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Veletanlic V, Sartalamacchia K, Diller JR, Ogden KM. Multiple rotavirus species encode fusion-associated small transmembrane (FAST) proteins with cell type-specific activity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.07.536061. [PMID: 37066280 PMCID: PMC10104117 DOI: 10.1101/2023.04.07.536061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/18/2023]
Abstract
Fusion-associated small transmembrane (FAST) proteins are viral nonstructural proteins that mediate cell-cell fusion to form multinucleated syncytia. We previously reported that human species B rotavirus NSP1-1 is a FAST protein that induces syncytia in primate epithelial cells but not rodent fibroblasts. We hypothesized that the NSP1-1 proteins of other rotavirus species could also mediate cell-cell fusion and that fusion activity might be limited to cell types derived from homologous hosts. To test this hypothesis, we predicted the structure and domain organization of NSP1-1 proteins of species B rotavirus from a human, goat, and pig, species G rotavirus from a pigeon and turkey, and species I rotavirus from a dog and cat. We cloned these sequences into plasmids and transiently expressed the NSP1-1 proteins in avian, canine, hamster, human, porcine, and simian cells. Regardless of host origin of the virus, each NSP1-1 protein induced syncytia in primate cells, while few induced syncytia in other cell types. To identify the domains that determined cell-specific fusion activity for human species B rotavirus NSP1-1, we engineered chimeric proteins containing domain exchanges with the p10 FAST protein from Nelson Bay orthoreovirus. Using the chimeric proteins, we found that the N-terminal and transmembrane domains determined the cell type specificity of fusion activity. Although the species and cell type criteria for fusion activity remain unclear, these findings suggest that rotavirus species B, G, and I NSP1-1 are functional FAST proteins whose N termini play a role in specifying the cells in which they mediate syncytia formation.
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Affiliation(s)
- Vanesa Veletanlic
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Kylie Sartalamacchia
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Julia R. Diller
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Kristen M. Ogden
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
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2
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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.
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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
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3
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Meissner ME, Talledge N, Mansky LM. Molecular Biology and Diversification of Human Retroviruses. FRONTIERS IN VIROLOGY 2022; 2:872599. [PMID: 35783361 PMCID: PMC9242851 DOI: 10.3389/fviro.2022.872599] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Studies of retroviruses have led to many extraordinary discoveries that have advanced our understanding of not only human diseases, but also molecular biology as a whole. The most recognizable human retrovirus, human immunodeficiency virus type 1 (HIV-1), is the causative agent of the global AIDS epidemic and has been extensively studied. Other human retroviruses, such as human immunodeficiency virus type 2 (HIV-2) and human T-cell leukemia virus type 1 (HTLV-1), have received less attention, and many of the assumptions about the replication and biology of these viruses are based on knowledge of HIV-1. Existing comparative studies on human retroviruses, however, have revealed that key differences between these viruses exist that affect evolution, diversification, and potentially pathogenicity. In this review, we examine current insights on disparities in the replication of pathogenic human retroviruses, with a particular focus on the determinants of structural and genetic diversity amongst HIVs and HTLV.
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Affiliation(s)
- Morgan E. Meissner
- Institute for Molecular Virology, University of Minnesota – Twin Cities, Minneapolis, MN 55455 USA
- Molecular, Cellular, Developmental Biology and Genetics Graduate Program, University of Minnesota – Twin Cities, Minneapolis, MN 55455 USA
| | - Nathaniel Talledge
- Institute for Molecular Virology, University of Minnesota – Twin Cities, Minneapolis, MN 55455 USA
- Division of Basic Sciences, School of Dentistry, University of Minnesota – Twin Cities, Minneapolis, MN 55455 USA
- Masonic Cancer Center, University of Minnesota – Twin Cities, Minneapolis, MN 55455 USA
| | - Louis M. Mansky
- Institute for Molecular Virology, University of Minnesota – Twin Cities, Minneapolis, MN 55455 USA
- Division of Basic Sciences, School of Dentistry, University of Minnesota – Twin Cities, Minneapolis, MN 55455 USA
- Molecular, Cellular, Developmental Biology and Genetics Graduate Program, University of Minnesota – Twin Cities, Minneapolis, MN 55455 USA
- Masonic Cancer Center, University of Minnesota – Twin Cities, Minneapolis, MN 55455 USA
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4
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The Hippo signaling component LATS2 enhances innate immunity to inhibit HIV-1 infection through PQBP1-cGAS pathway. Cell Death Differ 2022; 29:192-205. [PMID: 34385679 PMCID: PMC8738759 DOI: 10.1038/s41418-021-00849-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 07/28/2021] [Accepted: 08/02/2021] [Indexed: 01/03/2023] Open
Abstract
As the most primordial signaling pathway in animal physiology, the Hippo pathway and innate immunity play crucial roles not only in sensing cellular conditions or infections, but also in various metabolite homeostasis and tumorigenesis. However, the correlation between cellular homeostasis and antiviral defense is not well understood. The core kinase LATS1/2, could either enhance or inhibit the anti-tumor immunity in different cellular contexts. In this study, we found that LATS2 can interact with PQBP1, the co-factor of cGAS, thus enhanced the cGAS-STING mediated innate immune response to HIV-1 challenge. LATS2 was observed to upregulate type-I interferon (IFN-I) and cytokines in response to HIV-1 reverse-transcribed DNA and inhibited HIV-1 infection. Due to the involvement of PQBP1, the function of LATS2 in regulating cGAS activity is not relying on the downstream YAP/TAZ as that in the canonical Hippo pathway. The related kinase activity of LATS2 was verified, and the potential phosphorylation site of PQBP1 was identified. Our study established a novel connection between Hippo signaling and innate immunity, thus may provide new potential intervention target on antiviral therapeutics.
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Hiatt J, Cavero DA, McGregor MJ, Zheng W, Budzik JM, Roth TL, Haas KM, Wu D, Rathore U, Meyer-Franke A, Bouzidi MS, Shifrut E, Lee Y, Kumar VE, Dang EV, Gordon DE, Wojcechowskyj JA, Hultquist JF, Fontaine KA, Pillai SK, Cox JS, Ernst JD, Krogan NJ, Marson A. Efficient generation of isogenic primary human myeloid cells using CRISPR-Cas9 ribonucleoproteins. Cell Rep 2021; 35:109105. [PMID: 33979618 PMCID: PMC8188731 DOI: 10.1016/j.celrep.2021.109105] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 12/31/2020] [Accepted: 04/19/2021] [Indexed: 12/21/2022] Open
Abstract
Genome engineering of primary human cells with CRISPR-Cas9 has revolutionized experimental and therapeutic approaches to cell biology, but human myeloid-lineage cells have remained largely genetically intractable. We present a method for the delivery of CRISPR-Cas9 ribonucleoprotein (RNP) complexes by nucleofection directly into CD14+ human monocytes purified from peripheral blood, leading to high rates of precise gene knockout. These cells can be efficiently differentiated into monocyte-derived macrophages or dendritic cells. This process yields genetically edited cells that retain transcript and protein markers of myeloid differentiation and phagocytic function. Genetic ablation of the restriction factor SAMHD1 increased HIV-1 infection >50-fold, demonstrating the power of this system for genotype-phenotype interrogation. This fast, flexible, and scalable platform can be used for genetic studies of human myeloid cells in immune signaling, inflammation, cancer immunology, host-pathogen interactions, and beyond, and could facilitate the development of myeloid cellular therapies.
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Affiliation(s)
- Joseph Hiatt
- Medical Scientist Training Program, University of California, San Francisco, San Francisco, CA 94143, USA; Biomedical Sciences Graduate Program, University of California, San Francisco, San Francisco, CA 94143, USA; J. David Gladstone Institutes, San Francisco, CA 94158, USA; Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94143, USA; Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Devin A Cavero
- J. David Gladstone Institutes, San Francisco, CA 94158, USA; Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94143, USA; Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Michael J McGregor
- J. David Gladstone Institutes, San Francisco, CA 94158, USA; Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA; Quantitative Biosciences Institute, QBI, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Weihao Zheng
- Department of Medicine, Division of Experimental Medicine, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Jonathan M Budzik
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA; Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Theodore L Roth
- Medical Scientist Training Program, University of California, San Francisco, San Francisco, CA 94143, USA; Biomedical Sciences Graduate Program, University of California, San Francisco, San Francisco, CA 94143, USA; J. David Gladstone Institutes, San Francisco, CA 94158, USA; Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94143, USA; Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Kelsey M Haas
- J. David Gladstone Institutes, San Francisco, CA 94158, USA; Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA; Quantitative Biosciences Institute, QBI, University of California, San Francisco, San Francisco, CA 94158, USA
| | - David Wu
- Medical Scientist Training Program, University of California, San Francisco, San Francisco, CA 94143, USA; Biomedical Sciences Graduate Program, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Ujjwal Rathore
- J. David Gladstone Institutes, San Francisco, CA 94158, USA; Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94143, USA; Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA 94720, USA
| | | | - Mohamed S Bouzidi
- Vitalant Research Institute, San Francisco, CA 94118, USA; Department of Laboratory Medicine, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Eric Shifrut
- J. David Gladstone Institutes, San Francisco, CA 94158, USA; Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94143, USA; Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Youjin Lee
- J. David Gladstone Institutes, San Francisco, CA 94158, USA; Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94143, USA; Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Vigneshwari Easwar Kumar
- J. David Gladstone Institutes, San Francisco, CA 94158, USA; Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94143, USA; Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Eric V Dang
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94143, USA
| | - David E Gordon
- J. David Gladstone Institutes, San Francisco, CA 94158, USA; Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA; Quantitative Biosciences Institute, QBI, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Jason A Wojcechowskyj
- J. David Gladstone Institutes, San Francisco, CA 94158, USA; Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA; Quantitative Biosciences Institute, QBI, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Judd F Hultquist
- J. David Gladstone Institutes, San Francisco, CA 94158, USA; Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA; Quantitative Biosciences Institute, QBI, University of California, San Francisco, San Francisco, CA 94158, USA; Division of Infectious Diseases, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | | | - Satish K Pillai
- Vitalant Research Institute, San Francisco, CA 94118, USA; Department of Laboratory Medicine, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Jeffery S Cox
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Joel D Ernst
- Department of Medicine, Division of Experimental Medicine, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Nevan J Krogan
- J. David Gladstone Institutes, San Francisco, CA 94158, USA; Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA; Quantitative Biosciences Institute, QBI, University of California, San Francisco, San Francisco, CA 94158, USA.
| | - Alexander Marson
- J. David Gladstone Institutes, San Francisco, CA 94158, USA; Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94143, USA; Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA 94720, USA; Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA; Diabetes Center, University of California, San Francisco, San Francisco, CA 94143, USA; Parker Institute for Cancer Immunotherapy, San Francisco, CA 94129, USA; UCSF Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA 94158, USA; Chan Zuckerberg Biohub, San Francisco, CA 94158, USA.
