function, properties and funtions of cytokines

2.  Molecules that communicate among cells of
immune system are referred to as cytokines.
 Cytokines are low-molecular weight proteins.
 Cytokines are secreated by WBC's and other
cells.
 Cytokines asist in development of immune
effector cells.
 Cytokines acts as messengers of immune
response.
 Cytokines generally acts locally.

3.  Binding to receptors on target cell, cytokines
triggers signal-transduction that alters gene
expression of target cell.
 Dissociation constants ranging from 10-10 -10-
12M because of high affinity, picomolar
concentration of cytokines can mediate
biologial effect.

5.  Cytokine binding to receptors, exerts autocrine
action.
 Paracrine action occurs close to the producer cell.
 Pleiotropic action, cytokines affects different
target cell.
 Endocrine action target distant cells in body.
 Cytokines regulates intensity and duration of
immune response.

7.  Many cytokines are reffered as interleukins.
 Those secreted by some leukocytes and acts upon
other leukocytes are termed as interleukins.
 Chemokines, group of low-molecular weight
cytokines that affects chemotaxis.
 Chemokines molecules play important role in the
inflamatory response.

9.  Cytokines generally have molecular mass of less
than 30kDa.
 Cytokines belongs to
hematopoietin,interferon,chemokine, and TNF
families.
 Cytokines have high degree of alpha-helical
structure and little or no beta-sheet structure.
 Molecules share similar polypeptide fold, with
four alpha-helical regions(A-D).
 Runs roughly parallel to one another and
connected with loops.

11.  Various cells secrete cytokines but two
principle producers are T-cells and
Macroghages.
 Release of cytokines activates an entire
network of interacting cells that activates all
physiological response.
 Among these are development of cellular and
humoral response, induction of the inflamatory
response, regulation of hematopoiesis, cellular
proliferation and differentiation, and healing
of wounds.