Gene expression during differentiation of human dendritic cells from cord blood CD34 stem cells

Human cord blood CD34(+) stem cells were allowed to differentiate in the pr esence of cytokines stern cell factor (SCF), granulocyte-macrophage colony- stimulating factor (GM-CSF) and tumour necrosis factor alpha (TNF-alpha) in to functional CD1a(+) dendritic cells (DC). A maximum of 1.9 x 10(6) CD1a() cells were separated from the cells generated from 1.2 x 10(6) CD34(+) st em cells from an individual donor. The percentage of CD1a(+) cells separate d rose to a maximum of 27% at day 11 and fell to 8% at 21 days, Reverse tra nscription-polymerase chain reaction analysis showed that interleukin 2 rec eptor, interleukin 3 receptor, interleukin 6 receptor, interleukin 12 recep tor (IL-12R) and signal transducer and activator of transcription (STAT) 3, STAT 4 mRNA was expressed in all CD1a(+) cell populations throughout and a ppears to be constitutive. Expression of IL-12RmRNA was unexpected in CD1a( +) DC normally considered to be of myeloid lineage. Expression of interleuk in 12 (IL-12) p40 subunit mRNA was not detected. Intermittent expression of the IL-12p35 subunit and IL-4R mRNA suggested that gene expression is indu cible, but not obviously correlated with progressive DC development, Expres sion of mRNA for a spectrum of cytokine receptors indicates that CD1a(+) DC have the potential to respond to a variety of maturational signals. (C) 19 99 Academic Press.