Professor Yamashita, please tell us about your research theme.
We are looking at immunology, specifically, how the functions of T
cells are controlled by metabolism and epigenetics.
Naive T cells undergo clonal expansion upon antigen stimulation, during which metabolic and epigenetic reprogramming occurs, enabling their differentiation into various types of T cells.
I started my T cell research when I was working for a
pharmaceutical company some time ago. I became hooked on the
fascinating world of T cells and their remarkable development, and
I am still working on it today. Over the last 10 years I have been
looking in particular at how T cell metabolites regulate a great
many epigenetic control factors to try and understand the
relationship between metabolism and epigenetics.
What prompted you to start using the LiCellMo?
The biggest problem in my experiments so far has been picking the
right time to measure metabolites. When I heard that the LiCellMo
can chart the glucose consumption rate and lactate production, I
was keen to use it to determine the right time for taking
measurements when using analytical devices, so this was why I
started using it.
I also previously worked on research using mice in which glycolysis
enzymes were knocked out, and I found that mice without these
enzymes were unable to sustain either T cell differentiation or
signal transduction. This finding made me realize that glycolysis
needs to be observed very carefully.
The convenience of regular cultures -a useful
tool for both beginners
and experienced researchers in metabolic analysis
What were your impressions after using the LiCellMo?
With T cell differentiation, using the LiCellMo has made it possible
to compare metabolic changes and reactions at each of the specific
timepoints when you make CD4-positive T cells differentiate into
Th1 cells, Th2 cells, Th17 cells, and regulatory T cells, or when you
make CD8-positive T cells differentiate into cytotoxic T cells.
I felt that, for beginners in the field, the LiCellMo is an intuitive tool
for understanding metabolism, and it is likely to be useful even for
researchers who are unfamiliar with metabolic analyses. At the
same time, for researchers who are already working on metabolic
analyses, it is an attractive option because it can be used as a
powerful auxiliary tool for verifying predicted behaviors.
My impression is that it is extremely user-friendly and has a
simple design, so that even first-time
users can come to grips with it easily.
Once you start, the device takes care of
the measurements automatically, so
using it is as straightforward as doing a
regular culture. You don’t need any
special plates, so the preparation is
simple.
By observing changes in the consumption rate, you can grasp overall trends
Using the LiCellMo has made it possible to determine whether the
glucose consumption rate rises sharply or increases gradually
over time. This is the major benefit of chronological
measurements, and it is extremely useful to be able to see overall
changes in detail.
We used to measure metabolic states at 24 hours and 48 hours,
which were specific timepoints determined through experience,
but we had no way of knowing the reaction speed between these
points. For example, you may get the same results after 24 hours,
but by using the LiCellMo, you can now tell how the changes in
metabolic activation progress over this period with differences in
culture conditions.
Say you go from Ehime to Tokyo, the end result is the same
however you travel—you arrive in Tokyo. However, we can now
observe you en route to see whether you went by airplane or
whether you took a slower trip on the bullet train.
In an actual situation, the end result of a culture after 48 hours
looks the same whether or not you add a particular cytokine, but
we found out that the progress and speed during the intervening
period are different. The ability to acquire this sort of detailed
information is enormously valuable.
Chronological measurement has made it possible
to observe changes in differentiation and activation of T cells
What do you feel are the main strengths of the LiCellMo?
I think the biggest advantage has to be the ability to make
chronological measurements. Particularly in the field of the
immune system, with the differentiation or activation of T cells, B
cells, and macrophages, there are precise triggers that recognize
antigens, which is the starting point from which dramatic changes in metabolism occur. I think this makes the LiCellMo particularly
suitable for work in the field of immunology.
We have also
discovered that, after T cells are stimulated by an antigen and their
glycolysis is dramatically activated, a cytokine called IL-2 is
needed to sustain this glycolysis. Processes like this can be
confirmed in vitro using the LiCellMo. In fact, we have confirmed
that metabolism can be observed not only in T cells, but also in B
cells.
We have also found that, when differentiation of CD4-positive T
cells into helper T cell subsets, such as Th1 or Th2 cells, is induced
in vitro, the level of activation of glycolysis and the time for which
it is sustained vary greatly depending on the conditions. This is
also something that was only discovered when observations were
made over time. Information such as, for example, the level at
which glycolysis activation is sustained or how the consumption
rate changes over time can only be obtained through chronological
measurements.
Also, if you have a decrease in lactate, which is a downstream
molecule in glycolysis, a tool like the LiCellMo is absolutely
invaluable for determining whether this is due to changes in the
consumption rate or whether some other factors are involved.
Using the LiCellMo allows us to measure over time whether
glucose and lactate metabolism are being held back, or whether
they are decreasing because large amounts have been used.
This is the big advantage of the LiCellMo - the chronological
measurements show us things that we couldn’t grasp before from
measurements that were just single snapshots.
Functionality that allows measurement to be
finished whenever you want, and a 24-well
plate that ensures you have enough cells for
direct reuse in other analyses
The big advantage of the LiCellMo is that, if at any time during
measurement you want to carry out more detailed observations of
the cells, you have the flexibility to finish measuring and collect the
cells for transfer to another measuring device for more detailed
analysis. An important feature of the LiCellMo is that it uses
24-well plates, which ensures that you have enough cells for use in
other analyses, such as flow cytometry or Western blotting.
For example, while we measure the glucose consumption rate, we
collect cells every 48 hours and use them for analysis in separate
devices. We also observe changes in intracellular markers when
glycolysis is activated, so that we can verify in detail the
relationships between metabolism and molecular markers. In this
sense, the LiCellMo plays a very important role in complementing
the fragmented information that is all that other analysis devices
can provide.
How do you see the prospects for future research?
I would like to use the LiCellMo to screen for the effects of
disease-specific metabolites and proteins on cell metabolism,
particularly glycolysis.
For example, I envision the LiCellMo being
useful in observing activation of glycolysis accompanying
diseases, which could be used not just for discovering disease
markers, but also for screening substances potentially leading to
drug development.
In this interview, Professor Yamashita
discussed his reasons for adopting the
LiCellMo, and he shared some specific insights
into how this device is contributing to his
research into T cells. Looking to the future,
PHC’s LiCellMo is set to become a
game-changer in the field of immunological
research, with applications that include
screening pharmaceuticals for drug discovery.