[Human thymic dendritic cells].
Human thymic dendritic cells (DC) were enriched from thymocyte suspension by low density fractionation and elimination of CD3, CD8, CD19, CD56 and CD34-positive cells. Flow cytometry analysis shows that they belong to two distinct populations. The prominent (2/3) one is CD4+ CD45RA+ CD33-CD11c-, mostly immature as it lacks CD80, CD83 and CD86, and is HLA-DRint. High expression of CD123 and expression of pre-TCR-alpha transcripts links this subset to lymphoid, interferon-producing cells. The other DC are typically CD4+ CD33+ CD11c+ myeloid cells mostly mature CD83+ HLA-DRhi. Both subsets could be generated in vitro from thymic CD34+ progenitors. Finally although experimental evidence ascribed to thymic DC a major role in establishing central tolerance through deletion of self reactive thymocytes, the respective functions of human lymphoid and myeloid subsets in the human thymus remain to be established.
Dalloul
A H
AH
URA CNRS 625, CERVI, hôpital de la Pitié, boulevard de l'Hôpital, 75651 Paris, France.
D015703:Antigens, CD / Q000032:analysis / Q000235:genetics; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology*; D005434:Flow Cytometry; D006801:Humans; D013601:T-Lymphocytes / Q000276:immunology; D013950:Thymus Gland / Q000166:cytology* / Q000276:immunology*
D015703:Antigens, CD