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WO1999061613A2 - Mise en evidence des interactions critiques entre proteines d'arn par interference avec la traduction virale a mediation d'ires par l'arn d'une petite levure - Google Patents

Mise en evidence des interactions critiques entre proteines d'arn par interference avec la traduction virale a mediation d'ires par l'arn d'une petite levure Download PDF

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WO1999061613A2
WO1999061613A2 PCT/US1999/011281 US9911281W WO9961613A2 WO 1999061613 A2 WO1999061613 A2 WO 1999061613A2 US 9911281 W US9911281 W US 9911281W WO 9961613 A2 WO9961613 A2 WO 9961613A2
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rna
translation
protein
binding
mrna
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PCT/US1999/011281
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WO1999061613A3 (fr
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Saumitra Das
Asim Dasgupta
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The Regents Of The University Of California
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Priority to AU45424/99A priority Critical patent/AU770432B2/en
Priority to JP2000550997A priority patent/JP2002516100A/ja
Priority to CA002329155A priority patent/CA2329155A1/fr
Priority to EP99928330A priority patent/EP1088070A2/fr
Publication of WO1999061613A2 publication Critical patent/WO1999061613A2/fr
Publication of WO1999061613A3 publication Critical patent/WO1999061613A3/fr

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    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12N—MICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA
    • C12N15/00—Mutation or genetic engineering; DNA or RNA concerning genetic engineering, vectors, e.g. plasmids, or their isolation, preparation or purification; Use of hosts therefor
    • C12N15/09—Recombinant DNA-technology
    • C12N15/63—Introduction of foreign genetic material using vectors; Vectors; Use of hosts therefor; Regulation of expression
    • C12N15/67—General methods for enhancing the expression
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P31/00—Antiinfectives, i.e. antibiotics, antiseptics, chemotherapeutics
    • A61P31/12—Antivirals
    • A61P31/14—Antivirals for RNA viruses
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P31/00—Antiinfectives, i.e. antibiotics, antiseptics, chemotherapeutics
    • A61P31/12—Antivirals
    • A61P31/14—Antivirals for RNA viruses
    • A61P31/16—Antivirals for RNA viruses for influenza or rhinoviruses
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K14/00—Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof
    • C07K14/435—Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof from animals; from humans
    • C07K14/46—Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof from animals; from humans from vertebrates
    • C07K14/47—Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof from animals; from humans from vertebrates from mammals
    • C07K14/4701—Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof from animals; from humans from vertebrates from mammals not used
    • C07K14/4702—Regulators; Modulating activity
    • C07K14/4703—Inhibitors; Suppressors
    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12N—MICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA
    • C12N15/00—Mutation or genetic engineering; DNA or RNA concerning genetic engineering, vectors, e.g. plasmids, or their isolation, preparation or purification; Use of hosts therefor
    • C12N15/09—Recombinant DNA-technology
    • C12N15/11—DNA or RNA fragments; Modified forms thereof; Non-coding nucleic acids having a biological activity
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K38/00—Medicinal preparations containing peptides
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
    • Y02A50/30—Against vector-borne diseases, e.g. mosquito-borne, fly-borne, tick-borne or waterborne diseases whose impact is exacerbated by climate change

Definitions

  • the invention relates to selective inhibition of translation of certain mRNAs. More particularly, the invention relates to selective inhibition of an mRNA which is initiated at an internal ribosome entry site (IRES), such as a picornavirus RNA, by a small RNA or a molecular mimic thereof.
  • IRES internal ribosome entry site
  • This RNA or mimic interacts specifically with a cellular protein to prevent binding of that protein to the internal ribosome entry site, thereby inhibiting translation initiation at that entry site.
  • this invention relates to a composition and methods of use of about an 18-amino acid peptide that constitutes the RNA binding domain of La autoantigen, one cellular protein that binds to an IRES sequence.
  • Picornaviruses include inter alia polioviruses, which cause infantile paralysis, and rhinoviruses, which cause the common cold.
  • Picorna-related viruses which replicate by mechanisms similar to picornaviruses, include hepatitis A and C, major causes of human hepatitis.
  • poliovirus vaccines are available, cases of polio still develop where vaccination is not properly used.
  • Vaccines for other picornaviruses may not be feasible, for instance, due to the high rate of mutability of the viral coat proteins in the rhinoviruses. Therefore, there is a need for methods and compositions ' for selectively inhibiting picornavirus replication without toxic effects on the host cells.
  • Poliovirus the prototype member of the picornaviridae family, is a single stranded, plus-sense RNA virus which multiplies in the cytoplasm of infected cells.
  • the RNA genome comprises approximately 7,500 nucleotides and codes for a 250 kDa polyprotein (Kitamura, N. et al. Nature (1981) 291:547-553 and Racaniello, V.R. , et al . Proc Natl Acad Sci USA (1981) 78:4887-4891.
  • the unusually long 5' untranslated region (5'UTR) of poliovirus RNA 750 nucleotides is highly structured (Skinner, M.A. et al.
  • RNA genomes of two picorna-related viruses have been shown to utilize internal ribosome entry for translation initiation (Kohara, K.T. et al . J Virol (1992) 66.:1476-1483 and Glass, M.J. et al. Virolocrv (1993) 193:842-852) .
  • p52 Another protein called p52,more abundant in HeLa cells than in rabbit reticulocytes, has been found to specifically bind to the stem-loop structure between nucleotides 559-624 of type 2 poliovirus RNA (Me ⁇ rovitch, K. et al. Genes This p52 protein appears to be iden ⁇ sa ⁇ - ⁇ ' e ⁇ 'fcie**human La auto antigen
  • This nuclear protein which is recognized by antibodies from patients with the autoimmune disorder lupus erythematosus, leaches out of the nucleus into the cytoplasm in poliovirus-infected HeLa cells.
  • La protein corrects aberrant translation of poliovirus RNA in reticulocyte lysate which contains little or no p52 (Meerovitch et al. (1993, supra).
  • UV crosslinking studies have demonstrated another cellular protein, p57 to interact with IRES elements of encephalomyocarditis (EMC), foot-and-mouth disease, rhino-, polio- and hepatitis A viruses (Jang et al . 1990, supra; Borovjagin, A.V. et al . Nucleic Acids Res (1991) 19:4999-5005; Luz et al . 1991, supra ; Pestova, T.V. et al . J Virol (1991) 65:6194-6204; Borman et al . 1993, supra, and Chang, K.H. et al . J Virol (1993) 67:6716-6725) .
  • EMC encephalomyocarditis
  • RNA structures spanning nucleotides 286-456 of poliovirus have been shown to specifically interact with RNA structures spanning nucleotides 286-456 of poliovirus. These two proteins are reported to be present in HeLa cells in higher quantities than in reticulocyte lysate and appear to be involved specifically in poliovirus translation (Gebhard, J.R. et al . J Virol (1992) 66:3101-3109) . Another 54 kDa protein cross-links to a region between nucleotides 456-626 and is required for translation of all mRNAs (Gebhard et al. 1992, supra) .
  • RNA-protein complex formation has also been demonstrated with the regions encompassing nucleotides 98-182 and 510-629 of the poliovirus RNA (del Angel, P.A.G. et al . Proc Natl Acad Sci USA (1989) j36_: 8299-8303) .
  • yeast cells are incapable of translating poliovirus RNA both in vivo and in vitro and that this lack of translation represents selective translation inhibition which requires the 5'UTR of the viral RNA (Coward, P. et al . J Virol (1992) 66:286- 295) .
  • the inhibitory effect was found to be due to a transacting factor present in yeast lysate that can also inhibit the ability of HeLa cell extracts to translate poliovirus RNA.
  • Initial characterization of this inhibitor showed that its activity was heat stable, resistant to proteinase K digestion, phenol extraction and DNase digestion, but sensitive to RNase (Coward et al. 1992, supra) .
  • the present invention is directed to methods and compositions for inhibiting translation of an mRNA, such as poliovirus RNA, which is initiated at an internal ribosome entry site and requires binding of a protein factor to that site.
  • the invention is based on the identification of an RNA* of 60 nucleotides from the yeast S. cerevisiae which inhibits-* internally initiated translation but not cap-dependent? translation.
  • the yeast inhibitor RNA (I-RNA) binds to various cellular proteins that are reported to be involved in internal initiation of translation, competing with the 5'UTR of poliovirus RNA for binding to such proteinsj and selectively inhibiting translation of viral mRNA without affecting host cell protein synthesis.!
  • the inhibitor RNA When expressed in host cells, the inhibitor RNA specifically and efficiently inhibits translation of poliovirus RNA and thereby protects these cells from viral infection. Analyses of structural requirements of this RNA for inhibition of translation has enabled the design of substantially smaller RNA inhibitors of internally-initiated RNA translation and, ultimately, design of non-RNA molecular mimics of such inhibitor RNAs.
  • the invention is directed to a method to inhibit translation of an mRNA, which translation is initiated at an internal ribosome entry site of the mRNA and requires binding of a protein factor to that site.
  • This method comprises a step of providing, in a system that is capable of translating this mRNA, an inhibitory effective amount of a molecule that selectively binds to the required protein factor, thereby preventing that factor from binding to the internal ribosome entry site of the mRNA.
  • the inhibitor molecule is an RNA oligonucleotide consisting of less than 35 nucleotides or a structural mimic of such an RNA oligonucleotide .
  • the invention is directed to an expression construct encoding an RNA molecule comprising an RNA oligonucleotide consisting of less than 35 nucleotides linked to a heterologous nucleotide sequence, and to an inhibitor molecule suitable for use in the method of translation inhibition of the invention, which provides the three-dimensional array of intermolecular forces exhibited by an internal ribosome entry site of an mRNA.
