi Arabia
| | - Ibtihaj Al-Sharif
- Immunocompromised Host Research Section, Department of Infection and Immunity, King Faisal Specialist Hospital and Research Centre, PO Box 3354 (MBC-03), Riyadh, 11211, Kingdom of Saudi Arabia
| | - Razan Bakheet
- Immunocompromised Host Research Section, Department of Infection and Immunity, King Faisal Specialist Hospital and Research Centre, PO Box 3354 (MBC-03), Riyadh, 11211, Kingdom of Saudi Arabia
| | | | - Valarmathy Murugaiah
- Biosciences, College of Health, Medicine and Life Sciences, Brunel University London, London, UK
| | - Maha Al-Mozaini
- Immunocompromised Host Research Section, Department of Infection and Immunity, King Faisal Specialist Hospital and Research Centre, PO Box 3354 (MBC-03), Riyadh, 11211, Kingdom of Saudi Arabia.
- Department of Clinical Laboratories Sciences, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia.
| |
Collapse
|
20
|
Zhao X, Zhao Y, Du J, Gao P, Zhao K. The Interplay Among HIV, LINE-1, and the Interferon Signaling System. Front Immunol 2021; 12:732775. [PMID: 34566998 PMCID: PMC8459832 DOI: 10.3389/fimmu.2021.732775] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 08/20/2021] [Indexed: 12/17/2022] Open
Abstract
Human immunodeficiency viruses (HIVs) are retroviruses that replicate effectively in human CD4+ cells and cause the development of acquired immune deficiency syndrome (AIDS). On the other hand, type 1 long interspersed elements (LINE-1s or L1s) are the only active retroelements that can replicate autonomously in human cells. They, along with other active yet nonautonomous retroelements, have been associated with autoimmune diseases. There are many similarities between HIV and LINE-1. Being derived (or evolved) from ancient retroviruses, both HIV and LINE-1 replicate through a process termed reverse transcription, activate endogenous DNA and RNA sensors, trigger innate immune activation to promote interferon (IFN) expression, and are suppressed by protein products of interferon-stimulated genes (ISGs). However, these similarities make it difficult to decipher or even speculate the relationship between HIV and LINE-1, especially regarding the involvement of the IFN signaling system. In this review, we summarize previous findings on the relationships between HIV and innate immune activation as well as between LINE-1 and IFN upregulation. We also attempt to elucidate the interplay among HIV, LINE-1, and the IFN signaling system in hopes of guiding future research directions for viral suppression and immune regulation.
Collapse
Affiliation(s)
- Xu Zhao
- Institute of Virology and AIDS Research, First Hospital of Jilin University, Changchun, China.,Department of Hepatology, First Hospital of Jilin University, Changchun, China
| | - Yifei Zhao
- Institute of Virology and AIDS Research, First Hospital of Jilin University, Changchun, China
| | - Juan Du
- Institute of Virology and AIDS Research, First Hospital of Jilin University, Changchun, China.,Key Laboratory of Organ Regeneration & Transplantation of the Ministry of Education, First Hospital of Jilin University, Changchun, China
| | - Pujun Gao
- Department of Hepatology, First Hospital of Jilin University, Changchun, China
| | - Ke Zhao
- Institute of Virology and AIDS Research, First Hospital of Jilin University, Changchun, China.,Key Laboratory of Organ Regeneration & Transplantation of the Ministry of Education, First Hospital of Jilin University, Changchun, China
| |
Collapse
|
21
|
Banchenko S, Krupp F, Gotthold C, Bürger J, Graziadei A, O’Reilly FJ, Sinn L, Ruda O, Rappsilber J, Spahn CMT, Mielke T, Taylor IA, Schwefel D. Structural insights into Cullin4-RING ubiquitin ligase remodelling by Vpr from simian immunodeficiency viruses. PLoS Pathog 2021; 17:e1009775. [PMID: 34339457 PMCID: PMC8360603 DOI: 10.1371/journal.ppat.1009775] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 08/12/2021] [Accepted: 07/02/2021] [Indexed: 12/21/2022] Open
Abstract
Viruses have evolved means to manipulate the host's ubiquitin-proteasome system, in order to down-regulate antiviral host factors. The Vpx/Vpr family of lentiviral accessory proteins usurp the substrate receptor DCAF1 of host Cullin4-RING ligases (CRL4), a family of modular ubiquitin ligases involved in DNA replication, DNA repair and cell cycle regulation. CRL4DCAF1 specificity modulation by Vpx and Vpr from certain simian immunodeficiency viruses (SIV) leads to recruitment, poly-ubiquitylation and subsequent proteasomal degradation of the host restriction factor SAMHD1, resulting in enhanced virus replication in differentiated cells. To unravel the mechanism of SIV Vpr-induced SAMHD1 ubiquitylation, we conducted integrative biochemical and structural analyses of the Vpr protein from SIVs infecting Cercopithecus cephus (SIVmus). X-ray crystallography reveals commonalities between SIVmus Vpr and other members of the Vpx/Vpr family with regard to DCAF1 interaction, while cryo-electron microscopy and cross-linking mass spectrometry highlight a divergent molecular mechanism of SAMHD1 recruitment. In addition, these studies demonstrate how SIVmus Vpr exploits the dynamic architecture of the multi-subunit CRL4DCAF1 assembly to optimise SAMHD1 ubiquitylation. Together, the present work provides detailed molecular insight into variability and species-specificity of the evolutionary arms race between host SAMHD1 restriction and lentiviral counteraction through Vpx/Vpr proteins.
Collapse
Affiliation(s)
- Sofia Banchenko
- Charité–Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Medical Physics and Biophysics, Berlin, Germany
| | - Ferdinand Krupp
- Charité–Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Medical Physics and Biophysics, Berlin, Germany
| | - Christine Gotthold
- Charité–Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Medical Physics and Biophysics, Berlin, Germany
| | - Jörg Bürger
- Charité–Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Medical Physics and Biophysics, Berlin, Germany
- Microscopy and Cryo-Electron Microscopy Service Group, Max-Planck-Institute for Molecular Genetics, Berlin, Germany
| | - Andrea Graziadei
- Bioanalytics Unit, Institute of Biotechnology, Technische Universität Berlin, Berlin, Germany
| | - Francis J. O’Reilly
- Bioanalytics Unit, Institute of Biotechnology, Technische Universität Berlin, Berlin, Germany
| | - Ludwig Sinn
- Bioanalytics Unit, Institute of Biotechnology, Technische Universität Berlin, Berlin, Germany
| | - Olga Ruda
- Charité–Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Medical Physics and Biophysics, Berlin, Germany
| | - Juri Rappsilber
- Bioanalytics Unit, Institute of Biotechnology, Technische Universität Berlin, Berlin, Germany
- Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
| | - Christian M. T. Spahn
- Charité–Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Medical Physics and Biophysics, Berlin, Germany
| | - Thorsten Mielke
- Microscopy and Cryo-Electron Microscopy Service Group, Max-Planck-Institute for Molecular Genetics, Berlin, Germany
| | - Ian A. Taylor
- Macromolecular Structure Laboratory, The Francis Crick Institute, London, United Kingdom
| | - David Schwefel
- Charité–Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Medical Physics and Biophysics, Berlin, Germany
| |
Collapse
|
22
|
Wang C, Meng L, Wang J, Zhang K, Duan S, Ren P, Wei Y, Fu X, Yu B, Wu J, Yu X. Role of Intracellular Distribution of Feline and Bovine SAMHD1 Proteins in Lentiviral Restriction. Virol Sin 2021; 36:981-996. [PMID: 33751400 DOI: 10.1007/s12250-021-00351-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 12/28/2020] [Indexed: 11/28/2022] Open
Abstract
Human SAMHD1 (hSAM) restricts lentiviruses at the reverse transcription step through its dNTP triphosphohydrolase (dNTPase) activity. Besides humans, several mammalian species such as cats and cows that carry their own lentiviruses also express SAMHD1. However, the intracellular distribution of feline and bovine SAMHD1 (fSAM and bSAM) and its significance in their lentiviral restriction function is not known. Here, we demonstrated that fSAM and bSAM were both predominantly localized to the nucleus and nuclear localization signal (11KRPR14)-deleted fSAM and bSAM relocalized to the cytoplasm. Both cytoplasmic fSAM and bSAM retained the antiviral function against different lentiviruses and cytoplasmic fSAM could restrict Vpx-encoding SIV and HIV-2 more efficiently than its wild-type (WT) protein as cytoplasmic hSAM. Further investigation revealed that cytoplasmic fSAM was resistant to Vpx-induced degradation like cytoplasmic hSAM, while cytoplasmic bSAM was not, but they all demonstrated the same in vitro dNTPase activity and all could interact with Vpx as their WT proteins, indicating that cytoplasmic hSAM and fSAM can suppress more SIV and HIV-2 by being less sensitive to Vpx-mediated degradation. Our results suggested that fSAM- and bSAM-mediated lentiviral restriction does not require their nuclear localization and that fSAM shares more common features with hSAM. These findings may provide insights for the establishment of alternative animal models to study SAMHD1 in vivo.
