Cytokines Flashcards
Cytokines may exhibit which action, and function?
Autocrine action, signalling the cells that produce them
Cytokines are NOT:
antigen-specific
Cytokines are:
capable of activating more than one cell type
made by lymphocytes
small protein molecules
synthesized de novo in response to antigen or other cytokines
Several cytokines may have the same effect on the cells they bind, this is an example of:
redundancy
Characterization of cytokine activities is NOT made more difficult by their:
gene structure
Interferons:
inhibit virus replication by infected cells
A cytokine can do all of the following:
Bind to its specific receptor on the same cell that produced it.
Bind to receptor antagonists produced by pathogenic viruses.
Compete with other cytokines whose receptors share signal-transducing subunits.
Upregulate (increase) synthesis of high affinity subunits for its receptor.
Members of a cytokine receptor family:
are similar in protein structure and sometimes in regions of amino acid sequence.
The ability of a cytokine to change gene expression in the target cell is influenced by:
presence of high-affinity receptors of target cell
presence of soluble cytokine receptors
proximity of the producing and target cells
simultaneous production of another cytokine whose receptor uses the same signal transducing subunit
Cytokines are NOT:
stored in the cell for quick release
The IL-2R subfamily consists of reseptors for IL-2, IL-4, IL-7, IL-9 and IL-15. This group of cytokine receptors:
each has a unique high chain affinity and are cytokine specific
An antagonist for cytokine X may NOT be:
cytokine B which acts synergistically with cytokine X
A knock-out mouse for a particular cytokine allows immunologists to characterize cytokine function:
on all cell types simultaneously
Activated Tc can regulate immune responses by signalling activated lymphocytes to undergo:
apoptosis