  • the invention relates to a method to inhibit translation of an mRNA, which translation is initiated at an internal ribosome entry site of the mRNA and requires binding of a protein factor to said site, which method comprises: a step of providing, in a system that is capable of translating the subject mRNA, a translation inhibitory effective amount of a molecule that selectively binds to the factor, thereby preventing the factor from binding to the site of the mRNA, wherein the molecule is selected from the group consisting of: an RNA oligonucleotide consisting of less than 35 nucleotides; and a structural mimic of said RNA oligonucleotide.
  • the mRNA is a viral RNA of a virus selected from the group consisting of picornaviruses, flaviviruses, coronaviruses, hepatitis B viruses, rhabdoviruses, adenoviruses, and parainfluenza viruses.
  • the virus may be selected from the group consisting of polioviruses, rhinoviruses, hepatitis A viruses, coxsackie viruses, encephalomyocarditis viruses, foot-and-mouth disease viruses, echo viruses, hepatitis C viruses, infectious bronchitis viruses, duck hepatitis B viruses, human hepatitis B viruses, vesicular stomatitis viruses, and sendai viruses.
  • the mRNA to be inhibited may be a cellular mRNA with an internal ribosome entry sites, such as a cellular mRNA encoding an immunoglobulin heavy chain binding protein (Bip) .
  • the inhibitor molecule may be provided by adding the RNA oligonucleotide of the invention to the system that is capable of translating the mRNA.
  • the molecule is provided by adding to the system that is capable of translating the mRNA an RNA molecule comprising the RNA oligonucleotide linked to a heterologous nucleotide sequence.
  • the RNA oligonucleotide also may be provided by an expression construct for in si tu production of the RNA oligonucleotide in the system that is capable of translating the subject mRNA.
  • the system to be inhibited by the invention method may be a cell- free system or a host cell that is infected or at risk of infection with a virus which produces the subject mRNA.
  • the host cell may be a mammalian cell, either in a cell culture or in a host animal in which translation of the subject mRNA is to be inhibited.
  • the invention relates to a molecule that inhibits translation of an mRNA, which translation is initiated at an internal ribosome entry site of this mRNA and requires binding of a protein factor to that site. This mqlecule selectively binds to the factor, thereby preventing the factor from binding to the ribosome entry site of the mRNA.
  • the invention molecule is selected from the group consisting of an RNA oligonucleotide consisting of less than 35 nucleotides; and a structural mimic of such an RNA oligonucleotide.
  • this molecule is an RNA oligonucleotide having a sequence which comprises at least one portion selected from the group of sequences consisting of the sequence shown in Figure 1 A; a sequence complementary to the sequence shown in Figure 1 A the sequence of nucleotides 186-220 of poliovirus (stem-loop D) th_e sequence of nucleotides 578-618 of poliovirus (stem-loop G) the sequence of nucleotides 260-415 of poliovirus (stem-loop E) the sequence of nucleotides 448-556 of poliovirus (stem-loop F) and the sequence of an immunoglobulin heavy chain binding protein (Bip) mRNA which binds said protein factor to said internal ribosome entry site of said
  • the nucleotide sequence of the RNA oligonucleotide is the ribonucleotide sequence 5' GCGCGGGCAGCGCA 3'.
  • the invention is related to an RNA molecule comprising an RNA oligonucleotide linked to a heterologous nucleotide sequence and an expression construct encoding an RNA molecule wherein the RNA molecule comprises an RNA oligonucleotide of the invention linked to a heterologous nucleotide sequence.
  • the invention also provides screening assays for identifying molecules that inhibit translation of an mRNA, which translation is initiated at an internal ribosome entry site of this mRNA and requires binding of a protein factor to that site.
  • This inhibitor molecule selectively binds to the translation initiation factor, thereby preventing the factor from binding to the ribosome entry site of the mRNA.
  • Assays to identify initiation factor binding molecules of the invention include immobilized ligand binding assays, solution binding assays, scintillation proximity assays, di-hybrid screening assays, and the like.
  • the protein factor is a 52 kDa La autoantigen.
  • three other human cellular polypeptides of apparent molecular masses of 80, 70 and 37 kDa may be used to detect molecules which exhibit the translational inhibitory activity of I-RNA of the invention.
  • the present invention provides about an 18 amino acid peptide which constitutes the RNA binding domain of La and which La peptide (LAP) competes with full length or wildtype La to bind to the viral IRES sequence or genetic elements.
  • LAP La peptide
  • the LAP of the present invention is useful for selectively inhibiting viral mRNA translation in mammalian host cells.
  • the present invention provides for a therapeutic composition and methods of use thereof comprising LAP in a pharmaceutcially acceptable carrier which freely diffuse into human cells and blocks viral replication.
  • amino acid sequence of LAP comprises about:
  • B-LAP Biotin-Ala-Ala-Leu-Glu-Ala-Lys-Ile-Cys-His-Gln-Ile-Glu-Tyr-Tyr-
  • RNA viruses such as: polio virus; hepatitis virus, types A, B, C and non- A, non-B, non-C; Rhino and coxsackie viruses.
  • human RNA viruses such as: polio virus; hepatitis virus, types A, B, C and non- A, non-B, non-C; Rhino and coxsackie viruses.
  • Figure 1 shows the nucleotide sequence, cloning, expression and activity of the exemplary yeast translation inhibitor RNA (I-RNA).
  • Panel A Sequence of the 60- nucleotide purified yeast inhibitor RNA [SEQ ID NO:l] was determined as described in materials and methods. 5'- and 3'-termini of the RNA are indicated.
  • Panel B schematic Illustration of the pSDIR plasmid expressing I-RNA. The position of H/ndlll and EcoRI restriction endonuclease sites are shown. T7 and SP6 indicate the location of the respective promoters and the arrows show the direction of transcription.
  • Panel C The I-RNA (sense transcript) was transcribed in vitro using T7 RNA polymerase from plasmid pSDIR linearized with Hindlll restriction enzyme. Four micrograms of the synthesized RNA was then mixed with denaturing gel loading dye (US Biochemicals), heated at 550C for 10 min and then analyzed on a 1.2% agarose gel along with the
  • Panel D In vi tro translations of pG3CAT and p2CAT RNAs in HeLa cell-free translation lysates were performed in the absence or presence of the inhibitor RNA. Two ⁇ g of pG3CAT or P2 CAT RNAs were added per reaction containing 80 ⁇ g of HeLa cell lysates. Approximately 4 ⁇ g of partially purified yeast inhibitor RNA and 1 ⁇ g of synthetic inhibitor RNA were used in respective reactions indicated in the figure. The location of the CAT gene product is shown with an arrowhead.
  • Figure 2 illustrates the requirement of the poliovirus 5'UTR sequence for inhibition of translation by the yeast inhibitor RNA.
  • Panels A, B and C HeLa cell-free translation lysates were used to translate the RNAs listed above the lanes in each panel. In vi tro translations were performed with approximately 2 ⁇ g of either capped or uncapped RNA as indicated for each deletion mutant construct, in the absence or presence of 1 ⁇ g purified I-RNA. Each reaction contained 80 ⁇ g of HeLa cell lysate protein. The position of the CAT protein is indicated at the left of panel A.
  • Panel D The diagram shows poliovirus 5'-UTR deletion mutant constructs that were used for the above experiment. Vertically hatched boxes represent SP6 RNA polymerase promoters. Solid black boxes represent the sequences from the poliovirus 5'-UTR, and diagonally hatched boxes indicate CAT gene coding sequences. The number underneath the plasmids represents the nucleotide at the edge of the deletion.
  • Figure 3 illustrates formation of a complex between the I-RNA and cellular proteins which retards the I-RNA during gel electrophoresis and is competitively inhibited by the 5'-UTR of the poliovirus RNA.
  • 32 P-labeled I-RNA probe was incubated with or without HeLa S-10 extract in the binding reactions as described in the examples below.
  • the RNA-protein complexes were analyzed on a nondenaturing 4% polyacrylamide gel.
  • Panel A shows the mobility shift from free probe (FP) in absence of the S-10 extract (lane 2) to the complexed form (C) in presence of the S-10 extract.
  • Panel B shows the results of the competition experiments with unlabeled competitor RNAs.
  • the competitor RNAs used were: I-RNA (lane 3), 5'-UTR (lane 4) and nonspecific (Nsp) RNA (lane 5).
  • Panel B The numbers at left refer to the molecular mass of the protein markers (BRL) (lane M) . The numbers at right refer to the molecular mass of each protein which crosslinks to labeled I-RNA probe. 100-fold molar excess of the unlabeled competitor RNAs such as I-RNA (lane 3), UTR 559-624 RNA (lane 4), and nonspecific (Nsp) RNA (lane 5) were used in the binding reactions.
  • Figure 5 illustrates the predicted secondary structure of the 5'UTR of poliovirus RNA showing possible interaction sites with cellular proteins by different structural domains. The molecular masses of the cellular proteins with their possible sites of interactions (indicated by the nucleotides within parentheses) are shown. The figure is a modified version of secondary structure predictions published by Pilipenko et a . (1992, supra) , Jackson et al . (1990, supra) and Dildine, S.L. et al. J Virolo ⁇ v (1992) 66:4364-4376.
  • Figure 6 illustrates UV crosslinking of HeLa cell proteins to 32 P-labeled I-RNA, 5'UTR RNA, stem-loop SL-G and SL-D RNA probes.
  • Panel A The numbers at left refer to the molecular mass of the protein markers (lane M) .
