Hi there, my name is David Kent and I'm a group leader at
the Wellcome-MRC Cambridge Stem Cell Institute
at the University of Cambridge in the United Kingdom.
Today, I'm going to talk to you about
hematopoietic stem cells and, in particular, the power of clonal assays.
So, fundamentally, stem cells have to undergo
a series of divisions that involve a series of fate choices.
Those fate choices can very simplistically yet,
provocatively be summarized in this simple diagram.
This diagram shows where a stem cell has to decide whether or not to make a single stem cell,
which is equally capable of all the things that the stem cell is used to doing
or, a differentiated cell, which goes down and makes one of
the many different types of mature cells
in the adult cell system that the stem cell is based in.
At a population level,
this balance of fate decisions can go awry and you can get an accumulation of
either more immature leg stem cells or you can get an accumulation of
differentiated cells, which results in the depletion of these stem cells.
When you have this happen on a population level,
you end up with the result in the body of having too many immature cells situation like
cancer or, too many differentiated cells and
not enough stem cells to supply the system on a daily basis,
which is represented by tissue aging or degeneration.
Now, at a fundamental population level,
we're very interested in questions,
as scientists, about how this balance is established
and how it's maintained throughout life?
We know, fundamentally, that population asymmetry is required for homeostasis
but, when it goes wrong we want to understand,
at the stem cell level,
what the implications are for disease.
So, if we understand stem fate choice completely,
can we understand how to treat diseases of stem cell origin and can
we, indeed, try and figure out ways of supplying unlimited cell types for the body?