Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K35/00—Medicinal preparations containing materials or reaction products thereof with undetermined constitution
  • A61K35/12—Materials from mammals; Compositions comprising non-specified tissues or cells; Compositions comprising non-embryonic stem cells; Genetically modified cells
  • A61K35/14—Blood; Artificial blood
• • 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
  • C07K14/745—Blood coagulation or fibrinolysis factors
  • C07K14/755—Factors VIII, e.g. factor VIII C (AHF), factor VIII Ag (VWF)
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
  • A61P7/00—Drugs for disorders of the blood or the extracellular fluid
  • A61P7/02—Antithrombotic agents; Anticoagulants; Platelet aggregation inhibitors
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
  • A61P7/00—Drugs for disorders of the blood or the extracellular fluid
  • A61P7/04—Antihaemorrhagics; Procoagulants; Haemostatic agents; Antifibrinolytic agents
• • 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
  • C12N15/79—Vectors or expression systems specially adapted for eukaryotic hosts
  • C12N15/85—Vectors or expression systems specially adapted for eukaryotic hosts for animal cells
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K38/00—Medicinal preparations containing peptides

Definitions

• This invention relates to DNA sequences coding for modified factor VIII:C-like polypeptides and processes for producing them using those DNA sequences. More particularly, this invention relates to the production of modified factor VIII:C and modified factor VIII:C-like polypeptides which display the biological activity of factor VIII:C. In addition, the polypeptides of this invention are produced in higher yields than previously produced factor VIII:C-like polypeptides and are more easily purified into biochemically pure mature factor VIII.C.
• Factor VIII:C a large plasma glycoprotein, functions as the procoagulant component of factor VIII, which plays an integral role in the cascade mechanism of blood coagulation [see generally, W. J. Williams et al., Hematology. pp. 1085-90, McGraw-Hill, New York (1972)].
• Factor VIII:C circulates in the blood as a complex with factor VIIIR:Ag (also known as von Willebrand factor protein) which is a large protein associated with platelet aggregation and adhesive properties.
• Factor VIII:C is synthesized as a single chain macromolecular precursor, which is later cleaved to yield the fragments which constitute "mature" factor VIII:C.
• Mature factor VIII:C is composed of two chains bridged by a calcium ion; an amino-terminal heavy chain of 740 amino acids, and a carboxy-terminal light chain of 684 amino acids.
• the primary translation product of factor VIII:C is a single chain in which the heavy chain of mature factor VIII:C is separated from the light chain by a "maturation polypeptide" of 908 amino acids.
• This maturation polypeptide is initiated by proteolytic cleavage of the primary translation product by an unknown or yet unidentified protease at the Arg 1648 - Glu 1649 peptide bond.
• the initial nick event begins a series of successive proteolytic cleavages which shorten the nascent heavy chain from its carboxy terminus.
• the mature heavy chain of 740 amino acids results and in combination with the light chain of 684 amino acids, comprises mature factor VIII:C [see L.-O. Andersson et al. "Isolation and Characterization of Human Factor VIII: Molecular Forms In Commercial Factor VIII Concentrate, Cryoprecipitate, and Plasma," PNAS(USA), 83, pp. 2979-83 (1986)].
• This complex is then activated by thrombin by cleavage at the Arg 1689-Ser 1690 bond [D. Eaton et al., Biochemistry, 25, pp. 505-12 (1986)].
• Haemophilia A is a sex-linked hemorrhagic disease which is caused by a deficiency, either in amount or in biological activity, of factor VIII :C.
• the symptoms of acutely bleeding haemophilia patients are treated with factor VIII traditionally purified from normal sera.
• Various methods of purification have been described in the literature [see, Zimmerman et al., United States patent 4,361,509; Saundrey et al. United States patent 4,578,218; E.G.D. Tuddenhem et al., "The Properties of Factor VIII Coagulant Activity Prepared By Immunoadsorbent Chromatography, Journal of Laboratory Clinical Medicine, 93, pp. 40-53 (1979); D. E. G.
• Factor VIII :C when purified from plasma thus contains a heterogeneous mixture of heavy chains ranging in length from 1648 amino acids down to 740 amino acids which result from these numerous proteolytic events [Andersson et al., supra, p. 2983].
• the heterogenous mixture of chains observed in plasma-purified factor VIII:C has made recovery of a substantially pure mature factor VIII:C almost impossible.
