CCL11

CCL11, also known as eotaxin-1, is a small secreted protein that belongs to the C-C motif chemokine family. It is encoded by the CCL11 gene in humans and functions primarily as a chemoattractant for eosinophils, as well as other CCR3-expressing cells such as basophils and certain T helper cells.

The chemokine is produced by a variety of cell types, including endothelial cells, epithelial cells, fibroblasts, and macrophages, in response to inflammatory signals. Its activity is mediated through the CCR3 receptor, guiding eosinophils from the bloodstream to sites of tissue inflammation and contributing to the onset and maintenance of allergic responses. CCL11 activity is upregulated by cytokines such as IL-4, IL-13, and TNF-α, as well as microbial products in some contexts.

Clinically, CCL11 is implicated in allergic diseases characterized by eosinophilic inflammation, such as asthma, allergic rhinitis, and atopic dermatitis. Elevated levels of CCL11 have been observed in affected tissues and fluids, and the chemokine pathway has been explored as a potential target for therapeutic intervention, including strategies aimed at blocking CCR3 signaling or CCL11 activity.

Beyond allergy, CCL11 has been studied in aging research. In mice, increased circulating CCL11 has been associated with reduced hippocampal neurogenesis and impaired cognitive function, though the relevance to humans remains to be fully established and is the subject of ongoing investigation. CCL11 is part of the broader family of eotaxins, which also includes CCL24 and CCL26.