METHODS FOR PRODUCTION OF PLATELETS FROM PLURIPOTENT STEM CELLS AND COMPOSITIONS THEREOF
Methods for production of platelets from pluripotent stem cells, such as human embryonic stem cells (hESCs) and induced pluripotent stem cells (iPSCs) are provided. These methods may be performed without forming embryoid bodies or clusters of pluripotent stem cells, and may be performed without the use of stromal inducer cells. Additionally, the yield and/or purity can be greater than has been reported for prior methods of producing platelets from pluripotent stem cells. Also provided are compositions and pharmaceutical preparations comprising platelets, preferably produced from pluripotent stem cells.
1 .- 73 . (canceled)
74 . A composition comprising a plurality of cells, wherein at least 70% of the cells in the composition are CD41a(+), CD42b(+) megakaryocytes having a knockout of endogenous β2 microglobulin, wherein the CD41a(+), CD42b(+) megakaryocytes are human megakaryocytes.
75 . The composition of claim 74 , wherein at least 85% of the cells in the composition are CD41a(+), CD42b(+) megakaryocytes.
76 . The composition of claim 74 , wherein the CD41a(+), CD42b(+) megakaryocytes are also CD29(+) and CD61(+).
77 . The composition of claim 74 , wherein the plurality of cells is derived in vitro from pluripotent stem cells.
78 . The composition of claim 77 , wherein the pluripotent stem cells are embryonic stem cells.
79 . The composition of claim 77 , wherein the pluripotent stem cells are induced pluripotent stem cells.
80 . The composition of claim 74 , wherein the composition essentially lacks CD235A+ erythroid cells.
81 . The composition of claim 74 , wherein <0.1% of the cells in the composition express OCT4, NANOG, TRA-1-60, TRA-1-81 SSEA3, SSEA4, or Alkaline Phosphatase.
82 . The composition of claim 74 , wherein <0.1% of the cells in the composition express SSEA4 or TRA-1-60.
83 . The composition of claim 74 , wherein the cells of the composition are mitotically inactivated.
84 . The composition of claim 74 , wherein the megakaryocytes are engineered to have altered levels of expression of genes involved in membrane lipid ratios, protein glycosylation patterns, stress-induced proteins, or 14-3-3ζ translocation.
85 . The composition of claim 74 , wherein the megakaryocytes are engineered to express a recombinant protein.
86 . The composition of claim 85 , wherein the recombinant protein is selected from the group consisting of erythropoietin, insulin-like growth factor 1 (IGF-1), basic Fibroblast Growth Factor (bFGF), Transforming Growth Factor β-3 (TGFβ-3), granulocyte colony stimulating factor (GCSF), granulocyte macrophage colony stimulating factor (GMCSF), keratinocyte growth factor (KGF), fibronectin, vitronectin, thrombospondin, laminin, and tenasin.
87 . The composition of claim 85 , wherein the recombinant protein is a vascular endothelial growth factor (VEGF) inhibitor.
88 . The composition of claim 87 , wherein the VEGF inhibitor is an antibody.
89 . The composition of claim 74 , wherein the composition further comprises a BET inhibitor or a c-myc inhibitor.
90 . The composition of claim 89 , wherein the composition comprises a BET inhibitor, and wherein the BET inhibitor is GSK1210151A (I-BET151).
91 . The composition of claim 74 , wherein the composition further comprises a MMP inhibitor.
92 . The composition of claim 91 , wherein the MMP inhibitor is an MMP8-specific inhibitor.
93 . The composition of claim 92 , wherein the MMP8-specific inhibitor is (3R)-(+)-[2-(4-Methoxybenzenesulfonyl)-1,2,3,4-tetrahydroisoquinoline-3-hydroxamate]