• traditional treatment of haemophilia with factor VIII purified from plasma has serious drawbacks. Specifically, it can lead to the unintended transfer of the causative agents of hepatitis or the virus associated with Acquired Immune Deficiency Syndrome.
• the present invention solves the problems referred to above by providing DNA sequences which encode modified factor VIII:C and modified factor VIII:C-like polypeptides. These DNA sequences code for polypeptides which are produced in approximately twenty-times higher yields than previous recombinantly produced factor VIII:C and are more easily purified into biochemically pure mature factor VIII:C. According the present invention, DNA sequences coding for modified factor VIII:C are produced and expressed in high yields. As will be apparent from the disclosure and examples to follow, the modified factor VIII:C and modified factor VIII:C-like polypeptides of this invention are characterized by deletions removing a major part of the maturation polypeptide of factor VIII:C.
• the DNA sequences in our preferred embodiment have a deletion of substantially all of the nucleotides coding for the maturation polypeptide.
• Our most preferred embodiment contains a deletion of all the DNA sequence coding for the maturation polypeptide.
• the heavy chain of mature factor VIII:C is linked directly to the light chain. Following a one-nick proteolytic event, the mature form of factor VIII:C is generated.
• the present invention provides various anti-haemophilic compositions containing modified factor VIII:C and modified factor VIII:C- like polypeptides produced by the DNA sequences of this invention, and various methods of using those compositions in haemophilia treatment- therapy of acute or prolonged bleeding in haemophilia A.
• Figure 1 depicts a restriction map of the factor VIII:C cDNA.
• Figure 2 is a schematic depiction of the construction of the recombinant DNA molecule with the QD deletion.
• Figures 3A and 3B depict a schematic representation of the construction of the recombinant DNA molecule with the RE deletion.
• Figure 4 depicts a restriction endonuclease map of the RE deletion inserted into the mammalian cell expression vector pBG312 indicating the positions of the SV40 origin of replication/enhancer, the adeno- virus major late promoter, the factor VIII:C cDNA with the RE deletion, the 3' untranslated region of the factor VIII:C mRNA, and the polyadenylation site.
• Figure 5 depicts the results of an S1 analysis of Factor VIII:C mRNA isolated from transfected BMT10 cells.
• Figure 6 depicts the results of a Southern analysis of plasmid DNA isolated from transfected BMT10 cells.
• Figure 7 depicts the published DNA and amino acid sequence of factor VIII:C (EPO application 160,457).
• Nucleotide A monomeric unit of DNA or RNA consisting of a sugar moiety (pentose), a phosphate, and a nitrogenous heterocyclic base.
• the base is linked to the sugar moiety via the glycosidic carbon (1' carbon of the pentose) and that combination of base and sugar is called a nucleoside.
• the base characterizes the nucleotide.
• the four DNA bases are adenine ("A”), guanine (“G”), cytosine ("C”), and thymine (“T”).
• the four RNA bases are A, G, C, and uracil ("U”).
• DNA Sequence A linear array of nucleotides connected one to the other by phosphodiester bonds between the 3' and 5' carbons of adjacent pentoses.
• Codon A DNA sequence of three nucleotides (a triplet) which encodes through mRNA an amino acid, a translation start signal or a translation termination signal.
• a triplet the nucleotide triplets
• TTA, TTG, CTT, CTC, CTA and CTG encode for the amino acid leucine ("Leu")
• TAG, TAA and TGA are translation stop signals
• ATG is a translation start signal.
• Amino Acid A monomeric unit of a peptide, polypeptide or protein.
• the twenty amino acids are: phenylalanine ("Phe” or “F”), leucine ("Leu”, “L”), isoleucine ("He”, “I”), methionine ("Met”, “M”), valine ("Val", “V”), serine (“Ser”, “S”), proline ("Pro", “P”), threonine ("Thr", “T”), alanine ("Ala”, “A”), tyrosine (“Tyr”, “Y”), histidine (“His", "H”), glutamine (“Gin”, “Q”), asparagine ("Asn:N”), lysine ("Lys:K”), aspartic acid (“Asp", “D”), glutai ⁇ ic acid (“Glu", “E”), cysteine (“Cys", “C”), tryptophane (“Trp”, “W”), arginine ("Arg”, “R”) and g
• Reading Frame The grouping of codons during the translation of mRNA into amino acid sequences. During translation the proper reading frame must be maintained. For example, the DNA sequence GCTGGTTGTAAG may be expressed in three reading frames or phases, each of which affords a different amino acid sequence:
• GCT GGT TGT AAG Alignment—Ala-Gly-Cys-Lys G CTG GTT GTA AG—Leu-Val-Val GC TGG TTG TAA G—Trp-Leu-(STOP)
