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Li K, Rodosthenous RS, Kashanchi F, Gingeras T, Gould SJ, Kuo LS, Kurre P, Lee H, Leonard JN, Liu H, Lombo TB, Momma S, Nolan JP, Ochocinska MJ, Pegtel DM, Sadovsky Y, Sánchez-Madrid F, Valdes KM, Vickers KC, Weaver AM, Witwer KW, Zeng Y, Das S, Raffai RL, Howcroft TK. Advances, challenges, and opportunities in extracellular RNA biology: insights from the NIH exRNA Strategic Workshop. JCI Insight 2018; 3:98942. [PMID: 29618663 DOI: 10.1172/jci.insight.98942] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Extracellular RNA (exRNA) has emerged as an important transducer of intercellular communication. Advancing exRNA research promises to revolutionize biology and transform clinical practice. Recent efforts have led to cutting-edge research and expanded knowledge of this new paradigm in cell-to-cell crosstalk; however, gaps in our understanding of EV heterogeneity and exRNA diversity pose significant challenges for continued development of exRNA diagnostics and therapeutics. To unravel this complexity, the NIH convened expert teams to discuss the current state of the science, define the significant bottlenecks, and brainstorm potential solutions across the entire exRNA research field. The NIH Strategic Workshop on Extracellular RNA Transport helped identify mechanistic and clinical research opportunities for exRNA biology and provided recommendations on high priority areas of research that will advance the exRNA field.
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Affiliation(s)
- Kang Li
- Division of Vascular and Endovascular Surgery, Department of Surgery, University of California, San Francisco, and Veterans Affairs Medical Center, San Francisco, California, USA
| | | | - Fatah Kashanchi
- Laboratory of Molecular Virology, National Center for Biodefense and Infectious Diseases, George Mason University, Manassas, Virginia, USA
| | - Thomas Gingeras
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, USA
| | - Stephen J Gould
- Department of Biological Chemistry, Johns Hopkins University, Baltimore, Maryland, USA
| | - Lillian S Kuo
- National Institute of Allergy and Infectious Diseases, NIH, Bethesda, Maryland, USA
| | - Peter Kurre
- Doernbecher Children's Hospital, Department of Pediatrics and Papé Family Pediatric Research Institute, Oregon Health & Science University, Portland, Oregon, USA
| | - Hakho Lee
- Center for Systems Biology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Joshua N Leonard
- Department of Chemical and Biological Engineering, Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois, USA
| | - Huiping Liu
- Departments of Pharmacology and Medicine (Hematology and Oncology), Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Tania B Lombo
- NIH, Office of the Director, Environmental Influences on Child Health Outcomes Program, Bethesda, Maryland, USA
| | - Stefan Momma
- Institute of Neurology (Edinger Institute), Frankfurt University Medical School, German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Frankfurt, Heidelberg, Germany
| | - John P Nolan
- Scintillon Institute, San Diego, California, USA
| | | | - D Michiel Pegtel
- Department of Pathology, Cancer Center Amsterdam, Vrije Universiteit (VU) University Medical Center, Amsterdam, The Netherlands
| | - Yoel Sadovsky
- Magee-Womens Research Institute, Department of Microbiology and Molecular Genetics, Department of Obstetrics, Gynecology and Reproductive Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Francisco Sánchez-Madrid
- Instituto de Investigación Sanitaria Princesa, Hospital Universitario de la Princesa, Universidad Autónoma de Madrid, Centro Nacional de Investigaciones Cardiovasculares, Madrid, Spain
| | - Kayla M Valdes
- National Center for Advancing Translational Science, Bethesda, Maryland, USA
| | - Kasey C Vickers
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Alissa M Weaver
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Kenneth W Witwer
- Department of Molecular and Comparative Pathobiology, Department of Neurology, The Johns Hopkins University, Baltimore, Maryland, USA
| | - Yong Zeng
- Department of Chemistry, University of Kansas Cancer Center, Lawrence, Kansas, USA
| | - Saumya Das
- Cardiovascular Research Center, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Robert L Raffai
- Division of Vascular and Endovascular Surgery, Department of Surgery, University of California, San Francisco, and Veterans Affairs Medical Center, San Francisco, California, USA
