Interleukin 17

Structure of Interleukin 17F

Interleukin 17 (IL-17) is a pro-inflammatory cytokine that plays a crucial role in the immune system. It is part of a family of cytokines known as the IL-17 family, which includes six members: IL-17A, IL-17B, IL-17C, IL-17D, IL-17E (also known as IL-25), and IL-17F. These cytokines are produced by a variety of cells, including T helper 17 cells (Th17), a subset of CD4+ T cells.

Function

Interleukin 17 is primarily involved in the regulation of immune responses, particularly in the defense against extracellular bacteria and fungi. It stimulates the production of other pro-inflammatory cytokines, such as tumor necrosis factor (TNF) and interleukin 6 (IL-6), and promotes the recruitment of neutrophils to sites of infection.

IL-17 Family

The IL-17 family consists of six cytokines, each with distinct roles in immune regulation:

• IL-17A: The most studied member, involved in autoimmune diseases and chronic inflammatory conditions.
• IL-17B: Less understood, but implicated in inflammatory responses.
• IL-17C: Plays a role in epithelial cell responses to infection.
• IL-17D: Involved in the regulation of innate immunity.
• IL-17E (IL-25): Promotes Th2 cell responses and is involved in allergic reactions.
• IL-17F: Similar to IL-17A, involved in mucosal immunity.

Clinical Significance

IL-17 has been implicated in a variety of autoimmune diseases, including rheumatoid arthritis, psoriasis, and multiple sclerosis. It is also associated with chronic inflammatory conditions such as inflammatory bowel disease (IBD). Targeting IL-17 with specific monoclonal antibodies has become a therapeutic strategy in treating these diseases.

Related Pages

• Cytokine
• T helper 17 cells
• Autoimmune disease
• Inflammation