• Polypeptide A linear array of amino acids connected one to the other by peptide bonds between the ⁇ -amino and carboxy groups of adjacent amino acids.
• Genome The entire DNA of a cell or a virus. It includes inter alia the structural gene coding for the polypeptides of the substance, as well as operator, promoter and ribosome binding and interaction sequences, including sequences such as the Shine- Dalgarno sequences.
• Gene A DNA sequence which encodes through its template or messenger RNA ("mRNA") a sequence of amino acids characteristic of a specific polypeptide.
• mRNA messenger RNA
• Transcription The process of producing mRNA from a gene or DNA sequence.
• Translation The process of producing a polypeptide from mRNA.
• Expression The process undergone by a gene or DNA sequence to produce a polypeptide. It is a combination of transcription and translation.
• Plasmid A nonchromosomal double-stranded DNA sequence comprising an intact "replicon" such that the plasmid is replicated in a host cell. When the plasmid is placed within a unicellular organism, the characteristics of that organism may be changed or transformed as a result of the DNA of the plasmid.
• a plasmid carrying the gene for tetracycline resistance transforms a cell previously sensitive to tetracycline into one which is resistant to it.
• a cell transformed by a plasmid is called a "transformant”.
• Cloning Vehicle A plasmid, phage DNA, cosmid or other DNA sequence which is able to repli- cate in a host cell, characterized by one or a small number of endonuclease recognition sites at which such DNA sequences may be cut in a determinable fashion without attendant loss of an essential biological function of the DNA, e.g., replication, production of coat proteins or loss of promoter or binding sites, and which contains a marker suitable for use in the identification of transformed cells, e.g., tetracycline resistance or ampicillin resistance.
• a cloning vehicle is often called a vector.
• Recombinant DNA Molecule or Hybrid DNA A molecule consisting of segments of DNA from different genomes which have been joined end-to-end outside of living cells and able to be maintained in living cells.
• Expression Control Sequence A sequence of nucleotides that controls and regulates expression of genes when operatively linked to those genes.
• phage ⁇ include the lac system, the ⁇ -lactamase system, the trp system, the tac and trc systems, the major operator and promoter regions of phage ⁇ , the control region of fd coat protein, the early and late promoters of SV40, promoters derived from polyoma virus and adenovirus, metallothionine promoters, the promoter for 3-phosphoglycerate kinase or other glycolytic enzymes, the promoters of acid phosphatase, e.g., Pho5, the promoters of the yeast ⁇ -mating factors, and other sequences known to control the expression of genes of prokaryotic or eukaryotic microbial cells and their viruses or combinations thereof.
• Factor VIII:C A polypeptide having the amino acid sequence of Figure 7, and upon maturation and activation, being capable of functioning as co-factor for the factor IXa-dependent maturation of factor X in the blood coagulation cascade.
• factor VIII :C includes the glycoproteins also known as factor VIII procoagulant activity protein, factor VHI-clotting activity, antihemophilic globulin (AHG), antihemophilic factor (AHF), and antihemophilic factor A [see W. J. Williams et al., Hematoloqy, pp. 1056, 1074 and 1081].
• Maturation Polypeptide The maturation polypeptide of factor VIII :C is made up of the 908 amino acids from amino acid Ser (741) to amino acid Arg (1648) (see Figure 7). Maturation of factor VIII :C is initiated with a cleavage between amino acids 1648 and 1649 (which produces a C-terminal light chain) followed by a series of nicks which produce the mature N-terminal heavy chain.
• Mature Factor VIII:C As used in this application, mature factor VIII:C is composed of an N-terminal heavy chain (Ala 1- Arg 740) linked to a C-terminal light chain (Glu 1649-Tyr 2332) through an alkaline metal bridge, such as calcium ( Figure 7).
• Modified Factor VIII:C refers to polypeptides characterized by a deletion of a major portion of the maturation polypeptide of factor VIII:C. For example, where the entire maturation polypeptide has been deleted, "modified factor VIII:C” includes proteins that comprise the N-terminal mature heavy chain and the C-terminal mature light chain of factor VIII:C linked together as a single chain.
• Modified Factor VIII:C-Like Polypeptide includes proteins having the biological activity of modified factor VIII:C. It also includes proteins having an amino terminal methionine, e.g., f-Met-factor VIII:C, and proteins that are characterized by other amino acid deletions, additions or substitutions so long as those proteins substantially retain the biological activity of modified factor VIII:C.
