L’effet de l'interleukine-17 sur la survie et la glucocorticorésistance du neutrophile équin
Glucocorticoids are the most potent drugs for the control of the airway obstruction present in heaves and asthma, although the airway neutrophilia persist with these agents. It was previously reported that human and equine’s peripheral blood neutrophils are sensitive to glucocorticoid. Interleukin-17 (IL-17) is a cytokine contributing to glucocorticoid insensitivity airway epithelial cells in human. We therefore hypothesized that IL-17 has a similar effect on neutrophils and contributes to the persistence of these cells in the airways in response to glucocorticoid therapy.  In this study, we evaluated: 1. The expression of both subunits of IL-17 receptor (IL-17RA/ IL-17RC) in highly purified neutrophils. 2. The gene expression of proinflammatory cytokines in neutrophils to assess their activation by IL-17 and their effect in these cells treated with glucocorticoids. 3. The effects of IL-17 on the viability and apoptosis in neutrophils were performed.  Results showed that 1. Equine neutrophils express IL-17RA and IL-17RC at transcriptional at protein level. 2. IL-17 induces a selective activation in neutrophils, which results in an upregulation of IL-8, not attenuated by dexamethasone and finally, 3. IL-17 increases the viability of neutrophils stimulated with LPS by a decrease in apoptosis.  Our results indicate that IL-17 directly activates neutrophils to upregulate IL-8, a potent neutrophils chemoattractant, and that this response is not prevented by glucocorticoids. They also suggest a possible role of IL-17 in the persistence of neutrophils in the asthmatic airways by decreasing apoptosis.
interleukine-17 Neutrophils horse interleukine-17 subunits of receptor proinflammatory cytokines survival apoptosis