1. Typical cytokines secreted by types of CD4 T cells
Notable TFs
RORgT
FOXP3 (some T regs)
STAT1, T-bet, STAT4
STAT6, GATA3
Th17
IL-6, IL-17, IL-22
TGF-b, IL-10,
+/- IL-4
Reg.
CD4 T
cell
IL-2, IFN-g,
TNF-alpha,
TNF-beta (a.k.a: LT-alpha)
Th1
IL-4, IL-5,
IL-6, IL-10, IL-13
Th2 1

2. Overview of Th0 differentiation
High IL-6, IL-23, TGF-beta
CD25 CD4 T cell
Tr1 or Th3
TGF-beta
Low IL-6, IL-23
Low IFN-g & IL-4
IL-10
Th0
High IFN-g or IL-4
Th1
Th2
High IFN-g, IL-12
High IL-4 2

3. 3 Cross-talk among CD4 T cell subsets
Macrophage (impaired activation of other
CD4 T cell subsets)
IL-10 (-)
T reg.
TGF-b (-)
Th1
IFN-g (-)
TGF-b (-)
Th17
IFN-g (-)
IL-4 (-)
Th2
IL-10 (-)
Dendritic cell (decr. IL-12, decr. Th1 activation)
[(-) = suppresses] 3

4. 4 CLASSICAL PATHWAY: Ig + C1 ---> Ig-C1 C1 esterase activity
C > C4b + C4a
C > C2b + C2a
C4b + C2a ---> C4b2a
C4b2a
C > C3b + C3a
C4b2a + C3b ---> C4b2a3b
ALTERNATE PATHWAY:
C > C3b + C3a (spontaneous)
C3b + B ---> C3bB D
C3bB > C3bBb + Ba
C3bBb + P ---> C3bBbP [Note: P = Properdin]
C3bBbP
C > C3b + C3a
C3bBb + C3b ---> C3bBb3b (a.k.a.: C3b2Bb)
SHARED COMPONENTS:
C5 convertase
C > C5b + C5a
C5b + C6 + C7 + C8 + C9 ==> MAC 4