Collapse
Affiliation(s)
- Chu Wang
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, 130012, China.,The First Hospital and Institute of Immunology, Jilin University, Changchun, 130012, China
| | - Lina Meng
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, 130012, China
| | - Jialin Wang
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, 130012, China
| | - Kaikai Zhang
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, 130012, China
| | - Sizhu Duan
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, 130012, China
| | - Pengyu Ren
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, 130012, China
| | - Yingzhe Wei
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, 130012, China
| | - Xinyu Fu
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, 130012, China
| | - Bin Yu
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, 130012, China.,Key Laboratory for Molecular Enzymology and Engineering, the Ministry of Education, School of Life Sciences, Jilin University, Changchun, 130012, China
| | - Jiaxin Wu
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, 130012, China. .,Key Laboratory for Molecular Enzymology and Engineering, the Ministry of Education, School of Life Sciences, Jilin University, Changchun, 130012, China.
| | - Xianghui Yu
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, 130012, China. .,Key Laboratory for Molecular Enzymology and Engineering, the Ministry of Education, School of Life Sciences, Jilin University, Changchun, 130012, China.
| |
Collapse
|
23
|
Counsell JR, De Brabandere G, Karda R, Moore M, Greco A, Bray A, Diaz JA, Perocheau DP, Mock U, Waddington SN. Re-structuring lentiviral vectors to express genomic RNA via cap-dependent translation. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2021; 20:357-365. [PMID: 33553484 PMCID: PMC7838728 DOI: 10.1016/j.omtm.2020.12.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 12/01/2020] [Indexed: 11/28/2022]
Abstract
Lentiviral (LV) vectors based on human immunodeficiency virus type I (HIV-1) package two copies of their single-stranded RNA into vector particles. Normally, this RNA genome is reverse transcribed into a double-stranded DNA provirus that integrates into the cell genome, providing permanent gene transfer and long-term expression. Integration-deficient LV vectors have been developed to reduce the frequency of genomic integration and thereby limit their persistence in dividing cells. Here, we describe optimization of a reverse-transcriptase-deficient LV vector, which enables direct translation of LV RNA genomes upon cell entry, for transient expression of vector payloads as mRNA without a DNA intermediate. We have engineered a novel LV genome arrangement in which HIV-1 sequences are removed from the 5' end, to enable ribosomal entry from the 5' 7-methylguanylate cap for efficient translation of the vector payload. We have shown that this LV-mediated mRNA delivery platform provides transient transgene expression in vitro and in vivo. This has a potential application in gene and cell therapy scenarios requiring temporary payload expression in cells and tissues that can be targeted with pseudotyped LV vectors.
Collapse
Affiliation(s)
- John R Counsell
- Dubowitz Neuromuscular Centre, Molecular Neurosciences Section, Developmental Neurosciences Programme, UCL Great Ormond Street Institute of Child Health, 30 Guilford Street, London, UK.,NIHR Great Ormond Street Hospital Biomedical Research Centre, 30 Guilford Street, London WC1N 1EH, UK
| | - Guillaume De Brabandere
- Dubowitz Neuromuscular Centre, Molecular Neurosciences Section, Developmental Neurosciences Programme, UCL Great Ormond Street Institute of Child Health, 30 Guilford Street, London, UK.,NIHR Great Ormond Street Hospital Biomedical Research Centre, 30 Guilford Street, London WC1N 1EH, UK
| | - Rajvinder Karda
- Gene Transfer Technology Group, Institute for Women's Health, University College London, 86-96 Chenies Mews, London, UK
| | - Marc Moore
- Dubowitz Neuromuscular Centre, Molecular Neurosciences Section, Developmental Neurosciences Programme, UCL Great Ormond Street Institute of Child Health, 30 Guilford Street, London, UK.,NIHR Great Ormond Street Hospital Biomedical Research Centre, 30 Guilford Street, London WC1N 1EH, UK
| | - Antonio Greco
- Dubowitz Neuromuscular Centre, Molecular Neurosciences Section, Developmental Neurosciences Programme, UCL Great Ormond Street Institute of Child Health, 30 Guilford Street, London, UK.,NIHR Great Ormond Street Hospital Biomedical Research Centre, 30 Guilford Street, London WC1N 1EH, UK
| | - Alysha Bray
- Dubowitz Neuromuscular Centre, Molecular Neurosciences Section, Developmental Neurosciences Programme, UCL Great Ormond Street Institute of Child Health, 30 Guilford Street, London, UK.,NIHR Great Ormond Street Hospital Biomedical Research Centre, 30 Guilford Street, London WC1N 1EH, UK
| | - Juan Antinao Diaz
- Gene Transfer Technology Group, Institute for Women's Health, University College London, 86-96 Chenies Mews, London, UK
| | - Dany P Perocheau
- Gene Transfer Technology Group, Institute for Women's Health, University College London, 86-96 Chenies Mews, London, UK
| | - Ulrike Mock
- NIHR Great Ormond Street Hospital Biomedical Research Centre, 30 Guilford Street, London WC1N 1EH, UK
| | - Simon N Waddington
- Gene Transfer Technology Group, Institute for Women's Health, University College London, 86-96 Chenies Mews, London, UK.,MRC Antiviral Gene Therapy Research Unit, Faculty of Health Sciences, University of the Witswatersrand, Johannesburg, South Africa
| |
Collapse
|
24
|
Abstract
Exogenous retroviruses are RNA viruses that require reverse transcription for their replication. Among these viruses, human immunodeficiency virus (HIV) is infectious to humans and causes the development of acquired immune deficiency syndrome (AIDS). There are also endogenous retroelements that require reverse transcription for their retrotransposition, among which the type 1 long interspersed element (LINE-1) is the only type of retroelement that can replicate autonomously. It was once believed that retroviruses like HIV and retroelements like LINE-1 share similarities in processes such as reverse transcription and integration. Accordingly, many HIV suppressors are also potent LINE-1 inhibitors. However, in many cases, one suppressor uses two or more distinct mechanisms to repress HIV and LINE-1. In this review, we discuss some of these suppressors, focusing on their alternative mechanisms opposing the replication of HIV and LINE-1. Based on the differences in HIV and LINE-1 activity, the subcellular localization of these suppressors, and the impact of LINE-1 retrotransposition on human cells, we propose possible reasons for the inhibition of HIV and LINE-1 through different pathways by these suppressors, with the hope of accelerating future studies in associated research fields.
Collapse
Affiliation(s)
- Juan Du
- Institute of Virology and AIDS Research, First Hospital of Jilin University, Changchun, China.,Key Laboratory of Organ Regeneration & Transplantation of the Ministry of Education, First Hospital of Jilin University, Changchun, China
| | - Ke Zhao
- Institute of Virology and AIDS Research, First Hospital of Jilin University, Changchun, China.,Key Laboratory of Organ Regeneration & Transplantation of the Ministry of Education, First Hospital of Jilin University, Changchun, China
| |
Collapse
|
25
|
TRAF6 and TAK1 Contribute to SAMHD1-Mediated Negative Regulation of NF-κB Signaling. J Virol 2021; 95:JVI.01970-20. [PMID: 33177202 PMCID: PMC7925110 DOI: 10.1128/jvi.01970-20] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 11/04/2020] [Indexed: 02/07/2023] Open
Abstract
Sterile alpha motif and HD domain-containing protein 1 (SAMHD1) restricts HIV-1 replication by limiting the intracellular deoxynucleoside triphosphate (dNTP) pool. SAMHD1 also suppresses the activation of NF-κB in response to viral infections and inflammatory stimuli. However, the mechanisms by which SAMHD1 negatively regulates this pathway remain unclear. Here, we show that SAMHD1-mediated suppression of NF-κB activation is modulated by two key mediators of NF-κB signaling, tumor necrosis factor (TNF) receptor-associated factor 6 (TRAF6) and transforming growth factor β-activated kinase 1 (TAK1). We compared NF-κB activation stimulated by interleukin (IL)-1β in monocytic THP-1 control and SAMHD1 knockout (KO) cells with and without partial TRAF6 knockdown (KD), or in cells treated with TAK1 inhibitors. Relative to control cells, IL-1β-treated SAMHD1 KO cells showed increased phosphorylation of the inhibitor of NF-κB (IκBα), an indication of pathway activation, and elevated levels of TNF-α mRNA. Moreover, SAMHD1 KO combined with TRAF6 KD or pharmacological TAK1 inhibition reduced IκBα phosphorylation and TNF-α mRNA to the level of control cells. SAMHD1 KO cells infected with single-cycle HIV-1 showed elevated infection and TNF-α mRNA levels compared to control cells, and the effects were significantly reduced by TRAF6 KD or TAK1 inhibition. We further demonstrated that overexpressed SAMHD1 inhibited TRAF6-stimulated NF-κB reporter activity in HEK293T cells in a dose-dependent manner. SAMHD1 contains a nuclear localization signal (NLS), but an NLS-defective SAMHD1 exhibited a suppressive effect similar to the wild-type protein. Our data suggest that the TRAF6-TAK1 axis contributes to SAMHD1-mediated suppression of NF-κB activation and HIV-1 infection.IMPORTANCE Cells respond to pathogen infection by activating a complex innate immune signaling pathway, which culminates in the activation of transcription factors and secretion of a family of functionally and genetically related cytokines. However, excessive immune activation may cause tissue damage and detrimental effects on the host. Therefore, in order to maintain host homeostasis, the innate immune response is tightly regulated during viral infection. We have reported SAMHD1 as a novel negative regulator of the innate immune response. Here, we provide new insights into SAMHD1-mediated negative regulation of the NF-κB pathway at the TRAF6-TAK1 checkpoint. We show that SAMHD1 inhibits TAK1 activation and TRAF6 signaling in response to proinflammatory stimuli. Interestingly, TRAF6 knockdown in SAMHD1-deficient cells significantly inhibited HIV-1 infection and activation of NF-κB induced by virus infection. Our research reveals a new negative regulatory mechanism by which SAMHD1 participates in the maintenance of cellular homeostasis during HIV-1 infection and inflammation.
