Cytokines of Adaptive Immunity Flashcards
IL-2
mediates growth, survival, and differentiate of T lymphocytes
activity of IL-2
anti-apoptotic function to promote survival
-BCL-2
also promotes cell cycle through cyclin synthesis
-p27 degradation
regulatory T cells and IL-2
regulatory T cells suppress autoreactivity and inhibit the T cell response (inhibitory)
-IL-2 is require for their survival
receptor is constitutively expressed**
NK cells and IL-2
will stimulate their differentiation
IL2 and B cells?
stimulate antibody production
source of IL-2
mainly produced by CD4+ T cells
-activated by antigens and costimulators
secreted into the synapse between T cell and APC
IL-4
signature cytokine of Th2 cells
- stimulates differention of CD4+ Th2 cells
- inhibits the differentiate of Th1
activate mast cell/eosinophil mediated reactions
IL-4 on B cells?
will stimulate them to produce IgE
-IgE is parasitic response and allergies
IL-4 and macrophages?
induces arginase expression that leads to collagen production and fibrosis (alternative pathway of macrophage activation)
IL-5
activator of eosinophils
-Th2 release
stimulates growth and differentiate of eosinophils
also stimulates B cells to proliferate IgA (mucosal)
sources of IL-5
Th2 cells **
also activated mast cells
-acts to activate eosinophils
kills helminthes
IgG and IgA
IL-13
produced by Th2 CD4+ T cells**
-also produced by NK cells in early phase allergic response or basophils or eosinophils
shared effects with IL-4
IL-13 receptor expression?
B cells, mononuclear phagocytes, dendritic cells, eosinophils, basophils, fibroblasts, endothelial cells
Th1 and Th2 and endothelial cells?
can both induce extravasation
IL-13 clinical application?
promotes fibrosis (through arginase - decreased NO) induces TGF-beta (promotes fibrosis
IL-13 contributes to pathology of chronic asthma
induces mucus production, IgE class switching, inflammation
IFN gamma
Th1 release
activates macrophages
- stimulate them to kill phagocytosed microbes
- increase ROS and NO production
signal from T cells for IFN gamma?
via T cells - CD40 and IFN-gamma
via NK cells - IFN-gamma alone
activity of IFN-gamma
promotes Th1 and inhibits Th2 (with IL-12)
promotes B cells to switch to IgG
activity of IFN-gamma on APCs?
induces MHC I and II, costimulators and transporters and proteosome
source of IFN-gamma
NK cells
Th1 cells
CD8+ T cells
TGF-beta
inhibits proliferation of lymphocytes and leukocytes
conteracts effects of inflammatory cytokines
stimulates B cells to produce IgA
-mucosal immunity
stimulates healing
- fibroblasts and macrophages
- collagen synthesis and matrix remodeling
produced by T cells, LPS-activated phagocytes, and regulatory T cells
what cell type is responsible for the deposition of collagen?
macrophages (resident)
stimulation of fibrosis?
initial infection usually cleared by Th1 response
if it doesn’t clear, goes to Th2 response
-fibrotic response by macrophages and fibroblasts
cause of allergic asthma?
stimulus seen as a persistent infectious agent
- transition to Th2 response
- tissue lacks Th1 response
secondary stimulus exacerbates the fibrotic response