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6
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Li J, Gao C, Huang S, Jin L, Jin C. SAMHD1 expression is associated with low immune activation but not correlated with HIV‑1 DNA levels in CD4+ T cells of patients with HIV‑1. Mol Med Rep 2020; 22:879-885. [PMID: 32468062 PMCID: PMC7339818 DOI: 10.3892/mmr.2020.11153] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Accepted: 04/07/2020] [Indexed: 12/30/2022] Open
Abstract
Sterile α motif and histidine/aspartic acid domain‑containing protein 1 (SAMHD1) can inhibit reverse transcription of human immunodeficiency virus‑1 (HIV‑1) by hydrolyzing intracellular deoxy‑ribonucleoside triphosphate. However, its role in HIV‑1 disease progression has not been extensively studied. To study the impacts of SAMHD1 on HIV‑1 disease progression, especially on DNA levels, we investigated SAMHD1 levels in the peripheral blood of HIV‑1 elite controllers (ECs), antiretroviral therapy (ART) naive viremic progressors (VPs) and patients with HIV‑1 receiving ART (HIV‑ARTs) compared with healthy controls. In addition, the present study analyzed the relationship between SAMHD1 and interferon‑α, immune activation and HIV‑1 DNA levels. The results of the present study demonstrated elevated SAMHD1 expression in the peripheral blood mononuclear cells of all patients withHIV‑1, but higher SAMHD1 expression in the CD4+ T cells of only ECs compared with healthy controls. Immune activation was increased in the VPs and decreased in the ECs compared with healthy controls. Substantially lower HIV‑1 DNA levels were identified in ECs compared with those in VPs and HIV‑ARTs. SAMHD1 expression was associated with low levels of immune activation. No significant correlation was observed between SAMHD1 and HIV‑1 DNA levels. Overall, the findings of the present study indicated that SAMHD1 was highly expressed in ECs, which may be associated with low immune activation levels, but was not directly related to HIV‑1 DNA levels.
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Affiliation(s)
- Jie Li
- Department of Infectious Disease, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325027, P.R. China
| | - Chuanhua Gao
- Laboratory of Biochemistry and Biomaterials, Department of Materials, College of Chemical and Material Engineering, Quzhou University, Quzhou, Zhejiang 324000, P.R. China
| | - Shanshan Huang
- Department of Infectious Disease, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325027, P.R. China
| | - Longteng Jin
- Department of Childhood Infectious Disease, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325027, P.R. China
| | - Changzhong Jin
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310003, P.R. China
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7
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Abstract
We demonstrate that HIV-1 uses a common two-step cell-to-cell fusion mechanism for massive virus transfer from infected T lymphocytes and dissemination to myeloid target cells, including dendritic cells and macrophages as well as osteoclasts. This cell-to-cell infection process bypasses the restriction imposed by the SAMHD1 host cell restriction factor for HIV-1 replication, leading to the formation of highly virus-productive multinucleated giant cells as observed in vivo in lymphoid and nonlymphoid tissues of HIV-1-infected patients. Since myeloid cells are emerging as important target cells of HIV-1, these results contribute to a better understanding of the role of these myeloid cells in pathogenesis, including cell-associated virus sexual transmission, cell-to-cell virus spreading, and establishment of long-lived viral tissue reservoirs. Dendritic cells (DCs) and macrophages as well as osteoclasts (OCs) are emerging as target cells of HIV-1 involved in virus transmission, dissemination, and establishment of persistent tissue virus reservoirs. While these myeloid cells are poorly infected by cell-free viruses because of the high expression levels of cellular restriction factors such as SAMHD1, we show here that HIV-1 uses a specific and common cell-to-cell fusion mechanism for virus transfer and dissemination from infected T lymphocytes to the target cells of the myeloid lineage, including immature DCs (iDCs), OCs, and macrophages, but not monocytes and mature DCs. The establishment of contacts with infected T cells leads to heterotypic cell fusion for the fast and massive transfer of viral material into OC and iDC targets, which subsequently triggers homotypic fusion with noninfected neighboring OCs and iDCs for virus dissemination. These two cell-to-cell fusion processes are not restricted by SAMHD1 and allow very efficient spreading of virus in myeloid cells, resulting in the formation of highly virus-productive multinucleated giant cells. These results reveal the cellular mechanism for SAMHD1-independent cell-to-cell spreading of HIV-1 in myeloid cell targets through the formation of the infected multinucleated giant cells observed in vivo in lymphoid and nonlymphoid tissues of HIV-1-infected patients.
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8
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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.
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9
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Kandathil AJ, Sugawara S, Goyal A, Durand CM, Quinn J, Sachithanandham J, Cameron AM, Bailey JR, Perelson AS, Balagopal A. No recovery of replication-competent HIV-1 from human liver macrophages. J Clin Invest 2018; 128:4501-4509. [PMID: 30198905 DOI: 10.1172/jci121678] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 07/26/2018] [Indexed: 12/17/2022] Open
Abstract
Long-lived HIV-1 reservoirs that persist despite antiretroviral therapy (ART) are a major impediment to a cure for HIV-1. We examined whether human liver macrophages (LMs), the largest tissue macrophage population, comprise an HIV-1 reservoir. We purified LMs from liver explants and included treatment with a T cell immunotoxin to reduce T cells to 1% or less. LMs were purified from 9 HIV-1-infected persons, 8 of whom were on ART (range 8-140 months). Purified LMs were stimulated ex vivo and supernatants from 6 of 8 LMs from persons on ART transmitted infection. However, HIV-1 propagation from LMs was not sustained except in LMs from 1 person taking ART for less than 1 year. Bulk liver sequences matched LM-derived HIV-1 in 5 individuals. Additional in vitro experiments undertaken to quantify the decay of HIV-1-infected LMs from 3 healthy controls showed evidence of infection and viral release for prolonged durations (>170 days). Released HIV-1 propagated robustly in target cells, demonstrating that viral outgrowth was observable using our methods. The t1/2 of HIV-1-infected LMs ranged from 3.8-55 days. These findings suggest that while HIV-1 persists in LMs during ART, it does so in forms that are inert, suggesting that they are defective or restricted with regard to propagation.
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Affiliation(s)
| | - Sho Sugawara
- Department of Medicine, Johns Hopkins University, Baltimore, Maryland, USA
| | - Ashish Goyal
- Theoretical Biology and Biophysics, Los Alamos National Laboratory, Los Alamos, New Mexico, USA
| | - Christine M Durand
- Department of Medicine, Johns Hopkins University, Baltimore, Maryland, USA
| | - Jeffrey Quinn
- Department of Medicine, Johns Hopkins University, Baltimore, Maryland, USA
| | | | - Andrew M Cameron
- Department of Surgery, Johns Hopkins University, Baltimore, Maryland, USA
| | - Justin R Bailey
- Department of Medicine, Johns Hopkins University, Baltimore, Maryland, USA
| | - Alan S Perelson
- Theoretical Biology and Biophysics, Los Alamos National Laboratory, Los Alamos, New Mexico, USA
| | - Ashwin Balagopal
- Department of Medicine, Johns Hopkins University, Baltimore, Maryland, USA
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10
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Bakir TM. The role of SAMHD1 expression and its relation to HIV-2 (Vpx) gene production. Saudi Pharm J 2018; 26:903-908. [PMID: 30202235 PMCID: PMC6128726 DOI: 10.1016/j.jsps.2018.03.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 03/10/2018] [Indexed: 11/21/2022] Open
Abstract
SAMHD1 (sterile alpha motif and HD domain 1) is a protein that is found in myeloid cells, which restricts HIV1 replication. It depletes the de-oxy-nucleoside tri-phosphate (dNTPs) pool needed for a viral cDNA synthesis leading to inhibition of viral replication inside the cells. However, it does not restrict HIV2 replication in myeloid cells due to the presence of viral Vpx protein. Vpx is a virion-associated protein which augments viral infectivity and it only exists in HIV2 and it has been recently shown in Simian Immunodeficiency Virus (SIV) and which can induce degradation of SAMHD1 protein. This increases the amount of dNTPs for viral reverse transcription in cytoplasm and HIV infection. HIV2 reverse transcription is believed to be less active than HIV1 and this could be the reason for the absence of Vpx from HIV1. Protein expression and interaction between Vpx and SAMHD1 remains unclear. The interaction of SAMHD1 and HIV2-VPx patients' cells can be considered as a first step to help in the development for more effective anti-HIV drugs and possible novel intervention therapy in the future. Present review article provides comprehensive insights on the above issue. We performed a comprehensive literature search in the bibliographic database “Pubmed,” looking at studies discussing the SAMHDI and Vpx interactions.
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11
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Kenney AD, Dowdle JA, Bozzacco L, McMichael TM, St Gelais C, Panfil AR, Sun Y, Schlesinger LS, Anderson MZ, Green PL, López CB, Rosenberg BR, Wu L, Yount JS. Human Genetic Determinants of Viral Diseases. Annu Rev Genet 2017; 51:241-263. [PMID: 28853921 DOI: 10.1146/annurev-genet-120116-023425] [Citation(s) in RCA: 90] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Much progress has been made in the identification of specific human gene variants that contribute to enhanced susceptibility or resistance to viral diseases. Herein we review multiple discoveries made with genome-wide or candidate gene approaches that have revealed significant insights into virus-host interactions. Genetic factors that have been identified include genes encoding virus receptors, receptor-modifying enzymes, and a wide variety of innate and adaptive immunity-related proteins. We discuss a range of pathogenic viruses, including influenza virus, respiratory syncytial virus, human immunodeficiency virus, human T cell leukemia virus, human papilloma virus, hepatitis B and C viruses, herpes simplex virus, norovirus, rotavirus, parvovirus, and Epstein-Barr virus. Understanding the genetic underpinnings that affect infectious disease outcomes should allow tailored treatment and prevention approaches in the future.