Collapse
|
26
|
Kim ET, Roche KL, Kulej K, Spruce LA, Seeholzer SH, Coen DM, Diaz-Griffero F, Murphy EA, Weitzman MD. SAMHD1 Modulates Early Steps during Human Cytomegalovirus Infection by Limiting NF-κB Activation. Cell Rep 2020; 28:434-448.e6. [PMID: 31291579 DOI: 10.1016/j.celrep.2019.06.027] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 03/22/2019] [Accepted: 06/05/2019] [Indexed: 12/14/2022] Open
Abstract
Cellular SAMHD1 inhibits replication of many viruses by limiting intracellular deoxynucleoside triphosphate (dNTP) pools. We investigate the influence of SAMHD1 on human cytomegalovirus (HCMV). During HCMV infection, we observe SAMHD1 induction, accompanied by phosphorylation via viral kinase UL97. SAMHD1 depletion increases HCMV replication in permissive fibroblasts and conditionally permissive myeloid cells. We show this is due to enhanced gene expression from the major immediate-early (MIE) promoter and is independent of dNTP levels. SAMHD1 suppresses innate immune responses by inhibiting nuclear factor κB (NF-κB) activation. We show that SAMHD1 regulates the HCMV MIE promoter through NF-κB activation. Chromatin immunoprecipitation reveals increased RELA and RNA polymerase II on the HCMV MIE promoter in the absence of SAMHD1. Our studies reveal a mechanism of HCMV virus restriction by SAMHD1 and show how SAMHD1 deficiency activates an innate immune pathway that paradoxically results in increased viral replication through transcriptional activation of the HCMV MIE gene promoter.
Collapse
Affiliation(s)
- Eui Tae Kim
- Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA; Division of Protective Immunity and Division of Cancer Pathobiology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Kathryn L Roche
- Department of Translational Medicine, Baruch S. Blumberg Research Institute, Doylestown, PA 18902, USA; Evrys Bio, Pennsylvania Biotechnology Center, Doylestown, PA 18902, USA
| | - Katarzyna Kulej
- Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA; Division of Protective Immunity and Division of Cancer Pathobiology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Lynn A Spruce
- Protein and Proteomics Core, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Steven H Seeholzer
- Protein and Proteomics Core, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Donald M Coen
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
| | - Felipe Diaz-Griffero
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Eain A Murphy
- Department of Translational Medicine, Baruch S. Blumberg Research Institute, Doylestown, PA 18902, USA; Evrys Bio, Pennsylvania Biotechnology Center, Doylestown, PA 18902, USA
| | - Matthew D Weitzman
- Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA; Division of Protective Immunity and Division of Cancer Pathobiology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA.
| |
Collapse
|
27
|
de Lara LM, Parthasarathy RS, Rodriguez-Garcia M. Mucosal Immunity and HIV Acquisition in Women. CURRENT OPINION IN PHYSIOLOGY 2020; 19:32-38. [PMID: 33103019 DOI: 10.1016/j.cophys.2020.07.021] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Women acquire HIV through sexual transmission. Women worldwide represent half of the people living with HIV, but young women in endemic areas are disproportionally affected. Low transmission rates per sexual act in women suggest that local immune protective mechanisms in the genital tract have the potential to prevent infection. However, conditions that induce genital inflammation are known to increase the risk of HIV acquisition. The female genital tract (FGT) is divided into different anatomical compartments with distinct reproductive functions. The immune cells present in each of these compartments are specialized in balancing reproduction and protection against infections, and are the same cells that can encounter and respond to HIV. Understanding the physiological and pathological factors that influence mucosal immune cell presence, susceptibility to HIV-infection and anti-HIV immune responses in the FGT is necessary to develop preventive strategies. Here we review recent advances in our understanding of HIV infection in the human female genital tract, with an emphasis on the characterization of the mucosal cells susceptible to HIV-infection, innate immune responses and mucosal factors that increase genital inflammation and influence susceptibility to HIV acquisition in women.
Collapse
Affiliation(s)
- Laura Moreno de Lara
- Department of Immunology, Tufts University School of Medicine, Boston, MA.,Immunology Unit, Biomedical Research Centre (CIBM), University of Granada, Granada, Spain
| | - Ragav S Parthasarathy
- Department of Immunology, Tufts University School of Medicine, Boston, MA.,Immunology Program, Tufts Graduate School of Biomedical Sciences, Boston, MA, USA
| | - Marta Rodriguez-Garcia
- Department of Immunology, Tufts University School of Medicine, Boston, MA.,Immunology Program, Tufts Graduate School of Biomedical Sciences, Boston, MA, USA
| |
Collapse
|
28
|
Morris ER, Caswell SJ, Kunzelmann S, Arnold LH, Purkiss AG, Kelly G, Taylor IA. Crystal structures of SAMHD1 inhibitor complexes reveal the mechanism of water-mediated dNTP hydrolysis. Nat Commun 2020; 11:3165. [PMID: 32576829 PMCID: PMC7311409 DOI: 10.1038/s41467-020-16983-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 06/03/2020] [Indexed: 12/29/2022] Open
Abstract
SAMHD1 regulates cellular 2'-deoxynucleoside-5'-triphosphate (dNTP) homeostasis by catalysing the hydrolysis of dNTPs into 2'-deoxynucleosides and triphosphate. In CD4+ myeloid lineage and resting T-cells, SAMHD1 blocks HIV-1 and other viral infections by depletion of the dNTP pool to a level that cannot support replication. SAMHD1 mutations are associated with the autoimmune disease Aicardi-Goutières syndrome and hypermutated cancers. Furthermore, SAMHD1 sensitises cancer cells to nucleoside-analogue anti-cancer therapies and is linked with DNA repair and suppression of the interferon response to cytosolic nucleic acids. Nevertheless, despite its requirement in these processes, the fundamental mechanism of SAMHD1-catalysed dNTP hydrolysis remained unknown. Here, we present structural and enzymological data showing that SAMHD1 utilises an active site, bi-metallic iron-magnesium centre that positions a hydroxide nucleophile in-line with the Pα-O5' bond to catalyse phosphoester bond hydrolysis. This precise molecular mechanism for SAMHD1 catalysis, reveals how SAMHD1 down-regulates cellular dNTP and modulates the efficacy of nucleoside-based anti-cancer and anti-viral therapies.
Collapse
Affiliation(s)
- Elizabeth R Morris
- Macromolecular Structure Laboratory, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
| | - Sarah J Caswell
- Macromolecular Structure Laboratory, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK.,AstraZeneca, 50F49, Mereside, Alderley Park, Macclesfield, Cheshire, SK10 4TG, UK
| | - Simone Kunzelmann
- Structural Biology Science Technology Platform, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
| | - Laurence H Arnold
- Macromolecular Structure Laboratory, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK.,Pelago Bioscience, Banvaktsvägen 20, 171 48, Solna, Sweden
| | - Andrew G Purkiss
- Structural Biology Science Technology Platform, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
| | - Geoff Kelly
- The Medical Research Council Biomedical NMR Centre, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
| | - Ian A Taylor
- Macromolecular Structure Laboratory, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK.
| |
Collapse
|
29
|
Activating the DNA Damage Response and Suppressing Innate Immunity: Human Papillomaviruses Walk the Line. Pathogens 2020; 9:pathogens9060467. [PMID: 32545729 PMCID: PMC7350329 DOI: 10.3390/pathogens9060467] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 06/08/2020] [Accepted: 06/10/2020] [Indexed: 12/25/2022] Open
Abstract
Activation of the DNA damage response (DDR) by external agents can result in DNA fragments entering the cytoplasm and activating innate immune signaling pathways, including the stimulator of interferon genes (STING) pathway. The consequences of this activation can result in alterations in the cell cycle including the induction of cellular senescence, as well as boost the adaptive immune response following interferon production. Human papillomaviruses (HPV) are the causative agents in a host of human cancers including cervical and oropharyngeal; HPV are responsible for around 5% of all cancers. During infection, HPV replication activates the DDR in order to promote the viral life cycle. A striking feature of HPV-infected cells is their ability to continue to proliferate in the presence of an active DDR. Simultaneously, HPV suppress the innate immune response using a number of different mechanisms. The activation of the DDR and suppression of the innate immune response are essential for the progression of the viral life cycle. Here, we describe the mechanisms HPV use to turn on the DDR, while simultaneously suppressing the innate immune response. Pushing HPV from this fine line and tipping the balance towards activation of the innate immune response would be therapeutically beneficial.
