Cytokine

A cytokine is a small protein that immune and other cells release to signal one another, coordinating inflammation, infection defense and tissue repair.

Cytokines include interleukins, interferons, tumor necrosis factors and chemokines. A cell releases them in response to injury or a pathogen; they bind receptors on nearby or distant cells and instruct those cells to divide, migrate, release more cytokines or stand down. Some cytokines, such as IL-6 and TNF-alpha, are broadly pro-inflammatory, while others, such as IL-10, are anti-inflammatory, and the balance between them shapes how strong and how long an immune response is. Clinicians measure certain cytokines in blood to gauge inflammation, and several approved drugs work by blocking a single cytokine.

Readers meet the word in discussions of chronic inflammation, autoimmune disease and the cytokine storm seen in severe infections. CBD has been reported to alter cytokine release in cell and animal experiments, but those findings are preclinical and depend heavily on the model used; they do not establish an effect on inflammation in people.