title: Uptake and delivery of antigens by mesenchymal stromal cells.
abstract: OBJECTIVE
  Mesenchymal stromal cells (MSCs) are multipotent stem cells with immunosuppressive properties. Nevertheless, it has been previously reported that MSCs might also trigger the immune response. We studied whether MSCs may act as carriers, capturing antigens that can be endocytosed by antigen-presenting cells later on.
  
  
  METHODS
  We measured the cellular uptake of mannose receptor-mediated fluid phase macropinocytosis, assessed as cellular uptake of fluorescein isothiocyanate-dextran, and PKH-67-labeled cell lysates as a surrogate marker for antigen capture among dendritic cells (DCs, positive control), T lymphocytes (negative control) and MSCs.
  
  
  RESULTS
  All experiments confirmed that MCSs displayed pinocytic and endocytic capacities, which were lower than those observed for DCs but significantly higher than those observed for T cells. We also demonstrated that MSCs release previously endocytosed antigens, which subsequently can be captured by DCs.
  
  
  CONCLUSIONS
  MSCs have the ability to capture and release antigens.
authors.affiliation: Department of Hematology, University Hospital Virgen del Rocío/IBIS/CSIC/University of Seville, Seville, Spain.
authors.forename: Luis Ignacio
authors.initials: LI
authors.lastname: Sánchez-Abarca
authors.forename: Isabel
authors.initials: I
authors.lastname: Alvarez-Laderas
authors.forename: María
authors.initials: M
authors.lastname: Díez Campelo
authors.forename: Teresa
authors.initials: T
authors.lastname: Caballero-Velázquez
authors.forename: Carmen
authors.initials: C
authors.lastname: Herrero
authors.forename: Sandra
authors.initials: S
authors.lastname: Muntión
authors.forename: Cristina
authors.initials: C
authors.lastname: Calderón
authors.forename: Estefanía
authors.initials: E
authors.lastname: García-Guerrero
authors.forename: Fermín
authors.initials: F
authors.lastname: Sánchez-Guijo
authors.forename: Consuelo
authors.initials: C
authors.lastname: Del Cañizo
authors.forename: Jesús
authors.initials: J
authors.lastname: San Miguel
authors.forename: José Antonio
authors.initials: JA
authors.lastname: Pérez-Simón
mesh_terms: D000938:Antigen-Presenting Cells / Q000276:immunology; D003713:Dendritic Cells / Q000276:immunology / Q000378:metabolism; D004705:Endocytosis; D006681:HLA-D Antigens / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D007166:Immunosuppressive Agents; D037181:Lectins, C-Type / Q000276:immunology / Q000378:metabolism; D000090323:Mannose Receptor; D037241:Mannose-Binding Lectins / Q000276:immunology / Q000378:metabolism; D045164:Mesenchymal Stem Cell Transplantation; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000276:immunology / Q000378:metabolism; D039902:Multipotent Stem Cells; D010873:Pinocytosis; D011956:Receptors, Cell Surface / Q000276:immunology / Q000378:metabolism; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology / Q000378:metabolism
chemical_list: D006681:HLA-D Antigens; D007166:Immunosuppressive Agents; D037181:Lectins, C-Type; D000090323:Mannose Receptor; D037241:Mannose-Binding Lectins; D011956:Receptors, Cell Surface