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Affiliation(s)
- Adam D Kenney
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, Ohio 43210, USA; , , ,
| | - James A Dowdle
- Department of Cancer Biology and Genetics, The Ohio State University, Columbus, Ohio 43210, USA;
| | - Leonia Bozzacco
- Laboratory of Virology and Infectious Disease, The Rockefeller University, New York, NY 10065, USA.,Current affiliation: Target Information Group, Regeneron Pharmaceuticals, Inc., Tarrytown, New York 10591, USA;
| | - Temet M McMichael
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, Ohio 43210, USA; , , ,
| | - Corine St Gelais
- Center of Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio 43210, USA; , , ,
| | - Amanda R Panfil
- Center of Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio 43210, USA; , , ,
| | - Yan Sun
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA; ,
| | - Larry S Schlesinger
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, Ohio 43210, USA; , , , .,Texas Biomedical Research Institute, San Antonio, Texas 78227, USA;
| | - Matthew Z Anderson
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, Ohio 43210, USA; , , ,
| | - Patrick L Green
- Center of Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio 43210, USA; , , ,
| | - Carolina B López
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA; ,
| | - Brad R Rosenberg
- Program in Immunogenomics, John C. Whitehead Presidential Fellows Program, The Rockefeller University, New York, NY 10065, USA.,Current affiliation: Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA;
| | - Li Wu
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, Ohio 43210, USA; , , , .,Center of Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio 43210, USA; , , ,
| | - Jacob S Yount
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, Ohio 43210, USA; , , ,
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12
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Inhibition of Vpx-Mediated SAMHD1 and Vpr-Mediated Host Helicase Transcription Factor Degradation by Selective Disruption of Viral CRL4 (DCAF1) E3 Ubiquitin Ligase Assembly. J Virol 2017; 91:JVI.00225-17. [PMID: 28202763 DOI: 10.1128/jvi.00225-17] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Accepted: 02/09/2017] [Indexed: 12/21/2022] Open
Abstract
The lentiviral accessory proteins Vpx and Vpr are known to utilize CRL4 (DCAF1) E3 ligase to induce the degradation of the host restriction factor SAMHD1 or host helicase transcription factor (HLTF), respectively. Selective disruption of viral CRL4 (DCAF1) E3 ligase could be a promising antiviral strategy. Recently, we have determined that posttranslational modification (neddylation) of Cullin-4 is required for the activation of Vpx-CRL4 (DCAF1) E3 ligase. However, the mechanism of Vpx/Vpr-CRL4 (DCAF1) E3 ligase assembly is still poorly understood. Here, we report that zinc coordination is an important regulator of Vpx-CRL4 E3 ligase assembly. Residues in a conserved zinc-binding motif of Vpx were essential for the recruitment of the CRL4 (DCAF1) E3 complex and Vpx-induced SAMHD1 degradation. Importantly, altering the intracellular zinc concentration by treatment with the zinc chelator N,N,N'-tetrakis-(2'-pyridylmethyl)ethylenediamine (TPEN) potently blocked Vpx-mediated SAMHD1 degradation and inhibited wild-type SIVmac (simian immunodeficiency virus of macaques) infection of myeloid cells, even in the presence of Vpx. TPEN selectively inhibited Vpx and DCAF1 binding but not the Vpx-SAMHD1 interaction or Vpx virion packaging. Moreover, we have shown that zinc coordination is also important for the assembly of the HIV-1 Vpr-CRL4 E3 ligase. In particular, Vpr zinc-binding motif mutation or TPEN treatment efficiently inhibited Vpr-CRL4 (DCAF1) E3 ligase assembly and Vpr-mediated HLTF degradation or Vpr-induced G2 cell cycle arrest. Collectively, our study sheds light on a conserved strategy by the viral proteins Vpx and Vpr to recruit host CRL4 (DCAF1) E3 ligase, which represents a target for novel anti-human immunodeficiency virus (HIV) drug development.IMPORTANCE The Vpr and its paralog Vpx are accessory proteins encoded by different human immunodeficiency virus (HIV)/simian immunodeficiency virus (SIV) lentiviruses. To facilitate viral replication, Vpx has evolved to induce SAMHD1 degradation and Vpr to mediate HLTF degradation. Both Vpx and Vpr perform their functions by recruiting CRL4 (DCAF1) E3 ligase. In this study, we demonstrate that the assembly of the Vpx- or Vpr-CRL4 E3 ligase requires a highly conserved zinc-binding motif. This motif is specifically required for the DCAF1 interaction but not for the interaction of Vpx or Vpr with its substrate. Selective disruption of Vpx- or Vpr-CRL4 E3 ligase function was achieved by zinc sequestration using N,N,N'-tetrakis-(2'-pyridylmethyl)ethylenediamine (TPEN). At the same time, zinc sequestration had no effect on zinc-dependent cellular protein functions. Therefore, information obtained from this study may be important for novel anti-HIV drug development.
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13
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Daly MB, Roth ME, Bonnac L, Maldonado JO, Xie J, Clouser CL, Patterson SE, Kim B, Mansky LM. Dual anti-HIV mechanism of clofarabine. Retrovirology 2016; 13:20. [PMID: 27009333 PMCID: PMC4806454 DOI: 10.1186/s12977-016-0254-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Accepted: 03/17/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND HIV-1 replication kinetics inherently depends on the availability of cellular dNTPs for viral DNA synthesis. In activated CD4(+) T cells and other rapidly dividing cells, the concentrations of dNTPs are high and HIV-1 reverse transcription occurs in an efficient manner. In contrast, nondividing cells such as macrophages have lower dNTP pools, which restricts efficient reverse transcription. Clofarabine is an FDA approved ribonucleotide reductase inhibitor, which has shown potent antiretroviral activity in transformed cell lines. Here, we explore the potency, toxicity and mechanism of action of clofarabine in the human primary HIV-1 target cells: activated CD4(+) T cells and macrophages. RESULTS Clofarabine is a potent HIV-1 inhibitor in both activated CD4(+) T cells and macrophages. Due to its minimal toxicity in macrophages, clofarabine displays a selectivity index over 300 in this nondividing cell type. The anti-HIV-1 activity of clofarabine correlated with a significant decrease in both cellular dNTP levels and viral DNA synthesis. Additionally, we observed that clofarabine triphosphate was directly incorporated into DNA by HIV-1 reverse transcriptase and blocked processive DNA synthesis, particularly at the low dNTP levels found in macrophages. CONCLUSIONS Taken together, these data provide strong mechanistic evidence that clofarabine is a dual action inhibitor of HIV-1 replication that both limits dNTP substrates for viral DNA synthesis and directly inhibits the DNA polymerase activity of HIV-1 reverse transcriptase.
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Affiliation(s)
- Michele B Daly
- Center for Drug Discovery, Department of Pediatrics, Emory Center for AIDS Research, Emory University, Children's Healthcare of Atlanta, 1760 Haygood Dr., Atlanta, GA, 30322, USA
| | - Megan E Roth
- Institute for Molecular Virology, University of Minnesota, 18-242 Moos Tower, 515 Delaware St SE, Minneapolis, MN, 55455, USA.,Department of Diagnostic and Biological Sciences, School of Dentistry, University of Minnesota, Minneapolis, MN, 55455, USA.,Department of Microbiology and Immunology, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Laurent Bonnac
- Center for Drug Design, Academic Health Center, University of Minnesota, Minneapolis, MN, 55455, USA
| | - José O Maldonado
- Institute for Molecular Virology, University of Minnesota, 18-242 Moos Tower, 515 Delaware St SE, Minneapolis, MN, 55455, USA.,Department of Diagnostic and Biological Sciences, School of Dentistry, University of Minnesota, Minneapolis, MN, 55455, USA.,Department of Microbiology and Immunology, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Jiashu Xie
- Center for Drug Design, Academic Health Center, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Christine L Clouser
- Institute for Molecular Virology, University of Minnesota, 18-242 Moos Tower, 515 Delaware St SE, Minneapolis, MN, 55455, USA
| | - Steven E Patterson
- Center for Drug Design, Academic Health Center, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Baek Kim
- Center for Drug Discovery, Department of Pediatrics, Emory Center for AIDS Research, Emory University, Children's Healthcare of Atlanta, 1760 Haygood Dr., Atlanta, GA, 30322, USA.
| | - Louis M Mansky
- Institute for Molecular Virology, University of Minnesota, 18-242 Moos Tower, 515 Delaware St SE, Minneapolis, MN, 55455, USA. .,Department of Diagnostic and Biological Sciences, School of Dentistry, University of Minnesota, Minneapolis, MN, 55455, USA. .,Department of Microbiology and Immunology, University of Minnesota, Minneapolis, MN, 55455, USA. .,Center for Drug Design, Academic Health Center, University of Minnesota, Minneapolis, MN, 55455, USA.
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14
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Abstract
The enzyme reverse transcriptase (RT) was discovered in retroviruses almost 50 years ago. The demonstration that other types of viruses, and what are now called retrotransposons, also replicated using an enzyme that could copy RNA into DNA came a few years later. The intensity of the research in both the process of reverse transcription and the enzyme RT was greatly stimulated by the recognition, in the mid-1980s, that human immunodeficiency virus (HIV) was a retrovirus and by the fact that the first successful anti-HIV drug, azidothymidine (AZT), is a substrate for RT. Although AZT monotherapy is a thing of the past, the most commonly prescribed, and most successful, combination therapies still involve one or both of the two major classes of anti-RT drugs. Although the basic mechanics of reverse transcription were worked out many years ago, and the first high-resolution structures of HIV RT are now more than 20 years old, we still have much to learn, particularly about the roles played by the host and viral factors that make the process of reverse transcription much more efficient in the cell than in the test tube. Moreover, we are only now beginning to understand how various host factors that are part of the innate immunity system interact with the process of reverse transcription to protect the host-cell genome, the host cell, and the whole host, from retroviral infection, and from unwanted retrotransposition.
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15
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Hollenbaugh JA, Schader SM, Schinazi RF, Kim B. Differential regulatory activities of viral protein X for anti-viral efficacy of nucleos(t)ide reverse transcriptase inhibitors in monocyte-derived macrophages and activated CD4(+) T cells. Virology 2015; 485:313-21. [PMID: 26319213 PMCID: PMC4619155 DOI: 10.1016/j.virol.2015.08.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Revised: 07/27/2015] [Accepted: 08/08/2015] [Indexed: 01/05/2023]
Abstract
Vpx encoded by HIV-2 and SIVsm enhances retroviral reverse transcription in macrophages in vitro by mediating the degradation of the host SAMHD1 protein that hydrolyzes dNTPs and by elevating cellular dNTP levels. Here we employed RT-SHIV constructs (SIV encoding HIV-1 RT) to investigate the contribution of Vpx to the potency of NRTIs, which compete against dNTPs, in monocyte-derived macrophages (MDMs) and activated CD4(+) T cells. Relative to HIV-1, both SIV and RT-SHIV exhibited reduced sensitivities to AZT, 3TC and TDF in MDMs but not in activated CD4(+) T cells. However, when SIV and RT-SHIV constructs not coding for Vpx were utilized, we observed greater sensitivities to all NRTIs tested using activated CD4(+) T cells relative to the Vpx-coding counterparts. This latter phenomenon was observed for AZT only when using MDMs. Our data suggest that Vpx in RT-SHIVs may underestimate the antiviral efficacy of NRTIs in a cell type dependent manner.
