CA2272055A1 - Products and methods for gaucher disease therapy - Google Patents
Products and methods for gaucher disease therapy Download PDFInfo
- Publication number
- CA2272055A1 CA2272055A1 CA 2272055 CA2272055A CA2272055A1 CA 2272055 A1 CA2272055 A1 CA 2272055A1 CA 2272055 CA2272055 CA 2272055 CA 2272055 A CA2272055 A CA 2272055A CA 2272055 A1 CA2272055 A1 CA 2272055A1
- Authority
- CA
- Canada
- Prior art keywords
- gcc
- vector
- cell
- dna molecule
- nucleic acid
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 238000000034 method Methods 0.000 title claims abstract description 50
- 208000015872 Gaucher disease Diseases 0.000 title claims abstract description 33
- 238000002560 therapeutic procedure Methods 0.000 title description 6
- 108020004414 DNA Proteins 0.000 claims abstract description 64
- 108090000765 processed proteins & peptides Proteins 0.000 claims abstract description 50
- 229920001184 polypeptide Polymers 0.000 claims abstract description 47
- 102000004196 processed proteins & peptides Human genes 0.000 claims abstract description 47
- 102000053602 DNA Human genes 0.000 claims abstract description 31
- 150000007523 nucleic acids Chemical class 0.000 claims abstract description 29
- 102000039446 nucleic acids Human genes 0.000 claims abstract description 28
- 108020004707 nucleic acids Proteins 0.000 claims abstract description 28
- 238000011282 treatment Methods 0.000 claims abstract description 23
- 108020004999 messenger RNA Proteins 0.000 claims abstract description 15
- 108020005067 RNA Splice Sites Proteins 0.000 claims abstract description 9
- 210000004027 cell Anatomy 0.000 claims description 70
- 239000013598 vector Substances 0.000 claims description 61
- 125000003729 nucleotide group Chemical group 0.000 claims description 31
- 239000002773 nucleotide Substances 0.000 claims description 30
- 230000014509 gene expression Effects 0.000 claims description 27
- 238000012986 modification Methods 0.000 claims description 21
- 230000004048 modification Effects 0.000 claims description 21
- 210000004978 chinese hamster ovary cell Anatomy 0.000 claims description 16
- 230000035772 mutation Effects 0.000 claims description 13
- 108091035707 Consensus sequence Proteins 0.000 claims description 12
- 210000004962 mammalian cell Anatomy 0.000 claims description 12
- 241000124008 Mammalia Species 0.000 claims description 9
- 239000000203 mixture Substances 0.000 claims description 9
- 239000008194 pharmaceutical composition Substances 0.000 claims description 9
- 208000024891 symptom Diseases 0.000 claims description 8
- 238000004519 manufacturing process Methods 0.000 claims description 7
- 230000009261 transgenic effect Effects 0.000 claims description 6
- 210000005260 human cell Anatomy 0.000 claims description 4
- 239000002502 liposome Substances 0.000 claims description 4
- 238000012258 culturing Methods 0.000 claims description 2
- 230000001131 transforming effect Effects 0.000 claims description 2
- 238000001415 gene therapy Methods 0.000 abstract description 20
- 239000013604 expression vector Substances 0.000 abstract description 10
- 238000003780 insertion Methods 0.000 abstract description 2
- 230000037431 insertion Effects 0.000 abstract description 2
- 239000002299 complementary DNA Substances 0.000 description 27
- 230000000694 effects Effects 0.000 description 25
- 102000004190 Enzymes Human genes 0.000 description 18
- 108090000790 Enzymes Proteins 0.000 description 18
- 229940088598 enzyme Drugs 0.000 description 18
- 239000000047 product Substances 0.000 description 17
- 108091032973 (ribonucleotides)n+m Proteins 0.000 description 14
- 108090000623 proteins and genes Proteins 0.000 description 14
- 238000006243 chemical reaction Methods 0.000 description 12
- 238000001727 in vivo Methods 0.000 description 12
- 208000037265 diseases, disorders, signs and symptoms Diseases 0.000 description 11
- 108010017544 Glucosylceramidase Proteins 0.000 description 9
- 238000003556 assay Methods 0.000 description 9
- 238000002641 enzyme replacement therapy Methods 0.000 description 9
- 238000012163 sequencing technique Methods 0.000 description 9
- 210000000988 bone and bone Anatomy 0.000 description 8
- 201000010099 disease Diseases 0.000 description 8
- 230000001594 aberrant effect Effects 0.000 description 7
- 239000011324 bead Substances 0.000 description 7
- XEKOWRVHYACXOJ-UHFFFAOYSA-N Ethyl acetate Chemical compound CCOC(C)=O XEKOWRVHYACXOJ-UHFFFAOYSA-N 0.000 description 6
- 102000004547 Glucosylceramidase Human genes 0.000 description 6
- 108091028043 Nucleic acid sequence Proteins 0.000 description 6
- 125000003275 alpha amino acid group Chemical group 0.000 description 6
- 150000001413 amino acids Chemical class 0.000 description 6
- 238000002474 experimental method Methods 0.000 description 6
- 239000006166 lysate Substances 0.000 description 6
- 239000000758 substrate Substances 0.000 description 6
- 238000001890 transfection Methods 0.000 description 6
- 241000282412 Homo Species 0.000 description 5
- 241000699670 Mus sp. Species 0.000 description 5
- 241000700605 Viruses Species 0.000 description 5
- 239000003153 chemical reaction reagent Substances 0.000 description 5
- 239000012634 fragment Substances 0.000 description 5
- 238000001114 immunoprecipitation Methods 0.000 description 5
- 210000004185 liver Anatomy 0.000 description 5
- 239000013615 primer Substances 0.000 description 5
- 102000004169 proteins and genes Human genes 0.000 description 5
- 238000011160 research Methods 0.000 description 5
- 238000002741 site-directed mutagenesis Methods 0.000 description 5
- 239000003981 vehicle Substances 0.000 description 5
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 5
- 206010006002 Bone pain Diseases 0.000 description 4
- 108010060162 alglucerase Proteins 0.000 description 4
- CBTVGIZVANVGBH-UHFFFAOYSA-N aminomethyl propanol Chemical compound CC(C)(N)CO CBTVGIZVANVGBH-UHFFFAOYSA-N 0.000 description 4
- 238000004458 analytical method Methods 0.000 description 4
- 239000000872 buffer Substances 0.000 description 4
- 238000004113 cell culture Methods 0.000 description 4
- 239000013592 cell lysate Substances 0.000 description 4
- 229940049197 cerezyme Drugs 0.000 description 4
- 238000009396 hybridization Methods 0.000 description 4
- 108010039650 imiglucerase Proteins 0.000 description 4
- 230000006872 improvement Effects 0.000 description 4
- 238000000338 in vitro Methods 0.000 description 4
- 230000001404 mediated effect Effects 0.000 description 4
- 238000012545 processing Methods 0.000 description 4
- 230000009467 reduction Effects 0.000 description 4
- 150000003839 salts Chemical class 0.000 description 4
- 239000000243 solution Substances 0.000 description 4
- 241000894007 species Species 0.000 description 4
- 238000012546 transfer Methods 0.000 description 4
- 241001430294 unidentified retrovirus Species 0.000 description 4
- 238000011144 upstream manufacturing Methods 0.000 description 4
- YBSQGNFRWZKFMJ-UHFFFAOYSA-N Cerebroside B Natural products CCCCCCCCCCCCCCC(O)C(=O)NC(C(O)C=CCCC=C(C)CCCCCCCCC)COC1OC(CO)C(O)C(O)C1O YBSQGNFRWZKFMJ-UHFFFAOYSA-N 0.000 description 3
- 108091026890 Coding region Proteins 0.000 description 3
- 230000002159 abnormal effect Effects 0.000 description 3
- 239000002253 acid Substances 0.000 description 3
- 239000011543 agarose gel Substances 0.000 description 3
- 150000001875 compounds Chemical class 0.000 description 3
- 208000035475 disorder Diseases 0.000 description 3
- 239000003814 drug Substances 0.000 description 3
- 210000002540 macrophage Anatomy 0.000 description 3
- 230000005291 magnetic effect Effects 0.000 description 3
- 210000002826 placenta Anatomy 0.000 description 3
- 238000002360 preparation method Methods 0.000 description 3
- 238000010839 reverse transcription Methods 0.000 description 3
- 239000000523 sample Substances 0.000 description 3
- 210000000952 spleen Anatomy 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- 238000006467 substitution reaction Methods 0.000 description 3
- 108091003079 Bovine Serum Albumin Proteins 0.000 description 2
- YDNKGFDKKRUKPY-JHOUSYSJSA-N C16 ceramide Natural products CCCCCCCCCCCCCCCC(=O)N[C@@H](CO)[C@H](O)C=CCCCCCCCCCCCCC YDNKGFDKKRUKPY-JHOUSYSJSA-N 0.000 description 2
- 108020004705 Codon Proteins 0.000 description 2
- YQYJSBFKSSDGFO-UHFFFAOYSA-N Epihygromycin Natural products OC1C(O)C(C(=O)C)OC1OC(C(=C1)O)=CC=C1C=C(C)C(=O)NC1C(O)C(O)C2OCOC2C1O YQYJSBFKSSDGFO-UHFFFAOYSA-N 0.000 description 2
- 241000588724 Escherichia coli Species 0.000 description 2
- WQZGKKKJIJFFOK-GASJEMHNSA-N Glucose Natural products OC[C@H]1OC(O)[C@H](O)[C@@H](O)[C@@H]1O WQZGKKKJIJFFOK-GASJEMHNSA-N 0.000 description 2
- 206010019842 Hepatomegaly Diseases 0.000 description 2
- 102100034343 Integrase Human genes 0.000 description 2
- TWRXJAOTZQYOKJ-UHFFFAOYSA-L Magnesium chloride Chemical compound [Mg+2].[Cl-].[Cl-] TWRXJAOTZQYOKJ-UHFFFAOYSA-L 0.000 description 2
- 241000699666 Mus <mouse, genus> Species 0.000 description 2
- CRJGESKKUOMBCT-VQTJNVASSA-N N-acetylsphinganine Chemical compound CCCCCCCCCCCCCCC[C@@H](O)[C@H](CO)NC(C)=O CRJGESKKUOMBCT-VQTJNVASSA-N 0.000 description 2
- 108091034117 Oligonucleotide Proteins 0.000 description 2
- 238000002123 RNA extraction Methods 0.000 description 2
- 108010092799 RNA-directed DNA polymerase Proteins 0.000 description 2
- 206010041660 Splenomegaly Diseases 0.000 description 2
- 238000000246 agarose gel electrophoresis Methods 0.000 description 2
- 238000013459 approach Methods 0.000 description 2
- WQZGKKKJIJFFOK-VFUOTHLCSA-N beta-D-glucose Chemical compound OC[C@H]1O[C@@H](O)[C@H](O)[C@@H](O)[C@@H]1O WQZGKKKJIJFFOK-VFUOTHLCSA-N 0.000 description 2
- 230000004071 biological effect Effects 0.000 description 2
- 210000001185 bone marrow Anatomy 0.000 description 2
- 150000001720 carbohydrates Chemical class 0.000 description 2
- 229940106189 ceramide Drugs 0.000 description 2
- ZVEQCJWYRWKARO-UHFFFAOYSA-N ceramide Natural products CCCCCCCCCCCCCCC(O)C(=O)NC(CO)C(O)C=CCCC=C(C)CCCCCCCCC ZVEQCJWYRWKARO-UHFFFAOYSA-N 0.000 description 2
- 238000012512 characterization method Methods 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 2
- 108010057052 chitotriosidase Proteins 0.000 description 2
- 210000001728 clone cell Anatomy 0.000 description 2
- 239000013599 cloning vector Substances 0.000 description 2
- 230000000295 complement effect Effects 0.000 description 2
- 230000001054 cortical effect Effects 0.000 description 2
- 230000007812 deficiency Effects 0.000 description 2
- 238000012217 deletion Methods 0.000 description 2
- 230000037430 deletion Effects 0.000 description 2
- 239000003085 diluting agent Substances 0.000 description 2
- 230000008034 disappearance Effects 0.000 description 2
- 229940079593 drug Drugs 0.000 description 2
- 239000000499 gel Substances 0.000 description 2
- 239000008103 glucose Substances 0.000 description 2
- 230000000977 initiatory effect Effects 0.000 description 2
- 238000002955 isolation Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 230000007246 mechanism Effects 0.000 description 2
- 238000000520 microinjection Methods 0.000 description 2
- 238000010369 molecular cloning Methods 0.000 description 2
- 239000006225 natural substrate Substances 0.000 description 2
- VVGIYYKRAMHVLU-UHFFFAOYSA-N newbouldiamide Natural products CCCCCCCCCCCCCCCCCCCC(O)C(O)C(O)C(CO)NC(=O)CCCCCCCCCCCCCCCCC VVGIYYKRAMHVLU-UHFFFAOYSA-N 0.000 description 2
- 239000002953 phosphate buffered saline Substances 0.000 description 2
- 239000013612 plasmid Substances 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 239000011535 reaction buffer Substances 0.000 description 2
- 239000011541 reaction mixture Substances 0.000 description 2
- 230000001177 retroviral effect Effects 0.000 description 2
- 239000003161 ribonuclease inhibitor Substances 0.000 description 2
- 210000000130 stem cell Anatomy 0.000 description 2
- 239000000725 suspension Substances 0.000 description 2
- 230000008685 targeting Effects 0.000 description 2
- 230000001225 therapeutic effect Effects 0.000 description 2
- 210000001519 tissue Anatomy 0.000 description 2
- 238000003146 transient transfection Methods 0.000 description 2
- 238000012232 AGPC extraction Methods 0.000 description 1
- 206010067484 Adverse reaction Diseases 0.000 description 1
- 208000019901 Anxiety disease Diseases 0.000 description 1
- 101100314273 Arabidopsis thaliana TOR1 gene Proteins 0.000 description 1
- 239000004475 Arginine Substances 0.000 description 1
- 241000283707 Capra Species 0.000 description 1
- 108020004635 Complementary DNA Proteins 0.000 description 1
- SHZGCJCMOBCMKK-UHFFFAOYSA-N D-mannomethylose Natural products CC1OC(O)C(O)C(O)C1O SHZGCJCMOBCMKK-UHFFFAOYSA-N 0.000 description 1
- 102000012410 DNA Ligases Human genes 0.000 description 1
- 108010061982 DNA Ligases Proteins 0.000 description 1
- 239000003155 DNA primer Substances 0.000 description 1
- 230000006820 DNA synthesis Effects 0.000 description 1
- 108010054576 Deoxyribonuclease EcoRI Proteins 0.000 description 1
- 241000702421 Dependoparvovirus Species 0.000 description 1
- KCXVZYZYPLLWCC-UHFFFAOYSA-N EDTA Chemical compound OC(=O)CN(CC(O)=O)CCN(CC(O)=O)CC(O)=O KCXVZYZYPLLWCC-UHFFFAOYSA-N 0.000 description 1
- PNNNRSAQSRJVSB-SLPGGIOYSA-N Fucose Natural products C[C@H](O)[C@@H](O)[C@H](O)[C@H](O)C=O PNNNRSAQSRJVSB-SLPGGIOYSA-N 0.000 description 1
- 208000020322 Gaucher disease type I Diseases 0.000 description 1
- 102100031573 Hematopoietic progenitor cell antigen CD34 Human genes 0.000 description 1
- 101000911390 Homo sapiens Coagulation factor VIII Proteins 0.000 description 1
- 101000777663 Homo sapiens Hematopoietic progenitor cell antigen CD34 Proteins 0.000 description 1
- 206010020751 Hypersensitivity Diseases 0.000 description 1
- 206010061598 Immunodeficiency Diseases 0.000 description 1
- SHZGCJCMOBCMKK-DHVFOXMCSA-N L-fucopyranose Chemical compound C[C@@H]1OC(O)[C@@H](O)[C@H](O)[C@@H]1O SHZGCJCMOBCMKK-DHVFOXMCSA-N 0.000 description 1
