Abstract: Myeloproliferative leukemia receptor (mpl) ligands, such as thrombopoietin, act on a primitive subpopulation of human stem cells having the characteristics of self-renewal and ability to give rise to all hematopoietic cell lineages. Thrombopoietin supports both megakaryocytic differentiation and primitive progenitor cell expansion of CD34+ and CD34+ sub-populations (CD34+Lin−, CD34+Thy-1+Lin−, and CD34+Lin− Rh123lo). Thrombopoietin also stimulated quiescent human stem cells to begin cycling. Thus, mpl ligands are useful for expanding primitive stem cells for restoration of hematopoietic capabilities and for providing modified human stem cells for gene therapy applications.

Abstract: The separation device of the invention is directed to a container having an interior surface defining a channel. The container further has an inlet and an outlet. On the interior surface of the channel are pole tips which may be in a sawtooth configuration having sharp angles facing the interior of the channel that generate a high gradient magnetic field in the channel. Within the channel may be incorporated separating material. The separating material eliminates the direct contact of cells with the magnetic pole material. The separating material, as well as the sawtooth pole tips also serves the purpose of creating a field gradient across the entire container to avoid the problem of zero field gradient in the center of the container where the velocity is greatest, and where more cells flow. The separating material is designed to cause a substantially unobstructed flow of medium through the channel so that unlabeled substances are not trapped in the separating material.

Abstract: A purified soluble form of Flk-2 is provided, as the DNA sequence and as the protein. In addition, a partial DNA sequence of the human Flk-2 is also provided. The proteins find use in modulating hematopoiesis in culture and in vivo, as well as for the production of antibodies for assays of the proteins.

Abstract: A human hematopoietic system is provided in an immunocompromised mammalian host, where the hematopoietic system is functional for extended periods of time. Particularly, human fetal liver tissue and human fetal thymus is introduced into an appropriate site of a young immunocompromised mouse at a site supplied with a vascular system, whereby the fetal tissue results in novel formation of functional human bone marrow tissue.

Abstract: Myeloproliferative leukemia receptor (mpl) ligands, such as thrombopoietin, act on a primitive subpopulation of human stem cells having the characteristics of self-renewal and ability to give rise to all hematopoietic cell lineages. Thrombopoietin supports both megakaryocytic differentiation and primitive progenitor cell expansion of CD34.sup.+ and CD34.sup.+ sub-populations (CD34.sup.+ Lin.sup.-, CD34.sup.+ Thy-1.sup.+ Lin.sup.-, and CD34.sup.+ Lin.sup.- Rh123.sup.lo). Thrombopoietin also stimulated quiescent human stem cells to begin cycling. Thus, mpl ligands are useful for expanding primitive stem cells for restoration of hematopoietic capabilities and for providing modified human stem cells for gene therapy applications.

Abstract: This invention provides a method for obtaining a recombinant retroviral packaging cell capable of producing retroviral vectors as well as the recombinant packaging cell obtained by the method. Also provided is a method of producing recombinant retroviral particles obtained by introducing into the packaging cells obtained according to the methods disclosed herein, a recombinant retroviral vector and propagating the resulting producer cells under conditions favorable for the production and secretion of retroviral vector supernatant. The retroviral supernatant produced by these methods also is claimed herein. This invention further provides a method for screening retroviral vector supernatant for high transduction efficiency and methods for producing retroviral vector supernatant for transducing cells with high efficiency in gene therapy applications.

Abstract: The invention relates to methods of enriching for hematopoietic cell populations enriched in myeloid and/or lymphoid progenitor cells based on cell specific markers. The methods also provide an enriched population of prethymic lymphoid-committed progenitor population lacking long-term hematopoietic reconstitution potential. Compositions enriched for the cells and populations of cells obtained therefrom are also provided by the invention. Methods of use of the cells are also included. Methods of genetically modifying the cells are provided as are cells obtained thereby.

Abstract: The invention relates to methods of enriching for hematopoietic cell populations enriched in myeloid and/or lymphoid progenitor cells based on cell specific markers. The methods also provide an enriched population of prethymic lymphoid-committed progenitor population lacking long-term hematopoietic reconstitution potential. Compositions enriched for the cells and populations of cells obtained therefrom are also provided by the invention. Methods of use of the cells are also included. Methods of genetically modifying the cells are provided as are cells obtained thereby.

Abstract: The invention relates to methods of enriching for hematopoietic cell populations enriched in myeloid and/or lymphoid progenitor cells based on cell specific markers. The methods also provide an enriched population of prethymic lymphoid-committed progenitor population lacking long-term hematopoietic reconstitution potential. Compositions enriched for the cells and populations of cells obtained therefrom are also provided by the invention. Methods of use of the cells are also included. Methods of genetically modifying the cells are provided as are cells obtained thereby.

