Fractalkine

Fractalkine (also known as CX3CL1) is a large cytokine protein that plays a crucial role in the immune system. It is unique among the chemokine family due to its structure and function.

Structure

Fractalkine is a type of chemokine that is structurally different from other chemokines. It is the only member of the CX3C chemokine family, characterized by three amino acids between the first two cysteine residues. The protein is synthesized as a large molecule with a mucin-like stalk and a chemokine domain on top. This structure allows it to exist in both soluble and membrane-bound forms.

Function

Fractalkine serves multiple functions in the immune system. It acts as a chemoattractant, guiding leukocytes to sites of inflammation. It also functions as an adhesion molecule, helping leukocytes stick to endothelial cells in the blood vessels. In the brain, fractalkine is involved in neuron-glial cell communication, playing a role in the regulation of microglial cells.

Role in Disease

Abnormal levels of fractalkine have been associated with several diseases. High levels of the protein have been found in patients with atherosclerosis, rheumatoid arthritis, and certain types of cancer. In contrast, low levels of fractalkine have been linked to neurodegenerative diseases such as Alzheimer's disease.

Research and Therapeutic Potential

Given its role in various diseases, fractalkine is a potential target for therapeutic intervention. Several drugs that target the fractalkine receptor (CX3CR1) are currently under investigation. These drugs aim to reduce inflammation and slow the progression of diseases such as rheumatoid arthritis and atherosclerosis.