Chemokine (C-C motif) ligand 8 (CCL8), also known as monocyte chemoattractant protein 2 (MCP2), is a protein that in humans is encoded by the CCL8 gene. [3] [4]
CCL8 is a small cytokine belonging to the CC chemokine family. The CCL8 protein is produced as a precursor containing 109 amino acids, which is cleaved to produce mature CCL8 containing 75 amino acids. The gene for CCL8 is encoded by 3 exons and is located within a large cluster of CC chemokines on chromosome 17q11.2 in humans. [4] [5] MCP-2 is chemotactic for and activates many different immune cells, including mast cells, eosinophils and basophils, (that are implicated in allergic responses), and monocytes, T cells, and NK cells that are involved in the inflammatory response. [6] [7] CCL8 elicits its effects by binding to several different cell surface receptors called chemokine receptors. These receptors include CCR1, CCR2B, CCR3 and CCR5. [7] [8]
CCL8 is a CC chemokine that utilizes multiple cellular receptors to attract and activate human leukocytes. CCL8 is a potent inhibitor of HIV1 by virtue of its high-affinity binding to the receptor CCR5, one of the major co-receptors for HIV1. [9] In addition, CCL8 attributes to the growth of metastasis in breast cancer cells. The manipulation of this chemokine activity influences the histology of tumors promoting steps of metastatic processes. [10] CCL8 is also involved in attracting macrophages to the decidua in labor. [11]
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 addition to playing a major role in the activation of host immune responses, chemokines are important for biological processes, including morphogenesis and wound healing, as well as in the pathogenesis of diseases like cancers.
The chemokine ligand 2 (CCL2) is also referred to as monocyte chemoattractant protein 1 (MCP1) and small inducible cytokine A2. CCL2 is a small cytokine that belongs to the CC chemokine family. CCL2 tightly regulates cellular mechanics and thereby recruits monocytes, memory T cells, and dendritic cells to the sites of inflammation produced by either tissue injury or infection.
Chemokine ligand 5 is a protein which in humans is encoded by the CCL5 gene. The gene has been discovered in 1990 by in situ hybridisation and it is localised on 17q11.2-q12 chromosome. It is also known as RANTES. RANTES was first described by Dr. Tom Schall who named the protein, the original source of the name Rantes was from the Argentine movie Man Facing Southeast about an alien who shows up in a mental ward who was named Rantés, the rather clunky acronym was only made to fit the name.
Macrophage Inflammatory Proteins (MIP) belong to the family of chemotactic cytokines known as chemokines. In humans, there are two major forms, MIP-1α and MIP-1β, renamed CCL3 and CCL4 respectively, since 2000. However, other names are sometimes encountered in older literature, such as LD78α, AT 464.1 and GOS19-1 for human CCL3 and AT 744, Act-2, LAG-1, HC21 and G-26 for human CCL4. Other macrophage inflammatory proteins include MIP-2, MIP-3 and MIP-5.
Chemokine ligands 4 previously known as macrophage inflammatory protein (MIP-1β), is a protein which in humans is encoded by the CCL4 gene. CCL4 belongs to a cluster of genes located on 17q11-q21 of the chromosomal region. Identification and localization of the gene on the chromosome 17 was in 1990 although the discovery of MIP-1 was initiated in 1988 with the purification of a protein doublet corresponding to inflammatory activity from supernatant of endotoxin-stimulated murine macrophages. At that time, it was also named as "macrophage inflammatory protein-1" (MIP-1) due to its inflammatory properties.
Chemokine ligand 1 (CCL1) is also known as small inducible cytokine A1 and I-309 in humans. CCL1 is a small glycoprotein that belongs to the CC chemokine family.
Chemokine ligand 7 (CCL7) is a small cytokine that was previously called monocyte-chemotactic protein 3 (MCP3). CCL7 is a small protein that belongs to the CC chemokine family and is most closely related to CCL2.
Chemokine ligand 13 (CCL13) is a small cytokine belonging to the CC chemokine family. Its gene is located on human chromosome 17 within a large cluster of other CC chemokines. CCL13 induces chemotaxis in monocytes, eosinophils, T lymphocytes, and basophils by binding cell surface G-protein linked chemokine receptors such as CCR2, CCR3 and CCR5. Activity of this chemokine has been implicated in allergic reactions such as asthma. CCL13 can be induced by the inflammatory cytokines interleukin-1 and TNF-α.
Chemokine ligand 20 (CCL20) or liver activation regulated chemokine (LARC) or Macrophage Inflammatory Protein-3 (MIP3A) is a small cytokine belonging to the CC chemokine family. It is strongly chemotactic for lymphocytes and weakly attracts neutrophils. CCL20 is implicated in the formation and function of mucosal lymphoid tissues via chemoattraction of lymphocytes and dendritic cells towards the epithelial cells surrounding these tissues. CCL20 elicits its effects on its target cells by binding and activating the chemokine receptor CCR6.
Chemokine ligand 18 (CCL18) is a small cytokine belonging to the CC chemokine family. The functions of CCL18 have been well studied in laboratory settings, however the physiological effects of the molecule in living organisms have been difficult to characterize because there is no similar protein in rodents that can be studied. The receptor for CCL18 has been identified in humans only recently, which will help scientists understand the molecule's role in the body.
C-C motif chemokine 22 is a protein that in humans is encoded by the CCL22 gene.
C-X-C motif chemokine 5 is a protein that in humans is encoded by the CXCL5 gene.
CC chemokine receptors are integral membrane proteins that specifically bind and respond to cytokines of the CC chemokine family. They represent one subfamily of chemokine receptors, a large family of G protein-linked receptors that are known as seven transmembrane (7-TM) proteins since they span the cell membrane seven times. To date, ten true members of the CC chemokine receptor subfamily have been described. These are named CCR1 to CCR10 according to the IUIS/WHO Subcommittee on Chemokine Nomenclature.
Chemokine ligand 6 (CXCL6) is a small cytokine belonging to the CXC chemokine family that is also known as granulocyte chemotactic protein 2 (GCP-2). As its former name suggests, CXCL6 is a chemoattractant for neutrophilic granulocytes. It elicits its chemotactic effects by interacting with the chemokine receptors CXCR1 and CXCR2. The gene for CXCL6 is located on human chromosome 4 in a cluster with other CXC chemokine genes.
Chemokine ligand 12 (CCL12) is a small cytokine belonging to the CC chemokine family that has been described in mice. It is also known as monocyte chemotactic protein 5 (MCP-5) and, due to its similarity with the human chemokine MCP-1, sometimes it is called MCP-1-related chemokine. CCL12 specifically attracts eosinophils, monocytes and lymphocytes. This chemokine is found predominantly in lymph nodes and thymus under normal conditions, and its expression can be hugely induced in macrophages. It is thought to coordinate cell movements during early allergic reactions, and immune response to pathogens. The gene for CCL12 is found in a cluster of CC chemokines on mouse chromosome 11.
C-C chemokine receptor type 2 (CCR2 or CD192 is a protein that in humans is encoded by the CCR2 gene. CCR2 is a CC chemokine receptor.
C-C chemokine receptor type 1 is a protein that in humans is encoded by the CCR1 gene.
C-C chemokine receptor type 3 is a protein that in humans is encoded by the CCR3 gene.
C-C motif chemokine 4-like is a protein that in humans is encoded by the CCL4L1 gene.
Chemokine ligand 3-like 1, also known as CCL3L1, is a protein which in humans is encoded by the CCL3L1 gene.