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Affiliation(s)
- Joseph A Hollenbaugh
- Center for Drug Discovery, Department of Pediatrics, Emory University, Atlanta, GA, USA
| | - Susan M Schader
- Center for Drug Discovery, Department of Pediatrics, Emory University, Atlanta, GA, USA
| | - Raymond F Schinazi
- Center for Drug Discovery, Department of Pediatrics, Emory University, Atlanta, GA, USA; Veterans Affairs Medical Center, Atlanta, GA, USA
| | - Baek Kim
- Center for Drug Discovery, Department of Pediatrics, Emory University, Atlanta, GA, USA; College of Pharmacy, Kyung Hee University, Seoul, South Korea.
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16
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Choi J, Ryoo J, Oh C, Hwang S, Ahn K. SAMHD1 specifically restricts retroviruses through its RNase activity. Retrovirology 2015; 12:46. [PMID: 26032178 PMCID: PMC4450836 DOI: 10.1186/s12977-015-0174-4] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Accepted: 05/15/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Human SAMHD1 possesses dual enzymatic functions. It acts as both a dGTP-dependent triphosphohydrolase and as an exoribonuclease. The dNTPase function depletes the cellular dNTP pool, which is required for retroviral reverse transcription in differentiated myeloid cells and resting CD4(+) T cells; thus this activity mainly plays a role in SAMHD1-mediated retroviral restriction. However, a recent study demonstrated that SAMHD1 directly targets HIV-1 genomic RNA via its RNase activity, and that this function (rather than dNTPase activity) is sufficient for HIV-1 restriction. While HIV-1 genomic RNA is a potent target for SAMHD1 during viral infection, the specificity of SAMHD1-mediated RNase activity during infection by other viruses is unclear. RESULTS The results of the present study showed that SAMHD1 specifically degrades retroviral genomic RNA in monocyte-derived macrophage-like cells and in primary monocyte-derived macrophages. Consistent with this, SAMHD1 selectively restricted retroviral replication, but did not affect the replication of other common non-retro RNA genome viruses, suggesting that the RNase-mediated antiviral function of SAMHD1 is limited to retroviruses. In addition, neither inhibiting reverse transcription by treatment with several reverse transcriptase inhibitors nor infection with reverse transcriptase-defective HIV-1 altered RNA levels after viral challenge, indicating that the retrovirus-specific RNase function is not dependent on processes associated with retroviral reverse transcription. CONCLUSIONS The results presented herein suggest that the RNase activity of SAMHD1 is sufficient to control the replication of retroviruses, but not that of non-retro RNA viruses.
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Affiliation(s)
- Jongsu Choi
- Creative Research Initiative Center for Antigen Presentation, Seoul National University, Seoul, Republic of Korea. .,Department of Biological Sciences, Seoul National University, Seoul, Republic of Korea.
| | - Jeongmin Ryoo
- Creative Research Initiative Center for Antigen Presentation, Seoul National University, Seoul, Republic of Korea. .,Department of the Interdisciplinary Program in Genetic Engineering, Seoul National University, Seoul, Republic of Korea.
| | - Changhoon Oh
- Creative Research Initiative Center for Antigen Presentation, Seoul National University, Seoul, Republic of Korea. .,Department of the Interdisciplinary Program in Genetic Engineering, Seoul National University, Seoul, Republic of Korea.
| | - Sungyeon Hwang
- Creative Research Initiative Center for Antigen Presentation, Seoul National University, Seoul, Republic of Korea. .,Department of Biological Sciences, Seoul National University, Seoul, Republic of Korea.
| | - Kwangseog Ahn
- Creative Research Initiative Center for Antigen Presentation, Seoul National University, Seoul, Republic of Korea. .,Department of Biological Sciences, Seoul National University, Seoul, Republic of Korea.
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17
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Hertoghs N, van der Aar AMG, Setiawan LC, Kootstra NA, Gringhuis SI, Geijtenbeek TBH. SAMHD1 degradation enhances active suppression of dendritic cell maturation by HIV-1. THE JOURNAL OF IMMUNOLOGY 2015; 194:4431-7. [PMID: 25825449 DOI: 10.4049/jimmunol.1403016] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 02/26/2015] [Indexed: 11/19/2022]
Abstract
A hallmark of HIV-1 infection is the lack of sterilizing immunity. Dendritic cells (DCs) are crucial in the induction of immunity, and lack of DC activation might underlie the absence of an effective anti-HIV-1 response. We have investigated how HIV-1 infection affects maturation of DCs. Our data show that even though DCs are productively infected by HIV-1, infection does not induce DC maturation. HIV-1 infection actively suppresses DC maturation, as HIV-1 infection inhibited TLR-induced maturation of DCs and thereby decreased the immune stimulatory capacity of DCs. Interfering with SAMHD1 restriction further increased infection of DCs, but did not lead to DC maturation. Notably, higher infection observed with SAMHD1 depletion correlated with a stronger suppression of maturation. Furthermore, blocking reverse transcription rescued TLR-induced maturation. These data strongly indicate that HIV-1 replication does not trigger immune activation in DCs, but that HIV-1 escapes immune surveillance by actively suppressing DC maturation independent of SAMHD1. Elucidation of the mechanism of suppression can lead to promising targets for therapy or vaccine design.
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Affiliation(s)
- Nina Hertoghs
- Department of Experimental Immunology, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, the Netherlands; and
| | - Angelic M G van der Aar
- Department of Experimental Immunology, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, the Netherlands; and
| | - Laurentia C Setiawan
- Department of Experimental Immunology, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, the Netherlands; and Laboratory of Viral Immune Pathogenesis, Department of Experimental Immunology, Center for Infection and Immunity Amsterdam, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, the Netherlands
| | - Neeltje A Kootstra
- Department of Experimental Immunology, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, the Netherlands; and Laboratory of Viral Immune Pathogenesis, Department of Experimental Immunology, Center for Infection and Immunity Amsterdam, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, the Netherlands
| | - Sonja I Gringhuis
- Department of Experimental Immunology, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, the Netherlands; and
| | - Teunis B H Geijtenbeek
- Department of Experimental Immunology, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, the Netherlands; and
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18
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Lenzi GM, Domaoal RA, Kim DH, Schinazi RF, Kim B. Kinetic variations between reverse transcriptases of viral protein X coding and noncoding lentiviruses. Retrovirology 2014; 11:111. [PMID: 25524560 PMCID: PMC4282736 DOI: 10.1186/s12977-014-0111-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Accepted: 11/24/2014] [Indexed: 01/29/2023] Open
Abstract
Background Host SAM domain and HD domain-containing protein 1 (SAMHD1) suppresses reverse transcription kinetics of HIV-1 in nondividing cells such as macrophages by hydrolyzing and nearly depleting cellular dNTPs, which are the substrates of viral reverse transcriptase (RT). However, unlike HIV-1, HIV-2 and SIVsm encode viral protein X (Vpx), which counteracts the dNTPase activity of SAMHD1 and elevates dNTP concentration, allowing the viruses to replicate under abundant dNTP conditions even in nondividing cells. Findings Here we tested whether RTs of these Vpx coding and noncoding lentiviruses display different enzyme kinetic profiles in response to dNTP concentrations. For this test, we characterized an extensive collection of RTs from 7 HIV-1 strains, 4 HIV-2 strains and 7 SIV strains, and determined their steady-state kinetic parameters. The Km values of all HIV-1 RTs were consistently low and close to the low dNTP concentrations found in macrophages. However, the Km values of SIV and HIV-2 RTs were not only higher than those of HIV-1 RTs but also varied significantly, indicating that HIV-2/SIV RTs require higher dNTP concentrations for efficient DNA synthesis, compared to HIV-1 RT. However, the kcat values of all eighteen lentiviral RTs were very similar. Conclusions Our biochemical analysis supports the hypothesis that the enzymological properties, particularly, Km values, of lentivirus RTs, are mechanistically tied with the cellular dNTP availability in nondividing target cells, which is controlled by SAMHD1 and Vpx.
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Affiliation(s)
- Gina M Lenzi
- Center for Drug Discovery, Center for AIDS Research, Department of Pediatrics, Emory University School of Medicine, 1760 Haygood Drive, Atlanta, GA, USA.
| | - Robert A Domaoal
- Center for Drug Discovery, Center for AIDS Research, Department of Pediatrics, Emory University School of Medicine, 1760 Haygood Drive, Atlanta, GA, USA.
| | - Dong-Hyun Kim
- College of Pharmacy, Kyung-Hee University, Seoul, South Korea.
| | - Raymond F Schinazi
- Center for Drug Discovery, Center for AIDS Research, Department of Pediatrics, Emory University School of Medicine, 1760 Haygood Drive, Atlanta, GA, USA. .,Veterans Affairs Medical Center, Decatur, GA, USA.
| | - Baek Kim
- Center for Drug Discovery, Center for AIDS Research, Department of Pediatrics, Emory University School of Medicine, 1760 Haygood Drive, Atlanta, GA, USA. .,College of Pharmacy, Kyung-Hee University, Seoul, South Korea.
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19
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Identification of cellular proteins interacting with the retroviral restriction factor SAMHD1. J Virol 2014; 88:5834-44. [PMID: 24623419 DOI: 10.1128/jvi.00155-14] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Human and mouse SAMHD1 proteins block human immunodeficiency virus type 1 (HIV-1) infection in noncycling human monocytic cells by reducing the intracellular deoxynucleoside triphosphate (dNTP) concentrations. Phosphorylation of human SAMHD1 at threonine 592 (T592) by cyclin-dependent kinase 1 (CDK1) and cyclin A2 impairs its HIV-1 restriction activity, but not the dNTP hydrolase activity, suggesting that dNTP depletion is not the sole mechanism of SAMHD1-mediated HIV-1 restriction. Using coimmunoprecipitation and mass spectrometry, we identified and validated two additional host proteins interacting with human SAMHD1, namely, cyclin-dependent kinase 2 (CDK2) and S-phase kinase-associated protein 2 (SKP2). We observed that mouse SAMHD1 specifically interacted with cyclin A2, cyclin B1, CDK1, and CDK2. Given the role of these SAMHD1-interacting proteins in cell cycle progression, we investigated the regulation of these host proteins by monocyte differentiation and activation of CD4+ T cells and examined their effect on the phosphorylation of human SAMHD1 at T592. Our results indicate that primary monocyte differentiation and CD4+ T-cell activation regulate the expression of these SAMHD1-interacting proteins. Furthermore, our results suggest that, in addition to CDK1 and cyclin A2, CDK2 phosphorylates T592 of human SAMHD1 and thereby regulates its HIV-1 restriction function. IMPORTANCE SAMHD1 is the first dNTP triphosphohydrolase found in mammalian cells. Human and mouse SAMHD1 proteins block HIV-1 infection in noncycling cells. Previous studies suggested that phosphorylation of human SAMHD1 at threonine 592 by CDK1 and cyclin A2 negatively regulates its HIV-1 restriction activity. However, it is unclear whether human SAMHD1 interacts with other host proteins in the cyclin A2 and CDK1 complex and whether mouse SAMHD1 shares similar cellular interacting partners. Here, we identify five cell cycle-related host proteins that interact with human and mouse SAMHD1, including three previously unknown cellular proteins (CDK2, cyclin B1, and SKP2). Our results demonstrate that several SAMHD1-interacting cellular proteins regulate phosphorylation of SAMHD1 and play an important role in HIV-1 restriction function. Our findings help define the role of these cellular interacting partners of SAMHD1 that regulate its HIV-1 restriction function.
