Structural analysis of the spleen focusforming virus. Activation of cell growth by binding of friend spleen. It is often performed in combination with lung scanning to help diagnose masses or inflammation in the diaphragmatic area. Definition of spleen focus forming viruses in the dictionary. The friend spleen focus forming virus envelope glycoprotein, gp55, binds to the murine erythropoietin receptor epor and triggers growth activation in the absence of epo. A carboxyterminal mutant spleen focusforming virus sffv.
Induction of endogenous virus and of thymidine kinase by. An amount of virus equivalent to 2,500 sffu or 500 sffu as indicated was used for our experiments. The spleen focusforming virus sffv envelope gene, when introduced into mice in the absence of other sffv genes, induces acute erythroleukemia. The leukemogenic membrane glycoprotein gp55 encoded by friend spleen focus forming virus appears to bind to erythropoietin receptors epor to stimulate erythroblastosis. L wolff and s ruscetti laboratory of genetics, national. Spleen necrosis virus how is spleen necrosis virus abbreviated. Sep 26, 2011 to analyze the protective effect of type i ifn subtypes on adenovirusbased immunization, we employed the friend virus fv model. Friend strain of spleen focus forming virus is a recombinant between ecotropic murine type c virus and the env gene region of xenotropic type c virus murine leukemia virus xenotropic virus molecular. Molecular cloning of rauscher spleen focusforming virus. Strains of murine leukemia virus that are replicationdefective and rapidly. Information and translations of spleen focus forming viruses in the most comprehensive dictionary definitions.
This gene encodes an etsdomain transcription factor that activates gene expression during myeloid and b. Friend spleen focus forming virus genome contains the reading frame of gp52. Friend virus complex fv, which comprises replicationcompetent friend murine leukemia virus fmulv plus replicationdefective spleen focusforming virus sffv, induces a multistage erythroleukemia. The recent development of nontransformed fibroblast cell lines which contain the replicationdefective spleen focus forming virus sffv genome, free of replicating llv, has allowed investigation of an. Citeseerx the detection of a spleen focusforming virus. Spleen focusforming virus how is spleen focusforming. Friend spleen focus forming virus sffv causes rapid erythroleukemia in mice due to expression of its unique envelope glycoprotein, gp55. Apr 25, 2011 additionally, mir663 expression was regulated by atra. In vivo bioluminescence imaging mice were anesthetized with isoflurane and injected intraperitoneally with 150.
Biological activity of the spleen focusforming virus is encoded by a molecularly cloned subgenomic fragment of spleen focusforming virus dna. It consists of a replicationcompetent murine leukaemia virus rmulv which acts as a helper virus and a defective transforming component which causes spleen focus formation, rauscher spleen focus forming virus. Specific neutralization of defective spleen focusforming. The stock was prepared as a 10% wtvol spleen cell homogenate from balbc mice infected 14 d previously with 3,000 spleen focus forming units of noncloned virus stock. Erythroblast transformation by the friend spleen focus forming virus is associated with a block in erythropoietininduced stat1 phosphorylation and dna binding and correlates with high expression. The liver and spleen scan is performed to help diagnose abnormalities in the function and structure of the liver and spleen. Activation of erythropoietin receptors by friend viral gp55.
The pluripotential hemopoietic stem cells cfus of genetically resistant fv2rr adult c57bl6 b6 mice can be persistently infected by friend virus fv when exposed to defective spleen focus forming virus sffv and helper virus. Spleen focus forming virus sffv proviral integration oncogene spi1 elisa kits 10 spleen focus forming virus sffv proviral integration oncogene spi1 spi1 elisa kits from 6 manufacturers are. Gene disruption of spleen focus forming virus sffv proviral integration oncogene spi1 spi1pu. Spleen focus forming virus sffv proviral integration oncogene spi1 proteins 10 spleen focus forming virus sffv proviral integration oncogene spi1 spi1 proteins from 6 manufacturers are. Previous studies in our laboratory and others have been consistent with the hypothesis that the envelope env gene of the spleen focus forming virus sffv is the only gene essential for the induction of acute erythroleukemia. Descriptors are arranged in a hierarchical structure. Intracellular transport and leukemogenicity of spleen focus forming virus envelope glycoproteins with altered transmembrane domains. When expressed at the surface of murine erythroblasts, gp55 is highly mitogenic. In this study, we have used a vesicular stomatitis virus g envelope protein. Promoter optimisation of lentiviral vectors for efficient insulin gene. Lin, thomas samuel, the spleen focus forming virus envelope glycoprotein, gp55, and the block in the erythropoietininduced differentiation of friend murine erythroleukemia.