| | - T Kevin Howcroft
- Cancer Immunology, Hematology, and Etiology Branch, Division of Cancer Biology, National Cancer Institute, Bethesda, Maryland, USA
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Ainsztein AM, Brooks PJ, Dugan VG, Ganguly A, Guo M, Howcroft TK, Kelley CA, Kuo LS, Labosky PA, Lenzi R, McKie GA, Mohla S, Procaccini D, Reilly M, Satterlee JS, Srinivas PR, Church ES, Sutherland M, Tagle DA, Tucker JM, Venkatachalam S. The NIH Extracellular RNA Communication Consortium. J Extracell Vesicles 2015; 4:27493. [PMID: 26320938 PMCID: PMC4553264 DOI: 10.3402/jev.v4.27493] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Revised: 04/15/2015] [Accepted: 05/03/2015] [Indexed: 11/14/2022] Open
Abstract
The Extracellular RNA (exRNA) Communication Consortium, funded as an initiative of the NIH Common Fund, represents a consortium of investigators assembled to address the critical issues in the exRNA research arena. The overarching goal is to generate a multi-component community resource for sharing fundamental scientific discoveries, protocols, and innovative tools and technologies. The key initiatives include (a) generating a reference catalogue of exRNAs present in body fluids of normal healthy individuals that would facilitate disease diagnosis and therapies, (b) defining the fundamental principles of exRNA biogenesis, distribution, uptake, and function, as well as development of molecular tools, technologies, and imaging modalities to enable these studies,
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Affiliation(s)
- Alexandra M Ainsztein
- Division of Cell Biology and Biophysics, National Institute of General Medical Sciences (NIGMS), Bethesda, MD, USA
| | - Philip J Brooks
- Division of Clinical Innovation, National Center for Advancing Translational Sciences (NCATS), Bethesda, MD, USA
| | - Vivien G Dugan
- Office of Genomics and Advanced Technologies, Division of Microbiology and Infectious Diseases, National Institute of Allergy and Infectious Diseases (NIAID), Rockville, MD, USA
| | - Aniruddha Ganguly
- Cancer Diagnosis Program, Division of Cancer Treatment and Diagnosis, National Cancer Institute (NCI), Rockville, MD, USA
| | - Max Guo
- Genetics and Cell Biology Branch, Division of Aging Biology, National Institute on Aging (NIA), Bethesda, MD, USA
| | - T Kevin Howcroft
- Division of Cancer Biology, Cancer Immunology, Hematology, and Etiology Branch, National Cancer Institute (NCI), Rockville, MD, USA;
| | - Christine A Kelley
- Division of Discovery Science and Technology, National Institute of Biomedical Imaging and Bioengineering (NIBIB), Bethesda, MD, USA
| | - Lillian S Kuo
- National Center for Advancing Translational Science (NCATS), Bethesda, MD, USA
| | - Patricia A Labosky
- Office of Strategic Coordination, Division of Program Coordination, Planning, and Strategic Initiatives (DPCPSI), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Rebecca Lenzi
- Office of Strategic Coordination, Division of Program Coordination, Planning, and Strategic Initiatives (DPCPSI), National Institutes of Health (NIH), Bethesda, MD, USA
| | - George A McKie
- Ocular Infection, Inflammation, and Immunology, National Eye Institute (NEI), Rockville, MD, USA
| | - Suresh Mohla
- Division of Cancer Biology, Tumor Biology and Metastasis Branch (TBMB), National Cancer Institute (NCI), Rockville, MD, USA
| | | | - Matthew Reilly
- Division of Neuroscience & Behavior, National Institute on Alcohol Abuse and Alcoholism (NIAAA), Rockville, MD, USA
| | | | - Pothur R Srinivas
- Division of Cardiovascular Sciences, National Heart, Lung, and Blood Institute (NHLBI), Bethesda, MD, USA
| | - Elizabeth Stansell Church
- Pathogenesis and Basic Research Branch, Division of AIDS, National Institute of Allergy and Infectious Diseases (NIAID), Rockville, MD, USA
| | - Margaret Sutherland
- Neurodegeneration Cluster, National Institute of Neurological Disorders and Stroke (NINDS), Rockville, MD, USA
| | - Danilo A Tagle
- National Center for Advancing Translational Science (NCATS), Bethesda, MD, USA
| | - Jessica M Tucker
- National Institute of Biomedical Imaging and Bioengineering (NIBIB), Bethesda, MD, USA
| | - Sundar Venkatachalam
- Integrative Biology and Infectious Diseases Branch, National Institute of Dental and Craniofacial Research (NIDCR), Bethesda, MD, USA