- 241000713666 Lentivirus Species 0.000 description 1
- 239000006142 Luria-Bertani Agar Substances 0.000 description 1
- 208000015439 Lysosomal storage disease Diseases 0.000 description 1
- OVRNDRQMDRJTHS-FMDGEEDCSA-N N-acetyl-beta-D-glucosamine Chemical group CC(=O)N[C@H]1[C@H](O)O[C@H](CO)[C@@H](O)[C@@H]1O OVRNDRQMDRJTHS-FMDGEEDCSA-N 0.000 description 1
- 241000283973 Oryctolagus cuniculus Species 0.000 description 1
- 108010076504 Protein Sorting Signals Proteins 0.000 description 1
- 108091081024 Start codon Proteins 0.000 description 1
- 108010006785 Taq Polymerase Proteins 0.000 description 1
- 108700019146 Transgenes Proteins 0.000 description 1
- 229920004890 Triton X-100 Polymers 0.000 description 1
- 239000013504 Triton X-100 Substances 0.000 description 1
- 230000006838 adverse reaction Effects 0.000 description 1
- 238000013019 agitation Methods 0.000 description 1
- 230000003321 amplification Effects 0.000 description 1
- 238000010171 animal model Methods 0.000 description 1
- 239000003242 anti bacterial agent Substances 0.000 description 1
- 230000000692 anti-sense effect Effects 0.000 description 1
- 229940088710 antibiotic agent Drugs 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- ODKSFYDXXFIFQN-UHFFFAOYSA-N arginine Natural products OC(=O)C(N)CCCNC(N)=N ODKSFYDXXFIFQN-UHFFFAOYSA-N 0.000 description 1
- 125000000637 arginyl group Chemical group N[C@@H](CCCNC(N)=N)C(=O)* 0.000 description 1
- 230000003416 augmentation Effects 0.000 description 1
- 230000037396 body weight Effects 0.000 description 1
- 238000010322 bone marrow transplantation Methods 0.000 description 1
- 229940098773 bovine serum albumin Drugs 0.000 description 1
- 239000008366 buffered solution Substances 0.000 description 1
- 210000000170 cell membrane Anatomy 0.000 description 1
- 108091092328 cellular RNA Proteins 0.000 description 1
- 230000001413 cellular effect Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 239000007979 citrate buffer Substances 0.000 description 1
- 238000010367 cloning Methods 0.000 description 1
- 238000000975 co-precipitation Methods 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000009089 cytolysis Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000002950 deficient Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 239000012470 diluted sample Substances 0.000 description 1
- LOKCTEFSRHRXRJ-UHFFFAOYSA-I dipotassium trisodium dihydrogen phosphate hydrogen phosphate dichloride Chemical compound P(=O)(O)(O)[O-].[K+].P(=O)(O)([O-])[O-].[Na+].[Na+].[Cl-].[K+].[Cl-].[Na+] LOKCTEFSRHRXRJ-UHFFFAOYSA-I 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 231100000673 dose–response relationship Toxicity 0.000 description 1
- 241001493065 dsRNA viruses Species 0.000 description 1
- 238000001962 electrophoresis Methods 0.000 description 1
- 238000004520 electroporation Methods 0.000 description 1
- 210000002472 endoplasmic reticulum Anatomy 0.000 description 1
- 230000009088 enzymatic function Effects 0.000 description 1
- ZMMJGEGLRURXTF-UHFFFAOYSA-N ethidium bromide Chemical compound [Br-].C12=CC(N)=CC=C2C2=CC=C(N)C=C2[N+](CC)=C1C1=CC=CC=C1 ZMMJGEGLRURXTF-UHFFFAOYSA-N 0.000 description 1
- 229960005542 ethidium bromide Drugs 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 239000012091 fetal bovine serum Substances 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 230000037433 frameshift Effects 0.000 description 1
- 230000006870 function Effects 0.000 description 1
- 230000002068 genetic effect Effects 0.000 description 1
- ZJYYHGLJYGJLLN-UHFFFAOYSA-N guanidinium thiocyanate Chemical compound SC#N.NC(N)=N ZJYYHGLJYGJLLN-UHFFFAOYSA-N 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- HNDVDQJCIGZPNO-UHFFFAOYSA-N histidine Natural products OC(=O)C(N)CC1=CN=CN1 HNDVDQJCIGZPNO-UHFFFAOYSA-N 0.000 description 1
- 102000057593 human F8 Human genes 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 238000004020 luminiscence type Methods 0.000 description 1
- 210000004072 lung Anatomy 0.000 description 1
- 239000008176 lyophilized powder Substances 0.000 description 1
- 229910001629 magnesium chloride Inorganic materials 0.000 description 1
- 239000003550 marker Substances 0.000 description 1
- 238000011177 media preparation Methods 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 230000000869 mutational effect Effects 0.000 description 1
- 230000007935 neutral effect Effects 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
- 210000005259 peripheral blood Anatomy 0.000 description 1
- 239000011886 peripheral blood Substances 0.000 description 1
- 239000000546 pharmaceutical excipient Substances 0.000 description 1
- 238000000053 physical method Methods 0.000 description 1
- 230000008488 polyadenylation Effects 0.000 description 1
- 238000003752 polymerase chain reaction Methods 0.000 description 1
- 239000002243 precursor Substances 0.000 description 1
- 238000002731 protein assay Methods 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 229940047431 recombinate Drugs 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 238000009256 replacement therapy Methods 0.000 description 1
- 230000002629 repopulating effect Effects 0.000 description 1
- 230000002441 reversible effect Effects 0.000 description 1
- 239000006152 selective media Substances 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- JAJWGJBVLPIOOH-IZYKLYLVSA-M sodium taurocholate Chemical compound [Na+].C([C@H]1C[C@H]2O)[C@H](O)CC[C@]1(C)[C@@H]1[C@@H]2[C@@H]2CC[C@H]([C@@H](CCC(=O)NCCS([O-])(=O)=O)C)[C@@]2(C)[C@@H](O)C1 JAJWGJBVLPIOOH-IZYKLYLVSA-M 0.000 description 1
- 239000011343 solid material Substances 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 239000008223 sterile water Substances 0.000 description 1
- 239000006228 supernatant Substances 0.000 description 1
- 230000002459 sustained effect Effects 0.000 description 1
- 239000003104 tissue culture media Substances 0.000 description 1
- 238000010361 transduction Methods 0.000 description 1
- 230000026683 transduction Effects 0.000 description 1
- 230000010474 transient expression Effects 0.000 description 1
- 238000013519 translation Methods 0.000 description 1
- PIEPQKCYPFFYMG-UHFFFAOYSA-N tris acetate Chemical compound CC(O)=O.OCC(N)(CO)CO PIEPQKCYPFFYMG-UHFFFAOYSA-N 0.000 description 1
- 241000701161 unidentified adenovirus Species 0.000 description 1
- 230000029812 viral genome replication Effects 0.000 description 1
- 230000003442 weekly effect Effects 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
- C12Y—ENZYMES
- C12Y302/00—Hydrolases acting on glycosyl compounds, i.e. glycosylases (3.2)
- C12Y302/01—Glycosidases, i.e. enzymes hydrolysing O- and S-glycosyl compounds (3.2.1)
- C12Y302/01045—Glucosylceramidase (3.2.1.45), i.e. beta-glucocerebrosidase
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
- A61K48/00—Medicinal preparations containing genetic material which is inserted into cells of the living body to treat genetic diseases; Gene therapy
- A61K48/005—Medicinal preparations containing genetic material which is inserted into cells of the living body to treat genetic diseases; Gene therapy characterised by an aspect of the 'active' part of the composition delivered, i.e. the nucleic acid delivered
-
- 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
- C12N9/00—Enzymes; Proenzymes; Compositions thereof; Processes for preparing, activating, inhibiting, separating or purifying enzymes
- C12N9/14—Hydrolases (3)
- C12N9/24—Hydrolases (3) acting on glycosyl compounds (3.2)
- C12N9/2402—Hydrolases (3) acting on glycosyl compounds (3.2) hydrolysing O- and S- glycosyl compounds (3.2.1)
-
- A—HUMAN NECESSITIES
- A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
- A01K—ANIMAL HUSBANDRY; AVICULTURE; APICULTURE; PISCICULTURE; FISHING; REARING OR BREEDING ANIMALS, NOT OTHERWISE PROVIDED FOR; NEW BREEDS OF ANIMALS
- A01K2217/00—Genetically modified animals
- A01K2217/05—Animals comprising random inserted nucleic acids (transgenic)
Landscapes
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Genetics & Genomics (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Zoology (AREA)
- General Health & Medical Sciences (AREA)
- Wood Science & Technology (AREA)
- Bioinformatics & Cheminformatics (AREA)
- Medicinal Chemistry (AREA)
- Biotechnology (AREA)
- Molecular Biology (AREA)
- Biochemistry (AREA)
- General Engineering & Computer Science (AREA)
- Epidemiology (AREA)
- Biomedical Technology (AREA)
- Pharmacology & Pharmacy (AREA)
- Microbiology (AREA)
- Animal Behavior & Ethology (AREA)
- Public Health (AREA)
- Veterinary Medicine (AREA)
- Enzymes And Modification Thereof (AREA)
- Micro-Organisms Or Cultivation Processes Thereof (AREA)
- Medicines That Contain Protein Lipid Enzymes And Other Medicines (AREA)
Abstract
The invention relates to products and methods for medical treatment of Gaucher disease and, in particular, an improved Gcc DNA for insertion into any applicable expression vector for gene therapy treatment. The invention includes an isolated Gcc DNA molecule, wherein nucleic acid molecules have been modified at cryptic splice sites to prevent or decrease splicing of mRNA produced from the DNA molecule, while preserving the ability of the DNA to express functional Gcc polypeptides.
Description
PRODUCTS AND METHODS FOR GAUCHER DISEASE THERAPY
FIELD OF THE INVENTION
The invention relates to products and methods for medical treatment of Gaucher disease and, in particular, nucleic acid molecules, polypeptides and vectors for polypeptide or gene therapy treatment.
BACKGROUND OF THE INVENTION
Gaucher disease is a lysosomal storage disease caused by the deficiency of functional glucocerebrosidase (Gcc) enzyme. Gcc is present in all cell types. The defective enzyme cannot break down a fatty substance, glucocerebroside, which is an important component of cell membranes. The fat accumulates in macrophages (which are known as the "Gaucher cells").
The fat-laden macrophages are found typically in the liver, spleen, bone marrow and lungs. The amount of the enzyme deficiency varies from person to person as do the symptoms. Some patients may show no clinical symptoms, while others may die from the disease.
The symptoms of the disease and mutant forms of Gcc that cause Gaucher disease are described, for example, in U.S. 5,266,459 (Beutler) and U.S. 5,234,811 (Beutler and Sorge).
There are therapies for Gaucher disease. Ceredase is a form of the Gcc enzyme from placenta that is able to metabolize the fat in Gaucher cells. The enzyme restores normal function to a Gaucher cell. The amount of enzyme used in treatment varies. As much as 30-60 units per kilogram of bodyweight (Ulkglbw) may be given every other week.
Positive results have been reported with 2.3 Ulkglbw given three times a week. Lower doses, such as 1-5 Ulkglbw twice weekly, have also been used with success, but this is less frequent. The intarcellular half life of the enzyme is up to 60 hours. A large number of placentas are needed to make sufficient Ceredase, so this form of therapy is very expensive. It has been almost completely replaced by treatment with a recombinant form of the enzyme, Cerezyme but this therapy is also expensive. Cerezyme is dispensed as a powder whereas Ceredase comes as a liquid. Sterile water must be added to the Cerezyme bottle to dissolve the powder. The shelf life of the drugs is short (<3 months), and splitting doses is cumbersome and wasteful. Allergic reactions to Ceredase are common, but rarely life-threatening. Adverse reactions to Cerezyme appear to be less common, but experience with the drug is still very limited.
Gcc has been structurally modified in order to obtain improved pharmacokinetics over naturally occurring Gcc (which is derived from placenta). These modifications include amino acid modifications as well as carbohydrate changes. For example, U.S.
5,549,892 discloses a recombinant polypeptide that differs from naturally occurring Gcc by the presence of histidine in place of arginine at position 495. In another embodiment, the carbohydrate remodeled recombinant Gcc has increased fucose and N-acetyl glucosamine residues compared to remodeled naturally occurring Gcc. The increased pharmacokinetics of these compounds provides a therapeutic effect at doses that are lower than those required using remodeled, naturally occurring Gcc. However, this Gcc remains expensive to provide.
Furthermore, improved pharmacokinetics does not necessarily compensate for inadequate bioavailability of G cc.
Gene therapy has been administered to Gaucher patients. All experiments carried out to date have been undertaken using ex vivo, retrovirus-mediated transfection, which requires sophisticated laboratory facilities and is very expensive. Although transgene expression could be demonstrated in mice undergoing this procedure, experiments in humans have been disappointing. No clinically significant Gcc gene expression has been reported in humans undergoing retrovirus-mediated transfection with existing Gcc gene preparations. One problem of gene therapy is in reproducibly obtaining high-level, tissue-specific and enduring expression from genes transferred into cells. Currently, there is no suitable gene therapy vector that expresses at a high level for Gaucher disease gene therapy.
SUMMARY OF THE INVENTION
The invention includes a modified Gcc cDNA insert that can be inserted into any mammalian expression vector for use in the medical treatment of Gaucher disease. In a preferred embodiment, the modified cDNA was inserted into a vector named pINEX2.0 which was then used to transfect mammalian cells. When pINEX2.0 containing the unmodified Gcc cDNA coding sequence, pINEXS'GCC3', was transfected into cells, their RNA
purified from cell lysates and subjected to reverse transcription followed by the polymerase chain reaction (RT-PCR), two distinct major bands were observed after agarose gel electrophoresis (Fig. 1 ).