Abstract: A class of sulforhodamine labeling reagents capable of binding with a biomolecular species to produce a conjugate with fluorescent properties. The sulforhodamine labeling reagents have the structure: ##STR1## The group X is selected from an alkyl, an olefin, a monocyclic aliphatic saturated hydrocarbon, an aryl, or nothing at all. The group Y is selected from an amide, a substituted amide, or nothing at all. The group Z is selected from a monocyclic aliphatic hydrocarbon, an aryl, or an alkyl, as defined with respect to group X, a polyethylene glycol chain of the general form (CH.sub.2 CH.sub.2 O).sub.n, or nothing at all. The alkyl or polyethylene glycol chain may further have inert intermediate amide, ether, or disulfide functionalities. The group X, group Y, and group Z cannot all be nothing at all or non-existent. The group R is an electrophilic moiety suitable for conjugation of the fluorescent labeling reagent with a biomolecular species. Also disclosed is a method of making the reagents.

Abstract: The present invention provides a method for optimizing gene transfer into hematopoietic stem cells (HSCs) by contacting the cells with hydroxyurea prior to gene transfer to induce HSCs in G0 into active cell cycle. This method is useful for treating patients suffering from a disease that is suitably treated by gene therapy or involves hematopoietic cells. A method is also provided for enhancing the efficacy of bone marrow transplantation by administering hydroxyurea to increase HSC yields.

Abstract: Human hematopoietic stem cells are provided by separation of the stem cells from dedicated cells. The stem cells may than be maintained by regeneration in an appropriate growth medium. Means are provided for assaying for the stem cells as to their capability for producing members of each of the hematopoietic lineages. A method for treating a human by implanting a cellular composition comprising greater than 90% human hematopoietic stem cells is also disclosed.

Abstract: This invention provides a method for obtaining a recombinant retroviral packaging cell capable of producing retroviral vectors and the recombinant packaging cell obtained by the method. Also provided is a method of producing recombinant retroviral particles obtained by introducing into the packaging cells obtained according to the methods disclosed herein, a recombinant retroviral vector and propagating the resulting producer cells under conditions favorable for the production and secretion of retroviral vector supernatant. The retroviral supernatants produced by these methods also is claimed herein. This invention further provides a method for screening retroviral vector supernatant for high transduction efficiency and methods for producing retroviral vector supernatant for transducing cells with high efficiency in gene therapy applications.

Abstract: Boron compound complexing reagents, intermediate reagents of those reagents, and methods of synthesizing these reagents are disclosed. These reagents, including those shown as General Formula II may be used, after further reactions described herein, to complex with boronic compounds, such as phenylboronic acid or derivatives thereof. ##STR1## In one embodiment, group Z comprises a spacer selected from a saturated or unsaturated chain of up to about 6 carbon equivalents in length, an unbranched saturated or unsaturated chain from about 6 to 18 carbon equivalents in length with at least one intermediate amide or disulfide moieties, and a polyethylene glycol chain of from about 3 to 12 carbon equivalents in length; group R.sub.2 is one of an alkyl and a methylene group with an electronegative moiety; and BAS is a biologically active species.

Abstract: Boron compound complexing reagents, boron compound complexes, and methods of synthesizing these reagents and complexes are disclosed. These reagents and complexes include those shown in General Formula IV and General Formula VI. In one embodiment, the reagent of General Formula IV may be used to form a complex with a boron compound, such as a complex shown in General Formula VI. ##STR1## In one embodiment, group Z comprises a spacer selected from a saturated or unsaturated chain of up to about 6 carbon equivalents in length, an unbranched saturated or unsaturated chain of from about 6 to 18 carbon equivalents in length with at least one of intermediate amide or disulfide moieties, and a polyethylene glycol chain of from about 3 to 12 carbon equivalents in length; group R.sub.3 is selected from one of an H, an alkyl, and a methylene or ethylene moiety with an electronegative substituent; and BAS and BAS* are biologically active species.

Abstract: Boron compound complexing reagents and methods of synthesizing these reagents are disclosed. These reagents, including those shown as General Formula I and General Formula II may be used, after further reactions described herein, to complex with boronic compounds, such as phenylboronic acid or derivatives thereof.

Abstract: This invention provides novel human growth factor polypeptides, nucleotides encoding the growth factor polypeptides, and uses for the growth factor polypeptides and polynucleotides.

Abstract: This invention provides a novel antibody, designated .alpha.EM10, and a hybridoma cell line that produces the .alpha.EM10 antibody. Also provided are methods to obtain compositions enriched for hematopoietic stem cells. The methods employ a separation technique utilizing antibodies (.alpha.EM10) specific for a unique cell marker (EM10) that is expressed on stem and progenitor cells, while being less accessible or absent on more mature cells. Further provided are cell compositions enriched for EM10+ cells.

Abstract: An apparatus and process for measuring particles that prevents the particles from being contaminated during the measuring and optional sorting process wherein a flow chamber or region is mechanically isolated from a sterile enclosure which surrounds the flow chamber. The present invention in one embodiment provides an apparatus comprising of a droplet generator, a charging system, a deflecting system, a sterilization system, a light source, a detector, a cooling system and a vacuum system. The droplet generator and the charging system and the flow chamber associated with the droplet generator operate within an illumination frame where the particles (e.g. biological cells) are actually measured.

Abstract: Human hematopoietic stem cells are provided by separation of the stem cells from dedicated cells. The stem cells may than be maintained by regeneration in an appropriate growth medium. Means are provided for assaying for the stem cells as to their capability for producing members of each of the hematopoietic lineages.