| Cell differentiation and activation are complex processes
generally believed to occur in a continuous fashion.
However, techniques which monitor single cells
rather than a population of cells often reveal these
processes involve a series of discrete steps or switches.
For example, as reported for promyelocytic precursor
cells, HL60, stimulated with DMSO, differentiation
to neutrophils occurs through a multi-step process
in which cells are first primed and then differentiate
by an all-or-none mechanism (Chang et al., BMC Cell
Biology, 7:11; 2006). Using four-color flow cytometry,
we extended these studies to examine the extra- and
intracellular markers that correlate with these priming
and differentiation steps. In addition, we examined the
differences in expression of markers when HL60 cells
were stimulated with PMA to induce differentiation to
the monocytic lineage. Similarly, for primary leukocyte
activation, the expression of such activation markers
as CD25, CD69, CD38 and CD49a among others, can be
tracked on individual cells and correlated with the cells’
proliferative capacity. Thus, four-color flow cytometry
which can readily monitor differentiation and activation
steps on a single cell level can better uncover the actual
mechanisms involved in these complex processes than
can analyses of populations of cells. This leads to a more
complete understanding of the molecular mechanisms
that control differentiation and maturation of hematopoietic
cells crucial for the clinical manipulation of blood
cell production. |
日本
