B-cell development

1
B-cell development Activation
B cell and T cell
2
B-cell development
Maturation antigen-independent Activation and
Differentiation antigen-dependent
3
B-cell maturation
4
(No Transcript)
5
(No Transcript)
6
mIgs at different stage of B-cell differentiation
Roles of Pre-B-cell receptor
7
Molecules that are related to the B-c ell
development

• Transcription factors
• E2A, EBF regulation of RAG-1 and l5 expression
• BSAP (Pax-5) Vpre-B, l5, Ig heavy chain
• Sox-4
• Surface Markers stage specific
• Pro-B cell CD45R (B220), Ig-a/Ig-b, CD19,
  HSA(CD24), CD43, c-Kit, IL7R
• Pre- B cell Pre-BCR, CD25
• Immature B cell mIgM

8
Clonal deletion (negative selection)
90 of B-cells that express auto-antibodies
against self-antigens are eliminated in the bone
marrow
9
(No Transcript)
10
Light-chain editing escape negative selection
11
B-cell activation and Proliferation
Thymus-dependent (TD) and thymus-independent (TI)
Ag
12
Effective signals for B-cell activation
Competence signal drive from G0 into G1, signal
1 and signal 2 Progression signal drive from G1
into S
13
Initiation of Signal transduction activated by BCR
14
(No Transcript)
15
B-cell co-receptor complex
16
B-cell activation by TH
Ag binging to mIg signal 1 Receptor-mediated
endocytosis - Ag presentation /MHC II -
B7 expression Activation of TH cell -
B7-CD28 - Expression of CD40L B cell
activation - CD40/CD40L signal 2 -
Express cytokine receptors - Proliferation
17
T-B conjugate
Cytokines CD40L/CD40 interaction
18
Negative selection of mature B cells in the
periphery
Anergy
19
(No Transcript)
20
(No Transcript)
21
The Humoral response primary vs. secondary
response
22
(No Transcript)
23
Carrier effect
24
(No Transcript)
25
(No Transcript)
26
(No Transcript)
27

• B-cell differentiation in GC,
• Affinity maturation
• and selection FDC
• Class switching
• Formation of effector B cells

28
Somatic hypermutation affinity maturation
29
(No Transcript)
30
(No Transcript)
31
Antibody-dependent cell-mediated cytotoxicity
(ADCC)

• Membrane receptors for the Fc region of IgG
• Specificity of the antibody directs non-specific
  cytotoxic cells to specific target cells
• NK cells, macrophages, monocytes, neutrophils,
  eosinophils
• Release of lytic enzymes at the site of
  Fc-mediated contact result in damage to the
  target cells
• Tumor necrosis factor (TNF)
• Perforin-mediated membrane damage

32
(No Transcript)