IL1 is produced mainly by
(most important source) as well as some other cell types. Locally,
IL1 from stimulated macrophages stimulates and
cytokine production by as well as stimulating proliferation.
There are 2 forms of IL1: IL1alpha and
IL1beta , both with the same activities but different structures.
IL1alpha appears to be
primarily membrane-associated while IL1beta can circulate.
Both forms bind to the same
receptors, of which there there are two types found on different cell types, for example
T- and B-cells, macrophages, , cells, fat cells, bone cells
(osteoclasts), brain cells, cells of the , vascular endothelial cells and
smooth muscle cells (amongst others).
These secretions are involved in
, accounting in part for such inflammatory characteristics as
, cramps, fever and can produce a wasting syndrome called cachexia . Inducing adhesion molecule expression on vascular
endothelium is part of the inflammation syndrome - IL1 induces ICAM 1 expression, while TNFalpha induces ELAM 1 expression on endothelium.
by the in response to signals from the brain (cortisone), inhibit the
action of IL1 and are therefore used to reduce inflammation.