Compositions and methods for use in affecting hematopoietic stem cell populations in mammals

A method of preparing long-term repopulating human HSCs, the method comprising isolating hematopoietic progenitor cells (BPCs) from a human hematopoietic tissue and separating HPCs that express KDR on their surface (KDR+ HPCs) from HPCs that do not express KDR on their surface using a reagent selected from the group consisting of

• i) an antibody that specifically binds with KDR,
• ii) a portion of an immunoglobulin, wherein the portion specifically binds with KDR, and
• iii) a conjugated vascular endothelial growth factor, whereby the isolated KDR+ HPCs are enriched for long-term repopulating HSCs.

A method of expanding long-term repopulating human HSCs, the method comprising isolating HSCs that express KDR on their surface (KDR+ HSCs) from a human hematopoietic tissue using a reagent selected from the group consisting of

• i) an antibody that specifically binds with KDR,
• ii) a portion of an immunoglobulin, wherein the portion specifically binds with KDR, and
• iii) a conjugated vascular endothelial growth factor and incubating the HSCs with vascular endothelial growth factor to expand the HSCs.

A method of isolating a stem cell capable of giving rise to at least one of a muscle cell, a hepatic oval cell, a bone cell, a cartilage cell, a fat cell, a tendon cell, and a marrow stroma cell, the method comprising isolating a hematopoietic cell that expresses KDR on its surface from a human hematopoietic tissue using a reagent selected from the group consisting of

• i) an antibody that specifically binds with KDR,
• ii) a portion of an immunoglobulin, wherein the portion specifically binds with KDR, and;
• iii) a conjugated vascular endothelial growth factor, thereby isolating the stem cell.

A method of obtaining a cell population enriched for long-term repopulating human hematopoietic stem cells (HSCs), the method comprising isolating hematopoietic cells from a human hematopoietic tissue and separating cells that express KDR on their surface but do not express a late marker on their surface from cells that either do not express KDR on their surface or express a late marker on their surface, the isolation method comprising using a reagent selected from the group consisting of

• i) an antibody that specifically binds with KDR,
• ii) a portion of an immunoglobulin, wherein the portion specifically binds with KDR, and
• iii) a conjugated vascular endothelial growth factor, thereby obtaining a cell population that is enriched for long-term repopulating HSCs.

A method of preparing long-term repopulating human HSCs, the method comprising isolating cells that express KDR On their surface and do not express a first early marker on their surface (KDR+ early− cells) using, sequentially in either order, an antibody which specifically binds with the first early marker and a reagent selected from the group consisting of

• i) an antibody which specifically binds with KDR,
• ii) a portion of an immunoglobulin, wherein the portion specifically binds with KDR, and
• iii) a conjugated vascular endothelial growth factor.