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Kuo LS, Baugh LL, Denial SJ, Watkins RL, Liu M, Garcia JV, Foster JL. Overlapping effector interfaces define the multiple functions of the HIV-1 Nef polyproline helix. Retrovirology 2012; 9:47. [PMID: 22651890 PMCID: PMC3464899 DOI: 10.1186/1742-4690-9-47] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Accepted: 05/31/2012] [Indexed: 11/20/2022] Open
Abstract
Background HIV-1 Nef is a multifunctional protein required for full pathogenicity of the virus. As Nef has no known enzymatic activity, it necessarily functions through protein-protein interaction interfaces. A critical Nef protein interaction interface is centered on its polyproline segment (P69VRPQVPLRP78) which contains the helical SH3 domain binding protein motif, PXXPXR. We hypothesized that any Nef-SH3 domain interactions would be lost upon mutation of the prolines or arginine of PXXPXR. Further, mutation of the non-motif “X” residues, (Q73, V74, and L75) would give altered patterns of inhibition for different Nef/SH3 domain protein interactions. Results We found that mutations of either of the prolines or the arginine of PXXPXR are defective for Nef-Hck binding, Nef/activated PAK2 complex formation and enhancement of virion infectivity (EVI). Mutation of the non-motif “X” residues (Q, V and L) gave similar patterns of inhibition for Nef/activated PAK2 complex formation and EVI which were distinct from the pattern for Hck binding. These results implicate an SH3 domain containing protein other than Hck for Nef/activated PAK2 complex formation and EVI. We have also mutated Nef residues at the N-and C-terminal ends of the polyproline segment to explore interactions outside of PXXPXR. We discovered a new locus GFP/F (G67, F68, P69 and F90) that is required for Nef/activated PAK2 complex formation and EVI. MHC Class I (MHCI) downregulation was only partially inhibited by mutating the PXXPXR motif residues, but was fully inhibited by mutating the C-terminal P78. Further, we observed that MHCI downregulation strictly requires G67 and F68. Our mutational analysis confirms the recently reported structure of the complex between Nef, AP-1 μ1 and the cytoplasmic tail of MHCI, but does not support involvement of an SH3 domain protein in MHCI downregulation. Conclusion Nef has evolved to be dependent on interactions with multiple SH3 domain proteins. To the N- and C- terminal sides of the polyproline helix are multifunctional protein interaction sites. The polyproline segment is also adapted to downregulate MHCI with a non-canonical binding surface. Our results demonstrate that Nef polyproline helix is highly adapted to directly interact with multiple host cell proteins.
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Affiliation(s)
- Lillian S Kuo
- Department of Internal Medicine, University of Texas Southwestern Medical Center at Dallas, 5323 Harry Hines Boulevard, Y9.206, Dallas, TX 75390, USA
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Kwak YT, Raney A, Kuo LS, Denial SJ, Temple BRS, Garcia JV, Foster JL. Self-association of the Lentivirus protein, Nef. Retrovirology 2010; 7:77. [PMID: 20863404 PMCID: PMC2955668 DOI: 10.1186/1742-4690-7-77] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2010] [Accepted: 09/23/2010] [Indexed: 01/28/2023] Open
Abstract
BACKGROUND The HIV-1 pathogenic factor, Nef, is a multifunctional protein present in the cytosol and on membranes of infected cells. It has been proposed that a spatial and temporal regulation of the conformation of Nef sequentially matches Nef's multiple functions to the process of virion production. Further, it has been suggested that dimerization is required for multiple Nef activities. A dimerization interface has been proposed based on intermolecular contacts between Nefs within hexagonal Nef/FynSH3 crystals. The proposed dimerization interface consists of the hydrophobic B-helix and flanking salt bridges between R105 and D123. Here, we test whether Nef self-association is mediated by this interface and address the overall significance of oligomerization. RESULTS By co-immunoprecipitation assays, we demonstrated that HIV-1Nef exists as monomers and oligomers with about half of the Nef protomers oligomerized. Nef oligomers were found to be present in the cytosol and on membranes. Removal of the myristate did not enhance the oligomerization of soluble Nef. Also, SIVNef oligomerizes despite lacking a dimerization interface functionally homologous to that proposed for HIV-1Nef. Moreover, HIV-1Nef