Isolation, purification and sequencing of the RT-PCR products identified a major aberrantly spliced mRNA species which encodes only a 19 amino acid peptide before encountering a STOP codon. Surprisingly, this aberrant splicing event occurred completely within the Gcc cDNA coding sequence (Fig. 2), i.e. no vector sequences were involved. Site directed mutagenesis was performed to modify the nucleotide sequence in the region of aberrant mRNA
splicing without affecting polypeptide coding (Fig. 3). Modifications were aimed at disrupting the known consensus sequences for RNA-splicing (Krawczak et al. 1992). The effectiveness of these modifications were tested by transient transfection into CHO cells, followed by our human-specific immunoprecipitation assay for Gcc. Data (n=18) indicate a 5t1 (Std.
Error)-fold increase in Gcc activity was achieved when the modified replaced the unmodified insert in the pINEX2.0 expression vector.
The invention relates to an isolated Gcc DNA molecule, wherein the DNA
molecule has a modification in at least one nucleotide that disrupts a splicing consensus sequence and prevents splicing of mRNA produced from the DNA molecule, while preserving the ability of the DNA to express active Gcc. The modification impairs a consensus nucleotide sequence needed to induce splicing. The DNA molecule is preferably modified at two cryptic splice sites.
The DNA preferably includes a mutation in the 3' junction site. In one embodiment, the mutation is as shown in the 3' junction site in Table 1, or a functionally equivalent mutation. In another embodiment, the DNA
molecule includes a mutation in the 5' splice junction site. The mutation is preferably as shown in the 5' junction site in Table 1, or a functionally equivalent mutation.
The DNA molecule preferably includes all or part of the nucleotide sequence shown in figure 4(b).
Another aspect of the invention relates to a vector including a DNA molecule of the invention. The vector preferably includes a promoter that is functional in a mammalian cell.
The invention also includes mRNA produced from the DNA molecule or vector of the invention.
Another aspect of the invention relates to a method of medical treatment of Gaucher 24 disease in a mammal, including administering to the mammal an effective amount of a nucleic acid molecule of the invention or a vector of the invention and expressing an effective amount of the polypeptide encoded by the nucleic acid molecule for alleviating clinical symptoms of Gaucher disease.
The invention includes a host cell, or progeny thereof, including a nucleic acid molecule of the invention. The host cell is preferably selected from the group consisting of a mammalian cell, a human cell and a Chinese Hamster Ovary cell. The invention also includes a method for producing a recombinant host cell capable of expressing a Gcc nucleic acid molecule, the method including introducing into the host cell a vector of the invention. The invention also includes a method for expressing a Gcc polypeptide in a host cell including culturing the host cell under conditions suitable for DNA molecule expression. Another aspect of the invention relates to a method for producing a transgenic cell that expresses elevated levels of Gcc polypeptide relative to a non-transgenic cell, including transforming a cell with a vector of the invention.
The invention includes an isolated polypeptide encoded by and/or produced from a nucleic acid molecule of the invention, or a vector of the invention.
The invention includes a method of producing a genetically transformed cell which expresses or overexpresses a Gcc polypeptide, including: a) preparing a Gcc nucleic acid molecule according to any of claims 1-18; b) inserting the nucleic acid molecule in a vector so that the nucleic acid molecule is operably linked to a promoter; c) inserting the vector into a cell.
The invention includes a transgenic cell produced according to the method of the invention.
The invention also includes a pharmaceutical composition, including a carrier and (i) a nucleic acid molecule of the invention (ii) a vector of the invention or (iii) Gcc polypeptide produced from (i) or (ii), in an effective amount for reducing clinical symptoms of Gaucher disease. The carrier preferably carrier includes a liposome.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the invention will be described in relation to the drawings in which:
Figure 1. Separation of RT-PCR products from CHO cell permanently transfected with pINEX-5'-GCC-3'.
Figure 2. Diagrammatic Representation of possible RT-PCR products representing mRNA
splice variants from pINEX-5'-GCC-3'.
Figure 3. Comparison of consensus splice site donorlacceptor site and "Cryptic" splice sites in Gcc cDNA. Sequences of (a) unmodified Gcc cDNA contained in pINEXS'Gcc3' (b) In a preferred embodiment, this sequence represents modified Gcc cDNA contained in pINEX-WEIRD. The translated amino acid sequence for either the modified or unmodified Gcc cDNAs is also given, note that the modified nucleotides had no effect on the amino acid sequence.
Figure 4. (a) The sequences of the aberrantly processed transcript from the unmodified Gcc cDNA insert in pINEXS'Gcc3' and its translated polypeptide (b) Modified DNA
and its translated polypeptide. In a preferred embodiment, this sequence represents modified Gcc cDNA.
DETAILED DESCRIPTION OF THE INVENTION
The invention satisfies the need for a DNA (preferably a cDNA) that when inserted into any mammalian expression vector transcribes RNA that is resistant to aberrant processing in the transfected or transduced target cells and thus, is much more likely to translate the functional full length Gcc protein. Therefore, such a modified insert would improve the levels of Gcc expression when used in any vectors designed for in vivo or ex vivo gene therapy treatments of Gaucher disease. As well, when inserted into any efficient mammalian expression 5 vector, such as pINEX2.0, the modified Gcc cDNA as compared to the unmodified cDNA will increase the production levels of recombinate Gcc polypeptide for use in enzyme replacement therapy for Gaucher disease. Thus, the modified insert directs a higher level of Gcc expression through a mechanism that is independent of the mammalian expression vector used whether in vivo or in vitro. The modified insert is safe as preferably no change in the amino acid sequence of Gcc is encoded by the nucleotide changes, and should confer a sustained and appropriate level of cell-specific expression for gene therapy when coupled with the appropriate vector and transfection or transduction methodologies. The expressed DNA insert is preferably a modified Gcc cDNA or a modified fragment of a Gcc cDNA that express a polypeptide having Gcc activity which is effective for treatment of Gaucher disease. The DNA is modified to prevent aberrant cellular splicing of its mRNA produced when expressed in mammalian cells. The modified DNA
insert may be used with any expression vector to transfect or transduce any mammalian cell type, such as CHO cells for the expression of human Gcc for enzyme replacement. These would also include human stem cells for ex vivo gene therapy or macrophages for in vivo gene therapy.
The invention also includes the methods of making the modified DNA. The methods may be applied to a Gcc DNA from any source that requires modification to avoid undesirable splicing including humans, other mammals or synthetic DNA.
During the search to improve the efficiency of human Gcc expression it was determined that a major amount of the RNA transcribed from any vector was aberrantly spliced due to cryptic 5' and 3' splice sites contained in the human Gcc cDNA (Fig. 1 8~ 2).
Since this RNA
species encodes only a 19 amino acid peptide, it is far less stable than the properly spliced product encoding the complete 536 residues of Gcc (Maquat 1996), and therefore transcribed at a much higher level than is indicated from our steady-state RT-PCR data (Fig.
1 ). We modified the two cryptic sites in a manner that conserved the wild type amino acid sequence while destroying the consensus nucleotide sequences needed to induce splicing (Fig.
3). Transient expression of this modified insert indicated a 5-fold increase in Gcc expression. Such an increase in expression efficiency is not only valuable for any gene therapy approach, but also useful in decreasing the cost of enzyme replacement since the enzyme source is now Gcc-transfected mammalian cells.
Treatment using any vector containing a modified insert to prevent aberrent transcript processing (by gene therapy or by administration of polypeptide produced from a vector) will lower the cost of the present enzyme replacement therapy (currently as much as about US$100,000 per yr. for a patient) by increasing the yield of functional Gcc protein.
The modified insert when used with any appropriate expression vector is also used to direct the expression of Gcc for use in research and characterization of the enzyme's function.
Other useful DNA inserts include a nucleic acid molecule having at least about: 50%, 60%, 70%, 80%, 90%, 95%, 99% or 99.5% sequence identity to the modified Gcc nucleic acid molecule (the Gcc sequence in figure 4(b)) wherein the molecule having sequence identity has a modification in at least one nucleotide (preferably two nucleotides) that disrupts a splicing consensus sequence and prevents splicing of mRNA while it encodes a polypeptide having Gcc activity. Changes in the Gcc nucleotide sequence which result in production of a chemically equivalent (for example, as a result of redundancy of the genetic code) or chemically similar amino acid (for example where sequence similarity is present), may also be made to produce high levels of unspliced transcript from the Gcc cDNA for therapeutic use. The DNA molecule or DNA molecule fragment may be isolated from a native source (in sense or antisense orientations) and modified or synthesized (with or without subsequent modification). It may be a mutated native or synthetic sequence or a combination of these in order to prevent or decrease aberrently spliced transcripts.
Selection of Vector Separating the Gcc activity derived from transfected human cDNA from the endogenous Gcc activity of the host cells, e.g. CHO, was done to determine the efficiency of expression vectors. A high level of expression is needed not only for any in vivo or ex vivo gene therapy approach, but also for the efficiency of producing Gcc for enzyme replacement therapy now being done in transfected cells (Grabowski et al. 1995). We have developed an immuno-precipitation assay that is specific for the human enzyme and have used it to evaluate several expression vectors. The vector producing the highest level of Gcc in transiently transfected CHO cells was pINEX2.0 from INEX Pharmaceuticals. The vector contains a CMV-based promoter and a potential intron prior to the initiating ATG of the Gcc cDNA.
In general our results indicated that a CMV-based promoter gave the highest level of expression and that the placement of the vector's intron at the 5' end of the insert was supperior to placing it at the 3' end. Other suitable vectors will be apparent to a skilled person.
After some initial modifications to the 5' untranslated end of the cDNA
construct to ensure a match with the consensus sequences for protein initiation (Kozak 1987) and the 3' end to eliminate most of the untranslated nucleotides prior to the vector's polyadenylation signal, a lysate from transiently transfected CHO cells still produced low levels of Gcc specific activity, requiring our immunoprecipitation assay to detect the increase in human activity in the cells' total Gcc pool. A line of permanently-transfected CHO cells was prepared in order to analyzed the sequences) of the Gcc mRNA(s) being transcribed from the expression vector.
IDENTIFICATION AND CHARACTERIZATION OF DIFFERENTIALLY SPLICED RNA
Cells Expressing Differentially Spliced RNA
A CHO cell line was permanently co-transfected with the pINEX-5'-GCC-3' construct and a construct containing a selectable marker, pREP10. After selection and isolation of individual clones, the clones were assayed to determine specific activity of Gcc (in nmolelhrlmg total lysate protein). One clone, termed A7, was grown in larger scale and RNA
isolated from it. A
reverse transcription reaction followed by PCR, RT-PCR, was performed on total cellular RNA
from CHO control cells and A7 clone cells. Following agarose gel electrophoresis, two major bands were observed (see Fig. 1 ).
Restriction Digest Analysis The major bands of the RT-PCR reaction were electrophoretically separated on a larger scale and the bands) excised. The purified cDNA was ligated into the pCR2.1 cloning vector.
Restriction digest analysis of the clones obtained using Stu I and Eco RI, revealed a series of different patterns, consistent with possible aberrant splicing (data not shown).
Sequencing Analysis Sequencing of representative clones of each pattern, obtained from the high-andlor low-molecular weight bands, revealed a number of differentially spliced products.
In the high-molecular weight band, 5 out of 10 clones contained product that was spliced at the upstream site in the vector only, producing wild-type message. One out of 10 contained a completely unspliced product, and another 1 out of 10 contained a product with a restriction map consistent with both upstream (vector) and downstream (insert) splice events taking place (Fig. 2).
Remaining clones contained unidentifiable restriction maps and were therefore not sequenced.
Sequencing and restriction digest analysis of the low-molecular weight band revealed that in 7 of 10 clones both splices had taken place, and in 2 out of 10 only the upstream splice event (wild-type message) had occurred.
Sequencing results confirmed that the major alternatively spliced species resulted from the removal of sequences within the Gcc cDNA itself, through the recognition of cryptic 5' and 3' splice sites roughly corresponding to the known consensus sequences that induce RNA splicing in mammalian cells (Krawczak et al. 1992). The deduced amino acid sequence from this RNA
species predicts a reading frame shift after Arg" and an early stop two codons later (Fig. 3).
This would encode only a 19 amino acid peptide lacking even a complete signal sequence, necessary for targeting the protein to the cell's endoplasmic reticulum. In order to eliminate aberrant splicing, the Gcc cDNA was modified by site-directed mutagenesis to alter some of the critical nucleotides making up the consensus sequences (Krawczak et al. 1992) to ensure that the cryptic splice sites no longer be recognized by the RNA processing mechanism. Care was taken to preserve the amino acid coding sequence. Figure 3 shows the consensus sequence for the 5' or 3' splice junctions (Krawczak et al. 1992), the original nucleotide sequence of the Gcc cDNA, the deduced amino acid sequence, and the modifications undertaken to destroy the consensus splicing sequences. Other modifications to destroy the consensus splicing sequences will be apparent.
Transfection Experiments Eighteen independent transient transfection experiments were performed to compare Gcc expression levels between pINEX-5'-GCC-3' to pINEX-WEIRD. After correcting for transfection efficiency with f3-galactosidase (see Methods), pINEX-WEIRD
produced 5t1 (standard error) fold higher levels of Gcc activity (see example in Table 2).
Future work will confirm that all aberrent processing of the Gcc transcript from the modified Gcc cDNA is eliminated. If not, other modifications based on the known consensus splice-sites sequences will be undertaken.
Modified DNAIDNA Having Sequence Identity Many modifications may be made to the vector and Gcc DNA sequences and these will be apparent to one skilled in the art. The invention includes nucleotide modifications of the sequences disclosed in this application (or fragments thereof) that are capable of expressing Gcc in in vivo or in vitro cells. For example, the regulatory sequences may be modified or a nucleic acid sequence to be expressed may be modified using techniques known in the art.
Modifications include substitution, insertion or deletion of nucleotides or altering the relative positions or order of nucleotides. The invention includes DNA which has a sequence with sufficient identity to a nucleotide sequence described in this application to hybridize under moderate to high stringency hybridization conditions. Hybridization techniques are well known in the art (see Sambrook et al. Molecular Cloning: A Laboratory Manual, Most Recent Edition, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y.). High stringency washes have low salt (preferably about 0.2% SSC), and low stringency washes have high salt (preferably about 2% SSC). A temperature of about 37°C or about 42°C is considered low stringency, and a temperature of about 50-65°C is high stringency. The modified inserts encoding Gcc of the invention also include DNA molecules (or a fragment thereof) having at least 50% identity, at least 70% identity, at least 80% identity, at least 90% identity, at least 95%
identity, at least 96%
identity, at least 97% identity, at least 98% identity or, most preferred, at least 99%, 99.5% or 99.8% identity to a modified Gcc nucleic acid molecule acid as shown in figure 4(a), which have a modified consensus sequence to prevent splicing and which are capable of expressing DNA
molecules in vivo or in vitro. Identity refers to the similarity of two nucleotide sequences that are aligned so that the highest order match is obtained. Identity is calculated according to methods known in the art. For example, if a nucleotide sequence (called "Sequence A") has 90% identity to the Gcc sequence in figure 4(b)], then Sequence A will be identical to the referenced portion of figure 4(b) except that Sequence A may include up to 10 point mutations (such as deletions or substitutions with other nucleotides) per each 100 nucleotides of the referenced portion of figure 4(b). The invention also includes DNA sequences which are complementary to the aforementioned sequences. "Sequence identity" may be determined, for example, by the Gap program. The algorithm of Needleman and Wunsch (1970 J Mol. Biol. 48:443-453) is used in the Gap program.