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20
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Marno KM, Ogunkolade BW, Pade C, Oliveira NMM, O'Sullivan E, McKnight Á. Novel restriction factor RNA-associated early-stage anti-viral factor (REAF) inhibits human and simian immunodeficiency viruses. Retrovirology 2014; 11:3. [PMID: 24410916 PMCID: PMC3895926 DOI: 10.1186/1742-4690-11-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Accepted: 11/28/2013] [Indexed: 01/09/2023] Open
Abstract
Background The discovery of novel anti-viral restriction factors illuminates unknown aspects of innate sensing and immunity. We identified RNA-associated Early-stage Anti-viral Factor (REAF) using a whole genome siRNA screen for restriction factors to human immunodeficiency virus (HIV) that act in the early phase of viral replication. Results We observed more than 50 fold rescue of HIV-1 infection, using a focus forming unit (FFU) assay, following knockdown of REAF by specific siRNA. Quantitative PCR was used to show that REAF knockdown results in an increase of early and late reverse transcripts which impacts the level of integration. REAF thus appears to act at an early stage of the viral life cycle during reverse transcription. Conversely when REAF is over-expressed in target cells less infected cells are detectable and fewer reverse transcripts are produced. Human REAF can also inhibit HIV-2 and simian immunodeficiency virus (SIV) infection. REAF associates with viral nucleic acids and may act to prevent reverse transcription. Conclusions This report firmly places REAF alongside APOBECs and SAMHD1 as a potent inhibitor of HIV replication acting early in the replication cycle, just after cell entry. We propose that REAF is part of an anti-viral surveillance system destroying incoming retroviruses. This novel mechanism could apply to invasion of cells by any intracellular pathogen.
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Affiliation(s)
| | | | | | | | | | - Áine McKnight
- Centre for Immunology and Infectious Disease, Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK.
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21
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Immunopathogenesis of simian immunodeficiency virus infection in nonhuman primates. Curr Opin HIV AIDS 2013; 8:273-9. [PMID: 23615117 DOI: 10.1097/coh.0b013e328361cf5b] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
PURPOSE OF REVIEW Soon after the discovery of HIV-infected humans, rhesus macaques in a colony at the New England Primate Research Center showed similar signs of a progressive immune suppression. The discovery of the simian immunodeficiency virus (SIV)-associated disease opened the door to study an AIDS-like illness in nonhuman primates (NHP). Even after 3 decades, this animal model remains an invaluable tool to provide a greater insight into HIV immunopathogenesis. In this review, recent progress in deciphering pathways of immunopathogenesis in SIV-infected NHP is discussed. RECENT FINDINGS The immense diversity of mutations in SIV stocks prepared at different laboratories has recently been realized. The massive expansion of the enteric virome is a key finding in SIV-induced immunopathogenesis. Defining the function of host restriction factors, like the recently discovered SAMHD1, helps to evaluate the impact of the innate immune responses on virus replication. Utilization of pyrosequencing and defining molecular mechanisms of major histocompatibility complex (MHC) class I restriction helps to understand how the virus evades CD8 T-cell responses. The definition of MHC class I molecules in different NHP species provides new animal models to study SIV immunopathogenesis. T follicular helper cells have gained major interest in characterizing humoral immune responses in SIV infection and AIDS vaccine strategies. The ability of natural hosts to remain disease-free despite ongoing replication of SIV is continuing to puzzle the field. SUMMARY The HIV research field continues to realize the immense complexity of the host virus interaction. NHP present an invaluable tool to make progress towards an effective AIDS vaccine.
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Contribution of oligomerization to the anti-HIV-1 properties of SAMHD1. Retrovirology 2013; 10:131. [PMID: 24219908 PMCID: PMC3882887 DOI: 10.1186/1742-4690-10-131] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Accepted: 10/10/2013] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND SAMHD1 is a restriction factor that potently blocks infection by HIV-1 and other retroviruses. We have previously demonstrated that SAMHD1 oligomerizes in mammalian cells by immunoprecipitation. Here we investigated the contribution of SAMHD1 oligomerization to retroviral restriction. RESULTS Structural analysis of SAMHD1 and homologous HD domain proteins revealed that key hydrophobic residues Y146, Y154, L428 and Y432 stabilize the extensive dimer interface observed in the SAMHD1 crystal structure. Full-length SAMHD1 variants Y146S/Y154S and L428S/Y432S lost their ability to oligomerize tested by immunoprecipitation in mammalian cells. In agreement with these observations, the Y146S/Y154S variant of a bacterial construct expressing the HD domain of human SAMHD1 (residues 109-626) disrupted the dGTP-dependent tetramerization of SAMHD1 in vitro. Tetramerization-defective variants of the full-length SAMHD1 immunoprecipitated from mammalian cells and of the bacterially-expressed HD domain construct lost their dNTPase activity. The nuclease activity of the HD domain construct was not perturbed by the Y146S/Y154S mutations. Remarkably, oligomerization-deficient SAMHD1 variants potently restricted HIV-1 infection. CONCLUSIONS These results suggested that SAMHD1 oligomerization is not required for the ability of the protein to block HIV-1 infection.
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23
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Ren T, Cheng H. Differential transforming activity of the retroviral Tax oncoproteins in human T lymphocytes. Front Microbiol 2013; 4:287. [PMID: 24065965 PMCID: PMC3779817 DOI: 10.3389/fmicb.2013.00287] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Accepted: 09/05/2013] [Indexed: 12/11/2022] Open
Abstract
Human T cell leukemia virus type 1 and type 2 (HTLV-1 and -2) are two closely related retroviruses. HTLV-1 causes adult T cell leukemia and lymphoma, whereas HTLV-2 infection is not etiologically linked to human disease. The viral genomes of HTLV-1 and -2 encode highly homologous transforming proteins, Tax-1 and Tax-2, respectively. Tax-1 is thought to play a central role in transforming CD4+ T lymphocytes. Expression of Tax-1 is crucial for promoting survival and proliferation of virally infected human T lymphocytes and is necessary for initiating HTLV-1-mediated oncogenesis. In transgenic mice and humanized mouse model, Tax-1 has proven to be leukemogenic. Although Tax-1 is able to efficiently transform rodent fibroblasts and to induce lymphoma in mouse model, it rarely transforms primary human CD4+ T lymphocytes. In contrast, Tax-2 efficiently immortalizes human CD4+ T cells though it exhibits a lower transforming activity in rodent cells as compared to Tax-1. We here discuss our recent observation and views on the differential transforming activity of Tax-1 and Tax-2 in human T cells.
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Affiliation(s)
- Tong Ren
- Penn State Hershey Cancer Institute Hershey, PA, USA
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Watashi K, Liang G, Iwamoto M, Marusawa H, Uchida N, Daito T, Kitamura K, Muramatsu M, Ohashi H, Kiyohara T, Suzuki R, Li J, Tong S, Tanaka Y, Murata K, Aizaki H, Wakita T. Interleukin-1 and tumor necrosis factor-α trigger restriction of hepatitis B virus infection via a cytidine deaminase activation-induced cytidine deaminase (AID). J Biol Chem 2013. [PMID: 24025329 DOI: 10.1074/jbc.m113.50112] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Virus infection is restricted by intracellular immune responses in host cells, and this is typically modulated by stimulation of cytokines. The cytokines and host factors that determine the host cell restriction against hepatitis B virus (HBV) infection are not well understood. We screened 36 cytokines and chemokines to determine which were able to reduce the susceptibility of HepaRG cells to HBV infection. Here, we found that pretreatment with IL-1β and TNFα remarkably reduced the host cell susceptibility to HBV infection. This effect was mediated by activation of the NF-κB signaling pathway. A cytidine deaminase, activation-induced cytidine deaminase (AID), was up-regulated by both IL-1β and TNFα in a variety of hepatocyte cell lines and primary human hepatocytes. Another deaminase APOBEC3G was not induced by these proinflammatory cytokines. Knockdown of AID expression impaired the anti-HBV effect of IL-1β, and overexpression of AID antagonized HBV infection, suggesting that AID was one of the responsible factors for the anti-HBV activity of IL-1/TNFα. Although AID induced hypermutation of HBV DNA, this activity was dispensable for the anti-HBV activity. The antiviral effect of IL-1/TNFα was also observed on different HBV genotypes but not on hepatitis C virus. These results demonstrate that proinflammatory cytokines IL-1/TNFα trigger a novel antiviral mechanism involving AID to regulate host cell permissiveness to HBV infection.
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Affiliation(s)
- Koichi Watashi
- From the Department of Virology II, National Institute of Infectious Diseases, Tokyo 162-8640, Japan
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25
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Watashi K, Liang G, Iwamoto M, Marusawa H, Uchida N, Daito T, Kitamura K, Muramatsu M, Ohashi H, Kiyohara T, Suzuki R, Li J, Tong S, Tanaka Y, Murata K, Aizaki H, Wakita T. Interleukin-1 and tumor necrosis factor-α trigger restriction of hepatitis B virus infection via a cytidine deaminase activation-induced cytidine deaminase (AID). J Biol Chem 2013; 288:31715-27. [PMID: 24025329 PMCID: PMC3814766 DOI: 10.1074/jbc.m113.501122] [Citation(s) in RCA: 123] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Virus infection is restricted by intracellular immune responses in host cells, and this is typically modulated by stimulation of cytokines. The cytokines and host factors that determine the host cell restriction against hepatitis B virus (HBV) infection are not well understood. We screened 36 cytokines and chemokines to determine which were able to reduce the susceptibility of HepaRG cells to HBV infection. Here, we found that pretreatment with IL-1β and TNFα remarkably reduced the host cell susceptibility to HBV infection. This effect was mediated by activation of the NF-κB signaling pathway. A cytidine deaminase, activation-induced cytidine deaminase (AID), was up-regulated by both IL-1β and TNFα in a variety of hepatocyte cell lines and primary human hepatocytes. Another deaminase APOBEC3G was not induced by these proinflammatory cytokines. Knockdown of AID expression impaired the anti-HBV effect of IL-1β, and overexpression of AID antagonized HBV infection, suggesting that AID was one of the responsible factors for the anti-HBV activity of IL-1/TNFα. Although AID induced hypermutation of HBV DNA, this activity was dispensable for the anti-HBV activity. The antiviral effect of IL-1/TNFα was also observed on different HBV genotypes but not on hepatitis C virus. These results demonstrate that proinflammatory cytokines IL-1/TNFα trigger a novel antiviral mechanism involving AID to regulate host cell permissiveness to HBV infection.
