CCR3Rezeptor

CCR3 receptor, short for C-C chemokine receptor type 3, is a chemokine receptor belonging to the class A G protein-coupled receptors. It is expressed mainly on eosinophils, basophils, mast cells, and certain T helper 2 cells, with additional expression in some dendritic cells and airway epithelial cells under inflammatory conditions.

Ligands provide the primary functional input for CCR3. The main ligands are the eotaxins: CCL11 (eotaxin-1), CCL24 (eotaxin-2), and CCL26 (eotaxin-3). It can also bind other CC chemokines with lower affinity. Upon ligand binding, CCR3 couples to Gi-type G proteins, triggering intracellular signaling cascades that drive chemotaxis, calcium mobilization, and release of inflammatory mediators.

Physiological role involves mediating the recruitment of eosinophils and other CCR3-expressing cells to sites of inflammation. This contributes to defense against parasites and to allergic inflammation, with a major role in conditions such as asthma and atopic diseases. The receptor thus helps coordinate leukocyte trafficking during immune responses and tissue remodeling.

Clinical significance centers on its involvement in eosinophilic airway inflammation in allergic diseases. CCR3 is considered a potential therapeutic target, and several antagonists and antibodies have been evaluated to reduce eosinophil recruitment. Results have been mixed due to receptor redundancy and compensatory mechanisms; as of now, no CCR3-targeted therapy has become standard of care.

Genetics and expression note that the CCR3 gene is located on chromosome 3 in humans. It is part of a gene cluster encoding chemokine receptors and is regulated by inflammatory cues.