Immunophenotypical, morphologic, and functional characterization of maturation-associated plasmacytoid dendritic cell subsets in normal adult human bone marrow.
BACKGROUND
Information about maturation of plasmacytoid dendritic cell precursors (pre-pDCs) in normal bone marrow (BM) remains limited.


METHODS
Immunophenotypical, morphologic, and functional changes associated with maturation of pre-pDCs were analyzed in adult normal human BM (n = 45).


RESULTS
Three pre-pDC maturation stages, with an increasingly higher degree of maturity, were systematically identified: CD34++/HLA-DR++/+++/CD123++/CD45+/++ (Stage I), CD34+/HLA-DR+/++/CD123++/+++/CD45+/++ (Stage II), and CD34-/HLA-DR++/CD123++/+++/CD45++ (Stage III) cells. Lymphoid- and early myeloid-associated molecules, as well as CD86, were coexpressed in Stage I pre-pDCs, being down regulated afterward. CD304 and CD85j appeared in Stage I, progressively increasing their levels thereafter. Interestingly, cutaneous lymphocyte-associated antigen was heterogeneously expressed throughout the maturation, particularly in Stage I pre-pDCs. The morphologic appearance of Stage I pre-pDCs was consistent with their undifferentiated stage, while Stage II/III cells showed morphologic features of more differentiated cells. From the functional point of view, only Stage II and Stage III pre-pDCs were capable of inducing allogeneic T-cell proliferation, the later subset also showing interferon-g secretion; in contrast, Stage I pre-pDCs showed the highest endocytic ability.


CONCLUSIONS
In summary, three maturation stages of pre-pDCs can be identified in adult normal BM, which show unique phenotypical, morphologic, and functional characteristics; these results provide a frame of reference for a better understanding of pDC malignancies.
Martín-Martín
Lourdes
L
Instituto de Biología Molecular y Celular del Cáncer, Centro de Investigación del Cáncer/IBMCC (CSIC-USAL), Salamanca, Spain.
Almeida
Julia
J
Hernández-Campo
Pilar María
PM
Sánchez
María Luz
ML
Lécrevisse
Quentin
Q
Orfao
Alberto
A
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000943:Antigens, Differentiation / Q000276:immunology*; D001854:Bone Marrow Cells / Q000166:cytology / Q000276:immunology; D002454:Cell Differentiation / Q000276:immunology*; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010950:Plasma Cells / Q000166:cytology / Q000276:immunology
D000943:Antigens, Differentiation