title: Flow cytometric analysis of T cell proliferation in a mixed lymphocyte reaction with dendritic cells.
abstract: BACKGROUND
  Dendritic cells (DCs) are the most potent antigen-presenting cells. They can be generated in vitro from CD14+ cells, and also from CD34+ progenitor cells. Although T cell proliferation using [3H] thymidine incorporation assay has been used widely to check DC function, this technique only provides limited information about the T cell proliferation. Here, we describe a novel method for quantitative analysis of T cell proliferation using flow cytometry.
  
  
  METHODS
  DCs were generated from CD14+ cells from six healthy blood donors. Monocytes were isolated using positive selection with magnetic cell sorting (MACS) and then cultured with IL-4, GM-CSF, IL-1beta, IL-6, TNF-alpha and PGE(2) to yield fully mature DCs. Allogeneic naive T lymphocytes with known mismatches in HLA classes I and II were cocultured with DCs. Naive T cells without DC stimulation served as negative controls. T cells were harvested on days 0, 3, 5, 7, 9, 11 and analysed by flow cytometry. CD3-ECD and CD4-fluorescein isothiocyanate (FITC) or CD8-FITC antibodies were used to distinguish T cell subsets, whereas T cell activation was measured by assessment of HLA-DR, CD45RO, CD25 and CD71 expression. For T cell quantification, fluorescent microparticles were used. Dead cells were excluded with 7-AAD. The bromdeoxyridine (BrdU)-incorporation ELISA procedure was also performed in order to compare with the T cell proliferation assay with regard to absolute cell counts and CD71 expression.
  
  
  RESULTS
  The initial T cell concentration on day 1 was 203.9+/-39.7 (173-265) CD3+/CD4+ cells/micro l and 184.5+/-41.6 (148-260) CD3+/CD8+ cells/micro l. The maximal T cell proliferation was recorded on day 7 with a five- to tenfold T cell expansion which resulted in 1994.9+/-383 (1446-2404) CD3+/CD4+ cells/micro l and 944+/-303.7 (560-1483) CD3+/CD8+ cells/micro l. Furthermore, activation markers of both cell lineages were upregulated and reached maxima on days 7 (CD71) and 9 (CD25, HLA-DR). T cell count/micro l as well as CD71 expression both correlated significantly with BrdU incorporation.
  
  
  CONCLUSIONS
  Flow cytometric analysis permits simple, precise and rapid quantification of T cell proliferation in a mixed lymphocyte reaction with DCs. Activation, proliferation and cell viability can be simultaneously determined. CD71 is particularly well suited as an activation marker for the simultaneous measurement of T cell proliferation. Thus, specific T cell subsets involved in antigen-specific proliferation can be evaluated in detail.
authors.affiliation: Institute of Transfusion Medicine and Immunology, Red Cross Blood Service of Baden-Württemberg - Hessen, Germany. x.nguyen@blutspende.de
authors.forename: Xuan Duc
authors.initials: XD
authors.lastname: Nguyen
authors.forename: Hermann
authors.initials: H
authors.lastname: Eichler
authors.forename: Alex
authors.initials: A
authors.lastname: Dugrillon
authors.forename: Christoph
authors.initials: C
authors.lastname: Piechaczek
authors.forename: Michael
authors.initials: M
authors.lastname: Braun
authors.forename: Harald
authors.initials: H
authors.lastname: Klüter
mesh_terms: D001973:Bromodeoxyuridine / Q000378:metabolism; D017252:CD3 Complex / Q000378:metabolism; D015704:CD4 Antigens / Q000378:metabolism; D016827:CD8 Antigens / Q000378:metabolism; D003713:Dendritic Cells / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005434:Flow Cytometry / Q000379:methods*; D006801:Humans; D066298:In Vitro Techniques; D018950:Lipopolysaccharide Receptors / Q000378:metabolism; D008213:Lymphocyte Activation; D007959:Lymphocyte Culture Test, Mixed / Q000379:methods*; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology
chemical_list: D017252:CD3 Complex; D015704:CD4 Antigens; D016827:CD8 Antigens; D018950:Lipopolysaccharide Receptors; D001973:Bromodeoxyuridine