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Affiliation(s)
- Koichi Watashi
- From the Department of Virology II, National Institute of Infectious Diseases, Tokyo 162-8640, Japan
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Abstract
Replication of HIV-1 and other retroviruses is dependent on numerous host proteins in the cells. Some of the host proteins, however, function as restriction factors to block retroviral infection of target cells. The host protein SAMHD1 has been identified as the first mammalian deoxynucleoside triphosphate triphosphohydrolase (dNTPase), which blocks the infection of HIV-1 and other retroviruses in non-cycling immune cells. SAMHD1 protein is highly expressed in human myeloid-lineage cells and CD4+ T-lymphocytes, but its retroviral restriction function is only observed in noncycling cells. Recent studies have revealed biochemical mechanisms of SAMHD1-mediated retroviral restriction. In this review, the latest progress on SAMHD1 research is summarized and the mechanisms by which SAMHD1 mediates retroviral restriction are analyzed. Although the physiological function of SAMHD1 is largely unknown, this review provides perspectives about the role of endogenous SAMHD1 protein in maintaining normal cellular function, such as nucleic acid metabolism and the proliferation of cells.
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Hollenbaugh JA, Gee P, Baker J, Daly MB, Amie SM, Tate J, Kasai N, Kanemura Y, Kim DH, Ward BM, Koyanagi Y, Kim B. Host factor SAMHD1 restricts DNA viruses in non-dividing myeloid cells. PLoS Pathog 2013; 9:e1003481. [PMID: 23825958 PMCID: PMC3694861 DOI: 10.1371/journal.ppat.1003481] [Citation(s) in RCA: 133] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Accepted: 05/22/2013] [Indexed: 01/01/2023] Open
Abstract
SAMHD1 is a newly identified anti-HIV host factor that has a dNTP triphosphohydrolase activity and depletes intracellular dNTP pools in non-dividing myeloid cells. Since DNA viruses utilize cellular dNTPs, we investigated whether SAMHD1 limits the replication of DNA viruses in non-dividing myeloid target cells. Indeed, two double stranded DNA viruses, vaccinia and herpes simplex virus type 1, are subject to SAMHD1 restriction in non-dividing target cells in a dNTP dependent manner. Using a thymidine kinase deficient strain of vaccinia virus, we demonstrate a greater restriction of viral replication in non-dividing cells expressing SAMHD1. Therefore, this study suggests that SAMHD1 is a potential innate anti-viral player that suppresses the replication of a wide range of DNA viruses, as well as retroviruses, which infect non-dividing myeloid cells. Various viral pathogens such as HIV-1, herpes simplex virus (HSV) and vaccinia virus infect terminally-differentiated/non-dividing macrophages during the course of viral pathogenesis. Unlike dividing cells, non-dividing cells lack chromosomal DNA replication, do not enter the cell cycle, and harbor very low levels of cellular dNTPs, which are substrates of viral DNA polymerases. A series of recent studies revealed that the host protein SAMHD1 is dNTP triphosphohydrolase, which contributes to the poor dNTP abundance in non-dividing myeloid cells, and restricts proviral DNA synthesis of HIV-1 and other lentiviruses in macrophages, dendritic cells, and resting T cells. In this report, we demonstrate that SAMHD1 also controls the replication of large dsDNA viruses: vaccinia virus and HSV-1, in primary human monocyte-derived macrophages. SAMHD1 suppresses the replication of these DNA viruses to an even greater extent in the absence of viral genes that are involved in dNTP metabolism such as thymidine kinase. Therefore, this study supports that dsDNA viruses evolved to express enzymes necessary to increase the levels of dNTPs as a mechanism to overcome the restriction induced by SAMHD1 in myeloid cells.
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Affiliation(s)
- Joseph A. Hollenbaugh
- Department of Microbiology and Immunology, University of Rochester, Rochester, New York, United States of America
- Center for Drug Discovery, The Department of Pediatrics, Emory University, Atlanta, Georgia, United States of America
| | - Peter Gee
- Laboratory of Viral Pathogenesis, Institute for Virus Research, Kyoto University, Kyoto, Japan
| | - Jonathon Baker
- Department of Microbiology and Immunology, University of Rochester, Rochester, New York, United States of America
| | - Michele B. Daly
- Department of Microbiology and Immunology, University of Rochester, Rochester, New York, United States of America
- Center for Drug Discovery, The Department of Pediatrics, Emory University, Atlanta, Georgia, United States of America
| | - Sarah M. Amie
- Department of Microbiology and Immunology, University of Rochester, Rochester, New York, United States of America
| | - Jessica Tate
- Department of Microbiology and Immunology, University of Rochester, Rochester, New York, United States of America
| | - Natsumi Kasai
- Laboratory of Viral Pathogenesis, Institute for Virus Research, Kyoto University, Kyoto, Japan
| | - Yuka Kanemura
- Laboratory of Viral Pathogenesis, Institute for Virus Research, Kyoto University, Kyoto, Japan
| | - Dong-Hyun Kim
- Department of Pharmacy, Kyung-Hee University, Seoul, South Korea
| | - Brian M. Ward
- Department of Microbiology and Immunology, University of Rochester, Rochester, New York, United States of America
- * E-mail: (BW); (YK); (BK)
| | - Yoshio Koyanagi
- Laboratory of Viral Pathogenesis, Institute for Virus Research, Kyoto University, Kyoto, Japan
- * E-mail: (BW); (YK); (BK)
| | - Baek Kim
- Department of Microbiology and Immunology, University of Rochester, Rochester, New York, United States of America
- Center for Drug Discovery, The Department of Pediatrics, Emory University, Atlanta, Georgia, United States of America
- Department of Pharmacy, Kyung-Hee University, Seoul, South Korea
- * E-mail: (BW); (YK); (BK)
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Yu H, Usmani SM, Borch A, Krämer J, Stürzel CM, Khalid M, Li X, Krnavek D, van der Ende ME, Osterhaus AD, Gruters RA, Kirchhoff F. The efficiency of Vpx-mediated SAMHD1 antagonism does not correlate with the potency of viral control in HIV-2-infected individuals. Retrovirology 2013; 10:27. [PMID: 23497283 PMCID: PMC3599662 DOI: 10.1186/1742-4690-10-27] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2012] [Accepted: 02/22/2013] [Indexed: 11/30/2022] Open
Affiliation(s)
- Hangxing Yu
- Institute of Molecular Virology, Ulm University Medical Center, Ulm 89081, Germany
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29
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de Silva S, Hoy H, Hake TS, Wong HK, Porcu P, Wu L. Promoter methylation regulates SAMHD1 gene expression in human CD4+ T cells. J Biol Chem 2013; 288:9284-92. [PMID: 23426363 DOI: 10.1074/jbc.m112.447201] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The retrovirus restriction factor SAMHD1 is the first identified mammalian dNTP triphosphohydrolase that is highly expressed in human myeloid lineage cells and CD4(+) T lymphocytes. Although SAMHD1 expression is variable in human cell lines and tissue types, mechanisms underlying SAMHD1 gene regulation have not been defined. Recent studies showed that SAMHD1 is highly expressed in human primary CD4(+) T lymphocytes, but not in some CD4(+) T cell lines. Here, we report that SAMHD1 expression varies among four CD4(+) T cell lines and is transcriptionally regulated. Cloning and sequence analysis of the human SAMHD1 promoter revealed a CpG island that is methylated in CD4(+) T cell lines (such as Jurkat and Sup-T1), resulting in transcriptional repression of SAMHD1. We also found that the SAMHD1 promoter is unmethylated in primary CD4(+) T lymphocytes, which express high levels of SAMHD1, indicating a direct correlation between the methylation of the SAMHD1 promoter and transcriptional repression. SAMHD1 expression was induced in CD4(+) T cell lines by blocking DNA methyltransferase activity, suggesting that promoter methylation is one of the key epigenetic mechanisms by which SAMHD1 expression is regulated.
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Affiliation(s)
- Suresh de Silva
- Center for Retrovirus Research, Department of Veterinary Biosciences, The OhioState University, Columbus, OH 43210, USA
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30
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Zhang Q, Chen CY, Yedavalli VSRK, Jeang KT. NEAT1 long noncoding RNA and paraspeckle bodies modulate HIV-1 posttranscriptional expression. mBio 2013. [PMID: 23362321 DOI: 10.1128/mbio.00596-12.editor] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023] Open
Abstract
Most of the human genome is transcribed into protein-noncoding RNAs (ncRNAs), including small ncRNAs and long ncRNAs (lncRNAs). Over the past decade, rapidly emerging evidence has increasingly supported the view that lncRNAs serve key regulatory and functional roles in mammal cells. HIV-1 replication relies on various cell functions. To date, while the involvement of host protein factors and microRNAs (miRNAs) in the HIV-1 life cycle has been extensively studied, the relationship between lncRNAs and HIV-1 remains uncharacterized. Here, we have profiled 83 disease-related lncRNAs in HIV-1-infected T cells. We found NEAT1 to be one of several lncRNAs whose expression is changed by HIV-1 infection, and we have characterized its role in HIV-1 replication. We In the abstract, added definition of INS OK, or should "cis-acting" be added?report here that the knockdown of NEAT1 enhances virus production through increased nucleus-to-cytoplasm export of Rev-dependent instability element (INS)-containing HIV-1 mRNAs. IMPORTANCE Long protein-noncoding RNAs (lncRNAs) play roles in regulating gene expression and modulating protein activities. There is emerging evidence that lncRNAs are involved in the replication of viruses. To our knowledge, this report is the first to characterize a role contributed by an lncRNA, NEAT1, to HIV-1 replication. NEAT1 is essential for the integrity of the nuclear paraspeckle substructure. Based on our findings from NEAT1 knockdown, we have identified the nuclear paraspeckle body as another important subcellular organelle for HIV-1 replication.
