ID: 167: The anti-viral properties of IL-17A in allergic asthma

Abstract

In the latter part of the 20th century the prevalence of the chronic inflammatory disease Athma bronchiale increased especially in developed countries and affects children and adults. Besides a pathological expansion of Th2 cells, it has been also suggested that Th17 cells and their key cytokine IL17A play a relevant role during the development of asthma, although their particular role is not completely understood. Besides allergens, recurrent infections with Rhinovirus (RV), especially in early life, could increase the risk of asthma. Th17 cells and IL17A seem to modulate immune pathophysiology of viral infections, but their precise role during anti-viral immune responses is not yet clear. Therefore, we addressed the role of IL17A during allergic asthma and anti-viral immune responses. In a cohort of pre-school children with and without asthma, we found out that children with asthma suffer more often from lower respiratory tract infections than control children. Furthermore, we analysed a nasal–pharyngeal specimen for RV infection and isolated PBMCs from the whole blood of these children. We observed that the PBMCs of children with asthma and a RV infection in their upper airways express more IFNB and TBX21 but less OAS1 and IL17A than asthmatic children without a viral infection. In addition, we could show that rIL17A induces OAS1 gene expression and reduces viral replication in lung epithelial A549 cells. Thus, IL17A might be a promising anti-viral therapy for RV infection in asthma, because it would activate the cellular components to initiate OAS1 mediated anti-viral immune responses.