As a pro-inflammatory cytokine, IL-17 is important in the immune system against fungal and bacterial infections. The IL-17 cytokine family consists of six members that exert their effects by cooperating with five receptors that form the IL-17 receptor family. Although IL-17 is mainly a defensive factor, at times, overexpression of this cytokine will lead to inflammatory and damaging outcomes.
Pneumonia is a lower airway disease that can be caused by different agents. In this condition, IL-17 is secreted from different cells and can fight against infection or otherwise lead to progression of the disease. This article reviews the IL-17 role in pneumonia and different inflammatory pathways that it can affect.