Collapse
|
30
|
Valverde-Estrella L, López-Serrat M, Sánchez-Sànchez G, Vico T, Lloberas J, Celada A. Induction of Samhd1 by interferon gamma and lipopolysaccharide in murine macrophages requires IRF1. Eur J Immunol 2020; 50:1321-1334. [PMID: 32270872 DOI: 10.1002/eji.201948491] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 03/02/2020] [Accepted: 04/06/2020] [Indexed: 12/11/2022]
Abstract
SAMHD1 is an enzyme with phosphohydrolase activity. Mutations in SAMHD1 have been linked to the development of Aicardi-Goutières syndrome in humans. This enzyme also has the capacity to restrict HIV virus replication in macrophages. Here, we report that Samhd1 is highly expressed in murine macrophages and is regulated by proinflammatory (IFN-γ and LPS) but not by anti-inflammatory (IL-4 or IL-10) activators. The induction of Samhd1 follows the pattern of an intermediate gene that requires protein synthesis. In transient transfection experiments using the Samhd1 promoter, we found that a fragment of 27 bps of this gene, falling between -937 and -910 bps relative to the transcription start site, is required for IFN-γ-dependent activation. Using EMSAs, we determined that IFN-γ treatment led to the elimination of a protein complex. Chromatin immunoprecipitation assays and siRNA experiments revealed that IRF1 is required for IFN-γ- or LPS-induced Samhd1 expression. Therefore, our results indicate that Samhd1 is stimulated by proinflammatory agents IFN-γ and LPS. Moreover, they reveal that these two agents, via IRF1, eliminate a protein complex that may be related to a repressor, thereby, triggering Samhd1 expression.
Collapse
Affiliation(s)
- Lorena Valverde-Estrella
- Macrophage Biology Group, Department of Cellular Biology, Physiology and Immunology, Universitat de Barcelona, Barcelona, Spain
| | - Martí López-Serrat
- Macrophage Biology Group, Department of Cellular Biology, Physiology and Immunology, Universitat de Barcelona, Barcelona, Spain
| | - Guillem Sánchez-Sànchez
- Macrophage Biology Group, Department of Cellular Biology, Physiology and Immunology, Universitat de Barcelona, Barcelona, Spain
| | - Tania Vico
- Macrophage Biology Group, Department of Cellular Biology, Physiology and Immunology, Universitat de Barcelona, Barcelona, Spain
| | - Jorge Lloberas
- Macrophage Biology Group, Department of Cellular Biology, Physiology and Immunology, Universitat de Barcelona, Barcelona, Spain
| | - Antonio Celada
- Macrophage Biology Group, Department of Cellular Biology, Physiology and Immunology, Universitat de Barcelona, Barcelona, Spain
| |
Collapse
|
31
|
SAMHD1 Functions and Human Diseases. Viruses 2020; 12:v12040382. [PMID: 32244340 PMCID: PMC7232136 DOI: 10.3390/v12040382] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 03/27/2020] [Accepted: 03/28/2020] [Indexed: 12/12/2022] Open
Abstract
Deoxynucleoside triphosphate (dNTP) molecules are essential for the replication and maintenance of genomic information in both cells and a variety of viral pathogens. While the process of dNTP biosynthesis by cellular enzymes, such as ribonucleotide reductase (RNR) and thymidine kinase (TK), has been extensively investigated, a negative regulatory mechanism of dNTP pools was recently found to involve sterile alpha motif (SAM) domain and histidine-aspartate (HD) domain-containing protein 1, SAMHD1. When active, dNTP triphosphohydrolase activity of SAMHD1 degrades dNTPs into their 2'-deoxynucleoside (dN) and triphosphate subparts, steadily depleting intercellular dNTP pools. The differential expression levels and activation states of SAMHD1 in various cell types contributes to unique dNTP pools that either aid (i.e., dividing T cells) or restrict (i.e., nondividing macrophages) viral replication that consumes cellular dNTPs. Genetic mutations in SAMHD1 induce a rare inflammatory encephalopathy called Aicardi-Goutières syndrome (AGS), which phenotypically resembles viral infection. Recent publications have identified diverse roles for SAMHD1 in double-stranded break repair, genome stability, and the replication stress response through interferon signaling. Finally, a series of SAMHD1 mutations were also reported in various cancer cell types while why SAMHD1 is mutated in these cancer cells remains to investigated. Here, we reviewed a series of studies that have begun illuminating the highly diverse roles of SAMHD1 in virology, immunology, and cancer biology.
Collapse
|
32
|
Wang C, Zhang K, Meng L, Zhang X, Song Y, Zhang Y, Gai Y, Zhang Y, Yu B, Wu J, Wang S, Yu X. The C-terminal domain of feline and bovine SAMHD1 proteins has a crucial role in lentiviral restriction. J Biol Chem 2020; 295:4252-4264. [PMID: 32075911 PMCID: PMC7105322 DOI: 10.1074/jbc.ra120.012767] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 02/14/2020] [Indexed: 01/29/2023] Open
Abstract
SAM and HD domain-containing protein 1 (SAMHD1) is a host factor that restricts reverse transcription of lentiviruses such as HIV in myeloid cells and resting T cells through its dNTP triphosphohydrolase (dNTPase) activity. Lentiviruses counteract this restriction by expressing the accessory protein Vpx or Vpr, which targets SAMHD1 for proteasomal degradation. SAMHD1 is conserved among mammals, and the feline and bovine SAMHD1 proteins (fSAM and bSAM) restrict lentiviruses by reducing cellular dNTP concentrations. However, the functional regions of fSAM and bSAM that are required for their biological functions are not well-characterized. Here, to establish alternative models to investigate SAMHD1 in vivo, we studied the restriction profile of fSAM and bSAM against different primate lentiviruses. We found that both fSAM and bSAM strongly restrict primate lentiviruses and that Vpx induces the proteasomal degradation of both fSAM and bSAM. Further investigation identified one and five amino acid sites in the C-terminal domain (CTD) of fSAM and bSAM, respectively, that are required for Vpx-mediated degradation. We also found that the CTD of bSAM is directly involved in mediating bSAM's antiviral activity by regulating dNTPase activity, whereas the CTD of fSAM is not. Our results suggest that the CTDs of fSAM and bSAM have important roles in their antiviral functions. These findings advance our understanding of the mechanism of fSAM- and bSAM-mediated viral restriction and might inform strategies for improving HIV animal models.
Collapse
Affiliation(s)
- Chu Wang
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun 130012, China; The First Hospital and Institute of Immunology, Jilin University, Changchun 130012, China
| | - Kaikai Zhang
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun 130012, China
| | - Lina Meng
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun 130012, China
| | - Xin Zhang
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun 130012, China
| | - Yanan Song
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun 130012, China
| | - Ying Zhang
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun 130012, China
| | - Yanxin Gai
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun 130012, China
| | - Yuepeng Zhang
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun 130012, China
| | - Bin Yu
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun 130012, China; Key Laboratory for Molecular Enzymology and Engineering, the Ministry of Education, School of Life Sciences, Jilin University, Changchun 130012, China
| | - Jiaxin Wu
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun 130012, China; Key Laboratory for Molecular Enzymology and Engineering, the Ministry of Education, School of Life Sciences, Jilin University, Changchun 130012, China
| | - Song Wang
- Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130012, China
| | - Xianghui Yu
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun 130012, China; Key Laboratory for Molecular Enzymology and Engineering, the Ministry of Education, School of Life Sciences, Jilin University, Changchun 130012, China.
| |
Collapse
|
33
|
Qin Z, Bonifati S, St Gelais C, Li TW, Kim SH, Antonucci JM, Mahboubi B, Yount JS, Xiong Y, Kim B, Wu L. The dNTPase activity of SAMHD1 is important for its suppression of innate immune responses in differentiated monocytic cells. J Biol Chem 2020; 295:1575-1586. [PMID: 31914403 PMCID: PMC7008377 DOI: 10.1074/jbc.ra119.010360] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 12/22/2019] [Indexed: 12/18/2022] Open
Abstract
Sterile alpha motif and HD domain-containing protein 1 (SAMHD1) is a deoxynucleoside triphosphohydrolase (dNTPase) with a nuclear localization signal (NLS). SAMHD1 suppresses innate immune responses to viral infection and inflammatory stimuli by inhibiting the NF-κB and type I interferon (IFN-I) pathways. However, whether the dNTPase activity and nuclear localization of SAMHD1 are required for its suppression of innate immunity remains unknown. Here, we report that the dNTPase activity, but not nuclear localization of SAMHD1, is important for its suppression of innate immune responses in differentiated monocytic cells. We generated monocytic U937 cell lines stably expressing WT SAMHD1 or mutated variants defective in dNTPase activity (HD/RN) or nuclear localization (mNLS). WT SAMHD1 in differentiated U937 cells significantly inhibited lipopolysaccharide-induced expression of tumor necrosis factor α (TNF-α) and interleukin-6 (IL-6) mRNAs, as well as IFN-α, IFN-β, and TNF-α mRNA levels induced by Sendai virus infection. In contrast, the HD/RN mutant did not exhibit this inhibition in either U937 or THP-1 cells, indicating that the dNTPase activity of SAMHD1 is important for suppressing NF-κB activation. Of note, in lipopolysaccharide-treated or Sendai virus-infected U937 or THP-1 cells, the mNLS variant reduced TNF-α or IFN-β mRNA expression to a similar extent as did WT SAMHD1, suggesting that SAMHD1-mediated inhibition of innate immune responses is independent of SAMHD1's nuclear localization. Moreover, WT and mutant SAMHD1 similarly interacted with key proteins in NF-κB and IFN-I pathways in cells. This study further defines the role and mechanisms of SAMHD1 in suppressing innate immunity.
