La famille des IL-17 et la réponse allergique

Among the six members of the IL-17 family, three are clearly implicated in the regulation of the allergic response: IL-17A (also called IL-17), IL-17E (or IL-25) and IL-17F. IL-17A expresses strong homology with IL-17F and shares the same receptor. IL-17A is produced by various cells, mainly Th17 and iNKT17. IL-17A is a potent pro-inflammatory cytokine that induces the production of numerous other cytokines and chemokines and controls the recruitment and activation of neutrophils. However, in an experimental allergic asthma mouse model, IL-17A can induce either harmful or beneficial effect depending on the status of the allergic response. IL-17E, which is produced mainly by basophils and eosinophils in humans, acts mainly on Th2 cell differentiation either by polarizing naive CD4+ cells towards the Th2 pathway in an IL-4- dependent fashion, or by amplifying expansion and activation of memory Th2 cells in an IL-4-independent manner.