The DNA has a modification in at least one nucleotide that disrupts a splicing consensus sequence and prevents splicing of mRNA while it encodes a polypeptide having Gcc activity.
This means an enzyme that can both convert the natural substrate, glucocerebroside (D-glucosylceramide), to ceramide and glucose under the appropriate conditions, and also hydrolyzed an artificial substrate, 4-methylumbelliferyl-f3-D-glucopyranoside, at a rate of greater than 10 Nmoleslhrlmg of purified Gcc polypeptide.
Functionally Equivalent Nucleic Acid Molecules Identified by Hybridization Other functionally equivalent forms of the modified Gcc DNA of the invention can be identified using conventional DNA-DNA or DNA-RNA hybridization techniques.
Thus, the present invention also includes nucleotide sequences that hybridize to the sequence in figure 4(b) or its complementary sequence, wherein the molecule that hybridizes to the Gcc portion in 4(b) has a modification in at least one nucleotide (more preferably at least two nucleotides) that disrupts a splicing consensus sequence and prevents 5 aberrant splicing of mRNA while it encodes a polypeptide having Gcc activity. Such nucleic acid molecules preferably hybridize to the Gcc sequence in Figure 4(b) under moderate to high stringency conditions For example, high stringency washes have low salt (preferably about 0.2% SSC), and low stringency washes have high salt (preferably about 2% SSC). A temperature of about 37°C or about 42°C is considered low 10 stringency, and a temperature of about 50-65°C is high stringency (see Sambrook et al.
Molecular Cloning: A Laboratory Manual, Most Recent Edition, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y.).
A nucleic acid molecule is considered to be functionally equivalent to the modified Gcc nucleic acid molecules of the present invention if the nucleic acid molecule has a modification in at least one nucleotide that disrupts a splicing consensus sequence and prevents splicing of mRNA while it encodes a polypeptide having Gcc activity (Gcc activity means an enzyme that can both convert the natural substrate, glucocerebroside (D-glucosylceramide), to ceramide and glucose under the appropriate conditions, and also hydrolyzed an artificial substrate, 4-methylumbelliferyl-f3-D-glucopyranoside, at a rate of greater than 10 Nmoleslhrlmg of purified Gcc polypeptide.).
Cells Containing a Vector of the Invention The invention relates to a host cell (isolated cell in vitro or a cell in vivo, or a cell treated ex vivo and returned to an in vivo site) containing a vector and modified Gcc sequence of the invention. The preparation of transformed cells is done according to known techniques (see Materials and Methods for example of CHO cells containing a vector). The invention includes methods of expressing Gcc in the cell.
Pharmaceutical Compositions The pharmaceutical compositions of this invention used to treat patients having Gaucher Disease could include an acceptable carrier, auxiliary or excipient.
Polypeptides may be administered in pharmaceutical compositions in enzyme replacement therapy or in gene therapy.
The pharmaceutical compositions can be administered by ex vivo and in vivo methods such as electroporation, DNA microinjection, liposome DNA delivery, and virus vectors that have RNA or DNA genomes including retrovirus vectors, lentivirus vectors, Adenovirus vectors and Adeno-associated virus (AAA vectors. Dosages to be administered depend on patient needs, on the desired effect and on the chosen route of administration. The vectors may be introduced into the cells or their precursors using in vivo delivery vehicles such as liposomes or DNA or RNA virus vectors. They may also be introduced into these cells using physical techniques such as microinjection or chemical methods such as coprecipitation. The vector may be introduced into any mammalian cell type, such as CHO cells or human cells.
The pharmaceutical compositions can be prepared by known methods for the preparation of pharmaceutically acceptable compositions which can be administered to patients, and such that an effective quantity of the vector or polypeptide is combined in a mixture with a pharmaceutically acceptable vehicle. Suitable vehicles are described, for example in Remington's Pharmaceutical Sciences (Remington's Pharmaceutical Sciences, Mack Publishing Company, Easton, Pa., USA).
On this basis, the pharmaceutical compositions could include an active compound or substance, such as a polypeptide, in association with one or more pharmaceutically acceptable vehicles or diluents, and contained in buffered solutions with a suitable pH
and isoosmotic with the physiological fluids. The methods of combining the vectors with the vehicles or combining them with diluents is well known to those skilled in the art. The composition could include a targeting agent for the transport of the active compound to specified sites within the mammalian cells.
Method of Medical Treatment of Gaucher Disease Any vectors containing the DNA molecules of the invention may be administered to mammals, preferably humans, in gene therapy using techniques described below.
The polypeptide produced from the modified inserts may also be administered to mammals, preferably humans, in enzyme replacement therapy.
Gene Therapy Gene therapy to replace Gcc expression (Nolta et al. 1992; Tsai et al. 1992;
Sidransky et al. 1993; Schuening et al. 1997; Dunbar et al. 1998) may be useful to modify the development or progression of Gaucher disease. The invention includes methods for providing gene therapy for treatment of diseases, disorders or abnormal physical states characterized by insufficient Gcc expression or inadequate levels or activity of Gcc polypeptide.
The invention includes methods and compositions for providing a nucleotide sequence encoding Gcc or biologically functional equivalent nucleotide sequence to the cells of an individual such that expression of Gcc in the cells provides the biological activity or phenotype of Gcc polypeptide to those cells. Sufficient amounts of the nucleotide sequence are administered and expressed at sufficient levels to provide the biological activity or phenotype of Gcc polypeptide to the cells. For example, the method can involve a method of delivering a gene encoding Gcc to the cells of an individual having a disease, disorder or abnormal physical state, comprising administering to the individual a vector comprising DNA encoding Gcc wherein the DNA has modified sites to prevent undesirable splicing. The method may also relate to a method for providing an individual having a disease, disorder or abnormal physical state with biologically active Gcc polypeptide by administering DNA encoding Gcc. The method may be performed ex vivo or in vivo. Gene therapy methods and compositions are demonstrated, for example, in U.S. Patent Nos. 5,672,344, 5,645,829, 5,741,486, 5,656,465, 5,547,932, 5,529,774, 5,436,146, 5,399,346 and 5,670,488, 5,240,846.
The method also relates to a method for producing a stock of recombinant virus by producing virus suitable for gene therapy comprising modified DNA encoding Gcc. This method preferably involves transfecting cells permissive for virus replication (the virus containing modified Gcc) and collecting the virus produced.
Typically, a male or female is treated with the vector containing the invention (subject age will typically range from 1 to 60 years of age). At the time of treatment, he typically will have bone involvement, bone thinning and bone pain and will have an enlarged spleen and liver. The vector containing the invention is administered intravenously in order to achieve a desired level of enzyme in the patient. Treatments are repeated as deemed appropriate by a physician to ameliorate the clinical symptoms of Gaucher disease. Such treatments may be life-long.
Patients report significant improvement in bone involvement, pain and thinning, with reduction in frequency andlor intensity of pain episodes, or complete disappearance of skeletal pain often within the first six months of treatment. Patients also show improvement in cortical bone thickness. Enlargement of the spleen and liver are reduced. One of the disease markers, the enzyme chitotriosidase, shows a dramatic reduction during the course of a year.
Administration of Gcc Polypeptide The Gcc polypeptide is administered in pharmaceutical compositions in enzyme replacement therapy, examples of which are described above (Beutler et al.
1991; Barton et al.
1992; Fallet et al. 1992; Brady et al. 1994; Grabowski et al. 1995; Rosenthal et al. 1995)_ Typically, a male or female is treated with the polypeptide of the invention (subject age will typically range from 1 to 60 years of age). At the time of treatment, he typically will have bone involvement, bone thinning and bone pain and may have an enlarged spleen and liver.
The polypeptide of the invention is administered intravenously at about 30UIkg every 2 weeks in order to achieve a desired level of enzyme in the patient.
Patients report significant improvement in bone involvement, pain and thinning, with reduction in frequency and/or intensity of pain episodes, or complete disappearance of skeletal pain often within the first six months of treatment. Patients also show improvement in cortical bone thickness. Enlargement of the spleen and liver are reduced. One of the disease markers, the enzyme chitotriosidase, shows a dramatic reduction during the course of a year.
Research Tool Mammals and cell cultures transfected or transduced with vectors containing the invention are useful as research tools. Mammals and cell cultures are used in research according to numerous techniques known in the art. For example, one may obtain cells or mice (Tybulewicz et al. 1992) that express low levels of the normal or mutant Gcc polypeptide and use them in experiments to assess expression of a recombinant Gcc nucleotide sequence. In an example of such a procedure, experimental groups of mice are transformed with vectors containing recombinant Gcc genes to assess the levels of polypeptide produced, its functionality and the phenotype of the cells or mice (for example, physical characteristics of the cell structure). Some of the changes described above to optimize expression may be omitted if a lower level of expression is desired. It would be obvious to one skilled in the art that changes could be made to alter the levels of polypeptide expression.
In another example, a cell line (either an immortalized cell culture or a stem cell culture) is transformed with a DNA molecule of the invention (or variants) to measure levels of expression of the DNA molecule and the activity of the DNA molecule. For example, one may obtain mouse or human cell lines or cultures bearing the vector of the invention and obtain expression after the transfer of the cells into immunocompromised mice.
Using exogenous agents in combination with the hybrid gene Cells transfected or transduced with a DNA molecule or polypeptide according to the invention may, in appropriate circumstances, be treated with conventional medical treatment of Gaucher disease, such as enzyme replacement therapy. The appropriate combination of treatments would be apparent to a skilled physician.
Material and Methods Reag-ents:
All reagents used during the course of these experiments were of research grade or molecular biology grades, as appropriate. Substrate for the acid f3-glucosidase (Gcc) activity, 4-methylumbelliferyl-f3-D-glucopyranoside (MUGc), was purchased from Sigma and purified additionally as described below. Oligonucleotide primers were obtained, as a lyophilized powder, from the Hospital for Sick Children Biotechnology Service Centre's DNA
Synthesis Service. Tissue culture media (alpha-MEM) was obtained from the University of Toronto Media Preparation Service. Fetal bovine serum were obtained from CanSera through the Hospital for Sick Children Tissue Culture Service.
Lac Z, Neutral f3-Galactosidase Assay Samples of cell lysates were diluted into water to a final volume of 60 NL.
Substrate solution (190NL), prepared by dissolving 19mg of 4-MU- f3-gal (4-methylumbelliferyl- f3-galactoside) in 100 ml of pH 7.0 0.1 M citrate buffer, was added. The mixture was incubated at 37°C for 30 minutes and then stopped by the addition of 2.Oml of 0.1 M
MAP. Fluorescence of standard quantities of free 4-MU in 0.1 MAP (2-methyl-2-amino-1-propanol) and the assay mixtures were determined on a fluorescence spectrophotometer using 365nm excitation and 450nm emission wavelengths. Polypeptide concentration of the cell lysates were determined by the Bio-Rad method. Specific activity of the lysates were determined as nmole MUI mg polypeptide.
Acid f3-Glucosidase (Gcc) Activity (Specific or Total):
Samples were prepared by freeze-thaw lysis (5x) in PBS containing 0.1 % sodium taurocholate (NaTC), usually 100NL for a P100 dish of confluent CHO cells. A
sample of the lysate (5-20NL) was diluted with 0.25% BSA to a total volume of 100NL.
Reagents were added in the following order: citratelphosphate buffer (1 M/ 2M, pH 4.5), 25NL; 2%
NaTC in ddH20, 25NL; and 20mM of the MUGc substratesolution, 100NL. The reaction was typically allowed to proceed for 1 hour at 37°C and then stopped by the addition of 3.Oml of 0.1 M MAP, pH 10.5.
Fluorescence of the released 4-MU was measured with the use of on a Perkin Elmer LS 30 Luminescence Spectrometer with sipper attachment. Polypeptide content was determined using the BioRad Protein Assay reagent.
Substrate solution (20mM) was prepared by dissolving MUGc in ddH20 and heating to 40-50°C for 15-20 minutes with occasional agitation. The solution was cooled and then extracted 3X with an equal volume of ethyl acetate. The final aqueous solution was bubbled with N2 gas (to remove residual ethyl acetate) and aliquoted into tubes which were then frozen and stored at -20°C until needed. The substrate solution was thawed for use in a beaker of warm water, then vortexed vigorously to ensure complete dissolution of any solid material.
5 Immunoorecipitation Assay For each immunoprecipitation assay, 125NL of Goat anti-rabbit IgG coated magnetic beads (hereafter called "beads") were isolated from suspension using a permanent magnet stand (Advanced Magnetics). Beads were washed 3 times with phosphate-buffered saline containing 0.05% bovine serum albumin (PBSIBSA) by resuspension, and removal from 10 suspension using a magnetic stand, followed by removal of the supernatant.
After the final wash the beads were resuspended in 100NL of PBSIBSA and an appropriate amount of the rabbit anti-Gcc IgG (#5470), usually 4Ng per assay, was added. The mixture was placed in an appropriately sized tube, depending on volume, and allowed to incubate with rotation for 4 hours at 4°C. The bead-antibody complex was precipitated with the permanent magnet stand and 15 washed 3 times with PBSIBSA to remove any remaining free antibody and finally resuspended in 100NL of PBSIBSA. Cell lysates were prepared as above and diluted into a minimum of 400NL (to allow for adequate mixing). The washed antibody-bead complex (100NL) was added to the diluted sample and allowed to incubate overnight at 4°C with rotation. The samples were placed on ice in the permanent magnet stand and allowed to precipitate for ~30 minutes. The beads in each sample were washed (750NL) with PBSIBSA containing 0.1 % Triton X-100, then twice with PBSIBSA containing 0.2% NaTC. After the final wash, the beads were resuspended in PBSIBSAlTriton and assayed for Gcc activity (as described above).
Expression of Gcc in Transiently Transfected CHO Cells CHO cells were co-transfected with either 8Ng of pINEX-5'-GCC-3' or pINEX-WEIRD
and 2Ng pCMV-Lac Z (encoding E. coli f3-galactosidase as a control for transfection efficiency) using Superfect Reagent (QIAGEN GmBH, Germany), according to the manufacturer's protocol.
Cells were harvested after 2 days and the lysates analyzed for Gcc (using the immunoprecipitation assay) and f3-galactosidase activity. Final Gcc levels were adjusted based on the relative levels of f3-galactosidase activity in each lysate sample.
Cloned CHO Cells Permanently-Transfected with pINEX-5'-GCC-3':
CHO cells were co-transfected with 8Ng of pINEX-5'-GCC-3' and 2Ng pREP10 (containing a hygromycin resistence gene). Selective medium, containing 200Ng/mL
hygromycin was added, and the cells were allowed to grow for approximately two weeks, splitting as necessary. After two weeks the cells were harvested by trysinization, counted using a hemocytometer and diluted as necessary to isolate single cells using 96-well dishes. After 10 days, clones that were growing well were transferred into 100mm dishes and allowed to grow for a further 10 days, splitting as necessary. Cells from each clone were harvested and assayed for Gcc activity. The final clone selected, termed A7, had the highest Gcc activity of all the clones examined.