Collapse
Affiliation(s)
- Zhihua Qin
- Center for Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio 43210; Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242
| | - Serena Bonifati
- Center for Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio 43210
| | - Corine St Gelais
- Center for Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio 43210
| | - Tai-Wei Li
- Center for Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio 43210
| | - Sun-Hee Kim
- Center for Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio 43210
| | - Jenna M Antonucci
- Center for Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio 43210
| | - Bijan Mahboubi
- Center for Drug Discovery, Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia 30322
| | - Jacob S Yount
- Department of Microbial Infection and Immunity, Infectious Diseases Institute, The Ohio State University, Columbus, Ohio 43210
| | - Yong Xiong
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520
| | - Baek Kim
- Center for Drug Discovery, Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia 30322
| | - Li Wu
- Center for Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio 43210; Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242; Department of Microbial Infection and Immunity, Infectious Diseases Institute, The Ohio State University, Columbus, Ohio 43210.
| |
Collapse
|
34
|
Regulation of HIV-1 Gag-Pol Expression by Shiftless, an Inhibitor of Programmed -1 Ribosomal Frameshifting. Cell 2019; 176:625-635.e14. [PMID: 30682371 DOI: 10.1016/j.cell.2018.12.030] [Citation(s) in RCA: 76] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 10/21/2018] [Accepted: 12/19/2018] [Indexed: 01/26/2023]
Abstract
Programmed -1 ribosomal frameshifting (-1PRF) is a widely used translation recoding mechanism. HIV-1 expresses Gag-Pol protein from the Gag-coding mRNA through -1PRF, and the ratio of Gag to Gag-Pol is strictly maintained for efficient viral replication. Here, we report that the interferon-stimulated gene product C19orf66 (herein named Shiftless) is a host factor that inhibits the -1PRF of HIV-1. Shiftless (SFL) also inhibited the -1PRF of a variety of mRNAs from both viruses and cellular genes. SFL interacted with the -1PRF signal of target mRNA and translating ribosomes and caused premature translation termination at the frameshifting site. Downregulation of translation release factor eRF3 or eRF1 reduced SFL-mediated premature translation termination. We propose that SFL binding to target mRNA and the translating ribosome interferes with the frameshifting process. These findings identify SFL as a broad-spectrum inhibitor of -1PRF and help to further elucidate the mechanisms of -1PRF.
Collapse
|
35
|
Martín-Moreno A, Muñoz-Fernández MA. Dendritic Cells, the Double Agent in the War Against HIV-1. Front Immunol 2019; 10:2485. [PMID: 31708924 PMCID: PMC6820366 DOI: 10.3389/fimmu.2019.02485] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 10/04/2019] [Indexed: 12/19/2022] Open
Abstract
Human Immunodeficiency Virus (HIV) infects cells from the immune system and has thus developed tools to circumvent the host immunity and use it in its advance. Dendritic cells (DCs) are the first immune cells to encounter the HIV, and being the main antigen (Ag) presenting cells, they link the innate and the adaptive immune responses. While DCs work to promote an efficient immune response and halt the infection, HIV-1 has ways to take advantage of their role and uses DCs to gain faster and more efficient access to CD4+ T cells. Due to their ability to activate a specific immune response, DCs are promising candidates to achieve the functional cure of HIV-1 infection, but knowing the molecular partakers that determine the relationship between virus and cell is the key for the rational and successful design of a DC-based therapy. In this review, we summarize the current state of knowledge on how both DC subsets (myeloid and plasmacytoid DCs) act in presence of HIV-1, and focus on different pathways that the virus can take after binding to DC. First, we explore the consequences of HIV-1 recognition by each receptor on DCs, including CD4 and DC-SIGN. Second, we look at cellular mechanisms that prevent productive infection and weapons that turn cellular defense into a Trojan horse that hides the virus all the way to T cell. Finally, we discuss the possible outcomes of DC-T cell contact.
Collapse
Affiliation(s)
- Alba Martín-Moreno
- Sección de Inmunología, Laboratorio InmunoBiología Molecular, Hospital General Universitario Gregorio Marañón (HGUGM), Madrid, Spain.,Instituto Investigación Sanitaria Gregorio Marañón (IiSGM), Madrid, Spain
| | - Mª Angeles Muñoz-Fernández
- Sección de Inmunología, Laboratorio InmunoBiología Molecular, Hospital General Universitario Gregorio Marañón (HGUGM), Madrid, Spain.,Instituto Investigación Sanitaria Gregorio Marañón (IiSGM), Madrid, Spain.,Spanish HIV-HGM BioBank, Madrid, Spain.,Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER BBN), Madrid, Spain
| |
Collapse
|
36
|
Interferon γ and α Have Differential Effects on SAMHD1, a Potent Antiviral Protein, in Feline Lymphocytes. Viruses 2019; 11:v11100921. [PMID: 31600877 PMCID: PMC6832628 DOI: 10.3390/v11100921] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 10/05/2019] [Accepted: 10/06/2019] [Indexed: 12/15/2022] Open
Abstract
Sterile alpha motif and histidine/aspartic domain-containing protein 1 (SAMHD1) is a protein with anti-viral, anti-neoplastic, and anti-inflammatory properties. By degrading cellular dNTPs to constituent deoxynucleoside and free triphosphate, SAMHD1 limits viral DNA synthesis and prevents replication of HIV-1 and some DNA viruses such as HBV, vaccinia, and HSV-1. Recent findings suggest SAMHD1 is broadly active against retroviruses in addition to HIV-1, such as HIV-2, FIV, BIV, and EIAV. Interferons are cytokines produced by lymphocytes and other cells that induce a wide array of antiviral proteins, including some with activity again lentiviruses. Here we evaluated the role of IFNs on SAMHD1 gene expression, transcription, and post-translational modification in a feline CD4+ T cell line (FeTJ) and in primary feline CD4+ T lymphocytes. SAMHD1 mRNA in FetJ cells increased in a dose-related manner in response to IFNγ treatment concurrent with increased nuclear localization and phosphorylation. IFNα treatment induced SAMHD1 mRNA but did not significantly alter SAMHD1 protein detection, phosphorylation, or nuclear translocation. In purified primary feline CD4+ lymphocytes, IL2 supplementation increased SAMHD1 expression, but the addition of IFNγ did not further alter SAMHD1 protein expression or nuclear localization. Thus, the effect of IFNγ on SAMHD1 expression is cell-type dependent, with increased translocation to the nucleus and phosphorylation in FeTJ but not primary CD4+ lymphocytes. These findings imply that while SAMH1 is inducible by IFNγ, overall activity is cell type and compartment specific, which is likely relevant to the establishment of lentiviral reservoirs in quiescent lymphocyte populations.
Collapse
|
37
|
Human cytomegalovirus overcomes SAMHD1 restriction in macrophages via pUL97. Nat Microbiol 2019; 4:2260-2272. [PMID: 31548682 DOI: 10.1038/s41564-019-0557-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 08/09/2019] [Indexed: 12/30/2022]
Abstract
The host restriction factor sterile alpha motif and histidine-aspartate domain-containing protein 1 (SAMHD1) is an important component of the innate immune system. By regulating the intracellular nucleotide pool, SAMHD1 influences cell division and restricts the replication of viruses that depend on high nucleotide concentrations. Human cytomegalovirus (HCMV) is a pathogenic virus with a tropism for non-dividing myeloid cells, in which SAMHD1 is catalytically active. Here we investigate how HCMV achieves efficient propagation in these cells despite the SAMHD1-mediated dNTP depletion. Our analysis reveals that SAMHD1 has the capability to suppress HCMV replication. However, HCMV has evolved potent countermeasures to circumvent this block. HCMV interferes with SAMHD1 steady-state expression and actively induces SAMHD1 phosphorylation using the viral kinase pUL97 and by hijacking cellular kinases. These actions convert SAMHD1 to its inactive phosphorylated form. This mechanism of SAMHD1 inactivation by phosphorylation might also be used by other viruses to overcome intrinsic immunity.
Collapse
|
38
|
Interplay between Intrinsic and Innate Immunity during HIV Infection. Cells 2019; 8:cells8080922. [PMID: 31426525 PMCID: PMC6721663 DOI: 10.3390/cells8080922] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 08/13/2019] [Accepted: 08/15/2019] [Indexed: 02/06/2023] Open
Abstract
Restriction factors are antiviral components of intrinsic immunity which constitute a first line of defense by blocking different steps of the human immunodeficiency virus (HIV) replication cycle. In immune cells, HIV infection is also sensed by several pattern recognition receptors (PRRs), leading to type I interferon (IFN-I) and inflammatory cytokines production that upregulate antiviral interferon-stimulated genes (ISGs). Several studies suggest a link between these two types of immunity. Indeed, restriction factors, that are generally interferon-inducible, are able to modulate immune responses. This review highlights recent knowledge of the interplay between restriction factors and immunity inducing antiviral defenses. Counteraction of this intrinsic and innate immunity by HIV viral proteins will also be discussed.