• Modified factor VIII:C-Iike polypeptides within the above-definition also includes natural allelic variations that may exist and occur from individual to individual. Furthermore, it includes modified factor VIII:C-like polypeptides whose degree and location of glycosylation, or other post-translation modifications, may vary depending on the cellular environment of the producing host or tissue.
• the present invention relates to processes for the production of modified factor VIII:C and modified factor VIII:C-like polypeptides. More particularly, it provides DNA sequences whic ⁇ t.permit the production of modified factor VIIl:C and modified factor VIII:C-like polypeptides in high yields, in appropriate hosts. Polypeptides produced by the DNA sequences of this invention are useful in the clinical treatment of haemophilia A.
• the modified factor VIII:C produced by the DNA sequences of this invention lack a major portion of the maturation polypeptide of factor VIII:C.
• the DNA sequences of the present invention surprisingly express modified factor VIII:C in much higher yields than DNA sequences coding for factor VIII:C itself.
• modified factor VIII:C in high yields because of the absence of most or all of the maturation polypeptide.
• the mRNA for the modified gene may be translated more efficiently, because the RNA coding for the long maturation polypeptide does not have to be translated.
• factor VIII:C has many proteolytic targets which may be attacked while the polypeptide is in the cell, the modified factor VIII:C is less subject to such proteolytic attack because it lacks the proteolytic targets within the maturation polypeptide.
• Useful expression vectors include, for example, vectors consisting of segments of chromosomal, non-chromosomal and synthetic DNA sequences, such as various known derivatives of SV40, known bacterial plasmids, e.g., plasmids from E.coli including col E1, pCR1, pBR322, pMB9 and their derivatives, wider host range plasmids, e.g., KP4, phage DNAs, e.g., the numerous derivatives of phage ⁇ , e.g., NM 989, and other DNA phages, e.g., M13 and Filêtous single stranded DNA phages, yeast plasmids such as the 2 ⁇ plasmid or derivatives thereof, and vectors derived from combinations of plasmids and phage DNAs, such as plasmids which have been modified to employ phage DNA or other expression control sequences.
• pBG312 plasmids from E.
• any of a wide variety of expression control sequences sequences that con trol the expression of a DNA sequence when operatively linked to it — may be used in these vectors to express the DNA sequence of this invention.
• useful expression control sequences include, for example, the early and late promoters of SV40, the lac system, the trp system, the TAC or TRC system, the major operator and promoter regions of phage ⁇ , the control regions of fd coat protein, the promoter for 3-phosphoglycerate kinase or other glycolytic enzymes, the promoters of acid phosphatase, e.g., Pho5, the promoters of the yeast ⁇ -mating factors, and other sequences known to control the expression of genes of prokaryotic or eukaryotic cells or their viruses, and various combinations thereof.
• adenovirus-2 major late promoter expression control sequences we employ adenovirus-2 major late promoter expression control sequences.
• host cells are also useful in producing the modified factor VIII:C of this invention.
• These hosts may include well known eukaryotic and prokaryotic hosts, such as strains of E.coli, Pseudomonas, Bacillus, Streptomyces, fungi such as yeasts, and animal cells, such as CHO cells, African green monkey cells, such as COS1, COS7, BSC1, BSC40, and BMT10, and human cells and plant cells in tissue culture.
• eukaryotic and prokaryotic hosts such as strains of E.coli, Pseudomonas, Bacillus, Streptomyces, fungi such as yeasts
• animal cells such as CHO cells, African green monkey cells, such as COS1, COS7, BSC1, BSC40, and BMT10, and human cells and plant cells in tissue culture.
• African green monkey cells such as COS1, COS7, BSC1, BSC40, and BMT10
• human cells and plant cells in tissue culture in the preferred embodiments
• an expression control sequence a variety of factors should also be considered. These include, for example, the relative strength of the system, its controllability, and its compatibility with the DNA sequence encoding the modified factor VIII:C of this invention, particularly as regards potential secondary structures. Hosts should be selected by consideration of their compatibility with the chosen vector, the toxicity of our modified factor VIII:C to them, their secretion characteristics, their ability to fold proteins correctly, their fermentation requirements, and the ease of the purification of our modified factor Vlll:C from them and safety. Within these parameters one of skill in the art may select various vector/expression control system/host combinations that will produce useful amounts of our modified factor VIII:C on fermentation. For example, in one preferred embodiment of this invention, we use an pBG312 vector, with an adenovirus 2 major late promoter expression system in BMT10 African green monkey cells.