  • Individual 32 P- labeled RNA probes such as I-RNA (lanes 1, 2) , 5'UTR RNA (lanes 3, 4), stem-loop G RNA (lanes 5, 6) and stem-loop D RNA (lanes 7, 8) were incubated either with (lanes 2, 4, 6, 8) or without (lanes 1, 3, 5, 7) HeLa S-10 extract in the binding reactions followed by UV crosslinking and gel analysis.
  • the numbers at - 11 - right of panel A denote the approximate molecular masses of the crosslinked proteins.
  • Panel B 32 P-labeled stem-loop SL-G (UTR 559-624) and SL-D (UTR 178-224) RNA in lanes 1 and 2, respectively, were incubated with HeLa S-10 extract, crosslinked and analyzed side by side to compare the mobilities of the crosslinked proteins .
  • the numbers at right refer to the estimated molecular masses of the proteins indicated with the arrowheads .
  • Figure 7 shows that I-RNA competes with both stem- loops SL-G and SL-D for protein binding.
  • the 32 P-labeled RNA probes used in the UV-crosslinking experiments are listed on top of each panel .
  • the numbers at left of panel A indicate the molecular masses of protein markers in lane M.
  • Panel B Lane 1, no extract; lane 2, extract with no unlabeled RNA; lane 3, unlabeled 5'SL-G RNA competitor; lane 4, unlabeled I-RNA competitor; lane 5, unlabeled 5 'SL-D RNA competitor; lane 6, unlabeled nonspecific RNA competitor; lane 7, unlabeled SL-B RNA; lane 8, unlabeled SL-C RNA.
  • Panel C Lane 1, no extract; lane 2, extract with no unlabeled competitor; lane 3, unlabeled SL-D competitor; lane 4, unlabeled I-RNA competitor; lane 5, nonspecific RNA; lane 6, unlabeled SL-G competitor; lane 7, unlabeled SL-B RNA; lane 8, unlabeled SL-C RNA.
  • the arrowheads indicate protein-nucleotidyl complexes with proteins of molecular masses of 52, 54 and 57 kDa respectively, from bottom to top.
  • Figure 8 demonstrates that I-RNA inhibits internal initiation of translation in vitro.
  • Panel A The construct pBIP-LUC containing the 5'UTR of Bip mRNA linked to a reporter gene (luciferase) was translated in vitro in HeLa cell lysates in the absence (lane 1) or presence (lane 2) of the yeast inhibitor. As a control the construct pG3CAT was also translated in the absence (lane 3) or presence (lane 4) of the - 12 - yeast inhibitor. The products were analyzed on a SDS-14% polyacrylamide gel. The arrowhead at the left indicates the position of the luciferase gene product (LUC) and the arrowhead to the right indicates the product of CAT gene (CAT) .
  • LEC luciferase gene product
  • Panel B A bicistronic construct pPB310 containing the CAT gene and luciferase gene flanked by TMEV 5'UTR was translated in vi tro in HeLa cell lysates in absence (lane 1) or presence (lane 2) of I-RNA. The product were analyzed on a SDS-14% polyacrylamide gel .
  • the arrowheads at left denote the positions of the CAT gene product (CAT) and luciferase gene product (LUC) .
  • Figure 9 shows that I-RNA inhibits translation of poliovirus RNA in vivo .
  • Monolayers of HeLa cells were transfected with viral RNA alone, I-RNA alone or viral RNA and I-RNA together. After transfection the cells were labeled with 35 S-methionine and in vivo labeled proteins were analyzed on a SDS-14% polyacrylamide gel either directly (panel A) or after immunoprecipitation with anticapsid antibody (panel B) as described in the examples below.
  • Panel A The RNAs added to each transfection reaction are as indicated in the figure.
  • Panel B The panel shows the immunoprecipitated in vivo labeled proteins from the transfection reactions shown in panel A, lanes 1-5. The positions of the poliovirus capsid proteins are indicated to the left of panel B.
  • Figure 10 illustrates computer-predicted secondary structures of the yeast inhibitor RNA.
  • Panels A and B show two probable secondary structures of the RNA. The numbers refer to the positions of the nucleotides from the 5' -end of the RNA. The free energy calculated for each predicted structure is given below the respective structure.
  • Figure 11 shows that yeast I-RNA specifically inhibits internal ribosome entry site (IRES) -mediated translation in vi tro .
  • IRES internal ribosome entry site
  • A Inhibition by I-RNA of IRES-mediated translation from bicistronic constructs in HeLa cell extracts. Synthesis of luciferase (Luc) is initiated internally from virus IRES- elements and that of CAT is initiated in a Cap-dependent manner (5 'Cap-CAT-IRES-LUC 3').
  • Lanes 1, 4, 5 and 7 did not contain I- RNA. Lanes 2, 3, 6 and 8 contained 1 ⁇ g of I-RNA. (3) Effect of I-RNA on in vi tro translation mediated by various - 13 - monocistronic RNAs of immunoglobulin heavy chain binding protein (Bip, lanes 1, 2), CAT (lanes 3, 4, 9, 10), P2 CAT (containing PV 5'UTR, lanes 7,8), pGemLUC (lanes 5,6), pCITE (containing EMCV IRES, lanes 11, 12), and yeast ⁇ 36 mRNA (lanes 13, 14). Lanes 1, 3, 5, 7, 9, 11, 13 contained no inhibitor. Lanes 2, 4, 6, 8, 10, 12, 14 contained 1 ⁇ g I-RNA.
  • Figure 12 shows that the HeLa 52 kDa I-RNA-binding protein is identical to La autoantigen.
  • Two assays, gel retardation followed by supershifting with La-antibody (left) and UC-crosslinking followed by immunoprecipitation with La- antibody (right) were performed to identify the 52 Kda I-RNA binding HeLa cell protein as the La antigen.
  • Figure 13 shows that antisense I-RNA also binds a HeLa 52 kDa protein that interacts with UTR (559-624) .
  • a 52 kDa protein is complexed to both I-RNA and anti I-RNA (indicated with an arrowhead) which can be competed by cold UTR 559-624 (lane 2) .
  • Lane M contained 14C labeled protein molecular mass markers with sizes of 43 and 29 kDa respectively from the top.
  • Figure 14 shows inhibitory activity of a 14 nucleotide long RNA (BI-RNA) containing I-RNA sequences in specifically inhibiting translation by internal initiation (P2 CAT) but not cap dependent-translation (CAT).
  • the figure shows translation of CAT gene (indicated with an arrowhead) from P2 CAT (lanes 1-4) or pCAT (lane 5 and 6) construct in the absence (lane 1 and 5) or presence of either I-RNA (lane 2) or 1 ⁇ g (lane 3 and 6) and 2 ⁇ g (lane 4) of BI-RNA.
  • Figure 15 illustrates the sequence of an active 14 nucleotide BI-RNA containing I-RNA sequences in the context of the computer-predicted secondary structures of the yeast inhibitor RNA as shown in Figure 10.
  • the solid line in panel B encompasses the 14 nucleotides of the BI-RNA which were shown to inhibit translation using internal initiation as described in Figure 14.
  • nucleotide 13 of the native I-RNA structure is linked directly to nucleotide 30, by conventional phosphodiester linkage.
  • Figure 16 diagrams I-RNA deletion mutant constructs tested for translation inhibiting activity. The nucleotide positions of the mutation sites are indicated for each mutant. The names of the respective mutants are listed at the far left.
  • Figure 17 illustrates the IRNA binding domain of La peptide (LAP) by measuring the competitive binding inhibition of the wildtype LAP and deletion mutants of LAP.
  • Figure 18 illustrates the effect of La peptide in inhibiting replication of PV in cultured hepatoma cells using a titered plaque assay.
  • LAP was added to cells one hour after initiation of infection to rule out the possibility that LAP was interfering with virus attachment. Infection was continued up to 24 hours, at which time the infection was stopped and virus titer was determined by assaying cell-free extracts for plaque formation in HeLa cells. Compared with NSP (non-specific protein), LAP was effective in entering host cells and inhibiting PV replication.
  • FIG. 19 illustrates that IRNA-LAP combination is more effective in inhibiting HCV-IRES-mediated translation than individual molecules.
  • Figure 20 illustrates a mechanism wherby IRNA and LAP inhibit HCN IRES- mediated translation.
  • control sequences refers collectively to promoter sequences, ribosome binding sites, polyadenylation
  • a coding sequence is "operably linked to" control sequences when expression of the coding sequences is effected when the expression system is contained in an appropriate host cell.
  • a "host cell” is a cell which has been modified to contain, or is capable of modification to contain, an exogenous DNA or RNA sequence. This includes, for instance, a cell infected by a virus or a cell transformed by a recombinant DNA molecule.
  • a "heterologous" region of a DNA or RNA construct is an identifiable segment of DNA or RNA within or attached to another nucleic molecule that is not found in association with the other molecule in nature.
  • the present invention relates to a method to inhibit translation of an mRNA, which translation is initiated at an internal ribosome entry site of that mRNA and requires binding of a protein factor to said site.
  • the method comprises a step of providing, in a system that is capable of translating the mRNA, a translation inhibitory effective amount of a molecule that selectively binds to the factor, thereby preventing that factor from binding* to the ribosome entry site of the mRNA.
  • the translation inhibitor molecule of this invention is selected from the group consisting of an RNA oligonucleotide consisting of less than 35 nucleotides and a structural mimic of said RNA oligonucleotide.
  • Identification of a translation inhibitor molecule according to the present invention is exemplified in the first instance by the isolation and determination of the 60 nucleotide sequence of a naturally occurring inhibitor RNA from the yeast S. cerevisiae .
