title: mAb C19 targets a novel surface marker for the isolation of human cardiac progenitor cells from human heart tissue and differentiated hESCs.
abstract: OBJECTIVE
  Cardiac progenitor cells (CPCs) have been isolated from adult and developing hearts using an anti-mouse Sca-1 antibody. However, the absence of a human Sca-1 homologue has hampered the clinical application of the CPCs. Therefore, we generated novel monoclonal antibodies (mAbs) specifically raised against surface markers expressed by resident human CPCs. Here, we explored the suitability of one of these mAbs, mAb C19, for the identification, isolation and characterization of CPCs from fetal heart tissue and differentiating cultures of human embryonic stem cells (hESCs).
  
  
  RESULTS
  Using whole-cell immunization, mAbs were raised against Sca-1+ CPCs and screened for reactivity to various CPC lines by flow cytometry. mAb C19 was found to be specific for Sca-1+ CPCs, with high cell surface binding capabilities. mAb C19 stained small stem-like cells in cardiac tissue sections. Moreover, during differentiation of hESCs towards cardiomyocytes, a transient population of cells with mAb C19 reactivity was identified and isolated using magnetic-activated cell sorting. Their cell fate was tracked and found to improve cardiomyocyte purity from hESC-derived cultures. mAb C19+ CPCs, from both hESC differentiation and fetal heart tissues, were maintained and expanded in culture, while retaining their CPC-like characteristics and their ability to further differentiate into cardiomyocytes by stimulation with TGFβ1. Finally, gene expression profiling of these mAb C19+ CPCs suggested a highly angiogenic nature, which was further validated by cell-based angiogenesis assays.
  
  
  CONCLUSIONS
  mAb C19 is a new surface marker for the isolation of multipotent CPCs from both human heart tissues and differentiating hESCs.
authors.affiliation: Bioprocessing Technology Institute, Agency for Science, Technology and Research (A*STAR), Singapore; NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore.
authors.forename: Hau Wan
authors.initials: HW
authors.lastname: Leung
authors.affiliation: Department of Molecular Cell Biology, Leiden University Medical Centre, Leiden, The Netherlands.
authors.forename: Asja T
authors.initials: AT
authors.lastname: Moerkamp
authors.affiliation: Bioprocessing Technology Institute, Agency for Science, Technology and Research (A*STAR), Singapore.
authors.forename: Jayanthi
authors.initials: J
authors.lastname: Padmanabhan
authors.affiliation: Bioprocessing Technology Institute, Agency for Science, Technology and Research (A*STAR), Singapore.
authors.forename: Sze-Wai
authors.initials: SW
authors.lastname: Ng
authors.affiliation: Department of Molecular Cell Biology, Leiden University Medical Centre, Leiden, The Netherlands.
authors.forename: Marie-José
authors.initials: MJ
authors.lastname: Goumans
authors.affiliation: Bioprocessing Technology Institute, Agency for Science, Technology and Research (A*STAR), Singapore; Department of Bioengineering, National University of Singapore, Singapore. Electronic address: andre_choo@bti.a-star.edu.sg.
authors.forename: Andre
authors.initials: A
authors.lastname: Choo
mesh_terms: D000911:Antibodies, Monoclonal / Q000378:metabolism / Q000494:pharmacology; D000954:Antigens, Surface / Q000378:metabolism*; D018929:Cell Culture Techniques; D002454:Cell Differentiation; D002469:Cell Separation / Q000379:methods; D002478:Cells, Cultured; D053595:Embryonic Stem Cells / Q000166:cytology*; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D006801:Humans; D032386:Myoblasts, Cardiac / Q000166:cytology* / Q000378:metabolism*; D009206:Myocardium / Q000166:cytology*; D032383:Myocytes, Cardiac / Q000166:cytology / Q000378:metabolism; D018919:Neovascularization, Physiologic / Q000187:drug effects; D015203:Reproducibility of Results
chemical_list: D000911:Antibodies, Monoclonal; D000954:Antigens, Surface
keywords: Cardiomyocyte differentiation; Monoclonal antibodies; Multipotent; Resident cardiac progenitor cells; Sca-1; hESC differentiation