Collapse
|
39
|
SAMHD1 Regulates Human Papillomavirus 16-Induced Cell Proliferation and Viral Replication during Differentiation of Keratinocytes. mSphere 2019; 4:4/4/e00448-19. [PMID: 31391281 PMCID: PMC6686230 DOI: 10.1128/msphere.00448-19] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Human papillomaviruses induce a host of anogenital cancers, as well as oropharyngeal cancer (HPV+OPC); human papillomavirus 16 (HPV16) is causative in around 90% of HPV+OPC cases. Using telomerase reverse transcriptase (TERT) immortalized foreskin keratinocytes (N/Tert-1), we have identified significant host gene reprogramming by HPV16 (N/Tert-1+HPV16) and demonstrated that N/Tert-1+HPV16 support late stages of the viral life cycle. Expression of the cellular dNTPase and homologous recombination factor sterile alpha motif and histidine-aspartic domain HD-containing protein 1 (SAMHD1) is transcriptionally regulated by HPV16 in N/Tert-1. CRISPR/Cas9 removal of SAMHD1 from N/Tert-1 and N/Tert-1+HPV16 demonstrates that SAMHD1 controls cell proliferation of N/Tert-1 only in the presence of HPV16; the deletion of SAMHD1 promotes hyperproliferation of N/Tert-1+HPV16 cells in organotypic raft cultures but has no effect on N/Tert-1. Viral replication is also elevated in the absence of SAMHD1. This new system has allowed us to identify a specific interaction between SAMHD1 and HPV16 that regulates host cell proliferation and viral replication; such studies are problematic in nonimmortalized primary keratinocytes due to their limited life span. To confirm the relevance of our results, we repeated the analysis with human tonsil keratinocytes (HTK) immortalized by HPV16 (HTK+HPV16) and observed the same hyperproliferative phenotype following CRISPR/Cas9 editing of SAMHD1. Identical results were obtained with three independent CRISPR/Cas9 guide RNAs. The isogenic pairing of N/Tert-1 with N/Tert-1+HPV16, combined with HTK+HPV16, presents a unique system to identify host genes whose products functionally interact with HPV16 to regulate host cellular growth in keratinocytes.IMPORTANCE HPVs are causative agents in human cancers and are responsible for around of 5% of all cancers. A better understanding of the viral life cycle in keratinocytes will facilitate the development of novel therapeutics to combat HPV-positive cancers. Here, we present a unique keratinocyte model to identify host proteins that specifically interact with HPV16. Using this system, we report that a cellular gene, SAMHD1, is regulated by HPV16 at the RNA and protein levels in keratinocytes. Elimination of SAMHD1 from these cells using CRISPR/Cas9 editing promotes enhanced cellular proliferation by HPV16 in keratinocytes and elevated viral replication but not in keratinocytes that do not have HPV16. Our study demonstrates a specific intricate interplay between HPV16 and SAMHD1 during the viral life cycle and establishes a unique model system to assist exploring host factors critical for HPV pathogenesis.
Collapse
|
40
|
The missing link: allostery and catalysis in the anti-viral protein SAMHD1. Biochem Soc Trans 2019; 47:1013-1027. [PMID: 31296733 PMCID: PMC7045340 DOI: 10.1042/bst20180348] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 06/04/2019] [Accepted: 06/05/2019] [Indexed: 12/11/2022]
Abstract
Vertebrate protein SAMHD1 (sterile-α-motif and HD domain containing protein 1) regulates the cellular dNTP (2′-deoxynucleoside-5′-triphosphate) pool by catalysing the hydrolysis of dNTP into 2′-deoxynucleoside and triphosphate products. As an important regulator of cell proliferation and a key player in dNTP homeostasis, mutations to SAMHD1 are implicated in hypermutated cancers, and germline mutations are associated with Chronic Lymphocytic Leukaemia and the inflammatory disorder Aicardi–Goutières Syndrome. By limiting the supply of dNTPs for viral DNA synthesis, SAMHD1 also restricts the replication of several retroviruses, such as HIV-1, and some DNA viruses in dendritic and myeloid lineage cells and resting T-cells. SAMHD1 activity is regulated throughout the cell cycle, both at the level of protein expression and post-translationally, through phosphorylation. In addition, allosteric regulation further fine-tunes the catalytic activity of SAMHD1, with a nucleotide-activated homotetramer as the catalytically active form of the protein. In cells, GTP and dATP are the likely physiological activators of two adjacent allosteric sites, AL1 (GTP) and AL2 (dATP), that bridge monomer–monomer interfaces to stabilise the protein homotetramer. This review summarises the extensive X-ray crystallographic, biophysical and molecular dynamics experiments that have elucidated important features of allosteric regulation in SAMHD1. We present a comprehensive mechanism detailing the structural and protein dynamics components of the allosteric coupling between nucleotide-induced tetramerization and the catalysis of dNTP hydrolysis by SAMHD1.
Collapse
|
41
|
Kong J, Wang MM, He SY, Peng X, Qin XH. Structural characterization and directed modification of Sus scrofa SAMHD1 reveal the mechanism underlying deoxynucleotide regulation. FEBS J 2019; 286:3844-3857. [PMID: 31152619 DOI: 10.1111/febs.14943] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 03/12/2019] [Accepted: 05/30/2019] [Indexed: 12/12/2022]
Abstract
Sterile α-motif/histidine-aspartate domain-containing protein 1 (SAMHD1) is an intrinsic antiviral restriction factor known to play a vital role in preventing multiple viral infections and in the control of the cellular deoxynucleoside triphosphate (dNTP) pool. Human and mouse SAMHD1 have both been extensively studied; however, our knowledge on porcine SAMHD1 is limited. Here, we report our findings from comprehensive structural and functional studies on porcine SAMHD1. We determined the crystal structure of porcine SAMHD1 and showed that it forms a symmetric tetramer. Moreover, we modified the deoxynucleotide triphosphohydrolase (dNTPase) activity of SAMHD1 by site-directed mutagenesis based on the crystal structure, and obtained an artificial dimeric enzyme possessing high dNTPase activity. Taken together, our results define the mechanism underlying dNTP regulation and provide a deeper understanding of the regulation of porcine SAMHD1 functions. Directed modification of key residues based on the protein structure enhances the activity of the enzyme, which will be beneficial in the search for new antiviral strategies and for future translational applications.
Collapse
Affiliation(s)
- Jia Kong
- School of Chemical Engineering and Technology, Tianjin University, China.,School of Life Sciences, Tianjin University, China
| | - Mei-Mei Wang
- School of Life Sciences, Tianjin University, China
| | - Shuang-Yi He
- School of Life Sciences, Tianjin University, China
| | - Xin Peng
- School of Life Sciences, Tianjin University, China
| | - Xiao-Hong Qin
- School of Life Sciences, Tianjin University, China.,State Key Laboratory of Medicinal Chemical Biology, NanKai University, Tianjin, China
| |
Collapse
|
42
|
Martin-Gayo E, Yu XG. Role of Dendritic Cells in Natural Immune Control of HIV-1 Infection. Front Immunol 2019; 10:1306. [PMID: 31244850 PMCID: PMC6563724 DOI: 10.3389/fimmu.2019.01306] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Accepted: 05/22/2019] [Indexed: 01/14/2023] Open
Abstract
Dendritic cells (DCs) are professional antigen-presenting cells that link innate and adaptive immunity and are critical for the induction of protective immune responses against pathogens. Proportions of these cells are markedly decreased in the blood of untreated HIV-1-infected individuals, suggesting they might be intrinsically involved in HIV-1 pathogenesis. However, despite several decades of active research, the precise role and contribution of these cells to protective or detrimental host responses against HIV-1 are still remarkably unclear. Recent studies have shown that DCs possess a fine-tuned machinery to recognize HIV-1 replication products through a variety of innate pathogen sensing mechanisms, which may be instrumental for generating both cellular and humoral protective immune responses in persons who naturally control HIV-1 replication. Yet, dysregulated and abnormal activation of DCs might also contribute to sustained inflammation and immune activation accelerating disease progression during chronic progressive infection. Emerging data also suggest that DCs can influence the induction of potent broadly-neutralizing antibodies, and may, for this reason, have to be considered as important components of future HIV-1 vaccination strategies. Apart from their involvement in antiviral host immunity, at least a subgroup of DCs seem intrinsically susceptible to HIV-1 infection and may serve as a viral target cell population. Indeed recent studies suggest that specific DC subpopulations residing in the genital mucosa are preferentially infected by HIV-1 and play an active role in sexual transmission; therefore, DCs may contribute to viral dissemination and possible persistence of the viral reservoirs through either direct or indirect mechanisms. Here, we analyze the distinct and partially opposing roles of DCs during HIV-1 disease pathogenesis, with a focus on implications of DC biology natural immune control and HIV cure research efforts.
Collapse
Affiliation(s)
- Enrique Martin-Gayo
- Hospital Universitario de la Princesa, Universidad Autónoma de Madrid, Madrid, Spain
| | - Xu G Yu
- Ragon Institute of MGH, MIT, and Harvard, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
| |
Collapse
|
43
|
Increased SAMHD1 transcript expression correlates with interferon-related genes in HIV-1-infected patients. Med Microbiol Immunol 2018; 208:679-691. [PMID: 30564919 DOI: 10.1007/s00430-018-0574-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Accepted: 11/24/2018] [Indexed: 01/12/2023]
Abstract
PURPOSE To investigate the contribution of SAMHD1 to HIV-1 infection in vivo and its relationship with IFN response, the expression of SAMHD1 and IFN-related pathways was evaluated in HIV-1-infected patients. METHODS Peripheral blood mononuclear cells (PBMC) from 388 HIV-1-infected patients, both therapy naïve (n = 92) and long-term HAART treated (n = 296), and from 100 gender and age-matched healthy individuals were examined. CD4+ T cells, CD14+ monocytes and gut biopsies were also analyzed in HIV-1-infected subjects on suppressive antiretroviral therapy. Gene expression levels of SAMDH1, ISGs (MxA, MxB, HERC5, IRF7) and IRF3 were evaluated by real-time RT-PCR assays. RESULTS SAMHD1 levels in HIV-1-positive patients were significantly increased compared to those in healthy donors. SAMHD1 expression was enhanced in treated patients compared to naïve patients (p < 0.0001) and healthy donors (p = 0.0038). Virologically suppressed treated patients exhibited higher SAMHD1 levels than healthy donors (p = 0.0008), viraemic patients (p = 0.0001) and naïve patients (p < 0.0001). SAMHD1 levels were also increased in CD4+ T cells compared to those in CD14+ monocytes and in PBMC compared to those of GALT. Moreover, SAMHD1 was expressed more strongly than ISGs in HIV-1-infected patients and positive correlations were found between SAMHD1, ISGs and IRF3 levels. CONCLUSIONS SAMHD1 is more strongly expressed than the classical IFN-related genes, increased during antiretroviral therapy and correlated with ISGs and IRF3 in HIV-1-infected patients.