RNA Isolation and Reverse Transcription and PCR !RT-PCR):
Cells were grown in large dishes (P150), and RNA was isolated from control CHO
cells and the A7 clone, according to the one-step guanidinium isothiocyanate procedure(Chomczynski and Sacchi 1987). RNA (1 Ng), primer (SPR2 (see Table 1 ), 200pmol), RNase inhibitor, and ddH20 (to 12.5NL total), were mixed and incubated at 65°C for 20 minutes.
After cooling on ice for 5 minutes, the remaining components of the RT
reaction cocktail Were added (RT buffer, DTT, dNTPs, RNase inhibitor, and reverse transcriptase). The reaction cocktail (total 25NL) was incubated at 37°C for 90 min.
PCR was performed using the RT reaction products (1 NL) as template. After addition of ddHzO, and primers (SPF and 53GCC2000R (see Table 1 ), 20pmol each), the reaction was incubated at 95°C for 5 minutes to inactivate the reverse transcriptase. The remaining reaction components (dNTPs, MgCl2, and Taq polymerase (Gibco BRL)) were used at manufacturers suggested levels. Thermocycling was performed under the following conditions:
94°Cl3min; 30 cycles of 94°I1.5min, 55°I1 min, 72°I1.5min;
72°I10min. Samples of the PCR reaction (10NL) were loaded onto a 1.5% agarose gel using Tris-Acetate-EDTA buffer (TAE, 40mM
Tris-acetate / 2mM EDTA), electrophoresed and visualized using ethidium bromide.
Cloning of RT-PCR Products:
Electrophoresis of the RT-PCR products from the A7 clone cell line showed two major bands. One full RT-PCR reaction mixture (100NL) was separated eletrophoretically on an agarose gel, and the two major product bands were excised and purified using the Qiaex II Gel Extraction Kit (QIAGEN GmBH, Germany). The fragments were cloned into the TA
cloning vector (pCR2.1 ) according to the manufacturer's directions (Invitrogen, Carlsbad, CA). The inserts were sequenced using either 35S-T7 Sequencing Kit or 33P-cycle Sequencing Kit (Amersham Pharmacia Biotech, Sweden) from either the M13 forward or M13 reverse primer location on the vector. Sequencing gels were exposed to BioMaxMR film (Kodak) overnight and subsequently read.
Site-Directed Mutagenesis (Internal "Weird" Spice Fix):
The cryptic splice site located within the Gcc cDNA was modified by site-directed mutagenesis in order to remove potential consensus splice junction sites from the Gcc cDNA. A
PCR product was obtained using one oligonucleotide primer which mutagenized a number of bases in the putative 3' junction site (3' junction (see Table 1 )) and another for the putative 5'-splice junction site (5' junction (see Table 1 )). The PCR reaction contained:
1 X Pfu reaction buffer (10X stock provided by manufacturer), 0.4mM dNTP, 10ng template DNA
(pINEX-5'-GCC-3'), 500ng of each oligo, and 2.5U Pfu DNA Polymerise in a final volume of 50NL in the appropriate buffer.
Amplification was performed using a Robocycler 40 Temperature Cycler (Stratagene) for 30 cycles, with temperatures and times as follows: 94°C/45 sec., 59°C I 1 min. and 72°C I 1 min. 20 sec. The PCR product was used as a mega-primer in the second round of PCR. The second PCR reaction consisted of: 5NL of the above PCR reaction mixture, 1 X
Pfu reaction buffer (10X stock provided by manufacturer), 0.4mM dNTPs, 50 ng template (pINEX-5'-GCC-3'), 500ng upstream oligo (SPF) and 5U Pfu DNA polymerise in a final reaction volume of 100NL.
Reaction temperature conditions used were the same as for the initial PCR
above. The PCR
products were digested with 10U of Dra III and Xho I for 3 hr at 37°C.
The plasmid pINEX-5'-GCC-3' was digested in parallel using the same method. Digested products were electrophoretically separated on an agarose gel, and the appropriate pieces were excised and purified as described above. Ligation was performed in a 20NL final volume using 5U of T4 DNA Ligase (MBI Fermentas, Lithuania), incubating overnight at 16°C to produce pINEX-WEIRD. DNA was transformed into DH5 E. coli cells (Gibco BRL) and plated onto appropriate LB agar plates containing antibiotics. Plasmid DNA was isolated and screened by restriction digest and sequencing to confirm that they contained the appropriate insert.
The present invention has been described in detail and with particular reference to the preferred embodiments; however, it will be understood by one having ordinary skill in the art that changes can be made thereto without departing from the spirit and scope of the invention.
All publications, patents and patent applications are incorporated by reference in their entirety to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated by reference in its entirety.
REFERENCES
Barton NW, Brady RO, Dambrosia JM, Doppelt SH, Hill SC, Holder CA, Mankin HJ, et al (1992) Dose-dependent responses to macrophage-targeted glucocerebrosidase in a child with Gaucher disease. J Pediatr 1:277-280 Beutler E, Kay AC, Saven A, Garver P, Thurston DW, Rosenbloom BE (1991) Enzyme-replacement therapy for Gaucher's disease. N Engl J Med 325:1809-1810 Brady RO, Murray GJ, Barton NW (1994) Modifying exogenous glucocerebrosidase for effective replacement therapy in Gaucher disease. J Inherited Metab Dis 17:510-519 Chomczynski P, Sacchi N (1987) Single-step method of RNA isolation by acid guanidinium thiocyanate-phenol-chloroform extraction. Anal. Biochem. 162:156-9 Dunbar CE, Kohn DB, Schiffmann R, Barton NW, Nolta JA, Esplin JA, Pensiero M, et al (1998) Retroviral transfer of the glucocerebrosidase gene into CD34+ cells from patients with Gaucher disease: In vivo detection of transduced cells without myeloablation. Hum Gene Ther 9:2629-Fallet S, Grace ME, Sibille A, Mendelson DS, Shapiro RS, Hermann G, Grabowski GA (1992) Enzyme augmentation in moderate to life-threatening Gaucher disease. Pediatr Res 31:496-502 Grabowski GA, Barton NW, Pastores G, Dambrosia JM, Banerjee TK, McKee MA, Parker C, et al (1995) Enzyme therapy in type 1 Gaucher disease: Comparative efficacy of mannose-terminated glucocerebrosidase from natural and recombinant sources. Ann.
Intern. Med.
122:33-39 Kozak M (1987) At least six nucleotides preceding the AUG initiator codon enhance translation in mammalian cells. J. Mol. Biol. 196:947-950 Krawczak M, Reiss J, Cooper DN (1992) The mutational spectrum of single base-pair substitutions in mRNA splice junctions of human genes: causes and consequences. Hum.
Genet. 90:41-54 Maquat LE (1996) Defects in RNA splicing and the consequence of shortened translational reading frames. Am. J. Hum. Genet. 59:279-286 Nolta JA, Yu XJ, Bahner I, Kohn DB (1992) Retroviral-mediated transfer of the human glucocerebrosidase gene into cultured Gaucher bone marrow. J Clin Invest 90:342-348 Rosenthal DI, Doppelt SH, Mankin HJ, Dambrosia JM, Xavier RJ, McKusick KA, Rosen BR, et al (1995) Enzyme replacement therapy for Gaucher disease: Skeletal responses to macrophage-targeted glucocerebrosidase. Pediatrics 96:629-637 Schuening F, Longo WL, Atkinson ME, Zaboikin M (1997) Retrovirus-mediated transfer of the 5 cDNA for human glucocerebrosidase into peripheral blood repopulating cells of patients with Gaucher's disease. Hum Gene Ther 8:2143-2160 Sidransky E, Martin B, Ginns EI (1993) Treatment of Gaucher's disease. N Engl J Med 328:1566-1566 Tsai P, Lipton JM, Sahdev I, Najfeld V, Rankin LR, Slyper AH, Ludman M, et al (1992) Allogenic 10 bone marrow transplantation in severe Gaucher disease. Pediatr Res 31:503-Tybulewicz V, Tremblay ML, LaMarca ME, Willemsen R, Stubblefield BK, Winfield S, Zablocka B, et al (1992) Animal model of Gaucher's disease from targeted disruption of the mouse glucocerebrosidase gene. Nature 357:407-410 TABLE 1: Sequence of Oligos Used in this Study:
Oligo Name Oligo Sequence* (5' to 3') SPF GACCGATCCAGCCTCCGGACTCT
3-junction CATCCGTCGCCCACTGCGTGTACTCTCATAGCGGGAAAATGT
CAGGGCAGG
5'junction CCTTTGAGTAGAGTCTCCATCATGGCTGGC
_ ~sases unaeninea indicate bases changed in site-directed mutagenesis PCR
procedures.
Q
Z
D
t~
ca v d L
L
.
t7 v O
M
in d O
C C~
d X
C
o- ~ o o Z
X
u.
-p ~j Z ao t U
C C N
N ~O (O ~ 00 .ta ~ ~
= Q- e- 0 CO
O
V y U s a E
c o 0 ~ c~o 0 f-a U
O (/~
fIJ 0V G
O
ii ~ ~ ~ Q
c c U U Z 0 r a N
o O ~ M
E
O J
O .~ U
N ~ O
U C M N
J
~ ~ Z N Q.
E- fl.
FIELD OF THE INVENTION
The invention relates to products and methods for medical treatment of Gaucher disease and, in particular, nucleic acid molecules, polypeptides and vectors for polypeptide or gene therapy treatment.
BACKGROUND OF THE INVENTION
Gaucher disease is a lysosomal storage disease caused by the deficiency of functional glucocerebrosidase (Gcc) enzyme. Gcc is present in all cell types. The defective enzyme cannot break down a fatty substance, glucocerebroside, which is an important component of cell membranes. The fat accumulates in macrophages (which are known as the "Gaucher cells").
The fat-laden macrophages are found typically in the liver, spleen, bone marrow and lungs. The amount of the enzyme deficiency varies from person to person as do the symptoms. Some patients may show no clinical symptoms, while others may die from the disease.
The symptoms of the disease and mutant forms of Gcc that cause Gaucher disease are described, for example, in U.S. 5,266,459 (Beutler) and U.S. 5,234,811 (Beutler and Sorge).
There are therapies for Gaucher disease. Ceredase is a form of the Gcc enzyme from placenta that is able to metabolize the fat in Gaucher cells. The enzyme restores normal function to a Gaucher cell. The amount of enzyme used in treatment varies. As much as 30-60 units per kilogram of bodyweight (Ulkglbw) may be given every other week.
Positive results have been reported with 2.3 Ulkglbw given three times a week. Lower doses, such as 1-5 Ulkglbw twice weekly, have also been used with success, but this is less frequent. The intarcellular half life of the enzyme is up to 60 hours. A large number of placentas are needed to make sufficient Ceredase, so this form of therapy is very expensive. It has been almost completely replaced by treatment with a recombinant form of the enzyme, Cerezyme but this therapy is also expensive. Cerezyme is dispensed as a powder whereas Ceredase comes as a liquid. Sterile water must be added to the Cerezyme bottle to dissolve the powder. The shelf life of the drugs is short (<3 months), and splitting doses is cumbersome and wasteful. Allergic reactions to Ceredase are common, but rarely life-threatening. Adverse reactions to Cerezyme appear to be less common, but experience with the drug is still very limited.
Gcc has been structurally modified in order to obtain improved pharmacokinetics over naturally occurring Gcc (which is derived from placenta). These modifications include amino acid modifications as well as carbohydrate changes. For example, U.S.
5,549,892 discloses a recombinant polypeptide that differs from naturally occurring Gcc by the presence of histidine in place of arginine at position 495. In another embodiment, the carbohydrate remodeled recombinant Gcc has increased fucose and N-acetyl glucosamine residues compared to remodeled naturally occurring Gcc. The increased pharmacokinetics of these compounds provides a therapeutic effect at doses that are lower than those required using remodeled, naturally occurring Gcc. However, this Gcc remains expensive to provide.
Furthermore, improved pharmacokinetics does not necessarily compensate for inadequate bioavailability of G cc.
Gene therapy has been administered to Gaucher patients. All experiments carried out to date have been undertaken using ex vivo, retrovirus-mediated transfection, which requires sophisticated laboratory facilities and is very expensive. Although transgene expression could be demonstrated in mice undergoing this procedure, experiments in humans have been disappointing. No clinically significant Gcc gene expression has been reported in humans undergoing retrovirus-mediated transfection with existing Gcc gene preparations. One problem of gene therapy is in reproducibly obtaining high-level, tissue-specific and enduring expression from genes transferred into cells. Currently, there is no suitable gene therapy vector that expresses at a high level for Gaucher disease gene therapy.
SUMMARY OF THE INVENTION
The invention includes a modified Gcc cDNA insert that can be inserted into any mammalian expression vector for use in the medical treatment of Gaucher disease. In a preferred embodiment, the modified cDNA was inserted into a vector named pINEX2.0 which was then used to transfect mammalian cells. When pINEX2.0 containing the unmodified Gcc cDNA coding sequence, pINEXS'GCC3', was transfected into cells, their RNA
purified from cell lysates and subjected to reverse transcription followed by the polymerase chain reaction (RT-PCR), two distinct major bands were observed after agarose gel electrophoresis (Fig. 1 ).
Isolation, purification and sequencing of the RT-PCR products identified a major aberrantly spliced mRNA species which encodes only a 19 amino acid peptide before encountering a STOP codon. Surprisingly, this aberrant splicing event occurred completely within the Gcc cDNA coding sequence (Fig. 2), i.e. no vector sequences were involved. Site directed mutagenesis was performed to modify the nucleotide sequence in the region of aberrant mRNA
splicing without affecting polypeptide coding (Fig. 3). Modifications were aimed at disrupting the known consensus sequences for RNA-splicing (Krawczak et al. 1992). The effectiveness of these modifications were tested by transient transfection into CHO cells, followed by our human-specific immunoprecipitation assay for Gcc. Data (n=18) indicate a 5t1 (Std.
Error)-fold increase in Gcc activity was achieved when the modified replaced the unmodified insert in the pINEX2.0 expression vector.
The invention relates to an isolated Gcc DNA molecule, wherein the DNA
molecule has a modification in at least one nucleotide that disrupts a splicing consensus sequence and prevents splicing of mRNA produced from the DNA molecule, while preserving the ability of the DNA to express active Gcc. The modification impairs a consensus nucleotide sequence needed to induce splicing. The DNA molecule is preferably modified at two cryptic splice sites.
The DNA preferably includes a mutation in the 3' junction site. In one embodiment, the mutation is as shown in the 3' junction site in Table 1, or a functionally equivalent mutation. In another embodiment, the DNA
molecule includes a mutation in the 5' splice junction site. The mutation is preferably as shown in the 5' junction site in Table 1, or a functionally equivalent mutation.
The DNA molecule preferably includes all or part of the nucleotide sequence shown in figure 4(b).
Another aspect of the invention relates to a vector including a DNA molecule of the invention. The vector preferably includes a promoter that is functional in a mammalian cell.
The invention also includes mRNA produced from the DNA molecule or vector of the invention.
