Classifications

• • 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
  • C12N5/00—Undifferentiated human, animal or plant cells, e.g. cell lines; Tissues; Cultivation or maintenance thereof; Culture media therefor
  • C12N5/06—Animal cells or tissues; Human cells or tissues
  • C12N5/0602—Vertebrate cells
  • C12N5/0634—Cells from the blood or the immune system
  • C12N5/0647—Haematopoietic stem cells; Uncommitted or multipotent progenitors
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
  • A61P19/00—Drugs for skeletal disorders
  • A61P19/08—Drugs for skeletal disorders for bone diseases, e.g. rachitism, Paget's disease
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
  • A61P43/00—Drugs for specific purposes, not provided for in groups A61P1/00-A61P41/00
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
  • A61P5/00—Drugs for disorders of the endocrine system
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
  • A61P7/00—Drugs for disorders of the blood or the extracellular fluid
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
  • A61P7/00—Drugs for disorders of the blood or the extracellular fluid
  • A61P7/06—Antianaemics
• • 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
  • C12N2500/00—Specific components of cell culture medium
  • C12N2500/90—Serum-free medium, which may still contain naturally-sourced components
• • 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
  • C12N2501/00—Active agents used in cell culture processes, e.g. differentation
  • C12N2501/10—Growth factors
  • C12N2501/105—Insulin-like growth factors [IGF]
• • 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
  • C12N2501/00—Active agents used in cell culture processes, e.g. differentation
  • C12N2501/10—Growth factors
  • C12N2501/113—Acidic fibroblast growth factor (aFGF, FGF-1)
• • 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
  • C12N2501/00—Active agents used in cell culture processes, e.g. differentation
  • C12N2501/10—Growth factors
  • C12N2501/125—Stem cell factor [SCF], c-kit ligand [KL]
• • 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
  • C12N2501/00—Active agents used in cell culture processes, e.g. differentation
  • C12N2501/10—Growth factors
  • C12N2501/145—Thrombopoietin [TPO]
• • 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
  • C12N2501/00—Active agents used in cell culture processes, e.g. differentation
  • C12N2501/10—Growth factors
  • C12N2501/17—Angiopoietin
• • 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
  • C12N2501/00—Active agents used in cell culture processes, e.g. differentation
  • C12N2501/90—Polysaccharides
  • C12N2501/91—Heparin