  • This RNA selectively inhibits internally initiated translation but not cap-dependent translation, for instance, of picornavirus mRNAs.
  • the isolation and sequencing - 16 - of this small inhibitor RNA (I-RNA) is described in Example 1.
  • I-RNA small inhibitor RNA
  • Example 1 Preparation of a synthetic DNA clone encoding the sequence of an inhibitor RNA, and production of the RNA from the synthetic clone by transcription with T7 RNA polymerase, are illustrated in Example 2. These methods may be adapted to the production of other RNA oligonucleotides of the invention, using routine approaches which are well known in the art.
  • RNA constructs comprising both IRES- and 5' cap-mediated translation initiation sites. See, for instance, Example 3.
  • selective inhibition of internally initiated translation may be demonstrated in vi tro using recombinant bicistronic mRNA constructs of another viral mRNA, such as those described in Example 7, or of an internally initiated cellular mRNA, such as an mRNA encoding an immunoglobulin heavy chain binding protein as illustrated in Example 8.
  • the translation inhibitor molecule of the invention selectively inhibits translation from an internal ribosome entry site by binding to a protein factor which is required for initiation of translation at the ribosome entry site, thereby preventing that factor from binding to the ribosome entry site of the mRNA.
  • Such binding of the inhibitor molecule may be using competitive binding methods to show disruption of complexes between the required protein factors and a selected mRNA, such as those described in Example 4 for disruption of complexes between poliovirus RNA sequences and HeLa host cell protein factor by the exemplary yeast I-RNA of the invention.
  • direct binding of an inhibitor molecule of the invention to protein factors required for internal initiation of translation may be demonstrated conveniently using, for instance, the UV-crosslinking method described for the yeast I- RNA molecule in Example 5.
  • an inhibitor molecule of the invention to inhibit translation of a viral mRNA in vivo may be - 17 - demonstrated conveniently in cell cultures as shown for inhibition of poliovirus RNA translation in transfected cells by the yeast I-RNA, which inhibits viral replication and pathogenic effects, as illustrated in Example 9. Accordingly, based on the general guidance and examples herein, one may determine using routine methods whether a given molecule exhibits the activities of a translation inhibitor of the invention, namely, inhibition of translation of an mRNA, which translation is initiated at an internal ribosome entry site and requires binding of a protein factor to that site, by selectively binding to the factor, thereby preventing the factor from binding to ribosome entry site of the subject mRNA.
  • the translation inhibitor molecule of the invention is an RNA oligonucleotide, based on the sequence of the exemplary yeast I-RNA, consisting of less than 60 nucleotides, preferably consisting of less than 35 nucleotides, more preferably less than 25 nucleotides, and still more preferably less than 15 nucleotides.
  • RNA oligonucleotide based on the sequence of the exemplary yeast I-RNA, consisting of less than 60 nucleotides, preferably consisting of less than 35 nucleotides, more preferably less than 25 nucleotides, and still more preferably less than 15 nucleotides.
  • deletion mutants from both 5' and 3 '-ends of I-RNA. Ten, 20 or 30 nucleotides are deleted at a time from either the 5' or 3' terminus of the I-RNA. RNA produced from these clones by transcription with T7 RNA polymerase is tested for the ability to inhibit IRES-mediated translation but not cap-dependent translation, as described in the examples herein. Conventional methods are also used to generate a nested set of - 18 - deletions of 8-10 nucleotide sequences throughout the I-RNA molecule.
  • mutants which inhibit IRES-mediated translation will be tested for loss of binding activity to protein factors such as the p52 factor shown to bind to the yeast I-RNA or other factors mentioned hereinabove (for example p57) which are involved in I-RNA mediated inhibition of viral translation.
  • the p52 factor which binds to yeast I-RNA is identical to the human La autoantigen as shown by immunological assays. This identity was further confirmed by both immunoprecipitation following UV-crosslinking of the recombinant La protein to I-RNA and the ability to supershift the La-I-RNA complex with anti-La antibody ( Figure 12) . That binding of La to I-RNA is relevant to translation inhibition is indicated by the fact that purified recombinant La protein is able to restore PV IRES-mediated translation in the presence of the inhibitor RNA. Additional protein factors which bind to full-length or deleted I-RNAs and which can be used to identify other inhibitor molecules of the invention are described below.
  • a more selective mutational analysis also may be used to identify an active oligonucleotide of the invention based on the larger sequence of an active I-RNA such as the exemplary yeast I-RNA.
  • an antisense RNA having the sequence exactly complementary to the sequence of yeast I-RNA is as efficient in binding p52 as the sense I-RNA molecule. See Figure 13.
  • This result taken together with the fact that there is no apparent sequence homology of the yeast I- RNA with poliovirus RNA sequences bind host cell protein factors needed for initiation of translation suggest that secondary structure of I-RNA may play a crucial role in the inhibition of internal initiation of translation.
  • many aspects of the secondary structure of a sequence complementary to any RNA would be expected to be similar to the secondary structure of the sequence itself, since generally the same intrastrand base - 19 - pairings would be able to form in the complementary strand as in the original sequence.
  • the secondary structure of the 60 nucleotide long native I-RNA does not change significantly by addition of 11 extra nucleotides generated during the exemplary cloning procedure. Accordingly, by appropriate analysis of secondary structures, one can predict whether linking of an active RNA oligonucleotide of the invention to a heterologous sequence is likely to destabilize the secondary structure of the oligonucleotide and thereby destroy its translation inhibitory activity. In addition the retention of the required activity may be readily determined for any desired RNA oligonucleotide using the routine methods described herein.
  • RNA oligonucleotides corresponding to various loops in the predicted secondary structures of the yeast I-RNA, a 14 nucleotide long fragment of I-RNA was found to specifically inhibit poliovirus IRES-mediated translation. See Figure 14. It should be noted that the testing of RNA oligonucleotides comprising loops in computer-predicted secondary enables identification of active RNA oligonucleotides containing noncontiguous portions of the larger I-RNA sequence, such as the exemplary 14 nucleotide fragment which consists of nucleotides 7-13 covalently coupled (by conventional 5' -3' phosphodiester linkage) to nucleotides 30-36 of the yeast I-RNA.
  • Example 10 Experimental results of a systematic deletional analysis of the yeast I-RNA are illustrated in Example 10, below. This analysis shows that the minimum I-RNA sequence required to inhibit PV IRES-mediated translation appears to reside between nucleotides 30-45. This conclusion is supported - 20 - by two observations. First, a deletion mutant (1-3 RNA) which contains the entire I-RNA sequence except nucleotides 31-45 is totally inactive in inhibiting viral IRES-mediated translation. Second, a truncated I-RNA (nt 30-45, 1-9 RNA) retains considerable amount of translation-inhibitory activity.
  • RNA 25 nt long truncated RNA
  • 1-9 RNA 25 nt long truncated RNA
  • the shorter 1-9 RNA was only 50% as active as I-RNA in vivo.
  • Both 1-7 and 1-9 RNAs can assume secondary structures having stem-and-loop sequences.
  • 1-9 RNA is much less stable than I-RNA which may affect stability of 1-9 RNA inside a cell.
  • Known thio-derivatives or other nuclease-resistant nucleotide analogs may be used to increase stability and thus activity of 1-9 RNA or other inhibitor RNAs of the invention which are exogenously provided to cells.
  • the structure (s) of I-RNA or its truncated derivatives may be important in IRES-mediated translation inhibition.
  • the fact that addition of an extra ten nucleotides to the 3 '-end of 1-7 RNA (nt 26-50) significantly reduces its (1-6 RNA, nt . 26-60) translation-inhibitory activity may be indicative of alteration of structure of this RNA which should be avoided in designing the 3 '-end of an inhibitor RNA of the invention.
  • addition of another 5 nucleotides to the 5 '-end of 1-6 RNA drastically reduces its (1-5, nt 20-60) ability to inhibit translation, indicating a need to consider such 5' -end effects in inhibitor RNA design.
  • Another alternate approach to identify a sequence and secondary structure responsible for translation inhibition, for instance by p52 binding is to determine if a domain of I-RNA bound to p52 is resistant to RNase digestion according to routine methods known in the art.
  • 32 P-body labeled I-RNA is incubated with purified pR2 under binding conditions.
  • the resulting complex is digested with micrococcal nuclease or a mixture of RNases Tl, T2, and A.
  • the mixture is then analyzed for one or more protected fragments following phenol extraction and ethanol precipitation.
  • Protected fragment of 1-RNA are sequenced directly, for instance, using a commercially available sequencing kit.
  • An alternate sequencing - 21 - approach is to hybridize the protected fragment with cDNA encoding the I-RNA, followed by digestion of single stranded regions of the hybrid and sequence determination of the protected DNA fragment which is comparatively easier than RNA sequencing. The protected fragment is then tested for specific competition with unlabeled I-RNA but not with a non-specific RNA for translation inhibition and binding to the protein factor, as described herein.
  • binding of the 80 kDa protein to the viral 5' -UTR may be important for internal initiation to occur and 1-7 RNA may directly compete with the 5' -UTR in binding these polypeptides.
  • a recent report by Meyer et al. utilizing UV-crosslinking studies indicates the importance of a 80 kDa protein in IRES-mediated translation of foot-and-mouth disease virus (FMDV) (Meyer, K. , A. Petersen, M. Niepmann and E. Beck (1995) J. Virol. 69:2819-2824). This 80 kDa protein has been identified as initiation factor, eIF-4B. The results presented by Meyer et al .