• modified factor VIII:C and modified factor VIII-like polypeptides produced according to this invention may be purified by a variety of conventional steps and strategies.
• Useful purification steps include those used to purify natural and recombinant factor VIII:C [see, for example, L.-O. Andersson et al., PNAS (USA), 83, pp. 2979-83 (1986)].
• modified factor VIII:C and modified factor VIII:C-like polypeptides of this invention are useful in composition and methods for treatment of haemophilia A and in a variety of agents useful in treating uncontrolled bleeding. While the modified factor VIII:C and modified factor VIII:C-like polypeptides of this invention may be administered in such compositions and methods in the form in which they are produced, as single chain polypeptides, it should also be understood that it is within the scope of this invention to administer the modified factor VIII:C after subjecting it to proteolytic cleavage.
• modified factor VIII :C can be cleaved in vitro, into the heavy chain and light chain of mature factor VIII:C and linked with a calcuim or other alkaline metal bridge, before, during or after purification.
• modified factor VIII:C and modified factor VIII:C-like polypeptides of this invention may be formulated using known methods to prepare pharmaceutically useful compositions. Such compositions also will preferably include conventional pharmaceutically acceptable carriers and may include other medicinal agents, carriers, adjuvants, excipients, etc., e.g., human serum albumin or plasma preparations. See, e.g., Remington's Pharmaceutical Sciences (E. W. Martin). The resulting formulations will contain an amount of modified factor VIII:C effective in the recipient to treat uncontrolled bleeding. Administration of these polypeptides, or pharmaceutically acceptable derivatives thereof, may be via any of the conventional accepted modes of administration of factor VIII. These include parenteral, subcutaneous, or intravenous administration.
• compositions of this invention used in the therapy of haemophilia may also be in a variety of forms.
• the preferred form depends on the intended mode of administration and therapeutic application.
• the dosage and dose rate will depend on a variety of factors for example, whether the treatment is given to an acutely bleeding patient or as a prophylactic treatment.
• the factor VIII:C level should be high enough to prevent hemorrhage and promote epithelialization [see discussion in Williajns, Hematology, pp. 1335-43].
• FIG. 1 we have presented therein a restriction enzyme map of the factor VIII:C cDNA based upon the published sequence [W. I. Wood et al., Nature, 312, pp. 330-37 (1984); ( Figure 7)].
• the bar represents the coding sequence.
• Below the restriction enzyme map we have depicited the aminoterminal heavy chain of mature factor VIII:C attached by a calcium bridge to the carboxy-terminal light chain of mature factor VIII:C.
• Below the protein model on a bar congruent to the restriction enzyme map we have indicated the oligonucleotide probes (indicated with asterisks) which we used to screen human placenta, liver, and kidney cDNA libraries. These libraries were made using oligo (dT) as first- strand primer and ⁇ gt10 as vector.
• oligonucleotide primers left-arrows which we used to initiate first-strand cDNA synthesis using human kidney mRNA as template.
• Fragment 2 from the insert in the ⁇ gt10 recombinant 1.7977. Fragment 2 extended from Aval at 731 to EcoRI at 2289. Fragment 3 derived from the subclone pUC19.2874 of a genomic cosmid recombinant; it extended from EcoRI at 2289 to BamHI at 4743. Fragment 4 was isolated from clone 7.74575, starting from the BamHI site at 4743 and extending to the Ndel site at 5522. We isolated fragment 5 from the above-described derivative of clone 4.7573. Fragment 5 extended from Ndel at 5522 to Ncol at 7991.
• Fragment 6 is an assembly vector containing an E.coli replication origin and selectable marker for ampicillin resistance.
• pAT.SV2.tPA a gift from Richard Fisher. This is a plasmid in which the transcription of the tPA gene is under the control of the SV40 early promoter.
• pAT.SV2.tPA with Sall which cleaves within the tetracycline resistance marker, and with Ncol which cleaves within the SV40 early region.
