HSC

1
Review-2
2nd lymphoid tissues
T and B cells
Hematopoiesis
Thymus
T cells
Spleen
Immature B cells
Mature B cells
CLP
Self renewal
Dendritic cells
HSC
Peripheral tissues Lymphoid tissues
Dendritic cells
Monocytes
CMP
Macrophages
Granulocytes
Bone marrow
Erythrocytes Platelets
2
B cell maturation
Bone marrow
Spleen
Pre-B
Immature B
Mature B
Pro-B
Selection
V-J (IgL)
V-D-J (IgH)
?
?
?
pre-BCR
? or ?
sIgM
sIgM, sIgD
IL-7R
3
V(D)J recombination
DH
JH
CH
VH
IgH
D-J
12-23 rule
Rag-1/2
V-DJ
Diveristy
Rag-1/2
V-J
IgL
CL
JL
VL
4
Allelic exclusion
IgH
Ig?

Ig?

sIgM
apoptosis
pre-BCR
Negative selection
Anergy
Receptor editing
Apoptosis
5
T cell maturation
Thymus
?? T cell
DP
SP
DN
V-J
(TCR?)
Negative selection
T cell commitment V-D-J (TCR?, TCR?, TCRg)
Positive selection
CD4/CD8 commitment
?
pre-TCR
?
TCR??
IL7R
6
V(D)J recombination at the TCR loci
Allelic exclusion
Positive selection
apoptosis
DP
No interaction with self-MHC
DP
MHC-I TCR/CD8
TCR/CD4 MHC-II
CD8
CD4
7
Negative selection
mTEC
mDC
Self-antigen
AIRE
Self-antigen/MHC-I, II
Self-antigen/MHC-I
SP T cell
Higher threshold
Lower threshold
Negative selection
Positive selection
TCR affinity toward self-antigen/MHC
8
Circulation of B and T cells
Lymphatic circulation
Peripheral tissue
Intestine lumen
Peyers patch
LN
Blood circulation
B
T
Lymphatic circulation
antigen
spleen
9
T cell activation
Antigen presentation
Blood antigen
Peripheral antigen
DC
T cell
DC
Spleen
DC
T cell
Lymph node
Intestinal antigen
M cell
DC
T cell
Peyers patch
10
T cell activation
CD4 T cell
antigen
CTLA-4
APC
IL-2
CD28
B7
activation
Class II MHC
Antigen/MHC
TCR/CD4
CD40
Th1 or Th2 cytokines
CD40L
inflammation
B cell activation
11
B cell activation
Antigen
antigen
BCR
Co-receptor
CD22, Fc?RIIB
DC
B cell
MHC
activation
B cell
DC
CD40
B7
B cell
Antigen/MHC
chemokines
HEV
TCR/CD4
CD28
CD40L
TFH
12
B cell activation
Class switching
S region
S region
?1
?
Cytokine regulation
AID
?1
Plasma cell
Secretion of immunoglobulin