Definitions

• HSC hematopoietic stem cell
• Pluripotent HSCs are thus the basis of bone marrow transplantation and are considered attractive target cells for hematopoietic gene therapy for many clinical conditions.
• these important clinical applications have been severely hampered by the low numbers of HSCs that can be obtained from an animal, as well as difficulties in culturing HSCs in vitro and expanding HSCs for subsequent administration to a patient.
• stem cells such as hematopoietic stem cells
• the unknown factors can be supplied by co-culturing the stem cells with feeder cells which secrete an undefined panel of factors, or can be supplied by adding undefined serum products to the growth medium.
• Such supplemented medium contains many unknown factors and therefore is not chemically defined.
• the presence of unknown factors is problematic when the stem cells are being prepared for in vivo use, especially in humans.
• the unknown factors are from non-human sources (such as bovine serum products).
• the non-human components may cause an immune reaction in the recipient, or the undefined components could include undetected pathogenic agents such as prions or viruses that would be detrimental to the recipient of the stem cells.
• SUMMARY [005] Provided herein is a defined culture medium for expanding human hematopoietic stem cells.
• the defined medium includes certain growth factors that synergize with each other to stimulate expansion of human HSCs.
• a factor produced by non-transfected 293T cells promotes the in vitro expansion of human HSCs. That factor is shown herein to be insulin-like growth factor binding protein 2 (IGFBP-2).
• IGFBP-2 insulin-like growth factor binding protein 2
• the finding that IGFBP-2 promotes the expansion of human hematopoietic stem cells is unexpected in light of the inhibitory effects that exogenous IGFBP-2 has on cell proliferation in different IGF-dependent cell culture systems. (Hoefiich, et al, Cane. Res. 61 :8601-8619 (2001)).
• IGFBP-2 in combination with one or more Angptl proteins promotes the expansion of human HSCs in a defined culture medium.
• human HSCs are expanded in a defined medium by 250 fold or more.
• the method expanding human HSCs comprises incubating human cells in a defined culture medium.
• the defined culture medium can comprise IGFBP- 2 and an angiopoietin-like protein (Angptl).
• the defined culture medium can comprise IGFBP-2, Angptl5, fibroblast growth factor 1 (FGF-I), thrombopoietin (TPO), and stem cell factor (SCF).
• the method comprises incubating human cells for five days in a defined culture medium.
• the human cells are primary human cells.
• the human cells include at least one cell that is capable of differentiating into one or more blood cell types.
• the human cells include at least one hematopoietic stem cell.
• the human cells have been selected for cells that express a surface marker selected from the group consisting of CD 133 and CD34 prior to being incubated.
• Methods of administering hematopoietic stem cells to an individual are also provided.
• the method comprises obtaining cells from the individual or a donor.
• at least one of the cells is capable of differentiating into one or more blood cell types.
• the cells are expanded in vitro as provided herein.
• the cells are incubated in a defined culture medium comprising an IGFBP-2 and a growth factor selected from the group consisting of angiopoietin 2 or an Angptl. The incubated cells are then administered into the individual.
• a defined culture medium comprising an IGFBP-2 and a growth factor selected from the group consisting of angiopoietin 2 or an Angptl.
• the incubated cells are then administered into the individual.
• Hematopoietic stem cells that have been expanded in vitro as described herein are also provided.
• kits for expanding human hematopoietic stem cells in vitro are also provided.
• the kit comprises a defined medium suitable for culturing hematopoietic stem cells, an isolated IGFBP-2, and another growth factor selected from the group consisting of angiopoietin 2 or an Angptl.
• the growth factors can be supplied as separate components, a cocktail, or can be supplied already in combination with HSC growth medium.
• methods for expanding stem cells in culture including hematopoietic stem cells, by culturing a population of cells that contains stem cells in a culture medium which contains an effective amount of an angiopoietin, such as angiopoietin 2, under conditions sufficient for expansion of the cells.
• Isolated hematopoietic stem cells are also provided wherein the isolated hematopoietic cells specifically bind an angiopoietin.
• Culture media and kits for expanding hematopoietic stem cells in vitro are also provided.
• the culture media and kits comprise an angiopoietin, such as angiopoietin 2 and instructions for expanding hematopoietic stem cells in vitro.
• human HSCs can be expanded in a defined medium while maintaining pluripotency.
• the cells can be expanded in vitro for research use, or can be expanded in vitro for subsequent administration to an individual (also referred to herein as ex vivo expansion).
• FIG. IA shows total cell number versus days in culture of total human cord blood cells in the presence of Angptl5 (squares) or Angptl3 (diamonds).
• FIG. IB shows the amount of human chimerism in the bone marrow of NOD/SCED mice transplanted with 1 x 10 6 uncultured human mononuclear cord blood cells (col. 1), or the progeny of 1 x 10 6 initial human cord blood cells cultured in serum free STIF plus Angptl5 (col. 2) or AngptB (col. 3).
• (* Significantly different from lane 1 value. Student's t-test, p ⁇ 0.001.)
• FIG. 2A is a bar graph showing percent repopulation using murine HSCs after culturing in serum-free IMDM supplemented with 10 ng/ml SCF, 20 ng/ml TPO, 20 ng/ml IGF-2, and 10 ng/ml FGF-I, bar 1; freshly collected conditioned medium from 293T cells, bar 2; or in the same conditioned medium after freeze/thaw, bar 3.
• FIG. 2B top panel shows a representative FACS analysis of the repopulation of myeloid and lymphoid lineages in mice that received cultured cells from conditions represented by bar 2 of FIG. 2A, at 5 months post-transplant and a bar graph; the bottom panel shows a summary of the percent repopulation data from six mice that received cultured cells from conditions represented by bar 2 of FIG. 2 A for T-lymphoid (bar 1), B-lymphoid (bar 2), and myeloid (bar 3) cells.
• FIG. 3 shows a Western blot of IGFBP-2 (lane 1), serum-free 3T3 conditioned medium (lane 2), and serum-free 293T conditioned medium (lane 3) separated on an SDS PAGE gel and probed with anti-IGFBP-2 antibody.
• FIG. 4A shows percent repopulation 1 month (left panel) and 4 months (right panel) after engraftment of mice with murine HSCs after culturing in STIF medium plus Angptl3 (col. 1 and 4), STIF medium plus Angptl3 and IGFBP-2 (col. 2 and 5), STIF medium plus AngptB and Timp-1 (col. 3 and 6).
• FIG. 4B shows percent repopulation 1 month (left panel) and 4 months (right panel) after engraftment of mice with murine HSCs after culturing in STF medium plus AngptB (col. 1 and 4), STF medium plus IGFBP-2 (col. 2 and 5), STF medium plus AngptB and IGFBP-2 (col. 3 and 6).
• FIG. 4C shows limiting dilution analysis of the repopulating ability of adult BM SP CD45 + Sca-1 + cells before culture (left) and after culture for 21 days in conditioned STF medium containing 100 ng/ml of purified AngptB and 500 ng/ml IGFBP-2 (right).
• FIG. 5 A shows cell number over time in days of human HSCs cultured in STF medium containing Angptl 5 (squares), or cultured in STF medium (diamonds).
• FIG. 5B shows % repopulation by 8000 fresh cells (col. 1), 15000 fresh cells (col. 2), 8000 cells cultured in STF medium (col. 3), or 8000 cells cultured in STF medium containing Angptl5 and IGFBP-2 (col. 4).
• FIG. 5C shows FACS analysis of human hematopoietic engraftment at 2 months in a representative mouse that was transplanted with uncultured (fresh) or cultured human cord blood CD 133 + cells.
• FIG. 5D shows the summary of multilineage engraftment data from mice transplanted with uncultured cells (left panel) and cells cultured in STF medium containing Angptl5 and IGFBP-2 (right panel) showing % repopulation with myeloid (CD15/66b+, cols. 1, 4), B-lymphoid (CD34-CD19/20 + , cols. 2, 5), and primitive (CD34 + , cols. 3, 6) human cells.
• FIG. 5E shows % repopulation of secondary recipients with total hematopoietic (CD45/71 + , col. 1), myeloid (CD15/66b + , col. 2), B-lymphoid (CD34-CD19/20 + , col. 3), and primitive (CD34 + , col. 5) human cells, transplanted with bone marrow from the primary mice transplanted with cultured in STF medium containing Angptl5 and IGFBP-2 (lane 4 of Fig. 5B) and transplanted into sublethally irradiated secondary recipients.
• FIG. 6A shows total cell number over time of 2 x 10 5 human cord blood CD133 + cells in STF medium containing Angptl5 and IGFBP-2 cultured in low levels of O 2 (diamonds) and normal levels of O 2 (squares).
• FIG. 6B shows the number of CD34 + primitive cells over time for human HSCs cultured in STF medium containing Angptl5 and IGFBP-2 cultured in low levels of O 2 (diamonds) and normal levels of O 2 (squares).
• FIG. 6C shows limiting dilution analysis of the repopulating ability of cells before culture.
• FIG. 6D shows limiting dilution analysis of the repopulating ability of cells after culture for 10 days in STF medium containing 500 ng/ml of Angptl5 and 100 ng/ml IGFBP-2 in low levels of O 2 (squares) and normal levels of O 2 (diamonds).