• pBG312 is an animal cell expresion vector whose construction has been described elsewhere [R. Cate et al., Cell, 45, pp. 685-98 (1986)].
• the sequence of BG312, from EcoRI to BamHI has (clockwise): a SV40 replication origin; an adenovirus-2 major late promoter and complete tripartite leader [S. Zain et al., Cell, 16, pp.
• a hybrid splice signal consisting of an adenovirus-5 splice donor and an immunoglobulin variable region gene splice acceptor [R. J. Kaufman, and P. A. Sharp, J. Mol. Biol., 159, pp. 601-21 (1982)]; a polylinker containing sites. for HindlII, Xhol, EcoRI, Smal, Ndel, Sstl, and Bglll; the SV40 small t antigen intron flanked by its splice donor and acceptor; and the SV40 early polyadenylation site.
• the modified polypeptide produced on expression as a result of the QD deletion lacks 818 amino acids from within the 908 amino-acid maturation polypeptide, leaving 4 amino acids C-terminal to the carboxy terminus of the mature heavy chain, Arg 740, and leaving 86 amino acids N-terminal to the amino terminus of the light chain, Glu 1649 ( Figure 7).
• the 908 amino-acid maturation polypeptide is thus, replaced by a 90 amino-acid maturation polypeptide, with the protease substates for both initial maturation of the primary translation polypeptide and subsequent maturation of the heavy chain remaining intact.
• the 462 bp fragment obtained by digesting the expression plasmid for the full-length gene with HindiII between the codons for Arg 740 and Ser 741, removing the 5' AGCT with nuclease S1, and subsequently digesting with Kpnl which cleaves uniquely between the codons for Tyr 586 and Leu 587.
• this recombinant product when secreted from a mammalian cell, will bind to the von Willebrand protein present in cell culture fluid. Similarly, when injected, it will complex to and circulate with plasma von Willebrand protein. Upon thrombin cleavage at Arg 1689 - Ser 1690, the two-chain mature factor VIII:C will be activated and will dissociate from von Willebrand protein and assemble into its ternary complex with factor IXa and factor X on a platelet surface.
• the 462 bp fragment obtained by digesting the expression plasmid for the full-length gene with HindlII between the codons for Arg 740 and Ser 741, removing the 5' AGCT with nuclease SI, and subsequently digesting with Kpnl which cleaves uniquely between the codons for Tyr 586 and Leu 587.
• the transfectants will secrete modified factor VIII:C for up to 120 hours.
• the cm 2 /ml ratio is approximately 5.5; that is, a confluent monolayer of BMT10 transfectants in a 100 mm Petri dish (55 cm 2 ) is covered with 10 ml culture fluid.
• both the signalminus construct (negative control) and the RS deletion have shown no detectable factor VIII:C activity. This may be explained by the deletion of the von Willebrand protein binding domain in the RS deletion.
• BMT10 cells transfected with the QD and RE deletions produce at least 20 times more factor VIII:C than cells transfected with the full-length gene.
• nuclease S1 analysis In order to determine the levels of mRNA in each construction, we conducted a nuclease S1 analysis. This assay assists in the determination of the reason for the increased level of expression in our QD and RE deletions.
• RNA from 100 mm Petri dish cultures of BMT10 cells 120 hours after transfection using the unpublished method of W. Schleuning and J. Bertonis. Briefly, according to this method, we lysed BMT10 cells with 3 ml of 50 mM Tris-HCl (pH 7.5) - 5 mM EDTA - 1% SDS containing 100 ⁇ g/ml proteinase K for 20 minutes at 37°C. We transferred the lysate to a 50 ml conical tube containing 3 ml of phenol and then mechanically sheared the DNA for 15 seconds at high speed in a Polytron (Brinkmann Instruments). We extracted the aqueous phase with ether and adjusted it to 0.25 NaCl.
• the hybrid molecules were then digested for 60 minutes at 37°C by adding 190 ⁇ l nuclease S1 at a concentration of 100 units/ml in 0.28 M NaCl - 50 mM NaOAc (pH 4.6) - 4.5 mM ZnSO4.
• We terminated the digestion by adding EDTA to 10 mM and extracting with phenol.
• the 477 nucleotide Espl fragment has one end within the hybrid intron spliced out from the 5' untranslated region of the factor VIII:C mRNA [R. J. Kaufman and P. A. Sharp, J. Mol. Biol., 159, pp. 601-21 (1981)] and the other end within the codon for Ala 62 ( Figure 4).
• Figure 5A is the analysis for 10 ⁇ g of input RNA
• Figure 5B is the analysis for 1 ⁇ g of input RNA.
• Lane 1 in both figures contains as marker 500 cpm of the labeled 477 nucleotide single-stranded DNA fragment used to protect modified factor VIII:C mRNA from S1 digestion; that is, 10% of the input to each hybridization reaction.