  • RNA may interfere with IRES-mediated translation by binding these polypeptides. Accordingly, ability to interfere ultimately with binding of the 80 kDa protein is expected to be an indicator of an inhibitor having the translation inhibition activity of the I-RNA of the invention.
  • RNAs 1-4 and 1-8 RNAs may not efficiently inhibit translation because of their inability to interact with the 80 kDa polypeptide. Binding of the 70 kDa protein to 1-4 and 1-8 RNA may inhibit their ability to interfere with IRES-mediated translation, perhaps by preventing these RNAs from interacting with the 80 kDa polypeptide. Accordingly, lack of binding to the 70 kDa protein also is expected to be an indicator of an inhibitor having the translation inhibition activity of the I- RNA of the invention.
  • additional RNA sequences besides that of the exemplary yeast -I- RNA, may be used to derive additional translation inhibitory RNA oligonucleotides according to the invention.
  • additional active oligonucleotides may be derived from the complement ("antisense") of the sequence of the yeast I-RNA, since this complementary sequence also shows the translation inhibitory activity of the I-RNA sequence itself. See Figure 13. The same mutational and other analytical approaches described for the I-RNA sequence are applied, with appropriate routine modifications.
  • RNA sequences having little or no sequence homology with the exemplary yeast I-RNA may be modified as described herein to produce active RNA oligonucleotides of the invention.
  • certain loops of the 5'UTR of various picornaviral RNAs are responsible for binding of those mRNAs to the protein factors require for IRES-mediated translation initiation.
  • the present disclosure shows by deletion analyses that the yeast I-RNA requires the mRNA to have internal ribosome entry site (IRES) sequences to inhibit translation of poliovirus RNA in vi tro .
  • Oligonucleotides containing these sequences also will have translation inhibitory activity according to this invention.
  • RNA oligonucleotides consisting of the binding sequences of such factor-binding loops, and even the production of such RNA oligonucleotides of less than 35 nucleotides, for any purpose, appears to be unheralded.
  • RNA loops shown to bind to other protein factors besides the p52 protein exemplified in this disclosure are also suitable sources of natural sequences for RNA oligonucleotides of the invention.
  • searches for sequences that are similar to I-RNA sequence using FASTA (Pearson et al . 1988) on Biovax copy of GCG-formatted Genbank of three databases, namely viral, structural RNA and plants including yeast (version Sept. 1993) has identified partially related sequences. Thus, 89.5% homology was found (with a 19 nt overlap) with a region of the Japanese encephalitis viral genome.
  • I-RNA is treated with DMS, Si, cobra venom (CV) , as well as other nucleases as described (11) .
  • primer extension technique will be used (11) . Elongation of DNA chains should stop one nucleotide before the modified base and just before the cleaved internucleotide bond.
  • vi tro assays for identifying molecules which inhibit protein translation by the same mechanism as the yeast I-RNA of the invention such as antibodies or other compounds that modulate the activity of a protein translation initiation factor which binds to an internal ribosome entry site and which is inhibited by binding to the yeast I-RNA of the invention, also are provided by the invention.
  • Such assays may involve an immobilized ligand, for example, immobilizing a suitable initiation factor required for IRES-dependent protein translation initiation or a molecular mimic of such a factor, or, alternatively, a natural ligand to which such an initiation factor binds (e.g., I-RNA), detectably labelling the nonimmobilized binding partner, incubating the binding partners together and determining the effect of a test compound on the amount of label bound wherein a reduction in the label bound in the presence of the test compound compared to the amount of label bound in the absence of the test compound indicates that the test agent is an inhibitor of initiator factor binding.
  • an immobilized ligand for example, immobilizing a suitable initiation factor required for IRES-dependent protein translation initiation or a molecular mimic of such a factor, or, alternatively, a natural ligand to which such an initiation factor binds (e.g., I-RNA), detectably labelling the nonimmobilized binding partner, incubating the binding partners together
  • a scintillation proximity assay which involves immobilizing the factor or a mimic or fragment thereof on a solid support coated (or impregnated with) a fluorescent agent, labelling the ligand with a compound capable of exciting the fluorescent agent, contacting the immobilized initiation factor with the labeled ligand in the presence and absence of a putative modulator compound, detecting light emission by the fluorescent agent, and identifying modulating compounds as those compounds that affect the emission of light by the fluorescent - 26 - agent in comparison to the emission of light by the fluorescent agent in the absence of a modulating compound.
  • the initiation factor ligand may be immobilized and initiation factor may be labeled in the assay.
  • Yet another method contemplated by the invention for identifying compounds that modulate the interaction between an IRES-dependent protein initiation factor and a ligand is a di- hybrid screening assay.
  • This assay involves transforming or transfecting appropriate host cells with a DNA construct comprising a reporter gene under the control of a promoter regulated by a transcription factor having a DNA-binding domain and an activating domain, expressing in the host cells a first hybrid DNA sequence encoding a first fusion of part or all of a IRES-dependent translation initiation factor and either the DNA binding domain or the activating domain of the transcription factor, expressing in the host cells a second hybrid DNA sequence encoding part or all of the ligand and the DNA binding domain or activating domain of the transcription factor which is not incorporated in the first fusion, evaluating the effect of a putative modulating compound on the interaction between initiation factor and the ligand by detecting binding of the ligand to initiation factor in a particular host cell by measuring the production of reporter gene product in the host cell in the presence or absence of the putative modulator, and identifying modulating compounds as those compounds altering production of the reported gene product in comparison to production of the reporter gene product in the absence of the modulating compound.
  • the exA promoter Presently preferred for use in the assay are the exA promoter, the lexA DNA binding domain, the GAL4 transactivation domain, the lacZ reporter gene, and a yeast host cell.
  • Variations of the di-hybrid assay may include interactions of La or p80 proteins interacting with other components of the translation apparatus.
  • a modified version of the foregoing assay may be used in isolating a polynucleotide encoding a protein that binds to a translation initiation factor by transforming or transfecting appropriate host cells with a DNA construct comprising a reporter gene under the control of a promoter regulated by a - 27 - transcription factor having a DNA-binding domain and an activating domain, expressing in the host cells a first hybrid DNA sequence encoding a first fusion of part or all of the initiation factor and either the DNA binding domain or the activating domain of the transcription factor, expressing in the host cells a library of second hybrid DNA sequences encoding second fusions or part or all of putative initiation factor binding proteins or RNAs and the DNA binding domain or activating domain of the transcription factor which is not incorporated in the first fusion, detecting binding of an initiation factor binding protein or RNA to the initiation factor in a particular host cell by detecting the production of reporter gene product in the host cell, and isolating second hybrid DNA sequences
  • An additional assay for a translation inhibitor having the activity of the I-RNA of the invention is an La-dependent in vi tro translation assay. This approach is based on direct observation of inhibition of IRES-mediated in vitro translation as described in the examples.
  • compounds may be screened for inhibition of IRES-dependent translation in transfected cells, for instance, using a bicistronic RNA molecule with one protein product being translated in a CAP- dependent fashion and the second protein product translated via IRES, as described in Example 10, for instance.
  • Such a screen may be based on inhibition of IRES-dependent translation of a reporter molecule from a cell culture.
  • screening for inhibitors also may utilize detection of inhibition of virus production (either capsid protein as described in Example 10 or via plaque assay.
  • an animal-based screen for compounds that block production of picornavirus-mediated effects in an animal model system is used to evaluate efficacy of I-RNA mimics.
  • the methods and inhibitor molecules of the invention may be used for the treatment or prevention of viral infections - 28 - in cells or in animal or human subjects. It also may be used as a diagnostic tool to determine whether a particular RNA show IRES-mediated translation which generally indicates a viral mRNA.
  • the inhibitory RNA from yeast specifically inhibits IRES-mediated translation by a variety of picornaviral RNAs including those of poliovirus, rhinovirus, hepatitis A virus, coxsackievirus, and other members of the picornaviridae group.
  • the inhibitor RNA specifically binds proteins which interact with RNA structural elements within the viral 5'UTR.
  • viruses not belonging to the picornaviral group also use internal ribosome entry for translation.
  • a prime example is a flavivirus, hepatitis C (1,2) .
  • the yeast inhibitor also inhibits hepatitis C virus translation.
  • mRNA 3 of infectious bronchitis virus, a coronavirus also utilizes internal ribosome entry mechanism (3,4) .
  • mRNAs encoding reverse transcriptase of duck and human hepatitis B virus, vesicular stomatitis virus NS protein, adenovirus DNA polymerase, and Sendai virus P/C protein have been shown to use internal initiation of ribosome entry (5-9) .
  • the inhibitory RNAs and structural mimics of the invention can also be used to control the translation of an internally initiated mRNA, such as a viral mRNA, in a cell culture or host organism harboring such a mRNA.
  • the inhibitory RNA or mimic is supplied using standard methods of administration, such as those set forth in Remington's - 29 -
  • RNA or mimic is provided by injection, and formulated using conventional excipients therefor, such as Ringer's solution, Hank's solution, and the like.
  • Oral administration with proper formulation can also be effected. While most administration is systemic, in the case of localized conditions such as a nasal infection by rhinovirus, administration may be topical or otherwise local. Slow release mechanisms for drug delivery may also be used.
  • the inhibitory RNA sequence may be generated in si tu by providing an expression system which contains a DNA encoding the RNA or inhibitory effective fragment thereof in a "reverse orientation" expression system.
  • the expression system may either be designed to be operable in the host subject, such as a mammalian subject wherein the reverse oriented sequence is under the control of, for example, an SV-40 promoter, an adenovirus promoter, a vaccinia virus promoter or the like, so that the RNA is transcribed in situ .