• FIG. 8 shows SEQ ID NOs. 3-6, amino acid sequences for exemplary angiopoietin-like proteins.
• FIG. 9 shows SEQ ID NO. 1, the amino acid sequence for an exemplary angiopoietin 2 protein and SEQ ID NO. 2, the amino acid sequence for an exemplary IGFBP- 2 protein.
• HSCs hematopoietic stem cells
• human HSCs are expanded in a defined medium.
• ex vivo expanded human HSCs are available that are free from unknown factors or contaminants typically present in cultured cells.
• suitable cells are incubated in a defined (also referred to herein as chemically defined) medium.
• defined or chemically defined medium refers to a nutritive medium for culturing cells where every component and quantity thereof present in the medium is known.
• the medium is a liquid.
• the medium can be a solid such as a tablet or a powder or semisolid material such as a gel.
• the medium can be a liquid that includes a solid structure such as a mesh, porous bead(s), and the like.
• the defined medium can comprise a base mixture of components, such as Dulbecco's MEM, IMDM, X- Vivo 15 (Cambrex), RPMI- 1640 and StemSpan (Stem Cell Technologies).
• the base mixture can be supplemented with known quantities of other components such as heparin, serum albumin, insulin, transferrin, and the like, or combinations thereof.
• the medium is supplemented with 10 ⁇ g/ml heparin.
• the added components can be derived, for example, from any suitable animal source, including, human, bovine, and murine sources.
• StemSpan comprises IMDM supplemented with bovine serum albumin, human insulin, and human transferrin.
• the added components and growth factors can be isolated from a biological source (such as tissue, serum, or conditioned medium) or can be recombinantly produced.
• Suitable hosts for producing recombinant growth factors or other components include, for example, bacteria, yeast, or cell culture.
• the cell culture can be, for example, insect cell culture, or mammalian cell culture.
• the growth factor can be glycosylated. In some embodiments, the growth factor is glycosylated in the same or substantially the same manner as the naturally occurring growth factor.
• the growth factors or other added components described herein can be from any suitable animal, including, for example, mouse, non-human primate, and human.
• an "isolated” or “purified” component or growth factor is substantially free of other materials with which it is associated with when produced (e.g., as produced by the biological source or by recombinant methods such as expression in transfected cells).
• isolated means less than 0.1%, less than 0.01%, or less than 0.001% of the other materials with which the component or growth factor is associated with when produced is present.
• the defined medium is serum free.
• the defined medium includes isolated insulin-like growth factor binding protein 2 (IGFBP-2).
• IGFBPs IGF Binding Proteins
• IGFBP-2 is a family of circulating proteins that bind IGF-I and IGF-2 with an affinity equal or greater than that of the IGF receptors.
• IGFBP-2 is also known to have inhibitory effects on cell proliferation in different IGF-dependent cell culture systems. (Hoeflich, et al, Cane. Res. 61 :8601-8619 (2001)). Surprisingly, as demonstrated herein, IGFBP-2 has a positive effect on the in vitro expansion of human HSCs.
• IGFBP-2 protein sequence is provided, for example, in GenBank as Accession Number AAA36048 (human insulin-like growth factor binding protein 2; SEQ ID NO: 2, FIG. 9).
• suitable IGFBP-2 includes those proteins and/or polypeptides that have changes in the naturally occurring amino acid sequence wherein the altered sequence retains at least some functional ability of native IGFBP-2. Suitable alterations include changes to or elimination of non-essential amino acid residues as well as conservative amino acid changes ⁇ e.g., replacing an amino acid residue with an amino acid residue having a similar side chain).
• Suitable IGFBP-2 shares at least 60% sequence identity with SEQ ID NO. 9. In other embodiments, suitable IGFBP-2 shares at least 70% or at least 80% or at least 90%, or at least 95%, or at least 96, 97, 98, or 99% sequence identity with SEQ ID NO. 9 or a biologically active portion thereof.
• Suitable analogs of IGFBP-2 include fragments retaining the desired activity and related molecules. Molecules capable of binding the corresponding receptor of IGFBP-2 and initiating one or more biological actions associated with binding to the IGFBP-2 receptor are also within the scope of the technology (e.g., methods, HCSs, media, and kits) provided herein. ⁇ ngiopoietin-like proteins
• the one or more angiopoietin-like protein can be any member of a family of secreted glycosylated proteins that are similar in structure to angiopoietins (Oike et al., Int. J. Hematol. 80:21-8 (2004)).
• Angptl proteins contain an N-terminal coiled-coil domain and a C-terminal fibrinogen-like domain. Unlike angiopoietins, Angptl proteins do not bind to the tyrosine kinase receptor Tie2.
• Angptl proteins include Angptl 1, 2, 3, 4, 5, 6, and 7.
• Angptl proteins also include microf ⁇ brillar-associated glycoprotein 4 (Mfap4), and analogs and equivalents thereof.
• Mfap4 microf ⁇ brillar-associated glycoprotein 4
• Angptl2 has been described by Kim, I. et al. J Biol Chem 274, 26523-8 (1999)).
• Angptl proteins are available commercially (R&D Systems, Abnova Corp).
• the Angptl is Angptl 3.
• the Angptl is Angptl 5.
• Exemplary Angptl proteins are provided, for example in GenBank as Accession Number AAH12368 (human Angptl 1 : SEQ ID NO 3; human Angptl2 precursor; SEQ ID NO: 4) Accession Number AAH58287 (human Angptl3 precursor; SEQ ID NO: 5) Accession Number AAH23647 (human Angptl4; SEQ ID NO: 6) and Accession Number AAH49170 (human Angptl5; SEQ ID NO: 7). SEQ ID NOs: 3 through 7 are shown in FIG. 8. Other suitable Angptl proteins share at least 60% sequence identity with any one of SEQ ID NOs: 3 to 7.
• suitable Angptl proteins share at least 70% or at least 80% or at least 90%, or at least 95%, or at least 96, 97, 98, or 99% sequence identity with an exemplary Angptl sequence such as SEQ ID NOs: 3, 4, 5, 6, or 7, or biologically active portions thereof.
• An exemplary sequence for Angptl7 is found in GenBank Accession No. AAHOl 881.
• An exemplary sequence for Mfap4 is found in GenBank Accession No. NP_002395.
• suitable Angptls include those proteins and/or polypeptides that have changes in the naturally occurring amino acid sequence wherein the altered sequence retains at least some functional ability of the native Angptl. Suitable alterations include changes to or elimination of non-essential amino acid residues as well as conservative amino acid changes ⁇ e.g., replacing an amino acid residue with an amino acid residue having a similar side chain).
• Suitable analogs of Angptls include fragments retaining the desired activity and related molecules.
• a suitable analog of an Angptl is a fragment of the angiopoietin-like protein containing the coiled coil domain.
• the coiled coil domain of an angiopoietin-like protein is another analog.
• Fragments of Angptls such as the coiled-coil domain and the fibrinogen-like domain may be easier to express and to purify compared to full-length protein.
• Molecules capable of binding the corresponding receptor of the Angptl and initiating one or more biological actions associated with binding to the Angptl receptor are also within the scope of the technology provided herein.
• the defined medium includes angiopoietin 2.
• An exemplary angiopoietin 2 protein sequence is provided, for example, in GenBank as Accession Number NPJ)Ol 138 (human angiopoietin 2; SEQ ID NO: 1, FIG. 9).
• suitable angiopoietin 2 includes proteins and/or polypeptides that have changes in the naturally occurring amino acid sequence wherein the altered sequence retains at lease some functional ability of native angiopoietin 2. Suitable alterations include changes to or elimination of non-essential amino acid residues as well as conservative amino acid changes ⁇ e.g., replacing an amino acid residue with an amino acid residue having a similar side chain).
• Suitable angiopoietin 2 shares at least 60% sequence identity with SEQ ID NO. 1. In other embodiments, suitable angiopoietin 2 shares at least 70% or at least 80% or at least 90%, or at least 95%, or at least 96, 97, 98, or 99% sequence identity with SEQ ID NO. 1 or a biologically active portion thereof.
• Suitable analogs of angiopoietin 2 include fragments retaining the desired activity and related molecules. Molecules capable of binding the corresponding receptor of angiopoietin 2 and initiating one or more biological actions associated with binding to the angiopoietin 2 receptor are also within the scope of the technology provided herein. Other growth factors
• the media includes at least two of FGF, IGF, TPO and SCF or analogs and equivalents thereof. Equivalents thereof include molecules having similar biological activity to these factors (i.e. FGF, TPO, IGF and SCF) as wild-type or recombinantly produced cytokines.
• Analogs include fragments retaining the desired activity and related molecules.
• TPO is a ligand of the mpl receptor, thus molecules capable of binding the mpl receptor and initiating one or more biological actions associated with TPO binding to mpl are also within the scope of the technology.
• An example of a TPO mimetic is found in Cwirla et. al, Science 276:1696 (1997).
• Cytokines and growth factors are commercially available from several vendors such as, for example, Amgen (Thousand Oaks, Calif), R & D Systems (Minneapolis, MN) and Immunex (Seattle, Wash.).
