chemokinernas
Chemokines are a family of small signaling proteins secreted by cells that primarily act as chemoattractants, guiding the migration of various immune cells. The term "chemokine" is derived from "chemoattractant cytokine." These molecules play a crucial role in the inflammatory response, immune surveillance, and the development of lymphoid organs. They are characterized by their conserved cysteine residue pattern, particularly a conserved N-terminal disulfide bridge. Chemokines exert their effects by binding to specific G protein-coupled receptors (GPCRs) on the surface of target cells. This binding event triggers intracellular signaling cascades that alter cell motility. There are over 50 known chemokines, broadly classified into four groups based on the arrangement of their first two cysteine residues: CXC, CC, CX3C, and XC chemokines. The CXC group includes chemokines with an amino acid sequence of Cys-X-Cys, where X represents any amino acid. CC chemokines have the sequence Cys-Cys. CX3C chemokines have three amino acids between the cysteine residues, and XC chemokines have lost the intervening amino acid. Different chemokines attract different types of immune cells, such as neutrophils, monocytes, lymphocytes, and eosinophils, to specific locations in the body. Dysregulation of chemokine production or signaling has been implicated in various diseases, including autoimmune disorders, infectious diseases, and cancer.