and SIVNef form hetero-oligomers demonstrating the existence of homologous oligomerization interfaces that are distinct from that previously proposed (R105-D123). Intracellular cross-linking by formaldehyde confirmed that SF2Nef dimers are present in intact cells, but surprisingly self-association was dependent on R105, but not D123. SIV(MAC239)Nef can be cross-linked at its only cysteine, C55, and SF2Nef is also cross-linked, but at C206 instead of C55, suggesting that Nefs exhibit multiple dimeric structures. ClusPro dimerization analysis of HIV-1Nef homodimers and HIV-1Nef/SIVNef heterodimers identified a new potential dimerization interface, including a dibasic motif at R105-R106 and a six amino acid hydrophobic surface. CONCLUSIONS We have demonstrated significant levels of intracellular Nef oligomers by immunoprecipitation from cellular extracts. However, our results are contrary to the identification of salt bridges between R105 and D123 as necessary for self-association. Importantly, binding between HIV-1Nef and SIVNef demonstrates evolutionary conservation and therefore significant function(s) for oligomerization. Based on modeling studies of Nef self-association, we propose a new dimerization interface. Finally, our findings support a stochastic model of Nef function with a dispersed intracellular distribution of Nef oligomers.
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Affiliation(s)
- Youn Tae Kwak
- Baylor Institute for Immunology Research, 3434 Live Oak, Dallas, TX 75204, USA
| | - Alexa Raney
- Department of Internal Medicine, University of Texas Southwestern Medical Center at Dallas, 5323 Harry Hines Boulevard, Y9.206, Dallas, Texas 75390, USA
| | - Lillian S Kuo
- Department of Internal Medicine, University of Texas Southwestern Medical Center at Dallas, 5323 Harry Hines Boulevard, Y9.206, Dallas, Texas 75390, USA
| | - Sarah J Denial
- Division of Infectious Diseases, Center for AIDS Research, University of North Carolina, Chapel Hill, North Carolina 27599-7042, USA
| | - Brenda RS Temple
- Department of Biochemistry and Biophysics, R. L. Juliano Structural Bioinformatics Core, University of North Carolina, Chapel Hill, North Carolina 27599-7042, USA
| | - J Victor Garcia
- Division of Infectious Diseases, Center for AIDS Research, University of North Carolina, Chapel Hill, North Carolina 27599-7042, USA
| | - John L Foster
- Division of Infectious Diseases, Center for AIDS Research, University of North Carolina, Chapel Hill, North Carolina 27599-7042, USA
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O'Neill E, Kuo LS, Krisko JF, Tomchick DR, Garcia JV, Foster JL. Dynamic evolution of the human immunodeficiency virus type 1 pathogenic factor, Nef. J Virol 2006; 80:1311-20. [PMID: 16415008 PMCID: PMC1346962 DOI: 10.1128/jvi.80.3.1311-1320.2006] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2005] [Accepted: 10/27/2005] [Indexed: 11/20/2022] Open
Abstract
The human immunodeficiency virus type 1 (HIV-1) early gene product Nef is a multifunctional protein that alters numerous pathways of T-cell function, including endocytosis, signal transduction, vesicular trafficking, and immune modulation, and is a major determinant of pathogenesis. Individual Nef functions include PAK-2 activation, CD4 downregulation, major histocompatibility complex (MHC) class I downregulation, and enhancement of viral particle infectivity. How Nef accomplishes its multiple tasks presents a difficult problem of mechanistic analysis because of the complications associated with multiple, overlapping functional domains in the context of significant sequence variability. To address these issues we determined the conservation of each Nef residue based on 1,643 subtype B Nef sequences. Mutational analysis based on conservative substitutions and Nef sequence data allowed us to search for amino acids on the surface of Nef that are specifically required for PAK-2 activation. We found residues 85, 89, and 191 to be highly significant determinants for Nef's PAK-2 activation function but functionally unlinked to CD4 and MHC class I downregulation or enhancement of infectivity. These residues are not conserved across HIV-1 subtypes but are confined to separate sets of surface elements within a subtype. Thus, L85/H89/F191 and F85/F89/R191 are dominant in subtype B and subtype E or C, respectively. Our results provide support for developing subtype-specific interventions in HIV-1 disease.