• the concentrations of cytokines or growth factors range from about 0.1 ng/mL to about 1.0 ⁇ g/mL. In another embodiment, from about 1 ng/mL to about 500 ng/mL of the factor is used. In another embodiment, from about 10 ng/ml to 100 ng/ml of the factor is used. Other useful concentrations of the growth factors can be readily determined by one of ordinary skill in the art using the teachings contained herein.
• FGF-I, TPO, and SCF are also included in the medium. In another embodiment the SCF is present at 10 ng/ml, TPO at 20 ng/ml, and FGF-I at 10 ng/ml.
• IGF-2, FGF-I, TPO, and SCF are also included in the medium.
• Other useful concentrations of the growth factors or cytokines can be readily determined by one of ordinary skill in the art using the teachings contained herein.
• identity or homology to a given amino acid sequence can be determined as the percentage of identity between two sequences. The homology can be determined using methods known in the art, such as by means of computer programs such as GAP provided in the GCG program package (Program Manual for the Wisconsin Package, Version 8, August 1994, Genetics Computer Group, 575 Science Drive, Madison, Wis., USA 53711) (Needleman, S. B. and Wunsch, C. D., (1970), Journal of Molecular Biology, 48, p. 443-453).
• the cell or cells to be cultured can include any cell that is capable of differentiating into one or more blood cell types.
• Exemplary blood cell types include phagocytic immune cells ⁇ e.g., granulocytes), monocytes ⁇ e.g., macrophage precursor cells), macrophages, eosiniphils, erythrocytes, platelet forming cells ⁇ e.g., megakaryocytes), T lymphocytes, B lymphocytes, and natural killer (NK) cells.
• Suitable cells include primary cells obtained from an individual or donor. Suitable cells can also be capable of self renewal, that is, capable of propagating or increasing in number and remaining at the same developmental stage as the parent cell.
• Suitable cells can be isolated, for example, from any known source of hematopoietic stem cells, including, but not limited to, bone marrow, peripheral blood, mobilized peripheral blood (MPB), fetal liver, and umbilical cord blood.
• Umbilical cord blood is discussed, for example, in Issaragrishi et al., N. Engl. J. Med. 332:367-369 (1995).
• Bone marrow cells can be obtained from a source of bone marrow, including but not limited to, ilium (e.g., from the hip bone via the iliac crest), tibia, femora, vertebrate, or other bone cavities.
• Other sources of stem cells include, but are not limited to, ES cells, embryonic yolk sac, fetal liver, and fetal spleen. Methods for obtaining cells from an individual or donor are well known in the art.
• an appropriate solution can be used to flush the bone, including, but not limited to, salt solution, optionally supplemented with fetal calf serum (FCS) or other naturally occurring factors, in conjunction with an acceptable buffer.
• the buffer is at low concentration, generally from about 5 to about 25 mM.
• Convenient buffers include, but are not limited to, HEPES, phosphate buffers and lactate buffers. Bone marrow can also be aspirated from the bone in accordance with conventional techniques.
• Suitable cells and the hematopoietic cells of the technology can be derived from any animal, where hematopoietic stem cells are present.
• Suitable animals include human, non-human primate, cow, horse, dog, cat, mouse and the like, hi an embodiment, the cells are human cells, in still another embodiment, the cells are murine cells.
• Animal models for long-term engrafting potential of candidate human hematopoietic stem cell populations include the non-obese diabetic/severe combined immunodeficiency mouse (NOD/SCID) model, the SCID-hu bone model (Kyoizumi et al. (1992) Blood 79:1704; Murray et al. (1995) Blood 85(2) 368-378) and the in utero sheep model (Zanjani et al. (1992) J. Clin. Invest. 89:1179).
• NOD/SCID non-obese diabetic/severe combined immunodeficiency mouse
• LTCIC long-term culture-initiating cell
• Expansion includes, for example, an increase in the number of hematopoietic stem cells over the number of HSCs present in the cell population used to initiate the culture.
• the methods provided herein provide for the increased survival of existing cells, such as hematopoietic stem cells.
• survival refers to the ability to continue to remain alive or function.
• the methods provided herein can be used to stimulate the expansion of any stem cells which expand in the presence of angiopoietin 2, and/or an angiopoietin-like protein and/or IGFBPs, including other types of adult stem cells such as endothelial progenitor cells (Shi, Q. et al. (1998), Blood.
• the stem cells are endothelial progenitor cells, which are believed to share the same precursor - hemangioblasts -as HSCs.
• Subpopulations of cells can also be used in the methods provided herein. For example, a purified "side population" (SP) cells obtained from bone marrow or other sources can be used. Other enriched populations of HSCs can also be used. Methods for isolating enriched populations of HSCs are known to those in the art, e.g. methods for obtaining SP cells are described in Goodell et al., J. Exp. Med. 183, 1797-806 (Apr. 1, 1996).
• a subpopulation of cells enriched for stem cells can be used in the methods described herein. Separation of stem cells from a cell population can be performed by any number of methods, including cell sorting, ⁇ e.g., fluorescence activated cell sorting) magnetic beads, and packed columns.
• the methods typically rely on the presence of certain cell surface markers characteristic of stem cells and/or the absence of certain cell surface markers characteristic of differentiated cells.
• the methods can also rely on functional assays to measure the engraftment or differentiation potential of the population of cells. Such markers and functional assays are known in the art.
• An example of a enriched for stem cells is a population of cells selected for the CD34 + Thyl + LIN " phenotype as described in U.S. Pat. No. 5,061,620.
• a population of this phenotype typically has an average CAFC frequency of approximately 1/20 (Murray et al. (1995) supra; Lansdorp et al, J. Exp. Med. 177:1331 (1993)).
• Methods for isolating highly enriched populations of hematopoietic stem cells are further provided in U.S. patent application No. 5,681,559.
• hematopoietic stem cells have the ability to differentiate into any of several types of blood cells, including red blood cells, white blood cells, including lymphoid cells and myeloid cells.
• HSCs include hematopoietic cells having long-term engrafting potential in vivo. Long term engrafting potential ⁇ e.g., long term hematopoietic stem cells) can be determined using animal models or in vitro models.
• the cells can be enriched for stem cells or immature cells, e.g. in a blood cell lineage, prior to culturing according to the methods provided herein.
• the one or more cells comprise a population of cells that is substantially enriched in hematopoietic stem cells.
• the cells cultured according to the methods provided herein are substantially free of stromal cells.
• the cells used in the methods provided herein are selected or enriched for the presence of or absence of particular markers on the surface of the cell.
• the cells are selected for the presence of stem cell markers particular for the animal source of the primary tissue.
• the cells are selected for the absence of lineage specific markers.
• the cells are selected from the presence of particular markers and the absence of other markers. Methods for isolating cells that have particular markers or that do not have particular markers are well known to those skilled in the art.
• lineage specific markers the absence or low expression of lineage specific markers can be identified by the lack of binding of antibodies specific to the lineage specific markers.
• the cells or source of cells for use in the methods provided herein can be subjected to negative selection techniques to remove those cells that express lineage specific markers and retain those cells which are lineage negative ("Lin " ").
• Lin generally refers to cells which lack markers such as those associated with T cells (such as CD2, 3, 4 and 8), B cells (such as B220, CD48, CDlO, 19 and 20), myeloid cells (such as Mac-1, Gr-I, CD14, 15, 16 and 33), natural killer ( 11 NK") cells (such as CD244, CD2, 16 and 56), RBC (such as Terl 19, and glycophorin A), megakaryocytes (CD41), mast cells, eosinophils or basophils. Methods of negative selection are known in the art. Lineage specific markers also include CD38, HLA-DR and CD71. [072] Various techniques can be employed to separate the cells by initially removing cells of dedicated lineage or having a particular phenotype.
• Procedures for separation can include, but are not limited to, physical separation, magnetic separation (using antibody- coated magnetic beads), affinity chromatography, cytotoxic agents joined to a monoclonal antibody or used in conjunction with a monoclonal antibody, including, but not limited to, complement and cytotoxins, and "panning" with antibody attached to a solid matrix, e.g., plate, elutriation or any other convenient technique.
• Techniques providing accurate and rapid separation include, but are not limited to, flow cytometry (e.g., fluorescence activated cell sorting) and cytospin.