Loss of pathogenicity of spleen focusforming virus after. Spleen focus forming viruses is a descriptor in the national library of medicines controlled vocabulary thesaurus, mesh medical subject headings. Active rhoa favors retention of human hematopoietic stem. Fv is an immunosuppressive retrovirus complex of the nonpathogenic friend murine leukemia virus fmulv and the pathogenic, replicationdefective spleen focus forming virus sffv. Definition of spleen focusforming viruses in the dictionary. The nuclear protein binds to a purinerich sequence known as the pubox found on enhancers of target. Benjamin eberts lab contains the inserts spcas9, sp sgrna scaffold, sffv, and p2atrfp and is published in nat biotechnol.
Pdf the spleen focusforming virus envelope glycoprotein. Spleen focus forming virus sffv proviral integration oncogene spi1. Aug 30, 2016 lentivirus vectors encoding the proinsulin gene with or without a kozak sequence under the control of spleen focus forming virus, cytomegalovirus, elongation factor 1. Production of spleen focusforming virus and murine. Information and translations of spleen focusforming viruses in the most comprehensive dictionary definitions resource on the web. Immunization of rats with syngeneic cells infected with spleen focus forming virus sffv but not with its helper, friend murine leukemia virus fmulv, produces antisera which specifically neutralize sffv, and not fmulv, in the friend virus complex.
Spleen focus forming virus an overview sciencedirect. Active rhoa expression favors the retention of hematopoietic stemprogenitor cells in the niche rather than migration and was found to lock the cells in the g0 cell cycle phase thereby affecting their longterm selfrenewal potential. Benjamin eberts lab contains the inserts spcas9, sp sgrna scaffold, sffv, and p2aegfp and is published in nat biotechnol. Cellspecific and efficient expression in mouse and human b. Spleen focus forming virus sffv proviral integration. Spleen focus forming viruses description of spleen focus forming viruses. The induced friend virus complex is of n host range as expected with induced endogenous virus in ntype cells. Helix packing and orientation in the transmembrane dimer of. Spleen focusforming viruses is a descriptor in the national library of medicines controlled vocabulary thesaurus, mesh medical subject headings. Car expression is driven by the spleen focusforming virus promoter.
The friend erythroleukemia is induced in mice by a virus complex containing the defective spleen focus forming virus sffv and a helper murine leukemia virus. While variant dhfr gene transfer and expression have been. Yoshida m, yoshikura h 1980 analysis of spleen focus forming virus specific rna sequences coding for spleen focus forming virus specific glycoprotein with a molecular weight of 55,000 gp55. The structure of the envelope gene product gp52 of the spleen focus forming virus was analyzed and compared to that of envelope proteins gp70 and p15e of another pathogenic friend virus recombinant, friend mink cell focus inducing virus fmcf. Transfection of lvmir663 induced significant hl60 cell differentiation in vitro. The friend spleen focus forming virus fsffv codes for a transportdefective leukemogenic envelope glycoprotein designated as gp52. Comparison of gene delivery to the kidney by adenovirus. Linemeyer dl, ruscetti sk, scolnick em, evans lh, duesberg ph. Spleen focusforming viruses spleen focusforming viruses is a descriptor in the national library of medicines controlled vocabulary thesaurus, mesh medical subject headings. The objective of the study was to assess whether a combinational therapy of nanoparticlebased therapeutic vaccination and concomitant transient ablation of tregs augments antiviral immunity and improves virus control in chronically. Promoter optimisation of lentiviral vectors for efficient. Apr 14, 2016 regulatory t cells tregs have been shown to limit antiviral immunity during chronic retroviral infection and to restrict vaccineinduced t cell responses. After infection with epor virus, interleukin 3dependent da3 cells bound sup 125ilabeled epo and grew without interleukin 3 in the presence of epo.
