High-Level Transgene Expression In Induced Pluripotent Stem Cell-Derived Megakaryocytes: Correction Of Glanzmann Thrombasthenia

Megakaryocyte-specific transgene expression in patient-derived induced pluripotent stem cells (iPSCs) offers a new approach to study and potentially treat disorders affecting megakaryocytes and platelets. By using a Gp1ba promoter, we developed a strategy for achieving a high level of protein expression in human megakaryocytes. The feasibility of this approach was demonstrated in iPSCs derived from two patients with Glanzmann thrombasthenia (GT), an inherited platelet disorder caused by mutations in integrin alpha IIb beta 3. Hemizygous insertion of Gp1ba promoter-driven human alpha IIb complementary DNA into the AAVS1 locus of iPSCs led to high alpha IIb messenger RNA and protein expression and correction of surface alpha IIb beta 3 in megakaryocytes. Agonist stimulation of these cells displayed recovery of integrin alpha IIb beta 3 activation. Our findings demonstrate a novel approach to studying human megakaryocyte biology as well as functional correction of the GT defect, offering a potential therapeutic strategy for patients with diseases that affect platelet function.