Exam 2: Cytokines Flashcards
Properties of Cytokines
- produce proteins
- control the immune response, locally and systematically
- mechanism of communication among cells
- affect many diff. types of cells (pleiotropic)
An effective immune response is possible only when interaction between (blank), ( blank) and (blank) is possible.
hematopoietic, lymphoid and inflammatory cells
Cytokines are originally called:
lymphokines or monokines
Interleukines (IL)
Cytokines that mediate between lymphcytes and leukocytes
*37 known
Chemokines
Cytokines that recruit and activate leukocytes
Chemotaxis
cells move from an area of low chemical signal to an area of high chemical signal
Cytokines bind to
receptors on target cells, thus initiate activating or suppressive signals
Autocrine action of cytokine
A cytokine binds on a receptor on the same cell that produced the cytokine
Paracrine action of cytokine
A cytokine binds on a receptor found on a cell in close proximity to the producer cell it exerts
Endocrine Action of Cytokine
When a cytokine binds to a receptor found on a cell located in a distant part of the body
Pleiotropic Action of Cytokine
has different biological effects on different target cells
Redundancy Action of Cytokine
Two or more cytokines exert the same biological effect on the same cells
Synergistic Action of Cytokine
Two cytokines that work better together, compared to seperately
Antagonistic Action of Cytokine
action of one cytokine inhibits the effects of another cytokine
Cascade Action of Cytokine
Cytokine production that leads to more cytokines being produced
What is the structure of cytokine receptors?
Subunits:
- Cytokine binding
- signal transduction
IL-3, IL-5 and GM-CSF function to:
- affect hematopoietic cells
- activate monocytes
- induce differentiation of megakariocytes
- induce proliferation of neutrophils
- induce degranulation of basophils to release histamine
Chemokines function to:
- regulation the adhesion process
- chemotaxis
- activation of leukocytes
- *regulation of leukoctye homeostasis and inflammation
Where are chemokines produced:
- peripheral lymphoid tissue cells
- bone marrow
- other tissues
Chemokines are induced to participate in the inflammatory process by
TNF- alpha
C chemokines structure
the first 2 conserved cysteins are bound by side disulphide bonds
CC chemokines structure
the first 2 conserved cysteins are positioned one fater another and each has a side chain
CXC chemokines structure
between the 1st and 2nd conserved cysteins there is an aa other than cystein
CX3C chemokiens structure
three amino acids other than cystein are located in between the first two conserved cysteins and there is a mucin domain
Antigens stimulate TCR to release
IFN-gamma, IL-2, -4, -10, -13
Cytokine Signal Transduction
- ligand binds receptors
- Tyrosine kinase activity is generated
- Second messengers amplify and trasmit signal
- Transcription factors are generated
- Gene transcription leads to protein synthesis and cell division
- Cell Response
IL-1 RA regulates IL-1 by
blocking the receptor
TNF-R regulates TNF alpha
by competing for TNF-alpha with cell membrane and inhibits cytokines signalling
What are the cytokine functions on target cells:
a. affect cell behavior
b. Mitosis
c. Differentiation
d. Induce protein synthesis
e. all the above
E. all the above
Cytokines must bind to their receptors on target cells in order to trigger an intracellular signal. T/F
True
