C-X-C motif chemokine 5 (CXCL5 or ENA78) is a protein that in humans is encoded by the CXCL5 gene. [5] [6]
C-X-C motif chemokine 5 (CXCL5 or ENA78) is a protein that in humans is encoded by the CXCL5 gene. [5] [6]
The protein encoded by this gene, CXCL5 is a small cytokine belonging to the CXC chemokine family that is also known as epithelial-derived neutrophil-activating peptide 78 (ENA-78). It is produced following stimulation of cells with the inflammatory cytokines interleukin-1 or tumor necrosis factor-alpha. [7] Expression of CXCL5 has also been observed in eosinophils, and can be inhibited with the type II interferon IFN-γ. [8] This chemokine stimulates the chemotaxis of neutrophils possessing angiogenic properties. It elicits these effects by interacting with the cell surface chemokine receptor CXCR2. [8] The gene for CXCL5 has four exons and is located on human chromosome 4 amongst several other CXC chemokine genes. [7] [9] CXCL5 has been implicated in connective tissue remodelling. [8] CXCL5 has been also described to regulate neutrophil homeostasis. [10]
CXCL5 plays a role in reducing sensitivity to sunburn pain in some subjects, and is a "potential target which can be utilized to understand more about pain in other inflammatory conditions like arthritis and cystitis.". [11] CXCL5 is well known to have chemotactic and activating functions on neutrophil, mainly during acute inflammatory responses. However CXCL5 expression is also higher in atherosclerosis (a chronic inflammatory condition) but is not associated with neutrophil infiltration. Instead CXCL5 has a protective role in atherosclerosis by directly controlling macrophage foam cell formation. [12]
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.
Interleukin 8 is a chemokine produced by macrophages and other cell types such as epithelial cells, airway smooth muscle cells and endothelial cells. Endothelial cells store IL-8 in their storage vesicles, the Weibel-Palade bodies. In humans, the interleukin-8 protein is encoded by the CXCL8 gene. IL-8 is initially produced as a precursor peptide of 99 amino acids which then undergoes cleavage to create several active IL-8 isoforms. In culture, a 72 amino acid peptide is the major form secreted by macrophages.
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 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 8 (CCL8), also known as monocyte chemoattractant protein 2 (MCP2), is a protein that in humans is encoded by the CCL8 gene.
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 9 (CXCL9) is a small cytokine belonging to the CXC chemokine family that is also known as monokine induced by gamma interferon (MIG). The CXCL9 is one of the chemokine which plays role to induce chemotaxis, promote differentiation and multiplication of leukocytes, and cause tissue extravasation.
The chemokine ligand 1 (CXCL1) is a small peptide belonging to the CXC chemokine family that acts as a chemoattractant for several immune cells, especially neutrophils or other non-hematopoietic cells to the site of injury or infection and plays an important role in regulation of immune and inflammatory responses. It was previously called GRO1 oncogene, GROα, neutrophil-activating protein 3 (NAP-3) and melanoma growth stimulating activity, alpha (MGSA-α). CXCL1 was first cloned from a cDNA library of genes induced by platelet-derived growth factor (PDGF) stimulation of BALB/c-3T3 murine embryonic fibroblasts and named "KC" for its location in the nitrocellulose colony hybridization assay. This designation is sometimes erroneously believed to be an acronym and defined as "keratinocytes-derived chemokine". Rat CXCL1 was first reported when NRK-52E cells were stimulated with interleukin-1β (IL-1β) and lipopolysaccharide (LPS) to generate a cytokine that was chemotactic for rat neutrophils, cytokine-induced neutrophil chemoattractant (CINC). In humans, this protein is encoded by the gene Cxcl1 and is located on human chromosome 4 among genes for other CXC chemokines.
Chemokine ligand 2 (CXCL2) is a small cytokine belonging to the CXC chemokine family that is also called macrophage inflammatory protein 2-alpha (MIP2-alpha), Growth-regulated protein beta (Gro-beta) and Gro oncogene-2 (Gro-2). CXCL2 is 90% identical in amino acid sequence as a related chemokine, CXCL1. This chemokine is secreted by monocytes and macrophages and is chemotactic for polymorphonuclear leukocytes and hematopoietic stem cells. The gene for CXCL2 is located on human chromosome 4 in a cluster of other CXC chemokines. CXCL2 mobilizes cells by interacting with a cell surface chemokine receptor called CXCR2.
Chemokine ligand 3 (CXCL3) is a small cytokine belonging to the CXC chemokine family that is also known as GRO3 oncogene (GRO3), GRO protein gamma (GROg) and macrophage inflammatory protein-2-beta (MIP2b). CXCL3 controls migration and adhesion of monocytes and mediates its effects on its target cell by interacting with a cell surface chemokine receptor called CXCR2. More recently, it has been shown that Cxcl3 regulates cell autonomously the migration of the precursors of cerebellar granule neurons toward the internal layers of cerebellum, during the morphogenesis of cerebellum. Moreover, if the expression of Cxcl3 is reduced in cerebellar granule neuron precursors, this highly enhances the frequency of the medulloblastoma, the tumor of cerebellum. In fact, the reduced expression of Cxcl3 forces the cerebellar granule neuron precursors to remain at the surface of the cerebellum, where they highly proliferate under the stimulus of Sonic hedgehog, becoming target of transforming insults. Remarkably, the treatment with CXCL3 completely prevents the growth of medulloblastoma lesions in a Shh-type mouse model of medulloblastoma. Thus, CXCL3 is a target for medulloblastoma therapy. Cxcl3 is directly regulated transcriptionally by BTG2
CXC chemokine receptors are integral membrane proteins that specifically bind and respond to cytokines of the CXC 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. There are currently six known CXC chemokine receptors in mammals, named CXCR1 through CXCR6.
Chemokine ligand 7 (CXCL7) is a human gene.
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.
Interleukin 8 receptor, beta is a chemokine receptor. IL8RB is also known as CXCR2, and CXCR2 is now the IUPHAR Committee on Receptor Nomenclature and Drug classification-recommended name.
Interleukin 8 receptor, alpha is a chemokine receptor. This name and the corresponding gene symbol IL8RA have been replaced by the HGNC approved name C-X-C motif chemokine receptor 1 and the approved symbol CXCR1. It has also been designated as CD181. The IUPHAR Committee on Receptor Nomenclature and Drug Classification use the HGNC recommended name, CXCR1.
Interleukin 1 receptor, type I (IL1R1) also known as CD121a, is an interleukin receptor. IL1R1 also denotes its human gene.
Interleukin 9 receptor (IL9R) also known as CD129 is a type I cytokine receptor. IL9R also denotes its human gene.
Interleukin 17 receptor A, also known as IL17RA and CDw217, is a human gene.
Chemorepulsion is the directional movement of a cell away from a substance. Of the two directional varieties of chemotaxis, chemoattraction has been studied to a much greater extent. Only recently have the key components of the chemorepulsive pathway been elucidated. The exact mechanism is still being investigated, and its constituents are currently being explored as likely candidates for immunotherapies.