Collapse
|
44
|
Plitnik T, Sharkey ME, Mahboubi B, Kim B, Stevenson M. Incomplete Suppression of HIV-1 by SAMHD1 Permits Efficient Macrophage Infection. Pathog Immun 2018; 3:197-223. [PMID: 30656243 PMCID: PMC6333473 DOI: 10.20411/pai.v3i2.263] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Background: Sterile alpha motif and histidine/aspartic acid domain-containing protein (SAMHD1) is a dNTP triphosphorylase that reduces cellular dNTP levels in non-dividing cells, such as macrophages. Since dNTPs are required for reverse transcription, HIV-2 and most SIVs encode a Vpx protein that promotes proteasomal degradation of SAMHD1. It is unclear how HIV-1, which does not appear to harbor a SAMHD1 escape mechanism, is able to infect macrophages in the face of SAMHD1 restriction. Methods: To assess whether HIV-1 had a mechanism to negate SAMHD1 activity, we compared SAMHD1 and dNTP levels in macrophages infected by HIV-1 and SIV. We examined whether macrophages infected by HIV-1 still harbored antiviral levels of SAMHD1 by assessing their susceptibility to superinfection by vpx-deleted SIV. Finally, to assess whether HIV-1 reverse transcriptase (RT) has adapted to a low dNTP environment, we evaluated SAMHD1 sensitivity of chimeric HIV-1 and SIV variants in which the RT regions were functionally exchanged. Results: Here, we demonstrate that HIV-1 efficiently infects macrophages without modulating SAMHD1 activity or cellular dNTP levels, and that macrophages permissive to HIV-1 infection remained refractory to superinfection by vpx-deleted SIV. Furthermore, through the use of chimeric HIV/SIV, we demonstrate that the differential sensitivity of HIV-1 and SIV to SAMHD1 restriction is not dictated by RT. Conclusions: Our study reveals fundamental differences between HIV-1 and SIV in the strategy used to evade restriction by SAMHD1 and suggests a degree of resistance of HIV-1 to the antiviral environment created by SAMHD1. Understanding how these cellular restrictions antagonize viral replication will be important for the design of novel antiviral strategies.
Collapse
Affiliation(s)
- Timothy Plitnik
- Department of Microbiology & Immunology; Miller School of Medicine, University of Miami; Miami, Florida
| | - Mark E Sharkey
- Department of Medicine; Miller School of Medicine, University of Miami; Miami, Florida
| | - Bijan Mahboubi
- Department of Pediatrics, Emory University; Atlanta, Georgia.,Center for Drug Discovery, Children's Healthcare of Atlanta; Atlanta, Georgia
| | - Baek Kim
- Department of Pediatrics, Emory University; Atlanta, Georgia.,Center for Drug Discovery, Children's Healthcare of Atlanta; Atlanta, Georgia.,Department of Pharmacy, Kyung-Hee University; Seoul; South Korea
| | - Mario Stevenson
- Department of Microbiology & Immunology; Miller School of Medicine, University of Miami; Miami, Florida.,Department of Medicine; Miller School of Medicine, University of Miami; Miami, Florida
| |
Collapse
|
45
|
Colomer-Lluch M, Ruiz A, Moris A, Prado JG. Restriction Factors: From Intrinsic Viral Restriction to Shaping Cellular Immunity Against HIV-1. Front Immunol 2018; 9:2876. [PMID: 30574147 PMCID: PMC6291751 DOI: 10.3389/fimmu.2018.02876] [Citation(s) in RCA: 102] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 11/22/2018] [Indexed: 01/20/2023] Open
Abstract
Antiviral restriction factors are host cellular proteins that constitute a first line of defense blocking viral replication and propagation. In addition to interfering at critical steps of the viral replication cycle, some restriction factors also act as innate sensors triggering innate responses against infections. Accumulating evidence suggests an additional role for restriction factors in promoting antiviral cellular immunity to combat viruses. Here, we review the recent progress in our understanding on how restriction factors, particularly APOBEC3G, SAMHD1, Tetherin, and TRIM5α have the cell-autonomous potential to induce cellular resistance against HIV-1 while promoting antiviral innate and adaptive immune responses. Also, we provide an overview of how these restriction factors may connect with protein degradation pathways to modulate anti-HIV-1 cellular immune responses, and we summarize the potential of restriction factors-based therapeutics. This review brings a global perspective on the influence of restrictions factors in intrinsic, innate, and also adaptive antiviral immunity opening up novel research avenues for therapeutic strategies in the fields of drug discovery, gene therapy, and vaccines to control viral infections.
Collapse
Affiliation(s)
- Marta Colomer-Lluch
- IrsiCaixa AIDS Research Institute, Germans Trias i Pujol Research Institute, Universitat Autonoma de Barcelona, Badalona, Spain
| | - Alba Ruiz
- IrsiCaixa AIDS Research Institute, Germans Trias i Pujol Research Institute, Universitat Autonoma de Barcelona, Badalona, Spain
| | - Arnaud Moris
- Sorbonne Université, INSERM U1135, CNRS ERL 8255, Centre d'Immunologie et des Maladies Infectieuses (CIMI-Paris), Paris, France
| | - Julia G Prado
- IrsiCaixa AIDS Research Institute, Germans Trias i Pujol Research Institute, Universitat Autonoma de Barcelona, Badalona, Spain
| |
Collapse
|
46
|
Chen S, Bonifati S, Qin Z, St Gelais C, Wu L. SAMHD1 Suppression of Antiviral Immune Responses. Trends Microbiol 2018; 27:254-267. [PMID: 30336972 DOI: 10.1016/j.tim.2018.09.009] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 09/17/2018] [Accepted: 09/26/2018] [Indexed: 12/18/2022]
Abstract
SAMHD1 is a host triphosphohydrolase that degrades intracellular deoxynucleoside triphosphates (dNTPs) to a lower level that restricts viral DNA synthesis, and thus prevents replication of diverse viruses in nondividing cells. Recent progress indicates that SAMHD1 negatively regulates antiviral innate immune responses and inflammation through interacting with various key proteins in immune signaling and DNA damage-repair pathways. SAMHD1 can also modulate antibody production in adaptive immune responses. In this review, we summarize how SAMHD1 regulates antiviral immune responses through distinct mechanisms, and discuss the implications of these new functions of SAMHD1. Furthermore, we propose important new questions and future directions that can advance functional and mechanistic studies of SAMHD1-mediated immune regulation during viral infections.
Collapse
Affiliation(s)
- Shuliang Chen
- School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, PR China; Center for Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, OH 43210, USA
| | - Serena Bonifati
- Center for Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, OH 43210, USA
| | - Zhihua Qin
- Center for Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, OH 43210, USA
| | - Corine St Gelais
- Center for Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, OH 43210, USA
| | - Li Wu
- Center for Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, OH 43210, USA; Department of Microbial Infection and Immunity, The Ohio State University, Columbus, OH 43210, USA.
| |
Collapse
|
47
|
Goyvaerts C, Breckpot K. The Journey of in vivo Virus Engineered Dendritic Cells From Bench to Bedside: A Bumpy Road. Front Immunol 2018; 9:2052. [PMID: 30254636 PMCID: PMC6141723 DOI: 10.3389/fimmu.2018.02052] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 08/20/2018] [Indexed: 12/13/2022] Open
Abstract
Dendritic cells (DCs) are recognized as highly potent antigen-presenting cells that are able to stimulate cytotoxic T lymphocyte (CTL) responses with antitumor activity. Consequently, DCs have been explored as cellular vaccines in cancer immunotherapy. To that end, DCs are modified with tumor antigens to enable presentation of antigen-derived peptides to CTLs. In this review we discuss the use of viral vectors for in situ modification of DCs, focusing on their clinical applications as anticancer vaccines. Among the viral vectors discussed are those derived from viruses belonging to the families of the Poxviridae, Adenoviridae, Retroviridae, Togaviridae, Paramyxoviridae, and Rhabdoviridae. We will further shed light on how the combination of viral vector-based vaccination with T-cell supporting strategies will bring this strategy to the next level.
