Chapter 17
Immunoregulation
• To keep the individual homeostasis by
regulating
the
balance between
immunocyte
and
immunocyte,
between immunocyte and immune
molecule
and
between
immune
system and nerve system /endocrine
system.
Content
• Immuno-regulation
• Immuno-regulation
• Immuno-regulation
• Immuno-regulation
population level
on
on
on
on
genetic level
molecular level
cellular level
individual and
Section I regulation on genetic level
1. Genes encode TCR and BCR
2. Genes encode immune response
regulating molecules:
• MHC
• Immune response gene,Ir gene(HLA)
Section II. Immunologic regulation
on molecular level
1. Regulation of antigen to Ir
2. Regulation of antibody and Ag-Ab
complex to Ir
antibody feedback inhibition:
1. Regulation of antigen
Route of Ag entrance
Dosage of Ag
Structural characteristic: antigen
competition
2. Regulation of antibody
（1）regulation by immune complex
 When Ab increase, it binds to Ag and
weaken IR
 Regulation of Ag-Ab complex to I R ----Antibody feedback inhibition
IgM----stimulate IR
IgG----reduce IR
antibody feedback inhibition:
Ag
BCR
Ag
FcrR II
BCR
ITIM
Antibody Feedback Inhibition
(2) The idiotypic networks and
immunologic regulation
Idiotypic determinant or idiotype: a
unique determinant on an antibody or
BCR/TCR molecule,usually formed by one
or more of the hypervariable regions.
anti-idiotypic antibody (or TCR):
antibodies against idiotype of antibodies
or TCRs
Idiotypic networks
• A network of
complementary
interactions
involving idiotypes
and anti-idiotypic
antibodies(or
TCR).
• Ag——Ab1——Ab2—
—Ab3-------
3.regulation of complements
1) Promote APC capture antigens:
CR1 receptor on APC capture C3b-Ag-Ab complex
2) Promote the activation of B cell
CR2 on B cell
4. Immunoregulation by co-stimulatory
signal
B7----CD28
----CTLA-4
5. The regulation of signal transduction
(1). ITAMs and ITIMs
(2). Phosphorylation and dephosphorylation
PartⅢ The immunoloregulation
on cellular level
1. Regulation of T cell subsets
Th
CD4+CD25+Treg
2. Regulation of B cells
3. AICD (activation induced cell death)
Th1 和 Th2 细 胞 的 分 化
Th0
+IL-12
+IL-4
Th1
IL-2
IFN-g
Cell mediated
immunity
Th2
inhibit
IL-4
IL-10
Humoral
immunity
AICD
SectionIV
The immunologic
regulation on individual and
population level
I) Nerve-endocrine-immune system
regulation networks
II) Immune system regulate the
nerve and endocrine system.