Chemokine ligand 17 (CCL17) is a small cytokine

Cytokine

Cytokines are small cell-signaling protein molecules that are secreted by the glial cells of the nervous system and by numerous cells of the immune system and are a category of signaling molecules used extensively in intercellular communication...

 belonging to the CC chemokine

Chemokine

Chemokines are a family of small cytokines, or proteins secreted by cells. Their name is derived from their ability to induce directed chemotaxis in nearby responsive cells; they are chemotactic cytokines...

 family that is also known as thymus and activation regulated chemokine (TARC). CCL17 is expressed constitutively in thymus, but only transiently in phytohemagglutinin-stimulated peripheral blood mononuclear cells

PBMC

A peripheral blood mononuclear cell is any blood cell having a round nucleus. For example: a lymphocyte, a monocyte or a macrophage. These blood cells are a critical component in the immune system to fight infection and adapt to intruders. The lymphocyte population consists of T cells , B cells...

. This chemokine specifically binds and induces chemotaxis

Chemotaxis

Chemotaxis is the phenomenon in which somatic cells, bacteria, and other single-cell or multicellular organisms direct their movements according to certain chemicals in their environment. This is important for bacteria to find food by swimming towards the highest concentration of food molecules,...

 in T cell

T cell

T cells or T lymphocytes belong to a group of white blood cells known as lymphocytes, and play a central role in cell-mediated immunity. They can be distinguished from other lymphocytes, such as B cells and natural killer cells , by the presence of a T cell receptor on the cell surface. They are...

s and elicits its effects by interacting with the chemokine receptor CCR4. The gene for CCL17 is located on chromosome 16, in humans, along with other chemokines called CCL22

CCL22

C-C motif chemokine 22 is a protein that in humans is encoded by the CCL22 gene.The protein encoded by this gene is secreted by dendritic cells and macrophages, and elicits its effects on its target cells by interacting with cell surface chemokine receptors such as CCR4...

 and CX3CL1

CX3CL1

Chemokine ligand 1 is a large cytokine protein of 373 amino acids, it contains multiple domains and is the only known member of the CX3C chemokine family. It is also commonly known under the names fractalkine and neurotactin . The polypeptide structure of CXC3L1 differs from the typical...

.

Further reading