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Affiliation(s)
- Quan Zhang
- Molecular Virology Section, Laboratory of Molecular Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
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31
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NEAT1 long noncoding RNA and paraspeckle bodies modulate HIV-1 posttranscriptional expression. mBio 2013; 4:e00596-12. [PMID: 23362321 PMCID: PMC3560530 DOI: 10.1128/mbio.00596-12] [Citation(s) in RCA: 282] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Most of the human genome is transcribed into protein-noncoding RNAs (ncRNAs), including small ncRNAs and long ncRNAs (lncRNAs). Over the past decade, rapidly emerging evidence has increasingly supported the view that lncRNAs serve key regulatory and functional roles in mammal cells. HIV-1 replication relies on various cell functions. To date, while the involvement of host protein factors and microRNAs (miRNAs) in the HIV-1 life cycle has been extensively studied, the relationship between lncRNAs and HIV-1 remains uncharacterized. Here, we have profiled 83 disease-related lncRNAs in HIV-1-infected T cells. We found NEAT1 to be one of several lncRNAs whose expression is changed by HIV-1 infection, and we have characterized its role in HIV-1 replication. We In the abstract, added definition of INS OK, or should "cis-acting" be added?report here that the knockdown of NEAT1 enhances virus production through increased nucleus-to-cytoplasm export of Rev-dependent instability element (INS)-containing HIV-1 mRNAs. IMPORTANCE Long protein-noncoding RNAs (lncRNAs) play roles in regulating gene expression and modulating protein activities. There is emerging evidence that lncRNAs are involved in the replication of viruses. To our knowledge, this report is the first to characterize a role contributed by an lncRNA, NEAT1, to HIV-1 replication. NEAT1 is essential for the integrity of the nuclear paraspeckle substructure. Based on our findings from NEAT1 knockdown, we have identified the nuclear paraspeckle body as another important subcellular organelle for HIV-1 replication.
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32
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Zheng YH, Jeang KT, Tokunaga K. Host restriction factors in retroviral infection: promises in virus-host interaction. Retrovirology 2012; 9:112. [PMID: 23254112 PMCID: PMC3549941 DOI: 10.1186/1742-4690-9-112] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2012] [Accepted: 12/09/2012] [Indexed: 01/19/2023] Open
Abstract
Retroviruses have an intricate life cycle. There is much to be learned from studying retrovirus-host interactions. Among retroviruses, the primate lentiviruses have one of the more complex genome structures with three categories of viral genes: structural, regulatory, and accessory genes. Over time, we have gained increasing understanding of the lentivirus life cycle from studying host factors that support virus replication. Similarly, studies on host restriction factors that inhibit viral replication have also made significant contributions to our knowledge. Here, we review recent progress on the rapidly growing field of restriction factors, focusing on the antiretroviral activities of APOBEC3G, TRIM5, tetherin, SAMHD1, MOV10, and cellular microRNAs (miRNAs), and the counter-activities of Vif, Vpu, Vpr, Vpx, and Nef.
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Affiliation(s)
- Yong-Hui Zheng
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, USA
| | | | - Kenzo Tokunaga
- Department of Pathology, National Institute of Infectious Diseases, Tokyo, Japan
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St Gelais C, de Silva S, Amie SM, Coleman CM, Hoy H, Hollenbaugh JA, Kim B, Wu L. SAMHD1 restricts HIV-1 infection in dendritic cells (DCs) by dNTP depletion, but its expression in DCs and primary CD4+ T-lymphocytes cannot be upregulated by interferons. Retrovirology 2012; 9:105. [PMID: 23231760 PMCID: PMC3527137 DOI: 10.1186/1742-4690-9-105] [Citation(s) in RCA: 154] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2012] [Accepted: 11/29/2012] [Indexed: 01/10/2023] Open
Abstract
Background SAMHD1 is an HIV-1 restriction factor in non-dividing monocytes, dendritic cells (DCs), macrophages, and resting CD4+ T-cells. Acting as a deoxynucleoside triphosphate (dNTP) triphosphohydrolase, SAMHD1 hydrolyzes dNTPs and restricts HIV-1 infection in macrophages and resting CD4+ T-cells by decreasing the intracellular dNTP pool. However, the intracellular dNTP pool in DCs and its regulation by SAMHD1 remain unclear. SAMHD1 has been reported as a type I interferon (IFN)-inducible protein, but whether type I IFNs upregulate SAMHD1 expression in primary DCs and CD4+ T-lymphocytes is unknown. Results Here, we report that SAMHD1 significantly blocked single-cycle and replication-competent HIV-1 infection of DCs by decreasing the intracellular dNTP pool and thereby limiting the accumulation of HIV-1 late reverse transcription products. Type I IFN treatment did not upregulate endogenous SAMHD1 expression in primary DCs or CD4+ T-lymphocytes, but did in HEK 293T and HeLa cell lines. When SAMHD1 was over-expressed in these two cell lines to achieve higher levels than that in DCs, no HIV-1 restriction was observed despite partially reducing the intracellular dNTP pool. Conclusions Our results suggest that SAMHD1-mediated reduction of the intracellular dNTP pool in DCs is a common mechanism of HIV-1 restriction in myeloid cells. Endogenous expression of SAMHD1 in primary DCs or CD4+ T-lymphocytes is not upregulated by type I IFNs.
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Affiliation(s)
- Corine St Gelais
- Center for Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, 1900 Coffey Road, Columbus, Ohio 43210, USA
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34
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Coon S, Wang D, Wu L. Polymorphisms of the SAMHD1 gene are not associated with the infection and natural control of HIV type 1 in Europeans and African-Americans. AIDS Res Hum Retroviruses 2012; 28:1565-73. [PMID: 22530776 DOI: 10.1089/aid.2012.0039] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
The HIV-1 restriction factor SAM domain and HD domain-containing protein 1 (SAMHD1) blocks HIV-1 infection in human myeloid cells. Mutations in the SAMHD1 gene are associated with rare genetic diseases including Aicardi-Goutieres syndrome. However, it is unknown whether polymorphisms of SAMHD1 are associated with infection and natural control of HIV-1 in humans. Our objective was to determine whether the expression of SAMHD1 mRNA is affected by common single nucleotide polymorphisms (SNPs) in SAMHD1 and whether the SNPs are associated with HIV-1 infection status. Using a tagging SNP approach, we determined the association between eight tagging SNPs in SAMHD1 and the mRNA expression in B-lymphocyte cell lines from 70 healthy white donors. We identified one SNP (rs1291142) that was significantly associated with SAMHD1 mRNA expression, with minor allele carriers having 30% less mRNA levels (p=0.015). However, after analyzing the published genome-wide association study data of 857 HIV-1 controllers and 2088 HIV-1 progressors from the European and African-American cohorts, we did not find a significant association between SNPs in SAMHD1 and HIV-1 infection status, including SNP rs1291142 (p>0.05). We also observed 2- to 6-fold variations of SAMHD1 mRNA levels in primary B-lymphocytes, CD4(+) T-lymphocytes, and CD14(+) monocytes from five healthy donors. Our results suggest that common regulatory polymorphism(s) exist in the SAMHD1 gene that affects its mRNA expression in B-lymphocyte cell lines from healthy whites. However, polymorphisms of SAMHD1 are unlikely to contribute to the infection and natural control of HIV-1 in European and African-American individuals.
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Affiliation(s)
- Sirena Coon
- Center for Retrovirus Research, Department of Veterinary Bioscience, The Ohio State University, Columbus, Ohio
| | - Danxin Wang
- Department of Pharmacology, Program in Pharmacogenomics, School of Biomedical Science, The Ohio State University, Columbus, Ohio
| | - Li Wu
- Center for Retrovirus Research, Department of Veterinary Bioscience, The Ohio State University, Columbus, Ohio
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, Ohio
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35
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Jeang KT. Highlights, predictions, and changes. Retrovirology 2012; 9:96. [PMID: 23153244 PMCID: PMC3511057 DOI: 10.1186/1742-4690-9-96] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Accepted: 11/08/2012] [Indexed: 11/10/2022] Open
Abstract
Recent literature highlights at Retrovirology are described. Predictions are made regarding "hot" retrovirology research trends for the coming year based on recent journal access statistics. Changes in Retrovirology editor and the frequency of the Retrovirology Prize are announced.
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36
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Tang SW, Ducroux A, Jeang KT, Neuveut C. Impact of cellular autophagy on viruses: Insights from hepatitis B virus and human retroviruses. J Biomed Sci 2012; 19:92. [PMID: 23110561 PMCID: PMC3495035 DOI: 10.1186/1423-0127-19-92] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2012] [Accepted: 10/12/2012] [Indexed: 02/07/2023] Open
Abstract
Autophagy is a protein degradative process important for normal cellular metabolism. It is apparently used also by cells to eliminate invading pathogens. Interestingly, many pathogens have learned to subvert the cell’s autophagic process. Here, we review the interactions between viruses and cells in regards to cellular autophagy. Using findings from hepatitis B virus and human retroviruses, HIV-1 and HTLV-1, we discuss mechanisms used by viruses to usurp cellular autophagy in ways that benefit viral replication.
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Affiliation(s)
- Sai-Wen Tang
- Molecular Virology Section, Laboratory of Molecular Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, 20892-0460, USA
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37
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Wu L. SAMHD1: a new contributor to HIV-1 restriction in resting CD4+ T-cells. Retrovirology 2012; 9:88. [PMID: 23092163 PMCID: PMC3492151 DOI: 10.1186/1742-4690-9-88] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Accepted: 10/16/2012] [Indexed: 11/30/2022] Open
Abstract
Resting CD4+ T-cells are critical for establishing HIV-1 reservoirs. It has been known for over two decades that resting CD4+ T-cells are refractory to HIV-1 infection, but the underlying mechanisms are not fully understood. Compared with activated CD4+ T-cells that support HIV-1 infection, resting CD4+ T-cells have lower levels of dNTPs, which limit HIV-1 reverse transcription. The dNTPase SAMHD1 has been identified as an HIV-1 restriction factor in non-cycling myeloid cells. Two recent studies revealed that SAMHD1 restricts HIV-1 infection in resting CD4+ T-cells, suggesting a common mechanism of HIV-1 restriction in non-cycling cells that may contribute to viral immunopathogenesis.
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Affiliation(s)
- Li Wu
- Center for Retrovirus Research, Department of Veterinary Bioscience, The Ohio State University, 1900 Coffey Road, Columbus, OH 43210, USA.
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38
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Welbourn S, Miyagi E, White TE, Diaz-Griffero F, Strebel K. Identification and characterization of naturally occurring splice variants of SAMHD1. Retrovirology 2012; 9:86. [PMID: 23092512 PMCID: PMC3503569 DOI: 10.1186/1742-4690-9-86] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Accepted: 09/24/2012] [Indexed: 11/16/2022] Open
Abstract
Background Sterile Alpha Motif and HD domain-containing protein 1 (SAMHD1) is a recently identified host factor that restricts HIV-1 replication in dendritic and myeloid cells. SAMHD1 is a dNTPase that presumably reduces the cellular dNTP levels to levels too low for retroviral reverse transcription to occur. However, HIV-2 and SIV encoded Vpx counteracts the antiviral effects of SAMHD1 by targeting the protein for proteasomal degradation. SAMHD1 is encoded by a multiply spliced mRNA and consists of 16 coding exons. Results Here, we identified two naturally occurring splice variants lacking exons 8–9 and 14, respectively. Like wildtype SAMHD1, both splice variants localize primarily to the nucleus, interact with Vpx, and retain some sensitivity to Vpx-dependent degradation. However, the splice variants differ from full-length SAMHD1 in their metabolic stability and catalytic activity. While full-length SAMHD1 is metabolically stable in uninfected cells, both splice variants were inherently metabolically unstable and were rapidly degraded even in the absence of Vpx. Vpx strongly increased the rate of degradation of full-length SAMHD1 and further accelerated the degradation of the splice variants. However, the effect of Vpx on the splice variants was more modest due to the inherent instability of these proteins. Analysis of dNTPase activity indicates that neither splice variant is catalytically active. Conclusions The identification of SAMHD1 splice variants exposes a potential regulatory mechanism that could enable the cell to control its dNTPase activity on a post-transcriptional level.