  • the expression system will, be provided on a replicon compatible with the host cells.
  • the yeast I-RNA of the invention has been shown to inhibit IRES-dependent initiation of translation from the 5'UTR of picornaviruses including human picornaviruses (poliovirus, rhinoviruses, hepatitis A and coxsackievirus B3) and an animal picornavirus (foot-and-mouth virus; FMDV), as well as internal translation of a flavivirus (hepatitis C) mRNA.
  • mRNA 3 of infectious bronchitis virus a coronavirus which causes significant losses in the poultry industry, also utilizes an internal ribosome entry mechanism (3,4).
  • this invention also enables production of transgenic animals and transgenic plants, using available genetic engineering technology, which express an I-RNA molecule or related translation initiation inhibitor of the invention and thereby are resistant to pathogenic effects of viruses in which the I-RNA inhibits IRES-dependent translation.
  • transgenic plants and animals by conventional techniques, that are resistant to viruses and other pathogens whose replication depends upon internal initiation of translation.
  • Another aspect of the invention relates to isolation and modification of I-RNA genes in cells, particularly in yeast cells, which express an I-RNA of the invention that prevents IRES-dependent translation initiation of a desired mRNA in such cells or extracts thereof.
  • These genetic modifications inhibit expression or activity of the I-RNA, thereby allowing the desired IRES-dependent translation initiation.
  • identification of the sequence of the I-RNA molecule isolated from yeast, as described herein enables preparation of a labeled probe which can be used with conventional genetic engineering methods detect the I-RNA gene (e.g., by Southern blotting) and its initial transcription product (e.g., by Nothern blotting) .
  • the yeast I-RNA gene or homologous genes from other species or transcripts of such genes may be isolated by standard gene cloning approaches well known in the art. For example, a random genomic library of a desired species may be screened by hybridization using an I-RNA probe provided by the invention. Examination of the structure and genomic organization of the yeast I-RNA gene and homologous genes from other species will provide a better understanding of the normal function of such genes.
  • the present disclosure enables modifications of host cells to inhibit expression or activity of I-RNA.
  • introduction of such modifications will determine whether I-RNA activity is essential for survival of host cells which express such I-RNAs.
  • an antisense I-RNA is expressed in a host cell (e.g., yeast) which expresses an I-RNA molecule.
  • the vector for expression of the antisense I-RNA contains a selectable marker gene (e.g., URA 3) to ensure that only transformed cells are recovered. If no transformed cells expressing antisense I-RNA are recovered, inducible expression constructs may be tested to determine whether the antisense RNA vector can be transformed into the cell in absence of antisense I-RNA expression and whether subsequent expression inhibits any cellular function (s). Alternatively, the I-RNA gene may be eliminated using gene "knock out" methodology known in the art.
  • yeast cells exogenous DNA introduced into the cell efficiently and stably integrates into chromosomal DNA by homologous recombination, allowing efficient replacement of a wildtype ge e with a non-functional copy.
  • the non-functional copy is generated by replacing wildtype coding sequences with a selectable marker gene (e.g., LEU or URA) .
  • Transformation of diploid cells may circumvent possible lethal effects if some I- RNA activity is required for cell viability.
  • Yeast or other I- RNA-expressing host cells, or extracts thereof, which have reduced I-RNA activity as a result of either an antisense or gene knock out modification according to the invention, are useful for expression of mRNAs requiring IRES-dependent translation initiation.
  • yeast or other I- RNA host cells which can be modified by gene knockout methodologies, as known in the art, to remove the gene encoding La or homologs thereof to produce host strains that are permissive for expression of proteins whose synthesis is dependent upon internal initiation of translation.
  • gene knockout methodologies as known in the art, to remove the gene encoding La or homologs thereof to produce host strains that are permissive for expression of proteins whose synthesis is dependent upon internal initiation of translation.
  • RNA obtained by alcohol precipitation of the aqueous phase was end-labeled with ⁇ 32 P-ATP at the 5' -end, and single RNA bands were resolved by 20% PAGE/8M urea electrophoresis.
  • RNA band was eluted from gel slices and was assayed for its ability to inhibit internal initiation of translation from a poliovirus 5'UTR-CAT construct but not from a control CAT construct known to initiate translation in a cap-dependent manner (Pelletier e,t al. 1989) .
  • a single band which migrated as an RNA of 60 nucleotides was associated with the inhibitory activity.
  • yeast cell lysates were prepared as described previously (Rothblatt et al . 1986) except that they were not treated with micrococcal nuclease. Lysates were loaded onto a DEAE Sephacel (Pharmacia) column at 0.1M potassium acetate and step-eluted with buffers containing 0.3, 0.6 and 1M potassium acetate . The fractions were dialyzed back to 0.1M salt and assayed for translation inhibitory activity. The 1M fraction which showed inhibitory activity was subjected to DNase treatment followed by proteinase K digestion and phenol- chloroform extraction. The RNA from this fraction was then isolated by alcohol precipitation.
  • RNAs that copurified with the 1M fraction were then dephosphorylated and 5'end labeled by kinase reaction. Labeled RNA species were separated on a 20% acrylamide-8M urea sequencing gel. Labeled and cold RNA bands were run in parallel lanes and were eluted from the gel as follows. Individual gel slices were soaked in 500 ⁇ l of elution buffer (2M ammonium acetate and 1% SDS) at 37°C for 4 hr. After a brief centrifugation at room temperature the supernatant was collected, extracted with phenol: chloroform (1:1) , and alcohol precipitated in the presence of 20 ⁇ g of glycogen (Boehringer-Mannheim Biochemicals) . - 33 -
  • RNA pellets were resuspended in nuclease-free water and tested for the ability to inhibit translation of p2CAT RNA (Coward et al . 1992, supra) in the HeLa cell-free translation system.
  • HeLa cells were grown in spinner culture in minimal essential medium (GlBCO laboratories) supplemented with lg/L glucose and 6% newborn calf serum.
  • HeLa cell extracts were prepared as previously described (Rose et al . 1992; Coward et al . 1992, supra) . In vi tro translation in HeLa cell-free extracts was performed essentially as described earlier (Rose et al . 1978).
  • Figure 1A shows the sequence [SEQ ID NO:l] of the 60 nucleotide RNA.
  • EXAMPLE 2 Cloning and Transcription of the Yeast Inhibitor RNA Based on the determined RNA sequence, sense- and antisense-strand specific deoxyoligonucleotides were synthesized, annealed and cloned into the pGEM 3Z expression vector between the Hindlll and EcoRI sites in the polylinker region to form the recombinant plasmid pSDIR ( Figure IB) . The clone pSDIR was linearized with Hindlll restriction enzyme, then transcribed with the T7 RNA polymerase to generate the inhibitor RNA (sense transcript) .
  • RNA synthesized from the synthetic clone was active in specifically inhibiting poliovirus IRES- dependent translation as previously found with the partially purified inhibitor from yeast cells (Coward et al . 1992, supra) .
  • the mRNAs were transcribed in vi tro using either T7 or SP6 promoter from different linear plasmids by T7 or SP6 RNA polymerases. Both plasmid pG3CAT and P2CAT (Coward, et al . 1992, supra) were linearized with BamHl and the runoff transcripts were generated using SP6 RNA polymerases.
  • the plasmid pBIP-LUC construct was obtained from P. Sarnow (Macejak et a . 1991) and was linearized with Hpal enzyme and transcribed with T7 RNA polymerase.
  • the TMEV-IRES containing construct pPB310 was from Howard L. Lipton (Bandopadhyay et al. 1992) and was linearized with Hpal and transcribed with T7 RNA polymerase . - 35 -
  • Oligodeoxyribonucleotide templates for transcription by T7 RNA polymerase were synthesized on an Applied Biosynthesis DNA synthesizer and then purified. Equimolar amounts of the 18 mer T7 primer oligonucleotide and the template oligonucleotides were mixed in 0. IM NaCl and were annealed by heating at 100°C for 5 min followed by slow cooling to room temperature.
  • the SL-B, SL-C, SL-D, and SL-G, RNAs were synthesized in vitro following the method described above.
  • the inhibitor efficiently inhibited translation from pP2 CAT but not from the pG3 CAT (or pCAT) construct ( Figure ID) . Almost complete inhibition was observed when the ⁇ 5'-33 CAT construct was translated in the presence of the inhibitor RNA (data not shown) . Deletion of the first 320 nucleotides from the 5 '-end of the UTR did not have a significant effect on the ability of the inhibitor to inhibit translation from the ⁇ 5'-320/CAT construct ( Figure 2A, lanes 1 and 2). Almost 80% inhibition of translation was observed in the presence of the inhibitor (lanes 1 and 2) . Some of the inhibition observed with the inhibitor could be reversed when the template RNA was capped prior to translation ( Figure 2A, lanes 3 and 4) .
  • the inhibitor RNA could inhibit IRES- dependent translation by two possible mechanisms: binding to UTR sequences as an antisense RNA or binding to protein factors needed for internal entry of ribosomes.
  • uniformly 32 P-labeled inhibitor RNA probe was prepared and mixed with HeLa S10 extracts, and the resulting RNA-protein complexes were analyzed by nondenaturing polyacrylamide gel electrophoresis.
  • HeLa S10 cytoplasmic extract was prepared by collecting the supernatant after centrifugation of the HeLa cell free translation extract at 10,000g, for 30 min. at 4°C.
  • a 50 ⁇ g sample of S10 extract was preincubated at 30°C for 10 min with 4 ⁇ g of poly [d(I-C)] (Pharmacia) in a 15 ⁇ l reaction mixture containing 5mM HEPES pH 7.5, 25mM KCl, 2mM MgCl 2 , O.lmM EDTA, 3.8% Glycerol and 2mM DTT.