Another aspect of the invention relates to a method of medical treatment of Gaucher 24 disease in a mammal, including administering to the mammal an effective amount of a nucleic acid molecule of the invention or a vector of the invention and expressing an effective amount of the polypeptide encoded by the nucleic acid molecule for alleviating clinical symptoms of Gaucher disease.
The invention includes a host cell, or progeny thereof, including a nucleic acid molecule of the invention. The host cell is preferably selected from the group consisting of a mammalian cell, a human cell and a Chinese Hamster Ovary cell. The invention also includes a method for producing a recombinant host cell capable of expressing a Gcc nucleic acid molecule, the method including introducing into the host cell a vector of the invention. The invention also includes a method for expressing a Gcc polypeptide in a host cell including culturing the host cell under conditions suitable for DNA molecule expression. Another aspect of the invention relates to a method for producing a transgenic cell that expresses elevated levels of Gcc polypeptide relative to a non-transgenic cell, including transforming a cell with a vector of the invention.
The invention includes an isolated polypeptide encoded by and/or produced from a nucleic acid molecule of the invention, or a vector of the invention.
The invention includes a method of producing a genetically transformed cell which expresses or overexpresses a Gcc polypeptide, including: a) preparing a Gcc nucleic acid molecule according to any of claims 1-18; b) inserting the nucleic acid molecule in a vector so that the nucleic acid molecule is operably linked to a promoter; c) inserting the vector into a cell.
The invention includes a transgenic cell produced according to the method of the invention.
The invention also includes a pharmaceutical composition, including a carrier and (i) a nucleic acid molecule of the invention (ii) a vector of the invention or (iii) Gcc polypeptide produced from (i) or (ii), in an effective amount for reducing clinical symptoms of Gaucher disease. The carrier preferably carrier includes a liposome.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the invention will be described in relation to the drawings in which:
Figure 1. Separation of RT-PCR products from CHO cell permanently transfected with pINEX-5'-GCC-3'.
Figure 2. Diagrammatic Representation of possible RT-PCR products representing mRNA
splice variants from pINEX-5'-GCC-3'.
Figure 3. Comparison of consensus splice site donorlacceptor site and "Cryptic" splice sites in Gcc cDNA. Sequences of (a) unmodified Gcc cDNA contained in pINEXS'Gcc3' (b) In a preferred embodiment, this sequence represents modified Gcc cDNA contained in pINEX-WEIRD. The translated amino acid sequence for either the modified or unmodified Gcc cDNAs is also given, note that the modified nucleotides had no effect on the amino acid sequence.
Figure 4. (a) The sequences of the aberrantly processed transcript from the unmodified Gcc cDNA insert in pINEXS'Gcc3' and its translated polypeptide (b) Modified DNA
and its translated polypeptide. In a preferred embodiment, this sequence represents modified Gcc cDNA.
DETAILED DESCRIPTION OF THE INVENTION
The invention satisfies the need for a DNA (preferably a cDNA) that when inserted into any mammalian expression vector transcribes RNA that is resistant to aberrant processing in the transfected or transduced target cells and thus, is much more likely to translate the functional full length Gcc protein. Therefore, such a modified insert would improve the levels of Gcc expression when used in any vectors designed for in vivo or ex vivo gene therapy treatments of Gaucher disease. As well, when inserted into any efficient mammalian expression 5 vector, such as pINEX2.0, the modified Gcc cDNA as compared to the unmodified cDNA will increase the production levels of recombinate Gcc polypeptide for use in enzyme replacement therapy for Gaucher disease. Thus, the modified insert directs a higher level of Gcc expression through a mechanism that is independent of the mammalian expression vector used whether in vivo or in vitro. The modified insert is safe as preferably no change in the amino acid sequence of Gcc is encoded by the nucleotide changes, and should confer a sustained and appropriate level of cell-specific expression for gene therapy when coupled with the appropriate vector and transfection or transduction methodologies. The expressed DNA insert is preferably a modified Gcc cDNA or a modified fragment of a Gcc cDNA that express a polypeptide having Gcc activity which is effective for treatment of Gaucher disease. The DNA is modified to prevent aberrant cellular splicing of its mRNA produced when expressed in mammalian cells. The modified DNA
insert may be used with any expression vector to transfect or transduce any mammalian cell type, such as CHO cells for the expression of human Gcc for enzyme replacement. These would also include human stem cells for ex vivo gene therapy or macrophages for in vivo gene therapy.
The invention also includes the methods of making the modified DNA. The methods may be applied to a Gcc DNA from any source that requires modification to avoid undesirable splicing including humans, other mammals or synthetic DNA.
During the search to improve the efficiency of human Gcc expression it was determined that a major amount of the RNA transcribed from any vector was aberrantly spliced due to cryptic 5' and 3' splice sites contained in the human Gcc cDNA (Fig. 1 8~ 2).
Since this RNA
species encodes only a 19 amino acid peptide, it is far less stable than the properly spliced product encoding the complete 536 residues of Gcc (Maquat 1996), and therefore transcribed at a much higher level than is indicated from our steady-state RT-PCR data (Fig.
1 ). We modified the two cryptic sites in a manner that conserved the wild type amino acid sequence while destroying the consensus nucleotide sequences needed to induce splicing (Fig.
3). Transient expression of this modified insert indicated a 5-fold increase in Gcc expression. Such an increase in expression efficiency is not only valuable for any gene therapy approach, but also useful in decreasing the cost of enzyme replacement since the enzyme source is now Gcc-transfected mammalian cells.
Treatment using any vector containing a modified insert to prevent aberrent transcript processing (by gene therapy or by administration of polypeptide produced from a vector) will lower the cost of the present enzyme replacement therapy (currently as much as about US$100,000 per yr. for a patient) by increasing the yield of functional Gcc protein.
The modified insert when used with any appropriate expression vector is also used to direct the expression of Gcc for use in research and characterization of the enzyme's function.
Other useful DNA inserts include a nucleic acid molecule having at least about: 50%, 60%, 70%, 80%, 90%, 95%, 99% or 99.5% sequence identity to the modified Gcc nucleic acid molecule (the Gcc sequence in figure 4(b)) wherein the molecule having sequence identity has a modification in at least one nucleotide (preferably two nucleotides) that disrupts a splicing consensus sequence and prevents splicing of mRNA while it encodes a polypeptide having Gcc activity. Changes in the Gcc nucleotide sequence which result in production of a chemically equivalent (for example, as a result of redundancy of the genetic code) or chemically similar amino acid (for example where sequence similarity is present), may also be made to produce high levels of unspliced transcript from the Gcc cDNA for therapeutic use. The DNA molecule or DNA molecule fragment may be isolated from a native source (in sense or antisense orientations) and modified or synthesized (with or without subsequent modification). It may be a mutated native or synthetic sequence or a combination of these in order to prevent or decrease aberrently spliced transcripts.
Selection of Vector Separating the Gcc activity derived from transfected human cDNA from the endogenous Gcc activity of the host cells, e.g. CHO, was done to determine the efficiency of expression vectors. A high level of expression is needed not only for any in vivo or ex vivo gene therapy approach, but also for the efficiency of producing Gcc for enzyme replacement therapy now being done in transfected cells (Grabowski et al. 1995). We have developed an immuno-precipitation assay that is specific for the human enzyme and have used it to evaluate several expression vectors. The vector producing the highest level of Gcc in transiently transfected CHO cells was pINEX2.0 from INEX Pharmaceuticals. The vector contains a CMV-based promoter and a potential intron prior to the initiating ATG of the Gcc cDNA.
In general our results indicated that a CMV-based promoter gave the highest level of expression and that the placement of the vector's intron at the 5' end of the insert was supperior to placing it at the 3' end. Other suitable vectors will be apparent to a skilled person.
After some initial modifications to the 5' untranslated end of the cDNA
construct to ensure a match with the consensus sequences for protein initiation (Kozak 1987) and the 3' end to eliminate most of the untranslated nucleotides prior to the vector's polyadenylation signal, a lysate from transiently transfected CHO cells still produced low levels of Gcc specific activity, requiring our immunoprecipitation assay to detect the increase in human activity in the cells' total Gcc pool. A line of permanently-transfected CHO cells was prepared in order to analyzed the sequences) of the Gcc mRNA(s) being transcribed from the expression vector.
IDENTIFICATION AND CHARACTERIZATION OF DIFFERENTIALLY SPLICED RNA
Cells Expressing Differentially Spliced RNA
A CHO cell line was permanently co-transfected with the pINEX-5'-GCC-3' construct and a construct containing a selectable marker, pREP10. After selection and isolation of individual clones, the clones were assayed to determine specific activity of Gcc (in nmolelhrlmg total lysate protein). One clone, termed A7, was grown in larger scale and RNA
isolated from it. A
reverse transcription reaction followed by PCR, RT-PCR, was performed on total cellular RNA
from CHO control cells and A7 clone cells. Following agarose gel electrophoresis, two major bands were observed (see Fig. 1 ).
Restriction Digest Analysis The major bands of the RT-PCR reaction were electrophoretically separated on a larger scale and the bands) excised. The purified cDNA was ligated into the pCR2.1 cloning vector.
Restriction digest analysis of the clones obtained using Stu I and Eco RI, revealed a series of different patterns, consistent with possible aberrant splicing (data not shown).
Sequencing Analysis Sequencing of representative clones of each pattern, obtained from the high-andlor low-molecular weight bands, revealed a number of differentially spliced products.
In the high-molecular weight band, 5 out of 10 clones contained product that was spliced at the upstream site in the vector only, producing wild-type message. One out of 10 contained a completely unspliced product, and another 1 out of 10 contained a product with a restriction map consistent with both upstream (vector) and downstream (insert) splice events taking place (Fig. 2).
Remaining clones contained unidentifiable restriction maps and were therefore not sequenced.
Sequencing and restriction digest analysis of the low-molecular weight band revealed that in 7 of 10 clones both splices had taken place, and in 2 out of 10 only the upstream splice event (wild-type message) had occurred.
Sequencing results confirmed that the major alternatively spliced species resulted from the removal of sequences within the Gcc cDNA itself, through the recognition of cryptic 5' and 3' splice sites roughly corresponding to the known consensus sequences that induce RNA splicing in mammalian cells (Krawczak et al. 1992). The deduced amino acid sequence from this RNA
species predicts a reading frame shift after Arg" and an early stop two codons later (Fig. 3).
This would encode only a 19 amino acid peptide lacking even a complete signal sequence, necessary for targeting the protein to the cell's endoplasmic reticulum. In order to eliminate aberrant splicing, the Gcc cDNA was modified by site-directed mutagenesis to alter some of the critical nucleotides making up the consensus sequences (Krawczak et al. 1992) to ensure that the cryptic splice sites no longer be recognized by the RNA processing mechanism. Care was taken to preserve the amino acid coding sequence. Figure 3 shows the consensus sequence for the 5' or 3' splice junctions (Krawczak et al. 1992), the original nucleotide sequence of the Gcc cDNA, the deduced amino acid sequence, and the modifications undertaken to destroy the consensus splicing sequences. Other modifications to destroy the consensus splicing sequences will be apparent.
Transfection Experiments Eighteen independent transient transfection experiments were performed to compare Gcc expression levels between pINEX-5'-GCC-3' to pINEX-WEIRD. After correcting for transfection efficiency with f3-galactosidase (see Methods), pINEX-WEIRD
produced 5t1 (standard error) fold higher levels of Gcc activity (see example in Table 2).
Future work will confirm that all aberrent processing of the Gcc transcript from the modified Gcc cDNA is eliminated. If not, other modifications based on the known consensus splice-sites sequences will be undertaken.
Modified DNAIDNA Having Sequence Identity Many modifications may be made to the vector and Gcc DNA sequences and these will be apparent to one skilled in the art. The invention includes nucleotide modifications of the sequences disclosed in this application (or fragments thereof) that are capable of expressing Gcc in in vivo or in vitro cells. For example, the regulatory sequences may be modified or a nucleic acid sequence to be expressed may be modified using techniques known in the art.
Modifications include substitution, insertion or deletion of nucleotides or altering the relative positions or order of nucleotides. The invention includes DNA which has a sequence with sufficient identity to a nucleotide sequence described in this application to hybridize under moderate to high stringency hybridization conditions. Hybridization techniques are well known in the art (see Sambrook et al. Molecular Cloning: A Laboratory Manual, Most Recent Edition, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y.). High stringency washes have low salt (preferably about 0.2% SSC), and low stringency washes have high salt (preferably about 2% SSC). A temperature of about 37°C or about 42°C is considered low stringency, and a temperature of about 50-65°C is high stringency. The modified inserts encoding Gcc of the invention also include DNA molecules (or a fragment thereof) having at least 50% identity, at least 70% identity, at least 80% identity, at least 90% identity, at least 95%
identity, at least 96%
identity, at least 97% identity, at least 98% identity or, most preferred, at least 99%, 99.5% or 99.8% identity to a modified Gcc nucleic acid molecule acid as shown in figure 4(a), which have a modified consensus sequence to prevent splicing and which are capable of expressing DNA
molecules in vivo or in vitro. Identity refers to the similarity of two nucleotide sequences that are aligned so that the highest order match is obtained. Identity is calculated according to methods known in the art. For example, if a nucleotide sequence (called "Sequence A") has 90% identity to the Gcc sequence in figure 4(b)], then Sequence A will be identical to the referenced portion of figure 4(b) except that Sequence A may include up to 10 point mutations (such as deletions or substitutions with other nucleotides) per each 100 nucleotides of the referenced portion of figure 4(b). The invention also includes DNA sequences which are complementary to the aforementioned sequences. "Sequence identity" may be determined, for example, by the Gap program. The algorithm of Needleman and Wunsch (1970 J Mol. Biol. 48:443-453) is used in the Gap program.
The DNA has a modification in at least one nucleotide that disrupts a splicing consensus sequence and prevents splicing of mRNA while it encodes a polypeptide having Gcc activity.
This means an enzyme that can both convert the natural substrate, glucocerebroside (D-glucosylceramide), to ceramide and glucose under the appropriate conditions, and also hydrolyzed an artificial substrate, 4-methylumbelliferyl-f3-D-glucopyranoside, at a rate of greater than 10 Nmoleslhrlmg of purified Gcc polypeptide.
Functionally Equivalent Nucleic Acid Molecules Identified by Hybridization Other functionally equivalent forms of the modified Gcc DNA of the invention can be identified using conventional DNA-DNA or DNA-RNA hybridization techniques.
Thus, the present invention also includes nucleotide sequences that hybridize to the sequence in figure 4(b) or its complementary sequence, wherein the molecule that hybridizes to the Gcc portion in 4(b) has a modification in at least one nucleotide (more preferably at least two nucleotides) that disrupts a splicing consensus sequence and prevents 5 aberrant splicing of mRNA while it encodes a polypeptide having Gcc activity. Such nucleic acid molecules preferably hybridize to the Gcc sequence in Figure 4(b) under moderate to high stringency conditions For example, high stringency washes have low salt (preferably about 0.2% SSC), and low stringency washes have high salt (preferably about 2% SSC). A temperature of about 37°C or about 42°C is considered low 10 stringency, and a temperature of about 50-65°C is high stringency (see Sambrook et al.
