IL-2 and TH1/TH2 differentiation Flashcards
What cytokine controls T cell proliferation?
IL-2
IL-2 induces a low affinity receptor on naive T cells
IL-2R(beta)(gamma)(C)
APC-Tcell w/co stimulation induces
autocrine IL-2 stimulation, and express the alpha chain of the IL-2R(beta)(gamma)((C)
the out come is the high affinity receptor IL-2R(alpha)(beta)(gamma)(C)
IL-2 + high affinity receptor IL-2R(alpha)(beta)(gamma)(C) –>
T cell proliferation
As Ag declines, the number of ___ receptors decline
IL-2R
TGF-beta blocks
IL-2 induced proliferation
IL-12 induces Th0 cells into
Th1 cells
Th1 cells secrete (typically) _____ and promote
IL-2, IFN-gamma, TNF-beta, and promotes cell mediated immunity
IL-4 induces differentiation of _______ cells
Th2 cells which secrete L-4, IL-5, IL-6, IL-10, IL-13
Th2 cells activate
B-lymphocytes resulting in Ab production
Th1 and Th2 cells have mutually _____ effects
inhibitory effects on the reciprocal phenotype
IFN-gamma inhibits ___ T cells
Th2 prolif
IL-10/IL-4 inhibit ____ T cells
Th1 cell prolif
What is the role of dendritic cells in differentiation?
different subsets stimulate the diff. phenotypes
DC –IL-12–> ____ T cells
Th1
DC–IL-4–> ____ T cells
Th2
IL-12/IFNgamma
synergize in selecting Th1 cells
(IL-12/IFN-gamma) and IL-4 regulate
the antagonism of Th1 and Th2
Th1 cells in host defense
IL-12 controls their differentiation from Th0
Secrete IFN-gamma –> activates phagocytes to kill microbes (classical mac activation pw)
stimulate production of Ab which promote phagocytosis of microbes by the phagocytes
dendritic w/pathogen presents MHC II to Naive T cell, secretes IL-12—>
Th1 secretes IFN-gamma to
a) activate mac (classical)
b) stimulate B cells to produce IgG –> opsonization/phagocytosis
Role of Th2 cells in host defense
Does IL-4 produce Th2 cells or do Th2 cells produce IL-4?
Does IL-5 produce Th2 cells or do Th2 cells produce IL-5?
Th2 produce IL-4
IL-4 stimulates IgE antibody
IgE activates mast cells
IgE binds to helminths
IL-5 activates eosinophils
Eosinophils destroy helminths
IL-4 induces alternative activation of macrophage
Cytokine switching of Ab isotype
IgM
No stimulation needed
Cytokine switching of Ab isotype
IgG
IFN-gamma stimulated
Cytokine switching of Ab isotype
IgE
IL-4 stimulated
Cytokine switching of Ab isotype
IgA
mucosal immunity