• the use of physical separation techniques include, but are not limited to, those based on differences in physical (density gradient centrifugation and counter- flow centrifugal elutriation), cell surface (lectin and antibody affinity), and vital staining properties (mitochondria-binding dye rhol23 and DNA-binding dye Hoechst 33342). These procedures are well known to those of skill in this art.
• the cells obtained either with or without enrichment for hematopoietic stems cells as described above can be used immediately or frozen at liquid nitrogen temperatures and stored.
• the frozen cells can be thawed and used in the methods described herein.
• the cells obtained, for example from a primary tissue source or from a suitable animal, are incubated in a suitable medium. Suitable conditions comprise incubating at 33° to 39° C, and preferably around 37° C. HSCs can be cultured in an oxygen concentration of 1 to 10%. In some embodiments, the HSCs are cultured under hypoxic conditions. In some embodiments, the cells are incubated under normoxic conditions Normoxic conditions can be, for example, 5% CO 2 and oxygen at 15% or more. In some embodiments normoxic conditions are 21% O 2 . Hypoxic conditions can be, for example, 5% CO 2 and 5% O 2 .
• Media can be replaced throughout the culture period. In another embodiment, half of the medium is replaced twice per week with fresh media.
• the cells can be cultured from 3 to 30 days.
• the population of cells including HSCs is cultured for at least four weeks.
• the population of cells including HSCs is cultured for up to two weeks.
• the population of cells including HSCs is cultured for 7 to 14 days.
• the population of cells including HSCs is cultured for 10 days.
• HSCs can be propagated by culturing or incubating one or more cells in an expansion container and in a volume of a suitable medium. The cells can be cultured such that the culture well contains about 1-100 cells per well.
• the cells can be cultured at a density of about 1 x 10 2 cells to about 1 x 10 7 cells/mL of medium. In another embodiment, the cells can be cultured at a density of about 1 x 10 5 cells to about 1 x 10 6 cells/mL of medium. In another embodiment, the population of cells comprises Side Population (SP) bone marrow cells.
• SP bone marrow cells can be cultured at lower density, for example from about 1 x 10 2 to 5 x 10 3 cells/ml.
• the population of cells can be derived from mobilized peripheral blood.
• the mobilized peripheral blood cells can be cultured at a density of about 20,000 cells/mL to about 50,000 cells/mL; in another embodiment, the mobilized peripheral blood cells is cultured at a density of about 50,000 cells/mL.
• expansion container any suitable expansion container, flask, or appropriate tube such as a 12, 24 or 96 well plate, 12.5 cm 2 T flask or gas-permeable bag can be used in the methods provided herein.
• culture containers are commercially available from Falcon, Corning or Costar.
• expansion container also is intended to include any chamber or container for expanding cells whether or not free standing or incorporated into an expansion apparatus.
• Hematopoietic stem cells that have been expanded in vitro as described herein are also provided. It is understood that the descendants of stem cells grown in culture may not be completely identical (either morphologically, genetically, or phenotypically) to the parent cell. However, as provided herein, the descendants of the stem cells possess at least some ability to differentiate into one or more blood cell types as described, supra. Functional characteristics, such as the ability to develop into one or more blood cell types can be measured, for example, using methods and lineage markers as described herein. USES FOREX VIVO EXPANDED HEMATOPOIETIC STEM CELLS
• the expanded cultured hematopoietic stem cells of the technology can be used for a variety of applications, including transplantation, drug discovery, gene cloning, gene delivery, and, gene expression.
• the hematopoietic stem cells provided herein can be administered to a subject or an individual.
• the hematopoietic stem cells produced by the methods provided herein are used in cell-based therapies, such a bone marrow transplantation.
• Suitable subject or individuals include any animal as described above.
• the subject or individual can be any animal suitable for studying hematopoiesis or cell-based therapies in vivo, vertebrate.
• the subject or individual can be any animal in need of cell-based therapy.
• the individual is a mammal. Mammals include, but are not limited to, humans, non-human primates, mice, cows, horses, dogs, cats and the like. In a preferred embodiment, the mammal is a human.
• the transplanted stem cells can be autologous (derived from the individual being treated), allogenic (derived from a donor of the same species), or obtained from a histocompatibly matched donor.
• the transplanted stem cells can be xenogenic (derived from a animal of a different species from the recipient).
• Human autologous and allogeneic bone marrow transplantations are currently used as therapies for diseases such as leukemia, lymphoma, and other life-threatening diseases.
• an effective amount of expanded cells may range from as few as several hundred or fewer to as many as several million or more. It will be appreciated that the number of expanded cells to be administered will vary depending on the specifics of the disorder to be treated, including but not limited to size or total volume to be treated, as well as the needs and condition of the recipient, among other factors familiar to the medical professional. In some embodiments, between 10 3 and 10 10 cells per 100 kg person are administered or transplanted into the subject or individual. Methods of administering or transplanting are well known in the art and include, for example, infusion. Expanded cells provided herein can be administered, for example, by intravenous infusion.
• a single administration of cells is provided.
• multiple administrations are used. Multiple administrations can be provided over periodic time periods such as an initial treatment regime of 3 to 7 consecutive days, and then repeated at other times.
• the expanded cells can be used for reconstituting the full range of hematopoietic cells in an individual following therapies such as, but not limited to, radiation treatment and chemotherapy.
• therapies such as, but not limited to, radiation treatment and chemotherapy.
• Such therapies destroy hematopoietic cells either intentionally or as a side- effect of bone marrow transplantation or the treatment of lymphomas, leukemias and other neoplastic conditions, e.g., breast cancer.
• Expanded cells provided herein are also useful as a source of cells for specific hematopoietic lineages.
• the maturation, proliferation and differentiation of expanded hematopoietic cells into one or more selected lineages may be effected through culturing the cells with appropriate factors including, but not limited to, erythropoietin (EPO), colony stimulating factors, e.g., GM-CSF, G-CSF, or M-CSF, SCF, Flt-3 ligand, interleukins, e.g., IL-I, -2, -3, -4, -5, -6, -7, -8, -13, etc., or with stromal cells or other cells which secrete factors responsible for stem cell regeneration, commitment, and differentiation.
• EPO erythropoietin
• colony stimulating factors e.g., GM-CSF, G-CSF, or M-CSF
• SCF erythropoietin
• Hematopoietic stem cells provided by the methods described herein are useful for drug discovery. For example, culture conditions or growth factors that promote or inhibit such biological responses of stem cells can be identified by exposing the cells to the conditions or factors to be tested. In this way one may also identify, for example, receptors for these factors or agents that interfere with the biological activity of the factor.
• the hematopoietic stem cells produced by the methods provided herein can be used in assays for differentiating stem cells into various hematopoietic lineages. These assays may be readily adapted in order to identify substances such as factors which, for example, promote or inhibit stem cell self-regeneration, commitment, or differentiation. Gene cloning strategies
• the hematopoietic cells provided herein can be used to identify and clone genes whose expression is associated with proliferation, commitment, differentiation, and maturation of stem cells or other hematopoietic cells, e.g., by subtractive hybridization or by expression cloning using monoclonal antibodies specific for target antigens associated with these biological events or characteristic of a hematopoietic cell type.
• Gene delivery and expression can be used to identify and clone genes whose expression is associated with proliferation, commitment, differentiation, and maturation of stem cells or other hematopoietic cells, e.g., by subtractive hybridization or by expression cloning using monoclonal antibodies specific for target antigens associated with these biological events or characteristic of a hematopoietic cell type.
• Hematopoietic stem cells are also important targets for gene delivery and expression in a subject. Accordingly the hematopoietic cells provided herein can be genetically altered prior to reintroducing the cells into an individual. For example a gene whose expression is expected to have a therapeutic effect on the individual can be introduced into one more of the hematopoietic cells provided herein. The cells can be genetically altered before or after being cultured and/or expanded as described herein. Methods for introducing genes into the cultured cells are well known in the art.
• individuals can be treated by supplementing, augmenting and/or replacing defective and/or damaged cells with cells that express a therapeutic gene.
