Effect of Fungal Exposure on Airway Immunity in Asthma

Abstract

Objectives: The purpose of this study is to explore potential changes in cytokine and interferon expression during co-infection of rhinovirus and Alternaria. Methods: Alternaria filtrates were used to represent Alternaria spores in real-life. The responses were assessed by production of IL-6, IL-8 and interferon, which were measured by ELISA. mRNA expression was detected by quantitative real-time PCR. For data analysis, a two-sided t-test was performed to compare individual experimental groups. Results: Co-infection of Alternaria and rhinovirus enhanced IL-6 and IL-8 production significantly (p< 0.05). However, Alternaria significantly inhibited production of interferon which would otherwise be induced by rhinovirus. Average interferon-beta (IFN β) production was reduced by about 67%; interferon-lambda (IFN λ) was decrease by about 75%. The differences between treatment and control groups were also statistically significant (p < 0.05). Conclusions: These findings suggested that the Alternaria may cause an imbalanced mucosal antiviral response through inhibiting production of interferon while enhancing production of proinflammatory cytokines. These results indicated that Alternaria may lead to inhibit host innate immunity against virus infection, causing more inflammatory response.