title: Directed cardiomyogenesis of autologous human induced pluripotent stem cells recruited to infarcted myocardium with bioengineered antibodies.
abstract: OBJECTIVE
  Myocardial infarctions constitute a major factor contributing to non-natural mortality world-wide. Clinical trials of myocardial regenerative therapy, currently pursued by cardiac surgeons, involve administration of stem cells into the hearts of patients suffering from myocardial infarctions. Unfortunately, surgical acquisition of these cells from bone marrow or heart is traumatic, retention of these cells to sites of therapeutic interventions is low, and directed differentiation of these cellsin situinto cardiomyocytes is difficult. The specific aims of this work were: (1) to generate autologous, human, pluripotent, induced stem cells (ahiPSCs) from the peripheral blood of the patients suffering myocardial infarctions; (2) to bioengineer heterospecific antibodies (htAbs) and use them for recruitment of the ahiPSCs to infarcted myocardium; (3) to initiatein situdirected cardiomyogenesis of the ahiPSCs retained to infarcted myocardium.
  
  
  METHODS
  Peripheral blood was drawn from six patients scheduled for heart transplants. Mononuclear cells were isolated and reprogrammed, with plasmids carrying six genes (NANOG, POU5F1, SOX2, KLF4, LIN28A, MYC), to yield the ahiPSCs. Cardiac tissues were excised from the injured hearts of the patients, who received transplants during orthotopic surgery. These tissues were used to preparein vitromodels of stem cell therapy of infarcted myocardium. The htAbs were bioengineered, which simultaneously targeted receptors displayed on pluripotent stem cells (SSEA-4, SSEA-3, TRA-1-60, TRA-1-81) and proteins of myocardial sarcomeres (myosin, α-actinin, actin, titin). They were used to bridge the ahiPSCs to the infarcted myocardium. The retained ahiPSCs were directed with bone morphogenetic proteins and nicotinamides to differentiate towards myocardial lineage.
  
  
  RESULTS
  The patients' mononuclear cells were efficiently reprogrammed into the ahiPSCs. These ahiPSCs were administered to infarcted myocardium inin vitromodels. They were recruited to and retained at the treated myocardium with higher efficacy and specificity, if were preceded with the htAbs, than with isotype antibodies or plain buffers. The retained cells differentiated into cardiomyocytes.
  
  
  CONCLUSIONS
  The proof of concept has been attained,for reprogramming the patients' blood mononuclear cells (PBMCs) into the ahiPSCs, recruiting these cells to infarcted myocardium, and initiating their cardiomyogenesis. This novel strategy is ready to support the ongoing clinical trials aimed at regeneration of infarcted myocardium.
authors.affiliation: Phoenix Biomolecular Engineering Foundation, San Francisco, CA, USA ; National Magnetic Resonance Facility, National Institutes of Health, Madison, WI, USA ; University of Wisconsin, Madison, WI, USA.
authors.forename: Marek
authors.initials: M
authors.lastname: Malecki
authors.affiliation: University of Wisconsin, Madison, WI, USA ; American Youth Center, Washington, DC, USA.
authors.forename: Emily
authors.initials: E
authors.lastname: Putzer
authors.affiliation: University of Wisconsin, Madison, WI, USA ; University of Sheffield, Sheffield, UK, EU.
authors.forename: Chelsea
authors.initials: C
authors.lastname: Sabo
authors.affiliation: Phoenix Biomolecular Engineering Foundation, San Francisco, CA, USA ; Western University, Lebanon, OR, USA.
authors.forename: Afsoon
authors.initials: A
authors.lastname: Foorohar
authors.affiliation: Phoenix Biomolecular Engineering Foundation, San Francisco, CA, USA ; Western University, Pomona, CA, USA.
authors.forename: Carol
authors.initials: C
authors.lastname: Quach
authors.affiliation: University of Minnesota, Minneapolis, MN, USA.
authors.forename: Chris
authors.initials: C
authors.lastname: Stampe
authors.affiliation: AXS Bruker, Madison, WI, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Beauchaine
authors.affiliation: San Francisco State University, San Francisco, CA, USA.
authors.forename: Raf
authors.initials: R
authors.lastname: Malecki
authors.affiliation: BioSpin Bruker, Woodlands, TX, USA.
authors.forename: Xenia
authors.initials: X
authors.lastname: Tombokan
authors.affiliation: National Magnetic Resonance Facility, National Institutes of Health, Madison, WI, USA ; University of Wisconsin, Madison, WI, USA.
authors.forename: Mark
authors.initials: M
authors.lastname: Anderson
keywords: Myocardial infarction; autologous human induced pluripotent stem cell; cardiac regeneration; heterospecific, tetravalent antibodies; pluripotent stem cell tumorigenicity; recruitment and retention of stem cells; stage specific embryonic antigen; stem cell therapy; tumor related antigen