title: Culture of putative Langerhans cell bone marrow precursors: characterization of their phenotype.
abstract: We searched for the presence of human CD1-positive cells in bone marrow populations in order to characterize putative Langerhans cell precursors. Bone marrow progenitors were cultured in 0.8% methylcellulose supplemented with 10% granulocyte-macrophage (GM) colony-stimulating factor(s) GCT and HTB9. We compared the kinetics of these two factors and found that GCT was the more appropriate for our study. After 8 days of culture, colony-forming units of granulocyte-macrophages (CFU-GM) were tested for the presence of CD1-positive cells using the immunofluorescence technique. Positive cells were counted by cytofluorometric analysis: 9.4% CD1a (BL6), 13.4% CD1c (L161), 4.3% CD1b (NuT2), 4.6% CD2 (T11), and 25.5% CD33 (My9). Ultrastructural features and phenotype were then specified by the immunogold labeling technique using electron microscopy. A subpopulation of CD1-positive cells showed the ultrastructural morphology of bone marrow pro-monocyte/monocyte cells. By using well-characterized monoclonal antibodies, it was demonstrated that these cells expressed the following phenotype: CD14+, CD33+, CD4+, HLA-DR+, HLA-DP+, HLA-DQ-, OKT10-, CD2-. These data indicate that these bone marrow promonocyte/monocyte progenitors express a phenotype similar to that of epidermal Langerhans cells but the density of each antigen is much lower than that observed on mature skin dendritic cells.
authors.affiliation: Laboratory of Dermatology and Immunology, INSERM U 209, Lyon, France.
authors.forename: A
authors.initials: A
authors.lastname: de Fraissinette
authors.forename: D
authors.initials: D
authors.lastname: Schmitt
authors.forename: C
authors.initials: C
authors.lastname: Dezutter-Dambuyant
authors.forename: D
authors.initials: D
authors.lastname: Guyotat
authors.forename: M T
authors.initials: MT
authors.lastname: Zabot
authors.forename: J
authors.initials: J
authors.lastname: Thivolet
mesh_terms: D000911:Antibodies, Monoclonal; D000943:Antigens, Differentiation / Q000032:analysis; D001854:Bone Marrow Cells; D002478:Cells, Cultured; D003114:Colony-Forming Units Assay; D005434:Flow Cytometry; D006801:Humans; D007801:Langerhans Cells / Q000145:classification / Q000166:cytology* / Q000648:ultrastructure; D010641:Phenotype; D013234:Stem Cells / Q000145:classification / Q000166:cytology* / Q000648:ultrastructure
chemical_list: D000911:Antibodies, Monoclonal; D000943:Antigens, Differentiation