  • poly [d(I-C)] Puls
  • the nonspecific RNA used in the competition assays was the sequence of the polylinker region (EcoRI to Hindlll) of the pGem3Z vector (Promega) .
  • Three microliters of the gel loaded dye were added to the reaction mixture to a final concentration of 10% glycerol and 0.2% of both bromophenol blue and xylene cyanol.
  • the RNA-protein complexes were then analyzed on a 4% polyacrylamide gel (39:l-acrylamide:bis) in 0.5X TBE. As shown in Figure 3A, a single complex (denoted C) was clearly evident.
  • Increasing concentrations of unlabeled I-RNA competed with the formation of the labeled complex ( Figure 3B, lanes 2-5) .
  • RNA probes Forty to fifty fmole of the 32 P-labeled RNA probes (8xl0 4 cpm) were incubated with 50-100 ⁇ g of S-10 extract of HeLa cells as described above. After the binding reaction was complete, the samples were irradiated with UV light from a UV lamp (multiband UV-254/366NM Model U GL-25; UVP, Inc.) at a distance of 3-4 cm for 10 min. The unbound RNAs were digested with a mixture of 20 ⁇ g of RNase A and 10U of RNase Tl at 37°C for 30 min and then analyzed on SDS-14% polyacrylamide gels.
  • UV lamp multiband UV-254/366NM Model U GL-25; UVP, Inc.
  • Poliovirus 5'UTR contains several thermodynamically stable stem-loop structures that are believed to play important roles in viral RNA replication and translation (Figure 5) . Among these, stem-loops A, B and C are presumably involved in RNA replication. On the other hand stem-loops D-G are believed to be involved in viral mRNA translation (Dildine et al . 1992) . Stem-loop D (SL-D) , comprising nucleotides 186-221, has been shown to bind a 50 kDa protein (p50) (Najita et al .
  • stem-loop G representing poliovirus 5'UTR sequences from 559-624, binds to a 52 kDa protein (p52) which has recently been identified as the human La protein (Meerovitch et al . (1993, supra) ) .
  • RNA corresponding to nucleotides 178-224 of the 5'UTR was prepared.
  • the whole 5'UTR, stem-loop G (UTR 559-624) , and stem-loop D (UTR 178-224) were incubated separately with HeLa S-10 extract, and the resulting protein- nucleotide complexes were analyzed by UV-crosslinking as shown in Figure 6A.
  • a major protein-nucleotidyl complex of - 3 9 - approximately 52 kDa was detected in all four reactions (lanes 2 , 4 , 6 , and 8) .
  • RNA sequences representing stem-loops B and C were used as negative controls.
  • TMEV 5'UTR is known to contain IRES sequences and has been shown to initiate translation internally (Bandopadhyay et al . 1992). Initiation of translation occurring internally from the TMEV 5'UTR would result in synthesis of luciferase, whereas cap-dependent translation would normally produce the CAT protein.
  • I-RNA preferentially inhibits internal ribosome entry site (IRES) mediated translation by a variety of picornaviral RNAs including those of poliovirus, rhinovirus, hepatitis A virus, TMEV virus, and the like. See, for instance, Figure 11.
  • I-RNA preferentially inhibits internal ribosome entry site (IRES) mediated translation by a variety of picornaviral RNAs including those of poliovirus, rhinovirus, hepatitis A virus, TMEV virus, and the like. See, for instance, Figure 11.
  • yeast inhibitor RNA preferentially inhibits internal initiation of translation in a second viral control region, the TMEV 5'UTR.
  • EXAMPLE 9 Demonstration of Inhibition of Translation of Poliovirus RNA in vivo
  • poliovirus RNA was transfected into HeLa cells alone or together with the purified yeast RNA.
  • HeLa cell monolayers were grown in tissue culture flask in minimal essential medium (GlBCO) supplemented with 5% fetal bovine serum.
  • Poliovirus RNA (type 1 Mahoney) was isolated from infected HeLa cells as described earlier
  • RNA samples were then mixed with 30 ⁇ g of Lipofectin (GIBCO-REL) and 20 units of RNasin (Promega) and incubated for 30 min at room temperature. Finally, the samples were mixed with 4 ml of minimal essential medium (GlBCO) containing 2.5% fetal bovine serum, and added to petri dishes containing 70-80% confluent HeLa monolayer cells. The cells were then incubated at 37°C in a C0 2 incubator for 24 hr.
  • GlBCO minimal essential medium
  • Proteins were labeled by addition of 35 S-methionine and synthesis of viral proteins was monitored by direct analysis of cell-free extracts ( Figure 9, panel A) or by immunoprecipitation of viral capsid proteins by anticapsid antisera ( Figure 9, panel B) . More in particular, for in vivo labeling of proteins after transfection, cells were preincubated in methionine-free medium (MEM, GlBCO) for 40 min at 37°C. Then 100 ⁇ Ci of the trans labeled methionine (sp. act. >1000 Ci/mmole) was added to the cells and incubation was continued for another hour. 3S S- methionine-labeled HeLa cell extract was prepared as described previously (Ransone et al . 1987).
  • the immune complexes were precipitated with protein A Sepharose (75 ⁇ l ot a 20% solution - 43 - in RIPA buffer plus 0.2% BSA) and then analyzed on a SDS-14% polyacrylamide gel as described earlier (Coward et al . 1992, supra) .
  • yeast inhibitor RNA efficiently inhibited translation of poliovirus RNA in vivo. ⁇ Further, protection of monolayer cells from the cytolytic effects of poliovirus infection in the presence of the yeast inhibitor RNA paralleled restoration of host cell protein synthesis seen in lanes 3 and 7 ( Figure 9A) . - 44 -
  • I-RNA deletion mutants were generated by in vi tro transcription with T7 RNA polymerase from oligonucleotide templates. Different lengths of oligonucleotides were synthesized (Biosynthesis Inc.) each beginning with a T7 promoter adapter sequences followed by various lengths from different regions of I-RNA sequences. Oligodeoxyribonucleotide templates were mixed with equimolar amounts of the 17 mer T7 primer oligonucleotide in 0.1M NaCl, and annealed by heating at 100°C for 5 min followed by slow cooling to room temperature. The nucleotide positions of the different I-RNA deletion mutants are shown in Figure 16.
  • a similar deletion mutant that contained an extra 10 nucleotides at its 3' -end (1-6 R NA , nt 26-60) also was active, but not as active as 1-7 RNA.
  • a fragment of I-RNA containing nt 1-25 (1-8 RNA) was totally inactive in translation inhibition. Further deletion of 1- 7 RNA resulted in a smaller fragment (1-9, nt 30-45) which was capable of inhibiting IRES-mediated translation. The ability of this fragment (1-9) to inhibit translation is fully consistent with the previously noted inability of 1-3 RNA to arrest translation since 1-3 RNA lacks nts 31-45 ( Figure 3) .
  • poliovirus RNA was transfected (using liposomes) into HeLa cells singly or together with purified 1-7, 1-9, 1-4, 1-8 and I-RNA. Proteins were labeled by 35 S-methionine and the synthesis of viral proteins was monitored by immunoprecipitation of viral capsid proteins from cell extracts by anti-capsid antisera. No capsid protein could be precipitated from mock-transfected cells. Upon transfection of cells with poliovirus RNA alone, synthesis of capsid proteins was clearly detected.
  • the 52 kDa I-RNA binding protein described above was shown to be identical to the human La autoantigen and various other cellular protein factors were shown to bind to full-length or deleted I-RNAs.
  • RNA probe 5 to 10 fmol was added to respective reaction mixtures and the incubation continued for another 20 min at 30°C.
  • Three microliters of gel loading dye was added to the reaction mixture to a final concentration of 5% glycerol and 0.02% each of bromophenol blue and xylene cyanol .
  • the S10 extract was preincubated with either 2.5 ⁇ l of either nonimmune human sera or 2.5 ⁇ l of immune human sera against La protein on ice for 10 min, the respective 32P- labeled RNA probe was then added to the reaction mixture and incubation was continued for another 20 min on ice.
  • RNA protein complexes were then analyzed on a 4% polyacrylamide gel (39:1 ratio of acrylamide:bis) containing 5% glycerol in 0.5 X TBE.
  • 32P-labeled RNA-protein complexes generated as described above were irradiated with a UV lamp (multi band UV) 254/366 nm (model UGL; 25 UVP Inc.) at a distance of 2 to 3 cm for 15 min in a microtiter plate. Unbound RNAs were then digested with a mixture of 20 ⁇ g RNase A and 20 units of RNase Tl at 37°C for 15 min.
  • resuspended beads in lxSDS gel loading dye 50 mM Tris [pH 6.8], 100 mM DTT 2% SDS, 0.1% BPB, 10% glycerol
  • lxSDS gel loading dye 50 mM Tris [pH 6.8], 100 mM DTT 2% SDS, 0.1% BPB, 10% glycerol
  • UV-crosslinked complexes were then immunoprecipitated with anti-La or nonimmune sera and analyzed by SDS-PAGE.
  • a 52 kDa UV-crosslinked protein was specifically immunoprecipitated by anti-La antibody when complexes were formed with HeLa cell extract using either labeled I-RNA or UTR probes ( Figure 12, right gel, lanes 2 and 5) .
  • This 52 kDa band co-migrated with UV-crosslinked, anti-La immunoprecipitated complex formed by incubating purified La protein with 32 P I-RNA (lane 3) or 32 P 5' -UTR (lane 6) .