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Affiliation(s)
- Eduardo O'Neill
- Department of Internal Medicine, Division of Infectious Diseases Y9.206, University of Texas Southwestern Medical Center at Dallas, 5323 Harry Hines Blvd., Dallas, TX 75390-9113, USA
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Wei BL, Arora VK, Raney A, Kuo LS, Xiao GH, O'Neill E, Testa JR, Foster JL, Garcia JV. Activation of p21-activated kinase 2 by human immunodeficiency virus type 1 Nef induces merlin phosphorylation. J Virol 2006; 79:14976-80. [PMID: 16282498 PMCID: PMC1287594 DOI: 10.1128/jvi.79.23.14976-14980.2005] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The accessory human immunodeficiency virus type 1 (HIV-1) protein Nef activates the autophosphorylation activity of p21-activated kinase 2 (PAK2). Merlin, a cellular substrate of PAK2, is homologous to the ezrin-radixin-moesin family and plays a critical role in Rac signaling. To assess the possible impact on host cell metabolism of Nef-induced PAK2 activation, we investigated the phosphorylation of merlin in Nef expressing cells. Here we report that Nef induces merlin phosphorylation in multiple cell lines independently of protein kinase A. This intracellular phosphorylation of merlin directly correlates with in vitro assay of the autophosphorylation activity of Nef-activated PAK2. Importantly, merlin phosphorylation induced by Nef was also observed in human primary T cells. The finding that Nef induces phosphorylation of the key signaling molecule merlin suggests several possible roles for PAK2 activation in HIV pathogenesis.
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Affiliation(s)
- Bangdong L Wei
- Department of Internal Medicine, Division of Infectious Diseases, University of Texas Southwestern Medical Center at Dallas, 5323 Harry Hines Blvd., Dallas, TX 75390, USA
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Raney A, Kuo LS, Baugh LL, Foster JL, Garcia JV. Reconstitution and molecular analysis of an active human immunodeficiency virus type 1 Nef/p21-activated kinase 2 complex. J Virol 2005; 79:12732-41. [PMID: 16188976 PMCID: PMC1235864 DOI: 10.1128/jvi.79.20.12732-12741.2005] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) Nef activation of p21-activated kinase 2 (PAK-2) was recapitulated in a cell-free system consisting of in vitro-transcribed RNA, rabbit reticulocyte lysate, and microsomal membranes on the basis of the following observations: (i) Nef associated with a kinase endogenous to the rabbit reticulocyte lysate that was identified as PAK-2, (ii) Nef-associated kinase activity was detected with Nefs from HIV-1(SF2), HIV-1(YU2), and SIV(mac239), (iii) kinase activation was not detected with a myristoylation-defective Nef (HIV-1(SF2)NefG2A) or with a Nef defective in PAK-2 activation but fully competent in other Nef functions (HIV-1(SF2)NefF195I), and (iv) Nef-associated kinase activation required activated endogenous p21 GTPases (Rac1 or Cdc42). The cell-free system was used to analyze the mechanism of Nef activation of PAK-2. First, studies suggest that the p21 GTPases may act transiently to enhance Nef activation of PAK-2 in vitro. Second, addition of wortmannin to the cell-free system demonstrated that Nef activation of PAK-2 does not require PI 3-kinase activity. Third, ultracentrifugation analysis revealed that whereas the majority of Nef and PAK-2 partitioned to the supernatant, Nef-associated PAK-2 activity partitioned to the membrane-containing pellet as a low-abundance complex. Lastly, Nef activation of PAK-2 in vitro requires addition of microsomal membranes either during or after translation of the Nef RNA. These results are consistent with a model in which activation of PAK-2 by Nef occurs by recruiting PAK-2 to membranes. As demonstrated herein, the cell-free system is a new and important tool in the investigation of the mechanism of PAK-2 activation by Nef.