Collapse
|
48
|
Mereby SA, Maehigashi T, Holler JM, Kim DH, Schinazi RF, Kim B. Interplay of ancestral non-primate lentiviruses with the virus-restricting SAMHD1 proteins of their hosts. J Biol Chem 2018; 293:16402-16412. [PMID: 30181218 PMCID: PMC6200947 DOI: 10.1074/jbc.ra118.004567] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 08/29/2018] [Indexed: 11/26/2022] Open
Abstract
Lentiviruses infect both dividing CD4+ T cells and nondividing myeloid cells, and the infected myeloid cells serve as long-living viral reservoirs. Host sterile alpha motif– and histidine-aspartate domain–containing protein 1 (SAMHD1) kinetically restricts reverse transcription of primate lentiviruses, including human immunodeficiency virus, type 1 (HIV-1) and simian immunodeficiency virus (SIV), in nondividing myeloid cells. SAMHD1 enforces this restriction through its dNTP triphosphohydrolase (dNTPase) activity that depletes cellular dNTPs. Some primate lentiviruses, such as HIV-2, SIVsm, and SIVagm, counteract SAMHD1 restriction by using their viral accessory proteins (Vpx or Vpr) that induce the proteosomal degradation of SAMHD1 and increase dNTP levels. SAMHD1 is conserved among non-primate mammals such as cats, cows, and horses that also carry their own lentiviruses (feline and bovine immunodeficiency viruses and equine infectious anemia viruses, respectively). However, whether these viruses also target SAMHD1 is unknown. Here, we tested whether these ancestral non-primate lentiviruses also can counteract their host SAMHD1 proteins by promoting their proteosomal degradation. Using biochemical and various cell-based assays, we observed that SAMHD1 proteins from the non-primate host species display dGTP-dependent dNTPase activity, but that the non-primate lentiviruses fail to proteosomally degrade the SAMHD1 proteins of their hosts. Our findings suggest that accessory protein–mediated proteosomal degradation of SAMHD1 did not exist among the ancestral non-primate lentiviruses and was uniquely gained by some primate lentiviruses after their transmission to primate species.
Collapse
Affiliation(s)
- Sarah A Mereby
- From the Department of Pediatrics, School of Medicine, Emory University, Atlanta, Georgia 30322
| | - Tatsuya Maehigashi
- From the Department of Pediatrics, School of Medicine, Emory University, Atlanta, Georgia 30322
| | - Jessica M Holler
- From the Department of Pediatrics, School of Medicine, Emory University, Atlanta, Georgia 30322
| | - Dong-Hyun Kim
- Department of Pharmacy, Kyung-Hee University, Seoul 130-701, South Korea, and
| | - Raymond F Schinazi
- From the Department of Pediatrics, School of Medicine, Emory University, Atlanta, Georgia 30322
| | - Baek Kim
- From the Department of Pediatrics, School of Medicine, Emory University, Atlanta, Georgia 30322, .,Department of Pharmacy, Kyung-Hee University, Seoul 130-701, South Korea, and.,Center for Drug Discovery, Children's Healthcare of Atlanta, Atlanta, Georgia 30322
| |
Collapse
|
49
|
Martinez-Lopez A, Martin-Fernandez M, Buta S, Kim B, Bogunovic D, Diaz-Griffero F. SAMHD1 deficient human monocytes autonomously trigger type I interferon. Mol Immunol 2018; 101:450-460. [PMID: 30099227 DOI: 10.1016/j.molimm.2018.08.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Revised: 07/24/2018] [Accepted: 08/02/2018] [Indexed: 01/04/2023]
Abstract
Germline mutations in the human SAMHD1 gene cause the development of Aicardi-Goutières Syndrome (AGS), with a dominant feature being increased systemic type I interferon(IFN) production. Here we tested the state of type I IFN induction and response to, in SAMHD1 knockout (KO) human monocytic cells. SAMHD1 KO cells exhibited spontaneous transcription and translation of IFN-β and subsequent interferon-stimulated genes (ISGs) as compared to parental wild-type cells. This elevation of IFN-β and ISGs was abrogated via inhibition of the TBK1-IRF3 pathway in the SAMHD1 KO cells. In agreement, we found that SAMHD1 KO cells present high levels of phosphorylated TBK1 when compared to control cells. Moreover, addition of blocking antibody against type I IFN also reversed elevation of ISGs. These experiments suggested that SAMHD1 KO cells are persistently auto-stimulating the TBK1-IRF3 pathway, leading to an enhanced production of type I IFN and subsequent self-induction of ISGs.
Collapse
Affiliation(s)
- Alicia Martinez-Lopez
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY 10461, United States
| | - Marta Martin-Fernandez
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States
| | - Sofija Buta
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States
| | - Baek Kim
- Department of Pediatrics, Emory University, Atlanta, GA 30322, United States
| | - Dusan Bogunovic
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States
| | - Felipe Diaz-Griffero
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY 10461, United States.
| |
Collapse
|
50
|
Antonucci JM, Kim SH, St Gelais C, Bonifati S, Li TW, Buzovetsky O, Knecht KM, Duchon AA, Xiong Y, Musier-Forsyth K, Wu L. SAMHD1 Impairs HIV-1 Gene Expression and Negatively Modulates Reactivation of Viral Latency in CD4 + T Cells. J Virol 2018; 92:e00292-18. [PMID: 29793958 PMCID: PMC6052313 DOI: 10.1128/jvi.00292-18] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Accepted: 05/15/2018] [Indexed: 11/20/2022] Open
Abstract
Sterile alpha motif and HD domain-containing protein 1 (SAMHD1) restricts human immunodeficiency virus type 1 (HIV-1) replication in nondividing cells by degrading intracellular deoxynucleoside triphosphates (dNTPs). SAMHD1 is highly expressed in resting CD4+ T cells, which are important for the HIV-1 reservoir and viral latency; however, whether SAMHD1 affects HIV-1 latency is unknown. Recombinant SAMHD1 binds HIV-1 DNA or RNA fragments in vitro, but the function of this binding remains unclear. Here we investigate the effect of SAMHD1 on HIV-1 gene expression and reactivation of viral latency. We found that endogenous SAMHD1 impaired HIV-1 long terminal repeat (LTR) activity in monocytic THP-1 cells and HIV-1 reactivation in latently infected primary CD4+ T cells. Overexpression of wild-type (WT) SAMHD1 suppressed HIV-1 LTR-driven gene expression at a transcriptional level. Tat coexpression abrogated SAMHD1-mediated suppression of HIV-1 LTR-driven luciferase expression. SAMHD1 overexpression also suppressed the LTR activity of human T-cell leukemia virus type 1 (HTLV-1), but not that of murine leukemia virus (MLV), suggesting specific suppression of retroviral LTR-driven gene expression. WT SAMHD1 bound to proviral DNA and impaired reactivation of HIV-1 gene expression in latently infected J-Lat cells. In contrast, a nonphosphorylated mutant (T592A) and a dNTP triphosphohydrolase (dNTPase) inactive mutant (H206D R207N [HD/RN]) of SAMHD1 failed to efficiently suppress HIV-1 LTR-driven gene expression and reactivation of latent virus. Purified recombinant WT SAMHD1, but not the T592A and HD/RN mutants, bound to fragments of the HIV-1 LTR in vitro These findings suggest that SAMHD1-mediated suppression of HIV-1 LTR-driven gene expression potentially regulates viral latency in CD4+ T cells.IMPORTANCE A critical barrier to developing a cure for HIV-1 infection is the long-lived viral reservoir that exists in resting CD4+ T cells, the main targets of HIV-1. The viral reservoir is maintained through a variety of mechanisms, including regulation of the HIV-1 LTR promoter. The host protein SAMHD1 restricts HIV-1 replication in nondividing cells, but its role in HIV-1 latency remains unknown. Here we report a new function of SAMHD1 in regulating HIV-1 latency. We found that SAMHD1 suppressed HIV-1 LTR promoter-driven gene expression and reactivation of viral latency in cell lines and primary CD4+ T cells. Furthermore, SAMHD1 bound to the HIV-1 LTR in vitro and in a latently infected CD4+ T-cell line, suggesting that the binding may negatively modulate reactivation of HIV-1 latency. Our findings indicate a novel role for SAMHD1 in regulating HIV-1 latency, which enhances our understanding of the mechanisms regulating proviral gene expression in CD4+ T cells.
Collapse
Affiliation(s)
- Jenna M Antonucci
- Center for Retrovirus Research, The Ohio State University, Columbus, Ohio, USA
- Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio, USA
- Department of Microbiology, The Ohio State University, Columbus, Ohio, USA
| | - Sun Hee Kim
- Center for Retrovirus Research, The Ohio State University, Columbus, Ohio, USA
- Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio, USA
| | - Corine St Gelais
- Center for Retrovirus Research, The Ohio State University, Columbus, Ohio, USA
- Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio, USA
| | - Serena Bonifati
- Center for Retrovirus Research, The Ohio State University, Columbus, Ohio, USA
- Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio, USA
| | - Tai-Wei Li
- Center for Retrovirus Research, The Ohio State University, Columbus, Ohio, USA
- Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio, USA
| | - Olga Buzovetsky
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA
| | - Kirsten M Knecht
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA
| | - Alice A Duchon
- Center for Retrovirus Research, The Ohio State University, Columbus, Ohio, USA
- Center for RNA Biology, The Ohio State University, Columbus, Ohio, USA
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio, USA
| | - Yong Xiong
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA
| | - Karin Musier-Forsyth
- Center for Retrovirus Research, The Ohio State University, Columbus, Ohio, USA
- Center for RNA Biology, The Ohio State University, Columbus, Ohio, USA
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio, USA
| | - Li Wu
- Center for Retrovirus Research, The Ohio State University, Columbus, Ohio, USA
- Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio, USA
- Department of Microbiology, The Ohio State University, Columbus, Ohio, USA
- Center for RNA Biology, The Ohio State University, Columbus, Ohio, USA
| |
Collapse
|