  • a prominent -120 kDa complex seen in lanes 2 and 5 was not specific to La antibody as it could also be detected in lanes containing nonimmune serum.
  • the identity of the p52 protein bound by I-RNA was further confirmed by demonstrating that inhibition of IRES-mediated translation by I-RNA is reversed by addition of La antigen. Poliovirus is known to inhibit cap-dependent translation of host cell mRNAs by proteolytically cleaving the p220 component of the cap-binding protein complex. Therefore, extracts derived from virus-infected cells are only active in cap-independent IRES-mediated translation but not cap-dependent translation.
  • Ribosomal salt wash from HeLa cells was prepared as described by Brown and Ehrenfeld (33) with some modifications. Cultures of HeLa cells (4 x 10 5 cells /ml) were harvested by centrifugation, washed three times with cold isotonic buffer (35 mM HEPES, pH 7.5, 146 mM NaCl, 11 mM glucose) and resuspended in two times packed cell volume of lysis buffer (10 mM KCl, 1.5 mM Mg acetate, 20 mM HEPES, pH 7.4, and ImM DTT) followed by incubation on ice for 10 min for swelling. Cells were disrupted at 0/C with 50 strokes in a type B dounce homogenizer.
  • the ribosome pellet was resuspended at a concentration of approximately 250 A260/ml in lysis buffer with gentle shaking on an ice bath. KCl concentration was then - 50 - adjusted to 500 mM and the solution was stirred for 30 min on an ice bath. The resulting solution was centrifuged for 2 h at 50,000 rpm at 4°C. The supernatant (salt wash) was then subjected to 0-70% ammonium sulfate precipitation.
  • the pellet containing initiation factors was dissolved in low volume of dialysis buffer (without glycerol) followed by overnight dialysis at 4°C against the dialysis buffer containing 5mM Tris(pH 7.5), 100 mM KCl, 0.05 mM EDTA, 1 mM DTT and 5% glycerol.
  • the dialysate was then centrifuged at 10, 000 rpm for 10 min at 4°C and the supernatant was aliquoted in small volumes into several prechilled tubes and stored at -70°C.
  • La Peptide (LAP) Binding Domain Translation of certain human RNA viruses involves binding of ribosome to an internal sequence within the viral • mRNA known as internal ribosome entry site (IRES)-mediated translation. This is in contrast * to cellular mRNA translation which depends on binding of ribosomes to the 5' cap (7 methyl guanosine) structure of the mRNA.
  • IRES-mediated translation requires binding of cellular polypeptides to the IRES sequence first which is followed by ribosome binding.
  • One such protein that interacts with the IRES is the La autoantigen (-52 kDa cellular protein).
  • La binding to viral IRES element is a prerequisite to ribosome binding.
  • 18-amino acid peptide which corresponds to amino acids 11-28 of the wildtype La autoantigen and constitutes the RNA binding domain of La and we have further shown that the LAP binding domain sequence competes with full length La to bind to the viral IRES elements.
  • LAP the La peptide
  • the peptide appears to freely diffuse into human cells and block viral replication as evidenced by a 1000-fold reduction in viral plaques on tissue culture cells at micromolar concentration of LAP. Because LAP only inhibits viral protein production and does not interfere with cellular translation, LAP may be used as an antiviral agent. The efficacy of inhibition of viral replication by this peptide may be examined in small animal models.
  • one sequence of the present invention includes:
  • biotinylated derivative of this sequence may also be used: -- a --
  • B-LAP 2) Biotin-Ala- Ala-Leu-Glu-Ala-Lys-Ile-Cys-His-Gln-Ile-Glu-Tyr-
  • Poliovirus (PV) IRES-mediated translation is restricted in the yeast Saccharomyces cerevisiae due to a small RNA capable of inhibiting PV IRES-mediated translation.
  • the inhibitor RNA (called IRNA) specifically inhibited cap-independent; IRES-mediated translation but had little effect on cap-dependent translation of cellular mRNAs.
  • IRNA was found to bind strongly to several cellular polypeptides, including the La autoantigen that is required for picornaviral IRES-mediated translation. Other cellular peptides may be identified using the procedures as described herein.
  • HCV hepatitis C
  • PV IRES elements bind similar polypeptides
  • IRNA might also interfere with HCV IRES-mediated translation.
  • transient transfections and a hepatoma cell line constitutively expressing IRNA we have demonstrated specific inhibition of HCN IRES-mediated translation by IR ⁇ A.
  • hepatoma cell lines constitutively expressing IR ⁇ A became refractory to infection by both PV and a PN/HCV chimeric virus in which PN IRES is substituted by the HCN IRES (see Figure 18).
  • the binding of the La autoantigen to the HCV-IRES element was specifically and efficiently competed by IR ⁇ A.
  • An antivrial agent may be formulated with a therapeutically effective amount of LAP in a pharmaceutically acceptable carrier.
  • Methods of treatment employing a number of pharmaceutical formulations and routes of administration may be ascertained based upon standard clinical practice and procedures.
  • IR ⁇ A As an inhibitor, it was used as a tool to detect functionally important cellular protein factors in IRES-mediated translation of picorna and hepatitis C viruses. This invention contemplates such other inhibitors identified using methods as described herein. - 52 -
  • Pestivirus translation initiation occurs by internal ribosome entry. Virology 206:750-754.
  • testicular feminized (Tfm) mouse may be a product of internal translation initiation. Receptor (1994, Summer) 4 (2) :121-134.

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Abstract

L'invention concerne des peptides et des oligonucléotides d'ARN ainsi que leurs méthodes d'utilisation pour l'inhibition de la translation d'un ARNm, amorcée au niveau d'un site d'entrée ribosomique interne dudit ARNm et nécessitant la liaison d'un facteur protéique à ce site. Des peptides comprenant le domaine de fixation de l'autoantigène La (LAP) sont décrits. Des peptides à LAP, seuls ou combinés aux oligonucléotides d'ARNm inhibiteurs peuvent être utilisés comme agents antiviraux pour l'inhibition de la réplication virale induite par le site d'entrée ribosomique interne.
PCT/US1999/011281 1998-05-22 1999-05-21 Mise en evidence des interactions critiques entre proteines d'arn par interference avec la traduction virale a mediation d'ires par l'arn d'une petite levure WO1999061613A2 (fr)

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AU45424/99A AU770432B2 (en) 1998-05-22 1999-05-21 Interference with viral IRES-mediated translation by a small yeast RNA reveals critical RNA-protein interactions
JP2000550997A JP2002516100A (ja) 1998-05-22 1999-05-21 酵母小ｒｎａによるウイルスｉｒｅｓ媒介性翻訳への干渉は、重要なｒｎａ−タンパク質相互作用を明らかにする
CA002329155A CA2329155A1 (fr) 1998-05-22 1999-05-21 Mise en evidence des interactions critiques entre proteines d'arn par interference avec la traduction virale a mediation d'ires par l'arn d'une petite levure
EP99928330A EP1088070A2 (fr) 1998-05-22 1999-05-21 Mise en evidence des interactions critiques entre proteines d'arn par interference avec la traduction virale a mediation d'ires par l'arn d'une petite levure

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Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2815358A1 (fr) * 2000-10-17 2002-04-19 Parteurop Dev Polypeptides inhibiteurs de l'ires du virus de l'hepatite c et procede de criblage desdits polypeptides
EP1390392A4 (fr) * 2001-04-16 2005-03-02 Univ California Methodes d'inhibition de la replication virale
WO2007119889A1 (fr) 2006-04-18 2007-10-25 Japan Tobacco Inc. Nouveau compose de piperazine et son utilisation en tant qu'inhibiteur de la polymerase du vhc
US7659263B2 (en) 2004-11-12 2010-02-09 Japan Tobacco Inc. Thienopyrrole compound and use thereof as HCV polymerase inhibitor
EP2206715A1 (fr) 2004-02-24 2010-07-14 Japan Tobacco, Inc. Composé héterotétracycliques fusionnés et leur utilisation en tant qu'inhibiteurs de la polymérase du HCV
US7977331B1 (en) 2004-02-24 2011-07-12 Japan Tobacco Inc. Tetracyclic fused heterocyclic compound and use thereof as HCV polymerase inhibitor

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH11510361A (ja) * 1994-10-11 1999-09-14 ユニバーシティ・オブ・カリフォルニア 内部開始ｒｎａ翻訳の選択的阻止

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2815358A1 (fr) * 2000-10-17 2002-04-19 Parteurop Dev Polypeptides inhibiteurs de l'ires du virus de l'hepatite c et procede de criblage desdits polypeptides
WO2002033376A3 (fr) * 2000-10-17 2003-02-20 Parteurop Dev Polypeptides inhibiteurs de l'ires du virus de l'hepatite c, et procede de criblage
EP1390392A4 (fr) * 2001-04-16 2005-03-02 Univ California Methodes d'inhibition de la replication virale
EP2206715A1 (fr) 2004-02-24 2010-07-14 Japan Tobacco, Inc. Composé héterotétracycliques fusionnés et leur utilisation en tant qu'inhibiteurs de la polymérase du HCV
US7977331B1 (en) 2004-02-24 2011-07-12 Japan Tobacco Inc. Tetracyclic fused heterocyclic compound and use thereof as HCV polymerase inhibitor
US7659263B2 (en) 2004-11-12 2010-02-09 Japan Tobacco Inc. Thienopyrrole compound and use thereof as HCV polymerase inhibitor
WO2007119889A1 (fr) 2006-04-18 2007-10-25 Japan Tobacco Inc. Nouveau compose de piperazine et son utilisation en tant qu'inhibiteur de la polymerase du vhc

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