Card Set Information
cytokines - immunology studies
Complex communication occurs via what two chemical substances?
Cell surface molecules
Why are cytokines master regulators of the immune system?
Critical for lymphocyte development
Regulate innate & adaptive immunity
Can make you sick
What type of cells produce many cytokines?
Many cell types, including non-immune cells
What are the cytokine nomenclature?
What cell produce monokines?
monocytes (rarely used)
What cell produce Lymphokines?
What cell produces interleukins & what do they control?
Produced by many cell types
Control viral infections
What are colony-stimulating factors responsible for?
Maturation of leukocytes
What do chemokines control?
Control migration of leukocytes
What are growth factors responsible for?
Stem cell differentiation
What are the properties of cytokines?
Low molecular weight (<30kd) proteins or glycoproteins
Synthesized in active & inactive forms
Secretion is brief & self-limiting
- burst of cytokines released when need - short 1/2 life
Active @ low conc.
- high infinity receptor
How does cellular communication via cytokine occur?
A stimulus is required
The target cell must have cytokine receptors on the cell surface
Induces gene activation (signal transduction)
What do autocrine do?
Affect the secretory cell itself
What do Paracrine do?
Target only cells nearby
What do Endocrine do?
Travel through blood to reach distant cell
What is the function of pleitropic?
Have multiple effects & affects multiple cell types
What is the function of redundant?
Several cytokines that perform the same function
What is the function of synergistic?
Combined effect --> sum of the individual effects
What is the function of antagonistic?
What are the target cells and effects of pleiotropic?
- Activation, proliferation, differentiation
What is the cytokine involved in pleiotropic?
What is the target cell and effect of redundancy?
What are the cytokines involved in redundancy?
What is the target cell and effect of synergy?
- Induces class switch to IgE
What are the cytokines involved in synergy?
IL-4 + IL-5
What is the target cell and effect of antagonism?
- Block class switch to IgE & induced by IL-4
What are the cytokines involved in antagonism?
What are the function of cytokines?
Direct effector functions
: e.g. kill infectious agents/tumor cells
Induce inflammatory responses
Regulate hematopoiesis & immune responses
Induce process of wound healing
Communicate w/ nervous (neuronal) & hormonal (endocrine) systems
Can be cause of some diseases (over or deficient production)
What are the cytokine families?
Tumor necrosis factor (TNF)
What is hematopoietin?
Bone marrow cells + others
What is interferon?
Anti-viral & active immune system
What is chemokine?
What is tumor necrosis factor (TNF)?
What are the properties of cytokine receptors?
High affinity receptors
Often multi-chain complexes
What are the 5 groups of receptor families?
Class I cytokine receptors
Immunoglobin super family receptors
Class II cytokine receptors
Tumor necrosis factor receptors
Cytokine + receptor =
What is signal transduction?
Movement of signals from outside the cell to inside
Involves numerous, ordered, intracellular events
Reaches nucleus & changes DNA
Changes program of genes expressed
Usually rapid - milliseconds
small stimulus = large response
How is the immune reaction controlled by cytokines?
It is mediated by the release of
What do CD4+ helper T cells differentiate to?
What cytokines do Th1 produce and what do they aid in?
Produce IFHγ, IL-2 etc.
Aid is cell mediated immunity
What cytokines do Th2 produce and what do they aid in?
Produce IL-4, IL-5 etc.
Aid in antibody production
What does chronic Th1 stimulate?
Autoimmune disease e.g. type 1 diabetes, multiple sclerosis, Crohn's disease
Chronic inflammation & autoimmune diseases promotes Th1 because...
pro-inflammatory (TNF, IL-1, IL-6 etc)
Respond to intracellular pathogens
What does chronic Th2 stimulate?
Failure to respond to infection
Allergy and failure to respond to infection promotes Th2 because...
respond to parasites
What is cytokine storm?
Inappropriate (exaggerated) immune response
Over-activated immune response e.g. graft versus host disease (GVHD), avian influenza, smallpox
Rapid proliferation & highly activated immune cells
Systemic release of
>150 inflammatory mediators
(cytokines, oxygen free radicals & coagulation factors)
Especially TNFα & IL-6