• Lane 2 contained RNA isolated from BMT10 cells transfected with the signal- minus construct; lane 3, BMT10 cells transfected with the full-length factor VIII:C cDNA (construct 8.1); lane 4: BMT10 cells transfected with modified factor VIII:C cDNA (QD deletion); lane 5: BMT10 cells transfected with modified factor VIII:C cDNA (RE deletion); lane 6: BMT10 cells transfected with the cDNA from the RS deletion; lane 7: marker fragments obtained by digesting pBR322 with Hinfl and labeling their 3' ends with [ ⁇ - 32 P]dATP and Klenow enzyme (a gift of Richard Tizard).
• Equal amounts of a protected fragment of the expected length of 300 bases are evident in both figures for the 8.1, QD, RE, and RS constructs.
• a protected fragment of approximately 220 bases in length for the signal-minus construct is evident in both figures, reflecting the absence of a portion of the DNA sequence encoding the signal peptide.
• FIG. 5A A comparison of Figures 5A and 5B demonstrates that the input 477 probe is in molar excess during the hybridizations for each construct.
• the modified factor VIII:C activity levels are at least 20-fold higher for the QD and RE deletions compared to the RS and the full-length constructs, the amount of mRNA in all four constructs is very nearly the same. Therefore, the reason for the increase in expression for the QD and RE deletions is post-transcriptional in nature.
• the factor VIII:C probe was the 2924 bp Espl fragment isolated from the RE expression plasmid (see Figure 4) and 32P-labeled to a specific activity of 10 9 cpm/ ⁇ g by the random hexadeoxynucleotide primer method of Feinberg and Vogelstein [A. P. Feinberg and Vogelstein [A. P. Feinberg and Vogelstein [A. P. Feinberg and Vogelstein [A. P. Feinberg and
• Lane 1 contained the 1 kb ladder obtained from BRL and labeled with T4 DNA polymerase according to the manufacturer's protocol; lane 2: 1 ng supercoiled RE DNA; lane 3: 10 ng supercoiled RE DNA; lane 4: 10 ng RE DNA digested with Dpnl; lane 5: Dpnl digest of 0.5 A260 units
• Hirt fraction obtained from BMT10 cells transfected with the signal-minus construct lane 6: transfected with the full-length factor VIII:C cDNA (construct 8.1); lane 7: transfected with the QD deletion; lane 8: transfected with the RE deletion: lane 9: transfected with the RS deletion.
• Figure 6 shows nearly equal amounts of the supercoiled form of each construct after digestion with Dpnl (lanes 5-9), thus excluding the possibility that differences in DNA replication enhance the expression of the QD and RE deletions.
• Lane 2 contains 10 8 molecules of the RE construct and lane 3 contains 10 9 molecules, suggesting that the copy number is approximately 10 3 in the approximately 10 cells successfully transfected.
• Plasmid 411.BclI may be linearized uniquely with Bcll, resulting in a 5' GATC overhang which consists of the GAT codon for Asp 1658 and the first base of the CAA codon for Gin 1659.
• plasmid RD directed the expression of a factor VIII polypeptide with a fusion between Arg 740 and Asp 1658. Cleavage of the RD polypeptide after Arg 740 generates a twochain factor VIII molecule with a mature heavy chain calciumbridged to a 59 light chain, i.e. a light chain lacking the first 9 amino-terminal amino acids.
• a cleavage of RSD polypeptide after Arg 740 generates a 2-chain factor VIII molecule with a mature heavy chain and a delta 8 light chain, i.e. a light chain lacking the first eight amino terminal amino acids. Furthermore, because in the primary translation product Ser is also at position 741, RSD may also be viewed as a fusion between Ser 741 and Asp 1658. A cleavage after Ser 741 may generate a 2-chain factor VIII molecule with a heavy chain terminating at Ser 741 and a 59 light chain. L. TRANSFECTION OF AFRICAN
• a mutant tsA58 virus is a temperature-sensitive mutant of SV40 which does not produce progeny at 39°C.
• the large T-antigen protein specified by the tsA58 mutant is much more labile at the nonpermissive temperature than wild type large T-antigen protein [H. Tegtmeyer et al., J. Virol 16, pp. 168-78 (1975).
• the resulting cell line 6L inducibly expresses SV40 T-antigen at 33°C.
• transfected 6L cells with supercoiled expression plasmids RD or RSD The transfection was carried out using the DEAE-dextran technique and chloroquine as described in Example "F”.
• the cm 2/ml ratio was approximately 5.5; that is, a confluent monolayer of 6L transfectants in a 100mm Petri dish (55cm 2 ) was covered with 10ml culture fluid.
• Microorganisms, recombinant DNA molecules and the modified factor VIII:C DNA coding sequences of this invention are exemplified by a culture deposited in the culture collection of the American Type Culture Collection, in Rockville, Maryland, on July 22, 1986, and identified there as:
• Ad.RD.2 [E.coli HB101 (RD)], having ATCC accession number 67475; and Ad.RSD.1.2 [E.coli HB101 (RSD)], having ATCC accession number 67476.

