Cytokines (Exam 1) Flashcards
What are cytokines
small soluble proteins that are chemical messengers of the immune system
In general, what will occur after a cytokine binds to its receptor on a cell
signal cascade which will lead to gene activation and biological effects
Which signaling mechanisms do cytokines function best when used
autocrine or paracrine
What do cytokines regulate
intensity and duration of immune responses by stimulating or inhibiting the activation, proliferation, and differentiation of various cells
What characteristics are exhibited by cytokines
pleiotropy
redundancy
synergy
antagonism
What does it mean if a cytokine is pleiotrophic
a single cytokine can have actions on multiple cells
What does it mean if a cytokine is redundant
different cytokines can have the same actions
What does it mean if a cytokine exhibits synergy
different cytokines can work together to make a desired response
What does it mean if cytokines exhibit antagonism
one cytokine can block the actions of another cytokine
What is the structure of cytokines
mainly alpha helical
small, soluble proteins
What type of cytokine receptors are important in SCID
IL2 receptors
Why are IL2 receptors important in SCID
IL2 receptors share a common gamma chain. If mutated (like in SCID), none of the cytokine receptors function
What would a mutation in IL-7 lead to
lack of B and T cells as it is involved in development
What type of gene regulation does cytokine induce
transcriptional activation
What is a chemokine
a cytokine that functions in chemotaxis (attracts WBC to an area of inflammation)
What are the three types of IFN
alpha
beta
gamma
What is TNF
tumor necrosis factor
What do IFN alpha and beta protect against
viral infections
What is the function of IFN alpha and beta
activates NK cells to kill virus infected cells
induce resistant to viral replication in all cells
Increases MHC class I expression and antigen presentation in all cells
What does IFN gamma activate?
macrophages to stimulate intracellular killing
What does IFN gamma inhibit
TH2 response
What is a granuloma
activated macrophages and B cells containing an intracellular pathogen that has been sealed off to prevent spread to other tissues
What is the clinical function of quantiferon
tests for Tb by looking for Interferon gamma
Which T cell drives type 4 hypersensitivity reactions
Th1
What are the clinical uses of IFN alpha
HBV and HCV (hepatitis)
HTLV-1 (retro virus)
HHV-8 (Kaposi sarcoma)
What are the clinical uses of IFN beta
MS
prevents development of further plaques
What are the clinical uses of IFN gamma
Chronic granulomatus disease (no NADPH oxidase) it can upregulate activity of macrophages to try to compensate for lack of NADPH oxidase
What are the pro-inflammatory cytokines
IL-1, IL-6, TNF-alpha
How was TNF alpha initially discovered
as a cytokine with the ability to kill tumors
What is a side effect of TNF alpha
cachexia
Where is TNF alpha made
macrophages, T cells, fibroblasts
Where is TNF beta made
activated T cells and B cells
What are the monoclonal antibodies used to inhibit TNF alpha
Remicade
Enbrel
Humira
What diseases can monoclonal antibodies that inhibit TNF alpha be used to treat
Rheumatoid arthritis, Crohn’s disease, Psoriasia
What is a side effect of anti-TNF alpha drugs
increases susceptibility to disease
What do IL-1 and IL-6 stimulate
hematopoiesis
liver to make acute phase proteins
drives antibody production and help with switch to IgG
What are clinical uses for MRA (anti-IL-6-receptor)
used to treat RA
What is the main purpose of IL-2
T cell proliferation and activation (also B and NK cells but to a lesser extent)
What type of regulation is displayed by IL-2
autocrine (by T cells for T cells)
What are the IL-2 inhibitors discussed
Basiliximab and daclizumab (directed toward the alpha chain of the IL-2R
What are clinical uses for IL-2 inhibitors
used to increase the success of organ transplants
treat leukemias and melanomas
promising for treatment of retrovirus
How can HTLV-1 cause cancer
increases IL-2 synthesis which causes uncontrollable T cell proliferation
What type of cells produce IL-4
TH2 cells
What is IL-4 essential for
class switching to IgE inducing eosinophil developement and differentiation
What is a clinical use for IL-4 inhibitors
used for severe allergies
WHat class switch does IL-4 induce
switch to IgE
What are the IL-4 inhibitors
xolair
omalizumab
What makes IL-8
macrophages during acute inflammation
What is the function of IL-8
chemotaxis, recruits neutrophils to area
Which cytokine is a growth factor for WBCs
IL-3
Which cytokine is a growth factor for lymphocytes
IL-7
What is the function of M-CSF
essential for macrophage production
What is the function of G-CSF
essential for neutrophil production
What is the function of GM-CSF
growth factor for hematopoietic stem cells and granulocytes/monocytes
What is the function of erythropoietin
growth factor for RBCs
What is the drug name and function of the cytokine erythropoietin
Procrit: used to treat anemia
What is the drug name and function of the cytokine G-CSF
Filgastrin: used to boost immunity prior to bone marrow transplant
What is the drug name and function of the cytokine GM-CSF
Sargramostime: used to boost immunity during chemotherapy
