IL-6 is an important mediator of fever
. It is capable of crossing the blood-brain barrier
and initiating synthesis of protaglandings in the hypothalamus
, thereby changing the body's temperature setpoint. In muscle and fatty tissue, IL-6 stimulates energy mobilization that leads to increased body temperature. IL-6 can be secreted by macrophages
in response to specific microbial molecules, referred to as pathogen
-associated molecular patterns (PAMPs
). These PAMPs bind to an important group of detection molecules of the innate immune system
, called pattern recognition receptors
(PRRs), including Toll-like receptors (TLRs
). These are present on the cell surface and intracellular compartments and induce intracellular signaling cascades that give rise to inflammatory cytokine production.IL-6 stimulate the production of neutrophils
(a common cell in NMO) in the bone marrow. It supports the growth of B cells
and is antagonistic to regulatory T cells.
In addition to the membrane-bound receptor, a soluble form of IL-6R (sIL-6R) has been purified from human serum and urine. Many neuronal cells are unresponsive to stimulation by IL-6 alone, but differentiation and survival of neuronal cells can be mediated through the action of sIL-6R. The sIL-6R/IL-6 complex can stimulate neurites outgrowth and promote survival of neurons and, hence, may be important in nerve regeneration through remyelination.