C-C motif chemokine ligand 24

C-C motif chemokine ligand 24 (CCL24), also known as Eotaxin-2, is a small cytokine belonging to the CC chemokine family that is characterized by two adjacent cysteine residues. CCL24 interacts with chemokine receptor CCR3 to induce chemotaxis in eosinophils. This chemokine is produced by lymphocytes, macrophages, and endothelial cells, and is involved in immune responses, specifically in the recruitment of eosinophils to inflammatory sites.

Structure and Function

CCL24 is a small protein of 119 amino acids with a molecular weight of approximately 13 kDa. It is characterized by a conserved structure of four cysteine residues forming two disulfide bonds, which is typical for the CC chemokine family. The protein is secreted as a monomer, but can form dimers in solution.

The primary function of CCL24 is to bind to the CCR3 receptor on eosinophils, inducing chemotaxis. This means that it attracts eosinophils to the site of inflammation, where they can participate in the immune response. CCL24 is also involved in the recruitment of basophils and Th2 lymphocytes, which are other cell types involved in allergic reactions.

Clinical Significance

CCL24 has been implicated in several diseases, including asthma, allergic rhinitis, and atopic dermatitis. It is thought to contribute to the pathogenesis of these diseases by recruiting eosinophils and other inflammatory cells to the site of inflammation. In addition, elevated levels of CCL24 have been found in the blood of patients with HIV infection, suggesting a role in the immune response to this virus.

Research and Future Directions

Research is ongoing to better understand the role of CCL24 in disease and to develop potential therapies targeting this chemokine. For example, inhibitors of CCL24 could potentially be used to treat diseases characterized by excessive eosinophil recruitment, such as asthma and allergic rhinitis.