title: Functional and structural characterization of two populations of human monocyte-derived dendritic cells.
abstract: BACKGROUND
  The characterization of human monocyte-derived dendritic cells (HM-DC) subsets have been a very difficult and elusive task because of the lack of appropriate reagents. We, therefore utilized several diverse approaches to evaluate two populations of HM-DC including flow cytometry, ultra-structural evaluation by electron microscopy, and functional assays. In addition, we studied the kinetics of the expression of antigens on HM-DC at diverse intervals of time and identify surface markers and functional differences of these two HM-DC subsets.
  
  
  RESULTS
  This study identified that a phenotype of HM-DC as defined by CD11c+, CD86+, and CD40+ could be separated in the presence or absence of TGF-beta1 into two different subsets of DC: (i) HM-DC without Birbeck granuli (Mo-DC) and (ii) HM-DC with Birbeck granuli (Mo-LC). Furthermore, the functional studies showed that the HM-DC treated with TGF-beta1 (Mo-LC) exhibited the presence of Birbeck granuli and could actively divide. In addition, after undergoing more than four cell divisions, these cells split into at least two additional subsets of Mo-LC: (iia) Mo-LC with high forward scatter (FSC) and (iib) Mo-LC with normal FSC. In contrast, the Mo-DC cultured in absence of TGF-beta1 did not exhibit Birbeck granuli, showed reduced ability to divide, and kept the normal FSC when analyzed.
  
  
  CONCLUSIONS
  This study enabled us to determine in HM-DC: (i) the existence of antigenic and functional differences between various subpopulations of Mo-DC and Mo-LC; (ii) the existence of differences in the kinetics of antigens expression among the subsets of Mo-DC and Mo-LC; (iii) the existence of specific markers for each of the subpopulations of HM-DC.
authors.affiliation: Hematology-Oncology Section, Department of Medicine, University of Illinois at Chicago, 900 S. Ashland Avenue, Chicago, IL 60607, USA. rafaelnr@uic.edu
authors.forename: R
authors.initials: R
authors.lastname: Nunez
authors.forename: N
authors.initials: N
authors.lastname: Garay
authors.forename: A
authors.initials: A
authors.lastname: Bruno
authors.forename: C
authors.initials: C
authors.lastname: Villafane
authors.forename: E
authors.initials: E
authors.lastname: Bruno
authors.forename: L
authors.initials: L
authors.lastname: Filgueira
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology; D039521:CD11c Antigen / Q000378:metabolism*; D019013:CD40 Antigens / Q000378:metabolism*; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000145:classification / Q000166:cytology* / Q000648:ultrastructure*; D005434:Flow Cytometry; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D006801:Humans; D016130:Immunophenotyping; D015847:Interleukin-4 / Q000494:pharmacology; D007801:Langerhans Cells / Q000648:ultrastructure; D009000:Monocytes / Q000166:cytology* / Q000378:metabolism*; D016212:Transforming Growth Factor beta / Q000494:pharmacology; D053773:Transforming Growth Factor beta1
chemical_list: D000970:Antineoplastic Agents; D039521:CD11c Antigen; D019013:CD40 Antigens; C508960:TGFB1 protein, human; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; D015847:Interleukin-4; D016178:Granulocyte-Macrophage Colony-Stimulating Factor