Intracellular transport and leukemogenicity of spleen. Envelope gene of the friend spleen focusforming virus. Spleen focus forming viruses spleen focus forming viruses is a descriptor in the national library of medicines controlled vocabulary thesaurus, mesh medical subject headings. Inducibility of spleen focusforming virus by brdurd is controlled by the differentiated state of the cell article pdf available in proceedings of the national academy of sciences 785. The spleen focus forming virus sffv envelope gene, when introduced into mice in the absence of other sffv genes, induces acute erythroleukemia. Two recombinant retroviruses expressing eporr129c, spleen focus forming virus sffvcepor and myeloproliferative sarcoma virus. Until recently, it was not possible to examine putative cell surface antigens coded for by the replicationdefective portion spleen focus forming virus, sffv of the viral genome due to an excess of helper. Rauscher virus rv induces acute erythroteukaemia and a myeloproliferative disease in adult mice. Combination of nanoparticlebased therapeutic vaccination and. Descriptors are arranged in a hierarchical structure, which enables searching at various levels of specificity.
The human immunodeficiency virus hivspleen focusforming virus. Spleen focus forming virus an overview sciencedirect topics. Sffv is defined as spleen focus forming virus frequently. Erythroid cells expressing sffv gp55 proliferate in the absence of their normal regulator erythropoietin epo because of constitutive activation of epo signal transduction pathways.
All lower taxonomy nodes 5 common name isynonym iother names i sffv spleen focus forming viruses. The sffv envelope gene encodes a membrane glycoprotein, gp55. Friend spleen focusforming virus glycoprotein gp55 interacts. The rna of the rv complex resembles closely that of friend virus fv. The friend spleen focusforming virus sffv is a repli. Selection of an optimal promoter for gene transfer in normal b cells. Highlevel transduction and gene expression in hematopoietic. Erythroblast transformation by the friend spleen focus. It is a replicationcompetent murine leukemia virus. To directly compare the effects of gp55 with erythropoietin epo, the authors produced retrovirions that encode either gp55, epo, or epor. Erbb2her2specific nk cells for targeted therapy of. Summary rauscher virus rv induces acute erythroleukaemia and a myeloproliferative disease in adult mice. Molecular cloning of rauscher spleen focus forming virus and biological properties of the cloned virus.
Friend strain of spleen focusforming virus is a recombinant. Retinoic acid induces hl60 cell differentiation via the. Loxp sites were inserted in intron 3 and a loxpflanked neomycin selection cassette was inserted into intron 5. Friend spleen focusforming virus transforms rodent. Friend spleen focus forming virus sffv is a defective murine ctype retrovirus which causes a multistage erythroleukaemia in mice and erythroblastosis in bone marrow cultures15. Pdf inducibility of spleen focusforming virus by brdurd. Before the induction of the endogenous virus spleen focus forming virus. The spleen focus forming virus promoter conferred the strongest. Pmc free article linemeyer dl, menke jg, ruscetti sk, evans lh, scolnick em. Linemeyer dl, ruscetti sk, scolnick em, evans lh, duesberg ph 1981 biological activity of the spleen focusforming virus is encoded by a molecularly cloned subgenomic fragment of spleen focusforming virus dna. Spleen focusforming virus long terminal repeat insertional. A viral antigen specified by spleen focus forming virus and differentiation antigen controlled by the fv2 locus. Friend spleen focus forming virus transforms rodent fibroblasts in cooperation with a short form of the receptor tyrosine kinase stk kazuo nishigaki, charlotte hanson, tanya jelacic, delores thompson, and.
