Recent advances in the IL-17 cytokine family

The IL-17/IL-17 receptor family is the newest and least understood of the cytokine subclasses. Composed of ligands IL-17A-IL-17F and receptors IL-17RA-IL-17RE, these cytokines have many unique structural and functional features. Since the discovery of the ‘Th17’ subset in 2005, particular attention has been paid to IL-17A and IL-17F and their cognate receptors. To date, far less is known about the rest of the family. This review discusses recent advances in the field, with an emphasis on IL-17A biology.

► IL-17, signature of the CD4+ ‘Th17’ lineage, is also produced by innate cell types.
► il17a gene regulation and epigenetics helps explain Th cell plasticity.
► Data from animal models and humans reveal a vital role of IL-17 in fungal immunity.
► Anti-IL-17 therapeutics show early promise in the clinic.
► The IL-17 receptor activates noncanonical signal transduction pathways.