title: Ex vivo characterization of human thymic dendritic cell subsets.
abstract: Interactions between thymic dendritic cells (DC) and thymocytes are critical for proper development of T-cells. We identified human thymic DC populations on the basis of CD123, CD11c and CD14 expression. High levels of CD123 (IL-3R) and CD45RA defined the plasmacytoid DC (pDC) subset. Human thymic CD11c(+) DC expressed CD45RO and myeloid-related markers (CD13, CD33 and CD11b). CD11c(+) DC could be separated into two main subsets based on differential expression of CD14: CD11c(+) CD14(-) and CD11c(+) CD14(+) cells. Spontaneous production of IL-10 and IFNgamma without exogenous stimulation, was observed in the three DC subsets. Important phenotype modifications were observed in pDC cultures supplemented with IL-3. A down-regulation of CD123 and appearance of myeloid markers such as CD11b and CD11c on CD45RA(+) cells was noticed within the first 48h; at a later time there was a shift from CD45RA to CD45RO expression, as well as appearance of CD14 expression. CD11c(+) cells emerging in pDC culture did not express high levels of HLA-DR, CD83 and co-stimulatory molecules. This suggests an in vitro evolution of human thymic pDC toward a myeloid phenotype found in the CD11c(+) subset of thymic DC.
authors.affiliation: Unité de Régulation des Infections Rétrovirales, Institut Pasteur, 25 rue du Dr Roux, 75724 Paris Cedex 15, France. nathalis@bhcs.com <nathalis@bhcs.com>
authors.forename: Nathalie
authors.initials: N
authors.lastname: Schmitt
authors.forename: Marie-Christine
authors.initials: MC
authors.lastname: Cumont
authors.forename: Marie-Thérèse
authors.initials: MT
authors.lastname: Nugeyre
authors.forename: Bruno
authors.initials: B
authors.lastname: Hurtrel
authors.forename: Françoise
authors.initials: F
authors.lastname: Barré-Sinoussi
authors.forename: Daniel
authors.initials: D
authors.lastname: Scott-Algara
authors.forename: Nicole
authors.initials: N
authors.lastname: Israël
mesh_terms: D015703:Antigens, CD / Q000096:biosynthesis; D002478:Cells, Cultured; D002675:Child, Preschool; D016207:Cytokines / Q000096:biosynthesis; D003713:Dendritic Cells / Q000145:classification* / Q000276:immunology* / Q000378:metabolism; D006801:Humans; D016130:Immunophenotyping; D007223:Infant; D007231:Infant, Newborn; D013950:Thymus Gland / Q000166:cytology* / Q000276:immunology / Q000378:metabolism
chemical_list: D015703:Antigens, CD; D016207:Cytokines