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Affiliation(s)
- Sarah Welbourn
- Viral Biochemistry Section, Laboratory of Molecular Microbiology, National Institute of Allergy and Infectious Diseases, NIH, Building 4, Room 310; 4 Center Drive, MSC 0460, Bethesda, MD, 20892-0460, USA
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39
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Shen CJ, Jia YH, Tian RR, Ding M, Zhang C, Wang JH. Translation of Pur-α is targeted by cellular miRNAs to modulate the differentiation-dependent susceptibility of monocytes to HIV-1 infection. FASEB J 2012; 26:4755-64. [PMID: 22835829 DOI: 10.1096/fj.12-209023] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The postentry restriction of HIV-1 replication in monocytes can be relieved when they differentiate to dendritic cells (DCs) or macrophages. Multiple mechanisms have been proposed to interpret the differentiation-dependent susceptibility of monocytes to HIV-1 infection, and the absence of host-cell-encoded essential factors for HIV-1 completing the life cycle may provide an explanation. We have analyzed the gene expression profile in monocytes by mRNA microarray and compared it with that of differentiated DCs. We demonstrated that purine-rich element binding protein α (Pur-α), a host-cell-encoded ubiquitous, sequence-specific DNA- and RNA-binding protein, showed inadequate expression in monocytes, and the translation of Pur-α mRNA was repressed by cell-expressed microRNA (miRNA). These Pur-α-targeted miRNAs modulated the differentiation-dependent susceptibility of monocytes/DCs to HIV-1 infection, because rescue of Pur-α expression by transfection of miRNA inhibitors relieved the restriction of HIV-1 infection in monocytes, and ectopic input of miRNA mimics significantly reduced HIV-1 infection of monocyte-derived DCs (MDDCs). Collectively, our data emphasized that inadequate host factors contribute to HIV-1 restriction in monocytes, and cellular miRNAs modulate differentiation-dependent susceptibility of host cells to HIV-1 infection. Elaboration of HIV-1 restriction in host cells facilitates our understanding of viral pathogenesis and the search for a new antiviral strategy.
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Affiliation(s)
- Chan-Juan Shen
- Key Laboratory of Molecular Virology and Immunology, Institute Pasteur of Shanghai, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
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Co-evolution of primate SAMHD1 and lentivirus Vpx leads to the loss of the vpx gene in HIV-1 ancestor. PLoS One 2012; 7:e37477. [PMID: 22574228 PMCID: PMC3345027 DOI: 10.1371/journal.pone.0037477] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Accepted: 04/23/2012] [Indexed: 01/27/2023] Open
Abstract
Cross-species transmission and adaptation of simian immunodeficiency viruses (SIVs) to humans have given rise to human immunodeficiency viruses (HIVs). HIV type 1 (HIV-1) and type 2 (HIV-2) were derived from SIVs that infected chimpanzee (SIVcpz) and sooty mangabey (SIVsm), respectively. The HIV-1 restriction factor SAMHD1 inhibits HIV-1 infection in human myeloid cells and can be counteracted by the Vpx protein of HIV-2 and the SIVsm lineage. However, HIV-1 and its ancestor SIVcpz do not encode a Vpx protein and HIV-1 has not evolved a mechanism to overcome SAMHD1-mediated restriction. Here we show that the co-evolution of primate SAMHD1 and lentivirus Vpx leads to the loss of the vpx gene in SIVcpz and HIV-1. We found evidence for positive selection of SAMHD1 in orangutan, gibbon, rhesus macaque, and marmoset, but not in human, chimpanzee and gorilla that are natural hosts of Vpx-negative HIV-1, SIVcpz and SIVgor, respectively, indicating that vpx drives the evolution of primate SAMHD1. Ancestral host state reconstruction and temporal dynamic analyses suggest that the most recent common ancestor of SIVrcm, SIVmnd, SIVcpz, SIVgor and HIV-1 was a SIV that had a vpx gene; however, the vpx gene of SIVcpz was lost approximately 3643 to 2969 years ago during the infection of chimpanzees. Thus, HIV-1 could not inherit the lost vpx gene from its ancestor SIVcpz. The lack of Vpx in HIV-1 results in restricted infection in myeloid cells that are important for antiviral immunity, which could contribute to the AIDS pandemic by escaping the immune responses.
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de Silva S, Planelles V, Wu L. Differential effects of Vpr on single-cycle and spreading HIV-1 infections in CD4+ T-cells and dendritic cells. PLoS One 2012; 7:e35385. [PMID: 22570689 PMCID: PMC3343049 DOI: 10.1371/journal.pone.0035385] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Accepted: 03/15/2012] [Indexed: 01/20/2023] Open
Abstract
The Vpr protein of human immunodeficiency virus type 1 (HIV-1) contributes to viral replication in non-dividing cells, specifically those of the myeloid lineage. However, the effects of Vpr in enhancing HIV-1 infection in dendritic cells have not been extensively investigated. Here, we evaluated the role of Vpr during infection of highly permissive peripheral blood mononuclear cells (PBMCs) and CD4(+) T-cells and compared it to that of monocyte-derived dendritic cells (MDDCs), which are less susceptible to HIV-1 infection. Infections of dividing PBMCs and non-dividing MDDCs were carried out with single-cycle and replication-competent HIV-1 encoding intact Vpr or Vpr-defective mutants. In contrast to previous findings, we observed that single-cycle HIV-1 infection of both PBMCs and MDDCs was significantly enhanced in the presence of Vpr when the viral stocks were carefully characterized and titrated. HIV-1 DNA quantification revealed that Vpr only enhanced the reverse transcription and nuclear import processes in single-cycle HIV-1 infected MDDCs, but not in CD4(+) T-cells. However, a significant enhancement in HIV-1 gag mRNA expression was observed in both CD4(+) T-cells and MDDCs in the presence of Vpr. Furthermore, Vpr complementation into HIV-1 virions did not affect single-cycle viral infection of MDDCs, suggesting that newly synthesized Vpr plays a significant role to facilitate single-cycle HIV-1 infection. Over the course of a spreading infection, Vpr significantly enhanced replication-competent HIV-1 infection in MDDCs, while it modestly promoted viral infection in activated PBMCs. Quantification of viral DNA in replication-competent HIV-1 infected PBMCs and MDDCs revealed similar levels of reverse transcription products, but increased nuclear import in the presence of Vpr independent of the cell types. Taken together, our results suggest that Vpr has differential effects on single-cycle and spreading HIV-1 infections, which are dependent on the permissiveness of the target cell.
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Affiliation(s)
- Suresh de Silva
- Center for Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio, United States of America
| | - Vicente Planelles
- Division of Microbiology and Immunology, Department of Pathology, University of Utah, Salt Lake City, Utah, United States of America
| | - Li Wu
- Center for Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio, United States of America
- * E-mail:
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St. Gelais C, Coleman CM, Wang JH, Wu L. HIV-1 Nef enhances dendritic cell-mediated viral transmission to CD4+ T cells and promotes T-cell activation. PLoS One 2012; 7:e34521. [PMID: 22479639 PMCID: PMC3316695 DOI: 10.1371/journal.pone.0034521] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Accepted: 03/02/2012] [Indexed: 02/06/2023] Open
Abstract
HIV-1 Nef enhances dendritic cell (DC)-mediated viral transmission to CD4(+) T cells, but the underlying mechanism is not fully understood. It is also unknown whether HIV-1 infected DCs play a role in activating CD4(+) T cells and enhancing DC-mediated viral transmission. Here we investigated the role of HIV-1 Nef in DC-mediated viral transmission and HIV-1 infection of primary CD4(+) T cells using wild-type HIV-1 and Nef-mutated viruses. We show that HIV-1 Nef facilitated DC-mediated viral transmission to activated CD4(+) T cells. HIV-1 expressing wild-type Nef enhanced the activation and proliferation of primary resting CD4(+) T cells. However, when co-cultured with HIV-1-infected autologous DCs, there was no significant trend for infection- or Nef-dependent proliferation of resting CD4(+) T cells. Our results suggest an important role of Nef in DC-mediated transmission of HIV-1 to activated CD4(+) T cells and in the activation and proliferation of resting CD4(+) T cells, which likely contribute to viral pathogenesis.
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Affiliation(s)
- Corine St. Gelais
- Center for Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio, United States of America
| | - Christopher M. Coleman
- Center for Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio, United States of America
| | - Jian-Hua Wang
- Key Laboratory of Molecular Virology and Immunology, Institute Pasteur of Shanghai, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Li Wu
- Center for Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio, United States of America
- Department of Microbial Infection and Immunity, The Ohio State University Medical Center, Columbus, Ohio, United States of America
- * E-mail:
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Gifford RJ. Viral evolution in deep time: lentiviruses and mammals. Trends Genet 2011; 28:89-100. [PMID: 22197521 DOI: 10.1016/j.tig.2011.11.003] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2011] [Revised: 11/08/2011] [Accepted: 11/09/2011] [Indexed: 11/29/2022]
Abstract
Lentiviruses are a distinctive genus of retroviruses that cause chronic, persistent infections in mammals, including humans. The emergence of pandemic HIV type-1 (HIV-1) infection during the late 20th century shaped a view of lentiviruses as 'modern' viruses. However, recent research has revealed an entirely different perspective, elucidating aspects of an evolutionary relationship with mammals that extends across many millions of years. Such deep evolutionary history is likely to be typical of many host-virus systems, fundamentally underpinning their interactions in the present day. For this reason, establishing the deep history of virus and host interaction is key to developing a fully informed approach to tackling viral diseases. Here, I use the example of lentiviruses to illustrate how paleovirological, geographic and genetic calibrations allow observations of virus and host interaction across a wide range of temporal and spatial scales to be integrated into a coherent ecological and evolutionary framework.
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Affiliation(s)
- Robert J Gifford
- Aaron Diamond AIDS Research Center, 455 1st Avenue, New York, NY 10016, USA.
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