Methods for use of mpl ligands with primitive human stem cells

Patent Number: 6916470

The mpl ligand, also known as thrombopoietin, is important for stimulation of platelet production from hematopoietic stem cells. Thrombopoietin, in addition to shifting differentiation towards the megakaryocytic lineage, also has some ability to induce proliferation of early hematopoietic stem cells.

This patent uses the ability of thrombopoietin to stimulate stem cell proliferation in order to allow for transfection of stem cells.

The patent claims in its one independent claim "A method for genetically modifying a population of human hematopoietic stem cells, comprising the steps of: culturing in vitro an initial hematopoletic cells population comprising human CD34.sup.+ Thy-1.sup.+ hematopoletic stem cells in a medium comprising a mysloproliferative receptor (mpl) ligand, wherein said population of hematopoletic stem cells proliferates to expand the number of CD34.sup.+ cell in a final cell population; transducing said hematopoletic cell population with a viral vector comprising a gene of interest, wherein said final cell population comprises human hematopoletic stem cells that have been genetically modified by integration of said gene of interest into the cells; and transplanting said final cell populatlon into a recipient to provide long term hematopoletic reconstitution."

View this patent on the USPTO website.