Molecular Cloning: A Laboratory Manual, Most Recent Edition, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y.).
A nucleic acid molecule is considered to be functionally equivalent to the modified Gcc nucleic acid molecules of the present invention if the nucleic acid molecule has a modification in at least one nucleotide that disrupts a splicing consensus sequence and prevents splicing of mRNA while it encodes a polypeptide having Gcc activity (Gcc activity means an enzyme that can both convert the natural substrate, glucocerebroside (D-glucosylceramide), to ceramide and glucose under the appropriate conditions, and also hydrolyzed an artificial substrate, 4-methylumbelliferyl-f3-D-glucopyranoside, at a rate of greater than 10 Nmoleslhrlmg of purified Gcc polypeptide.).
Cells Containing a Vector of the Invention The invention relates to a host cell (isolated cell in vitro or a cell in vivo, or a cell treated ex vivo and returned to an in vivo site) containing a vector and modified Gcc sequence of the invention. The preparation of transformed cells is done according to known techniques (see Materials and Methods for example of CHO cells containing a vector). The invention includes methods of expressing Gcc in the cell.
Pharmaceutical Compositions The pharmaceutical compositions of this invention used to treat patients having Gaucher Disease could include an acceptable carrier, auxiliary or excipient.
Polypeptides may be administered in pharmaceutical compositions in enzyme replacement therapy or in gene therapy.
The pharmaceutical compositions can be administered by ex vivo and in vivo methods such as electroporation, DNA microinjection, liposome DNA delivery, and virus vectors that have RNA or DNA genomes including retrovirus vectors, lentivirus vectors, Adenovirus vectors and Adeno-associated virus (AAA vectors. Dosages to be administered depend on patient needs, on the desired effect and on the chosen route of administration. The vectors may be introduced into the cells or their precursors using in vivo delivery vehicles such as liposomes or DNA or RNA virus vectors. They may also be introduced into these cells using physical techniques such as microinjection or chemical methods such as coprecipitation. The vector may be introduced into any mammalian cell type, such as CHO cells or human cells.
The pharmaceutical compositions can be prepared by known methods for the preparation of pharmaceutically acceptable compositions which can be administered to patients, and such that an effective quantity of the vector or polypeptide is combined in a mixture with a pharmaceutically acceptable vehicle. Suitable vehicles are described, for example in Remington's Pharmaceutical Sciences (Remington's Pharmaceutical Sciences, Mack Publishing Company, Easton, Pa., USA).
On this basis, the pharmaceutical compositions could include an active compound or substance, such as a polypeptide, in association with one or more pharmaceutically acceptable vehicles or diluents, and contained in buffered solutions with a suitable pH
and isoosmotic with the physiological fluids. The methods of combining the vectors with the vehicles or combining them with diluents is well known to those skilled in the art. The composition could include a targeting agent for the transport of the active compound to specified sites within the mammalian cells.
Method of Medical Treatment of Gaucher Disease Any vectors containing the DNA molecules of the invention may be administered to mammals, preferably humans, in gene therapy using techniques described below.
The polypeptide produced from the modified inserts may also be administered to mammals, preferably humans, in enzyme replacement therapy.
Gene Therapy Gene therapy to replace Gcc expression (Nolta et al. 1992; Tsai et al. 1992;
Sidransky et al. 1993; Schuening et al. 1997; Dunbar et al. 1998) may be useful to modify the development or progression of Gaucher disease. The invention includes methods for providing gene therapy for treatment of diseases, disorders or abnormal physical states characterized by insufficient Gcc expression or inadequate levels or activity of Gcc polypeptide.
The invention includes methods and compositions for providing a nucleotide sequence encoding Gcc or biologically functional equivalent nucleotide sequence to the cells of an individual such that expression of Gcc in the cells provides the biological activity or phenotype of Gcc polypeptide to those cells. Sufficient amounts of the nucleotide sequence are administered and expressed at sufficient levels to provide the biological activity or phenotype of Gcc polypeptide to the cells. For example, the method can involve a method of delivering a gene encoding Gcc to the cells of an individual having a disease, disorder or abnormal physical state, comprising administering to the individual a vector comprising DNA encoding Gcc wherein the DNA has modified sites to prevent undesirable splicing. The method may also relate to a method for providing an individual having a disease, disorder or abnormal physical state with biologically active Gcc polypeptide by administering DNA encoding Gcc. The method may be performed ex vivo or in vivo. Gene therapy methods and compositions are demonstrated, for example, in U.S. Patent Nos. 5,672,344, 5,645,829, 5,741,486, 5,656,465, 5,547,932, 5,529,774, 5,436,146, 5,399,346 and 5,670,488, 5,240,846.
The method also relates to a method for producing a stock of recombinant virus by producing virus suitable for gene therapy comprising modified DNA encoding Gcc. This method preferably involves transfecting cells permissive for virus replication (the virus containing modified Gcc) and collecting the virus produced.
Typically, a male or female is treated with the vector containing the invention (subject age will typically range from 1 to 60 years of age). At the time of treatment, he typically will have bone involvement, bone thinning and bone pain and will have an enlarged spleen and liver. The vector containing the invention is administered intravenously in order to achieve a desired level of enzyme in the patient. Treatments are repeated as deemed appropriate by a physician to ameliorate the clinical symptoms of Gaucher disease. Such treatments may be life-long.
Patients report significant improvement in bone involvement, pain and thinning, with reduction in frequency andlor intensity of pain episodes, or complete disappearance of skeletal pain often within the first six months of treatment. Patients also show improvement in cortical bone thickness. Enlargement of the spleen and liver are reduced. One of the disease markers, the enzyme chitotriosidase, shows a dramatic reduction during the course of a year.
Administration of Gcc Polypeptide The Gcc polypeptide is administered in pharmaceutical compositions in enzyme replacement therapy, examples of which are described above (Beutler et al.
1991; Barton et al.
1992; Fallet et al. 1992; Brady et al. 1994; Grabowski et al. 1995; Rosenthal et al. 1995)_ Typically, a male or female is treated with the polypeptide of the invention (subject age will typically range from 1 to 60 years of age). At the time of treatment, he typically will have bone involvement, bone thinning and bone pain and may have an enlarged spleen and liver.
The polypeptide of the invention is administered intravenously at about 30UIkg every 2 weeks in order to achieve a desired level of enzyme in the patient.
Patients report significant improvement in bone involvement, pain and thinning, with reduction in frequency and/or intensity of pain episodes, or complete disappearance of skeletal pain often within the first six months of treatment. Patients also show improvement in cortical bone thickness. Enlargement of the spleen and liver are reduced. One of the disease markers, the enzyme chitotriosidase, shows a dramatic reduction during the course of a year.
Research Tool Mammals and cell cultures transfected or transduced with vectors containing the invention are useful as research tools. Mammals and cell cultures are used in research according to numerous techniques known in the art. For example, one may obtain cells or mice (Tybulewicz et al. 1992) that express low levels of the normal or mutant Gcc polypeptide and use them in experiments to assess expression of a recombinant Gcc nucleotide sequence. In an example of such a procedure, experimental groups of mice are transformed with vectors containing recombinant Gcc genes to assess the levels of polypeptide produced, its functionality and the phenotype of the cells or mice (for example, physical characteristics of the cell structure). Some of the changes described above to optimize expression may be omitted if a lower level of expression is desired. It would be obvious to one skilled in the art that changes could be made to alter the levels of polypeptide expression.
In another example, a cell line (either an immortalized cell culture or a stem cell culture) is transformed with a DNA molecule of the invention (or variants) to measure levels of expression of the DNA molecule and the activity of the DNA molecule. For example, one may obtain mouse or human cell lines or cultures bearing the vector of the invention and obtain expression after the transfer of the cells into immunocompromised mice.
Using exogenous agents in combination with the hybrid gene Cells transfected or transduced with a DNA molecule or polypeptide according to the invention may, in appropriate circumstances, be treated with conventional medical treatment of Gaucher disease, such as enzyme replacement therapy. The appropriate combination of treatments would be apparent to a skilled physician.
Material and Methods Reag-ents:
All reagents used during the course of these experiments were of research grade or molecular biology grades, as appropriate. Substrate for the acid f3-glucosidase (Gcc) activity, 4-methylumbelliferyl-f3-D-glucopyranoside (MUGc), was purchased from Sigma and purified additionally as described below. Oligonucleotide primers were obtained, as a lyophilized powder, from the Hospital for Sick Children Biotechnology Service Centre's DNA
Synthesis Service. Tissue culture media (alpha-MEM) was obtained from the University of Toronto Media Preparation Service. Fetal bovine serum were obtained from CanSera through the Hospital for Sick Children Tissue Culture Service.
Lac Z, Neutral f3-Galactosidase Assay Samples of cell lysates were diluted into water to a final volume of 60 NL.
Substrate solution (190NL), prepared by dissolving 19mg of 4-MU- f3-gal (4-methylumbelliferyl- f3-galactoside) in 100 ml of pH 7.0 0.1 M citrate buffer, was added. The mixture was incubated at 37°C for 30 minutes and then stopped by the addition of 2.Oml of 0.1 M
MAP. Fluorescence of standard quantities of free 4-MU in 0.1 MAP (2-methyl-2-amino-1-propanol) and the assay mixtures were determined on a fluorescence spectrophotometer using 365nm excitation and 450nm emission wavelengths. Polypeptide concentration of the cell lysates were determined by the Bio-Rad method. Specific activity of the lysates were determined as nmole MUI mg polypeptide.
Acid f3-Glucosidase (Gcc) Activity (Specific or Total):
Samples were prepared by freeze-thaw lysis (5x) in PBS containing 0.1 % sodium taurocholate (NaTC), usually 100NL for a P100 dish of confluent CHO cells. A
sample of the lysate (5-20NL) was diluted with 0.25% BSA to a total volume of 100NL.
Reagents were added in the following order: citratelphosphate buffer (1 M/ 2M, pH 4.5), 25NL; 2%
NaTC in ddH20, 25NL; and 20mM of the MUGc substratesolution, 100NL. The reaction was typically allowed to proceed for 1 hour at 37°C and then stopped by the addition of 3.Oml of 0.1 M MAP, pH 10.5.
Fluorescence of the released 4-MU was measured with the use of on a Perkin Elmer LS 30 Luminescence Spectrometer with sipper attachment. Polypeptide content was determined using the BioRad Protein Assay reagent.
Substrate solution (20mM) was prepared by dissolving MUGc in ddH20 and heating to 40-50°C for 15-20 minutes with occasional agitation. The solution was cooled and then extracted 3X with an equal volume of ethyl acetate. The final aqueous solution was bubbled with N2 gas (to remove residual ethyl acetate) and aliquoted into tubes which were then frozen and stored at -20°C until needed. The substrate solution was thawed for use in a beaker of warm water, then vortexed vigorously to ensure complete dissolution of any solid material.
5 Immunoorecipitation Assay For each immunoprecipitation assay, 125NL of Goat anti-rabbit IgG coated magnetic beads (hereafter called "beads") were isolated from suspension using a permanent magnet stand (Advanced Magnetics). Beads were washed 3 times with phosphate-buffered saline containing 0.05% bovine serum albumin (PBSIBSA) by resuspension, and removal from 10 suspension using a magnetic stand, followed by removal of the supernatant.
After the final wash the beads were resuspended in 100NL of PBSIBSA and an appropriate amount of the rabbit anti-Gcc IgG (#5470), usually 4Ng per assay, was added. The mixture was placed in an appropriately sized tube, depending on volume, and allowed to incubate with rotation for 4 hours at 4°C. The bead-antibody complex was precipitated with the permanent magnet stand and 15 washed 3 times with PBSIBSA to remove any remaining free antibody and finally resuspended in 100NL of PBSIBSA. Cell lysates were prepared as above and diluted into a minimum of 400NL (to allow for adequate mixing). The washed antibody-bead complex (100NL) was added to the diluted sample and allowed to incubate overnight at 4°C with rotation. The samples were placed on ice in the permanent magnet stand and allowed to precipitate for ~30 minutes. The beads in each sample were washed (750NL) with PBSIBSA containing 0.1 % Triton X-100, then twice with PBSIBSA containing 0.2% NaTC. After the final wash, the beads were resuspended in PBSIBSAlTriton and assayed for Gcc activity (as described above).
Expression of Gcc in Transiently Transfected CHO Cells CHO cells were co-transfected with either 8Ng of pINEX-5'-GCC-3' or pINEX-WEIRD
and 2Ng pCMV-Lac Z (encoding E. coli f3-galactosidase as a control for transfection efficiency) using Superfect Reagent (QIAGEN GmBH, Germany), according to the manufacturer's protocol.
Cells were harvested after 2 days and the lysates analyzed for Gcc (using the immunoprecipitation assay) and f3-galactosidase activity. Final Gcc levels were adjusted based on the relative levels of f3-galactosidase activity in each lysate sample.
Cloned CHO Cells Permanently-Transfected with pINEX-5'-GCC-3':
CHO cells were co-transfected with 8Ng of pINEX-5'-GCC-3' and 2Ng pREP10 (containing a hygromycin resistence gene). Selective medium, containing 200Ng/mL
hygromycin was added, and the cells were allowed to grow for approximately two weeks, splitting as necessary. After two weeks the cells were harvested by trysinization, counted using a hemocytometer and diluted as necessary to isolate single cells using 96-well dishes. After 10 days, clones that were growing well were transferred into 100mm dishes and allowed to grow for a further 10 days, splitting as necessary. Cells from each clone were harvested and assayed for Gcc activity. The final clone selected, termed A7, had the highest Gcc activity of all the clones examined.
RNA Isolation and Reverse Transcription and PCR !RT-PCR):
Cells were grown in large dishes (P150), and RNA was isolated from control CHO
cells and the A7 clone, according to the one-step guanidinium isothiocyanate procedure(Chomczynski and Sacchi 1987). RNA (1 Ng), primer (SPR2 (see Table 1 ), 200pmol), RNase inhibitor, and ddH20 (to 12.5NL total), were mixed and incubated at 65°C for 20 minutes.
After cooling on ice for 5 minutes, the remaining components of the RT
reaction cocktail Were added (RT buffer, DTT, dNTPs, RNase inhibitor, and reverse transcriptase). The reaction cocktail (total 25NL) was incubated at 37°C for 90 min.
PCR was performed using the RT reaction products (1 NL) as template. After addition of ddHzO, and primers (SPF and 53GCC2000R (see Table 1 ), 20pmol each), the reaction was incubated at 95°C for 5 minutes to inactivate the reverse transcriptase. The remaining reaction components (dNTPs, MgCl2, and Taq polymerase (Gibco BRL)) were used at manufacturers suggested levels. Thermocycling was performed under the following conditions:
94°Cl3min; 30 cycles of 94°I1.5min, 55°I1 min, 72°I1.5min;
72°I10min. Samples of the PCR reaction (10NL) were loaded onto a 1.5% agarose gel using Tris-Acetate-EDTA buffer (TAE, 40mM
Tris-acetate / 2mM EDTA), electrophoresed and visualized using ethidium bromide.