• the cells may be derived from cells of a normal matched donor or stem cells from the individual to be treated (i.e., autologous).
• autologous i.e., autologous
• Expression vectors may be introduced into and expressed in autologous or allogeneic expanded hematopoietic cells, or the genome of cells may be modified by homologous or non-homologous recombination by methods known in the art. In this way, one may correct genetic defects in an individual or provide genetic capabilities naturally lacking in stem cells. For example, diseases including, but not limited to, ⁇ -thalassemia, sickle cell anemia, adenosine deaminase deficiency, recombinase deficiency, and recombinase regulatory gene deficiency may be corrected in this fashion.
• diseases including, but not limited to, ⁇ -thalassemia, sickle cell anemia, adenosine deaminase deficiency, recombinase deficiency, and recombinase regulatory gene deficiency may be corrected in this fashion.
• Diseases not associated with hematopoietic cells may also be treated, e.g., diseases related to the lack of secreted proteins including, but not limited to hormones, enzymes, and growth factors.
• Inducible expression of a gene of interest under the control of an appropriate regulatory initiation region will allow production (and secretion) of the protein in a fashion similar to that in the cell which normally produces the protein in nature.
• the hematopoietic stem cells provided herein can be genetically modified.
• the introduction of the gene into the hematopoietic stem cell can be by standard techniques, e.g. infection, transfection, transduction or transformation.
• the HSC cells can be transduced with a therapeutic gene.
• the transduction can be via a viral vector such as a retroviral vector (e.g. as described in for example, WO 94/29438, WO 97/21824 and WO 97/21825) or a pox viral vector.
• a retroviral vector e.g. as described in for example, WO 94/29438, WO 97/21824 and WO 97/21825
• a pox viral vector e.g. as described in for example, WO 94/29438, WO 97/21824 and WO 97/21825
• the transduced cells are subsequently administered to the recipient.
• the technology provided herein encompasses treatment of diseases amenable to gene transfer into HSCs, by administering the gene ex vivo or in vivo by the methods disclosed herein.
• diseases including, but not limited to, ⁇ -thalassemia, sickle cell anemia, adenosine deaminase deficiency, recombinase deficiency, recombinase regulatory gene deficiency, etc. can be corrected by introduction of a therapeutic gene.
• Other indications of gene therapy are introduction of drug resistance genes to enable normal stem cells to have an advantage and be subject to selective pressure during chemotherapy. Suitable drug resistance genes include, but are not limited to, the gene encoding the multidrug resistance (MDR) protein.
• MDR multidrug resistance
• Examples of modes of gene transfer include e.g., naked DNA, CaPO 4 precipitation, DEAE dextran, electroporation, protoplast fusion, lipofection, cell microinjection, and viral vectors, adjuvant- assisted DNA, gene gun, catheters, etc.
• a viral vector is used.
• One or more polynucleotide of interest can be inserted into a vector using methods well known in the art.
• insert and vector DNA can be contacted, under suitable conditions, with a restriction enzyme to create complementary ends on each molecule that can pair with each other and be joined together with a ligase.
• synthetic nucleic acid linkers can be ligated to the termini of restricted polynucleotide. These synthetic linkers contain nucleic acid sequences that correspond to a particular restriction site in the vector DNA.
• an oligonucleotide containing a termination codon and an appropriate restriction site can be ligated for insertion into a vector containing, for example, some or all of the following: a selectable marker gene, such as the neomycin gene for selection of stable or transient transfectants in mammalian cells; enhancer/promoter sequences from the immediate early gene of human CMV for high levels of transcription; transcription termination and RNA processing signals from SV40 for mRNA stability; SV40 polyoma origins of replication and CoIEl for proper episomal replication; versatile multiple cloning sites; and T7 and SP6 RNA promoters for in vitro transcription of sense and antisense RNA.
• a selectable marker gene such as the neomycin gene for selection of stable or transient transfectants in mammalian cells
• enhancer/promoter sequences from the immediate early gene of human CMV for high levels of transcription
• transcription termination and RNA processing signals from SV40 for mRNA stability transcription termination and RNA
• Modification of hematopoietic stem cells can comprise the use of an expression cassette created for either constitutive or inducible expression of the introduced transgene.
• an expression cassette can include regulatory elements such as a promoter, an initiation codon, a stop codon, and a polyadenylation signal. Suitable elements that are operable in the stem cells or in cells that arise from the stem cells after infusion into an individual can be used. Moreover, it is necessary that these elements be operably linked to the nucleotide sequence that encodes the protein such that the nucleotide sequence can be expressed in the stem cells and thus the protein can be produced. Initiation codons and stop codons are generally considered to be part of a nucleotide sequence that encodes the protein.
• promoters examples include Granzyme A for expression in T-cells and NK cells, the CD34 promoter for expression in stem and progenitor cells, the CD8 promoter for expression in cytotoxic T-cells, and the CDl Ib promoter for expression in myeloid cells.
• regulatable promoters can be used. Regulatable promoters such as inducible promoters are available commercially.
• the exogenous genetic material that includes the transgene operably linked to the regulatory elements may remain present in the cell as a functioning cytoplasmic molecule, a functioning episomal molecule or it may integrate into the cell's chromosomal DNA.
• Exogenous genetic material may be introduced into cells where it remains as separate genetic material in the form of a plasmid.
• linear DNA which can integrate into the chromosome
• reagents which promote DNA integration into chromosomes, may be added.
• DNA sequences, which are useful to promote integration may also be included in the DNA molecule.
• RNA may be introduced into the cell.
• Selectable markers can be used to monitor uptake of the desired gene into the hematopoietic stem cells of the technology.
• These marker genes can be under the control of any promoter or an inducible promoter. These are well known in the art and include genes that change the sensitivity of a cell to a stimulus such as a nutrient, an antibiotic, etc. Genes include those for neo, puro, and tk, multiple drug resistance (MDR), etc. Other genes express proteins that can readily be screened for such as green fluorescent protein (GFP), blue fluorescent protein (BFP), luciferase, and LacZ.
• GFP green fluorescent protein
• BFP blue fluorescent protein
• luciferase luciferase
• therapeutic gene can be an entire gene or only the functionally active fragment of the gene capable of compensating for the deficiency in the patient that arises from the defective endogenous gene.
• Therapeutic gene also encompasses antisense oligonucleotides or genes useful for antisense suppression and ribozymes for ribozyme- mediated therapy.
• Therapeutic genes that encode dominant inhibitory oligonucleotides and peptides as well as genes that encode regulatory proteins and oligonucleotides also are encompassed by this technology.
• gene therapy will involve the transfer of a single therapeutic gene although more than one gene may be necessary for the treatment of particular diseases.
• the therapeutic gene can be a normal, e.g., wild-type, copy of the defective gene or a functional homolog. In a separate embodiment, the therapeutic gene is a dominant inhibiting mutant of the wild-type. More than one gene can be administered per vector or alternatively, more than one gene can be delivered using several compatible vectors. Depending on the genetic defect, the therapeutic gene can include the regulatory and untranslated sequences. For gene therapy in human patients, the therapeutic gene will generally be of human origin although genes from other closely related species that exhibit high homology and biologically identical or equivalent function in humans may be used, if the gene product does not induce an adverse immune reaction in the recipient.
• a primate insulin gene whose gene product is capable of converting glucose to glycogen in humans would be considered a functional equivalent of the human gene.
• the therapeutic gene suitable for use in treatment will vary with the disease.
• a suitable therapeutic gene for treating sickle cell anemia is a normal copy of the globin gene.
• a suitable therapeutic gene for treating SCID is the normal ADA gene.
• FIG. IB shows the amount of human chimerism in the bone marrow of NOD/SCID mice transplanted with 1 x 10 6 uncultured human mononuclear cord blood cells, or the cultured progeny of 1 x 10 6 initial human cord blood cells.
• Non-transfected 293T cells stimulates ex vivo expansion of HSCs [0104]
• serum- free conditioned medium collected from non-transfected 293T cells stimulates ex vivo expansion of HSCs [0105]
