I.
Spleen
preparation
a.
Mice
are
sacrificed
by
cervical
dislocation
by
fully
trained
personnel.
b.
Spleens
are
removed
and
suspended
immediately
in
MLC
buffer
and
then
placed
on
ice.
c.
Spleens
are
mashed
through
0.75µM
nylon
cell
strainers
with
a
5
mL
syringe
barrel.
d.
Cell
suspensions
are
washed
twice
in
ice
cold
phosphate
buffered
saline
(PBS).
e.
Supernatant
is
decanted
and
the
cells
are
re-suspended
in
1
mL
of
Red
Blood
Cell
lysis
buffer
and
then
incubated
at
room
temperature
(24°C)
for
5
min.
f.
Hemolyzed
red
cells
and
buffer
layer
are
decanted,
PBS+
is
added
and
the
remaining
splenocytes
are
washed
three
more
times.
g.
Cell
suspensions
are
put
on
ice
for
subsequent
staining
and
analysis
by
flow
cytometry.
II.
Splenocyte
staining
for
flow
cytometry
a.
Splenocytes
are
resuspended
in
FACS
buffer
before
being
aliquoted
into
96-well
plates
to
give
at
least
5x105
cells
in
each
well.
b.
Fc
blocking
antibody
(20µL)
is
added
to
each
well
and
incubated
at
4°C
for
20
min.
c.
Cells
are
washed
in
160µL
FACS
buffer
and
centrifuged
for
4
min
at
1340
rpm
at
4°C.
d.
Antibody
cocktail
is
added
to
each
well
(30µL)
and
incubated
for
30
min
at
4°C
in
the
dark.
e.
Cells
are
washed
in
160µL
FACS
buffer
and
centrifuged
for
4
min
at
1340
rpm
at
4°C.
f.
The
cells
are
then
analyzed
according
to
the
manufacturers
instructions
using
a
BD
Biosciences
LSR
II
with
BD
FACSDiva
Software
Version
6.1.1.
III.
Cell
counts
acquisition
and
analysis
a.
Samples
are
acquired
on
a
BD
LSR
II
according
to
manufacturer’s
protocol
and
acquired
cell
count
files
are
then
analyzed
with
FlowJo
software
(see
examples).
Submitting
investigator's
note:
These
files
are
available
upon
request
from
the
investigators.
b.
Lymphocytes
are
characterized
based
on
their
forward
(FSC-A)
and
side
scatter
(SSC-A)
signatures,
and
single
cells
identified
based
on
their
FSC-A
and
FSC-H
signatures.
c.
Population
gates
for
CD4+
B220-
cells
are
set
and
CD4+
CD8-
cells
are
gated
from
that
population
(Fig.
1).
d.
CD4+
CD8-
cells
are
binned
into
three
populations
based
on
their
emission
of
CD44
and
CD25
labeled
antibodies.
These
three
groups
are
CD4+CD25+CD44int
CD4+CD25-CD44hi
and
CD4+CD25-CD44lo
(Fig.
1).
e.
Data
are
exported
and
analyzed
in
the
R
statistical
package
as
percent
of
total
lymphocytes
and
percent
of
total
CD4+
T
cells.

Figure
1.
Population
gates
of
specific
cell
population.
Stained
cells |
FACS
staining |
| Lymphocytes |
FSC-A,
SSC-A
|
|
Single
cells |
CD4+,
B220-,
CD8- |
| Regulatory
T
cells |
CD4+,
CD25+,
CD44Int |
| Naive
T
cells |
CD4+,
CD25-,
CD44Lo |
| Memory/Effector
T
cells |
CD4+,
CD25-,
CD44Hi |
CD4
T
cells
-
regulatory
(Treg)
percent
of
lymphocytes
percent
of
CD4
T
cells
CD4
T
cells
-
memory
effector
percent
of
lymphocytes
percent
of
CD4
T
cells
CD4
T
cells
–
naïve
percent
of
lymphocytes
percent
of
CD4
T
cells