Cloning of RT-PCR Products:
Electrophoresis of the RT-PCR products from the A7 clone cell line showed two major bands. One full RT-PCR reaction mixture (100NL) was separated eletrophoretically on an agarose gel, and the two major product bands were excised and purified using the Qiaex II Gel Extraction Kit (QIAGEN GmBH, Germany). The fragments were cloned into the TA
cloning vector (pCR2.1 ) according to the manufacturer's directions (Invitrogen, Carlsbad, CA). The inserts were sequenced using either 35S-T7 Sequencing Kit or 33P-cycle Sequencing Kit (Amersham Pharmacia Biotech, Sweden) from either the M13 forward or M13 reverse primer location on the vector. Sequencing gels were exposed to BioMaxMR film (Kodak) overnight and subsequently read.
Site-Directed Mutagenesis (Internal "Weird" Spice Fix):
The cryptic splice site located within the Gcc cDNA was modified by site-directed mutagenesis in order to remove potential consensus splice junction sites from the Gcc cDNA. A
PCR product was obtained using one oligonucleotide primer which mutagenized a number of bases in the putative 3' junction site (3' junction (see Table 1 )) and another for the putative 5'-splice junction site (5' junction (see Table 1 )). The PCR reaction contained:
1 X Pfu reaction buffer (10X stock provided by manufacturer), 0.4mM dNTP, 10ng template DNA
(pINEX-5'-GCC-3'), 500ng of each oligo, and 2.5U Pfu DNA Polymerise in a final volume of 50NL in the appropriate buffer.
Amplification was performed using a Robocycler 40 Temperature Cycler (Stratagene) for 30 cycles, with temperatures and times as follows: 94°C/45 sec., 59°C I 1 min. and 72°C I 1 min. 20 sec. The PCR product was used as a mega-primer in the second round of PCR. The second PCR reaction consisted of: 5NL of the above PCR reaction mixture, 1 X
Pfu reaction buffer (10X stock provided by manufacturer), 0.4mM dNTPs, 50 ng template (pINEX-5'-GCC-3'), 500ng upstream oligo (SPF) and 5U Pfu DNA polymerise in a final reaction volume of 100NL.
Reaction temperature conditions used were the same as for the initial PCR
above. The PCR
products were digested with 10U of Dra III and Xho I for 3 hr at 37°C.
The plasmid pINEX-5'-GCC-3' was digested in parallel using the same method. Digested products were electrophoretically separated on an agarose gel, and the appropriate pieces were excised and purified as described above. Ligation was performed in a 20NL final volume using 5U of T4 DNA Ligase (MBI Fermentas, Lithuania), incubating overnight at 16°C to produce pINEX-WEIRD. DNA was transformed into DH5 E. coli cells (Gibco BRL) and plated onto appropriate LB agar plates containing antibiotics. Plasmid DNA was isolated and screened by restriction digest and sequencing to confirm that they contained the appropriate insert.
The present invention has been described in detail and with particular reference to the preferred embodiments; however, it will be understood by one having ordinary skill in the art that changes can be made thereto without departing from the spirit and scope of the invention.
All publications, patents and patent applications are incorporated by reference in their entirety to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated by reference in its entirety.
REFERENCES
Barton NW, Brady RO, Dambrosia JM, Doppelt SH, Hill SC, Holder CA, Mankin HJ, et al (1992) Dose-dependent responses to macrophage-targeted glucocerebrosidase in a child with Gaucher disease. J Pediatr 1:277-280 Beutler E, Kay AC, Saven A, Garver P, Thurston DW, Rosenbloom BE (1991) Enzyme-replacement therapy for Gaucher's disease. N Engl J Med 325:1809-1810 Brady RO, Murray GJ, Barton NW (1994) Modifying exogenous glucocerebrosidase for effective replacement therapy in Gaucher disease. J Inherited Metab Dis 17:510-519 Chomczynski P, Sacchi N (1987) Single-step method of RNA isolation by acid guanidinium thiocyanate-phenol-chloroform extraction. Anal. Biochem. 162:156-9 Dunbar CE, Kohn DB, Schiffmann R, Barton NW, Nolta JA, Esplin JA, Pensiero M, et al (1998) Retroviral transfer of the glucocerebrosidase gene into CD34+ cells from patients with Gaucher disease: In vivo detection of transduced cells without myeloablation. Hum Gene Ther 9:2629-Fallet S, Grace ME, Sibille A, Mendelson DS, Shapiro RS, Hermann G, Grabowski GA (1992) Enzyme augmentation in moderate to life-threatening Gaucher disease. Pediatr Res 31:496-502 Grabowski GA, Barton NW, Pastores G, Dambrosia JM, Banerjee TK, McKee MA, Parker C, et al (1995) Enzyme therapy in type 1 Gaucher disease: Comparative efficacy of mannose-terminated glucocerebrosidase from natural and recombinant sources. Ann.
Intern. Med.
122:33-39 Kozak M (1987) At least six nucleotides preceding the AUG initiator codon enhance translation in mammalian cells. J. Mol. Biol. 196:947-950 Krawczak M, Reiss J, Cooper DN (1992) The mutational spectrum of single base-pair substitutions in mRNA splice junctions of human genes: causes and consequences. Hum.
Genet. 90:41-54 Maquat LE (1996) Defects in RNA splicing and the consequence of shortened translational reading frames. Am. J. Hum. Genet. 59:279-286 Nolta JA, Yu XJ, Bahner I, Kohn DB (1992) Retroviral-mediated transfer of the human glucocerebrosidase gene into cultured Gaucher bone marrow. J Clin Invest 90:342-348 Rosenthal DI, Doppelt SH, Mankin HJ, Dambrosia JM, Xavier RJ, McKusick KA, Rosen BR, et al (1995) Enzyme replacement therapy for Gaucher disease: Skeletal responses to macrophage-targeted glucocerebrosidase. Pediatrics 96:629-637 Schuening F, Longo WL, Atkinson ME, Zaboikin M (1997) Retrovirus-mediated transfer of the 5 cDNA for human glucocerebrosidase into peripheral blood repopulating cells of patients with Gaucher's disease. Hum Gene Ther 8:2143-2160 Sidransky E, Martin B, Ginns EI (1993) Treatment of Gaucher's disease. N Engl J Med 328:1566-1566 Tsai P, Lipton JM, Sahdev I, Najfeld V, Rankin LR, Slyper AH, Ludman M, et al (1992) Allogenic 10 bone marrow transplantation in severe Gaucher disease. Pediatr Res 31:503-Tybulewicz V, Tremblay ML, LaMarca ME, Willemsen R, Stubblefield BK, Winfield S, Zablocka B, et al (1992) Animal model of Gaucher's disease from targeted disruption of the mouse glucocerebrosidase gene. Nature 357:407-410 TABLE 1: Sequence of Oligos Used in this Study:
Oligo Name Oligo Sequence* (5' to 3') SPF GACCGATCCAGCCTCCGGACTCT
3-junction CATCCGTCGCCCACTGCGTGTACTCTCATAGCGGGAAAATGT
CAGGGCAGG
5'junction CCTTTGAGTAGAGTCTCCATCATGGCTGGC
_ ~sases unaeninea indicate bases changed in site-directed mutagenesis PCR
procedures.
Q
Z
D
t~
ca v d L
L
.
t7 v O
M
in d O
C C~
d X
C
o- ~ o o Z
X
u.
-p ~j Z ao t U
C C N
N ~O (O ~ 00 .ta ~ ~
= Q- e- 0 CO
O
V y U s a E
c o 0 ~ c~o 0 f-a U
O (/~
fIJ 0V G
O
ii ~ ~ ~ Q
c c U U Z 0 r a N
o O ~ M
E
O J
O .~ U
N ~ O
U C M N
J
~ ~ Z N Q.
E- fl.
Claims (22)
1. An isolated Gcc DNA molecule, wherein the DNA molecule has a modification in at least one nucleotide that disrupts a splicing consensus sequence and prevents splicing of mRNA
produced from the DNA molecule, while preserving the ability of the DNA to express active Gcc.
produced from the DNA molecule, while preserving the ability of the DNA to express active Gcc.
2. The DNA molecule of claim 1, wherein the modification impairs a consensus nucleotide sequence needed to induce splicing.
3. The DNA molecule of claim 2, wherein the DNA molecule is modified at two cryptic splice sites.
4. The DNA molecule of claim 1 or 3, comprising a mutation in the 3' junction site.
5. The DNA molecule of claim 4, wherein the mutation is as shown in the 3' junction site in Table 1, or a functionally equivalent mutation.
6. The DNA molecule of claim 1 or 3, comprising a mutation in the 5' splice junction site
7. The DNA molecule of claim 6, wherein the mutation is as shown in the 5' junction site in Table 1, or a functionally equivalent mutation.
8. The DNA molecule of claim 1, comprising all or part of the nucleotide sequence shown in figure 4(b).
9. A vector comprising the DNA molecule of any of claims 1 to 8.
10. The vector of claim 9, comprising a promoter that is functional in a mammalian cell.
11. mRNA produced from the DNA molecule of any of claims 1 to 8 or the vector of claim 9 or claim 10.
12. A method of medical treatment of Gaucher disease in a mammal, comprising administering to the mammal an effective amount of the nucleic acid molecule of any of claims 1 to 8 or the vector of claim 9 or claim 10 and expressing an effective amount of the polypeptide encoded by the nucleic acid molecule for alleviating clinical symptoms of Gaucher disease.
13. A host cell, or progeny thereof, comprising the nucleic acid molecule of any of claims 1 to 8 or the vector of claim 9 or claim 10.
24~
24~
14. The host cell of claim 13, selected from the group consisting of a mammalian cell, a human cell and a Chinese Hamster Ovary cell.
15. A method for producing a recombinant host cell capable of expressing a Gcc nucleic acid molecule, the method comprising introducing into the host cell the vector of claim 9 or 10.
16. A method for expressing a Gcc polypeptide in the host cell of claim 13 or 14 comprising culturing the host cell under conditions suitable for DNA molecule expression.
17. A method for producing a transgenic cell that expresses elevated levels of Gcc polypeptide relative to a non-transgenic cell, comprising transforming a cell with the vector of claim 9 or 10.
18. An isolated polypeptide encoded by and/or produced from the nucleic acid molecule of any of claims 1 to 8, or the vector of claim 9 or 10.
19. A method of producing a genetically transformed cell which expresses or overexpresses a Gcc polypeptide, comprising:
(a) preparing a Gcc nucleic acid molecule according to any of claims 1-18;
(b) inserting the nucleic acid molecule in a vector so that the nucleic acid molecule is operably linked to a promoter;
(c) inserting the vector into a cell.
(a) preparing a Gcc nucleic acid molecule according to any of claims 1-18;
(b) inserting the nucleic acid molecule in a vector so that the nucleic acid molecule is operably linked to a promoter;
(c) inserting the vector into a cell.
20. A transgenic cell produced according to the method of claim 19.
21. A pharmaceutical composition, comprising a carrier and (i) the nucleic acid molecule of any of claims 1 to 8 (ii) the vector of claims 9 or 10 or (iii) Gcc polypeptide produced from (i) or (ii), in an effective amount for reducing clinical symptoms of Gaucher disease.
22. The composition of claim 21, wherein the carrier comprises a liposome.
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CA 2272055 CA2272055A1 (en) | 1999-06-02 | 1999-06-02 | Products and methods for gaucher disease therapy |
US09/586,216 US6696272B1 (en) | 1999-06-02 | 2000-06-02 | Products and methods for gaucher disease therapy |
US10/706,466 US20040082535A1 (en) | 1999-06-02 | 2003-11-12 | Products and methods for gaucher disease therpy |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CA 2272055 CA2272055A1 (en) | 1999-06-02 | 1999-06-02 | Products and methods for gaucher disease therapy |
Publications (1)
Publication Number | Publication Date |
---|---|
CA2272055A1 true CA2272055A1 (en) | 2000-12-02 |
Family
ID=29588998
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CA 2272055 Abandoned CA2272055A1 (en) | 1999-06-02 | 1999-06-02 | Products and methods for gaucher disease therapy |
Country Status (1)
Country | Link |
---|---|
CA (1) | CA2272055A1 (en) |
-
1999
- 1999-06-02 CA CA 2272055 patent/CA2272055A1/en not_active Abandoned
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP2836226B1 (en) | Compositions and methods for the treatment of hemoglobinopathies | |
JP2021502058A (en) | Compositions and methods for editing RNA | |
US5549892A (en) | Enhanced in vivo uptake of glucocerebrosidase | |
US10894077B2 (en) | Synthetic methylmalonyl-CoA mutase transgene for the treatment of MUT class methylmalonic acidemia (MMA) | |
WO2016094880A1 (en) | Delivery, use and therapeutic applications of crispr systems and compositions for genome editing as to hematopoietic stem cells (hscs) | |
JP2002522509A (en) | Lysosomal storage disease therapeutic compositions and methods | |
US6696272B1 (en) | Products and methods for gaucher disease therapy | |
EP0397678A1 (en) | Method for the delivery of genetic material across the blood brain barrier | |
Elliger et al. | Enhanced secretion and uptake of β-glucuronidase improves adeno-associated viral-mediated gene therapy of mucopolysaccharidosis type VII mice | |
US5888820A (en) | Retroviral vector capable of transducing the aldehyde dehydrogenase-1 gene and uses of said vector | |
US9944918B2 (en) | Synthetic methylmalonyl-CoA mutase transgene for the treatment of MUT class methylmalonic acidemia (MMA) | |
Stewart et al. | Optimizing transgene configuration and protein fusions to maximize dopamine production for the gene therapy of Parkinson's disease | |
JP2002501032A (en) | Acute intermittent porphyria (AIP) and other methods of treating porphyria | |
Kauppinen et al. | Congenital erythropoietic porphyria: prolonged high-level expression and correction of the heme biosynthetic defect by retroviral-mediated gene transfer into porphyric and erythroid cells | |
CA2272055A1 (en) | Products and methods for gaucher disease therapy | |
Heinemann et al. | Alternative polyadenylation of apolipoprotein B RNA is a major cause of B-48 protein formation in rat hepatoma cell lines transfected with human apoB-100 minigenes. | |
KR100403893B1 (en) | Recombinant Virus Encoding Glutamate Dicarboxylase (GAD) Activity | |
EP3929294A1 (en) | Pyruvate kinase deficiency (pkd) gene editing treatment method | |
RU2820602C2 (en) | Non-destructive gene therapy for treating mma | |
JP2002508976A (en) | Reduced immunogenic nucleotide expression system for use in gene therapy | |
KR20230125806A (en) | Therapeutic LAMA2 payload for the treatment of congenital muscular dystrophy | |
WO2024123842A1 (en) | Systems and methods for the treatment of hemoglobinopathies | |
JP2001025389A (en) | Tsa7005 gene | |
Baranov et al. | The current state and prospects of the gene therapy of duchenne muscular dystrophy worldwide and in Russia | |
Bellantuono | Gene therapy for chronic granulomatous disease |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
EEER | Examination request | ||
FZDE | Dead |