• Twenty freshly isolated CD45.2 bone marrow SP Sca-1+ CD45+ cells were cultured for 10 days in serum- free IMDM supplemented with 10 ng/ml SCF, 20 ng/ml TPO, 20 ng/ml IGF-2, and 10 ng/ml FGF-I (STIF medium; FIG. 2 A, bar 1), in freshly collected serum-free conditioned STIF medium from 293T cells (bar 2), or in the same conditioned medium after freeze/thaw (bar 3).
• Data shown in the top panel are representative FACS plots of peripheral blood mononuclear cells from one mouse at 5 months post-transplant (from bar 2 of FIG. IA). Percentages of cells in each quadrant are listed. The summary of percent repopulation data from mice in bar 2 of FIG. IA for T- lymphoid, B-lymphoid, and myeloid cells is plotted in the bottom panel.
• Serum- free 293T conditioned medium was analyzed by mass spectrometry in order to identify potential candidate proteins that stimulated ex vivo expansion of HSCs. Peptides from several proteins were identified. A partial list of peptides identified in the mass spectrometry analysis of the fraction of serum- free IMDM based conditioned medium of 293T cells that contained proteins smaller than 70 kD is shown in Table I. Proteins found in common with the control serum- free IMDM sample are not shown. [0108] Table I
• IGFBP-2 is expressed in serum-free 293T conditioned medium.
• FIG. 3 shows western blot analysis of purified human IGFBP-2 (positive control; lane 1), serum-free 3T3 conditioned medium (negative control; lane 2), and serum- free 293T conditioned medium (lane 3) detected by anti-human IGFBP-2 polyclonal antibody.
• Purified IGFBP-2 stimulates ex vivo expansion of HSCs.
• IGFBP-2 stimulates ex vivo expansion of HSCs.
• FIG. 4C shows limiting dilution analysis of the repopulating ability of adult BM SP CD45 + Sca-1 + cells before culture (left) and after culture for 21 days in serum-free conditioned STF medium containing 100 ng/ml of purified AngptB and 500 ng/ml IGFBP-2 (right).
• IGFBP-2 can replace IGF-2 in supporting the ex vivo expansion of mouse HSCs.
• IGFBP-2 promoted the ex vivo expansion human cord blood HSCs CD133 + cells by over 250 fold.
• Culture of 1 x 10 5 human cord blood CD133 + cells was initiated in serum-free STF medium, or in serum-free STF medium supplemented with 500 ng/ml Angptl5 and 500 ng/ml IGFBP-2 and cultured in a low O 2 environment (5% O 2 ). Total cell numbers were counted. As shown in FIG. 5 A, the number of total cells increased' greater than 200 fold after 11 days of culture either in serum-free STF medium or serum-free STF medium containing Angptl5 and IGFBP-2.
• FIG. 5 C shows human hematopoietic engraftment at 2 months in a representative mouse that was transplanted with uncultured (fresh) or cultured human cord blood CD133 + cells. Representative FACS plots of bone marrow cells from one mouse at the condition represented by lane 1 of (FIG.
• FIG. 5D The summary of multi-lineage engraftment of mice transplanted with uncultured cells (FIG. 5B lane 2) and cells cultured in STF medium containing Angptl5 and IGFBP-2 (FIG. 5B lane 4) is shown in FIG. 5D.
• Some mice transplanted with uncultured cells had zero percent donor repopulation and these data points are not plotted. (* Values are significantly different from the values of the uncultured cells. Student's t-test, p ⁇ 0.05.)
• FIG. 5D The progeny of 8,000 cells, after culture, repopulated myeloid and lymphoid lineages 2 months post-transplant, demonstrating the expansion of human stem cell activity.
• Some mice transplanted with uncultured cells had zero percent donor repopulation and these data points are not plot
• 5D shows human hematopoietic engraftment at 2 months in a representative mouse that was transplanted with uncultured or cultured human cord blood CD133 + cells.
• Some mice transplanted with uncultured cells had zero percent donor repopulation and these data points are not plotted, (total hematopoietic (cols. 1, and 5, CD45/71+), myeloid (cols. 2 and 6, CD15/66b+), B- lymphoid (cols. 3 and 7, CD34-CD 19/20+), and primitive (cols. 4 and 8 CD34+) lineages are shown.
• CD45.2 donor cells were cultured for 10 d in serum- free conditioned STIF medium or in the same medium with 500 ng/ml purified human angiopoietin 1, human angiopoietin 2, mouse angiopoietin 3, or human angiopoietin 4.
• the cells cotransplanted with 1 x 10 5 freshly isolated CD45.1 competitor bone marrow cells, into recipient mice.
• the mixture injected intravenously via the retro-orbital route into each of a group of 6-9 week old CD45.1 mice previously irradiated with a total dose of 10 Gy. Reconstitution 4 months post transplant was measured.
• peripheral blood was collected at the indicated times post-transplant and the presence of CD45.1 + and CD45.2 + cells in lymphoid and myeloid compartments were measured as described (Zhang, CC. and Lodish, H.F. Blood 105, 4314-20 (2005)).
• peripheral blood cells were collected by retro-orbital bleeding, followed by lysis of red blood cells and staining with anti-CD45.2- FITC, and anti-CD45.1-PE, or anti-Thyl.2-PE (for T-lymphoid lineage), anti-B220-PE (for B-lymphoid lineage), anti-Mac- 1 -PE, anti-Gr-1-PE (cells costaining with anti-Mac- 1 and anti-Gr-1 were deemed the myeloid lineage), or anti-Terl 19-PE (for erythroid lineage) monoclonal antibodies (BD Pharmingen). As shown in the FIG. 7, angiopoietin 2 stimulates ex vivo expansion of HSCs.
• mice C57 BL/6 CD45.2 and CD45.1 mice were purchased from the Jackson Laboratory or the National Cancer Institute. NOD/SCID (NOD.CB17-Prkdcscid/J) mice were purchased from the Jackson Laboratory and were maintained at the Whitehead Institute animal facility. All animal experiments were performed with the approval of M. LT. Committee on Animal Care.
• Serum-free STIF medium is StemSpan serum-free medium (StemCell Technologies) supplemented with 10 ⁇ g/ml heparin (Sigma), 10 ng/ml mouse SCF, 20 ng/ml mouse TPO, 20 ng/ml mouse IGF-2 (all from R&D Systems), and 10 ng/ml human FGF-I (Invitrogen). Serum-free STF medium is the same medium without IGF-2. Indicated amounts of purified Angptl3 (a gift from R&D Systems), Angptl5 (Abnova, Taiwan), or IGFBP-2 (R&D Systems) were added. Conditioned medium was collected from confluent 293T or 3T3 cells after overnight culture.
• Mouse HSC culture Twenty BM SP Sca-1 + CD45 + cells isolated from 8-10 week old C57BL/6 CD45.2 mice were plated in one well of a U-bottom 96-well plate (3799; Corning) with 160 ⁇ l of indicated medium. Cells were cultured at 37°C in 5% CO 2 and normal O 2 . For the purpose of competitive transplantation, cells were pooled from at least 6 culture wells and mixed with competitors before the indicated numbers of cells were transplanted into each mouse.
• Human cell culture Human total cord blood mononuclear cells were purchased from Cambrex. Cells were plated at 1 x 10 6 cells/ml of STIF medium, with 100 ng/ml Angptl3 or Angptl5. Medium volume was increased by adding fresh medium at day 5, 8, 12, 15, and 18 to maintain cell densities at 5 x 10 5 -1.5 x 10 5 cells/ml. Cells were cultured at 37 0 C in 5% CO 2 and normal O 2 . Human cyropreserved cord blood CD133 + cells used in the experiments of FIGs. 5 and 6 were purchased from Cambrex and StemCell Technologies Inc.
• Cells were plated at 1 x 10 4 cells/well in one well of a U-bottom 96-well plate (3799; Corning) with 200 ⁇ l of the indicated medium for 2 days. At day 3, cells were pooled from individual wells and transferred to 6-well plates at 5 x 10 4 cells/ml. Fresh medium was added at days 4 and 7 to keep the cell density at 2 x 10 5 cells/ml (day 4) or 7 x 10 5 /ml (day 7). Cells were cultured at 37°C in 5% CO 2 , and normal O 2 or 5% O 2 (low O 2 ) levels. [0130] NOD/SCID transplant.
• Uncultured or cultured progeny of human total cord blood mononuclear cells or CD133 + cells at indicated days were collected and injected intravenously via the retro-orbital route into sub-lethally irradiated (350 rad) NOD/SCID mice.
• Six to eight weeks or at indicated time after transplantation bone marrow nucleated cells from transplanted animals were analyzed by flow cytometry for the presence of human cells.
• bone marrow aspirates from one hind leg of a primary recipient were used to transplant two secondary recipients, as described. (Hogan, et al.,. Proc Natl Acad Sd USA 99, 413-8 (2002)).
• peripheral blood cells of recipient CD45.1 mice were collected by retro-orbital bleeding, followed by lysis of red blood cells and staining with anti-CD45.2-FITC, and anti-CD45.1-PE, or anti-Thyl .2-PE (for T- lymphoid lineage), anti-B220-PE (for B-lymphoid lineage), anti-Mac- 1 -PE, anti-Gr-1- PE (cells costaining with anti-Mac-1 and anti-Gr-1 were deemed the myeloid lineage), or anti-Terl 19-PE (for erythroid lineage) monoclonal antibodies (BD Pharmingen).
• T- lymphoid lineage for T- lymphoid lineage
• anti-B220-PE for B-lymphoid lineage
• anti-Mac- 1 -PE for B-lymphoid lineage
• anti-Gr-1- PE cells costaining with anti-Mac-1 and anti-Gr-1 were deemed the myeloid line
• mice CD45.2 donor cells were mixed with 1 x 10 5 freshly isolated CD45.1 competitor bone marrow cells, and the mixture injected intravenously via the retro-orbital route into each of a group of 6-9 week old CD45.1 mice previously irradiated with a total dose of 10 Gy.
• peripheral blood was collected at the indicated times post-transplant and the presence of CD45.1 + and CD45.2 + cells in lymphoid and myeloid compartments were measured as described (Zhang, CC and Lodish, H. F. Blood 103, 2513- 21 (2004), Zhang, CC and Lodish, H.F., Blood (2005)).
• Calculation of CRUs in limiting dilution experiments was conducted using L-CaIc software (StemCell Technologies) (Zhang, et al, Proc Natl Acad Sci USA 103, 2184-9 (2006)).