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Affiliation(s)
- Alexa Raney
- Department of Internal Medicine, Division of Infectious Diseases, University of Texas Southwestern Medical Center at Dallas, 75390-9113, USA
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Harms JS, Eakle KA, Kuo LS, Bremel RD, Splitter GA. Comparison of bovine leukemia virus (BLV) and CMV promoter-driven reporter gene expression in BLV-infected and non-infected cells. Genet Vaccines Ther 2004; 2:11. [PMID: 15327692 PMCID: PMC516020 DOI: 10.1186/1479-0556-2-11] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/13/2004] [Accepted: 08/24/2004] [Indexed: 11/25/2022]
Abstract
Background Viral promoters are used in mammalian expression vectors because they generally have strong activity in a wide variety of cells of differing tissues and species. Methods The utility of the BLV LTR/promoter (BLVp) for use in mammalian expression vectors was investigated through direct comparison to the CMV promoter (CMVp). Promoter activity was measured using luciferase assays of cell lines from different tissues and species stably transduced with BLVp or CMVp driven luciferase vectors including D17, FLK, BL3.1 and primary bovine B cells. Cells were also modified through the addition of BLV Tax expression vectors and/or BLV infection as well as treatment with trichostatin A (TSA). Results Results indicate the BLV promoter, while having low basal activity compared to the CMV promoter, can be induced to high-levels of activity similar to the CMV promoter in all cells tested. Tax or BLV infection specifically enhanced BLVp activity with no effect on CMVp activity. In contrast, the non-specific activator, TSA, enhanced both BLVp and CMVp activity. Conclusion Based on these data, we conclude the BLV promoter could be very useful for transgene expression in mammalian expression vectors.
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Affiliation(s)
- Jerome S Harms
- Department of Animal Health and Biomedical Sciences, University of Wisconsin-Madison, Madison, WI 53706-1581, USA
| | - Kurt A Eakle
- GALA Biotech, 8137 Forsythia Street, Middleton, WI 53562, USA
| | - Lillian S Kuo
- Department of Animal Health and Biomedical Sciences, University of Wisconsin-Madison, Madison, WI 53706-1581, USA
| | - Robert D Bremel
- IoGenetics LLC, 3591 Anderson St., Suite 218, Madison, WI 53704, USA
| | - Gary A Splitter
- Department of Animal Health and Biomedical Sciences, University of Wisconsin-Madison, Madison, WI 53706-1581, USA
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Zhang YY, Hansson BG, Kuo LS, Widell A, Nordenfelt E. Hepatitis B virus DNA in serum and liver is commonly found in Chinese patients with chronic liver disease despite the presence of antibodies to HBsAg. Hepatology 1993; 17:538-44. [PMID: 7682978 DOI: 10.1002/hep.1840170403] [Citation(s) in RCA: 79] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Sera from 410 patients from the Wuhan area in the central part of China with the diagnosis of chronic liver disease were analyzed for markers of hepatitis B, C and D virus infections. All sera, plus liver biopsy specimens from 188 of the patients, were also tested for hepatitis B virus DNA by polymerase chain reaction. Sixty-eight percent were HBsAg positive in serum, whereas 29% showed markers of past hepatitis B virus infection. Hepatitis B virus DNA was detected in all HBeAg-positive sera but also in 58% of patients with HBe antibody. In the liver specimens of the corresponding patient groups, 97% and 78%, respectively, were hepatitis B virus DNA positive. However, more noteworthy was that of the HBsAg-negative/HBs-antibody positive patients 30% had detectable hepatitis B virus DNA in serum and 32% had hepatitis B virus DNA in liver tissue, whereas in a control group of healthy blood donors, of which 90% had HBs antibody, none was hepatitis B virus DNA positive. Our results demonstrate that among patients with chronic liver disease, infections with hepatitis B virus or hepatitis B virus-related virus(es) may frequently occur without being revealed by conventional serological methods. Hepatitis C and D viruses seem to be of only minor importance in the pathogenesis of chronic liver disease in this part of China.
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Affiliation(s)
- Y Y Zhang
- Department of Medical Microbiology, University of Lund, Malmö General Hospital, Sweden
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