Cytokines, Chemokines, and Their Receptors Flashcards
What is a cytokine?
Proteins secreted by cells that mediate the functions of the immune system.
- soluble proteins/glycoproteins
- regulate the intensity and duration of the immune response
- necessary for leukocyte activation
What cells secrete cytokines?
lymphocytes
monocytes
all cells of innate and adaptive immunity
other cells, endothelial and epithelial
The term ___ refers to fact that many proteins are produced by one immune cell to act on neighboring cells (i.e., they work between cells).
interleukin
What term is preferred name because it is the most inclusive term?
cytokine
List the general properties of cytokines.
- Cytokine secretion is brief and self-limited
- Cytokine action is pleitropic and redundant
- Cytokines influence each other
- Cytokines can act locally and systemically
- Cytokines initiate their actions by binding to specific membrane-bound receptors.
- Cytokine receptor ligation leads to gene expression which alters cellular function.
Cytokine secretion is ___ and ___-___ because they are not stored within cells. Transcription and translation increases cytokines hours after challenge. The ___ is unstable so expression is transient.
brief; self-limiting; mRNA
Cytokine action is ___, ___, synergistic and antagonistic.
pleitropic; redundant
T/F. Cytokines influence each other.
True.
Cytokines can act ___ and ___ via autocrine (IL2) and paracrine (most cytokines) signaling. Chemokines and some cytokines (expressed in high quantities) use ___ signaling.
locally; systemically; endocrine
Cytokines initiate their actions by binding to specific ___-___ receptors. Cytokine ___ ligation leads to gene expression which alters cellular function.
membrane-bound; receptor
T/F. Cytokines that are primarily involved in innate immunity set up an inflammatory response.
True.
What are the proinflammatory cytokines?
TNF-α; IL-1; IL-6; IL-12; IFN
What are the anti-inflammatory cytokines?
IL-10; TGF-beta
___ is the principal mediator of the acute inflammatory response to Gram-negative bacteria (as well as other infectious microbes), endotoxic shock, and chronic inflammatory conditions.
TNF-α
TNF-α facilitates the expression of ___ on activated leukocytes, E- and P-selectin on endothelial cells, and expression of integrin ligands, ___ and ___.
integrins; VCAM-1; ICAM-1
T/F. TNF-α can have detrimental, not beneficial effects.
False, TNF-α can have detrimental effects as well as beneficial effects.
T/F. The two forms of IL-1 are not that similar but they bind to the same receptor.
True.
What cytokine is produced by phagocytes AND neutrophils and has the same effects as TNF-α?
IL-1
IL-6 is primarily produced by macrophages and T cells (but many other cells can make it) and involved with induction of ___ response (can have similar effects as TNF-α and IL-1) but, primarily involved with induction of the ___ ___ response.
inflammatory; acute phase
What marker is used to detect induction of the acute phase response?
CRP
___ and ___ bind to bacteria to opsonize them and activate the complement cascade.
CRP; MBP
Serum ___ is probably involved with cell trafficking.
amyloid
During an infection, what two cytokines cause you to feel sick?
IL-1 and IL-6.
Immune response, sleep, fever, SNS, and HPA axis are all stimulated.
Appetite, libido is suppressed and mood is altered.
IL-12 is the primary mediator of ___ immune response to ___ pathogens.
innate; intracellular