Atopy-Dependent and Independent Immune Responses in the Heightened Severity of Atopics to Respiratory Viral Infections: Rat Model Studies

• Main Authors: Jean-François Lauzon-Joset, Anya C. Jones, Kyle T. Mincham, Jenny A. Thomas, Louis A. Rosenthal, Anthony Bosco, Patrick G. Holt, Deborah H. Strickland
• Format: Article
• Language: English
• Published: Frontiers Media S.A. 2018-08-01
• Series: Frontiers in Immunology
• Subjects: rhinovirus; Th2-atopy; type I interferon; allergic asthma; microarray
• Online Access: https://www.frontiersin.org/article/10.3389/fimmu.2018.01805/full

Allergic (Th2high immunophenotype) asthmatics have a heightened susceptibility to common respiratory viral infections such as human rhinovirus. Evidence suggests that the innate interferon response is deficient in asthmatic/atopic individuals, while other studies show no differences in antiviral response pathways. Unsensitized and OVA-sensitized/challenged Th2high (BN rats) and Th2low immunophenotype (PVG rats) animals were inoculated intranasally with attenuated mengovirus (vMC0). Sensitized animals were exposed/unexposed during the acute viral response phase. Cellular and transcriptomic profiling was performed on bronchoalveolar lavage cells. In unsensitized PVG rats, vMC0 elicits a prototypical antiviral response (neutrophilic airways inflammation, upregulation of Th1/type I interferon-related pathways). In contrast, response to infection in the Th2high BN rats was associated with a radically altered intrinsic host response to respiratory viral infection, characterized by macrophage influx/Th2-associated pathways. In sensitized animals, response to virus infection alone was not altered compared to unsensitized animals. However, allergen exposure of sensitized animals during viral infection unleashes a notably exaggerated airways inflammatory response profile orders of magnitude higher in BN versus PVG rats despite similar viral loads. The co-exposure responses in the Th2high BN incorporated type I interferon/Th1, alternative macrophage activation/Th2 and Th17 signatures. Similar factors may underlie the hyper-susceptibility to infection-associated airways inflammation characteristic of the human Th2high immunophenotype.