Chemokine (C-C motif) ligand 16 (CCL16) is a small
cytokine
Cytokines are a broad and loose category of small proteins (~5–25 kDa) important in cell signaling. Cytokines are peptides and cannot cross the lipid bilayer of cells to enter the cytoplasm. Cytokines have been shown to be involved in autocrin ...
belonging to the CC
chemokine
Chemokines (), or chemotactic cytokines, are a family of small cytokines or signaling proteins secreted by cells that induce directional movement of leukocytes, as well as other cell types, including endothelial and epithelial cells. In additio ...
family that is known under several
pseudonym
A pseudonym (; ) or alias () is a fictitious name that a person or group assumes for a particular purpose, which differs from their original or true name (orthonym). This also differs from a new name that entirely or legally replaces an individua ...
s, including Liver-expressed chemokine (LEC) and Monotactin-1 (MTN-1). This chemokine is expressed by the
liver
The liver is a major organ only found in vertebrates which performs many essential biological functions such as detoxification of the organism, and the synthesis of proteins and biochemicals necessary for digestion and growth. In humans, it ...
,
thymus
The thymus is a specialized primary lymphoid organ of the immune system. Within the thymus, thymus cell lymphocytes or ''T cells'' mature. T cells are critical to the adaptive immune system, where the body adapts to specific foreign invaders. ...
, and
spleen
The spleen is an organ found in almost all vertebrates. Similar in structure to a large lymph node, it acts primarily as a blood filter. The word spleen comes . and is chemoattractive for
monocyte
Monocytes are a type of leukocyte or white blood cell. They are the largest type of leukocyte in blood and can differentiate into macrophages and conventional dendritic cells. As a part of the vertebrate innate immune system monocytes also ...
s and
lymphocyte
A lymphocyte is a type of white blood cell (leukocyte) in the immune system of most vertebrates. Lymphocytes include natural killer cells (which function in cell-mediated, cytotoxic innate immunity), T cells (for cell-mediated, cytotoxic ad ...
s.
Cellular expression of CCL16 can be strongly induced in monocytes by
IL-10,
IFN-γ
Interferon gamma (IFN-γ) is a dimerized soluble cytokine that is the only member of the type II class of interferons. The existence of this interferon, which early in its history was known as immune interferon, was described by E. F. Wheelock ...
and bacterial
lipopolysaccharide
Lipopolysaccharides (LPS) are large molecules consisting of a lipid and a polysaccharide that are bacterial toxins. They are composed of an O-antigen, an outer core, and an inner core all joined by a covalent bond, and are found in the outer ...
. Its
gene
In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a b ...
is located on
chromosome 17
Chromosome 17 is one of the 23 pairs of chromosomes in humans. People normally have two copies of this chromosome. Chromosome 17 spans more than 83 million base pairs (the building material of DNA) and represents between 2.5 and 3% of the total D ...
, in humans, among a cluster of other CC chemokines.
CCL16 elicits its effects on cells by interacting with cell surface chemokine receptors such as
CCR1
C-C chemokine receptor type 1 is a protein that in humans is encoded by the ''CCR1'' gene.
CCR1 has also recently been designated CD191 (cluster of differentiation 191).
Function
This gene encodes a member of the beta chemokine receptor fami ...
,
CCR2
C-C chemokine receptor type 2 (CCR2 or CD192 ( cluster of differentiation 192) is a protein that in humans is encoded by the ''CCR2'' gene. CCR2 is a CC chemokine receptor.
Gene
This CCR2 gene is located in the chemokine receptor gene clust ...
,
CCR5
C-C chemokine receptor type 5, also known as CCR5 or CD195, is a protein on the surface of white blood cells that is involved in the immune system as it acts as a receptor for chemokines.
In humans, the ''CCR5'' gene that encodes the CCR5 p ...
and
CCR8
Chemokine (C-C motif) receptor 8, also known as CCR8, is a protein which in humans is encoded by the ''CCR8'' gene. CCR8 has also recently been designated CDw198 (cluster of differentiation w198).
Function
This gene encodes a member of the bet ...
.
C-C motif chemokine ligand 16 has been found in high levels in the blood plasma of humans.
CCL16 may be useful for trafficking eosinophils. This ligand has been found to have a functional affinity for H4 receptors that are expressed by eosinophils and mast cells.
This chemokine has been shown to suppress rapid proliferation of myeloid progenitor cells.
References
Cytokines
{{gene-17-stub