Landscapes

• Health & Medical Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Organic Chemistry (AREA)
• General Health & Medical Sciences (AREA)
• Genetics & Genomics (AREA)
• Hematology (AREA)
• Medicinal Chemistry (AREA)
• Zoology (AREA)
• Bioinformatics & Cheminformatics (AREA)
• Biomedical Technology (AREA)
• Biotechnology (AREA)
• Pharmacology & Pharmacy (AREA)
• Animal Behavior & Ethology (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Biophysics (AREA)
• Wood Science & Technology (AREA)
• Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
• General Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Engineering & Computer Science (AREA)
• Molecular Biology (AREA)
• Biochemistry (AREA)
• Diabetes (AREA)
• Gastroenterology & Hepatology (AREA)
• Virology (AREA)
• Plant Pathology (AREA)
• Toxicology (AREA)
• Physics & Mathematics (AREA)
• Proteomics, Peptides & Aminoacids (AREA)
• Cell Biology (AREA)
• Developmental Biology & Embryology (AREA)
• Immunology (AREA)
• Microbiology (AREA)
• Epidemiology (AREA)
• Preparation Of Compounds By Using Micro-Organisms (AREA)
• Peptides Or Proteins (AREA)
• Micro-Organisms Or Cultivation Processes Thereof (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=25401456

Family Applications (1)

Country Status (5)

Families Citing this family (67)

Citations (8)

Family Cites Families (3)

• 1986
  • 1986-08-04 KR KR1019870700355A patent/KR910006424B1/ko not_active Application Discontinuation
• 1987
  • 1987-07-31 EP EP19870905356 patent/EP0275305A4/en not_active Withdrawn
  • 1987-07-31 AU AU78040/87A patent/AU595640B2/en not_active Ceased
  • 1987-07-31 WO PCT/US1987/001814 patent/WO1988000831A1/en not_active Application Discontinuation
  • 1987-07-31 JP JP62504812A patent/JP2525438B2/ja not_active Expired - Lifetime

Patent Citations (8)

Non-Patent Citations (2)

Also Published As

Similar Documents

Legal Events