Landscapes

• Health & Medical Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Bioinformatics & Cheminformatics (AREA)
• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• General Health & Medical Sciences (AREA)
• Biomedical Technology (AREA)
• Hematology (AREA)
• General Chemical & Material Sciences (AREA)
• Pharmacology & Pharmacy (AREA)
• Animal Behavior & Ethology (AREA)
• Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Medicinal Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Zoology (AREA)
• Genetics & Genomics (AREA)
• Wood Science & Technology (AREA)
• Biotechnology (AREA)
• Diabetes (AREA)
• Developmental Biology & Embryology (AREA)
• Cell Biology (AREA)
• Microbiology (AREA)
• Immunology (AREA)
• Biochemistry (AREA)
• General Engineering & Computer Science (AREA)
• Physical Education & Sports Medicine (AREA)
• Orthopedic Medicine & Surgery (AREA)
• Endocrinology (AREA)
• Rheumatology (AREA)
• Micro-Organisms Or Cultivation Processes Thereof (AREA)
• Materials For Medical Uses (AREA)
• Medicines That Contain Protein Lipid Enzymes And Other Medicines (AREA)
• Medicines Containing Material From Animals Or Micro-Organisms (AREA)

Priority Applications (4)

Applications Claiming Priority (4)

Related Child Applications (2)

Publications (2)

Family

ID=39790348

Family Applications (1)

Country Status (4)

Cited By (11)

Families Citing this family (9)

Family Cites Families (20)

• 2008
  • 2008-05-02 US US12/598,770 patent/US8609411B2/en not_active Expired - Fee Related
  • 2008-05-02 JP JP2010507549A patent/JP2010525836A/ja active Pending
  • 2008-05-02 WO PCT/US2008/062365 patent/WO2008137641A2/en not_active Ceased
  • 2008-05-02 EP EP08747459A patent/EP2155862A2/en not_active Withdrawn
• 2013
  • 2013-11-12 US US14/077,776 patent/US20140308747A1/en not_active Abandoned

Also Published As

Similar Documents

Legal Events