Iranian Journal of Pediatrics
Tehran University of Medical Sciences Press
Vol. 18, No. 3, 2008, pp. 213-221
Bioline Code: pe08034
Full paper language: English
Document type: Research Article
Document available free of charge
Iranian Journal of Pediatrics, Vol. 18, No. 3, 2008, pp. 213-221
© Copyright 2008 - TUMS PUBLICATIONS
Juvenile Myelomonocytic Leukemia (JMML) Cells Spontaneously Differentiate into Dendritic-cell Like Populations|
Juvenile myelomonocytic leukemia (JMML) is a rare myelodysplastic/ myeloproliferative malignancy of early childhood, characterized by monocytosis, hepatosplenomegaly and an aggressive clinical course.
In semi-solid culture JMML progenitor cells proliferate spontaneously into colony forming units. In order to study the mechanisms of proliferation and differentiation of JMML cells we developed a suspension culture system without additional exogenous growth factor supplement. Mononuclear cells (MNC) from peripheral blood, bone marrow or spleen of 14 patients with JMML and 24 controls were studied.
JMML cells expressed higher levels of the proliferation marker Ki67 (median 24% [7-39%] vs a median of 3.5% in controls). 90% of JMML cells were CD68-positive (vs 35% in controls) and by day 7 all JMML samples contained CD1a- positive cells. Electron microscopy demonstrated cytoplasmic vesicular structures resembling multilamellar MHC II comparetiments, which together with the expression of CD1a - support a dendritic cell (DC)-phenotype.
Differentiation into CD1a-positive DC seems to be a frequent phenomenon in cultured JMML MNC, which in vivo may contribute to clinical characteristics such as skin and organ infiltration.
Juvenile myelomonocytic leukemia; CD1a; Dendritic cells; Suspension cell culture; Electron microscopy; Immunostaining
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