C-C motif chemokine 11 (CCL11)

C-C motif chemokine 11 (CCL11), commonly known as eotaxin‑1, is a small cytokine belonging to the CC chemokine family. It is primarily secreted by epithelial cells, fibroblasts, smooth muscle cells, and macrophages within the respiratory tract. Its main biological function is to selectively recruit eosinophils via binding to the G protein-coupled receptor CCR3 on their surface—a process central to allergic airway inflammation such as asthma. Unlike many other chemokines that attract multiple leukocyte types, eotaxin‑1 shows high selectivity for eosinophils but can also interact with basophils and Th2 lymphocytes through CCR3. Beyond its role in allergy-driven diseases, elevated levels of eotaxin‑1/CCL11 have been implicated in aging-associated processes including cellular senescence—particularly through pro-inflammatory signaling pathways that promote oxidative stress—and cognitive decline observed both with normal aging and certain disease states like long COVID or after chemotherapy exposure. Increased expression has also been linked to bone inflammation via upregulation during osteoclast activity. The gene encoding human eotaxin‑1/CCL11 resides on chromosome 17q12 within three exons. While there are currently no approved drugs specifically targeting CCL11 itself clinically available, several investigational agents aim at blocking its action via antagonism of its principal receptor CCR3—an approach being explored mainly for severe asthma characterized by persistent airway eosinophilia.

Other names

Eotaxin-1EotaxinEosinophil chemotactic proteinSCYA11

Drugs targeting this pathway typically act by blocking the interaction between CCL11 and its primary receptor CCR3 on eosinophils, thereby inhibiting the recruitment and activation of these cells during inflammatory responses.