SITOKIN
ABSTRACT: Many critical
interactions among cells of the immune system are controlled by soluble
mediators called cytokines. These cytokines are a diverse group of
intercellular signaling peptides and glycoproteins with low molecular weights
and most of them are genetically and structurally unrelated to one another.
Several hundred have been identified to date. Each is secreted by particular
cell types in response to a variety stimuli and produces characteristic effects
on the growth, mobility, differentiation, or function of target cells.
Collectivelly, they regulate not only immune and inflammatory responses but
also wound healing, hematopoiesis, angiogenesis, and many other biologic processes.
They are extremely potent compound that act at
slight concentrations by binding to specific surface receptors on target
cells. Unlike endocrine hormones, they are not produced by specialized glands
and secreted into the circulation, but rather are produced locally by a variety of tissues and
cells. Only a few cytokines, such as transforming growth factor beta,
erythropoietin, stem cell factor (SCF), monocyte colony-stimulating factor
(M-CSF), are normally present in detectable amounts in the blood and are able
to influence distant target cells. Most other cytokines, unless produced in
excess, act only locally over short distances, in either a paracrine manner
(ie, on adjacent cells) or an autocrine manner (ie, on producing cell itself).
Penulis: Admadi Soeroso
Kode Jurnal: jpkedokterandd080007
