title: Identification of a novel role of T cells in postnatal vasculogenesis: characterization of endothelial progenitor cell colonies.
abstract: BACKGROUND
  The colony number of early endothelial progenitor cells (EPCs) has been used as a quantitative indicator of the number of EPCs in the blood or as a biological marker of cardiovascular diseases. In the present study, we found a subset of T cells that were localized at the center of the EPC colony and played a pivotal role in colony formation and differentiation of early EPCs.
  
  
  RESULTS
  We found that CD3+ CD31+ CXCR4+ T cells (referred to as angiogenic T cells in the present study) constituted the center of EPC colonies during cultures of human peripheral blood mononuclear cells. These angiogenic T cells were required for colony formation and differentiation of early EPCs. They secreted high levels of angiogenic cytokines such as vascular endothelial growth factor, interleukin-8, and matrix metalloproteinases. Angiogenic T cells showed superior angiogenic potential to the other subset of T cells in the experiments with regard to Matrigel tube formation, adhesion, transendothelial migration, and collagen invasion assay, mainly through the stromal cell-derived factor 1/CXCR-4 axis. Furthermore, angiogenic T cells enhanced endothelial cell proliferation and function. In vivo study showed that angiogenic T cells play an important role in the process of vessel formation. Clinical study showed that the level of angiogenic T cells in the peripheral blood was well correlated with EPC colony numbers and had inverse relationships with age and the number of risk factors for coronary artery disease.
  
  
  CONCLUSIONS
  These findings suggest that angiogenic T cells could be a potential therapeutic target for ischemic cardiovascular diseases.
authors.affiliation: Innovative Research Institute for Cell Therapy, Seoul National University Hospital, Seoul, Korea.
authors.forename: Jin
authors.initials: J
authors.lastname: Hur
authors.forename: Han-Mo
authors.initials: HM
authors.lastname: Yang
authors.forename: Chang-Hwan
authors.initials: CH
authors.lastname: Yoon
authors.forename: Choon-Soo
authors.initials: CS
authors.lastname: Lee
authors.forename: Kyung-Woo
authors.initials: KW
authors.lastname: Park
authors.forename: Ji-Hyun
authors.initials: JH
authors.lastname: Kim
authors.forename: Tae-Youn
authors.initials: TY
authors.lastname: Kim
authors.forename: Ju-Young
authors.initials: JY
authors.lastname: Kim
authors.forename: Hyun-Jae
authors.initials: HJ
authors.lastname: Kang
authors.forename: In-Ho
authors.initials: IH
authors.lastname: Chae
authors.forename: Byung-Hee
authors.initials: BH
authors.lastname: Oh
authors.forename: Young-Bae
authors.initials: YB
authors.lastname: Park
authors.forename: Hyo-Soo
authors.initials: HS
authors.lastname: Kim
mesh_terms: D015703:Antigens, CD / Q000032:analysis; D015415:Biomarkers; D017252:CD3 Complex / Q000032:analysis; D002318:Cardiovascular Diseases / Q000473:pathology*; D002454:Cell Differentiation; D004730:Endothelium, Vascular / Q000254:growth & development* / Q000502:physiology; D006801:Humans; D018919:Neovascularization, Physiologic; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000032:analysis; D013234:Stem Cells / Q000166:cytology / Q000276:immunology / Q000502:physiology*; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology / Q000502:physiology*
chemical_list: D015703:Antigens, CD; D015415:Biomarkers; D017252:CD3 Complex; D019408:Platelet Endothelial Cell Adhesion Molecule-1