Spleen focusforming viruses harvard catalyst profiles. Immunization of rats with syngeneic cells infected with spleen focus forming virus sffv but not with its helper, friend murine leukemia virus fmulv, produces antisera which specifically neutralize sffv, and not fmulv, in the friend virus. Nov 19, 2018 this protocol describes a suite of lentiviral transfer plasmids that can be used for highyield, time and costefficient, and constitutive or inducible production of soluble and membrane proteins. Molecular cloning of biologically active rauscher spleen. A frequent event in the generation of these malignant cells is deregulation of the hematopoieticspecific transcription factor pu. These latter cells, but not parental da3 cells, became factorindependent after superinfection either with epo virus or with friend spleen focus forming virus. Friend spleen focus forming virus definition and examples.
Studies on target cells of friend spleen focusforming virus. Dec 16, 2019 lentiviral vector lvluc2p2apuro expressing luciferase driven by the spleen focusforming virus promoter was purchased from imanis life sciences rochester, mn. The detection of a spleen focusforming virus neoantigen. Spleen cells taken from mice infected as adults with two different variants of the spleen focusforming virus sffv, sffvp and sffva, as well as spleen cells. Two recombinant retroviruses expressing eporr129c, spleen focus forming virus sffvcepor and myeloproliferative sarcoma virus mpsvcepor, were used to infect fetal liver cells that served as a source of hematopoietic progenitors. Rescue of spleen focus forming activity was obtained on infection of these cells with mulvf or mulvmol, but not with mulvgross. Spleen focusforming virus in friend and rauscher leukemia virus preparations. The spleen focus forming virus sffvf component of the friend virus fv complex is a defective virus and is the erythroidspecific component of the complex which stimulates. The genomic locus was called spi1, for sffv proviral integration. Spleen scan definition of spleen scan by medical dictionary. We used a lentivirus lv backbone incorporating the spleen focus forming virus sffvf promoter to drive mir663 expression, as the cmv cytomegalovirus promoter is ineffective in some lymphocyte cells. Diseases associated with spi1 include inflammatory diarrhea and primary mediastinal bcell lymphoma. The spleen focusforming virus envelope glycoprotein.
It can act as a helper virus when complexing with a defective transforming component, rauscher spleen focus forming virus. T1 production of spleen focus forming virus and murine leukemia virus by early erythroblasts after friend virus infection. Titers of fresh virus stocks were determined in balbcj mice 8 days after retroorbital administration of diluted virus stocks by counting the foci on the spleen stained with bouins solution and expressed as spleen focus forming units sffu. Are spleen focusforming virus sequences related to. L wolff and s ruscetti laboratory of genetics, national cancer institute, bethesda, maryland 20892. A strain of murine leukemia virus associated with mouse tumors similar to those caused by the friend murine leukemia virus. Transient depletion of regulatory t cells in transgenic mice. Lentiviral transduction of mammalian cells for fast, scalable. Extended selfrenewal capacity of pluripotent hemopoietic. It contains a 32s, presumably defective, genome, which most likely is responsible for spleen focus formation, and a 35s helper virus. The spleen focus forming virus sffv, a rapidly transforming, replicationdefective virus in friend virus fv complex that is readily neutralized by antisera directed against its helper virus, was. The spleen focus forming virus sffvf component of the friend virus fv complex is a defective virus and is the erythroidspecific component of the complex which stimulates erythropoiesis in. This gene encodes an etsdomain transcription factor that activates gene expression during myeloid and blymphoid cell development citation needed.
We have previously shown that the external domain of gp52 carries the determinants responsible for its transport defect. The spleen focusforming virus sffv envelope gene, when. Wikigenes spi1 spleen focus forming virus sffv proviral. The fv stock used in these experiments was fv complex containing btropic friend murine leukemia helper virus and polycythemiainducing spleen focus forming virus. A protective role for the lectin cd169siglec1 against a. Acquired data were analysed using flowjo software tree star inc, ashland.
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