About CCL25 / TECK:
Chemokine (C-C Motif) ligand 25, also known as CCL25, is a small cytokine that’s a member of the CC chemokine family. Also known as TECK, or Thymus-Expressed Chemokine, it plays a similar role to other CC chemokine family members like CCL17 in the development of T-cells. These T-cells, also known as T lymphocytes, play a central role in cell-mediated immunity. Here, we are going to look at what is currently known about CCL25, including information on its structure, function, mechanism, and interactions.
The gen for CCL25 is located on chromosome 19 in humans. It has a size of 150 amino acids and a molecular mass of 16609 Da. Like other CC cytokines, this protein is a dimer, characterized by two adjacent cysteines. 3 isoforms of CCL25 can also be produced by alternative splicing. Structure modelling of CCL25 is not complete, as the structures of CC chemokine family can be difficult to fully research. Primary molecule replacement techniques have helped to uncover some structures of CC chemokines but research on CCL25 is limited at the moment.
Research into the function of CCL25 is ongoing. Most clear, for now, is its involvement in the development of T-Cells. This recombinant protein shows chemotactic activity with thymocytes, macrophages, THP-1 cells, and dendritic cells, meaning that those particular cells can direct their movements according to the presence of CCL25 in their environment. On the other hand, it is inactive on peripheral blood lymphocytes and neutrophils. CCL2 has been suspected to play a major role in diseases like allergic asthma and ileitis.
CCL25, also known as TECK, primarily activates by binding to chemokine receptor CCR9. The purpose of this binding is the development of T-Cells through its chemotactic response qualities in regards to thymocytes, macrophages, and dendritic cells. The CCL25/CCR9 mechanism also promotes migration and invasion of T-Cells in hepatocellular and breast cell cancer lines. CCL25 also selectively enhances resistance to TNF-alpha mediated apoptosis in T-ALL and T-CLL T-Cells.
The source of CCL25 in the thymus is a novel thymic dendritic cell-specific CC chemokine, possibly involved in T-Cell development. Besides chemotactic activity in certain cells as mentioned above, it has distinctive mechanisms of lymphocyte recruitment that encourages functional specialization of immune responses in different parts of gastrointestinal tract. Both Foxn1-positive and -negative epithetical cells express Dll4 and CCL25. CCL25’s interactions with CCR9 are required for modulating protection against large intestinal inflammation in 2 models of chronic colitis.
Research on CCL25 (also known as Chemokine (C-C Motif) ligand 25, Thymus-Expressed Chemokine, or TECK) is ongoing, particularly into the structure and mechanism of the small protein. As with all members of the CC chemokine family, our understanding of them is not yet fully complete, with further interactions being discovered at a relatively fast past.